[{"awards": "2332418 Zappa, Christopher", "bounds_geometry": "POLYGON((163 -71,164.2 -71,165.4 -71,166.6 -71,167.8 -71,169 -71,170.2 -71,171.4 -71,172.6 -71,173.8 -71,175 -71,175 -71.5,175 -72,175 -72.5,175 -73,175 -73.5,175 -74,175 -74.5,175 -75,175 -75.5,175 -76,173.8 -76,172.6 -76,171.4 -76,170.2 -76,169 -76,167.8 -76,166.6 -76,165.4 -76,164.2 -76,163 -76,163 -75.5,163 -75,163 -74.5,163 -74,163 -73.5,163 -73,163 -72.5,163 -72,163 -71.5,163 -71))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 28 Apr 2025 00:00:00 GMT", "description": "Non-Technical Abstract The deep world ocean is flooded with near 0\u00b0C water, drawn from the margins of Antarctica. Antarctic Bottom Water, as it is referred to, is mainly derived from cold water formed the over the continental shelves of the Weddell and Ross Seas, where the coastal water is exposed to frigid polar air masses spreading off the Antarctic ice sheet. Antarctic Bottom Water is a key component of the global ocean overturning system, which is fundamental to the global ocean heat, carbon and nutrient inventories, and hence the climate and marine ecosystem. The processes producing the dense shelf waters involve small scale factors associated with ocean/atmosphere/sea and glacial ice interaction. What is lacking from previous work is a coordinated, synchronous observational study of the seaward spreading, from formation, to export across the continental shelf edge, to its descent into the deep ocean. This work fills the gap, by investigating the characteristics of dense shelf water formed within Terra Nova Bay, Ross Sea, its transformation, modification and northward spreading within the Drygalski Trough in the western Ross Sea, feeding into the spill-over at the continental slope into the deep boundary current adjacent to Cape Adare. The sequence of events will be observed with a series of instrumented moorings along the pathway from Terra Nova Bay, along the Drygalski Trough and onto the boundary current adjacent to Cape Adare. The project is an international collaboration that involves the USA (this proposal), S. Korea, New Zealand and Italy. Technical Abstract The lower kilometer or two of the world ocean is flooded with near 0\u00b0C water derived from the Southern Ocean, the Antarctic Bottom Water (AABW). The cold end-member of AABW is formed over various sectors of the continental shelf of Antarctica, notable in the Weddell and Ross Seas. The governing processes producing the dense shelf waters involve small scale spatial and temporal factors associated with ocean/sea ice interaction, often related to coastal polynyas and katabatic winds, along with further modification by ocean-glacial ice interaction. There have been studies of the formation of dense shelf water, of export of shelf water over the shelf/slope, the descent of gravity currents into the AABW realm, and of flow paths of AABW spreading across the deep ocean well into the northern hemisphere. What is lacking is a coordinated, synchronous observational study of the seaward spreading, from formation of the dense shelf water to its spreading to the shelf/slope break and descent into the deep ocean. This program fills the gap, by investigating the characteristics of dense shelf water formed within Terra Nova Bay (TNB), Ross Sea, its transformation, modification and northward spreading within the Drygalski Trough in the western Ross Sea, feeding into the spill-over at the continental slope and the deep boundary current adjacent to Cape Adare. The team will deploy a series of moorings \u2013 two heavily instrumented full water column moorings within TNB to capture high-salinity shelf water (HSSW) production and a series of bottom-focused moorings to evaluate the transformation and northward spreading of the dense saline water. The broad science goals of the project will be addressed by this program through a coordinated analysis of these mooring measurements. The project is an international collaboration that involves the USA (this proposal), S. Korea, New Zealand and Italy. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 175.0, "geometry": "POINT(169 -73.5)", "instruments": null, "is_usap_dc": true, "keywords": "Terra Nova Bay; SALINITY/DENSITY; OCEAN CURRENTS; Ross Sea; POLYNYAS; TURBULENCE; OCEAN TEMPERATURE; WATER MASSES; OCEAN MIXED LAYER", "locations": "Ross Sea; Terra Nova Bay", "north": -71.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Zappa, Christopher; Gordon, Arnold", "platforms": null, "repositories": null, "science_programs": null, "south": -76.0, "title": "Formation, Transformation, and Northward Spreading of Dense Saline Water Derived from Terra Nova Bay, Ross Sea, Antarctica", "uid": "p0010506", "west": 163.0}, {"awards": "2114454 Greenbaum, Jamin", "bounds_geometry": "POLYGON((-107.5 -74.5,-107.3 -74.5,-107.1 -74.5,-106.9 -74.5,-106.7 -74.5,-106.5 -74.5,-106.3 -74.5,-106.1 -74.5,-105.9 -74.5,-105.7 -74.5,-105.5 -74.5,-105.5 -74.6,-105.5 -74.7,-105.5 -74.8,-105.5 -74.9,-105.5 -75,-105.5 -75.1,-105.5 -75.2,-105.5 -75.3,-105.5 -75.4,-105.5 -75.5,-105.7 -75.5,-105.9 -75.5,-106.1 -75.5,-106.3 -75.5,-106.5 -75.5,-106.7 -75.5,-106.9 -75.5,-107.1 -75.5,-107.3 -75.5,-107.5 -75.5,-107.5 -75.4,-107.5 -75.3,-107.5 -75.2,-107.5 -75.1,-107.5 -75,-107.5 -74.9,-107.5 -74.8,-107.5 -74.7,-107.5 -74.6,-107.5 -74.5))", "dataset_titles": "AXCTD and AXBT Profiles from the Amundsen Sea", "datasets": [{"dataset_uid": "601894", "doi": "10.15784/601894", "keywords": "Amundsen Sea; Antarctica; Araon; AXBT; AXCTD; Cryosphere; CTD; Helicopter; Icebreaker; Oceans; Thwaites Glacier; XBT", "people": "Greenbaum, Jamin; Greenbaum, Jamin Stevens", "repository": "USAP-DC", "science_program": null, "title": "AXCTD and AXBT Profiles from the Amundsen Sea", "url": "https://www.usap-dc.org/view/dataset/601894"}], "date_created": "Mon, 10 Feb 2025 00:00:00 GMT", "description": "The ice shelves around the perimeter Antarctica hold back inland ice that has the potential to raise global sea level by meters. By how much and how rapidly this could occur is a central question in glaciology. The underside of these ice shelves is in contact with the ocean, and there are signs that warming of ocean water is causing melting and retreat of these shelves, with direct implications for sea-level rise. This project will seize an emergent opportunity to work with Australian and South Korean colleagues to acquire snapshot profiles of ocean temperature, salinity, and velocity, and improve bathymetric knowledge, where no prior data exist. The team will work near three glaciers draining ice with substantial sea-level potential from the East and West Antarctic Ice Sheets. The targets are Shackleton and Cook Ice Shelves in East Antarctica, and Thwaites Glacier in West Antarctica. An undergraduate student will be engaged through the Scripps Undergraduate Research Fellowship program and the team will work through the Scripps Educational Alliances program to identify educational outreach opportunities through which to build community engagement in this project. The team will use high-resolution general circulation model simulations to optimize sensor targeting (to be deployed from helicopter and fixed-wing aircraft) and evaluate the relative roles of subglacial freshwater discharge and ocean forcing on subglacial melt rates. The aim is to better understand why grounding-line melt rates are higher at the East Antarctic sites despite data indicating warmer ambient ocean temperatures at the West Antarctic sites. Such behavior could be explained by discharge of subglacial freshwater into ice-shelf cavities, but insufficient data currently exist to test this hypothesis. The team aims to build on ongoing international, collaborative airborne oceanographic sampling with colleagues in the Republic of Korea, Australia, and the United States. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -105.5, "geometry": "POINT(-106.5 -75)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e BEIDOU \u003e GNSS RECEIVER", "is_usap_dc": true, "keywords": "ROTORCRAFT/HELICOPTER; CONDUCTIVITY; OCEAN TEMPERATURE; Amundsen Sea", "locations": "Amundsen Sea", "north": -74.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Greenbaum, Jamin", "platforms": "AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.5, "title": "RAPID: International Collaborative Airborne Sensor Deployments near Antarctic Ice Shelves", "uid": "p0010497", "west": -107.5}, {"awards": "2437938 Goodge, John", "bounds_geometry": "POLYGON((155 -82,156 -82,157 -82,158 -82,159 -82,160 -82,161 -82,162 -82,163 -82,164 -82,165 -82,165 -82.3,165 -82.6,165 -82.9,165 -83.2,165 -83.5,165 -83.8,165 -84.1,165 -84.4,165 -84.7,165 -85,164 -85,163 -85,162 -85,161 -85,160 -85,159 -85,158 -85,157 -85,156 -85,155 -85,155 -84.7,155 -84.4,155 -84.1,155 -83.8,155 -83.5,155 -83.2,155 -82.9,155 -82.6,155 -82.3,155 -82))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 16 Jan 2025 00:00:00 GMT", "description": "Non-Technical Abstract This project will examine ancient Antarctic rocks to understand the continent\u2019s early history, including how Antarctica was once connected to other continents. By studying rock samples from the Nimrod Complex, the project will gather data on the age and makeup of these rocks, showing how Antarctica\u0027s crust formed and changed over time. This work will not only expand scientific knowledge about Earth\u0027s history but also provide valuable training for college students at multiple universities, helping to grow a diverse community of researchers who can tackle big questions in Earth science. Technical Abstract This project seeks to unravel the origin, evolution, and geological significance of the Nimrod Complex in Antarctica\u2019s East Antarctic craton through detailed age and isotopic analysis of its igneous and metamorphic rocks. Using U-Pb zircon geochronology along with O-isotope, Hf-isotope, and trace element analyses, we will construct a comprehensive petrochronological profile of these Mesoarchean to Paleoproterozoic rocks to reveal their magmatic sources, metamorphic history, and role in the broader tectonic framework. The project aims to trace sediment sources and tectonic influences across sedimentary units spanning the Paleoproterozoic to lower Paleozoic eras, adding crucial data to supercontinent reconstructions (Columbia, Rodinia, and Gondwana) and Antarctic tectonic models. Broader impacts include collaborations between universities to develop a diverse STEM workforce, inter-laboratory partnerships, and a robust isotopic dataset that will contribute to models of Antarctic crustal evolution and its implications for ice sheet stability. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 165.0, "geometry": "POINT(160 -83.5)", "instruments": null, "is_usap_dc": true, "keywords": "ISOTOPES; Miller Range; Geologists Range; Zircon; Transantarctic Mountains; FIELD INVESTIGATION", "locations": "Transantarctic Mountains; Miller Range; Geologists Range", "north": -82.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "ARCHAEAN \u003e MESOARCHEAN; ARCHAEAN \u003e NEOARCHEAN; PROTEROZOIC \u003e MESOPROTEROZOIC; PROTEROZOIC \u003e PALEOPROTEROZOIC; PROTEROZOIC \u003e NEOPROTEROZOIC", "persons": "Goodge, John; Kylander-Clark, Andrew; Bell, Elizabeth; Pecha, Mark", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -85.0, "title": "The Nimrod Complex, an Ancient Window into East Antarctic Crustal Evolution", "uid": "p0010495", "west": 155.0}, {"awards": "2422677 Hall, Brenda", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 29 Oct 2024 00:00:00 GMT", "description": "Non-Technical The future response of the East Antarctic Ice Sheet (EAIS) to climate change and its consequent effect on global sea level remains a pressing problem, with implications for societal well-being, the economy, and national security. Projections of future ice-sheet behavior rely in part on understanding gained from ice-sheet response to past climate change, which can be found in geologic records. This project uses geologic features produced at the base of the ice sheet to examine a large change in EAIS behavior and to place ages on when this change occurred. By comparison to climate records from the same time, the project results will allow assessment of ice-sheet response to a climate that likely was warmer than at present. Such information will improve understanding of possible ice-sheet responses to a warming climate, as well as the underlying mechanisms. A better assessment of the likely EAIS response to future warming climate will aid in setting national and international policy and improve public welfare, by promoting more accurate predictions of the amounts and rates of sea-level rise. This project will contribute to the education of young scientists, thereby increasing the STEM workforce, which is in the national interest. A general-audience book will be produced to explain the importance of Antarctica to the public. Technical Accurate, well-dated reconstructions of the behavior of the East Antarctic Ice Sheet (EAIS) afford insight into its response to future climate change. This project uses new insights in subglacial hydrology and erosion to identify and date a major missing piece of Antarctic glacial history, involving massive expansion of the EAIS over the Transantarctic Mountains. This expansion led to formation of an extensive erosional landscape that was characterized by subglacial meltwater and represents a significant shift in ice-sheet behavior. Understanding the age and reasons for such an expansion are important in part, because the subglacial meltwater must have been linked to the Wilkes Subglacial Basin \u2013 an area thought to be susceptible to large-scale ice collapse under warm climates. The project will constrain the extent and age of this surface through 1) detailed geomorphological mapping from imagery, 2) reassessment of existing chronologic data, and 3) new surface exposure dating of existing samples. Results will test the hypothesis that the scoured surface and the ice-sheet behavior that it represents is much younger than its traditionally assigned age of \u226514 Ma and thus relevant to current investigations into ice-sheet behavior under warmer-than-present climates. The work affords mentoring opportunities for students of all ages and will include the production of a book on the landscapes of the Transantarctic Mountains designed to introduce the public to the importance of Antarctica. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Antarctica; GLACIAL LANDFORMS", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Hall, Brenda; Denton, George", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Erosional landscapes of the Transantarctic Mountains produced by East Antarctic subglacial water?", "uid": "p0010488", "west": null}, {"awards": "2418105 Zoet, Lucas", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 10 Oct 2024 00:00:00 GMT", "description": "Glaciers move in response to gravity pulling them downhill and much of the resistance to this motion is supplied by the bedrock that they sit on. For fast moving glaciers this motion is largely the result of basal ice sliding over and around bedrock bumps, and the specific processes at the ice-bed interface that facilitate this sliding play a dominant role in setting the glacier speed. Sliding atop the ice-bed interface is known to create cavities (pockets of water) downstream of bedrock bumps. These cavities facilitate water flow, control areas of ice-bed contact, regulate basal drag, dictate subglacial erosion, and affect ice mechanics in general. Thus, the length and shape of cavities (geometry) as they separate from the bed is of fundamental importance in glaciology. This project will determine the fundamental processes that set the shapes of those cavities. This work will benefit the scientific community by producing improved estimates to basal sliding and subglacial hydrology which are two of the main uncertainties in glacier-flow modeling. It will also lead to a better understanding of subglacial erosion which effectively controls the basal bump geometries. This in turn will lead to improved understanding of the fundamentals of glacier and ice-sheet dynamics. Therefore, the outcome of the project could ultimately improve future projections of sea-level rise, benefitting society at large. In addition, this project will train a postdoctoral researcher and undergraduate students from tribal institutions. This project will: 1) Use a novel experimental device to generate a cavity geometry data set for a range of independent controls; and 2) Use the results from part one to constrain numerical models that will allow for the exploration of a greater range of parameter space than is possible in the physical experiments alone. Using a novel cryogenic ring-shear device, this project will systematically assess three likely controls on cavity geometry: effective stress, sliding speed, and bump geometry, while simultaneously tracking strain indicators within the ice and the geometry of the cavity through the transparent walls of the device. These experiments will be conducted with the University of Wisconsin-Madison, state-of-the-art ring-shear device and represent the first instance where all three parameters\u2019 effects on the resultant cavity geometry can be measured simultaneously. The lab experiment findings of cavity geometry and strain rates within the ice will be used to help constrain the process-based numerical modeling of cavity formation. The numerical simulations of ice flow around obstacles will provide information about the stress and strain distribution within the ice, and from this data we can explore the ability of existing theories to predict cavity geometry for fast-flowing ice. The physics within the numerical model will be updated as needed to incorporate processes such as a stress dependent ice rheology or changes in the ice-bed contact physics that are currently unaccounted for. Outcomes will be 1) a detailed understanding of the physics that govern cavity geometry and 2) a simple parameterization of the lab and modeling results that can be easily incorporated into glaciological models for improved estimates of subglacial sliding, hydrology, and erosion. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; Madison, WI", "locations": "Madison, WI", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Zoet, Lucas", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Determining the Controls on Subglacial Cavity Geometry", "uid": "p0010481", "west": null}, {"awards": "2332479 MacAyeal, Douglas", "bounds_geometry": "POLYGON((161 -76,162.4 -76,163.8 -76,165.2 -76,166.6 -76,168 -76,169.4 -76,170.8 -76,172.2 -76,173.6 -76,175 -76,175 -76.3,175 -76.6,175 -76.9,175 -77.2,175 -77.5,175 -77.8,175 -78.1,175 -78.4,175 -78.7,175 -79,173.6 -79,172.2 -79,170.8 -79,169.4 -79,168 -79,166.6 -79,165.2 -79,163.8 -79,162.4 -79,161 -79,161 -78.7,161 -78.4,161 -78.1,161 -77.8,161 -77.5,161 -77.2,161 -76.9,161 -76.6,161 -76.3,161 -76))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 08 Oct 2024 00:00:00 GMT", "description": "Non-Technical Abstract: This project explores the areas or crash-zones where floating ice shelves in Antarctica compressively flow against obstructions such as islands and plugs of stagnant ice frozen to the sea bed. The significance of these crash-zones is that they are responsible for generating the resistive forces that allow ice shelves to slow down the flow of ice farther inland into the ocean. Ice conditions within these boundaries thus determine how Antarctica\u2019s ice sheets contribute to sea-level rise. The research will feature on-the-ice glaciological and geophysical field measurements near pressure ridges near Scott Base and the transition to the ice road where large wave-like pressure ridges form on the ice-shelf surface. This field area is along the coast of Ross Island adjacent to major logistical stations of the US and New Zealand Antarctic programs. Thus the research will help station managers better preserve one of the key roadways that connects the stations to the major runway used to fly to virtually all other parts of Antarctica. The research will also interact with educational programs such as featured in the long-standing Juneau Icefield Research Project as well as potential involvement of an artist from the US Antarctic Program\u2019s Polar STEAM in the second field season. Technical Abstract: This project explores the dynamics of boundaries where ice shelves compressively flow against obstructions such as islands and areas of grounded ice. The significance of these boundaries is that they are responsible for generating the resistive forces that allow ice shelves to impede or slow down the flow of grounded inland ice into the ocean. Ice conditions within these boundaries thus determine how Antarctica\u2019s ice sheets contribute to sea-level rise. The research will feature glaciological and geophysical field surveys in a compressive boundary area near pressure ridges adjacent to Scott Base and the transition to the ice road along the coast of Ross Island, an area affecting access to major logistical hubs of the US and New Zealand Antarctic programs. Field data will be combined with remote sensing, numerical modeling and theory development to answer key questions about the dynamics of compressive boundaries such as: is there a limit to compressive stress due to ice fracture and the bending of the ice shelf into sinusoidal pressure ridges? Over what time scales does this compressive stress build, fluctuate and decay, and how is it related to the processes that form rumples? Are there ways in which the ridges actually protect the compressive boundary from damage such as by setting up a means to scatter ocean swell impinging from the open ocean? How should compressive ice-shelf boundaries be represented in large scale ice-sheet/shelf models for the prediction of future sea-level rise? A variety of broader impact work will be done both specifically targeting the research field area and more broadly addressing scientific and societal concerns. The field area contains a critical logistics roadway that connects McMurdo Station, Scott Base and a runway essential for continent-wide air logistics. The project will inform how to stabilize the roadway against excessive damage from summer ablation and other factors. Other broader impacts include: (a) Open-Science evaluation of climate systems engineering strategies for glacial geoengineering mitigation of sea-level rise, (b) cooperation with the Juneau Icefield Research Program (JIRP) education component, (c) support and facilitation of an online FieldSafe workshop and associated panel discussion to support early-career Antarctic field teams to mitigate environmental and interpersonal risks in remote field sites, and (d) potential involvement of an artist from the US Antarctic Program\u2019s Polar STEAM in the second field season. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 175.0, "geometry": "POINT(168 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Ice Shelf Dynamics; McMurdo Sound", "locations": "McMurdo Sound", "north": -76.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas; Banwell, Alison; Campbell, Seth; Schild, Kristin; Cassoto, Ryan", "platforms": null, "repositories": null, "science_programs": null, "south": -79.0, "title": "Collaborative Research: Ice-Shelf Rumpling and its Influence on Ice-Shelf Buttressing Processes.", "uid": "p0010478", "west": 161.0}, {"awards": "2336328 Larochelle, Stacy", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 08 Oct 2024 00:00:00 GMT", "description": "Ice sheets lose ice mass through gravity-driven flow to the ocean where ice breaks into icebergs and melts, contributing to global sea level rise. Water commonly found at the base of ice sheets facilitates this process by lubricating the ice-rock interface. The recent discovery of vast, kilometer-thick groundwater reservoirs beneath the Antarctic Ice Sheet thus raises important questions about the potential impact of groundwater on ice flow. It has been hypothesized that groundwater flow to the ice-sheet bed may accelerate ice flow as the ice sheet shrinks in response to global warming. Evaluating this hypothesis is challenging due to poorly understood interactions between water, ice, and rock, but is crucial for anticipating the response of ice sheets and sea level to climate change. Understanding how groundwater responds to a changing ice sheet also has important implications for the heat, chemical elements, and microorganisms it stores and transports. To assess the impact of groundwater processes on ice dynamics, a new idealized modeling framework will be developed, incorporating several novel hydromechanical couplings between ice sheets, subglacial drainage systems, and groundwater aquifers. This framework will enable testing the hypotheses that (1) aquifers decelerate ice mass loss in the absence of a well-developed subglacial drainage system, but that (2) an efficient, channelized drainage system can reduce and even reverse this decelerating effect, and that (3) the impact of these phenomena is most pronounced for steep ice flowing rapidly over thick sedimentary basins and depends in a complex way on aquifer permeability. Existing geodetic, seismic, and other geophysical datasets at well-studied Thwaites Glacier and Whillans Ice Stream will be used to constrain model parameters and investigate the impact of groundwater processes in contrasting glaciologic settings. This work will help rule out or highlight subglacial groundwater as one of the next major challenges for efforts to predict the future of the Antarctic Ice Sheet and sea-level rise on decadal to millennial timescales. The project will contribute to educating the next generation of scientists by supporting an early-career PI and a graduate student, as well as participation in a field and research educational program in Alaska and the production of chapters for an online, open-source, free interactive textbook. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GROUND WATER; GLACIERS/ICE SHEETS; Antarctica", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Larochelle, Stacy; Kingslake, Jonathan", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Modeling the Coupled Dynamics of Groundwater, Subglacial Hydrology and Ice Sheets", "uid": "p0010479", "west": null}, {"awards": "0087144 Conway, Howard", "bounds_geometry": "POLYGON((-150 -83.5,-148 -83.5,-146 -83.5,-144 -83.5,-142 -83.5,-140 -83.5,-138 -83.5,-136 -83.5,-134 -83.5,-132 -83.5,-130 -83.5,-130 -83.65,-130 -83.8,-130 -83.95,-130 -84.1,-130 -84.25,-130 -84.4,-130 -84.55,-130 -84.7,-130 -84.85,-130 -85,-132 -85,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-150 -84.85,-150 -84.7,-150 -84.55,-150 -84.4,-150 -84.25,-150 -84.1,-150 -83.95,-150 -83.8,-150 -83.65,-150 -83.5))", "dataset_titles": "Impulse HF radar data from Conway Ridge", "datasets": [{"dataset_uid": "601810", "doi": "10.15784/601810", "keywords": "Antarctica; Cryosphere; Siple Coast", "people": "Hoffman, Andrew; Conway, Howard; Christianson, Knut", "repository": "USAP-DC", "science_program": null, "title": "Impulse HF radar data from Conway Ridge", "url": "https://www.usap-dc.org/view/dataset/601810"}], "date_created": "Mon, 22 Jul 2024 00:00:00 GMT", "description": "Marine ice sheets are low-pass filters of climate variability that take centuries to adjust to interior and near-terminus changes in mass balance. Constraining these century-scale changes from satellite observations that span only the last 40 years is challenging. Here, we take a different approach of carefully synthesizing different data sets to infer changes in the configurations of van der Veen and Mercer Ice Streams on the Siple Coast over the past 3000 years from englacial features encoded in ice-penetrating radar data. Englacial radar data from Conway Ridge reveal smooth, surface conformal layers overlying disrupted stratigraphy that suggest the van der Veen Ice Stream was 40 km wider over 3000 years ago. Englacial layer dating indicates that the ice stream narrowed to its present configuration between $\\sim3000$ and $\\sim1000$ years ago. Similarly disrupted stratigraphy and buried crevasses suggest that ice flowing from Mercer to Whillans Ice Stream across the northwestern tip of the ridge slowed shortly after. Using an ice-flow model capable of simulating shear margin migration, we evaluate whether small changes in ice thickness can lead to large changes in shear margin location. Our results suggest that the tip of Conway Ridge is sensitive to thinning and thickening, and that when the basal strength at the tip of the ridge increases with the height above flotation, the ice sheet shear margins can change quickly.", "east": -130.0, "geometry": "POINT(-140 -84.25)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIER ELEVATION/ICE SHEET ELEVATION; Siple Coast", "locations": "Siple Coast", "north": -83.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hoffman, Andrew; Conway, Howard", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Glacial History of Ridge AB, West Antarctica", "uid": "p0010470", "west": -150.0}, {"awards": "2209726 Lindzey, Laura", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "QIceRadar Antarctic Index of Radar Depth Sounding Data", "datasets": [{"dataset_uid": "200413", "doi": " 10.5281/zenodo.12123013", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "QIceRadar Antarctic Index of Radar Depth Sounding Data", "url": "https://zenodo.org/records/12123013"}], "date_created": "Wed, 19 Jun 2024 00:00:00 GMT", "description": "Ice penetrating radar is one of the primary tools that researchers use to study ice sheets and glaciers. With radar, it is possible to see a cross-section of the ice, revealing internal layers and the shape of the rocks under the ice. Among other things, this is important for calculating how much potential sea level change is locked up in the polar ice sheets, and how stable the ice sheets are likely to be in a warming world. This type of data is logistically challenging and expensive to collect. Historically, individual research groups have obtained funding to collect these data sets, and then the data largely stayed within that institution. There has been a recent push to make more and more data openly available, enabling the same datasets to be used by multiple research groups. However, it is still difficult to figure out what data is available because there is no centralized index. Additionally, each group releases data in a different format, which creates an additional hurdle to its use. This project addresses both of those challenges to data reuse by providing a unified tool for discovering where ice penetrating radar data already exists, then allowing the researcher to download and visualize the data. It is integrated into open-source mapping software that many in the research community already use, and makes it possible for non-experts to explore these datasets. This is particularly valuable for early-career researchers and for enabling interdisciplinary work. The US alone has spent many tens of millions of dollars on direct grants to enable the acquisition and analysis of polar ice penetrating radar data, and even more on the associated infrastructure and support costs. Unfortunately, much of these data is not publicly released, and even the data that has been released is not easily accessible. There is significant technical work involved in figuring out how to locate, download and view the data. This project is developing a tool that will both lower the barrier to entry for using this data and improve the workflows of existing users. Quantarctica and QGreenland have rapidly become indispensable tools for the polar research community, making diverse data sets readily available to researchers. However, ice penetrating radar is a major category of data that is not currently supported \u2013 it is possible to see the locations of existing survey lines, and the ice thickness maps that have been interpreted from their data, but it is not readily possible to see the radargrams themselves in context with all of the other information. This capability is important because there is far more visual information contained in a radargram than simply its interpreted basal elevation or ice thickness. This project is developing software that will enable researchers to to view radargram images and interpreted surface and basal horizons in context with the existing map-view datasets in Quantarctica and QGreenland. A data layer shows the locations of all known ice penetrating radar surveys, color-coded based on availability. This layer enables data discovery and browsing. The plugin itself interacts with the data layer, first to download selected data, then to visualize the radargrams along with a cursor that moves simultaneously along the radargram and along the map view, making it straightforward to determine the precise geolocation of radar features. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "AIRCRAFT; GLACIERS/ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Polar Cyberinfrastructure", "paleo_time": null, "persons": "Lindzey, Laura", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e AIRCRAFT", "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "Elements: Making Ice Penetrating Radar More Accessible: A tool for finding, downloading and visualizing georeferenced radargrams within the QGIS ecosystem", "uid": "p0010464", "west": -180.0}, {"awards": "2129252 Iverson, Neal", "bounds_geometry": null, "dataset_titles": "Permeability anisotropy of foliated glacier ice", "datasets": [{"dataset_uid": "601801", "doi": "10.15784/601801", "repository": "USAP-DC", "science_program": null, "title": "Permeability anisotropy of foliated glacier ice", "url": "http://www.usap-dc.org/view/dataset/601801"}], "date_created": "Fri, 14 Jun 2024 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Stream; Lab Experiment; Rheology; Snow/ice; Snow/Ice; Water Content", "locations": "Antarctica; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fowler, Jacob; Iverson, Neal", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "1444690 Bell, Robin; 0958658 Bell, Robin", "bounds_geometry": null, "dataset_titles": "Deep ICE (DICE) Radar Dataset from Ross Ice Shelf (ROSETTA-Ice); Shallow Ice Radar (SIR) Dataset from Ross Ice Shelf (ROSETTA-Ice)", "datasets": [{"dataset_uid": "601789", "doi": null, "keywords": "Airborne Radar; Antarctica; Cryosphere; Ice Thickness; Remote Sensing; Ross Ice Shelf", "people": "Millstein, Joanna; Cordero, Isabel; Frearson, Nicholas; Dhakal, Tejendra; Bertinato, Christopher; Wilner, Joel; Dong, LingLing; Das, Indrani; Spergel, Julian; Chu, Winnie; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "Deep ICE (DICE) Radar Dataset from Ross Ice Shelf (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601789"}, {"dataset_uid": "601794", "doi": null, "keywords": "Antarctica; Cryosphere; Remote Sensing; Ross Ice Shelf", "people": "Cordero, Isabel; Wearing, Martin; Spergel, Julian; Packard, Sarah; Dong, LingLing; Das, Indrani; Bell, Robin; Bertinato, Christopher; Chu, Winnie; Dhakal, Tejendra; Frearson, Nicholas; Keeshin, Skye", "repository": "USAP-DC", "science_program": null, "title": "Shallow Ice Radar (SIR) Dataset from Ross Ice Shelf (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601794"}], "date_created": "Fri, 17 May 2024 00:00:00 GMT", "description": "The Lamont-Doherty Earth Observatory of Columbia University was awarded a multi-year grant (May 1, 2010- April 30, 2015) to develop an ice imaging system, or \"IcePod,\" for use in measuring the surface and subsurface topography of ice sheets. IcePod will enable research on the effects of global climate change on ice sheets and the effects of sub-glacial water on potential sea-level rise. IcePod sensors are contained in a Common Science Support Pod and operated on NYANG LC-130 aircraft during routine and targeted missions over Greenland and Antarctica. The IcePod instrument package consists of ice-penetrating radar, infrared and visible cameras, laser altimeter, inertial measurement unit, GPS receiver and data acquisition system. IcePod will also enable other instruments to be used in the modular Common Science Support Pod, and will become a shared community research facility providing data to the science community. Funding will support activities in both Greenland and Antarctica needed to commission IcePod, to develop a data reduction flow and data delivery system for IcePod data, and to engineer a UPS to provide IcePod with clean, reliable power for system operation.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Greenland; C-130; Remote Sensing; RADAR; GLACIERS/ICE SHEETS; Antarctica", "locations": "Antarctica; Greenland", "north": null, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Earth Sciences; Antarctic Instrumentation and Support; Antarctic Astrophysics and Geospace Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Bell, Robin; Frearson, Nicholas; Zappa, Christopher; Studinger, Michael S.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e C-130", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Development of an Ice Imaging System for Monitoring Changing Ice Sheets Mounted on the NYANG LC-130", "uid": "p0010462", "west": null}, {"awards": "2423761 Blackburn, Terrence", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Thermogenic Methane Production in Antarctic Subglacial Hydrocarbon Seeps", "datasets": [{"dataset_uid": "601918", "doi": "10.15784/601918", "keywords": "Antarctica; Carbon Isotopes; Cryosphere; East Antarctica; Elephant Moraine; Geochronology; Isotope Data; Subglacial", "people": "Piccione, Gavin", "repository": "USAP-DC", "science_program": null, "title": "Thermogenic Methane Production in Antarctic Subglacial Hydrocarbon Seeps", "url": "https://www.usap-dc.org/view/dataset/601918"}], "date_created": "Tue, 14 May 2024 00:00:00 GMT", "description": "Non-technical abstract Earth\u2019s climatic changes have been recorded in the ice core collected from the Antarctic ice sheet. While these records provide a high resolution view of how polar temperatures changed through time, it is not always clear what Earth process influence Antarctic climate. One likely contributor to Antarctic temperature changes is the cyclic changes in Earth\u2019s orientation as it orbits the sun. These so-called Milankovitch cycles control the amount and pattern of sunlight reaching the polar regions, that in turn result in periods of climatic warming or cooling. While the orbital variations and control on incoming solar energy remain well understood, how they influence Antarctic climate remains unresolved. It is the goal of this project to determine how variations in Earth\u2019s orbit may be locally influencing Antarctic temperatures. The researchers on this project are pursing this goal by identifying periods of past ice melting on the surface of Antarctica using minerals that precipitate from the meltwaters that resulted from past warm periods. The timing of this past melting will be determined by radioisotopic dating of the minerals using the natural radioactive decay of uranium to thorium. By dating numerous samples, collected in past scientific expeditions throughout the Antarctic continent, these researchers aim to reconstruct the frequency and spatial pattern of past warming and in doing so, determine what aspect of Earth\u2019s orbital variations influences Antarctic ice loss. Technical abstract Antarctic ice cores provide high resolution records of Pleistocene Southern Hemisphere temperatures that show an overall coherence with Northern Hemisphere temperature variations. One explanation for this bi-hemispheric temperature covariance relies on changes in atmospheric CO2 that result from varying northern hemisphere insolation. An alternative posits that the apparent coherence of polar temperatures is due to the misleading covariance between northern hemisphere summer insolation and, the southern hemisphere summer duration. At present there is an insufficient understanding of the role that local insolation plays in Antarctic climate. The goal of this research project is to identify the temporal spatial patterns of solar forcing in Antarctica. To reach this goal, the project team will: 1) develop a way to identify periods of past surface melt production in Antarctica using U-Th dating of pedogenic carbonates; and 2) utilize the evidence of past surface melting to calibrate energy balance models and interrogate past Antarctic surface temperatures and; 3) compare the timing of Antarctic warm periods to potential solar forcing mechanisms such as peak summer insolation or summer duration. A means of identifying the spatial and temporal pattern at which local insolation influences Antarctic temperature would provide a transformative solution to the contradiction in current climate records. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; PALEOCLIMATE RECONSTRUCTIONS", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blackburn, Terrence", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "EAGER: Pedogenic Carbonates Record Insolation Driven Surface Melting in Antarctica", "uid": "p0010459", "west": -180.0}, {"awards": "2200448 Simms, Alexander", "bounds_geometry": null, "dataset_titles": "Constraining the Radiocarbon Reservoir Age for the Southern Ocean Using Whale Bones Salvaged from Early 20th Century Whaling Stations", "datasets": [{"dataset_uid": "601784", "doi": "10.15784/601784", "keywords": "Antarctica; C-14; Cryosphere; Radiocarbon Dates; Whale Bone; Whales", "people": "Southon, John; Friedlaender, Ari; Baker, C. Scott; Sremba, Angela; Simms, Alexander; Divola, Claire", "repository": "USAP-DC", "science_program": null, "title": "Constraining the Radiocarbon Reservoir Age for the Southern Ocean Using Whale Bones Salvaged from Early 20th Century Whaling Stations", "url": "https://www.usap-dc.org/view/dataset/601784"}], "date_created": "Thu, 09 May 2024 00:00:00 GMT", "description": "Much of our understanding of ice sheet behavior due to warming temperatures is based on how past ice sheets responded to warming associated with the end of the last ice age, 20,000 years ago. These studies rely on accurate dating of features left behind by the past ice sheets. The most commonly used method for determining the age of these features over the last ~40,000 years is radiocarbon dating. However, radiocarbon dating is not without its nuances, which are particularly pronounced around Antarctica. One of these nuances is determining the offset between the materials measured radiocarbon age and its true age. The purpose of this research is to use historically harvested whale bones from the Antarctic Peninsula, whose age is independently known, to determine that offset. A better understanding of that offset will allow more accurate estimates of past rates of ice sheet and sea-level changes across the Antarctic Peninsula over the last ~40,000 years. Much of our understanding of how the Antarctic Ice Sheet will respond to future climate changes is based on studies of its past behavior. Those studies often rely on reconstructing its evolution since the Last Glacial Maximum, 20,000 years ago. Radiocarbon dating is the most commonly used method of dating Quaternary deposits for these reconstructions. However, the use of radiocarbon in Antarctica is hampered by some of the largest and least constrained radiocarbon reservoirs on the planet. The purpose of this research is to determine the radiocarbon reservoir for whale bones. This research will leverage an existing collection of 25 whale bones used for prior DNA research to determine the late Holocene radiocarbon reservoir for the Antarctic Peninsula. The whale bones are from specimens harvested at the turn of the 20th century prior to nuclear testing in the 1950s. Thus, their radiocarbon age will provide valuable new constraints on the radiocarbon reservoir for shallow waters around Antarctica. An added benefit of this approach is that given the DNA determination, we will also be able to determine if that radiocarbon reservoir varies across three species of whales, thus testing the common assumption that the radiocarbon reservoir does not vary significantly across different species. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "ORGANIC CARBON; West Antarctica", "locations": "West Antarctica", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Simms, Alexander", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "New constraints on 14C reservoirs around the Antarctic Peninsula and the Southern Ocean based on historically-harvested whale bones", "uid": "p0010457", "west": null}, {"awards": "1906143 Buizert, Christo", "bounds_geometry": null, "dataset_titles": "CO2 amount fractions from WAIS Divide, Antarctica", "datasets": [{"dataset_uid": "601775", "doi": "10.15784/601775", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "CO2 amount fractions from WAIS Divide, Antarctica", "url": "http://www.usap-dc.org/view/dataset/601775"}], "date_created": "Thu, 18 Apr 2024 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; CO2; Cryosphere; Ice Core Data; WAIS Divide Ice Core; West Antarctic Ice Sheet Divide", "locations": "West Antarctic Ice Sheet Divide; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Wendt, Kathleen", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": null, "uid": null, "west": null}, {"awards": "2215771 Kreutz, Karl", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 01 Apr 2024 00:00:00 GMT", "description": "This award is for acquisition of new instrumentation to support acquisition of the new LA-HR-ICPMS instrumentation for the trace-element analysis of various environmental samples. This instrumentation will replace the original (and heavily used over two decades) ThermoScientific Element2 ICP-MS installed at the University of Maine\u2019s Climate Change Institute (CCI). The new acquisition will significantly expand research capabilities of the CCI/ICP-MS Facility to improve the analysis of aqueous samples, supplemented with a laser ablation (LA) front end for ice, biological, and other solid materials. The current ICP-MS Facility was established in 2002 with an NSF/MRI award, which since then has served as a vital resource for climate, environmental, ecosystem, and engineering research and training at the U. Maine, across the state of Maine and beyond. The routine use and primary support of the Facility come from the Principal Investigators and their collaborators that group under three research areas: glaciochemistry and climate/environmental reconstruction; paleoceanography and marine biogeochemistry; and environmental sensor development and material science engineering. The U. Maine is the State\u2019s Land \u0026 Sea Grant university and only PhD granting institution, so the campus is the de facto academic research and research training hub of the state of Maine. The proposed advances of this research \u0026 training instrumentation will immediately impact current and future NSF-funded research projects that support extensive national and international collaborations. Specific to this proposal are collaborations with the University of Venice (Italy) and the University of Cambridge/British Antarctic Survey to develop laser ablation ICP-MS imaging of ice cores, and collaborations with New Zealand, Swiss, Chinese, Canadian, and Brazilian colleagues to analyze ice, thereby maintaining our leadership role in global ice core and climate change research. Likewise, the enhanced carbonate analysis capacity of the Element XR will have an immediate impact on NSF-funded research projects in the Gulf of Maine and in the South Pacific. The proposed instrumentation will facilitate new and important collaborations between academic colleges (College of Natural Science, Forestry, and Agriculture and the College of Engineering) and research units - the CCI and the Frontier Institute for Research in Sensor Technology - across the campus, as well as enabling new and broader scientific collaborations with other academic and scientific institutions across Maine. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "OCEAN CHEMISTRY; GLACIERS/ICE SHEETS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Kreutz, Karl; Mukhopadhyay, Sharmila M; Allen, Katherine A; Mayewski, Paul A.; Kurbatov, Andrei V.", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "MRI: Acquisition of LA-HR-ICPMS instrumentation for climate, environmental, ecosystem, and engineering research at the University of Maine", "uid": "p0010456", "west": null}, {"awards": "2231230 Joughin, Ian", "bounds_geometry": "POLYGON((90 -65,93.5 -65,97 -65,100.5 -65,104 -65,107.5 -65,111 -65,114.5 -65,118 -65,121.5 -65,125 -65,125 -65.2,125 -65.4,125 -65.6,125 -65.8,125 -66,125 -66.2,125 -66.4,125 -66.6,125 -66.8,125 -67,121.5 -67,118 -67,114.5 -67,111 -67,107.5 -67,104 -67,100.5 -67,97 -67,93.5 -67,90 -67,90 -66.8,90 -66.6,90 -66.4,90 -66.2,90 -66,90 -65.8,90 -65.6,90 -65.4,90 -65.2,90 -65))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 29 Feb 2024 00:00:00 GMT", "description": "The snow that falls on Antarctica compresses to ice that flows toward the coast as a large sheet, returning it to the ocean over periods of centuries to millennia. In many places around Antarctica, the ice sheet extends from the land to over the ocean, forming floating ice shelves on the periphery. If this cycle is in balance, the ice sheets help maintain a stable sea level. When the climate cools or warms, however, sea level falls or rises as the ice sheet gains or loses ice. The peripheral ice shelves are important for regulating sea level because they help hold back the flow of ice to the ocean. Warming ocean waters thin ice shelves by melting their undersides, allowing ice to flow faster to the ocean, and raising sea level globally. Thus, an important question is how much sea level will rise in response to warming ocean temperatures over the next century(s) that further thin Antarctica\u2019s ice shelves. Currently, West Antarctica produces the majority of the continent\u2019s contribution to sea level. Albeit with large uncertainty, ice-sheet models indicate that Totten and Denman glaciers in East Antarctica could also produce substantial sea-level rise in the next century(s). This international study will focus on improving understanding of how much these glaciers will contribute to sea level under various warming scenarios. The project will use numerical models constrained by oceanographic and remote sensing observations to determine how Totten and Denman glaciers will respond to increased melting. Remote sensing data will provide updated and improved estimates of the melt rate for each ice shelf. Two float profilers will be deployed from aircraft by British and Australian partners in front of each ice shelf to repeatedly measure the temperature and salinity of the water column, with the results telemetered back via satellite link. The melt and oceanographic data will be used to constrain parameterized transfer functions for ice-shelf cavity melting in response to ocean temperature, improving on current parameterizations based on limited data. These melt functions will be used with ocean temperatures from climate models to force an open-source ice-flow numerical model for each glacier to determine the century-scale response for a variety of scenarios, helping to reduce uncertainty in sea level contributions from this part of Antarctica. Processes other than melt that might further alter the contribution to sea level over the next few centuries will also be examined. On the observational side, the demonstrated deployment of float profilers from a sonobuoy launch tube in polar settings would help raise the technology readiness of operational in-situ monitoring of the rapidly changing polar shelf seas, paving the way for an expansion of observations of ocean hydrographic properties from remote areas that currently are poorly understood. In addition to being of scientific value, reduced uncertainty in sea-level rise projections has strong societal benefit to coastal communities struggling with long-range planning to mitigate the effects of sea-level rise over the coming decades to centuries. Outreach activities by team members will help raise public awareness of Antarctica\u0027s dramatic changes and the resulting consequences. This is a project jointly funded by the National Science Foundation\u2019s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 125.0, "geometry": "POINT(107.5 -66)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; ICE SHEETS", "locations": "Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Joughin, Ian; Shapero, Daniel; Smith, Benjamin E", "platforms": null, "repositories": null, "science_programs": null, "south": -67.0, "title": "NSFGEO-NERC: Understanding the Response to Ocean Melting for Two of East Antarctica\u0027s Most Vulnerable Glaciers: Totten and Denman", "uid": "p0010454", "west": 90.0}, {"awards": "1939139 Scherer, Reed; 1939146 Siddoway, Christine", "bounds_geometry": "POLYGON((-120 -66,-117.5 -66,-115 -66,-112.5 -66,-110 -66,-107.5 -66,-105 -66,-102.5 -66,-100 -66,-97.5 -66,-95 -66,-95 -67.1,-95 -68.2,-95 -69.3,-95 -70.4,-95 -71.5,-95 -72.6,-95 -73.7,-95 -74.8,-95 -75.9,-95 -77,-97.5 -77,-100 -77,-102.5 -77,-105 -77,-107.5 -77,-110 -77,-112.5 -77,-115 -77,-117.5 -77,-120 -77,-120 -75.9,-120 -74.8,-120 -73.7,-120 -72.6,-120 -71.5,-120 -70.4,-120 -69.3,-120 -68.2,-120 -67.1,-120 -66))", "dataset_titles": "Pliocene diatom abundance, IODP 379-U1532; Population morphometrics of the Southern Ocean diatom Fragilariopsis kerguelensis related to Sea Surface Temperature; U-Pb zircon and apatite fission track dates for IRD (ice-rafted cobbles and mineral grains) from IODP379 drill sites", "datasets": [{"dataset_uid": "601828", "doi": "10.15784/601828", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Geochronology; Marie Byrd Land; Subglacial Bedrock; Thermochronology", "people": "Siddoway, Christine", "repository": "USAP-DC", "science_program": null, "title": "U-Pb zircon and apatite fission track dates for IRD (ice-rafted cobbles and mineral grains) from IODP379 drill sites", "url": "https://www.usap-dc.org/view/dataset/601828"}, {"dataset_uid": "601769", "doi": null, "keywords": "Antarctica; Biogenic Silica; Diatom", "people": "Scherer, Reed Paul; Furlong, Heather", "repository": "USAP-DC", "science_program": null, "title": "Pliocene diatom abundance, IODP 379-U1532", "url": "https://www.usap-dc.org/view/dataset/601769"}, {"dataset_uid": "601804", "doi": "10.15784/601804", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Oceanography; Sabrina Coast; Sea Surface Temperature; Southern Ocean", "people": "Ruggiero, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Population morphometrics of the Southern Ocean diatom Fragilariopsis kerguelensis related to Sea Surface Temperature", "url": "https://www.usap-dc.org/view/dataset/601804"}], "date_created": "Tue, 20 Feb 2024 00:00:00 GMT", "description": "Part I, Non-technical Abstract Concerns that the West Antarctic Ice Sheet (WAIS) might be susceptible to releasing its ice as giant icebergs into the Southern Ocean due to a warming climate, raising global sea level, were first expressed more than 40 years ago. To best-assess this threat, scientists need to know whether such events occurred in the geologically recent past, during warm intervals of past glacial-interglacial cycles. Ocean drilling near the most vulnerable sector of the WAIS, in 2019, yielded seafloor geologic records demonstrating times when icebergs dropped large volumes of sands and pebbles, called ice-rafted detritus (IRD) in deep water of the Amundsen Sea. Occurring together with IRD that was eroded from bedrock beneath the ice sheets, there are abundant microfossils of diatoms (algal plankton), which indicate high biological productivity in the open ocean. The new sediment cores provide a complete, uninterrupted record of a time of dramatic fluctuations of ice sheet extent that occurred over the last 3 million years. Therefore, they provide the means to obtain clear answers to the question whether ice sheet collapse occurred in the past and offering clues to its potential future. This project will investigate sediment intervals where IRD coincides with evidence of high diatom production, to test whether these two criteria indicate rapid ice sheet collapse. Geochemical analysis of IRD pebbles will help trace the source of the icebergs to likely on-land sites. By analyzing conditions of high diatom and IRD accumulation in deep ocean sediment, where local coastal influences can be avoided, we will assess oceanographic and climatic conditions associated with past ice sheet collapse events. Diatoms provide powerful evidence of temperature and ocean productivity changes in the past, that, when linked to time, can translate into rates of ice sheet drawdown. These results will provide critical data for designing, constraining and testing the next suite computer models that can determine the likelihood and timing of future ice sheet collapse in a warming world. The project will include training of undergraduate and graduate students from diverse backgrounds, and the public will be introduced to Antarctic science and engaged through several different outreach efforts. Part 2, Technical Abstract New drillcores from the Amundsen Sea, Antarctica (IODP Expedition 379) contain a continuous record of oceanographic changes and iceberg rafted debris (IRD) spanning the last 5 million years. This study aims to identify the signature of retreat/collapse of the West Antarctic Ice Sheet (WAIS) in these continental margin, deep-sea sediments by quantitatively analyzing, in detail, diatom and IRD records across glacial-interglacial lithostratigraphic transitions to establish the timing and frequency of Late Pliocene and Pleistocene WAIS collapse events. The investigators will secure age constraints and diagnostic observations of marine paleoenvironmental conditions for selected interglacial intervals of cores from sites U1532 and U1533, using high resolution micropaleontology of diatom assemblages coupled with microstratigraphic analysis of IRD depositional events, while petrography, geochronology and thermochronology of iceberg rafted clasts will provide evidence of iceberg sources and pathways. Depositional paleotemperatures will be assessed via a new paleotemperature proxy based on quantitative assessment of morphologic changes in the dominant Southern Ocean diatom Fragilariopsis kerguelensis. Their results will contribute to parameterization of new ice sheet models that seek to reconstruct and forecast West Antarctic Ice Sheet behavior. This project will directly contribute to undergraduate education at an undergraduate-only college and at a public university that serves a demographic typified by first generation university students and underrepresented groups. Spanning geology, geochemistry, sedimentology, paleontology and paleoceanography, the proposed work will allow undergraduate students to develop diverse skills through hands-on research within a collaborative team that is dedicated to societally relevant research. The two graduate students will conduct original research and work alongside/mentor undergraduates, making for a well-rounded research experience that prepares them for success in future academic or employment sectors. The discoveries that come from this deep-sea record from West Antarctica will be communicated by students and investigators at national and international conferences and an array of public science outreach events. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -71.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICEBERGS; SEA SURFACE TEMPERATURE; Amundsen Sea; MICROFOSSILS", "locations": "Amundsen Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE", "persons": "Scherer, Reed Paul; Siddoway, Christine", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Collaborative Research: Testing the Linchpin of WAIS Collapse with Diatoms and IRD in Pleistocene and Late Pliocene Strata of the Resolution Drift, Amundsen Sea, Antarctica", "uid": "p0010451", "west": -120.0}, {"awards": "1841607 Banwell, Alison; 1841467 MacAyeal, Douglas", "bounds_geometry": "POLYGON((-68.28 -71.1,-68.202 -71.1,-68.124 -71.1,-68.046 -71.1,-67.968 -71.1,-67.89 -71.1,-67.812 -71.1,-67.734 -71.1,-67.656 -71.1,-67.578 -71.1,-67.5 -71.1,-67.5 -71.14999999999999,-67.5 -71.19999999999999,-67.5 -71.25,-67.5 -71.3,-67.5 -71.35,-67.5 -71.39999999999999,-67.5 -71.44999999999999,-67.5 -71.5,-67.5 -71.55,-67.5 -71.6,-67.578 -71.6,-67.656 -71.6,-67.734 -71.6,-67.812 -71.6,-67.89 -71.6,-67.968 -71.6,-68.046 -71.6,-68.124 -71.6,-68.202 -71.6,-68.28 -71.6,-68.28 -71.55,-68.28 -71.5,-68.28 -71.44999999999999,-68.28 -71.39999999999999,-68.28 -71.35,-68.28 -71.3,-68.28 -71.25,-68.28 -71.19999999999999,-68.28 -71.14999999999999,-68.28 -71.1))", "dataset_titles": "Dataset for: Banwell et al. 2024, \u0027Observed meltwater-induced flexure and fracture at a doline on George VI Ice Shelf, Antarctica\u0027, Journal of Glaciology.", "datasets": [{"dataset_uid": "601771", "doi": "10.15784/601771", "keywords": "Antarctica; Antarctic Peninsula; AWS; Cryosphere; GNSS; GPS Data; Ice-Shelf Flexure; Ice Shelf Fracture; Ice-Shelf Melt; Timelaps Images", "people": "Stevens, Laura; Banwell, Alison; Willis, Ian; Dell, Rebecca; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Dataset for: Banwell et al. 2024, \u0027Observed meltwater-induced flexure and fracture at a doline on George VI Ice Shelf, Antarctica\u0027, Journal of Glaciology.", "url": "https://www.usap-dc.org/view/dataset/601771"}], "date_created": "Thu, 15 Feb 2024 00:00:00 GMT", "description": "The evolution of surface and shallow subsurface meltwater across Antarctic ice shelves has important implications for their (in)stability, as demonstrated by the 2002 rapid collapse of the Larsen B Ice Shelf. It is vital to understand the causes of ice-shelf (in)stability because ice shelves buttress against the discharge of inland ice and therefore influence ice-sheet contributions to sea-level rise. Ice-shelf break-up may be triggered by stress variations associated with surface meltwater movement, ponding, and drainage. These variations may cause an ice shelf to flex and fracture. This four-year project will provide key geophysical observations to improve understanding of ice-shelf meltwater and its effects on (in)stability. The work will be conducted on the George VI Ice Shelf on the Antarctic Peninsula, where hundreds of surface lakes form each summer. Over a 27-month period, global positioning systems, seismometers, water pressure transducers, automatic weather stations, and in-ice thermistor strings will be deployed to record ice shelf flexure, fracture seismicity, water depths, and surface and subsurface melting, respectively, in and around several surface lakes on the George VI Ice Shelf, within roughly 20 km of the British Antarctic Survey\u0027s Fossil Bluff Station. Field data will be used to validate and extend the team\u0027s approach to modelling ice-shelf flexure and stress, and possible \"Larsen-B style\" ice-shelf instability and break-up. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -67.5, "geometry": "POINT(-67.89 -71.35)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Antarctica; ICE MOTION; Ice-Shelf Flexure; GPS Data", "locations": "Antarctica", "north": -71.1, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Banwell, Alison; Macayeal, Douglas", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -71.6, "title": "NSFGEO-NERC: Ice-shelf Instability Caused by Active Surface Meltwater Production, Movement, Ponding and Hydrofracture", "uid": "p0010449", "west": -68.28}, {"awards": "2333940 Zhong, Shijie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 08 Jan 2024 00:00:00 GMT", "description": "Satellite observations of Earth\u2019s surface gravity and elevation changes indicate rapid melting of ice sheets in recent decades in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica. This rapid melting may lead to significant global sea level rise which is a major societal concern. Measurements from the Global Positioning System (GPS) show rapid land uplift in these regions as the ice sheets melt. When an ice sheet melts, the melt water flows to oceans, causing global sea level to rise. However, the sea level change at a given geographic location is also influenced by two other factors associated with the ice melting process: 1) the vertical motion of the land and 2) gravitational attraction. The vertical motion of the land is caused by the change of pressure force on the surface of the solid Earth. For example, the removal of ice mass reduces the pressure force on the land, leading to uplift of the land below the ice sheet, while the addition of water in oceans increases the pressure force on the seafloor, causing it to subside. The sea level always follows the equipotential surface of the gravity which changes as the mass on the Earth\u2019s surface (e.g., the ice and water) or/and in its interiors (e.g., at the crust-mantle boundary) is redistributed. Additionally, the vertical motion of the land below an ice sheet has important effects on the evolution and stability of the ice sheet and may determine whether the ice sheet will rapidly collapse or gradually stabilize. The main goal of this project is to build an accurate and efficient computer model to study the displacement and deformation of the Antarctic crust and mantle in response to recent ice melting. The project will significantly improve existing and publicly available computer code, CitcomSVE. The horizontal and vertical components of the Earth\u2019s surface displacement depends on mantle viscosity and elastic properties of the Earth. Although seismic imaging studies demonstrate that the Antarctica mantle is heterogeneous, most studies on the ice-melting induced deformation in Antarctica have assumed that mantle viscosity and elastic properties only vary with the depth due to computational limitations. In this project, the new computational method in CitcomSVE avoids such assumptions and makes it possible to include realistic 3-D mantle viscosity and elastic properties in computing the Antarctica crustal and mantle displacement. This project will interpret the GPS measurements of the surface displacements in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica and use the observations to place constraints on mantle viscosity and deformation mechanisms. The project will also seek to predict the future land displacement Antarctica, which will lead to a better understand of Antarctica ice sheets. Finally, the project has direct implications for the study of global sea level change and the dynamics of the Greenland ice sheet. Technical Description Glacial isostatic adjustment (GIA) is important for understanding not only fundamental science questions including mantle viscosity, mantle convection and lithospheric deformation but also societally important questions of global sea-level change, polar ice melting, climate change, and groundwater hydrology. Studies of rock deformation in laboratory experiments, post-seismic deformation, and mantle dynamics indicate that mantle viscosity is temperature- and stress-dependent. Although the effects of stress-dependent (i.e., non-Newtonian) viscosity and transient creep rheology on GIA process have been studied, observational evidence remains elusive. There has been significant ice mass loss in recent decades in northern Antarctica Peninsula (NAP) and Amundsen Sea Embayment (ASE) of West Antarctica. The ice mass loss has caused rapid bedrock uplift as measured by GPS techniques which require surprisingly small upper mantle viscosity of ~1018 Pas. The rapid uplifts may have important feedback effects on ongoing ice melting because of their influence on grounding line migration, and the inferred small viscosity may have implications for mantle rheology and deformation on decadal time scales. The main objective of the project is to test hypotheses that the GPS observations in NAP and ASE regions are controlled by 3-D non-Newtonian or/and transient creep viscosity by developing new GIA modeling capability based on finite element package CitcomSVE. The project will carry out the following three tasks: Task 1 is to build GIA models for the NAP and ASE regions to examine the effects of 3-D temperature-dependent mantle viscosity on the surface displacements and to test hypothesis that the 3-D mantle viscosity improves the fit to the GPS observations. Task 2 is to test the hypothesis that non-Newtonian or/and transient creep rheology controls GIA process on decadal time scales by computing GIA models and comparing model predictions with GPS observations for the NAP and ASE regions. Task 3 is to implement transient creep (i.e., Burgers model) rheology into finite element package CitcomSVE for modeling the GIA process on global and regional scales and to make the package publicly available to the scientific community. The project will develop the first numerical GIA model with Burgers transient rheology and use the models to examine the effects of 3-D temperature-dependent viscosity, non-Newtonian viscosity and transient rheology on GIA-induced surface displacements in Antarctica. The project will model the unique GPS observations of unusually large displacement rates in the NAP and ASE regions to place constraints on mantle rheology and to distinguish between 3-D temperature-dependent, non-Newtonian and transient mantle viscosity. The project will expand the capability of the publicly available software package CitcomSVE for modeling viscoelastic deformation and tidal deformation on global and regional scales. The project will advance our understanding in lithospheric deformation and mantle rheology on decadal time scales, which helps predict grounding line migration and understand ice sheet stability in West Antarctica. The project will strengthen the open science practice by improving the publicly available code CitcomSVE at github. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "WAIS; CRUSTAL MOTION; COMPUTERS; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE", "locations": "WAIS", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Zhong, Shijie", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Investigating Effects of Transient and Non-Newtonian Mantle Viscosity on Glacial Isostatic Adjustment Process and their Implications for GPS Observations in Antarctica", "uid": "p0010441", "west": -180.0}, {"awards": "2224760 Gooseff, Michael", "bounds_geometry": "POINT(162.87 -77)", "dataset_titles": "EDI Data Portal: McMurdo Dry Valleys LTER", "datasets": [{"dataset_uid": "200379", "doi": "", "keywords": null, "people": null, "repository": "Environmental Data Initiative (EDI)", "science_program": null, "title": "EDI Data Portal: McMurdo Dry Valleys LTER", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=MCM"}], "date_created": "Tue, 14 Nov 2023 00:00:00 GMT", "description": "Non-technical Abstract The McMurdo Dry Valleys LTER seeks to understand how changes in the temporal variability of ecological connectivity interact with existing landscape legacies to alter the structure and functioning of this extreme polar desert ecosystem. This research has broad implications, as it will help us to understand how natural ecosystems respond to ongoing anthropogenic global change. At the same time, this project also serves an important educational and outreach function, providing immersive research and educational experiences to students and artists from diverse backgrounds, and helping to ensure a diverse and well-trained next generation of leaders in polar ecosystem science and stewardship. Ultimately, the results of this project will help us to better understand and prepare for the effects of climate change and develop scientific insights that are relevant far beyond Antarctic ecosystems. The McMurdo Dry Valleys (MDVs) make up an extreme polar desert ecosystem in the largest ice-free region of Antarctica. The organisms in this ecosystem are generally small. Bacteria, microinvertebrates, cyanobacterial mats, and phytoplankton can be found across the streams, soils, glaciers, and ice-covered lakes. These organisms have adapted to the cold and arid conditions that prevail outside of lakes for all but a brief period in the austral summer when the ecosystem is connected by liquid water. In the summer when air temperatures rise barely above freezing, soils warm and glacial meltwater flows through streams into the open moats of lakes. Most biological activity across the landscape occurs in summer. Through the winter, or polar night (6 months of darkness), glaciers, streams, and soil biota are inactive until sufficient light, heat, and liquid water return, while lake communities remain active all year. Over the past 30 years, the MDVs have been disturbed by cooling, heatwaves, floods, rising lake levels, as well as permafrost and lake ice thaw. Considering the clear ecological responses to this variation in physical drivers, and climate models predicting further warming and more precipitation, the MDV ecosystem sits at a threshold between the current extreme cold and dry conditions and an uncertain future. This project seeks to determine how important the legacy of past events and conditions versus current physical and biological interactions shape the current ecosystem. Four hypotheses will be tested, related to 1) whether the status of specific organisms are indicative ecosystem stability, 2) the relationship between legacies of past events to current ecosystem resilience (resistance to big changes), 3) carryover of materials between times of high ecosystem connectivity and activity help to maintain ecosystem stability, and 4) changes in disturbances affect how this ecosystem persists through the annual polar night (i.e., extended period of dark and cold). Technical Abstract In this iteration of the McMurdo LTER project (MCM6), the project team will test ecological connectivity and stability theory in a system subject to strong physical drivers (geological legacies, extreme seasonality, and contemporary climate change) and driven by microbial organisms. Since microorganisms regulate most of the world\u2019s critical biogeochemical functions, these insights will be relevant far beyond polar ecosystems and will inform understanding and expectations of how natural and managed ecosystems respond to ongoing anthropogenic global change. MCM6 builds on previous foundational research, both in Antarctica and within the LTER network, to consider the temporal aspects of connectivity and how it relates to ecosystem stability. The project will examine how changes in the temporal variability of ecological connectivity interact with the legacies of the existing landscape that have defined habitats and biogeochemical cycling for millennia. The project team hypothesizes that the structure and functioning of the MDV ecosystem is dependent upon legacies and the contemporary frequency, duration, and magnitude of ecological connectivity. This hypothesis will be tested with new and continuing monitoring, experiments, and analyses of long-term datasets to examine: 1) the stability of these ecosystems as reflected by sentinel taxa, 2) the relationship between ecological legacies and ecosystem resilience, 3) the importance of material carryover during periods of low connectivity to maintaining biological activity and community stability, and 4) how changes in disturbance dynamics disrupt ecological cycles through the polar night. Tests of these hypotheses will occur in field and modeling activities using new and long-term datasets already collected. New datasets resulting from field activities will be made freely available via widely-known online databases (MCM LTER and EDI). The project team has also developed six Antarctic Core Ideas that encompass themes from data literacy to polar food webs and form a consistent thread across the education and outreach activities. Building on past success, collaborations will be established with teachers and artists embedded within the science teams, who will work to develop educational modules with science content informed by direct experience and artistic expression. Undergraduate mentoring efforts will incorporate computational methods through a new data-intensive scientific training program for MCM REU students. The project will also establish an Antarctic Research Experience for Community College Students at CU Boulder, to provide an immersive educational and research experience for students from diverse backgrounds in community colleges. MCM LTER will continue its mission of training and mentoring students, postdocs, and early career scientists as the next generation of leaders in polar ecosystem science and stewardship. Historically underrepresented participation will be expanded at each level of the project. To aid in these efforts, the project has established Education \u0026 Outreach and Diversity, Equity, and Inclusion committees to lead, coordinate, support, and integrate these activities through all aspects of MCM6. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 162.87, "geometry": "POINT(162.87 -77)", "instruments": null, "is_usap_dc": true, "keywords": "COMMUNITY DYNAMICS; ABLATION ZONES/ACCUMULATION ZONES; SOIL TEMPERATURE; DIATOMS; FIELD INVESTIGATION; PERMANENT LAND SITES; BUOYS; GROUND-BASED OBSERVATIONS; SEDIMENTS; SNOW WATER EQUIVALENT; SPECIES/POPULATION INTERACTIONS; WATER-BASED PLATFORMS; FIXED OBSERVATION STATIONS; VIRUSES; PHYTOPLANKTON; ACTIVE LAYER; FIELD SURVEYS; RADIO TRANSMITTERS; DATA COLLECTIONS; ECOLOGICAL DYNAMICS; LANDSCAPE; GROUND WATER; SNOW/ICE CHEMISTRY; LAND-BASED PLATFORMS; ANIMALS/INVERTEBRATES; ECOSYSTEM FUNCTIONS; HUMIDITY; GEOCHEMISTRY; SURFACE WINDS; RIVERS/STREAM; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; SNOW; LAND RECORDS; ATMOSPHERIC PRESSURE; SURFACE TEMPERATURE; ATMOSPHERIC RADIATION; BACTERIA/ARCHAEA; AIR TEMPERATURE; GLACIERS; SNOW/ICE TEMPERATURE; SOIL CHEMISTRY; METEOROLOGICAL STATIONS; WATER QUALITY/WATER CHEMISTRY; TERRESTRIAL ECOSYSTEMS; MOORED; PROTISTS; STREAMFLOW STATION; Dry Valleys; LAKE/POND; LAKE ICE; SNOW DEPTH; AQUATIC ECOSYSTEMS; SNOW DENSITY; FIELD SITES", "locations": "Dry Valleys", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science", "paleo_time": null, "persons": "Gooseff, Michael N.; Adams, Byron; Barrett, John; Diaz, Melisa A.; Doran, Peter; Dugan, Hilary A.; Mackey, Tyler; Morgan-Kiss, Rachael; Salvatore, Mark; Takacs-Vesbach, Cristina; Zeglin, Lydia H.", "platforms": "LAND-BASED PLATFORMS; LAND-BASED PLATFORMS \u003e FIELD SITES; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e DATA COLLECTIONS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e RADIO TRANSMITTERS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e FIXED OBSERVATION STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e METEOROLOGICAL STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e STREAMFLOW STATION; WATER-BASED PLATFORMS; WATER-BASED PLATFORMS \u003e BUOYS; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED \u003e BUOYS", "repo": "Environmental Data Initiative (EDI)", "repositories": "Environmental Data Initiative (EDI)", "science_programs": "LTER", "south": -77.0, "title": "LTER: MCM6 - The Roles of Legacy and Ecological Connectivity in a Polar Desert Ecosystem", "uid": "p0010440", "west": 162.87}, {"awards": "0637004 McGwire, Kenneth", "bounds_geometry": null, "dataset_titles": "Ice core image analyses by McGwire site 91 and site 93", "datasets": [{"dataset_uid": "601745", "doi": "10.15784/601745", "repository": "USAP-DC", "science_program": null, "title": "Ice core image analyses by McGwire site 91 and site 93", "url": "http://www.usap-dc.org/view/dataset/601745"}], "date_created": "Mon, 16 Oct 2023 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Snow/ice; Snow/Ice", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McGwire, Kenneth C.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": null, "bounds_geometry": null, "dataset_titles": "VSMOW-SLAP d170, d180, and 17O-excess data from WAIS Divide Ice Core Project, Siple Dome and Taylor Dome", "datasets": [{"dataset_uid": "601743", "doi": "10.15784/601743", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "VSMOW-SLAP d170, d180, and 17O-excess data from WAIS Divide Ice Core Project, Siple Dome and Taylor Dome", "url": "http://www.usap-dc.org/view/dataset/601743"}], "date_created": "Fri, 13 Oct 2023 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Delta 18O; Delta O-17; Epica Dome C; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Talos Dome; Taylor Dome; Vostok", "locations": "Talos Dome; Siple Dome; Taylor Dome; Talos Dome; Epica Dome C; Vostok; Antarctica; Siple Dome; Taylor Dome; Epica Dome C", "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": "Steig, Eric J.; Schoenemann, Spruce", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": null, "uid": null, "west": null}, {"awards": "1149085 Bassis, Jeremy", "bounds_geometry": "POLYGON((66 -68,66.9 -68,67.8 -68,68.7 -68,69.6 -68,70.5 -68,71.4 -68,72.3 -68,73.2 -68,74.1 -68,75 -68,75 -68.6,75 -69.2,75 -69.8,75 -70.4,75 -71,75 -71.6,75 -72.2,75 -72.8,75 -73.4,75 -74,74.1 -74,73.2 -74,72.3 -74,71.4 -74,70.5 -74,69.6 -74,68.7 -74,67.8 -74,66.9 -74,66 -74,66 -73.4,66 -72.8,66 -72.2,66 -71.6,66 -71,66 -70.4,66 -69.8,66 -69.2,66 -68.6,66 -68))", "dataset_titles": "Antarctic Ice Shelf Rift Propagation Rates", "datasets": [{"dataset_uid": "601740", "doi": "10.15784/601740", "keywords": "Amery Ice Shelf; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; MODIS", "people": "Walker, Catherine; Bassis, Jeremy", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Shelf Rift Propagation Rates", "url": "https://www.usap-dc.org/view/dataset/601740"}], "date_created": "Fri, 13 Oct 2023 00:00:00 GMT", "description": "Bassis/1149085 This CAREER award supports a project to develop physically based bounds on the amount ice sheets can contribute to sea level rise in the coming centuries. To simulate these limits, a three-dimensional discrete element model will be developed and applied to simulate regions of interest in the Greenland and Antarctic ice sheets. These regions will include Helheim Glacier, Jakobshavn Isbr\u00e4e, Pine Island Glacier and sections of the Larsen Ice Shelf. In the discrete element model the ice will be discretized into distinct blocks or boulders of ice that interact through inelastic collisions, frictional forces and bonds. The spectrum of best to worst case scenarios will be examined by varying the strength and number of bonds between neighboring blocks of ice. The worst case scenario corresponds to completely disarticulated ice that behaves in a manner akin to a granular material while the best case scenario corresponds to completely intact ice with no preexisting flaws or fractures. Results from the discrete element model will be compared with those from analogous continuum models that incorporate a plastic yield stress into the more traditional viscous flow approximations used to simulate ice sheets. This will be done to assess if a fracture permitting plastic rheology can be efficiently incorporated into large-scale ice sheet models to simulate the evolution of ice sheets over the coming centuries. This award will also support to forge a partnership with two science teachers in the Ypsilanti school district in southeastern Michigan. The Ypsilanti school district is a low income, resource- poor region with a population that consists of ~70% underrepresented minorities and ~69% of students qualify for a free or reduced cost lunch. The cornerstone of the proposed partnership is the development of lesson plans and content associated with a hands-on ice sheet dynamics activity for 6th and 7th grade science students. The activity will be designed so that it integrates into existing classroom lesson plans and is aligned with State of Michigan Science Technology, Engineering and Math (STEM) curriculum goals. The aim of this program is to not only influence the elementary school students, but also to educate the teachers to extend the impact of the partnership beyond the duration of this study. Graduate students will be mentored and engaged in outreach activities and assist in supervising undergraduate students. Undergraduates will play a key role in developing an experimental, analogue ice dynamics lab designed to illustrate how ice sheets and glaciers flow and allow experimental validation of the proposed research activities. The research program advances ice sheet modeling infrastructure by distributing results through the community based Community Ice Sheet Model.", "east": 75.0, "geometry": "POINT(70.5 -71)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Amery Ice Shelf", "locations": "Amery Ice Shelf", "north": -68.0, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Bassis, Jeremy", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "CAREER: Bound to Improve - Improved Estimates of the Glaciological Contribution to Sea Level Rise", "uid": "p0010437", "west": 66.0}, {"awards": "2053169 Kingslake, Jonathan", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 15 Sep 2023 00:00:00 GMT", "description": "When ice sheets and glaciers lose ice faster than it accumulates from snowfall, they shrink and contribute to sea-level rise. This has consequences for coastal communities around the globe by, for example, increasing the frequency of damaging storm surges. Sea-level rise is already underway and a major challenge for the geoscience community is improving predictions of how this will evolve. The Antarctic Ice Sheet is the largest potential contributor to sea-level rise and its future is highly uncertain. It loses ice through two main mechanisms: the formation of icebergs and melting at the base of floating ice shelves on its periphery. Ice flows under gravity towards the ocean and the rate of ice flow controls how fast ice sheets and glaciers shrink. In Greenland and Antarctica, ice flow is focused into outlet glaciers and ice streams, which flow much faster than surrounding areas. Moreover, parts of the Greenland Ice Sheet speed up and slow down substantially on hourly to seasonal time scales, particularly where meltwater from the surface reaches the base of the ice. Meltwater reaching the base changes ice flow by altering basal water pressure and consequently the friction exerted on the ice by the rock and sediment beneath. This phenomenon has been observed frequently in Greenland but not in Antarctica. Recent satellite observations suggest this phenomenon also occurs on outlet glaciers in the Antarctic Peninsula. Meltwater reaching the base of the Antarctic Ice Sheet is likely to become more common as air temperature and surface melting are predicted to increase around Antarctica this century. This project aims to confirm the recent satellite observations, establish a baseline against which to compare future changes, and improve understanding of the direct influence of meltwater on Antarctic Ice Sheet dynamics. This is a project jointly funded by the National Science Foundation\u2019s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries. This project will include a field campaign on Flask Glacier, an Antarctic Peninsula outlet glacier, and a continent-wide remote sensing survey. These activities will allow the team to test three hypotheses related to the Antarctic Ice Sheet\u2019s dynamic response to surface meltwater: (1) short-term changes in ice velocity indicated by satellite data result from surface meltwater reaching the bed, (2) this is widespread in Antarctica today, and (3) this results in a measurable increase in mean annual ice discharge. The project is a collaboration between US- and UK-based researchers and will be supported logistically by the British Antarctic Survey. The project aims to provide insights into both the drivers and implications of short-term changes in ice flow velocity caused by surface melting. For example, showing conclusively that meltwater directly influences Antarctic ice dynamics would have significant implications for understanding the response of Antarctica to atmospheric warming, as it did in Greenland when the phenomenon was first detected there twenty years ago. This work will also potentially influence other fields, as surface meltwater reaching the bed of the Antarctic Ice Sheet may affect ice rheology, subglacial hydrology, submarine melting, calving, ocean circulation, and ocean biogeochemistry. The project aims to have broader impacts on science and society by supporting early-career scientists, UK-US collaboration, education and outreach, and adoption of open data science approaches within the glaciological community. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; GLACIER MOTION/ICE SHEET MOTION; Antarctic Peninsula; BASAL SHEAR STRESS", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kingslake, Jonathan; Sole, Andrew; Livingstone, Stephen; Winter, Kate; Ely, Jeremy", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "NSFGEO-NERC: Investigating the Direct Influence of Meltwater on Antarctic Ice Sheet Dynamics", "uid": "p0010436", "west": null}, {"awards": "2012958 Meyer, Colin", "bounds_geometry": null, "dataset_titles": "Frozen fringe friction ; Ring shear bed deformation measurements ", "datasets": [{"dataset_uid": "601757", "doi": "10.15784/601757", "keywords": "Antarctica", "people": "Zoet, Lucas", "repository": "USAP-DC", "science_program": null, "title": "Ring shear bed deformation measurements ", "url": "https://www.usap-dc.org/view/dataset/601757"}, {"dataset_uid": "601756", "doi": "10.15784/601756", "keywords": "Antarctica", "people": "Zoet, Lucas", "repository": "USAP-DC", "science_program": null, "title": "Frozen fringe friction ", "url": "https://www.usap-dc.org/view/dataset/601756"}], "date_created": "Wed, 13 Sep 2023 00:00:00 GMT", "description": "The fastest-changing regions of the Antarctic and Greenland Ice Sheets that contribute most to sea-level rise are underlain by soft sediments that facilitate glacier motion. Glacier ice can infiltrate several meters into these sediments, depending on the temperature and water pressure at the base of the glacier. To understand how ice infiltration into subglacial sediments affects glacier slip, the team will conduct laboratory experiments under relevant temperature and pressure conditions and compare the results to state-of-the-art mathematical models. Through an undergraduate research exchange between University of Wisconsin-Madison, Dartmouth College, and the College of Menominee Nation, Native American students will work on laboratory experiments in one summer and mathematical theory in the following summer. Ice-sediment interactions are a central component of ice-sheet and landform-development models. Limited process understanding poses a key uncertainty for ice-sheet models that are used to forecast sea-level rise. This uncertainty underscores the importance of developing experimentally validated, theoretically robust descriptions of processes at the ice-sediment interface. To achieve this, the team aims to build on long-established theoretical, experimental, and field investigations that have elucidated the central role of premelting and surface-energy effects in controlling the dynamics of frost heave in soils. Project members will theoretically describe and experimentally test the role of premelting at the basal ice-sediment interface. The experiments are designed to provide quantitative insight into the impact of ice infiltration into sediments on glacier sliding, erosion, and subglacial landform evolution. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "BASAL SHEAR STRESS; GLACIER MOTION/ICE SHEET MOTION; GLACIERS/ICE SHEETS", "locations": null, "north": null, "nsf_funding_programs": "Arctic Natural Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Meyer, Colin; Rempel, Alan; Zoet, Lucas", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Freeze-on of Subglacial Sediments in Experiments and Theory", "uid": "p0010434", "west": null}, {"awards": "2035078 Giometto, Marco; 2034874 Salesky, Scott", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 08 Sep 2023 00:00:00 GMT", "description": "1. A non-technical explanation of the project\u0027s broader significance and importance, that serves as a public justification for NSF funding. This part should be understandable to an educated reader who is not a scientist or engineer. Katabatic or drainage winds, carry high-density air from a higher elevation down a slope under the force of gravity. Although katabatic flows are ubiquitous in alpine and polar regions, a surface-layer similarity theory is currently lacking for these flows, undermining the accuracy of numerical weather and climate prediction models. This project is interdisciplinary, and will give graduate and undergraduate students valuable experience interacting with researchers outside their core discipline. Furthermore, this project will broaden participating in science through recruitment of students from under-represented groups at OU and CU through established programs. The Antarctic Ice Sheet drives many processes in the Earth system through its modulation of regional and global atmospheric and oceanic circulations, storage of fresh water, and effects on global albedo and climate. An understanding of the surface mass balance of the ice sheets is critical for predicting future sea level rise and for interpreting ice core records. Yet, the evolution of the ice sheets through snow deposition, erosion, and transport in katabatic winds (which are persistent across much of the Antarctic) remains poorly understood due to the lack of an overarching theoretical framework, scarcity of in situ observational datasets, and a lack of accurate numerical modeling tools. Advances in the fundamental understanding and modeling capabilities of katabatic transport processes are urgently needed in view of the future climatic and snowfall changes that are projected to occur within the Antarctic continent. This project will leverage the expertise of a multidisciplinary team of investigators (with backgrounds spanning cryospheric science, environmental fluid mechanics, and atmospheric science) to address these knowledge gaps. 2. A technical description of the project that states the problem to be studied, the goals and scope of the research, and the methods and approaches to be used. In many cases, the technical project description may be a modified version of the project summary submitted with the proposal. Using field observations and direct numerical simulations of katabatic flow, this project is expected--- for the first time---to lead to a surface-layer similarity theory for katabatic flows relating turbulent fluxes to mean vertical gradients. The similarity theory will be used to develop surface boundary conditions for large eddy simulations (LES), enabling the first accurate LES of katabatic flow. The numerical tools that the PIs will develop will allow them to investigate how the partitioning between snow redistribution, transport, and sublimation depends on the environmental parameters typically encountered in Antarctica (e.g. atmospheric stratification, surface sloping angles, and humidity profiles), and to develop simple models to infer snow transport based on satellite remote sensing and regional climate models This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "TURBULENCE; ATMOSPHERIC RADIATION; DATA COLLECTIONS; SNOW/ICE; SNOW; FIELD INVESTIGATION; AIR TEMPERATURE; HUMIDITY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Salesky, Scott; Giometto, Marco; Das, Indrani", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e DATA COLLECTIONS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Snow Transport in Katabatic Winds and Implications for the Antarctic Surface Mass Balance: Observations, Theory, and Numerical Modeling", "uid": "p0010433", "west": null}, {"awards": "2231558 Smith, Nathan; 2231559 Tinto, Kirsteen", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 01 Sep 2023 00:00:00 GMT", "description": "The unique Antarctic environment offers insight into processes and records not seen anywhere else on Earth, and is critical to understanding our planet\u2019s history and future. The remoteness and logistics of Antarctic science brings together researchers from diverse disciplines who otherwise wouldn\u2019t be presented with opportunities for collaboration, and often rarely attend the same academic conferences. The Interdisciplinary Antarctic Earth Science (IAES) conference is a biennial gathering that supports the collaboration of U.S. bio-, cryo-, geo-, and atmospheric science researchers working in the Antarctic. This proposal will support the next two IAES conferences to be held in 2022 and 2024, as well as a paired deep-field camp planning workshop. The IAES conference is important to the mission of the NSF in supporting interdisciplinary collaboration in the Antarctic Earth sciences, but also fulfills recommendations by the National Academy for improving cross-disciplinary awareness, data sharing, and early career researcher mentoring and development. The size and scope of the IAES conference allow it to serve as a hub for novel, interdisciplinary collaboration, as well as help develop the next generation of Antarctic Earth scientists. The goals of the IAES conference are to develop and deepen scientific collaborations across the Antarctic Earth science community, and create a framework for future deep-field, as well as non-field-based research. Across a 2.5 day hybrid conference, the IAES themes will include 1) connecting surficial processes, geology, and the deep earth; 2) landscape, ice sheet, ocean and atmospheric interactions; 3) exploring the hidden continent; and 4) evolution and ecology of ancient and modern organisms, ecosystems, and environments. The conference will share science through presentations of current research and keynote talks, broaden participation through welcoming new researchers from under-represented communities and disciplines, and deepen collaboration through interdisciplinary networking highlighting potential research connections, novel mentorship activities, and promoting data re-use, and application of remote sensing and modeling. Discussions resulting from the IAES conference will be used to develop white papers on future Antarctic collaborative research and deep-field camps based on community-driven research priorities. Community surveys and feedback will be solicited throughout the project to guide the future development of the IAES conference. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GEOMORPHIC LANDFORMS/PROCESSES; GEOCHEMISTRY; California; ICE CORE RECORDS; ECOLOGICAL DYNAMICS; GLACIERS/ICE SHEETS; PALEOCLIMATE RECONSTRUCTIONS", "locations": "California", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Smith, Nathan; Tinto, Kirsty", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Conference: Interdisciplinary Antarctic Earth Science Conference \u0026 Deep-Field Planning Workshop", "uid": "p0010432", "west": -180.0}, {"awards": "2232891 Postlethwait, John", "bounds_geometry": "POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 14 Aug 2023 00:00:00 GMT", "description": "Antarctic animals face tremendous threats as Antarctic ice sheets melt and temperatures rise. About 34 million years ago, when Antarctica began to cool, most species of fish became locally extinct. A group called the notothenioids, however, survived due to the evolution of antifreeze. The group eventually split into over 120 species. Why did this group of Antarctic fishes evolve into so many species? One possible reason why a single population splits into two species relates to sex genes and sex chromosomes. Diverging species often have either different sex determining genes (genes that specify whether an individual\u2019s gonads become ovaries or testes) or have different sex chromosomes (chromosomes that differ between males and females within a species, like the human X and Y chromosomes). We know the sex chromosomes of only a few notothenioid species and know the genetic basis for sex determination in none of them. The aims of this research are to: 1) identify sex chromosomes in species representing every major group of Antarctic notothenioid fish; 2) discover possible sex determining genes in every major group of Antarctic notothenioid fish; and 3) find sex chromosomes and possible sex determining genes in two groups of temperate, warmer water, notothenioid fish. These warmer water fish include groups that never experienced the frigid Southern Ocean and groups that had ancestors inhabiting Antarctic oceans that later adjusted to warmer waters. This project will help explain the mechanisms that led to the division of a group of species threatened by climate change. This information is critical to conserve declining populations of Antarctic notothenioids, which are major food sources for other Antarctic species such as bird and seals. The project will offer a diverse group of undergraduates the opportunity to develop a permanent exhibit at the Eugene Science Center Museum. The exhibit will describe the Antarctic environment and explain its rapid climate change. It will also introduce the continent\u2019s bizarre fishes that live below the freezing point of water. The project will collaborate with the university\u2019s Science and Comics Initiative and students in the English Department\u2019s Comics Studies Minor to prepare short graphic novels explaining Antarctic biogeography, icefish specialties, and the science of this project as it develops. As Antarctica cooled, most species disappeared from the continent\u2019s waters, but cryonotothenioid fish radiated into a species flock. What facilitated this radiation? Coyne\u2019s \u201ctwo rules of speciation\u201d offer explanations for why species diverge: 1) the dysgenic sex in an interspecies hybrid is the one with two different sex chromosomes (i.e., in humans, it would be XY males and not XX females); and 2) \u201csex chromosomes play an outsized role in speciation\u201d. These ideas propel the project\u2019s main hypothesis: new sex chromosomes and new sex determination genes associate with cryonotothenioid speciation events. The main objective of the research is to identify notothenioid sex chromosomes and candidate sex-determination genes in many notothenioid species. The project\u2019s first aim is to identify Antarctic fish sex chromosomes, asking the question: Did new sex chromosomes accompany speciation events? Knowledge gaps include: which species have cryptic sex chromosomes; which have newly evolved sex chromosomes; and which are chromosomally XX/XY or ZZ/ZW. Methods involve population genomics (RAD-seq and Pool-seq) for more than 20 Antarctic cryonotothenioids. The prediction is frequent turnover of sex chromosomes. The project\u2019s second aim is to Identify candidate Antarctic cryonotothenioid sex-determination genes, asking the question: Did new sex-determination genes accompany Antarctic cryonotothenioid speciation events? A knowledge gap is the identity of sex determination genes in any notothenioid. Preliminary data show that three sex-linked loci are in or adjacent to three different candidate sex determination genes: 1) a duplicate of bmpr1ba in blackfin icefish; 2) a tandem duplicate of gsdf in South Georgia icefish; and 3) a transposed duplicate of gsdf in striped notothen. Methods involve annotating the genomic neighborhoods of cryonotothenioid sex linked loci for anomalies in candidate sex genes, sequencing sex chromosomes, and testing sex gene variants by CRISPR mutagenesis in zebrafish. The prediction is frequent turnover of sex determination genes. The project\u2019s third aim is to identify sex chromosomes and sex-determination genes in temperate notothenioids. Basally diverging temperate notothenioids (\u2018basals\u2019) lack identifiable sex chromosomes, consistent with temperature-cued sex determination, and one \u2018basal\u2019 species is a hermaphrodite. The constantly cold Southern Ocean rules out temperature, a common sex determination cue in many temperate fish, favoring genetic sex determination. Some cryonotothenioids re-invaded temperate waters (\u2018returnees\u2019). Knowledge gaps include whether basals and returnees have strong sex determination genes. Methods employ pool-seq. The prediction is that genetic sex determination is weak in basals and that returnees have the same, but weaker, sex-linked loci as their Antarctic sister clade. A permanent exhibit will be established at the Eugene Science Center Museum tentatively entitled: The Antarctic: its fishes and climate change. Thousands of visitors, especially school children will be exposed, to the science of Antarctic ecosystems and the impacts of climate change. The research team will collaborate with the university\u2019s Science and Comics Initiative to produce short graphic novels explaining Antarctic biogeography, icefish specialties, and this project. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Speciation; Southern Ocean; Dragonfish; Antarctica; Plunderfish; Fish; Notothenioid; FISH; Eleginopsioidea; Icefish; MARINE ECOSYSTEMS; Cryonotothenioid; Sub-Antarctic", "locations": "Antarctica; Southern Ocean; Sub-Antarctic", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Postlethwait, John; Desvignes, Thomas", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "ANT LIA: The Role of Sex Determination in the Radiation of Antarctic Notothenioid Fish", "uid": "p0010431", "west": -180.0}, {"awards": "2317263 Cross, Andrew", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 14 Aug 2023 00:00:00 GMT", "description": "The seaward motion of ice sheets and glaciers is primarily controlled by basal sliding at the base of the ice sheet and internal viscous flow within the ice mass. The latter of these \u2014 viscous flow \u2014 is dependent on various factors, including temperature, stress, grain size, and the alignment of ice crystals during flow to produce a \"crystal orientation fabric\" (COF). Historically, ice flow has been modeled using an equation, termed \u201cGlen\u2019s law\u201d, that describes ice-flow rate as a function of temperature and stress. Glen\u2019s law was constrained under relatively high-stress conditions and is often attributed to the motion of crystal defects within ice grains. More recently, however, grain boundary sliding (GBS) has been invoked as the rate-controlling process under low-stress, \u201csuperplastic\u201d conditions. The grain boundary sliding hypothesis is contentious because GBS is not thought to produce a COF, whereas geophysical measurements and polar ice cores demonstrate strong COFs in polar ice masses. However, very few COF measurements have been conducted on ice samples subjected to superplastic flow conditions in the laboratory. This project would measure the evolution of ice COF across the transition from superplastic to Glen-type creep. Results will be used to interrogate the role of superplastic GBS creep within polar ice masses, and thereby provide constraints on polar ice discharge models. Polycrystalline ice samples with grain sizes ranging from 5 \u00b5m to 1000 \u00b5m will be fabricated and deformed in a laboratory, using a 1-atm cryogenic axial-torsion apparatus. Experiments will be conducted at temperatures of -30\u00b0C to -10\u00b0C, and at a constant uniaxial strain rate. Under these conditions, 5% to 99.99% of strain should be accommodated by superplastic, GBS-limited creep, depending on the sample grain size. The deformed samples will then be imaged using cryogenic electron backscatter diffraction (cryo-EBSD) and high-angular-resolution electron backscatter diffraction (HR-EBSD) to quantify COF, grain size, grain shape, and crystal defect (dislocation) densities, among other microstructural properties. These measurements will be used to decipher the rate-controlling mechanisms operating within different thermomechanical regimes, and resolve a long-standing debate over whether superplastic creep can produce a COF in ice. In addition to the polycrystal experiments, ice bicrystals will be fabricated and deformed to investigate the micromechanical behavior of individual grain boundaries under superplastic conditions. Ultimately, these results will be used to provide a microstructural toolbox for identifying superplastic creep using geophysical (e.g., seismic, radar) and glaciological (e.g., ice core) observations. This project will support one graduate student, one or more undergraduate summer students, and an early-career researcher. In addition, this project will support a workshop aimed at bringing together experimentalists, glaciologists, and ice modelers to facilitate cross-disciplinary knowledge sharing and collaborative problem solving. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; Rheology; ROCKS/MINERALS/CRYSTALS; GLACIERS/ICE SHEETS", "locations": "United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cross, Andrew", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Microstructural Evolution during Superplastic Ice Creep", "uid": "p0010430", "west": null}, {"awards": "2317927 Hills, Benjamin", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Radar Reflectivity at Whillans Ice Plain", "datasets": [{"dataset_uid": "200401", "doi": "10.5281/zenodo.11201199", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Radar Reflectivity at Whillans Ice Plain", "url": "https://doi.org/10.5281/zenodo.11201199"}], "date_created": "Mon, 07 Aug 2023 00:00:00 GMT", "description": "Ice flow is resisted by frictional forces that keep a glacier from immediately sliding into the ocean. Friction comes in two varieties: internal friction within the ice column which resists ice deformation and basal friction which resists ice sliding over its bedrock substrate. Partitioning between internal and basal friction is difficult since both have similar expressions at the most common target for data collection\u2014the ice-sheet surface. However, understanding this partitioning is important because the physical processes that control internal and basal friction act and evolve at different timescales. This project combines spaceborne remote sensing observations from the ice-sheet surface with ice-penetrating radar data that images the internal structure of the ice sheet in order to partition the contribution of each source of friction. Results will advance the fundamental understanding of ice flow and will strengthen projections of future sea-level rise. Broader Impacts of the project include facilitating data reuse for the ice-sheet research community; the strategy for distributing the software toolkit includes student mentorship and hackathon teaching. The researcher will expand the impact of existing ice-penetrating datasets by 1) developing new open-source algorithms for extraction of englacial stratigraphy; 2) creating stratigraphy data products that can be assimilated into future studies of ice motion; and 3) using statistical analyses to integrate radar datasets into larger-scale interpretations with remote sensing datasets of ice-surface velocity, altimetry, climate variables, and model-derived basal friction. The computational tools developed as part of this effort will be integrated and released as a reusable software toolkit for ice-penetrating radar data analysis. The toolkit will be validated and tested by deployment to cloud-hosted JupyterHub instances, which will serve as a singular interface to access radar and remote sensing data, load them into a unified framework, step through a predefined processing flow, and carry out statistical analyses. In some areas, the imaged englacial stratigraphy will deviate from the ice-dynamic setting expected based on surface measurements alone. There, the internal dynamics (or ice-dynamic history) are inconsistent with the surface dynamics, likely because internal friction is poorly constrained and misattributed to basal friction instead. This work will develop the data and statistical tools for constraining internal friction from ice-penetrating radar, making those data products and tools available for future work. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING", "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; BT-67; Antarctica; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; DHC-6; ICE SHEETS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Hills, Benjamin", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e BT-67; AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6", "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "Postdoctoral Fellowship: OPP-PRF: Disentangling Ice-sheet Internal and Basal Processes through Novel Ice-penetrating Radar Integration Built on Scalable, Cloud-based Infrastructure", "uid": "p0010428", "west": -180.0}, {"awards": "2302832 Reilly, Brendan", "bounds_geometry": "POLYGON((-70 -55,-67 -55,-64 -55,-61 -55,-58 -55,-55 -55,-52 -55,-49 -55,-46 -55,-43 -55,-40 -55,-40 -56.1,-40 -57.2,-40 -58.3,-40 -59.4,-40 -60.5,-40 -61.6,-40 -62.7,-40 -63.8,-40 -64.9,-40 -66,-43 -66,-46 -66,-49 -66,-52 -66,-55 -66,-58 -66,-61 -66,-64 -66,-67 -66,-70 -66,-70 -64.9,-70 -63.8,-70 -62.7,-70 -61.6,-70 -60.5,-70 -59.4,-70 -58.3,-70 -57.2,-70 -56.1,-70 -55))", "dataset_titles": "NRM, ARM, IRM, and magnetic susceptibility investigations on U1537 and U1538 cube samples; Rock magnetic data from IODP Exp. 382 Sites U1537 and U1538 to support Reilly et al. \"A geochemical mechanism for \u003e10 m offsets of magnetic reversals inferred from the comparison of two Scotia Sea drill sites\"", "datasets": [{"dataset_uid": "200412", "doi": "10.7288/V4/MAGIC/19778", "keywords": null, "people": null, "repository": "MagIC (EarthRef)", "science_program": null, "title": "NRM, ARM, IRM, and magnetic susceptibility investigations on U1537 and U1538 cube samples", "url": "http://dx.doi.org/10.7288/V4/MAGIC/19778"}, {"dataset_uid": "200411", "doi": "10.5281/zenodo.10035106", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Rock magnetic data from IODP Exp. 382 Sites U1537 and U1538 to support Reilly et al. \"A geochemical mechanism for \u003e10 m offsets of magnetic reversals inferred from the comparison of two Scotia Sea drill sites\"", "url": "https://zenodo.org/records/10035107"}], "date_created": "Wed, 12 Jul 2023 00:00:00 GMT", "description": "The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica\u2019s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica\u2019s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth\u0027s most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica\u2019s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -40.0, "geometry": "POINT(-55 -60.5)", "instruments": null, "is_usap_dc": true, "keywords": "PALEOMAGNETISM; SEDIMENTS; Scotia Sea", "locations": "Scotia Sea", "north": -55.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE; PHANEROZOIC \u003e CENOZOIC", "persons": "Reilly, Brendan", "platforms": null, "repo": "MagIC (EarthRef)", "repositories": "MagIC (EarthRef); Zenodo", "science_programs": null, "south": -66.0, "title": "Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation", "uid": "p0010424", "west": -70.0}, {"awards": "1847173 Duddu, Ravindra", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 07 Jul 2023 00:00:00 GMT", "description": "Iceberg calving is a complex natural fracture process and a dominant cause of mass loss from the floating ice shelves on the margins of the Antarctic ice sheet. There is concern that rapid changes at these ice shelves can destabilize parts of the ice sheet and accelerate their contribution to sea-level rise. The goal of this project is to understand and simulate the fracture mechanics of calving and to develop physically-consistent calving schemes for ice-sheet models. This would enable more reliable estimation of Antarctic mass loss by reducing the uncertainty in projections. The research plan is integrated with an education and outreach plan that aims to (1) enhance computational modeling skills of engineering and Earth science students through a cross-college course and a high-performance computing workshop and (2) increase participation and diversity in engineering and sciences by providing interdisciplinary research opportunities to undergraduates and by deploying new cyberlearning tools to engage local K-12 students in the Metro Nashville Public Schools in computational science and engineering, and glaciology. This project aims to provide fundamental understanding of iceberg calving by advancing the frontiers in computational fracture mechanics and nonlinear continuum mechanics and translating it to glaciology. The project investigates crevasse propagation using poro-damage mechanics models for hydrofracture that are consistent with nonlinear viscous ice rheology, along with the thermodynamics of refreezing in narrow crevasses at meter length scales. It will develop a fracture-physics based scheme to better represent calving in ice-sheet models using a multiscale method. The effort will also address research questions related to calving behavior of floating ice shelves and glaciers, with the goal of enabling more reliable prediction of calving fronts in whole-Antarctic ice-sheet simulations over decadal-to-millennial time scales. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; GLACIER MOTION/ICE SHEET MOTION", "locations": "United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Duddu, Ravindra", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "CAREER: Fracture Mechanics of Antarctic Ice Shelves and Glaciers - Representing Iceberg Calving in Ice Sheet Models and Developing Cyberlearning Tools for Outreach", "uid": "p0010423", "west": null}, {"awards": "2021699 Trusel, Luke", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic ice sheet daily surface melt detection from ASCAT (2007-2022); ASCAT-ERA5 Antarctic Peninsula Daily Surface Meltwater Production (2007-2022); Trusel et al 2022, Geophysical Research Letters: Publication data and code", "datasets": [{"dataset_uid": "200362", "doi": "10.5281/zenodo.7995543", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "ASCAT-ERA5 Antarctic Peninsula Daily Surface Meltwater Production (2007-2022)", "url": "https://zenodo.org/record/7995543"}, {"dataset_uid": "200364", "doi": "10.5281/zenodo.7995998", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Antarctic ice sheet daily surface melt detection from ASCAT (2007-2022)", "url": "https://zenodo.org/record/7995998"}, {"dataset_uid": "200363", "doi": "10.5281/zenodo.6374343", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Trusel et al 2022, Geophysical Research Letters: Publication data and code", "url": "https://zenodo.org/record/6374343"}], "date_created": "Fri, 02 Jun 2023 00:00:00 GMT", "description": "Melting of snow and ice at the surface of the Antarctic ice sheet can lead to the formation of meltwater lakes, an important precursor to ice-shelf collapse and accelerated ice-sheet mass loss. Understanding the present state of Antarctic surface melt provides a baseline to gauge how quickly melt impacts could evolve in the future and to reduce uncertainties in estimates of future sea-level rise. This project will use a suite of complimentary measurements from Earth-observing satellites, ground observations, and numerical climate and ice-shelf models to enhance understanding of surface melt and lakes, as well as the processes linking these systems. The project directly supports the scientific training of a postdoctoral associate and several undergraduate researchers. In addition, it will promote public scientific literacy and the broadening of quantitative skills for high-school students through the development and implementation of an educational unit in a partnership with an education and outreach expert and two high school teachers. Accurate prediction of sea-level contributions from Antarctica critically requires understanding current melting and supraglacial lake conditions. This project will quantify Antarctic surface melt and supraglacial lakes, and the linkages between the two phenomena. Scatterometer data will enable generation of a 19-year multi-sensor melt time series. Synthetic aperture radar data will document melt conditions across all Antarctic ice shelves at the highest spatial resolution to date (40 m). Multispectral satellite imagery will be used to delineate and measure the depth of supraglacial lakes--for the first time studying the spatial and temporal variations of Antarctic supraglacial lakes. Melt and lake observations will be compared to identify agreement and disagreement. Melt observations will be used to evaluate biases in a widely used, reanalysis-driven, regional climate model. This model will then be used to examine climatic and glaciological variables associated with supraglacial lakes. Finally, in situ observations and climate model output will drive a numerical model that simulates the entire lifecycle of surface melt and possible subsequent lake formation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Antarctica; Surface Hydrology", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Trusel, Luke; Moussavi, Mahsa", "platforms": null, "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Water on the Antarctic Ice Sheet: Quantifying Surface Melt and Mapping Supraglacial Lakes", "uid": "p0010422", "west": -180.0}, {"awards": "2228257 Michaud, Alexander", "bounds_geometry": "POINT(-112.05 -79.28)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 31 May 2023 00:00:00 GMT", "description": "Ice cores from glaciers and ice sheets provide detailed archives of past environmental conditions, furthering our understanding of Earth\u2019s climate. Microorganisms in the West Antarctic Ice Sheet are buried over glaciological time and form a stratigraphy record providing the opportunity of analysis of the order and position of layers of geological events, with potential links to Southern Hemisphere climate. However, microbial cells that land on the ice sheet are subject to the stresses of changing habitat conditions due to burial and conditions associated with long-term isolation in ice. These processes may lead to a loss of fidelity within the stratigraphic record of microbial cells. We know little about how and if microorganisms survive burial and remain alive over glacial-interglacial time periods within an ice sheet. This analysis will identify the viable and preserved community of microorganisms and core genomic adaptation that permit cell viability, which will advance knowledge in the areas of microbiology and glaciology while increasing fidelity of ice core measurements relevant to past climate and potential future global climate impacts. This exploratory endeavor has the potential to be a transformative step toward understanding the ecology of one of the most understudied environments on Earth. The project will partner with the Museum of Science, Boston, to increase public scientific literacy via education and outreach. Additionally, this project will support two early-career scientists and two undergraduates in interdisciplinary research at the intersection of microbiology and climate science. Results from this project will provide the first DNA data based on single-cell whole genomic sequencing from the Antarctic Ice Sheet and inform whether post-depositional processes impact the interpretations of paleoenvironmental conditions from microbes. The goals to determine the taxonomic identity of viable and preserved microbial cells, and decode the genetic repertoire that confers survival of burial and long-term viability within glacial ice, will be achieved by utilizing subsamples from a ~60,000 year old record of the West Antarctic Ice Sheet Divide (WD) Ice Core. WD samples will be melted using the Desert Research Institute\u2019s ice core melting system that is optimized for glaciobiological sampling. Microbial cells from the meltwater will be sorted using fluorescence-activated cell sorting, and individually sorted cells will have their genomes sequenced. The fluorescence-based methods will discern the viable (metabolically active) cells from those cells that are non-viable but preserved in the ice (DNA-containing). The genomic analysis will identify the taxonomy of each cell, presence of known genes that confer survival in permanently frozen environments, and comparatively analyze genomes to determine the core set of genes required by viable cells to persist in an ice sheet. The outcomes of this work will expand the potential for biological measurements and contamination control from archived ice cores. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": null, "is_usap_dc": true, "keywords": "WAIS Divide; TERRESTRIAL ECOSYSTEMS; ICE SHEETS; BACTERIA/ARCHAEA; ICE CORE RECORDS", "locations": "WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Michaud, Alexander; Winski, Dominic A.", "platforms": null, "repositories": null, "science_programs": null, "south": -79.28, "title": "EAGER: ANT LIA: Persist or Perish: Records of Microbial Survival and Long-term Persistence from the West Antarctic Ice Sheet", "uid": "p0010421", "west": -112.05}, {"awards": "1745078 Brook, Edward J.", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Atmospheric methane across the Last Glacial Maximum and deglaciation from the GISP2, NEEM and WAIS Divide ice cores ; Atmospheric methane interpolar difference and four-box troposphere model output across the Last Glacial Maximum and Deglaciation; Carbon-13 and Deuterium isotopic composition of atmospheric methane across Heinrich Stadial 4, and Dansgaard Oesgher Event 8, WAIS Divide Replicate Ice Core, Antarctica; Carbon-13 isotopic composition of atmospheric methane across Heinrich Stadials 1 and 5, and Dansgaard Oesgher Event 12, WAIS Divide Ice Core, Antarctica", "datasets": [{"dataset_uid": "601737", "doi": "10.15784/601737", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Greenland; Ice Core Records; Methane; West Antarctic Ice Sheet", "people": "Martin, Kaden; Edwards, Jon S.; Lee, James; Brook, Edward J.; Rosen, Julia; Riddell-Young, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "Atmospheric methane across the Last Glacial Maximum and deglaciation from the GISP2, NEEM and WAIS Divide ice cores ", "url": "https://www.usap-dc.org/view/dataset/601737"}, {"dataset_uid": "601736", "doi": "10.15784/601736", "keywords": "Antarctica; Greenland; Methane; Paleoclimate; West Antarctic Ice Sheet", "people": "Fischer, Hubertus; Blunier, Thomas; Schmitt, Jochen; M\u00fchl, Michaela; Edwards, Jon S.; Lee, James; Martin, Kaden; Brook, Edward J.; Buizert, Christo; Rosen, Julia; Riddell-Young, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "Atmospheric methane interpolar difference and four-box troposphere model output across the Last Glacial Maximum and Deglaciation", "url": "https://www.usap-dc.org/view/dataset/601736"}, {"dataset_uid": "601813", "doi": "10.15784/601813", "keywords": "Abrupt Climate Change; Antarctica; Atmospheric Gases; Biogeochemical Cycles; Carbon Cycle; Cryosphere; Greenhouse Gas; Methane; West Antarctic Ice Sheet Divide", "people": "Clark, Reid; Bauska, Thomas; Riddell-Young, Benjamin; Lee, James; Brook, Edward J.; Iseli, Rene; Schmitt, Jochen; Menking, Andy; Fischer, Hubertus", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Carbon-13 and Deuterium isotopic composition of atmospheric methane across Heinrich Stadial 4, and Dansgaard Oesgher Event 8, WAIS Divide Replicate Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601813"}, {"dataset_uid": "601683", "doi": "10.15784/601683", "keywords": "Antarctica; Methane; West Antarctic Ice Sheet", "people": "Riddell-Young, Benjamin", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Carbon-13 isotopic composition of atmospheric methane across Heinrich Stadials 1 and 5, and Dansgaard Oesgher Event 12, WAIS Divide Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601683"}], "date_created": "Mon, 01 May 2023 00:00:00 GMT", "description": "This project will develop methods to measure the ratios of carbon-13 to carbon-12, and heavy to light hydrogen in methane in air trapped in ice cores. The ratios of the different forms of carbon and hydrogen are \"fingerprints\" of different sources of this gas in the past--for example wetlands in the tropics versus methane frozen in the sea floor. Once the analysis method is developed, the measurements will be used to examine why methane changed abruptly in the past, both during the last ice age, and during previous warm periods. The data will be used to understand how methane sources like wildfires, methane hydrates, and wetlands respond to climate change. This information is needed to understand future risks of large changes in methane in the atmosphere as Earth warms. The project involves two tasks. First, the investigators will build and test a gas extraction system for methane isotopic measurements using continuous flow methods, with the goal of equaling or bettering the precision attained by the few other laboratories that make these measurements. The system will be interfaced with existing mass spectrometers at Oregon State University. The system consists of a vacuum chamber and sequence of traps, purification columns, and furnaces that separate methane from other gases and convert it to carbon dioxide or hydrogen for mass spectrometry. Second, the team will measure the isotopic composition of methane across large changes in concentration associated with two past interglacial periods and during abrupt methane changes of the last ice age. These measurements will be used to understand if the main reason for these concentration changes is climate-driven changes in emissions from wetlands, or whether other sources are involved, for example methane hydrates or wildfires. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; TRACE GASES/TRACE SPECIES; METHANE", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Tracing Past Methane Variations with Stable Isotopes in Antarctic Ice Cores", "uid": "p0010416", "west": -180.0}, {"awards": "2306186 Schroeder, Dustin", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 05 Apr 2023 00:00:00 GMT", "description": "Understanding ice structure, depth, internal velocity, and basal conditions is key to understanding current and future glacier and ice sheet behavior in Greenland and Antarctica. Most radio glaciology research projects are limited to whatever airborne ice-penetrating radar (IPR) data happens to already exist in the area of interest. Collecting new IPR data is a long and slow process, usually well outside the scope of individual research teams, especially in resource-intensive Antarctic glaciology research. This proposal seeks to field-test and validate two community-driven instruments that help address this gap in Antarctic research: a snowmobile-towed radar as well as a UAV (uncrewed aerial vehicle) system. Both systems are based off a common software control system and share the same code and post-processing tools. As part of this proposal, this code will be made available under an open-source license for other researchers to use and adapt, along with instructions for creating compatible hardware setups from commercially available parts, in order for them to be able to study glaciers and ice sheets at higher capacity and lower cost. The snowmobile-towed radar will be a multi-frequency, polarimetric chirped radar system designed to illuminate thermal, material, and roughness properties at the ice-bed interface. The PEREGRINE UAV system is a chirped radar with 56 MHz of bandwidth built into a small fixed-wing uncrewed aircraft that packs away into a single Pelican case for rapid small-scale surveys. The variables to be measured by these systems are critical observational data for projecting future behavior of the Antarctic ice sheet. The project spans two years and incorporates two seasons of field testing planned for Summit Station, Greenland, due to the need to test on a thick, cold ice sheet as well as the lower cost and risk of supporting instrument testing in the Arctic compared to Antarctica. The period between the field seasons will be used to initiate or continue conversations with researchers interested in incorporating our instruments into future fieldwork or adapting our core radar system into new instruments. This will give us an opportunity to develop new capabilities in response to this feedback and conduct relevant system tests during the second field season. A period after the second field season is reserved for the development of detailed documentation and preparation for the open release of code and systems. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Greenland", "locations": "Greenland", "north": -60.0, "nsf_funding_programs": "Polar Cyberinfrastructure; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Schroeder, Dustin", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "EAGER: Community-Driven Ice Penetrating Radar Systems for Observing Complex Ice-Sheet Thermal Structure and Flow", "uid": "p0010413", "west": -180.0}, {"awards": "1543445 Zhang, Jing", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "3-km Surface Mass and Energy Budget for the Larsen C Ice Shelf; Antarctic passive microwave Kmeans derived surface melt days, 1979-2020", "datasets": [{"dataset_uid": "601685", "doi": "10.15784/601685", "keywords": "Antarctica; Glaciology; Larsen C Ice Shelf; Model Data; Surface Energy Budget; Surface Mass Balance; WRF Model", "people": "Luo, Liping; Zhang, Jing", "repository": "USAP-DC", "science_program": null, "title": "3-km Surface Mass and Energy Budget for the Larsen C Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601685"}, {"dataset_uid": "601457", "doi": "10.15784/601457", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Melt Days; Passive Microwave; Snow/ice; Snow/Ice; Surface Melt", "people": "Johnson, Andrew; Fahnestock, Mark; Hock, Regine", "repository": "USAP-DC", "science_program": null, "title": "Antarctic passive microwave Kmeans derived surface melt days, 1979-2020", "url": "https://www.usap-dc.org/view/dataset/601457"}], "date_created": "Fri, 24 Feb 2023 00:00:00 GMT", "description": "Hock/1543432 Over the last half century the Antarctic Peninsula has been among the most rapidly warming regions in the world. This has led to increased glacier melt, widespread glacier retreat, ice-shelf collapses, and glacier speed-ups. Many of these changes are driven by changing precipitation and increased melt due to warmer air temperatures. This project will use a combination of two models - a regional atmospheric model and a model of processes at the glacier surface - to simulate future changes in temperature and snowfall, and the resulting changes in glacier mass. The combination of models will be tested against the observational record (since 1979 when satellite observations became available), to verify that it can reproduce observed change, and then run to the year 2100. Results will provide better estimates of the impacts of future climate changes over the Antarctic Pensinsula and the expected glacier mass changes driven by the evolving climate. The project will use the large changes observed on the Peninsula to validate a model framework suitable for understanding the impact of these changes on the glaciers and ice shelves there, with the goal of developing optimally constrained future climate and surface mass change scenarios for the region. The framework will provide both a coherent picture of the impacts of past changes on the region\u0027s ice cover, and also the best available constraints on forcings that will determine ice mass loss from this region going forward under a standard scenario. The Weather Forecasting and Research (WRF) Model will be used over the domain of the Antarctic Peninsula and neighboring islands to quantify trends in spatio-temporal patterns of mass change with a focus on surface melt. The WRF model will be enhanced to account for the specific conditions of glacier surfaces, and the modified model will be used to simulate climate conditions and resulting surface mass budgets and melt over the period 1979-2100. Tying modeled past climate changes to the surface and satellite-based observational record will provide a foundation for interpreting projected future change. Results will be validated using available weather station observations, surface mass-balance data, and satellite-derived records of melt. The activity will foster partnerships through collaboration with colleagues in Spain, Germany and The Netherlands and will support an early-career postdoctoral researcher and two graduate students, introduce undergraduate and high-school students to original research and provide training of students through inclusion of data and results in course curriculums.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; MODELS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Zhang, Jing; Hock, Regine; Fahnestock, Mark", "platforms": "OTHER \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Present and Projected Future Forcings on Antarctic Peninsula Glaciers and Ice Shelves using the Weather Forecasting and Research (WRF) Model", "uid": "p0010408", "west": -180.0}, {"awards": "2224680 Prothro, Lindsay; 2224679 Miller, Lauren; 2224681 Venturelli, Ryan", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 24 Feb 2023 00:00:00 GMT", "description": "Sediments that collect on the seafloor provide a wealth of information about past and present environmental change. Around Antarctica, these seafloor sediments are influenced by an ice sheet that grinds and transports sediments from the continent\u2019s interior into the surrounding ocean. Since the Last Glacial Maximum (about 20,000 years ago) when the ice sheet extended hundreds to thousands of kilometers seaward, ice has retreated inland to the configuration we observe today and left behind signatures of its growth and decline, as well as indicators of ocean change, in the seafloor sediments. Ongoing glacial and ocean processes are reflected in the characteristics of contemporary sediments, whereas older sediments beneath the seafloor offer a longer temporal perspective of changes to the ice sheet and surrounding ocean. Using data generated from archived sediment cores that are predominantly housed in the Antarctic Core Collection at Oregon State University, we aim to confirm if recent sediments clearly reflect the specific instrumental and historical field-based observations of ocean and glacial change seen in different regions of Antarctica. These modern changes will be placed into context with those recorded by sediments deposited on the seafloor hundreds to thousands of years ago. This project will explore interlinked physical, biological, and geochemical properties of seafloor sediments to address the influence of glacial and oceanographic processes on ice-proximal marine sedimentation during the 20th and 21st centuries and since the Last Glacial Maximum, with a focus on sediment fluxes, meltwater drainage, ice-rafted debris deposition, and radiocarbon chronologies. We will integrate multi-proxy analyses to interrogate the seafloor sediment record around Antarctica, targeting regions offshore of relatively fast-flowing and fast-changing glacial systems today and regions offshore of slower flowing, more stable (i.e., unchanging or relatively minimally changing) parts of the ice sheet. This work will leverage the application of new techniques and knowledge to legacy sediment cores that NSF has invested greatly in collecting and archiving. This project is led by three early-career women project investigators who seek to foster collaborative and open research practices and professional growth of the project team which will include three graduate students, numerous undergraduate students, and a postdoctoral research associate. The project team will co-produce educational materials with Math4Science, an organization that connects STEM professionals with public secondary education students and their math and science teachers through curricula; and develop and implement best practices in working with marine sediment core data through a collaboration with the Oregon State University Marine and Geology Repository and the United States Antarctic Program - Data Center. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MARINE SEDIMENTS; GLACIERS/ICE SHEETS; Antarctica; Geochemistry; Stratigraphy; Glacial Processes; SEDIMENTS; Last Glacial Maximum", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Prothro, Lindsay; Venturelli, Ryan A; Miller, Lauren", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Circum-Antarctic Processes from Archived Marine Sediment Cores (ANTS)", "uid": "p0010406", "west": -180.0}, {"awards": "1542723 Alexander, Becky", "bounds_geometry": "POINT(-112.05 -79.28)", "dataset_titles": "WAIS Divide ice core nitrate isotopes", "datasets": [{"dataset_uid": "601456", "doi": "10.15784/601456", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chemistry; Ice Core Records; Nitrate; Nitrate Isotopes; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Alexander, Becky", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide ice core nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601456"}], "date_created": "Mon, 13 Feb 2023 00:00:00 GMT", "description": "The Earth\u0027s atmosphere is a highly oxidizing medium. The abundance of oxidants such as ozone in the atmosphere strongly influences the concentrations of pollutants and greenhouse gases, with implications for human health and welfare. Because oxidants are not preserved in geological archives, knowledge of how oxidants have varied in the past under changing climate conditions is extremely limited. This award will measure a proxy for oxidant concentrations in a West Antarctic ice core over several major climate transitions over the past 50,000 years. These measurements will complement similar measurements from a Greenland ice core, which showed significant changes in atmospheric oxidants over major climate transitions covering this same time period. The addition of measurements from Antarctica will allow researchers to examine if the oxidant changes suggested by the Greenland ice core record are regional or global in scale. Knowledge of how oxidants vary naturally with climate will better inform predictions of the composition of the future atmosphere under a warming climate. This award will support measurements of the isotopic composition of nitrate in a West Antarctic ice core as a proxy for oxidant concentrations in the past atmosphere. The nitrogen isotopes of nitrate provide information on the degree of preservation of nitrate in the ice core record, and thus aid in the interpretation of the observed variability in the observed nitrate concentrations and oxygen isotopes in ice core records. By providing information about the spatial scale of oxidant changes over abrupt climate change events during the last glacial period, this project may also improve our understanding of mechanisms driving these abrupt events. Insight from this project will prove valuable for forecasting the response of stratospheric circulation to climate change, which has large implications for climate feedbacks and tropospheric composition. In addition, the information gleaned from this project on the mechanisms and feedbacks during abrupt climate change events will help determine the likelihood of such rapid events occurring in the future, which would have dramatic impacts on humankind. This award will provide training for one graduate and one undergraduate student, and will support the development of a hands-on activity related to rapid climate change to be used at the annual Polar Science Weekend at the Pacific Science Center in Seattle, WA.", "east": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": null, "is_usap_dc": true, "keywords": "Nitrate Isotopes; ICE CORE RECORDS; WAIS Divide; LABORATORY", "locations": "WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.28, "title": "Measuring an Ice-core Proxy for Relative Oxidant Abundances over Glacial-interglacial and Rapid Climate changes in a West Antarctic Ice Core", "uid": "p0010403", "west": -112.05}, {"awards": "1841844 Steig, Eric; 1841858 Souney, Joseph; 1841879 Aydin, Murat", "bounds_geometry": "POINT(-105 -86)", "dataset_titles": null, "datasets": null, "date_created": "Mon, 06 Feb 2023 00:00:00 GMT", "description": "The goal of this project is to drill and recover an ice core from Hercules Dome, Antarctica. The geographic setting of Hercules Dome makes it well-situated to investigate changes in the size of the West Antarctic ice sheet over long time periods. The base of the West Antarctic ice sheet lies below sea level, which makes this part of Antarctica vulnerable to melting from the relatively warm deep water of the Southern Ocean. An important research question is whether the West Antarctic Ice Sheet collapsed during Earth\u0027s last prolonged warm period, about 125,000 years ago, when the ocean was warmer and sea level was several meters higher than today. Evidence for or against such a collapse will be recorded in the chemistry and physical properties of the ice. The Hercules Dome ice core will be obtained over three to four field seasons in Antarctica using efficient drilling technology. This grant includes support for project management, pre-drilling science community engagement, ice-core recovery, and education and outreach activities. Hercules Dome is located at the edge of the East Antarctic ice sheet, south of the Transantarctic Mountains at 86 degrees South, 105 degrees West. Glaciological conditions at Hercules Dome are simple, with well-defined layering to the bed, optimal for the recovery of a deep ice core reaching to the last interglacial period at depths between 1600 and 2800 meters. An ice core from Hercules Dome will provide a research opportunity for ice-core analysts and others to make progress on a number of science priorities, including the environmental conditions of the last interglacial period, the history of gases and aerosols, and the magnitude and timing of changes in temperature and snow accumulation over the last 150,000 years. Together with the network of ice cores obtained by U.S. and international researchers over the last few decades, results from Hercules Dome will yield improved estimates of the boundary conditions necessary for the implementation and validation of ice-sheet models critical to the projection of future Antarctic ice-sheet change and sea level. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -105.0, "geometry": "POINT(-105 -86)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Hercules Dome; FIELD SURVEYS; AIR TEMPERATURE; SNOW/ICE CHEMISTRY; GLACIER ELEVATION/ICE SHEET ELEVATION; PALEOCLIMATE RECONSTRUCTIONS", "locations": "Hercules Dome", "north": -86.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.; Fudge, T. J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": "Hercules Dome Ice Core", "south": -86.0, "title": "Collaborative Research: An Ice Core from Hercules Dome, East Antarctica", "uid": "p0010401", "west": -105.0}, {"awards": "2152622 Morlighem, Mathieu", "bounds_geometry": "POLYGON((-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-103 -74,-102 -74,-101 -74,-100 -74,-100 -74.3,-100 -74.6,-100 -74.9,-100 -75.2,-100 -75.5,-100 -75.8,-100 -76.1,-100 -76.4,-100 -76.7,-100 -77,-101 -77,-102 -77,-103 -77,-104 -77,-105 -77,-106 -77,-107 -77,-108 -77,-109 -77,-110 -77,-110 -76.7,-110 -76.4,-110 -76.1,-110 -75.8,-110 -75.5,-110 -75.2,-110 -74.9,-110 -74.6,-110 -74.3,-110 -74))", "dataset_titles": "Sliding-Law Parameter and Airborne Radar-Derived Basal Reflectivity Data Underneath Thwaites Glacier, Antarctica", "datasets": [{"dataset_uid": "601658", "doi": "10.15784/601658", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites; Thwaites Glacier", "people": "Das, Indrani", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Sliding-Law Parameter and Airborne Radar-Derived Basal Reflectivity Data Underneath Thwaites Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601658"}], "date_created": "Tue, 20 Dec 2022 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites Glacier has been accelerating and widening over the past three decades. How fast Thwaites will disintegrate or how quickly it will find a new stable state have become some of the most important questions of the future of the West Antarctic Ice Sheet and its contribution to sea-level rise over the next decades to centuries and beyond. This project will rely on three independent numerical models of ice flow, coupled to an ocean circulation model to (1) improve our understanding of the interactions between the ice and the underlying bedrock, (2) analyze how sensitive the glacier is to external changes, (3) assess the processes that may lead to a collapse of Thwaites, and, most importantly, (4) forecast future ice loss of Thwaites. By providing predictions based on a suite of coupled ice-ocean models, this project will also assess the uncertainty in model projections. The project will use three independent ice-sheet models: Ice Sheet System Model, Ua, and STREAMICE, coupled to the ocean circulation model of the MIT General Circulation Model. The team will first focus on the representation of key physical processes of calving, ice damage, and basal slipperiness that have either not been included, or are poorly represented, in previous ice-flow modelling work. The team will then quantify the relative role of different proposed external drivers of change (e.g., ocean-induced ice-shelf thinning, loss of ice-shelf pinning points) and explore the stability regime of Thwaites Glacier with the aim of identifying internal thresholds separating stable and unstable grounding-line retreat. Using inverse methodology, the project will produce new physically consistent high-resolution (300-m) data sets on ice-thicknesses from available radar measurements. Furthermore, the team will generate new remote sensing data sets on ice velocities and rates of elevation change. These will be used to constrain and validate the numerical models, and will also be valuable stand-alone data sets. This process will allow the numerical models to be constrained more tightly by data than has previously been possible. The resultant more robust model predictions of near-future impact of Thwaites Glacier on global sea levels can inform policy-relevant decision-making. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -100.0, "geometry": "POINT(-105 -75.5)", "instruments": null, "is_usap_dc": true, "keywords": "COMPUTERS; Amundsen Sea; ICE SHEETS", "locations": "Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "NOT APPLICABLE", "persons": "Morlighem, Mathieu; Das, Indrani", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "NSF-NERC: PROcesses, drivers, Predictions: Modeling the response of Thwaites Glacier over the next Century using Ice/Ocean Coupled Models (PROPHET)", "uid": "p0010400", "west": -110.0}, {"awards": "1542756 Koutnik, Michelle", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.9,-175 -78.8,-175 -79.7,-175 -80.6,-175 -81.5,-175 -82.4,-175 -83.3,-175 -84.2,-175 -85.1,-175 -86,-175.5 -86,-176 -86,-176.5 -86,-177 -86,-177.5 -86,-178 -86,-178.5 -86,-179 -86,-179.5 -86,180 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77))", "dataset_titles": "Beardmore Glacier model in \u0027icepack\u0027", "datasets": [{"dataset_uid": "200339", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beardmore Glacier model in \u0027icepack\u0027", "url": "https://github.com/danshapero/beardmore"}], "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "Reconstructions of past changes in thickness and extent of the Antarctic ice sheet are important for evaluating past and present sea-level change, and for validating numerical models necessary to make realistic predictions of changes under future climate and ocean conditions. Models estimate that the Ross Sea sector was one of the largest contributors to sea-level rise from Antarctica as the ice sheet adjusted during the past ten thousand years from the glacial period to the Holocene. In this sector, ice flow into the embayment comes through West Antarctic ice streams and through East Antarctic outlet glaciers that flow through the Transantarctic Mountains. Observational data constrain the last glacial maximum and the Holocene retreat, but models are necessary to understand the environmental conditions needed for outlet glaciers to reach observed high stands, to fit the observed patterns of retreat, and to understand how the contribution of ice from West Antarctica and from East Antarctica changed over time. The investigators will use available geological and geophysical data in combination with forward ice-flow models and inverse models to investigate the evolution of the four Transantarctic outlet glaciers where sufficient data exist. The objectives of this new modeling are to constrain the glaciological conditions necessary for these glaciers to thicken during the last glacial, thin during the Holocene, and reach their present-day state. By testing specific hypotheses this work contributes to an interdisciplinary effort to understand Holocene deglaciation of the Ross Sea Embayment. In addition, the modeling will address the resolving power of the available data to answer key questions for each target glacier. Broader impacts include mentoring a graduate student, public outreach, incorporation of research into high-school and university classes, and support of an early-career investigator.", "east": -175.0, "geometry": "POINT(170 -81.5)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS; Transantarctic Mountains; GLACIER THICKNESS/ICE SHEET THICKNESS", "locations": "Transantarctic Mountains", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Smith, Ben; Conway, Howard; Shapero, Daniel", "platforms": null, "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -86.0, "title": "Holocene Deglaciation of the Western Ross Embayment: Constraints from East Antarctic Outlet Glaciers", "uid": "p0010398", "west": 155.0}, {"awards": "1643961 Anandakrishnan, Sridhar", "bounds_geometry": "POLYGON((-80 -83,-79.8 -83,-79.6 -83,-79.4 -83,-79.2 -83,-79 -83,-78.8 -83,-78.6 -83,-78.4 -83,-78.2 -83,-78 -83,-78 -83.2,-78 -83.4,-78 -83.6,-78 -83.8,-78 -84,-78 -84.2,-78 -84.4,-78 -84.6,-78 -84.8,-78 -85,-78.2 -85,-78.4 -85,-78.6 -85,-78.8 -85,-79 -85,-79.2 -85,-79.4 -85,-79.6 -85,-79.8 -85,-80 -85,-80 -84.8,-80 -84.6,-80 -84.4,-80 -84.2,-80 -84,-80 -83.8,-80 -83.6,-80 -83.4,-80 -83.2,-80 -83))", "dataset_titles": "Rutford Ice Stream short period data", "datasets": [{"dataset_uid": "200336", "doi": "https://doi.org/10.7914/SN/5B_2018", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Rutford Ice Stream short period data", "url": "http://fdsn.adc1.iris.edu/networks/detail/5B_2018/"}], "date_created": "Wed, 16 Nov 2022 00:00:00 GMT", "description": "Anandakrishnan/1643961 This award supports a project to study conditions under the Rutford Ice Stream, a large glacier that flows from the interior of the West Antarctic Ice Sheet to the Filchner Ronne Ice Shelf and then on to the ocean. The speed and volume of ice delivered to the ocean by this and similar glaciers is central to the question of sea-level change in the coming decades: if the volume of ice carried by Rutford to the ocean increases, then it will contribute to a rise in sea level. Numerical models of glacier flow that are used to forecast future conditions must include a component that accounts for the sliding of the ice over its bed. The sliding process is poorly modeled because of lack of detailed information about the bottom of glaciers, leading to increased uncertainty in the ice-flow models. Data from this project will provide such information. During this project, in collaboration with researchers at the British Antarctic Survey, a detailed survey of the properties of the bed of Rutford Ice Stream will be carried out. These surveys include using seismic instruments (which are sensitive to naturally occurring earthquakes within glaciers--called icequakes) to monitor the distribution of those icequakes at the bed. The locations, size, and timing of icequakes are controlled by the properties of the bed such as porosity, water pressure, and stress. As part of this project, a hole will be drilled to the bed of the glacier to monitor water pressures and to extract a sample of the basal material. By comparing the pressure variations with icequake production, the properties of the basal material over a large area can be better determined. Those results will aid in the application of numerical models by informing their description of the sliding process. This award requires field work in Antarctica. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -78.0, "geometry": "POINT(-79 -84)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Seismicity; Ice Dynamic; Rutford Ice Stream", "locations": "Rutford Ice Stream", "north": -83.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "platforms": null, "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -85.0, "title": "Rutford Ice Stream Cooperative Research Program with British Antarctic Survey", "uid": "p0010392", "west": -80.0}, {"awards": "2130663 Neff, Peter", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic Subsea Cable Workshop Report", "datasets": [{"dataset_uid": "601691", "doi": "10.15784/601691", "keywords": "Antarctica; Communication; Internet; Report", "people": "Andreasen, Julia; Pundsack, Jonathan W; Howe, Bruce; Yoshimi, Garrett; Neff, Peter; Jacobs, Gwen; Roop, Heidi A; Lassner, David; Timm, Kristin", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Subsea Cable Workshop Report", "url": "https://www.usap-dc.org/view/dataset/601691"}], "date_created": "Tue, 01 Nov 2022 00:00:00 GMT", "description": "Current networking capacity at McMurdo Station is insufficient to even be considered \u201cbroadband,\u201d with a summer population of up to 1000 people sharing what is equivalent to the connection enjoyed by a typical family of three in the United States. The changing Antarctic ice sheets and Southern Ocean are large, complex systems that require cutting edge technology to do cutting edge research, with remote technology becoming increasingly useful and even necessary to monitor changes at sufficient spatial and temporal scales. Antarctic science also often involves large data-transfer needs not currently met by existing satellite communication infrastructure. This workshop will gather representatives from across Antarctic science disciplines\u2014from astronomy to zoology\u2014as well as research and education networking experts to explore the scientific advances that would be enabled through dramatically increased real-time network connectivity, and also consider opportunities for subsea cable instrumentation. This workshop will assess the importance of a subsea fiber optic cable for high-capacity real-time connectivity in the US Antarctic Program, which is at the forefront of some of the greatest climate-related challenges facing our planet. The workshop will: (1) document unmet or poorly met current scientific and logistic needs for connectivity; (2) explore connectivity needs for planned future research and note the scientific advances that would be possible if the full value of modern cyberinfrastructure-empowered research could be brought to the Antarctic research community; and (3) identify scientific opportunities in planning a fully instrumented communication cable as a scientific observatory. Due to the ongoing COVID-19 pandemic, the workshop will be hosted and streamed online. While the workshop will be limited to invited personnel in order to facilitate a collaborative working environment, broad community input will be sought via survey and via comment on draft outputs. A workshop summary document and report will be delivered to NSF. Increasing US Antarctic connectivity by orders of magnitude will be transformative for science and logistics, and it may well usher in a new era of Antarctic science that is more accessible, efficient and sustainable. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Minneapolis, MN; SNOW/ICE", "locations": "Minneapolis, MN; Antarctica", "north": -60.0, "nsf_funding_programs": "Polar Cyberinfrastructure", "paleo_time": null, "persons": "Pundsack, Jonathan W; Roop, Heidi A", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "2021 Antarctic Subsea Cable Workshop: High-Speed Connectivity Needs to Advance US Antarctic Science", "uid": "p0010389", "west": -180.0}, {"awards": "1916982 Teyssier, Christian; 1917176 Siddoway, Christine; 1917009 Thomson, Stuart", "bounds_geometry": "POLYGON((-160.16 -67.15,-154.572 -67.15,-148.984 -67.15,-143.39600000000002 -67.15,-137.808 -67.15,-132.22 -67.15,-126.632 -67.15,-121.04400000000001 -67.15,-115.456 -67.15,-109.868 -67.15,-104.28 -67.15,-104.28 -68.165,-104.28 -69.18,-104.28 -70.19500000000001,-104.28 -71.21000000000001,-104.28 -72.225,-104.28 -73.24,-104.28 -74.255,-104.28 -75.27,-104.28 -76.285,-104.28 -77.3,-109.868 -77.3,-115.456 -77.3,-121.044 -77.3,-126.632 -77.3,-132.22 -77.3,-137.808 -77.3,-143.396 -77.3,-148.98399999999998 -77.3,-154.572 -77.3,-160.16 -77.3,-160.16 -76.285,-160.16 -75.27,-160.16 -74.255,-160.16 -73.24,-160.16 -72.225,-160.16 -71.21000000000001,-160.16 -70.19500000000001,-160.16 -69.18,-160.16 -68.165,-160.16 -67.15))", "dataset_titles": "Apatite fission track thermochronology data for detrital minerals, offshore clasts, and bedrock; U-Pb detrital zircon geochronological data, obtained by LA-ICP-MS", "datasets": [{"dataset_uid": "200333", "doi": "", "keywords": null, "people": null, "repository": "in progress", "science_program": null, "title": "Apatite fission track thermochronology data for detrital minerals, offshore clasts, and bedrock", "url": ""}, {"dataset_uid": "200332", "doi": "", "keywords": null, "people": null, "repository": "in progress", "science_program": null, "title": "U-Pb detrital zircon geochronological data, obtained by LA-ICP-MS", "url": ""}], "date_created": "Wed, 19 Oct 2022 00:00:00 GMT", "description": "Sediment records off the coast of Marie Byrd Land (MBL), Antarctica suggest frequent and dramatic changes in the size of the West Antarctic Ice Sheet (WAIS) over short (tens of thousands of years) and long (millions of years) time frames in the past. WAIS currently overrides much of MBL and covers the rugged and scoured bedrock landscape. The ice sheet carved narrow linear troughs that reach depths of two to three thousand meters below sea level as outlet glaciers flowed from the interior of the continent to the oceans. As a result, large volumes of fragmented continental bedrock were carried out to the seabed. The glaciers cut downward into a region of crystalline rocks (i.e. granite) whose temperature change as a function of rock depth happens to be significant. This strong geothermal gradient in the bedrock is favorable for determining when the bedrock experienced rapid exhumation or \"uncovering\". Analyzing the chemistry of minerals (zircon and apatite) within the eroded rocks will provide information about the rate and timing of the glacier removal of bedrock from the Antarctic continent. The research addresses the following questions: When did the land become high enough for a large ice sheet to form? What was the regional pre-glacial topography? Under what climate conditions, and at what point in the growth of an ice sheet, did glaciers begin to cut sharply into bedrock to form the narrow troughs that flow seaward? The research will lead to greater understanding of past Antarctic ice sheet fluctuations and identify precise timing of glacial incision. These results will refine ice sheet history and aid the international societal response to contemporary ice sheet change and its global consequences. The project will contribute to the training of two graduate and two undergraduate students in STEM. The objective is to clarify the onset of WAIS glacier incision and assess the evolution of Cenozoic paleo-topography. Low-temperature (T) thermochronology and Pecube 3-D thermo-kinematic modeling will be applied to date and characterize episodes of glacial erosional incision. Single-grain double- and triple-dating of zircon and apatite will reveal the detailed crustal thermal evolution of the region enabling the research team to determine the comparative topographic influences on glaciation versus bedrock uplift induced by Eocene to present tectonism/magmatism. High-T mineral thermochronometers across Marie Byrd Land (MBL) record rapid extension-related cooling at ~100 Ma from temperatures of \u003e800 degrees C to \u0026#8804; 300 degrees C. This signature forms a reference horizon, or paleogeotherm, through which the Cenozoic landscape history using low-T thermochronometers can be explored. MBL\u0027s elevated geothermal gradient, sustained during the Cenozoic, created favorable conditions for sensitive apatite and zircon low-T thermochronometers to record bedrock cooling related to glacial incision. Students will be trained to use state-of-the-art analytical facilities in Arizona and Minnesota, expanding the geo- and thermochronologic history of MBL from bedrock samples and offshore sedimentary deposits. The temperature and time data they acquire will provide constraints on paleotopography, isostasy, and the thermal evolution of MBL that will be modeled in 3D using Pecube model simulations. Within hot crust, less incision is required to expose bedrock containing the distinct thermochronometric profile; a prediction that will be tested with inverse Pecube 3-D models of the thermal field through which bedrock and detrital samples cooled. Using results from Pecube, the ICI-Hot team will examine time-varying topography formed in response to changes in erosion rates, topographic relief, geothermal gradient and/or flexural isostatic rigidity. These effects are manifestations of dynamic processes in the WAIS, including ice sheet loading, ice volume fluctuations, relative motion upon crustal faults, and magmatism-related elevation increase across the MBL dome. The project makes use of pre-existing sample collections housed at the US Polar Rock Repository, IODP\u0027s Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -104.28, "geometry": "POINT(-132.22 -72.225)", "instruments": null, "is_usap_dc": true, "keywords": "Marie Byrd Land; GLACIERS/ICE SHEETS; Zircon; Subglacial Topography; FIELD SURVEYS; TECTONICS; Ice Sheet; Thermochronology; Apatite; ROCKS/MINERALS/CRYSTALS; Erosion; United States Of America; LABORATORY", "locations": "United States Of America; Marie Byrd Land", "north": -67.15, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC", "persons": "Siddoway, Christine; Thomson, Stuart; Teyssier, Christian", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "in progress", "repositories": "in progress", "science_programs": null, "south": -77.3, "title": "Collaborative Research: Ice sheet erosional interaction with hot geotherm in West Antarctica", "uid": "p0010386", "west": -160.16}, {"awards": "1543533 Johnson, Jesse; 1543530 van der Veen, Cornelis", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 19 Oct 2022 00:00:00 GMT", "description": "Van der Veen/1543530 The objective of this research is to gain better understanding of the West Antarctic ice flow in the transition region from grounded ice to floating ice shelves and investigate the conditions that can initiate and sustain major retreat of these glaciers. Several major Antarctic outlet glaciers and ice streams will be investigated using a suite of observational techniques and modeling tools. Glaciers include Thwaites Glacier, which has become a focal point in the discussion of West Antarctic retreat, Whillans Ice Stream as an example of the archetype ice stream, and Byrd Glacier, a major outlet glacier draining East Antarctica through the Transantarctic Mountains into the Ross Ice Shelf. This study will investigate whether the ongoing changes in these glaciers will lead to long-term mass loss (the onset of ice sheet collapse), or whether these glaciers will quickly stabilize with a new geometry. To adequately incorporate the dynamic behavior of outlet glaciers and ice streams requires inclusion of the relevant physical processes, and the development of regional models that employ a numerical grid with a horizontal grid spacing sufficiently refined to capture smaller-scale bed topographic features that may control the flow of these glaciers. This award revisits the issue of stability of marine-terminating glaciers whose grounding line is located on a retrograded bed slope. In particular, an attempt will be made to resolve the question whether observed rapid changes are the result of perturbations at the terminus or grounding line, or whether these changes reflect ice-dynamical forcing over the grounded reaches. High-resolution satellite imagery will be used to investigate ice-flow perturbations on smaller spatial scales than has been done before, to evaluate the importance of localized sites of high basal resistance on grounding-line stability. This collaborative project involves a range of modeling strategies including force-budget analysis, flow-band modeling, Full Stokes modeling for local studies, and using the Ice Sheet System Model developed at JPL for regional modeling. Broader Impacts include training two graduate students in computer simulations and ice sheet modeling algorithms. The work will also expand on a web-based interactive flowline model, so that it includes more realistic grounding line dynamics.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Ice Sheet Dynamics; MODELS; Iceberg Calving; GLACIERS/ICE SHEETS; Numerical Glacier Modeling; Basal Sliding; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "van der Veen, Cornelis; Stearns, Leigh; Paden, John", "platforms": "OTHER \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Stability and Dynamics of Antarctic Marine Outlet Glaciers", "uid": "p0010387", "west": -180.0}, {"awards": "1644118 Dunbar, Robert", "bounds_geometry": "POLYGON((-108 -73,-107.3 -73,-106.6 -73,-105.9 -73,-105.2 -73,-104.5 -73,-103.8 -73,-103.1 -73,-102.4 -73,-101.7 -73,-101 -73,-101 -73.3,-101 -73.6,-101 -73.9,-101 -74.2,-101 -74.5,-101 -74.8,-101 -75.1,-101 -75.4,-101 -75.7,-101 -76,-101.7 -76,-102.4 -76,-103.1 -76,-103.8 -76,-104.5 -76,-105.2 -76,-105.9 -76,-106.6 -76,-107.3 -76,-108 -76,-108 -75.7,-108 -75.4,-108 -75.1,-108 -74.8,-108 -74.5,-108 -74.2,-108 -73.9,-108 -73.6,-108 -73.3,-108 -73))", "dataset_titles": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "datasets": [{"dataset_uid": "601611", "doi": "10.15784/601611", "keywords": "Amundsen Sea; Antarctica; Chemistry:Water; CTD; D18O; NBP0001; NBP0702; NBP0901; NBP1901; NBP2002; Oceans; Oxygen Isotope; R/v Nathaniel B. Palmer; Seawater Isotope; Southern Ocean", "people": "Hennig, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "url": "https://www.usap-dc.org/view/dataset/601611"}], "date_created": "Wed, 21 Sep 2022 00:00:00 GMT", "description": "Estimating Antarctic ice sheet growth or loss is important to predicting future sea level rise. Such estimates rely on field measurements or remotely sensed based observations of the ice sheet surface, ice margins, and or ice shelves. This work examines the introduction of freshwater into the ocean to surrounding Antarctica to track meltwater from continental ice. Polar ice is depleted in two stable isotopes, 18O and D, deuterium, relative to Southern Ocean seawater and precipitation. Measurements of seawater isotopic composition in conjunction with precise observations of seawater temperature and salinity, will permit discrimination of freshwater derived from melting glacial ice from that derived from regional precipitation or sea ice melt. This research describes an accepted method for determining rates and locations of meltwater entering the oceans from polar ice sheets. As isotopic and salinity perturbations are cumulative in many Antarctic coastal seas, the method allows for the detection of any marked acceleration in meltwater introduction in specific regions, using samples collected and analyzed over a period of years to decades. Impact of the project derives from use of an independent method capable of constraining knowledge about current ice sheet melt rates, their stability and potential impact on sea level rise. The project allows for sample collection taken from foreign vessels of opportunity sailing in Antarctic waters, and subsequent sharing and interpretation of data. Research partners include the U.S., Korea, China, New Zealand, the United Kingdom, and Germany. Participating collaborators will collect seawater samples for isotopic and salinity analysis at Stanford University. USAP cruises will concentrate on sampling the Ross Sea, and the West Antarctic. The work plan includes interpretation of isotopic data using box model and mixing curve analyses as well as using isotope enabled ROMS (Regional Ocean Modeling System) models. The broader impacts of the research will include development of an educational module that illustrates the scientific method and how ocean observations help society understand how Earth is changing.", "east": -101.0, "geometry": "POINT(-104.5 -74.5)", "instruments": null, "is_usap_dc": true, "keywords": "Stable Isotopes; WATER TEMPERATURE; SALINITY; Oxygen Isotope; Meltwater Inventory; Pine Island Bay; OCEAN CHEMISTRY", "locations": "Pine Island Bay", "north": -73.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Dunbar, Robert", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.0, "title": "Estimation of Antarctic Ice Melt using Stable Isotopic Analyses of Seawater", "uid": "p0010380", "west": -108.0}, {"awards": "2218402 Fegyveresi, John", "bounds_geometry": "POLYGON((-115 -85.5,-113.5 -85.5,-112 -85.5,-110.5 -85.5,-109 -85.5,-107.5 -85.5,-106 -85.5,-104.5 -85.5,-103 -85.5,-101.5 -85.5,-100 -85.5,-100 -85.65,-100 -85.8,-100 -85.95,-100 -86.1,-100 -86.25,-100 -86.4,-100 -86.55,-100 -86.7,-100 -86.85,-100 -87,-101.5 -87,-103 -87,-104.5 -87,-106 -87,-107.5 -87,-109 -87,-110.5 -87,-112 -87,-113.5 -87,-115 -87,-115 -86.85,-115 -86.7,-115 -86.55,-115 -86.4,-115 -86.25,-115 -86.1,-115 -85.95,-115 -85.8,-115 -85.65,-115 -85.5))", "dataset_titles": "Multi-Site Brittle Ice Data and Measurements", "datasets": [{"dataset_uid": "601786", "doi": "10.15784/601786", "keywords": "Antarctica; Brittle Ice; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Glaciology; Ice Core; Ice Core Records; Ice Core Records; Physical Properties; Simple Dome; Siple Dome; South Pole; SPICEcore; Subgrain Boundaries; WAIS Divide", "people": "Fegyveresi, John; Barnett, Samantha", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Multi-Site Brittle Ice Data and Measurements", "url": "https://www.usap-dc.org/view/dataset/601786"}], "date_created": "Mon, 19 Sep 2022 00:00:00 GMT", "description": "Ice cores are a vital source of information about past climate. Research that utilizes ice cores benefits from an undamaged ice-core record. There is often a zone within ice sheets where the ice is brittle upon extraction in a core. Brittle-ice behavior occurs when the rapid decompression of the core as it is being extracted from the ice-sheet results in extensive fracturing. Ice from this zone can compromise the undamaged record. This project seeks to improve our understanding of the mechanisms involved in brittle-ice behavior and onset, with the goal of helping to guide field-site operations, core handling preparation, and planned laboratory measurement techniques for future ice-coring projects, including the upcoming work at Hercules Dome. This project requires no field work, as it will use existing observations and existing ice cores to gain an understanding of brittle ice. This is a high-risk and timely proposal that is early-concept and exploratory in nature, making it appropriate for the EAGER solicitation. The project will support an early-career researcher and provide training for a master\u2019s student who is a woman. And, finally, the project will develop educational and outreach materials for graduate and undergraduate courses and elementary schools. This project will examine and catalog brittle ice from several existing ice-core samples to specifically assess various ice physical properties affecting brittleness potential, including bubble size and number-density, ice fabric, grain statistics, fracture characteristics, and the location and properties of grain and subgrain boundaries. End members of this sample assessment have been identified and include Siple Dome, which exhibited major brittle behavior and damage, and South Pole ice core, which exhibited very-minor brittle behavior and almost no damage. Output datasets will include calibrated relationships for bubble number-density, mean grain and bubble sizes, subgrain prevalence and orientation, and a usable indicator for estimating brittle-ice onset and magnitude. There is an immediate applicability of results from this effort for the Hercules Dome drilling project. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -100.0, "geometry": "POINT(-107.5 -86.25)", "instruments": null, "is_usap_dc": true, "keywords": "Hercules Dome Ice Core; West Antarctica; Grain Statistics; LABORATORY; Ice Core; ICE SHEETS; Physical Properties; Brittle Ice; C-Axis Fabric; Bubble; ICE CORE RECORDS", "locations": "West Antarctica", "north": -85.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fegyveresi, John", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Hercules Dome Ice Core", "south": -87.0, "title": "EAGER: Constraining the Expected Brittle-ice Behavior for the Hercules Dome Ice-core Site.", "uid": "p0010378", "west": -115.0}, {"awards": "1842542 Morgan, Daniel", "bounds_geometry": "POLYGON((160 -77,160.4 -77,160.8 -77,161.2 -77,161.6 -77,162 -77,162.4 -77,162.8 -77,163.2 -77,163.6 -77,164 -77,164 -77.1,164 -77.2,164 -77.3,164 -77.4,164 -77.5,164 -77.6,164 -77.7,164 -77.8,164 -77.9,164 -78,163.6 -78,163.2 -78,162.8 -78,162.4 -78,162 -78,161.6 -78,161.2 -78,160.8 -78,160.4 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 09 Aug 2022 00:00:00 GMT", "description": "The goal of this study is to identify and distinguish different source areas of glacial sediment in the McMurdo Dry Valleys, Antarctica to determine past glacial flow direction. Understanding ice flow is critical for determining how the Antarctic Ice Sheets have behaved in the past. Such insight is fundamental for allowing scientists to predict how the Antarctic Ice Sheets will evolve and, in turn, forecast how much and how fast sea level may rise. The project study site, the McMurdo Dry Valleys, contain a tremendous record of glacial deposits on land that extends back at least 14 million years. Chemistry of the rocks within the glacial deposits hold clues to the sources of ice that deposited the material. The chemical analyses of the glacial deposits will allow mapping of the former extent of glaciations providing a better understand of ice flow history. The mapping of the largest ice sheet expansion of the past 14 million years in the McMurdo Dry Valleys is of broad interest to the global climate change community. Undergraduate students comprise the majority of the field teams and will be responsible for sample preparation and analysis in the laboratory. This project utilizes new geochemical techniques to test hypotheses about the source, extent, and flow patterns of the glacier ice that deposited glacial tills in the McMurdo Dry Valleys, Antarctica (MDV). The MDV contain an unparalleled terrestrial archive of glacial deposits, which record multiple sources of ice that deposited them. These include the northeast flowing ice that overrode the Transantarctic Mountains, the eastward expansion of the East Antarctic Ice Sheet, the westward extension of the Ross Ice Shelf representing an expansion of the West Antarctic Ice Sheet, and the growth of local alpine glaciers. The glacial tills and drifts in the Antarctic are typically isolated in patches or disjointed outcrop patterns making it difficult to correlate tills and determine their source. This project will undertake a systematic study of the tills in the McMurdo Dry Valleys to determine their provenance with a variety of geochemical techniques including major and minor element analyses with X-ray fluorescence, heavy mineral composition, soil salt concentration, and determining the uranium-lead (U-Pb) ages of zircon sands contained in these tills. The primary tool will be the age distribution of the population of detrital zircon in a glacial drift because it reflects the source of the tills and provides a unique geochemical \"fingerprint\" used to distinguish source areas while correlating units across different sites. A deliverable from this project will be a community available library of zircon fingerprints for mapped glacial tills from archived samples at the Polar Rock Repository and the systematic collection of samples in the MDV. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 164.0, "geometry": "POINT(162 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIATION; Dry Valleys", "locations": "Dry Valleys", "north": -77.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Morgan, Daniel", "platforms": null, "repositories": null, "science_programs": null, "south": -78.0, "title": "Unlocking the Glacial History of the McMurdo Dry Valleys, Antarctica by Fingerprinting Glacial Tills with Detrital Zircon U-Pb Age Populations", "uid": "p0010368", "west": 160.0}, {"awards": "2205008 Walker, Catherine", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "Most of the mass loss from the Antarctic Ice Sheet, a major contributor to sea level rise, occurs at its margins, where ice meets the ocean. Glaciers and ice streams flow towards the coast and can go afloat over the water, forming ice shelves. Ice shelves make up almost half of the entire Antarctic coastline, and hold back the flow of inland ice in Antarctica continent; thus they are integral to the overall stability of the Antarctic Ice Sheet. Ice shelves lose mass by two main processes: iceberg calving and basal melting. Temporal and spatial fluctuations in both are driven by various processes; a major driver of ice shelf melt is the heat provided by the neighboring Southern Ocean. Ocean heat, in turn, is driven by various aspects of the ice shelf environment. One of the most significant contributors to changes in the ocean\u2019s heat content is the presence of sea ice. This research will focus on the effects of coastal polynyas (areas of open water amidst sea ice), how they modulate the local ocean environment, and how that environment drives ice shelf basal melting. To date, the relationship between polynyas and ice shelf melt has not been characterized on an Antarctic-wide scale. Understanding the feedbacks between polynya size and duration, ocean stratification, and ice shelf melt, and the strength of those feedbacks, will improve the ability to characterize influences on the long-term stability of ice shelves, and in turn, the Antarctic Ice Sheet as a whole. A critical aspect of this study is that it will provide a framework for understanding ice shelf-ocean interaction across a diverse range of geographic settings. This, together with improvements of various models, will help interpret the impacts of future climate change on these systems, as their responses are likely quite variable and, overall, different from the large-scale response of the ice sheet. This project will also provide a broader context to better design future observational studies of specific coastal polynya and ice shelf processes. This study focuses on four main hypotheses: 1) Variations of coastal polynya extent are correlated with those of the ice shelf melt rates, and this correlation varies around Antarctica; 2) Polynya extent modulates a feedback between ice shelf melt and accretion regimes through stratification of local waters; 3) Polynya extent together with seafloor bathymetry regulate the volume of warm offshore waters that reach ice margins; and 4) The strength of the feedback between polynya and glacier ice varies with geographic setting and influences the long-term stability of the glacial system. Observational data, including ice-penetrating radar, radar and laser altimetry, and in situ hydrographic data, and derived data sets from the Southern Ocean State Estimate (SOSE) project and BedMachine Antarctica, will be used in conjunction with ocean (MIT global circulation model, MITgcm) and ice sheet (Ice sheet and Sea-level System Model, ISSM) models to reveal underlying dynamics. The joint analysis of the observational data enables an investigation of polynya, ocean, and ice shelf signals and their interplay over time across a range of settings. The results of this data analysis also provide inputs and validation data for the modeling tasks, which will allow for characterization of the feedbacks in our observations. The coupled modeling will enable us to examine the interaction between polynya circulation and ice shelves in different dynamical regimes and to understand ice and ocean feedback over time. Diagnosing and interpreting the pan-Antarctic spatial variability of the polynya-ice shelf interaction are the main objectives of this research and separates this study from other projects targeted at the interactive processes in specific regions. As such, this research focuses on seven preliminary target sites around the Antarctic coast to establish a framework for interpreting coupled ice shelf-ocean variability across a diverse range of geographic settings. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; ICE EXTENT; GLACIERS/ICE SHEETS", "locations": "United States Of America", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Walker, Catherine; Zhang, Weifeng; Seroussi, Helene", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Investigating the Role of Coastal Polynya Variability in Modulating Antarctic Marine-Terminating Glacier Drawdown", "uid": "p0010364", "west": -180.0}, {"awards": "2149518 Fudge, Tyler", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations", "datasets": [{"dataset_uid": "601854", "doi": "10.15784/601854", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Shackleton, Sarah; Kirkpatrick, Liam; Carter, Austin; Fudge, T. J.; Marks Peterson, Julia", "repository": "USAP-DC", "science_program": "COLDEX", "title": "ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations", "url": "https://www.usap-dc.org/view/dataset/601854"}], "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "Ice cores provide valuable records of past climate such as atmospheric concentrations of greenhouse gasses and unmatched evidence of past abrupt climate change. Key to understanding past climate changes are the measurements of annual layers that are used to determine the age of the ice, and the timing and pace of major climate events. The current measurement limit for annual layers in ice cores is at the centimeter scale. This project aims to improve the depth resolution of measurements of the chemical impurities in ice using measurements such as electrical conductivity, hyperspectral imaging, major elements measured with laser ablation, and ice grain properties. This will advance understanding of the preservation and layering in ice cores and improve the accuracy and length of annual timescales for existing ice cores. Most of the past time preserved in an ice core is near the bed where the layers have been thinned to only a fraction of their original thickness. Interpreting highly compressed portions of ice cores is increasingly important as projects target climate records in basal ice, and old ice recovered from blue-ice areas. This project will integrate precisely co-registered electrical conductivity measurements, hyperspectral imaging, laser ablation mass spectrometer measurements of impurities, and ice physical properties to investigate sub-centimeter chemical and physical variations in polar ice. Critical to resolving thin ice layers is understanding the across-core variations that may obscure or distort the vertical layering. Analyses will be focused on samples from the WDC-06A (WAIS Divide), SPC-14 (South Pole), and GISP2 (Greenland Ice Sheet Project 2) ice cores that have well-established seasonal cycles that yielded benchmark timescales, as well a large-diameter ice core from the Allan Hills blue ice area. This work will develop state-of-the-art instrumentation and FAIR (findable, accessible, interoperable, and reusable) data handling workflow at the National Science Foundation Ice Core Facility available to the community both to enhance understanding of existing ice cores, and for use in future projects. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE CORE RECORDS; Ice Core", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Fegyveresi, John M", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Testing Next Generation Measurement Techniques for Reconstruction of Paleoclimate Archives from Thin or Disturbed Ice Cores Sections", "uid": "p0010365", "west": -180.0}, {"awards": "1654922 de la Pena, Santiago", "bounds_geometry": "POINT(0 -90)", "dataset_titles": " South Pole Weather and Accumulation Measurements 2017-2020", "datasets": [{"dataset_uid": "601591", "doi": "10.15784/601591", "keywords": "Accumulation; Antarctica; Snow; South Pole; Surface Mass Balance", "people": "de la Pe\u00f1a, Santiago", "repository": "USAP-DC", "science_program": null, "title": " South Pole Weather and Accumulation Measurements 2017-2020", "url": "https://www.usap-dc.org/view/dataset/601591"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "Non-Technical Description: Snow accumulation in the interior of the Antarctic Ice Sheet, and how much snow is redistributed by wind are important components of the climate system of Antarctica, yet remain largely unknown. Because of the extreme meteorological conditions found in Antarctica, direct observations of snowfall and related weather are few, leaving a gap in the regional climate records in the continent. Snow accumulation across the Antarctic Ice Sheet is a critical component for the assessment of the contribution of Antarctica to sea level rise, and accurate measurements are required to evaluate results from regional climate models, used to reconstruct climate trends of the recent past for the whole ice sheet. Owing to the size of Antarctica alone, small fluctuations in the total snow accumulation at the surface have a significant effect on the mass budget of the ice sheet and thus on global sea level. In this work will develop an instrument suite for deployment at the South Pole research station in Antarctica. The monitoring station will have new state-of-the-art sensors will record measurements of weather, snow accumulation, and structural conditions within the layer of packed snow. The autonomous system will be tested in the coldest and darkest winter on the planet, and will provide the first continuous measurements of snow accumulation processes in the interior of the ice sheet, which will be used to validate atmospheric and regional climate models. Technical Description: The overarching goal of the proposed work is to improve our understanding of the spatiotemporal variability in ice-sheet surface mass balance and densification rates within the layer of firn, a layer roughly 100 m thick consisting of the buried and compacted snow that has yet to densify into solid ice. For this, we will A) design and install a cost-efficient, reliable, and easily deployable surface mass balance and firn monitoring system for Antarctica; B) adapt the system to operate autonomously for long periods of time under the harshest meteorological conditions; C) use observations for evaluation of surface mass balance simulated by atmospheric reanalyzes and regional climate model; and D) measure the surface mass balance, surface density, and firn compaction rates to derive ice sheet surface elevation change in areas with low ice dynamics. The set up of the monitoring station is unique in that it is able to monitor separately height change due to surface mass balance variability and absolute surface mass balance, the latter in units of water equivalence, and differentiation of the two is crucial for understanding the role of surface processes in ice sheet mass balance. An installed sonic ranger will provide hourly measurements of surface height change that is due to snow accumulation. Surface height change alone is not sufficient to evaluate atmospheric models of surface mass balance, which is measured in in units of mass; a key variable missing is density. To overcome this, the system will be equipped with a SnowFox sensor that is able to capture the variations in surface mass balance in terms of mass through time. Combining the height change with mass change will allow us to determine the density of the material as well, which is very important for conversion of observed height changes due to surface processes into mass changes. Therefore, we aim to better evaluate the short-term variability in surface height and mass fluctuations due to surface mass balance to improve our understanding of the total mass change and to evaluate atmospheric models, which are typically used for ice sheet-wide mass balance studies.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": null, "is_usap_dc": true, "keywords": "South Pole; SNOW", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Instrumentation and Support; Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "de la Pe\u00f1a, Santiago", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "EAGER: An Operational System to Measure Surface Mass Balance Deep in the Interior of the Antarctic Ice Sheet", "uid": "p0010360", "west": 0.0}, {"awards": "1744649 Christianson, Knut", "bounds_geometry": "POLYGON((-120 -85.5,-117.5 -85.5,-115 -85.5,-112.5 -85.5,-110 -85.5,-107.5 -85.5,-105 -85.5,-102.5 -85.5,-100 -85.5,-97.5 -85.5,-95 -85.5,-95 -85.62,-95 -85.74,-95 -85.86,-95 -85.98,-95 -86.1,-95 -86.22,-95 -86.34,-95 -86.46000000000001,-95 -86.58,-95 -86.7,-97.5 -86.7,-100 -86.7,-102.5 -86.7,-105 -86.7,-107.5 -86.7,-110 -86.7,-112.5 -86.7,-115 -86.7,-117.5 -86.7,-120 -86.7,-120 -86.58,-120 -86.46000000000001,-120 -86.34,-120 -86.22,-120 -86.1,-120 -85.98,-120 -85.86,-120 -85.74,-120 -85.62,-120 -85.5))", "dataset_titles": "Hercules Dome ApRES Data; Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data; Hercules Dome Ice-Penetrating Radar Swath Topographies; Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets; ITASE Impulse Radar Hercules Dome to South Pole", "datasets": [{"dataset_uid": "601711", "doi": "10.15784/601711", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Paden, John; Holschuh, Nicholas; Hoffman, Andrew; Christianson, Knut", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome Ice-Penetrating Radar Swath Topographies", "url": "https://www.usap-dc.org/view/dataset/601711"}, {"dataset_uid": "601606", "doi": "10.15784/601606", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Christianson, Knut", "repository": "USAP-DC", "science_program": null, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "url": "https://www.usap-dc.org/view/dataset/601606"}, {"dataset_uid": "601712", "doi": "10.15784/601712", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Welch, Brian; Jacobel, Robert; Hoffman, Andrew; Christianson, Knut", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "ITASE Impulse Radar Hercules Dome to South Pole", "url": "https://www.usap-dc.org/view/dataset/601712"}, {"dataset_uid": "601739", "doi": "10.15784/601739", "keywords": "Antarctica; Apres; Crystal Orientation Fabric; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hercules Dome; Ice Dynamic; Ice Penetrating Radar; Radar Interferometry; Radar Polarimetry", "people": "Horlings, Annika; Hoffman, Andrew; Hills, Benjamin; Fudge, Tyler J; Erwin, Emma; Steig, Eric J.; Christianson, Knut; Holschuh, Nicholas", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome ApRES Data", "url": "https://www.usap-dc.org/view/dataset/601739"}, {"dataset_uid": "601710", "doi": "10.15784/601710", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Hills, Benjamin; Hoffman, Andrew; Christianson, Knut; O\u0027Connor, Gemma; Horlings, Annika; Holschuh, Nicholas; Christian, John", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data", "url": "https://www.usap-dc.org/view/dataset/601710"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington\u0027s annual Polar Science Weekend in Seattle, and art-science collaboration. This project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a \"Raymond Bump\") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -86.1)", "instruments": null, "is_usap_dc": true, "keywords": "West Antarctica; ICE DEPTH/THICKNESS; East Antarctica", "locations": "West Antarctica; East Antarctica", "north": -85.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Hoffman, Andrew; Holschuh, Nicholas", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.7, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "uid": "p0010359", "west": -120.0}, {"awards": "2114502 Tinto, Kirsteen", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 19 Jul 2022 00:00:00 GMT", "description": "This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). An important part of understanding future climate change is predicting changes in how fast the ice in Antarctica is moving. If ice flows more quickly towards the ocean, it will have a direct impact on sea level rise. One of the things that can influence the ice flow is the type of rock below the ice coverage in Antarctica. Sedimentary basins are large regions where sedimentary rocks accumulated in the past, often under ancient seas. It has been observed that where there are sediments below the ice, the ice can flow faster. This project seeks to understand what is below the ice and how the underlying rock influences the ice flow. Is it hard, crystalline rock? Is it a sedimentary basin? What is the relationship between sediments and ice flow? The answers to these questions will be addressed by using a combination of available data and geophysical methods. Information from well-known rock-types will be used to train the computer to recognize these features by using an application of artificial intelligence known as machine learning, which will help the characterization and identification of unknown sedimentary basins beneath the ice. The results of this project will be disseminated to a broad audience by holding workshops for teacher and students to explain our findings under the ice and to introduce the machine learning technique. Open-source codes used during this project will be made available for use in higher-level classrooms as well as in further studies. To date, no comprehensive distribution of onshore and offshore sedimentary basins over Antarctica has been developed. A combination of large-scale datasets will be used to characterize known basins and identify new sedimentary basins to produce the first continent-wide mapping of sedimentary basins and provide improved basal parametrizations conditions that have the potential to support more realistic ice sheet models. Available geophysical compilations of data and the location of well-known sedimentary basins will be used to apply an ensemble machine learning algorithm. The machine learning algorithm will learn complex relationships by voting among a collection of randomized decision trees. The gravity signal related to sedimentary basins known from other (e.g. seismic) techniques will be evaluated and unknown basins from aerogravity data regression analyses will be proposed by calculating a gravity residual that reflects density inhomogeneities. The gravimetric sedimentary basins identified from the regression analyses will be compared with an independent method of identifying sedimentary distribution, the Werner deconvolution method of estimating depth to magnetic sources. The hypothesis, which is sedimentary basins are correlated to fast ice flow behavior, will be tested by comparing the location of the sedimentary basins with locations of high ice flow by using available ice velocity observations. A relationship between sedimentary basins and ice streams will be defined qualitatively and quantitatively, aiming to evaluate if there are ice streams where no sedimentary basins are reported, or sedimentary basins with no ice streams related. The findings of these project can confirm if the presence of abundant sediments is a pre-requisite for ice streaming. Analyzing previously known sedimentary basins and identifying new ones in Antarctica is central to evaluating the influence of subglacial sediments on the ice sheet flow. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GRAVITY ANOMALIES; ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Constantino, Renata", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Pan-Antarctic Assessment of Sedimentary Basins and the Onset of Streaming Ice Flow from Machine Learning and Aerogravity Regression Analyses", "uid": "p0010351", "west": -180.0}, {"awards": "1644277 Aschwanden, Andy", "bounds_geometry": "POLYGON((-75 -60,-72 -60,-69 -60,-66 -60,-63 -60,-60 -60,-57 -60,-54 -60,-51 -60,-48 -60,-45 -60,-45 -61.5,-45 -63,-45 -64.5,-45 -66,-45 -67.5,-45 -69,-45 -70.5,-45 -72,-45 -73.5,-45 -75,-48 -75,-51 -75,-54 -75,-57 -75,-60 -75,-63 -75,-66 -75,-69 -75,-72 -75,-75 -75,-75 -73.5,-75 -72,-75 -70.5,-75 -69,-75 -67.5,-75 -66,-75 -64.5,-75 -63,-75 -61.5,-75 -60))", "dataset_titles": "Linear Theory of Orographic Precipitation QGIS Plugin; Parallel Ice Sheet Model (PISM) v2", "datasets": [{"dataset_uid": "601589", "doi": "10.15784/601589", "keywords": "Antarctica", "people": "Aschwanden, Andy", "repository": "USAP-DC", "science_program": null, "title": "Parallel Ice Sheet Model (PISM) v2", "url": "https://www.usap-dc.org/view/dataset/601589"}, {"dataset_uid": "601590", "doi": "10.15784/601590", "keywords": "Antarctica", "people": "Aschwanden, Andy", "repository": "USAP-DC", "science_program": null, "title": "Linear Theory of Orographic Precipitation QGIS Plugin", "url": "https://www.usap-dc.org/view/dataset/601590"}], "date_created": "Thu, 14 Jul 2022 00:00:00 GMT", "description": "Aschwanden/1644277 This award supports a project to study the phenomenon of the rain shadow (technically called orographic precipitation) in the Antarctic Peninsula and its interaction with a mountain range covered in ice and snow. Orographic precipitation gives rise to the largest climatic and ecological gradients on Earth. Air ascending on the windward side of the mountain range expands and cools, condensing the water vapor it carries and producing heavy rain- or snow-fall. As the air descends on the leeward flank, the air warms and dries out, leaving little-to-no precipitation. This pattern of snowfall, caused by the interaction of winds and the landscape, is hypothesized to control the shape of the ice cap itself. The investigators hypothesize that feedbacks between precipitation and topography control ice flux and temperature, impacting basal conditions (frozen versus wet) and motion, which over long time scales can affect basal topography via erosion. The authors propose to investigate the feedbacks between orographically driven precipitation, ice dynamics, thermodynamics, and basal erosion and uplift over the northern Antarctic Peninsula by coupling an orographic precipitation model to the Parallel Ice Sheet Model (PISM). Using idealized and more realistic geometries, they will begin with a 2-D flow band model, which will be expanded into three dimensions to determine the strength of the feedbacks as a function of bedrock geometry and the intensity of the orographic precipitation gradient. The Antarctic Peninsula is targeted as the ideal case study, in the context of its rapid modern and future change as well as its deflation since the Last Glacial Maximum. The broader impacts of the work include the strengthening of predictive models by capturing feedbacks related to orographic precipitation not included in current models. This is likely to provide a more realistic assessment of the impacts of orographic precipitation in a regime of changing climate. The project will support an early career scientist and a female mid-career scientist and will support one PhD student, and provide summer research experience for one undergraduate student as an REU supplement. The project does not require field work in the Antarctic.", "east": -45.0, "geometry": "POINT(-60 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Antarctic Ice Sheet", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aschwanden, Andy; Pettit, Erin", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0, "title": "Collaborative Research: Feedbacks between Orographic Precipitation and Ice Dynamics", "uid": "p0010348", "west": -75.0}, {"awards": "2139497 Balco, Gregory", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 21 Jun 2022 00:00:00 GMT", "description": "This project will conduct basic research into geological dating techniques that are useful for determining the age of glacial deposits in polar regions, Antarctica in particular. These techniques are necessary for determining how large the polar ice sheets were in the geologic past, including during past periods of warm climate that likely resemble present and near-future conditions. Thus, they represent an important technical capability needed for estimating the response of polar ice sheets to climate warming. Because changes in the size of polar ice sheets are the largest potential contribution to future global sea-level change, this capability is also relevant to understanding likely sea-level impacts of future climate change. The research in this project comprises several observational and experimental approaches to improving the speed, efficiency, cost, and accuracy of these techniques, as well as a scientific outreach program aimed at making the resulting capabilities more broadly available to other researchers. The project supports a postdoctoral scholar and contributes to human resources development in polar and climate science. The project focuses on several areas of cosmogenic-nuclide geochemistry, which is a geochemical dating method that relies on the production and decay of cosmic-ray-produced radionuclides in surface rocks. Measurements of these nuclides can be used to quantify the duration of surface exposure and ice cover at locations in Antarctica that are covered and uncovered by changes in the size of the Antarctic ice sheets, thus providing a means of reconstructing past ice-sheet change. The first proposed set of experiments are aimed at implementing a \u0027virtual mineral separation\u0027 approach to cosmogenic noble gas analysis that may allow measurement of nuclide concentrations in certain minerals without physically separating the minerals from the host rock. If feasible, this would realize significant speed and cost improvements for this type of analysis. A second set of experiments will focus on means of identifying and quantifying non-cosmogenic background inventories of some relevant nuclides, which is intended to improve the measurement sensitivity and precision for cosmic-ray-produced inventories of these nuclides. A third focus area aims to improve capabilities to measure multiple cosmic-ray-produced nuclides in the same sample, which has the potential to improve the accuracy of dating methods based on these nuclides and to expand the situations in which these methods can be applied. If successful, these experiments are likely to improve a number of applications of cosmogenic-nuclide geochemistry relevant to Antarctic research, including subglacial bedrock exposure dating, dating of multimillion-year-old glacial deposits, and surface-process studies useful in understanding landform evolution and ecosystem dynamics. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "California; LABORATORY; AMD; GEOCHEMISTRY; Amd/Us; USAP-DC; USA/NSF", "locations": "California", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Balco, Gregory", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -90.0, "title": "Targeted Basic Research to Enable Antarctic Science Applications of Cosmogenic-Nuclide Geochemistry", "uid": "p0010343", "west": -180.0}, {"awards": "1744771 Balco, Gregory", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities; 5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "datasets": [{"dataset_uid": "601601", "doi": "10.15784/601601", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Halberstadt, Anna Ruth; Buchband, Hannah; Balco, Gregory", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601601"}, {"dataset_uid": "601602", "doi": "10.15784/601602", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Balco, Gregory; Buchband, Hannah; Halberstadt, Anna Ruth", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601602"}], "date_created": "Tue, 21 Jun 2022 00:00:00 GMT", "description": "The purpose of this project is to use geological data that record past changes in the Antarctic ice sheets to test computer models for ice sheet change. The geologic data mainly consist of dated glacial deposits that are preserved above the level of the present ice sheet, and range in age from thousands to millions of years old. These provide information about the size, thickness, and rate of change of the ice sheets during past times when the ice sheets were larger than present. In addition, some of these data are from below the present ice surface and therefore also provide some information about past warm periods when ice sheets were most likely smaller than present. The primary purpose of the computer model is to predict future ice sheet changes, but because significant changes in the size of ice sheets are slow and likely occur over hundreds of years or longer, the only way to determine whether these models are accurate is to test their ability to reproduce past ice sheet changes. The primary purpose of this project is to carry out such a test. The research team will compile relevant geologic data, in some cases generate new data by dating additional deposits, and develop methods and software to compare data to model simulations. In addition, this project will (i) contribute to building and sustaining U.S. science capacity through postdoctoral training in geochronology, ice sheet modeling, and data science, and (ii) improve public access to geologic data and model simulations relevant to ice sheet change through online database and website development. Technical aspects of this project are primarily focused on the field of cosmogenic-nuclide exposure-dating, which is a method that relies on the production of rare stable and radio-nuclides by cosmic-ray interactions with rocks and minerals exposed at the Earth\u0027s surface. Because the advance and retreat of ice sheets results in alternating cosmic-ray exposure and shielding of underlying bedrock and surficial deposits, this technique is commonly used to date and reconstruct past ice sheet changes. First, this project will contribute to compiling and systematizing a large amount of cosmogenic-nuclide exposure age data collected in Antarctica during the past three decades. Second, it will generate additional geochemical data needed to improve the extent and usefulness of measurements of stable cosmogenic nuclides, cosmogenic neon-21 in particular, that are useful for constraining ice-sheet behavior on million-year timescales. Third, it will develop a computational framework for comparison of the geologic data set with existing numerical model simulations of Antarctic ice sheet change during the past several million years, with particular emphasis on model simulations of past warm periods, for example the middle Pliocene ca. 3-3.3 million years ago, during which the Antarctic ice sheets are hypothesized to have been substantially smaller than present. Fourth, guided by the results of this comparison, it will generate new model simulations aimed at improving agreement between model simulations and geologic data, as well as diagnosing which processes or parameterizations in the models are or are not well constrained by the data. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "BERYLLIUM-10 ANALYSIS; AMD; ICE SHEETS; GLACIATION; Amd/Us; LABORATORY; USA/NSF; Antarctica; ALUMINUM-26 ANALYSIS; USAP-DC", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Balco, Gregory", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Synoptic Evaluation of Long-Term Antarctic Ice Sheet Model Simulations using a Continent-Wide Database of Cosmogenic-Nuclide Measurements", "uid": "p0010342", "west": -180.0}, {"awards": "1643669 Petrenko, Vasilii; 1643664 Severinghaus, Jeffrey; 1643716 Buizert, Christo", "bounds_geometry": "POLYGON((112 -66,112.2 -66,112.4 -66,112.6 -66,112.8 -66,113 -66,113.2 -66,113.4 -66,113.6 -66,113.8 -66,114 -66,114 -66.1,114 -66.2,114 -66.3,114 -66.4,114 -66.5,114 -66.6,114 -66.7,114 -66.8,114 -66.9,114 -67,113.8 -67,113.6 -67,113.4 -67,113.2 -67,113 -67,112.8 -67,112.6 -67,112.4 -67,112.2 -67,112 -67,112 -66.9,112 -66.8,112 -66.7,112 -66.6,112 -66.5,112 -66.4,112 -66.3,112 -66.2,112 -66.1,112 -66))", "dataset_titles": "Concentration and isotopic composition of atmospheric N2O over the last century; Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2; Law Dome DE08-OH site noble gases in ice: testing the 86Krexcess proxy; Law Dome firn air and ice core 14CO concentration", "datasets": [{"dataset_uid": "601597", "doi": "10.15784/601597", "keywords": "Antarctica; Ice Core; Law Dome; Noble Gas", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Law Dome DE08-OH site noble gases in ice: testing the 86Krexcess proxy", "url": "https://www.usap-dc.org/view/dataset/601597"}, {"dataset_uid": "601598", "doi": "10.15784/601598", "keywords": "Antarctica; Firn; Firn Density; Gravitational Settling; Inert Gases; Law Dome", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2", "url": "https://www.usap-dc.org/view/dataset/601598"}, {"dataset_uid": "601693", "doi": "10.15784/601693", "keywords": "Antarctic; Antarctica; Anthropogenic Emission; Atmosphere; Greenhouse Gas; Greenland; Ice Core Data; Nitrification And Denitrification Processes; Nitrous Oxide; Site-Specific 15N Isotopomer; Styx Glacier", "people": "Yoshida, Naohiro ; Etheridge, David; Ghosh, Sambit; Toyoda, Sakae ; Buizert, Christo ; Ahn, Jinho ; Joong Kim, Seong; Langenfelds, Ray L ", "repository": "USAP-DC", "science_program": null, "title": "Concentration and isotopic composition of atmospheric N2O over the last century", "url": "https://www.usap-dc.org/view/dataset/601693"}, {"dataset_uid": "601846", "doi": "10.15784/601846", "keywords": "Antarctica; Carbon-14; Cryosphere; Firn Air; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Law Dome; Snow/ice; Snow/Ice", "people": "Petrenko, Vasilii", "repository": "USAP-DC", "science_program": null, "title": "Law Dome firn air and ice core 14CO concentration", "url": "https://www.usap-dc.org/view/dataset/601846"}], "date_created": "Fri, 17 Jun 2022 00:00:00 GMT", "description": "Hydroxyl radicals are responsible for removal of most atmospheric trace gases, including pollutants and important greenhouse gases. They have been called the \"detergent of the atmosphere\". Changes in hydroxyl radical concentration in response to large changes in reactive trace gas emissions, which may happen in the future, are uncertain. This project aims to provide the first estimates of the variability of atmospheric hydroxyl radicals since about 1880 AD when anthropogenic emissions of reactive trace gases were minimal. This will improve understanding of their stability in response to large changes in emissions. The project will also investigate whether ice cores record past changes in Southern Hemisphere westerly winds. These winds are a key component of the global climate system, and have an important influence on ocean circulation and possibly on atmospheric carbon dioxide concentrations. The project team will include three early career scientists, a postdoctoral researcher, and graduate and undergraduate students, working in collaboration with senior scientists and Australian collaborators. Firn air and shallow ice to a depth of about 233 m will be sampled at the Law Dome high-accumulation coastal site in East Antarctica. Trapped air will be extracted from the ice cores on site immediately after drilling. Carbon-14 of carbon monoxide (14CO) will be analyzed in firn and ice-core air samples. Corrections will be made for the in situ cosmogenic 14CO component in the ice, allowing for the atmospheric 14CO history to be reconstructed. This 14CO history will be interpreted with the aid of a chemistry-transport model to place the first observational constraints on the variability of Southern Hemisphere hydroxyl radical concentration after about 1880 AD. An additional component of the project will analyze Krypton-86 in the firn-air and ice-core samples. These measurements will explore whether ice-core Krypton-86 acts as a proxy for barometric pressure variability, and whether this proxy can be used in Antarctic ice cores to infer past movement of the Southern Hemisphere westerly winds. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 114.0, "geometry": "POINT(113 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; TRACE GASES/TRACE SPECIES; Law Dome; Amd/Us; USAP-DC; LABORATORY; ICE CORE AIR BUBBLES; USA/NSF", "locations": "Law Dome", "north": -66.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Petrenko, Vasilii; Murray, Lee T; Buizert, Christo; Petrenko, Vasilii; Murray, Lee T", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.0, "title": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability", "uid": "p0010341", "west": 112.0}, {"awards": "2201129 Fischer, Karen", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Crustal thicknesses in Antarctica from Sp receiver functions; Lithospheric thicknesses in Antarctica from Sp receiver functions", "datasets": [{"dataset_uid": "601899", "doi": "10.15784/601899", "keywords": "Antarctica; Cryosphere; LAB; Lithosphere; Lithospheric Thickness", "people": "Fischer, Karen; Brown, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Lithospheric thicknesses in Antarctica from Sp receiver functions", "url": "https://www.usap-dc.org/view/dataset/601899"}, {"dataset_uid": "601898", "doi": "10.15784/601898", "keywords": "Antarctica; Crust; Cryosphere; Moho", "people": "Fischer, Karen; Brown, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Crustal thicknesses in Antarctica from Sp receiver functions", "url": "https://www.usap-dc.org/view/dataset/601898"}], "date_created": "Tue, 14 Jun 2022 00:00:00 GMT", "description": "The western portion of the Antarctic continent is very active in terms of plate tectonic processes that can produce significant variations in the Earths mantle temperature as well as partial melting of the mantle. In addition to these internal processes, the ice sheet in western Antarctica is melting due to Earths warming climate and adding water to the ocean. These changes in ice mass cause adjustments in rocks within the Earth\u0027s crust, allowing the surface to rebound in some locations and fall in others, altering the geographical pattern of sea-level change. However, the solid Earth response depends strongly on the strength of the rocks at a wide range of timescales which is not well-known and varies with temperature and other rock properties. This project has three primary goals. (1) It will assess how processes such as rifting, mantle upwelling and lithospheric instability have altered the lithosphere and underlying asthenosphere of western Antarctica, contributing to a planet-wide understanding of these processes. (2) It will use new measurements of mantle and crust properties to estimate the rate at which heat from the solid Earth flows into the base of the ice, which is important for modeling the rates at which the ice melts and flows. (3) It will places bounds on mantle viscosity, which is key for modeling the interaction of the solid Earth with changing ice and water masses and their implications for sea-level rise. To accomplish these goals, new resolution of crust and mantle structure will be obtained by analyzing seismic waves from distant earthquakes that have been recorded at numerous seismic stations in Antarctica. These analyses will include new combinations of seismic wave data that provide complementary information about mantle temperature, heat flow and viscosity. This project will provide educational and career opportunities to a Brown University graduate student, undergraduates from groups underrepresented in science who will come to Brown University for a summer research program, and other undergraduates. The project will bring together faculty and students for a seminar at Brown that explores the connections between the solid Earth and ice processes in Antarctica. Project research will be incorporated in outreach to local public elementary schools and high schools. This research addresses key questions about mantle processes and properties in western Antarctica. What are the relative impacts of rifting, mantle plumes, and lithospheric delamination in the evolution of the lithosphere and asthenosphere? Where is topography isostatically compensated, and where are dynamic processes such as plate flexure or tractions from 3-D mantle flow required? What are the bounds on heat flow and mantle viscosity, which represent important inputs to models of ice sheet evolution and its feedback from the solid Earth? To address these questions, this project will measure mantle and crust properties using seismic tools that have not yet been applied in Antarctica: regional-scale measurement of mantle attenuation from surface waves; Sp body wave phases to image mantle velocity gradients such as the lithosphere-asthenosphere boundary; and surface wave amplification and ellipticity. The resulting models of seismic attenuation and velocity will be jointly interpreted to shed new light on temperature, bulk composition, volatile content, and partial melt, using a range of laboratory-derived constitutive laws, while considering data from mantle xenoliths. To test the relative roles of rifting, mantle plumes, and delamination, and to assess isostatic support for Antarctic topography, the predictions of these processes will be compared to the new models of crust and mantle properties. To improve bounds on western Antarctic heat flow, seismic attenuation and velocity will be used in empirical comparisons and in direct modeling of vertical temperature gradients. To better measure mantle viscosity at the timescales of glacial isostatic adjustment, frequency-dependent viscosity will be estimated from the inferred mantle conditions. This project will contribute to the education and career development of the following: a Brown University Ph.D. student, Brown undergraduates, and undergraduates from outside the university will be involved through the Department of Earth, Environmental and Planetary Sciences (DEEPS) Leadership Alliance NSF Research Experience for Undergraduates (REU) Site which focuses on geoscience summer research experiences for underrepresented students. The project will be the basis for a seminar at Brown that explores the connections between the solid Earth and cryosphere in Antarctica and will contribute to outreach in local public elementary and high schools. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; West Antarctica; USA/NSF; SEISMIC SURFACE WAVES; AMD; PLATE TECTONICS; Amd/Us; GLACIERS/ICE SHEETS; FIELD INVESTIGATION", "locations": "West Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Fischer, Karen; Dalton, Colleen", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity", "uid": "p0010339", "west": -180.0}, {"awards": "1947558 Leckie, Robert; 1947657 Dodd, Justin; 1947646 Shevenell, Amelia", "bounds_geometry": "POLYGON((-180 -72.5,-177.6 -72.5,-175.2 -72.5,-172.8 -72.5,-170.4 -72.5,-168 -72.5,-165.6 -72.5,-163.2 -72.5,-160.8 -72.5,-158.4 -72.5,-156 -72.5,-156 -73.15,-156 -73.8,-156 -74.45,-156 -75.1,-156 -75.75,-156 -76.4,-156 -77.05,-156 -77.7,-156 -78.35,-156 -79,-158.4 -79,-160.8 -79,-163.2 -79,-165.6 -79,-168 -79,-170.4 -79,-172.8 -79,-175.2 -79,-177.6 -79,180 -79,178.4 -79,176.8 -79,175.2 -79,173.6 -79,172 -79,170.4 -79,168.8 -79,167.2 -79,165.6 -79,164 -79,164 -78.35,164 -77.7,164 -77.05,164 -76.4,164 -75.75,164 -75.1,164 -74.45,164 -73.8,164 -73.15,164 -72.5,165.6 -72.5,167.2 -72.5,168.8 -72.5,170.4 -72.5,172 -72.5,173.6 -72.5,175.2 -72.5,176.8 -72.5,178.4 -72.5,-180 -72.5))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 08 Jun 2022 00:00:00 GMT", "description": "Nontechnical abstract Presently, Antarctica\u2019s glaciers are melting as Earth\u2019s atmosphere and the Southern Ocean warm. Not much is known about how Antarctica\u2019s ice sheets might respond to ongoing and future warming, but such knowledge is important because Antarctica\u2019s ice sheets might raise global sea levels significantly with continued melting. Over time, mud accumulates on the sea floor around Antarctica that is composed of the skeletons and debris of microscopic marine organisms and sediment from the adjacent continent. As this mud is deposited, it creates a record of past environmental and ecological changes, including ocean depth, glacier advance and retreat, ocean temperature, ocean circulation, marine ecosystems, ocean chemistry, and continental weathering. Scientists interested in understanding how Antarctica\u2019s glaciers and ice sheets might respond to ongoing warming can use a variety of physical, biological, and chemical analyses of these mud archives to determine how long ago the mud was deposited and how the ice sheets, oceans, and marine ecosystems responded during intervals in the past when Earth\u2019s climate was warmer. In this project, researchers from the University of South Florida, University of Massachusetts, and Northern Illinois University will reconstruct the depth, ocean temperature, weathering and nutrient input, and marine ecosystems in the central Ross Sea from ~17 to 13 million years ago, when the warm Miocene Climate Optimum transitioned to a cooler interval with more extensive ice sheets. Record will be generated from new sediments recovered during the International Ocean Discovery Program (IODP) Expedition 374 and legacy sequences recovered in the 1970\u2019s during the Deep Sea Drilling Program. Results will be integrated into ice sheet and climate models to improve the accuracy of predictions. The research provides experience for three graduate students and seven undergraduate students via a multi-institutional REU program focused on increasing diversity in Antarctic Earth Sciences. Technical Abstract Deep-sea sediments reveal that the Miocene Climatic Optimum (MCO) was the warmest climate interval of the last ~20 Ma, was associated with global carbon cycle changes and ice growth, and immediately preceded the Middle Miocene Climate Transition (MMCT; ~14 Ma), one of three major intervals of Antarctic ice expansion and global cooling. Ice-proximal studies are required to assess: where and when ice grew, ice sheet extent, continental shelf geometry, high-latitude heat and moisture supply, oceanic and/or atmospheric temperature influence on ice dynamics, regional sea ice extent, meltwater input, and regions of bottom water formation. Existing studies indicate that ice expanded beyond the Transantarctic Mountains and onto the prograding Ross Sea continental shelf multiple times between ~17 and 13.5 Ma. However, these records are either too ice-proximal/terrestrial to adequately assess ocean-ice interactions or under-studied. To address this data gap, this work will: 1) generate micropaleontologic and geochemical records of oceanic and atmospheric temperature, water depth, ocean circulation, and paleoproductivity from existing Ross Sea marine sedimentary sequences, and 2) use these proxy records to test the hypothesis that dynamic glacial expansion in the Ross Sea sector during the MCO was driven by heat and moisture transport to the high latitudes during an interval of enhanced climate sensitivity. Downcore geochemical and micropaleontologic studies will focus on an expanded (120 m/my) early to middle Miocene (~17-16 Ma) diatom-bearing/rich mudstone/diatomite unit from IODP Site U1521, drilled on the Ross Sea continental shelf. A hiatus (~16-14.6 Ma) suggests ice expansion during the MCO, followed by diamictite to mudstone unit indicative of slight retreat (14.6 -14 Ma) immediately preceding the MMCT. Data from Site U1521 will be integrated with foraminiferal geochemical and micropaleontologic data from DSDP Leg 28 (1972/73) and RISP J-9 (1978-79) to develop a MCO to late Miocene regional view of ocean-ice sheet interactions using legacy core material previously processed for foraminifera. This integrated record will: 1) document the timing and extent of glacial advances and retreats across the prograding Ross Sea shelf during the middle and late Miocene, 2) provide orbital-scale paleotemperature reconstructions (TEX86, Mg/Ca, \u03b418O, MBT/CBT) to establish atmosphere-ocean-ice interactions during an extreme high-latitude warm interval, and 3) provide orbital-scale nutrient/paleoproductivity, ocean circulation, and paleoenvironmental data required to assess climate feedbacks associated with Miocene Antarctic ice sheet and global climate system development. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -156.0, "geometry": "POINT(-176 -75.75)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; LABORATORY; AMD; PALEOCLIMATE RECONSTRUCTIONS; Ross Sea; USAP-DC; USA/NSF", "locations": "Ross Sea", "north": -72.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -79.0, "title": "Collaborative Proposal: Miocene Climate Extremes: A Ross Sea Perspective from IODP Expedition 374 and DSDP Leg 28 Marine Sediments", "uid": "p0010335", "west": 164.0}, {"awards": "2203487 Ben Mansour, Walid", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 06 Jun 2022 00:00:00 GMT", "description": "Non-Technical abstract The physical state of the mantle beneath the Antarctic Ice Sheet plays a key role in the interaction between the Antarctic ice cover and the solid earth, strongly influencing the glacial system\u0027s evolution. Generally, mantle temperature profiles are determined by analyzing rock samples from the mantle to determine pressure-temperature conditions, and/or by conversion of seismic velocity anomalies to temperature anomalies. However, mantle rocks have been found only in a very few places in Antarctica, and seismic anomalies reflect not only thermal anomalies but also compositional variations. In this project, the investigators will (1) use the most recent geophysical datasets sensitive to temperature and composition (high-resolution seismic velocity model, topography, satellite gravity), (2) Combine the sensitivity of these datasets in a to retrieve the most reliable model of thermal and compositional structure, (3) translate the results into 2-dimensional maps of temperature slices and the composition of iron in the mantle,(4) compare the results with results from other continents to better understand Antarctic geological history, and (5) use the new thermal model along with established rock relationships to estimate mantle viscosity. Technical abstract The thermochemical structure of the lithosphere beneath Antarctica is fundamental for understanding the geological evolution of the continent and its relationship to surrounding Gondwana continents. In addition, the thermal structure controls the solid earth response to glacial unloading, with important implications for ice sheet models and the future of the West Antarctic Ice Sheet. However, it is challenging to get an accurate picture of temperature and composition from only sparse petrological/geochemical analysis, and most previous attempts to solve this problem geophysically have relied on seismic or gravity data alone. Here, we propose to use a probabilistic joint inversion (high resolution regional seismic data, satellite gravity data, topography) and petrological modelling approach to determine the 3D thermochemical structure of the mantle. The inversion will be carried out using a Markov-chain Bayesian Monte Carlo methodology, providing quantitative estimates of uncertainties. Mapping the 3-dimensional thermochemical structure (thermal and composition) will provide a comprehensive view of the horizontal (50-100 km resolution) and vertical (from the surface down to 380 km) variations. This new model will give us the temperature variation from the surface down to 380 km and the degree of depletion of the lithospheric mantle and the sub-lithospheric mantle. This new model will also be compared to recent models of Gondwana terranes 200 Myrs to build a new model of the thermochemical evolution of the cratonic mantle. The new thermal and chemical structures can be used to better understand the geothermal heat flux beneath the ice sheet as well as improve glacial isostatic adjustment and ice sheet models. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; GRAVITY FIELD; AMD; COMPUTERS; GEOCHEMISTRY; PLATE BOUNDARIES; Amd/Us; SEISMIC SURFACE WAVES; USA/NSF; USAP-DC", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Ben-Mansour, Walid; Wiens, Douglas", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Thermal and Compositional Structure of Antarctica from Probabilistic Joint Inversion of Seismic, Gravity, and Topography Data and Petrological Modelling", "uid": "p0010334", "west": -180.0}, {"awards": "2019719 Brook, Edward", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "2019-2020 Allan Hills Field Report; 2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report; 2023-2024 Allan Hills End-of-Season Science Report; Airborne Radar Data: 2022-23 (CXA1) flight based HDF5/matlab format data; Airborne Radar Data: 2022-23 (CXA1) transect based (science organized) unfocused data; Airborne Radar Data: 2023-24 (CXA2) flight based data HDF5/matlab format; Airborne Radar Data: 2023-24 (CXA2) transect based (science organized) unfocused data; ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations; Allan Hills 2022-23 Shallow Ice Core Field Report; Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022; Allan Hills I-188 Field Season Report 2022-2023; Allan Hills ice water stable isotope record for dD, d18O; Basal Ice Unit Thickness Mapped by the NSF COLDEX MARFA Ice Penetrating Radar; CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903; COLDEX VHF MARFA Open Polar Radar radargrams; Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area; Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903; I-165-M GPR Field Report 2019-2020; MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903; NSF COLDEX 2022-23 Level 2 Basal Specularity Content Profiles; NSF COLDEX 2022-23 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets; NSF COLDEX 2023-24 Level 2 Basal Specularity Content Profiles; NSF COLDEX 2023-24 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets; NSF COLDEX Ice Penetrating Radar Derived Grids of the Southern Flank of Dome C; NSF COLDEX/Open Polar Radar Example Delay Doppler Classification of Englacial Reflectors; NSF COLDEX Raw MARFA Ice Penetrating Radar data; Oxygen and hydrogen isotope compositions and associated d-excess of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area; Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area; Replicate O-17-excess by continuous flow laser spectroscopy for an ice core section at Summit, Greenland; Rising Seas: Representations of Antarctica, Climate Change, and Sea Level Rise in U.S. Newspaper Coverage; Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old; Social network analysis to understand participant engagement in transdisciplinary team science: a large U.S. science and technology center case study; Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "datasets": [{"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Kurbatov, Andrei V.; Mayewski, Paul A.; Brook, Edward; Introne, Douglas; Higgins, John; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "601896", "doi": "10.15784/601896", "keywords": "Allan Hills; Antarctica; Ch4; CO2; Cryosphere; Glaciology; Glaciology; Ice Core Data; Ice Core Records", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601896"}, {"dataset_uid": "601897", "doi": "10.15784/601897", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciology; Ice Core Data; MOT; Ocean Temperature; Paleoclimate; Xe/Kr", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601897"}, {"dataset_uid": "601878", "doi": "10.15784/601878", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Cryosphere; Methane", "people": "Shackleton, Sarah; Marks Peterson, Julia; Brook, Edward; Kalk, Michael; Severinghaus, Jeffrey P.; Hishamunda, Valens", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old", "url": "https://www.usap-dc.org/view/dataset/601878"}, {"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Higgins, John; Severinghaus, Jeffrey P.; Introne, Douglas; Mayewski, Paul A.; Brook, Edward; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "601912", "doi": "10.15784/601912", "keywords": "Antarctica; Coldex; Cryosphere; East Antarctica; East Antarctic Plateau; Glaciology; Radar Echo Sounder", "people": "Singh, Shivangini; Vega Gonzalez, Alejandra; Young, Duncan A.; Yan, Shuai; Blankenship, Donald D.; Kerr, Megan", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Basal Ice Unit Thickness Mapped by the NSF COLDEX MARFA Ice Penetrating Radar", "url": "https://www.usap-dc.org/view/dataset/601912"}, {"dataset_uid": "601697", "doi": "10.15784/601697", "keywords": "Allan Hills; Antarctica; Apres; Ice Core; Ice Penetrating Radar; Temperature Profiles", "people": "Brook, Edward J.; Conway, Howard", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report", "url": "https://www.usap-dc.org/view/dataset/601697"}, {"dataset_uid": "601854", "doi": "10.15784/601854", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Shackleton, Sarah; Kirkpatrick, Liam; Carter, Austin; Fudge, T. J.; Marks Peterson, Julia", "repository": "USAP-DC", "science_program": "COLDEX", "title": "ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations", "url": "https://www.usap-dc.org/view/dataset/601854"}, {"dataset_uid": "200419", "doi": "", "keywords": null, "people": null, "repository": "University Digital Conservancy", "science_program": null, "title": "Rising Seas: Representations of Antarctica, Climate Change, and Sea Level Rise in U.S. Newspaper Coverage", "url": "https://hdl.handle.net/11299/265195"}, {"dataset_uid": "200420", "doi": "10.18738/T8/J38CO5", "keywords": null, "people": null, "repository": "OPR", "science_program": null, "title": "Airborne Radar Data: 2022-23 (CXA1) flight based HDF5/matlab format data", "url": "https://data.cresis.ku.edu/data/rds/2022_Antarctica_BaslerMKB/"}, {"dataset_uid": "200421", "doi": "10.18738/T8/J38CO5", "keywords": null, "people": null, "repository": "OPR", "science_program": null, "title": "Airborne Radar Data: 2023-24 (CXA2) flight based data HDF5/matlab format", "url": "https://data.cresis.ku.edu/data/rds/2023_Antarctica_BaslerMKB/"}, {"dataset_uid": "601826", "doi": "10.15784/601826", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Manos, John-Morgan; Epifanio, Jenna; Conway, Howard; Shaya, Margot; Horlings, Annika", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills I-188 Field Season Report 2022-2023", "url": "https://www.usap-dc.org/view/dataset/601826"}, {"dataset_uid": "601824", "doi": "10.15784/601824", "keywords": "Allan Hills; Antarctica; Coldex; Cryosphere", "people": "Epifanio, Jenna; Marks Peterson, Julia; Higgins, John; Brook, Edward J.; Shackleton, Sarah; Carter, Austin; Manos, John-Morgan; Hudak, Abigail; Banerjee, Asmita; Morton, Elizabeth; Jayred, Michael; Goverman, Ashley; Mayo, Emalia", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2023-2024 Allan Hills End-of-Season Science Report", "url": "https://www.usap-dc.org/view/dataset/601824"}, {"dataset_uid": "601819", "doi": "10.15784/601819", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Nesbitt, Ian; Carter, Austin; Higgins, John; Shackleton, Sarah; Morgan, Jacob; Epifanio, Jenna; Kuhl, Tanner; Morton, Elizabeth; Zajicek, Anna", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2019-2020 Allan Hills Field Report", "url": "https://www.usap-dc.org/view/dataset/601819"}, {"dataset_uid": "200432", "doi": "10.18738/T8/XPMLCC", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "Airborne Radar Data: 2022-23 (CXA1) transect based (science organized) unfocused data", "url": "https://dataverse.tdl.org/dataset.xhtml?persistentId=doi:10.18738/T8/XPMLCC"}, {"dataset_uid": "200433", "doi": "10.18738/T8/FV6VNT", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "Airborne Radar Data: 2023-24 (CXA2) transect based (science organized) unfocused data", "url": "https://dataverse.tdl.org/dataset.xhtml?persistentId=doi:10.18738/T8/FV6VNT"}, {"dataset_uid": "200434", "doi": "10.18738/T8/99IEOG", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2022-23 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets", "url": "https://doi.org/10.18738/T8/99IEOG"}, {"dataset_uid": "200435", "doi": "10.18738/T8/PNBFOL", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2023-24 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets", "url": "https://doi.org/10.18738/T8/PNBFOL"}, {"dataset_uid": "601768", "doi": "10.15784/601768", "keywords": "Antarctica; Coldex; East Antarctic Plateau; Glaciology; Radar Echo Sounder", "people": "Ng, Gregory; Kempf, Scott D.; Chan, Kristian; Kerr, Megan; Greenbaum, Jamin; Blankenship, Donald D.; Young, Duncan A.; Buhl, Dillon", "repository": "USAP-DC", "science_program": "COLDEX", "title": "NSF COLDEX Raw MARFA Ice Penetrating Radar data", "url": "https://www.usap-dc.org/view/dataset/601768"}, {"dataset_uid": "200452", "doi": "https://hdl.handle.net/11299/270020", "keywords": null, "people": null, "repository": "UMN University Digital Conservancy", "science_program": null, "title": "Social network analysis to understand participant engagement in transdisciplinary team science: a large U.S. science and technology center case study", "url": "https://hdl.handle.net/11299/270020"}, {"dataset_uid": "200470", "doi": "doi:10.15784/601822", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "Oxygen and hydrogen isotope compositions and associated d-excess of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601822"}, {"dataset_uid": "200469", "doi": "https://doi.org/10.15784/601821", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601821"}, {"dataset_uid": "601620", "doi": "10.15784/601620", "keywords": "18O; Allan Hills; Allan Hills Blue Ice; Antarctica; Blue Ice; Delta 15N; Delta 18O; Dole Effect; Firn Thickness; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chronology; Ice Core Records", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022", "url": "https://www.usap-dc.org/view/dataset/601620"}, {"dataset_uid": "601696", "doi": "10.15784/601696", "keywords": "Allan Hills; Antarctica; Ice Core", "people": "Brook, Edward J.; Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills 2022-23 Shallow Ice Core Field Report", "url": "https://www.usap-dc.org/view/dataset/601696"}, {"dataset_uid": "601669", "doi": "10.15784/601669", "keywords": "Allan Hills; Antarctica; GPR; Ice Core; Report", "people": "Nesbitt, Ian; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "I-165-M GPR Field Report 2019-2020", "url": "https://www.usap-dc.org/view/dataset/601669"}, {"dataset_uid": "200468", "doi": "https://doi.org/10.15784/601820", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601820"}, {"dataset_uid": "601895", "doi": "10.15784/601895", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Noble Gas", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601895"}, {"dataset_uid": "200461", "doi": "10.18738/T8/6T5JS6", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2022-23 Level 2 Basal Specularity Content Profiles", "url": "https://doi.org/10.18738/T8/6T5JS6"}, {"dataset_uid": "200467", "doi": "doi:10.15784/601825", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601825"}, {"dataset_uid": "601659", "doi": "10.15784/601659", "keywords": "Antarctica; Continuous Flow; Glaciology; Greenland; Ice Core Data; Laser Spectroscopy; Oxygen Isotope; Triple Oxygen Isotopes", "people": "Davidge, Lindsey", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Replicate O-17-excess by continuous flow laser spectroscopy for an ice core section at Summit, Greenland", "url": "https://www.usap-dc.org/view/dataset/601659"}, {"dataset_uid": "200465", "doi": "10.18738/T8/DM10IG", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "COLDEX VHF MARFA Open Polar Radar radargrams", "url": "https://doi.org/10.18738/T8/DM10IG"}, {"dataset_uid": "200464", "doi": "10.18738/T8/DM10IG", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX/Open Polar Radar Example Delay Doppler Classification of Englacial Reflectors", "url": "https://doi.org/10.18738/T8/DM10IG"}, {"dataset_uid": "200463", "doi": "10.18738/T8/M77ANK", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX Ice Penetrating Radar Derived Grids of the Southern Flank of Dome C", "url": "https://doi.org/10.18738/T8/M77ANK"}, {"dataset_uid": "200462", "doi": "10.18738/T8/KHUT1U", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2023-24 Level 2 Basal Specularity Content Profiles", "url": "https://doi.org/10.18738/T8/KHUT1U"}], "date_created": "Sat, 21 May 2022 00:00:00 GMT", "description": "Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth\u2019s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth\u2019s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community. Knowledge of Earth\u2019s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth\u2019s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; Antarctica; Amd/Us; Coldex; USAP-DC; FIELD SURVEYS; ICE DEPTH/THICKNESS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Polar Special Initiatives; Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.; Neff, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "OPR; Texas Data Repository; UMN University Digital Conservancy; University Digital Conservancy; USAP-DC", "science_programs": "COLDEX", "south": -90.0, "title": "Center for Oldest Ice Exploration", "uid": "p0010321", "west": -180.0}, {"awards": "1744856 Bromirski, Peter; 1246151 Bromirski, Peter; 1744958 Wei, Yong; 1744759 Dunham, Eric", "bounds_geometry": null, "dataset_titles": "Data for: Ocean Surface Gravity Wave Excitation of Flexural Gravity and Extensional Lamb Waves in Ice Shelves; Datasets for Model Simulations of Tsunami Propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves (Thwaites); Datasets of bathymetric model grids for model simulations of tsunami Propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves; Model simulation data of tsunami propagation in the Pacific Ocean; Model simulations of tsunami propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves (Ross Sea); Model Tsunami Propagation Simulation From Circum-Pacific Subduction Zones to West Antarctic Ice Shelves; Simulation of flexural-gravity wave response of Antarctic ice shelves to tsunami and infragravity waves", "datasets": [{"dataset_uid": "601561", "doi": "10.15784/601561", "keywords": "Amundsen Sea; Antarctica; Glaciology", "people": "Tazhimbetov, Nurbek; Dunham, Eric; Almquist, Martin", "repository": "USAP-DC", "science_program": null, "title": "Simulation of flexural-gravity wave response of Antarctic ice shelves to tsunami and infragravity waves", "url": "https://www.usap-dc.org/view/dataset/601561"}, {"dataset_uid": "601924", "doi": "10.15784/601924", "keywords": "Antarctica; Cryosphere; Model Simulation; Pacific Ocean; Subduction Zone Earthquakes; Tsunami; Tsunami impact; West Antarctica Ice Shelf", "people": "Wei, Yong", "repository": "USAP-DC", "science_program": null, "title": "Datasets of bathymetric model grids for model simulations of tsunami Propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves", "url": "https://www.usap-dc.org/view/dataset/601924"}, {"dataset_uid": "200323", "doi": "10.25740/qy001dt7463", "keywords": null, "people": null, "repository": "Stanford Digital Repository", "science_program": null, "title": "Data for: Ocean Surface Gravity Wave Excitation of Flexural Gravity and Extensional Lamb Waves in Ice Shelves", "url": "https://doi.org/10.25740/qy001dt7463"}, {"dataset_uid": "601923", "doi": "10.15784/601923", "keywords": "Antarctica; Cryosphere; Model Simulation; Ross Sea Ice Shelf; Thwaites Region; Tsunami; Tsunami impact; West Antarctica Ice Shelf", "people": "Wei, Yong", "repository": "USAP-DC", "science_program": null, "title": "Datasets for Model Simulations of Tsunami Propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves (Thwaites)", "url": "https://www.usap-dc.org/view/dataset/601923"}, {"dataset_uid": "601922", "doi": "10.15784/601922", "keywords": "Antarctica; Cryosphere; Model Simulation; Ross Ice Shelf; Ross Sea Ice Shelf; Subduction Zone Earthquakes; Tsunami; Tsunami impact; West Antarctica Ice Shelf", "people": "Wei, Yong", "repository": "USAP-DC", "science_program": null, "title": "Model simulations of tsunami propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves (Ross Sea)", "url": "https://www.usap-dc.org/view/dataset/601922"}, {"dataset_uid": "200424", "doi": "N/A", "keywords": null, "people": null, "repository": "NOAA Center for Tsunami Research (NCTR)", "science_program": null, "title": "Model Tsunami Propagation Simulation From Circum-Pacific Subduction Zones to West Antarctic Ice Shelves", "url": " https://nctr.pmel.noaa.gov/antarctica/ "}, {"dataset_uid": "601921", "doi": "10.15784/601921", "keywords": "Antarctica; Cryosphere; Model Output; Model Simulation; Pacific Ocean; Subduction Zone Earthquakes; Tsunami; Tsunami impact; West Antarctic Ice Sheet", "people": "Wei, Yong", "repository": "USAP-DC", "science_program": null, "title": "Model simulation data of tsunami propagation in the Pacific Ocean", "url": "https://www.usap-dc.org/view/dataset/601921"}], "date_created": "Mon, 16 May 2022 00:00:00 GMT", "description": "Understanding and being able to more reliably forecast ice mass loss from Antarctica is a critical research priority for Antarctic Science. Massive ice shelves buttress marine terminating glaciers, slowing the rate that land ice reaches the sea and, in turn, restraining the rate of sea level rise. To date, most work has focused on the destabilizing impacts of warmer air and water temperatures, resulting in melting that thins and weakens ice shelves. However, recent findings indicate that sea ice does not protect ice shelves from wave impacts as much as previously thought, which has raised the possibility that tsunamis and other ocean waves could affect shelf stability. This project will assess the potential for increased shelf fracturing from the impact of tsunamis and from heightened wave activity due to climate-driven changes in storm patterns and reduced sea-ice extent by developing models to investigate how wave impacts damage ice shelves. The modeling effort will allow for regional comparisons between large and small ice shelves, and provide an evaluation of the impacts of changing climate and storm patterns on ice shelves, ice sheets, glaciers, and, ultimately, sea level rise. This project will train graduate students in mathematical modeling and interdisciplinary approaches to Earth and ocean sciences. This project takes a four-pronged approach to estimating the impact of vibrations on ice shelves at the grounding zone due to tsunamis, very long period, infragravity, and storm-driven waves. First, the team will use high-resolution tsunami modeling to investigate the response of ice shelves along the West Antarctic coast to waves originating in different regions of the Pacific Ocean. Second, it will compare the response to wave impacts on grounding zones of narrow and wide ice shelves. Third, it will assess the exposure risk due to storm forcing through a reanalysis of weather and wave model data; and, finally, the team will model the propagation of ocean-wave-induced vibrations in the ice from the shelf front to and across the grounding zone. In combination, this project aims to identify locations along the Antarctic coast that are subject to enhanced, bathymetrically-focused, long-period ocean-wave impacts. Linkages between wave impacts and climate arise from potential changes in sea-ice extent in front of shelves, and changes in the magnitude, frequency, and tracks of storms. Understanding the effects of ocean waves and climate on ice-shelf integrity is critical to anticipate their contribution to the amplitude and timing of sea-level rise. Wave-driven reductions in ice-shelf stability may enhance shelf fragmentation and iceberg calving, reducing ice shelf buttressing and eventually accelerating sea-level rise. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "COMPUTERS; AMD; Amd/Us; SEA ICE; Amundsen Sea; USAP-DC; USA/NSF; Ross Ice Shelf; MODELS", "locations": "Amundsen Sea; Ross Ice Shelf", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Dunham, Eric; Bromirski, Peter; Wei, Yong", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "NOAA Center for Tsunami Research (NCTR); Stanford Digital Repository; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Do Ocean Wave Impacts Pose a Hazard to the Stability of West Antarctic Ice Shelves?", "uid": "p0010320", "west": null}, {"awards": "1643174 Padman, Laurence; 1643285 Joughin, Ian", "bounds_geometry": "POLYGON((-104 -73,-102.2 -73,-100.4 -73,-98.6 -73,-96.8 -73,-95 -73,-93.2 -73,-91.4 -73,-89.6 -73,-87.8 -73,-86 -73,-86 -73.8,-86 -74.6,-86 -75.4,-86 -76.2,-86 -77,-86 -77.8,-86 -78.6,-86 -79.4,-86 -80.2,-86 -81,-87.8 -81,-89.6 -81,-91.4 -81,-93.2 -81,-95 -81,-96.8 -81,-98.6 -81,-100.4 -81,-102.2 -81,-104 -81,-104 -80.2,-104 -79.4,-104 -78.6,-104 -77.8,-104 -77,-104 -76.2,-104 -75.4,-104 -74.6,-104 -73.8,-104 -73))", "dataset_titles": "Beta Version of Plume Model; Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier; icepack; Pine Island Basin Scale Model", "datasets": [{"dataset_uid": "200314", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "icepack", "url": "https://github.com/icepack/icepack"}, {"dataset_uid": "200290", "doi": "http://hdl.handle.net/1773/46687", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier", "url": "https://doi.org/10.6069/2MZZ-6B61"}, {"dataset_uid": "200313", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beta Version of Plume Model", "url": "https://github.com/icepack/plumes"}, {"dataset_uid": "200315", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Pine Island Basin Scale Model", "url": "https://github.com/fastice/icesheetModels"}], "date_created": "Fri, 13 May 2022 00:00:00 GMT", "description": "The West Antarctic Ice Sheet contains enough ice to raise global sea levels by 3-4 meters. Ice-sheet volume falls, and sea level increases, when more ice is lost to the ocean by glacier flow than is replaced by snowfall. Glacier speed is reduced when ice shelves, which are the floating extensions of the ice sheets, are present. Processes that affect ice shelf thickness and extent therefore influence the rates of grounded ice loss and sea-level rise. West Antarctica is currently losing ice, at an accelerating rate, with most loss occurring in the Amundsen Sea region via discharge from Pine Island and Thwaites glaciers. This loss was initiated by increased circulation of relatively warm ocean water beneath these glacier\u0027s ice shelves, causing them to thin by melting. However, this melting also depends on how the changing shape of the ice shelves affects the ocean circulation beneath them and the speeds of the grounded glaciers upstream. Limited understanding of these processes leads to uncertainties in estimates of future ice loss. This interdisciplinary project brings together glaciologists and oceanographers from three US institutions to study the interactions between changing glacier flow, ice shelf shape and extent, and ocean circulation. Data and numerical models will be used to identify the key processes that determine how rapidly this region can shed ice. The project team will train postdocs and graduate students in cutting-edge modeling techniques, and educate the public about Antarctic ice loss through talks, school science fairs, and Seattle Science Center\u0027s annual Polar Science Weekend. The project team will conduct simulations, using a combination of ice-sheet and ocean models, to reduce uncertainties in projected ice loss from Pine Island and Thwaites glaciers by: (i) assessing how ice-shelf melt rates will change as the ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of sub-shelf melt rates to changes in ocean state on the nearby continental shelf. These studies will reduce uncertainty on ice loss and sea-level rise estimates, and lay the groundwork for development of future fully-coupled ice-sheet/ocean models. The project will first develop high-resolution ice-shelf-cavity circulation models driven by modern observed regional ocean state and validated with estimates of melt derived from satellite observations. Next, an ice-flow model will be used to estimate the future grounding retreat. An iterative process with the ocean-circulation and ice-flow models will then simulate melt rates at each stage of retreat. These results will help assess the validity of the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway, which was based on simplified models of melt rate. These models will also provide a better understanding of the sensitivity of melt to regional forcing such as changes in Circumpolar Deep Water temperature and wind-driven changes in thermocline height. Finally, several semi-coupled ice-ocean simulations will help determine the influence of the ocean-circulation driven melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response.", "east": -86.0, "geometry": "POINT(-95 -77)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; USA/NSF; ICE SHEETS; AMD; USAP-DC; MODELS; Amd/Us; Pine Island Glacier", "locations": "Pine Island Glacier", "north": -73.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Joughin, Ian; Dutrieux, Pierre; Padman, Laurence; Springer, Scott", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "GitHub", "repositories": "GitHub; Uni. Washington ResearchWorks Archive", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Modeling ice-ocean interaction for the rapidly evolving ice shelf cavities of Pine Island and Thwaites glaciers, Antarctica ", "uid": "p0010318", "west": -104.0}, {"awards": "2146791 Lai, Chung Kei Chris", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 06 May 2022 00:00:00 GMT", "description": "Melt from the Greenland and Antarctic ice sheets is increasingly contributing to sea-level rise. This ice sheet mass loss is primarily driven by the thinning, retreat, and acceleration of glaciers in contact with the ocean. Observations from the field and satellites indicate that glaciers are sensitive to changes at the ice-ocean interface and that the increase in submarine melting is likely to be driven by the discharge of meltwater from underneath the glacier known as subglacial meltwater plumes. The melting of glacier ice also directly adds a large volume of freshwater into the ocean, potentially causing significant changes in the circulation of ocean waters that regulate global heat transport, making ice-ocean interactions an important potential factor in climate change and variability. The ability to predict, and hence adequately respond to, climate change and sea-level rise therefore depends on our knowledge of the small-scale processes occurring in the vicinity of subglacial meltwater plumes at the ice-ocean interface. Currently, understanding of the underlying physics is incomplete; for example, different models of glacier-ocean interaction could yield melting rates that vary over a factor of five for the same heat supply from the ocean. It is then very difficult to assess the reliability of predictive models. This project will use comprehensive laboratory experiments to study how the melt rates of glaciers in the vicinity of plumes are affected by the ice roughness, ice geometry, ocean turbulence, and ocean density stratification at the ice-ocean interface. These experiments will then be used to develop new and improved predictive models of ice-sheet melting by the ocean. This project builds bridges between modern experimental fluid mechanics and glaciology with the goal of leading to advances in both fields. As a part of this work, two graduate students will receive interdisciplinary training and each year two undergraduate students will be trained in experimental fluid mechanics to assist in this work and develop their own research projects. This project consists of a comprehensive experimental program designed for studying the melt rates of glacier ice under the combined influences of (1) turbulence occurring near and at the ice-ocean interface, (2) density stratification in the ambient water column, (3) irregularities in the bottom topology of an ice shelf, and (4) differing spatial distributions of multiple meltwater plumes. The objective of the experiments is to obtain high-resolution data of the velocity, density, and temperature near/at the ice-ocean interface, which will then be used to improve understanding of melt processes down to scales of millimeters, and to devise new, more robust numerical models of glacier evolution and sea-level rise. Specially, laser-based, optical techniques in experimental fluid mechanics (particle image velocity and laser-induced fluorescence) will be used to gather the data, and the experiments will be conducted using refractive-index matching techniques to eliminate changes in refractive indices that could otherwise bias the measurements. The experiments will be run inside a climate-controlled cold room to mimic field conditions (ocean temperature from 0-10 degrees C). The project will use 3D-printing to create different casting molds for making ice blocks with different types of roughness. The goal is to investigate how ice melt rate changes as a function of the properties of the plume, the ambient ocean water, and the geometric properties of the ice interface. Based on the experimental findings, this project will develop and test a new integral-plume-model coupled to a regional circulation model (MITgcm) that can be used to predict the effects of glacial melt on ocean circulation and sea-level rise. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Glacier-Ocean Boundary Layer; Alaska; USAP-DC; USA/NSF; ABLATION ZONES/ACCUMULATION ZONES; GLACIERS; AMD; Amd/Us; Antarctica; LABORATORY", "locations": "Antarctica; Alaska", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Lai, Chung; Robel, Alexander", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Revising Models of the Glacier-Ocean Boundary Layer with Novel Laboratory Experiments ", "uid": "p0010317", "west": null}, {"awards": "1543361 Kurbatov, Andrei; 1543454 Dunbar, Nelia", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "Cryptotephra in SPC-14 ice core; SPICEcore visable tephra", "datasets": [{"dataset_uid": "601667", "doi": "10.15784/601667", "keywords": "Antarctica; Electron Microprobe; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; South Pole; Tephra", "people": "Iverson, Nels", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore visable tephra", "url": "https://www.usap-dc.org/view/dataset/601667"}, {"dataset_uid": "601666", "doi": "10.15784/601666", "keywords": "Antarctica; Cryptotephra; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; South Pole; SPICEcore; Tephra", "people": "Helmick, Meredith; Kurbatov, Andrei V.; Hartman, Laura; Yates, Martin", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Cryptotephra in SPC-14 ice core", "url": "https://www.usap-dc.org/view/dataset/601666"}], "date_created": "Fri, 01 Apr 2022 00:00:00 GMT", "description": "Dunbar/1543454 Antarctic ice cores offer unparalleled records of earth?s climate back to almost one million years and perhaps beyond. Layers of volcanic ash (tephra) embedded in glacial ice can be used to establish an accurate ice core chronology. In order to use a visible or ultrafine volcanic ash layer as a time-stratigraphic marker, a unique geochemical fingerprint must be established, and this forms the basis of our research. This award will investigate the volcanic record in the 1751 m ice core that was completed at the South Pole during the 2015/16 field season. The core is in an ideal location to link the existing, established, volcanic records in East and West Antarctica, and therefore to connect and integrate those records, allowing the climate records of ice cores to be directly compared, as well as to focus research on the most widespread and significant volcanic eruptions from West Antarctica. Tephra derived from well-dated, large, tropical volcanic eruptions that may have had an impact on climate will also be studied. Recent success in identifying and analyzing very fine ash particles from these types of eruptions makes it likely that we will be able to pinpoint some of these eruptions, which will allow the sulfate peaks associated with these layers to be positively identified and dated. Volcanic forcing time series developed from earlier South Pole ice cores based on preserved sulfate were crucial for testing climate models, but without tephra analysis, the origin of these layers remains uncertain. Work on the tephra layers in the South Pole ice core has a number of significant specific objectives, some with practical applications to the basic science goals of Antarctic ice coring, and others that represent independent scientific contributions in their own right. These include: (1) providing independently dated time-intervals in the core, particularly for the deepest ice, (2) quantitatively linking tephra records across Antarctica with the goal of allowing direct and robust climate comparisons between these different parts of the continent, (3) providing information for large local eruptions, that will lead to direct estimates of eruption magnitude and dispersal patterns of Antarctic volcanoes, several of which will likely erupt again. The initial stages of the work will be carried out by identifying silicate-bearing horizons in the ice core, using several methods. Once found, silicate particles will be imaged so that morphological characteristics of the particles can be used to identify volcanic origin. Particles identified as tephra will then be chemically analyzed using electron microprobe and laser ablation ICP-MS. Samples that yield a robust chemical fingerprint will be statistically correlated to known eruptions, and this will be used to address the goals described above. Broader impacts of this project fall into the areas of education of future generation of researchers, outreach and international cooperation. These activities will continue to promote forward progress in integrating the Antarctic tephra record and more broadly tying it to the global volcanic record.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": null, "is_usap_dc": true, "keywords": "VOLCANIC DEPOSITS; South Pole", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Dunbar, Nelia; Iverson, Nels; Kurbatov, Andrei V.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Tephrochronology of a South Pole Ice Core", "uid": "p0010311", "west": 0.0}, {"awards": "0944150 Hall, Brenda", "bounds_geometry": "POLYGON((163.6 -77.5,163.7 -77.5,163.8 -77.5,163.9 -77.5,164 -77.5,164.1 -77.5,164.2 -77.5,164.3 -77.5,164.4 -77.5,164.5 -77.5,164.6 -77.5,164.6 -77.57,164.6 -77.64,164.6 -77.71,164.6 -77.78,164.6 -77.85,164.6 -77.92,164.6 -77.99,164.6 -78.06,164.6 -78.13,164.6 -78.2,164.5 -78.2,164.4 -78.2,164.3 -78.2,164.2 -78.2,164.1 -78.2,164 -78.2,163.9 -78.2,163.8 -78.2,163.7 -78.2,163.6 -78.2,163.6 -78.13,163.6 -78.06,163.6 -77.99,163.6 -77.92,163.6 -77.85,163.6 -77.78,163.6 -77.71,163.6 -77.64,163.6 -77.57,163.6 -77.5))", "dataset_titles": "Marshall Valley Radiocarbon Data; Marshall Valley U-Series Data; Royal Society Range Headland Moraine Belt Radiocarbon Data; Salmon Valley Radiocarbon Data", "datasets": [{"dataset_uid": "601529", "doi": "10.15784/601529", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marshall Valley; Radiocarbon; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601529"}, {"dataset_uid": "601556", "doi": "10.15784/601556", "keywords": "Antarctica; Last Glacial Maximum; McMurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Salmon Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601556"}, {"dataset_uid": "601528", "doi": "10.15784/601528", "keywords": "234U/230Th Dating; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Last Glacial Maximum; Marshall Drift; Marshall Valley; MIS 6; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley U-Series Data", "url": "https://www.usap-dc.org/view/dataset/601528"}, {"dataset_uid": "601555", "doi": "10.15784/601555", "keywords": "Antarctica; Last Glacial Maximum; McMurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Royal Society Range Headland Moraine Belt Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601555"}], "date_created": "Thu, 03 Mar 2022 00:00:00 GMT", "description": "This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth\u0027s climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area. ", "east": 164.6, "geometry": "POINT(164.1 -77.85)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; Amd/Us; AMD; USA/NSF; GLACIAL LANDFORMS; USAP-DC; Royal Society Range; GLACIER ELEVATION/ICE SHEET ELEVATION", "locations": "Royal Society Range", "north": -77.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Denton, George", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.2, "title": "Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles", "uid": "p0010302", "west": 163.6}, {"awards": "1643248 Hall, Brenda", "bounds_geometry": "POLYGON((163.3 -77.8,163.43 -77.8,163.56 -77.8,163.69 -77.8,163.82 -77.8,163.95 -77.8,164.08 -77.8,164.21 -77.8,164.34 -77.8,164.47 -77.8,164.6 -77.8,164.6 -77.85,164.6 -77.9,164.6 -77.95,164.6 -78,164.6 -78.05,164.6 -78.1,164.6 -78.15,164.6 -78.2,164.6 -78.25,164.6 -78.3,164.47 -78.3,164.34 -78.3,164.21 -78.3,164.08 -78.3,163.95 -78.3,163.82 -78.3,163.69 -78.3,163.56 -78.3,163.43 -78.3,163.3 -78.3,163.3 -78.25,163.3 -78.2,163.3 -78.15,163.3 -78.1,163.3 -78.05,163.3 -78,163.3 -77.95,163.3 -77.9,163.3 -77.85,163.3 -77.8))", "dataset_titles": "Marshall Valley Radiocarbon Data; Marshall Valley U-Series Data; Pyramid Trough Radiocarbon Data; Walcott Glacier area radiocarbon data; Walcott Glacier Exposure Data", "datasets": [{"dataset_uid": "601615", "doi": "10.15784/601615", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Howchin Glacier; Radiocarbon; Radiocarbon Dates; Ross Sea Drift; Royal Society Range; Walcott Glacier", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Walcott Glacier area radiocarbon data", "url": "https://www.usap-dc.org/view/dataset/601615"}, {"dataset_uid": "601528", "doi": "10.15784/601528", "keywords": "234U/230Th Dating; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Last Glacial Maximum; Marshall Drift; Marshall Valley; MIS 6; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley U-Series Data", "url": "https://www.usap-dc.org/view/dataset/601528"}, {"dataset_uid": "601529", "doi": "10.15784/601529", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marshall Valley; Radiocarbon; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601529"}, {"dataset_uid": "601616", "doi": "10.15784/601616", "keywords": "Antarctica; Beryllium-10; Exposure Age; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; McMurdo Sound; Royal Society Range; Walcott Glacier", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Walcott Glacier Exposure Data", "url": "https://www.usap-dc.org/view/dataset/601616"}, {"dataset_uid": "601614", "doi": "10.15784/601614", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pyramid Trough; Radiocarbon; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Pyramid Trough Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601614"}], "date_created": "Thu, 03 Mar 2022 00:00:00 GMT", "description": "Hall/1643248 This award supports a project to reconstruct the behavior of a portion of the East Antarctic Ice Sheet (the Ross Ice Sheet), using glacial geologic mapping and radiocarbon dating of algal deposits contained in glacial moraines, at the end of the last glacial period. The results will be compared with other dating methods that will be used on alpine glaciers that terminated in the mountains of the Royal Society Range in East Antarctica during the last glacial maximum and whose landforms intersect with those of the Ross Ice Sheet. Results from this comparison will contribute to a better understanding of the Antarctic ice sheet during the most recent global warming that ended the last ice age. This period is of interest since it will help inform our understanding of Antarctic ice sheet behavior in a future climate warming. Such data also will help inform models that attempt to simulate not only the behavior of the ice sheet during the end of the last ice age, but also its future response to elevated atmospheric carbon dioxide. The work will contribute to the education and training of both graduate and undergraduate students and results from the work will be incorporated in classes at the University of Maine. Results derived from the research will be disseminated to the public through lectures and visits to K-12 classrooms and data from this project will be downloadable from a University of Maine web site, as well as from public data repositories. The Antarctic Ice Sheet exerts a key control on global sea levels, both past and future, and strongly influences Southern Hemisphere and even global climate and ocean circulation. And yet a complete understanding of the evolution of the ice sheet over the last glacial cycle and of the mechanisms that caused it to advance and retreat is still lacking. Of particular interest is the response of the Antarctic Ice Sheet to the global warming that ended the last ice age, because it yields important clues about likely future ice-sheet behavior under a warming climate. In this project, scientists will reconstruct the thinning history of the Antarctic Ice Sheet in the Ross Sea sector during the last glacial/interglacial transition on the headlands of the southern Royal Society Range. They will use a combination of glacial geomorphological mapping and radiocarbon dating of algal deposits enclosed within recessional moraines. Finally, this record will be compared with a beryllium- and radiocarbon-dated chronology that will be produced of adjacent independent alpine glaciers that terminated on land during the last glacial maximum and whose deposits show cross-cutting relationships with those of the ice sheet. Results from this comparison will bear on the behavior of the Antarctic Ice Sheet during the termination of the last ice age. This work will support six students, including at least three undergraduates, and involves field work in the Antarctic.", "east": 164.6, "geometry": "POINT(163.95 -78.05)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIER ELEVATION/ICE SHEET ELEVATION; Royal Society Range; USA/NSF; USAP-DC; Amd/Us; AMD; LABORATORY; GLACIAL LANDFORMS", "locations": "Royal Society Range", "north": -77.8, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Hall, Brenda; Denton, George", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.3, "title": "Response of the Antarctic Ice Sheet to the last great global warming", "uid": "p0010301", "west": 163.3}, {"awards": "1643917 Fricker, Helen", "bounds_geometry": "POLYGON((-163.646 -84.186,-162.58715 -84.186,-161.5283 -84.186,-160.46945 -84.186,-159.4106 -84.186,-158.35175 -84.186,-157.2929 -84.186,-156.23405 -84.186,-155.1752 -84.186,-154.11635 -84.186,-153.0575 -84.186,-153.0575 -84.20871,-153.0575 -84.23142,-153.0575 -84.25413,-153.0575 -84.27684,-153.0575 -84.29955,-153.0575 -84.32226,-153.0575 -84.34497,-153.0575 -84.36768,-153.0575 -84.39039,-153.0575 -84.4131,-154.11635 -84.4131,-155.1752 -84.4131,-156.23405 -84.4131,-157.2929 -84.4131,-158.35175 -84.4131,-159.4106 -84.4131,-160.46945 -84.4131,-161.5283 -84.4131,-162.58715 -84.4131,-163.646 -84.4131,-163.646 -84.39039,-163.646 -84.36768,-163.646 -84.34497,-163.646 -84.32226,-163.646 -84.29955,-163.646 -84.27684,-163.646 -84.25413,-163.646 -84.23142,-163.646 -84.20871,-163.646 -84.186))", "dataset_titles": "Wideband magnetotelluric responses from Whillans Ice Stream, West Antarctica", "datasets": [{"dataset_uid": "601526", "doi": "10.15784/601526", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Stream; Magnetotelluric; Subglacial; Whillans Ice Stream", "people": "Fricker, Helen; Gustafson, Chloe; Key, Kerry; Siegfried, Matthew", "repository": "USAP-DC", "science_program": null, "title": "Wideband magnetotelluric responses from Whillans Ice Stream, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601526"}], "date_created": "Sat, 26 Feb 2022 00:00:00 GMT", "description": "The Antarctic ice sheet is underlain by a dynamic water system that lubricates the flow of ice streams and outlet glaciers, provides a habitat for a diverse microbial ecosystem, and delivers freshwater and nutrients to the Southern Ocean. However, imaging this subglacial environment is difficult: Antarctica is a vast continent with ice up to four kilometers (2.5 miles) thick. To detect water at the ice-bed interface and in deeper groundwater reservoirs, this project will adapt a technique called electromagnetic sounding that is well-established on land and in the ocean for imaging fluids beneath the surface. Groundwater is estimated to be a significant part of the subglacial water budget in Antarctica, yet previous observational approaches have been unable to characterize its volume and distribution. This project will thus yield critical information about how ice-rock-water-ocean systems interact and inform our understanding of ice-sheet processes, global nutrient cycles, and freshwater flux to the ocean. The project will provide cross-disciplinary training for a graduate student and postdoctoral scientist, and develop an educational outreach program through the Birch Aquarium. Standard geophysical surveying techniques used in glaciology to image subglacial water (radio-echo sounding and active-source seismology) are not directly sensitive to water content. In contrast, ground-based electromagnetic (EM) methods are sensitive to water content through its impact on bulk conductivity. Although EM methods are well-established for high-precision mapping of hydrology in other geological environments, their application on ice sheets is in its infancy. The proposed work will adapt both passive- and active-source EM techniques to glaciological questions to quantify the three-dimensional structure of subglacial water beneath an ice stream and in a grounding zone. The project will perform a suite of synthetic inversion studies to determine the range of applications of EM techniques in glaciology and execute a field experiment on the Whillans Ice Plain to investigate two hypotheses about the subglacial water system based on previous observational and modeling results: (1) Subglacial Lake Whillans is underlain by a deep, saline groundwater reservoir; and (2) there is an estuary-like zone of mixing between fresh subglacial water and seawater near, and possibly landward, of the grounding line.", "east": -153.0575, "geometry": "POINT(-158.35175 -84.29955)", "instruments": null, "is_usap_dc": true, "keywords": "Whillans Ice Stream; GROUND WATER; USA/NSF; USAP-DC; AMD; GEOMAGNETIC INDUCTION; Amd/Us; FIELD SURVEYS", "locations": "Whillans Ice Stream", "north": -84.186, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Key, Kerry; Fricker, Helen; Siegfried, Matthew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.4131, "title": "Mapping Antarctic Subglacial Water with Novel Electromagnetic Techniques", "uid": "p0010300", "west": -163.646}, {"awards": "0342484 Harwood, David", "bounds_geometry": "POINT(167.083333 -77.888889)", "dataset_titles": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "datasets": [{"dataset_uid": "601451", "doi": "10.15784/601451", "keywords": "Andrill; Antarctica; Continental Shelf; Diamict; McMurdo Sound; Miocene; Paleoclimate; Particle Size", "people": "Passchier, Sandra; Candice, Falk", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601451"}], "date_created": "Fri, 04 Feb 2022 00:00:00 GMT", "description": "ANDRILL is a scientific drilling program to investigate Antarctica\u0027s role in global climate change over the last sixty million years. The approach integrates geophysical surveys, new drilling technology, multidisciplinary core analysis, and ice sheet modeling to address four scientific themes: (1) the history of Antarctica\u0027s climate and ice sheets; (2) the evolution of polar biota and ecosystems; (3) the timing and nature of major tectonic and volcanic episodes; and (4) the role of Antarctica in the Earth\u0027s ocean-climate system. \u003cbr/\u003e\u003cbr/\u003eThis award initiates what may become a long-term program with drilling of two previously inaccessible sediment records beneath the McMurdo Ice Shelf and in South McMurdo Sound. These stratigraphic records cover critical time periods in the development of Antarctica\u0027s major ice sheets. The McMurdo Ice Shelf site focuses on the Ross Ice Shelf, whose size is a sensitive indicator of global climate change. It has recently undergone major calving events, and there is evidence of a thousand-kilometer contraction since the last glacial maximum. As a generator of cold bottom water, the shelf may also play a key role in ocean circulation. The core obtained from this site will also offer insight into sub-ice shelf sedimentary, biologic, and oceanographic processes; the history of Ross Island volcanism; and the flexural response of the lithosphere to volcanic loading, which is important for geophysical and tectonic studies of the region.\u003cbr/\u003e\u003cbr/\u003eThe South McMurdo Sound site is located adjacent to the Dry Valleys, and focuses on the major ice sheet overlying East Antarctica. A debate persists regarding the stability of this ice sheet. Evidence from the Dry Valleys supports contradictory conclusions; a stable ice sheet for at least the last fifteen million years or an active ice sheet that cycled through expansions and contractions as recently as a few millions of years ago. Constraining this history is critical to deep-time models of global climate change. The sediment cores will be used to construct an overall glacial and interglacial history for the region; including documentation of sea-ice coverage, sea level, terrestrial vegetation, and melt-water discharge events. The core will also provide a general chronostratigraphic framework for regional seismic studies and help unravel the area\u0027s complex tectonic history.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society\u0027s understanding of global climate change. Education is supported at the postdoctoral, graduate, undergraduate, and K-12 levels. Teachers and curriculum specialists are integrated into the research program, and a range of video resources will be produced, including a science documentary for television release. New research infrastructure includes equipment for core analysis and ice sheet modeling, as well as development of a unique drilling system to penetrate ice shelves. Drill development and the overall project are co-supported by international collaboration with scientists and the National Antarctic programs of New Zealand, Germany, and Italy. The program also forges new collaborations between research and primarily undergraduate institutions within the United States. \u003cbr/\u003e\u003cbr/\u003eAs key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica\u0027s ice sheets are important to society\u0027s understanding of global climate change. ANDRILL offers new data on marine and terrestrial temperatures, and changes our understanding of extreme climate events like the formation of polar ice caps. Such data are critical to developing accurate models of the Earth\u0027s climatic future.", "east": 167.083333, "geometry": "POINT(167.083333 -77.888889)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; FIELD SURVEYS; ICE SHEETS; USA/NSF; Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; Ross Ice Shelf; SEDIMENTS", "locations": "Ross Ice Shelf", "north": -77.888889, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harwood, David; Levy, Richard", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.888889, "title": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change", "uid": "p0010297", "west": 167.083333}, {"awards": "1744954 Lubin, Dan", "bounds_geometry": "POINT(-148.81 -81.65)", "dataset_titles": "Siple Dome Surface Energy Flux", "datasets": [{"dataset_uid": "601540", "doi": "10.15784/601540", "keywords": "Antarctica; Siple Dome; Spectroscopy", "people": "Lubin, Dan; Ghiz, Madison", "repository": "USAP-DC", "science_program": null, "title": "Siple Dome Surface Energy Flux", "url": "https://www.usap-dc.org/view/dataset/601540"}], "date_created": "Wed, 02 Feb 2022 00:00:00 GMT", "description": "Atmospheric warming has been a major factor in the loss of ice shelves on the Antarctic Peninsula. In West Antarctica, oceanic warming is presently regarded as the largest source of stress on both the ice-shelves and at the grounding lines of the ice sheets. The loss of ice shelf buttressing and grounding line retreat may have already induced irreversible loss of Thwaites Glacier. To advance predictive models more data is needed regarding both water-induced fracturing on an ice shelf and marine ice cliff instability near the grounding line. This project will help advance understanding of atmospheric circulation and solar radiation over West Antarctica and the Ross Ice Shelf that lead to surface melting. In support of this project, and incorporating Antarctic science from this work, UCSD educators will sponsor a workshop series for exemplary middle and/or high school science teachers designed to address this need. Teacher participants will be carefully selected for their demonstrated leadership skills and will eventually become part of an cadre of \"master\" science teachers who will serve as local leaders in disseminating strategies and tools for addressing the NGSS (Ca Next Gen. of Sci. Eng. Stds.) to teachers throughout the county. For the summer field seasons requested, UCSD scientists will deploy a suite instruments to measure downwelling and net shortwave and longwave fluxes, sensible and latent heat fluxes, and near-surface meteorology. This suite of instruments will be self-reliant with power requirements and will be supportable in the field with a single Twin Otter aircraft. The investigators plan to deploy this suite as a remote ice camp with a field party of 2-3 personnel, making measurements for at up to one month during each of the sampled summer field seasons. These measurements will be analyzed and interpreted to determine mesoscale conditions that govern surface melt in West Antarctica, in the context of improving coupled climate model parameterizations. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -148.81, "geometry": "POINT(-148.81 -81.65)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Siple Dome; USAP-DC; ATMOSPHERIC RADIATION; AMD; FIELD SURVEYS; Amd/Us; USA/NSF", "locations": "Siple Dome", "north": -81.65, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Lubin, Dan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.65, "title": "Surface Energy Balance on West Antarctica and the Ross Ice Shelf", "uid": "p0010296", "west": -148.81}, {"awards": "1946326 Doran, Peter", "bounds_geometry": "POLYGON((161 -77.4,161.3 -77.4,161.6 -77.4,161.9 -77.4,162.2 -77.4,162.5 -77.4,162.8 -77.4,163.1 -77.4,163.4 -77.4,163.7 -77.4,164 -77.4,164 -77.46,164 -77.52,164 -77.58,164 -77.64,164 -77.7,164 -77.76,164 -77.82,164 -77.88,164 -77.94,164 -78,163.7 -78,163.4 -78,163.1 -78,162.8 -78,162.5 -78,162.2 -78,161.9 -78,161.6 -78,161.3 -78,161 -78,161 -77.94,161 -77.88,161 -77.82,161 -77.76,161 -77.7,161 -77.64,161 -77.58,161 -77.52,161 -77.46,161 -77.4))", "dataset_titles": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: Infrared Stimulated Luminescence data; EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: in situ 14C data", "datasets": [{"dataset_uid": "601520", "doi": "10.15784/601520", "keywords": "Antarctica; Sample/collection Description; Sample/Collection Description; Sample Location; Taylor Valley", "people": "Doran, Peter; Stone, Michael", "repository": "USAP-DC", "science_program": "LTER", "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: Infrared Stimulated Luminescence data", "url": "https://www.usap-dc.org/view/dataset/601520"}, {"dataset_uid": "601521", "doi": "10.15784/601521", "keywords": "Antarctica; Carbon-14; Sample/collection Description; Sample/Collection Description; Sample Location; Taylor Valley", "people": "Doran, Peter; Stone, Michael", "repository": "USAP-DC", "science_program": null, "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: in situ 14C data", "url": "https://www.usap-dc.org/view/dataset/601521"}], "date_created": "Mon, 31 Jan 2022 00:00:00 GMT", "description": "Correlating ecosystem responses to past climate forcing is highly dependent on the use of reliable techniques for establishing the age of events (dating techniques). In Antarctic dry regions (land areas without glaciers), carbon-14 dating has been used to assess the ages of organic deposits left behind by ancient lakes. However, the reliability of the ages is debatable because of possible contamination with \"old carbon\" from the surrounding landscape. The proposed research will attempt to establish two alternate dating techniques, in situ carbon-14 cosmogenic radionuclide exposure dating and optically stimulated luminescence (OSL), as reliable alternate dating methods for lake history in Antarctic dry areas that are not contaminated by the old carbon. The end goal will be to increase scientific understanding of lake level fluctuation in the lakes of Taylor Valley, Antarctica so that inference about past climate, glacier, and ecosystem response can be inferred. The results of this study will provide a coarse-scale absolute chronology for lake level history in Taylor Valley, demonstrate that exposure dating and OSL are effective means to understand the physical dynamics of ancient water bodies, and increase the current understanding of polar lacustrine and ice sheet responses to past and present climatic changes. These chronologies will allow polar lake level fluctuations to be correlated with past changes in global and regional climate, providing information critical for understanding and modeling the physical responses of these environments to modern change. This research supports a PhD student; the student will highlight this work with grade school classes in the United States. This research aims to establish in situ carbon-14 exposure dating and OSL as reliable alternate (to carbon-14 of organic lake deposits) geochronometers that can be used to settle the long-disputed lacustrine history and chronology of Taylor Valley, Antarctica and elsewhere. Improved lake level history will have significant impacts for the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) site as the legacy of fluctuating lake levels of the past affects the distribution of organic matter and nutrients, and impacts biological connectivity valley-wide. This work will provide insight into the carbon reservoir of large glacial lakes in the late Holocene and have implications for previously reported radiocarbon chronologies. OSL samples will be analyzed in the Desert Research Institute Luminescence Laboratory in Reno, NV. For the in situ carbon-14 work, rock samples extracted from boulders and bedrock surfaces will be prepared at Tulane University. The prepared in situ carbon-14 samples will be analyzed at the National Ocean Sciences Accelerator Mass Spectrometry laboratory in Woods Hole, MA. The two datasets will be combined to produce a reliable, coarse scale chronology for late Quaternary lake level fluctuations in Taylor Valley. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 164.0, "geometry": "POINT(162.5 -77.7)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Amd/Us; Taylor Valley; AGE DETERMINATIONS; USA/NSF; AMD; USAP-DC", "locations": "Taylor Valley", "north": -77.4, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Earth Sciences", "paleo_time": null, "persons": "Doran, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "LTER", "south": -78.0, "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers", "uid": "p0010294", "west": 161.0}, {"awards": "1644128 Welten, Kees; 1644094 Caffee, Marc", "bounds_geometry": "POINT(-112.12 -79.48)", "dataset_titles": "WAIS Divide Core 10Be data, 2850-3240 m", "datasets": [{"dataset_uid": "601692", "doi": "10.15784/601692", "keywords": "10Be; Antarctica; Beryllium; Cosmogenic Radionuclides; Ice Core Data; WAIS Divide", "people": "Caffee, Marc; Woodruff, Thomas; Welten, Kees", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Core 10Be data, 2850-3240 m", "url": "https://www.usap-dc.org/view/dataset/601692"}], "date_created": "Mon, 15 Nov 2021 00:00:00 GMT", "description": "Welten/1644128 This award supports a project to use existing samples from the West Antarctic Ice Sheet (WAIS) Divide ice core to align its timescale with that of the Greenland ice cores using common chronological markers. The upper 2850 m of the WAIS Divide core, which was drilled to a depth of 3405 m, has been dated with high precision. The timescale of the remaining (bottom) 550 m of the core has larger uncertainties, limiting our understanding of the timing of abrupt climate events in Antarctica relative to those in Greenland during the last ice age. The intellectual merit of this project is to further constrain the relative timing of these abrupt climate events in Greenland and Antarctica to obtain crucial insight into the underlying mechanism. The main objective of this project is to improve the current timescale of the WAIS Divide core from 31,000 to 65,000 years ago by synchronizing this core with the Greenland ice cores using common signals in Beryllium-10, a radioactive isotope of Be that is produced in the atmosphere by cosmic rays and is deposited onto the snow within 1-2 years of its production. The 10Be flux is largely independent of climate signals since its production varies with solar activity and the geomagnetic field. This project will further strengthen collaborations between the PI\u0027s in Berkeley and Purdue with ice core researchers in the US and Europe, involve undergraduate students in many aspects of its research, and continue outreach to under-represented students. The direct ice-to-ice synchronization of the WAIS Divide ice core with the Greenland Ice Core Chronology (GICC05) using cosmogenic 10Be is expected to reduce the uncertainty in the relative timing of more than 20 abrupt climate events in Greenland and Antarctica to a few decades. To achieve this goal the investigators will obtain a continuous high-resolution record of 10Be in the WAIS Divide core from 2850 to 3390 m depth, and compare the obtained 10Be record with existing 10Be records of the Greenland ice cores, including GISP2 and NGRIP. The scientists will separate 10Be from ~1000 ice samples of the WAIS Divide core and measure the 10Be concentration in each sample using accelerator mass spectrometry (AMS). Broader impacts of the 10Be measurements are that they will also provide information on the Laschamp event, a ~2000 year long period of low geomagnetic field strength around 41,000 years ago, and improve the calibration of the 14C dating method for organic samples older than 30,000 years. The broader impacts of the project include (1) the involvement and training of undergraduate students in ice core research and accelerator mass spectrometry measurements, (2) the incorporation of ice core and climate research into ongoing outreach programs at Purdue University and Berkeley SSL, (3) better understanding of abrupt climate changes in the past will improve our ability to predict future climate change, (4) evaluating the possible threat of a future geomagnetic excursion in the next few hundred years. This award does not require support in Antarctica.", "east": -112.12, "geometry": "POINT(-112.12 -79.48)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; LABORATORY; Amd/Us; WAIS Divide; AMD; USAP-DC; DEPTH AT SPECIFIC AGES", "locations": "WAIS Divide", "north": -79.48, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Welten, Kees; Caffee, Marc", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.48, "title": "Synchronizing the WAIS Divide and Greenland Ice Cores from 30-65 ka BP using high-resolution 10Be measurements", "uid": "p0010280", "west": -112.12}, {"awards": "1643394 Buizert, Christo", "bounds_geometry": "POLYGON((-180 -65,-144 -65,-108 -65,-72 -65,-36 -65,0 -65,36 -65,72 -65,108 -65,144 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.5,-180 -85,-180 -82.5,-180 -80,-180 -77.5,-180 -75,-180 -72.5,-180 -70,-180 -67.5,-180 -65))", "dataset_titles": "Antarctica 40,000 Year Temperature and Elevation Reconstructions; GISP2 and WAIS Divide Ice Cores 60,000 Year Surface Temperature Reconstructions; WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "datasets": [{"dataset_uid": "200257", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "GISP2 and WAIS Divide Ice Cores 60,000 Year Surface Temperature Reconstructions", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/34133"}, {"dataset_uid": "200255", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Antarctica 40,000 Year Temperature and Elevation Reconstructions", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/32632"}, {"dataset_uid": "200256", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/24530"}], "date_created": "Wed, 10 Nov 2021 00:00:00 GMT", "description": "Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ISOTOPES; Antarctica; USA/NSF; AMD; ICE CORE RECORDS; USAP-DC; VOLCANIC DEPOSITS; MODELS; Amd/Us", "locations": "Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Buizert, Christo; Wettstein, Justin", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Timing and Spatial Expression of the Bipolar Seesaw in Antarctica from Synchronized Ice Cores", "uid": "p0010279", "west": -180.0}, {"awards": "2138556 Halberstadt, Anna Ruth", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities; 5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "datasets": [{"dataset_uid": "601602", "doi": "10.15784/601602", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Balco, Gregory; Buchband, Hannah; Halberstadt, Anna Ruth", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601602"}, {"dataset_uid": "601601", "doi": "10.15784/601601", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Halberstadt, Anna Ruth; Buchband, Hannah; Balco, Gregory", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601601"}], "date_created": "Tue, 09 Nov 2021 00:00:00 GMT", "description": "Geologic data provide crucial insights into Antarctic Ice Sheet dynamics; for example, progressive exposure of mountain peaks emerging from the ice sheet reveal ice elevation changes, and the past \u2018footprint\u2019 of marine-based ice sheets is imprinted on the seafloor. Numerical ice sheet simulations can link these geologic records in space and time to make larger-scale inferences about continent-wide ice sheet evolution. This work integrates both marine and terrestrial geologic datasets with numerical simulations to investigate Antarctic Ice Sheet behavior (and contribution to global sea level) throughout the last deglaciation, ~20,000 years ago until present. Specifically, this research addresses two issues regarding the relationship between simulations and data and their use in reconstructing past ice-sheet behavior: (1) Geologic records from the modern seafloor suggest significantly earlier retreat of marine-based ice compared to terrestrial records of mountain peak exposure (ice thinning). Computer experiments investigate several hypotheses for this mismatch in timing. (2) Exposure age data (terrestrial measurements recording ice elevation changes) are often interpreted to reflect ice dynamics hundreds of kilometers away from the study site. This work uses simulations to explore the linkage between ice elevation changes \u2018upstream\u2019 as glaciers flow through mountainous regions and ice dynamics further \u2018downstream\u2019 where ice contacts the ocean. This work will produce a publicly available, customizable, and easily accessible toolkit for comparing simulations and data, including a database of geologic records to use as constraints. The project is interdisciplinary, bridging a communication gap between the ice-sheet simulations and geologic data-collecting communities. This project combines numerical simulations and geologic data to explore fundamental knowledge gaps regarding the interpretation and use of marine and terrestrial datasets. This work will produce an ensemble of continent-wide coupled ice sheet and glacial isostatic adjustment simulations, constrained with comprehensive existing geologic data, to reproduce a history of deglacial Antarctic Ice Sheet evolution that is compatible with the geologic record as well as glaciologically and gravitationally self-consistent. Comparison between simulations and data is improved through high-resolution nested ice sheet modeling techniques, which provide unprecedented context for exposure age data generally located in regions of complex topography. Numerical simulations will be performed with systematically varied parameters and boundary conditions, and can thus support an investigation of (1) chronological mismatches between terrestrial thinning and marine ice sheet retreat during the mid-Holocene, and (2) how marine grounding-line dynamics are propagated upstream to coastal outlet glaciers and further interior under a variety of different scenarios. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; GLACIERS/ICE SHEETS; USAP-DC; USA/NSF; MODELS; AMD; Amd/Us", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Halberstadt, Anna Ruth", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "OPP-PRF: High-resolution Nested Antarctic Ice Sheet Modeling to Reconcile Marine and Terrestrial Geologic Data", "uid": "p0010278", "west": -180.0}, {"awards": "2136938 Tedesco, Marco; 2136940 Newman, Dava; 2136939 Cervone, Guido", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Surface melt-related multi-source remote-sensing and climate model data over Helheim Glacier, Greenland for segmentation and machine learning applications; Surface melt-related multi-source remote-sensing and climate model data over Larsen C Ice Shelf, Antarctica for segmentation and machine learning applications", "datasets": [{"dataset_uid": "601841", "doi": "10.15784/601841", "keywords": "Antarctica; Climate Modeling; Cryosphere; Downscaling; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland; Ice Sheet; Machine Learning; MAR; Remote Sensing; Sea Level Rise; Snow/ice; Snow/Ice; Surface Melt", "people": "Alexander, Patrick; Antwerpen, Raphael; Cervone, Guido; Fettweis, Xavier; L\u00fctjens, Bj\u00f6rn; Tedesco, Marco", "repository": "USAP-DC", "science_program": null, "title": "Surface melt-related multi-source remote-sensing and climate model data over Helheim Glacier, Greenland for segmentation and machine learning applications", "url": "https://www.usap-dc.org/view/dataset/601841"}, {"dataset_uid": "601842", "doi": "10.15784/601842", "keywords": "Antarctica; Climate Modeling; Cryosphere; Downscaling; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Larsen C Ice Shelf; Machine Learning; MAR; Remote Sensing; Sea Level Rise; Snow/ice; Snow/Ice; Surface Melt", "people": "Alexander, Patrick; Tedesco, Marco; L\u00fctjens, Bj\u00f6rn; Fettweis, Xavier; Cervone, Guido; Antwerpen, Raphael", "repository": "USAP-DC", "science_program": null, "title": "Surface melt-related multi-source remote-sensing and climate model data over Larsen C Ice Shelf, Antarctica for segmentation and machine learning applications", "url": "https://www.usap-dc.org/view/dataset/601842"}], "date_created": "Mon, 08 Nov 2021 00:00:00 GMT", "description": "This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Climate change is promoting increased melting in Greenland and Antarctica, contributing to the global sea level rise. Understanding what drives the increase and the amount of meltwater from the ice sheets is paramount to improve our skills to project future sea level rise and associated consequences. Melting in Antarctica mostly occurs along ice shelves (tongues of ice floating in the water). They do not contribute directly to sea level when they melt but their disappearance allows the glaciers at the top to flow faster towards the ocean, increasing the contribution of Antarctica to sea level rise. Satellite data can only offer a partial view of what is happening, either because of limited coverage or because of the presence of clouds, which often obstruct the view in this part of the world. Models, on the other hand, can provide estimates but the spatial detail they can provide is still limited by many factors. This project will use artificial intelligence to overcome these problems and to merge satellite data and model outputs to generate daily maps of surface melting with unprecedented detail. These techniques are similar to those used in cell phones to sharpen images or to create landscapes that look \u201creal\u201d but are only existing in the \u201ccomputer world,\u201d but they have never been applied to melting in Antarctica for improving estimates of sea level rise. Meltwater in Antarctica has been shown to impact ice shelf stability through the fracturing and flexural processes. Image scarcity has often forced the community to use general climate and regional climate models to explore hydrological features. Notwithstanding models having been considerably refined over the past years, they still require improvements in capturing the processes driving the energy balance and, most importantly, the feedback among the drivers and the energy balance terms that drive the hydrological processes. Moreover, spatial resolution is still too coarse to properly capture hydrological processes, especially over ice shelves. Machine learning (ML) tools can help in this regard, especially when it is computationally infeasible to run physics-based models at desired resolutions in space and time, like in the case of ice shelf surface hydrology. This project will train Generative Adversarial Networks (GANs) with the outputs of a regional climate model and remote sensing data to generate unprecedented, high-resolution (100 m) maps of surface melting. Beside improving the spatial resolution, and hence providing a long-needed and crucial dataset to the polar community, the tool here proposed will be able to provide satellite-like maps on a daily basis, hence addressing also those issues related to the lack of spatial coverage. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MODELS; Amd/Us; AMD; USA/NSF; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; USAP-DC; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Polar Cyberinfrastructure; Polar Cyberinfrastructure; Polar Cyberinfrastructure", "paleo_time": null, "persons": "Tedesco, Marco", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: EAGER: Generation of high resolution surface melting maps over Antarctica using regional climate models, remote sensing and machine learning", "uid": "p0010277", "west": -180.0}, {"awards": "2139002 Huth, Alexander", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Simulations of ice-shelf rifting on Larsen C Ice Shelf", "datasets": [{"dataset_uid": "601718", "doi": "10.15784/601718", "keywords": "Antarctica; Glaciology; Iceberg; Ice Shelf Dynamics; Larsen C Ice Shelf; Model Data; Modeling", "people": "Huth, Alexander", "repository": "USAP-DC", "science_program": null, "title": "Simulations of ice-shelf rifting on Larsen C Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601718"}], "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "Icebergs influence climate by controlling how freshwater from ice sheets is distributed into the ocean, where roughly half of ice sheet mass loss is attributed to iceberg calving in the current climate. The freshwater deposited by icebergs as they drift and melt can affect ocean circulation, sea-ice formation, and biological primary productivity. Furthermore, calving of icebergs from ice shelves, the floating extensions of ice sheets, can influence ice sheet evolution and sea-level rise by reducing the resistive stresses provided by ice shelves on the seaward flow of upstream grounded ice. The majority of mass calved from ice shelves occurs in the form of tabular icebergs, which are typically hundreds of meters thick and on the order of tens to hundreds of kilometers in length and width. Tabular calving occurs when full-thickness ice shelf fractures known as rifts propagate to the edges of the ice shelf. These calving events are infrequent, often with decades between events on an individual ice shelf. Changes in tabular calving behavior, i.e., the size and frequency of calving events, can strongly influence climate and ice sheet evolution. However, tabular calving behavior, and how it responds to changes in climate, is neither well understood nor accurately represented in climate models. In this project, a tabular calving parameterization for climate models will be developed. The parameterization will be derived according to data generated from a series of realistic and idealized century-scale tabular calving simulations, which will be performed with a novel ice flow and damage framework that can be applied at the scale of individual ice sheet-ice shelf systems: the CD-MPM-SSA (Continuum Damage Material Point Method for Shelfy-Stream Approximation). During these simulations, the geometry of the ice shelf, mechanical/rheological properties of the ice, and climate forcings such as ocean temperature will be varied to determine the rifting and calving response. The calving parameterization derived from these experiments will be implemented in a Geophysical Fluid Dynamics Laboratory (GFDL) climate model, where it will be coupled with a bonded-particle iceberg model. Then, experiments will be run to study the feedback between changes in iceberg calving behavior and climate. Success of this project will improve our understanding and representation of the ice mass budget, ice sheet evolution, and ocean freshwater fluxes, and will improve projections of climate change and sea-level rise. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; ICEBERGS; AMD; Antarctic Ice Sheet; USA/NSF; GLACIERS/ICE SHEETS; Amd/Us; MODELS", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Huth, Alex", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "OPP-PRF Calving, Icebergs, and Climate", "uid": "p0010276", "west": -180.0}, {"awards": "2230824 Nitsche, Frank; 1936530 Carbotte, Suzanne", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "Samples and data obtained by researchers working in Antarctica are valuable, unique assets which typically require a substantial and expensive logistical effort to acquire. Preservation of these data increases the return on the significant public investment for acquisition, enabling future re-use for new analyses, and ensure that data behind scientific publications are available for others to review. The US Antarctic Program Data Center (USAP-DC) will provide an open-disciplinary hybrid repository for project metadata and the diverse research data obtained from the Antarctic region by NSF funded researchers for which other data repositories do not exist. In addition, a Project Catalog will provide a single online resource for the US Antarctic scientific community to manage information about their research activities and will link project metadata to the various distributed repositories where Antarctic data resides. In doing so, the USAP-DC will follow community best practices and standards to ensure data are citable, shareable, and discoverable. It will also facilitate registration of data descriptions into the Antarctic Master Directory to meet US goals for data sharing under the International Antarctic Treaty. With full open access to interfaces to search for and download data, USAP-DC will make a wide range of data products resulting from NSF funded research in Antarctica available not only to the research community but also to the broader public. The data center is operated using community standards for metadata and data access which helps ensure data re-usability into the future. The new Project catalog, which is designed to support consolidation of information on research products of USAP awards over the lifetime of a project, will make it simpler for NSF program managers, but also for individual researchers and especially larger collaborative research groups to keep track of datasets and related information produced as part of their projects. Through tutorials and meetings at conferences USAP-DC will contribute to raise awareness and inform the research community, especially new investigators about data management best practices. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; Antarctica; Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; GLACIERS/ICE SHEETS; COMPUTERS; ICE CORE RECORDS; SNOW/ICE; Database; ECOLOGICAL DYNAMICS; USAP-DC; OCEAN CHEMISTRY; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Polar Cyberinfrastructure; Polar Cyberinfrastructure", "paleo_time": null, "persons": "Carbotte, Suzanne; Tinto, Kirsty; Nitsche, Frank O.", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Supporting Antarctic Research with Ongoing Operations and Development of the USAP-DC Project Catalog and Data Repository", "uid": "p0010274", "west": -180.0}, {"awards": "2139051 Guitard, Michelle", "bounds_geometry": "POLYGON((-45 -57,-44.3 -57,-43.6 -57,-42.9 -57,-42.2 -57,-41.5 -57,-40.8 -57,-40.1 -57,-39.4 -57,-38.7 -57,-38 -57,-38 -57.5,-38 -58,-38 -58.5,-38 -59,-38 -59.5,-38 -60,-38 -60.5,-38 -61,-38 -61.5,-38 -62,-38.7 -62,-39.4 -62,-40.1 -62,-40.8 -62,-41.5 -62,-42.2 -62,-42.9 -62,-43.6 -62,-44.3 -62,-45 -62,-45 -61.5,-45 -61,-45 -60.5,-45 -60,-45 -59.5,-45 -59,-45 -58.5,-45 -58,-45 -57.5,-45 -57))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "Antarctic Ice Sheet stability remains a large uncertainty in predicting future sea level. Presently, the greatest ice mass loss is observed in locations where relatively warm water comes into contact with glaciers and ice shelves, melting them from below. This has led researchers to hypothesize that the interactions that occur between the ocean and the ice are important for determining ice sheet stability and that increased warm water presence will accelerate Antarctic ice mass loss and lead to greater sea level rise in the coming century. To better predict future ice sheet behavior, it is critical to understand past ice-ocean interactions around Antarctica, especially during warm periods and at times when Earth\u2019s climate was undergoing major changes. Past Antarctic ice mass and environmental conditions like ocean temperature can be reconstructed using sediments, which capture an environmental record as they accumulate on the ocean floor. By looking at sediment composition and by analyzing geochemical signatures within the sediment, it is possible to piece together a record of climate change on hundred- to million-year timescales. This project will reconstruct upper ocean temperatures and Antarctic ice retreat/advance cycles from 2.6 to 0.7 million years ago, which encompasses the Mid-Pleistocene Transition, a time in Earth\u2019s history that marks the shift from 41-thousand year glacial cycles to 100-thousand year glacial cycles. A record will be generated from existing sediment cores collected from the Scotia Sea during International Ocean Discovery Program Expedition 382. The Mid-Pleistocene Transition (MPT; ~1.25\u20130.7 Ma) marks the shift from glacial-interglacial cycles paced by obliquity (~41 kyr cycles) to those paced by eccentricity (~100-kyr cycles). This transition occurred despite little variation in Earth\u2019s orbital parameters, suggesting a role for internal climate feedbacks. The MPT was accompanied by decreasing atmospheric pCO2, increasing deep ocean carbon storage, and changes in deep water formation and distribution, all of which are linked to Antarctic margin atmosphere-ice-ocean interactions. However, Pleistocene records that document such interactions are rarely preserved on the shelf due to repeated Antarctic Ice Sheet (AIS) advance; instead, they are preserved in deep Southern Ocean basins. This project takes advantage of the excellent preservation and recovery of continuous Pleistocene sediment sequences collected from the Scotia Sea during International Ocean Discovery Program Expedition 382 to test the following hypotheses: 1) Southern Ocean upper ocean temperatures vary on orbital timescales during the early to middle Pleistocene (2.6\u20130.7 Ma), and 2) Southern Ocean temperatures co-vary with AIS advance/retreat cycles. Paleotemperatures will be reconstructed using the TetraEther indeX of 86 carbons (TEX86), a proxy that utilizes marine archaeal biomarkers. The Scotia Sea TEX86-based paleotemperature record will be compared to records of AIS variability, including ice rafted debris. Expedition 382 records will be compared to orbitally paced climatic time series and the benthic oxygen isotope record of global ice volume and bottom water temperature to determine if a correlation exists between upper ocean temperature, AIS retreat/advance, and orbital climate forcing. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -38.0, "geometry": "POINT(-41.5 -59.5)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; SEA SURFACE TEMPERATURE; USAP-DC; USA/NSF; LABORATORY; AMD; Scotia Sea", "locations": "Scotia Sea", "north": -57.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Michelle, Guitard", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -62.0, "title": "Investigating the influence of ocean temperature on Antarctic Ice Sheet evolution during the early to middle Pleistocene ", "uid": "p0010275", "west": -45.0}, {"awards": "1744949 Campbell, Seth; 1744927 Mitrovica, Jerry; 1745015 Zimmerer, Matthew", "bounds_geometry": "POLYGON((-145 -74,-141.6 -74,-138.2 -74,-134.8 -74,-131.4 -74,-128 -74,-124.6 -74,-121.2 -74,-117.8 -74,-114.4 -74,-111 -74,-111 -74.6,-111 -75.2,-111 -75.8,-111 -76.4,-111 -77,-111 -77.6,-111 -78.2,-111 -78.8,-111 -79.4,-111 -80,-114.4 -80,-117.8 -80,-121.2 -80,-124.6 -80,-128 -80,-131.4 -80,-134.8 -80,-138.2 -80,-141.6 -80,-145 -80,-145 -79.4,-145 -78.8,-145 -78.2,-145 -77.6,-145 -77,-145 -76.4,-145 -75.8,-145 -75.2,-145 -74.6,-145 -74))", "dataset_titles": "Mt. Waesche ground-penetrating radar data 2018-2019", "datasets": [{"dataset_uid": "601490", "doi": "10.15784/601490", "keywords": "Antarctica; GPR; Mt. Waesche", "people": "Braddock, Scott", "repository": "USAP-DC", "science_program": null, "title": "Mt. Waesche ground-penetrating radar data 2018-2019", "url": "https://www.usap-dc.org/view/dataset/601490"}], "date_created": "Fri, 22 Oct 2021 00:00:00 GMT", "description": "This study will collect a novel dataset to determine how the West Antarctic Ice Sheet (WAIS) responded to a warmer climate during the last interglacial period (~125,000 years ago) by reconstructing the glacial history at the Mt. Waesche volcano. Reconstructing WAIS geometry when the ice sheet was smaller than present is difficult and data are lacking because the evidence lies beneath the present ice sheet. This study will drill through the ice sheet and recover bedrock that can be analyzed for its surface exposure history to help determine when the surface became overridden by the ice sheet. This study will provide constraints on the past maximum and minimum spatial extent of WAIS during the last glacial-interglacial cycle. Understanding the geometry of a reduced WAIS during intervals when the planet was warmer than present may provide a possible analogue for future environmental conditions given predicted temperature trends. A reduction of WAIS results in rising sea levels which threatens coastal communities across the globe. The data will help improve numerical ice sheet models to better predict WAIS response to current and future climate trends. The project supports a teacher educational workshop and the training of graduate and undergraduate students. The goal of this project is to obtain rock samples from beneath the WAIS through shallow (\u003c80 m) drilling at Mt. Waesche, a volcano in Marie Byrd Land, near an ice dome of WAIS (2000 m elevation). The lithologies of lava flows exposed on the flank of the volcano are well-suited for cosmogenic 3He and 36Cl as well as 40Ar/39Ar measurements which will establish eruption and exposure age. Existing 40Ar/39Ar data indicate basaltic lava flows on the volcano flank as young as 350 ka. Thus, measured cosmogenic nuclides measured in rock cores from beneath the ice surface will be indicative of relatively recent exposure during periods of reduced ice elevation, most likely, during the last interglacial. The first field season is focused on identifying appropriate locations for drilling and a ground penetrating radar (GPR) survey of the subglacial topography \u003c100m under the blue ice area. Mapping and dating the adjacent exposed lava flows will allow tracing of lava flows of known age and composition below the ice margin that will be targeted for drilling the following year. The second field season activities include drilling 8 boreholes (two transects) through blue ice with the Winkie drill near the ice margin to 80 m depth to obtain rock cores from the sub-ice lava flows. 3He exposure ages will constrain the duration and minimum extent of past surface lowering of the WAIS in Marie Byrd Land. Deeper GPR imaging (up to 700 m) will hope to reveal additional evidence of lava/ice interactions that would independently place constraints on lower ice levels during past eruptions. Results from this study will be compared with the modeled ice elevation histories at Mt. Waesche to validate ice sheet modeling efforts. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -111.0, "geometry": "POINT(-128 -77)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Mt. Waesche; USA/NSF; SNOW/ICE; GLACIER THICKNESS/ICE SHEET THICKNESS; PALEOCLIMATE RECONSTRUCTIONS; LABORATORY; LAVA COMPOSITION/TEXTURE; Amd/Us; AMD; USAP-DC", "locations": "Mt. Waesche", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Braddock, Scott; Campbell, Seth; Ackert, Robert; Zimmerer, Matthew; Mitrovica, Jerry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Collaborative Research: Constraining West Antarctic Ice Sheet elevation during the last interglacial", "uid": "p0010272", "west": -145.0}, {"awards": "1921418 Yan, Stephen", "bounds_geometry": null, "dataset_titles": "2019 initial L-band radar data for Dome Concordia; 2019 initial L-band radar data for EGRIP", "datasets": [{"dataset_uid": "601488", "doi": "10.15784/601488", "keywords": "Antarctica; Greenland", "people": "Taylor, Drew; Gogineni, Prasad; Taylor, Ryan; O\u0027Neill, Charles", "repository": "USAP-DC", "science_program": null, "title": "2019 initial L-band radar data for EGRIP", "url": "https://www.usap-dc.org/view/dataset/601488"}, {"dataset_uid": "601489", "doi": "10.15784/601489", "keywords": "Antarctica", "people": "Gogineni, Prasad; Taylor, Ryan; O\u0027Neill, Charles; Taylor, Drew", "repository": "USAP-DC", "science_program": null, "title": "2019 initial L-band radar data for Dome Concordia", "url": "https://www.usap-dc.org/view/dataset/601489"}], "date_created": "Mon, 11 Oct 2021 00:00:00 GMT", "description": "Predicting the response of ice sheets to changing climate and their contribution to sea level requires accurate representation in numerical models of basal conditions under the ice. There remain large data gaps for these basal boundary conditions under the East Antarctic Ice Sheet as well as in West Antarctica, including basal melt rates under ice shelves. This project will develop and test a prototype ground-based radar system to sound and image ice more than 4km thick, detect thin water films at the ice bed, and determine basal melt rates under ice shelves. The team will work with European partners (France, Italy, Germany) at Dome C to conduct deep-field Antarctic testing of the new radar. The project will build and test an L-band radar system (1.2-1.4GHz) with peak transmit power of 2kW. In addition to sounding and imaging thick ice, detection goals include resolving thin water films (\u003e0.5mm). Such a system would target glaciological problems including site selection for ice in the 1.5-million-year age range, basal stress boundary conditions under grounded ice, and melt rates under floating shelves. By demonstrating feasibility, the project aims to influence sensor selection for satellite missions. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; GLACIER THICKNESS/ICE SHEET THICKNESS; Amd/Us; USAP-DC; AMD; Greenland; USA/NSF; FIELD SURVEYS; Antarctica", "locations": "Antarctica; Greenland", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Science and Technology", "paleo_time": null, "persons": "Gogineni, Prasad; O\u0027Neill, Charles; Yan, Stephen; Taylor, Drew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "EAGER: L-Band Radar Ice Sounder for Measuring Ice Basal Conditions and Ice-Shelf Melt Rate", "uid": "p0010271", "west": null}, {"awards": "2035637 Tabor, Clay; 2035580 Aarons, Sarah", "bounds_geometry": null, "dataset_titles": "Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area; Oxygen and hydrogen isotope compositions and associated d-excess of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area.; Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.; Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "datasets": [{"dataset_uid": "601821", "doi": "10.15784/601821", "keywords": "ALHIC1903; Allan Hills; Antarctica; Blue Ice; Cryosphere; Dust; Leach; Rare Earth Element", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601821"}, {"dataset_uid": "601820", "doi": "10.15784/601820", "keywords": "ALHIC1903; Allan Hills; Antarctica; Cryosphere; Dust; Ice Core Data; Isotope; Nd; Neodymium; Sr; Strontium", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": null, "title": "Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601820"}, {"dataset_uid": "601822", "doi": "10.15784/601822", "keywords": "ALHIC1903; Allan Hills; Antarctica; Cryosphere; Deuterium; Hydrogen; Ice; Ice Core Data; Isotope; Oxygen; Water", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Oxygen and hydrogen isotope compositions and associated d-excess of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601822"}, {"dataset_uid": "601825", "doi": "10.15784/601825", "keywords": "Accumulation Rate; ALHIC1903; Allan Hills; Antarctica; Blue Ice; Concentration; Cryosphere; Dust; Flux", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": null, "title": "Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601825"}], "date_created": "Wed, 06 Oct 2021 00:00:00 GMT", "description": "This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The spatial extent of the West Antarctic Ice Sheet during the last interglacial period (129,000 to 116,000 years ago) is currently unknown, yet this information is fundamental to projections of the future stability of the ice sheet in a warming climate. Paleoclimate records and proxy evidence such as dust can inform on past environmental conditions and ice-sheet coverage. This project will combine new, high-sensitivity geochemical measurements of dust from Antarctic ice collected at Allan Hills with existing water isotope records to document climate and environmental changes through the last interglacial period. These changes will then be compared with Earth-system model simulations of dust and water isotopes to determine past conditions and constrain the sensitivity of the West Antarctic Ice Sheet to warming. The project will test the hypothesis that the uncharacteristically volcanic dust composition observed at another peripheral ice core site at Taylor Glacier during the last interglacial period is related to changes in the spatial extent of the West Antarctic Ice Sheet. This project aims to characterize mineral dust transport during the penultimate glacial-interglacial transition. The team will apply high-precision geochemical techniques to the high-volume, high-resolution ice core drilled at the Allan Hills site in combination with Earth system model simulations to: (1) determine if the volcanic dust signature found in interglacial ice from Taylor Glacier is also found at Allan Hills, (2) determine the likely dust source(s) to this site during the last interglacial, and (3) probe the atmospheric and environmental changes during the last interglacial with a diminished West Antarctic Ice Sheet. The team will develop a suite of measurements on previously drilled ice from Allan Hills, including isotopic compositions of Strontium and Neodymium, trace element concentrations, dust-size distribution, and imaging of ice-core dust to confirm the original signal observed and provide a broader spatial reconstruction of dust transport. In tandem, the team will conduct Earth system modeling with prognostic dust and water-isotope capability to test the sensitivity of dust transport under several plausible ice-sheet and freshwater-flux configurations. By comparing dust reconstruction and model simulations, the team aims to elucidate the driving mechanisms behind dust transport during the last interglacial period. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "MICROPARTICLE CONCENTRATION; FIELD SURVEYS; GEOCHEMISTRY; ICE EXTENT; Amd/Us; USA/NSF; PALEOCLIMATE RECONSTRUCTIONS; AMD; Allan Hills; ICE CORE RECORDS; USAP-DC", "locations": "Allan Hills", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Aarons, Sarah; Tabor, Clay", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Peripheral East Antarctic ice as a unique recorder of climate variability during the Last Interglacial", "uid": "p0010270", "west": null}, {"awards": "1745043 Simkins, Lauren; 1745055 Stearns, Leigh", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Circum-Antarctic grounding-line sinuosity; Elevation transects from Pine Island Bay; Pennell Trough, Ross Sea bathymetry and glacial landforms", "datasets": [{"dataset_uid": "601774", "doi": "10.15784/601774", "keywords": "Antarctica; Bed Roughness; Cryosphere; Geomorphology; Pine Island Bay", "people": "Munevar Garcia, Santiago", "repository": "USAP-DC", "science_program": null, "title": "Elevation transects from Pine Island Bay", "url": "https://www.usap-dc.org/view/dataset/601774"}, {"dataset_uid": "601484", "doi": "10.15784/601484", "keywords": "Antarctica; Bed Roughness; Bed Slope; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pinning Points", "people": "Stearns, Leigh; Riverman, Kiya; Simkins, Lauren", "repository": "USAP-DC", "science_program": null, "title": "Circum-Antarctic grounding-line sinuosity", "url": "https://www.usap-dc.org/view/dataset/601484"}, {"dataset_uid": "601474", "doi": "10.15784/601474", "keywords": "Antarctica; Bathymetry; Elevation; Geomorphology; Glacial History; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; NBP1502; Pennell Trough; Ross Sea; R/v Nathaniel B. Palmer", "people": "Munevar Garcia, Santiago; Prothro, Lindsay; Simkins, Lauren; Greenwood, Sarah; Anderson, John; Eareckson, Elizabeth", "repository": "USAP-DC", "science_program": null, "title": "Pennell Trough, Ross Sea bathymetry and glacial landforms", "url": "https://www.usap-dc.org/view/dataset/601474"}], "date_created": "Tue, 28 Sep 2021 00:00:00 GMT", "description": "Current ice mass loss in Antarctica is largely driven by changes at glacier grounding lines, where inland ice transitions from being grounded to floating in the ocean. The rate and pattern of glacier retreat in these circumstances is thought to be controlled by the terrain under the ice. This project incorporates evidence of past ice-retreat events and other field data, such as grounding-line positions and dates, subglacial topography, and meltwater features, into numerical models of ice flow to investigate the influence that grounding-line processes and subglacial topography have on glacier retreat rates over the past 15,000 years. Recent observations suggest that Antarctic ice mass loss is largely driven by perturbations at or near the grounding line. However, the lack of information on subglacial and grounding-line environments causes large uncertainties in projections of mass loss and sea-level rise. This project will integrate geologic data from the deglaciated continental shelf into numerical models of varying complexity from one to three-dimensions. Rarely do numerical ice-sheet models of Antarctica have multiple constraints on dynamics over the past ~15,000 years (a period that spans the deglaciation of the Antarctic continental shelf since the Last Glacial Maximum). The geologic constraints include grounding-line positions, deglacial chronologies, and information on grounding line-ice shelf processes. The models will be used to investigate necessary perturbations and controls that meet the geological constraints. The multidisciplinary approach of merging geologic reconstructions of paleo-ice behavior with numerical models of ice response will allow the research team to test understanding of subglacial controls on grounding-line dynamics and assess the stability of modern grounding lines. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MARINE SEDIMENTS; USAP-DC; Amd/Us; GLACIERS; BATHYMETRY; GLACIAL LANDFORMS; Antarctica; AMD; USA/NSF; R/V NBP", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Simkins, Lauren; Stearns, Leigh; Anderson, John; van der Veen, Cornelis", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations", "uid": "p0010269", "west": -180.0}, {"awards": "1916665 Mahon, Andrew; 1916661 Halanych, Kenneth; 2225144 Halanych, Kenneth", "bounds_geometry": "POLYGON((-72 -61,-69.8 -61,-67.6 -61,-65.4 -61,-63.2 -61,-61 -61,-58.8 -61,-56.6 -61,-54.4 -61,-52.2 -61,-50 -61,-50 -61.8,-50 -62.6,-50 -63.4,-50 -64.2,-50 -65,-50 -65.8,-50 -66.6,-50 -67.4,-50 -68.2,-50 -69,-52.2 -69,-54.4 -69,-56.6 -69,-58.8 -69,-61 -69,-63.2 -69,-65.4 -69,-67.6 -69,-69.8 -69,-72 -69,-72 -68.2,-72 -67.4,-72 -66.6,-72 -65.8,-72 -65,-72 -64.2,-72 -63.4,-72 -62.6,-72 -61.8,-72 -61))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 22 Sep 2021 00:00:00 GMT", "description": "Antarctica is among the most rapidly warming places on the planet, and some reports suggest the Antarctic environment is approaching, or possibly beyond, the tipping point for ice shelf collapse. The loss of ice around Antarctica is dramatically changing habitat availability for marine fauna, particularly benthic marine invertebrate species. Building on past studies, this research will provide insights into how changing climate impacts species distribution and community structure. Geological data suggests that during periods when ice extent was much reduced relative to modern levels, marine seaways connected the Ross and Weddell Seas on either side of Antarctica. However, most theories about the origins of current marine invertebrate distribution patterns fail to consider this transantarctic connection. This research will use molecular genomic tools to probe the DNA of Antarctic marine invertebrates and explore alternative hypotheses about factors that may have shaped current patterns of animal biodiversity in the Southern Ocean. Research will inform predictions about how species distributions may change as Antarctic ice sheets continue to deteriorate and provide critical information on how organisms adjust their ranges in response to environmental change. This work includes several specific outreach activities including presentations in K-8 classrooms, several short-format videos on Antarctic genomics and field work, and two 3-day workshops on bioinformatics approaches. A minimum of 4 graduate students, a postdoc and several undergraduates will also be trained during this project. The overarching goal of this research is to understand environmental factors that have shaped patterns of present-day diversity in Antarctic benthic marine invertebrates. Evidence from sediment cores and modeling suggests ice shelf collapses have occurred multiple times in the last few million years. During these periods, transantarctic seaways connected the Ross and Weddell Seas. This research will assess whether the presence of transantarctic waterways helps explain observed similarities between the Ross and Weddell Seas benthic marine invertebrate fauna better than other current hypotheses (e.g., dispersal by the Antarctic Circumpolar Current, or expansion from common glacial refugia). Seven Antarctic benthic invertebrate taxa will be targeted to test alternative hypothesis about the origins of population genetic structure in the Southern Ocean using Single Nucleotide Polymorphism (SNP) markers that sample thousands of loci across the genome. Additionally, research will test the current paradigm that divergence between closely related, often cryptic, species is the result of population bottlenecks caused by glaciation. Specifically, SNP data will be mapped on to draft genomes of three of our target taxa to assess the degree of genetic divergence and look for signs of selection. Research findings may be applicable to other marine ecosystems around the planet. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -50.0, "geometry": "POINT(-61 -65)", "instruments": null, "is_usap_dc": true, "keywords": "Marguerite Bay; USA/NSF; AMD; Weddell Sea; USAP-DC; FIELD SURVEYS; Amd/Us; MARINE ECOSYSTEMS; ANIMALS/INVERTEBRATES", "locations": "Weddell Sea; Marguerite Bay", "north": -61.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Halanych, Kenneth; Mahon, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -69.0, "title": "Collaborative Research: Have transantarctic dispersal corridors impacted Antarctic marine biodiversity?", "uid": "p0010266", "west": -72.0}, {"awards": "2049332 Chu, Winnie", "bounds_geometry": "POLYGON((-180 -75,-175 -75,-170 -75,-165 -75,-160 -75,-155 -75,-150 -75,-145 -75,-140 -75,-135 -75,-130 -75,-130 -76.1,-130 -77.2,-130 -78.3,-130 -79.4,-130 -80.5,-130 -81.6,-130 -82.7,-130 -83.8,-130 -84.9,-130 -86,-135 -86,-140 -86,-145 -86,-150 -86,-155 -86,-160 -86,-165 -86,-170 -86,-175 -86,180 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -84.9,155 -83.8,155 -82.7,155 -81.6,155 -80.5,155 -79.4,155 -78.3,155 -77.2,155 -76.1,155 -75,157.5 -75,160 -75,162.5 -75,165 -75,167.5 -75,170 -75,172.5 -75,175 -75,177.5 -75,-180 -75))", "dataset_titles": "Frozen Legacies - This repository hosts scientific journals and processing codes via Python and MATLab for the historical SPRI-NSF-TUD Campaign in Antarctica.", "datasets": [{"dataset_uid": "200466", "doi": "", "keywords": null, "people": null, "repository": "Frozen Legacies ", "science_program": null, "title": "Frozen Legacies - This repository hosts scientific journals and processing codes via Python and MATLab for the historical SPRI-NSF-TUD Campaign in Antarctica.", "url": "https://github.com/tarzona/frozenlegacies"}], "date_created": "Wed, 15 Sep 2021 00:00:00 GMT", "description": "This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Ice shelves play a critical role in restricting the seaward flow of grounded glacier ice by providing buttressing at their bases and sides. Processes that affect the long-term stability of ice shelves can therefore influence the future contribution of the Antarctic Ice Sheet to global sea-level rise. The Ross Ice Shelf is the largest ice shelf on Earth, and it buttresses massive areas of West and East Antarctica. Previous studies of modern ice velocity indicated that the Ross Ice Shelf\u2019s mass loss is roughly balanced by its mass gain. However, more recent work that extends further back in time reveals the ice shelf is likely not in steady state, with possible long-term thinning since the late 1990s. Consequently, to accurately interpret modern-day ice-shelf changes, long-term observations are critical to evaluate how these recent variations fit into the historical context of ice-shelf variability. This project will examine more than four decades of historical and modern airborne radar sounding observations of the Ross Ice Shelf (spanning 1971 to 2017) to investigate ice-shelf changes on decadal timescales. The team will process, calibrate, and analyze radar data collected during 1971-79 field campaigns and compare them against modern observations collected between 2011-17. They will estimate basal melt rates by examining changes in ice-shelf thickness, and will determine other important metrics for melt, including ice-shelf roughness, englacial temperature, and marine-ice formation. The project will support the education of a Ph.D. student at each of the three participating institutions. In addition, the project will support the training of undergraduate and high-school researchers in radioglaciology and Antarctic sciences. The project will test the hypothesis that, over decadal timescales, the basal melt rates beneath the Ross Ice Shelf have been low, particularly under shallow ice drafts, leading to overall thickening and increased buttressing potential. The team aims to provide a direct estimate of basal melt rates based on changes in ice-shelf thickness that occurred between 1971 and 2017. This project will extend similar work completed at Thwaites Glacier and improve the calibration methods on the vertical scaling for fast-time and depth conversion. The work will also leverage the dense modern surveys to improve the geolocation of radar film collected on earlier field campaigns to produce a more precise comparison of local shelf thickness with the modern data. In addition, the team will conduct englacial attenuation analysis to calculate englacial temperature to infer the trends in local basal melting. They will also examine the radiometric and scatterometric character of bed echoes at the ice-ocean boundary to characterize changes in ice-shelf basal roughness, marine-ice formation related to local basal freezing, and structural damage from fracture processes. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -130.0, "geometry": "POINT(-167.5 -80.5)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Antarctic Ice Sheet; GLACIER THICKNESS/ICE SHEET THICKNESS; USAP-DC; AMD; Transantarctic Mountains; Amd/Us; Siple Coast; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; FIELD SURVEYS; USA/NSF; Ross Ice Shelf", "locations": "Ross Ice Shelf; Antarctic Ice Sheet; Siple Coast; Transantarctic Mountains", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Chu, Winnie; Schroeder, Dustin; Siegfried, Matthew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "Frozen Legacies ", "repositories": "Frozen Legacies ", "science_programs": null, "south": -86.0, "title": "Collaborative Research: Investigating Four Decades of Ross Ice Shelf Subsurface Change with Historical and Modern Radar Sounding Data", "uid": "p0010265", "west": 155.0}, {"awards": "2103032 Schmittner, Andreas", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 09 Sep 2021 00:00:00 GMT", "description": "This project investigates Antarctic ice-ocean interactions of the last 20,000 years. The Antarctic ice sheet is an important component of Earth\u2019s climate system, as it interacts with the atmosphere, the surrounding Southern Ocean, and the underlaying solid Earth. The ice sheet is also the largest potential contributor to future sea-level rise and a major uncertainty in climate projections. Climate change may trigger instabilities that may lead to fast and irreversible collapse of parts of the ice sheet. However, little is known about how interactions between the Antarctic ice sheet and the rest of the climate system affect its behavior, climate, and sea level, partly because most climate models currently do not have fully-interactive ice-sheet components. The project team will construct a numerical climate model that includes an interactive Antarctic ice sheet, improving computational infrastructure for research. The model code will be made freely available to the public on a code-sharing site. In addition, the team will synthesize paleoclimate data and compare these with model simulations. This model-data comparison will test three scientific hypotheses regarding past changes in deep-ocean circulation, ice sheet, carbon, and sea level. The project will contribute to a better understanding of ice-ocean interactions and past climate variability. The project will test ideas that ice-ocean interactions have been important for setting deep ocean circulation and carbon storage during the Last Glacial Maximum and subsequent deglaciation. The new model will consist of three existing and well-tested components: (1) an isotope-enabled climate-carbon cycle model of intermediate complexity; (2) a model of the combined Antarctic ice sheet, solid Earth, and sea level; and (3) an iceberg model. The coupling will include ocean-temperature effects on basal melting of ice shelves; freshwater fluxes from the ice sheet to the ocean; and calving, transport and melting of icebergs. Once constructed and optimized, the model will be applied to simulate the Last Glacial Maximum and subsequent deglaciation. Differences between model versions with full, partial, or no coupling will be used to investigate the effects of ice-ocean interactions on the Meridional Overturning Circulation, deep ocean carbon storage, and ice-sheet fluctuations. Paleoclimate data synthesis will include temperature, carbon and nitrogen isotopes, radiocarbon ages, protactinium-thorium ratios, neodymium isotopes, carbonate ion, dissolved oxygen, relative sea level, and terrestrial cosmogenic ages into one multi-proxy database with a consistent updated chronology. The project will support an early-career scientist, one graduate student, undergraduate students, and new and ongoing national and international collaborations. Outreach activities in collaboration with a local science museum will benefit rural communities in Oregon by improving their climate literacy. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE CORE RECORDS; Amd/Us; USA/NSF; OCEAN TEMPERATURE; GLACIERS/ICE SHEETS; BIOGEOCHEMICAL CYCLES; MODELS; AMD; United States Of America; OCEAN CURRENTS; ICEBERGS; PALEOCLIMATE RECONSTRUCTIONS", "locations": "United States Of America", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Schmittner, Andreas; Haight, Andrew ; Clark, Peter", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Investigating Antarctic Ice Sheet-Ocean-Carbon Cycle Interactions During the Last Deglaciation", "uid": "p0010256", "west": -180.0}, {"awards": "2114786 Warnock, Jonathan", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 09 Sep 2021 00:00:00 GMT", "description": "The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica\u2019s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica\u2019s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth\u0027s most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica\u2019s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "MICROFOSSILS; FIELD SURVEYS; Weddell Sea Embayment; USA/NSF; SEA ICE; USAP-DC; PALEOCLIMATE RECONSTRUCTIONS; SEA SURFACE TEMPERATURE; AMD; Amd/Us", "locations": "Weddell Sea Embayment", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Warnock, Jonathan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation", "uid": "p0010260", "west": null}, {"awards": "1542936 Goehring, Brent; 1542976 Balco, Gregory", "bounds_geometry": "POLYGON((-145.7 -64.195,-113.988 -64.195,-82.276 -64.195,-50.564 -64.195,-18.852 -64.195,12.86 -64.195,44.572 -64.195,76.284 -64.195,107.996 -64.195,139.708 -64.195,171.42 -64.195,171.42 -66.2096,171.42 -68.2242,171.42 -70.2388,171.42 -72.2534,171.42 -74.268,171.42 -76.2826,171.42 -78.2972,171.42 -80.3118,171.42 -82.3264,171.42 -84.341,139.708 -84.341,107.996 -84.341,76.284 -84.341,44.572 -84.341,12.86 -84.341,-18.852 -84.341,-50.564 -84.341,-82.276 -84.341,-113.988 -84.341,-145.7 -84.341,-145.7 -82.3264,-145.7 -80.3118,-145.7 -78.2972,-145.7 -76.2826,-145.7 -74.268,-145.7 -72.2534,-145.7 -70.2388,-145.7 -68.2242,-145.7 -66.2096,-145.7 -64.195))", "dataset_titles": "Interface for viewing observational data related to exposure ages measurements and calculated geologic ages derived therefrom", "datasets": [{"dataset_uid": "200199", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Interface for viewing observational data related to exposure ages measurements and calculated geologic ages derived therefrom", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Fri, 03 Sep 2021 00:00:00 GMT", "description": "The overall goal of this project is to determine the effect of past changes in the size of the Antarctic Ice Sheet on global sea level. At the peak of the last ice age 25,000 years ago, sea level was 120 meters (400 feet) lower than it is at present because water that is now part of the ocean was instead part of expanded glaciers and ice sheets in North America, Eurasia, and Antarctica. Between then and now, melting and retreat of this land ice caused sea level to rise. In this project, we aim to improve our understanding of how changes in the size of the Antarctic Ice Sheet contributed to this process. The overall strategy to accomplish this involves (i) visiting areas in Antarctica that are not now covered by ice; (ii) looking for geological evidence, specifically rock surface and sediment deposits, that indicates that these areas were covered by thicker ice in the past; and (iii) determining the age of these geological surfaces and deposits. This project addresses the final part of this strategy -- determining the age of Antarctic glacial rock surfaces or sediment deposits -- using a relatively new technique that involves measuring trace elements in rock surfaces that are produced by cosmic-ray bombardment after the rock surfaces are exposed by ice retreat. By applying this method to rock samples collected in previous visits to Antarctica, the timing of past expansion and contraction of the ice sheet can be determined. The main scientific outcomes expected from this project are (i) improved understanding of how Antarctic Ice Sheet changes contributed to past global sea level rise; and (ii) improved understanding of modern observed Antarctic Ice Sheet changes in a longer-term context. This second outcome will potentially improve predictions of future ice sheet behavior. Other outcomes of the project include training of individual undergraduate and graduate students, as well as the development of a new course on sea level change to be taught at Tulane University in New Orleans, a city that is being affected by sea level change today. This project will use measurements of in-situ-produced cosmogenic carbon-14 in quartz from existing samples collected at several sites in Antarctica to resolve major ambiguities in existing Last Glacial Maximum to present ice sheet reconstructions. This project is important because of the critical nature of accurate reconstructions of ice sheet change in constraining reconstructions of past sea level change. Although carbon-14 is most commonly exploited as a geochronometer through its production in the upper atmosphere and incorporation into organic materials, it is also produced within the crystal lattice of rocks and minerals that are exposed to the cosmic-ray flux at the Earth\u0027s surface. In this latter case, its concentration is proportional to the duration of surface exposure, and measurements of in-situ-produced carbon-14 can be used to date geological events that form or expose rock surfaces, for example, ice sheet expansion and retreat. Although carbon-14 is one of several trace radionuclides that can be used for this purpose, it is unique among them in that its half-life is short relative to the time scale of glacial-interglacial variations. Thus, in cases where rock surfaces in polar regions have been repeatedly covered and uncovered by ice sheet change during many glacial-interglacial cycles, carbon-14 measurements are uniquely suited to accurately dating the most recent episode of ice sheet advance and retreat. We aim to use this property to improve our understanding of Antarctic Ice Sheet change at a number of critically located sites at which other surface exposure dating methods have yielded ambiguous results. Geographically, these are focused in the Weddell Sea embayment of Antarctica, which is an area where the geometry of the Antarctic continent potentially permits large glacial-interglacial changes in ice volume but where existing geologic records of ice sheet change are particularly ambiguous. In addition, in-situ carbon-14 measurements, applied where independently constrained deglaciation chronologies already exist, can potentially allow us to date the last period of ice sheet advance as well as the most recent retreat.", "east": 171.42, "geometry": "POINT(12.86 -74.268)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Cosmogenic Dating; GLACIER THICKNESS/ICE SHEET THICKNESS; AMD; USAP-DC; GLACIER ELEVATION/ICE SHEET ELEVATION; GLACIERS/ICE SHEETS; Carbon-14; USA/NSF; Weddell Sea Embayment; LABORATORY; FIELD SURVEYS; GLACIATION", "locations": "Weddell Sea Embayment", "north": -64.195, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Goehring, Brent; Balco, Gregory", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -84.341, "title": "COLLABORATIVE RESEARCH: Resolving Ambiguous Exposure-Age Chronologies of Antarctic Deglaciation with Measurements of In-Situ-Produced Cosmogenic Carbon-14", "uid": "p0010254", "west": -145.7}, {"awards": "0838843 Kurbatov, Andrei; 1745006 Brook, Edward J.; 1744993 Higgins, John; 1744832 Severinghaus, Jeffrey; 1745007 Mayewski, Paul", "bounds_geometry": "POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667))", "dataset_titles": "Allan Hills 2022-23 Shallow Ice Core Field Report; Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022; Allan Hills Stable Water Isotopes; CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903; Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903; I-165-M GPR Field Report 2019-2020; MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903; Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old", "datasets": [{"dataset_uid": "601696", "doi": "10.15784/601696", "keywords": "Allan Hills; Antarctica; Ice Core", "people": "Brook, Edward J.; Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills 2022-23 Shallow Ice Core Field Report", "url": "https://www.usap-dc.org/view/dataset/601696"}, {"dataset_uid": "601620", "doi": "10.15784/601620", "keywords": "18O; Allan Hills; Allan Hills Blue Ice; Antarctica; Blue Ice; Delta 15N; Delta 18O; Dole Effect; Firn Thickness; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chronology; Ice Core Records", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022", "url": "https://www.usap-dc.org/view/dataset/601620"}, {"dataset_uid": "601896", "doi": "10.15784/601896", "keywords": "Allan Hills; Antarctica; Ch4; CO2; Cryosphere; Glaciology; Glaciology; Ice Core Data; Ice Core Records", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601896"}, {"dataset_uid": "601895", "doi": "10.15784/601895", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Noble Gas", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601895"}, {"dataset_uid": "601878", "doi": "10.15784/601878", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Cryosphere; Methane", "people": "Shackleton, Sarah; Marks Peterson, Julia; Brook, Edward; Kalk, Michael; Severinghaus, Jeffrey P.; Hishamunda, Valens", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old", "url": "https://www.usap-dc.org/view/dataset/601878"}, {"dataset_uid": "609541", "doi": "10.7265/N5NP22DF", "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope", "people": "Kurbatov, Andrei V.; Introne, Douglas; Mayewski, Paul A.; Spaulding, Nicole", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills Stable Water Isotopes", "url": "https://www.usap-dc.org/view/dataset/609541"}, {"dataset_uid": "601669", "doi": "10.15784/601669", "keywords": "Allan Hills; Antarctica; GPR; Ice Core; Report", "people": "Nesbitt, Ian; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "I-165-M GPR Field Report 2019-2020", "url": "https://www.usap-dc.org/view/dataset/601669"}, {"dataset_uid": "601897", "doi": "10.15784/601897", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciology; Ice Core Data; MOT; Ocean Temperature; Paleoclimate; Xe/Kr", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601897"}], "date_created": "Fri, 27 Aug 2021 00:00:00 GMT", "description": "Bubbles of ancient air trapped in ice cores have been used to directly reconstruct atmospheric composition, and its links to Antarctic and global climate, over the last 800,000 years. Previous field expeditions to the Allan Hills Blue Ice Area, Antarctica, have recovered ice cores that extend as far back as 2.7 million years, by far the oldest polar ice samples yet recovered. These ice cores extend direct observations of atmospheric carbon dioxide and methane concentrations and indirect records of Antarctic climate into a period of Earth\u0027s climate history that represents a plausible geologic analogue to future anthropogenic climate change. The results demonstrate a smaller glacial-interglacial variability of climate and greenhouse gases, and a persistent linkage between Antarctic climate and atmospheric carbon dioxide, between 1 and 2 million years ago. Through this project, the team will return to the Allan Hills Blue Ice Area to recover additional ice cores that date to 2 million years or older. The climate records developed from these ice cores will provide new insights into the chemical composition of the atmosphere and Antarctic climate during times of comparable or even greater warmth than the present day. Project results will help answer questions about issues associated with anthropogenic change including the relationship between temperature change and the mass balance of Antarctic ice and the relationship between atmospheric greenhouse gases and global climate change. Earth has been cooling, and ice sheets expanding, over the past ~52 million years. Superimposed on this cooling are periodic changes in Earth\u0027s climate system driven by variations in the eccentricity, precession, and obliquity of Earth\u0027s orbit around the Sun. Climate reconstructions based on measurements of oxygen isotopes in foraminiferal calcite indicate that, from ~2.8 to 1.2 million years before present (Ma), Earth\u0027s climate system oscillated between glacial and interglacial states every ~40,000 years (the \"40k world\"). Between 1.2-0.8 Ma and continuing to the present, the period of glacial cycles increased in amplitude and lengthened to ~100,000 years (the \"100k world\"). Ice cores preserve ancient air that allows direct reconstructions of atmospheric carbon dioxide and methane. They also archive proxy records of regional climate, mean ocean temperature, global oxygen cycling, and the aridity of nearby continents. Studies of stratigraphically continuous ice cores, extending to 800,000 years before present, have demonstrated that atmospheric carbon dioxide is strongly linked to climate, and it is of great interest to extend the ice-core record into the 40k world. Recent discoveries of well-preserved ice dating from 1.0 to 2.7 Ma from ice cores drilled in the Allan Hills Blue Ice Area (BIA), Antarctica, demonstrate the potential to retrieve stratigraphically discontinuous old ice at shallow depths (\u003c200 meters). This project will continue this work by retrieving new large-volume ice cores and measuring paleoclimate properties in both new and existing ice from the Allan Hills BIA. The experimental objectives are to more fully characterize fundamental properties of the climate system and the carbon cycle during the 40k world. Project results will have implications for Pleistocene climate change, and will provide new constraints on the processes that regulate atmospheric carbon dioxide, methane, and oxygen on geologic timescales. Given a demonstrated age of the ice at the Allan Hills BIA of at least 2 million years, the team will drill additional cores to prospect for ice that predates the initiation of Northern Hemisphere glaciation at the Plio-Pleistocene transition (~2.8 Ma). This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 159.41667, "geometry": "POINT(159.29167 -76.7)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; SNOW/ICE; Allan Hills; FIELD SURVEYS; USA/NSF; Amd/Us; LABORATORY", "locations": "Allan Hills", "north": -76.66667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Kurbatov, Andrei V.; Brook, Edward J.; Severinghaus, Jeffrey P.; Higgins, John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.73333, "title": "Collaborative research: Snapshots of Early and Mid-Pleistocene Climate and Atmospheric Composition from the Allan Hills Blue Ice Area ", "uid": "p0010253", "west": 159.16667}, {"awards": "2114839 Passchier, Sandra", "bounds_geometry": null, "dataset_titles": "Argon thermochronological data on Pliocene ice-rafted detrital mineral grains from IODP Expedition 379 in the Amundsen Sea sector; Grain-size data for the Pliocene section at IODP Site U1533, Amundsen Sea", "datasets": [{"dataset_uid": "601900", "doi": "10.15784/601900", "keywords": "Amundsen Sea Sector; Antarctica; Cryosphere; Glaciation; Grain Size; Pliocene; Sediment Core Data; Sedimentology", "people": "Passchier, Sandra; Mino-Moreira, Lisbeth", "repository": "USAP-DC", "science_program": null, "title": "Grain-size data for the Pliocene section at IODP Site U1533, Amundsen Sea", "url": "https://www.usap-dc.org/view/dataset/601900"}, {"dataset_uid": "601907", "doi": "10.15784/601907", "keywords": "40Ar/39Ar; Amundsen Sea; Amundsen Sea Sector; Antarctica; Cryosphere; Ice-Rafted Detritus; IODP; Paleoclimate; Pliocene; Provenance; Sedimentology", "people": "Hemming, Sidney R.; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on Pliocene ice-rafted detrital mineral grains from IODP Expedition 379 in the Amundsen Sea sector", "url": "https://www.usap-dc.org/view/dataset/601907"}], "date_created": "Wed, 25 Aug 2021 00:00:00 GMT", "description": "The West Antarctic Ice Sheet is the most vulnerable polar ice mass to warming and already a major contributor to global mean sea level rise. Its fate in the light of prolonged warming is a topic of major uncertainty. Accelerated sea level rise from ice mass loss in the polar regions is a major concern as a cause of increased coastal flooding affecting millions of people. This project will disclose a unique geological archive buried beneath the seafloor off the Amundsen Sea, Antarctica, which will reveal how the West Antarctic Ice Sheet behaved in a warmer climate in the past. The data and insights can be used to inform ice-sheet and ocean modeling used in coastal policy development. The project will also support the development of a competitive U.S. STEM workforce. Online class exercises for introductory geology classes will provide a gateway for qualified students into undergraduate research programs and this project will enhance the participation of women in science by funding the education of current female Ph.D. students. The project targets the long-term variability of the West Antarctic Ice Sheet over several glacial-interglacial cycles in the early Pliocene sedimentary record drilled by the International Ocean Discovery Program (IODP) Expedition 379 in the Amundsen Sea. Data collection includes 1) the sand provenance of ice-rafted debris and shelf diamictites and its sources within the Amundsen Sea and Antarctic Peninsula region; 2) sedimentary structures and sortable silt calculations from particle size records and reconstructions of current intensities and interactions; and 3) the bulk provenance of continental rise sediments compared to existing data from the Amundsen Sea shelf with investigations into downslope currents as pathways for Antarctic Bottom Water formation. The results are analyzed within a cyclostratigraphic framework of reflectance spectroscopy and colorimetry (RSC) and X-ray fluorescence scanner (XRF) data to gain insight into orbital forcing of the high-latitude processes. The early Pliocene Climatic Optimum (PCO) ~4.5-4.1 Ma spans a major warm period recognized in deep-sea stable isotope and sea-surface temperature records. This period also coincides with a global mean sea level highstand of \u003e 20 m requiring contributions in ice mass loss from Antarctica. The following hypotheses will be tested: 1) that the West Antarctic Ice Sheet retreated from the continental shelf break through an increase in sub iceshelf melt and iceberg calving at the onset of the PCO ~4.5 Ma, and 2) that dense shelf water cascaded down through slope channels after ~4.5 Ma as the continental shelf became exposed during glacial terminations. The project will reveal for the first time how the West Antarctic Ice Sheet operated in a warmer climate state prior to the onset of the current \u201cicehouse\u201d period ~3.3 Ma. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; TERRIGENOUS SEDIMENTS; Amd/Us; SEDIMENTS; FIELD SURVEYS; Amundsen Sea; USAP-DC; AMD", "locations": "Amundsen Sea", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "West Antarctic Ice-sheet Change and Paleoceanography in the Amundsen Sea Across the Pliocene Climatic Optimum", "uid": "p0010252", "west": null}, {"awards": "1941292 St-Laurent, Pierre; 1941304 Sherrell, Robert; 1941327 Stammerjohn, Sharon; 1941483 Yager, Patricia; 1941308 Fitzsimmons, Jessica", "bounds_geometry": "POLYGON((-120 -71,-118 -71,-116 -71,-114 -71,-112 -71,-110 -71,-108 -71,-106 -71,-104 -71,-102 -71,-100 -71,-100 -71.4,-100 -71.8,-100 -72.2,-100 -72.6,-100 -73,-100 -73.4,-100 -73.8,-100 -74.2,-100 -74.6,-100 -75,-102 -75,-104 -75,-106 -75,-108 -75,-110 -75,-112 -75,-114 -75,-116 -75,-118 -75,-120 -75,-120 -74.6,-120 -74.2,-120 -73.8,-120 -73.4,-120 -73,-120 -72.6,-120 -72.2,-120 -71.8,-120 -71.4,-120 -71))", "dataset_titles": "Dataset: A numerical simulation of the ocean, sea ice and ice shelves in the Amundsen Sea (Antarctica) over the period 2006-2022 and its associated code and input files; Expedition Data of NBP2202; Numerical experiments examining the response of onshore oceanic heat supply to yearly changes in the Amundsen Sea icescape (Antarctica); Vertical ocean profiles collected by a Conductivity-Temperature-Depth (CTD) package in the Amundsen Sea", "datasets": [{"dataset_uid": "200400", "doi": "10.17882/99231", "keywords": null, "people": null, "repository": "SEANOE", "science_program": null, "title": "Numerical experiments examining the response of onshore oceanic heat supply to yearly changes in the Amundsen Sea icescape (Antarctica)", "url": "https://doi.org/10.17882/99231"}, {"dataset_uid": "601785", "doi": "10.15784/601785", "keywords": "Amundsen Sea; Antarctica; Cryosphere; CTD; NBP2202; Oceanography; R/v Nathaniel B. Palmer", "people": "Stammerjohn, Sharon", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Vertical ocean profiles collected by a Conductivity-Temperature-Depth (CTD) package in the Amundsen Sea", "url": "https://www.usap-dc.org/view/dataset/601785"}, {"dataset_uid": "200399", "doi": "10.25773/bt54-sj65", "keywords": null, "people": null, "repository": "William \u0026 Mary ScholarWorks", "science_program": null, "title": "Dataset: A numerical simulation of the ocean, sea ice and ice shelves in the Amundsen Sea (Antarctica) over the period 2006-2022 and its associated code and input files", "url": "https://doi.org/10.25773/bt54-sj65"}, {"dataset_uid": "200311", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2202", "url": "https://www.rvdata.us/search/cruise/NBP2202"}], "date_created": "Fri, 20 Aug 2021 00:00:00 GMT", "description": "Part I: Non-technical summary: The Amundsen Sea is adjacent to the West Antarctic Ice Sheet (WAIS) and hosts the most productive coastal ecosystem in all of Antarctica, with vibrant green waters visible from space and an atmospheric carbon dioxide uptake rate ten times higher than the Southern Ocean average. The region is also an area highly impacted by climate change and glacier ice loss. Upwelling of warm deep water is causing melt under the ice sheet, which is contributing to sea level rise and added nutrient inputs to the region. This is a project that is jointly funded by the National Science Foundation\u2019s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own country. In this collaboration, the US team will undertake biogeochemical sampling alongside a UK-funded physical oceanographic program to evaluate the contribution of micronutrients such as iron from glacial meltwater to ecosystem productivity and carbon cycling. Measurements will be incorporated into computer simulations to examine ecosystem responses to further glacial melting. Results will help predict future impacts on the region and determine whether the climate sensitivity of the Amundsen Sea ecosystem represents the front line of processes generalizable to the greater Antarctic. This study is aligned with the large International Thwaites Glacier Collaboration (ITGC) and will make data available to the full scientific community. The program will provide training for undergraduate, graduate, post-doctoral, and early-career scientists in both science and communication. The team will also develop out-of-school science experiences for middle and high schoolers related to climate change and Antarctica. Part II: Technical summary: The Amundsen Sea hosts the most productive polynya in all of Antarctica, with atmospheric carbon dioxide uptake rates ten times higher than the Southern Ocean average. The region is vulnerable to climate change, experiencing rapid losses in sea ice, a changing icescape and some of the fastest melting glaciers flowing from the West Antarctic Ice Sheet, a process being studied by the International Thwaites Glacier Collaboration. The biogeochemical composition of the outflow from the glaciers surrounding the Amundsen Sea is largely unstudied. In collaboration with a UK-funded physical oceanographic program, ARTEMIS is using shipboard sampling for trace metals, carbonate system, nutrients, organic matter, and microorganisms, with biogeochemical sensors on autonomous vehicles to gather data needed to understand the impact of the melting ice sheet on both the coastal ecosystem and the regional carbon cycle. These measurements, along with access to the advanced physical oceanographic measurements will allow this team to 1) bridge the gap between biogeochemistry and physics by adding estimates of fluxes and transport of limiting micronutrients; 2) provide biogeochemical context to broaden understanding of the global significance of ocean-ice shelf interactions; 3) determine processes and scales of variability in micronutrient supply that drive the ten-fold increase in carbon dioxide uptake, and 4) identify small-scale processes key to iron and carbon cycling using optimized field sampling. Observations will be integrated into an ocean model to enhance predictive capabilities of regional ocean function. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -100.0, "geometry": "POINT(-110 -73)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; USA/NSF; USAP-DC; AMD; Amundsen Sea; Amd/Us; SHIPS", "locations": "Amundsen Sea", "north": -71.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Yager, Patricia; Medeiros, Patricia; Sherrell, Robert; St-Laurent, Pierre; Fitzsimmons, Jessica; Stammerjohn, Sharon", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "SEANOE", "repositories": "R2R; SEANOE; USAP-DC; William \u0026 Mary ScholarWorks", "science_programs": "Thwaites (ITGC)", "south": -75.0, "title": "NSFGEO-NERC: Collaborative Research: Accelerating Thwaites Ecosystem Impacts for the Southern Ocean (ARTEMIS)", "uid": "p0010249", "west": -120.0}, {"awards": "2122248 Waters, Laura", "bounds_geometry": "POLYGON((-127.143608 -77.1380528,-127.1012394 -77.1380528,-127.0588708 -77.1380528,-127.0165022 -77.1380528,-126.9741336 -77.1380528,-126.931765 -77.1380528,-126.8893964 -77.1380528,-126.8470278 -77.1380528,-126.8046592 -77.1380528,-126.7622906 -77.1380528,-126.719922 -77.1380528,-126.719922 -77.14809141,-126.719922 -77.15813002,-126.719922 -77.16816863,-126.719922 -77.17820724,-126.719922 -77.18824585,-126.719922 -77.19828446,-126.719922 -77.20832307,-126.719922 -77.21836168,-126.719922 -77.22840029,-126.719922 -77.2384389,-126.7622906 -77.2384389,-126.8046592 -77.2384389,-126.8470278 -77.2384389,-126.8893964 -77.2384389,-126.931765 -77.2384389,-126.9741336 -77.2384389,-127.0165022 -77.2384389,-127.0588708 -77.2384389,-127.1012394 -77.2384389,-127.143608 -77.2384389,-127.143608 -77.22840029,-127.143608 -77.21836168,-127.143608 -77.20832307,-127.143608 -77.19828446,-127.143608 -77.18824585,-127.143608 -77.17820724,-127.143608 -77.16816863,-127.143608 -77.15813002,-127.143608 -77.14809141,-127.143608 -77.1380528))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 19 Aug 2021 00:00:00 GMT", "description": "This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The geologic record reveals that volcanic activity increases when glaciers retreat and major ice sheets thin. This relationship produces a positive feedback mechanism where the uptick in volcanism increases greenhouse gasses concentrations, leading to climate warming and further deglaciation. Although the pattern between volcanism and deglaciation is observed in the geologic record, the exact mechanism(s) by which glaciers impact a volcanic plumbing system is unknown. This project focuses on Mount Waesche, a volcano in West Antarctica, that frequently erupts during warm, interglacial periods and undergoes a period of less activity during cold, glacial periods. This project will examine compositions of the rocks and minerals from Mount Waesche to determine magma storage depths, allowing the investigators to understand how magma plumbing systems change in response to glacial cycles. These results will be compared with geodynamic simulations to understand the physics behind the effects of deglaciation on the magmatic plumbing systems within Earth\u2019s crust. The investigators will additionally partner with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online. Isotopic and sedimentary datasets reveal that volcanic activity typically increases during interglacial periods. However, the physical mechanisms through which changes in the surface loading affect volcanic magmatic plumbing systems remain unconstrained. Recently generated 40Ar/39Ar eruption ages indicate that 86% of the dated samples from Mt. Waesche, a late Quaternary volcano in Marie Byrd land, correlate with interglacial periods, suggesting this volcano uniquely responds to changes in the West Antarctic Ice Sheet. We propose to combine the petrology of Mount Waesche\u2019s volcanic record, constraints on changing ice loads through time, and geodynamic modelling to: (1) Determine how pre-eruptive storage conditions change during glacial and interglacial periods using whole rock and mineral compositions of volcanic rocks; (2) Conduct geodynamic modeling to elucidate the relationship between lithospheric structure, temporal variations in ice sheet thickness, and subsequent changes in crustal stresses and magmatic transport and, therefore, the mechanism(s) by which deglaciation impacts magmatic plumbing systems; (3) Use the outcomes of objectives (1) and (2) to provide new constraints on the changes in ice sheet thickness through time that could plausibly trigger future volcanic and magmatic activity in West Antarctica. This collaborative approach will provide a novel methodology to determine prior magnitudes and rates of ice load changes within the Marie Byrd Land region of Antarctica. Lastly, estimates of WAIS elevation changes from this study will be compared to ongoing studies at Mount Waesche focused on constraining last interglacial ice sheet draw down using cosmogenic exposure ages obtained from shallow drilling. The scope of work also includes a partnership with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -126.719922, "geometry": "POINT(-126.931765 -77.18824585)", "instruments": null, "is_usap_dc": true, "keywords": "Mt. Waesche; GEOCHEMISTRY; LITHOSPHERIC PLATE MOTION; STRESS; Amd/Us; West Antarctica; Executive Committee Range; NOT APPLICABLE; USAP-DC; AMD; MAJOR ELEMENTS; USA/NSF; ROCKS/MINERALS/CRYSTALS", "locations": "West Antarctica; Mt. Waesche; Executive Committee Range", "north": -77.1380528, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Waters, Laura; Naliboff, John; Zimmerer, Matthew", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -77.2384389, "title": "Integrating petrologic records and geodynamics: Quantifying the effects of glaciation on crustal stress and eruptive patterns at Mt. Waesche, Executive Committee Range, Antarctica", "uid": "p0010248", "west": -127.143608}, {"awards": null, "bounds_geometry": null, "dataset_titles": "Antarctic Ice Thickness, Slipperiness, and Subglacial Lake Locations", "datasets": [{"dataset_uid": "601470", "doi": "10.15784/601470", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Thickness, Slipperiness, and Subglacial Lake Locations", "url": "http://www.usap-dc.org/view/dataset/601470"}], "date_created": "Fri, 13 Aug 2021 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Antarctic Ice Sheet; Ice Thickness; Subglacial Lake", "locations": "Antarctica; Antarctic Ice Sheet", "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": "Stubblefield, Aaron; Siegfried, Matthew; Arthern, Robert; Kingslake, Jonathan", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "1644171 Blackburn, Terrence", "bounds_geometry": "POLYGON((162 -77.5,162.2 -77.5,162.4 -77.5,162.6 -77.5,162.8 -77.5,163 -77.5,163.2 -77.5,163.4 -77.5,163.6 -77.5,163.8 -77.5,164 -77.5,164 -77.525,164 -77.55,164 -77.575,164 -77.6,164 -77.625,164 -77.65,164 -77.675,164 -77.7,164 -77.725,164 -77.75,163.8 -77.75,163.6 -77.75,163.4 -77.75,163.2 -77.75,163 -77.75,162.8 -77.75,162.6 -77.75,162.4 -77.75,162.2 -77.75,162 -77.75,162 -77.725,162 -77.7,162 -77.675,162 -77.65,162 -77.625,162 -77.6,162 -77.575,162 -77.55,162 -77.525,162 -77.5))", "dataset_titles": "Isotopic ratios for subglacial precipitates from East Antarctica; U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "datasets": [{"dataset_uid": "601806", "doi": "10.15784/601806", "keywords": "Antarctica; Cryosphere; Erosion; Isotope Data; Major Elements; Soil; Taylor Glacier; Taylor Valley", "people": "Piccione, Gavin; Tulaczyk, Slawek; Blackburn, Terrence; Edwards, Graham", "repository": "USAP-DC", "science_program": null, "title": "U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601806"}, {"dataset_uid": "200240", "doi": "10.26022/IEDA/111548 ", "keywords": null, "people": null, "repository": "EarthChem", "science_program": null, "title": "Isotopic ratios for subglacial precipitates from East Antarctica", "url": "https://doi.org/10.26022/IEDA/111548"}], "date_created": "Fri, 13 Aug 2021 00:00:00 GMT", "description": "A\u00a0nontechnical\u00a0description of the project The primary scientific goal of the project is to test whether Taylor Valley, Antarctica has been eroded significantly by glaciers in the last ~2 million years (Ma). Taylor Valley is one of the Dry Valleys of the Transantarctic Mountains, which are characterized by low mean annual temperatures, low precipitation, and limited erosion. These conditions have allowed fragile glacial landforms to be preserved for up to 15 Ma. Sediment eroded and deposited by glaciers is found on the valley walls and floors, with progressively younger deposits preserved at lower elevations. Scientists can date glacial deposits to understand the process and timing of past glacial erosion. Previous work in the Dry Valleys region suggested that extremely cold glaciers like Taylor Glacier, a major outlet glacier entering the valleys, were not erosive during the last several million years. This research will test a new hypothesis that glacial erosion and sediment production beneath Taylor Glacier have been active in the last few million years. This hypothesis will be tested using a new isotopic dating method called \"comminution dating\u0027 which determines when fine-grained sediment particles called silt were formed. If the sediment age is young, then the results will suggest that glacial processes have been more dynamic than previously thought. Overall, this study will increase our understanding of the nature and extent of past glaciations in Antarctica. Because the silt produced by erosion sediment is a nutrient for local ecosystems, the results will also shed light on delivery of nutrients to soils, streams, and coastal zones in high polar regions. This project will be led by an early career scientist and includes training of a Ph.D. student. A\u00a0technical description of the project There is a long-standing scientific controversy about the stability of the East Antarctic Ice Sheet with much evidence centered in the Dry Valleys region of South Victoria Land. A prevailing view of geomorphologists is that the landscape has been very stable and that the effects of glaciation have been minimal for the past ~15 Ma. This project will distinguish between two end-member scenarios of glacial erosion and deposition by Taylor Glacier, an outlet glacier of the East Antarctic Ice Sheet that terminates in Taylor Valley in the Dry Valleys region of Antarctica. In the first scenario, all valley relief is generated prior to 15 Ma when non-polar climates enabled warm-based glaciers to incise and widen ancient river channels. In this case, younger glacial deposits record advances of cold-based glaciers of decreasing ice volume and limited glacial erosion, and sediment generation resulted in glacial deposits composed primarily of older recycled sediments. In the second scenario, selective erosion of the valley floor has continued to deepen Taylor Valley but has not affected the adjacent peaks over the last 2 Ma. In this scenario, the \"bathtub rings\" of Quaternary glacial deposits situated at progressively lower elevations through time could be due to the lowering of the valley floor by subglacial erosion and with it, production of new sediment which is now incorporated into these deposits. While either scenario would result in the present-day topography, they differ in the implied evolution of regional glacial ice volume over time and the timing of both valley relief production and generation of fine-grained particles. The two scenarios will be tested by placing time constraints on fine particle production using U-series comminution dating. This new geochronologic tool exploits the loss of 234U due to alpha-recoil. The deficiency in 234U only becomes detectable in fine-grained particles with a sufficiently high surface-area-to-volume ratio which can incur appreciable 234U loss. The timing of comminution and particle size controls the magnitude of 234U loss. While this geochronologic tool is in its infancy, the scientific goal of this proposal can be achieved by resolving between ancient and recently comminuted fine particles, a binary question that the preliminary modeling and measured data show is readily resolved.", "east": 164.0, "geometry": "POINT(163 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Taylor Valley", "locations": "Taylor Valley", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blackburn, Terrence; Tulaczyk, Slawek", "platforms": null, "repo": "USAP-DC", "repositories": "EarthChem; USAP-DC", "science_programs": null, "south": -77.75, "title": "U-Series Comminution Age Constraints on Taylor Valley Erosion", "uid": "p0010243", "west": 162.0}, {"awards": "1745057 Walker, Sally; 1745080 Gillikin, David; 1745064 Perez-Huerta, Alberto", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Analysis of striae groups and interstrial increments from Adamussium colbecki valves from Explorers Cove and Bay of Sails; Annual growth of Adamussium colbecki from Explorers Cove and Bay of Sails; Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores; Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.; Stable isotopes of Oxygen and Carbon in Adamissium colbecki from Explorers Cove and Bay of Sails", "datasets": [{"dataset_uid": "601469", "doi": "10.15784/601469", "keywords": "Adamussium Colbecki; Antarctica; McMurdo", "people": "Walker, Sally; Cronin, Kelly", "repository": "USAP-DC", "science_program": null, "title": "Analysis of striae groups and interstrial increments from Adamussium colbecki valves from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601469"}, {"dataset_uid": "601764", "doi": "10.15784/601764", "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Walker, Sally; Camarra, Steve; Verheyden, Anouk; Puhalski, Emma; Gillikin, David; Cronin, Kelly", "repository": "USAP-DC", "science_program": null, "title": "Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.", "url": "https://www.usap-dc.org/view/dataset/601764"}, {"dataset_uid": "601761", "doi": "10.15784/601761", "keywords": "Adamussium Colbecki; Antarctica; Bay Of Sails; Carbon; Explorers Cove; McMurdo Sound; Oxygen; Stable Isotopes", "people": "Cronin, Kelly; Perez-Huerta, Alberto; Bowser, Samuel S.; Verheyden, Anouk; Camarra, Steve; Puhalski, Emma; Andrus, Fred; Walker, Sally; Gillikin, David", "repository": "USAP-DC", "science_program": null, "title": "Stable isotopes of Oxygen and Carbon in Adamissium colbecki from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601761"}, {"dataset_uid": "601468", "doi": "10.15784/601468", "keywords": "Adamussium Colbecki; Antarctica; Growth; McMurdo Sound; Shell Fish", "people": "Cronin, Kelly; Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Annual growth of Adamussium colbecki from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601468"}, {"dataset_uid": "600077", "doi": "10.15784/600077", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; McMurdo Sound; Oceans; Sample/collection Description; Sample/Collection Description", "people": "Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600077"}], "date_created": "Fri, 06 Aug 2021 00:00:00 GMT", "description": "The goal of this project is to discover whether the Antarctic scallop, Adamussium colbecki, provides a guide to sea-ice conditions in nearshore Antarctica today and in the past. Scallops may grow slower and live longer in habitats where sea ice persists for many years, limited by food, compared to habitats where sea ice melts out annually. Also, the chemicals retained in the shell during growth may provide crucial habitat information related to not only changing sea-ice conditions but also the type of food, whether it is recycled from the seafloor or produced by algae blooming when sea ice has melted. Unlocking the ecological imprint captured within the shell of the Antarctic Scallop will increase our understanding of changing sea-ice conditions in Antarctica. Further, because the Antarctic scallop had relatives living at the time when the Antarctic ice sheet first appeared, the scallop shell record may contain information on the stability of the ice sheet and the history of Antarctic shallow seas. Funding will also be integral for training a new generation of geoscientists in fossil and chemical forensics related to shallow sea habitats in Antarctica. Scallops are worldwide in distribution, are integral for structuring marine communities have an extensive fossil record dating to the late Devonian, and are increasingly recognized as important paleoenvironmental proxies because they are generally well preserved in the sediment and rock record. The primary goal of this project is to assess the differences in growth, lifespan, and chemistry (stable isotopes, trace elements) archived in the shell of the Antarctic scallop that may be indicative of two ice states: persistent (multiannual) sea ice at Explorers Cove (EC) and annual sea ice (that melts out every year) at Bay of Sails (BOS), western McMurdo Sound, Antarctica. This project will investigate growth and lifespan proxies (physical and geochemical) and will use high-resolution records of stable oxygen isotopes to determine if a melt-water signal is archived in A. colbecki shells and whether that signal captures the differing ice behavior at two sites (EC versus BOS). Stable isotopes of carbon and nitrogen in association with trace elements will be used to examine subannual productivity spikes indicative of phytoplankton blooms, which are predicted to be more pronounced during open ocean conditions. Small growth increments in the outer calcite layer will be assessed to determine if they represent fortnightly growth, if so, they could provide a high-resolution proxy for monthly environmental processes. Unlocking the environmental archive preserved in A. colbecki shells may prove to be an important proxy for understanding changing sea-ice conditions in Antarctica\u0027s past. Funding will support a Ph.D. student and undergraduates from multiple institutions working on independent research projects. Web content focused on Antarctic marine communities will be designed for museum outreach, reaching thousands of middle-school children each year. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; AMD; Dry Valleys; USAP-DC; LABORATORY; USA/NSF", "locations": "Dry Valleys", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walker, Sally; Gillikin, David; Perez-Huerta, Alberto; Andrus, Fred", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative research: The Antarctic Scallop as Key to Paleoenvironments and Sea Ice Conditions: Understanding the Modern to Predict the Past", "uid": "p0010238", "west": -180.0}, {"awards": "1952199 Schneider, David", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Variable-resolution CESM2 over Antarctica (ANTSI): Monthly outputs used for evaluation", "datasets": [{"dataset_uid": "200417", "doi": "10.5281/zenodo.7335891", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Variable-resolution CESM2 over Antarctica (ANTSI): Monthly outputs used for evaluation", "url": "https://zenodo.org/records/7335892"}], "date_created": "Wed, 21 Jul 2021 00:00:00 GMT", "description": "The Antarctic Ice Sheet (AIS) is sensitive to and an indicator of climate change. While ice loss is largely driven by ocean warming, this might be mitigated by enhanced snowfall on the ice sheet. By developing an understanding of the processes governing snowfall variability and change on the AIS, this project will contribute to understanding the long-term role of the AIS as a contributor to sea-level rise. This project is strongly embedded in the collaborative, open-source framework of the Community Earth System Model version 2 (CESM2) and will deliver new datasets of Antarctic precipitation for use by the research community. The project will help to build a diverse geoscience workforce by recruiting and training a student to be directly involved in the research through the Significant Opportunities in Atmospheric Research and Science (SOARS) program. The project will leverage the Climate Model Intercomparison Project 6 climate model ensemble as a whole, and CESM2 in particular, to disentangle the major sources of uncertainty and to elucidate the underlying mechanisms of Antarctic precipitation change, with a particular focus on the role of atmospheric circulation changes relative to the role of atmospheric warming. Using the variable resolution capabilities of CESM2, the team will provide the community with precipitation estimates at a very high horizontal resolution. The analyses will also use a forthcoming 100-member large ensemble. The project seeks to answer the following questions: 1) How well does the CESM2 represent the present-day Antarctic surface climate, precipitation, and surface mass balance, including the mean and its variability? 2) What is the sensitivity of simulated Antarctic precipitation to model resolution in present-day and future climates? 3) What are the roles of thermodynamics (warming atmosphere and ocean) and dynamics (changes in atmospheric circulation) in observed and projected snowfall changes? How do these break down into forced and internal variability? In particular, is there a significant forced precipitation trend due to circulation changes driven by stratospheric ozone depletion and recovery and increases in greenhouse gas concentration? 4) What processes and boundary conditions drive the ensemble spread of Antarctic precipitation in single-model and multi-model ensembles? How does the spread driven by initial surface conditions (including sea ice cover, surface fluxes, inversion strength) compare with the irreducible uncertainty due to internal climate system variability? This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; ICE SHEETS; Amd/Us; Antarctica; AMD; SNOW; MODELS; USAP-DC", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Schneider, David; Datta, Rajashree Tri", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Uncertainty and Mechanisms of Antarctica\u2019s Changing Snowfall and its Role in Sea Level Change", "uid": "p0010233", "west": -180.0}, {"awards": "1445205 Putkonen, Jaakko", "bounds_geometry": "POLYGON((157.6 -83.2,157.62 -83.2,157.64 -83.2,157.66 -83.2,157.68 -83.2,157.7 -83.2,157.72 -83.2,157.74 -83.2,157.76 -83.2,157.78 -83.2,157.8 -83.2,157.8 -83.21,157.8 -83.22,157.8 -83.23,157.8 -83.24,157.8 -83.25,157.8 -83.26,157.8 -83.27,157.8 -83.28,157.8 -83.29,157.8 -83.3,157.78 -83.3,157.76 -83.3,157.74 -83.3,157.72 -83.3,157.7 -83.3,157.68 -83.3,157.66 -83.3,157.64 -83.3,157.62 -83.3,157.6 -83.3,157.6 -83.29,157.6 -83.28,157.6 -83.27,157.6 -83.26,157.6 -83.25,157.6 -83.24,157.6 -83.23,157.6 -83.22,157.6 -83.21,157.6 -83.2))", "dataset_titles": "Cosmogenic-Nuclide data at ICE-D; Old Ice, Ong Valley, Transantarctic Mountains", "datasets": [{"dataset_uid": "601665", "doi": "10.15784/601665", "keywords": "Antarctica; Buried Ice; Cosmogenic Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Old Ice; Ong Valley", "people": "Putkonen, Jaakko; Bergelin, Marie", "repository": "USAP-DC", "science_program": null, "title": "Old Ice, Ong Valley, Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601665"}, {"dataset_uid": "200295", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic-Nuclide data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Fri, 16 Jul 2021 00:00:00 GMT", "description": "Putkonen/1445205 This award supports the study of a large body of ice that is buried beneath approximately a meter of debris in the Ong Valley of the Transantarctic Mountains of East Antarctica. Preliminary analyses of this material suggest that it could be over a million years old. Most glacial ice contains tiny air bubbles that have trapped the atmospheric gases and other atmospherically transported materials existing at the time that the ice was deposited such as plant pollen, microbes and mineral dust. Samples will be collected from this buried ice mass, down to a depth of 10 meters, and cosmogenic nuclide concentrations both in the overlying debris and in the till contained in the ice will be measured. This site could contain some of the oldest ice on Earth and studies of the material contained within it may help researchers to better understand the processes involved in its survival for such long periods of time. This work will also help inform scientists about the processes involved in the development of landforms here on earth as well as those on Mars where similar dirt covered glaciers are found today. Samples of the buried ice will be collected in Ong Valley and analyzed to determine the cosmogenic nuclide concentrations in both the overlying debris and in the mineral matter suspended in the ice. The combined analysis of the target cosmogenic nuclides (Beryllium-10, Aluminum-26, and Neon-21) will allow the age of the ice to be uniquely determined and will enable determination of the rate that the ice is sublimating. The intellectual merit of this research is to unequivocally determine the age of the ice and the sublimation rate of the ice in Ong Valley, Antarctica and to better understand if this an uniquely Antarctic process or whether it could exist elsewhere on earth or on other planets. The work may also lead to the recognition of the oldest buried ice ever found on Earth and would provide a source from which direct information about the atmospheric chemistry, ancient life forms, and geology of that time could be measured. The broader impacts of this work are that it will be relevant to researchers in a number of different fields including glaciology, paleoclimatology, planetary geology, and biology. Several students will also participate in the project, conducting Antarctic field work, making measurements in the lab, attending meetings, participating in outreach activities, and producing videos. A graduate student will also write a thesis on this research. The results will be published in scientific journals and presented at conferences. The project requires field work in Antarctica.", "east": 157.8, "geometry": "POINT(157.7 -83.25)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; FIELD SURVEYS; Transantarctic Mountains; GLACIERS/ICE SHEETS; AMD; Amd/Us", "locations": "Transantarctic Mountains", "north": -83.2, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "putkonen, jaakko; Balco, Gregory; Morgan, Daniel", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -83.3, "title": "Collaborative Research: Long Term Sublimation/Preservation of Two Separate, Buried Glacier Ice Masses, Ong Valley, Southern Transantarctic Mountains", "uid": "p0010231", "west": 157.6}, {"awards": "1745097 Cassano, John; 1744878 Lazzara, Matthew", "bounds_geometry": "POLYGON((-115 -79,-114.4 -79,-113.8 -79,-113.2 -79,-112.6 -79,-112 -79,-111.4 -79,-110.8 -79,-110.2 -79,-109.6 -79,-109 -79,-109 -79.1,-109 -79.2,-109 -79.3,-109 -79.4,-109 -79.5,-109 -79.6,-109 -79.7,-109 -79.8,-109 -79.9,-109 -80,-109.6 -80,-110.2 -80,-110.8 -80,-111.4 -80,-112 -80,-112.6 -80,-113.2 -80,-113.8 -80,-114.4 -80,-115 -80,-115 -79.9,-115 -79.8,-115 -79.7,-115 -79.6,-115 -79.5,-115 -79.4,-115 -79.3,-115 -79.2,-115 -79.1,-115 -79))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 06 Jul 2021 00:00:00 GMT", "description": "The near surface atmosphere over West Antarctica is one of the fastest warming locations on the planet. This atmospheric warming, along with oceanic forcing, is contributing to ice sheet melt and hence rising global sea levels. An observational campaign, focused on the atmospheric boundary layer over the West Antarctic ice sheet, is envisioned. A robust set of year-round, autonomous, atmospheric and surface measurements, will be made using an instrumented 30-m tall tower at the West Antarctic ice sheet divide field camp. An additional unmanned aerial system field campaign will be conducted during the second year of this project and will supplement the West Antarctic ice sheet tall tower observations by sampling the depths of the boundary layer. The broader subject of the Antarctic ABL clearly supports a range of research activities ranging from the physics of turbulent mixing, its parameterization and constraints on meteorological forecasts, and even climatological effects, such as surface mass and energy balances. With the coming of the Thwaites WAIS program, a suite of metrological observables would be a welcome addition to the joint NSF/NERC (UK) Thwaites field campaigns. The meteorologists of this proposal have pioneered 30-m tall tower (TT) and unmanned aerial system (UAS) development in the Antarctic, and are well positioned to successfully carry out and analyze this work. In turn, the potential for these observations to advance our understanding of how the atmosphere exchanges heat with the ice sheet is high. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -109.0, "geometry": "POINT(-112 -79.5)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; Amd/Us; HUMIDITY; ATMOSPHERIC TEMPERATURE; West Antarctic Ice Sheet; BOUNDARY LAYER TEMPERATURE; USAP-DC; ATMOSPHERIC PRESSURE MEASUREMENTS; FIELD SURVEYS; BOUNDARY LAYER WINDS; USA/NSF", "locations": "West Antarctic Ice Sheet", "north": -79.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Cassano, John; Lazzara, Matthew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -80.0, "title": "Collaborative Research: Observing the Atmospheric Boundary over the West Antarctic Ice Sheet", "uid": "p0010225", "west": -115.0}, {"awards": "2000992 Romans, Brian", "bounds_geometry": "POINT(-172.873074 -74.274008)", "dataset_titles": "Grain size of Plio-Pleistocene continental slope and rise sediments, Hillary Canyon, Ross Sea", "datasets": [{"dataset_uid": "601807", "doi": "10.15784/601807", "keywords": "Antarctica; Cryosphere; Grain Size; Ross Sea", "people": "Romans, Brian W.; Varela, Natalia", "repository": "USAP-DC", "science_program": null, "title": "Grain size of Plio-Pleistocene continental slope and rise sediments, Hillary Canyon, Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601807"}], "date_created": "Tue, 06 Jul 2021 00:00:00 GMT", "description": "Part I: Non-technical description: Predicting how polar ice sheets will respond to future global warming is difficult because all the processes that contribute to their melting are not well understood. This is important because the more ice on land that melts, the higher sea levels will rise. The most significant uncertainty in current estimates of sea-level rise in the coming decades is the potential contribution from the Antarctic Ice Sheet. One way to increase our knowledge about how large ice sheets respond to climate change in response to natural factors is to examine the geologic past. Natural global warming (and cooling) events in Earth\u2019s history provide examples that we can use to better understand processes, interactions, and responses we can\u2019t directly observe today. One such time period, approximately three million years ago (known as the Pliocene), was the last time atmospheric carbon dioxide levels were as high as they are today and, therefore, represents a time period to study to better understand the ice sheet response to a warming climate. Specifically, this project is interested in understanding how ocean currents near Antarctica, which transport heat and store carbon, behaved during these past climate events. The history of past ice sheet-ocean interactions are recorded in sediments that were deposited, layer upon layer, in the deep sea offshore Antarctica. In January-February 2018, a team of scientists and crew set sail to the Ross Sea, offshore west Antarctica, on the scientific ocean drilling vessel JOIDES Resolution to recover such sediment archives. This project focuses on a sediment core from that expedition, which captures the relatively warm Pliocene time interval, as well as the subsequent transition into cooler climates typical of the past two million years. The researchers will analyze the sediment with multiple complementary measurements, including: grain size, composition, chemistry of organic matter, physical structures, microfossil type and abundance, and more. These analyses will be done by the research team, including several students, at their respective laboratories and will then integrated into a unified record of ice sheet-ocean interactions. Ultimately, the results will be used to improve modeled projections of how the Antarctic Ice Sheet could respond to future climate change. Part II: Technical description: Geological records from the Antarctic Ice Sheet (AIS) margin demonstrate that the ice sheet oscillated in response to orbital variations in insolation (i.e., ~400, 100, 41, and 20 kyr), and it appears to be more sensitive to specific frequencies that regulate mean annual insolation (i.e., 41-kyr obliquity), particularly when the ice sheet extends into marine environments and is impacted by ocean circulation. However, the relationship between orbital forcing and the production of Antarctic Bottom Water (AABW) is unconstrained. Thus, a knowledge gap exists in understanding how changing insolation impacts ice marginal and Southern Ocean conditions that directly influence ventilation of the global ocean. The researchers hypothesize that insolation-driven changes directly affected the production and export of AABW to the Southern Ocean from the Pliocene through the Pleistocene. For example, obliquity amplification during the warmer Pliocene may have led to enhanced production and export of dense waters from the shelf due to reduced AIS extent, which, in turn, led to greater AABW outflow. To determine the relationship of AABW production to orbital regime, they plan to reconstruct both from a single, continuous record from the levee of Hillary Canyon, a major conduit of AABW outflow, on the Ross Sea continental rise. To test their hypothesis, they will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) They will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. They will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) They will use grain-size data, physical properties, XRF core scanning, CT imaging, and hyperspectral imaging to guide lithofacies analysis to infer processes occurring during glacial, deglacial, and interglacial periods. Statistical techniques and optimization methods will be applied to test for astronomical forcing of sedimentary packages in order to provide a cyclostratigraphic framework and interpret the orbital-forcing regime. (3) They will use bulk sedimentary carbon and nitrogen abundance and isotope data to determine how relative contributions of terrigenous and marine organic matter change in response to orbital forcing. All of these data will be integrated with sedimentological records to deconvolve organic matter production from its deposition or remobilization due to AABW outflow as a function of the oscillating extent of the AIS. These data sets will be integrated into a unified chronostratigraphy to determine the relationship between AABW outflow and orbital-forcing scenarios under the varying climate regimes of the Plio-Pleistocene. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -172.873074, "geometry": "POINT(-172.873074 -74.274008)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; LABORATORY; AMD; USA/NSF; SEDIMENTS; Amd/Us; Ross Sea", "locations": "Ross Sea", "north": -74.274008, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.274008, "title": "COLLABORATIVE RESEARCH: Orbital-scale Variability of the West Antarctic Ice Sheet and the Formation of Bottom Water in the Ross Sea during the Pliocene-Pleistocene", "uid": "p0010227", "west": -172.873074}, {"awards": "1947882 Robel, Alexander", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 01 Jul 2021 00:00:00 GMT", "description": "Uncertainty in projections of future sea level rise comes, in part, from ice-sheet melting under the influence of unpredictable variations in ocean and atmospheric temperature near ice sheets. Using state-of-the-art modeling techniques, the Antarctic Ice Sheet Large Ensemble (AISLENS) Project will estimate the range of possible Antarctic Ice Sheet melt during the recent past and over the next several centuries that could result from such climate variations. The AISLENS Project will also facilitate research by providing modeling output as an open product to the broader climate and glaciology communities. The project will support an early career faculty member, and interdisciplinary training for a graduate student, postdoctoral fellow and undergraduate student. As a part of this project, an undergraduate course on \"Sea Level Rise and Coastal Engineering\" will be also developed, bringing together Earth Science and Civil Engineering students in an interdisciplinary setting and contributing to their education in sea level science and coastal adaptation. This will be done in the geographic context of the Southeastern US, the region of most concentrated vulnerability to sea-level rise in the US. The primary goal of the proposed research is to understand and quantify the role of internal climate variability in driving ice loss from the Antarctic Ice Sheet over the recent past and into the future. The AISLENS Project will encompass hundreds of simulations of Antarctic ice sheet evolution from 1950 to 2300 forced by realistic variations in climate, including snowfall and melt from fluctuating oceanic and atmospheric temperatures. Plausible realizations of Antarctic climate forcing will be generated from stochastic emulation of output from the Energy Exascale Earth System Model (E3SM) under past and future emissions scenarios. These realizations of variable climate will be used to force the MPAS Albany Land Ice (MALI) model, a state-of-the-art model of ice flow in the Antarctic Ice Sheet. In this project, AISLENS will be used to conduct uncertainty and attribution analyses. In the uncertainty analysis, the evolution of ensemble spread in simulations of the future evolution of the Antarctic Ice Sheet will be systematically decomposed to determine which temporal and spatial scales of climate variability contribute the most to future ice-sheet projection uncertainty. In the attribution analysis, a range of satellite-based observations of recent Antarctic ice loss will be compared to the envelope of internal variability of Antarctic ice loss simulated in AISLENS simulations encompassing the recent past. This analysis will provide context to recent observations indicating significant variability of Antarctic climate forcing and provide a possible path forward for conducting robust statistical inference studies for observed ice-sheet changes. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Antarctica; Antarctic Ice Sheet; AMD; USAP-DC; USA/NSF; MODELS; Amd/Us", "locations": "Antarctic Ice Sheet; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Robel, Alexander", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": null, "title": "The Antarctic Ice Sheet Large Ensemble (AISLENS) Project: Assessing the Role of Climate Variability in Past and Future Ice Sheet Mass Loss", "uid": "p0010223", "west": null}, {"awards": "2032463 Talghader, Joseph; 2032473 Kurbatov, Andrei", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Visual, thermal, chemical, and stable isotope effects of near-infrared laser cutting on freezer ice", "datasets": [{"dataset_uid": "601753", "doi": "10.15784/601753", "keywords": "Antarctica; Sampling", "people": "Talghader, Joseph; Kurbatov, Andrei V.; Mah, Merlin", "repository": "USAP-DC", "science_program": null, "title": "Visual, thermal, chemical, and stable isotope effects of near-infrared laser cutting on freezer ice", "url": "https://www.usap-dc.org/view/dataset/601753"}], "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "This project will take initial development steps toward a laser-cut ice-sampling capability in glaciers and ice sheets. The collection of ice samples from the Polar Ice Sheets involves large amounts of time, effort, and expense. However, the most important science data are often retrieved from small sections of an ice core and, while replicate coring can supplement this section of ice core, there is often a need to retrieve additional ice samples based on subsequent scientific findings or borehole logging at a research site. In addition, there are currently no easy methods of extracting ice samples from a borehole drilled by non-coring mechanical drills that are faster, lighter, and less expensive to operate. There are numerous science applications that could potentially benefit from laser-cut ice samples, including sampling ice overlying buried impact craters and bolides, filling critical gaps in chemical records retrieved from damaged ice cores, and obtaining ice samples from sites where coring drills apply stresses that may fracture the ice. This award will explore a laser cutting technology to rapidly extract high-quality ice samples from a borehole wall. The project will investigate and validate the existing technology of laser ice sampling and will use a fiberoptic cable to deliver light pulses to a borehole instrument rather than attempting to assemble a complete laser system in an instrument deployed in a borehole. This offers a new way of retrieving ice samples from a polar ice sheet without the need to drill a borehole to collect ice-core samples (i.e., the hole could be mechanically drilled). This technology could also be used in existing boreholes or those that are made by augering through ice (i.e., not coring) or made with hot water. If successful, this technique would create the ability to rapidly retrieve ice samples with a small logistical footprint and enable science that might not be supportable otherwise. The proposed technology could eventually provide better access to ice-core samples to study past atmospheric composition for understanding past climate and inform on future potential for ice-sheet change. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Laser Cutting; Ice Core; USA/NSF; AMD; SULFATE; FIELD SURVEYS; OXYGEN COMPOUNDS; USAP-DC; LABORATORY; Sulfate", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Talghader, Joseph; Kurbatov, Andrei V.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Laser Cutting Technology for Borehole Sampling", "uid": "p0010218", "west": -180.0}, {"awards": "2022920 Zhan, Zhongwen", "bounds_geometry": "POINT(180 -90)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "This EAGER award will explore the Distributed Acoustic Sensing emerging technology that transforms a single optical fiber into a massively multichannel seismic array. This technology may provide a scalable and affordable way to deploy dense seismic networks. Experimental Distributed Acoustic Sensing equipment will be tested in the Antarctic exploiting unused (dark) strands in the existing fiber-optic cable that connects the U.S. Amundsen-Scott South Pole Station to the Remote Earth Science and Seismological Observatory (SPRESSO) located about 7.5-km from the main station. Upon processing the seismic signals, the Distributed Acoustic Sensing may provide a new tool to structurally image firn, glacial ice, and glacial bedrock. Learning how Distributed Acoustic Sensing would work on the ice sheet, scientists can then check seismological signals propagating through the Earth\u0027s crust and mantle variously using natural icequakes and earthquakes events in the surrounding area. The investigators propose to convert at least 8 km of pre-existing fiber optic cable at the Amundsen-Scott South Pole station into more than 8000 sensors to explore the potential of Distributed acoustic sensing (DAS) as a breakthrough data engine for polar seismology. The DAS array will operate for about one year, allowing them to (1) evaluate and calibrate the performance of the DAS technology in the extreme cold, very low noise (including during the exceptionally quiet austral winter) polar plateau environment; (2) record and analyze local ambient and transient signals from ice, anthropogenic signals, ocean microseism, atmospheric and other processes, as well as to study local, regional, and teleseismic tectonic events; (3) structurally image the firn, glacial ice, glacial bed, crust, and mantle, variously using active sources, ambient seismic noise, and natural icequake and earthquake events. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(180 -90)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; South Pole Station; GLACIERS/ICE SHEETS; NSF/USA; Amd/Us; SEISMIC SURFACE WAVES; SEISMOLOGICAL STATIONS; USAP-DC", "locations": "South Pole Station", "north": -90.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Zhan, Zhongwen", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repositories": null, "science_programs": null, "south": -90.0, "title": "EAGER: Pilot Fiber Seismic Networks at the Amundsen-Scott South Pole Station", "uid": "p0010214", "west": 180.0}, {"awards": "2027615 Paden, John", "bounds_geometry": null, "dataset_titles": "2022 Antarctica Ground; 2023 Antarctica Ground", "datasets": [{"dataset_uid": "200476", "doi": "", "keywords": null, "people": null, "repository": "CReSIS OPR", "science_program": null, "title": "2022 Antarctica Ground", "url": "https://data.cresis.ku.edu/data/accum/2022_Antarctica_Ground/"}, {"dataset_uid": "200477", "doi": "", "keywords": null, "people": null, "repository": "CReSIS OPR", "science_program": null, "title": "2023 Antarctica Ground", "url": "https://data.cresis.ku.edu/data/accum/2023_Antarctica_Ground/"}], "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "This project will develop a new ice-penetrating radar system that can simultaneously map glacier geometry and glacier flow along repeat profiles. Forecasting an ice-sheet\u2019s contribution to sea level requires an estimate for the initial ice-sheet geometry and the parameters that govern ice flow and slip across bedrock. Existing ice-sheet models cannot independently determine this information from conventional observations of ice-surface velocities and glacier geometry. This introduces substantial uncertainty into simulations of past and future ice-sheet behavior. Thus, this new radar capability is conceived to provide the needed data to support higher-fidelity simulations of past and future ice-sheet behavior and more accurate projections of future sea level. The new radar system will integrate two existing radars (the multi-channel coherent radio-echo depth sounder and the accumulation radar) developed by the Center for the Remote Sensing of Ice Sheets, as well as adding new capabilities. An eight-element very high frequency (VHF; 140-215 MHz) array will have sufficient cross-track aperture to swath map internal layers and the ice-sheet base in three dimensions. A single ultra high frequency (UHF; 600-900 MHz) antenna will have the range and phase resolution to map internal layer displacement with 0.25-mm precision. The VHF array will create 3D mappings of layer geometry that enable measurements of vertical velocities by accounting for spatial offsets between repeat profiles and changing surface conditions. The vertical displacement measurement will then be made by determining the difference in radar phase response recorded by the UHF antenna for radar profiles collected at the same locations at different times. The UHF antenna will be dual-polarized and thus capable of isolating both components of complex internal reflections. This should enable inferences of ice crystal orientation fabric and widespread mapping of ice viscosity. Initial field testing of the radar will occur on the McMurdo Ice Shelf and then progress to Thwaites Glacier, Antarctica. The dual-band radar system technology and processing algorithms will be developed with versatile extensible hardware and user-friendly software so that this system will serve as a prototype for a future community radar system. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS", "is_usap_dc": true, "keywords": "Amd/Us; USA/NSF; Airborne Radar; AMD; ICE SHEETS; Thwaites Glacier; USAP-DC; Eastwind Glacier", "locations": "Thwaites Glacier; Eastwind Glacier", "north": null, "nsf_funding_programs": "Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Paden, John; Rodriguez-Morales, Fernando ; Christianson, Knut", "platforms": null, "repo": "CReSIS OPR", "repositories": "CReSIS OPR", "science_programs": "Thwaites (ITGC)", "south": null, "title": "Collaborative Research: EAGER: A Dual-Band Radar for Measuring Internal Ice Deformation: a Multipass Ice-Penetrating Radar Experiment on Thwaites Glacier and the McMurdo Ice Shelf", "uid": "p0010215", "west": null}, {"awards": "1851022 Fudge, Tyler; 1851094 Baker, Ian", "bounds_geometry": null, "dataset_titles": "Code for calculating mean gradient for EDC sulfate data; EPICA Dome C Sulfate Data 7-3190m; Forward Diffusion Model used to calculate widening of volcanic layer widths; Volcanic Widths in Dome C Interglacials and Glacials", "datasets": [{"dataset_uid": "601855", "doi": "10.15784/601855", "keywords": "Antarctica; Cryosphere", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Volcanic Widths in Dome C Interglacials and Glacials", "url": "https://www.usap-dc.org/view/dataset/601855"}, {"dataset_uid": "601759", "doi": "10.15784/601759", "keywords": "Antarctica", "people": "Fudge, T. J.; Severi, Mirko", "repository": "USAP-DC", "science_program": "COLDEX", "title": "EPICA Dome C Sulfate Data 7-3190m", "url": "https://www.usap-dc.org/view/dataset/601759"}, {"dataset_uid": "601857", "doi": "10.15784/601857", "keywords": "Antarctica; Cryosphere", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Forward Diffusion Model used to calculate widening of volcanic layer widths", "url": "https://www.usap-dc.org/view/dataset/601857"}, {"dataset_uid": "601856", "doi": "10.15784/601856", "keywords": "Antarctica; Cryosphere", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Code for calculating mean gradient for EDC sulfate data", "url": "https://www.usap-dc.org/view/dataset/601856"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "The ice of the polar ice sheets is among the purest substances on Earth, yet the small amount of impurities --such as acids-- are important to how the ice flows and what can be learned from ice cores about past climate. The goal of this project is to understand the role of such acids on the deformation of polycrystalline ice by comparing the deformation behavior of pure and sulfuric acid-doped samples. Sulfuric acid was chosen both because of its importance for interpreting past climate and because it can lead to water veins in ice at low temperatures. This work will focus on the location, movement, and impact of acids in polycrystalline ice that are more complex than in single crystals of ice. By deforming samples and performing microstructural characterization, the role of acids on deformation rate, grain evolution, and the movement of the acids themselves, will be assessed. The work will lead to the education of a Ph.D. student at Dartmouth College, introduce undergraduate students to research at both the University of Washington and Dartmouth College. Despite the ubiquitous use of the constitutive relation for ice commonly referred to as \"Glen\u0027s Flow Law\", significant uncertainty exists particularly with regard to the role of impurities and the development of oriented fabrics. The aim of this project is to improve the constitutive relationship for ice by performing deformation tests and microstructural characterization of pure and sulfuric acid-doped ice. The project will focus on sulfuric acid\u0027s impact on ice viscosity, fabric evolution, and diffusivity. Sulfuric acid can have both direct and indirect effects on the mechanical properties of polycrystalline ice. The direct effects change the dislocation velocity and/or density, and the indirect effects change the grain size and fabric. The complexity and interaction of these effects means that it is not possible to understand the effects of sulfuric acid by simply examining ice core specimens. In this project, the team will deform four types of ice: lab-grown ice samples doped with similar-to-natural concentrations of sulfuric acid, lab-grown high-purity ice, layered doped and pure ice, and natural ice from Antarctic ice cores. Deformation will be performed in both uniaxial compression and simple shear. The addition of simple shear tests is critical for relating the laboratory-observed deformation behavior to the behavior of polar ice sheets where the shear strain dominates ice motion in basal ice. After deformation to strains from 5 percent up to 25 percent, the microstructural development will be assessed with methods including a variety of scanning electron microscope techniques, Raman microscopy, synchrotron-based Nano-X-ray fluorescence, and ion chromatography. These analysis techniques will allow the determination of 1) the segregation and movement of impurities, 2) the rate of grain-boundary migration, 3) the number of recrystallized grains; and 4) the full orientation of the ice crystals. The results will enable both microstructural modeling of the effects of sulfuric acid and numerical modeling of diffusion in ice cores. The net result will be a better understanding of ice deformation that improves ice-core interpretation and ice-sheet modeling. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "AMD; Polycrystalline Ice; LABORATORY; Epica Dome C; SNOW/ICE; USA/NSF; USAP-DC; Ice Core; Amd/Us", "locations": "Epica Dome C", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Science and Technology; Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Fudge, T. J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation", "uid": "p0010211", "west": null}, {"awards": "1643455 Enderlin, Ellyn; 1933764 Enderlin, Ellyn", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Crane Glacier centerline observations and modeling results ; Remotely-sensed iceberg geometries and meltwater fluxes", "datasets": [{"dataset_uid": "601679", "doi": "10.15784/601679", "keywords": "Antarctica; Elevation; Glaciology; Iceberg; Meltwater; Submarine Melt", "people": "Dickson, Adam; Enderlin, Ellyn; Miller, Emily; Dryak, Mariama; Oliver, Caitlin; Aberle, Rainey", "repository": "USAP-DC", "science_program": null, "title": "Remotely-sensed iceberg geometries and meltwater fluxes", "url": "https://www.usap-dc.org/view/dataset/601679"}, {"dataset_uid": "601617", "doi": "10.15784/601617", "keywords": "Antarctica; Antarctic Peninsula; Crane Glacier; Glacier Dynamics; Glacier Mass Discharge; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Modeling; Model Output", "people": "Marshall, Hans-Peter; Aberle, Rainey; Enderlin, Ellyn; Kopera, Michal; Meehan, Tate", "repository": "USAP-DC", "science_program": null, "title": "Crane Glacier centerline observations and modeling results ", "url": "https://www.usap-dc.org/view/dataset/601617"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "Enderlin/1643455 This award supports a project that will use a novel remote sensing method, which was initially developed to investigate melting of icebergs around Greenland, to examine spatial and temporal variations in ocean forcing around the Antarctic ice sheet periphery. Nearly three-quarters of the Antarctic ice sheet is fringed by regions of floating glacier ice called ice shelves. These ice shelves play an important role in modulating the flow of ice from the ice sheet interior towards the coast, similar to how dams regulate the downstream flow of water from reservoirs. Therefore, a reduction in ice shelf size due to changing air and ocean temperatures can have serious implications for the flux of glacier ice reaching the Antarctic coast, and thus, sea level change. Observations of recent ocean warming in the Amundsen Sea, thinning of the ice shelves, and increased ice flux from the West Antarctic ice sheet interior suggests that ice shelf destabilization triggered by ocean warming may already be underway in some regions. Although detailed observations are available in the Amundsen Sea region, our understanding of spatial and temporal variations in ocean conditions and their influence on ice shelf stability is limited by the scarceness of observations spanning the ice sheet periphery. The project will yield insights into variability in the submarine melting of ice shelves and will help advance the career of a female early-career scientist in a male-dominated field. The project will use repeat, very high-resolution (~0.5 m pixel width and length) satellite images acquired by the WorldView satellites, to estimate rates of iceberg melting in key coastal regions around Antarctica. The satellite images will be used to construct maps of iceberg surface elevation, which will be differenced in time to derive time series of iceberg volume change and area-averaged melt rates. Where ocean data are available, the melt rates will be compared to these data to assess whether variations in ocean temperature can explain observed iceberg melt variability. Large spatial gradients in melt rates will be compared to estimates of iceberg drift rates, which will be inferred from the repeat satellite images as well as numerically modeled drift rates produced by (unfunded) collaborators, to quantify the effects of water shear on iceberg melt rates. Spatial and temporal patterns in iceberg melting will also be compared to independently derived ice shelf thickness datasets. Overall, the analysis should yield insights into the effects of changes in ocean forcing on the submarine melting of Antarctic ice shelves and icebergs. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amery Ice Shelf; FIELD SURVEYS; Totten Glacier; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; USAP-DC; Antarctic Peninsula; ICEBERGS; Mertz Glacier; OCEAN TEMPERATURE; USA/NSF; Amd/Us; Amundsen Sea; Ronne Ice Shelf; Filchner Ice Shelf; AMD", "locations": "Antarctic Peninsula; Totten Glacier; Ronne Ice Shelf; Filchner Ice Shelf; Amery Ice Shelf; Mertz Glacier; Amundsen Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Enderlin, Ellyn", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Antarctic Submarine Melt Variability from Remote Sensing of Icebergs", "uid": "p0010210", "west": -180.0}, {"awards": "1844793 Aksoy, Mustafa", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic Firn Brightness Temperatures Measured by AMSR2 and SSMIS (Concordia, Vostok, and the Entire Ice Sheet)); In-Situ Density, Temperature, Grain Size, and Layer Thickness data for the Antarctic Ice Sheet", "datasets": [{"dataset_uid": "601551", "doi": "10.15784/601551", "keywords": "Antarctica; Antarctic Ice Sheet", "people": "Aksoy, Mustafa; Kaurejo, Dua; Kar, Rahul", "repository": "USAP-DC", "science_program": null, "title": "In-Situ Density, Temperature, Grain Size, and Layer Thickness data for the Antarctic Ice Sheet", "url": "https://www.usap-dc.org/view/dataset/601551"}, {"dataset_uid": "601550", "doi": "10.15784/601550", "keywords": "Antarctica; Antarctic Ice Sheet; Satellite; Vostok", "people": "Aksoy, Mustafa; Kaurejo, Dua; Kar, Rahul", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Firn Brightness Temperatures Measured by AMSR2 and SSMIS (Concordia, Vostok, and the Entire Ice Sheet))", "url": "https://www.usap-dc.org/view/dataset/601550"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "This project will test the hypothesis that physical and thermal properties of Antarctic firn--partially compacted granular snow in an intermediate stage between snow and glacier ice--can be remotely measured from space. Although these properties, such as internal temperature, density, grain size, and layer thickness, are highly relevant to studies of Antarctic climate, ice-sheet dynamics, and mass balance, their measurement currently relies on sparse in-situ surveys under challenging weather conditions. Sensors on polar-orbiting satellites can observe the entire Antarctic every few days during their years-long lifetime. Consequently, the approaches developed in this study, when coupled with the advancing technologies of small and low-cost CubeSats, aim to contribute to Antarctic science and lead to cost-effective, convenient, and accurate long-term analyses of the Antarctic system while reducing the human footprint on the continent. Moreover, the project will be solely based on publicly-available datasets; thus, while contributing to interdisciplinary undergraduate and graduate research and education at the grantee\u0027s institution, the project will also encourage engagement of citizen scientists through its website. The overarching goal of this project is to characterize Antarctic firn layers in terms of their thickness, physical temperature, density, and grain size through multi-frequency microwave radiometer measurements from space. Electromagnetic penetration depth changes with frequency in ice; thus, multi-frequency radiometers are able to profile firn layer properties versus depth. To achieve its objective, the project will utilize the Global Precipitation Measurement (GPM) satellite constellation as a single multi-frequency microwave radiometer system with 11 frequency channels observing the Antarctic Ice Sheet. Archived in-situ measurements of Antarctic firn density, grain size, temperature, and layer thickness will be collected and separated into training and test datasets. Microwave emissions simulated using the training data will be compared to GPM constellation measurements to evaluate and improve state-of-the-art forward microwave emission models. Based on these models, the project will develop numerical retrieval algorithms for the thermal and physical properties of Antarctic firn. Results of retrievals will be validated using the test dataset, and uncertainty and error analyses will be conducted. Lastly, changes in the thermal and physical characteristics of Antarctic firn will be examined through long-term retrieval studies exploiting GPM constellation measurements. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; FIRN; Amd/Us; USA/NSF; ICE SHEETS; SNOW DENSITY; Multi-Frequency Passive Remote Sensing; University At Albany; USAP-DC; SNOW/ICE TEMPERATURE; SATELLITES; SNOW/ICE", "locations": "University At Albany", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aksoy, Mustafa", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Characterization of Antarctic Firn by Multi-Frequency Passive Remote Sensing from Space", "uid": "p0010206", "west": -180.0}, {"awards": "1914668 Aschwanden, Andy; 1914698 Hansen, Samantha; 1914767 Winberry, Paul; 1914743 Becker, Thorsten", "bounds_geometry": "POLYGON((90 -65,99 -65,108 -65,117 -65,126 -65,135 -65,144 -65,153 -65,162 -65,171 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,171 -90,162 -90,153 -90,144 -90,135 -90,126 -90,117 -90,108 -90,99 -90,90 -90,90 -87.5,90 -85,90 -82.5,90 -80,90 -77.5,90 -75,90 -72.5,90 -70,90 -67.5,90 -65))", "dataset_titles": "East Antarctic Seismicity from different Automated Event Detection Algorithms; Full Waveform Ambient Noise Tomography for East Antarctica", "datasets": [{"dataset_uid": "601762", "doi": "10.15784/601762", "keywords": "Antarctica; Geoscientificinformation; Machine Learning; Seismic Event Detection; Seismology; Seismometer", "people": "Walter, Jacob; Hansen, Samantha; Ho, Long", "repository": "USAP-DC", "science_program": null, "title": "East Antarctic Seismicity from different Automated Event Detection Algorithms", "url": "https://www.usap-dc.org/view/dataset/601762"}, {"dataset_uid": "601763", "doi": "10.15784/601763", "keywords": "Ambient Noise; Antarctica; East Antarctica; Geoscientificinformation; Seismic Tomography; Seismology", "people": "Hansen, Samantha; Emry, Erica", "repository": "USAP-DC", "science_program": null, "title": "Full Waveform Ambient Noise Tomography for East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601763"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "Part I: Nontechnical Earths warming climate has the potential to drive widespread collapse of glaciers and ice sheets across the planet, driving global sea-level rise. Understanding both the rate and magnitude of such changes is essential for predicting future sea-level and how it will impact infrastructure and property. Collapse of the ice sheets of Antarctica has the potential to raise global sea-level by up to 60 meters. However, not all regions of Antarctica are equally suspectable to collapse. One area with potential for collapse is the Wilkes Subglacial Basin in East Antarctica, a region twice the size of California\u0027s Central Valley. Geologic evidence indicates that the ice-sheet in this region has retreated significantly in response to past global warming events. While the geologic record clearly indicates ice-sheets in this area are vulnerable, the rate and magnitude of any future retreat will be influenced significantly by geology of the region. In particular, ice-sheets sitting above warm Earth will collapse more quickly during warming climate. Constraining the geologic controls on the stability of the ice-sheets of the Wilkes Subglacial Basin remains challenging since the ice-sheet hides the geology beneath kilometers of ice. As a step in understanding the potential for future ice loss in the Wilkes Subglacial Basin this project will conduct geophysical analysis of existing data to better constrain the geology of the region. These results will constrain new models designed to understand the tectonics that control the behavior of the ice-sheets in the region. These new models will highlight the geological properties that exert the most significant control on the future of the ice-sheets of the Wilkes Subglacial Basin. Such insights are critical to guide future efforts aimed at collecting in-situ observations needed to more fully constrain Antarctica\u0027s potential for future sea-level. Part II: Technical Description In polar environments, inward-sloping marine basins are susceptible to an effect known as the marine ice-sheet instability (MISI): run-away ice stream drainage caused by warm ocean water eroding the ice shelf from below. The magnitude and time-scale of the ice-sheet response strongly depend on the physical conditions along the ice-bed interface, which are, to a first order, controlled by the tectonic evolution of the basin. Topography, sedimentology, geothermal heat flux, and mantle viscosity all play critical roles in ice-sheet stability. However, in most cases, these solid-Earth parameters for regions susceptible to the MISI are largely unknown. One region with potential susceptibility to MISI is the Wilkes Subglacial Basin of East Antarctica. The project will provide an integrated investigation of the Wilkes Subglacial Basin, combining geophysical analyses with both mantle flow and ice-sheet modeling to understand the stability of the ice sheet in this region, and the associated potential sea level rise. The work will be focused on four primary objectives: (1) to develop an improved tectonic model for the region based on existing seismic observations as well as existing geophysical and geological data; (2) to use the new tectonic model and seismic data to estimate the thermal, density, and viscosity structure of the upper mantle and to develop a heat flow map for the WSB; (3) to simulate mantle flow and to assess paleotopography based on our density and viscosity constraints; and (4) to assess ice-sheet behavior by modeling (a) past ice-sheet stability using our paleotopography estimates and (b) future ice-sheet stability using our heat flow and mantle viscosity estimates. Ultimately, the project will generate improved images of the geophysical structure beneath the WSB that will allow us to assess the geodynamic origin for this region and to assess the influence of geologic parameters on past, current, and future ice-sheet behavior. These efforts will then highlight areas and geophysical properties that should be the focus of future geophysical deployments. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(135 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "TECTONICS; AMD; Wilkes Subglacial Basin; ICE SHEETS; USA/NSF; Amd/Us; SEISMOLOGICAL STATIONS; SEISMIC SURFACE WAVES; East Antarctica; USAP-DC", "locations": "East Antarctica; Wilkes Subglacial Basin", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Becker, Thorsten; Binder, April; Hansen, Samantha; Aschwanden, Andy; Winberry, Paul", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes\r\nSubglacial Basin (RESISSt)", "uid": "p0010204", "west": 90.0}, {"awards": "1644159 Jacobs, Stanley", "bounds_geometry": "POLYGON((-180 -72.5,-177 -72.5,-174 -72.5,-171 -72.5,-168 -72.5,-165 -72.5,-162 -72.5,-159 -72.5,-156 -72.5,-153 -72.5,-150 -72.5,-150 -73.15,-150 -73.8,-150 -74.45,-150 -75.1,-150 -75.75,-150 -76.4,-150 -77.05,-150 -77.7,-150 -78.35,-150 -79,-153 -79,-156 -79,-159 -79,-162 -79,-165 -79,-168 -79,-171 -79,-174 -79,-177 -79,180 -79,178.2 -79,176.4 -79,174.6 -79,172.8 -79,171 -79,169.2 -79,167.4 -79,165.6 -79,163.8 -79,162 -79,162 -78.35,162 -77.7,162 -77.05,162 -76.4,162 -75.75,162 -75.1,162 -74.45,162 -73.8,162 -73.15,162 -72.5,163.8 -72.5,165.6 -72.5,167.4 -72.5,169.2 -72.5,171 -72.5,172.8 -72.5,174.6 -72.5,176.4 -72.5,178.2 -72.5,-180 -72.5))", "dataset_titles": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020; Ross Island area salinity and temperature records 1956 to 2020", "datasets": [{"dataset_uid": "601611", "doi": "10.15784/601611", "keywords": "Amundsen Sea; Antarctica; Chemistry:Water; CTD; D18O; NBP0001; NBP0702; NBP0901; NBP1901; NBP2002; Oceans; Oxygen Isotope; R/v Nathaniel B. Palmer; Seawater Isotope; Southern Ocean", "people": "Hennig, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "url": "https://www.usap-dc.org/view/dataset/601611"}, {"dataset_uid": "601458", "doi": "10.15784/601458", "keywords": "Antarctica; CTD; Oceans; Physical Oceanography; Ross Island; Ross Sea; Salinity; Temperature", "people": "Jacobs, Stanley; Giulivi, Claudia F.", "repository": "USAP-DC", "science_program": null, "title": "Ross Island area salinity and temperature records 1956 to 2020", "url": "https://www.usap-dc.org/view/dataset/601458"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "Overview and Intellectual merit: This project extends and combines historical and recent ocean data sets to investigate ice-ocean-interactions along the Pacific continental margin of the West Antarctic Ice Sheet. The synthesis focuses on the strikingly different environments on and near the cold Ross Sea and warm Amundsen Sea continental shelves, where available measurements reach back to ~1958 and 1994, respectively. On the more extensively covered Ross Sea continental shelf, multiple reoccupations of ocean stations and transects are used to extend our knowledge of long-term ocean freshening and the mass balance of the world?s largest ice shelf. On the more rugged Amundsen Sea continental shelf, which contains the earth?s fastest melting ice shelves, continuing research on observed thermohaline variability also pursues connections between outer shelf shoals and vulnerable ice shelf grounding zones. This interdisciplinary work updates a prior study of ice shelf response to ocean thermal forcing, and uses chemical tracers to measure changes in shelf, deep and bottom water transformations and production rates. Broader Impacts : Recent and potential future rates of sea level rise are the primary broad-scale impacts of the ice and ocean changes revealed by observations in the study area. The overriding question is whether global and regional sea levels will accelerate gradually, allowing carbon usage reductions to head off the worst consequences, or so rapidly that they will contribute to major social and economic upheavals. Collaborations and data acquired by foreign vessels are also utilized to better understand the causes of rapid change in these shelf seas and ice shelves, along with associated wider implications. Data that are re-gridded, re-edited or newly collated will be archived, and results made available via presentations, publications, and press releases if warranted. This proposal does not require fieldwork in the Antarctic This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -150.0, "geometry": "POINT(-174 -75.75)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; USA/NSF; COMPUTERS; Ross Sea; SHIPS; USAP-DC; SALINITY/DENSITY; OCEAN TEMPERATURE", "locations": "Ross Sea", "north": -72.5, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "West Antarctic Ice Shelf- Ocean Interactions ", "uid": "p0010208", "west": 162.0}, {"awards": "1739027 Tulaczyk, Slawek", "bounds_geometry": "POLYGON((-125 -73,-122.1 -73,-119.2 -73,-116.3 -73,-113.4 -73,-110.5 -73,-107.6 -73,-104.7 -73,-101.8 -73,-98.9 -73,-96 -73,-96 -73.7,-96 -74.4,-96 -75.1,-96 -75.8,-96 -76.5,-96 -77.2,-96 -77.9,-96 -78.6,-96 -79.3,-96 -80,-98.9 -80,-101.8 -80,-104.7 -80,-107.6 -80,-110.5 -80,-113.4 -80,-116.3 -80,-119.2 -80,-122.1 -80,-125 -80,-125 -79.3,-125 -78.6,-125 -77.9,-125 -77.2,-125 -76.5,-125 -75.8,-125 -75.1,-125 -74.4,-125 -73.7,-125 -73))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 24 Jun 2021 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Collapse of the West Antarctic Ice Sheet (WAIS) could raise the global sea level by about 5 meters (16 feet) and the scientific community considers it the most significant risk for coastal environments and cities. The risk arises from the deep, marine setting of WAIS. Although scientists have been aware of the precarious setting of this ice sheet since the early 1970s, it is only now that the flow of ice in several large drainage basins is undergoing dynamic change consistent with a potentially irreversible disintegration. Understanding WAIS stability and enabling more accurate prediction of sea-level rise through computer simulation are two of the key objectives facing the polar science community today. This project will directly address both objectives by: (1) using state-of-the-art technologies to observe rapidly deforming parts of Thwaites Glacier that may have significant control over the future evolution of WAIS, and (2) using these new observations to improve ice-sheet models used to predict future sea-level rise. This project brings together a multidisciplinary team of UK and US scientists. This international collaboration will result in new understanding of natural processes that may lead to the collapse of the WAIS and will boost infrastructure for research and education by creating a multidisciplinary network of scientists. This team will mentor three postdoctoral researchers, train four Ph.D. students and integrate undergraduate students in this research project. The project will test the overarching hypothesis that shear-margin dynamics may exert powerful control on the future evolution of ice flow in Thwaites Drainage Basin. To test the hypothesis, the team will set up an ice observatory at two sites on the eastern shear margin of Thwaites Glacier. The team argues that weak topographic control makes this shear margin susceptible to outward migration and, possibly, sudden jumps in response to the drawdown of inland ice when the grounding line of Thwaites retreats. The ice observatory is designed to produce new and comprehensive constraints on englacial properties, including ice deformation rates, ice crystal fabric, ice viscosity, ice temperature, ice water content and basal melt rates. The ice observatory will also establish basal conditions, including thickness and porosity of the till layer and the deeper marine sediments, if any. Furthermore, the team will develop new knowledge with an emphasis on physical processes, including direct assessment of the spatial and temporal scales on which these processes operate. Seismic surveys will be carried out in 2D and 3D using wireless geophones. A network of broadband seismometers will identify icequakes produced by crevassing and basal sliding. Autonomous radar systems with phased arrays will produce sequential images of rapidly deforming internal layers in 3D while potentially also revealing the geometry of a basal water system. Datasets will be incorporated into numerical models developed on different spatial scales. One will focus specifically on shear-margin dynamics, the other on how shear-margin dynamics can influence ice flow in the whole drainage basin. Upon completion, the project aims to have confirmed whether the eastern shear margin of Thwaites Glacier can migrate rapidly, as hypothesized, and if so what the impacts will be in terms of sea-level rise in this century and beyond. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -96.0, "geometry": "POINT(-110.5 -76.5)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; GLACIER MOTION/ICE SHEET MOTION; Thwaites Glacier; USAP-DC; USA/NSF; Magmatic Volatiles; AMD; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; ICE SHEETS; Amd/Us", "locations": "Thwaites Glacier", "north": -73.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Instrumentation and Support; Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": "Thwaites (ITGC)", "south": -80.0, "title": "NSF-NERC: Thwaites Interdisciplinary Margin Evolution (TIME): The Role of Shear Margin Dynamics in the Future Evolution of the Thwaites Drainage Basin", "uid": "p0010199", "west": -125.0}, {"awards": "1643120 Iverson, Neal", "bounds_geometry": null, "dataset_titles": "Ice permeameter experimental parameters and results; Softening of temperate ice by interstitial water; Tertiary creep rates if temperate ice containing greater than 0.7% liquid water", "datasets": [{"dataset_uid": "601833", "doi": "10.15784/601833", "keywords": "Antarctica; Cryosphere", "people": "Iverson, Neal", "repository": "USAP-DC", "science_program": null, "title": "Tertiary creep rates if temperate ice containing greater than 0.7% liquid water", "url": "https://www.usap-dc.org/view/dataset/601833"}, {"dataset_uid": "601460", "doi": "10.15784/601460", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Stream; Lab Experiment; Rheology; Snow/ice; Snow/Ice; Water Content", "people": "Iverson, Neal", "repository": "USAP-DC", "science_program": null, "title": "Softening of temperate ice by interstitial water", "url": "https://www.usap-dc.org/view/dataset/601460"}, {"dataset_uid": "601515", "doi": "10.15784/601515", "keywords": "Antarctica; Glacier Flow; Glacier Hydrology; Glaciological Instruments And Methods; Glaciology; Ice Physics; Ice Stream; Snow/ice; Snow/Ice", "people": "Fowler, Jacob; Iverson, Neal", "repository": "USAP-DC", "science_program": null, "title": "Ice permeameter experimental parameters and results", "url": "https://www.usap-dc.org/view/dataset/601515"}], "date_created": "Wed, 23 Jun 2021 00:00:00 GMT", "description": "Iverson/1643120 This award supports a project to study temperate ice, using both experimental methods and modeling, in order to determine the effect of water on its flow resistance and structure and to study the mobility of water within the ice. A new mathematical model of ice stream flow and temperature is developed in conjunction with these experiments. The model includes water production, storage, and movement in deforming ice and their effects on flow resistance at ice stream margins and on water availability for lubrication of ice stream beds. Results will improve estimates of the evolution of ice stream speed and geometry in a warming climate, and so improve the accuracy of assessments of the contribution of the Antarctic ice sheet to sea level rise over the next century. Ice streams are zones of rapid flow within the Antarctic ice sheet and are primarily responsible for its discharge of ice to the ocean and major effect on sea-level rise. Water plays a central role in the flow of ice streams. It lubricates their bases and softens their margins, where flow speeds abruptly transition from rapid to slow. Within ice stream margins some ice is \"temperate\", meaning that it is at its melting temperature and thus contains intercrystalline water that significantly softens the ice. Two postdoctoral researchers will be supported, trained, and mentored for academic careers, and three undergraduates will be introduced to research in the geosciences. This award is part the NSF/GEO-UK NERC lead agency opportunity (NSF 14-118) and is a collaboration between Iowa State University in the United States and Oxford University in the United Kingdom. The two-phase deformation of temperate ice will be studied, with the objective of determining its effect on the flow of Antarctic ice streams. The project has two components that reinforce each other. First there will be laboratory experiments in which a rotary device at Iowa State University will be used to determine relationships between the water content of temperate ice and its rheology and permeability. The second component will involve the development at Oxford University of a two-phase, fluid-dynamical theory of temperate ice and application of this theory in models of ice-stream dynamics. Results of the experiments will guide the constitutive rules and parameter ranges considered in the theory, and application of elements of the theory will improve interpretations of the experimental results. The theory and resultant models will predict the coupled distributions of temperate ice, water, stress, deformation, and basal slip that control the evolution of ice-stream speed and geometry. The modeling will result in parameterizations that allow ice streaming to be included in continental-scale models of ice sheets in a simplified but physically defensible way.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; Rheology; Antarctica; LABORATORY; Ice Stream; USA/NSF; USAP-DC; Lab Experiment; Water Content", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Iverson, Neal; Zoet, Lucas", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "NSFGEO-NERC: Collaborative Research: Two-Phase Dynamics of Temperate Ice", "uid": "p0010197", "west": null}, {"awards": "1744970 Shevenell, Amelia", "bounds_geometry": "POLYGON((120 -66,120.1 -66,120.2 -66,120.3 -66,120.4 -66,120.5 -66,120.6 -66,120.7 -66,120.8 -66,120.9 -66,121 -66,121 -66.1,121 -66.2,121 -66.3,121 -66.4,121 -66.5,121 -66.6,121 -66.7,121 -66.8,121 -66.9,121 -67,120.9 -67,120.8 -67,120.7 -67,120.6 -67,120.5 -67,120.4 -67,120.3 -67,120.2 -67,120.1 -67,120 -67,120 -66.9,120 -66.8,120 -66.7,120 -66.6,120 -66.5,120 -66.4,120 -66.3,120 -66.2,120 -66.1,120 -66))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 22 Jun 2021 00:00:00 GMT", "description": "Glacial retreat in West Antarctica is correlated with ocean warming; however, less is known about the ocean\u0027s effect on East Antarctica\u0027s glaciers including Totten Glacier located on the Sabrina Coast. The retreat of Totten Glacier has global significance as the glacier drains a sector of the East Antarctic Ice Sheet that contains enough ice to raise global sea levels by as much as 3.5 meters. This study looks to determine the influence of ocean temperatures on East Antarctic glaciers, including Totten Glacier, over the last ~18,000 years by studying seafloor sediment around Antarctica. These sediments, or muds, include the remains of microscopic marine organisms as well as tiny particles originating from eroded Antarctic bedrock. These muds provide a record of past environmental changes including ocean temperatures and the advance and retreat of glaciers. Scientists use a variety of physical and chemical analyses to determine how long ago this mud was deposited, the temperature of the ocean at that location through time, and the relative location of glacial ice. In this project, researchers will refine and test new methods for measuring ocean temperature from the sediments to better understand the influence of ocean temperatures on East Antarctic glacier response. Results will be integrated into ice sheet and climate models to improve the accuracy of ice sheet modeling efforts and subsequent sea level predictions. Results from this project will be disseminated at scientific conferences, in the scientific literature, and more broadly to the general public via the St. Petersburg Science Festival and at the Oceanography Camp for Girls. The influence of ocean temperatures on East Antarctic glaciers is largely unknown. This research focuses on ice-proximal Antarctic margin paleoceanographic proxy calibration and validation, which will improve understanding of past ocean-ice sheet interactions on a variety of timescales. In this project, researchers from the University of South Florida will (1) further develop and refine two ocean temperature proxies, foraminifer Mg/Ca and TEX86, for use in ice-proximal Antarctic continental margin sediments and (2) investigate deglacial to present (~18-0 ka) ocean-ice interactions at the outlet of the climatically sensitive Aurora Subglacial Basin. The proposed research utilizes sediment trap, sediment core, and physical oceanographic data previously collected from the Sabrina Coast continental shelf during NSF-funded cruise NBP14-02. Studies of existing sediment cores will integrate multiple paleotemperature, meltwater/salinity, nutrient, bottom water oxygen, and sea ice proxies with geophysical and lithologic data to understand past regional ocean-ice interactions. While the recent international Antarctic research focus has been on understanding the drivers of West Antarctic Ice Sheet retreat, models suggest it would be imprudent to ignore the East Antarctic Ice Sheet, which is proving more sensitive to climate perturbations than previously realized. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 121.0, "geometry": "POINT(120.5 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; FIELD INVESTIGATION; USA/NSF; USAP-DC; PALEOCLIMATE RECONSTRUCTIONS; Sabrina Coast; AMD; Amd/Us", "locations": "Sabrina Coast", "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -67.0, "title": "Deglacial to Recent Paleoceanography of the Sabrina Coast, East Antarctica: A Multi-proxy Study of Ice-ocean Interactions at the Outlet of the Aurora Subglacial Basin", "uid": "p0010194", "west": 120.0}, {"awards": "1750903 Ingels, Jeroen; 1750888 Aronson, Richard; 1750630 Smith, Craig", "bounds_geometry": "POLYGON((-64 -66,-63.3 -66,-62.6 -66,-61.9 -66,-61.2 -66,-60.5 -66,-59.8 -66,-59.1 -66,-58.4 -66,-57.7 -66,-57 -66,-57 -66.3,-57 -66.6,-57 -66.9,-57 -67.2,-57 -67.5,-57 -67.8,-57 -68.1,-57 -68.4,-57 -68.7,-57 -69,-57.7 -69,-58.4 -69,-59.1 -69,-59.8 -69,-60.5 -69,-61.2 -69,-61.9 -69,-62.6 -69,-63.3 -69,-64 -69,-64 -68.7,-64 -68.4,-64 -68.1,-64 -67.8,-64 -67.5,-64 -67.2,-64 -66.9,-64 -66.6,-64 -66.3,-64 -66))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 21 Jun 2021 00:00:00 GMT", "description": "Worldwide publicity surrounding the calving of an iceberg the size of Delaware in July 2017 from the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula presents a unique and time-sensitive opportunity for research and education on polar ecosystems in a changing climate. The goal of this project is to convene a workshop, drawing from the large fund of intellectual capital in the US and international Antarctic research communities. The two-day workshop will be held at Florida State University where a consortium of researchers with expertise in Antarctic biological, ecological, and ecosystem sciences will be gathered to share knowledge, identify important research knowledge gaps, and outline strategic plans for research. The workshop will help advance scientific and public understanding of the continent-wide changes that Antarctic ice shelves and surrounding ecosystems experience as ice shelves change. The primary products will be reports focusing on synthesizing, coordinating and integrating research efforts to understand the ecological impacts of ice-shelf collapses and large iceberg calving along the Antarctic Peninsula. The workshop will also provide an immediate, interactive experience for K-12 school children with a hands-on ?Saturday Polar Academy?, a children?s poster session, and question-answer session during the workshop. Children will have the opportunity to interact with Antarctic researchers and become familiar with Antarctic science, organisms, ecosystems and current issues, feeding their scientific curiosity. The calving of A-68, the 5,800-km2 iceberg shed in July 2017 from the Larsen C Ice Shelf presents a unique and time-sensitive research opportunity. The scientific momentum and public interest created by this most recent event will be leveraged to convene a workshop at the earliest opportunity, drawing from the large intellectual capital in the US and international Antarctic research communities. The two-day workshop will be held at Florida State University, Coastal and Marine Laboratory on the Gulf Coast organized by Jeroen Ingels (Florida State University; FSU), Richard Aronson (Florida Institute of Technology; FIT), and Craig Smith (University of Hawaii at Manoa; UHM). A consortium of researchers with a diversity of expertise in Antarctic biological, ecological, and ecosystem sciences will be gathered to share knowledge, identify important research priorities and knowledge gaps, and outline strategic plans for research to advance understanding of the continent-wide changes that Antarctic ice shelves and surrounding ecosystems experience as ice shelves change.", "east": -57.0, "geometry": "POINT(-60.5 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "MARINE ECOSYSTEMS; USAP-DC; LABORATORY; AMD; Weddell Sea; GLACIERS/ICE SHEETS; ECOLOGICAL DYNAMICS; USA/NSF; SEA ICE; Amd/Us; Antarctica", "locations": "Antarctica; Weddell Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ingels, Jeroen; Aronson, Richard; Smith, Craig", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -69.0, "title": "Collaborative Research: RAPID/Workshop - Antarctic Ecosystem Research following Ice Shelf Collapse and Iceberg Calving Events", "uid": "p0010189", "west": -64.0}, {"awards": "2045611 Rasbury, Emma; 2042495 Blackburn, Terrence", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": " Subglacial Precipitates Record Antarctic Ice Sheet Response to Pleistocene Millennial Climate Cycles; Subglacial precipitates record Antarctic ice sheet response to Southern Ocean warming ; Thermogenic Methane Production in Antarctic Subglacial Hydrocarbon Seeps; U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "datasets": [{"dataset_uid": "601918", "doi": "10.15784/601918", "keywords": "Antarctica; Carbon Isotopes; Cryosphere; East Antarctica; Elephant Moraine; Geochronology; Isotope Data; Subglacial", "people": "Piccione, Gavin", "repository": "USAP-DC", "science_program": null, "title": "Thermogenic Methane Production in Antarctic Subglacial Hydrocarbon Seeps", "url": "https://www.usap-dc.org/view/dataset/601918"}, {"dataset_uid": "601594", "doi": "10.15784/601594", "keywords": "Antarctica; East Antarctica", "people": "Piccione, Gavin; Blackburn, Terrence", "repository": "USAP-DC", "science_program": null, "title": " Subglacial Precipitates Record Antarctic Ice Sheet Response to Pleistocene Millennial Climate Cycles", "url": "https://www.usap-dc.org/view/dataset/601594"}, {"dataset_uid": "601911", "doi": null, "keywords": "Antarctica; Cryosphere", "people": "Gagliardi, Jessica", "repository": "USAP-DC", "science_program": null, "title": "Subglacial precipitates record Antarctic ice sheet response to Southern Ocean warming ", "url": "https://www.usap-dc.org/view/dataset/601911"}, {"dataset_uid": "601806", "doi": "10.15784/601806", "keywords": "Antarctica; Cryosphere; Erosion; Isotope Data; Major Elements; Soil; Taylor Glacier; Taylor Valley", "people": "Piccione, Gavin; Tulaczyk, Slawek; Blackburn, Terrence; Edwards, Graham", "repository": "USAP-DC", "science_program": null, "title": "U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601806"}], "date_created": "Fri, 18 Jun 2021 00:00:00 GMT", "description": "Over the past century, climate science has constructed an extensive record of Earth\u2019s ice age cycles through the chemical and isotopic characterization of various geologic archives such as polar ice cores, deep-ocean sediments, and cave speleothems. These climatic archives provide an insightful picture of ice age cycles and of the related large global sea level fluctuations triggered by these significant climate rhythms. However, such records still provide limited insight as to how or which of Earth\u2019s ice sheets contributed to higher sea levels during past warm climate periods. This is of particular importance for our modern world: the Antarctic ice sheet is currently the world\u2019s largest freshwater reservoir, which, if completely melted, would raise the global sea level by over 60 meters (200 feet). Yet, geologic records of Antarctic ice sheet sensitivity to warm climates are particularly limited and difficult to obtain, because the direct records of ice sheet geometry smaller than the modern one are still buried beneath the mile-thick ice covering the continent. Therefore, it remains unclear how much this ice sheet contributed to past sea level rise during warm climate periods or how it will respond to the anticipated near-future climate warming. In the proposed research we seek to develop sub-ice chemical precipitates\u2014minerals that form in lakes found beneath the ice sheet\u2014as a climatic archive, one that records how the Antarctic ice sheet responded to past climatic change. These sub-ice mineral formations accumulated beneath the ice for over a hundred thousand years, recording the changes in chemical and isotopic subglacial properties that occur in response to climate change. Eventually these samples were eroded by the ice sheet and moved to the Antarctic ice margin where they were collected and made available to study. This research will utilize advanced geochemical, isotopic and geochronologic techniques to develop record of the Antarctica ice sheet\u2019s past response to warm climate periods, directly informing efforts to understand how Antarctica will response to future warming. Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth\u2019s past warm periods. Large uncertainties, however, in reconstructions of past and future sea levels, result from the poorly constrained climate sensitivity of the Antarctic Ice sheet (AIS). This research project aims to develop the use of subglacial precipitates as an archive the Antarctic ice sheet (AIS) past response to climate change. The subglacial precipitates from East Antarctica form in water bodies beneath Antarctic ice and in doing so provide an entirely new and unique measure of how the AIS responds to climate change. In preliminary examination of these precipitates, we identified multiple samples consisting of cyclic opal and calcite that spans hundreds of thousands of years in duration. Our preliminary geochemical characterization of these samples indicates that the observed mineralogic changes result from a cyclic change in subglacial water compositions between isotopically and chemically distinct waters. Opal-forming waters are reduced (Ce* \u003c1 and high Fe/Mn) and exhibit elevated 234U/238U compositions similar to the saline groundwater brines found at the periphery of the AIS. Calcite-forming waters, are rather, oxidized and exhibit \u03b418O compositions consistent with derivation from the depleted polar plateau (\u003c -50 \u2030). 234U-230Th dates permit construction of a robust timeseries describing these mineralogic and compositional changes through time. Comparisons of these time series with other Antarctic climate records (e.g., ice core records) reveal that calcite forming events align with millennial scale changes in local temperature or \u201cAntarctic isotopic maximums\u201d, which represent Southern Hemisphere warm periods resulting in increased Atlantic Meridional overturing circulation. Ultimately, this project seeks to develop a comprehensive model as to how changes in the thermohaline cycle induce a glaciologic response which in turn induces a change in the composition of subglacial waters and the mineralogic phase recorded within the precipitate archive. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; FIELD INVESTIGATION; AMD; USA/NSF; Amd/Us; USAP-DC; East Antarctica", "locations": "East Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Blackburn, Terrence; Tulaczyk, Slawek; Hain, Mathis; Rasbury, Troy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Reconstructing East Antarctica\u2019s Past Response to Climate using Subglacial Precipitates", "uid": "p0010192", "west": -180.0}, {"awards": "1443556 Thomson, Stuart; 1443342 Licht, Kathy", "bounds_geometry": null, "dataset_titles": "Apatite (U-Th)/He and TREE Data Central Transantarctic Mountains", "datasets": [{"dataset_uid": "601462", "doi": "10.15784/601462", "keywords": "Antarctica; Beardmore Glacier; Erosion; Landscape Evolution; Shackleton Glacier; Transantarctic Mountains; (U-Th)/He", "people": "Licht, Kathy; Thomson, Stuart; He, John; Reiners, Peter; Hemming, Sidney R.", "repository": "USAP-DC", "science_program": null, "title": "Apatite (U-Th)/He and TREE Data Central Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601462"}], "date_created": "Wed, 09 Jun 2021 00:00:00 GMT", "description": "Antarctica is almost entirely covered by ice, in places over two miles thick. This ice hides a landscape that is less well known than the surface of Mars and represents one of Earth\u0027s last unexplored frontiers. Ice-penetrating radar images provide a remote glimpse of this landscape including ice-buried mountains larger than the European Alps and huge fjords twice as deep as the Grand Canyon. The goal of this project is to collect sediment samples derived from these landscapes to determine when and under what conditions these features formed. Specifically, the project seeks to understand the landscape in the context of the history and dynamics of the overlying ice sheet and past mountain-building episodes. This project accomplishes this goal by analyzing sand collected during previous sea-floor drilling expeditions off the coast of Antarctica. This sand was supplied from the continent interior by ancient rivers when it was ice-free over 34 million year ago, and later by glaciers. The project will also study bedrock samples from rare ice-free parts of the Transantarctic Mountains. The primary activity is to apply multiple advanced dating techniques to single mineral grains contained within this sand and rock. Different methods and minerals yield different dates that provide insight into how Antarctica?s landscape has eroded over the many tens of millions of years during which sand was deposited offshore. The dating techniques that are being developed and enhanced for this study have broad application in many branches of geoscience research and industry. The project makes cost-effective use of pre-existing sample collections housed at NSF facilities including the US Polar Rock Repository, the Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. The project will contribute to the STEM training of two graduate and two undergraduate students, and includes collaboration among four US universities as well as international collaboration between the US and France. The project also supports outreach in the form of a two-week open workshop giving ten students the opportunity to visit the University of Arizona to conduct STEM-based analytical work and training on Antarctic-based projects. Results from both the project and workshop will be disseminated through presentations at professional meetings, peer-reviewed publications, and through public outreach and media. The main objective of this project is to reconstruct a chronology of East Antarctic subglacial landscape evolution to understand the tectonic and climatic forcing behind landscape modification, and how it has influenced past ice sheet inception and dynamics. Our approach focuses on acquiring a record of the cooling and erosion history contained in East Antarctic-derived detrital mineral grains and clasts in offshore sediments deposited both before and after the onset of Antarctic glaciation. Samples will be taken from existing drill core and marine sediment core material from offshore Wilkes Land (100\u00b0E-160\u00b0E) and the Ross Sea. Multiple geo- and thermo-chronometers will be employed to reconstruct source region cooling history including U-Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar. This offshore record will be augmented and tested by applying the same methods to onshore bedrock samples in the Transantarctic Mountains obtained from the US Polar Rock Repository and through fieldwork. The onshore work will additionally address the debated incision history of the large glacial troughs that cut the range, now occupied by glaciers draining the East Antarctic Ice Sheet. This includes collection of samples from several age-elevation transects, apatite 4He/3He thermochronometry, and Pecube thermo-kinematic modeling. Acquiring an extensive geo- and thermo-chronologic database will also provide valuable new information on the poorly known ice-hidden geology and tectonics of subglacial East Antarctica that has implications for improving supercontinent reconstructions and understanding continental break-up.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; LANDSCAPE; AGE DETERMINATIONS; FIELD INVESTIGATION; GLACIAL PROCESSES; Transantarctic Mountains; USA/NSF; Thermochronology; Amd/Us; USAP-DC; TRACE ELEMENTS; Provenance Analysis; AMD; LANDFORMS; GLACIAL LANDFORMS", "locations": "Transantarctic Mountains", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Thomson, Stuart; Reiners, Peter; Licht, Kathy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: East Antarctic Glacial Landscape Evolution (EAGLE): A Study using Combined Thermochronology, Geochronology and Provenance Analysis", "uid": "p0010188", "west": null}, {"awards": "1245871 McCarthy, Christine", "bounds_geometry": null, "dataset_titles": "Dataset for Tidal modulation of ice streams: Effect of periodic sliding velocity on ice friction and healing; Rate-state friction parameters for ice-on-rock oscillation experiments; RSFitOSC", "datasets": [{"dataset_uid": "200237", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "RSFitOSC", "url": "https://github.com/rmskarbek/RSFitOSC"}, {"dataset_uid": "601497", "doi": "10.15784/601497", "keywords": "Antarctica", "people": "Savage, Heather; McCarthy, Christine M.; Skarbek, Rob", "repository": "USAP-DC", "science_program": null, "title": "Dataset for Tidal modulation of ice streams: Effect of periodic sliding velocity on ice friction and healing", "url": "https://www.usap-dc.org/view/dataset/601497"}, {"dataset_uid": "601467", "doi": "10.15784/601467", "keywords": "Antarctica", "people": "Savage, Heather; McCarthy, Christine M.; Skarbek, Rob", "repository": "USAP-DC", "science_program": null, "title": "Rate-state friction parameters for ice-on-rock oscillation experiments", "url": "https://www.usap-dc.org/view/dataset/601467"}], "date_created": "Fri, 04 Jun 2021 00:00:00 GMT", "description": "1245871/McCarthy This award supports a project to conduct laboratory experiments with a new, custom-fabricated cryo-friction apparatus to explore ice deformation oscillatory stresses like those experienced by tidewater glaciers in nature. The experimental design will explore the dynamic frictional properties of periodically loaded ice sliding on rock. Although the frictional strength of ice has been studied in the past these studies have all focused on constant rates of loading and sliding. The results of this work will advance understanding of ice stream dynamics by improving constraints on key material and frictional properties and allowing physics-based predictions of the amplitude and phase of glacier strain due to tidally induced stress variations. The intellectual merit of this work is that it will result in a better understanding of dynamic rheological parameters and will provide better predictive tools for dynamic glacier flow. The proposed experiments will provide dynamic material properties of ice and rock deformation at realistic frequencies experienced by Antarctic glaciers. The PIs will measure the full spectrum of material response from elastic to anelastic to viscous. The study will provide better constraints to improve predictive capability for glacier and ice-stream response to external forcing. The broader impacts of the work include providing estimates of material properties that can be used to broaden our understanding of glacier flow and that will ultimately be used for models of sea level rise and ice sheet stability. The ability to predict sea level in the near future is contingent on understanding of the processes responsible for flow of Antarctic ice streams and glaciers. Modulation of glacier flow by ocean tides represents a natural experiment that can be used to improve knowledge of ice and bed properties, and of the way in which these properties depend on time-varying forcings. Presently, the influence of tidal forcing on glacier movement is poorly understood, and knowledge of ice properties under tidal loading conditions is limited. The study will generate results of interest beyond polar science by examining phenomena that are of interest to seismology, glaciology and general materials science. The project will provide valuable research and laboratory experience for two undergraduate interns and will provide experience for the PI (currently a postdoc) in leading a scientific project. The three PIs are early career scientists. This proposal does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; Amd/Us; AMD; Ice Deformation; LABORATORY; BASAL SHEAR STRESS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McCarthy, Christine M.; Savage, Heather", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "GitHub", "repositories": "GitHub; USAP-DC", "science_programs": null, "south": null, "title": "Laboratory Study of Ice Deformation under Tidal Loading Conditions with Application to Antarctic Glaciers", "uid": "p0010186", "west": null}, {"awards": "1935438 McCarthy, Christine", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 03 Jun 2021 00:00:00 GMT", "description": "The ice sheets of Antarctica and Greenland are losing mass and contributing to accelerating global sea-level rise. Satellite altimetry provides precise measurement of ice-sheet volume change, but computing ice-sheet mass change\u2014the quantity relevant for estimating the ice sheet\u2019s sea-level contribution\u2014requires knowing the density of the ice sheet. The density near the ice-sheet surface also affects age estimates of air bubbles recovered in ice cores, which are a key source of information on past climate changes. Ice-sheet density is primarily controlled by the rate at which firn (snow that has persisted for a year or more on ice sheets) compacts into ice, but there is currently no widely accepted theory of how this compaction occurs. The goal of this project is thus to advance understanding of how firn densifies. The team will conduct laboratory experiments and analyze ice-penetrating radar and ice-core data from Antarctica. A key desired outcome of the project is a new model of firn densification that can be used to improve satellite-based altimetry measurements of present-day ice-sheet change and reconstructions of past climate changes from ice cores. This project will combine laboratory experiments, numerical modeling, and geophysical techniques to determine the rheology of firn as it compacts to form ice. The team will use two methods to measure firn compaction: (1) lab-based experiments and (2) analysis of ice-core and radar data. For the lab-based work, the team will conduct a suite of compaction experiments on synthetic firn samples under uni-axial strain and constant temperature and axial stress. They will also measure the grain-size evolution. By running a large number of experiments (\u003e 25), the team will constrain key parameters that determine how firn compaction rate depends on density, temperature, grain size, and axial stress. The experiments will be conducted in a table-top apparatus at temperatures as low as -40 degrees C and axial stresses up to 4 MPa. For the field-data-based component, the team will analyze ice-core and ice-penetrating radar data to produce the first coincident set of radar-derived firn compaction rates, borehole temperatures, firn densities, and firn grain sizes. Results from lab and field data will be tied together using a numerical firn compaction model. This model is formulated using conservation of mass, momentum, and energy, along with an explicit description of firn rheology and grain-size evolution. Constraints on firn rheology will be incorporated into this model and the team will use it to examine fundamental questions about how changes in the climate affect firn density. This is a crucial unknown that contributes significant measurement uncertainty in estimates of past and present climate change. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "AMD; LABORATORY; USA/NSF; COMPUTERS; USAP-DC; FIRN; Antarctic Ice Sheet; Amd/Us", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Arctic Natural Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "McCarthy, Christine M.; Kingslake, Jonathan", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Understanding Firn Rheology Through Laboratory Compaction Experiments and Radar Data", "uid": "p0010185", "west": null}, {"awards": "1743310 Kingslake, Jonathan", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Vulnerability of Antarctica\u2019s ice shelves to meltwater-driven fracture", "datasets": [{"dataset_uid": "601395", "doi": "10.15784/601395", "keywords": "Antarctica; Computer Model; Fractures; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meltwater; Model Data", "people": "Lai, Ching-Yao", "repository": "USAP-DC", "science_program": null, "title": "Vulnerability of Antarctica\u2019s ice shelves to meltwater-driven fracture", "url": "https://www.usap-dc.org/view/dataset/601395"}], "date_created": "Wed, 02 Jun 2021 00:00:00 GMT", "description": "Ice shelves slow the movement of the grounded ice sheets that feed them. This reduces the rate at which ice sheets lose mass to the oceans and contribute to sea-level rise. But ice shelves can be susceptible to collapse, particularly when surface meltwater accumulates in vulnerable areas. Meltwater lakes can create and enlarge fractures within the ice shelves, thereby triggering or hastening ice-shelf collapse. Also, water refreezing within ice shelves warms the ice and could affect the flow of the ice by changing its viscosity, which depends on temperature. The drainage of water across the surface of Antarctica and where it accumulates has received little attention. This drainage was assumed to be insignificant, but recent work shows that meltwater can drain for tens of kilometers across ice-shelf surfaces and access areas that would otherwise not accumulate meltwater. Surface meltwater drainage could play a major role in the future stability of ice sheets. This drainage is the focus of this project. The team will develop and test physics-based mathematical models of water flow and ice-shelf flow, closely informed by remote sensing observations, to ask (1) how drainage systems will grow in response to the increased melt rates that are predicted for this century, (2) how this drainage is influenced by ice dynamics and (3) whether enlarged drainage systems could deliver meltwater to areas of ice shelves that are vulnerable to water-driven collapse. The team hypothesizes that refreezing of meltwater in snow and firn will prove important for hydrology by impacting the permeability of the snow/firn and for ice-shelf dynamics by releasing latent heat within the ice and lowering ice viscosity. The project will examine these issues by (1) conducting a remote sensing survey of the structure and temporal evolution of meltwater systems around Antarctica, (2) developing and analyzing mathematical models of water flow across ice shelves, and (3) examining idealized and realistic models of ice-shelf flow. This project will support a first-time NSF PI, a post-doctoral researcher and a graduate student. An outreach activity will make use of the emerging technology of Augmented Reality to visualize the dynamics of ice sheets in three dimensions to excite the public about glaciology at outreach events around New York City. This approach will be made publicly available for wider use as Augmented Reality continues to grow in popularity. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; USAP-DC; Antarctica; ICE SHEETS; Amd/Us; Ice Shelf; COMPUTERS; Surface Meltwater", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kingslake, Jonathan", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Satellite observations and modelling of surface meltwater flow and its impact on ice shelves", "uid": "p0010184", "west": -180.0}, {"awards": "1643355 Steig, Eric; 1643394 Buizert, Christo", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctica 40,000 Year Temperature and Elevation Reconstructions; Layer and Thinning based Accumulation Rate Reconstructions; WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "datasets": [{"dataset_uid": "200220", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "url": "https://www.ncdc.noaa.gov/paleo/study/24530"}, {"dataset_uid": "200219", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Antarctica 40,000 Year Temperature and Elevation Reconstructions", "url": "https://www.ncdc.noaa.gov/paleo-search/study/32632"}, {"dataset_uid": "601448", "doi": "10.15784/601448", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Snow/ice; Snow/Ice", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Layer and Thinning based Accumulation Rate Reconstructions", "url": "https://www.usap-dc.org/view/dataset/601448"}], "date_created": "Fri, 28 May 2021 00:00:00 GMT", "description": "Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Steig, Eric J.; Buizert, Christo", "platforms": null, "repo": "NCEI", "repositories": "NCEI; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Timing and Spatial Expression of the Bipolar Seesaw", "uid": "p0010183", "west": -180.0}, {"awards": "1745135 Walter, Jacob; 1543286 Walter, Jacob; 1543399 Peng, Zhigang", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 19 May 2021 00:00:00 GMT", "description": "The continent of Antarctica has approximately the same surface area as the continental United States, though we know significantly less about its underlying geology and seismic activity. Multinational investments in geophysical infrastructure over the last few decades, especially broadband seismometers operating for several years, are allowing us to observe many interesting natural phenomena, including iceberg calving, ice stream slip, and tectonic earthquakes. To specifically leverage those past investments, we will analyze past and current data to gain a better understanding of Antarctic seismicity. Our recent research revealed that certain large earthquakes occurring elsewhere in the world triggered ice movement near various stations throughout Antarctica. We plan to conduct an exhaustive search of the terabytes of available data, using cutting-edge computational techniques, to uncover additional evidence for ice crevassing, ice stream slip, and earth movement during earthquakes. One specific focus of our research will include investigating whether some of these phenomena may be triggered by external influences, including passing surface waves from distant earthquakes, ocean tides, or seasonal melt. We plan to produce a catalog of the identified activity and share it publicly, so the public and researchers can easily access it. To reach a broader audience, we will present talks to high school classes, including Advanced Placement classes, in the Austin, Texas and Atlanta, Georgia metropolitan areas with emphasis on general aspects of seismic hazard, climate variability, and the geographies of Antarctica. This project will provide research opportunities for undergraduates, training for graduate students, and support for an early-career scientist. In recent years, a new generation of geodetic and seismic instrumentation has been deployed as permanent stations throughout Antarctica (POLENET), in addition to stations deployed for shorter duration (less than 3 years) experiments (e.g. AGAP/TAMSEIS). These efforts are providing critical infrastructure needed to address fundamental questions about both crustal-scale tectonic structures and ice sheets, and their interactions. We plan to conduct a systematic detection of tectonic and icequake activities in Antarctica, focusing primarily on background seismicity, remotely-triggered seismicity, and glacier slip events. Our proposed tasks include: (1) Identification of seismicity throughout the Antarctic continent for both tectonic and ice sources. (2) An exhaustive search for additional triggered events in Antarctica during the last ~15 years of global significant earthquakes. (3) Determination of triggered source mechanisms and whether those triggered events also occur at other times, by analyzing years of data using a matched-filter analysis (where the triggered local event is used to detect similar events). (4) Further analysis of GPS measurements over a ~5.5 year period from Whillans Ice Plain, which suggests that triggering of stick-slip events occurred after the largest earthquakes. An improved knowledge of how the Antarctic ice sheet responds to external perturbations such as dynamic stresses from large distant earthquakes and recent ice unloading could lead to a better understanding of ice failure and related dynamic processes. By leveraging the vast logistical investment to install seismometers in Antarctica over the last decade, our project will build an exhaustive catalog of tectonic earthquakes, icequakes, calving events, and any other detectable near-surface seismic phenomena.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; GLACIERS/ICE SHEETS; USA/NSF; TECTONICS; Amd/Us; AMD; USAP-DC; SEISMOLOGICAL STATIONS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walter, Jacob; Peng, Zhigang", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Triggering of Antarctic Icequakes, Slip Events, and other Tectonic Phenomena by Distant Earthquakes", "uid": "p0010182", "west": -180.0}, {"awards": "1543501 Howat, Ian", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "The Reference Model of Antarctica", "datasets": [{"dataset_uid": "200218", "doi": "", "keywords": null, "people": null, "repository": "PGC", "science_program": null, "title": "The Reference Model of Antarctica", "url": "https://www.pgc.umn.edu/data/rema/"}], "date_created": "Tue, 18 May 2021 00:00:00 GMT", "description": "Howat/1543501 This award will provide support to map the topography of the Antarctic continent at high spatial resolution and precision to measure ice sheet change, constrain models, correct satellite observations and support logistics. Antarctica remains the most poorly mapped landmass on Earth, yet, accurate and complete surface topography is essential for a wide range of scientific and logistical activities. The group will use a combination of very high-resolution satellite imagery, existing ground and airborne survey data and the NSF\u0027s supercomputer infrastructure to construct the Reference Elevation Model of Antarctica (REMA): a continuous, time-stamped reference surface that will be one to two orders of magnitude higher resolution than currently available. REMA will be constructed from stereoscopic, submeter resolution imagery collected by the WorldView satellite constellation, obtained at no cost in partnership with the National Geospatial Intelligence Agency and the NSF-supported Polar Geospatial Center (PGC). The high spatial and radiometric resolution of the imagery enables photogrammetric digital elevation model (DEM) extraction over low contrast terrains such as snow, ice and shadows. These DEM\u0027s have horizontal and vertical offsets of up to several meters that can be reduced to the DEM relative accuracy of 0.2 meter with a single ground control point. We will use available control points from ground and lidar surveys to register individual DEMs and optimized, least-squares co-registration to provide control between overlapping DEM\u0027s over large regions. REMA will have a posting of 10 meters and accuracy better than 1 meter. It will be distributed openly by the Polar Geospatial Center. This project will involve substantial undergraduate participation, providing training in geospatial science and remote sensing, and REMA will be used extensively for the outreach programs of the Byrd Polar and Climate Research Center. This project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Topography; AMD; USA/NSF; Amd/Us; USAP-DC; Antarctica; ICE SHEETS; COMPUTERS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Howat, Ian; Myoung-Jong Noh, ", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "PGC", "repositories": "PGC", "science_programs": null, "south": -90.0, "title": "The Reference Elevation Model of Antarctica", "uid": "p0010180", "west": -180.0}, {"awards": "1643652 Hofmann, Eileen; 1643618 Arrigo, Kevin", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic biological model output; Antarctic dFe model dyes", "datasets": [{"dataset_uid": "200211", "doi": "10.26008/1912/bco-dmo.858663.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic biological model output", "url": "https://www.bco-dmo.org/dataset/858663"}, {"dataset_uid": "200210", "doi": "10.26008/1912/bco-dmo.782848.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic dFe model dyes", "url": "https://www.bco-dmo.org/dataset/782848"}], "date_created": "Thu, 29 Apr 2021 00:00:00 GMT", "description": "Coastal waters surrounding Antarctica represent some of the most biologically rich and most untouched ecosystems on Earth. In large part, this biological richness is concentrated within the numerous openings that riddle the expansive sea ice (these openings are known as polynyas) near the Antarctic continent. These polynyas represent regions of enhanced production known as hot-spots and support the highest animal densities in the Southern Ocean. Many of them are also located adjacent to floating extensions of the vast Antarctic Ice Sheet and receive a substantial amount of meltwater runoff each year during the summer. However, little is known about the specific processes that make these ecosystems so biologically productive. Of the 46 Antarctic coastal polynyas that are presently known, only a handful have been investigated in detail. This project will develop ecosystem models for the Ross Sea polynya, Amundsen polynya, and Pine Island polynya; three of the most productive Antarctic coastal polynyas. The primary goal is to use these models to better understand the fundamental physical, chemical, and biological interacting processes and differences in these processes that make these systems so biologically productive yet different in some respects (e.g. size and productivity) during the present day settings. Modeling efforts will also be extended to potentially assess how these ecosystems may have functioned in the past and how they might change in the future under different physical and chemical and climatic settings. The project will advance the education of underrepresented minorities through Stanford?s Summer Undergraduate Research in Geoscience and Engineering (SURGE) Program. SURGE will provide undergraduates the opportunity to gain mentored research experiences at Stanford University in engineering and the geosciences. Old Dominion University also will utilize an outreach programs for local public and private schools as well as an ongoing program supporting the Boy Scout Oceanography merit badge program to create outreach and education impacts. Polynyas (areas of open water surrounded by sea ice) are disproportionately productive regions of polar ecosystems, yet controls on their high rates of production are not well understood. This project will provide quantitative assessments of the physical and chemical processes that control phytoplankton abundance and productivity within polynyas, how these differ for different polynyas, and how polynyas may change in the future. Of particular interest are the interactions among processes within the polynyas and the summertime melting of nearby ice sheets, including the Thwaites and Pine Island glaciers. In this proposed study, we will develop a set of comprehensive, high resolution coupled physical-biological models and implement these for three major, but diverse, Antarctic polynyas. These polynyas, the Ross Sea polynya, the Amundsen polynya, and Pine Island polynya, account for \u003e50% of the total Antarctic polynya production. The research questions to be addressed are: 1) What environmental factors exert the greatest control of primary production in polynyas around Antarctica? 2) What are the controlling physics that leads to the heterogeneity of dissolved iron (dFe) supply to the euphotic zone in polynyas around the Antarctic continental shelf? What effect does this have on local rates of primary production? 3) What are the likely changes in the supply of dFe to the euphotic zone in the next several decades due to climate-induced changes in the physics (winds, sea-ice, ice shelf basal melt, cross-shelf exchange, stratification and vertical mixing) and how will this affect primary productivity around the continent? The Ross Sea, Amundsen, and Pine Island polynyas are some of the best-sampled polynyas in Antarctica, facilitating model parameterization and validation. Furthermore, these polynyas differ widely in their size, location, sea ice dynamics, relationship to melting ice shelves, and distance from the continental shelf break, making them ideal case studies. For comparison, the western Antarctic Peninsula (wAP), a productive continental shelf where polynyas are a relatively minor contributor to biological production, will also be modeled. Investigating specific processes within different types Antarctic coastal waters will provide a better understand of how these important biological oases function and how they might change under different environmental conditions.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Trace Metal; AMD; PELAGIC; POLYNYAS; PHYTOPLANKTON; MODELS; Amd/Us; USAP-DC; MICROALGAE; USA/NSF; Polynya; TRACE ELEMENTS; ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "van Dijken, Gert; Arrigo, Kevin; Dinniman, Michael; Hofmann, Eileen", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Elucidating Environmental Controls of Productivity in Polynas and the Western Antarctic Peninsula", "uid": "p0010175", "west": -180.0}, {"awards": "1543325 Landolt, Scott; 1543377 Seefeldt, Mark", "bounds_geometry": "POLYGON((166.918 -77.8675,167.2997 -77.8675,167.6814 -77.8675,168.0631 -77.8675,168.4448 -77.8675,168.8265 -77.8675,169.2082 -77.8675,169.5899 -77.8675,169.9716 -77.8675,170.3533 -77.8675,170.735 -77.8675,170.735 -77.98145,170.735 -78.0954,170.735 -78.20935,170.735 -78.3233,170.735 -78.43725,170.735 -78.5512,170.735 -78.66515,170.735 -78.7791,170.735 -78.89305,170.735 -79.007,170.3533 -79.007,169.9716 -79.007,169.5899 -79.007,169.2082 -79.007,168.8265 -79.007,168.4448 -79.007,168.0631 -79.007,167.6814 -79.007,167.2997 -79.007,166.918 -79.007,166.918 -78.89305,166.918 -78.7791,166.918 -78.66515,166.918 -78.5512,166.918 -78.43725,166.918 -78.3233,166.918 -78.20935,166.918 -78.0954,166.918 -77.98145,166.918 -77.8675))", "dataset_titles": "Precipitation Observations for the Northwest Ross Ice Shelf - 2017-12 to 2019-11", "datasets": [{"dataset_uid": "601441", "doi": "10.15784/601441", "keywords": "Accumulation; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meteorology; Precipitation; Ross Ice Shelf; Snow; Snow/ice; Snow/Ice; Weatherstation; Weather Station Data", "people": "Seefeldt, Mark", "repository": "USAP-DC", "science_program": null, "title": "Precipitation Observations for the Northwest Ross Ice Shelf - 2017-12 to 2019-11", "url": "https://www.usap-dc.org/view/dataset/601441"}], "date_created": "Tue, 27 Apr 2021 00:00:00 GMT", "description": "Accurately measuring precipitation in Antarctica is important for purposes such as calculating Antarctica?s mass balance and contribution to global sea level rise, interpreting ice core records, and validating model- and satellite-based precipitation estimates. There is a critical need for reliable, autonomous, long-term measurements of Antarctic precipitation in order to better understand its variability in space in time. Such records over time are essentially absent from the continent, despite their importance. This project will deploy and test instrumentation to measure and record rates of snowfall and blowing snow in Antarctica. Project goals are based on installation of four low-power, autonomous Antarctic precipitation systems (APS) co-located at automatic weather station (AWS) sites in the Ross Island region of Antarctica. The APSs are designed with an integrated sensor approach to provide multiple types of observations of snow accumulation types at the test sites. The APSs are designed to construct an accurate timeline of snow accumulation, and to distinguish the water equivalent of fallen precipitation from surface blowing (lofted) snow, a prime confounding factor. The standard suite of instruments to be deployed includes: precipitation gauge with double Alter windshield, laser disdrometer, laser snow height sensor, optical precipitation detector, anemometer at gauge height, and a visible /infrared webcam. These instruments have previously been shown to work well in cold regions applications.", "east": 170.735, "geometry": "POINT(168.8265 -78.43725)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; AMD; Amd/Us; USA/NSF; SNOW; Wind Data; WEATHER STATIONS; Ross Ice Shelf", "locations": "Ross Ice Shelf", "north": -77.8675, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Seefeldt, Mark; Landolt, Scott", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e WEATHER STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.007, "title": "Collaborative Research: Implementing Low-power, Autonomous Observing Systems to Improve the Measurement and Understanding of Antarctic Precipitation", "uid": "p0010173", "west": 166.918}, {"awards": "1246151 Bromirski, Peter; 1246416 Stephen, Ralph", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.4,-175 -77.8,-175 -78.2,-175 -78.6,-175 -79,-175 -79.4,-175 -79.8,-175 -80.2,-175 -80.6,-175 -81,-175.5 -81,-176 -81,-176.5 -81,-177 -81,-177.5 -81,-178 -81,-178.5 -81,-179 -81,-179.5 -81,180 -81,179 -81,178 -81,177 -81,176 -81,175 -81,174 -81,173 -81,172 -81,171 -81,170 -81,170 -80.6,170 -80.2,170 -79.8,170 -79.4,170 -79,170 -78.6,170 -78.2,170 -77.8,170 -77.4,170 -77,171 -77,172 -77,173 -77,174 -77,175 -77,176 -77,177 -77,178 -77,179 -77,-180 -77))", "dataset_titles": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ; Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "datasets": [{"dataset_uid": "200207", "doi": "10.7914/SN/XH_2014", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ", "url": "http://www.fdsn.org/networks/detail/XH_2014/"}, {"dataset_uid": "200209", "doi": "10.7283/58E3-GA46", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "url": "https://doi.org/10.7283/58E3-GA46"}], "date_created": "Thu, 15 Apr 2021 00:00:00 GMT", "description": "Bromirski/1246151 This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is \"locally\" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.", "east": 170.0, "geometry": "POINT(177.5 -79)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; GLACIER MOTION/ICE SHEET MOTION; USAP-DC; Amd/Us; AMD; USA/NSF; Iris; Ross Ice Shelf", "locations": "Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Bromirski, Peter; Gerstoft, Peter; Stephen, Ralph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "IRIS", "repositories": "IRIS; UNAVCO", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations", "uid": "p0010169", "west": -175.0}, {"awards": "1600823 Halzen, Francis; 2042807 Halzen, Francis; 0639286 Halzen, Francis; 0937462 Halzen, Francis", "bounds_geometry": "POINT(-180 -90)", "dataset_titles": "Amanda 7 Year Data Set; IceCube data releases", "datasets": [{"dataset_uid": "200374", "doi": "", "keywords": null, "people": null, "repository": "IceCube", "science_program": null, "title": "IceCube data releases", "url": "https://icecube.wisc.edu/science/data-releases/"}, {"dataset_uid": "601438", "doi": "10.15784/601438", "keywords": "Amanda-ii; Antarctica; Neutrino; Neutrino Candidate Events; Neutrino Telescope; South Pole", "people": "Halzen, Francis; Riedel, Benedikt", "repository": "USAP-DC", "science_program": "IceCube", "title": "Amanda 7 Year Data Set", "url": "https://www.usap-dc.org/view/dataset/601438"}], "date_created": "Wed, 07 Apr 2021 00:00:00 GMT", "description": "This award funds the continued management and operations (M\u0026O) of the IceCube Neutrino Observatory (ICNO) located at the South Pole Station. The core team of researchers and engineers maintain the existing ICNO infrastructure at the South Pole and home institution, guaranteeing an uninterrupted stream of scientifically unique, high-quality data. The M\u0026O activities are built upon eight highly successful years of managing the overall ICNO operations after the start of science operations in 2008. Construction of ICNO was supported by NSF\u0027s Major Research Equipment and Facilities Construction (MREFC) account and was completed on schedule and within budget in 2010. Effective coordination of efforts by the core M\u0026O personnel and efforts by personnel within the IceCube Collaboration has yielded significant increases in the performance of this cubic-kilometer detector over time. The scientific output from the IceCube Collaboration during the past five years has been outstanding. The broader impacts of the ICNO/M\u0026O activities are strong, involving postdoctoral, graduate, and (in some cases) undergraduate students in the day-today operation \u0026 calibration of the neutrino detector. The extraordinary physics results recently produced by ICNO and its extraordinary location at South Pole have a high potential to excite the imagination of high school children and the public in general at a national and international level. The current ICNO/M\u0026O effort produces better energy and angular resolution information about detected neutrino events, has more efficient data filters and more accurate detector simulations, and enables continuous software development for systems that are needed to acquire and analyze data. This has produced data acquisition and data management systems with high robustness, traceability, and maintainability. The current ICNO/M\u0026O effort includes: (1) resources for both distributed and centrally managed activities, and (2) additional accountability mechanisms for \"in-kind\" and institutional contributions. Both are necessary to ensure that the detector maintains its capability to produce quality scientific data at the level required to achieve the detector\u0027s scientific discovery objectives. Recent ICNO discoveries of cosmic high-energy neutrinos (some reaching energies close to and over 2.5 PeV) and oscillating atmospheric neutrinos in a previously unexplored energy range from 10 to 60 GeV became possible because of the \"state-of-the-art\" detector configuration, excellently supported infrastructure, and cutting-edge science analyses. The ICNO has set limits on Dark Matter annihilations, made precision measurements of the angular distribution of cosmic ray muons, and characterized in detail physical properties of the Antarctic 2.5-km thick ice sheet at South Pole. The discovery of high-energy cosmic neutrinos by IceCube with a flux at the level anticipated for those associated with high-energy gamma- and cosmic-ray accelerators brightens the prospect for identifying the sources of the highest energy particles.", "east": -180.0, "geometry": "POINT(-180 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e ICECUBE", "is_usap_dc": true, "keywords": "USA/NSF; South Pole; OBSERVATORIES; Amd/Us; AMD; GLACIERS/ICE SHEETS; Icecube; Neutrino; USAP-DC", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "Halzen, Francis; Karle, Albrecht", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e OBSERVATORIES", "repo": "IceCube", "repositories": "IceCube; USAP-DC", "science_programs": "IceCube", "south": -90.0, "title": "Management and Operations of the IceCube Neutrino Observatory 2021-2026", "uid": "p0010168", "west": -180.0}, {"awards": "2317097 Venturelli, Ryan; 1738989 Venturelli, Ryan", "bounds_geometry": "POLYGON((-114 -74,-112.2 -74,-110.4 -74,-108.6 -74,-106.8 -74,-105 -74,-103.2 -74,-101.4 -74,-99.6 -74,-97.8 -74,-96 -74,-96 -74.2,-96 -74.4,-96 -74.6,-96 -74.8,-96 -75,-96 -75.2,-96 -75.4,-96 -75.6,-96 -75.8,-96 -76,-97.8 -76,-99.6 -76,-101.4 -76,-103.2 -76,-105 -76,-106.8 -76,-108.6 -76,-110.4 -76,-112.2 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74))", "dataset_titles": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica; Cosmogenic-Nuclide data at ICE-D; Firn and Ice Density at Winkie Nunatak; Ice-penetrating radar data from the northern embayment of the Mt. Murphy massif; Ice-penetrating radar data from the Thwaites Glacier grounding zone; In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers; NBP1902 Expedition data; Pine Island Bay Relative Sea-Level Data", "datasets": [{"dataset_uid": "601860", "doi": "10.15784/601860", "keywords": "Antarctica; Cryosphere; Grounding Zone; Ice Penetrating Radar; Thwaites Glacier", "people": "Goehring, Brent; Balco, Greg; Campbell, Seth", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Ice-penetrating radar data from the Thwaites Glacier grounding zone", "url": "https://www.usap-dc.org/view/dataset/601860"}, {"dataset_uid": "601677", "doi": "10.15784/601677", "keywords": "Antarctica; Ice Penetrating Radar; Pine Island Glacier; Subglacial Bedrock", "people": "Braddock, Scott", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601677"}, {"dataset_uid": "601554", "doi": "10.15784/601554", "keywords": "Antarctica; Pine Island Bay; Radiocarbon; Raised Beaches", "people": "Braddock, Scott; Hall, Brenda", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Pine Island Bay Relative Sea-Level Data", "url": "https://www.usap-dc.org/view/dataset/601554"}, {"dataset_uid": "601834", "doi": "10.15784/601834", "keywords": "Antarctica; Cryosphere; Mount Murphy", "people": "Campbell, Seth; Balco, Greg; Goehring, Brent", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Ice-penetrating radar data from the northern embayment of the Mt. Murphy massif", "url": "https://www.usap-dc.org/view/dataset/601834"}, {"dataset_uid": "601838", "doi": "10.15784/601838", "keywords": "Antarctica; Cryosphere; Density; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Density; Ice Core Records; Snow/ice; Snow/Ice", "people": "Venturelli, Ryan", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Firn and Ice Density at Winkie Nunatak", "url": "https://www.usap-dc.org/view/dataset/601838"}, {"dataset_uid": "200296", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic-Nuclide data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "601705", "doi": "10.15784/601705", "keywords": "Antarctica; Cosmogenic Radionuclides; Mount Murphy; Subglacial Bedrock", "people": "Balco, Gregory; Venturelli, Ryan; Goehring, Brent", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers", "url": "https://www.usap-dc.org/view/dataset/601705"}, {"dataset_uid": "200083", "doi": "10.7284/908147", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1902 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1902"}], "date_created": "Tue, 16 Mar 2021 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Thwaites Glacier system dominates the contribution to sea-level rise from Antarctica. Predicting how this system will evolve in coming decades, and thereby its likely contribution to sea level, requires detailed understanding of how it has responded to changes in climate and oceanographic conditions in the past. This project will provide a record of regional sea-level change by establishing chronologies for raised marine beaches as well as the timing and duration of periods of retreat of Thwaites Glacier during the past 10,000 years by sampling and dating bedrock presently covered by Thwaites Glacier via subglacial drilling. Together with climatic and oceanographic conditions from other records, these will provide boundary conditions for past-to-present model simulations as well as those used to predict future glacier changes under a range of climate scenarios. Specifically, the project will test the hypothesis--implied by existing geological evidence from the region--that present rapid retreat of the Thwaites Glacier system is reversible. The team aims to utilize two approaches: 1. To reconstruct relative sea level during the Holocene, it will map and date raised marine and shoreline deposits throughout Pine Island Bay. Chronological constraints on sea-level change will be provided by radiocarbon dating of organic material in landforms and sediments that are genetically related to past sea level, such as shell fragments, bones of marine fauna, and penguin guano. 2. To obtain geological evidence for past episodes of grounding-line retreat, the team will apply cosmogenic-nuclide exposure-dating of subglacial bedrock. Using drill systems recently developed for subglacial bedrock recovery, the team will obtain subglacial bedrock from sites where ice thickness is dynamically linked to grounding-line position in the Thwaites system (specifically in the Hudson Mountains, and near Mount Murphy). Observation of significant cosmogenic-nuclide concentrations--the team will primarily measure Beryllium-10 and in situ Carbon-14--in these samples would provide direct, unambiguous evidence for past episodes of thinning linked to grounding-line retreat as well as constraints on their timing and duration. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -96.0, "geometry": "POINT(-105 -75)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; FIELD INVESTIGATION; GLACIERS/ICE SHEETS; GLACIAL LANDFORMS; LABORATORY; Amd/Us; USAP-DC; GLACIATION; Amundsen Sea; USA/NSF", "locations": "Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Goehring, Brent; Hall, Brenda; Campbell, Seth; Venturelli, Ryan A; Balco, Gregory", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "ICE-D; R2R; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "uid": "p0010165", "west": -114.0}, {"awards": "2001714 Muto, Atsuhiro; 2002346 Tinto, Kirsteen", "bounds_geometry": "POLYGON((-115 -70,-113 -70,-111 -70,-109 -70,-107 -70,-105 -70,-103 -70,-101 -70,-99 -70,-97 -70,-95 -70,-95 -70.8,-95 -71.6,-95 -72.4,-95 -73.2,-95 -74,-95 -74.8,-95 -75.6,-95 -76.4,-95 -77.2,-95 -78,-97 -78,-99 -78,-101 -78,-103 -78,-105 -78,-107 -78,-109 -78,-111 -78,-113 -78,-115 -78,-115 -77.2,-115 -76.4,-115 -75.6,-115 -74.8,-115 -74,-115 -73.2,-115 -72.4,-115 -71.6,-115 -70.8,-115 -70))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 02 Mar 2021 00:00:00 GMT", "description": "Predictions of future changes of the Antarctic ice sheet are essential for understanding changes in the global sea level expected for the coming centuries. These predictions rely on models of ice-sheet flow that in turn rely on knowledge of the physical conditions of the Antarctic continent beneath the ice. Exploration of Antarctica by land, sea, and air has advanced our understanding of the geological material under the Antarctic ice sheet, but this information has not yet been fully integrated into ice-sheet models. This project will take advantage of existing data from decades of US and international investment in geophysical surveys to create a new understanding of the geology underlying the Amundsen Sea and the adjacent areas of the West Antarctic Ice Sheet\u2014a portion of Antarctica that is considered particularly vulnerable to collapse. A series of new datasets called \u201cBed Classes\u201d will be developed that will translate the geological properties of the Antarctic continent in ways that can be incorporated into ice-sheet models. This project will develop a new regional geologic/tectonic framework for the Amundsen Sea Embayment and its ice catchments using extensive marine and airborne geophysical data together with ground-based onshore geophysical and geological constraints to delineate sedimentary basins, bedrock ridges, faults, and volcanic structures. Using this new geologic interpretation of the region, several key issues regarding the geologic influence on ice-sheet stability will be addressed: whether the regional heat flow is dominated by localization along the faults or lithology; the role of geology on the sources, sinks, and flow-paths of subglacial water; the distribution of sediments that determine bed-character variability; and the extent of geologic control on the current Thwaites Glacier grounding line. The impact of improved geological knowledge on ice-sheet models will be tested with the development of a set of \u201cBed Class\u201d grids to capture these new insights for use in the models. Bed Classes will be tested within the Parallel Ice Sheet Model framework with initial experiments to identify the sensitivity of model simulations to geological parameterizations. Through a series of workshops with ice-sheet modelers, the Bed Classes will be refined and made accessible to the broader modelling community. This work aims to ensure that the Bed-Class concept can be applied more broadly to ice-sheet models working in different geographic areas and on different timescales. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-105 -74)", "instruments": null, "is_usap_dc": true, "keywords": "Amundsen Sea; COMPUTERS; GRAVITY ANOMALIES; Amd/Us; GLACIERS/ICE SHEETS; AMD; USA/NSF; USAP-DC", "locations": "Amundsen Sea", "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Earth Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Tinto, Kirsty; Bell, Robin; Porter, David; Muto, Atsu", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -78.0, "title": "Collaborative Research: Building Geologically Informed Bed Classes to Improve Projections of Ice Sheet Change", "uid": "p0010164", "west": -115.0}, {"awards": "2048351 Lindow, Julia", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 26 Feb 2021 00:00:00 GMT", "description": "Part I: Nontechnical Antarcticas ice sheets constitute the largest ice mass on Earth, with approximately 53 meters of sea level equivalent stored in the East Antarctic Ice Sheet alone. The history of the East Antarctic Ice Sheet is therefore important to understanding and predicting changes in sea level and Earths climate. There is conflicting evidence regarding long-term stability of the East Antarctic Ice Sheet, over the last twenty million years. To better understand past ice sheet changes, together with the history of the Transantarctic Mountains, accurate time scales are needed. One of the few dating methods applicable to the Antarctic glacial deposits, that record past ice sheet changes, is the measurement of rare isotopes produced by cosmic rays in surface rock samples, referred to as cosmogenic nuclides. Whenever a rock surface is exposed/free of cover, cosmic rays produce rare isotopes such as helium-3, beryllium-10, and neon-21within the minerals. This project will involve measurement of all three isotopes in some of the oldest glacial deposits found at high elevation in the Transantarctic Mountains. Because the amount of each isotope is directly linked to the exposure time, this can be used to calculate the age of a surface. This method requires knowledge of the rates that cosmic radiation produces each isotope, which depends upon mineral composition, and is presently a limitation of the method. The goal of this project is to advance and enhance existing measurement methods and expand the range of possibilities in surface dating with new measurements of all three isotopes in pyroxene, a mineral that is commonly found throughout the Transantarctic Mountains. This technological progress will allow a better application of the surface exposure dating method, which in turn will help to reconstruct Antarctic ice sheet history and provide valuable knowledge of former ice-extent. Understanding Antarcticas ice-sheet history is crucial to predict its influence on past and future sea level changes. Part II: Technical Description Measurements of in-situ produced cosmogenic nuclides in Antarctic surficial rock samples provide unique time scales for glacial and landscape evolution processes. However, due to analytical challenges, pyroxene-bearing and widely distributed lithologies like the Ferrar dolerite of the Transantarctic Mountains, are underutilized. This proposal aims to changes this and to improve the cosmogenic nuclide methodologies for stable isotopes (21Ne and 3He) and radioactive nuclides (10Be) in pyroxenes. Proposed methodological improvements will be directly applicable to erosion rates and deposition ages of important glacial deposits, such as the controversial Sirius Group tills, and also to younger glacial features. Bennett Platform is the focus of this study because it is one of the southern-most Sirius Group outcrops along the Transantarctic Mountains, where cosmogenic ages are sparse. Preliminary measurements demonstrate large discrepancies between 3He and 21Ne age determinations in Sirius Group pyroxenes. One possible explanation is composition dependence of the 21Ne production rates. Coupled measurements of 3He, 21Ne, and 10Be in well-characterized pyroxene mineral separates from Ferrar dolerite will be used to better constrain the production rates, major element and trace element dependencies, the assumptions of the method, and ultimately advance the application of cosmogenic nuclides to mafic Antarctic lithologies. The main goals of this study are to improve measurement protocols for 10Be in pyroxene, and the determination of the composition dependence of 21Ne production rates by measuring mineral compositions (by electron microprobe), and nuclide concentrations in mineral pairs from young lava flows. Further aims are the validation of the nucleogenic contributions and the effects of helium diffusive loss through measurements of 3He/21Ne production ratios, combined with measurements of shielded samples of the Ferrar dolerite. Combined measurements of 3He, 21Ne and 10Be in pyroxenes have rarely been published for individual samples in Antarctica. The new and unique measurements of this study will advance the applicability of in-situ produced cosmogenic nuclides to both young and ancient Antarctic surfaces. The study will be performed using existing samples: no field work is requested. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; FIELD INVESTIGATION; LABORATORY; Transantarctic Mountains; USAP-DC; GLACIAL LANDFORMS; Amd/Us", "locations": "Transantarctic Mountains", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Lindow, Julia; Kurz, Mark D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "New Cosmogenic 21Ne and 10Be Measurements in the Transantarctic Mountains", "uid": "p0010163", "west": null}, {"awards": "1738992 Pettit, Erin C; 1929991 Pettit, Erin C", "bounds_geometry": "POLYGON((-114 -74,-113 -74,-112 -74,-111 -74,-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-104 -74.2,-104 -74.4,-104 -74.6,-104 -74.8,-104 -75,-104 -75.2,-104 -75.4,-104 -75.6,-104 -75.8,-104 -76,-105 -76,-106 -76,-107 -76,-108 -76,-109 -76,-110 -76,-111 -76,-112 -76,-113 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74))", "dataset_titles": "AMIGOS-IIIa \"Cavity\" Aquadopp current data Jan 2020 - Mar 2021; AMIGOS-IIIa \"Cavity\" Seabird CTD data Jan 2020 - Dec 2021; AMIGOS-III Cavity and Channel Snow Height and Thermistor Snow Temperature Data; AMIGOS-IIIc \"Channel\" Aquadopp current data Jan 2020 - Mar 2021; AMIGOS-IIIc \"Channel\" Seabird CTD data Jan 2020 - Dec 2021; CTD data from the NBP 19/02 cruise as part of the TARSAN project in the Amundsen Sea during austral summer 2018/2019; Dotson-Crosson Ice Shelf data from a tale of two ice shelves paper; Pinning-point shear-zone fractures in Thwaites Eastern Ice Shelf (2002 - 2022); Sentinel-1-derived monthly-averaged velocity components from Thwaites Eastern Ice Shelf, 2016 - 2022; SIIOS Temporary Deployment; Sub-ice-shelf seafloor elevation derived from point-source active-seismic data on Thwaites Eastern Ice Shelf and Dotson Ice Shelf, December 2019 and January 2020; Thwaites Eastern Ice Shelf GPS displacements; Thwaites Glacier grounding lines for 2014 and 2019/20 from height above flotation; Two-year velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2001-2020; Visala WXT520 weather station data at the Cavity and Channel AMIGOS-III sites; Yearly velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2013-2022", "datasets": [{"dataset_uid": "200321", "doi": "10.5285/e338af5d-8622-05de-e053-6c86abc06489", "keywords": null, "people": null, "repository": "British Oceanographic Data Centre", "science_program": null, "title": "CTD data from the NBP 19/02 cruise as part of the TARSAN project in the Amundsen Sea during austral summer 2018/2019", "url": "https://www.bodc.ac.uk/data/published_data_library/catalogue/10.5285/e338af5d-8622-05de-e053-6c86abc06489/"}, {"dataset_uid": "601549", "doi": "10.15784/601549", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Pine Island Bay; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Visala WXT520 weather station data at the Cavity and Channel AMIGOS-III sites", "url": "https://www.usap-dc.org/view/dataset/601549"}, {"dataset_uid": "601499", "doi": "10.15784/601499", "keywords": "Amundsen Sea; Antarctica; Glaciology; Grounding Line; Ice Shelf; Thwaites Glacier", "people": "Wild, Christian; Scambos, Ted; Truffer, Martin; Muto, Atsu; Pettit, Erin; Alley, Karen", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Thwaites Glacier grounding lines for 2014 and 2019/20 from height above flotation", "url": "https://www.usap-dc.org/view/dataset/601499"}, {"dataset_uid": "601548", "doi": "10.15784/601548", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIc \"Channel\" Aquadopp current data Jan 2020 - Mar 2021", "url": "https://www.usap-dc.org/view/dataset/601548"}, {"dataset_uid": "601547", "doi": "10.15784/601547", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIa \"Cavity\" Aquadopp current data Jan 2020 - Mar 2021", "url": "https://www.usap-dc.org/view/dataset/601547"}, {"dataset_uid": "601552", "doi": "10.15784/601552", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Pine Island Bay; Snow Accumulation; Snow Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-III Cavity and Channel Snow Height and Thermistor Snow Temperature Data", "url": "https://www.usap-dc.org/view/dataset/601552"}, {"dataset_uid": "601545", "doi": "10.15784/601545", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Salinity; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIc \"Channel\" Seabird CTD data Jan 2020 - Dec 2021", "url": "https://www.usap-dc.org/view/dataset/601545"}, {"dataset_uid": "200204", "doi": "https://doi.org/10.7914/SN/1L_2019", "keywords": null, "people": null, "repository": "International Federation of Digital Seismograph Networks", "science_program": null, "title": "SIIOS Temporary Deployment", "url": "http://www.fdsn.org/networks/detail/1L_2019/"}, {"dataset_uid": "601544", "doi": "10.15784/601544", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Salinity; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIa \"Cavity\" Seabird CTD data Jan 2020 - Dec 2021", "url": "https://www.usap-dc.org/view/dataset/601544"}, {"dataset_uid": "601827", "doi": "10.15784/601827", "keywords": "Antarctica; Cryosphere; Dotson Ice Shelf; Thwaites Glacier", "people": "Alley, Karen; Wallin, Bruce; Pomraning, Dale; Wild, Christian; Scambos, Ted; Truffer, Martin; Pettit, Erin; Roccaro, Alexander; Muto, Atsuhiro", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Sub-ice-shelf seafloor elevation derived from point-source active-seismic data on Thwaites Eastern Ice Shelf and Dotson Ice Shelf, December 2019 and January 2020", "url": "https://www.usap-dc.org/view/dataset/601827"}, {"dataset_uid": "601578", "doi": "10.15784/601578", "keywords": "Antarctica; Dotson Ice Shelf; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Wild, Christian; Segabinazzi-Dotto, Tiago", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Dotson-Crosson Ice Shelf data from a tale of two ice shelves paper", "url": "https://www.usap-dc.org/view/dataset/601578"}, {"dataset_uid": "601478", "doi": "10.15784/601478", "keywords": "Antarctica; Glaciology; Ice Shelf; Ice Velocity; Strain Rate; Thwaites Glacier", "people": "Pettit, Erin; Truffer, Martin; Scambos, Ted; Wild, Christian; Klinger, Marin; Wallin, Bruce; Alley, Karen; Muto, Atsu", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Two-year velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2001-2020", "url": "https://www.usap-dc.org/view/dataset/601478"}, {"dataset_uid": "601904", "doi": "10.15784/601904", "keywords": "Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Glaciology; Ice Shelf; Remote Sensing; Satellite Imagery; Thwaites; Thwaites Glacier; Velocity", "people": "Banerjee, Debangshu; Lilien, David; Truffer, Martin; Luckman, Adrian; Wild, Christian; Pettit, Erin; Scambos, Ted; Muto, Atsuhiro; Alley, Karen", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Yearly velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2013-2022", "url": "https://www.usap-dc.org/view/dataset/601904"}, {"dataset_uid": "601903", "doi": "10.15784/601903", "keywords": "Antarctica; Cryosphere; Fractures; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Thwaites", "people": "Banerjee, Debangshu; Lilien, David; Truffer, Martin; Luckman, Adrian; Wild, Christian; Pettit, Erin; Scambos, Ted; Muto, Atsuhiro; Alley, Karen", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Pinning-point shear-zone fractures in Thwaites Eastern Ice Shelf (2002 - 2022)", "url": "https://www.usap-dc.org/view/dataset/601903"}, {"dataset_uid": "601925", "doi": "10.15784/601925", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GNSS; Ice Shelf; Ice Velocity; Thwaites Glacier", "people": "Pettit, Erin; Scambos, Ted; Truffer, Martin; Alley, Karen; Wild, Christian", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Thwaites Eastern Ice Shelf GPS displacements", "url": "https://www.usap-dc.org/view/dataset/601925"}, {"dataset_uid": "601914", "doi": null, "keywords": "Antarctica; Cryosphere; Glaciology; Ice Shelf; Thwaites Glacier; Velocity", "people": "Alley, Karen; Muto, Atsuhiro; Wild, Christian; Truffer, Martin; Luckman, Adrian; Banerjee, Debangshu; Lilien, David; Scambos, Ted; Pettit, Erin", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Sentinel-1-derived monthly-averaged velocity components from Thwaites Eastern Ice Shelf, 2016 - 2022", "url": "https://www.usap-dc.org/view/dataset/601914"}], "date_created": "Mon, 22 Feb 2021 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites and neighboring glaciers in the Amundsen Sea Embayment are rapidly losing mass in response to recent climate warming and related changes in ocean circulation. Mass loss from the Amundsen Sea Embayment could lead to the eventual collapse of the West Antarctic Ice Sheet, raising the global sea level by up to 2.5 meters (8 feet) in as short as 500 years. The processes driving the loss appear to be warmer ocean circulation and changes in the width and flow speed of the glacier, but a better understanding of these changes is needed to refine predictions of how the glacier will evolve. One highly sensitive process is the transitional flow of glacier ice from land onto the ocean to become a floating ice shelf. This flow of ice from grounded to floating is affected by changes in air temperature and snowfall at the surface; the speed and thickness of ice feeding it from upstream; and the ocean temperature, salinity, bathymetry, and currents that the ice flows into. The project team will gather new measurements of each of these local environmental conditions so that it can better predict how future changes in air, ocean, or the ice will affect the loss of ice to the ocean in this region. Current and anticipated near-future mass loss from Thwaites Glacier and nearby Amundsen Sea Embayment region is mainly attributed to reduction in ice-shelf buttressing due to sub-ice-shelf melting by intrusion of relatively warm Circumpolar Deep Water into sub-ice-shelf cavities. Such predictions for mass loss, however, still lack understanding of the dominant processes at and near grounding zones, especially their spatial and temporal variability, as well as atmospheric and oceanic drivers of these processes. This project aims to constrain and compare these processes for the Thwaites and the Dotson Ice Shelves, which are connected through upstream ice dynamics, but influenced by different submarine troughs. The team\u0027s specific objectives are to: 1) install atmosphere-ice-ocean multi-sensor remote autonomous stations on the ice shelves for two years to provide sub-daily continuous observations of concurrent oceanic, glaciologic, and atmospheric conditions; 2) measure ocean properties on the continental shelf adjacent to ice-shelf fronts (using seal tagging, glider-based and ship-based surveys, and existing moored and conductivity-temperature-depth-cast data), 3) measure ocean properties into sub-ice-shelf cavities (using autonomous underwater vehicles) to detail ocean transports and heat fluxes; and 4) constrain current ice-shelf and sub-ice-shelf cavity geometry, ice flow, and firn properties for the ice-shelves (using radar, active-source seismic, and gravimetric methods) to better understand the impact of ocean and atmosphere on the ice-sheet change. The team will also engage the public and bring awareness to this rapidly changing component of the cryosphere through a \"Live from the Ice\" social media campaign in which the public can follow the action and data collection from the perspective of tagged seals and autonomous stations. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -104.0, "geometry": "POINT(-109 -75)", "instruments": null, "is_usap_dc": true, "keywords": "Thwaites Glacier; FIELD SURVEYS; GLACIERS/ICE SHEETS", "locations": "Thwaites Glacier", "north": -74.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Truffer, Martin; Scambos, Ted; Muto, Atsu; Heywood, Karen; Boehme, Lars; Hall, Robert; Wahlin, Anna; Lenaerts, Jan; Pettit, Erin", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "British Oceanographic Data Centre", "repositories": "British Oceanographic Data Centre; International Federation of Digital Seismograph Networks; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment", "uid": "p0010162", "west": -114.0}, {"awards": "1643353 Christianson, Knut; 1643301 Gerbi, Christopher", "bounds_geometry": null, "dataset_titles": "ImpDAR: an impulse radar processor; SeidarT; South Pole Lake ApRES Radar; South Pole Lake GNSS; South Pole Lake: ground-based ice-penetrating radar", "datasets": [{"dataset_uid": "200203", "doi": "", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "South Pole Lake: ground-based ice-penetrating radar", "url": "http://hdl.handle.net/1773/45293"}, {"dataset_uid": "601503", "doi": "10.15784/601503", "keywords": "Antarctica; Apres; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; South Pole; Subglacial Lakes; Vertical Velocity", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake ApRES Radar", "url": "https://www.usap-dc.org/view/dataset/601503"}, {"dataset_uid": "200244", "doi": " https://zenodo.org/badge/latestdoi/382590632", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "SeidarT", "url": "https://github.com/UMainedynamics/SeidarT"}, {"dataset_uid": "601502", "doi": "10.15784/601502", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GNSS; GPS; GPS Data; South Pole; Subglacial Lakes", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake GNSS", "url": "https://www.usap-dc.org/view/dataset/601502"}, {"dataset_uid": "200202", "doi": "http://doi.org/10.5281/zenodo.3833057", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "ImpDAR: an impulse radar processor", "url": "https://www.github.com/dlilien/ImpDAR"}], "date_created": "Wed, 17 Feb 2021 00:00:00 GMT", "description": "Gerbi/1643301 This award supports a project to develop software that will allow researchers considering seismic or radar field surveys to test, ahead of time, whether the data they plan to collect will have sufficient resolution to measure the natural variations in the mechanical properties of ice, which determine the response of flowing ice to changing climatic conditions. The mechanical properties of ice depend largely on the temperature and the orientation of the crystals that make up the ice. The most accurate method for measuring ice crystal orientation and temperature is through drilling and direct analysis of an ice core. However, this method is very costly, time-consuming, and limited in spatial coverage. Geophysical techniques, such as seismic and radar, can cover much more area, but we have little knowledge about the practical limitations of these techniques as they relate to calculating mechanical properties. This project addresses that knowledge gap through construction of a computational toolbox that will allow accurate assessment of the ability of geophysical surveys to image crystal orientation and ice temperature. Researchers can then use these tools to adjust the field survey plans to maximize the return on investment. By working to improve the efficiency and effectiveness of future geophysical work related to glacial flow, this proposal will improve scientists? ability to quantify sea-level variations within the larger context of climate change. The project includes building new user-friendly, publicly accessible software and instructional modules. The work will provide training for graduate and undergraduate students, who will play a role in research and develop instructional materials. Ice viscosity, the resistance of ice to flow, exerts significant control over ice velocity. Therefore, mapping ice viscosity is important for understanding the current and future behavior of glaciers and ice sheets. To do so, scientists must determine the temperature and crystal orientation fabric throughout the ice. Seismic and radar techniques can survey large areas quickly, and thus are promising, yet not fully tested, methods to efficiently measure the thermal and mechanical structure of flowing ice. As part of this project, scientists will develop and use a computational framework to quantify the degree to which seismic and radar techniques can resolve the crystal orientation fabric and temperature of streaming ice, and then test how sensitive ice flow is to the attendant uncertainty. To meet these goals, a numerical toolbox will be built which will allow the glacier/ice stream geometry and physical properties (temperature, crystal orientation fabric, density and acidity) to be varied. The toolbox will be capable of both creating synthetic radar and seismic profiles through forward modeling and inverting synthetic profiles to allow evaluation of how well geophysical techniques can image the original thermal and mechanical structure. These simulated radar and seismic data will allow scientists to better quantify the influence of the variability in mechanical properties of the ice on flow velocities and patterns. The results of this work will guide planning for future field campaigns, making them more effective and efficient. This project does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; GLACIERS/ICE SHEETS; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; South Pole; USA/NSF; AMD; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; FIELD SURVEYS; Amd/Us", "locations": "South Pole; United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Gerbi, Christopher; Campbell, Seth; Vel, Senthil", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "Uni. Washington ResearchWorks Archive", "repositories": "GitHub; Uni. Washington ResearchWorks Archive; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Computational Methods Supporting Joint Seismic and Radar Inversion for Ice Fabric and Temperature in Streaming Flow", "uid": "p0010160", "west": null}, {"awards": "1443525 Schwartz, Susan", "bounds_geometry": "POLYGON((-165 -83.8,-163 -83.8,-161 -83.8,-159 -83.8,-157 -83.8,-155 -83.8,-153 -83.8,-151 -83.8,-149 -83.8,-147 -83.8,-145 -83.8,-145 -83.92,-145 -84.04,-145 -84.16,-145 -84.28,-145 -84.4,-145 -84.52,-145 -84.64,-145 -84.76,-145 -84.88,-145 -85,-147 -85,-149 -85,-151 -85,-153 -85,-155 -85,-157 -85,-159 -85,-161 -85,-163 -85,-165 -85,-165 -84.88,-165 -84.76,-165 -84.64,-165 -84.52,-165 -84.4,-165 -84.28,-165 -84.16,-165 -84.04,-165 -83.92,-165 -83.8))", "dataset_titles": "YD (2012-2017): Whillians Ice Stream Subglacial Access Research Drilling", "datasets": [{"dataset_uid": "200201", "doi": "https://doi.org/10.7914/SN/YD_2012", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "YD (2012-2017): Whillians Ice Stream Subglacial Access Research Drilling", "url": "http://www.fdsn.org/networks/detail/YD_2012/"}], "date_created": "Fri, 12 Feb 2021 00:00:00 GMT", "description": "This project evaluates the role that water and rock/ice properties at the base of a fast moving glacier, or ice stream, play in controlling its motion. In Antarctica, where surface melting is limited, the speed of ice flow through the grounding zone (where ice on land detaches, and begins to float on ocean water) controls the rate at which glaciers contribute to sea level rise. The velocity of the ice stream is strongly dependent on resistance from the bed, so understanding the processes that control resistance to flow is critical in predicting ice sheet mass balance. In fact, the Intergovernmental Panel on Climate Change (IPCC) recognized this and stated in their 4th assessment report that reliable predictions of future global sea-level rise require improved understanding of ice sheet dynamics, which include basal controls on fast ice motion. Drilling to obtain direct observations of basal properties over substantial regions is prohibitively expensive. This project uses passive source seismology to \"listen to\" and analyze sounds generated by water flow and/or sticky spots at the ice/bed interface to evaluate the role that basal shear stress plays in ice flow dynamics. Because polar science is captivating to both scientists and the general public, it serves as an excellent topic to engage students at all levels with important scientific concepts and processes. In conjunction with this research, polar science educational materials will be developed to be used by students spanning middle school through the University level. Starting in summer 2015, a new polar science class for high school students in the California State Summer School for Mathematics and Science (COSMOS) will be offered at the University of California-Santa Cruz. This curriculum will be shared with the MESA Schools Program, a Santa Cruz and Monterey County organization that runs after-school science clubs led by teachers at several local middle and high schools with largely minority and underprivileged populations. This proposal extends the period of borehole and surface geophysical monitoring of the Whillians Ice Stream (WIS) established under a previous award for an additional 2 years. Data from the WIS network demonstrated that basal heterogeneity, revealed by microseismicity, shows variation over scales of 100\u0027s of meters. An extended observation period will allow detailed seismic characterization of ice sheet bed properties over a crucial length scale comparable to the local ice thickness. Due to the fast ice velocity (\u003e300 m/year), a single instrumented location will move approximately 1 km during the extended 3 year operational period, allowing continuous monitoring of seismic emissions as the ice travels over sticky spots and other features in the bed (e.g., patches of till or subglacial water bodies). Observations over ~1km length scales will help to bridge a crucial gap in current observations of basal conditions between extremely local observations made in boreholes and remote observations of basal shear stress inferred from inversions of ice surface velocity data.", "east": -145.0, "geometry": "POINT(-155 -84.4)", "instruments": null, "is_usap_dc": true, "keywords": "Whillans Ice Stream; GLACIERS/ICE SHEETS; FIELD INVESTIGATION", "locations": "Whillans Ice Stream", "north": -83.8, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek; Schwartz, Susan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "IRIS", "repositories": "IRIS", "science_programs": "WISSARD", "south": -85.0, "title": "High Resolution Heterogeneity at the Base of Whillans Ice Stream and its Control on Ice Dynamics", "uid": "p0010159", "west": -165.0}, {"awards": "1643795 Mikesell, Thomas", "bounds_geometry": "POLYGON((-134.5 -75,-130.85 -75,-127.2 -75,-123.55 -75,-119.9 -75,-116.25 -75,-112.6 -75,-108.95 -75,-105.3 -75,-101.65 -75,-98 -75,-98 -75.85,-98 -76.7,-98 -77.55,-98 -78.4,-98 -79.25,-98 -80.1,-98 -80.95,-98 -81.8,-98 -82.65,-98 -83.5,-101.65 -83.5,-105.3 -83.5,-108.95 -83.5,-112.6 -83.5,-116.25 -83.5,-119.9 -83.5,-123.55 -83.5,-127.2 -83.5,-130.85 -83.5,-134.5 -83.5,-134.5 -82.65,-134.5 -81.8,-134.5 -80.95,-134.5 -80.1,-134.5 -79.25,-134.5 -78.4,-134.5 -77.55,-134.5 -76.7,-134.5 -75.85,-134.5 -75))", "dataset_titles": "2D shear-wave velocity model across the West Antarctic Rift System from POLENET-ANET seismic data", "datasets": [{"dataset_uid": "601423", "doi": "10.15784/601423", "keywords": "Antarctica; Crust; Moho; Seismic Tomography; Seismology; Seismometer; Shear Wave Velocity; Surface Wave Dispersion; West Antarctica", "people": "Mikesell, Dylan", "repository": "USAP-DC", "science_program": "POLENET", "title": "2D shear-wave velocity model across the West Antarctic Rift System from POLENET-ANET seismic data", "url": "https://www.usap-dc.org/view/dataset/601423"}], "date_created": "Fri, 15 Jan 2021 00:00:00 GMT", "description": "Non-technical description: Global sea-level rise is a significant long-term risk for human population and infrastructure. To mitigate and properly react to this threat, society needs accurate predictions of future sea-level variations. The largest uncertainty in these predictions comes from estimating the amount of ice that melts from polar ice sheets, especially from the West Antarctica ice sheet. Right now, scientists estimate the mass variations of ice sheets in two ways. The first way is using airplanes and repeated flybys to monitor the variation of ice sheet topography and estimate the gain or loss of ice. The second way is using satellite measurements to track gravity fluctuations that correlate with the variation of ice sheet volume. Both techniques work, but both have limitations including cost and resolution. This project uses a passive seismic monitoring method to estimate the change in weight of the ice pressing on the Earth\u0027s crust. One advantage of this seismic method is that vibrations are recorded continuously; therefore, it is possible to monitor the changes of the ice sheet with better temporal resolution. The sensitivity of the seismic waves also provides a picture of the structure of the interface between the ice and the rocks beneath the ice, where most of the dynamics and changes of the ice sheet take place. This information is difficult to obtain with other methods. In this project, the researchers will process and analyze previously acquired seismic data from the POLENET-ANET array, measuring variations in seismic wave speed through time to assess the amount of ice lost or gained. They will also determine important information about the mechanical properties at the ice-rock interface. The project will support a postdoctoral scholar to develop this new branch of seismological research and more generally the field of environmental seismology. This project will also support the education of a PhD student who will work in close collaboration with the postdoctoral scholar and the two researchers. Technical description: The researchers plan to monitor ice-mass variations in the West-Antarctic ice sheet by measuring and interpreting seismic velocity changes in crust beneath the ice sheet. This project will extend similar work already completed on the Greenland ice sheet, where ice-mass fluctuations were found to lead to poroelastic changes in the crust and modify the seismic-wave velocity. This investigation uses a passive seismology method, whereby repetitive seismic noise correlation functions are computed from records of Earth\u0027s ambient seismic noise field. Measurements of the temporal changes in the correlation functions are made and then related to variations of the poroelastic properties of the crust. The physical model for the relationship between ice-mass change and surface-wave velocity change has previously been verified using GRACE satellite data in Greenland. This project will specifically focus on the recent rapid ice loss in Western Antarctica using data from the POLENET-ANET seismic network. A comparison between the ice-sheet behaviors in Greenland and Antarctica will provide clarification about the underlying physical processes responsible for the observed seismic velocity changes. This new method will be a transformative approach to monitor ice sheets with the potential for much higher spatial and temporal resolution than existing methods. The fact that this method relies on seismic waves makes the approach completely independent from other modern ice-sheet monitoring techniques.", "east": -98.0, "geometry": "POINT(-116.25 -79.25)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; SEISMIC SURFACE WAVES; West Antarctica", "locations": "West Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Mordret, Aurelien; Mikesell, Dylan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "POLENET", "south": -83.5, "title": "Collaborative Research: Monitoring Antarctic Ice Sheet Changes with Ambient Seismic Noise Methods", "uid": "p0010155", "west": -134.5}, {"awards": "1443321 Bromley, Gordon; 1443329 Balco, Gregory", "bounds_geometry": "POLYGON((-180 -85.40705,-179.659078 -85.40705,-179.318156 -85.40705,-178.977234 -85.40705,-178.636312 -85.40705,-178.29539 -85.40705,-177.954468 -85.40705,-177.613546 -85.40705,-177.272624 -85.40705,-176.931702 -85.40705,-176.59078 -85.40705,-176.59078 -85.422615,-176.59078 -85.43818,-176.59078 -85.453745,-176.59078 -85.46931,-176.59078 -85.484875,-176.59078 -85.50044,-176.59078 -85.516005,-176.59078 -85.53157,-176.59078 -85.547135,-176.59078 -85.5627,-176.931702 -85.5627,-177.272624 -85.5627,-177.613546 -85.5627,-177.954468 -85.5627,-178.29539 -85.5627,-178.636312 -85.5627,-178.977234 -85.5627,-179.318156 -85.5627,-179.659078 -85.5627,180 -85.5627,179.277561 -85.5627,178.555122 -85.5627,177.832683 -85.5627,177.110244 -85.5627,176.387805 -85.5627,175.665366 -85.5627,174.942927 -85.5627,174.220488 -85.5627,173.498049 -85.5627,172.77561 -85.5627,172.77561 -85.547135,172.77561 -85.53157,172.77561 -85.516005,172.77561 -85.50044,172.77561 -85.484875,172.77561 -85.46931,172.77561 -85.453745,172.77561 -85.43818,172.77561 -85.422615,172.77561 -85.40705,173.498049 -85.40705,174.220488 -85.40705,174.942927 -85.40705,175.665366 -85.40705,176.387805 -85.40705,177.110244 -85.40705,177.832683 -85.40705,178.555122 -85.40705,179.277561 -85.40705,-180 -85.40705))", "dataset_titles": "Interface for viewing observational data related to exposure ages measurements and calculated geologic ages derived therefrom", "datasets": [{"dataset_uid": "200199", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Interface for viewing observational data related to exposure ages measurements and calculated geologic ages derived therefrom", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Sun, 20 Dec 2020 00:00:00 GMT", "description": "This investigation will reconstruct past behavior of the East Antarctic Ice Sheet during periods of warmer-than-present climate, such as the Pliocene, in order to better project the likely response of Earth\u0027s largest ice sheet to anthropogenic warming. Containing the equivalent of ~55 m sea-level rise, the future evolution of the East Antarctic Ice Sheet has clear societal ramifications on a global scale as temperatures continue to rise. Therefore, determining ice-sheet sensitivity to climate on the scale predicted for the next two centuries is a matter of increasing urgency, particularly in light of evidence suggesting the East Antarctic Ice Sheet is more dynamic than previously thought. This research will provide a terrestrial geologic record of long-term ice-sheet behavior from sites immediately adjacent the East Antarctic Ice Sheet in the Transantarctic Mountains, with which the project will help ascertain how the ice sheet responded to past warm periods. The project will focus primarily on the Pliocene warm period, 5 to 3 million years ago, as this represents the closest analogue to 21st Century climate conditions. The proposed research will investigate glacial deposits corresponding to the East Antarctic Ice Sheet in the central Transantarctic Mountains in order to expand the geologic record of past ice-sheet behavior. The overarching research objectives are to improve understanding of the East Antarctic Ice Sheet\u0027s configuration during periods of warmer-than-present climate, such as the Pliocene warm period, and to determine whether the ice sheet underwent significant volume changes or remained relatively stable in response to warming. To address these goals, the investigation will map and date glacial deposits preserved at mountain sites immediately adjacent the ice sheet. Specifically, we will: (i) employ multiple cosmogenic nuclides (10Be, 26Al, 21Ne) to establish more fully ice-thickness histories for the upper Shackleton and Beardmore Glaciers, where they exit the ice sheet; (ii) use this record to identify periods during which the East Antarctic Ice Sheet was at least as extensive as today; and (iii) use these data to assess long-term ice-sheet variability in East Antarctica, with particular emphasis on Pliocene warm episodes. This research will require Antarctic fieldwork, glacial-geologic mapping, and cosmogenic surface-exposure dating.", "east": -176.59078, "geometry": "POINT(178.092415 -85.484875)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Transantarctic Mountains; GLACIERS/ICE SHEETS; AMD; GLACIER THICKNESS/ICE SHEET THICKNESS; GLACIER ELEVATION/ICE SHEET ELEVATION; NOT APPLICABLE; Antarctica", "locations": "Antarctica; Transantarctic Mountains", "north": -85.40705, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Balco, Gregory; Bromley, Gorden; BROMLEY, GORDON", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -85.5627, "title": "Collaborative Research: Potential Direct Geologic Constraint of Ice Sheet Thickness in the Central Transantarctic Mountains during the Pliocene Warm Period", "uid": "p0010153", "west": 172.77561}, {"awards": "0838757 Balco, Gregory; 0838968 Putkonen, Jaakko", "bounds_geometry": "POLYGON((-158.00085 -83.2093,-157.945063 -83.2093,-157.889276 -83.2093,-157.833489 -83.2093,-157.777702 -83.2093,-157.721915 -83.2093,-157.666128 -83.2093,-157.610341 -83.2093,-157.554554 -83.2093,-157.498767 -83.2093,-157.44298 -83.2093,-157.44298 -83.50197,-157.44298 -83.79464,-157.44298 -84.08731,-157.44298 -84.37998,-157.44298 -84.67265,-157.44298 -84.96532,-157.44298 -85.25799,-157.44298 -85.55066,-157.44298 -85.84333,-157.44298 -86.136,-157.498767 -86.136,-157.554554 -86.136,-157.610341 -86.136,-157.666128 -86.136,-157.721915 -86.136,-157.777702 -86.136,-157.833489 -86.136,-157.889276 -86.136,-157.945063 -86.136,-158.00085 -86.136,-158.00085 -85.84333,-158.00085 -85.55066,-158.00085 -85.25799,-158.00085 -84.96532,-158.00085 -84.67265,-158.00085 -84.37998,-158.00085 -84.08731,-158.00085 -83.79464,-158.00085 -83.50197,-158.00085 -83.2093))", "dataset_titles": "Interface to observational data and geologic age information calculated therefrom; Web page with links to files containing cosmogenic noble gas concentrations and related analytical data", "datasets": [{"dataset_uid": "200198", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Web page with links to files containing cosmogenic noble gas concentrations and related analytical data", "url": "http://noblegas.berkeley.edu/~balcs/ongvalley/"}, {"dataset_uid": "200197", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Interface to observational data and geologic age information calculated therefrom", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Sun, 20 Dec 2020 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The proposed project will investigate the coldest and driest parts of the Transantarctic Mountains (Ong Valley at Nimrod Glacier and Moraine Canyon at Amundsen Glacier) where the lack of running water and biological activity in the modern environment is thought to have preserved the landscape, essentially unchanged, for millions of years. Contrary to this common belief, it is hypothesized that the landscape does evolve, perhaps as fast as many surfaces in the Dry Valleys area where both loose soil and bedrock surfaces have been degrading at a rate of about 1-2 m/Myrs for the past several million years. The research team will rely on analysis of the both stable and radioactive cosmogenic isotopes that accumulate in near surface soil and bedrock. Collectively these measurements allow comparison of the long term landscape evolution to current processes and environmental drivers such as wind speed. The results of this work will improve understanding of the evolution of the Earth\u0027s surface and directly aid in evaluating imagery of Martian geomorphology. Continued reliance on students provides a broader impact to this proposed research and firmly grounds this effort in its educational mission.", "east": -157.44298, "geometry": "POINT(-157.721915 -84.67265)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; NOT APPLICABLE; Antarctica", "locations": "Antarctica", "north": -83.2093, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Balco, Gregory; Putkonen, Jaakko; Morgan, Daniel", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "PI website", "repositories": "ICE-D; PI website", "science_programs": null, "south": -86.136, "title": "Collaborative Research: Systematic Analysis of Landscape Evolution and Surface Ages in Transantarctic Mountains", "uid": "p0010152", "west": -158.00085}, {"awards": "0838783 Conway, Howard; 0838256 Todd, Claire; 0838784 Balco, Gregory", "bounds_geometry": "POLYGON((-66.27517 -83.23921,-65.341961 -83.23921,-64.408752 -83.23921,-63.475543 -83.23921,-62.542334 -83.23921,-61.609125 -83.23921,-60.675916 -83.23921,-59.742707 -83.23921,-58.809498 -83.23921,-57.876289 -83.23921,-56.94308 -83.23921,-56.94308 -83.359865,-56.94308 -83.48052,-56.94308 -83.601175,-56.94308 -83.72183,-56.94308 -83.842485,-56.94308 -83.96314,-56.94308 -84.083795,-56.94308 -84.20445,-56.94308 -84.325105,-56.94308 -84.44576,-57.876289 -84.44576,-58.809498 -84.44576,-59.742707 -84.44576,-60.675916 -84.44576,-61.609125 -84.44576,-62.542334 -84.44576,-63.475543 -84.44576,-64.408752 -84.44576,-65.341961 -84.44576,-66.27517 -84.44576,-66.27517 -84.325105,-66.27517 -84.20445,-66.27517 -84.083795,-66.27517 -83.96314,-66.27517 -83.842485,-66.27517 -83.72183,-66.27517 -83.601175,-66.27517 -83.48052,-66.27517 -83.359865,-66.27517 -83.23921))", "dataset_titles": "Interface to observational data collected in this project and geologic age information derived therefrom. Dynamic content, continuously updated.; Web page linking to documents containing data collected in this project. Static content", "datasets": [{"dataset_uid": "200194", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Interface to observational data collected in this project and geologic age information derived therefrom. Dynamic content, continuously updated.", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200195", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Web page linking to documents containing data collected in this project. Static content", "url": "http://noblegas.berkeley.edu/~balcs/pensacola/"}], "date_created": "Sat, 19 Dec 2020 00:00:00 GMT", "description": "This award supports a project to find and date geologic evidence of past ice-marginal positions in the Pensacola Mountains, which border the Foundation Ice Stream at the head of the Weddell Sea embayment. The project will involve glacial geologic mapping and cosmogenic-nuclide surface exposure dating of glacially transported erratics. An ice-flow model will be used to link our exposure-dating results together in a glaciologically consistent way, and to relate them to regional LGM to Holocene elevation changes. A secondary focus of the project seeks to improve the effectiveness of exposure-dating methods in understanding ice sheet change. Changes in the location of the ice margin, and thus the exposure ages that record these changes, are controlled not only by regional ice sheet mass balance, but also by local effects on snow- and icefields immediately adjacent to the exposure-dating sites. This part of the project will combine glaciological observations near the present ice margin with targeted exposure- age sampling in an effort to better understand the processes controlling the ice margin location, and improve the interpretation of very recent exposure-age data as a record of latest Holocene to present ice sheet changes. The intellectual merit of the project is that it will provide direct geologic evidence of LGM-to-Holocene ice volume change in a region of Antarctica where no such evidence now exists. The broader impacts of the work involve both gathering information needed for accurate understanding of past and present global sea level change. Secondly, this project will help to develop and maintain the human and intellectual resources necessary for continued excellence in polar research and global change education, by linking experienced Antarctic researchers with early career scientists who seek to develop their expertise in both research and education. In addition, it brings together two early career scientists whose careers are focused at opposite ends of the research-education spectrum, thus facilitating better integration of research and education both in the careers of these scientists and in the outcome of this project. This award has field work in Antarctica.", "east": -56.94308, "geometry": "POINT(-61.609125 -83.842485)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; GLACIER THICKNESS/ICE SHEET THICKNESS; NOT APPLICABLE; GLACIER ELEVATION/ICE SHEET ELEVATION; Antarctica", "locations": "Antarctica", "north": -83.23921, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Balco, Gregory; Todd, Claire; Conway, Howard", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "ICE-D", "repositories": "ICE-D; PI website", "science_programs": null, "south": -84.44576, "title": "Collaborative Research: Last Glacial Maximum and Deglaciation Chronology for the Foundation Ice Stream and Southeastern Weddell Sea Embayment", "uid": "p0010151", "west": -66.27517}, {"awards": "1842021 Campbell, Seth", "bounds_geometry": "POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.5,-111 -83,-111 -83.5,-111 -84,-111 -84.5,-111 -85,-111 -85.5,-111 -86,-111 -86.5,-111 -87,-116.7 -87,-122.4 -87,-128.1 -87,-133.8 -87,-139.5 -87,-145.2 -87,-150.9 -87,-156.6 -87,-162.3 -87,-168 -87,-168 -86.5,-168 -86,-168 -85.5,-168 -85,-168 -84.5,-168 -84,-168 -83.5,-168 -83,-168 -82.5,-168 -82))", "dataset_titles": "2017 GPR Observations of the Whillans and Mercer Ice Streams; Whillans and Mercer Shear Margin Ice Flow simulation in ISSM", "datasets": [{"dataset_uid": "601403", "doi": "10.15784/601403", "keywords": "Antarctica; Crevasses; Glaciology; GPR; GPS; Ice Sheet Flow Model; Ice Shelf Dynamics; Snow/ice; Snow/Ice; Whillans Ice Stream", "people": "Kaluzienski, Lynn", "repository": "USAP-DC", "science_program": null, "title": "2017 GPR Observations of the Whillans and Mercer Ice Streams", "url": "https://www.usap-dc.org/view/dataset/601403"}, {"dataset_uid": "601404", "doi": "10.15784/601404", "keywords": "Antarctica; Glaciology; Ice Sheet Flow Model; Ice Shelf Dynamics; Mercer Ice Stream; Model Data; Snow/ice; Snow/Ice; Whillans Ice Stream", "people": "Kaluzienski, Lynn", "repository": "USAP-DC", "science_program": null, "title": "Whillans and Mercer Shear Margin Ice Flow simulation in ISSM", "url": "https://www.usap-dc.org/view/dataset/601404"}], "date_created": "Mon, 14 Dec 2020 00:00:00 GMT", "description": "The Siple Coast in West Antarctica has undergone significant glacier changes over the last millenium. Several ice streams--rapidly moving streams of ice bordered by slow-moving ice--exist in this region that feeds into the Ross Ice Shelf. A long-term slowdown of Whillans Ice Stream appears to be occurring, and this is affecting the zone between the Whillans and Mercer Ice Streams. However, the consistency of this slowdown and resulting changes to the shear margin between the two ice streams are unknown. The goal of this project is to quantify the observed changes over the past decade and understand the dynamic processes that cause them. A collateral benefit of and driver for this as a RAPID project is to test a method for assessing where crevassing will develop in this zone of steep velocity gradients. Such a method may benefit not only near-term field-project planning in the 2018-19 field season, but also planning for future fieldwork and traverses. The team will use remote sensing feature-tracking techniques to determine transient velocity patterns and shifts in the shear-zone location over the last 10-plus years. This velocity time series will be incorporated into a large-scale ice-sheet model to estimate ice-sheet susceptibility to changing boundary conditions over the next century based on likely regional ice-flux scenarios. This approach is an extension of recent work conducted by the team that shows promise for predicting areas of changing high strain rates indicative of an active glacier shear margin. The ultimate objectives are to characterize the flow field of merging ice streams over time and investigate lateral boundary migration. This will provide a better understanding of shear-margin control on ice-shelf and up-glacier stability. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -111.0, "geometry": "POINT(-139.5 -84.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Whillans Ice Stream; USAP-DC; Amd/Us; USA/NSF; GLACIER MOTION/ICE SHEET MOTION; MODELS; AMD", "locations": "Whillans Ice Stream", "north": -82.0, "nsf_funding_programs": "Polar Special Initiatives; Antarctic Glaciology", "paleo_time": null, "persons": "Campbell, Seth; Koons, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.0, "title": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence", "uid": "p0010145", "west": -168.0}, {"awards": "1908399 Bizimis, Michael; 1908548 Feakins, Sarah", "bounds_geometry": "POLYGON((74.787 -67.27617,74.816483 -67.27617,74.845966 -67.27617,74.875449 -67.27617,74.904932 -67.27617,74.934415 -67.27617,74.963898 -67.27617,74.993381 -67.27617,75.022864 -67.27617,75.052347 -67.27617,75.08183 -67.27617,75.08183 -67.31817,75.08183 -67.36017,75.08183 -67.40217,75.08183 -67.44417,75.08183 -67.48617,75.08183 -67.52817,75.08183 -67.57017,75.08183 -67.61217,75.08183 -67.65417,75.08183 -67.69617,75.052347 -67.69617,75.022864 -67.69617,74.993381 -67.69617,74.963898 -67.69617,74.934415 -67.69617,74.904932 -67.69617,74.875449 -67.69617,74.845966 -67.69617,74.816483 -67.69617,74.787 -67.69617,74.787 -67.65417,74.787 -67.61217,74.787 -67.57017,74.787 -67.52817,74.787 -67.48617,74.787 -67.44417,74.787 -67.40217,74.787 -67.36017,74.787 -67.31817,74.787 -67.27617))", "dataset_titles": "Ejtibbett/EOTproxymodel: Proxy Model Comparison for the Eocene-Oligocene Transition [Computational Notebook]; Paleoceanography and biomarker data from the Antarctic Peninsula over the past 37-3 million years; Prydz Bay East Antarctica, biomarkers and pollen, 36-33 million years; Sabrina Coast East Antarctica, Pollen and Biomarker Data from 59-38 million years ago; Southern High Latitude Temperature Proxies from the Late Eocene and Early Oligocene [Dataset]", "datasets": [{"dataset_uid": "200317", "doi": "10.25921/n9kg-yw91", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Paleoceanography and biomarker data from the Antarctic Peninsula over the past 37-3 million years", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/35613"}, {"dataset_uid": "200335", "doi": "10.5281/zenodo.7254536", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Southern High Latitude Temperature Proxies from the Late Eocene and Early Oligocene [Dataset]", "url": "https://zenodo.org/record/7254536#.Y2BLgOTMI2w"}, {"dataset_uid": "200334", "doi": "10.5281/zenodo.7254786", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Ejtibbett/EOTproxymodel: Proxy Model Comparison for the Eocene-Oligocene Transition [Computational Notebook]", "url": "https://zenodo.org/record/7254786#.Y2BLAeTMI2w"}, {"dataset_uid": "200206", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Prydz Bay East Antarctica, biomarkers and pollen, 36-33 million years", "url": "https://www.ncdc.noaa.gov/paleo-search/study/32052"}, {"dataset_uid": "200259", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Sabrina Coast East Antarctica, Pollen and Biomarker Data from 59-38 million years ago", "url": "https://www.ncdc.noaa.gov/paleo/study/34772"}], "date_created": "Sat, 05 Dec 2020 00:00:00 GMT", "description": "The East Antarctic Ice Sheet holds the largest volume of freshwater on the planet, in total enough to raise sea level by almost two hundred feet. Even minor adjustments in the volume of ice stored have major implications for coastlines and climates around the world. The question motivating this project is how did the ice grow to cover the continent over thirty million years ago when Antarctica changed from a warmer environment to an ice-covered southern continent? The seafloor of Prydz Bay, a major drainage basin of the East Antarctic Ice Sheet (EAIS), has been drilled previously to recover sediments dating from millions of years prior to and across the time when inception of continental ice sheets occurred in Antarctica. The last remnants of plant material found as \u0027biomarkers\u0027 in the ocean sediments record the chemical signatures of rain and snowfall that fed the plants and later the expanding glaciers. Sediment carried by glaciers was also deposited on the seafloor and can be analyzed to discover how glaciers flowed across the landscape. Here, the researchers will identify precipitation changes that result from, and drive, ice sheet growth. This study will gather data and further analyze samples from the seafloor sediment archives of the International Ocean Discovery Program\u0027s (IODP) core repositories. Ultimately these findings can help inform temperature-precipitation-ice linkages within climate and ice sheet models. The project will support the training of three female, early career scientists (PhD \u0026 MS students, and research technician) and both PIs and the PhD student will continue their engagement with broadening participation efforts (e.g., Women in Science and Engineering Program; local chapters of Society for the advancement of Native Americans and Chicanos in Science and other access programs) to recruit undergraduate student participants from underrepresented minorities at both campuses and from local community colleges. Antarctic earth science education materials will be assisted by professional illustrations to be open access and used in public education and communication efforts to engage local communities in Los Angeles CA and Columbia SC. The researchers at the University of Southern California and the University of South Carolina will together study the penultimate moment of the early Cenozoic greenhouse climate state: the ~4 million years of global cooling that culminated in the Eocene/Oligocene transition (~34 Ma). Significant gaps remain in the understanding of the conditions that preceded ice expansion on Antarctica. In particular, the supply of raw material for ice sheets (i.e., moisture) and the timing, frequency, and duration of precursor glaciations is poorly constrained. This collaborative proposal combines organic and inorganic proxies to examine how Antarctic hydroclimate changed during the greenhouse to icehouse transition. The central hypothesis is that the hydrological cycle weakened as cooling proceeded. Plant-wax hydrogen and carbon isotopes (hydroclimate proxies) and Hf-Nd isotopes of lithogenous and hydrogenous sediments (mechanical weathering proxies) respond strongly and rapidly to precipitation and glacial advance. This detailed and sensitive combined approach will test whether there were hidden glaciations (and/or warm events) that punctuated the pre-icehouse interval. Studies will be conducted on Prydz Bay marine sediment cores in a depositional area for products of weathering and erosion that were (and are) transported through Lambert Graben from the center of Antarctica. The project will yield proxy information about the presence of plants and the hydroclimate of Antarctica and the timing of glacial advance, and is expected to show drying associated with cooling and ice-sheet growth. The dual approach will untangle climate signals from changes in fluvial versus glacial erosion of plant biomarkers. This proposal is potentially transformative because the combination of organic and inorganic proxies can reveal rapid transitions in aridity and glacial expansion, that may have been missed in slower-response proxies and more distal archives. The research is significant as hydroclimate seems to be a key player in the temperature-cryosphere hysteresis. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 75.08183, "geometry": "POINT(74.934415 -67.48617)", "instruments": null, "is_usap_dc": true, "keywords": "MICROFOSSILS; Prydz Bay; PALEOCLIMATE RECONSTRUCTIONS; Sabrina Coast; DROUGHT/PRECIPITATION RECONSTRUCTION; ISOTOPES; AIR TEMPERATURE RECONSTRUCTION", "locations": "Prydz Bay; Sabrina Coast", "north": -67.27617, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Feakins, Sarah; Scher, Howard", "platforms": null, "repo": "NCEI", "repositories": "NCEI; Zenodo", "science_programs": null, "south": -67.69617, "title": "Collaborative Research: Organic and Inorganic Geochemical Investigation of Hydrologic Change in East Antarctica in the 4 Million Years Before Full Glaciation", "uid": "p0010143", "west": 74.787}, {"awards": "1643798 Emry, Erica; 1643873 Hansen, Samantha", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "GEOSCOPE Network; IU: Global Seismograph Network; Shear Wave Velocity of the Antarctic Upper Mantle from Full Waveform Inversion and Long Period Ambient Seismic Noise; XP (2000-2004): A Broadband Seismic Investigation of Deep Continental Structure Across the East-West Antarctic Boundary ; YT (2007-2023): IPY POLENET-Antarctica: Investigating links between geodynamics and ice sheets; ZJ (2012-2015): Transantarctic Mountains Northern Network ; ZM (2007-2013): A Broadband Seismic Experiment to Image the Lithosphere beneath the Gamburtsev Mountains, East Antarctica", "datasets": [{"dataset_uid": "200168", "doi": "10.18715/GEOSCOPE.G", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "GEOSCOPE Network", "url": "http://geoscope.ipgp.fr/networks/detail/G/"}, {"dataset_uid": "200172", "doi": "10.7914/SN/ZM_2007", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": " ZM (2007-2013): A Broadband Seismic Experiment to Image the Lithosphere beneath the Gamburtsev Mountains, East Antarctica", "url": "http://www.fdsn.org/networks/detail/ZM_2007/"}, {"dataset_uid": "200169", "doi": "10.7914/SN/IU", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IU: Global Seismograph Network", "url": "http://www.fdsn.org/networks/detail/IU/"}, {"dataset_uid": "200171", "doi": "10.7914/SN/YT_2007", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "YT (2007-2023): IPY POLENET-Antarctica: Investigating links between geodynamics and ice sheets", "url": "http://www.fdsn.org/networks/detail/YT_2007/"}, {"dataset_uid": "601909", "doi": "10.15784/601909", "keywords": "Ambient Seismic Noise; Antarctica; Cryosphere; Full-Waveform Inversion; Seismic Tomography; Shear Wave Velocity", "people": "Emry, Erica; Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Shear Wave Velocity of the Antarctic Upper Mantle from Full Waveform Inversion and Long Period Ambient Seismic Noise", "url": "https://www.usap-dc.org/view/dataset/601909"}, {"dataset_uid": "200170", "doi": "10.7914/SN/XP_2000", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "XP (2000-2004): A Broadband Seismic Investigation of Deep Continental Structure Across the East-West Antarctic Boundary ", "url": "http://www.fdsn.org/networks/detail/XP_2000/"}, {"dataset_uid": "200173", "doi": "10.7914/SN/ZJ_2012", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "ZJ (2012-2015): Transantarctic Mountains Northern Network ", "url": "http://www.fdsn.org/networks/detail/ZJ_2012/"}], "date_created": "Thu, 15 Oct 2020 00:00:00 GMT", "description": "Nontechnical description of proposed research: This project will apply cutting-edge seismic imaging methods to existing seismic data to study the three-dimensional structure of the Earth beneath the ice-covered Antarctic continent. The study will improve understanding of Earth structure and hotspots and geologically recent and ancient rift systems. The results will be useful for models of ice movement and bedrock elevation changes due to variation in ice sheet thickness. The results will also help guide future seismic data collection. The researchers will transfer existing software from the high-performance computers at The University of Rhode Island to the Alabama supercomputer facilities. The project will also broaden public understanding of scientific research in Antarctica by engaging with the students and teachers in Socorro County, New Mexico to discuss career opportunities in science, technology, engineering, and mathematics (STEM), the Earth Sciences, and the importance of computers in scientific research. Project personnel from Alabama will visit Socorro and share research with students at New Mexico Tech and at the Socorro High School. The project will also train undergraduate and graduate students in the expanding field of computational seismology, by applying these approaches to study Antarctic geology. Technical description of proposed research: The project seeks to better resolve the three-dimensional Antarctic mantle structure and viscosity and to identify locations of ancient rifts within the stable East Antarctic lithosphere. To accomplish this, the researchers will utilize full-waveform tomographic inversion techniques that combine long-period ambient noise data with earthquake constraints to more accurately resolve structure than traditional tomographic approaches. The proposed research will be completed using the Alabama supercomputer facilities and the programs and methodology developed at The University of Rhode Island. The new tomographic results will be useful in assessing lithospheric structure beneath Dronning Maud Land as well as the Wilkes and Aurora Subglacial Basins in East Antarctica, where previous rifting episodes and mid-lithospheric discontinuities will be explored. In West Antarctica, the work will elucidate the easternmost extent of the West Antarctic Rift System as well as rifted structure and possible compositional variations within the Weddell Sea. The accuracy of existing Antarctic seismic models will be quantified through model validation approaches. The researchers will highlight regions of Antarctica where tomographic resolution is still lacking and where future deployments would improve resolution.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "SEISMIC SURFACE WAVES; USA/NSF; USAP-DC; SEISMOLOGICAL STATIONS; Amd/Us; AMD; POLNET; TECTONICS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Emry, Erica; Hansen, Samantha", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repo": "IRIS", "repositories": "IRIS; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Imaging Seismic Heterogeneity within the Antarctic Mantle with Full Waveform Ambient Noise Tomography", "uid": "p0010139", "west": -180.0}, {"awards": "0732450 Van Dover, Cindy; 0732917 McCormick, Michael; 0732711 Smith, Craig; 0732983 Vernet, Maria", "bounds_geometry": "POLYGON((-60.5 -63.1,-59.99 -63.1,-59.48 -63.1,-58.97 -63.1,-58.46 -63.1,-57.95 -63.1,-57.44 -63.1,-56.93 -63.1,-56.42 -63.1,-55.91 -63.1,-55.4 -63.1,-55.4 -63.29,-55.4 -63.48,-55.4 -63.67,-55.4 -63.86,-55.4 -64.05,-55.4 -64.24,-55.4 -64.43,-55.4 -64.62,-55.4 -64.81,-55.4 -65,-55.91 -65,-56.42 -65,-56.93 -65,-57.44 -65,-57.95 -65,-58.46 -65,-58.97 -65,-59.48 -65,-59.99 -65,-60.5 -65,-60.5 -64.81,-60.5 -64.62,-60.5 -64.43,-60.5 -64.24,-60.5 -64.05,-60.5 -63.86,-60.5 -63.67,-60.5 -63.48,-60.5 -63.29,-60.5 -63.1))", "dataset_titles": "LARISSA: Impact of ice-shelf loss on geochemical profiles and microbial community composition in marine sediments of the Larsen A embayment, Antarctic Peninsula; NBP1001 cruise data; NBP1203 cruise data; Species Abundance Data from the Larsen Ice Shelf Ice acquired during R/V Nathaniel B. Palmer expedition NBP1203", "datasets": [{"dataset_uid": "601073", "doi": "10.15784/601073", "keywords": "Antarctica; Antarctic Peninsula; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; LARISSA; Microbiology", "people": "McCormick, Michael", "repository": "USAP-DC", "science_program": null, "title": "LARISSA: Impact of ice-shelf loss on geochemical profiles and microbial community composition in marine sediments of the Larsen A embayment, Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601073"}, {"dataset_uid": "601304", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Biota; Box Corer; LARISSA; Larsen Ice Shelf; Macrofauna; Megafauna; NBP1203; Oceans; R/v Nathaniel B. Palmer; Seafloor Sampling; Species Abundance", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Species Abundance Data from the Larsen Ice Shelf Ice acquired during R/V Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601304"}, {"dataset_uid": "000143", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1203 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP1203"}, {"dataset_uid": "000142", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1001 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP1001"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "A profound transformation in ecosystem structure and function is occurring in coastal waters of the western Weddell Sea, with the collapse of the Larsen B ice shelf. This transformation appears to be yielding a redistribution of energy flow between chemoautotrophic and photosynthetic production, and to be causing the rapid demise of the extraordinary seep ecosystem discovered beneath the ice shelf. This event provides an ideal opportunity to examine fundamental aspects of ecosystem transition associated with climate change. We propose to test the following hypotheses to elucidate the transformations occurring in marine ecosystems as a consequence of the Larsen B collapse: (1) The biogeographic isolation and sub-ice shelf setting of the Larsen B seep has led to novel habitat characteristics, chemoautotrophically dependent taxa and functional adaptations. (2) Benthic communities beneath the former Larsen B ice shelf are fundamentally different from assemblages at similar depths in the Weddell sea-ice zone, and resemble oligotrophic deep-sea communities. Larsen B assemblages are undergoing rapid change. (3) The previously dark, oligotrophic waters of the Larsen B embayment now support a thriving phototrophic community, with production rates and phytoplankton composition similar to other productive areas of the Weddell Sea. To document rapid changes occurring in the Larsen B ecosystem, we will use a remotely operated vehicle, shipboard samplers, and moored sediment traps. We will characterize microbial, macrofaunal and megafaunal components of the seep community; evaluate patterns of surface productivity, export flux, and benthic faunal composition in areas previously covered by the ice shelf, and compare these areas to the open sea-ice zone. These changes will be placed within the geological, glaciological and climatological context that led to ice-shelf retreat, through companion research projects funded in concert with this effort. Together these projects will help predict the likely consequences of ice-shelf collapse to marine ecosystems in other regions of Antarctica vulnerable to climate change. The research features international collaborators from Argentina, Belgium, Canada, Germany, Spain and the United Kingdom. The broader impacts include participation of a science writer; broadcast of science segments by members of the Jim Lehrer News Hour (Public Broadcasting System); material for summer courses in environmental change; mentoring of graduate students and postdoctoral fellows; and showcasing scientific activities and findings to students and public through podcasts.", "east": -55.4, "geometry": "POINT(-57.95 -64.05)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NBP1203; USAP-DC; Amd/Us; LARISSA; Larsen Ice Shelf; Species Abundance Data; R/V NBP; Antarctic Peninsula; NBP1001; USA/NSF; AMD; Antarctica; MARINE ECOSYSTEMS", "locations": "Antarctica; Antarctic Peninsula; Larsen Ice Shelf", "north": -63.1, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "McCormick, Michael; Vernet, Maria; Van Dover, Cindy; Smith, Craig", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": "LARISSA", "south": -65.0, "title": "Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach - Marine Ecosystems.", "uid": "p0010135", "west": -60.5}, {"awards": "1542885 Dunham, Eric", "bounds_geometry": null, "dataset_titles": "Earthquake Sequence Dynamics at the Interface Between an Elastic Layer and Underlying Half-Space in Antiplane Shear", "datasets": [{"dataset_uid": "601320", "doi": "10.15784/601320", "keywords": "Antarctica; Computer Model; Glaciology; Model Data; Shear Stress; Solid Earth; Whillans Ice Stream", "people": "Abrahams, Lauren", "repository": "USAP-DC", "science_program": null, "title": "Earthquake Sequence Dynamics at the Interface Between an Elastic Layer and Underlying Half-Space in Antiplane Shear", "url": "https://www.usap-dc.org/view/dataset/601320"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "This project investigates a rapidly moving section of the West Antarctic Ice Sheet known as the Whillans Ice Stream. Ice streams and outlet glaciers are the major pathways for ice discharge from ice sheets into the ocean. Consequently, understanding ice stream dynamics, specifically the processes controlling the frictional resistance of ice sliding on sediments at its base, is essential for predictive modeling of how Earth\u0027s ice sheets will respond to a changing climate. Rather than flowing smoothly, Whillans Ice Stream advances in stick-slip cycles: brief periods of rapid sliding, equivalent to magnitude 7 earthquakes, alternating with much longer periods of repose. The PIs will perform simulations of these stick-slip cycles using computer codes originally developed for modeling tectonic earthquakes. By matching observed ice motions, the PIs will constrain the range of frictional processes acting at the base of the ice stream. An additional focus of the project is on brittle fracture processes in ice, expressed through seismic waves radiated by faulting and/or crevassing episodes that accompany the large-scale sliding events. An understanding of ice fracture provides a basis for assessing the susceptibility of ice shelves to rifting and catastrophic disintegration. Project results will be incorporated into outreach activities (from elementary school to community college events) as well as a polar science class for the California State Summer School for Mathematics and Science (COSMOS) program for high school students. Simulations of the stick-slip cycle will employ 3D dynamic rupture models that simultaneously solve for the seismic wavefield and rupture process, consistent with elastodynamic material response and friction laws on the ice stream bed. Stresses and frictional properties will be varied to achieve consistency with surface GPS and broadband seismic data as well as borehole seismograms from the WISSARD project. The results will be interpreted using laboratory till friction experiments, which link velocity-weakening/strengthening behavior to temperature and water content, and to related experiments quantifying basal drag from ice flow over rough beds. The source mechanism of seismicity accompanying the slip events (shear faulting versus crevassing) will be determined using 3D waveform modeling in conjunction with mechanical models of the seismic source processes. This proposal does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "SEISMIC PROFILE; AMD; Antarctica; GROUND-BASED OBSERVATIONS; USA/NSF; USAP-DC; Amd/Us", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Dunham, Eric", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Characterizing Brittle Failure and Fracture Propagation in Fast Ice Sliding with Dynamic Rupture Models based on Whillans Ice Stream Seismic/Geodetic Data", "uid": "p0010138", "west": null}, {"awards": "1141411 Baker, Ian", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Laboratory Experiments with H2SO4-Doped Ice; The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "datasets": [{"dataset_uid": "601081", "doi": "10.15784/601081", "keywords": null, "people": "Hammonds, Kevin", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Experiments with H2SO4-Doped Ice", "url": "https://www.usap-dc.org/view/dataset/601081"}, {"dataset_uid": "600380", "doi": "10.15784/600380", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Physical Properties; Snow", "people": "Baker, Ian", "repository": "USAP-DC", "science_program": null, "title": "The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "url": "https://www.usap-dc.org/view/dataset/600380"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "Baker/1141411 This award supports a project to undertake a systematic examination of the effects of soluble impurities, particularly sulfuric acid, on the creep of polycrystalline ice as function of temperature, strain rate and impurity concentration. The working hypothesis is that soluble impurities will increase the flow rate of polycrystalline ice compared to high-purity ice, that this effect will be temperature dependent and that the impurities by affecting the re-crystallization and grain growth will change the fabric of the ice. Both H2SO4-doped and high-purity poly-crystalline ice will be produced by freezing sheets of ice, breaking them up, sieving the ice particles and then sintering them in a mold into fine-grained cylindrical specimens with at least ten grains across their diameter. The resulting microstructures (dislocation structure, grain size and shape, grain boundary character and micro-structural location of the acid) will be characterized using a variety of techniques including: optical microscopy, scanning electron microscopy, including secondary electron imaging, electron backscattered patterns, energy dispersive X-ray spectroscopy, electron channeling contrast imaging, and X-ray topography. The creep of both the H2SO4-doped and the high-purity polycrystalline ice will be undertaken at a range of temperatures and stresses. The ice?s response to the creep deformation (grain boundary sliding, dislocation motion, re-crystallization, grain boundary migration, impurity redistribution) will be studied using a combination of methods. The creep behavior will be modeled and related to the microstructure. Of particular interest is how impurities affect the activation energy for creep. The intellectual merit of the work is that it will lead to a better understanding of glacier ice and will enable glaciologists to model the influence of impurities on the flow and fabric development in polycrystalline ice. The broader impacts of the project include the knowledge that will be gained of the effects of impurities on the flow of ice which will allow paleoclimatologists to better interpret ice core data and will allow scientists developing predictive models to better address the flow of ice sheets under various climate change scenarios. The project will also lead to the education and training of a Ph.D. student, several undergraduates and some high school students. Results from the research will be published in refereed journals. Several undergraduates, typically two per year, will also perform the work. Dartmouth aggressively courts minority students at all degree levels, and we will seek women or minority group undergraduates for this project. The undergraduates will be supported by Dartmouth?s nationally-honored Women In Science Project or by REU funding. The undergraduates? research will integrate closely with the Ph.D. student?s studies. Hanover High School students will also be involved in the project and develop an educational kit to introduce students to the properties of ice. Results from the research will be published in refereed journals and presented at conferences.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; USAP-DC; SNOW/ICE; Amd/Us; LABORATORY; Antarctica; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "uid": "p0010133", "west": -180.0}, {"awards": "1644197 Simms, Alexander", "bounds_geometry": "POLYGON((-65 -61,-64 -61,-63 -61,-62 -61,-61 -61,-60 -61,-59 -61,-58 -61,-57 -61,-56 -61,-55 -61,-55 -61.4,-55 -61.8,-55 -62.2,-55 -62.6,-55 -63,-55 -63.4,-55 -63.8,-55 -64.2,-55 -64.6,-55 -65,-56 -65,-57 -65,-58 -65,-59 -65,-60 -65,-61 -65,-62 -65,-63 -65,-64 -65,-65 -65,-65 -64.6,-65 -64.2,-65 -63.8,-65 -63.4,-65 -63,-65 -62.6,-65 -62.2,-65 -61.8,-65 -61.4,-65 -61))", "dataset_titles": "Electron Microprobe Analysis of feldspar separates from rock and sediment OSL samples from Joinville and Livingston Island Beaches; Granulometry of Joinville and Livingston Island beaches; Ground-Penetrating Radar data from Livingston Island in the Antarctic Peninsula; Ground Penetrating Radar Profiles from Beaches on Joinville Island, Antarctic Peninsula; Joinville and Livingston Islands - rock and sediment OSL ages; OSL data - Joinville and Livingston Islands - Raw data; Radiocarbon Ages from Beaches on Joinville Island, Antarctic Peninsula", "datasets": [{"dataset_uid": "601634", "doi": "10.15784/601634", "keywords": "Antarctica; Joinville Island; Raised Beaches; Sea Level", "people": "Simms, Alexander", "repository": "USAP-DC", "science_program": null, "title": "Radiocarbon Ages from Beaches on Joinville Island, Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601634"}, {"dataset_uid": "601632", "doi": "10.15784/601632", "keywords": "Antarctica; Joinville Island", "people": "Simms, Alexander", "repository": "USAP-DC", "science_program": null, "title": "Ground Penetrating Radar Profiles from Beaches on Joinville Island, Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601632"}, {"dataset_uid": "601633", "doi": "10.15784/601633", "keywords": "Antarctica; Joinville Island", "people": "Simms, Alexander", "repository": "USAP-DC", "science_program": null, "title": "Ground-Penetrating Radar data from Livingston Island in the Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601633"}, {"dataset_uid": "601531", "doi": "10.15784/601531", "keywords": "Antarctica; Geochronology; Joinville Island; Livingston Island; OSL dating; Raised Beaches", "people": "DeWitt, Regina", "repository": "USAP-DC", "science_program": null, "title": "Electron Microprobe Analysis of feldspar separates from rock and sediment OSL samples from Joinville and Livingston Island Beaches", "url": "https://www.usap-dc.org/view/dataset/601531"}, {"dataset_uid": "601534", "doi": "10.15784/601534", "keywords": "Antarctica; Geochronology; Joinville Island; Livingston Island; OSL dating; Raised Beaches", "people": "DeWitt, Regina", "repository": "USAP-DC", "science_program": null, "title": "Joinville and Livingston Islands - rock and sediment OSL ages", "url": "https://www.usap-dc.org/view/dataset/601534"}, {"dataset_uid": "601532", "doi": "10.15784/601532", "keywords": "Antarctica; Geochronology; Joinville Island; Livingston Island; OSL dating; Raised Beaches", "people": "DeWitt, Regina", "repository": "USAP-DC", "science_program": null, "title": "OSL data - Joinville and Livingston Islands - Raw data", "url": "https://www.usap-dc.org/view/dataset/601532"}, {"dataset_uid": "601400", "doi": "10.15784/601400", "keywords": "Antarctica; Grain Size; Granulometry; Joinville Island; Livingston Island; LMG0412; Raised Beaches", "people": "Simms, Alexander; Theilen, Brittany", "repository": "USAP-DC", "science_program": null, "title": "Granulometry of Joinville and Livingston Island beaches", "url": "https://www.usap-dc.org/view/dataset/601400"}], "date_created": "Thu, 08 Oct 2020 00:00:00 GMT", "description": "Nontechnical Description Glacier ice loss from Antarctica has the potential to lead to a significant rise in global sea level. One line of evidence for accelerated glacier ice loss has been an increase in the rate at which the land has been rising across the Antarctic Peninsula as measured by GPS receivers. However, GPS observations of uplift are limited to the last two decades. One goal of this study is to determine how these newly observed rates of uplift compare to average rates of uplift across the Antarctic Peninsula over a longer time interval. Researchers will reconstruct past sea levels using the age and elevation of ancient beaches now stranded above sea level on the low-lying coastal hills of the Antarctica Peninsula to determine the rate of uplift over the last 5,000 years. The researchers will also analyze the structure of the beaches using ground-penetrating radar and the characteristics of beach sediments to understand how sea-level rise and past climate changes are recorded in beach deposits. The benefits of these new records will be threefold: (1) they will help determine the natural variability of the Antarctic Ice Sheet and relative sea level (2) they will provide new insight about uplift and the structure of the Earth\u0027s interior; and 3) they will help researchers refine the methods used to determine the age of geologic deposits. The study results will be shared in outreach events at K-12 schools and with visitors of the Santa Barbara Natural History Museum. Three graduate students will be supported through this project. Technical description Paleo sea-level data is critical for reconstructing the size and extent of past ice sheets, documenting increased uplift following glacial retreat, and correcting gravity-based measurements of ice-mass loss for the impacts of post-glacial rebound. However, there are only 14 sites with relative sea-level data for Antarctica compared to over 500 sites used in a recent study of the North American Ice-Sheet complex. The purpose of this project is to use optically stimulated luminescence to date a series of newly discovered raised beaches along the eastern Antarctic Peninsula and an already known, but only preliminarily dated, series of raised beaches in the South Shetland Islands. Data to be collected at the raised beaches include the age and elevation, ground-penetrating radar profiles, and the roundness of cobbles and the lithology of ice-rafted debris. The study will test three hypotheses: (1) uplift rates have increased in modern times relative to the late Holocene across the Antarctic Peninsula, (2) the sea-level history at the northern tip of the Antarctic Peninsula is distinctly different than that of the South Shetland Islands, and (3) cobble roundness and the source of ice-rafted debris on raised beaches varied systematically through time reflecting the climate history of the northern Antarctic Peninsula.", "east": -55.0, "geometry": "POINT(-60 -63)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "Antarctic Peninsula; COASTAL LANDFORMS/PROCESSES; USAP-DC; SEA LEVEL RECONSTRUCTION; South Shetland Islands; AMD; FIELD INVESTIGATION; Amd/Us; USA/NSF", "locations": "South Shetland Islands; Antarctic Peninsula", "north": -61.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Simms, Alexander; DeWitt, Regina", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "Collaborative Research: New Constraints on Post-Glacial Rebound and Holocene Environmental History along the Northern Antarctic Peninsula from Raised Beaches", "uid": "p0010132", "west": -65.0}, {"awards": "1443433 Licht, Kathy; 1443213 Kaplan, Michael", "bounds_geometry": "POLYGON((159 -83.8,159.5 -83.8,160 -83.8,160.5 -83.8,161 -83.8,161.5 -83.8,162 -83.8,162.5 -83.8,163 -83.8,163.5 -83.8,164 -83.8,164 -83.87,164 -83.94,164 -84.01,164 -84.08,164 -84.15,164 -84.22,164 -84.29,164 -84.36,164 -84.43,164 -84.5,163.5 -84.5,163 -84.5,162.5 -84.5,162 -84.5,161.5 -84.5,161 -84.5,160.5 -84.5,160 -84.5,159.5 -84.5,159 -84.5,159 -84.43,159 -84.36,159 -84.29,159 -84.22,159 -84.15,159 -84.08,159 -84.01,159 -83.94,159 -83.87,159 -83.8))", "dataset_titles": "10Be and 26Al cosmogenic nuclide surface exposure data; 3He input data", "datasets": [{"dataset_uid": "601375", "doi": "10.15784/601375", "keywords": "Antarctica; Cosmogenic Dating; Transantarctic Mountains", "people": "Winckler, Gisela; Schaefer, Joerg; Kaplan, Michael", "repository": "USAP-DC", "science_program": null, "title": "10Be and 26Al cosmogenic nuclide surface exposure data", "url": "https://www.usap-dc.org/view/dataset/601375"}, {"dataset_uid": "601376", "doi": "10.15784/601376", "keywords": "Antarctica; Transantarctic Mountains", "people": "Schaefer, Joerg; Winckler, Gisela; Kaplan, Michael", "repository": "USAP-DC", "science_program": null, "title": "3He input data", "url": "https://www.usap-dc.org/view/dataset/601376"}], "date_created": "Tue, 29 Sep 2020 00:00:00 GMT", "description": "Licht/1443433 Sediments deposited by the Antarctic ice sheet are an archive of its history with time and help geologists to determine how the remote interior of the ice sheet has changed over the past several hundred thousand years. This project will focus on the formation and dynamics of moraines (accumulations of dirt and rocks that are incorporated in the glacier surface or have been pushed along by the glacier as it moves) near the blue ice area of Mt. Achernar in the central Transantarctic Mountains in Antarctica.. The study will improve basic understanding of the formation of these moraines. Fieldwork at the site will focus on imaging the internal structure of the moraine to determine the processes by which it, and others like it, form over time. Additional analyses will include measurements of ice flow and collection of rock samples to determine the timing of debris deposition and the changes in the sources of sediments from deep within the Antarctic continent. The project will provide both graduate and undergraduate students training in paleoclimate studies, geology, and numerical modeling approaches. The broader impacts of the proposed work include hands on training in the Earth Sciences for graduate and undergraduate students, collaboration with colleagues in New Zealand and Sweden to provide an international research experience for students from the US, and three educational modules to be delivered by student researchers regarding Antarctica\u0027s role in global environments. The research is societally relevant and multidisciplinary and the topics are ideal for sharing with the public. All research findings will be made publicly available to others via timely publication in high-impact, peer-reviewed journals and all data will be submitted to the National Snow and Ice Data Center, and excess samples will be provided to the U.S. Polar Rock Repository. Direct observations of ice sheet history from the margins of Antarctica\u0027s polar plateau are essential for testing numerical ice sheet models, and the laterally extensive, blue-ice moraines of the Mt. Achernar Moraine complex in the central Transantarctic Mountains contain a unique and nearly untapped direct, quasi-continuous record of ice sheet change over multiple glacial cycles. The project objectives include improved understanding of processes and rates of blue ice moraine formation, as well as identifying the topographic, glaciological, and climatic controls on their evolution. Data to be collected with fieldwork in Antarctica include: imaging of internal ice structure with ground-penetrating radar, measurement of ice flow velocity and direction with a global positioning system (GPS) array, analysis of debris concentration and composition in glacier ice, state-of-the-art cosmogenic multi-nuclide analyses to determine exposure ages of moraine debris, mapping of trimlines and provenance analysis. Numerical model simulations, constrained by field data, will be used to evaluate the factors influencing changes in glacier flow that potentially impact the accumulation of the moraine debris. All together, the new data and modeling efforts will improve conceptual models of blue ice moraine formation, and thereby make them a more valuable proxy for developing a better understanding of the history of the ice sheet.", "east": 164.0, "geometry": "POINT(161.5 -84.15)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; GLACIAL PROCESSES; Mt. Achernar; ABLATION ZONES/ACCUMULATION ZONES; GLACIER ELEVATION/ICE SHEET ELEVATION; Antarctica; Antarctic Ice Sheet; Transantarctic Mountains; GLACIATION; USAP-DC; ICE MOTION; AMD; LABORATORY; Amd/Us", "locations": "Transantarctic Mountains; Antarctic Ice Sheet; Mt. Achernar; Antarctica", "north": -83.8, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Kaplan, Michael; Schaefer, Joerg; Winckler, Gisela; Licht, Kathy", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.5, "title": "Collaborative Research: Multidisciplinary Analysis of Antarctic Blue Ice Moraine Formation and their Potential as Climate Archives over Multiple Glacial Cycles", "uid": "p0010131", "west": 159.0}, {"awards": "1644187 Tulaczyk, Slawek", "bounds_geometry": "POLYGON((161 -76.9,161.75 -76.9,162.5 -76.9,163.25 -76.9,164 -76.9,164.75 -76.9,165.5 -76.9,166.25 -76.9,167 -76.9,167.75 -76.9,168.5 -76.9,168.5 -77.04,168.5 -77.18,168.5 -77.32,168.5 -77.46,168.5 -77.6,168.5 -77.74,168.5 -77.88,168.5 -78.02,168.5 -78.16,168.5 -78.3,167.75 -78.3,167 -78.3,166.25 -78.3,165.5 -78.3,164.75 -78.3,164 -78.3,163.25 -78.3,162.5 -78.3,161.75 -78.3,161 -78.3,161 -78.16,161 -78.02,161 -77.88,161 -77.74,161 -77.6,161 -77.46,161 -77.32,161 -77.18,161 -77.04,161 -76.9))", "dataset_titles": "ANTAEM project airborne EM resistivity data from McMurdo Region", "datasets": [{"dataset_uid": "601373", "doi": "10.15784/601373", "keywords": "Antarctica; Dry Valleys; Hydrology; Ice Shelf; McMurdo; Permafrost", "people": "Tulaczyk, Slawek", "repository": "USAP-DC", "science_program": null, "title": "ANTAEM project airborne EM resistivity data from McMurdo Region", "url": "https://www.usap-dc.org/view/dataset/601373"}], "date_created": "Sun, 13 Sep 2020 00:00:00 GMT", "description": "In Antarctica, millions of years of freezing have led to the development of hundreds of meters of thick permafrost (i.e., frozen ground). Recent research demonstrated that this slow freezing has trapped and concentrated water into local and regional briny aquifers, many times more salty than seawater. Because salt depresses the freezing point of water, these saline brines are able to persist as liquid water at temperatures well below the normal freezing point of freshwater. Such unusual groundwater systems may support microbial life, supply nutrients to coastal ocean and ice-covered lakes, and influence motion of glaciers. These briny aquifers also represent potential terrestrial analogs for deep life habitats on other planets, such as Mars, and provide a testing ground for the search for extraterrestrial water. Whereas much effort has been invested in understanding the physics, chemistry, and biology of surface and near-surface waters in cold polar regions, it has been comparably difficult to investigate deep subsurface aquifers in such settings. Airborne ElectroMagnetics (AEM) subsurface imaging provides an efficient way for mapping salty groundwater. An international collaboration with the University of Aarhus in Denmark will enable knowledge and skill transfer in AEM techniques that will enhance US polar research capabilities and provide US undergraduates and graduate students with unique training experiences. This project will survey over 1000 km2 of ocean and land near McMurdo Station in Antarctica, and will reveal if cold polar deserts hide a subsurface pool of liquid water. This will have significant implications for understanding cold polar glaciers, ice-covered lakes, frozen ground, and polar microbiology as well as for predictions of their response to future change. Improvements in permafrost mapping techniques and understanding of permafrost and of underlying groundwaters will benefit human use of high polar regions in the Antarctic and the Arctic. The project will provide the first integrative system-scale overview of subsurface water distribution and hydrological connectivity in a partly ice-free coastal region of Antarctica, the McMurdo Dry Valleys. Liquid water is relatively scarce in this environment but plays an outsized role by influencing, and integrating, biological, biogeochemical, glaciological, and geological processes. Whereas surface hydrology and its role in ecosystem processes has been thoroughly studied over the last several decades, it has been difficult to map out and characterize subsurface water reservoirs and to understand their interactions with regional lakes, glaciers, and coastal waters. The proposed project builds on the \"proof-of-concept\" use of AEM technology in 2011. Improvements in sensor and data processing capabilities will result in about double the depth of penetration of the subsurface during the new data collection when compared to the 2011 proof-of-concept survey, which reached depths of 300-400m. The first field season will focus on collecting deep soundings with a ground-based system in key locations where: (i) independent constraints on subsurface structure exist from past drilling projects, and (ii) the 2011 resistivity dataset indicates the need for deeper penetration and high signal-to-noise ratios achievable only with a ground-based system. The regional airborne survey will take place during the second field season and will yield subsurface electrical resistivity data from across several valleys of different sizes and different ice cover fractions.", "east": 168.5, "geometry": "POINT(164.75 -77.6)", "instruments": null, "is_usap_dc": true, "keywords": "FROZEN GROUND; GLACIERS/ICE SHEETS; HELICOPTER; GROUND WATER; RIVERS/STREAMS; Dry Valleys", "locations": "Dry Valleys", "north": -76.9, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Earth Sciences", "paleo_time": null, "persons": "Tulaczyk, Slawek; Mikucki, Jill", "platforms": "AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER \u003e HELICOPTER", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.3, "title": "Collaborative Research: Antarctic Airborne ElectroMagnetics (ANTAEM) - Revealing Subsurface Water in Coastal Antarctica", "uid": "p0010129", "west": 161.0}, {"awards": "1724670 Williams, Trevor", "bounds_geometry": "POLYGON((-70 -60,-65 -60,-60 -60,-55 -60,-50 -60,-45 -60,-40 -60,-35 -60,-30 -60,-25 -60,-20 -60,-20 -62.5,-20 -65,-20 -67.5,-20 -70,-20 -72.5,-20 -75,-20 -77.5,-20 -80,-20 -82.5,-20 -85,-25 -85,-30 -85,-35 -85,-40 -85,-45 -85,-50 -85,-55 -85,-60 -85,-65 -85,-70 -85,-70 -82.5,-70 -80,-70 -77.5,-70 -75,-70 -72.5,-70 -70,-70 -67.5,-70 -65,-70 -62.5,-70 -60))", "dataset_titles": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "datasets": [{"dataset_uid": "601378", "doi": "10.15784/601378", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601378"}, {"dataset_uid": "601379", "doi": "10.15784/601379", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601379"}, {"dataset_uid": "601377", "doi": "10.15784/601377", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601377"}], "date_created": "Thu, 10 Sep 2020 00:00:00 GMT", "description": "Abstract for the general public: The margins of the Antarctic ice sheet have advanced and retreated repeatedly over the past few million years. Melting ice from the last retreat, from 19,000 to 9,000 years ago, raised sea levels by 8 meters or more, but the extents of previous retreats are less well known. The main goal of this project is to understand how Antarctic ice retreats: fast or slow, stepped or steady, and which parts of the ice sheet are most prone to retreat. Antarctica loses ice by two main processes: melting of the underside of floating ice shelves and calving of icebergs. Icebergs themselves are ephemeral, but they carry mineral grains and rock fragments that have been scoured from Antarctic bedrock. As the icebergs drift and melt, this \u0027iceberg-rafted debris\u0027 falls to the sea-bed and is steadily buried in marine sediments to form a record of iceberg activity and ice sheet retreat. The investigators will read this record of iceberg-rafted debris to find when and where Antarctic ice destabilized in the past. This information can help to predict how Antarctic ice will behave in a warming climate. The study area is the Weddell Sea embayment, in the Atlantic sector of Antarctica. Principal sources of icebergs are the nearby Antarctic Peninsula and Weddell Sea embayment, where ice streams drain about a quarter of Antarctic ice. The provenance of the iceberg-rafted debris (IRD), and the icebergs that carried it, will be found by matching the geochemical fingerprint (such as characteristic argon isotope ages) of individual mineral grains in the IRD to that of the corresponding source area. In more detail, the project will: 1. Define the geochemical fingerprints of the source areas of the glacially-eroded material using samples from each major ice stream entering the Weddell Sea. Existing data indicates that the hinterland of the Weddell embayment is made up of geochemically distinguishable source areas, making it possible to apply geochemical provenance techniques to determine the origin of Antarctica icebergs. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till samples to characterize detritus supplied by the Recovery and Foundation ice streams. 2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information identifies which groups of ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents), and the stratigraphy of the cores shows the relative sequence of ice stream activity through time. A further dimension is added by determining the time lag between fine sediment erosion and deposition, using a new method of uranium-series isotope measurements in fine grained material. Technical abstract: The behavior of the Antarctic ice sheets and ice streams is a critical topic for climate change and future sea level rise. The goal of this proposal is to constrain ice sheet response to changing climate in the Weddell Sea during the three most recent glacial terminations, as analogues for potential future warming. The project will also examine possible contributions to Meltwater Pulse 1A, and test the relative stability of the ice streams draining East and West Antarctica. Much of the West Antarctic ice may have melted during the Eemian (130 to 114 Ka), so it may be an analogue for predicting future ice drawdown over the coming centuries. Geochemical provenance fingerprinting of glacially eroded detritus provides a novel way to reconstruct the location and relative timing of glacial retreat during these terminations in the Weddell Sea embayment. The two major objectives of the project are to: 1. Define the provenance source areas by characterizing Ar, U-Pb, and Nd isotopic signatures, and heavy mineral and Fe-Ti oxide compositions of detrital minerals from each major ice stream entering the Weddell Sea, using onshore tills and existing sediment cores from the Ronne and Filchner Ice Shelves. Pilot data demonstrate that detritus originating from the east and west sides of the Weddell Sea embayment can be clearly distinguished, and published data indicates that the hinterland of the embayment is made up of geochemically distinguishable source areas. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till to characterize detritus supplied by the Recovery and Foundation ice streams. 2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information will identify which ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents). The stratigraphy of the cores will show the relative sequence of ice stream activity through time. A further time dimension is added by determining the time lag between fine sediment erosion and deposition, using U-series comminution ages.", "east": -20.0, "geometry": "POINT(-45 -72.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "TERRIGENOUS SEDIMENTS; Subglacial Till; USAP-DC; ICEBERGS; AMD; USA/NSF; ISOTOPES; AGE DETERMINATIONS; Argon; Provenance; Till; Amd/Us; R/V POLARSTERN; FIELD INVESTIGATION; SEDIMENT CHEMISTRY; Weddell Sea; Antarctica; LABORATORY", "locations": "Weddell Sea; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Williams, Trevor; Hemming, Sidney R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V POLARSTERN", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance", "uid": "p0010128", "west": -70.0}, {"awards": "1738913 Scambos, Ted", "bounds_geometry": "POLYGON((-118 -70,-116 -70,-114 -70,-112 -70,-110 -70,-108 -70,-106 -70,-104 -70,-102 -70,-100 -70,-98 -70,-98 -71,-98 -72,-98 -73,-98 -74,-98 -75,-98 -76,-98 -77,-98 -78,-98 -79,-98 -80,-100 -80,-102 -80,-104 -80,-106 -80,-108 -80,-110 -80,-112 -80,-114 -80,-116 -80,-118 -80,-118 -79,-118 -78,-118 -77,-118 -76,-118 -75,-118 -74,-118 -73,-118 -72,-118 -71,-118 -70))", "dataset_titles": "Profile CTD Data During Installation of AMIGOS-III Cavity and Channel On-Ice Moorings", "datasets": [{"dataset_uid": "601623", "doi": "10.15784/601623", "keywords": "Amundsen Sea; Antarctica; CTD; Ice Shelf", "people": "SCAMBOS, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Profile CTD Data During Installation of AMIGOS-III Cavity and Channel On-Ice Moorings", "url": "https://www.usap-dc.org/view/dataset/601623"}], "date_created": "Wed, 09 Sep 2020 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Science Coordination Office will facilitate planning and coordination of the science and broader impacts of several international research projects studying Thwaites Glacier--one of the largest glaciers in Antarctica. The glacier is located on the Pacific coast of the Antarctic continent. It is flowing almost twice as fast now as in the 1970s, and is one of the largest likely contributors to sea-level rise over the coming decades to centuries. Many of the factors that will affect the speed and retreat of Thwaites Glacier will be addressed by the set of projects funded by the Thwaites initiative. The Science Coordination Office comprises a US-UK science and communications team that will work with each project\u0027s scientists and students, logistics planners, and NSF and NERC to ensure the overall success of the project. The Office will maintain an informative website, and will produce content to explain the activities of the scientists and highlight the results of the work. The role of the Science Coordination Office will be to enhance integration and coordination among the science projects selected for the joint NSF-NERC Thwaites initiative to achieve maximum collective scientific and societal impact. The Office will facilitate scientific and logistical planning; facilitate data management, sharing, and discovery; and facilitate and support web content, outreach, and education for this high-profile research endeavor. The Office\u0027s role will be key to enabling the program to achieve its scientific goals and for the program to be broadly recognized and valued by scientists, the public, and policymakers. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -98.0, "geometry": "POINT(-108 -75)", "instruments": null, "is_usap_dc": true, "keywords": "OCEAN TEMPERATURE; GLACIER MOTION/ICE SHEET MOTION; BATHYMETRY; FIELD INVESTIGATION; FIELD SURVEYS; SNOW; SEDIMENTS; Antarctic Ice Sheet; WATER MASSES; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; GLACIERS/ICE SHEETS; MARINE GEOPHYSICS", "locations": "Antarctic Ice Sheet", "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Scambos, Ted; Vaughan, David G.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "NSF-NERC The Future of Thwaites Glacier and its Contribution to Sea-level Rise Science Coordination Office", "uid": "p0010127", "west": -118.0}, {"awards": "1745116 Scambos, Ted", "bounds_geometry": "POLYGON((-75 -69,-74 -69,-73 -69,-72 -69,-71 -69,-70 -69,-69 -69,-68 -69,-67 -69,-66 -69,-65 -69,-65 -69.5,-65 -70,-65 -70.5,-65 -71,-65 -71.5,-65 -72,-65 -72.5,-65 -73,-65 -73.5,-65 -74,-66 -74,-67 -74,-68 -74,-69 -74,-70 -74,-71 -74,-72 -74,-73 -74,-74 -74,-75 -74,-75 -73.5,-75 -73,-75 -72.5,-75 -72,-75 -71.5,-75 -71,-75 -70.5,-75 -70,-75 -69.5,-75 -69))", "dataset_titles": "Density, hydrology and geophysical measurements from the Wilkins Ice Shelf firn aquifer; Weather, Firn Core, and Ground-penetrating radar data from southern Wilkins and George VI ice shelves, 2018-2019", "datasets": [{"dataset_uid": "601905", "doi": "10.15784/601905", "keywords": "AMIGOS; Antarctica; Cryosphere; George VI Ice Shelf; Glaciology; Ground Penetrating Radar; Ice Core Data; Ice Shelf; Wilkins Ice Shelf", "people": "Scambos, Ted; Miller, Julie; Miege, Clement; Montgomery, Lynn; Wallin, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Weather, Firn Core, and Ground-penetrating radar data from southern Wilkins and George VI ice shelves, 2018-2019", "url": "https://www.usap-dc.org/view/dataset/601905"}, {"dataset_uid": "601390", "doi": "10.15784/601390", "keywords": "Airborne Radar; Antarctica; Antarctic Peninsula; Firn; Firn Aquifer; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hydrology; Snow/ice; Snow/Ice; Wilkins Ice Shelf", "people": "Forster, Richard; Solomon, Kip; Miller, Olivia; Miller, Julie; Scambos, Ted; Mi\u00e8ge, Cl\u00e9ment; Montgomery, Lynn; Wallin, Bruce; Koenig, Lora", "repository": "USAP-DC", "science_program": null, "title": "Density, hydrology and geophysical measurements from the Wilkins Ice Shelf firn aquifer", "url": "https://www.usap-dc.org/view/dataset/601390"}], "date_created": "Tue, 08 Sep 2020 00:00:00 GMT", "description": "Snow or firn aquifers are areas of subsurface meltwater storage that form in glaciated regions experiencing intense summer surface melting and high snowfall. Aquifers can induce hydrofracturing, and thereby accelerate flow or trigger ice-shelf instability leading to increased ice-sheet mass loss. Widespread aquifers have recently been discovered in Greenland. These have been modelled and mapped using new satellite and airborne remote-sensing techniques. In Antarctica, a series of catastrophic break-ups at the Wilkins Ice Shelf on the Antarctic Peninsula that was previously attributed to effects of surface melting and brine infiltration is now recognized as being consistent with a firn aquifer--possibly stimulated by long-period ocean swell--that enhanced ice-shelf hydrofracture. This project will verify inferences (from the same mapping approach used in Greenland) that such aquifers are indeed present in Antarctica. The team will survey two high-probability sites: the Wilkins Ice Shelf, and the southern George VI Ice Shelf. This two-year study will characterize the firn at the two field sites, drill shallow (~60 m maximum) ice cores, examine snow pits (~2 m), and install two AMIGOS (Automated Met-Ice-Geophysics Observing System) stations that include weather, GPS, and firn temperature sensors that will collect and transmit measurements for at least a year before retrieval. Ground-penetrating radar survey in areas surrounding the field sites will track aquifer extent and depth variations. Ice and microwave model studies will be combined with the field-observed properties to further explore the range of firn aquifers and related upper-snow-layer conditions. This study will provide valuable experience for three early-career scientists. An outreach effort through field blogging, social media posts, K-12 presentations, and public lectures is planned to engage the public in the team?s Antarctic scientific exploration and discovery. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -65.0, "geometry": "POINT(-70 -71.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": true, "keywords": "USAP-DC; Firn Aquifer; USA/NSF; FIELD INVESTIGATION; AMD; GLACIERS/ICE SHEETS; Wilkens Ice Shelf; Antarctic Peninsula; Amd/Us", "locations": "Antarctic Peninsula; Wilkens Ice Shelf", "north": -69.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "Antarctic Firn Aquifers: Extent, Characteristics, and Comparison with Greenland Occurrences", "uid": "p0010126", "west": -75.0}, {"awards": "1935755 Lamp, Jennifer; 1935907 Balco, Gregory; 1935945 Tremblay, Marissa", "bounds_geometry": "POLYGON((160 -77.25,160.4 -77.25,160.8 -77.25,161.2 -77.25,161.6 -77.25,162 -77.25,162.4 -77.25,162.8 -77.25,163.2 -77.25,163.6 -77.25,164 -77.25,164 -77.325,164 -77.4,164 -77.475,164 -77.55,164 -77.625,164 -77.7,164 -77.775,164 -77.85,164 -77.925,164 -78,163.6 -78,163.2 -78,162.8 -78,162.4 -78,162 -78,161.6 -78,161.2 -78,160.8 -78,160.4 -78,160 -78,160 -77.925,160 -77.85,160 -77.775,160 -77.7,160 -77.625,160 -77.55,160 -77.475,160 -77.4,160 -77.325,160 -77.25))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 25 Aug 2020 00:00:00 GMT", "description": ". ______________________________________________________________________________________________________________ Part I: Nontechnical Description Scientists study the Earth\u0027s past climate in order to understand how the climate will respond to ongoing global change in the future. One of the best analogs for future climate might the period that occurred approximately 3 million years ago, during an interval known as the mid-Pliocene Warm Period. During this period, the concentration of carbon dioxide in the atmosphere was similar to today\u0027s and sea level was 15 or more meters higher, due primarily to warming and consequent ice sheet melting in polar regions. However, the temperatures in polar regions during the mid-Pliocene Warm Period are not well determined, in part because we do not have records like ice cores that extend this far back in time. This project will provide constraints on surface temperatures in Antarctica during the mid-Pliocene Warm Period using a new type of climate substitute, known as cosmogenic noble gas paleothermometry. This project focuses on an area of Antarctica called the McMurdo Dry Valleys. In this area, climate models suggest that temperatures were more than 10 C warmer during the mid-Pliocene than they are today, but indirect geologic observations suggest that temperatures may have been similar to today. The McMurdo Dry Valleys are also a place where rocks have been exposed to Earth surface conditions for several million years, and where this new climate substitute can be readily applied. The team will reconstruct temperatures in the McMurdo Dry Valleys during the mid-Pliocene Warm Period in order to resolve the discrepancy between models and indirect geologic observations and provide much-needed constraints on the sensitivity of Antarctic ice sheets to warming temperatures. The temperature reconstructions generated in this project will have scientific impact in multiple disciplines, including climate science, glaciology, geomorphology, and planetary science. In addition, the project will (1) broaden the participation of underrepresented groups by supporting two early-career female principal investigators, (2) build STEM talent through the education and training of a graduate student, (3) enhance infrastructure for research via publication of a publicly-accessible, open-source code library, and (4) be broadly disseminated via social media, blog posts, publications, and conference presentations. Part II: Technical Description The mid-Pliocene Warm Period (3-3.3 million years ago) is the most recent interval of the geologic past when atmospheric CO2 concentrations exceeded 400 ppm and is widely considered an analog for how Earth\u2019s climate system will respond to current global change. Climate models predict polar amplification - the occurrence of larger changes in temperatures at high latitudes than the global average due to a radiative forcing - both during the mid-Pliocene Warm Period and due to current climate warming. However, the predicted magnitude of polar amplification is highly uncertain in both cases. The magnitude of polar amplification has important implications for the sensitivity of ice sheets to warming and the contribution of ice sheet melting to sea level change. Proxy-based constraints on polar surface air temperatures during the mid-Pliocene Warm Period are sparse to non-existent. In Antarctica, there is only indirect evidence for the magnitude of warming during this time. This project will provide constraints on surface temperatures in the McMurdo Dry Valleys of Antarctica during the mid-Pliocene Warm Period using a newly developed technique called cosmogenic noble gas (CNG) paleothermometry. CNG paleothermometry utilizes the diffusive behavior of cosmogenic 3He in quartz to quantify the temperatures rocks experience while exposed to cosmic-ray particles within a few meters of the Earth\u2019s surface. The very low erosion rates and subzero temperatures characterizing the McMurdo Dry Valleys make this region uniquely suited for the application of CNG paleothermometry for addressing the question: what temperatures characterized the McMurdo Dry Valleys during the mid-Pliocene Warm Period? To address this question, the team will collect bedrock samples at several locations in the McMurdo Dry Valleys where erosion rates are known to be low enough that cosmic ray exposure extends into the mid-Pliocene or earlier. They will pair cosmogenic 3He measurements, which will record the thermal histories of our samples, with measurements of cosmogenic 10Be, 26Al, and 21Ne, which record samples exposure and erosion histories. We will also make in situ measurements of rock and air temperatures at sample sites in order to quantify the effect of radiative heating and develop a statistical relationship between rock and air temperatures, as well as conduct diffusion experiments to quantify the kinetics of 3He diffusion specific to each sample. This suite of observations will be used to model permissible thermal histories and place constraints on temperatures during the mid-Pliocene Warm Period interval of cosmic-ray exposure. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 164.0, "geometry": "POINT(162 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; AMD; LABORATORY; USA/NSF; Amd/Us; ISOTOPES; Dry Valleys; AIR TEMPERATURE RECONSTRUCTION; GEOCHEMISTRY; USAP-DC", "locations": "Dry Valleys", "north": -77.25, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Tremblay, Marissa; Granger, Darryl; Balco, Gregory; Lamp, Jennifer", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -78.0, "title": "Collaborative \r\nResearch: Reconstructing Temperatures during the Mid-Pliocene Warm \r\nPeriod in the McMurdo Dry Valleys with Cosmogenic Noble Gases", "uid": "p0010123", "west": 160.0}, {"awards": "1745049 Tyler, Scott", "bounds_geometry": null, "dataset_titles": "Ice Diver Madison Run #1 March 1, 2020", "datasets": [{"dataset_uid": "601368", "doi": "10.15784/601368", "keywords": "Antarctica; North America; Temperature", "people": "Tyler, Scott W.", "repository": "USAP-DC", "science_program": null, "title": "Ice Diver Madison Run #1 March 1, 2020", "url": "https://www.usap-dc.org/view/dataset/601368"}], "date_created": "Mon, 03 Aug 2020 00:00:00 GMT", "description": "Nontechnical Abstract Studies in Antarctica are, at present, severely limited by the costs of placing measurement instruments within and beneath thousands of meters of ice. Our aim is to enable dense, widespread measurement-networks by advancing development of low-cost ice melt probe technology to deploy instruments. Ice melt probes use electrical energy to descend through thick ice with little support structure on the ice surface. We are extending previous technology by using anti-freeze to maintain a partially open melt-hole above a descending probe, deploying as we go a new a new fiber-optic technology to measure ice temperature. Ice temperature measurements will reveal spatial patterns of heat welling up from the Earth beneath the ice, which in turn will contribute greatly to finding ancient ice that contains global climate records, and to understanding how ice flow may raise sea levels. Our immediate objective in this 1-year project is to test and refine our anti-freeze-based method in a 15 meter-tall ice column at the University of Wisconsin, so as to reduce technical risk in future field tests. Technical Abstract The overarching aim of our development is to enable widespread, spatially dense deployments of instruments within and beneath the Antarctic Ice Sheet for a variety of investigations, beginning with observations of basal temperature and geothermal flux at the base of the ice sheet. Dense, widespread deployment requires logistical costs far below current costs for ice drilling and coring. Our approach is to extend ice melt probe technology (which is inherently light, logistically) to allow the progressive deployment of cable for Distributed Temperature Sensing (DTS) from the ice surface as the probe descends, without greatly increasing logistical costs. Our extension is based on arresting refreezing of the melt-hole above the probe (at a diameter a few times the cable diameter) by injecting anti-freeze - specifically, ethanol at temperature near 0C - a few meters above the probe during descent. After thermal equilibration of the liquid ethanol/water column with the ice, DTS measurements yield the depth-profile of ice sheet temperature, from which basal temperature and (over frozen beds) geothermal flux can be inferred. We have carried out initial trials of our approach in a cold-room laboratory, but field work based only on such small-scale tests may still involve unnecessary risk. We therefore propose further testing at a facility of the Ice Drilling Design and Operations (IDDO) facility in Madison, WI. The new trials will test our approaches to melt-hole control and probe recovery in the taller column, will test cable and cable-tension-management methods more nearly approximating those needed to work on ice sheets, and will demonstrate the Distributed Temperature Sensing in its field configuration. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; North America; ICE DEPTH/THICKNESS; NOT APPLICABLE", "locations": "North America", "north": null, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Tyler, Scott W.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Toward Dense Observation of Geothermal Fluxes in Antarctica Via Logistically Light Instrument Deployment", "uid": "p0010121", "west": null}, {"awards": "1543347 Rosenheim, Brad; 1543396 Christner, Brent; 1543405 Leventer, Amy; 1543453 Lyons, W. Berry; 1543537 Priscu, John; 1543441 Fricker, Helen", "bounds_geometry": "POLYGON((-163.611 -84.33543,-162.200034 -84.33543,-160.789068 -84.33543,-159.378102 -84.33543,-157.967136 -84.33543,-156.55617 -84.33543,-155.145204 -84.33543,-153.734238 -84.33543,-152.323272 -84.33543,-150.912306 -84.33543,-149.50134 -84.33543,-149.50134 -84.3659157,-149.50134 -84.3964014,-149.50134 -84.4268871,-149.50134 -84.4573728,-149.50134 -84.4878585,-149.50134 -84.5183442,-149.50134 -84.5488299,-149.50134 -84.5793156,-149.50134 -84.6098013,-149.50134 -84.640287,-150.912306 -84.640287,-152.323272 -84.640287,-153.734238 -84.640287,-155.145204 -84.640287,-156.55617 -84.640287,-157.967136 -84.640287,-159.378102 -84.640287,-160.789068 -84.640287,-162.200034 -84.640287,-163.611 -84.640287,-163.611 -84.6098013,-163.611 -84.5793156,-163.611 -84.5488299,-163.611 -84.5183442,-163.611 -84.4878585,-163.611 -84.4573728,-163.611 -84.4268871,-163.611 -84.3964014,-163.611 -84.3659157,-163.611 -84.33543))", "dataset_titles": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset; Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland; CTD data from Mercer Subglacial Lake and access borehole; Discrete bulk sediment properties data from Mercer Subglacial Lake; Isotopic data from Whillans Ice Stream grounding zone, West Antarctica; Mercer Subglacial Lake radiocarbon and stable isotope data ; Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995); Mercer Subglacial Lake (SLM) noble gas and isotopic data; Mercer Subglacial Lake water column viral metagenomic sequencing; Salsa sediment cores; Sediment porewater properties data from Mercer Subglacial Lake; Water column biogeochemical data from Mercer Subglacial Lake", "datasets": [{"dataset_uid": "200342", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Mercer Subglacial Lake water column viral metagenomic sequencing", "url": "https://www.ncbi.nlm.nih.gov/biosample/32811410"}, {"dataset_uid": "200214", "doi": "10.7283/YW8Z-TK03", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/YW8Z-TK03"}, {"dataset_uid": "200246", "doi": "", "keywords": null, "people": null, "repository": "OSU-MGR", "science_program": null, "title": "Salsa sediment cores", "url": "https://osu-mgr.org"}, {"dataset_uid": "200215", "doi": "10.7283/C503-KS23", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/C503-KS23"}, {"dataset_uid": "601663", "doi": "10.15784/601663", "keywords": "Antarctica; Carbon; Cell Counts; Geochemistry; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mercer Subglacial Lake; Microbes; Nutrients; SALSA; Stable Isotopes; Trace Elements; West Antarctic Ice Sheet", "people": "Priscu, John; Dore, John; Skidmore, Mark; Hawkings, Jon; Steigmeyer, August; Li, Wei; Barker, Joel; Tranter, Martyn; Science Team, SALSA", "repository": "USAP-DC", "science_program": null, "title": "Water column biogeochemical data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601663"}, {"dataset_uid": "200216", "doi": "10.7283/F8NH-CV04", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F8NH-CV04"}, {"dataset_uid": "601672", "doi": "10.15784/601672", "keywords": "Antarctica; Isotope; Mercer Subglacial Lake; Radiocarbon; Subglacial Lake", "people": "Rosenheim, Brad; Venturelli, Ryan", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake radiocarbon and stable isotope data ", "url": "https://www.usap-dc.org/view/dataset/601672"}, {"dataset_uid": "200213", "doi": "10.7283/F7BB-JH05", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F7BB-JH05"}, {"dataset_uid": "200282", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995)", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA790995"}, {"dataset_uid": "601661", "doi": "10.15784/601661", "keywords": "Antarctica; Carbon; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Iron; Mercer Subglacial Lake; Mineralogy; Particle Size; Physical Properties; SALSA; Sediment Core; Sulfur; West Antarctic Ice Sheet", "people": "Campbell, Timothy; Michaud, Alexander; Hawkings, Jon; Skidmore, Mark; Tranter, Martyn; Venturelli, Ryan A; Dore, John; Science Team, SALSA", "repository": "USAP-DC", "science_program": null, "title": "Discrete bulk sediment properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601661"}, {"dataset_uid": "200212", "doi": "10.7283/PT0Q-JB95", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/PT0Q-JB95"}, {"dataset_uid": "601360", "doi": "10.15784/601360", "keywords": "Antarctica; Radiocarbon; Sediment; Whillans Ice Stream", "people": "Venturelli, Ryan A", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Isotopic data from Whillans Ice Stream grounding zone, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601360"}, {"dataset_uid": "601472", "doi": "10.15784/601472", "keywords": "Antarctica; Bistatic Radar; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS Data; Greenland; Lake Whillans; Radar; Store Glacier; Whillans Ice Stream; WISSARD", "people": "Schroeder, Dustin; Siegfried, Matthew; Peters, Sean; MacKie, Emma; Dawson, Eliza; Christoffersen, Poul; Bienert, Nicole", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland", "url": "https://www.usap-dc.org/view/dataset/601472"}, {"dataset_uid": "601498", "doi": "10.15784/601498", "keywords": "Antarctica; Mercer Subglacial Lake; Noble Gas", "people": "Lyons, W. Berry; Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake (SLM) noble gas and isotopic data", "url": "https://www.usap-dc.org/view/dataset/601498"}, {"dataset_uid": "601657", "doi": "10.15784/601657", "keywords": "Antarctica; Conductivity; CTD; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hot Water Drill; Mercer Subglacial Lake; Physical Properties; SALSA; Subglacial Lake; Temperature", "people": "Leventer, Amy; Dore, John; Priscu, John; Rosenheim, Brad", "repository": "USAP-DC", "science_program": null, "title": "CTD data from Mercer Subglacial Lake and access borehole", "url": "https://www.usap-dc.org/view/dataset/601657"}, {"dataset_uid": "200217", "doi": "10.7283/3JMY-Y504", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/3JMY-Y504"}, {"dataset_uid": "601664", "doi": "10.15784/601664", "keywords": "Antarctica; Gas; Geochemistry; Glacier; Glaciology; Mercer Subglacial Lake; Methane; SALSA; Sediment Core; West Antarctic Ice Sheet", "people": "Skidmore, Mark; Science Team, SALSA; Steigmeyer, August; Tranter, Martyn; Michaud, Alexander; Dore, John", "repository": "USAP-DC", "science_program": null, "title": "Sediment porewater properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601664"}], "date_created": "Thu, 16 Jul 2020 00:00:00 GMT", "description": "The Antarctic subglacial environment remains one of the least explored regions on Earth. This project will examine the physical and biological characteristics of Subglacial Lake Mercer, a lake that lies 1200m beneath the West Antarctic Ice Sheet. This study will address key questions relating to the stability of the ice sheet, the subglacial hydrological system, and the deep-cold subglacial biosphere. The education and outreach component aims to widely disseminate results to the scientific community and to the general public through short films, a blog, and a website. Subglacial Lake Mercer is one of the larger hydrologically active lakes in the southern basin of the Whillans Ice Plain, West Antarctica. It receives about 25 percent of its water from East Antarctica with the remainder originating from West Antarctica, is influenced by drain/fill cycles in a lake immediately upstream (Subglacial Lake Conway), and lies about 100 km upstream of the present grounding line of the Ross Ice Shelf. This site will yield information on the history of the Whillans and Mercer Ice Streams, and on grounding line migration. The integrated study will include direct sampling of basal ice, water, and sediment from the lake in concert with surface geophysical surveys over a three-year period to define the hydrological connectivity among lakes on the Whillans Ice Plain and their flow paths to the sea. The geophysical surveys will furnish information on subglacial hydrology, aid the site selection for hot-water drilling, and provide spatial context for interpreting findings. The hot-water-drilled boreholes will be used to collect basal ice samples, provide access for direct measurement of subglacial physical, chemical, and biological conditions in the water column and sediments, and to explore the subglacial water cavities using a remotely operated vehicle equipped with sensors, cameras, and sampling equipment. Data collected from this study will address the overarching hypothesis \"Contemporary biodiversity and carbon cycling in hydrologically-active subglacial environments associated with the Mercer and Whillans ice streams are regulated by the mineralization and cycling of relict marine organic matter and through interactions among ice, rock, water, and sediments\". The project will be undertaken by a collaborative team of scientists, with expertise in microbiology, biogeochemistry, hydrology, geophysics, glaciology, marine geology, paleoceanography, and science communication.", "east": -149.50134, "geometry": "POINT(-156.55617 -84.4878585)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; Antarctica; ISOTOPES; Subglacial Lake; USAP-DC; VIRUSES; PALEOCLIMATE RECONSTRUCTIONS; BACTERIA/ARCHAEA; LABORATORY; Radiocarbon; Whillans Ice Stream; AMD; SALSA; ECOSYSTEM FUNCTIONS; RADIOCARBON; FIELD INVESTIGATION; ICE MOTION; Mercer Ice Stream; Amd/Us; USA/NSF; GLACIERS/ICE SHEETS", "locations": "Antarctica; Mercer Ice Stream; Whillans Ice Stream", "north": -84.33543, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Instrumentation and Support; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Rosenheim, Brad; Fricker, Helen; Priscu, John; Leventer, Amy; Dore, John; Lyons, W. Berry; Christner, Brent", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "GenBank", "repositories": "GenBank; NCBI GenBank; OSU-MGR; UNAVCO; USAP-DC", "science_programs": null, "south": -84.640287, "title": "Collaborative Research: Subglacial Antarctic Lakes Scientific Access (SALSA): Integrated Study of Carbon Cycling in Hydrologically-active Subglacial Environments", "uid": "p0010119", "west": -163.611}, {"awards": "1443690 Young, Duncan", "bounds_geometry": "POLYGON((95 -68,100.5 -68,106 -68,111.5 -68,117 -68,122.5 -68,128 -68,133.5 -68,139 -68,144.5 -68,150 -68,150 -70.2,150 -72.4,150 -74.6,150 -76.8,150 -79,150 -81.2,150 -83.4,150 -85.6,150 -87.8,150 -90,144.5 -90,139 -90,133.5 -90,128 -90,122.5 -90,117 -90,111.5 -90,106 -90,100.5 -90,95 -90,95 -87.8,95 -85.6,95 -83.4,95 -81.2,95 -79,95 -76.8,95 -74.6,95 -72.4,95 -70.2,95 -68))", "dataset_titles": "Airborne potential fields data from Titan Dome, Antarctica; ICECAP Basal Interface Specularity Content Profiles: IPY and OIB; ICECAP: Gridded boundary conditions for Little Dome C, Antarctica, and extracted subglacial lake locations; ICECAP: High resolution survey of the Little Dome C region in support of the IPICS Old Ice goal; ICECAP radargrams in support of the international old ice search at Dome C - 2016; Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau; SPICECAP/ICECAP II Instrument Measurements (LASER, MAGNETICS and POSITIONING); Titan Dome, East Antarctica, Aerogeophysical Survey", "datasets": [{"dataset_uid": "601411", "doi": "10.15784/601411", "keywords": "Antarctica; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ICECAP; Ice Penetrating Radar; Internal Reflecting Horizons", "people": "Tozer, Carly; Ritz, Catherine; Blankenship, Donald D.; Schroeder, Dustin; Mulvaney, Robert; Roberts, Jason; Frezzotti, Massimo; Paden, John; Muldoon, Gail R.; Quartini, Enrica; Kempf, Scott D.; Ng, Gregory; Greenbaum, Jamin; Cavitte, Marie G. P; Young, Duncan A.", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau", "url": "https://www.usap-dc.org/view/dataset/601411"}, {"dataset_uid": "601461", "doi": "10.15784/601461", "keywords": "Antarctica; ICECAP; Titan Dome", "people": "Greenbaum, Jamin; Jingxue, Guo; Blankenship, Donald D.; Young, Duncan A.; Bo, Sun", "repository": "USAP-DC", "science_program": null, "title": "Airborne potential fields data from Titan Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601461"}, {"dataset_uid": "601463", "doi": "10.15784/601463", "keywords": "Antarctica; Epica Dome C; ICECAP; Ice Penetrating Radar; Subglacial Lake", "people": "Young, Duncan A.; Roberts, Jason; Ritz, Catherine; Frezzotti, Massimo; Quartini, Enrica; Cavitte, Marie G. P; Van Ommen, Tas; Blankenship, Donald D.; Steinhage, Daniel; Tozer, Carly; Urbini, Stefano; Corr, Hugh F. J.", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "ICECAP: Gridded boundary conditions for Little Dome C, Antarctica, and extracted subglacial lake locations", "url": "https://www.usap-dc.org/view/dataset/601463"}, {"dataset_uid": "200233", "doi": "http://dx.doi.org/doi:10.26179/5wkf-7361", "keywords": null, "people": null, "repository": "AADC", "science_program": null, "title": "ICECAP radargrams in support of the international old ice search at Dome C - 2016", "url": "https://data.aad.gov.au/metadata/records/AAS_4346_ICECAP_OIA_RADARGRAMS"}, {"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Young, Duncan A.; Roberts, Jason; Greenbaum, Jamin; Blankenship, Donald D.; Schroeder, Dustin; Siegert, Martin; van Ommen, Tas", "repository": "USAP-DC", "science_program": null, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "url": "https://www.usap-dc.org/view/dataset/601371"}, {"dataset_uid": "601437", "doi": "10.15784/601437", "keywords": "Airborne Laser Altimetry; Airborne Radar; Airplane; Antarctica; Bedrock Elevation; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness; Radar Echo Sounder; Surface Elevation; Titan Dome", "people": "Young, Duncan; Beem, Lucas H.; Young, Duncan A.; Greenbaum, Jamin; Ng, Gregory; Blankenship, Donald D.; Cavitte, Marie G. P; Jingxue, Guo; Bo, Sun", "repository": "USAP-DC", "science_program": null, "title": "Titan Dome, East Antarctica, Aerogeophysical Survey", "url": "https://www.usap-dc.org/view/dataset/601437"}, {"dataset_uid": "601355", "doi": "10.15784/601355", "keywords": "Aerogeophysics; Antarctica; Bed Elevation; Bed Reflectivity; Epica Dome C; Ice Thickness", "people": "Ng, Gregory; Young, Duncan A.; Roberts, Jason; Blankenship, Donald D.; van Ommen, Tas; Richter, Thomas; Greenbaum, Jamin; Cavitte, Marie G. P; Beem, Lucas H.; Quartini, Enrica; Tozer, Carly; Habbal, Feras; Kempf, Scott D.; Ritz, Catherine", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "ICECAP: High resolution survey of the Little Dome C region in support of the IPICS Old Ice goal", "url": "https://www.usap-dc.org/view/dataset/601355"}, {"dataset_uid": "200235", "doi": "10.26179/jydx-yz69", "keywords": null, "people": null, "repository": "AADC", "science_program": null, "title": "SPICECAP/ICECAP II Instrument Measurements (LASER, MAGNETICS and POSITIONING)", "url": "https://data.aad.gov.au/metadata/records/AAS_4346_ICECAP_OIA_Level1B_AEROGEOPHYSICS"}], "date_created": "Tue, 07 Jul 2020 00:00:00 GMT", "description": "Non-technical description: East Antarctica holds a vast, ancient ice sheet. The bedrock hidden beneath this ice sheet may provide clues to how today\u0027s continents formed, while the ice itself contains records of Earth\u0027s atmosphere from distant eras. New drilling technologies are now available to allow for direct sampling of these materials from more than two kilometers below the ice surface. However, getting this material will require knowing where to look. The Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP) project will use internationally collected airborne survey data to search East Antarctica near the South Pole for key locations that will provide insight into Antarctica\u0027s geology and for locating the oldest intact ice on Earth. Ultimately, scientists are interested in obtaining samples of the oldest ice to address fundamental questions about the causes of changes in the timing of ice-age conditions from 40,000 to 100,000 year cycles. SPICECAP data analysis will provide site survey data for future drilling and will increase the overall understanding of Antarctica\u0027s hidden ice and geologic records. The project involves international collaboration and leveraging of internationally collected data. The SPICECAP project will train new interdisciplinary scientists at the undergraduate, graduate, and postdoctoral levels. Technical description: This study focuses on processing and interpretation of internationally collected aerogeophysical data from the Southern Plateau of the East Antarctic Ice Sheet. The data include ice penetrating radar data, laser altimetry, gravity and magnetics.\u00a0 The project will provide information on geological trends under the ice, the topography and character of the ice/rock interface, and the stratigraphy of the ice. The project will also provide baseline site characterization for future drilling. Future drilling sites and deep ice cores for old ice require that the base of the ice sheet be frozen to the bed (i.e. no free water at the interface between rock and ice) and the assessment will map the extent of frozen vs. thawed areas. Specifically, three main outcomes are anticipated for this project. First, the study will provide an assessment of the viability of Titan Dome, a subglacial highland region located near South Pole, as a potential old ice drilling prospect. The assessment will include determining the\u00a0hydraulic context of the bed by processing and interpreting the radar data,\u00a0ice sheet mass balance through time by mapping englacial reflectors in the ice and connecting them to ice stratigraphy in the recent South Pole,\u00a0and ice sheet geometry using laser altimetry. Second, the study will provide an assessment of the geological context of the Titan Dome region with respect to understanding regional geologic boundaries and the potential for bedrock sampling. For these two goals, we will use data opportunistically collected by China, and the recent PolarGAP dataset. Third, the study will provide an assessment of the risk posture for RAID site targeting in the Titan Dome region, and the Dome C region. This will use a high-resolution dataset the team collected previously at Dome C, an area similar to the coarser resolution data collected at Titan Dome, and will enable an understanding of what is missed by the wide lines spacing at Titan Dome. Specifically, we will model subglacial hydrology with and without the high resolution data, and statistically examine the detection of subglacial mountains (which could preserve old ice) and subglacial lakes (which could destroy old ice), as a function of line spacing.", "east": 150.0, "geometry": "POINT(122.5 -79)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e LIDAR ALTIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e NUCLEAR PRECESSION MAGNETOMETER", "is_usap_dc": true, "keywords": "BT-67; MAGNETIC ANOMALIES; Epica Dome C; GRAVITY ANOMALIES; GLACIER ELEVATION/ICE SHEET ELEVATION; GLACIER THICKNESS/ICE SHEET THICKNESS", "locations": "Epica Dome C", "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Young, Duncan A.; Blankenship, Donald D.; Roberts, Jason; Bo, Sun", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e BT-67", "repo": "USAP-DC", "repositories": "AADC; USAP-DC", "science_programs": "Dome C Ice Core", "south": -90.0, "title": "Collaborative Research: Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP)", "uid": "p0010115", "west": 95.0}, {"awards": "0125252 Padman, Laurence; 0125602 Padman, Laurence", "bounds_geometry": "POLYGON((-180 -40.231,-144 -40.231,-108 -40.231,-72 -40.231,-36 -40.231,0 -40.231,36 -40.231,72 -40.231,108 -40.231,144 -40.231,180 -40.231,180 -45.2079,180 -50.1848,180 -55.1617,180 -60.1386,180 -65.1155,180 -70.0924,180 -75.0693,180 -80.0462,180 -85.0231,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.0231,-180 -80.0462,-180 -75.0693,-180 -70.0924,-180 -65.1155,-180 -60.1386,-180 -55.1617,-180 -50.1848,-180 -45.2079,-180 -40.231))", "dataset_titles": "Antarctic Tide Gauge Database, version 1; AntTG_Database_Tools; CATS2008: Circum-Antarctic Tidal Simulation version 2008; CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023; pyTMD; TMD_Matlab_Toolbox_v2.5", "datasets": [{"dataset_uid": "200158", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "pyTMD", "url": "https://github.com/tsutterley/pyTMD"}, {"dataset_uid": "601772", "doi": "10.15784/601772", "keywords": "Antarctica; Cryosphere; Inverse Modeling; Model Data; Ocean Currents; Oceans; Sea Surface; Southern Ocean; Tide Model; Tides", "people": "Sutterley, Tyler; Howard, Susan L.; Greene, Chad A.; Padman, Laurence; Erofeeva, Svetlana", "repository": "USAP-DC", "science_program": null, "title": "CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023", "url": "https://www.usap-dc.org/view/dataset/601772"}, {"dataset_uid": "200156", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "AntTG_Database_Tools", "url": "https://github.com/EarthAndSpaceResearch/AntTG_Database_Tools"}, {"dataset_uid": "601235", "doi": "10.15784/601235", "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "people": "Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana", "repository": "USAP-DC", "science_program": null, "title": "CATS2008: Circum-Antarctic Tidal Simulation version 2008", "url": "https://www.usap-dc.org/view/dataset/601235"}, {"dataset_uid": "200157", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "TMD_Matlab_Toolbox_v2.5", "url": "https://github.com/EarthAndSpaceResearch/TMD_Matlab_Toolbox_v2.5"}, {"dataset_uid": "601358", "doi": "10.15784/601358", "keywords": "Antarctica; Oceans; Sea Surface Height; Tide Gauges; Tides", "people": "Howard, Susan L.; Padman, Laurence; King, Matt", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Tide Gauge Database, version 1", "url": "https://www.usap-dc.org/view/dataset/601358"}], "date_created": "Tue, 07 Jul 2020 00:00:00 GMT", "description": "The ocean tide is a large component of total variability of ocean surface height and currents in the seas surrounding Antarctica, including under the floating ice shelves. Maximum tidal height range exceeds 7 m (near the grounding line of Rutford Ice Stream) and maximum tidal currents exceed 1 m/s (near the shelf break in the northwest Ross Sea). Tides contribute to several important climate and ecosystems processes including: ocean mixing, production of dense bottom water, flow of warm Circumpolar Deep Water onto the continental shelves, melting at the bases of ice shelves, fracturing of the ice sheet near a glacier or ice stream\u2019s grounding line, production and decay of sea ice, and sediment resuspension. Tide heights and, in particular, currents can change as the ocean background state changes, and as the geometry of the coastal margins of the Antarctic Ice Sheet varies through ice shelf thickness changes and ice-front and grounding-line advances or retreats. For satellite-based studies of ocean surface height and ice shelf thickness changes, tide heights are a source of substantial noise that must be removed. Similarly, tidal currents can also be a substantial noise signal when trying to estimate mean ocean currents from short-term measurements such as from acoustic Doppler current profilers mounted on ships and CTD rosettes. Therefore, tide models play critical roles in understanding current and future ocean and ice states, and as a method for removing tides in various measurements. A paper in Reviews of Geophysics (Padman, Siegfried and Fricker, 2018, see list of project-related publications below) provides a detailed review of tides and tidal processes around Antarctica.\r\n\nThis project provides a gateway to tide models and a database of tide height coefficients at the Antarctic Data Center, and links to toolboxes to work with these models and data.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e TIDE GAUGES", "is_usap_dc": true, "keywords": "Tide Gauges; OCEAN CURRENTS; Sea Surface Height; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; Tides; Antarctica; MODELS; FIELD INVESTIGATION", "locations": "Antarctica", "north": -40.231, "nsf_funding_programs": "Arctic System Science; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana; King, Matt", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e MODELS \u003e MODELS", "repo": "GitHub", "repositories": "GitHub; USAP-DC", "science_programs": null, "south": -90.0, "title": "Ocean Tides around Antarctica and in the Southern Ocean", "uid": "p0010116", "west": -180.0}, {"awards": "1341658 Mukhopadhyay, Sujoy", "bounds_geometry": "POLYGON((-116.45 -84.786,-116.443 -84.786,-116.436 -84.786,-116.429 -84.786,-116.422 -84.786,-116.415 -84.786,-116.408 -84.786,-116.401 -84.786,-116.394 -84.786,-116.387 -84.786,-116.38 -84.786,-116.38 -84.7864,-116.38 -84.7868,-116.38 -84.7872,-116.38 -84.7876,-116.38 -84.788,-116.38 -84.7884,-116.38 -84.7888,-116.38 -84.7892,-116.38 -84.7896,-116.38 -84.79,-116.387 -84.79,-116.394 -84.79,-116.401 -84.79,-116.408 -84.79,-116.415 -84.79,-116.422 -84.79,-116.429 -84.79,-116.436 -84.79,-116.443 -84.79,-116.45 -84.79,-116.45 -84.7896,-116.45 -84.7892,-116.45 -84.7888,-116.45 -84.7884,-116.45 -84.788,-116.45 -84.7876,-116.45 -84.7872,-116.45 -84.7868,-116.45 -84.7864,-116.45 -84.786))", "dataset_titles": "Ohio Range Subglacial rock core cosmogenic nuclide data", "datasets": [{"dataset_uid": "601351", "doi": "10.15784/601351", "keywords": "Aluminum-26; Antarctica; Beryllium-10; Cosmogenic Dating; Cosmogenic Radionuclides; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Fluctuations; Ohio Range; Rocks", "people": "Mukhopadhyay, Sujoy", "repository": "USAP-DC", "science_program": null, "title": "Ohio Range Subglacial rock core cosmogenic nuclide data", "url": "https://www.usap-dc.org/view/dataset/601351"}], "date_created": "Sun, 28 Jun 2020 00:00:00 GMT", "description": "Modeling fluctuations in the extent of the West Antarctic Ice Sheet (WAIS) over time is a principal goal of the glaciological community. These models will provide a critical basis for predictions of future sea level change, and therefore this work great societal relevance. The mid-Pliocene time interval is of particular interest, as it is the most recent period in which global temperatures were warmer and atmospheric CO2 concentrations may have been higher than current levels. However, observational constraints on fluctuations in the WAIS older than the last glacial maximum are rare. The investigators propose to collect geochemical data from the Ohio Range and Scott Glacier to quantify past variability in the height of the WAIS. Limited available cosmogenic nuclide data are broadly consistent with a model indicating that Pliocene WAIS elevations and volumes were smaller than at present, and that WAIS collapse was common. The PIs will use geologic observations and cosmogenic nuclide concentrations from bedrock samples at multiple locations and at multiple elevations, including sub-ice samples, to constrain WAIS ice volume changes in a \"dipstick\" like fashion. Data obtained from the proposed research will provide targets for data-ice sheet model comparisons to accurately characterize Plio-Pleistocene and future WAIS behavior. As part of this project, the investigators will work with the Natural History Museum and the Earth \u0026 Planetary Science department at Harvard to develop an exhibit that will become part of the Museum\u0027s recently opened Earth and Planetary Science Gallery. The project involves mentoring of a female graduate student as well as an undergraduate student.", "east": -116.38, "geometry": "POINT(-116.415 -84.788)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Sheet Fluctuations; ALUMINUM-26 ANALYSIS; BERYLLIUM-10 ANALYSIS; Cosmogenic Radionuclides; USAP-DC; FIELD INVESTIGATION; AMD; Ohio Range; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; LABORATORY", "locations": "Ohio Range", "north": -84.786, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Mukhopadhyay, Sujoy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.79, "title": "Constraining Plio-Pleistocene West Antarctic Ice Sheet Behavior from the Ohio Range and Scott Glacier", "uid": "p0010113", "west": -116.45}, {"awards": "1246465 Brook, Edward J.", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "WAIS Divide Ice Core Marine Isotope Stage 3 CO2 record", "datasets": [{"dataset_uid": "601337", "doi": "10.15784/601337", "keywords": "Antarctica; Carbon Cycle; CO2; Gas Chromatograph; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; WAIS Divide", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Marine Isotope Stage 3 CO2 record", "url": "https://www.usap-dc.org/view/dataset/601337"}], "date_created": "Mon, 22 Jun 2020 00:00:00 GMT", "description": "Brook/1246465 This award supports a project to measure the carbon dioxide (CO2) concentration in the WAIS Divide ice core covering the time period 25,000 to 60,000 years before present, and to analyze the isotopic composition of CO2 in selected time intervals. The research will improve understanding of how and why atmospheric CO2 varied during the last ice age, focusing particularly on abrupt transitions in the concentration record that are associated with abrupt climate change. These events represents large perturbations to the global climate system and better information about the CO2 response should inform our understanding of carbon cycle-climate feedbacks and radiative forcing of climate. The research will also improve analytical methods in support of these goals, including completing development of sublimation methods to replace laborious mechanical crushing of ice to release air for analysis. The intellectual merit of the proposed work is that it will increase knowledge about the magnitude and timing of atmospheric CO2 variations during the last ice age, and their relationship to regional climate in Antarctica, global climate history, and the history of abrupt climate change in the Northern Hemisphere. The temporal resolution of the proposed record will in most intervals be ~ 4 x higher than previous data sets for this time period, and for selected intervals up to 8-10 times higher. Broader impacts of the proposed work include a significant addition to the amount of data documenting the history of the most important long-lived greenhouse gas in the atmosphere and more information about carbon cycle-climate feedbacks - important parameters for predicting future climate change. The project will contribute to training a postdoctoral researcher, research experience for an undergraduate and a high school student, and outreach to local middle school and other students. It will also improve the analytical infrastructure at OSU, which will be available for future projects.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Carbon Cycle; Ice Core Records; USAP-DC; CO2; FIELD INVESTIGATION; CARBON DIOXIDE; LABORATORY; WAIS Divide", "locations": "WAIS Divide", "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Completing the WAIS Divide Ice Core CO2 record", "uid": "p0010110", "west": -112.1115}, {"awards": "1443576 Panter, Kurt", "bounds_geometry": "POLYGON((-154.1 -86.9,-154.03 -86.9,-153.96 -86.9,-153.89 -86.9,-153.82 -86.9,-153.75 -86.9,-153.68 -86.9,-153.61 -86.9,-153.54 -86.9,-153.47 -86.9,-153.4 -86.9,-153.4 -86.92,-153.4 -86.94,-153.4 -86.96,-153.4 -86.98,-153.4 -87,-153.4 -87.02,-153.4 -87.04,-153.4 -87.06,-153.4 -87.08,-153.4 -87.1,-153.47 -87.1,-153.54 -87.1,-153.61 -87.1,-153.68 -87.1,-153.75 -87.1,-153.82 -87.1,-153.89 -87.1,-153.96 -87.1,-154.03 -87.1,-154.1 -87.1,-154.1 -87.08,-154.1 -87.06,-154.1 -87.04,-154.1 -87.02,-154.1 -87,-154.1 -86.98,-154.1 -86.96,-154.1 -86.94,-154.1 -86.92,-154.1 -86.9))", "dataset_titles": "Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica ", "datasets": [{"dataset_uid": "601331", "doi": "10.15784/601331", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochronology; Glacial Volcanism; Magma Differentiation; Major Elements; Mantle Melting; Solid Earth; Trace Elements; Transantarctic Mountains", "people": "Panter, Kurt", "repository": "USAP-DC", "science_program": null, "title": "Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601331"}], "date_created": "Fri, 05 Jun 2020 00:00:00 GMT", "description": "Predictions of future sea level rise require better understanding of the changing dynamics of the Greenland and Antarctic ice sheets. One way to better understand the past history of the ice sheets is to obtain records from inland ice for past geological periods, particularly in Antarctica, the world?s largest remaining ice sheet. Such records are exceedingly rare, and can be acquired at volcanic outcrops in the La Gorce Mountains of the central Transantarctic Mountains. Volcanoes now exposed within the La Gorce Mountains erupted beneath the East Antarctic ice sheet and the data collected will record how thick the ice sheet was in the past. In addition, information will be used to determine the thermal conditions at the base of the ice sheet, which impacts ice sheet stability. The project will also investigate the origin of volcanic activity in Antarctica and links to the West Antarctic Rift System (WARS). The WARS is a broad area of extended (i.e. stretched) continental crust, similar to that found in East Africa, and volcanism is wide spread and long-lived (65 million years to currently active) and despite more than 50 years of research, the fundamental cause of volcanism and rifting in Antarctica is still vigorously debated. The results of this award therefore also potentially impact the study of oceanic volcanism in the entire southwestern Pacific region (e.g., New Zealand and Australia), where volcanic fields of similar composition and age have been linked by common magma sources and processes. The field program includes a graduate student who will work on the collection, analysis, and interpretation of petrological data as part of his/her Masters project. The experience and specialized analytical training being offered will improve the quality of the student?s research and optimize their opportunities for their future. The proposed work fosters faculty and student national and international collaboration, including working with multi-user facilities that provide advanced technological mentoring of science students. Results will be broadly disseminated in peer-reviewed journals, public presentations at science meetings, and in outreach activities. Petrologic and geochemical data will be disseminated to be the community through the Polar Rock Repository. The study of subglacially erupted volcanic rocks has been developed to the extent that it is now the most powerful proxy methodology for establishing precise ?snapshots? of ice sheets, including multiple critical ice parameters. Such data should include measurements of ice thickness, surface elevation and stability, which will be used to verify, or reject, published semi-empirical models relating ice dynamics to sea level changes. In addition to establishing whether East Antarctic ice was present during the formation of the volcanoes, data will be used to derive the coeval ice thicknesses, surface elevations and basal thermal regime(s) in concert with a precise new geochronology using the 40Ar/39Ar dating method. Inferences from measurement of standard geochemical characteristics (major, trace elements and Sr, Nd, Pb, O isotopes) will be used to investigate a possible relationship between the volcanoes and the recently discovered subglacial ridge under the East Antarctic ice, which may be a rift flank uplift. The ridge has never been sampled, is undated and its significance is uncertain. The data will provide important new information about the deep Earth and geodynamic processes beneath this mostly ice covered and poorly understood sector of the Antarctic continent.", "east": -153.4, "geometry": "POINT(-153.75 -87)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; Mantle Melting; Magma Differentiation; Geochronology; Glacial Volcanism; GEOCHEMISTRY; Major Elements; ISOTOPES; Trace Elements; Transantarctic Mountains; LABORATORY; LAVA COMPOSITION/TEXTURE; USAP-DC; LAND RECORDS", "locations": "Transantarctic Mountains", "north": -86.9, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Panter, Kurt", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.1, "title": "Investigating Early Miocene Sub-ice Volcanoes in Antarctica for Improved Modeling and understanding of a Large Magmatic Province", "uid": "p0010105", "west": -154.1}, {"awards": "1744883 Wiens, Douglas", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "ANT-20: A 3D seismic model of the upper mantle and transition zone structure beneath Antarctica and the surrounding southern oceans; CWANT-PSP: A 3-D shear velocity model from a joint inversion of receiver functions and surface wave dispersion derived from ambient noise and teleseismic earthquakes.", "datasets": [{"dataset_uid": "200178", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "CWANT-PSP: A 3-D shear velocity model from a joint inversion of receiver functions and surface wave dispersion derived from ambient noise and teleseismic earthquakes.", "url": "http://ds.iris.edu/ds/products/emc-cwant-psp/"}, {"dataset_uid": "200179", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "ANT-20: A 3D seismic model of the upper mantle and transition zone structure beneath Antarctica and the surrounding southern oceans", "url": "http://ds.iris.edu/ds/products/emc-ant-20/"}], "date_created": "Tue, 02 Jun 2020 00:00:00 GMT", "description": "The geological structure and history of Antarctica remains poorly understood because much of the continental crust is covered by ice. Here, the PIs will analyze over 15 years of seismic data recorded by numerous projects in Antarctica to develop seismic structural models of the continent. The seismic velocity models will reveal features including crustal thinning due to rifting in West Antarctica, the structures associated with mountain building, and the boundaries between different tectonic blocks. The models will be compared to continents that are better understood geologically to constrain the tectonic evolution of Antarctica. In addition, the work will provide better insight into how the solid earth interacts with and influences the development of the ice sheet. Surface heat flow will be mapped and used to identify regions in Antarctica with potential melting at the base of the ice sheet. This melt can lead to reduced friction and lower resistance to ice sheet movement. The models will help to determine whether the earth response to ice mass changes occurs over decades, hundreds, or thousands of years. Estimates of mantle viscosity calculated from the seismic data will be used to better understand the pattern and timescales of the response of the solid earth to changes in ice mass in various parts of Antarctica. The study will advance our knowledge of the structure of Antarctica by constructing two new seismic models and a thermal model using different but complementary methodologies. Because of the limitations of different seismic analysis methods, efforts will be divided between a model seeking the highest possible resolution within the upper 200 km depth in the well instrumented region (Bayesian Monte-Carlo joint inversion), and another model determining the structure of the entire continent and surrounding oceans extending through the mantle transition zone (adjoint full waveform inversion). The Monte-Carlo inversion will jointly invert Rayleigh wave group and phase velocities from earthquakes and ambient noise correlation along with P-wave receiver functions and Rayleigh H/V ratios. The inversion will be done in a Bayesian framework that provides uncertainty estimates for the structural model. Azimuthal anisotropy will be determined from Rayleigh wave velocities, providing constraints on mantle fabric and flow patterns. The seismic data will also be inverted for temperature structure, providing estimates of lithospheric thickness and surface heat flow. The larger-scale model will cover the entire continent as well as the surrounding oceans, and will be constructed using an adjoint inversion of phase differences between three component seismograms and synthetic seismograms calculated in a 3D earth model using the spectral element method. This model will fit the entire waveforms, including body waves and both fundamental and higher mode surface waves. Higher resolution results will be obtained by using double-difference methods and by incorporating Green\u0027s functions from ambient noise cross-correlation, and solving for both radial and azimuthal anisotropy. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USA/NSF; Carbon Cycle; SEISMIC PROFILE; Seismology; Southern Ocean; Amd/Us; Antarctica; West Antarctica; MODELS; SEISMIC SURFACE WAVES; AMD; TECTONICS; USAP-DC", "locations": "Antarctica; West Antarctica; Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wiens, Douglas; Shen, Weisen", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -90.0, "title": "Comprehensive Seismic and Thermal Models for Antarctica and the Southern Oceans: A Synthesis of 15-years of Seismic Exploration", "uid": "p0010103", "west": -180.0}, {"awards": "1643722 Brook, Edward J.", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "South Pole Ice Core Methane Data and Gas Age Time Scale; South Pole ice core (SPC14) total air content (TAC)", "datasets": [{"dataset_uid": "601546", "doi": "10.15784/601546", "keywords": "Antarctica; South Pole", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) total air content (TAC)", "url": "https://www.usap-dc.org/view/dataset/601546"}, {"dataset_uid": "601329", "doi": "10.15784/601329", "keywords": "Antarctica; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; South Pole", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Methane Data and Gas Age Time Scale", "url": "https://www.usap-dc.org/view/dataset/601329"}], "date_created": "Tue, 02 Jun 2020 00:00:00 GMT", "description": "Brook/1643722 This award supports a project to measure the concentration of the gas methane in air trapped in an ice core collected from the South Pole. The data will provide an age scale (age as a function of depth) by matching the South Pole methane changes with similar data from other ice cores for which the age vs. depth relationship is well known. The ages provided will allow all other gas measurements made on the South Pole core (by the PI and other NSF supported investigators) to be interpreted accurately as a function of time. This is critical because a major goal of the South Pole coring project is to understand the history of rare gases in the atmosphere like carbon monoxide, carbon dioxide, ethane, propane, methyl chloride, and methyl bromide. Relatively little is known about what controls these gases in the atmosphere despite their importance to atmospheric chemistry and climate. Undergraduate assistants will work on the project and be introduced to independent research through their work. The PI will continue visits to local middle schools to introduce students to polar science, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) as part of the project. Methane concentrations from a major portion (2 depth intervals, excluding the brittle ice-zone which is being measured at Penn State University) of the new South Pole ice core will be used to create a gas chronology by matching the new South Pole ice core record with that from the well-dated WAIS Divide ice core record. In combination with measurements made at Penn State, this will provide gas dating for the entire 50,000-year record. Correlation will be made using a simple but powerful mid-point method that has been previously demonstrated, and other methods of matching records will be explored. The intellectual merit of this work is that the gas chronology will be a fundamental component of this ice core project, and will be used by the PI and other investigators for dating records of atmospheric composition, and determining the gas age-ice age difference independently of glaciological models, which will constrain processes that affected firn densification in the past. The methane data will also provide direct stratigraphic markers of important perturbations to global biogeochemical cycles (e.g., rapid methane variations synchronous with abrupt warming and cooling in the Northern Hemisphere) that will tie other ice core gas records directly to those perturbations. A record of the total air content will also be produced as a by-product of the methane measurements and will contribute to understanding of this parameter. The broader impacts include that the work will provide a fundamental data set for the South Pole ice core project and the age scale (or variants of it) will be used by all other investigators working on gas records from the core. The project will employ an undergraduate assistant(s) in both years who will conduct an undergraduate research project which will be part of the student\u0027s senior thesis or other research paper. The project will also offer at least one research position for the Oregon State University Summer REU site program. Visits to local middle schools, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) will also be part of the project.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "AMD; LABORATORY; METHANE; ICE CORE RECORDS; Gas Chromatography; South Pole; USAP-DC", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "A High Resolution Atmospheric Methane Record from the South Pole Ice Core", "uid": "p0010102", "west": 0.0}, {"awards": "1807522 Jones, Tyler", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Mid-Holocene high-resolution water isotope time series for the WAIS Divide ice core; Seasonal temperatures in West Antarctica during the Holocene ; Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "datasets": [{"dataset_uid": "601274", "doi": "10.15784/601274", "keywords": "Antarctica; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Jones, Tyler R.; Bradley, Elizabeth; Morris, Valerie; Price, Michael; White, James; Vaughn, Bruce; Garland, Joshua", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/601274"}, {"dataset_uid": "601603", "doi": "10.15784/601603", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Seasonality; Seasonal Temperatures; Temperature; Water Isotopes; West Antarctic Ice Sheet", "people": "Jones, Tyler R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal temperatures in West Antarctica during the Holocene ", "url": "https://www.usap-dc.org/view/dataset/601603"}, {"dataset_uid": "601326", "doi": "10.15784/601326", "keywords": "Antarctica; Delta 18O; Delta Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Snow/ice; Snow/Ice; WAIS Divide Ice Core; Water Isotopes; West Antarctic Ice Sheet", "people": "Morris, Valerie; Jones, Tyler R.; Vaughn, Bruce; White, James", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Mid-Holocene high-resolution water isotope time series for the WAIS Divide ice core", "url": "https://www.usap-dc.org/view/dataset/601326"}], "date_created": "Tue, 26 May 2020 00:00:00 GMT", "description": "Ice cores contain detailed accounts of Earth\u0027s climate history. The collection of an ice core can be logistically challenging, and extraction of data from the core can be time-consuming as well as susceptible to both human and machine error. Furthermore, locked in measurements from ice cores is information that scientists have not yet found ways to recover. This project will apply techniques from information theory to ice-core data to unlock that information. The primary goal is to demonstrate that information theory can (a) identify regions of a specific ice-core record that are in need of further analysis and (b) provide some specific guidance for that analysis. A secondary goal is to demonstrate that information theory has practical and scientific utility for studies of past climate. This project aims to use information theory in two distinct ways: first, to identify regions of a core where information appears to be damaged or missing, perhaps due to human and/or machine error. In the segment of the West Antarctic Ice Sheet Divide core that is 5000-8000 years old, for instance, information-theoretic methods reveal significant levels of noise, probably due to a laboratory instrument, and something that was not visible in the raw data. This is a particularly important segment of the record, as it contains valuable clues about climatic shifts and the onset of the Holocene. Targeted re-sampling of this segment of the core and reanalysis with newer laboratory apparatus could resolve the data issues. The second way in which information theory can potentially aid in ice-core analysis is by extracting climate signals from the data--such as the accumulation rate at the core site over the period of its formation. This quantity usually requires significant time and effort to produce, but information theory could help to streamline that process. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "AMD; West Antarctic Ice Sheet; ISOTOPES; Amd/Us; USAP-DC; USA/NSF; Water Isotopes; WAIS Divide Ice Core; Deuterium; LABORATORY", "locations": "West Antarctic Ice Sheet", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Garland, Joshua; Jones, Tyler R.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Targeted resampling of deep polar ice cores using information theory", "uid": "p0010100", "west": -112.085}, {"awards": "1743643 Passchier, Sandra", "bounds_geometry": null, "dataset_titles": "Major and trace element analyses of Eocene-Oligocene marine sediments from ODP Site 696, South Orkney Microcontinent; Particle-size distributions of Eocene-Oligocene sediment from ODP Site 696, South Orkney Microcontinent", "datasets": [{"dataset_uid": "601581", "doi": "10.15784/601581", "keywords": "Antarctica; Glaciation; IODP 696; Marine Geoscience; Marine Sediments; Paleoceanography; Sediment Core Data; Weddell Sea", "people": "Light, Jennifer; Horowitz Castaldo, Josie; Lepp, Allison; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 696, South Orkney Microcontinent", "url": "https://www.usap-dc.org/view/dataset/601581"}, {"dataset_uid": "601582", "doi": "10.15784/601582", "keywords": "Antarctica; Glaciation; IODP 650; IODP 696; Paleoceanography; Provenance; Sediment Core Data; Weathering; Weddell Sea", "people": "Lepp, Allison; Li, Xiaona; Hojnacki, Victoria; Passchier, Sandra; States, Abbey", "repository": "USAP-DC", "science_program": null, "title": "Major and trace element analyses of Eocene-Oligocene marine sediments from ODP Site 696, South Orkney Microcontinent", "url": "https://www.usap-dc.org/view/dataset/601582"}], "date_created": "Tue, 26 May 2020 00:00:00 GMT", "description": "Abstract (non-technical) Sea level rise is a problem of global importance and it is increasingly affecting the tens of millions of Americans living along coastlines. The melting of glaciers in mountain areas worldwide in response to global warming is a major cause of sea level rise and increases in nuisance coastal flooding. However, the world\u0027s largest land-based ice sheets are situated in the Polar Regions and their response under continued warming is very difficult to predict. One reason for this uncertainty is a lack of observations of ice behavior and melt under conditions of warming, as it is a relatively new global climate state lasting only a few generations so far. Researchers will investigate ice growth on Antarctica under past warm conditions using geological archives embedded in the layers of sand and mud under the sea floor near Antarctica. By peeling back at the layers beneath the seafloor investigators can read the history book of past events affecting the ice sheet. The Antarctic continent on the South Pole, carries the largest ice mass in the world. The investigator\u0027s findings will substantially improve scientists understanding of the response of ice sheets to global warming and its effect on sea level rise. Abstract (technical) The melt of land based ice is raising global sea levels with at present only minor contributions from polar ice sheets. However, the future role of polar ice sheets in climate change is one of the most critical uncertainties in predictions of sea level rise around the globe. The respective roles of oceanic and atmospheric greenhouse forcing on ice sheets are poorly addressed with recent measurements of polar climatology, because of the extreme rise in greenhouse forcing the earth is experiencing at this time. Data on the evolution of the West Antarctic ice sheet is particularly sparse. To address the data gap, researchers will reconstruct the timing and spatial distribution of Antarctic ice growth through the last greenhouse to icehouse climate transition around 37 to 33 Ma. They will collect sedimentological and geochemical data on core samples from a high-latitude paleoarchive to trace the shutdown of the chemical weathering system, the onset of glacial erosion, ice rafting, and sea ice development, as East and West Antarctic ice sheets coalesced in the Weddell Sea sector. Their findings will lead to profound increases in the understanding of the role of greenhouse forcing in ice sheet development and its effect on the global climate system. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; SEDIMENTS; LABORATORY; USA/NSF; USAP-DC; Weddell Sea", "locations": "Weddell Sea", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Timing and Spatial Distribution of Antarctic Ice Sheet Growth and Sea-ice Formation across the Eocene-Oligocene Transition", "uid": "p0010101", "west": null}, {"awards": "1419979 Severinghaus, Jeffrey", "bounds_geometry": "POLYGON((166.65 -78.62,166.654 -78.62,166.658 -78.62,166.662 -78.62,166.666 -78.62,166.67 -78.62,166.674 -78.62,166.678 -78.62,166.682 -78.62,166.686 -78.62,166.69 -78.62,166.69 -78.6205,166.69 -78.621,166.69 -78.6215,166.69 -78.622,166.69 -78.6225,166.69 -78.623,166.69 -78.6235,166.69 -78.624,166.69 -78.6245,166.69 -78.625,166.686 -78.625,166.682 -78.625,166.678 -78.625,166.674 -78.625,166.67 -78.625,166.666 -78.625,166.662 -78.625,166.658 -78.625,166.654 -78.625,166.65 -78.625,166.65 -78.6245,166.65 -78.624,166.65 -78.6235,166.65 -78.623,166.65 -78.6225,166.65 -78.622,166.65 -78.6215,166.65 -78.621,166.65 -78.6205,166.65 -78.62))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 18 May 2020 00:00:00 GMT", "description": "The PIs will design and build a new rapid access ice drill (RAID) for use in Antarctica. This drill will have the ability to rapidly drill through ice up to 3300 m thick and then collect samples of the ice, ice-sheet bed interface, and bedrock substrate below. This drilling technology will provide a new way to obtain in situ measurements and samples for interdisciplinary studies in geology, glaciology, paleoclimatology, microbiology, and astrophysics. The RAID drilling platform will give the scientific community access to records of geologic and climatic change on a variety of timescales, from the billion-year rock record to thousand-year ice and climate histories. Successful development of the RAID system will provide a research tool that is currently unavailable. Development of this platform will enable scientists to address critical questions about the deep interface between the Antarctic ice sheets and the substrate below. Development of RAID will provide a way to address many of the unknowns associated with general stability of the Antarctic ice sheets in the face of changing climate and sea level rise. The scientific rationale for RAID was reviewed in a previous proposal (Goodge 1242027). The PIs were granted ?Phase I? funding to develop a more detailed conceptual design for the RAID drill that would provide a better understanding of construction costs as well as operation and maintenance costs for RAID once it is constructed. Phase I support also allowed the PIs to work with the research community to develop more detailed science requirements for the drill. This proposal requests continued funding (Phase II) to construct, assemble and test the RAID drilling platform, through to staging it in Antarctic for future scientific operations.", "east": 166.69, "geometry": "POINT(166.67 -78.6225)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "WAIS Divide Ice Core; ICE CORE AIR BUBBLES; FIELD INVESTIGATION; USAP-DC; Minna Bluff", "locations": "Minna Bluff", "north": -78.62, "nsf_funding_programs": "Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -78.625, "title": "Collaborative Research: Phase 2 Development of A Rapid Access Ice Drilling (RAID) Platform for Research in Antarctica", "uid": "p0010099", "west": 166.65}, {"awards": "1142035 Obbard, Rachel; 1142167 Pettit, Erin", "bounds_geometry": "POLYGON((-112.3 -79.2,-112.2 -79.2,-112.1 -79.2,-112 -79.2,-111.9 -79.2,-111.8 -79.2,-111.7 -79.2,-111.6 -79.2,-111.5 -79.2,-111.4 -79.2,-111.3 -79.2,-111.3 -79.23,-111.3 -79.26,-111.3 -79.29,-111.3 -79.32,-111.3 -79.35,-111.3 -79.38,-111.3 -79.41,-111.3 -79.44,-111.3 -79.47,-111.3 -79.5,-111.4 -79.5,-111.5 -79.5,-111.6 -79.5,-111.7 -79.5,-111.8 -79.5,-111.9 -79.5,-112 -79.5,-112.1 -79.5,-112.2 -79.5,-112.3 -79.5,-112.3 -79.47,-112.3 -79.44,-112.3 -79.41,-112.3 -79.38,-112.3 -79.35,-112.3 -79.32,-112.3 -79.29,-112.3 -79.26,-112.3 -79.23,-112.3 -79.2))", "dataset_titles": "ApRES Firn Density Study; ApRES Vertical Strain Study; GPS Horizontal Strain Network; South Pole (SPICEcore) Borehole Deformation; WAIS Divide Borehole Deformation", "datasets": [{"dataset_uid": "601314", "doi": "10.15784/601314", "keywords": "Acoustic Televiewer; Anisotropy; Antarctica; Borehole Logging; Deformation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Flow; WAIS Divide; WAIS Divide Ice Core", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Borehole Deformation", "url": "https://www.usap-dc.org/view/dataset/601314"}, {"dataset_uid": "601322", "doi": "10.15784/601322", "keywords": "Antarctica; Firn; Firn Density; Glaciology; Ice Penetrating Radar; Phase Sensitive Radar; Radar; Snow/ice; Snow/Ice; WAIS Divide", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "ApRES Firn Density Study", "url": "https://www.usap-dc.org/view/dataset/601322"}, {"dataset_uid": "601323", "doi": "10.15784/601323", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Penetrating Radar; Ice Strain; Phase Sensitive Radar; Radar; Snow/ice; Snow/Ice; WAIS Divide", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "ApRES Vertical Strain Study", "url": "https://www.usap-dc.org/view/dataset/601323"}, {"dataset_uid": "200141", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "GPS Horizontal Strain Network", "url": ""}, {"dataset_uid": "601315", "doi": "10.15784/601315", "keywords": "Acoustic Televiewer; Anisotropy; Antarctica; Borehole Logging; Deformation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Flow; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPICEcore) Borehole Deformation", "url": "https://www.usap-dc.org/view/dataset/601315"}], "date_created": "Fri, 15 May 2020 00:00:00 GMT", "description": "1142167/Pettit This award supports a project to develop a better understanding of the relation between ice microstructure, impurities, and ice flow and their connection to climate history for the West Antarctic Ice Sheet (WAIS) ice core site. This work builds on several ongoing studies at Siple Dome in West Antarctica and Dome C in East Antarctica. It is well known that the microstructure of ice evolves with depth and time in an ice sheet. This evolution of microstructure depends on the ice flow field, temperature, and impurity content. The ice flow field, in turn, depends on microstructure, leading to feedbacks that create layered variation in microstructure that relates to climate and flow history. The research proposed here focuses on developing a better understanding of: 1) how ice microstructure evolves with time and stress in an ice sheet and how that relates to impurity content, temperature, and strain rate; 2) how variations in ice microstructure and impurity content affect ice flow patterns near ice divides (on both small (1cm to 1m) and large (1m to 100km) scales); and 3) in what ways is the spatial variability of ice microstructure and its effect on ice flow important for interpretation of climate history in the WAIS Divide ice core. The study will integrate existing ice core and borehole data with a detailed study of ice microstructure using Electron Backscatter Diffraction (EBSD) techniques and measurements of borehole deformation through time using Acoustic Televiewers. This will be the first study to combine these two novel techniques for studying the relation between microstructure and deformation and it will build on other data being collected as part of other WAIS Divide borehole logging projects (e.g. sonic velocity, optical dust logging, temperature and other measurements on the ice core including fabric measurements from thin section analyses as well as studies of ice chemistry and stable isotopes. The intellectual merit of the work is that it will improve interpretation of ice core data (especially information on past accumulation) and overall understanding of ice flow. The broader impacts are that the work will ultimately contribute to a better interpretation of ice core records for both paleoclimate studies and for ice flow history, both of which connect to the broader questions of the role of ice in the climate system. The work will also advance the careers of two early-career female scientists, including one with a hearing impairment disability. This project will support a PhD student at the UAF and provide research and field experience for two or three undergraduates at Dartmouth. The PIs plan to include a teacher on their field team and collaborate with UAF\u0027s \"From STEM to STEAM\" toward enhancing the connection between art and science.", "east": -111.3, "geometry": "POINT(-111.8 -79.35)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; GLACIERS/ICE SHEETS; WAIS Divide; ICE CORE RECORDS; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; Radar", "locations": "WAIS Divide", "north": -79.2, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Obbard, Rachel", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "UNAVCO; USAP-DC", "science_programs": "WAIS Divide Ice Core; SPICEcore", "south": -79.5, "title": "Collaborative Research: VeLveT Ice - eVoLution of Fabric and Texture in Ice at WAIS Divide, West Antarctica", "uid": "p0010098", "west": -112.3}, {"awards": "9319877 Finn, Carol; 9319854 Bell, Robin; 9319369 Blankenship, Donald", "bounds_geometry": "POLYGON((-155 -77.5,-150 -77.5,-145 -77.5,-140 -77.5,-135 -77.5,-130 -77.5,-125 -77.5,-120 -77.5,-115 -77.5,-110 -77.5,-105 -77.5,-105 -78.2,-105 -78.9,-105 -79.6,-105 -80.3,-105 -81,-105 -81.7,-105 -82.4,-105 -83.1,-105 -83.8,-105 -84.5,-110 -84.5,-115 -84.5,-120 -84.5,-125 -84.5,-130 -84.5,-135 -84.5,-140 -84.5,-145 -84.5,-150 -84.5,-155 -84.5,-155 -83.8,-155 -83.1,-155 -82.4,-155 -81.7,-155 -81,-155 -80.3,-155 -79.6,-155 -78.9,-155 -78.2,-155 -77.5))", "dataset_titles": "SOAR-BSB Airborne gravity data for the CASERTZ/WAIS project; SOAR-IRE airborne gravity data for the CASERTZ/WAIS project; SOAR-TKD airborne gravity data for the CASERTZ/WAIS project; SOAR-WAZ Airborne gravity data for the CASERTZ/WAIS project", "datasets": [{"dataset_uid": "601288", "doi": "10.15784/601288", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Solid Earth; WAIS", "people": "Bell, Robin; Arko, Robert A.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-BSB Airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601288"}, {"dataset_uid": "601289", "doi": "10.15784/601289", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Solid Earth; WAIS", "people": "Bell, Robin; Arko, Robert A.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-TKD airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601289"}, {"dataset_uid": "601290", "doi": "10.15784/601290", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Solid Earth; WAIS", "people": "Bell, Robin; Arko, Robert A.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-IRE airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601290"}, {"dataset_uid": "601291", "doi": "10.15784/601291", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Solid Earth; WAIS", "people": "Arko, Robert A.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WAZ Airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601291"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "Blankenship: 9319369 Bell: 9319854 Behrendt: 9319877 This award supports a project to conduct an integrated geophysical survey over a large portion of the West Antarctic Ice Sheet (WAIS) toward an understanding of the dynamic behavior of the ice sheet and the nature of the lithosphere beneath the ice sheet. West Antarctica is characterized by two kinds of the Earth s most dynamic systems, a continental rift (the West Antarctic Rift System) and a marine based ice sheet (the WAIS). Active continental rift systems, caused by divergent plate motions, result in thinned continental crust. Associated with the thin crust are fault-bounded sedimentary basins, active volcanism, and elevated heat flow. Marine ice sheets are characterized by rapidly moving streams of ice, penetrating and draining a slowly moving ice reservoir. Evidence left by past marine ice sheets indicates that they may have a strongly non- linear response to long-term climate change which results in massive and rapid discharges of ice. Understanding the evolution of the ice stream system and its interaction with the interior ice is the key to understanding this non-linear response. Subglacial geology and ice dynamics are generally studied in isolation, but evidence is mounting that the behavior of the West Antarctic ice streams may be closely linked to the nature of the underlying West Antarctic rift system. The fast moving ice streams appear to glide on a lubricating layer of water-saturated till. This till requires easily eroded sediment and a source of water, both of which may be controlled by the geology of the rift system; the sediments from the fault-bounded basins and the water from the elevated heat flux associated with active lithospheric extension. This project represents an interdisciplinary aerogeophysical study to characterize the lithosphere of the West Antarctic rift system beneath critical regions of the WAIS. The objective is to determine the effects of the rift architect ure, as manifested by the distribution of sedimentary basins and volcanic constructs, on the ice stream system. The research tool is a unique geophysical aircraft with laser altimetry, ice penetrating radar, aerogravity, and aeromagnetic systems integrated with a high precision kinematic GPS navigation system. It is capable of imaging both the surface and bed of the ice sheet while simultaneously measuring the gravity and magnetic signature of the subglacial lithosphere. Work to be done under this award will build on work already completed in the southern sector of central West Antarctica and it will focus on the region of the Byrd Subglacial Basin and Ice Stream D. The ice sheet in these regions is completely covered by satellite imagery and so this project will be integrated with remote sensing studies of the ice stream. The changing dynamics of Ice Stream D, as with other West Antarctic ice streams, seem to be correlated with changes in the morphological provinces of the underlying rift system. The experimental targets proceed from the divide of the interior ice, downstream through the onset of streaming to the trunk of Ice Stream D. This study will be coordinated with surface glaciological investigations of Ice Stream D and will be used to guide cooperative over-snow seismic investigations of the central West Antarctic rift system. The data will also be used to select a site for future deep ice coring along the crest of the WAIS. These data represent baseline data for long term global change monitoring work and represent crucial boundary conditions for ice sheet modeling efforts.", "east": -105.0, "geometry": "POINT(-130 -81)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": true, "keywords": "USAP-DC; MAGNETIC FIELD; GRAVITY FIELD; Antarctica; GLACIERS/ICE SHEETS; Marie Byrd Land; Airborne Gravity", "locations": "Marie Byrd Land; Antarctica", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Blankenship, Donald D.; Finn, C. A.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.5, "title": "Collaborative Research: Lithospheric Controls on the Behavior of the West Antarctic Ice Sheet: Corridor Aerogeophysics of Eastern Ross Transect Zone", "uid": "p0010094", "west": -155.0}, {"awards": "9615282 Siddoway, Christine; 9615281 Luyendyk, Bruce", "bounds_geometry": "POLYGON((-170 -76,-166.5 -76,-163 -76,-159.5 -76,-156 -76,-152.5 -76,-149 -76,-145.5 -76,-142 -76,-138.5 -76,-135 -76,-135 -76.8,-135 -77.6,-135 -78.4,-135 -79.2,-135 -80,-135 -80.8,-135 -81.6,-135 -82.4,-135 -83.2,-135 -84,-138.5 -84,-142 -84,-145.5 -84,-149 -84,-152.5 -84,-156 -84,-159.5 -84,-163 -84,-166.5 -84,-170 -84,-170 -83.2,-170 -82.4,-170 -81.6,-170 -80.8,-170 -80,-170 -79.2,-170 -78.4,-170 -77.6,-170 -76.8,-170 -76))", "dataset_titles": "Bedrock sample data, Ford Ranges region (Marie Byrd Land); SOAR-WMB Airborne gravity data", "datasets": [{"dataset_uid": "601829", "doi": "10.15784/601829", "keywords": "Antarctica; Cryosphere; Gondwana; Marie Byrd Land; Migmatite", "people": "Siddoway, Christine", "repository": "USAP-DC", "science_program": null, "title": "Bedrock sample data, Ford Ranges region (Marie Byrd Land)", "url": "https://www.usap-dc.org/view/dataset/601829"}, {"dataset_uid": "601294", "doi": "10.15784/601294", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Ross Sea; Solid Earth", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WMB Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601294"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "OPP 9615281 Luyendyk OPP 9615282 Siddoway Abstract This award supports a collaborative project that combines air and ground geological-geophysical investigations to understand the tectonic and geological development of the boundary between the Ross Sea Rift and the Marie Byrd Land (MBL) volcanic province. The project will determine the Cenozoic tectonic history of the region and whether Neogene structures that localized outlet glacier flow developed within the context of Cenozoic rifting on the eastern Ross Embayment margin, or within the volcanic province in MBL. The geological structure at the boundary between the Ross Embayment and western MBL may be a result of: 1) Cenozoic extension on the eastern shoulder of the Ross Sea rift; 2) uplift and crustal extension related to Neogene mantle plume activity in western MBL; or a combination of the two. Faulting and volcanism, mountain uplift, and glacier downcutting appear to now be active in western MBL, where generally East-to-West-flowing outlet glaciers incise Paleozoic and Mesozoic bedrock, and deglaciated summits indicate a previous North-South glacial flow direction. This study requires data collection using SOAR (Support Office for Aerogeophysical Research, a facility supported by Office of Polar Programs which utilizes high precision differential GPS to support a laser altimeter, ice-penetrating radar, a towed proton magnetometer, and a Bell BGM-3 gravimeter). This survey requires data for 37,000 square kilometers using 5.3 kilometer line spacing with 15.6 kilometer tie lines, and 86,000 square kilometers using a grid of 10.6 by 10.6 kilometer spacing. Data will be acquired over several key features in the region including, among other, the eastern edge of the Ross Sea rift, over ice stream OEO, the transition from the Edward VII Peninsula plateau to the Ford Ranges, the continuation to the east of a gravity high known from previous reconnaissance mapping over the Fosdick Metamorphic Complex, an d the extent of the high-amplitude magnetic anomalies (volcanic centers?) detected southeast of the northern Ford Ranges by other investigators. SOAR products will include glaciology data useful for studying driving stresses, glacial flow and mass balance in the West Antarctic Ice Sheet (WAIS). The ground program is centered on the southern Ford Ranges. Geologic field mapping will focus on small scale brittle structures for regional kinematic interpretation, on glaciated surfaces and deposits, and on datable volcanic rocks for geochronologic control. The relative significance of fault and joint sets, the timing relationships between them, and the probable context of their formation will also be determined. Exposure ages will be determined for erosion surfaces and moraines. Interpretation of potential field data will be aided by on ground sampling for magnetic properties and density as well as ground based gravity measurements. Oriented samples will be taken for paleomagnetic studies. Combined airborne and ground investigations will obtain basic data for describing the geology and structure at the eastern boundary of the Ross Embayment both in outcrop and ice covered areas, and may be used to distinguish between Ross Sea rift- related structural activity from uplift and faulting on the perimeter of the MBL dome and volcanic province. Outcrop geology and structure will be extrapolated with the aerogeophysical data to infer the geology that resides beneath the WAIS. The new knowledge of Neogene tectonics in western MBL will contribute to a comprehensive model for the Cenozoic Ross rift and to understanding of the extent of plume activity in MBL. Both are important for determining the influence of Neogene tectonics on the ice streams and WAIS.", "east": -135.0, "geometry": "POINT(-152.5 -80)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e LGS", "is_usap_dc": true, "keywords": "GRAVITY; USAP-DC; Ross Sea; TECTONICS; Marie Byrd Land", "locations": "Ross Sea; Marie Byrd Land", "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Luyendyk, Bruce P.; Siddoway, Christine", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.0, "title": "Air-Ground Study of Tectonics at the Boundary Between the Eastern Ross Embayment and Western Marie Byrd Land, Antarctica: Basement Geology and Structure", "uid": "p0010096", "west": -170.0}, {"awards": "9978236 Bell, Robin", "bounds_geometry": "POLYGON((101 -75.5,101.9 -75.5,102.8 -75.5,103.7 -75.5,104.6 -75.5,105.5 -75.5,106.4 -75.5,107.3 -75.5,108.2 -75.5,109.1 -75.5,110 -75.5,110 -75.85,110 -76.2,110 -76.55,110 -76.9,110 -77.25,110 -77.6,110 -77.95,110 -78.3,110 -78.65,110 -79,109.1 -79,108.2 -79,107.3 -79,106.4 -79,105.5 -79,104.6 -79,103.7 -79,102.8 -79,101.9 -79,101 -79,101 -78.65,101 -78.3,101 -77.95,101 -77.6,101 -77.25,101 -76.9,101 -76.55,101 -76.2,101 -75.85,101 -75.5))", "dataset_titles": "SOAR-Lake Vostok Survey airborne radar data; SOAR-Lake Vostok Survey bed elevation data; SOAR-Lake Vostok Survey Gravity data; SOAR-Lake Vostok Survey ice thickness data; SOAR-Lake Vostok survey magnetic anomaly data; SOAR-Lake Vostok Survey surface elevation data", "datasets": [{"dataset_uid": "601296", "doi": " 10.1594/IEDA/306564", "keywords": "Airborne Magnetic; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Lake Vostok; Magnetic; Magnetic Anomaly; Magnetometer; Potential Field; SOAR; Solid Earth", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok survey magnetic anomaly data", "url": "https://www.usap-dc.org/view/dataset/601296"}, {"dataset_uid": "601299", "doi": "10.1594/IEDA/306565", "keywords": "Airborne Laser Altimeters; Airborne Laser Altimetry; Airborne Radar; Airplane; Antarctica; Bed Elevation; Bedrock Elevation; Digital Elevation Model; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Lake Vostok; Radar; Radar Echo Sounder; SOAR", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey bed elevation data", "url": "https://www.usap-dc.org/view/dataset/601299"}, {"dataset_uid": "601300", "doi": "10.1594/IEDA/306568", "keywords": "Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Navigation; Radar; SOAR; Subglacial Lakes", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey airborne radar data", "url": "https://www.usap-dc.org/view/dataset/601300"}, {"dataset_uid": "601295", "doi": "10.1594/IEDA/306563", "keywords": "Airborne Gravity; Airplane; Antarctica; East Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Lake Vostok; Potential Field; Solid Earth", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey Gravity data", "url": "https://www.usap-dc.org/view/dataset/601295"}, {"dataset_uid": "601298", "doi": "10.1594/IEDA/306566", "keywords": "Airborne Altimetry; Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Sheet Elevation; Ice Surface; Lake Vostok; Radar Echo Sounder; SOAR; Surface Elevation", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey surface elevation data", "url": "https://www.usap-dc.org/view/dataset/601298"}, {"dataset_uid": "601297", "doi": "10.1594/IEDA/306567", "keywords": "Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Sheet; Ice Stratigraphy; Ice Thickness; Ice Thickness Distribution; Lake Vostok; Radar; Radar Altimetry; Radar Echo Sounder; SOAR; Subglacial Lake", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey ice thickness data", "url": "https://www.usap-dc.org/view/dataset/601297"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "9978236 Bell Abstract This award, provided by the Office of Polar Programs under the Life in Extreme Environments (LExEn) Program, supports a geophysical study of Lake Vostok, a large lake beneath the East Antarctic Ice Sheet. Subglacial ecosystems, in particular subglacial lake ecosystems are extreme oligotrophic environments. These environments, and the ecosystems which may exist within them, should provide key insights into a range of fundamental questions about the development of Earth and other bodies in the Solar System including: 1) the processes associated with rapid evolutionary radiation after the extensive Neoproterozoic glaciations; 2) the overall carbon cycle through glacial and interglacial periods; and 3) the possible adaptations organisms may require to thrive in environments such as on Europa, the ice covered moon of Jupiter. Over 70 subglacial lakes have been identified beneath the 3-4 kilometer thick ice of Antarctica. One lake, Lake Vostok, is sufficiently large to be clearly identified from space with satellite altimetry. Lake Vostok is similar to Lake Ontario in area but with a much larger volume including measured water depths of 600 meters. The overlying ice sheet is acting as a conveyer belt continually delivering new water, nutrients, gas hydrates, sediments and microbes as the ice sheet flows across the lake. The goal of this program is to determine the fundamental boundary conditions for this subglacial lake as an essential first step toward understanding the physical processes within the lake. An aerogeophysical survey over the lake and into the surrounding regions will be acquired to meet this goal. This data set includes gravity, magnetic, laser altimetry and ice penetrating radar data and will be used to compile a basic set of ice surface elevation, subglacial topography, gravity and magnetic anomaly maps. Potential field methods widely used in the oil industry will be modified to estimate the subglacial topography from gravity data where the ice penetrating radar will be unable to recover the depth of the lake. A similar method can be modified to estimate the thickness of the sediments beneath the lake from magnetic data. These methods will be tested and applied to subglacial lakes near South Pole prior to the Lake Vostok field campaign and will provide valuable comparisons to the planned survey. Once the methods have been adjusted for the Lake Vostok application, maps of the water cavity and sediment thickness beneath the lake will be produced. These maps will become tools to explore the geologic origin of the lake. The two endmember models are, first, that the lake is an active tectonic rift such as Lake Baikal and, second, the lake is the result of glacial scouring. The distinct characteristics of an extensional rift can be easily identified with our aerogeophysical survey. The geological interpretation of the airborne geophysical survey will provide the first geological constraints of the interior of the East Antarctic continent based on modern data. In addition, the underlying geology will influence the ecosystem within the lake. One of the critical issues for the ecosystem within the lake will be the flux of nutrients. A preliminary estimation of the regions of freezing and melting based on the distance between distinctive internal layers observed on the radar data will be made. These basic boundary conditions will provide guidance for a potential international effort aimed at in situ exploration of the lake and improve the understanding of East Antarctic geologic structures.", "east": 110.0, "geometry": "POINT(105.5 -77.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e MAGNETOMETERS \u003e MGF; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e AIRGRAV", "is_usap_dc": true, "keywords": "Gravity; GLACIERS/ICE SHEETS; East Antarctica; USAP-DC; Lake Vostok; Airborne Radar; Subglacial Lake; MAGNETIC FIELD; GRAVITY", "locations": "East Antarctica; Lake Vostok", "north": -75.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Studinger, Michael S.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Work\r\n", "uid": "p0010097", "west": 101.0}, {"awards": "9615704 Bell, Robin; 9615832 Blankenship, Donald", "bounds_geometry": "POLYGON((-180 -74,-176 -74,-172 -74,-168 -74,-164 -74,-160 -74,-156 -74,-152 -74,-148 -74,-144 -74,-140 -74,-140 -75.6,-140 -77.2,-140 -78.8,-140 -80.4,-140 -82,-140 -83.6,-140 -85.2,-140 -86.8,-140 -88.4,-140 -90,-144 -90,-148 -90,-152 -90,-156 -90,-160 -90,-164 -90,-168 -90,-172 -90,-176 -90,180 -90,174 -90,168 -90,162 -90,156 -90,150 -90,144 -90,138 -90,132 -90,126 -90,120 -90,120 -88.4,120 -86.8,120 -85.2,120 -83.6,120 -82,120 -80.4,120 -78.8,120 -77.2,120 -75.6,120 -74,126 -74,132 -74,138 -74,144 -74,150 -74,156 -74,162 -74,168 -74,174 -74,-180 -74))", "dataset_titles": "SOAR-PPT Airborne gravity data; SOAR-WLK Airborne gravity data", "datasets": [{"dataset_uid": "601293", "doi": "10.15784/601293", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Potential Field; Solid Earth; Transantarctic Mountains", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WLK Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601293"}, {"dataset_uid": "601292", "doi": "10.15784/601292", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Potential Field; Solid Earth; Transantarctic Mountains", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-PPT Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601292"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "Bell and Buck: OPP 9615704 Blankenship: OPP 9615832 Abstract Continental extension produces a great variety of structures from the linear narrow rifts of the East African Rift to the diffuse extension of the Basin and Range Province of the Western U.S. Rift shoulder uplift varies dramatically between rift flanks. The cause of variable rift width and crustal thinning is fairly well explained by variable initial heat flow and crustal thickness. Mechanical stretching of the lithosphere has been linked to rift shoulder uplift but the cause of variable rift flank uplift remains poorly understood. The Transantarctic Mountains (TAM) are an extreme example of rift flank uplift, extending over 3500 km across Antarctica and reaching elevations up to 4500 m and thus constitute a unique feature of EarthOs crust. The range was formed in the extensional environment associated with the Mesozoic and Cenozoic breakup of Gondwanaland. Geological and geophysical work has shown that the TAM developed along the long-lived lithospheric boundary between East and West Antarctica reactivated by a complex history of extensional and translational microplate motions. The TAM are not uniform along strike. Along the OWilkes FrontO, the northern segment of the rift extends from North Victoria Land to Byrd Glacier. The Wilkes Front architecture consists of (1) thin, extended crust forming the Victoria Land Basin in the Ross Sea, (2) the TAM rift shoulder, and (3) a long-wavelength down- ward forming the Wilkes Basin. Contrasting structures are mapped along the OPensacola/PoleO Front, the southern segment of the rift extending from the Nimrod Glacier to the Pensacola Mountains. Along this southern section no rift basin has been mapped to date and the down-ward along the East Antarctic, or ObacksideO, edge of the mountains is less pronounced. A flexural model linking the extension in the Ross Sea to the formation of both the mountains and the Wilkes Basin has been considered as a me chanism for uplift of the entire mountain range. The variability in fundamental architecture along the TAM indicates that neither a single event nor a sequence of identical events produced the rift flank uplift. The observation of variable architecture suggests complex mechanisms and possibly a fundamental limitation in maximum sustainable rift flank elevation. The motivation for studying the TAM is to try to understand the geodynamics of this extreme elevation rift flank. Are the geodynamics of the area unique, or does the history of glaciation and related erosion contribute to the extreme uplift? With the existing data sets it is difficult to confidently constrain the geological architecture across representative sections of the TAM. Any effort to refine geodynamic mechanisms requires this basic understanding of the TAM architecture. The goal of this project is to (1) constrain the architecture of the rift system as well as the distribution and structure of sedimentary basins, glacial erosion and mafic igneous rocks surrounding the rift flank by acquiring three long wavelength geophysical transects with integrated gravity, magnetics, ice- penetrating radar, and ice surface measurements, (2) quantify the contribution of various geodynamic mechanisms to understand the geological conditions which can lead to extreme rift flank uplift, and (3) use the improved understanding of architecture and geophysical data to test geodynamic models in order to improve our understanding both of the TAM geodynamics and the general problem of the geodynamics of rift flank uplift worldwide. This project will allow development of a generalized framework for understanding the development of rift flank uplift as well as address the question of the specific geodynamic evolution of the TAM.", "east": -140.0, "geometry": "POINT(170 -82)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": true, "keywords": "USAP-DC; Transantarctic Mountains; GRAVITY FIELD; TECTONICS", "locations": "Transantarctic Mountains", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Buck, W. Roger; Blankenship, Donald D.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Contrasting Architecture and Dynamics of the Transantarctic Mountains", "uid": "p0010095", "west": 120.0}, {"awards": "1443470 Aydin, Murat", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "South Pole ice core (SPC14) discrete methane data; SP19 Gas Chronology; SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "datasets": [{"dataset_uid": "601270", "doi": "10.15784/601270", "keywords": "Antarctica", "people": "Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601270"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Aydin, Murat; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}], "date_created": "Thu, 26 Mar 2020 00:00:00 GMT", "description": "In the past, Earth\u0027s climate underwent dramatic changes that influenced physical, chemical, geological, and biological processes on a global scale. Such changes left an imprint in Earth\u0027s atmosphere, as shown by the variability in abundances of trace gases like carbon dioxide and methane. In return, changes in the atmospheric trace gas composition affected Earth\u0027s climate. Studying compositional variations of the past atmosphere helps us understand the history of interactions between global biogeochemical cycles and Earth?s climate. The most reliable information on past atmospheric composition comes from analysis of air entrapped in polar ice cores. This project aims to generate ice-core records of relatively short-lived, very-low-abundance trace gases to determine the range of past variability in their atmospheric levels and investigate the changes in global biogeochemical cycles that caused this variability. This project measures three such gases: carbonyl sulfide, methyl chloride, and methyl bromide. Changes in carbonyl sulfide can indicate changes in primary productivity and photosynthetic update of carbon dioxide. Changes in methyl chloride and methyl bromide significantly impact natural variability in stratospheric ozone. In addition, the processes that control atmospheric levels of methyl chloride and methyl bromide are shared with those controlling levels of atmospheric methane. The measurements will be made in the new ice core from the South Pole, which is expected to provide a 40,000-year record. The primary focus of this project is to develop high-quality trace gas records for the entire Holocene period (the past 11,000 years), with additional, more exploratory measurements from the last glacial period including the period from 29,000-36,000 years ago when there were large changes in atmospheric methane. Due to the cold temperatures of the South Pole ice, the proposed carbonyl sulfide measurements are expected to provide a direct measure of the past atmospheric variability of this gas without the large hydrolysis corrections that are necessary for interpretation of measurements from ice cores in warmer settings. Furthermore, we will test the expectation that contemporaneous measurements from the last glacial period in the deep West Antarctic Ice Sheet Divide ice core will not require hydrolysis loss corrections. With respect to methyl chloride, we aim to verify and improve the existing Holocene atmospheric history from the Taylor Dome ice core in Antarctica. The higher resolution of our measurements compared with those from Taylor Dome will allow us to derive a more statistically significant relationship between methyl chloride and methane. With respect to methyl bromide, we plan to extend the existing 2,000-year database to 11,000 years. Together, the methyl bromide and methyl chloride records will provide strong measurement-based constraints on the natural variability of stratospheric halogens during the Holocene period. In addition, the methyl bromide record will provide insight into the correlation between methyl chloride and methane during the Holocene period due to common sources and sinks.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; CARBONYL SULFIDE; HALOCARBONS AND HALOGENS; TRACE GASES/TRACE SPECIES; Antarctic; USAP-DC", "locations": "Antarctic", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Carbonyl Sulfide, Methyl Chloride, and Methyl Bromide Measurements in the New Intermediate-depth South Pole Ice Core", "uid": "p0010089", "west": -180.0}, {"awards": "1643715 Moussavi, Mahsa Sadat; 1643733 Trusel, Luke", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Supraglacial Lakes in Antarctica", "datasets": [{"dataset_uid": "601401", "doi": "10.15784/601401", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Landsat-8; Satellite Imagery; Supraglacial Lake", "people": "Halberstadt, Anna Ruth; Moussavi, Mahsa; Pope, Allen; Trusel, Luke; Abdalati, Waleed", "repository": "USAP-DC", "science_program": null, "title": "Supraglacial Lakes in Antarctica", "url": "https://www.usap-dc.org/view/dataset/601401"}], "date_created": "Mon, 16 Mar 2020 00:00:00 GMT", "description": "Melting of snow and ice at the surface of the Antarctic ice sheet can lead to the formation of meltwater lakes, an important precursor to ice-shelf collapse and accelerated ice-sheet mass loss. Understanding the present state of Antarctic surface melt provides a baseline to gauge how quickly melt impacts could evolve in the future and to reduce uncertainties in estimates of future sea-level rise. This project will use a suite of complimentary measurements from Earth-observing satellites, ground observations, and numerical climate and ice-shelf models to enhance understanding of surface melt and lakes, as well as the processes linking these systems. The project directly supports the scientific training of a postdoctoral associate and several undergraduate researchers. In addition, it will promote public scientific literacy and the broadening of quantitative skills for high-school students through the development and implementation of an educational unit in a partnership with an education and outreach expert and two high school teachers. Accurate prediction of sea-level contributions from Antarctica critically requires understanding current melting and supraglacial lake conditions. This project will quantify Antarctic surface melt and supraglacial lakes, and the linkages between the two phenomena. Scatterometer data will enable generation of a 19-year multi-sensor melt time series. Synthetic aperture radar data will document melt conditions across all Antarctic ice shelves at the highest spatial resolution to date (40 m). Multispectral satellite imagery will be used to delineate and measure the depth of supraglacial lakes--for the first time studying the spatial and temporal variations of Antarctic supraglacial lakes. Melt and lake observations will be compared to identify agreement and disagreement. Melt observations will be used to evaluate biases in a widely used, reanalysis-driven, regional climate model. This model will then be used to examine climatic and glaciological variables associated with supraglacial lakes. Finally, in situ observations and climate model output will drive a numerical model that simulates the entire lifecycle of surface melt and possible subsequent lake formation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Supraglacial Lake; ICE SHEETS; Satellite Imagery; LANDSAT; Antarctica; USAP-DC; AMD; USA/NSF; SENTINEL-2A", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Moussavi, Mahsa; Pope, Allen; Trusel, Luke", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SENTINEL-2 \u003e SENTINEL-2A", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Water on the Antarctic Ice Sheet: Quantifying Surface Melt and Mapping Supraglacial Lakes", "uid": "p0010088", "west": -180.0}, {"awards": "1643864 Talghader, Joseph", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": " Automated c-axis stage images of WDC-06A 420 vertical thin section from WAIS Divide, Antarctica", "datasets": [{"dataset_uid": "601254", "doi": "10.15784/601254", "keywords": "Antarctica; C-axis; Ice; Microscopy; Thin Sections", "people": "Talghader, Joseph; Mah, Merlin", "repository": "USAP-DC", "science_program": null, "title": " Automated c-axis stage images of WDC-06A 420 vertical thin section from WAIS Divide, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601254"}], "date_created": "Sat, 08 Feb 2020 00:00:00 GMT", "description": "Part I: Nontechnical One of the most interesting historical records that science can provide is contained in the ice of Antarctica. Layer by layer over hundreds of thousands of years, snow has precipitated on the ice sheet, become compacted, and turned into additional ice. Any dust or other impurities in the air or snow have been precipitated as well and thus each snowfall leaves a snapshot record of the atmosphere that existed at or near the time of deposition. A detailed chronology of volcanic eruptions can be obtained from the ice layers where ash and other volcanic products were deposited. Normally, the analysis of volcanic layers requires the physical extraction of a core from the ice sheet; however, chronologies from cores have discontinuities and are difficult, time-consuming, and expensive to obtain. Borehole logging is a measurement method where one lowers instrumentation into a drilled hole in the ice, whether or not core has been retrieved. To date, this technology has only been used to measure optical systems to identify volcanic ash and other impurity layers. In this program, a profiling technology will be developed that measures the conductivity of the ice. A radio-frequency emitter lowered into the borehole will create a return signal that changes depending on the local conductivity, which depends on the concentration of dissolved ions. For example, dissolved sulfates are a critical marker of volcanic activity that may not be coincident with deposited ash. Other dissolved ions, such as chloride, can be indicative of other processes. It is expected that this borehole profiling instrument will be able to help rapidly identify volcanic eruptions that had potentially global impact, distinguish between different dissolved ions via their frequency dependencies, and assist in establishing chronologies between different ice cores and boreholes. Part II: Technical Description Borehole logging of the polar ice sheets is one of the most important methods that earth scientists have to identify and date volcanic eruptions. However, current technology only indicates the presence and depth of ash from an eruption. In order to extract more detailed information, one must obtain an ice core, and laboriously measure each section in the laboratory using electrical conductivity or dielectric measurements to determine the presence or absence of dissolved sulfate and its location relative to the corresponding ash, if any. This program will investigate and demonstrate a borehole logging-compatible radio-frequency dielectric sensor to detect and measure spikes in dissolved major ions chemistry in ice, particularly in intervals corresponding to volcanically produced sulfates. The sulfate layers are one of the primary signatures of volcanic products. However, other ions, such as chlorides, calcium, and others are also commonly seen in ice, and the dielectric logging technology of this program would also measure these. It is expected that certain sets of ions will be distinguishable by their frequency dependencies. This technique could guide other investigators, who are using conventional core scanning and sampling methods, to regions of special interest in corresponding core. We plan to construct a ring-based electrode system and test this system on a variety of artificial ice boreholes and ice cores. This unit will not include a pressure vessel or other borehole logger packing. We will test different means of applying electrical signals including short pulses and periodic waves. We will further utilize differential measurements with low noise circuits and filters to achieve maximum sensitivity. We will correlate the signals extracted with known molarities of sulfates and other ions and measured ECM records. We will perform scaled-down experiments using real ice cores stored in Bay?s lab at UC Berkeley. This will permit testing of different designs in ice with natural impurities and polycrystalline structure. This small collection includes cores from a variety of locations in Antarctica and Greenland, and a variety of ages as old as a million years.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": null, "is_usap_dc": true, "keywords": "WAIS Divide; USAP-DC; Amd/Us; GLACIERS/ICE SHEETS; USA/NSF; FIELD INVESTIGATION; Ice Core; AMD", "locations": "WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Talghader, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Borehole Logging to Classify Volcanic Signatures in Antarctic Ice", "uid": "p0010080", "west": -112.085}, {"awards": "1443437 Carlson, Anders; 1443268 Beard, Brian", "bounds_geometry": "POLYGON((-80 -65,-79 -65,-78 -65,-77 -65,-76 -65,-75 -65,-74 -65,-73 -65,-72 -65,-71 -65,-70 -65,-70 -65.5,-70 -66,-70 -66.5,-70 -67,-70 -67.5,-70 -68,-70 -68.5,-70 -69,-70 -69.5,-70 -70,-71 -70,-72 -70,-73 -70,-74 -70,-75 -70,-76 -70,-77 -70,-78 -70,-79 -70,-80 -70,-80 -69.5,-80 -69,-80 -68.5,-80 -68,-80 -67.5,-80 -67,-80 -66.5,-80 -66,-80 -65.5,-80 -65))", "dataset_titles": "Radiogenic isotopes of ODP Site 178-1096; Sand content of ODP Site 178-1096", "datasets": [{"dataset_uid": "200109", "doi": " doi:10.1594/PANGAEA.909411", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Sand content of ODP Site 178-1096", "url": "https://doi.pangaea.de/10.1594/PANGAEA.909411 "}, {"dataset_uid": "200108", "doi": " doi:10.1594/PANGAEA.909407 ", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Radiogenic isotopes of ODP Site 178-1096", "url": "https://doi.pangaea.de/10.1594/PANGAEA.909407"}], "date_created": "Fri, 31 Jan 2020 00:00:00 GMT", "description": "Collapse of the West Antarctic ice sheet (WAIS) could raise global sea level by up to 3 meters, at a rate of up to ~1 meter per century, yielding major societal impacts. The goal of this project is to determine if such a collapse occurred in the recent past. This will include development of new geochemical tools to evaluate the sedimentary geologic record around the WAIS to evaluate WAIS behavior during past warm periods. The primary activities to be carried out by the research team are to: 1) characterize the chemistry and magnetic properties of sediments being discharged from different portions of the WAIS and use these properties to ?fingerprint? inputs from different sources on the continent; 2) measure these same properties in a marine sediment core to document major changes in the WAIS over the last 150,000 years. Determining if the WAIS has collapsed in the recent past can provide important information on WAIS potential to grow unstable in the future. The tools to be developed here can then be used on older records around the WAIS to examine the frequency of ice sheet instability in the past. The project will support a postdoctoral researcher as well as undergraduate students. This project will develop sediment provenance proxies to trace the sources of sediment discharged by the West Antarctic Ice Sheet (WAIS) to the continental rise. Specific questions to be addressed are: 1) the degree that sediment from different WAIS terranes can be geochemically and magnetically differentiated; 2) the ability of terrane provenance proxies to detect WAIS collapse in the late Quaternary. The WAIS erodes sediments from various West Antarctic geologic terranes that are deposited in adjacent drift sites. The geochemistry and magnetic properties of drift sediments reflect the tectonic and metamorphic history of their source terranes. Deglaciation of a terrane during WAIS collapse should be detectable by the loss of the terrane?s geochemical and magnetic signature in continental-rise detrital sediments. Continental shelf late-Holocene sediments from near the current WAIS groundling line will be analyzed for silt- and clay-size Sr-Nd-Pb isotopes, magnetic properties, and major-trace elements. The suite of cores includes the eastern Ross Sea to the northern tip of the Antarctic Peninsula and will establish provenance signatures of the Ross and Amundsen Provinces of Marie Byrd Land, Pine Island Bay, Thurston Island/Eight Coast Block, Ellsworth-Whitmore Crustal Block, and Antarctic Peninsula terranes. Many of these terranes have similar tectonic and metamorphic histories but Sr-Nd isotope data from detrital sediments suggest at least 3 distinct provenance signatures. An initial down core study of Ocean Drilling Program Site 1096 in the Bellingshausen Sea will be conducted to detect if the WAIS was unstable during the last interglacial period.", "east": -70.0, "geometry": "POINT(-75 -67.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "West Antarctic Ice Sheet; GLACIERS/ICE SHEETS; West Antarctica; PALEOCLIMATE RECONSTRUCTIONS; NOT APPLICABLE; USAP-DC; ISOTOPES; GEOCHEMISTRY; Bellingshausen Sea", "locations": "West Antarctic Ice Sheet; West Antarctica; Bellingshausen Sea", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Anders, Carlson; Beard, Brian; Stoner, Joseph", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "PANGAEA", "repositories": "PANGAEA", "science_programs": null, "south": -70.0, "title": "Collaborative Research: Development of a Suite of Proxies to Detect Past Collapse of the West Antarctic Ice Sheet", "uid": "p0010079", "west": -80.0}, {"awards": "1246111 Dalziel, Ian", "bounds_geometry": "POLYGON((-44 -53,-42.9 -53,-41.8 -53,-40.7 -53,-39.6 -53,-38.5 -53,-37.4 -53,-36.3 -53,-35.2 -53,-34.1 -53,-33 -53,-33 -53.4,-33 -53.8,-33 -54.2,-33 -54.6,-33 -55,-33 -55.4,-33 -55.8,-33 -56.2,-33 -56.6,-33 -57,-34.1 -57,-35.2 -57,-36.3 -57,-37.4 -57,-38.5 -57,-39.6 -57,-40.7 -57,-41.8 -57,-42.9 -57,-44 -57,-44 -56.6,-44 -56.2,-44 -55.8,-44 -55.4,-44 -55,-44 -54.6,-44 -54.2,-44 -53.8,-44 -53.4,-44 -53))", "dataset_titles": "BAS Geological Collection: Central Scotia Sea (full data link not provided); Nathaniel B Palmer NBP 1408; South Georgia: SOG1, SOG2, SOG3", "datasets": [{"dataset_uid": "200107", "doi": "", "keywords": null, "people": null, "repository": "British Antarctic Survey", "science_program": null, "title": "BAS Geological Collection: Central Scotia Sea (full data link not provided)", "url": "https://www.bas.ac.uk/data/our-data/collections/geological-collections/"}, {"dataset_uid": "200105", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "South Georgia: SOG1, SOG2, SOG3", "url": "https://www.unavco.org/data/gps-gnss/gps-gnss.html"}, {"dataset_uid": "200106", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Nathaniel B Palmer NBP 1408", "url": "http://www.marine-geo.org/tools/search/entry.php?id=NBP1408"}], "date_created": "Tue, 28 Jan 2020 00:00:00 GMT", "description": "Intellectual Merit: Opening of Drake Passage and the West Scotia Sea south of Tierra del Fuego broke the final continental barrier to onset of a complete Antarctic Circumpolar Current (ACC). Initiation of the ACC has been associated in time with a major, abrupt, drop in global temperatures and the rapid expansion of the Antarctic ice sheets at 33-34 Ma. Events leading to the formation of the Drake Passage gateway are poorly known. Understanding the tectonic evolution of the floor of the Central Scotia Sea (CSS) and the North Scotia Ridge is a key to this understanding. Previous work has demonstrated that superimposed constructs formed a volcanic arc that likely blocked direct eastward flow from the Pacific to the Atlantic through the opening Drake Passage gateway as the active South Sandwich arc does today. The PIs propose a cruise to test, develop and refine, with further targeted mapping and dredging, their theory of CSS tectonics and the influence it had on the onset and development of the ACC. In addition they propose an installation of GPS receiver to test their paleogeographic reconstructions and determine whether South Georgia is moving as part of the South American plate. Broader impacts: A graduate student will be involved in all stages of the research. Undergraduate students will also be involved as watch-standers. A community college teacher will participate in the cruise. The PIs will have a website on which there will be images of the actual ocean floor dredging in operation. The teacher will participate with web and outreach support through PolarTREC. Results of the cruise are of broad interest to paleoceanographers, paleoclimate modelers and paleobiogeographers.", "east": -33.0, "geometry": "POINT(-38.5 -55)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Scotia Sea; PLATE BOUNDARIES; TECTONIC PROCESSES; NOT APPLICABLE; COASTAL ELEVATION; Southern Ocean; USAP-DC", "locations": "Scotia Sea; Southern Ocean", "north": -53.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Dalziel, Ian W.; Lawver, Lawrence; Krissek, Lawrence", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "British Antarctic Survey", "repositories": "British Antarctic Survey; MGDS; UNAVCO", "science_programs": null, "south": -57.0, "title": "Collaborative Research: Role of the Central Scotia Sea Floor and North Scotia Ridge in the Onset and Development of the Antarctic Circumpolar Current", "uid": "p0010078", "west": -44.0}, {"awards": "1341496 Girton, James", "bounds_geometry": "POLYGON((-142 -66,-135.3 -66,-128.6 -66,-121.9 -66,-115.2 -66,-108.5 -66,-101.8 -66,-95.1 -66,-88.4 -66,-81.7 -66,-75 -66,-75 -66.8,-75 -67.6,-75 -68.4,-75 -69.2,-75 -70,-75 -70.8,-75 -71.6,-75 -72.4,-75 -73.2,-75 -74,-81.7 -74,-88.4 -74,-95.1 -74,-101.8 -74,-108.5 -74,-115.2 -74,-121.9 -74,-128.6 -74,-135.3 -74,-142 -74,-142 -73.2,-142 -72.4,-142 -71.6,-142 -70.8,-142 -70,-142 -69.2,-142 -68.4,-142 -67.6,-142 -66.8,-142 -66))", "dataset_titles": "Bottom Photographs from the Antarctic Peninsula acquired during R/V Laurence M. Gould expedition LMG1703; Expedition Data; Expedition data of NBP1701", "datasets": [{"dataset_uid": "002661", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1701", "url": "https://www.rvdata.us/search/cruise/NBP1701"}, {"dataset_uid": "001369", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1701"}, {"dataset_uid": "601302", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Benthic Images; Benthos; Biota; LMG1708; Oceans; Photo; Photo/video; Photo/Video; R/v Laurence M. Gould; Ship; Yoyo Camera", "people": "Girton, James", "repository": "USAP-DC", "science_program": null, "title": "Bottom Photographs from the Antarctic Peninsula acquired during R/V Laurence M. Gould expedition LMG1703", "url": "https://www.usap-dc.org/view/dataset/601302"}], "date_created": "Tue, 10 Dec 2019 00:00:00 GMT", "description": "Current oceanographic interest in the interaction of relatively warm water of the Southern Ocean Circumpolar Deep Water ( CDW) as it moves southward to the frigid waters of the Antarctic continental shelves is based on the potential importance of heat transport from the global ocean to the base of continental ice shelves. This is needed to understand the longer term mass balance of the continent, the stability of the vast Antarctic ice sheets and the rate at which sea-level will rise in a warming world. Improved observational knowledge of the mechanisms of how warming CDW moves across the Antarctic Circumpolar Current (ACC) is needed. Understanding this dynamical transport, believed to take place by the eddy flux of time-varying mesoscale circulation features, will improve coupled ocean-atmospheric climate models. The development of the next generation of coupled ocean-ice- climate models help us understand future changes in atmospheric heat fluxes, glacial and sea-ice balance, and changes in the Antarctic ecosystems. A recurring obstacle to our understanding is the lack of data in this distant region. In this project, a number of subsurface profiling EM-APEX floats adapted to operate under sea ice will be launched on up to 4 cruises of opportunity to the Pacific sector during Austral summer. The floats will be launched south of the Polar Front and measure shear, turbulence, temperature, and salinity to 2000m depth for up to 2 year missions while following the CDW layer.", "east": -75.0, "geometry": "POINT(-108.5 -70)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA", "is_usap_dc": true, "keywords": "OCEAN TEMPERATURE; R/V NBP; USAP-DC; ICE DEPTH/THICKNESS; HEAT FLUX; OCEAN CURRENTS; SALINITY/DENSITY; LMG1703; Bellingshausen Sea; Yoyo Camera; WATER MASSES; R/V LMG; NBP1701", "locations": "Bellingshausen Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Girton, James; Rynearson, Tatiana", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -74.0, "title": "Collaborative Research: Pathways of Circumpolar Deep Water to West Antarctica from Profiling Float and Satellite Measurements", "uid": "p0010074", "west": -142.0}, {"awards": "1443105 Steig, Eric", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core; South Pole high resolution ice core water stable isotope record for dD, d18O; South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601429", "doi": "10.15784/601429", "keywords": "Antarctica; Climate; Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrogen; Ice; Ice Core; Ice Core Chemistry; Oxygen; Paleoclimate; Snow/ice; Snow/Ice; South Pole; Stable Isotopes", "people": "Jones, Tyler R.; White, James; Vaughn, Bruce; Morris, Valerie; Kahle, Emma; Schauer, Andrew; Steig, Eric J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core", "url": "https://www.usap-dc.org/view/dataset/601429"}, {"dataset_uid": "601239", "doi": "10.15784/601239", "keywords": "Antarctica; Cavity Ring Down Spectrometers; Delta 18O; Delta Deuterium; Deuterium Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Oxygen Isotope; Snow/ice; Snow/Ice; Stable Isotopes", "people": "Steig, Eric J.; Schauer, Andrew; Kahle, Emma; Vaughn, Bruce; Morris, Valerie; Jones, Tyler R.; White, James", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole high resolution ice core water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601239"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}, {"dataset_uid": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Conway, Howard; Stevens, Max; Steig, Eric J.; Schauer, Andrew; Vaughn, Bruce; Morris, Valerie; Kahle, Emma; Koutnik, Michelle; Fudge, T. J.; Buizert, Christo; White, James; Epifanio, Jenna; Jones, Tyler R.; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "url": "https://www.usap-dc.org/view/dataset/601396"}], "date_created": "Sun, 17 Nov 2019 00:00:00 GMT", "description": "This project will develop a record of the stable-isotope ratios of water from an ice core at the South Pole, Antarctica. Water-isotope ratio measurements provide a means to determine variability in temperature through time. South Pole is distinct from most other locations in Antarctica in showing no warming in recent decades, but little is known about temperature variability in this location prior to the installation of weather stations in 1957. The measurements made as part of this project will result in a much longer temperature record, extending at least 40,000 years, aiding our ability to understand what controls Antarctic climate, and improving projections of future Antarctic climate change. Data from this project will be critical to other investigators working on the South Pole ice core, and of general interest to other scientists and the public. Data will be provided rapidly to other investigators and made public as soon as possible. This project will obtain records of the stable-isotope ratios of water on the ice core currently being obtained at South Pole. The core will reach a depth of 1500 m and an age of 40,000 years. The project will use laser spectroscopy to obtain both an ultra-high-resolution record of oxygen 18/16 and deuterium-hydrogen ratios, and a lower-resolution record of oxygen 17/16 ratios. The high-resolution measurements will be used to aid in dating the core, and to provide estimates of isotope diffusion that constrain the process of firn densification. The novel 17/16 measurement provides additional constraints on the isotope fractionation due to the temperature-dependent supersaturation ratio, which affects the fractionation of water during the liquid-solid condensate transition. Together, these techniques will allow for improved accuracy in the use of the water isotope ratios as proxies for ice-sheet temperature, sea-surface temperature, and atmospheric circulation. The result will be a record of decadal through centennial and millennial scale climate change in a climatically distinct region in East Antarctica that has not been previously sampled by deep ice coring. The project will support a graduate student who will be co-advised by faculty at the University of Washington and the University of Colorado, and will be involved in all aspects of the work.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "SPICEcore; D18O; LABORATORY; OXYGEN ISOTOPE ANALYSIS; Oxygen Isotope; South Pole; USAP-DC; GLACIERS/ICE SHEETS; Antarctica; AMD; FIELD INVESTIGATION; Ice Core", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Steig, Eric J.; White, James", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole", "uid": "p0010065", "west": 0.0}, {"awards": "1738942 Wellner, Julia", "bounds_geometry": "POLYGON((-120 -71,-118 -71,-116 -71,-114 -71,-112 -71,-110 -71,-108 -71,-106 -71,-104 -71,-102 -71,-100 -71,-100 -71.5,-100 -72,-100 -72.5,-100 -73,-100 -73.5,-100 -74,-100 -74.5,-100 -75,-100 -75.5,-100 -76,-102 -76,-104 -76,-106 -76,-108 -76,-110 -76,-112 -76,-114 -76,-116 -76,-118 -76,-120 -76,-120 -75.5,-120 -75,-120 -74.5,-120 -74,-120 -73.5,-120 -73,-120 -72.5,-120 -72,-120 -71.5,-120 -71))", "dataset_titles": "A multibeam-bathymetric compilation for the southern Amundsen Sea shelf, 1999-2019; Expedition Data of NBP2002; Expedition Data of NBP2202; NBP1902 Expedition data; Physical and geochemical data from sediment cores collected offshore Thwaites Glacier", "datasets": [{"dataset_uid": "200311", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2202", "url": "https://www.rvdata.us/search/cruise/NBP2202"}, {"dataset_uid": "200161", "doi": "10.5285/F2DFEDA9-BF44-4EF5-89A3-EE5E434A385C", "keywords": null, "people": null, "repository": "UK PDC", "science_program": null, "title": "A multibeam-bathymetric compilation for the southern Amundsen Sea shelf, 1999-2019", "url": "https://doi.org/10.5285/F2DFEDA9-BF44-4EF5-89A3-EE5E434A385C"}, {"dataset_uid": "200083", "doi": "10.7284/908147", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1902 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1902"}, {"dataset_uid": "200248", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2002", "url": "https://www.rvdata.us/search/cruise/NBP2002"}, {"dataset_uid": "601514", "doi": "10.15784/601514", "keywords": "Antarctica; Chemistry:sediment; Chemistry:Sediment; Glaciomarine Sediment; Grain Size; Magnetic Susceptibility; Marine Geoscience; Marine Sediments; NBP1902; NBP2002; Physical Properties; R/v Nathaniel B. Palmer; Sediment Core Data; Thwaites Glacier; Trace Elements; XRF", "people": "Lepp, Allison", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Physical and geochemical data from sediment cores collected offshore Thwaites Glacier", "url": "https://www.usap-dc.org/view/dataset/601514"}], "date_created": "Fri, 01 Nov 2019 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Satellite observations extending over the last 25 years show that Thwaites Glacier is rapidly thinning and accelerating. Over this same period, the Thwaites grounding line, the point at which the glacier transitions from sitting on the seabed to floating, has retreated. Oceanographic studies demonstrate that the main driver of these changes is incursion of warm water from the deep ocean that flows beneath the floating ice shelf and causes basal melting. The period of satellite observation is not long enough to determine how a large glacier, such as Thwaites, responds to long-term and near-term changes in the ocean or the atmosphere. As a result, records of glacier change from the pre-satellite era are required to build a holistic understanding of glacier behavior. Ocean-floor sediments deposited at the retreating grounding line and further offshore contain these longer-term records of changes in the glacier and the adjacent ocean. An additional large unknown is the topography of the seafloor and how it influences interactions of landward-flowing warm water with Thwaites Glacier and affects its stability. Consequently, this project focuses on the seafloor offshore from Thwaites Glacier and the records of past glacial and ocean change contained in the sediments deposited by the glacier and surrounding ocean. Uncertainty in model projections of the future of Thwaites Glacier will be significantly reduced by cross-disciplinary investigations seaward of the current grounding line, including extracting the record of decadal to millennial variations in warm water incursion, determining the pre-satellite era history of grounding-line migration, and constraining the bathymetric pathways that control flow of warm water to the grounding line. Sedimentary records and glacial landforms preserved on the seafloor will allow reconstruction of changes in drivers and the glacial response to them over a range of timescales, thus providing reference data that can be used to initiate and evaluate the reliability of models. Such data will further provide insights on the influence of poorly understood processes on marine ice sheet dynamics. This project will include an integrated suite of marine and sub-ice shelf research activities aimed at establishing boundary conditions seaward of the Thwaites Glacier grounding line, obtaining records of the external drivers of change, improving knowledge of processes leading to collapse of Thwaites Glacier, and determining the history of past change in grounding line migration and conditions at the glacier base. These objectives will be achieved through high-resolution geophysical surveys of the seafloor and analysis of sediments collected in cores from the inner shelf seaward of the Thwaites Glacier grounding line using ship-based equipment, and from beneath the ice shelf using a corer deployed through the ice shelf via hot water drill holes. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -100.0, "geometry": "POINT(-110 -73.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS", "is_usap_dc": true, "keywords": "BATHYMETRY; Antarctica; MARINE SEDIMENTS; AMD; MARINE GEOPHYSICS; Amd/Us; USAP-DC; Thwaites Glacier; LABORATORY; Southern Ocean; ICE SHEETS; USA/NSF; GLACIERS/ICE SHEETS; R/V NBP", "locations": "Antarctica; Southern Ocean; Thwaites Glacier", "north": -71.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wellner, Julia; Larter, Robert; Minzoni, Rebecca; Hogan, Kelly; Anderson, John; Graham, Alastair; Hillenbrand, Claus-Dieter; Nitsche, Frank O.; Simkins, Lauren; Smith, James A.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; UK PDC; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: THwaites Offshore Research (THOR)", "uid": "p0010062", "west": -120.0}, {"awards": "1443566 Bay, Ryan", "bounds_geometry": "POINT(90 -90)", "dataset_titles": "Laser Dust Logging of the South Pole Ice Core (SPICE)", "datasets": [{"dataset_uid": "601222", "doi": "10.15784/601222", "keywords": "Antarctica; Dust; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; SPICEcore", "people": "Bay, Ryan", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Laser Dust Logging of the South Pole Ice Core (SPICE)", "url": "https://www.usap-dc.org/view/dataset/601222"}], "date_created": "Thu, 31 Oct 2019 00:00:00 GMT", "description": "Bay/1443566 This award supports the deployment and analysis of data from an oriented laser dust logger in the South Pole ice core borehole to complement study of the ice core record. Before the core is even processed, data from the borehole probe will immediately determine the depth-age relationship, augment 3D mapping of South Pole stratigraphy, aid in searches for the oldest ice in Antarctica, and reveal layers of volcanic or extraterrestrial fallout. Regarding the intellectual merit, the oriented borehole log will be essential for investigating features in the ice sheet that may have implications for ice core chronology, ice flow, ice sheet physical properties and stability in response to climate change. The tools and techniques developed in this program have applications in glaciology, biogeoscience and exploration of other planetary bodies. The program aims for a deeper understanding of the consequences and causes of abrupt climate change. The broader impacts of the project are that it will include outreach and education, providing a broad training ground for students and post-docs. Data and metadata will be made available through data centers and repositories such as the National Snow and Ice Data Center web portal. The laser dust logger detects reproducible paleoclimate features at sub-centimeter depth scale. Dust logger data are being used for synchronizing records and dating any site on the continent, revealing accumulation anomalies and episodes of rapid ice sheet thinning, and discovering particulate horizons of special interest. In this project we will deploy a laser dust logger equipped with a magnetic compass to find direct evidence of preferentially oriented dust. Using optical scattering measurements from IceCube calibration studies at South Pole and borehole logs at WAIS Divide, we have detected a persistent anisotropy correlated with flow and crystal fabric which suggests that the majority of insoluble particulates must be located within ice grains. With typical concentrations of parts-per-billion, little is known about the location of impurities within the polycrystalline structure of polar ice. While soluble impurities are generally thought to concentrate at inter-grain boundaries and determine electrical conductivity, the fate of insoluble particulates is much less clear, and microscopic examinations are extremely challenging. These in situ borehole measurements will help to unravel intimate relationships between impurities, flow, and crystal fabric. Data from this project will further develop a unique record of South Pole surface roughness as a proxy for paleowind and provide new insights for understanding glacial radar propagation. This project has field work in Antarctica.", "east": 90.0, "geometry": "POINT(90 -90)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; Antarctica; ICE CORE RECORDS; USAP-DC", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bay, Ryan", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Laser Dust Logging of a South Pole Ice Core", "uid": "p0010061", "west": 90.0}, {"awards": "1142517 Aydin, Murat; 1141839 Steig, Eric; 1142646 Twickler, Mark", "bounds_geometry": "POINT(90 -90)", "dataset_titles": "South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; South Pole ice core (SPC14) discrete methane data; South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Conway, Howard; Stevens, Max; Steig, Eric J.; Schauer, Andrew; Vaughn, Bruce; Morris, Valerie; Kahle, Emma; Koutnik, Michelle; Fudge, T. J.; Buizert, Christo; White, James; Epifanio, Jenna; Jones, Tyler R.; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "url": "https://www.usap-dc.org/view/dataset/601396"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Aydin, Murat; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601221", "doi": "10.15784/601221", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Depth; Ice Core Records; Snow/ice; Snow/Ice; SPICEcore", "people": "Fudge, T. J.; Kahle, Emma; Nicewonger, Melinda R.; Hargreaves, Geoff; Nunn, Richard; Steig, Eric J.; Aydin, Murat; Casey, Kimberly A.; Fegyveresi, John; Twickler, Mark; Souney, Joseph Jr.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth", "url": "https://www.usap-dc.org/view/dataset/601221"}, {"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}], "date_created": "Wed, 30 Oct 2019 00:00:00 GMT", "description": "1142517/Saltzman This proposal requests support for a project to drill and recover a new ice core from South Pole, Antarctica. The South Pole ice core will be drilled to a depth of 1500 m, providing an environmental record spanning approximately 40 kyrs. This core will be recovered using a new intermediate drill, which is under development by the U.S. Ice Drilling Design and Operations (IDDO) group in collaboration with Danish scientists. This proposal seeks support to provide: 1) scientific management and oversight for the South Pole ice core project, 2) personnel for ice core drilling and core processing, 3) data management, and 3) scientific coordination and communication via scientific workshops. The intellectual merit of the work is that the analysis of stable isotopes, atmospheric gases, and aerosol-borne chemicals in polar ice has provided unique information about the magnitude and timing of changes in climate and climate forcing through time. The international ice core research community has articulated the goal of developing spatial arrays of ice cores across Antarctica and Greenland, allowing the reconstruction of regional patterns of climate variability in order to provide greater insight into the mechanisms driving climate change. The broader impacts of the project include obtaining the South Pole ice core will support a wide range of ice core science projects, which will contribute to the societal need for a basic understanding of climate and the capability to predict climate and ice sheet stability on long time scales. Second, the project will help train the next generation of ice core scientists by providing the opportunity for hands-on field and core processing experience for graduate students and postdoctoral researchers. A postdoctoral researcher at the University of Washington will be directly supported by this project, and many other young scientists will interact with the project through individual science proposals. Third, the project will result in the development of a new intermediate drill which will become an important resource to US ice core science community. This drill will have a light logistical footprint which will enable a wide range of ice core projects to be carried out that are not currently feasible. Finally, although this project does not request funds for outreach activities, the project will run workshops that will encourage and enable proposals for coordinated outreach activities involving the South Pole ice core science team.", "east": 90.0, "geometry": "POINT(90 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; Amd/Us; Antarctica; ANALYTICAL LAB; USA/NSF; AMD; South Pole; ICE CORE RECORDS; FIELD INVESTIGATION; Ice Core", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Twickler, Mark; Souney, Joseph Jr.; Aydin, Murat; Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: A 1500m Ice Core from South Pole", "uid": "p0010060", "west": 90.0}, {"awards": "1745137 Schroeder, Dustin", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic topographic and subglacial lake geostatistical simulations; Radar Sounding Observations of the Amundsen Sea Embayment, 2004-2005", "datasets": [{"dataset_uid": "601213", "doi": "10.15784/601213", "keywords": "Active Lakes; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Model Data; Snow/ice; Snow/Ice; Subglacial Lakes; Topography", "people": "Scheidt, Celine; Caers, Jef; Schroeder, Dustin; Siegfried, Matthew; MacKie, Emma", "repository": "USAP-DC", "science_program": null, "title": "Antarctic topographic and subglacial lake geostatistical simulations", "url": "https://www.usap-dc.org/view/dataset/601213"}, {"dataset_uid": "601436", "doi": "10.15784/601436", "keywords": "Amundsen Sea; Antarctica; Bed Reflectivity; Ice Penetrating Radar; Radar Echo Sounder", "people": "Culberg, Riley; Schroeder, Dustin; Jordan, Thomas M.; Seroussi, Helene; Young, Duncan A.; Vaughan, David G.; Chu, Winnie; Hilger, Andrew M.", "repository": "USAP-DC", "science_program": null, "title": "Radar Sounding Observations of the Amundsen Sea Embayment, 2004-2005", "url": "https://www.usap-dc.org/view/dataset/601436"}], "date_created": "Sat, 12 Oct 2019 00:00:00 GMT", "description": "Earth\u0027s geologic record shows that the great ice sheets have contributed to rates of sea-level rise that have been much higher than those observed today. That said, some sectors of the current Antarctic ice sheet are losing mass at large and accelerating rates. One of the primary challenges for placing these recent and ongoing changes in the context of geologically historic rates, and for making projections decades to centuries into the future, is the difficulty of observing conditions and processes beneath the ice sheet. Whereas satellite observations allow tracking of the ice-surface velocity and elevation on the scale of glacier catchments to ice sheets, airborne ice-penetrating radar has been the only approach for assessing conditions on this scale beneath the ice. These radar observations have been made since the late 1960s, but, because many different instruments have been used, it is difficult to track change in subglacial conditions through time. This project will develop the technical tools and approaches required to cross-compare among these measurements and thus open up opportunities for tracking and understanding changes in the critical subglacial environment. Intertwined with the research and student training on this project will be an outreach education effort to provide middle school and high school students with improved resources and enhanced exposure to geophysical, glaciological, and remote-sensing topics through partnership with the National Science Olympiad. The radar sounding of ice sheets is a powerful tool for glaciological science with broad applicability across a wide range of cryosphere problems and processes. Radar sounding data have been collected with extensive spatial and temporal coverage across the West Antarctic Ice Sheet, including areas where multiple surveys provide observations that span decades in time or entire cross-catchment ice-sheet sectors. However, one major obstacle to realizing the scientific potential of existing radar sounding observations in Antarctica is the lack of analysis approaches specifically developed for cross-instrument interpretation. This project aims to directly address these barriers to full utilization of the collective Antarctic radar sounding record by developing a suite of processing and interpretation techniques to enable the synthesis of radar sounding data sets collected with systems that range from incoherent to coherent, single-channel to swath-imaging, and digital to optically-recorded radar sounders. The approaches will be assessed for two target regions: the Amundsen Sea Embayment and the Siple Coast. All pre- and post-processed sounding data produced by this project will be publically hosted for use by the wider research community. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS", "is_usap_dc": true, "keywords": "GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; Amd/Us; Airborne Radar; USA/NSF; ICE DEPTH/THICKNESS; Antarctica; Radar; AMD; USAP-DC", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Schroeder, Dustin; MacKie, Emma", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "CAREER: Cross-Instrument Synthesis of Antarctic Radar Sounding Observations", "uid": "p0010058", "west": -180.0}, {"awards": "1341728 Stone, John", "bounds_geometry": "POLYGON((-86.3 -81,-86.17 -81,-86.04 -81,-85.91 -81,-85.78 -81,-85.65 -81,-85.52 -81,-85.39 -81,-85.26 -81,-85.13 -81,-85 -81,-85 -81.03,-85 -81.06,-85 -81.09,-85 -81.12,-85 -81.15,-85 -81.18,-85 -81.21,-85 -81.24,-85 -81.27,-85 -81.3,-85.13 -81.3,-85.26 -81.3,-85.39 -81.3,-85.52 -81.3,-85.65 -81.3,-85.78 -81.3,-85.91 -81.3,-86.04 -81.3,-86.17 -81.3,-86.3 -81.3,-86.3 -81.27,-86.3 -81.24,-86.3 -81.21,-86.3 -81.18,-86.3 -81.15,-86.3 -81.12,-86.3 -81.09,-86.3 -81.06,-86.3 -81.03,-86.3 -81))", "dataset_titles": "Cosmogenic nuclide data, Harter Nunatak; Cosmogenic nuclide data, John Nunatak; Cosmogenic nuclide data, Mt Axtell; Cosmogenic nuclide data, Mt Goodwin; Cosmogenic nuclide data, Mt Tidd; Cosmogenic nuclide data, Mt Turcotte; Pirrit Hills subglacial bedrock core RB-2, cosmogenic Be-10, Al-26 data", "datasets": [{"dataset_uid": "200076", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Mt Tidd", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200080", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, John Nunatak", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200079", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Harter Nunatak", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200075", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Mt Axtell", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "601214", "doi": "10.15784/601214", "keywords": "Aluminum-26; Antarctica; Be-10; Bedrock Core; Beryllium-10; Chemistry:rock; Chemistry:Rock; Cosmogenic; Cosmogenic Dating; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Data; Pirrit Hills; Rocks; Solid Earth; Subglacial Bedrock", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Pirrit Hills subglacial bedrock core RB-2, cosmogenic Be-10, Al-26 data", "url": "https://www.usap-dc.org/view/dataset/601214"}, {"dataset_uid": "200078", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Mt Goodwin", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200077", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Mt Turcotte", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Tue, 08 Oct 2019 00:00:00 GMT", "description": "Stone/1341728 This award supports a project to determine if the West Antarctic Ice Sheet (WAIS) has thinned and collapsed in the past and if so, when did this occur. This topic is of interest to geologists who have long been studying the history and behavior of ice sheets (including the WAIS) in order to determine what climatic conditions allow an ice sheet to survive and what conditions have caused them to collapse in the past. The bulk of this research has focused on the last ice age, when climate conditions were far colder than the present; this project will focus on the response of ice sheets to warmer climates in the past. A new and potentially transformative approach that uses the analysis of atoms transformed by cosmic-rays in bedrock beneath the WAIS will allow a definitive test for ice free conditions in the past. This is because the cosmic rays capable of producing the necessary reactions can penetrate only a few meters through glacier ice. Therefore, if they are detected in samples from hundreds of meters below the current ice sheet surface this would provide definitive proof of mostly ice-free conditions in the past. The concentrations of different cosmic ray products in cores from different depths will help answer the question of how frequently bedrock has been exposed, how much the ice sheet has thinned, and which time periods in the past produced climatic conditions capable of making the ice sheet unstable. Short bedrock cores beneath the ice sheet near the Pirrit Hills in West Antarctica will be collected using a new agile sub-ice geological drill (capable of drilling up to 200 meters beneath the ice surface) that is being developed by the Ice Drilling Program Office (IDPO) to support this and other projects. Favorable drilling sites have already been identified based on prior reconnaissance mapping, sample analysis and radar surveys of the ice-sheet bed. The cores collected in this study will be analyzed for cosmic-ray-produced isotopes of different elements with a range of half-lives from 5700 yr (C-14) to 1.4 Myr (Be-10), as well as stable Ne-21. The presence or absence of these isotopes will provide a definitive test of whether bedrock surfaces were ice-free in the past and due to their different half-lives, ratios of the isotopes will place constraints on the age, frequency and duration of past exposure episodes. Results from bedrock surfaces at different depths will indicate the degree of past ice-sheet thinning. The aim is to tie evidence of deglaciation in the past to specific periods of warmer climate and thus to gauge the ice sheet\u0027s response to known climate conditions. This project addresses the broad question of ice-sheet sensitivity to climate warming, which previously has been largely determined indirectly from sea-level records. In contrast, this project will provide direct measurements that provide evidence of ice-sheet thinning in West Antarctica. Results from this work will help to identify the climatic factors and thresholds capable of endangering the WAIS in future. The project will make a significant contribution to the ongoing study of climate change, ice-sheet melting and associated sea-level rise. This project has field work in Antarctica.", "east": -85.0, "geometry": "POINT(-85.65 -81.15)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "DEPTH AT SPECIFIC AGES; USAP-DC; Antarctica; NOT APPLICABLE", "locations": "Antarctica", "north": -81.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "ICE-D", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -81.3, "title": "EXPROBE-WAIS: Exposed Rock Beneath the West Antarctic Ice Sheet, A Test for Interglacial Ice Sheet Collapse", "uid": "p0010057", "west": -86.3}, {"awards": "1443190 Parizek, Byron", "bounds_geometry": "POLYGON((-130 -73,-125.5 -73,-121 -73,-116.5 -73,-112 -73,-107.5 -73,-103 -73,-98.5 -73,-94 -73,-89.5 -73,-85 -73,-85 -73.9,-85 -74.8,-85 -75.7,-85 -76.6,-85 -77.5,-85 -78.4,-85 -79.3,-85 -80.2,-85 -81.1,-85 -82,-89.5 -82,-94 -82,-98.5 -82,-103 -82,-107.5 -82,-112 -82,-116.5 -82,-121 -82,-125.5 -82,-130 -82,-130 -81.1,-130 -80.2,-130 -79.3,-130 -78.4,-130 -77.5,-130 -76.6,-130 -75.7,-130 -74.8,-130 -73.9,-130 -73))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 16 Sep 2019 00:00:00 GMT", "description": "Accurate reconstructions and predictions of glacier movement on timescales of human interest require a better understanding of available observations and the ability to model the key processes that govern ice flow. The fact that many of these processes are interconnected, are loosely constrained by data, and involve not only the ice, but also the atmosphere, ocean, and solid Earth, makes this a challenging endeavor, but one that is essential for Earth-system modeling and the resulting climate and sea-level forecasts that are provided to policymakers worldwide. Based on the amount of ice present in the West Antarctic Ice Sheet and its ability to flow and/or melt into the ocean, its complete collapse would result in a global sea-level rise of 3.3 to 5 meters, making its stability and rate of change scientific questions of global societal significance. Whether or not a collapse eventually occurs, a better understanding of the potential West Antarctic contribution to sea level over the coming decades and centuries is necessary when considering the fate of coastal population centers. Recent observations of the Amundsen Sea Embayment of West Antarctica indicate that it is experiencing faster mass loss than any other region of the continent. At present, the long-term stability of this embayment is unknown, with both theory and observations suggesting that collapse is possible. This study is focused on this critical region. We will test an ice-sheet model against existing observations, improve treatment of key processes in the model, and make projections with uncertainty assessments. This is a three-year modeling study using the open-source Ice Sheet System Model in coordination with other models to improve projections of future sea-level change. Project goals are to: 1. hindcast the past two-to-three decades of evolution of the Amundsen Sea Embayment sector to determine controlling processes, incorporate and test parameterizations, and assess and improve model initialization, spinup, and performance; 2. improve the model by utilizing sensitivity studies with regional process-oriented models to create numerically efficient parameterizations for key sub-grid-scale processes; 3. project a range of likely evolutions of the Amundsen Sea Embayment sector and their respective contributions to sea level in the next several centuries; 4. attribute sources of errors in the hindcast and provide an assessment of the uncertainties in the projections, including a range of likely outcomes given various forcings and inclusion or omission of physical processes in the model. At present, the long-term stability of the Amundsen Sea Embayment is unknown, with both theory (the \"marine ice sheet instability hypothesis\") and observations (rapid thinning and grounding-line retreat approaching regions where the bed deepens inland) suggesting that collapse is possible. But incompletely understood physical processes (e.g., basal hydrology, rheology, and sliding; tidal effects; ice-ocean interaction along the shelf and within the grounding zone) and lack of resolution in basal topography datasets making the ultimate outcome uncertain. Thus, there is a pressing need for high-resolution simulations of this region that include numerical representations of controlling physical processes (many of which are applicable elsewhere) within a higher-order ice-sheet model capable of assimilating recent observations and providing uncertainty analyses associated with model and data limitations. By focusing on the Amundsen Sea Embayment as a connected region across the 10-10,000-meter scales using a hierarchy of one, two, and three-dimensional models along with the sensitivity analysis tools built into the Ice Sheet System Model, this project aims to produce (1) the most reliable results to date when compared with studies that consider only one ice stream or the entire ice sheet and (2) estimates of differing dynamic responses arising from errors in data, model parameterizations, and forcings. Given the uncertainties, the project will produce a range of predictions with characteristic trends that can be recognized within future observational data sets. As new data become available, some predicted rates of change could be culled from the predictive paths generated by this study.", "east": -85.0, "geometry": "POINT(-107.5 -77.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; GLACIER MOTION/ICE SHEET MOTION; NOT APPLICABLE", "locations": "Antarctica", "north": -73.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Pollard, David; Parizek, Byron R.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -82.0, "title": "Collaborative Research: Evaluating Retreat in the Amundsen Sea Embayment: Assessing Controlling Processes, Uncertainties, and Projections", "uid": "p0010054", "west": -130.0}, {"awards": "1443346 Stone, John; 1443248 Hall, Brenda", "bounds_geometry": "POLYGON((-174 -84.2,-172.4 -84.2,-170.8 -84.2,-169.2 -84.2,-167.6 -84.2,-166 -84.2,-164.4 -84.2,-162.8 -84.2,-161.2 -84.2,-159.6 -84.2,-158 -84.2,-158 -84.36,-158 -84.52,-158 -84.68,-158 -84.84,-158 -85,-158 -85.16,-158 -85.32,-158 -85.48,-158 -85.64,-158 -85.8,-159.6 -85.8,-161.2 -85.8,-162.8 -85.8,-164.4 -85.8,-166 -85.8,-167.6 -85.8,-169.2 -85.8,-170.8 -85.8,-172.4 -85.8,-174 -85.8,-174 -85.64,-174 -85.48,-174 -85.32,-174 -85.16,-174 -85,-174 -84.84,-174 -84.68,-174 -84.52,-174 -84.36,-174 -84.2))", "dataset_titles": "Cosmogenic nuclide data from glacial deposits along the Liv Glacier coast; Ice-D Antarctic Cosmogenic Nuclide database - site DUNCAN; Ice-D Antarctic Cosmogenic Nuclide database - site MAASON; Liv and Amundsen Glacier Radiocarbon Data", "datasets": [{"dataset_uid": "200087", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Ice-D Antarctic Cosmogenic Nuclide database - site MAASON", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200088", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Ice-D Antarctic Cosmogenic Nuclide database - site DUNCAN", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "601226", "doi": "10.15784/601226", "keywords": "Antarctica; Be-10; Beryllium-10; Cosmogenic; Cosmogenic Dating; Cosmogenic Radionuclides; Deglaciation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Liv Glacier; Rocks; Ross Ice Sheet; Surface Exposure Dates; Transantarctic Mountains", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Cosmogenic nuclide data from glacial deposits along the Liv Glacier coast", "url": "https://www.usap-dc.org/view/dataset/601226"}, {"dataset_uid": "601208", "doi": "10.15784/601208", "keywords": "Antarctica; Carbon; Glaciology; Holocene; Radiocarbon; Ross Embayment; Ross Sea; Transantarctic Mountains", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Liv and Amundsen Glacier Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601208"}], "date_created": "Thu, 05 Sep 2019 00:00:00 GMT", "description": "The response of the Antarctic Ice Sheet to future climatic changes is recognized as the greatest uncertainty in projections of future sea level. An understanding of past ice fluctuations affords insight into ice-sheet response to climate and sea-level change and thus is critical for improving sea-level predictions. This project will examine deglaciation of the southern Ross Sea over the past few thousand years to document oscillations in Antarctic ice volume during a period of relatively stable climate and sea level. We will help quantify changes in ice volume, improve understanding of the ice dynamics responsible, and examine the implications for future sea-level change. The project will train future scientists through participation of graduate students, as well as undergraduates who will develop research projects in our laboratories. Previous research indicates rapid Ross Sea deglaciation as far south as Beardmore Glacier early in the Holocene epoch (which began approximately 11,700 years before present), followed by more gradual recession. However, deglaciation in the later half of the Holocene remains poorly constrained, with no chronological control on grounding-line migration between Beardmore and Scott Glaciers. Thus, we do not know if mid-Holocene recession drove the grounding line rapidly back to its present position at Scott Glacier, or if the ice sheet withdrew gradually in the absence of significant climate forcing or eustatic sea level change. The latter possibility raises concerns for future stability of the Ross Sea grounding line. To address this question, we will map and date glacial deposits on coastal mountains that constrain the thinning history of Liv and Amundsen Glaciers. By extending our chronology down to the level of floating ice at the mouths of these glaciers, we will date their thinning history from glacial maximum to present, as well as migration of the Ross Sea grounding line southwards along the Transantarctic Mountains. High-resolution dating will come from Beryllium-10 surface-exposure ages of erratics collected along elevation transects, as well as Carbon-14 dates of algae within shorelines from former ice-dammed ponds. Sites have been chosen specifically to allow close comparison of these two dating methods, which will afford constraints on Antarctic Beryllium-10 production rates.", "east": -158.0, "geometry": "POINT(-166 -85)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; NOT APPLICABLE; Antarctica; ICE SHEETS; USAP-DC", "locations": "Antarctica", "north": -84.2, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Stone, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "ICE-D", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -85.8, "title": "Collaborative Research: High-resolution Reconstruction of Holocene Deglaciation in the Southern Ross Embayment", "uid": "p0010053", "west": -174.0}, {"awards": "1443397 Kreutz, Karl; 1443663 Cole-Dai, Jihong; 1443336 Osterberg, Erich", "bounds_geometry": "POINT(-180 -90)", "dataset_titles": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.; South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; South Pole ice core (SPC14) discrete methane data; South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements; SPICEcore 400-480 m Major Ions SDSU; The South Pole Ice Core (SPICEcore) chronology and supporting data", "datasets": [{"dataset_uid": "601206", "doi": "10.15784/601206", "keywords": "Antarctica; Calcium (ca); Chemistry:ice; Chemistry:Ice; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciochemistry; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Ice Core Records; Ice Core Stratigraphy; Nitrate; Nitrogen Isotopes; Paleoclimate; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Brook, Edward J.; Severinghaus, Jeffrey P.; Osterberg, Erich; Waddington, Edwin D.; Iverson, Nels; Alley, Richard; Casey, Kimberly A.; Nicewonger, Melinda R.; Aydin, Murat; Ferris, David G.; Jones, Tyler R.; Kahle, Emma; Morris, Valerie; Steig, Eric J.; Sowers, Todd A.; Beaudette, Ross; Ortman, Nikolas; Epifanio, Jenna; Kreutz, Karl; Cox, Thomas S.; Thundercloud, Zayta; Cole-Dai, Jihong; Fegyveresi, John; McConnell, Joseph; Sigl, Michael; Souney, Joseph Jr.; Bay, Ryan; Buizert, Christo; Dunbar, Nelia; Fudge, T. J.; Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "The South Pole Ice Core (SPICEcore) chronology and supporting data", "url": "https://www.usap-dc.org/view/dataset/601206"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601675", "doi": "10.15784/601675", "keywords": "Antarctica; South Pole; SPICEcore", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.", "url": "https://www.usap-dc.org/view/dataset/601675"}, {"dataset_uid": "601430", "doi": "10.15784/601430", "keywords": "Antarctica; Ions; South Pole; SPICEcore", "people": "Cole-Dai, Jihong; Larrick, Carleigh", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore 400-480 m Major Ions SDSU", "url": "https://www.usap-dc.org/view/dataset/601430"}, {"dataset_uid": "601553", "doi": "10.15784/601553", "keywords": "Antarctica; Dust; Ice Core; South Pole", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements", "url": "https://www.usap-dc.org/view/dataset/601553"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Aydin, Murat; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}], "date_created": "Thu, 29 Aug 2019 00:00:00 GMT", "description": "This collaborative project explores the signatures and causes of natural climate change in the region surrounding Antarctica over the last 40,000 years as the Earth transitioned from an ice age into the modern warm period. The researchers will investigate how the wind belts that surround Antarctica changed in their strength and position through time, and document explosive volcanic eruptions and CO2 cycling in the Southern Ocean as potential climate forcing mechanisms over this interval. Understanding how and why the climate varied naturally in the past is critical for improving understanding of modern climate change and projections of future climate under higher levels of atmospheric CO2. The investigators plan to conduct a suite of chemical measurements along the 1500m length of the South Pole Ice Core, including major ion and trace element concentrations, and microparticle (dust) concentrations and size distributions. These measurements will (1) extend the South Pole record of explosive volcanic eruptions to 40,000 years using sulfate and particle data; (2) establish the relative timing of climate changes in dust source regions of Patagonia, New Zealand, and Australia using dust flux data; (3) investigate changes in the strength and position of the westerly wind belt using dust size distribution data; and (4) quantify the flux of bioavailable trace metals deposited as dust to the Southern Ocean over time. These chemistry records will also be critical for creating the timescale that will be used by all researchers studying records from the South Pole core. The project will support four graduate students and several undergraduate students across three different institutions, and become a focus of the investigators\u0027 efforts to disseminate outcomes of climate change science to the broader community.", "east": -180.0, "geometry": "POINT(-180 -90)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; ICE CORE RECORDS; USAP-DC; Amd/Us; USA/NSF; LABORATORY; AMD", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Osterberg, Erich", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "uid": "p0010051", "west": -180.0}, {"awards": "1826712 McMahon, Kelton; 1443386 Emslie, Steven; 1443585 Polito, Michael; 1443424 McMahon, Kelton", "bounds_geometry": "POLYGON((-180 -60,-166 -60,-152 -60,-138 -60,-124 -60,-110 -60,-96 -60,-82 -60,-68 -60,-54 -60,-40 -60,-40 -61.8,-40 -63.6,-40 -65.4,-40 -67.2,-40 -69,-40 -70.8,-40 -72.6,-40 -74.4,-40 -76.2,-40 -78,-54 -78,-68 -78,-82 -78,-96 -78,-110 -78,-124 -78,-138 -78,-152 -78,-166 -78,180 -78,178 -78,176 -78,174 -78,172 -78,170 -78,168 -78,166 -78,164 -78,162 -78,160 -78,160 -76.2,160 -74.4,160 -72.6,160 -70.8,160 -69,160 -67.2,160 -65.4,160 -63.6,160 -61.8,160 -60,162 -60,164 -60,166 -60,168 -60,170 -60,172 -60,174 -60,176 -60,178 -60,-180 -60))", "dataset_titles": "Amino acid nitrogen isotope values of modern and ancient Ad\u00e9lie penguin eggshells from the Ross Sea and Antarctic Peninsula regions; Amino acid nitrogen isotope values of penguins from the Antarctic Peninsula region 1930s to 2010s; Ancient Adelie penguin colony revealed by snowmelt at Cape Irizar, Ross Sea, Antarctica; Carbon and nitrogen stable isotope values of Antarctic Krill from the South Shetland Islands and the northern Antarctic Peninsula 2007 and 2009; Radiocarbon dates from pygoscelid penguin tissues excavated at Stranger Point, King George Island, Antarctic Peninsula; Radiocarbon dating and stable isotope values of penguin and seal tissues recovered from ornithogenic soils on Platter Island, Danger Islands Archipelago, Antarctic Peninsula in December 2015.; Radioisotope dates and carbon (\u03b413C) and nitrogen (\u03b415N) stable isotope values from modern and mummified Ad\u00e9lie Penguin chick carcasses and tissue from the Ross Sea, Antarctica; Radiometric dating, geochemical proxies, and predator biological remains obtained from aquatic sediment cores on South Georgia Island.; Receding ice drove parallel expansions in Southern Ocean penguin; SNP data from \"Receding ice drove parallel expansions in Southern Ocean penguins\".; Stable isotope analysis of multiple tissues from chick carcasses of three pygoscelid penguins in Antarctica; Stable isotopes of Adelie Penguin chick bone collagen; The rise and fall of an ancient Adelie penguin \u0027supercolony\u0027 at Cape Adare, Antarctica", "datasets": [{"dataset_uid": "601327", "doi": "10.15784/601327", "keywords": "Adelie Penguin; Antarctica; Biota; Cape Adare; East Antarctica; Population Movement; Pygoscelis Adeliae; Radiocarbon; Ross Sea; Sea Level Rise; Stable Isotopes", "people": "Patterson, William; McKenzie, Ashley; Emslie, Steven D.", "repository": "USAP-DC", "science_program": null, "title": "The rise and fall of an ancient Adelie penguin \u0027supercolony\u0027 at Cape Adare, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601327"}, {"dataset_uid": "601212", "doi": "10.15784/601212", "keywords": "Abandoned Colonies; Antarctica; Antarctic Peninsula; Beach Deposit; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Holocene; Penguin; Radiocarbon; Radiocarbon Dates; Snow/ice; Snow/Ice; Stranger Point", "people": "Emslie, Steven D.", "repository": "USAP-DC", "science_program": null, "title": "Radiocarbon dates from pygoscelid penguin tissues excavated at Stranger Point, King George Island, Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601212"}, {"dataset_uid": "601210", "doi": "10.15784/601210", "keywords": "Antarctica; Antarctic Krill; Antarctic Peninsula; Biota; Carbon Isotopes; Isotope Data; Krill; Nitrogen Isotopes; Oceans; Southern Ocean; Stable Isotope Analysis", "people": "Polito, Michael", "repository": "USAP-DC", "science_program": null, "title": "Carbon and nitrogen stable isotope values of Antarctic Krill from the South Shetland Islands and the northern Antarctic Peninsula 2007 and 2009", "url": "https://www.usap-dc.org/view/dataset/601210"}, {"dataset_uid": "601232", "doi": "10.15784/601232", "keywords": "Amino Acids; Antarctica; Antarctic Peninsula; Biota; Isotope Data; Nitrogen Isotopes; Oceans; Penguin; Southern Ocean; Stable Isotope Analysis", "people": "Polito, Michael; McMahon, Kelton", "repository": "USAP-DC", "science_program": null, "title": "Amino acid nitrogen isotope values of penguins from the Antarctic Peninsula region 1930s to 2010s", "url": "https://www.usap-dc.org/view/dataset/601232"}, {"dataset_uid": "601374", "doi": "10.15784/601374", "keywords": "Adelie Penguin; Antarctica; Cape Irizar; Drygalski Ice Tongue; Ross Sea; Stable Isotopes", "people": "Emslie, Steven D.", "repository": "USAP-DC", "science_program": null, "title": "Ancient Adelie penguin colony revealed by snowmelt at Cape Irizar, Ross Sea, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601374"}, {"dataset_uid": "601382", "doi": "10.15784/601382", "keywords": "25 De Mayo/King George Island; Antarctica; Biota; Delta 13C; Delta 15N; Dietary Shifts; Opportunistic Sampling; Penguin; Pygoscelis Penguins; Stranger Point", "people": "Emslie, Steven D.; Ciriani, Yanina", "repository": "USAP-DC", "science_program": null, "title": "Stable isotope analysis of multiple tissues from chick carcasses of three pygoscelid penguins in Antarctica", "url": "https://www.usap-dc.org/view/dataset/601382"}, {"dataset_uid": "601913", "doi": "10.15784/601913", "keywords": "Adelie Penguin; Antarctica; Cryosphere; Foraging; Polynya; Pygoscelis Adeliae; Ross Sea; Stable Isotopes", "people": "Powers, Shannon; Emslie, Steven D.; Reaves, Megan", "repository": "USAP-DC", "science_program": null, "title": "Stable isotopes of Adelie Penguin chick bone collagen", "url": "https://www.usap-dc.org/view/dataset/601913"}, {"dataset_uid": "601509", "doi": "10.15784/601509", "keywords": "Antarctica; Antarctic Fur Seal; Elemental Concentrations; King Penguin; Population Dynamics; South Atlantic Ocean; South Georgia Island; Stable Isotope Analysis; Sub-Antarctic", "people": "Polito, Michael; McMahon, Kelton; Maiti, Kanchan; Kristan, Allyson", "repository": "USAP-DC", "science_program": null, "title": "Radiometric dating, geochemical proxies, and predator biological remains obtained from aquatic sediment cores on South Georgia Island.", "url": "https://www.usap-dc.org/view/dataset/601509"}, {"dataset_uid": "601760", "doi": "10.15784/601760", "keywords": "Adelie Penguin; Amino Acids; Antarctica; Antarctic Peninsula; Ross Sea; Stable Isotope Analysis; Trophic Position", "people": "Patterson, William; Emslie, Steven D.; Michelson, Chantel; Polito, Michael; Wonder, Michael; McCarthy, Matthew; McMahon, Kelton", "repository": "USAP-DC", "science_program": null, "title": "Amino acid nitrogen isotope values of modern and ancient Ad\u00e9lie penguin eggshells from the Ross Sea and Antarctic Peninsula regions", "url": "https://www.usap-dc.org/view/dataset/601760"}, {"dataset_uid": "200181", "doi": "10.6084/m9.figshare.c.4475300.v1", "keywords": null, "people": null, "repository": "Figshare", "science_program": null, "title": "SNP data from \"Receding ice drove parallel expansions in Southern Ocean penguins\".", "url": "https://doi.org/10.6084/m9.figshare.c.4475300.v1"}, {"dataset_uid": "601263", "doi": "10.15784/601263", "keywords": "Abandoned Colonies; Antarctica; Holocene; Penguin; Ross Sea; Stable Isotope Analysis", "people": "Patterson, William; Emslie, Steven D.; Kristan, Allyson", "repository": "USAP-DC", "science_program": null, "title": "Radioisotope dates and carbon (\u03b413C) and nitrogen (\u03b415N) stable isotope values from modern and mummified Ad\u00e9lie Penguin chick carcasses and tissue from the Ross Sea, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601263"}, {"dataset_uid": "601364", "doi": "10.15784/601364", "keywords": "Antarctica; Antarctic Peninsula; Arctocephalus Gazella; Carbon; Holocene; Nitrogen; Paleoecology; Penguin; Pygoscelis Spp.; Stable Isotope Analysis; Weddell Sea", "people": "Herman, Rachael; Kalvakaalva, Rohit; Clucas, Gemma; Polito, Michael", "repository": "USAP-DC", "science_program": null, "title": "Radiocarbon dating and stable isotope values of penguin and seal tissues recovered from ornithogenic soils on Platter Island, Danger Islands Archipelago, Antarctic Peninsula in December 2015.", "url": "https://www.usap-dc.org/view/dataset/601364"}, {"dataset_uid": "200180", "doi": "", "keywords": null, "people": null, "repository": "NCBI BioProject", "science_program": null, "title": "Receding ice drove parallel expansions in Southern Ocean penguin", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA589336"}], "date_created": "Thu, 08 Aug 2019 00:00:00 GMT", "description": "The Antarctic marine ecosystem is highly productive and supports a diverse range of ecologically and commercially important species. A key species in this ecosystem is Antarctic krill, which in addition to being commercially harvested, is the principle prey of a wide range of marine organisms including penguins, seals and whales. The aim of this study is to use penguins and other krill predators as sensitive indicators of past changes in the Antarctic marine food web resulting from climate variability and the historic harvesting of seals and whales by humans. Specifically this study will recover and analyze modern (\u003c20 year old), historic (20-200 year old) and ancient (200-10,000 year old) penguin and other krill predator tissues to track their past diets and population movements relative to shifts in climate and the availability of Antarctic krill. Understanding how krill predators were affected by these factors in the past will allow us to better understand how these predators, the krill they depend on, and the Antarctic marine ecosystem as a whole will respond to current challenges such as global climate change and an expanding commercial fishery for Antarctic krill. The project will further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. This project will support the cross-institutional training of undergraduate and graduate students in advanced analytical techniques in the fields of ecology and biogeochemistry. In addition, this project includes educational outreach aimed encouraging participation in science careers by engaging K-12 students in scientific issues related to Antarctica, penguins, marine ecology, biogeochemistry, and global climate change. This research will help place recent ecological changes in the Southern Ocean into a larger historical context by examining decadal and millennial-scale shifts in the diets and population movements of Antarctic krill predators (penguins, seals, and squid) in concert with climate variability and commercial harvesting. This will be achieved by coupling advanced stable and radio isotope techniques, particularly compound-specific stable isotope analysis, with unprecedented access to modern, historical, and well-preserved paleo-archives of Antarctic predator tissues dating throughout the Holocene. This approach will allow the project to empirically test if observed shifts in Antarctic predator bulk tissue stable isotope values over the past millennia were caused by climate-driven shifts at the base of the food web in addition to, or rather than, shifts in predator diets due to a competitive release following the historic harvesting of krill eating whale and seals. In addition, this project will track the large-scale abandonment and reoccupation of penguin colonies around Antarctica in response to changes in climate and sea ice conditions over the past several millennia. These integrated field studies and laboratory analyses will provide new insights into the underlying mechanisms that influenced past shifts in the diets and population movements of charismatic krill predators such as penguins. This will allow for improved projections of the ecosystem consequences of future climate change and anthropogenic harvesting scenarios in the Antarctica that are likely to affect the availability of Antarctic krill.", "east": -40.0, "geometry": "POINT(-120 -69)", "instruments": null, "is_usap_dc": true, "keywords": "ANIMAL ECOLOGY AND BEHAVIOR; South Shetland Islands; Penguin; Stable Isotopes; Polar; Ross Sea; USA/NSF; Weddell Sea; AMD; MARINE ECOSYSTEMS; USAP-DC; Antarctica; PENGUINS; Southern Hemisphere; FIELD INVESTIGATION; Amd/Us; Krill; MACROFOSSILS", "locations": "Southern Hemisphere; Ross Sea; South Shetland Islands; Weddell Sea; Polar; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Polito, Michael; Kelton, McMahon; Patterson, William; McCarthy, Matthew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "Figshare; NCBI BioProject; USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators", "uid": "p0010047", "west": 160.0}, {"awards": "1443420 Dodd, Justin", "bounds_geometry": "POLYGON((167.07 -77.87,167.073 -77.87,167.076 -77.87,167.079 -77.87,167.082 -77.87,167.085 -77.87,167.088 -77.87,167.091 -77.87,167.094 -77.87,167.097 -77.87,167.1 -77.87,167.1 -77.873,167.1 -77.876,167.1 -77.879,167.1 -77.882,167.1 -77.885,167.1 -77.888,167.1 -77.891,167.1 -77.894,167.1 -77.897,167.1 -77.9,167.097 -77.9,167.094 -77.9,167.091 -77.9,167.088 -77.9,167.085 -77.9,167.082 -77.9,167.079 -77.9,167.076 -77.9,167.073 -77.9,167.07 -77.9,167.07 -77.897,167.07 -77.894,167.07 -77.891,167.07 -77.888,167.07 -77.885,167.07 -77.882,167.07 -77.879,167.07 -77.876,167.07 -77.873,167.07 -77.87))", "dataset_titles": "Diatom Oxygen Isotope Evidence of Pliocene (~4.68 to 3.44 Ma) Antarctic Ice Sheet Dynamics and Ross Sea Paleoceanography", "datasets": [{"dataset_uid": "601220", "doi": "10.15784/601220", "keywords": "And-1B; Andrill; Antarctica; Chemistry:sediment; Chemistry:Sediment; Delta 18O; Diatom; Mass Spectrometer; Oxygen Isotope; Paleoclimate; Pliocene; Sediment; Wais Project; West Antarctic Ice Sheet", "people": "Abbott, Tirzah; Dodd, Justin", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Diatom Oxygen Isotope Evidence of Pliocene (~4.68 to 3.44 Ma) Antarctic Ice Sheet Dynamics and Ross Sea Paleoceanography", "url": "https://www.usap-dc.org/view/dataset/601220"}], "date_created": "Tue, 06 Aug 2019 00:00:00 GMT", "description": "Abstract During the Early Pliocene, 4.8 to 3.4 million years ago, warmer-than-present global temperatures resulted in a retreat of the Ross Ice Shelf and West Antarctic Ice Sheet. Understanding changes in ocean dynamics during times of reduced ice volume and increased temperatures in the geologic past will improve the predictive models for these conditions. The primary goal of the proposed research is to develop a new oxygen isotope record of Pliocene oceanographic conditions near the Antarctic continent. Oxygen isotope values from the carbonate tests of benthic foraminifera have become the global standard for paleo-oceanographic studies, but foraminifera are sparse in high-latitude sediment cores. This research will instead make use of oxygen isotope measurements from diatom silica preserved in a marine sediment core from the Ross Sea. The project is the first attempt at using this method and will advance understanding of global ocean dynamics and ice sheet-ocean interactions during the Pliocene. The project will foster the professional development of two early-career scientists and serve as training for graduate and undergraduate student researchers. The PIs will use this project to introduce High School students to polar/oceanographic research, as well as stable isotope geochemistry. Collaboration with teachers via NSTA and Polar Educators International will ensure the implementation of excellent STEM learning activities and curricula for younger students. Technical Description This project will produce a high-resolution oxygen isotope record from well-dated diatom rich sediments that have been cross-correlated with global benthic foraminifera oxygen isotope records. Diatom silica frustules deposited during the Early Pliocene and recovered by the ANDRILL Project (AND-1B) provide ideal material for this objective. Diatomite unites in the AND-1B core are nearly pure, with little evidence of opal formation. A diatom oxygen isotope record from this core offers the potential to constrain lingering uncertainties about Ross Sea and Southern Ocean paleoceanography and Antarctic Ice Sheet history during a time of high atmospheric carbon dioxide concentrations. Specifically, oxygen isotope variations will be used to constrain changes in the water temperature and/or freshwater flux in the Pliocene Ross Sea. Diatom species data from the AND-1B core have been used to infer variations in the extent and duration of seasonal sea ice coverage, sea surface temperatures, and mid-water advection onto the continental shelf. However, the diatom oxygen isotope record will provide the first direct measure of water/oxygen isotope values at the Antarctic continental margin during the Pliocene.", "east": 167.1, "geometry": "POINT(167.085 -77.885)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "OXYGEN ISOTOPES; USAP-DC; Antarctica; NOT APPLICABLE", "locations": "Antarctica", "north": -77.87, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Dodd, Justin; Scherer, Reed Paul; Warnock, Jonathan", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.9, "title": "Diatom and Oxygen Isotope Evidence of Pliocene Antarctic Ice Sheet Dynamics and Ross Sea Paleoceanography", "uid": "p0010042", "west": 167.07}, {"awards": "1543267 Brook, Edward J.; 1543229 Severinghaus, Jeffrey", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Multi-site ice core Krypton stable isotope ratios; Noble Gas Data from recent ice in Antarctica for 86Kr problem", "datasets": [{"dataset_uid": "601195", "doi": "10.15784/601195", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Krypton; Noble Gas; Xenon", "people": "Severinghaus, Jeffrey P.; Shackleton, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Noble Gas Data from recent ice in Antarctica for 86Kr problem", "url": "https://www.usap-dc.org/view/dataset/601195"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Bertler, Nancy; Etheridge, David; Shackleton, Sarah; Pyne, Rebecca L.; Buizert, Christo; Mulvaney, Robert; Severinghaus, Jeffrey P.; Brook, Edward J.; Baggenstos, Daniel; Mosley-Thompson, Ellen; Bereiter, Bernhard", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Etheridge, David; Brook, Edward J.; Bereiter, Bernhard; Severinghaus, Jeffrey P.; Bertler, Nancy; Buizert, Christo; Shackleton, Sarah; Baggenstos, Daniel; Pyne, Rebecca L.; Mulvaney, Robert; Mosley-Thompson, Ellen", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Severinghaus, Jeffrey P.; Bertler, Nancy; Pyne, Rebecca L.; Shackleton, Sarah; Buizert, Christo; Mulvaney, Robert; Mosley-Thompson, Ellen; Etheridge, David; Bereiter, Bernhard; Baggenstos, Daniel; Brook, Edward J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}], "date_created": "Wed, 10 Jul 2019 00:00:00 GMT", "description": "Brook 1543267 Approximately half of the human caused carbon dioxide emissions to the atmosphere are absorbed by the ocean, which reduces the amount of global warming associated with these emissions. Much of this carbon uptake occurs in the Southern Ocean around Antarctica, where water from the deep ocean comes to the surface. How much water \"up-wells,\" and therefore how much carbon is absorbed, is believed to depend on the strength and location of the major westerly winds in the southern hemisphere. These wind patterns have been shifting southward in recent decades, and future changes could impact the global carbon cycle and promote the circulation of relatively warm water from the deep ocean on to the continental shelf, which contributes to enhanced Antarctic ice melt and sea level rise. Understanding of the westerly winds and their role in controlling atmospheric carbon dioxide levels and the circulation of ocean water is therefore very important. The work supported by this award will study past movement of the SH westerlies in response to natural climate variations. Of particular interest is the last deglaciation (20,000 to 10,000 years ago), when the global climate made a transition from an ice age climate to the current warm period. During this period, atmospheric carbon dioxide rose from about 180 ppm to 270 parts per million, and one leading hypothesis is that the rise in carbon dioxide was driven by a southward movement of the southern hemisphere westerlies. The broader impacts of the work include a perspective on past movement of the southern hemisphere westerlies and their link to atmospheric carbon dioxide, which could guide projections of future oceanic carbon dioxide uptake, with strong societal benefits; international collaboration with German scientists; training of a postdoctoral investigator; and outreach to public schools. This project will investigate whether the abundance of a noble gas, krypton-86, trapped in Antarctic ice cores, records atmospheric pressure variability, and whether or not this pressure variability can be used to infer past movement of the Southern Hemisphere westerly winds. The rationale for the project is that models of air movement in the snow pack (firn) in Antarctica indicate that pressure variations drive air movement that disturbs the normal enrichment in krypton-86 caused by gravitational settling of gases. Calculations predict that the krypton-86 deviation from gravitational equilibrium reflects the magnitude of pressure variations. In turn, atmospheric data show that pressure variability over Antarctica is linked to the position of the southern hemisphere westerly winds. Preliminary data from the West Antarctic Ice Sheet (WAIS) Divide ice core show a large excursion in krypton-86 during the transition from the last ice age to the current warm period. The investigators will perform krypton-86 analysis on ice core and firn air samples to establish whether the Kr-86 deviation is linked to pressure variability, refine the record of krypton isotopes from the WAIS Divide ice core, investigate the role of pressure variability in firn air transport using firn air models, and investigate how barometric pressure variability in Antarctica is linked to the position/strength of the SH westerlies in past and present climates.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USA/NSF; FIRN; ICE CORE RECORDS; USAP-DC; Greenland; Xenon; Noble Gas; Ice Core; Amd/Us; Antarctica; AMD; LABORATORY; Krypton; ATMOSPHERIC PRESSURE", "locations": "Greenland; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Brook, Edward J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative research: Kr-86 as a proxy for barometric pressure variability and movement of the SH westerlies during the last\r\ndeglaciation", "uid": "p0010037", "west": -180.0}, {"awards": "1443534 Bell, Robin; 1443677 Padman, Laurence; 1443498 Fricker, Helen; 1443497 Siddoway, Christine", "bounds_geometry": "POLYGON((-180 -77,-177 -77,-174 -77,-171 -77,-168 -77,-165 -77,-162 -77,-159 -77,-156 -77,-153 -77,-150 -77,-150 -77.9,-150 -78.8,-150 -79.7,-150 -80.6,-150 -81.5,-150 -82.4,-150 -83.3,-150 -84.2,-150 -85.1,-150 -86,-153 -86,-156 -86,-159 -86,-162 -86,-165 -86,-168 -86,-171 -86,-174 -86,-177 -86,180 -86,178.1 -86,176.2 -86,174.3 -86,172.4 -86,170.5 -86,168.6 -86,166.7 -86,164.8 -86,162.9 -86,161 -86,161 -85.1,161 -84.2,161 -83.3,161 -82.4,161 -81.5,161 -80.6,161 -79.7,161 -78.8,161 -77.9,161 -77,162.9 -77,164.8 -77,166.7 -77,168.6 -77,170.5 -77,172.4 -77,174.3 -77,176.2 -77,178.1 -77,-180 -77))", "dataset_titles": "Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data; CATS2008: Circum-Antarctic Tidal Simulation version 2008; CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023; Deep ICE (DICE) Radar Dataset from Ross Ice Shelf (ROSETTA-Ice); LiDAR Nadir and Swath Data from Ross Ice Shelf, Antarctica (ROSETTA-Ice); ROSETTA-Ice data page; Ross Sea ocean model simulation used to support ROSETTA-Ice ; Shallow Ice Radar (SIR) Dataset from Ross Ice Shelf (ROSETTA-Ice)", "datasets": [{"dataset_uid": "601788", "doi": null, "keywords": "Antarctica; Cryosphere; Ross Ice Shelf", "people": "Boghosian, Alexandra; Bertinato, Christopher; Locke, Caitlin; Dhakal, Tejendra; Becker, Maya K; Starke, Sarah", "repository": "USAP-DC", "science_program": null, "title": "LiDAR Nadir and Swath Data from Ross Ice Shelf, Antarctica (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601788"}, {"dataset_uid": "601794", "doi": null, "keywords": "Antarctica; Cryosphere; Remote Sensing; Ross Ice Shelf", "people": "Cordero, Isabel; Wearing, Martin; Spergel, Julian; Packard, Sarah; Dong, LingLing; Das, Indrani; Bell, Robin; Bertinato, Christopher; Chu, Winnie; Dhakal, Tejendra; Frearson, Nicholas; Keeshin, Skye", "repository": "USAP-DC", "science_program": null, "title": "Shallow Ice Radar (SIR) Dataset from Ross Ice Shelf (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601794"}, {"dataset_uid": "601789", "doi": null, "keywords": "Airborne Radar; Antarctica; Cryosphere; Ice Thickness; Remote Sensing; Ross Ice Shelf", "people": "Millstein, Joanna; Cordero, Isabel; Frearson, Nicholas; Dhakal, Tejendra; Bertinato, Christopher; Wilner, Joel; Dong, LingLing; Das, Indrani; Spergel, Julian; Chu, Winnie; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "Deep ICE (DICE) Radar Dataset from Ross Ice Shelf (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601789"}, {"dataset_uid": "601772", "doi": "10.15784/601772", "keywords": "Antarctica; Cryosphere; Inverse Modeling; Model Data; Ocean Currents; Oceans; Sea Surface; Southern Ocean; Tide Model; Tides", "people": "Sutterley, Tyler; Howard, Susan L.; Greene, Chad A.; Padman, Laurence; Erofeeva, Svetlana", "repository": "USAP-DC", "science_program": null, "title": "CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023", "url": "https://www.usap-dc.org/view/dataset/601772"}, {"dataset_uid": "200100", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "ROSETTA-Ice data page", "url": "http://wonder.ldeo.columbia.edu/data/ROSETTA-Ice/"}, {"dataset_uid": "601235", "doi": "10.15784/601235", "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "people": "Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana", "repository": "USAP-DC", "science_program": null, "title": "CATS2008: Circum-Antarctic Tidal Simulation version 2008", "url": "https://www.usap-dc.org/view/dataset/601235"}, {"dataset_uid": "601242", "doi": "10.15784/601242", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Penetrating Radar; Ice-Shelf Basal Melting; Radar Echo Sounder; Radar Echo Sounding; Snow/ice; Snow/Ice", "people": "Mosbeux, Cyrille; Cordero, Isabel; Tinto, Kirsty; Siegfried, Matthew; Siddoway, Christine; Dhakal, Tejendra; Das, Indrani; Bell, Robin; Padman, Laurence; Fricker, Helen; Frearson, Nicholas; Hulbe, Christina", "repository": "USAP-DC", "science_program": null, "title": "Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data", "url": "https://www.usap-dc.org/view/dataset/601242"}, {"dataset_uid": "601255", "doi": "10.15784/601255", "keywords": "Antarctica; Basal Melt; Ice Shelf; Model Output; Ocean Circulation Model; Ross Ice Shelf; Ross Sea", "people": "Howard, Susan L.; Springer, Scott; Padman, Laurence", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea ocean model simulation used to support ROSETTA-Ice ", "url": "https://www.usap-dc.org/view/dataset/601255"}], "date_created": "Wed, 03 Jul 2019 00:00:00 GMT", "description": "The Ross Ice Shelf is the largest existing ice shelf in Antarctica, and is currently stabilizing significant portions of the land ice atop the Antarctic continent. An ice shelf begins where the land ice goes afloat on the ocean, and as such, the Ross Ice Shelf interacts with the ocean and seafloor below, and the land ice behind. Currently, the Ross Ice Shelf slows down, or buttresses, the fast flowing ice streams of the West Antarctic Ice Sheet (WAIS), a marine-based ice sheet, which if melted, would raise global sea level by 3-4 meters. The Ross Ice Shelf average ice thickness is approximately 350 meters, and it covers approximately 487,000 square kilometers, an area slightly larger than the state of California. The Ross Ice Shelf has disappeared during prior interglacial periods, suggesting in the future it may disappear again. Understanding the dynamics, stability and future of the West Antarctic Ice Sheet therefore requires in-depth knowledge of the Ross Ice Shelf. The ROSETTA-ICE project brings together scientists from 4 US institutions and from the Institute of Geological and Nuclear Sciences Limited, known as GNS Science, New Zealand. The ROSETTA-ICE data on the ice shelf, the water beneath the ice shelf, and the underlying rocks, will allow better predictions of how the Ross Ice Shelf will respond to changing climate, and therefore how the WAIS will behave in the future. The interdisciplinary ROSETTA-ICE team will train undergraduate and high school students in cutting edge research techniques, and will also work to educate the public via a series of vignettes integrating ROSETTA-ICE science with the scientific and human history of Antarctic research. The ROSETTA-ICE survey will acquire gravity and magnetics data to determine the water depth beneath the ice shelf. Radar, LIDAR and imagery systems will be used to map the Ross Ice Shelf thickness and fine structure, crevasses, channels, debris, surface accumulation and distribution of marine ice. The high resolution aerogeophysical data over the Ross Ice Shelf region in Antarctica will be acquired using the IcePod sensor suite mounted externally on an LC-130 aircraft operating from McMurdo Station, Antarctica. Field activities will include ~36 flights on LC-130 aircraft over two field seasons in Antarctica. The IcePod instrument suite leverages the unique experience of the New York Air National Guard operating in Antarctica for NSF scientific research as well as infrastructure and logistics. The project will answer questions about the stability of the Ross Ice Shelf in future climate, and the geotectonic evolution of the Ross Ice Shelf Region, a key component of the West Antarctic Rift system. The comprehensive benchmark data sets acquired will enable broad, interdisciplinary analyses and modeling, which will also be performed as part of the project. ROSETTA-ICE will illuminate Ross ice sheet-ice shelf-ocean dynamics as the system nears a critical juncture but still is intact. Through interacting with an online data visualization tool, and comparing the ROSETTA-ICE data and results from earlier studies, we will engage students and young investigators, equipping them with new capabilities for the study of critical earth systems that influence global climate.", "east": 161.0, "geometry": "POINT(-174.5 -81.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LIDAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e PROTON MAGNETOMETER", "is_usap_dc": true, "keywords": "Airborne Radar; LIDAR; Ross Ice Shelf; SALINITY; SALINITY/DENSITY; CONDUCTIVITY; ICE DEPTH/THICKNESS; Tidal Models; GRAVITY ANOMALIES; Ross Sea; Antarctica; BATHYMETRY; C-130; MAGNETIC ANOMALIES; USAP-DC; Airborne Gravity", "locations": "Ross Sea; Antarctica; Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Bell, Robin; Frearson, Nicholas; Das, Indrani; Fricker, Helen; Padman, Laurence; Springer, Scott; Siddoway, Christine; Tinto, Kirsty", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e C-130", "repo": "USAP-DC", "repositories": "PI website; USAP-DC", "science_programs": null, "south": -86.0, "title": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE)", "uid": "p0010035", "west": -150.0}, {"awards": "1246357 Bart, Philip", "bounds_geometry": null, "dataset_titles": "NBP1502 Cruise Geophysics and underway data; NBP1502 YoYo camera benthic images from Ross Sea", "datasets": [{"dataset_uid": "601182", "doi": "10.15784/601182", "keywords": "Antarctica; Benthic; Benthic Images; Benthos; Bentic Fauna; Camera Tow; Marine Geoscience; Marine Sediments; NBP1502; Photo; Photo/video; Photo/Video; Ross Sea; R/v Nathaniel B. Palmer; Southern Ocean; Yoyo Camera", "people": "Bart, Philip", "repository": "USAP-DC", "science_program": null, "title": "NBP1502 YoYo camera benthic images from Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601182"}, {"dataset_uid": "000245", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1502 Cruise Geophysics and underway data", "url": "https://www.rvdata.us/search/cruise/NBP1502"}], "date_created": "Mon, 03 Jun 2019 00:00:00 GMT", "description": "Intellectual Merit: Evidence from the eastern Ross Sea continental shelf indicates that the West Antarctic Ice Sheet advanced and retreated during the last glacial cycle, but it is unclear whether the ice sheet advanced to the shelf edge or just to the middle shelf. These two end-member scenarios offer different interpretations as to why, how, and when the West Antarctic Ice Sheet oscillated. The PI proposes to acquire seismic, multibeam, and core data from Whales Deep, to evaluate the timing and duration of two advances of grounded ice to the outer and middle shelf of the Whales Deep Basin, a West Antarctic Ice Sheet paleo ice stream trough in eastern Ross Sea. Grounding events are represented by seismically resolvable Grounding Zone Wedges. The PI will collect radiocarbon dates on in situ benthic foraminifera from the grounding zone diamict as well as ramped pyrolysis radiocarbon dates on acid insoluble organics from open-marine mud overlying the grounding zone diamict. Using these data the PI will calculate the duration of the two grounding events. Furthermore, the PI will test a numerical model prediction that West Antarctic Ice Sheet retreat must have involved melting at the marine terminus of the ice sheet. Pore-water from the grounding zone diamict will be extracted from piston cores to determine salinity and \u0026#948;18O values that should indicate if significant melting occurred at the grounding line. Broader impacts: The data collected will provide constraints on the timing and pattern of Last Glacial Maximum advance and retreat that can be incorporated into interpretations of ice-surface elevation changes. The proposed activities will provide valuable field and research training to undergraduate/graduate students and a Louisiana high-school science teacher. The research will be interactively shared with middle- and high-school science students and with visitors to the LSU Museum of Natural Science Weekend-Science Program.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e AIRGUN ARRAYS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e LONG STREAMERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "STRATIGRAPHIC SEQUENCE; R/V NBP; Ross Sea; Antarctica; MICROFOSSILS; RADIOCARBON; PALEOCLIMATE RECONSTRUCTIONS; SEDIMENTS; Southern Ocean; OCEANS; GEOSCIENTIFIC INFORMATION", "locations": "Antarctica; Ross Sea; Southern Ocean", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bart, Philip; Steinberg, Deborah", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "Timing and Duration of the LGM and Post-LGM Grounding Events in Whales Deep Paleo Ice Stream, Eastern Ross Sea Middle Continental Shelf", "uid": "p0000877", "west": null}, {"awards": "1443552 Paul Winberry, J.; 1443356 Conway, Howard", "bounds_geometry": "POLYGON((-175 -82.7,-173.9 -82.7,-172.8 -82.7,-171.7 -82.7,-170.6 -82.7,-169.5 -82.7,-168.4 -82.7,-167.3 -82.7,-166.2 -82.7,-165.1 -82.7,-164 -82.7,-164 -82.77,-164 -82.84,-164 -82.91,-164 -82.98,-164 -83.05,-164 -83.12,-164 -83.19,-164 -83.26,-164 -83.33,-164 -83.4,-165.1 -83.4,-166.2 -83.4,-167.3 -83.4,-168.4 -83.4,-169.5 -83.4,-170.6 -83.4,-171.7 -83.4,-172.8 -83.4,-173.9 -83.4,-175 -83.4,-175 -83.33,-175 -83.26,-175 -83.19,-175 -83.12,-175 -83.05,-175 -82.98,-175 -82.91,-175 -82.84,-175 -82.77,-175 -82.7))", "dataset_titles": "2015_Antarctica_Ground; Geophysical data from Crary Ice Rise, Ross Sea Embayment", "datasets": [{"dataset_uid": "200177", "doi": "", "keywords": null, "people": null, "repository": "CReSIS/ku.edu", "science_program": null, "title": "2015_Antarctica_Ground", "url": "https://data.cresis.ku.edu/data/accum/2015_Antarctica_Ground/"}, {"dataset_uid": "601181", "doi": "10.15784/601181", "keywords": "Antarctica; Bed Elevation; Crary Ice Rise; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Ice Sheet Elevation; Ice Shelf; Ice Thickness; Internal Stratigraphy; Radar; Ross Ice Shelf; Snow/ice; Snow/Ice; Surface Elevation", "people": "Winberry, Paul; Conway, Howard; Koutnik, Michelle; Paden, John", "repository": "USAP-DC", "science_program": null, "title": "Geophysical data from Crary Ice Rise, Ross Sea Embayment", "url": "https://www.usap-dc.org/view/dataset/601181"}], "date_created": "Mon, 06 May 2019 00:00:00 GMT", "description": "Recent observations and model results suggest that collapse of the Amundsen Sea sector of West Antarctica may already be underway. However, the timeline of collapse and the effects of ongoing climatic and oceanographic changes are key unanswered questions. Complete disintegration of the ice sheet would raise global sea level by more than 3 m, which would have significant societal impacts. Improved understanding of the controls on ice-sheet evolution is needed to make better predictions of ice-sheet behavior. Results from numerical models show that buttressing from surrounding ice shelves and/or from small-scale grounded ice rises should act to slow the retreat and discharge of ice from the interior ice sheet. However, there are very few field observations with which to develop and validate models. Field observations conducted in the early 1980s on Crary Ice Rise in the Ross Sea Embayment are a notable exception. This project will revisit Crary Ice Rise with new tools to make a suite of measurements designed to address questions about how the ice rise affects ice discharge from the Ross Sea sector of West Antarctica. The team will include a graduate and undergraduate student, and will participate in a range of outreach activities. New tools including radar, seismic, and GPS instruments will be used to conduct targeted geophysical measurements both on Crary Ice Rise and across its grounding line. The project will use these new measurements, together with available ancillary data to inform a numerical model of grounding line dynamics. The model and measurements will be used to address the (1) How has the ice rise evolved over timescales ranging from: the past few decades; the past millennia after freeze-on; and through the deglaciation? (2) What history of ice dynamics is preserved in the radar-detected internal stratigraphy? (3) What dynamical effect does the presence/absence of the ice rise have on discharge of the Ross Ice Streams today? (4) How is it contributing to the slow-down of the proximal Whillans and Mercer ice streams? (5) What dynamical response will the ice rise have under future environmental change?", "east": -164.0, "geometry": "POINT(-169.5 -83.05)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Amd/Us; FIELD SURVEYS; Antarctica; USA/NSF; AMD; USAP-DC; Radar; GLACIERS/ICE SHEETS", "locations": "Antarctica", "north": -82.7, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Koutnik, Michelle; Winberry, Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "CReSIS/ku.edu", "repositories": "CReSIS/ku.edu; USAP-DC", "science_programs": null, "south": -83.4, "title": "Collaborative Research: Grounding Line Dynamics: Crary Ice Rise Revisited", "uid": "p0010026", "west": -175.0}, {"awards": "1543031 Ivany, Linda", "bounds_geometry": null, "dataset_titles": "NetCDF outputs from middle Eocene climate simulation using the GENESIS global circulation model ; Organic carbon isotope data from serially sampled Eocene driftwood from the La Meseta Fm., Seymour ; Oxygen isotope data from serially sampled Eocene bivalves from the La Meseta Fm., Seymour Island, Antarctica ", "datasets": [{"dataset_uid": "601175", "doi": "10.15784/601175 ", "keywords": "Antarctica; Atmosphere; Climate Model; Computer Model; Eocene; Genesis; Global Circulation Model; Modeling; Model Output; Seasonality; Temperature", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "NetCDF outputs from middle Eocene climate simulation using the GENESIS global circulation model ", "url": "https://www.usap-dc.org/view/dataset/601175"}, {"dataset_uid": "601173", "doi": "10.15784/601173 ", "keywords": "Antarctica; Carbon Isotopes; Driftwood; Eocene; Geochemistry; Geochronology; Isotope Data; La Meseta Formation; Mass Spectrometer; Mass Spectrometry; Organic Carbon Isotopes; Seasonality; Seymour Island; Wood", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "Organic carbon isotope data from serially sampled Eocene driftwood from the La Meseta Fm., Seymour ", "url": "https://www.usap-dc.org/view/dataset/601173"}, {"dataset_uid": "601174", "doi": "10.15784/601174", "keywords": "Antarctica; Biota; Bivalves; Cucullaea; Eocene; Glaciers/ice Sheet; Glaciers/Ice Sheet; Isotope Data; La Meseta Formation; Mass Spectrometer; Mass Spectrometry; Oxygen Isotope; Paleotemperature; Retrotapes; Seasonality; Seymour Island", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "Oxygen isotope data from serially sampled Eocene bivalves from the La Meseta Fm., Seymour Island, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601174"}], "date_created": "Tue, 23 Apr 2019 00:00:00 GMT", "description": "In order to understand what environmental conditions might look like for future generations, we need to turn to archives of past times when the world was indeed warmer, before anyone was around to commit them to collective memory. The geologic record of Earth\u0027s past offers a glimpse of what could be in store for the future. Research by Ivany and her team looks to Antarctica during a time of past global warmth to see how seasonality of temperature and rainfall in coastal settings are likely to change in the future. They will use the chemistry of fossils (a natural archive of these variables) to test a provocative hypothesis about near-monsoonal conditions in the high latitudes when the oceans are warm. If true, we can expect high-latitude shipping lanes to become more hazardous and fragile marine ecosystems adapted to constant cold temperatures to suffer. With growing information about how human activities are likely to affect the planet in the future, we will be able to make more informed decisions about policies today. This research involves an international team of scholars, including several women scientists, training of graduate students, and a public museum exhibit to educate children about how we study Earth\u0027s ancient climate and what we can learn from it. Antarctica is key to an understanding how Earth?s climate system works under conditions of elevated CO2. The poles are the most sensitive regions on the planet to climate change, and the equator-to-pole temperature gradient and the degree to which high-latitude warming is amplified are important components for climate models to capture. Accurate proxy data with good age control are therefore critical for testing numerical models and establishing global patterns. The La Meseta Formation on Seymour Island is the only documented marine section from the globally warm Eocene Epoch exposed in outcrop on the continent; hence its climate record is integral to studies of warming. Early data suggest the potential for strongly seasonal precipitation and runoff in coastal settings. This collaboration among paleontologists, geochemists, and climate modelers will test this using seasonally resolved del-18O data from fossil shallow marine bivalves to track the evolution of seasonality through the section, in combination with independent proxies for the composition of summer precipitation (leaf wax del-D) and local seawater (clumped isotopes). The impact of the anticipated salinity stratification on regional climate will be evaluated in the context of numerical climate model simulations. In addition to providing greater clarity on high-latitude conditions during this time of high CO2, the combination of proxy and model results will provide insights about how Eocene warmth may have been maintained and how subsequent cooling came about. As well, a new approach to the analysis of shell carbonates for 87Sr/86Sr will allow refinements in age control so as to allow correlation of this important section with other regions to clarify global climate gradients. The project outlined here will develop new and detailed paleoclimate records from existing samples using well-tuned as well as newer proxies applied here in novel ways. Seasonal extremes are climate parameters generally inaccessible to most studies but critical to an understanding of climate change; these are possible to resolve in this well-preserved, accretionary-macrofossil-bearing section. This is an integrated study that links marine and terrestrial climate records for a key region of the planet across the most significant climate transition in the Cenozoic.", "east": -56.0, "geometry": "POINT(-56.5 -64.25)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "PALEOCLIMATE RECONSTRUCTIONS; USAP-DC; ISOTOPES; NOT APPLICABLE; MACROFOSSILS; Antarctica", "locations": "Antarctica", "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Ivany, Linda; Lu, Zunli; Junium, Christopher; Samson, Scott", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.5, "title": "Seasonality, Summer Cooling, and Calibrating the Approach of the Icehouse in Late Eocene Antarctica", "uid": "p0010025", "west": -57.0}, {"awards": "1743326 Kingslake, Jonathan", "bounds_geometry": null, "dataset_titles": "Report on Antarctic surface hydrology workshop, LDEO, 2018 ", "datasets": [{"dataset_uid": "601170", "doi": "10.15784/601170", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrology; Ice Sheet Stability; Ice Shelf; Report; Workshop", "people": "Banwell, Alison; Bell, Robin; Das, Indrani; DeConto, Robert; Tedesco, Marco; Lenaerts, Jan; Schoof, Christian; Kingslake, Jonathan; Trusel, Luke", "repository": "USAP-DC", "science_program": null, "title": "Report on Antarctic surface hydrology workshop, LDEO, 2018 ", "url": "https://www.usap-dc.org/view/dataset/601170"}], "date_created": "Tue, 26 Mar 2019 00:00:00 GMT", "description": "Ice shelves are the floating portions of glaciers that terminate in the ocean. They are common around the periphery of Antarctica. The accumulation of surface meltwater on or near the surface of ice shelves can play a role in ice-shelf collapse, which leads to accelerated loss of grounded ice and sea-level rise. Recent studies have showed that present-day meltwater generation and movement across the surface of Antarctica is more widespread than previously thought and is expected to increase. Consequently, there is a growing need to address the role of surface water in forecasts of ice-shelf behavior. While much progress has been made, understanding of the role of water in ice-shelf collapse is still in its infancy. This award supports a workshop that will bring together experts from multiple disciplines that, together, can advance understanding of Antarctic surface hydrology and its role in the future stability of ice shelves. This workshop will bring together U.S. and international scientists with expertise in ice-sheet dynamics, glacial hydrology, climatology, and other disciplines to identify critical knowledge gaps and move the community towards answering fundamental questions such as: What climate dynamics are responsible for surface meltwater generation in Antarctica? What controls the spatiotemporal distribution of meltwater ponds on Antarctic ice shelves? Where is meltwater generated, where does it pond today, and how will this change this century? How will meltwater impact ice shelves? How will surface hydrology impact sea-level this century? The deliberations will be captured in a workshop report and review paper that will be broadly distributed.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; ICE SHEETS; North America; USAP-DC", "locations": "North America", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kingslake, Jonathan; Tedesco, Marco; Trusel, Luke", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Workshop on Antarctic Surface Hydrology and Future Ice-shelf Stability", "uid": "p0010021", "west": null}, {"awards": "1758224 Salvatore, Mark", "bounds_geometry": "POLYGON((-180 -83,-178 -83,-176 -83,-174 -83,-172 -83,-170 -83,-168 -83,-166 -83,-164 -83,-162 -83,-160 -83,-160 -83.4,-160 -83.8,-160 -84.2,-160 -84.6,-160 -85,-160 -85.4,-160 -85.8,-160 -86.2,-160 -86.6,-160 -87,-162 -87,-164 -87,-166 -87,-168 -87,-170 -87,-172 -87,-174 -87,-176 -87,-178 -87,180 -87,178 -87,176 -87,174 -87,172 -87,170 -87,168 -87,166 -87,164 -87,162 -87,160 -87,160 -86.6,160 -86.2,160 -85.8,160 -85.4,160 -85,160 -84.6,160 -84.2,160 -83.8,160 -83.4,160 -83,162 -83,164 -83,166 -83,168 -83,170 -83,172 -83,174 -83,176 -83,178 -83,-180 -83))", "dataset_titles": "Laboratory Hyperspectral Reflectance Data of Central Transantarctic Mountain Rocks and Sediments; Orbital imagery used for SpecMap project", "datasets": [{"dataset_uid": "002735", "doi": null, "keywords": null, "people": null, "repository": "PGC", "science_program": null, "title": "Orbital imagery used for SpecMap project", "url": "https://www.pgc.umn.edu/projects/specmap/"}, {"dataset_uid": "601163", "doi": "10.15784/601163", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Remote Sensing; Rocks; Solid Earth; Spectroscopy; Transantarctic Mountains", "people": "Salvatore, Mark", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Hyperspectral Reflectance Data of Central Transantarctic Mountain Rocks and Sediments", "url": "https://www.usap-dc.org/view/dataset/601163"}], "date_created": "Thu, 14 Mar 2019 00:00:00 GMT", "description": "Intellectual Merit: Ice free rock outcrops in the Transantarctic Mountains provide the only accessible windows into the interior of the ice covered Antarctic continent; they are extremely remote and difficult to study. This region also hosts the highest latitude ice-free valley systems on the planet. Based on two interdisciplinary workshops, the Transantarctic region near the Shackleton Glacier has been identified as a high priority site for further studies, with a field camp proposed for the 2015-2016 Antarctic field season. The geology of this region has been studied since the heroic era of Antarctic exploration, in the early 1900s, but geologic mapping has not been updated in more than forty years, and existing maps are at poor resolution (typically 1:250,000). This project would utilize the WorldView-2 multispectral orbital dataset to supplement original geologic mapping efforts near the proposed 2015-2016 Shackleton Glacier camp. The WorldView-2 satellite is the only multispectral orbiting sensor capable of imaging the entirety of the Transantarctic Mountains, and all necessary data are currently available to the Polar Geospatial Center. High-latitude atmospheric correction of multispectral data for geologic investigations has only recently been tested, but has never been applied to WorldView-2 data, and never for observations of this type. Therefore, this research will require technique refinements and methodological developements to accomplish the goals. Atmospheric correction refinements and spectral validation will be made possible by laboratory spectroscopic measurements of rock samples currently stored at the U.S. Polar Rock Repository, at the Ohio State University. This project will result in spectral unit identification and boundary mapping at a factor of four higher resolution (1:62,500) than previous geologic mapping efforts, and more detailed investigations (1:5,123) are possible at resolutions more than a factor of forty-eight improved over previous geologic maps. Validated spectral mapping at these improved resolutions will allow for detailed lithologic, and potentially biologic, mapping using existing satellite imagery. This will greatly enhance planning capabilities, thus maximizing the efficiency of the scientific research and support logistics associated with the Shackleton Glacier deep field camp. Broader impacts: The proposed work will have multiple impacts on the broader scientific community. First, the refinement of existing atmospheric correction methodologies, and the development of new spectral mapping techniques, may substantially improve our ability to remotely investigate geologic surfaces throughout Antarctica. The ability to validate this orbital dataset will be of use to both current and future geologic, environmental, and biologic studies, potentially across the entire continent. The project will yield a specific spectral mapping product (at a scale of 1:62,500) to the scientific community by a targeted date of 01 March 2014, in order to support proposals submitted to the National Science Foundation for the proposed 2015/2016 Shackleton Glacier camp. High-resolution spectral mapping products (up to a maximum resolution of 2 meters per pixel) will also be generated for regions of particular scientific interest. The use of community based resources, such as Polar Geospatial Center (PGC) imagery and U.S. Polar Rock Repository rock samples, will generate new synergistic and collaborative research possibilities within the Antarctic research community. In addition, the lead PI (Salvatore) is an early career scientist who is active in both Antarctic and planetary remote sensing. There are overlaps in the calibration, correction, and validation of remote spectral datasets for Antarctic and planetary applications which can lead to benefits and insights to an early career PI, as well as the two communities.", "east": -160.0, "geometry": "POINT(180 -85)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; Antarctica; GEOCHEMISTRY; LANDSCAPE; REFLECTED INFRARED; USAP-DC", "locations": "Antarctica", "north": -83.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Salvatore, Mark", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "PGC", "repositories": "PGC; USAP-DC", "science_programs": null, "south": -87.0, "title": "EAGER: Surface Variability and Spectral Analyses of the Central Transantarctic Mountains, Antarctica", "uid": "p0010020", "west": 160.0}, {"awards": "9725024 Jacobs, Stanley", "bounds_geometry": "POLYGON((140 -65,141 -65,142 -65,143 -65,144 -65,145 -65,146 -65,147 -65,148 -65,149 -65,150 -65,150 -65.3,150 -65.6,150 -65.9,150 -66.2,150 -66.5,150 -66.8,150 -67.1,150 -67.4,150 -67.7,150 -68,149 -68,148 -68,147 -68,146 -68,145 -68,144 -68,143 -68,142 -68,141 -68,140 -68,140 -67.7,140 -67.4,140 -67.1,140 -66.8,140 -66.5,140 -66.2,140 -65.9,140 -65.6,140 -65.3,140 -65))", "dataset_titles": "Expedition Data; R/V Nathaniel B. Palmer NBP0008 - Expedition Data; \r\nSummer Oceanographic Measurements near the Mertz Polynya NBP0008", "datasets": [{"dataset_uid": "001885", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "200022", "doi": "10.15784/601161 ", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "\r\nSummer Oceanographic Measurements near the Mertz Polynya NBP0008", "url": "https://www.usap-dc.org/view/dataset/601161"}, {"dataset_uid": "200023", "doi": "10.7284/905461", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "R/V Nathaniel B. Palmer NBP0008 - Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}], "date_created": "Mon, 11 Mar 2019 00:00:00 GMT", "description": "This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999.", "east": 150.0, "geometry": "POINT(145 -66.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC; Southern Ocean; WATER MASSES; Antarctica", "locations": "Southern Ocean; Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley; Visbeck, Martin", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -68.0, "title": "Circumpolar Deep Water and the West Antarctic Ice Sheet", "uid": "p0010019", "west": 140.0}, {"awards": "1457577 Wise, Sherwood", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 21 Feb 2019 00:00:00 GMT", "description": "This proposal would provide funding for continued operation of the Antarctic Marine Geology Research Facility (AMGRF) at Florida State University. This facility is the NSF repository of sediment cores from the ocean floor surrounding Antarctica, and makes sediment cores available to the entire scientific community, providing the equipment and knowledge necessary for scientists to collect samples for specialized measurements. The sediments provide a record of past climate, ocean circulation, and ice sheet history, and were recovered at great cost using piston cores deployed from research vessels and rotary coring from drilling platforms. The funding supports a curator, an assistant curator, and a student work force from FSU. This staff supports visiting scientists, manages the collections and the equipment used for core characterization and sampling, and maintain data bases. The AMGRF houses a unique collection of sediment cores from the Southern Oceans and has served in this role for the past 50 years. The Antarctic Marine Geology Research Facility (AMGRF) at Florida State University, the NSF repository of Southern Ocean piston- and drill-cores, has been conducting marine geological research and providing numerous services to the Antarctic and Earth Science Community in its present building for the past 50 years. This proposal requests operating funds to (a) continue provide these services, (b) manage archives and databases, (c) complete necessary upgrades of the AMGRF Cold-Room, and (d) continue our education and outreach programs for students and the general public. The AMGRF archives and curates more than 23,000 m of cored sediment (over 7,000 cores) collected by United States Antarctic Program (USAP) vessels. The Facility also archives and curates some 5,500 m of rotary-cored material from international programs such as ANDRILL. The standard core processing services include core splitting, Multi-Sensor Track analyses, core photography, whole-core x-rays, etc., core description publications (macroscopic and microscopic), and core sampling. Facility personnel also provide curatorial support services to field-based projects upon request. Analytical equipment at the AMGRF serves the research needs of Facility personnel (for the generation of detailed core descriptions), NSF Principal Investigators involved with the United States Antarctic Program (USAP), and qualified users from the scientific community in the U.S. and beyond. This equipment provides users of the Facility with the necessary tools to rapidly and objectively analyze the piston cores and drill cores sent to the Facility each year. The AMGRF maintains a core and sample database with the latest map-sample search capabilities that can be accessed through the continuously upgraded Facility website. This searchable database contains basic information about all the cores stored at the facility, as well as information on samples taken from 1964 to the present. In addition to the sediment core archives the AMGRF also keeps archives of ship and deck-logs, a collection of ca. 862,000 microscope slides, and a library of AMGRF related publications. Facility personnel routinely provide tours and lectures for students and the general public.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "MARINE SEDIMENTS; USAP-DC; NOT APPLICABLE; Antarctica", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Salters, Vincent", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": null, "title": "Curation of National Antarctic Sediment Collections", "uid": "p0010014", "west": null}, {"awards": "1246776 Nyblade, Andrew; 1246712 Wiens, Douglas; 1246666 Huerta, Audrey; 1249513 Dalziel, Ian; 1249631 Wilson, Terry; 1419268 Aster, Richard; 1247518 Smalley, Robert", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Network/Campaign: Antarctica POLENET - ANET; POLENET - Network YT", "datasets": [{"dataset_uid": "200012", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "POLENET - Network YT", "url": "http://ds.iris.edu/mda/YT/?timewindow=2007-2018"}, {"dataset_uid": "200011", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Network/Campaign: Antarctica POLENET - ANET", "url": "https://www.unavco.org/data/gps-gnss/data-access-methods/dai2/app/dai2.html#grouping=Antarctica%20POLENET%20-%20ANET;scope=Station;sampleRate=normal;groupingMod=contains"}], "date_created": "Sun, 17 Feb 2019 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to continue and expand GPS and seismic for ANET-POLENET Phase 2 to advance understanding of geodynamic processes and their influence on the West Antarctic Ice Sheet. ANET-POLENET science themes include: 1) determining ice mass change since the last glacial maximum, including modern ice mass balance; 2) solid earth influence on ice sheet dynamics; and 3) tectonic evolution of West Antarctica and feedbacks with ice sheet evolution. Nine new remote continuous GPS stations, to be deployed in collaboration with U.K. and Italian partners, will augment ANET-POLENET instrumentation deployed during Phase 1. Siting is designed to better constrain uplift centers predicted by GIA models and indicated by Phase 1 results. ANET-POLENET Phase 2 builds on Phase 1 scientific, technological, and logistical achievements including 1) seismic images of crust and mantle structure that resolve the highly heterogeneous thermal and viscosity structure of the Antarctic lithosphere and underlying mantle; 2) newly identified intraplate glacial, volcanic, and tectonic seismogenic processes; 3) improved estimates of intraplate vertical and horizontal crustal motions and refinement of the Antarctic GPS reference frame; and 4) elucidation of controls on glacial isostatic adjustment-induced crustal motions due to laterally varying earth structure. The PIs present a nominal plan to reduce ANET by approximately half to a longer-term community \"backbone network\" in the final 2 years of this project. Broader impacts: Monitoring and understanding mass change and dynamic behavior of the Antarctic ice sheet using in situ GPS and seismological studies will help improve understanding of how Antarctic ice sheets respond to a warming world and how will this response impacts sea-level and other global changes. Seismic and geodetic data collected by the backbone ANET-POLENET network are openly available to the scientific community. ANET-POLENET is integral in the development and realization of technological and logistical innovations for year-round operation of instrumentation at remote polar sites, helping to advance scientifically and geographically broad studies of the polar regions. The ANET-POLENET team will establish a training initiative to mentor young polar scientists in complex, multidisciplinary and internationally collaborative research. ANET-POLENET will continue the broad public outreach to the public about polar science through the polenet.org website, university lectures, and K-12 school visits. This research involves multiple international partners.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Geodesy; USAP-DC; SEISMIC SURFACE WAVES; CRUSTAL MOTION; TECTONICS; Broadband Seismic; NOT APPLICABLE; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wilson, Terry; Dalziel, Ian W.; Bevis, Michael; Aster, Richard; Huerta, Audrey D.; Winberry, Paul; Anandakrishnan, Sridhar; Nyblade, Andrew; Wiens, Douglas; Smalley, Robert", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "IRIS", "repositories": "IRIS; UNAVCO", "science_programs": "POLENET", "south": -90.0, "title": "Collaborative Research: POLENET-Antarctica: Investigating Links Between Geodynamics and Ice Sheets - Phase 2", "uid": "p0010013", "west": -180.0}, {"awards": "1750630 Smith, Craig", "bounds_geometry": "POLYGON((-64 -66,-63.3 -66,-62.6 -66,-61.9 -66,-61.2 -66,-60.5 -66,-59.8 -66,-59.1 -66,-58.4 -66,-57.7 -66,-57 -66,-57 -66.3,-57 -66.6,-57 -66.9,-57 -67.2,-57 -67.5,-57 -67.8,-57 -68.1,-57 -68.4,-57 -68.7,-57 -69,-57.7 -69,-58.4 -69,-59.1 -69,-59.8 -69,-60.5 -69,-61.2 -69,-61.9 -69,-62.6 -69,-63.3 -69,-64 -69,-64 -68.7,-64 -68.4,-64 -68.1,-64 -67.8,-64 -67.5,-64 -67.2,-64 -66.9,-64 -66.6,-64 -66.3,-64 -66))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 15 Feb 2019 00:00:00 GMT", "description": "Worldwide publicity surrounding the calving of an iceberg the size of Delaware in July 2017 from the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula presents a unique and time-sensitive opportunity for research and education on polar ecosystems in a changing climate. The goal of this project was to convene a workshop, drawing from the large fund of intellectual capital in the US and international Antarctic research communities. The two-day workshop was designed to bring scientists with expertise in Antarctic biological, ecological, and ecosystem sciences to Florida State University to share knowledge, identify important research knowledge gaps, and outline strategic plans for research. \r\n\r\nMajor outcomes from the project were as follows. The international workshop to share and review knowledge concerning the response of Antarctic ecosystems to ice-shelf collapse was held at the Florida State University Coastal and Marine Laboratory (FSUCML) on 18-19 November 2017. Thirty-eight U.S. and international scientists attended the workshop, providing expertise in biological, ecological, geological, biogeographical, and glaciological sciences. Twenty-six additional scientists were either not able to attend or were declined because of having reached maximum capacity of the venue or for not responding to our invitation before the registration deadline.\r\n\r\nThe latest results of ice-shelf research were presented, providing an overview of the current scientific knowledge and understanding of the biological, ecological,\r\ngeological and cryospheric processes associated with ice-shelf collapse and its\r\necosystem-level consequences. In addition, several presentations focused on future plans to investigate the impacts of the recent Larsen C collapse. The following presentations were given at the meeting:\r\n\r\n1) Cryospheric dynamics and ice-shelf collapse \u2013 past and future (M. Truffer,\r\nUniversity of Alaska, Fairbanks)\r\n2) The geological history and geological impacts of ice-shelf collapse on the Antarctic Peninsula (Scottt Ishman, Amy Leventer)\r\n3) Pelagic ecosystem responses to ice-shelf collapse (Mattias Cape, Amy Leventer)\r\n4) Benthic ecosystem response to ice-shelf collapse (Craig Smith, Pavica Sr\u0161en, Ann Vanreusel)\r\n5) Larsen C and biotic homogenization of the benthos (Richard Aronson, James\r\nMcClintock, Kathryn Smith, Brittany Steffel)\r\n6) British Antarctic Survey: plans for Larsen C investigations early 2018 and in the\r\nfuture (Huw Griffiths)\r\n7) Feedback on the workshop \u201cClimate change impacts on marine ecosystems:\r\nimplications for management of living resources and conservation\u201d held 19-22\r\nSeptember 2017, Cambridge, UK (Alex Rogers)\r\n8) Past research activities and plans for Larsen field work by the Alfred Wegener\r\nInstitute, Germany (Charlotte Havermans, Dieter Piepenburg.\r\n\r\nOne of the salient points emerging from the presentations and ensuing discussions was that, given our poor abilities to predict ecological outcomes of ice-shelf collapses, major cross-disciplinary efforts are needed on a variety of spatial and temporal scales to achieve a broader, predictive understanding of ecosystem\r\nconsequences of climatic warming and ice-shelf failure. As part of the workshop, the FSUCML Polar Academy Team\u2014Dr. Emily Dolan, Dr. Heidi Geisz, Barbara Shoplock, and Dr. Jeroen Ingels\u2014initiated AntICE: \"Antarctic Influences of Climate Change on Ecosystems\" (AntICE). They reached out to various groups of school children in the local area (and continue to do so). The AntICE Team have been interacting with these children at Wakulla High School and Wakulla Elementary in Crawfordville; children from the Cornerstone Learning Community, Maclay Middle School, Gilchrist Elementary, and the School of Arts and Sciences in Tallahassee; and the Tallahassee-area homeschooling community to educate them about Antarctic ecosystems and ongoing climate change. The underlying idea was to\r\nmake the children aware of climatic changes in the Antarctic and their effect on\r\necosystems so they, in turn, can spread this knowledge to their communities, family\r\nand friends \u2013 acting as \u2018Polar Ambassadors\u2019. We collaborated with the Polar-ICE\r\nproject, an NSF-funded educational project that established the Polar Literacy\r\nInitiative. This program developed the Polar Literacy Principles, which outline\r\nessential concepts to improve public understanding of Antarctic and Arctic\r\necosystems. In the Polar Academy work, we used the Polar Literacy principles, the\r\nPolar Academy Team\u2019s own Antarctic scientific efforts, and the experience of the FSU outreach and education program to engage with the children. We focused on the importance of Antarctic organisms and ecosystems, the uniqueness of its biota and the significance of its food webs, as well as how all these are changing and will\r\nchange further with climate change. Using general presentations, case studies,\r\nscientific methodology, individual experiences, interactive discussions and Q\u0026A\r\nsessions, the children were guided through the many issues Antarctic ecosystems\r\nare facing. Over 300 \u0027Polar ambassadors\u0027 attended the interactive lectures and\r\nafterwards took their creativity to high latitudes by creating welcome letters, displays, dioramas, sculptures, videos and online media to present at the scientific workshop. Over 50 projects were created by the children (Please see supporting files for images). We were also joined by a photographer, Ryan David Reines, to document the event. More information, media and links to online outreach products are available at https://marinelab.fsu.edu/labs/ingels/outreach/polar-academy/", "east": -57.0, "geometry": "POINT(-60.5 -67.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; USAP-DC; ECOLOGICAL DYNAMICS; NOT APPLICABLE; MARINE ECOSYSTEMS; Weddell Sea", "locations": "Weddell Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Craig", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -69.0, "title": "Collaborative Research: RAPID/Workshop- Antarctic Ecosystem Research following Ice Shelf Collapse and Iceberg Calving Events", "uid": "p0010012", "west": -64.0}, {"awards": "1443680 Smith, Craig; 1443733 Winsor, Peter; 1443705 Vernet, Maria", "bounds_geometry": "POLYGON((-66 -64,-65.6 -64,-65.2 -64,-64.8 -64,-64.4 -64,-64 -64,-63.6 -64,-63.2 -64,-62.8 -64,-62.4 -64,-62 -64,-62 -64.1,-62 -64.2,-62 -64.3,-62 -64.4,-62 -64.5,-62 -64.6,-62 -64.7,-62 -64.8,-62 -64.9,-62 -65,-62.4 -65,-62.8 -65,-63.2 -65,-63.6 -65,-64 -65,-64.4 -65,-64.8 -65,-65.2 -65,-65.6 -65,-66 -65,-66 -64.9,-66 -64.8,-66 -64.7,-66 -64.6,-66 -64.5,-66 -64.4,-66 -64.3,-66 -64.2,-66 -64.1,-66 -64))", "dataset_titles": "Andvord Bay Glacier Timelapse; Andvord Bay sediment core data collected during the FjordEco project (LMG1510 and NBP1603); Expedition Data; Expedition data of LMG1702; FjordEco Phytoplankton Ecology Dataset in Andvord Bay ; Fjord-Eco Sediment OrgC OrgN Data - Craig Smith; LMG1510 Expedition data; NBP1603 Expedition data; Sediment macrofaunal abundance and family richness from inner Andvord Bay to the open continental shelf", "datasets": [{"dataset_uid": "200040", "doi": "10.7284/907085", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "LMG1510 Expedition data", "url": "https://www.rvdata.us/search/cruise/LMG1510"}, {"dataset_uid": "601158", "doi": "10.15784/601158", "keywords": "Antarctica; Antarctic Peninsula; Biota; Ecology; Fjord; Phytoplankton", "people": "Forsch, Kiefer; Vernet, Maria; Manck, Lauren; Pan, B. Jack", "repository": "USAP-DC", "science_program": "FjordEco", "title": "FjordEco Phytoplankton Ecology Dataset in Andvord Bay ", "url": "https://www.usap-dc.org/view/dataset/601158"}, {"dataset_uid": "601111", "doi": "10.15784/601111", "keywords": "Antarctica; Antarctic Peninsula; Glaciers/ice Sheet; Glaciers/Ice Sheet; Iceberg; Photo; Photo/video; Photo/Video", "people": "Truffer, Martin; Winsor, Peter", "repository": "USAP-DC", "science_program": "FjordEco", "title": "Andvord Bay Glacier Timelapse", "url": "https://www.usap-dc.org/view/dataset/601111"}, {"dataset_uid": "002733", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1702", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "200039", "doi": "10.7284/907205", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1603 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1603"}, {"dataset_uid": "601236", "doi": "10.15784/601236", "keywords": "Abundance; Andvord Bay; Antarctica; Antarctic Peninsula; Biota; Fjord; LMG1510; Marine Sediments; Oceans; Polychaete; Polychaete Family Richness; R/v Laurence M. Gould; Sediment Core Data; Sediment Macrofauna", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "FjordEco", "title": "Sediment macrofaunal abundance and family richness from inner Andvord Bay to the open continental shelf", "url": "https://www.usap-dc.org/view/dataset/601236"}, {"dataset_uid": "000402", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "601193", "doi": "10.15784/601193", "keywords": "Antarctica; Geochronology; Grain Size; LMG1510; NBP1603; Sediment; Sediment Core Data", "people": "Nittrouer, Charles; Eidam, Emily; Homolka, Khadijah; Smith, Craig", "repository": "USAP-DC", "science_program": null, "title": "Andvord Bay sediment core data collected during the FjordEco project (LMG1510 and NBP1603)", "url": "https://www.usap-dc.org/view/dataset/601193"}, {"dataset_uid": "001366", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "601157", "doi": "10.15784/601157", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Snow/ice; Snow/Ice", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "FjordEco", "title": "Fjord-Eco Sediment OrgC OrgN Data - Craig Smith", "url": "https://www.usap-dc.org/view/dataset/601157"}], "date_created": "Wed, 13 Feb 2019 00:00:00 GMT", "description": "Marine communities along the western Antarctic Peninsula are highly productive ecosystems which support a diverse assemblage of charismatic animals such as penguins, seals, and whales as well as commercial fisheries such as that on Antarctic krill. Fjords (long, narrow, deep inlets of the sea between high cliffs) along the central coast of the Peninsula appear to be intense, potentially climate sensitive, hotspots of biological production and biodiversity, yet the structure and dynamics of these fjord ecosystems are very poorly understood. Because of this intense biological activity and the charismatic fauna it supports, these fjords are also major destinations for a large Antarctic tourism industry. This project is an integrated field and modeling program to evaluate physical oceanographic processes, glacial inputs, water column community dynamics, and seafloor bottom community structure and function in these important yet little understood fjord systems. These Antarctic fjords have characteristics that are substantially different from well-studied Arctic fjords, likely yielding much different responses to climate warming. This project will provide major new insights into the dynamics and climate sensitivity of Antarctic fjord ecosystems, highlighting contrasts with Arctic sub-polar fjords, and potentially transforming our understanding of the ecological role of fjords in the rapidly warming west Antarctic coastal marine landscape. The project will also further the NSF goal of training new generations of scientists, providing scientific training for undergraduate, graduate, and postdoctoral students. This includes the unique educational opportunity for undergraduates to participate in research cruises in Antarctica and the development of a novel summer graduate course on fjord ecosystems. Internet based outreach activities will be enhanced and extended by the participation of a professional photographer who will produce magazine articles, websites, radio broadcasts, and other forms of public outreach on the fascinating Antarctic ecosystem. This project will involve a 15-month field program to test mechanistic hypotheses concerning oceanographic and glaciological forcing, and phytoplankton and benthic community response in the Antarctic fjords. Those efforts will be followed by a coupled physical/biological modeling effort to evaluate the drivers of biogeochemical cycles in the fjords and to explore their potential sensitivity to enhanced meltwater and sediment inputs. Fieldwork over two oceanographic cruises will utilize moorings, weather stations, and glacial, sea-ice and seafloor time-lapse cameras to obtain an integrated view of fjord ecosystem processes. The field team will also make multiple shipboard measurements and will use towed and autonomous underwater vehicles to intensively evaluate fjord ecosystem structure and function during spring/summer and autumn seasons. These integrated field and modeling studies are expected to elucidate fundamental properties of water column and sea bottom ecosystem structure and function in the fjords, and to identify key physical-chemical-glaciological forcing in these rapidly warming ecosystems.", "east": -62.0, "geometry": "POINT(-64 -64.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "OCEAN CURRENTS; Bellingshausen Sea; LMG1702; COMMUNITY DYNAMICS; FJORDS; R/V LMG; MARINE ECOSYSTEMS; USAP-DC; ECOSYSTEM FUNCTIONS; ANIMALS/INVERTEBRATES; SEDIMENTATION; NOT APPLICABLE; BENTHIC", "locations": "Bellingshausen Sea", "north": -64.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Winsor, Peter; Truffer, Martin; Smith, Craig; Powell, Brian; Merrifield, Mark; Vernet, Maria; Kohut, Josh", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": "FjordEco", "south": -65.0, "title": "Collaborative Research: Fjord Ecosystem Structure and Function on the West Antarctic Peninsula - Hotspots of Productivity and Biodiversity? (FjordEco)", "uid": "p0010010", "west": -66.0}, {"awards": "1443347 Condron, Alan; 1443394 Pollard, David", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic Ice Sheet simulations for role of freshwater in future warming scenarios; Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming; Simulated changes in Southern Ocean salinity", "datasets": [{"dataset_uid": "601449", "doi": "10.15784/601449", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meltwater", "people": "Condron, Alan", "repository": "USAP-DC", "science_program": null, "title": "Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming", "url": "https://www.usap-dc.org/view/dataset/601449"}, {"dataset_uid": "601154", "doi": "10.15784/601154 ", "keywords": "Antarctic; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Sheet Model; Meltwater; Model Data; Modeling; Model Output", "people": "Pollard, David", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Sheet simulations for role of freshwater in future warming scenarios", "url": "https://www.usap-dc.org/view/dataset/601154"}, {"dataset_uid": "601442", "doi": "10.15784/601442", "keywords": "Antarctica; Computer Model; Freshwater; Glaciers/ice Sheet; Glaciers/Ice Sheet; Model Data; Ocean Model; Oceans; Salinity", "people": "Condron, Alan", "repository": "USAP-DC", "science_program": null, "title": "Simulated changes in Southern Ocean salinity", "url": "https://www.usap-dc.org/view/dataset/601442"}], "date_created": "Mon, 04 Feb 2019 00:00:00 GMT", "description": "There is compelling historical evidence that the West Antarctic Ice Sheet (WAIS) is vulnerable to rapid retreat and collapse. Recent observations, compared to observations made 20-30 years before, indicate that both ice shelves (thick ice with ocean below) and land ice (thick ice with land below), are now melting at a much faster rate. Some numerical models suggest that significant ice retreat may begin within many of our lifetimes, starting with the abrupt collapse of Pine Island and Thwaites Glaciers in the next 50 years. This may be followed by retreat of much of the WAIS and then the collapse of parts of the East Antarctic ice sheet (EAIS). This research project will assess the extent to which global ocean circulation and climate will be impacted if enormous volumes of fresh water and ice flow into the Southern Ocean. It will establish whether a rapid collapse of WAIS in the near-future poses any significant threat to the stability of modern-day climate and human society. This is a topic that has so far received little attention as most prior research has focused on the response of climate to melting the Greenland ice sheet. Yet model simulations predict that the volumes of fresh water and ice released from Antarctica in the next few centuries could be up at least ten-times larger than from Greenland. The Intellectual Merit of this project stems from its ability to establish a link between the physical Antarctic system (ice sheet dynamics, fresh water discharge and iceberg calving) and global climate. The PIs (Principal Investigators) will assess the sensitivity of ocean circulation and climate to increased ice sheet melt using a combination of ocean, iceberg, ice sheet and climate models. Results from this study will help identify areas of the ice sheet that are vulnerable to collapse and also regions of the ocean where a significant freshening will have a considerable impact on climate, and serve to guide the deployment of an observational monitoring system capable of warning us when ice and fresh water discharge start to approach levels capable of disrupting ocean circulation and global climate. This project will support and train two graduate students, and each PI will be involved with local primary and secondary schools, making presentations, mentoring science fair projects, and contributing to curriculum development. A novel, web-based, interactive, cryosphere learning tool will be developed to help make school children more aware of the importance of the Polar Regions in global climate, and this software will be introduced to science teachers at a half day workshop organized by the UMass STEM Education Institute. Recent numerical simulations using a continental ice sheet/shelf model show the potential for more rapid and greater Antarctic ice sheet retreat in the next 50-300 years (under the full range of IPCC RCP (Intergovernmental Panel on Climate Change, Representative Concentration Pathways) future warming scenarios) than previously projected. Exactly how the release of enormous volumes of ice and fresh water to the Southern Ocean will impact global ocean circulation and climate has yet to be accurately assessed. This is in part because previous model simulations were too coarse to accurately resolve narrow coastal boundary currents, shelf breaks, fronts, and mesoscale eddies that are all very important for realistically simulating fresh water transport in the ocean. In this award, future projections of fresh water discharge and iceberg calving from Antarctic will be used to force a high resolution eddy-resolving ocean model (MITgcm) coupled to a new iceberg module and a fully-coupled global climate model (CCSM4). High resolution ocean/iceberg simulations will determine the role of mesoscale eddies in freshwater transport and give new insight into how fresh water is advected to far-field locations, including deep water formation sites in the North Atlantic. These simulations will provide detailed information about subsurface temperatures and changes in ocean circulation close to the ice front and grounding line. An accompanying set of fully coupled climate model simulations (NCAR CCSM4) will identify multidecadal-to-centennial changes in the climate system triggered by increased high-latitude Southern Ocean freshwater forcing. Particular attention will be given to changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC), wind stress, sea ice formation, and global temperatures. In doing so, this project will more accurately determine whether abrupt and potentially catastrophic changes in global climate are likely to be triggered by changes in the Antarctic system in the near-future.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e DATA ANALYSIS \u003e ENVIRONMENTAL MODELING \u003e COMPUTER", "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; AMD; MODELS; Amd/Us; Antarctica; GLACIERS/ICE SHEETS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Pollard, David; Condron, Alan; DeConto, Robert", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Assessing the Global Climate Response to Melting of the Antarctic Ice Sheet", "uid": "p0010007", "west": -180.0}, {"awards": "1443464 Sowers, Todd; 1443472 Brook, Edward J.; 1443710 Severinghaus, Jeffrey", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "South Pole CH4 data for termination; South Pole Ice Core Isotopes of N2 and Ar; South Pole ice core (SPC14) discrete methane data; South Pole ice core total air content; South Pole (SPICECORE) 15N, 18O, O2/N2 and Ar/N2; SP19 Gas Chronology", "datasets": [{"dataset_uid": "601152", "doi": "10.15784/601152", "keywords": "Antarctica; Antarctic Ice Sheet; Chemistry:gas; Chemistry:Gas; Chemistry:ice; Chemistry:Ice; Delta 18O; Dole Effect; Firn Thickness; Gas Isotopes; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Gravitational Settling; Ice; Ice Core Chemistry; Ice Core Data; Ice Core Gas Records; Ice Core Records; Inert Gases; Nitrogen; Nitrogen Isotopes; Oxygen; Oxygen Isotope; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPICECORE) 15N, 18O, O2/N2 and Ar/N2", "url": "https://www.usap-dc.org/view/dataset/601152"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601517", "doi": "10.15784/601517", "keywords": "Antarctica; Argon; Argon Isotopes; Firn; Firn Temperature Gradient; Firn Thickness; Gas Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Nitrogen; Nitrogen Isotopes; South Pole; SPICEcore", "people": "Severinghaus, Jeffrey P.; Morgan, Jacob", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Isotopes of N2 and Ar", "url": "https://www.usap-dc.org/view/dataset/601517"}, {"dataset_uid": "601230", "doi": "10.15784/601230", "keywords": "Antarctica; Atmospheric CH4; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Data; Methane; Methane Concentration; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole CH4 data for termination", "url": "https://www.usap-dc.org/view/dataset/601230"}, {"dataset_uid": "601231", "doi": "10.15784/601231", "keywords": "Air Content; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core total air content", "url": "https://www.usap-dc.org/view/dataset/601231"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Aydin, Murat; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}], "date_created": "Sat, 02 Feb 2019 00:00:00 GMT", "description": "Gases trapped in ice cores have revealed astonishing things about the greenhouse gas composition of the past atmosphere, including the fact that carbon dioxide concentrations never rose above 300 parts per million during the last 800,000 years. This places today\u0027s concentration of 400 parts per million in stark contrast. Furthermore, these gas records show that natural sources of greenhouse gas such as oceans and ecosystems act as amplifiers of climate change by increasing emissions of gases during warmer periods. Such amplification is expected to occur in the future, adding to the human-produced gas burden. The South Pole ice core will build upon these prior findings by expanding the suite of gases to include, for the first time, those potent trace gases that both trapped heat and depleted ozone during the past 40,000 years. The present project on inert gases and methane in the South Pole ice core will improve the dating of this crucial record, to unprecedented precision, so that the relative timing of events can be used to learn about the mechanism of trace gas production and destruction, and consequent climate change amplification. Ultimately, this information will inform predictions of future atmospheric chemical cleansing mechanisms and climate in the context of our rapidly changing atmosphere. This award also engages young people in the excitement of discovery and polar research, helping to entrain the next generations of scientists and educators. Education of graduate students, a young researcher (Buizert), and training of technicians, will add to the nation?s human resource base. This award funds the construction of the gas chronology for the South Pole 1500m ice core, using measured inert gases (d15N and d40Ar--Nitrogen and Argon isotope ratios, respectively) and methane in combination with a next-generation firn densification model that treats the stochastic nature of air trapping and the role of impurities on densification. The project addresses fundamental gaps in scientific understanding that limit the accuracy of gas chronologies, specifically a poor knowledge of the controls on ice-core d15N and the possible role of layering and impurities in firn densification. These gaps will be addressed by studying the gas enclosure process in modern firn at the deep core site. The work will comprise the first-ever firn air pumping experiment that has tightly co-located measurements of firn structural properties on the core taken from the same borehole. The project will test the hypothesis that the lock-in horizon as defined by firn air d15N, CO2, and methane is structurally controlled by impermeable layers, which are in turn created by high-impurity content horizons in which densification is enhanced. Thermal signals will be sought using the inert gas measurements, which improve the temperature record with benefits to the firn densification modeling. Neon, argon, and oxygen will be measured in firn air and a limited number of deep core samples to test whether glacial period layering was enhanced, which could explain low observed d15N in the last glacial period. Drawing on separate volcanic and methane synchronization to well-dated ice cores to create independent ice and gas tie points, independent empirical estimates of the gas age-ice age difference will be made to check the validity of the firn densification model-inert gas approach to calculating the gas age-ice age difference. These points will also be used to test whether the anomalously low d15N seen during the last glacial period in east Antarctic ice cores is due to deep air convection in the firn, or a missing impurity dependence in the firn densification models. The increased physical understanding gained from these studies, combined with new high-precision measurements, will lead to improved accuracy of the gas chronology of the South Pole ice core, which will enhance the overall science return from this gas-oriented core. This will lead to clarification of timing of atmospheric gas variations and temperature, and aid in efforts to understand the biogeochemical feedbacks among trace gases. These feedbacks bear on the future response of the Earth System to anthropogenic forcing. Ozone-depleting substances will be measured in the South Pole ice core record, and a precise gas chronology will add value. Lastly, by seeking a better understanding of the physics of gas entrapment, the project aims to have an impact on ice-core science in general.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "USAP-DC; AMD; LABORATORY; Antarctica; NITROGEN ISOTOPES; USA/NSF; METHANE; Amd/Us; FIELD INVESTIGATION", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Sowers, Todd A.; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core", "uid": "p0010005", "west": 0.0}, {"awards": "1144176 Lyons, W. Berry; 1144192 Tulaczyk, Slawek; 1727387 Mikucki, Jill; 1144177 Pettit, Erin", "bounds_geometry": "POLYGON((161.8 -77.7,161.88 -77.7,161.96 -77.7,162.04000000000002 -77.7,162.12 -77.7,162.2 -77.7,162.28 -77.7,162.36 -77.7,162.44 -77.7,162.51999999999998 -77.7,162.6 -77.7,162.6 -77.70700000000001,162.6 -77.714,162.6 -77.721,162.6 -77.728,162.6 -77.735,162.6 -77.742,162.6 -77.749,162.6 -77.756,162.6 -77.76299999999999,162.6 -77.77,162.51999999999998 -77.77,162.44 -77.77,162.36 -77.77,162.28 -77.77,162.2 -77.77,162.12 -77.77,162.04000000000002 -77.77,161.96 -77.77,161.88 -77.77,161.8 -77.77,161.8 -77.76299999999999,161.8 -77.756,161.8 -77.749,161.8 -77.742,161.8 -77.735,161.8 -77.728,161.8 -77.721,161.8 -77.714,161.8 -77.70700000000001,161.8 -77.7))", "dataset_titles": "Ablation Stake Data from of Taylor Glacier near Blood Falls; Antarctica Support 2014/2015 - C-528 Blood Falls GPS/GNSS Observations Dataset; Blood Falls, McMurdo Dry Va. International Federation of Digital Seismograph Networks. Dataset/Seismic Network; FLIR thermal imaging data near Blood Falls, Taylor Glacier; Ground Penetrating Radar Data near Blood Falls, Taylor Glacier; Ice Temperature in Shallow Boreholes Near Blood Falls at the Terminus of Taylor Glacier, McMurdo Dry Valleys, Antarctica; NCBI short read archive -Metagenomic survey of Antarctic Groundwater; Terrestrial Radar Interferometry near Blood Falls, Taylor Glacier; The Geochemistry of englacial brine from Taylor Glacier, Antarctica; Time Lapse imagery of the Blood Falls feature, Antarctica ; Vaisala Integrated Met Station near Blood Falls, Taylor Glacier", "datasets": [{"dataset_uid": "601139", "doi": "10.15784/601139", "keywords": "Antarctica; Borehole; Borehole Logging; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Temperature; Snow/ice; Snow/Ice; Temperature; Temperature Profiles", "people": "Tulaczyk, Slawek", "repository": "USAP-DC", "science_program": null, "title": "Ice Temperature in Shallow Boreholes Near Blood Falls at the Terminus of Taylor Glacier, McMurdo Dry Valleys, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601139"}, {"dataset_uid": "200074", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI short read archive -Metagenomic survey of Antarctic Groundwater", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRR6667787"}, {"dataset_uid": "601179", "doi": "10.15784/601179", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Subglacial Brine", "people": "Lyons, W. Berry; Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "The Geochemistry of englacial brine from Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601179"}, {"dataset_uid": "601169", "doi": "10.15784/601169", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Infrared Imagery; Photo/video; Photo/Video; Taylor Glacier; Thermal Camera; Timelaps Images", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "FLIR thermal imaging data near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601169"}, {"dataset_uid": "601168", "doi": "10.15784/601168", "keywords": "Antarctica; Atmosphere; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meteorology; Taylor Glacier; Temperature; Weather Station Data; Wind Speed", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Vaisala Integrated Met Station near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601168"}, {"dataset_uid": "601167", "doi": "10.15784/601167", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Photo; Photo/video; Photo/Video; Snow/ice; Snow/Ice; Taylor Glacier; Timelaps Images", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Time Lapse imagery of the Blood Falls feature, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601167"}, {"dataset_uid": "601166", "doi": "10.15784/601166", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Snow/ice; Snow/Ice; Taylor Glacier", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Terrestrial Radar Interferometry near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601166"}, {"dataset_uid": "601165", "doi": "10.15784/601165", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Snow/ice; Snow/Ice; Taylor Glacier", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Ground Penetrating Radar Data near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601165"}, {"dataset_uid": "601164", "doi": "10.15784/601164", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Snow/ice; Snow/Ice", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Ablation Stake Data from of Taylor Glacier near Blood Falls", "url": "https://www.usap-dc.org/view/dataset/601164"}, {"dataset_uid": "200028", "doi": "10.7283/FCEN-8050", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica Support 2014/2015 - C-528 Blood Falls GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/fcen-8050"}, {"dataset_uid": "200029", "doi": "10.7914/SN/YW_2013", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Blood Falls, McMurdo Dry Va. International Federation of Digital Seismograph Networks. Dataset/Seismic Network", "url": "http://www.fdsn.org/networks/detail/YW_2013/"}], "date_created": "Wed, 28 Nov 2018 00:00:00 GMT", "description": "Recent discoveries of widespread liquid water and microbial ecosystems below the Antarctic ice sheets have generated considerable interest in studying Antarctic subglacial environments. Understanding subglacial hydrology, the persistence of life in extended isolation and the evolution and stability of subglacial habitats requires an integrated, interdisciplinary approach. The collaborative project, Minimally Invasive Direct Glacial Exploration (MIDGE) of the Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys will integrate geophysical measurements, molecular microbial ecology and geochemical analyses to explore a unique Antarctic subglacial system known as Blood Falls. Blood Falls is a hypersaline, subglacial brine that supports an active microbial community. The subglacial brine is released from a crevasse at the surface of the Taylor Glacier providing an accessible portal into an Antarctic subglacial ecosystem. Recent geochemical and molecular analyses support a marine source for the salts and microorganisms in Blood Falls. The last time marine waters inundated this part of the McMurdo Dry Valleys was during the Late Tertiary, which suggests the brine is ancient. Still, no direct samples have been collected from the subglacial source to Blood Falls and little is known about the origin of this brine or the amount of time it has been sealed below Taylor Glacier. Radar profiles collected near Blood Falls delineate a possible fault in the subglacial substrate that may help explain the localized and episodic nature of brine release. However it remains unclear what triggers the episodic release of brine exclusively at the Blood Falls crevasse or the extent to which the brine is altered as it makes its way to the surface. The MIDGE project aims to determine the mechanism of brine release at Blood Falls, evaluate changes in the geochemistry and the microbial community within the englacial conduit and assess if Blood Falls waters have a distinct impact on the thermal and stress state of Taylor Glacier, one of the most studied polar glaciers in Antarctica. The geophysical study of the glaciological structure and mechanism of brine release will use GPR, GPS, and a small passive seismic network. Together with international collaborators, the \u0027Ice Mole\u0027 team from FH Aachen University of Applied Sciences, Germany (funded by the German Aerospace Center, DLR), MIDGE will develop and deploy innovative, minimally invasive technologies for clean access and brine sample retrieval from deep within the Blood Falls drainage system. These technologies will allow for the collection of samples of the brine away from the surface (up to tens of meters) for geochemical analyses and microbial structure-function experiments. There is concern over the contamination of pristine subglacial environments from chemical and biological materials inherent in the drilling process; and MIDGE will provide data on the efficacy of thermoelectric probes for clean access and retrieval of representative subglacial samples. Antarctic subglacial environments provide an excellent opportunity for researching survivability and adaptability of microbial life and are potential terrestrial analogues for life habitats on icy planetary bodies. The MIDGE project offers a portable, versatile, clean alternative to hot water and mechanical drilling and will enable the exploration of subglacial hydrology and ecosystem function while making significant progress towards developing technologies for minimally invasive and clean sampling of icy systems.", "east": 162.6, "geometry": "POINT(162.2 -77.735)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; BACTERIA/ARCHAEA; USAP-DC", "locations": null, "north": -77.7, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Tulaczyk, Slawek; Pettit, Erin; Lyons, W. Berry; Mikucki, Jill", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "IRIS; NCBI GenBank; UNAVCO; USAP-DC", "science_programs": null, "south": -77.77, "title": "Collaborative Research: MIDGE: Minimally Invasive Direct Glacial Exploration of Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys", "uid": "p0000002", "west": 161.8}, {"awards": "1443263 Higgins, John; 1443306 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Allan Hills ice water stable isotope record for dD, d18O; Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores; Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores; Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores; Greenhouse gas composition in the Allan Hills S27 ice core; Methane concentration in Allan Hills ice cores; Stable isotope composition of the trapped air in the Allan Hills S27 ice core; Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "datasets": [{"dataset_uid": "601203", "doi": "10.15784/601203", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Chemistry:ice; Chemistry:Ice; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenhouse Gas; Ice; Ice Core Data; Ice Core Gas Records; Methane; Snow/ice; Snow/Ice", "people": "Bender, Michael; Brook, Edward J.; Yan, Yuzhen; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Methane concentration in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601203"}, {"dataset_uid": "601201", "doi": "10.15784/601201", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Argon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Data; Ice Core Gas Records; Krypton; Mass Spectrometer; Noble Gas; Snow/ice; Snow/Ice; Xenon", "people": "Yan, Yuzhen; Ng, Jessica; Higgins, John; Severinghaus, Jeffrey P.; Bender, Michael", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601201"}, {"dataset_uid": "601128", "doi": "10.15784/601128", "keywords": "Allan Hills; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Record; Mass Spectrometry; Stable Water Isotopes", "people": "Kurbatov, Andrei V.; Mayewski, Paul A.; Introne, Douglas; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601128"}, {"dataset_uid": "601129", "doi": "10.15784/601129", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Isotope Data; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Kurbatov, Andrei V.; Mayewski, Paul A.; Introne, Douglas; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601129"}, {"dataset_uid": "601130", "doi": "10.15784/601130", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Delta Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Gas Records; Ice Core Records; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Introne, Douglas; Kurbatov, Andrei V.; Mayewski, Paul A.; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601130"}, {"dataset_uid": "601483", "doi": "10.15784/601483", "keywords": "Allan Hills; Antarctica; Argon; Ice; Ice Core Data; Ice Core Gas Records; Isotope; Mass Spectrometry; Nitrogen; Oxygen", "people": "Higgins, John; Bender, Michael; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601483"}, {"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Higgins, John; Severinghaus, Jeffrey P.; Introne, Douglas; Mayewski, Paul A.; Brook, Edward; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Kurbatov, Andrei V.; Mayewski, Paul A.; Brook, Edward; Introne, Douglas; Higgins, John; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "601512", "doi": "10.15784/601512", "keywords": "Allan Hills; Antarctica; Blue Ice; Ice Core; Ice Core Gas Records; Isotope; Nitrogen; Oxygen", "people": "Yan, Yuzhen; Higgins, John; Bender, Michael", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable isotope composition of the trapped air in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601512"}, {"dataset_uid": "601425", "doi": "10.15784/601425", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Ice Core; Methane", "people": "Brook, Edward J.; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Greenhouse gas composition in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601425"}, {"dataset_uid": "601202", "doi": "10.15784/601202", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Carbon Dioxide; Carbon Isotopes; Chemistry:ice; Chemistry:Ice; CO2; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Gas Records; Ice Core Records; Mass Spectrometer; Mass Spectrometry; Methane; Snow/ice; Snow/Ice", "people": "Brook, Edward J.; Bender, Michael; Yan, Yuzhen; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601202"}], "date_created": "Thu, 18 Oct 2018 00:00:00 GMT", "description": "Bubbles of ancient air trapped in ice cores permit the direct reconstruction of atmospheric composition and allow us to link greenhouse gases and global climate over the last 800,000 years. Previous field expeditions to the Allan Hills blue ice area, Antarctica, have recovered ice cores that date to one million years, the oldest ice cores yet recovered from Antarctica. These records have revealed that interglacial CO2 concentrations decreased by 800,000 years ago and that, in the warmer world 1 million years ago, CO2 and Antarctic temperature were linked as during the last 800,000 years. This project will return to the Allan Hills blue ice area to recover additional ice cores that date to 1 million years or older. The climate records developed from the drilled ice cores will provide new insights into the chemical composition of the atmosphere and Antarctic climate during times of comparable or even greater warmth than the present day. Our results will help answer questions about issues associated with anthropogenic change. These include the relationship between temperature change and the mass balance of Antarctic ice; precipitation and aridity variations associated with radiatively forced climate change; and the climate significance of sea ice extent. The project will entrain two graduate students and a postdoctoral scholar, and will conduct outreach including workshops to engage teachers in carbon science and ice cores. Between about 2.8-0.9 million years ago, Earth\u0027s climate was characterized by 40,000-year cycles, driven or paced by changes in the tilt of Earth\u0027s spin axis. Much is known about the \"40,000-year\" world from studies of deep-sea sediments, but our understanding of climate change during this period is incomplete because we lack records of Antarctic climate and direct records of atmospheric greenhouse gas concentrations. We propose to address these issues by building on our recent studies of ancient ice from the Main Ice Field, Allan Hills, Antarctica. During previous field seasons we recovered ice extending, discontinuously, from 0.1-1.0 million years old. Ice was dated by measuring the 40Ar/38Ar (Argon) ratio of the trapped gases. Our discovery of million year-old ice demonstrates that there is gas-record-quality ice from the 40,000-year world in the Allan Hills Main Ice Field. We have identified two different sites, each overlying bedrock at ~ 200 m depth, that are attractive targets for coring ice dating to 1 million years and older. This project aims to core the ice at these two sites, re-occupy a previous site with million year-old ice and drill it down to the bedrock, and generate 10-20 short (~10-meter) cores in areas where our previous work and terrestrial meteorite ages suggest ancient surface ice. We plan to date the ice using the 40Ar/38Ar ages of trapped Argon. We also plan to characterize the continuity of our cores by measuring the deuterium and oxygen isotope ratios in the ice, methane, ratios of Oxygen and Argon to Nitrogen in trapped gas, the Nitrogen-15 isotope (d15N) of Nitrogen, and the Oxygen-18 isotope (d18O) of Oxygen. As the ice may be stratigraphically disturbed, these measurements will provide diagnostic properties for assessing the continuity of the ice-core records. Successful retrieval of ice older than one million years will provide the opportunity for follow-up work to measure the CO2 concentration and other properties within the ice to inform on the temperature history of the Allan Hills region, dust sources and source-area aridity, moisture sources, densification conditions, global average ocean temperature, and greenhouse gas concentrations. We will analyze the data in the context of leading hypotheses of the 40,000-year world and the Mid-Pleistocene Transition to the 100,000-year world. We expect to advance understanding of climate dynamics during these periods.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Amd/Us; AMD; Allan Hills; USA/NSF; FIELD INVESTIGATION; USAP-DC; Ice Core; LABORATORY", "locations": "Allan Hills", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Kurbatov, Andrei V.; Higgins, John; Bender, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": null, "title": "Collaborative Research: Window into the World with 40,000-year Glacial Cycles from Climate Records in Million Year-old Ice from the Allan Hills Blue Ice Area", "uid": "p0000760", "west": null}, {"awards": "1245915 Ray, Laura", "bounds_geometry": null, "dataset_titles": "Ground Penetrating Radar Grid Survey of the McMurdo Shear Zone", "datasets": [{"dataset_uid": "601102", "doi": "10.15784/601102", "keywords": "Antarctica; Firn; Folds; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Snow/ice; Snow/Ice", "people": "Ray, Laura; Arcone, Steven; Kaluzienski, Lynn; Koons, Peter; Lever, Jim; Walker, Ben", "repository": "USAP-DC", "science_program": null, "title": "Ground Penetrating Radar Grid Survey of the McMurdo Shear Zone", "url": "https://www.usap-dc.org/view/dataset/601102"}], "date_created": "Thu, 27 Sep 2018 00:00:00 GMT", "description": "Hamilton/1246400 This award supports an integrated field observation, remote sensing and numerical modeling study of the McMurdo Shear Zone (SZ). The SZ is a 5-10 km wide strip of heavily crevassed ice that separates the McMurdo and Ross ice shelves, and is an important region of lateral support for the Ross Ice Shelf. Previous radar and remote sensing studies reveal an enigmatic picture of the SZ in which crevasses detected at depth have no apparent surface expression, and have orientations which are possibly inconsistent with the observed flow field. In the proposed work, we seek to test the hypothesis that the SZ is a zone of chaotic Lagrangian mixing with (intersecting) buried crevasses which leads to rheological instability, potentially allowing large scale velocity discontinuities. The work will involve detailed field-based observations of crevasse distributions and structure using ground-penetrating radar, and GPS and remote sensing observations of the flow and stress field in the SZ. Because of the hazardous nature of the SZ, the radar surveys will be conducted largely with the aid of a lightweight robotic vehicle. Observations will be used to develop a finite element model of ice shelf shear margin behavior. The intellectual merit of this project is an increased understanding of ice shelf shear margin dynamics. Shear margins play a key role in ice shelf stability, and ice shelves in turn modulate the flux of ice from the ice sheet across the grounding line to the ocean. Insights from this project will improve large-scale models being developed to predict ice sheet evolution and future rates of sea level rise, which are topics of enormous societal concern. The broader impacts of the project include an improved basis for US Antarctic Program logistics planning as well as numerous opportunities to engage K-12 students in scientific discovery. Intensified crevassing in the shear zone between the Ross and McMurdo ice shelves would preclude surface crossing by heavy traverse vehicles which would lead to increased costs of delivering fuel to South Pole and a concomitant loss of flight time provided by heavy-lift aircraft for science missions on the continent. Our multidisciplinary research combining glaciology, numerical modeling, and robotics engineering is an engaging way to show how robotics can assist scientists in collecting hazardous field measurements. Our outreach activities will leverage Dartmouth\u0027s current NSF GK-12 program, build on faculty-educator relationships established during University of Maine\u0027s recent GK-12 program, and incorporate project results into University of Maine\u0027s IDEAS initiative, which integrates computational modeling with the existing science curriculum at the middle school level. This award has field work in Antarctica.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Ray, Laura", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Flow and Fracture Dynamics in an Ice Shelf Lateral Margin: Observations and Modeling of the McMurdo Shear Zone", "uid": "p0000701", "west": null}, {"awards": "0838763 Anandakrishnan, Sridhar; 0839059 Powell, Ross; 0839107 Powell, Ross; 0839142 Tulaczyk, Slawek; 0838855 Jacobel, Robert; 0838947 Tulaczyk, Slawek; 0838764 Anandakrishnan, Sridhar", "bounds_geometry": null, "dataset_titles": "Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line; Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats in W Antarctica - Lake and Ice Stream Subglacial Access Research Drilling (LISSARD); Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES); IRIS ID#s 201035, 201162, 201205; IRIS offers free and open access to a comprehensive data store of raw geophysical time-series data collected from a large variety of sensors, courtesy of a vast array of US and International scientific networks, including seismometers (permanent and temporary), tilt and strain meters, infrasound, temperature, atmospheric pressure and gravimeters, to support basic research aimed at imaging the Earth\u0027s interior.; Paleogene marine and terrestrial development of the West Antarctic Rift System: Biomarker Data Set; Paleogene marine and terrestrial development of the West Antarctic Rift System: Palynomorph Data Set; Radar Studies of Subglacial Lake Whillans and the Whillans Ice Stream Grounding Zone; The IRIS DMC archives and distributes data to support the seismological research community.; UNAVCO ID#s WHL1, WHL2, LA02, LA09 (full data link not provided)", "datasets": [{"dataset_uid": "609594", "doi": "10.7265/N54J0C2W", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; GPS; Radar; Whillans Ice Stream", "people": "Jacobel, Robert", "repository": "USAP-DC", "science_program": null, "title": "Radar Studies of Subglacial Lake Whillans and the Whillans Ice Stream Grounding Zone", "url": "https://www.usap-dc.org/view/dataset/609594"}, {"dataset_uid": "601122", "doi": "10.15784/601122", "keywords": "Antarctica; Flexure Zone; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Ice-Shelf Basal Melting; Ice-Shelf Strain Rate", "people": "Begeman, Carolyn", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line", "url": "https://www.usap-dc.org/view/dataset/601122"}, {"dataset_uid": "000148", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IRIS ID#s 201035, 201162, 201205", "url": "http://ds.iris.edu/"}, {"dataset_uid": "001405", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IRIS offers free and open access to a comprehensive data store of raw geophysical time-series data collected from a large variety of sensors, courtesy of a vast array of US and International scientific networks, including seismometers (permanent and temporary), tilt and strain meters, infrasound, temperature, atmospheric pressure and gravimeters, to support basic research aimed at imaging the Earth\u0027s interior.", "url": "http://www.iris.edu/hq/data_and_software"}, {"dataset_uid": "000150", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "UNAVCO ID#s WHL1, WHL2, LA02, LA09 (full data link not provided)", "url": "http://www.unavco.org/"}, {"dataset_uid": "601245", "doi": "10.15784/601245", "keywords": "Antarctica; Pollen; West Antarctica; WISSARD", "people": "Warny, Sophie; Casta\u00f1eda, Isla; Coenen, Jason; Askin, Rosemary; Baudoin, Patrick; Scherer, Reed Paul", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Paleogene marine and terrestrial development of the West Antarctic Rift System: Palynomorph Data Set", "url": "https://www.usap-dc.org/view/dataset/601245"}, {"dataset_uid": "601234", "doi": "10.15784/601234", "keywords": "ACL; Antarctica; Biomarker; BIT Index; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Stream; Whillans Ice Stream; WISSARD", "people": "Scherer, Reed Paul; Baudoin, Patrick; Warny, Sophie; Casta\u00f1eda, Isla; Coenen, Jason; Askin, Rosemary", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Paleogene marine and terrestrial development of the West Antarctic Rift System: Biomarker Data Set", "url": "https://www.usap-dc.org/view/dataset/601234"}, {"dataset_uid": "600155", "doi": "10.15784/600155", "keywords": "Antarctica; Glaciology; Oceans; Southern Ocean; WISSARD", "people": "Powell, Ross", "repository": "USAP-DC", "science_program": null, "title": "Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES)", "url": "https://www.usap-dc.org/view/dataset/600155"}, {"dataset_uid": "001406", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "The IRIS DMC archives and distributes data to support the seismological research community.", "url": "http://ds.iris.edu/ds/nodes/dmc/"}, {"dataset_uid": "600154", "doi": "10.15784/600154", "keywords": "Antarctica; Biota; Diatom; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Lake Whillans; Paleoclimate; Ross Sea; Southern Ocean; Subglacial Lake; WISSARD", "people": "Powell, Ross", "repository": "USAP-DC", "science_program": null, "title": "Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats in W Antarctica - Lake and Ice Stream Subglacial Access Research Drilling (LISSARD)", "url": "https://www.usap-dc.org/view/dataset/600154"}], "date_created": "Mon, 10 Sep 2018 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The LISSARD project (Lake and Ice Stream Subglacial Access Research Drilling) is one of three research components of the WISSARD integrative initiative (Whillans Ice Stream Subglacial Access Research Drilling) that is being funded by the Antarctic Integrated System Science Program of NSF\u0027s Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The LISSARD component of WISSARD focuses on the role of active subglacial lakes in determining how fast the West Antarctic ice sheet loses mass to the global ocean and influences global sea level changes. The importance of Antarctic subglacial lakes has only been recently recognized, and the lakes have been identified as high priority targets for scientific investigations because of their unknown contributions to ice sheet stability under future global warming scenarios. LISSARD has several primary science goals: A) To provide an observational basis for improving treatments of subglacial hydrological and mechanical processes in models of ice sheet mass balance and stability; B) To reconstruct the past history of ice stream stability by analyzing archives of past basal water and ice flow variability contained in subglacial sediments, porewater, lake water, and basal accreted ice; C) To provide background understanding of subglacial lake environments to benefit RAGES and GBASE (the other two components of the WISSARD project); and D) To synthesize data and concepts developed as part of this project to determine whether subglacial lakes play an important role in (de)stabilizing Antarctic ice sheets. We propose an unprecedented synthesis of approaches to studying ice sheet processes, including: (1) satellite remote sensing, (2) surface geophysics, (3) borehole observations and measurements and, (4) basal and subglacial sampling. \u003cbr/\u003e\u003cbr/\u003eINTELLECTUAL MERIT: The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. \u003cbr/\u003e\u003cbr/\u003eBROADER IMPACTS: Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS", "is_usap_dc": true, "keywords": "USAP-DC; Ice Penetrating Radar; Antarctic; Subglacial Lake; Subglacial Hydrology; Grounding Line; Sea Level Rise; Bed Reflectivity; Ice Sheet Stability; Stability; Radar; Sub-Ice-Shelf; Geophysics; Biogeochemical; LABORATORY; Sediment; Sea Floor Sediment; Ice Thickness; Model; Ice Stream Stability; Basal Ice; SATELLITES; Ice Sheet Thickness; Subglacial; Antarctica; NOT APPLICABLE; Antarctic Ice Sheet; Ice Sheet; FIELD SURVEYS; Surface Elevation; Geochemistry; FIELD INVESTIGATION; Not provided", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek; Fisher, Andrew; Powell, Ross; Anandakrishnan, Sridhar; Jacobel, Robert; Scherer, Reed Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "USAP-DC", "repositories": "IRIS; UNAVCO; USAP-DC", "science_programs": "WISSARD", "south": null, "title": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)", "uid": "p0000105", "west": null}, {"awards": "1141866 Conway, Howard; 1141889 Winberry, J. Paul", "bounds_geometry": null, "dataset_titles": "Beardmore Glacier High-Frequency Impulse Radar Data; Geophysical measurements Beardmore Glacier, Antarctica; Project code ZF for passive seismic and 17-030 for active source", "datasets": [{"dataset_uid": "601713", "doi": "10.15784/601713", "keywords": "Antarctica; Beardmore Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Conway, Howard; Hoffman, Andrew; Christianson, Knut", "repository": "USAP-DC", "science_program": null, "title": "Beardmore Glacier High-Frequency Impulse Radar Data", "url": "https://www.usap-dc.org/view/dataset/601713"}, {"dataset_uid": "601121", "doi": "10.15784/601121", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness; Radar", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Geophysical measurements Beardmore Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601121"}, {"dataset_uid": "000210", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Project code ZF for passive seismic and 17-030 for active source", "url": "https://ds.iris.edu/mda/17-030"}], "date_created": "Sun, 09 Sep 2018 00:00:00 GMT", "description": "Conway/1141866 This award supports a project to conduct a suite of experiments to study spatial and temporal variations of basal conditions beneath Beardmore Glacier, an East Antarctic outlet glacier that discharges into the Ross Sea Embayment. The intellectual merit of the project is that it should help verify whether or not global warming will play a much larger role in the future mass balance of ice sheets than previously considered. Recent observations of rapid changes in discharge of fast-flowing outlet glaciers and ice streams suggest that dynamical responses to warming could affect that ice sheets of Greenland and Antarctica. Assessment of possible consequences of these responses is hampered by the lack of information about the basal boundary conditions. The leading hypothesis is that variations in basal conditions exert strong control on the discharge of outlet glaciers. Airborne and surface-based radar measurements of Beardmore Glacier will be made to map the ice thickness and geometry of the sub-glacial trough and active and passive seismic experiments, together with ground-based radar and GPS measurements will be made to map spatial and temporal variations of conditions at the ice-bed interface. The observational data will be used to constrain dynamic models of glacier flow. The models will be used to address the primary controls on the dynamics of Antarctic outlet glaciers, the conditions at the bed, their spatial and temporal variation, and how such variability might affect the sliding and flow of these glaciers. The work will also explore whether or not these outlet glaciers could draw down the interior of East Antarctica, and if so, how fast. The study will take three years including two field seasons to complete and results from the work will be disseminated through public and professional meetings and journal publications. All data and metadata will be made available through the NSIDC web portal. The broader impacts of the work are that it will help elucidate the fundamental physics of outlet glacier dynamics which is needed to improve predictions of the response of ice sheets to changing environmental conditions. The project will also provide support for early career investigators and will provide training and support for one graduate and two undergraduate students. All collaborators are currently involved in scientific outreach and graduate student education and they are committed to fostering diversity.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC; Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Winberry, Paul", "platforms": "Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "IRIS; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: East Antarctic Outlet Glacier Dynamics", "uid": "p0000437", "west": null}, {"awards": null, "bounds_geometry": null, "dataset_titles": "Location of surface crevasses in Antarctica", "datasets": [{"dataset_uid": "601117", "doi": "10.15784/601117", "repository": "USAP-DC", "science_program": null, "title": "Location of surface crevasses in Antarctica", "url": "http://www.usap-dc.org/view/dataset/601117"}], "date_created": "Wed, 05 Sep 2018 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Crevasses; Fractures; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Shelf; Satellite Remote Sensing", "locations": "Antarctica", "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": "Emetc, Veronika", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "1443126 MacAyeal, Douglas", "bounds_geometry": "POLYGON((166.1631 -77.9007,166.19736 -77.9007,166.23162 -77.9007,166.26588 -77.9007,166.30014 -77.9007,166.3344 -77.9007,166.36866 -77.9007,166.40292 -77.9007,166.43718 -77.9007,166.47144 -77.9007,166.5057 -77.9007,166.5057 -77.90423,166.5057 -77.90776,166.5057 -77.91129,166.5057 -77.91482,166.5057 -77.91835,166.5057 -77.92188,166.5057 -77.92541,166.5057 -77.92894,166.5057 -77.93247,166.5057 -77.936,166.47144 -77.936,166.43718 -77.936,166.40292 -77.936,166.36866 -77.936,166.3344 -77.936,166.30014 -77.936,166.26588 -77.936,166.23162 -77.936,166.19736 -77.936,166.1631 -77.936,166.1631 -77.93247,166.1631 -77.92894,166.1631 -77.92541,166.1631 -77.92188,166.1631 -77.91835,166.1631 -77.91482,166.1631 -77.91129,166.1631 -77.90776,166.1631 -77.90423,166.1631 -77.9007))", "dataset_titles": "McMurdo Ice Shelf AWS data; McMurdo Ice Shelf GPS survey of vertical motion; Supraglacial Lake Depths on McMurdo Ice Shelf, Antarctica; Time-lapse video of McMurdo Ice Shelf surface melting and hydrology", "datasets": [{"dataset_uid": "601107", "doi": "10.15784/601107", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity; Ice Shelf; Ice-Shelf Flexure; Snow/ice; Snow/Ice; Surface Melt", "people": "MacAyeal, Douglas; Banwell, Alison", "repository": "USAP-DC", "science_program": null, "title": "McMurdo Ice Shelf GPS survey of vertical motion", "url": "https://www.usap-dc.org/view/dataset/601107"}, {"dataset_uid": "601116", "doi": "10.15784/601116", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Snow/ice; Snow/Ice; Subglacial And Supraglacial Water Depth; Supraglacial Lake; Supraglacial Meltwater; Water Depth", "people": "MacAyeal, Douglas; Banwell, Alison", "repository": "USAP-DC", "science_program": null, "title": "Supraglacial Lake Depths on McMurdo Ice Shelf, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601116"}, {"dataset_uid": "601106", "doi": "10.15784/601106", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrology; Ice Shelf; Snow/ice; Snow/Ice; Surface Hydrology; Surface Mass Balance; Weather Station Data", "people": "MacAyeal, Douglas; Banwell, Alison", "repository": "USAP-DC", "science_program": null, "title": "McMurdo Ice Shelf AWS data", "url": "https://www.usap-dc.org/view/dataset/601106"}, {"dataset_uid": "601113", "doi": "10.15784/601113", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Photo/video; Photo/Video; Supraglacial Meltwater", "people": "Banwell, Alison; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Time-lapse video of McMurdo Ice Shelf surface melting and hydrology", "url": "https://www.usap-dc.org/view/dataset/601113"}], "date_created": "Tue, 24 Jul 2018 00:00:00 GMT", "description": "Meltwater lakes that sit on top of Antarctica\u0027s floating ice shelves have likely contributed to the dramatic changes seen in Antarctica\u0027s glacial ice cover over the past two decades. In 2002, the 1,600-square-kilometer Larsen B Ice Shelf located on the Eastern side of the Antarctic Peninsula, for example, broke into thousands of small icebergs, which subsequently floated away as a result of the formation of more than 2,000 meltwater lakes on its surface over the prior decade. Our research project addresses the reasons why surface lakes form on Antarctic ice shelves and how these surface lakes subsequently contribute to the forces that may contribute to ice-shelf breakup like that of the Larsen B. Our project focuses primarily on making precise global positioning system (GPS) measurements of ice-shelf bending in response to the filling and draining of a surface lake on the McMurdo Ice Shelf. The observed vertical displacements (on the order of tens of centimeters) in response to lake filling will be used to calibrate and test computer simulation models that predict the response of ice shelves to surface lakes more generally and in a variety of future climate conditions. Our project will make hourly measurements of both vertical ice-shelf movements (using GPS surveying instruments) and of temperature and sunlight conditions (that drive melting) around a surface lake located close to the McMurdo Station airfield. Following this initial data-gathering effort, computer simulations and other more theoretical analysis will be undertaken to determine the suitability of the chosen McMurdo Ice Shelf surface lake as a field-laboratory for continued study. Ultimately, the research will contribute to understanding of the glaciological processes that link climate change to rising sea level. A successful outcome of the research will allow glaciologists to better assess the processes that promote or erode the influence Antarctic ice shelves have in controlling the transfer of ice from the interior of Antarctica into the ocean. The project will undertake two outreach activities: (1) web-posting of a field-activity journal and (2) establishing an open-access glaciological teaching and outreach web-sharing site for the International Glaciological Society. The proposed project seeks to experimentally verify a theory of ice-shelf instability proposed to explain the explosive break-up of Larsen B Ice Shelf in 2002. This theory holds that the filling and draining of supraglacial lakes on floating ice shelves induces sufficient flexure stress within the ice to (a) induce upward/downward propagating fractures originating at the base/surface of the ice shelf that (b) dissect the ice shelf into fragments that tend to have widths less than about half the ice thickness. The significance of narrow widths is that they promote capsize of the ice-shelf fragments during the break-up process. This capsize releases large amounts of gravitational potential energy (comparable to thousands of kilotons of TNT for the Larsen B Ice Shelf) thereby promoting explosiveness of the Larsen B event. The observational motivation for experimentally verifying the surface-lake mechanism for ice-shelf breakup is based on the fact that \u003e2,000 surface lakes developed on the Larsen B Ice Shelf in the decade prior to its break up, and that these lakes were observed (via satellite imagery) to drain in a coordinated fashion during the day prior to the initiation of the break up. The field-observation component of the project will focus on a supraglacial lake on the McMurdo Ice Shelf where there is persistent summer season surface melting. The lake will be studied during a single provisional field season to determine whether grooming of surrounding surface streams and shorelines with heavy construction equipment will allow surface water to be manually encouraged to fill the lake. If successfully encouraged to develop, the McMurdo Ice Shelf surface lake will allow measurements of key ice-shelf flexure and stress variables needed to develop the theory of ice-shelf surface lakes without having to access the much more logistically demanding surface lakes of ice-shelves located elsewhere in Antarctica. Data to be gathered during the 6-week provisional field season include: energy- and water-balance parameters determining how the surface lake grows and fills, and various global positioning system measurements of the vertical bending of the ice sheet in response to the changing meltwater load contained within the surface lake. These data will be used to (1) constrain a computer model of viscoelastic flexure and possible fracture of the ice shelf in response to the increasing load of meltwater in the lake, and (2) determine whether continued study of the incipient surface-meltwater lake features on the McMurdo Ice Shelf provides a promising avenue for constraining the more-general behavior of surface meltwater lakes on other ice shelves located in warmer parts of Antarctica. Computer models constrained by the observational data obtained from the field project will inform energy- and water-balance models of ice shelves in general, and allow more accurate forecasts of changing ice-shelf conditions surrounding the inland ice of Antarctica. The project will create the first-ever ground-based observations useful for spawning the development of models capable of predicting viscoelastic and fracture behavior of ice shelves in response to supraglacial lake evolution, including slow changes due to energy balance effects, as well as fast changes due to filling and draining.", "east": 166.5057, "geometry": "POINT(166.3344 -77.91835)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS", "is_usap_dc": true, "keywords": "USAP-DC; AWOS", "locations": null, "north": -77.9007, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e AWOS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.936, "title": "Impact of Supraglacial Lakes on Ice-Shelf Stability", "uid": "p0000138", "west": 166.1631}, {"awards": "1644159 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "CTDP/LADCP profile data along Dotson ice shelf calving front from 2000 to 2016", "datasets": [{"dataset_uid": "601105", "doi": "10.15784/601105", "repository": "USAP-DC", "science_program": null, "title": "CTDP/LADCP profile data along Dotson ice shelf calving front from 2000 to 2016", "url": "http://www.usap-dc.org/view/dataset/601105"}], "date_created": "Thu, 12 Jul 2018 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Amundsen Sea; Antarctica; Dotson Ice Shelf; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ocean Properties; Oceans; Physical Oceanography; West Antarctica", "locations": "Amundsen Sea; West Antarctica; Antarctica; Dotson Ice Shelf", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Stammerjohn, Sharon; Dutrieux, Pierre; Jacobs, Stanley; Jenkins, Adrian", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "1341311 Timmermann, Axel", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "784 ka transient Antarctic ice-sheet model simulation data", "datasets": [{"dataset_uid": "000247", "doi": "", "keywords": null, "people": null, "repository": "IBS Center for Climate Physics ICCP", "science_program": null, "title": "784 ka transient Antarctic ice-sheet model simulation data", "url": "http://climatedata.ibs.re.kr/grav/data/psu-love/antarctic-ice-sheet"}], "date_created": "Tue, 26 Jun 2018 00:00:00 GMT", "description": "Timmerman/1341311 This award supports a project to study the physical processes that synchronize glacial-scale variability between the Northern Hemisphere ice sheets and the Antarctic ice-sheet. Using a coupled numerical ice-sheet earth-system model, the research team will explore the cryospheric responses to past changes in greenhouse gas concentrations and variations in earth\u0027s orbit and tilt. First capturing the sensitivity of each individual ice-sheet to these forcings and then determining their joint variability induced by changes in sea level, ocean temperatures and atmospheric circulation, the researchers will quantify the relative roles of local versus remote effects on long-term ice volume variability. The numerical experiments will provide deeper physical insights into the underlying dynamics of past Antarctic ice-volume changes and their contribution to global sea level. Output from the transient earth system model simulations will be directly compared with ice-core data from previous and ongoing drilling efforts, such as West Antarctic Ice Sheet (WAIS) Divide. Specific questions that will be addressed include: 1) Did the high-latitude Southern Hemispheric atmospheric and oceanic climate, relevant to Antarctic ice sheet forcing, respond to local insolation variations, CO2, Northern Hemispheric changes, or a combination thereof?; 2) How did WAIS and East Antarctic Ice Sheet (EAIS) vary through the Last Glacial Termination and into the Holocene (21 ka- present)?; 3) Did the WAIS (or EAIS) contribute to rapid sea-level fluctuations during this period, such as Meltwater Pulse 1A? 4) Did WAIS collapse fully at Stage 5e (~ 125 ka), and what was its timing relative to the maximum Greenland retreat?; and 5) How did the synchronized behavior of Northern Hemisphere and Southern Hemisphere ice-sheet variations affect the strength of North Atlantic Deep Water and Antarctic Bottom Water formation and the respective overturning cells? The transient earth-system model simulations conducted as part of this project will be closely compared with paleo-climate reconstructions from ice cores, sediment cores and terrestrial data. This will generate an integrated understanding of the hemispheric contributions of deglacial climate change, the origin of meltwater pulses, and potential thresholds in the coupled ice-sheet climate system in response to different types of forcings. A well-informed long-term societal response to sea level rise requires a detailed understanding of ice-sheet sensitivities to external forcing. The proposed research will strongly contribute to this task through numerical modeling and paleo-data analysis. The research team will make the resulting model simulations available on the web-based data server at the Asia Pacific Data Research Center (APDRC) to enable further analysis by the scientific community. As part of this project a female graduate student and a postdoctoral researcher will receive training in earth-system and ice-sheet modeling and paleo-climate dynamics. This award has no field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Timmermann, Axel", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "IBS Center for Climate Physics ICCP", "repositories": "IBS Center for Climate Physics ICCP", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Bipolar Coupling of late Quaternary Ice Sheet Variability", "uid": "p0000379", "west": -180.0}, {"awards": "1443341 Hawley, Robert; 1443471 Koutnik, Michelle", "bounds_geometry": "POLYGON((110 -89,117 -89,124 -89,131 -89,138 -89,145 -89,152 -89,159 -89,166 -89,173 -89,180 -89,180 -89.1,180 -89.2,180 -89.3,180 -89.4,180 -89.5,180 -89.6,180 -89.7,180 -89.8,180 -89.9,180 -90,173 -90,166 -90,159 -90,152 -90,145 -90,138 -90,131 -90,124 -90,117 -90,110 -90,110 -89.9,110 -89.8,110 -89.7,110 -89.6,110 -89.5,110 -89.4,110 -89.3,110 -89.2,110 -89.1,110 -89))", "dataset_titles": "7MHz radar in the vicinity of South Pole; Firn density and compaction rates 50km upstream of South Pole; Firn temperatures 50km upstream of South Pole; Shallow radar near South Pole; South Pole area GPS velocities; SPICEcore Advection", "datasets": [{"dataset_uid": "601369", "doi": "10.15784/601369", "keywords": "Antarctica; Ice Sheet", "people": "Waddington, Edwin D.; Fudge, T. J.; Koutnik, Michelle; Lilien, David; Conway, Howard; Stevens, Max", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "7MHz radar in the vicinity of South Pole", "url": "https://www.usap-dc.org/view/dataset/601369"}, {"dataset_uid": "601100", "doi": "10.15784/601100", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Velocity", "people": "Fudge, T. J.; Waddington, Edwin D.; Koutnik, Michelle; Lilien, David; Conway, Howard", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole area GPS velocities", "url": "https://www.usap-dc.org/view/dataset/601100"}, {"dataset_uid": "601099", "doi": "10.15784/601099", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar; Snow Accumulation; Snow/ice; Snow/Ice", "people": "Waddington, Edwin D.; Fudge, T. J.; Koutnik, Michelle; Lilien, David; Conway, Howard", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Shallow radar near South Pole", "url": "https://www.usap-dc.org/view/dataset/601099"}, {"dataset_uid": "601525", "doi": "10.15784/601525", "keywords": "Antarctica; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Snow/ice; Snow/Ice; South Pole; SPICEcore; Temperature", "people": "Stevens, Christopher Max; Lilien, David; Conway, Howard; Koutnik, Michelle; Waddington, Edwin D.; Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Firn temperatures 50km upstream of South Pole", "url": "https://www.usap-dc.org/view/dataset/601525"}, {"dataset_uid": "601680", "doi": "10.15784/601680", "keywords": "Antarctica; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Snow/ice; Snow/Ice; South Pole; Temperature", "people": "Stevens, Christopher Max; Waddington, Edwin D.; Lilien, David; Conway, Howard; Fudge, T. J.; Koutnik, Michelle", "repository": "USAP-DC", "science_program": null, "title": "Firn density and compaction rates 50km upstream of South Pole", "url": "https://www.usap-dc.org/view/dataset/601680"}, {"dataset_uid": "601266", "doi": "10.15784/601266", "keywords": "Antarctica; Ice Core Data; South Pole; SPICEcore", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore Advection", "url": "https://www.usap-dc.org/view/dataset/601266"}], "date_created": "Thu, 14 Jun 2018 00:00:00 GMT", "description": "Ice-core records are critical to understanding past climate variations. An Antarctic ice core currently being drilled at the South Pole will allow detailed investigation of atmospheric gases and fill an important gap in understanding the pattern of climate variability across Antarctica. Critical to the interpretation of any ice core are: 1) accurate chronologies for both the ice and the trapped gas and 2) demonstration that records from the ice core reliably reflect climate. The proposed research will improve the ice and gas chronologies by making measurements of snow compaction in the upstream catchment in order to constrain age models of the ice. These measurements will be a key data set needed for better understanding and predicting time-varying conditions in the upper part of the ice sheet. The research team will measure the modern spatial gradients in accumulation rate, surface temperature, and water stable isotopes from shallow ice cores in the upstream catchment in order to determine the climate history from the ice-core record. The new ice-flow measurements will make it possible to define the path of ice from upstream to the South Pole ice-core drill site to assess spatial gradients in snowfall and to infer histories of snowfall from internal layers within the ice sheet. The project will be led by an early-career scientist, provide broad training to graduate students, and engage in public outreach on polar science. Ice-core records of stable isotopes, aerosol-born particles, and atmospheric gases are critical to understanding past climate variations. The proposed research will improve the ice and gas chronologies in the South Pole ice core by making in situ measurements of firn compaction in the upstream catchment to constrain models of the gas-age ice-age difference. The firn measurements will be a key data set needed to form a constitutive relationship for firn, and will drive better understanding and prediction of transient firn evolution. The research team will measure the modern gradients in accumulation rate, surface temperature, and water stable isotopes in the upstream catchment to separate spatial (advection) variations from temporal (climate) variations in the ice-core records. The ice-flow measurements will define the flowline upstream of the drill site, assess spatial gradients in accumulation, and infer histories of accumulation from radar-observed internal layers. Results will directly enhance interpretation of South Pole ice-core records, and also advance understanding of firn densification and drive next-generation firn models.", "east": 180.0, "geometry": "POINT(145 -89.5)", "instruments": null, "is_usap_dc": true, "keywords": "FIRN; Firn; USAP-DC; South Pole; Radar; FIELD SURVEYS; ICE CORE RECORDS", "locations": "South Pole", "north": -89.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Conway, Howard; Waddington, Edwin D.; Fudge, T. J.; Hawley, Robert L.; Osterberg, Erich", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Characterization of Upstream Ice and Firn Dynamics affecting the South Pole Ice Core", "uid": "p0000200", "west": 110.0}, {"awards": "1341585 Sorlien, Christopher", "bounds_geometry": "POLYGON((-180 -73.33,-179.1 -73.33,-178.2 -73.33,-177.3 -73.33,-176.4 -73.33,-175.5 -73.33,-174.6 -73.33,-173.7 -73.33,-172.8 -73.33,-171.9 -73.33,-171 -73.33,-171 -73.864,-171 -74.398,-171 -74.932,-171 -75.466,-171 -76,-171 -76.534,-171 -77.068,-171 -77.602,-171 -78.136,-171 -78.67,-171.9 -78.67,-172.8 -78.67,-173.7 -78.67,-174.6 -78.67,-175.5 -78.67,-176.4 -78.67,-177.3 -78.67,-178.2 -78.67,-179.1 -78.67,180 -78.67,178.5 -78.67,177 -78.67,175.5 -78.67,174 -78.67,172.5 -78.67,171 -78.67,169.5 -78.67,168 -78.67,166.5 -78.67,165 -78.67,165 -78.136,165 -77.602,165 -77.068,165 -76.534,165 -76,165 -75.466,165 -74.932,165 -74.398,165 -73.864,165 -73.33,166.5 -73.33,168 -73.33,169.5 -73.33,171 -73.33,172.5 -73.33,174 -73.33,175.5 -73.33,177 -73.33,178.5 -73.33,-180 -73.33))", "dataset_titles": "Ross Sea unconformities digital grids in depth and two-way time", "datasets": [{"dataset_uid": "601098", "doi": "10.15784/601098", "keywords": "Antarctica; Continental Margin; Geology/Geophysics - Other; Marine Geoscience; Miocene; Oligocene; Seismic Reflection", "people": "Wilson, Douglas S.; Sorlien, Christopher", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea unconformities digital grids in depth and two-way time", "url": "https://www.usap-dc.org/view/dataset/601098"}], "date_created": "Fri, 25 May 2018 00:00:00 GMT", "description": "Intellectual Merit: This project will produce a new compilation of Ross Sea seismic stratigraphy, including new interpretations, that can be used to provide boundary conditions on the tectonic and glacial evolution of West Antarctica and the Ross Sea. The principal goals include compilation of, and interpretation of, all available existing seismic reflection data for the Western Ross Sea, coupled with geophysical modeling to produce paleo-bathymetric reconstructions for the entire 800 km-wide Ross Sea. Specific tasks will include: extending existing work on mapping travel time to reflectors, identifying relations in the seismic data that indicate subsidence through sea level, constructing velocity models for converting travel time to thickness, and using the velocity models to estimate density and porosity of sediments for backstripping analysis. Modeling/backstripping efforts will be used to constrain past bathymetry. Digital interpretations and stratigraphic grids will be provided as supplements to publications. In that way the results of this study can be used in thermal subsidence modeling and restoration of eroded rock to other parts of Ross Embayment and Marie Byrd Land by others. Digital products may be provided in advance of publication to modelers in a way that will not hurt publication chances. Broader impacts: The results of this work will be important for paleo-geographic reconstructions of Antarctica and will therefore be of use to a broad range of researchers, particularly those working in the Ross Sea region. The digital products can be used to test models for the past fluctuations of West Antarctic ice sheets, and in planning for future sediment drilling projects. Two undergraduates to be chosen from applicants will be involved in summer internships held at the University of Rhode Island. Outreach will also include a new website and one or more Wikipedia entries related to Ross Sea sub-sea floor characteristics. The project includes an international collaboration with Dr. Chiara Sauli and others at Instituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Italy.", "east": -171.0, "geometry": "POINT(177 -76)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -73.33, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sorlien, Christopher; Luyendyk, Bruce P.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.67, "title": "Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea", "uid": "p0000271", "west": 165.0}, {"awards": "1443232 Waddington, Edwin", "bounds_geometry": "POLYGON((110 -89,117 -89,124 -89,131 -89,138 -89,145 -89,152 -89,159 -89,166 -89,173 -89,180 -89,180 -89.1,180 -89.2,180 -89.3,180 -89.4,180 -89.5,180 -89.6,180 -89.7,180 -89.8,180 -89.9,180 -90,173 -90,166 -90,159 -90,152 -90,145 -90,138 -90,131 -90,124 -90,117 -90,110 -90,110 -89.9,110 -89.8,110 -89.7,110 -89.6,110 -89.5,110 -89.4,110 -89.3,110 -89.2,110 -89.1,110 -89))", "dataset_titles": "AC-ECM for SPICEcore; ECM (DC and AC) multi-track data and images from 2016 processing season", "datasets": [{"dataset_uid": "601366", "doi": "10.15784/601366", "keywords": "Antarctica", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "ECM (DC and AC) multi-track data and images from 2016 processing season", "url": "https://www.usap-dc.org/view/dataset/601366"}, {"dataset_uid": "601189", "doi": " 10.15784/601189 ", "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; South Pole; SPICEcore; Volcanic", "people": "Fudge, T. J.; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "AC-ECM for SPICEcore", "url": "https://www.usap-dc.org/view/dataset/601189"}], "date_created": "Tue, 08 May 2018 00:00:00 GMT", "description": "Ice cores record detailed histories of past climate variations. The South Pole ice core will allow investigation of atmospheric trace gases and fill an important gap in understanding the pattern of climate variability across Antarctica. An accurate timescale that assigns an age to the ice at each depth in the core is essential to interpretation of the ice-core records. This work will use electrical methods to identify volcanic eruptions throughout the past ~40,000 years in the core by detecting the enhanced electrical conductance in those layers due to volcanic impurities in the ice. These eruptions will be pattern-matched to other cores across Antarctica, synchronizing the timing of climate variations among cores and allowing the precise timescales developed for other Antarctic ice cores to be transferred to the South Pole ice core. The well-dated records of volcanic forcing will be combined with records of atmospheric gases, stable water-isotopes, and aerosols to better understand the large natural climate variations of the past 40,000 years. The electrical conductance method and dielectric profiling measurements will be made along the length of each section of the South Pole ice core at the National Ice Core Lab. These measurements will help to establish a timescale for the core. Electrical measurements will provide a continuous record of volcanic events for the entire core including through the brittle ice (550-1250m representing ~10,000-20,000 year-old ice) where the core quality and thin annual layers may prevent continuous melt analysis and cause discrete measurements to miss volcanic events. The electrical measurements also produce a 2-D image of the electrical layering on a longitudinal cut surface of each core. These data will be used to identify any irregular or absent layering that would indicate a stratigraphic disturbance in the core. A robust chronology is essential to interpretation of the paleoclimate records from the South Pole ice core. The investigators will engage teachers through talks and webinars with the National Science Teachers Association and will share information with the public at events such as Polar Science Weekend at the Pacific Science Center. Results will be disseminated through publications and conference presentations and the data will be archived and publicly available.", "east": 180.0, "geometry": "POINT(145 -89.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; Amd/Us; AMD; LABORATORY", "locations": null, "north": -89.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Waddington, Edwin D.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Using Electrical Conductance Measurements to Develop the South Pole Ice Core Chronology", "uid": "p0000378", "west": 110.0}, {"awards": "1246045 Waddington, Edwin", "bounds_geometry": "POLYGON((-180 -70,-144 -70,-108 -70,-72 -70,-36 -70,0 -70,36 -70,72 -70,108 -70,144 -70,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,180 -82,180 -84,180 -86,180 -88,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88,-180 -86,-180 -84,-180 -82,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70))", "dataset_titles": "Code for inference of fabric from sonic velocity and thin-section measurements.; Code for models involving stochastic treatment of ice fabric", "datasets": [{"dataset_uid": "000244", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for models involving stochastic treatment of ice fabric", "url": "https://github.com/mjhay/stochastic_fabric"}, {"dataset_uid": "000243", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for inference of fabric from sonic velocity and thin-section measurements.", "url": "https://github.com/mjhay/neem_sonic_model"}], "date_created": "Mon, 02 Apr 2018 00:00:00 GMT", "description": "Waddington/1246045 This award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Waddington, Edwin D.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -90.0, "title": "Anisotropic Ice and Stratigraphic Disturbances", "uid": "p0000073", "west": -180.0}, {"awards": "0944021 Brook, Edward J.; 0943466 Hawley, Robert; 0944307 Conway, Howard", "bounds_geometry": "POLYGON((-163 -79,-162.8 -79,-162.6 -79,-162.4 -79,-162.2 -79,-162 -79,-161.8 -79,-161.6 -79,-161.4 -79,-161.2 -79,-161 -79,-161 -79.05,-161 -79.1,-161 -79.15,-161 -79.2,-161 -79.25,-161 -79.3,-161 -79.35,-161 -79.4,-161 -79.45,-161 -79.5,-161.2 -79.5,-161.4 -79.5,-161.6 -79.5,-161.8 -79.5,-162 -79.5,-162.2 -79.5,-162.4 -79.5,-162.6 -79.5,-162.8 -79.5,-163 -79.5,-163 -79.45,-163 -79.4,-163 -79.35,-163 -79.3,-163 -79.25,-163 -79.2,-163 -79.15,-163 -79.1,-163 -79.05,-163 -79))", "dataset_titles": "Roosevelt Island Borehole Firn temperatures; Roosevelt Island Borehole Optical Televiewer logs; Roosevelt Island Ice Core Time Scale and Associated Data; Roosevelt Island: Radar and GPS", "datasets": [{"dataset_uid": "601070", "doi": "10.15784/601070", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; GPS Data; Ice Velocity; Navigation; Radar; Roosevelt Island; Ross Sea", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island: Radar and GPS", "url": "https://www.usap-dc.org/view/dataset/601070"}, {"dataset_uid": "601359", "doi": "10.15784/601359", "keywords": "Antarctica; CO2; Ice Core; Roosevelt Island", "people": "Brook, Edward J.; Lee, James", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Ice Core Time Scale and Associated Data", "url": "https://www.usap-dc.org/view/dataset/601359"}, {"dataset_uid": "601086", "doi": "10.15784/601086", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Roosevelt Island; Snow/ice; Snow/Ice", "people": "Clemens-Sewall, David; Hawley, Robert L.", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Borehole Optical Televiewer logs", "url": "https://www.usap-dc.org/view/dataset/601086"}, {"dataset_uid": "601085", "doi": "10.15784/601085", "keywords": "Antarctica; Borehole; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Records; Ice Fabric; Optical Images; Roosevelt Island; Snow/ice; Snow/Ice; Temperature", "people": "Hawley, Robert L.; Clemens-Sewall, David; Giese, Alexandra", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Borehole Firn temperatures", "url": "https://www.usap-dc.org/view/dataset/601085"}], "date_created": "Fri, 16 Feb 2018 00:00:00 GMT", "description": "This award supports a project to use the Roosevelt Island ice core as a glaciological dipstick for the eastern Ross Sea. Recent attention has focused on the eastern Ross Embayment, where there are no geological constraints on ice thickness changes, due to the lack of protruding rock \"dipsticks\" where the ice sheet can leave datable records of high stands. Recent work has shown how dated ice cores can be used as dipsticks to derive ice-thickness histories. Partners from New Zealand and Denmark will extract an ice core from Roosevelt Island during the 2010-2011 and 2011-12 austral summers. Their science objective is to contribute to understanding of climate variability over the past 40kyr. The science goal of this project is not the climate record, but rather the history of deglaciation in the Ross Sea. The new history from the eastern Ross Sea will be combined with the glacial histories from the central Ross Sea (Siple Dome and Byrd) and existing and emerging histories from geologic and marine records along the western Ross Sea margin and will allow investigators to establish an updated, self-consistent model of the configuration and thickness of ice in the Ross Embayment during the LGM, and the timing of deglaciation. Results from this work will provide ground truth for new-generation ice-sheet models that incorporate ice streams and fast-flow dynamics. Realistic ice-sheet models are needed not only for predicting the response to future possible environments, but also for investigating past behaviors of ice sheets. This research contributes to the primary goals of the West Antarctic Ice Sheet Initiative as well as the IPY focus on ice-sheet history and dynamics. It also contributes to understanding spatial and temporal patterns of climate change and climate dynamics over the past 40kyr, one of the primary goals of the International Partnerships in Ice Core Sciences (IPICS). The project will help to develop the next generation of scientists and will contribute to the education and training of two Ph.D. students. All participants will benefit from the international collaboration, which will expose them to different field and laboratory techniques and benefit future collaborative work. All participants are involved in scientific outreach and undergraduate education, and are committed to fostering diversity. Outreach will be accomplished through regularly scheduled community and K-12 outreach events, talks and popular writing by the PIs, as well as through University press offices.", "east": -161.0, "geometry": "POINT(-162 -79.25)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "AMD; FIELD INVESTIGATION; Amd/Us; Deglaciation; USAP-DC; USA/NSF; NOT APPLICABLE; Ice Core; Not provided; Ross Sea Embayment", "locations": "Ross Sea Embayment", "north": -79.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Conway, Howard; Brook, Edward J.; Hawley, Robert L.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.5, "title": "Collaborative Research: Deglaciation of the Ross Sea Embayment - constraints from Roosevelt Island", "uid": "p0000272", "west": -163.0}, {"awards": "1246353 Anderson, John", "bounds_geometry": "POLYGON((-180 -74,-144.9 -74,-109.8 -74,-74.7 -74,-39.6 -74,-4.5 -74,30.6 -74,65.7 -74,100.8 -74,135.9 -74,171 -74,171 -74.3,171 -74.6,171 -74.9,171 -75.2,171 -75.5,171 -75.8,171 -76.1,171 -76.4,171 -76.7,171 -77,135.9 -77,100.8 -77,65.7 -77,30.6 -77,-4.5 -77,-39.6 -77,-74.7 -77,-109.8 -77,-144.9 -77,180 -77,180 -77,180 -77,180 -77,180 -77,180 -77,180 -77,180 -77,180 -77,180 -77,180 -77,180 -76.7,180 -76.4,180 -76.1,180 -75.8,180 -75.5,180 -75.2,180 -74.9,180 -74.6,180 -74.3,180 -74,180 -74,180 -74,180 -74,180 -74,180 -74,180 -74,180 -74,180 -74,180 -74,-180 -74))", "dataset_titles": "Circum-Antarctic grounding-line sinuosity; NBP1502A Cruise Core Data; NBP1502 Cruise Geophysics and underway data; Pennell Trough, Ross Sea bathymetry and glacial landforms", "datasets": [{"dataset_uid": "601484", "doi": "10.15784/601484", "keywords": "Antarctica; Bed Roughness; Bed Slope; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pinning Points", "people": "Stearns, Leigh; Riverman, Kiya; Simkins, Lauren", "repository": "USAP-DC", "science_program": null, "title": "Circum-Antarctic grounding-line sinuosity", "url": "https://www.usap-dc.org/view/dataset/601484"}, {"dataset_uid": "000245", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1502 Cruise Geophysics and underway data", "url": "https://www.rvdata.us/search/cruise/NBP1502"}, {"dataset_uid": "601083", "doi": "10.15784/601083", "keywords": "Antarctica; Chemistry:sediment; Chemistry:Sediment; Geochronology; Marine Geoscience; Marine Sediments; NBP1502; R/v Nathaniel B. Palmer; Sediment Core", "people": "Prothro, Lindsay; Simkins, Lauren; Anderson, John", "repository": "USAP-DC", "science_program": null, "title": "NBP1502A Cruise Core Data", "url": "https://www.usap-dc.org/view/dataset/601083"}, {"dataset_uid": "601474", "doi": "10.15784/601474", "keywords": "Antarctica; Bathymetry; Elevation; Geomorphology; Glacial History; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; NBP1502; Pennell Trough; Ross Sea; R/v Nathaniel B. Palmer", "people": "Munevar Garcia, Santiago; Prothro, Lindsay; Simkins, Lauren; Greenwood, Sarah; Anderson, John; Eareckson, Elizabeth", "repository": "USAP-DC", "science_program": null, "title": "Pennell Trough, Ross Sea bathymetry and glacial landforms", "url": "https://www.usap-dc.org/view/dataset/601474"}], "date_created": "Tue, 06 Feb 2018 00:00:00 GMT", "description": "Intellectual Merit: The PI hypothesizes that bedforms found in the Central and Joides troughs can be interpreted as having been formed by rapid retreat, and possible collapse of an ice stream that occupied this area. To test this hypothesis, the PI proposes to conduct a detailed marine geological and geophysical survey of Central and Joides Troughs in the western Ross Sea. This project will bridge gaps between the small and isolated areas previously surveyed and will acquire a detailed sedimentological record of the retreating grounding line. The PI will reconstruct the retreat history of the Central and Joides troughs to century-scale resolution using radiocarbon dating methods and by looking at geomorphic features that are formed at regular time intervals. Existing multibeam, deep tow side-scan sonar, and core data will provide a framework for this research. The western Ross Sea is an ideal study area to investigate a single ice stream and the dynamics controlling its stability, including interactions between both East and West Antarctic Ice Sheets. Broader impacts: This proposal includes a post-doc, a graduate and two undergraduate students. The post-doc is involved with teaching an in-service K-12 teacher development and training course at Rice University for high-need teachers with a focus on curriculum enhancement. The project fosters collaboration for the PI and students with researchers at Louisiana State University and international colleagues at the Institute for Paleobiology at the Polish Academy of Sciences. The results from this project could lead to a better understanding of ice sheet and ice stream stability. This project will yield implications for society\u0027s understanding of climate change, as this work improves understanding of the behavior of ice sheets and their links to global climate.", "east": 179.99, "geometry": "POINT(175.495 -75.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e CARBON ANALYZERS", "is_usap_dc": true, "keywords": "AMD; Amd/Us; USAP-DC; USA/NSF; R/V NBP; NBP1502", "locations": null, "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -77.0, "title": "Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum.", "uid": "p0000395", "west": 171.0}, {"awards": "1143833 Orsi, Alejandro; 1143836 Leventer, Amy; 1143834 Huber, Bruce; 1430550 Domack, Eugene", "bounds_geometry": "POLYGON((116 -65.2,116.5 -65.2,117 -65.2,117.5 -65.2,118 -65.2,118.5 -65.2,119 -65.2,119.5 -65.2,120 -65.2,120.5 -65.2,121 -65.2,121 -65.38,121 -65.56,121 -65.74,121 -65.92,121 -66.1,121 -66.28,121 -66.46,121 -66.64,121 -66.82,121 -67,120.5 -67,120 -67,119.5 -67,119 -67,118.5 -67,118 -67,117.5 -67,117 -67,116.5 -67,116 -67,116 -66.82,116 -66.64,116 -66.46,116 -66.28,116 -66.1,116 -65.92,116 -65.74,116 -65.56,116 -65.38,116 -65.2))", "dataset_titles": "AU1402 Final UCTD data; AU1402 mooring data; Bottom photos from the Southern Ocean acquired during R/V Nathaniel B. Palmer expedition NBP1402 ; NBP1402 diatom data; NBP1402 Final CTD data; NBP1402 Final UCTD data; NBP1402 JPC43 Diatom Data; NBP14-02 JPC-54 and JPC-55 Pollen Assemblage data; NBP14-02 JPC-55 Bulk Sediment Carbon and Nitrogen data; NBP14-02 JPC-55 foraminifer assemblage data; NBP1402 Lowered ADCP data; Near-bottom Videos from the Southern Ocean acquired during R/V Nathaniel B. Palmer expedition NBP1402; Sabrina Coast mooring data - sediment trap mooring 2014", "datasets": [{"dataset_uid": "601310", "doi": null, "keywords": "Antarctica; Benthic Images; Benthos; East Antarctica; Marine Geoscience; NBP1402; Photo; Photo/video; Photo/Video; R/v Nathaniel B. Palmer; Totten Glacier; Yoyo Camera", "people": "Orsi, Alejandro; Huber, Bruce; Domack, Eugene Walter; Leventer, Amy; Post, Alexandra; Gulick, Sean; Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "Bottom photos from the Southern Ocean acquired during R/V Nathaniel B. Palmer expedition NBP1402 ", "url": "https://www.usap-dc.org/view/dataset/601310"}, {"dataset_uid": "601845", "doi": "10.15784/601845", "keywords": "Antarctica; Cryosphere; Diatom; NBP1402; Totten Glacier", "people": "Leventer, Amy; NBP1402 science party, ", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 diatom data", "url": "https://www.usap-dc.org/view/dataset/601845"}, {"dataset_uid": "601068", "doi": "10.15784/601068", "keywords": "ADCP Acoustic Doppler Current Profiler; Antarctica; NBP1402; Oceans; Physical Oceanography; Sabrina Coast; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 Lowered ADCP data", "url": "https://www.usap-dc.org/view/dataset/601068"}, {"dataset_uid": "601440", "doi": "10.15784/601440", "keywords": "Antarctica; Diatom; Holocene; Jumbo Piston Corer; NBP1402; R/v Nathaniel B. Palmer; Sabrina Coast; Sediment Core Data; Species Abundance; Totten Glacier", "people": "Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 JPC43 Diatom Data", "url": "https://www.usap-dc.org/view/dataset/601440"}, {"dataset_uid": "601147", "doi": "10.15784/601147", "keywords": "Antarctica; CTD Data; NBP1402; Ocean Temperature; Physical Oceanography; Sabrina Coast; Salinity; Southern Ocean; Temperature; Underway CTD", "people": "Orsi, Alejandro", "repository": "USAP-DC", "science_program": null, "title": "AU1402 Final UCTD data", "url": "https://www.usap-dc.org/view/dataset/601147"}, {"dataset_uid": "601148", "doi": "10.15784/601148", "keywords": "Antarctica; Au1402; Mooring; NBP1402; Oceans; Ocean Temperature; Physical Oceanography; R/v Aurora Australis; R/v Nathaniel B. Palmer; Sabrina Coast; Salinity; Southern Ocean; Temperature", "people": "Orsi, Alejandro", "repository": "USAP-DC", "science_program": null, "title": "AU1402 mooring data", "url": "https://www.usap-dc.org/view/dataset/601148"}, {"dataset_uid": "601312", "doi": null, "keywords": "Antarctica; Benthic Images; Camera; East Antarctica; Marine Geoscience; NBP1402; Photo/video; Photo/Video; R/v Nathaniel B. Palmer; Sabrina Coast; Totten Glacier; Video Data; Yoyo Camera", "people": "Huber, Bruce; Leventer, Amy; Shevenell, Amelia; Gulick, Sean; Blankenship, Donald D.; Domack, Eugene Walter; Orsi, Alejandro; Post, Alexandra", "repository": "USAP-DC", "science_program": null, "title": "Near-bottom Videos from the Southern Ocean acquired during R/V Nathaniel B. Palmer expedition NBP1402", "url": "https://www.usap-dc.org/view/dataset/601312"}, {"dataset_uid": "601067", "doi": "10.15784/601067", "keywords": "Antarctica; CTD Data; NBP1402; Oceans; Physical Oceanography; Sabrina Coast; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 Final CTD data", "url": "https://www.usap-dc.org/view/dataset/601067"}, {"dataset_uid": "601069", "doi": "10.15784/601069", "keywords": "Antarctica; Mooring; NBP1402; Oceans; Physical Oceanography; Sabrina Coast; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Sabrina Coast mooring data - sediment trap mooring 2014", "url": "https://www.usap-dc.org/view/dataset/601069"}, {"dataset_uid": "601146", "doi": "10.15784/601146", "keywords": "Antarctica; CTD Data; NBP1402; Oceans; Ocean Temperature; Physical Oceanography; R/v Nathaniel B. Palmer; Sabrina Coast; Salinity; Southern Ocean; Temperature", "people": "Orsi, Alejandro", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 Final UCTD data", "url": "https://www.usap-dc.org/view/dataset/601146"}, {"dataset_uid": "601042", "doi": "10.15784/601042", "keywords": "Antarctica; Biota; Continental Margin; Foraminifera; NBP1402; Oceans; Paleoclimate; Sabrina Coast; Sample/collection Description; Sample/Collection Description; Southern Ocean; Totten Glacier", "people": "Leventer, Amy; Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "NBP14-02 JPC-55 foraminifer assemblage data", "url": "https://www.usap-dc.org/view/dataset/601042"}, {"dataset_uid": "601044", "doi": "10.15784/601044", "keywords": "Antarctica; Carbon; Chemistry:sediment; Chemistry:Sediment; Geochemistry; Marine Sediments; NBP1402; Nitrogen; Oceans; Sabrina Coast; Sediment Core; Southern Ocean; Totten Glacier", "people": "Smith, Catherine; Shevenell, Amelia; Domack, Eugene Walter", "repository": "USAP-DC", "science_program": null, "title": "NBP14-02 JPC-55 Bulk Sediment Carbon and Nitrogen data", "url": "https://www.usap-dc.org/view/dataset/601044"}, {"dataset_uid": "601046", "doi": "10.15784/601046", "keywords": "Antarctica; Biota; Marine Sediments; NBP1402; Oceans; Paleoclimate; Pollen; Sabrina Coast; Sediment Core; Southern Ocean; Totten Glacier", "people": "Shevenell, Amelia; Smith, Catherine; Domack, Eugene Walter", "repository": "USAP-DC", "science_program": null, "title": "NBP14-02 JPC-54 and JPC-55 Pollen Assemblage data", "url": "https://www.usap-dc.org/view/dataset/601046"}], "date_created": "Fri, 26 Jan 2018 00:00:00 GMT", "description": "This project will investigate the marine component of the Totten Glacier and Moscow University Ice Shelf, East Antarctica. This system is of critical importance because it drains one-eighth of the East Antarctic Ice Sheet and contains a volume equivalent to nearly 7 meters of potential sea level rise, greater than the entire West Antarctic Ice Sheet. This nearly completely unexplored region is the single largest and least understood marine glacial system that is potentially unstable. Despite intense scrutiny of marine based systems in the West Antarctic Ice Sheet, little is known about the Totten Glacier system. This study will add substantially to the meager oceanographic and marine geology and geophysics data available in this region, and will significantly advance understanding of this poorly understood glacial system and its potentially sensitive response to environmental change. Independent, space-based platforms indicate accelerating mass loss of the Totten system. Recent aerogeophysical surveys of the Aurora Subglacial Basin, which contains the deepest ice in Antarctica and drains into the Totten system, have provided the subglacial context for measured surface changes and show that the Totten Glacier has been the most significant drainage pathway for at least two previous ice flow regimes. However, the offshore context is far less understood. Limited physical oceanographic data from the nearby shelf/slope break indicate the presence of Modified Circumpolar Deep Water within a thick bottom layer at the mouth of a trough with apparent access to Totten Glacier, suggesting the possibility of sub-glacial bottom inflow of relatively warm water, a process considered to be responsible for West Antarctic Ice Sheet grounding line retreat. This project will conduct a ship-based marine geologic and geophysical survey of the region, combined with a physical oceanographic study, in order to evaluate both the recent and longer-term behavior of the glacial system and its relationship to the adjacent oceanographic system. This endeavor will complement studies of other Antarctic ice shelves, oceanographic studies near the Antarctic Peninsula, and ongoing development of ice sheet and other ocean models.", "east": 121.0, "geometry": "POINT(118.5 -66.1)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD", "is_usap_dc": true, "keywords": "Totten Glacier; NBP1402; Sabrina Coast; LABORATORY; Diatom; R/V NBP; Amd/Us; Bottom Photos; R/V AA; Not provided; USAP-DC; AMD; USA/NSF", "locations": "Sabrina Coast; Totten Glacier", "north": -65.2, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Orsi, Alejandro; Huber, Bruce; Leventer, Amy; Domack, Eugene Walter", "platforms": "Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V AA; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.0, "title": "Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics", "uid": "p0000008", "west": 116.0}, {"awards": "0838735 Nitsche, Frank O.", "bounds_geometry": "POLYGON((-140 -68,-136 -68,-132 -68,-128 -68,-124 -68,-120 -68,-116 -68,-112 -68,-108 -68,-104 -68,-100 -68,-100 -68.75,-100 -69.5,-100 -70.25,-100 -71,-100 -71.75,-100 -72.5,-100 -73.25,-100 -74,-100 -74.75,-100 -75.5,-104 -75.5,-108 -75.5,-112 -75.5,-116 -75.5,-120 -75.5,-124 -75.5,-128 -75.5,-132 -75.5,-136 -75.5,-140 -75.5,-140 -74.75,-140 -74,-140 -73.25,-140 -72.5,-140 -71.75,-140 -71,-140 -70.25,-140 -69.5,-140 -68.75,-140 -68))", "dataset_titles": "Bathymetry compilation of Pine Island Bay, Amundsen Sea, Antarctica; OSO0910 Expedition Data", "datasets": [{"dataset_uid": "000525", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "OSO0910 Expedition Data", "url": "https://www.marine-geo.org/tools/search/entry.php?id=OSO0910"}, {"dataset_uid": "000225", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Bathymetry compilation of Pine Island Bay, Amundsen Sea, Antarctica", "url": "http://dx.doi.org/10.1594/IEDA/320080"}], "date_created": "Fri, 26 Jan 2018 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The West Antarctic Ice Sheet is believed to be vulnerable to climate change as it is grounded below sea level, is drained by rapidly flowing ice streams and is fringed by floating ice shelves subject to melting by incursions of relatively warm Antarctic circumpolar water. Currently, the most rapidly thinning glaciers in Antarctica occur in the Amundsen and Bellingshausen Sea sectors. This study seeks to place the present day observations into a longer-term geological context over a broad scale by high-resolution swath bathymetric mapping of continental shelf sea floor features that indicate past ice presence and behavior. Gaps in existing survey coverage of glacial lineations and troughs indicating ice flow direction and paleo-grounding zone wedges over the Ross, Amundsen and Bellingshausen Sea sectors are targeted. The surveys will be conducted as part of the 2010 Icebreaker Oden science opportunity and will take advantage of the vessel?s state-of-the-art swath mapping system.\u003cbr/\u003e\u003cbr/\u003eBroader impacts:\u003cbr/\u003eThis activity will supplement and complement more focused regional studies by US, Swedish, UK, French, Japanese and Polish collaborators also sailing on the Oden. The PI will compile bathymetric data to be acquired by the Oden and other ships in the region over the duration of the project into the existing bathymetric data base. The compiled data set will be made publically available through the NSF founded Antarctic Multibeam Bathymetry and Geophysical Data Synthesis (AMBS) site. It will also be integrated into the GEBCO International Bathymetric Chart of the Southern Ocean (IBCSO) and so significantly improve the basis for ship navigation in the Pacific sector of the Southern Ocean. Undergraduate students will be involved in the research under supervision of the PI via the Lamont summer internship program. The PI is a young investigator and this will be his first NSF grant as a PI.", "east": -100.0, "geometry": "POINT(-120 -71.75)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES", "is_usap_dc": true, "keywords": "BATHYMETRY; SHIPS; Southern Ocean; Antarctica; Polar; GLACIERS/ICE SHEETS; R/V NBP", "locations": "Polar; Southern Ocean; Antarctica", "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Nitsche, Frank O.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "MGDS", "repositories": "MGDS", "science_programs": null, "south": -75.5, "title": "Ice sheet Dynamics and Processes along the West Antarctic Continental Shelf", "uid": "p0010001", "west": -140.0}, {"awards": "1245899 Kowalewski, Douglas", "bounds_geometry": "POLYGON((-180 -70,-174 -70,-168 -70,-162 -70,-156 -70,-150 -70,-144 -70,-138 -70,-132 -70,-126 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,178 -85,176 -85,174 -85,172 -85,170 -85,168 -85,166 -85,164 -85,162 -85,160 -85,160 -83.5,160 -82,160 -80.5,160 -79,160 -77.5,160 -76,160 -74.5,160 -73,160 -71.5,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": "Region Climate Model Output Plio-Pleistocene", "datasets": [{"dataset_uid": "601080", "doi": "10.15784/601080", "keywords": "Antarctica; Climate Model; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; McMurdo; Paleoclimate; Ross Sea", "people": "Kowalewski, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Region Climate Model Output Plio-Pleistocene", "url": "https://www.usap-dc.org/view/dataset/601080"}], "date_created": "Tue, 16 Jan 2018 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to complement the ANDRILL marine record with a terrestrial project that will provide chronological control for past fluctuations of the West Antarctic Ice Sheet (WAIS) and alpine glaciers in McMurdo Sound. The project will develop high-resolution maps of drifts deposited from grounded marine-based ice and alpine glaciers on islands and peninsulas in McMurdo Sound. In addition, the PIs will acquire multi-clast/multi-nuclide cosmogenic analyses of these mapped drift sheets and alpine moraines and use regional climate modeling to shed light on the range of possible environmental conditions in the McMurdo region during periods of grounded ice expansion and recession. The PIs will make use of geological records for ice sheet and alpine glacier fluctuations preserved on the flanks of Mount Discovery, Black Island, and Brown Peninsula. Drifts deposited from grounded, marine-based ice will yield spatial constraints for former advances and retreats of the WAIS. Moraines from alpine glaciers, hypothesized to be of interglacial origin, could yield a first-order record of hydrologic change in the region. Synthesizing the field data, the team proposes to improve the resolution of existing regional-scale climate models for the Ross Embayment. The overall approach and anticipated results will provide the first steps towards linking the marine and terrestrial records in this critical sector of Antarctica. Broader impacts: Results from the proposed work will be integrated with outreach programs at Boston University, Columbia University, and Worcester State University. The team will actively collaborate with the American Museum of Natural History to feature this project prominently in museum outreach. The team will also include a PolarTREC teacher as a member of the research team. The geomorphological results will be presented in 3D at Boston University?s Antarctic Digital Image Analyses Lab. The research will form the basis of a PhD dissertation at Boston University.", "east": -120.0, "geometry": "POINT(-160 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kowalewski, Douglas", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: West Antarctic Ice Sheet stability, Alpine Glaciation, and Climate Variability: a Terrestrial Perspective from Cosmogenic-nuclide Dating in McMurdo Sound", "uid": "p0000391", "west": 160.0}, {"awards": "1425989 Sarmiento, Jorge", "bounds_geometry": "POLYGON((-180 -52.6153,-168.67689 -52.6153,-157.35378 -52.6153,-146.03067 -52.6153,-134.70756 -52.6153,-123.38445 -52.6153,-112.06134 -52.6153,-100.73823 -52.6153,-89.41512 -52.6153,-78.09201 -52.6153,-66.7689 -52.6153,-66.7689 -55.18958,-66.7689 -57.76386,-66.7689 -60.33814,-66.7689 -62.91242,-66.7689 -65.4867,-66.7689 -68.06098,-66.7689 -70.63526,-66.7689 -73.20954,-66.7689 -75.78382,-66.7689 -78.3581,-78.09201 -78.3581,-89.41512 -78.3581,-100.73823 -78.3581,-112.06134 -78.3581,-123.38445 -78.3581,-134.70756 -78.3581,-146.03067 -78.3581,-157.35378 -78.3581,-168.67689 -78.3581,180 -78.3581,178.62318 -78.3581,177.24636 -78.3581,175.86954 -78.3581,174.49272 -78.3581,173.1159 -78.3581,171.73908 -78.3581,170.36226 -78.3581,168.98544 -78.3581,167.60862 -78.3581,166.2318 -78.3581,166.2318 -75.78382,166.2318 -73.20954,166.2318 -70.63526,166.2318 -68.06098,166.2318 -65.4867,166.2318 -62.91242,166.2318 -60.33814,166.2318 -57.76386,166.2318 -55.18958,166.2318 -52.6153,167.60862 -52.6153,168.98544 -52.6153,170.36226 -52.6153,171.73908 -52.6153,173.1159 -52.6153,174.49272 -52.6153,175.86954 -52.6153,177.24636 -52.6153,178.62318 -52.6153,-180 -52.6153))", "dataset_titles": "Biogeochemical profiling float data from the Southern Ocean Carbon and Climate Observation and Modeling (SOCCOM) program.UCSD Research Data Collections DOI:10.6075/J09021PC; Expedition Data; Model output NOAA GFDL CM2_6 Cant Hant storage", "datasets": [{"dataset_uid": "000208", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Biogeochemical profiling float data from the Southern Ocean Carbon and Climate Observation and Modeling (SOCCOM) program.UCSD Research Data Collections DOI:10.6075/J09021PC", "url": "http://library.ucsd.edu/dc/object/bb66239018"}, {"dataset_uid": "001369", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1701"}, {"dataset_uid": "601144", "doi": "10.15784/601144", "keywords": "Antarctica; Anthropogenic Heat; Atmosphere; Carbon Storage; Climate Change; Eddy; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Heat Budget; Modeling; Model Output; Oceans; Paleoclimate; Snow/ice; Snow/Ice; Southern Ocean", "people": "Chen, Haidi", "repository": "USAP-DC", "science_program": null, "title": "Model output NOAA GFDL CM2_6 Cant Hant storage", "url": "https://www.usap-dc.org/view/dataset/601144"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project seeks to drive a transformative shift in our understanding of the crucial role of the Southern Ocean in taking up anthropogenic carbon and heat, and resupplying nutrients from the abyss to the surface. An observational program will generate vast amounts of new biogeochemical data that will provide a greatly improved view of the dynamics and ecosystem responses of the Southern Ocean. A modeling component will apply these observations to enhancing understanding of the current ocean, reducing uncertainty in projections of future carbon and nutrient cycles and climate. Because it serves as the primary gateway through which the intermediate, deep, and bottom waters of the ocean interact with the surface layers and thus the atmosphere, the Southern Ocean has a profound influence on the oceanic uptake of anthropogenic carbon and heat as well as nutrient resupply from the abyss to the surface. Yet it is the least observed and understood region of the world ocean. The oceanographic community is on the cusp of two major advances that have the potential to transform understanding of the Southern Ocean. The first is the development of new biogeochemical sensors mounted on autonomous profiling floats that allow sampling of ocean biogeochemistry and acidification in 3-dimensional space with a temporal resolution of five to ten days. The SOCCOM float program proposed will increase the average number of biogeochemical profiles measured per month in the Southern Ocean by ~10-30x. The second is that the climate modeling community now has the computational resources and physical understanding to develop fully coupled climate models that can represent crucial mesoscale processes in the Southern Ocean, as well as corresponding models that assimilate observations to produce a state estimate. Together with the observations, this new generation of models provides the tools to vastly improve understanding of Southern Ocean processes and the ability to quantitatively assess uptake of anthropogenic carbon and heat, as well as nutrient resupply, both today and into the future. In order to take advantage of the above technological and modeling breakthroughs, SOCCOM will implement the following research programs: * Theme 1: Observations. Scripps Institution of Oceanography will lead a field program to expand the number of Southern Ocean autonomous profiling floats and equip them with sensors to measure pH, nitrate, and oxygen. The University of Washington and Monterey Bay Aquarium Research Institute will design, build, and oversee deployment of the floats. Scripps will also develop a mesoscale eddying Southern Ocean state estimate that assimilates physical and biogeochemical data into the MIT ocean general circulation model. * Theme 2: Modeling. University of Arizona and Princeton University, together with NOAA\u0027s Geophysical Fluid Dynamics Laboratory (GFDL), will use SOCCOM observations to develop data/model assessment metrics and next-generation model analysis and evaluation, with the goal of improving process level understanding and reducing the uncertainty in projections of our future climate. Led by Climate Central, an independent, non-profit journalism and research organization that promotes understanding of climate science, SOCCOM will collaborate with educators and media professionals to inform policymakers and the public about the challenges of climate change and its impacts on marine life in the context of the Southern Ocean. In addition, the integrated team of SOCCOM scientists and educators will: * communicate data and results of the SOCCOM efforts quickly to the public through established data networks, publications, broadcast media, and a public portal; * train a new generation of diverse ocean scientists, including undergraduate students, graduate students, and postdoctoral fellows versed in field techniques, data calibration, modeling, and communication of research to non-scientists; * transfer new sensor technology and related software to autonomous instrument providers and manufacturers to ensure that they become widely useable.", "east": -66.7689, "geometry": "POINT(-130.26855 -65.4867)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; R/V NBP; NBP1701; CLIMATE MODELS", "locations": null, "north": -52.6153, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Sarmiento, Jorge; Rynearson, Tatiana", "platforms": "OTHER \u003e MODELS \u003e CLIMATE MODELS; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "PI website", "repositories": "PI website; R2R; USAP-DC", "science_programs": null, "south": -78.3581, "title": "Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM)", "uid": "p0000197", "west": 166.2318}, {"awards": "1543256 Shuster, David", "bounds_geometry": null, "dataset_titles": "Detrital low-temperature thermochronometry from Bourgeois Fjord, AP; Expedition Data; Expedition data of LMG1702", "datasets": [{"dataset_uid": "002733", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1702", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "000402", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "601259", "doi": "10.15784/601259", "keywords": "Antarctica; Antarctic Peninsula", "people": "Clinger, Anna", "repository": "USAP-DC", "science_program": null, "title": "Detrital low-temperature thermochronometry from Bourgeois Fjord, AP", "url": "https://www.usap-dc.org/view/dataset/601259"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "The extreme mountain topographies of alpine landscapes at mid latitudes (e.g., European Alps, Patagonia, Alaska) are thought to have formed by the erosive action of glaciers, yet our understanding of exactly when and how those topographies developed is limited. If glacial ice was responsible for forming them, then those landscapes must have developed primarily over the last 2-3 million years when ice was present at those latitudes; this timing has only recently been confirmed by observations. In contrast, the Antarctic Peninsula, which contains similarly spectacular topographic relief, is known to have hosted alpine glaciers as early as 37 million years ago, and is currently covered by ice. Thus, if caused by glacial erosion, the high relief of the peninsula should have formed much earlier than what has been observed at mid latitude sites, yet we know nearly nothing about the timing of its development. The primary benefit of this research will be to study the timing of topography development along the Antarctic Peninsula by applying state of the art chemical analyses to sediments collected offshore. This research is important because studying a high latitude site will enable comparison with sites at mid latitudes and test current hypotheses on the development of glacial landscapes in general. This project aims to apply low-temperature thermochronometry based on the (U-Th)/He system in apatite to investigate the exhumation history, the development of the present topography, and the pattern of glacial erosion in the central Antarctic Peninsula. A number of recent studies have used this approach to study the dramatic, high-relief landscapes formed by Pleistocene alpine glacial erosion in temperate latitudes: New Zealand, the Alps, British Columbia, Alaska, and Patagonia. These studies have not only revealed when these landscapes formed, but have also provided new insights into the physical mechanisms of glacial erosion. The Antarctic Peninsula is broadly akin to temperate alpine landscapes in that the dominant landforms are massive glacial troughs. However, what we know about Antarctic glacial history suggests that the timing and history of glacial erosion was most likely very different from the temperate alpine setting: The Antarctic Peninsula has been glaciated since the Eocene, and Pleistocene climate cooling is hypothesized to have suppressed, rather than enhanced, glacial erosion. Our goal is to evaluate these hypotheses by developing a direct thermochronometric record of when and how the present glacial valley relief formed. We propose to learn about the timing and process of glacial valley formation through apatite (U-Th)/He and 4He/3He measurements on glacial sediment collected near the grounding lines of major glaciers draining the Peninsula. In effect, since we cannot sample bedrock directly that is currently covered by ice, we will rely on these glaciers to do it for us.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": false, "keywords": "R/V LMG; LMG1702; Antarctic Peninsula; ICE SHEETS", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kohut, Josh; Shuster, David; Balco, Gregory; Jenkins, Bethany", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-Temperature Detrital Thermochronometry", "uid": "p0000876", "west": null}, {"awards": "1143981 Domack, Eugene", "bounds_geometry": "POLYGON((-69.9517 -52.7581,-69.02971 -52.7581,-68.10772 -52.7581,-67.18573 -52.7581,-66.26374 -52.7581,-65.34175 -52.7581,-64.41976 -52.7581,-63.49777 -52.7581,-62.57578 -52.7581,-61.65379 -52.7581,-60.7318 -52.7581,-60.7318 -54.31551,-60.7318 -55.87292,-60.7318 -57.43033,-60.7318 -58.98774,-60.7318 -60.54515,-60.7318 -62.10256,-60.7318 -63.65997,-60.7318 -65.21738,-60.7318 -66.77479,-60.7318 -68.3322,-61.65379 -68.3322,-62.57578 -68.3322,-63.49777 -68.3322,-64.41976 -68.3322,-65.34175 -68.3322,-66.26374 -68.3322,-67.18573 -68.3322,-68.10772 -68.3322,-69.02971 -68.3322,-69.9517 -68.3322,-69.9517 -66.77479,-69.9517 -65.21738,-69.9517 -63.65997,-69.9517 -62.10256,-69.9517 -60.54515,-69.9517 -58.98774,-69.9517 -57.43033,-69.9517 -55.87292,-69.9517 -54.31551,-69.9517 -52.7581))", "dataset_titles": "Expedition Data; Processed Camera Images acquired during the Laurence M. Gould expedition LMG1311", "datasets": [{"dataset_uid": "001366", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "601311", "doi": "10.15784/601311", "keywords": "Antarctica; Antarctic Peninsula; Benthic Images; Camera; LARISSA; LMG1311; Marine Geoscience; Photo; Photo/video; Photo/Video; R/v Laurence M. Gould", "people": "Domack, Eugene Walter", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Processed Camera Images acquired during the Laurence M. Gould expedition LMG1311", "url": "https://www.usap-dc.org/view/dataset/601311"}, {"dataset_uid": "000402", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "This project aims to identify which portions of the glacial cover in the Antarctic Peninsula are losing mass to the ocean. This is an important issue to resolve because the Antarctic Peninsula is warming at a faster rate than any other region across the earth. Even though glaciers across the Antarctic Peninsula are small, compared to the continental ice sheet, defining how rapidly they respond to both ocean and atmospheric temperature rise is critical. It is critical because it informs us about the exact mechanisms which regulate ice flow and melting into the ocean. For instance, after the break- up of the Larsen Ice Shelf in 2002 many glaciers began to flow rapidly into the sea. Measuring how much ice was involved is difficult and depends upon accurate estimates of volume and area. One way to increase the accuracy of our estimates is to measure how fast the Earth\u0027s crust is rebounding or bouncing back, after the ice has been removed. This rebound effect can be measured with very precise techniques using instruments locked into ice free bedrock surrounding the area of interest. These instruments are monitored by a set of positioning satellites (the Global Positioning System or GPS) in a continuous fashion. Of course the movement of the Earth\u0027s bedrock relates not only to the immediate response but also the longer term rate that reflects the long vanished ice masses that once covered the entire Antarctic Peninsula?at the time of the last glaciation. These rebound measurements can, therefore, also tell us about the amount of ice which covered the Antarctic Peninsula thousands of years ago. Glacial isostatic rebound is one of the complicating factors in allowing us to understand how much the larger ice sheets are losing today, something that can be estimated by satellite techniques but only within large errors when the isostatic (rebound) correction is unknown. The research proposed consists of maintaining a set of six rebound stations until the year 2016, allowing for a longer time series and thus more accurate estimates of immediate elastic and longer term rebound effects. It also involves the establishment of two additional GPS stations that will focus on constraining the \"bull\u0027s eye\" of rebound suggested by measurements over the past two years. In addition, several more geologic data points will be collected that will help to reconstruct the position of the ice sheet margin during its recession from the full ice sheet of the last glacial maximum. These will be based upon the coring of marine sediment sequences now recognized to have been deposited along the margins of retreating ice sheets and outlets. Precise dating of the ice margin along with the new and improved rebound data will help to constrain past ice sheet configurations and refine geophysical models related to the nature of post glacial rebound. Data management will be under the auspices of the UNAVCO polar geophysical network or POLENET and will be publically available at the time of station installation. This project is a small scale extension of the ongoing LARsen Ice Shelf, Antarctica Project (LARISSA), an IPY (International Polar Year)-funded interdisciplinary study aimed at understanding earth system connections related to the Larsen Ice Shelf and the northern Antarctic Peninsula.", "east": -60.7318, "geometry": "POINT(-65.34175 -60.54515)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": false, "keywords": "LMG1702; R/V LMG", "locations": null, "north": -52.7581, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Kohut, Josh; Domack, Eugene Walter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -68.3322, "title": "Continuation of the LARISSA Continuous GPS Network in View of Observed Dynamic Response to Antarctic Peninsula Ice Mass Balance and Required Geologic Constraints", "uid": "p0000233", "west": -69.9517}, {"awards": "1565576 Pettit, Erin", "bounds_geometry": "POLYGON((-62.2 -65.5,-62.12 -65.5,-62.04 -65.5,-61.96 -65.5,-61.88 -65.5,-61.8 -65.5,-61.72 -65.5,-61.64 -65.5,-61.56 -65.5,-61.48 -65.5,-61.4 -65.5,-61.4 -65.53,-61.4 -65.56,-61.4 -65.59,-61.4 -65.62,-61.4 -65.65,-61.4 -65.68,-61.4 -65.71,-61.4 -65.74,-61.4 -65.77,-61.4 -65.8,-61.48 -65.8,-61.56 -65.8,-61.64 -65.8,-61.72 -65.8,-61.8 -65.8,-61.88 -65.8,-61.96 -65.8,-62.04 -65.8,-62.12 -65.8,-62.2 -65.8,-62.2 -65.77,-62.2 -65.74,-62.2 -65.71,-62.2 -65.68,-62.2 -65.65,-62.2 -65.62,-62.2 -65.59,-62.2 -65.56,-62.2 -65.53,-62.2 -65.5))", "dataset_titles": "Scar Inlet Terrestrial Radar Interferometry; Weather data from LARISSA / SCAR Inlet Rapid AMIGOS and cGPS stations", "datasets": [{"dataset_uid": "601078", "doi": "10.15784/601078", "keywords": "Antarctica; Antarctic Peninsula; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Navigation; Radar; Radar Interferometer", "people": "Truffer, Martin", "repository": "USAP-DC", "science_program": null, "title": "Scar Inlet Terrestrial Radar Interferometry", "url": "https://www.usap-dc.org/view/dataset/601078"}, {"dataset_uid": "601084", "doi": "10.15784/601084", "keywords": "Antarctica; Antarctic Peninsula; Atmosphere; Automated Weather Station; Flask Glacier; Foehn Winds; Glaciers/ice Sheet; Glaciers/Ice Sheet; LARISSA; Larsen B Ice Shelf; Meteorology; Scar Inlet; Weatherstation; Wind Speed", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Weather data from LARISSA / SCAR Inlet Rapid AMIGOS and cGPS stations", "url": "https://www.usap-dc.org/view/dataset/601084"}], "date_created": "Wed, 20 Dec 2017 00:00:00 GMT", "description": "Pettit/1565576 This award supports a Rapid Response Research (RAPID) project to observe the current weakened state of the Scar Inlet Ice Shelf, and potentially capture data during its anticipated disintegration. The Scar Inlet Ice Shelf (SIIS) is the southern remnant of the former Larsen B Ice Shelf, which disintegrated in March of 2002. Since then, the SIIS has weakened significantly but has not yet broken up. Cooler conditions than those seen prior to 2006 have reduced the chance of a disintegration in recent years, although a single warm season is likely to be enough to trigger such an event. The predicted \"Super El Nino\" for this austral summer may have significant effects on Antarctica\u0027s weather, potentially leading to a break-up or disintegration this year. Given the very weak state of the SIIS, it is urgent that we act now to better understand the processes involved in shelf disintegration or break-up of ice shelves. The goal of this work is to collect several key data sets, publish initial observations and preliminary conclusions, and then make the complete data record available to all scientists. Extreme changes in the stress conditions on the SIIS resulted from both the loss of the Larsen B ice plate and the continued inflow of ice from three large glaciers (Flask, Leppard, and Starbuck). The SIIS now has a number of large rifts and it is expected to break up or disintegrate in the very near future. Past research has made use of satellite data and weather instruments, establishing many of the current ideas regarding ice shelf break-ups and ice shelf weakening. Additional ground-based data to be collected under this study will test a number of hypotheses regarding pre-disintegration characteristics, triggering mechanisms, fracturing processes, runaway feedback effects, and stabilizing mechanisms. The project will collect extensive multi-instrument field observations of the SIIS and possibly capture a major disintegration event. In collaboration with the British Antarctic Survey, a team of 4 people will be deployed via Twin Otter for up to 4 weeks to a site with a broad view of the shelf and will install several temporary observing instruments there. The study derives its intellectual merit from the role of the Antarctic Peninsula as a microcosm of how other parts of Antarctica might evolve and de-glaciate in the next few centuries. The broader impacts include an opportunity to educate the public about the anticipated collapse of this remnant ice shelf and its relationship to future changes in Antarctica. The potential for wide media coverage (through a connection with the National Geographic) will underscore the critical changes scientists are observing in the crysophere driven by climate change. This proposal requires field work in Antarctica.", "east": -61.4, "geometry": "POINT(-61.8 -65.65)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -65.5, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "LARISSA", "south": -65.8, "title": "RAPID: Observing the Disintegration of the Scar Inlet Ice Shelf", "uid": "p0000274", "west": -62.2}, {"awards": "1543452 Blankenship, Donald", "bounds_geometry": "POLYGON((90 -64,97 -64,104 -64,111 -64,118 -64,125 -64,132 -64,139 -64,146 -64,153 -64,160 -64,160 -64.6,160 -65.2,160 -65.8,160 -66.4,160 -67,160 -67.6,160 -68.2,160 -68.8,160 -69.4,160 -70,153 -70,146 -70,139 -70,132 -70,125 -70,118 -70,111 -70,104 -70,97 -70,90 -70,90 -69.4,90 -68.8,90 -68.2,90 -67.6,90 -67,90 -66.4,90 -65.8,90 -65.2,90 -64.6,90 -64))", "dataset_titles": "EAGLE/ICECAP II GEOPHYSICAL OBSERVATIONS (SURFACE AND BED ELEVATION, ICE THICKNESS, GRAVITY DISTURBANCE AND MAGNETIC ANOMALIES); EAGLE/ICECAP II INSTRUMENT MEASUREMENTS (LASER, MAGNETICS and POSITIONING); EAGLE/ICECAP II RADARGRAMS; EAGLE/ICECAP II Raw data (gps, raw serial packet data, raw radar records, gravimeter data and camera images); ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "datasets": [{"dataset_uid": "200044", "doi": "https://dx.doi.org/10.26179/5bbedd001756b", "keywords": null, "people": null, "repository": "AADC", "science_program": null, "title": "EAGLE/ICECAP II Raw data (gps, raw serial packet data, raw radar records, gravimeter data and camera images)", "url": "https://data.aad.gov.au/metadata/records/AAS_4346_EAGLE_ICECAP_LEVEL0_RAW_DATA"}, {"dataset_uid": "200042", "doi": "http://dx.doi.org/doi:10.26179/5bcfef4e3a297", "keywords": null, "people": null, "repository": "AADC", "science_program": null, "title": "EAGLE/ICECAP II INSTRUMENT MEASUREMENTS (LASER, MAGNETICS and POSITIONING)", "url": "https://data.aad.gov.au/metadata/records/AAS_4346_EAGLE_ICECAP_Level1B_AEROGEOPHYSICS"}, {"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Young, Duncan A.; Roberts, Jason; Greenbaum, Jamin; Blankenship, Donald D.; Schroeder, Dustin; Siegert, Martin; van Ommen, Tas", "repository": "USAP-DC", "science_program": null, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "url": "https://www.usap-dc.org/view/dataset/601371"}, {"dataset_uid": "200043", "doi": "http://dx.doi.org/doi:10.26179/5bcff4afc287d", "keywords": null, "people": null, "repository": "AADC", "science_program": null, "title": "EAGLE/ICECAP II RADARGRAMS", "url": "https://data.aad.gov.au/metadata/records/AAS_4346_EAGLE_ICECAP_LEVEL2_RADAR_DATA"}, {"dataset_uid": "200041", "doi": "https://doi.org/10.26179/5bcfffdabcf92", "keywords": null, "people": null, "repository": "AADC", "science_program": null, "title": "EAGLE/ICECAP II GEOPHYSICAL OBSERVATIONS (SURFACE AND BED ELEVATION, ICE THICKNESS, GRAVITY DISTURBANCE AND MAGNETIC ANOMALIES)", "url": "https://data.aad.gov.au/metadata/records/AAS_4346_EAGLE_ICECAP_LEVEL2_AEROGEOPHYSICS"}], "date_created": "Tue, 05 Dec 2017 00:00:00 GMT", "description": "Previous studies of the Indo-Pacific region of Antarctica show that the margin of the ice sheet in this region has advanced and retreated into deep interior basins many times in the past. The apparent instability of this region makes it an important target for study in terms of understanding the future of the East Antarctic ice sheet and sea level rise. This project will study a number of processes that control the ice-shelf stability of this region, with the aim of improving projections of the rate and magnitude of future sea-level rise. This project will engage a range of students and train this next generation of scientists in the complex, interdisciplinary issue of ice-ocean interaction. The project will integrate geophysical data collected from aircraft over three critical sections of the East Antarctic grounding line (Totten Glacier, Denman Glacier, and Cook Ice Shelf) with an advanced ocean model. Using Australian and French assets, the team will collect new data around Denman Glacier and Cook Ice Shelf whereas analysis of Totten Glacier will be based on existing data. The project will assess three hypotheses to isolate the processes that drive the differences in observed grounding line thinning among these three glaciers: 1. bathymetry and large-scale ocean forcing control cavity circulation; 2. ice-shelf draft and basal morphology control cavity circulation; 3. subglacial freshwater input across the grounding line controls cavity circulation. The key outcomes of this new project will be to: 1. evaluate of ice-ocean coupling in areas of significant potential sea-level contribution; 2. relate volume changes of grounded and floating ice to regional oceanic heat transport and sub-ice shelf ocean dynamics in areas of significant potential sea-level and meridional overturning circulation impacts; and 3. improve boundary conditions to evaluate mass, heat, and freshwater budgets of East Antarctica\u0027s continental margins.", "east": 160.0, "geometry": "POINT(125 -67)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e MAGNETOMETERS \u003e GEOMET 823A; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "BT-67; Antarctica; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; USAP-DC; SEAFLOOR TOPOGRAPHY; GRAVITY ANOMALIES; MAGNETIC ANOMALIES; Polar; Sea Floor", "locations": "Antarctica; Sea Floor; Polar", "north": -64.0, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Young, Duncan A.; Grima, Cyril; Blankenship, Donald D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e BT-67", "repo": "AADC", "repositories": "AADC; USAP-DC", "science_programs": null, "south": -70.0, "title": "East Antarctic Grounding Line Experiment (EAGLE)", "uid": "p0000254", "west": 90.0}, {"awards": "1344349 Tulaczyk, Slawek; 1344348 Mikucki, Jill", "bounds_geometry": null, "dataset_titles": "2011 Time-domain ElectroMagnetics data for McMurdo Dry Valleys; Marinobacter lipolyticus BF04_CF-4 genomic scaffold, whole genome shotgun sequence; Marinobacter sp. BF14_3D 16S ribosomal RNA gene, partial sequence", "datasets": [{"dataset_uid": "000196", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Marinobacter sp. BF14_3D 16S ribosomal RNA gene, partial sequence", "url": "https://www.ncbi.nlm.nih.gov/nuccore/KX364066"}, {"dataset_uid": "601071", "doi": "10.15784/601071", "keywords": "Antarctica; Dry Valleys; Electromagnetic Data; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; McMurdo", "people": "Tulaczyk, Slawek", "repository": "USAP-DC", "science_program": null, "title": "2011 Time-domain ElectroMagnetics data for McMurdo Dry Valleys", "url": "https://www.usap-dc.org/view/dataset/601071"}, {"dataset_uid": "000197", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Marinobacter lipolyticus BF04_CF-4 genomic scaffold, whole genome shotgun sequence", "url": "https://www.ncbi.nlm.nih.gov/nuccore?term=PRJNA165567"}], "date_created": "Wed, 08 Nov 2017 00:00:00 GMT", "description": "Intellectual Merit: The MCM-SkyTEM project mapped resistivity in the McMurdo Dry Valleys and at Cape Barne on the Ross Island during the 2011-12 austral season using an airborne transient electromagnetic method. The SkyTEM system is mounted to a helicopter enabling a broad geophysical survey of subsurface resistivity structure over terrain that is inaccessible to traditional ground-based methods. Resistivity measurements obtained distinguish between highly resistive geologic materials such as glacier ice, bedrock and permafrost, and conductive materials such as unfrozen sediments or permafrost with liquid brine to depths of about 300 m. The PIs request funding to derive data products relevant to physical and chemical conditions in potential subsurface microbial habitats of the McMurdo Dry Valleys, similar cold regions on Earth and other planetary bodies. They will use these data products to characterize the hydrologic history of McMurdo Dry Valleys as well as the subsurface hydrologic connectivity in the region to investigate the implications for nutrient and microbial transport. The PIs will make these data products accessible to the research community. Broader impacts: Polar microbial habitats are of high societal and scientific interest because they represent important testing grounds for the limits of life on Earth and other planetary bodies. Project deliverables will include teaching aids for undergraduate and graduate students. Two Ph.D. students will obtain advanced research training as part of this project. The PIs and students on this project will also engage in informal public outreach opportunities by presenting at local K-12 schools and reaching out to local media outlets on stories relating to SkyTEM research.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Integrated System Science; Antarctic Earth Sciences; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Tulaczyk, Slawek; Mikucki, Jill", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "NCBI GenBank; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: EAGER: Processing, Interpretation and Dissemination of the Proof-of-Concept Transient Electromagnetic Survey of the McMurdo Dry Valleys Region", "uid": "p0000329", "west": null}, {"awards": "1043471 Kaplan, Michael", "bounds_geometry": "POLYGON((-112.5 -79.468,-112.4586 -79.468,-112.4172 -79.468,-112.3758 -79.468,-112.3344 -79.468,-112.293 -79.468,-112.2516 -79.468,-112.2102 -79.468,-112.1688 -79.468,-112.1274 -79.468,-112.086 -79.468,-112.086 -79.4712,-112.086 -79.4744,-112.086 -79.4776,-112.086 -79.4808,-112.086 -79.484,-112.086 -79.4872,-112.086 -79.4904,-112.086 -79.4936,-112.086 -79.4968,-112.086 -79.5,-112.1274 -79.5,-112.1688 -79.5,-112.2102 -79.5,-112.2516 -79.5,-112.293 -79.5,-112.3344 -79.5,-112.3758 -79.5,-112.4172 -79.5,-112.4586 -79.5,-112.5 -79.5,-112.5 -79.4968,-112.5 -79.4936,-112.5 -79.4904,-112.5 -79.4872,-112.5 -79.484,-112.5 -79.4808,-112.5 -79.4776,-112.5 -79.4744,-112.5 -79.4712,-112.5 -79.468))", "dataset_titles": "List of samples of WAIS Divide and Byrd (deep) ice that were analyzed for radiogenic isotopes at LDEO", "datasets": [{"dataset_uid": "601065", "doi": "10.15784/601065", "keywords": "Antarctica; Dust; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Sample/collection Description; Sample/Collection Description; WAIS Divide; WAIS Divide Ice Core", "people": "Kaplan, Michael", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "List of samples of WAIS Divide and Byrd (deep) ice that were analyzed for radiogenic isotopes at LDEO", "url": "https://www.usap-dc.org/view/dataset/601065"}], "date_created": "Sun, 29 Oct 2017 00:00:00 GMT", "description": "1043471/Kaplan This award supports a project to obtain the first set of isotopic-based provenance data from the WAIS divide ice core. A lack of data from the WAIS prevents even a basic knowledge of whether different sources of dust blew around the Pacific and Atlantic sectors of the southern latitudes. Precise isotopic measurements on dust in the new WAIS ice divide core are specifically warranted because the data will be synergistically integrated with other high frequency proxies, such as dust concentration and flux, and carbon dioxide, for example. Higher resolution proxies will bridge gaps between our observations on the same well-dated, well-preserved core. The intellectual merit of the project is that the proposed analyses will contribute to the WAIS Divide Project science themes. Whether an active driver or passive recorder, dust is one of the most important but least understood components of regional and global climate. Collaborative and expert discussion with dust-climate modelers will lead to an important progression in understanding of dust and past atmospheric circulation patterns and climate around the southern latitudes, and help to exclude unlikely air trajectories to the ice sheets. The project will provide data to help evaluate models that simulate the dust patterns and cycle and the relative importance of changes in the sources, air trajectories and transport processes, and deposition to the ice sheet under different climate states. The results will be of broad interest to a range of disciplines beyond those directly associated with the WAIS ice core project, including the paleoceanography and dust- paleoclimatology communities. The broader impacts of the project include infrastructure and professional development, as the proposed research will initiate collaborations between LDEO and other WAIS scientists and modelers with expertise in climate and dust. Most of the researchers are still in the early phase of their careers and hence the project will facilitate long-term relationships. This includes a graduate student from UMaine, an undergraduate student from Columbia University who will be involved in lab work, in addition to a LDEO Postdoctoral scientist, and possibly an additional student involved in the international project PIRE-ICETRICS. The proposed research will broaden the scientific outlooks of three PIs, who come to Antarctic ice core science from a variety of other terrestrial and marine geology perspectives. Outreach activities include interaction with the science writers of the Columbia\u0027s Earth Institute for news releases and associated blog websites, public speaking, and involvement in an arts/science initiative between New York City\u0027s arts and science communities to bridge the gap between scientific knowledge and public perception.", "east": -112.086, "geometry": "POINT(-112.293 -79.484)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.468, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kaplan, Michael; Winckler, Gisela; Goldstein, Steven L.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.5, "title": "A Study of Atmospheric Dust in the WAIS Divide Ice Core Based on Sr-Nd-Pb-He Isotopes", "uid": "p0000081", "west": -112.5}, {"awards": "1246378 Shevenell, Amelia", "bounds_geometry": "POLYGON((-65.32 -64.15,-65.309 -64.15,-65.298 -64.15,-65.287 -64.15,-65.276 -64.15,-65.265 -64.15,-65.254 -64.15,-65.243 -64.15,-65.232 -64.15,-65.221 -64.15,-65.21 -64.15,-65.21 -64.186,-65.21 -64.222,-65.21 -64.258,-65.21 -64.294,-65.21 -64.33,-65.21 -64.366,-65.21 -64.402,-65.21 -64.438,-65.21 -64.474,-65.21 -64.51,-65.221 -64.51,-65.232 -64.51,-65.243 -64.51,-65.254 -64.51,-65.265 -64.51,-65.276 -64.51,-65.287 -64.51,-65.298 -64.51,-65.309 -64.51,-65.32 -64.51,-65.32 -64.474,-65.32 -64.438,-65.32 -64.402,-65.32 -64.366,-65.32 -64.33,-65.32 -64.294,-65.32 -64.258,-65.32 -64.222,-65.32 -64.186,-65.32 -64.15))", "dataset_titles": "Anvers Trough Foraminifer Stable Isotope data; Geochemical and sedimentologic data from NBP01-01 JPC-34", "datasets": [{"dataset_uid": "601064", "doi": "10.15784/601064", "keywords": "Antarctica; Antarctic Peninsula; Anvers Trough; Chemistry:sediment; Chemistry:Sediment; Foraminifera; Geochemistry; Isotope; LMG1211; LMG1311; Marine Sediments; Oceans; Paleoclimate; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "Anvers Trough Foraminifer Stable Isotope data", "url": "https://www.usap-dc.org/view/dataset/601064"}, {"dataset_uid": "601180", "doi": "10.15784/601180", "keywords": "Antarctica; Be-10; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Late Quaternary; Magnetic Susceptibility; Mass Spectrometry; NBP0101; Paleoenvironment; Prydz Bay; Radiocarbon; R/v Nathaniel B. Palmer; Sediment; Sediment Core; Sediment Core Data", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "Geochemical and sedimentologic data from NBP01-01 JPC-34", "url": "https://www.usap-dc.org/view/dataset/601180"}], "date_created": "Fri, 27 Oct 2017 00:00:00 GMT", "description": "Intellectual Merit: Southern Ocean processes play an important role in Late Quaternary glacial-interglacial climate change. However, the direct influence of newly upwelled warm nutrient-rich Circumpolar Deep Water on the Antarctic cryosphere remains speculative. The PI proposes to test the hypothesis that Circumpolar Deep Water-derived ocean heat negatively impacts the mass-balance of Antarctica?s ice sheets during deglaciations using precisely dated late Quaternary paleoceanographic studies of Antarctic margin sediments and a suite of geochemical proxies measured on three existing glacial marine sediment cores from the Prydz Channel, Antarctica. Specifically, the PI will use these data to reconstruct the Late Quaternary history of the Lambert Glacier/Amery Ice Shelf system; evaluate the timing, speed, and style of retreat of the Lambert Glacier/Amery Ice Shelf system during the last deglaciation, and to assess the impact of Circumpolar Deep Water intrusions on the Lambert Glacier/Amery Ice Shelf system in the Late Quaternary. Diatom bound radiocarbon and optically stimulated luminescence techniques will be used to obtain precise stratigraphic age control for the Prydz Channel siliceous muddy ooze intervals. In addition, the PI will measure sedimentary 10Be concentrations to determine the origin of the siliceous muddy ooze units and to track past changes in the position of the ice shelf front. Broader impacts: This proposal will support an early career female scientist and will provide professional development and research experiences for women/minority graduate and undergraduate students. The PI will take advantage of USF?s Oceanography Camp for Girls.", "east": -65.21, "geometry": "POINT(-65.265 -64.33)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": true, "keywords": "Amd/Us; R/V NBP; USAP-DC", "locations": null, "north": -64.15, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.51, "title": "Late Quaternary Evolution of the Lambert Glacier/Amery Ice Shelf System, Prydz Bay, Antarctica", "uid": "p0000381", "west": -65.32}, {"awards": "1246378 Shevenell, Amelia", "bounds_geometry": "POLYGON((70 -68,70.5 -68,71 -68,71.5 -68,72 -68,72.5 -68,73 -68,73.5 -68,74 -68,74.5 -68,75 -68,75 -68.2,75 -68.4,75 -68.6,75 -68.8,75 -69,75 -69.2,75 -69.4,75 -69.6,75 -69.8,75 -70,74.5 -70,74 -70,73.5 -70,73 -70,72.5 -70,72 -70,71.5 -70,71 -70,70.5 -70,70 -70,70 -69.8,70 -69.6,70 -69.4,70 -69.2,70 -69,70 -68.8,70 -68.6,70 -68.4,70 -68.2,70 -68))", "dataset_titles": "Anvers Trough Foraminifer Stable Isotope data; Geochemical and sedimentologic data from NBP01-01 JPC-34", "datasets": [{"dataset_uid": "601064", "doi": "10.15784/601064", "keywords": "Antarctica; Antarctic Peninsula; Anvers Trough; Chemistry:sediment; Chemistry:Sediment; Foraminifera; Geochemistry; Isotope; LMG1211; LMG1311; Marine Sediments; Oceans; Paleoclimate; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "Anvers Trough Foraminifer Stable Isotope data", "url": "https://www.usap-dc.org/view/dataset/601064"}, {"dataset_uid": "601180", "doi": "10.15784/601180", "keywords": "Antarctica; Be-10; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Late Quaternary; Magnetic Susceptibility; Mass Spectrometry; NBP0101; Paleoenvironment; Prydz Bay; Radiocarbon; R/v Nathaniel B. Palmer; Sediment; Sediment Core; Sediment Core Data", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "Geochemical and sedimentologic data from NBP01-01 JPC-34", "url": "https://www.usap-dc.org/view/dataset/601180"}], "date_created": "Fri, 27 Oct 2017 00:00:00 GMT", "description": "Intellectual Merit: Southern Ocean processes play an important role in Late Quaternary glacial-interglacial climate change. However, the direct influence of newly upwelled warm nutrient-rich Circumpolar Deep Water on the Antarctic cryosphere remains speculative. The PI proposes to test the hypothesis that Circumpolar Deep Water-derived ocean heat negatively impacts the mass-balance of Antarctica?s ice sheets during deglaciations using precisely dated late Quaternary paleoceanographic studies of Antarctic margin sediments and a suite of geochemical proxies measured on three existing glacial marine sediment cores from the Prydz Channel, Antarctica. Specifically, the PI will use these data to reconstruct the Late Quaternary history of the Lambert Glacier/Amery Ice Shelf system; evaluate the timing, speed, and style of retreat of the Lambert Glacier/Amery Ice Shelf system during the last deglaciation, and to assess the impact of Circumpolar Deep Water intrusions on the Lambert Glacier/Amery Ice Shelf system in the Late Quaternary. Diatom bound radiocarbon and optically stimulated luminescence techniques will be used to obtain precise stratigraphic age control for the Prydz Channel siliceous muddy ooze intervals. In addition, the PI will measure sedimentary 10Be concentrations to determine the origin of the siliceous muddy ooze units and to track past changes in the position of the ice shelf front. Broader impacts: This proposal will support an early career female scientist and will provide professional development and research experiences for women/minority graduate and undergraduate students. The PI will take advantage of USF?s Oceanography Camp for Girls.", "east": 75.0, "geometry": "POINT(72.5 -69)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": true, "keywords": "Amd/Us; R/V NBP; USAP-DC", "locations": null, "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "Late Quaternary Evolution of the Lambert Glacier/Amery Ice Shelf System, Prydz Bay, Antarctica", "uid": "p0000381", "west": 70.0}, {"awards": "1246170 Hall, Brenda; 1246110 Stone, John", "bounds_geometry": "POLYGON((154 -79.75,154.7 -79.75,155.4 -79.75,156.1 -79.75,156.8 -79.75,157.5 -79.75,158.2 -79.75,158.9 -79.75,159.6 -79.75,160.3 -79.75,161 -79.75,161 -79.8,161 -79.85,161 -79.9,161 -79.95,161 -80,161 -80.05,161 -80.1,161 -80.15,161 -80.2,161 -80.25,160.3 -80.25,159.6 -80.25,158.9 -80.25,158.2 -80.25,157.5 -80.25,156.8 -80.25,156.1 -80.25,155.4 -80.25,154.7 -80.25,154 -80.25,154 -80.2,154 -80.15,154 -80.1,154 -80.05,154 -80,154 -79.95,154 -79.9,154 -79.85,154 -79.8,154 -79.75))", "dataset_titles": "Darwin and Hatherton Glaciers; Hatherton Glacier Radiocarbon Data", "datasets": [{"dataset_uid": "601063", "doi": "10.15784/601063", "keywords": "Antarctica; Geochronology; Hatherton Glacier; Radiocarbon; Sample/collection Description; Sample/Collection Description; Transantarctic Mountains", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Hatherton Glacier Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601063"}, {"dataset_uid": "200038", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Darwin and Hatherton Glaciers", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Mon, 23 Oct 2017 00:00:00 GMT", "description": "Hall/1246170 This award supports a project to reconstruct past ice-surface elevations from detailed glacial mapping and dating of moraines (using 14C dates of algae from former ice-marginal ponds and 10Be surface exposure ages) in the region of the Darwin-Hatherton Glaciers in Antarctica in order to try and resolve very different interpretations that currently exist about the glacial history in the region. The results will be integrated with existing climate and geophysical data into a flow-line model to gain insight into glacier response to climate and ice-dynamics perturbations during the Late Glacial Maximum (LGM) in Antarctica. The work will contribute to a better understanding of both LGM ice thickness and whether or not there is any evidence that Antarctica contributed to Meltwater Pulse (MWP)-1A a very controversial topic in Antarctic glacial geology. The intellectual merit of the work relates to the fact that reconstructing past fluctuations of the Antarctic Ice Sheet (AIS) is critical for understanding the sensitivity of ice volume to sea-level and climatic change. Constraints on past behavior help put ongoing changes into context and provide a basis for predicting future sea-level rise. Broader impacts include the support of two graduate and two undergraduate students, as well as a female early-career investigator. Graduate students will be involved in all stages of the project from planning and field mapping to geochronological analyses, interpretation, synthesis and reporting. Two undergraduates will work on lab-based research from the project. The project also will include visits to K-12 classrooms to talk about glaciers and climate change, correspondence with teachers and students from the field, and web-based outreach. This award has field work in Antarctica.", "east": 161.0, "geometry": "POINT(157.5 -80)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; FIELD INVESTIGATION; Antarctica", "locations": "Antarctica", "north": -79.75, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Stone, John; Conway, Howard", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -80.25, "title": "Collaborative Research: Assessing the Antarctic Contribution to Sea-level Changes during the Last Deglaciation: Constraints from Darwin Glacier", "uid": "p0000304", "west": 154.0}, {"awards": "1460449 Goehring, Brent; 1341420 Balco, Gregory; 1341364 Todd, Claire", "bounds_geometry": "POLYGON((164.08 -74.6,164.0842 -74.6,164.0884 -74.6,164.0926 -74.6,164.0968 -74.6,164.101 -74.6,164.1052 -74.6,164.1094 -74.6,164.1136 -74.6,164.1178 -74.6,164.122 -74.6,164.122 -74.6023,164.122 -74.6046,164.122 -74.6069,164.122 -74.6092,164.122 -74.6115,164.122 -74.6138,164.122 -74.6161,164.122 -74.6184,164.122 -74.6207,164.122 -74.623,164.1178 -74.623,164.1136 -74.623,164.1094 -74.623,164.1052 -74.623,164.101 -74.623,164.0968 -74.623,164.0926 -74.623,164.0884 -74.623,164.0842 -74.623,164.08 -74.623,164.08 -74.6207,164.08 -74.6184,164.08 -74.6161,164.08 -74.6138,164.08 -74.6115,164.08 -74.6092,164.08 -74.6069,164.08 -74.6046,164.08 -74.6023,164.08 -74.6))", "dataset_titles": "Interface to observational data associated with exposure-age measurements and resulting calculated ages. Dynamic content, updated.", "datasets": [{"dataset_uid": "200196", "doi": null, "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Interface to observational data associated with exposure-age measurements and resulting calculated ages. Dynamic content, updated.", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Wed, 18 Oct 2017 00:00:00 GMT", "description": "The investigators will map glacial deposits and date variations in glacier variability at several ice-free regions in northern Victoria Land, Antarctica. These data will constrain the nature and timing of past ice thickness changes for major glaciers that drain into the northwestern Ross Sea. This is important because during the Last Glacial Maximum (15,000 - 18,000 years ago) these glaciers were most likely flowing together with grounded ice from both the East and West Antarctic Ice Sheets that expanded across the Ross Sea continental shelf to near the present shelf edge. Thus, the thickness of these glaciers was most likely controlled in part by the extent and thickness of the Ross Sea ice sheet and ice shelf. The data the PIs propose to collect can provide constraints on the position of the grounding line in the western Ross Sea during the Last Glacial Maximum, the time that position was reached, and ice thickness changes that occurred after that time. The primary intellectual merit of this project will be to improve understanding of a period of Antarctic ice sheet history that is relatively unconstrained at present and also potentially important in understanding past ice sheet-sea level interactions. This proposal will support an early career researcher\u0027s ongoing program of undergraduate education and research that is building a socio-economically diverse student body with students from backgrounds underrepresented in the geosciences. This proposal will also bring an early career researcher into Antarctic research.", "east": 164.122, "geometry": "POINT(164.101 -74.6115)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; Cosmogenic Dating; Exposure Age; LABORATORY; NOT APPLICABLE; Amd/Us; Ross Sea", "locations": "Ross Sea", "north": -74.6, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Goehring, Brent; Balco, Gregory; Todd, Claire", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -74.623, "title": "Collaborative Research: Terrestrial Exposure-Age Constraints on the last Glacial Maximum Extent of the Antarctic Ice Sheet in the Western Ross Sea", "uid": "p0000306", "west": 164.08}, {"awards": "1142007 Kurbatov, Andrei", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic Ice Core Tephra Analysis; Antarctic Tephra Data Base AntT static web site", "datasets": [{"dataset_uid": "601052", "doi": "10.15784/601052", "keywords": "Antarctica; Geochemistry; Geochronology; Glaciology; Intracontinental Magmatism; IntraContinental Magmatism; Sample/collection Description; Sample/Collection Description; Tephra", "people": "Dunbar, Nelia; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Tephra Data Base AntT static web site", "url": "https://www.usap-dc.org/view/dataset/601052"}, {"dataset_uid": "601038", "doi": "10.15784/601038", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Intracontinental Magmatism; IntraContinental Magmatism; Tephra", "people": "Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Antarctic Ice Core Tephra Analysis", "url": "https://www.usap-dc.org/view/dataset/601038"}], "date_created": "Fri, 06 Oct 2017 00:00:00 GMT", "description": "Many key questions in climate research (e.g. relative timing of climate events in different geographic areas, climate-forcing mechanisms, natural threshold levels in the climate system) are dependent on accurate reconstructions of the temporal and spatial distribution of past rapid climate change events in continental, atmospheric, marine and polar realms. This collaborative interdisciplinary research project aims to consolidate, into a single user-friendly database, information about volcanic products detected in Antarctica. By consolidating information about volcanic sources, and physical and geochemical characteristics of volcanic products, this systematic data collection approach will improve the ability of researchers to identify volcanic ash, or tephra, from specific volcanic eruptions that may be spread over large areas in a geologically instantaneous amount of time. Development of this database will assist in the identification and cross-correlation of time intervals in various paleoclimate archives that contain volcanic layers from often unknown sources. The AntT project relies on a cyberinfrastructure framework developed in house through NSF funded CDI-Type I: CiiWork for data assimilation, interpretation and open distribution model. In addition to collection and integration of existing information about volcanic products, this project will focus on filling the information gaps about unique physico-chemical characteristics of very fine (\u003c3 micrometer) volcanic particles (cryptotephra) that are present in Antarctic ice cores. This component of research will involve improving analytical methodology for detecting cryptotephra layers in ice, and will train a new generation of scientists to apply an array of modern state?of?the-art instrumentation available to the project team. The recognized importance of tephra in establishing a chronological framework for volcanic and sedimentary successions has already resulted in the development of robust regional tephrochronological frameworks (e.g. Europe, Kamchatka, New Zealand, Western North America). The AntT project will provide this framework for Antarctic tephrochronology, as needed for precise correlation records between Antarctic ice cores (e.g. WAIS Divide, RICE, ITASE) and global paleoclimate archives. The results of AntT will be of particular significance to climatologists, paleoclimatologists, atmospheric chemists, geochemists, climate modelers, solar-terrestrial physicists, environmental statisticians, and policy makers for designing solutions to mitigate or cope with likely future impacts of climate change events on modern society.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Hartman, Laura; Wheatley, Sarah D.; Kurbatov, Andrei V.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Developing an Antarctic Tephra Database for Interdisciplinary Paleoclimate Research (AntT)", "uid": "p0000328", "west": -180.0}, {"awards": "1542778 Alley, Richard", "bounds_geometry": null, "dataset_titles": "c-Axis Fabric of the South Pole Ice Core, SPC14; South Pole Ice Core (SPC14) Bubble Number-Density Data; South Pole Ice Core (SPIcecore) Visual Observations", "datasets": [{"dataset_uid": "601088", "doi": "10.15784/601088", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; South Pole; Visual Observations", "people": "Alley, Richard; Fegyveresi, John", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPIcecore) Visual Observations", "url": "https://www.usap-dc.org/view/dataset/601088"}, {"dataset_uid": "601880", "doi": "10.15784/601880", "keywords": "Antarctic; Antarctica; Bubble Number Density; Cryosphere; Glaciers; Glaciology; Ice; Ice Core Data; Ice Core Records; NSF-ICF Microtome and Photography Stage; Paleoclimate; Physical Properties; Snow; South Pole", "people": "Fegyveresi, John", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPC14) Bubble Number-Density Data", "url": "https://www.usap-dc.org/view/dataset/601880"}, {"dataset_uid": "601057", "doi": "10.15784/601057", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; South Pole; SPICEcore", "people": "Voigt, Donald E.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "c-Axis Fabric of the South Pole Ice Core, SPC14", "url": "https://www.usap-dc.org/view/dataset/601057"}], "date_created": "Fri, 29 Sep 2017 00:00:00 GMT", "description": "Alley/1542778 This award supports a three-year effort to study physical properties of the South Pole ice core to help provide a high-time-resolution history of trace gases and other paleoclimatic indicators from an especially cold site with high preservation potential for important signals. The physical-properties studies include visual inspection to identify any flow disturbances and for identifying annual layers and other features, and combined bubble, grain and ice crystal orientation studies to better understand the processes occurring in the ice that affect the climate record and the ice-sheet behavior. Success of these efforts will provide necessary support for dating and quality control to others studying the ice core, as well as determining the climate history of the site, flow state, and key physical processes in ice. The intellectual merits of the project include better understanding of physical processes, paleoclimatic reconstruction, dating of the ice, and quality assurance. Visual inspection of the core will help identify evidence of flow disturbances that would disrupt the integrity of the climate record and will reveal volcanic horizons and other features of interest. Annual layer counting will be conducted to help estimate accumulation rate over time as recorded in the ice core. Measurements of C-axis fabric, grain size and shapes, and bubble characteristics will provide information about processes occurring in the ice sheet as well as the history of ice flow, current flow state and how the ice is flowing and how easily it will flow in the future. Analysis of this data in conjunction with microCT data will help to reveal grain-scale processes. The broader impacts of the project include support for an early-career, post-doctoral researcher, and improved paleoclimatic data of societal relevance. The results will be incorporated into the active program of education and outreach which have educated many students, members of the public and policy makers through the sharing of information and educational materials about all aspects of ice core science and paleoclimate.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard; Fegyveresi, John; Voigt, Donald E.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": null, "title": "Climate History and Flow Processes from Physical Analyses of the SPICECORE South Pole Ice Core", "uid": "p0000141", "west": null}, {"awards": "1142002 Kaplan, Michael", "bounds_geometry": "POLYGON((-58 -63.7,-57.95 -63.7,-57.9 -63.7,-57.85 -63.7,-57.8 -63.7,-57.75 -63.7,-57.7 -63.7,-57.65 -63.7,-57.6 -63.7,-57.55 -63.7,-57.5 -63.7,-57.5 -63.73,-57.5 -63.76,-57.5 -63.79,-57.5 -63.82,-57.5 -63.85,-57.5 -63.88,-57.5 -63.91,-57.5 -63.94,-57.5 -63.97,-57.5 -64,-57.55 -64,-57.6 -64,-57.65 -64,-57.7 -64,-57.75 -64,-57.8 -64,-57.85 -64,-57.9 -64,-57.95 -64,-58 -64,-58 -63.97,-58 -63.94,-58 -63.91,-58 -63.88,-58 -63.85,-58 -63.82,-58 -63.79,-58 -63.76,-58 -63.73,-58 -63.7))", "dataset_titles": "10Be and 14C data from northern Antarctic Peninsula", "datasets": [{"dataset_uid": "601051", "doi": "10.15784/601051", "keywords": "Antarctica; Antarctic Peninsula; Glaciers/ice Sheet; Glaciers/Ice Sheet; GPS; James Ross Island; Sample/collection Description; Sample/Collection Description; Solid Earth", "people": "Kaplan, Michael", "repository": "USAP-DC", "science_program": null, "title": "10Be and 14C data from northern Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601051"}], "date_created": "Tue, 19 Sep 2017 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to investigate last glacial maximum through Holocene glacial change on the northeastern Antarctic Peninsula, an area distinguished by dramatic ice shelf collapses and retreat of upstream glaciers. However, there is a lack of long-term context to know the relative significance of recent events over longer time scales. The PIs will obtain data on former ice margin positions, ice thicknesses, glacier retreat and thinning rates, and Holocene glacier change in the James Ross Island Archipelago and areas near the former Larsen-A ice shelf. These data include maximum- and minimum-limiting 14C and cosmogenic-nuclide exposure dates integrated with geomorphology and stratigraphy. Understanding the extent, nature, and history of glacial events is important for placing current changes in glacial extent into a long-term context. This research will also contribute to understanding the sensitivity of ice shelves and glaciers in this region to climate change. Records of changes in land-terminating glaciers will also address outstanding questions related to climate change since the LGM and through the Holocene. The PIs will collect samples during cooperative field projects with scientists of the Instituto Anta\u0026#769;rtico Argentino and the Korea Polar Research Institute planned as part of existing, larger, research projects. Broader impacts: The proposed work includes collaborations with Argentina and Korea. The PIs are currently involved in or are initiating education and outreach activities that will be incorporated into this project. These include interactions with the American Museum of Natural History, the United States Military Academy at West Point, and undergraduate involvement in their laboratories. This project provides a significant opportunity to engage the public as it focuses on an area where environmental changes are the object of attention in the popular media.", "east": -57.5, "geometry": "POINT(-57.75 -63.85)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; GLACIATION; Not provided", "locations": "Antarctic Peninsula", "north": -63.7, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Kaplan, Michael", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.0, "title": "Terrestrial Geological Context for Glacier Change in the Northeast Antarctica Peninsula", "uid": "p0000337", "west": -58.0}, {"awards": "1142085 Alley, Richard", "bounds_geometry": null, "dataset_titles": "Firn-temperature time series in Dronning Maud Land, East Antarctica", "datasets": [{"dataset_uid": "601050", "doi": "10.15784/601050", "keywords": "Antarctica; Borehole Logging; Dronning Maud Land; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Physical Properties; Snow; Temperature", "people": "Muto, Atsu", "repository": "USAP-DC", "science_program": null, "title": "Firn-temperature time series in Dronning Maud Land, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601050"}], "date_created": "Mon, 11 Sep 2017 00:00:00 GMT", "description": "Alley/1142085 This award supports a project to continue the collection and analyses of firn temperature data from three automated firn thermal profiling units deployed in Dronning Maud Land sector of East Antarctica as part of the Norway-US IPY Traverse project between 2007 and 2009. The intellectual merits of this project are as follows: 1) to constrain and improve the parameterization of firn thermal properties (thermal conductivity and specific heat capacity) that are required for the borehole paleothermometry, 2) to study the change in firn temperature since the deployment of thermal profiling units ~5 years ago and derive the surface temperature trend for that time period, and 3) to compare and contrast the surface temperatures and their trends derived from the measured firn temperatures and satellite thermal infrared data for the past three decades. The project also involves acquiring and deploying an automated system to record transient temperatures at multiple depths in the top 16 meters of the shallow borehole at Dome Fuji, to provide useful data and to prepare for the possibility of conducting temperature-logging in the existing deep (3035 m) and shallow (112 m) boreholes at Dome Fuji in the near future. The preparation of the shallow borehole and the installation of the automated system will be carried out by collaborators from the Japanese Antarctic Research Expedition (JARE) in 2012-13 Antarctic field season. The data collected by this automated system will be used to constrain the thermal properties of upper firn layer at Dome Fuji, as well as comparing with data from other sites, increasing the geographic extent of these studies. The broader impacts of the project include presentation of results at scientific conferences and publication of results in peer-reviewed journals. Public outreach will include targeted work with science teachers and middle school students.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Revealing Late Holocence Climate Variability in Antarctica from Borehole Paleothermometry", "uid": "p0000440", "west": null}, {"awards": "1245879 Nitsche, Frank O.", "bounds_geometry": null, "dataset_titles": "NBP1503 data collected during field expedition", "datasets": [{"dataset_uid": "200001", "doi": "10.7284/901478", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1503 data collected during field expedition", "url": "https://www.rvdata.us/search/cruise/NBP1503"}], "date_created": "Sun, 30 Jul 2017 00:00:00 GMT", "description": "Intellectual Merit: This project will determine the potential vulnerability of key ice streams to incursions of warmer ocean water onto the continental shelf and if this mechanism could already explain any of the observed thinning of the ice sheet. It will provide important constrains on ice dynamic of the investigated section of the EAIS, and thus will be critical for future ice sheet models and provide mechanisms for EAIS contributions to past sea level high-stand. The PI proposes to investigate four key ice stream systems on the continental shelf between ~90\u00b0E and 160\u00b0E. They will use multibeam bathymetry to identify if and where cross-shelf troughs exist to help determine whether these troughs could provide potential pathways for warmer ocean water. Furthermore, detailed analysis of morphological features of these troughs could provide information on past ice dynamic, maximum extent, and flow direction of related paleo ice streams. The PIs will also conduct water column measurements along these troughs and on the continental slope to determine whether warmer ocean water could enter the shelf in the near future, or if such water has already entered any troughs, and thus might be causing the observed thinning of some ice streams. Broader impacts: This project includes the participation and support of undergraduate and graduate students in field work and data analysis. The possible involvement of a PolarTREC teacher and the Earth2Class teachers program will reach out to K-12 students.", "east": 134.6, "geometry": "POINT(125.05 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "WATER TEMPERATURE; Polar; SALINITY; Antarctica; Southern Ocean; R/V NBP; BATHYMETRY", "locations": "Polar; Antarctica; Southern Ocean", "north": -63.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Nitsche, Frank O.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -66.0, "title": "Vulnerability of East Antarctic Ice Streams to warm Ocean Water Incursions", "uid": "p0000394", "west": 115.5}, {"awards": "0944348 Taylor, Kendrick; 0944266 Twickler, Mark", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "Summary of Results from the WAIS Divide Ice Core Project; WAIS Divide WDC06A Core Quality Versus Depth", "datasets": [{"dataset_uid": "601030", "doi": "10.15784/601030", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide Ice Core", "people": "Twickler, Mark; Souney, Joseph Jr.; Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide WDC06A Core Quality Versus Depth", "url": "https://www.usap-dc.org/view/dataset/601030"}, {"dataset_uid": "601021", "doi": "10.15784/601021", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide Ice Core", "people": "Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Summary of Results from the WAIS Divide Ice Core Project", "url": "https://www.usap-dc.org/view/dataset/601021"}], "date_created": "Fri, 09 Jun 2017 00:00:00 GMT", "description": "Taylor/0944348\u003cbr/\u003e\u003cbr/\u003eThis award supports renewal of funding of the WAIS Divide Science Coordination Office (SCO). The Science Coordination Office (SCO) was established to represent the research community and facilitates the project by working with support organizations responsible for logistics, drilling, and core curation. During the last five years, 26 projects have been individually funded to work on this effort and 1,511 m of the total 3,470 m of ice at the site has been collected. This proposal seeks funding to continue the SCO and related field operations needed to complete the WAIS Divide ice core project. Tasks for the SCO during the second five years include planning and oversight of logistics, drilling, and core curation; coordinating research activities in the field; assisting in curation of the core in the field; allocating samples to individual projects; coordinating the sampling effort; collecting, archiving, and distributing data and other information about the project; hosting an annual science meeting; and facilitating collaborative efforts among the research groups. The intellectual merit of the WAIS Divide project is to better predict how human-caused increases in greenhouse gases will alter climate requires an improved understanding of how previous natural changes in greenhouse gases influenced climate in the past. Information on previous climate changes is used to validate the physics and results of climate models that are used to predict future climate. Antarctic ice cores are the only source of samples of the paleo-atmosphere that can be used to determine previous concentrations of carbon dioxide. Ice cores also contain records of other components of the climate system such as the paleo air and ocean temperature, atmospheric loading of aerosols, and indicators of atmospheric transport. The WAIS Divide ice core project has been designed to obtain the best possible record of greenhouse gases during the last glacial cycle (last ~100,000 years). The site was selected because it has the best balance of high annual snowfall (23 cm of ice equivalent/year), low dust Antarctic ice that does not compromise the carbon dioxide record, and favorable glaciology. The main science objectives of the project are to investigate climate forcing by greenhouse gases, initiation of climate changes, stability of the West Antarctic Ice Sheet, and cryobiology in the ice core. The project has numerous broader impacts. An established provider of educational material (Teachers? Domain) will develop and distribute web-based resources related to the project and climate change for use in K?12 classrooms. These resources will consist of video and interactive graphics that explain how and why ice cores are collected, and what they tell us about future climate change. Members of the national media will be included in the field team and the SCO will assist in presenting information to the general public. Video of the project will be collected and made available for general use. Finally, an opportunity will be created for cryosphere students and early career scientists to participate in field activities and core analysis. An ice core archive will be available for future projects and scientific discoveries from the project can be used by policy makers to make informed decisions.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Mark, Twickler; Taylor, Kendrick C.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Collaborative Research: Climate, Ice Dynamics and Biology using a Deep Ice Core from the West Antarctic Ice Sheet Ice Divide", "uid": "p0000080", "west": -112.1115}, {"awards": "1341360 Steig, Eric", "bounds_geometry": "POINT(106 -77.5)", "dataset_titles": "Seasonal 17O Isotope Data from Lake Vostok and WAIS Divide Snow Pits", "datasets": [{"dataset_uid": "601031", "doi": "10.15784/601031", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Lake Vostok; Snow Pit; WAIS Divide Ice Core", "people": "Schoenemann, Spruce; Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal 17O Isotope Data from Lake Vostok and WAIS Divide Snow Pits", "url": "https://www.usap-dc.org/view/dataset/601031"}], "date_created": "Tue, 06 Jun 2017 00:00:00 GMT", "description": "Steig/1341360 This award supports a two-year project to develop a method for rapid and precise measurements of the difference in 18O/16O and 17O/16O isotope ratios in water, referred to as the 17O-excess. Measurement of 17O-excess is a recent innovation in geochemistry, complementing traditional measurements of the ratios of hydrogen (D/H) and oxygen (18O/16O). Conventional measurements of 17O/16O are limited in number because of the time-consuming and laborious nature of the analyses, which involves the conversion of water to oxygen via fluorination, followed by high-precision mass spectrometry. This project will use a novel cavity ring-down spectroscopy (CRDS) system developed by a joint effort of the University of Washington and Picarro, Inc. (Santa Clara, CA), along with the Centre for Ice and Climate (Neils Bohr Institute, Copenhagen). The primary intellectual merit of the research is the improvement of the CRDS method for measurements of 17Oexcess of discrete samples of water, to obtain precision and accuracy competitive with conventional methods using mass spectrometry. This will be achieved by quantification of the effects of water vapor concentration variability and instrument memory, precise calibration of the instrument against standard waters, and improvements to the spectroscopic analyses. The CRDS system will also be coupled to continuous-flow systems for ice core analysis, in collaboration with the University of Colorado, Boulder. The goal is to have an operational system available for ice core processing associated with the next major U.S.-led ice core project at South Pole, in 2015-2017. The broader impacts of the research include the ability to measure 17O-excess in ambient atmospheric water vapor, which can be used to improve understanding of convection, moisture transport, and condensation. The instrument development work proposed here is relevant to research supported by several NSF-GEO programs, including Hydrology, Climate and Large Scale Dynamics, Paleoclimate, Atmosphere Chemistry, and both the Arctic and Antarctic Programs. This proposal will support a postdoctoral researcher.", "east": 106.0, "geometry": "POINT(106 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.5, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -77.5, "title": "Development of a Laser Spectroscopy System for Analysis of 17Oexcess on Ice Cores", "uid": "p0000316", "west": 106.0}, {"awards": "1148982 Hansen, Samantha", "bounds_geometry": "POLYGON((153.327 -73.032547,154.5063012 -73.032547,155.6856024 -73.032547,156.8649036 -73.032547,158.0442048 -73.032547,159.223506 -73.032547,160.4028072 -73.032547,161.5821084 -73.032547,162.7614096 -73.032547,163.9407108 -73.032547,165.120012 -73.032547,165.120012 -73.3530275,165.120012 -73.673508,165.120012 -73.9939885,165.120012 -74.314469,165.120012 -74.6349495,165.120012 -74.95543,165.120012 -75.2759105,165.120012 -75.596391,165.120012 -75.9168715,165.120012 -76.237352,163.9407108 -76.237352,162.7614096 -76.237352,161.5821084 -76.237352,160.4028072 -76.237352,159.223506 -76.237352,158.0442048 -76.237352,156.8649036 -76.237352,155.6856024 -76.237352,154.5063012 -76.237352,153.327 -76.237352,153.327 -75.9168715,153.327 -75.596391,153.327 -75.2759105,153.327 -74.95543,153.327 -74.6349495,153.327 -74.314469,153.327 -73.9939885,153.327 -73.673508,153.327 -73.3530275,153.327 -73.032547))", "dataset_titles": "Crustal Structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for Tectonic Origins; Shear Wave Splitting Analysis and Seismic Anisotropy beneath the Northern Transantarctic Mountains; Upper Mantle Seismic Structure beneath the Northern Transantarctic Mountains from Regional P- and S-wave Tomography; Upper Mantle Shear Wave Velocity Structure beneath the Northern Transantarctic Mountains", "datasets": [{"dataset_uid": "601019", "doi": "10.15784/601019", "keywords": "Antarctica; Geology/Geophysics - Other; GPS; Sample/collection Description; Sample/Collection Description; Seismology; Shearwave Spitting; Solid Earth; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Shear Wave Splitting Analysis and Seismic Anisotropy beneath the Northern Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601019"}, {"dataset_uid": "601017", "doi": "10.15784/601017", "keywords": "Antarctica; Geology/Geophysics - Other; Model; Seismology; Solid Earth; Tomography; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Upper Mantle Seismic Structure beneath the Northern Transantarctic Mountains from Regional P- and S-wave Tomography", "url": "https://www.usap-dc.org/view/dataset/601017"}, {"dataset_uid": "601018", "doi": "10.15784/601018", "keywords": "Antarctica; Geology/Geophysics - Other; Model; Seismology; Solid Earth; Tomography; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Upper Mantle Shear Wave Velocity Structure beneath the Northern Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601018"}, {"dataset_uid": "601194", "doi": "10.15784/601194", "keywords": "Antarctica; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Crustal Structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for Tectonic Origins", "url": "https://www.usap-dc.org/view/dataset/601194"}], "date_created": "Sun, 04 Jun 2017 00:00:00 GMT", "description": "Intellectual Merit: To understand Antarctica\u0027s geodynamic development, origin of the Transantarctic Mountains (TAMs) and the Wilkes Subglacial Basin (WSB) must be determined. Current constraints on the crustal thickness and seismic velocity structure beneath the TAMs and the WSB are limited, leading to uncertainties over competing geologic models that have been suggested to explain their formation. The PI proposes to broaden the investigation of this region with a new seismic deployment, the Transantarctic Mountains Northern Network (TAMNNET), a 15-station array across the northern TAMs and the WSB that will fill a major gap in seismic coverage. Data from TAMNNET will be combined with that from other previous and ongoing seismic initiatives and will be analyzed using proven modeling techniques to generate a detailed image of the seismic structure beneath the TAMs and the WSB. These data will be used to test three fundamental hypotheses: the TAMs are underlain by thickened crust, the WSB is characterized by thin crust and thick sedimentary layers, and slow seismic velocities are prevalent along strike beneath the TAMs. Results from the proposed study will provide new information about the nature and formation of the Antarctic continent and will help to advance our understanding of important global processes, such as mountain building and basin formation. The proposed research also has important implications for other fields of Antarctic science. Constraints on the origin of the TAMs uplift are critical for climate and ice sheet models, and new information acquired about variations in the thermal and lithospheric structure beneath the TAMs and the WSB will be used to estimate critical ice sheet boundary conditions. Broader impacts: This project incorporates three educational strategies to promote the integration of teaching and research. Graduate students will be trained in Antarctic tectonics and seismic processing through hands-on fieldwork and data analysis techniques. Through NSF\u0027s PolarTREC program, the PI will work with K-12 educators. The PI will develop a three-week summer field program for recent high school graduates and early-career undergraduate students from Minority-Serving Institutions in Alabama. Teaching materials and participant experiences will be shared with individuals outside the program via a course website. Following the summer program, participants who were particularly engaged will be offered internship opportunities to analyze TAMNNET data. In successive years, the students could assist with fieldwork and could be recruited into the graduate program under the PI\u0027s supervision. Ultimately, this program would not only serve to educate undergraduates but would also generate a pipeline of underrepresented students into the geosciences.", "east": 165.120012, "geometry": "POINT(159.223506 -74.6349495)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -73.032547, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Hansen, Samantha", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.237352, "title": "CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin", "uid": "p0000300", "west": 153.327}, {"awards": "1246223 Hastings, Meredith", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "WAIS Divide WDC06A Nitrate Isotope Record", "datasets": [{"dataset_uid": "601022", "doi": "10.15784/601022", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrate; WAIS Divide; WAIS Divide Ice Core", "people": "Buffen, Aron; Hastings, Meredith", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide WDC06A Nitrate Isotope Record", "url": "https://www.usap-dc.org/view/dataset/601022"}], "date_created": "Tue, 02 May 2017 00:00:00 GMT", "description": "Hastings/1246223 This award supports a project with the aim of distinguishing the sources of nitrate deposition to the West Antarctic Ice Sheet (WAIS) using isotopic ratios snow in archive snow and ice samples. The isotopic composition of nitrate has been shown to contain information about the source of the nitrate (i.e. nitrogen oxides = NOx = NO+NO2) and the oxidation processes that convert NOx to nitrate in the atmosphere prior to deposition. A difficulty in interpreting records in the context of NOx sources is that nitrate can be post-depositionally processed in surface snow, such that the archived record does not reflect the composition of the atmosphere. This intellectual merit of this work specifically aims to investigate variability in the isotopic composition of nitrate in snow and ice from the WAIS in the context of accumulation rate, NOx source emissions, and atmospheric chemistry. These records will be interpreted in the context of our understanding of biospheric (biomass burning, microbial processes in soils), atmospheric (lightning, transport, chemistry), and climate (temperature, accumulation rate) changes over time. A graduate student will be supported as part of this project, and both graduate student and PI will be involved in communicating the utility and results of polar research to elementary school students in the Providence, RI area. The broader impacts of the project also include making efforts to attract more young, female scientists to polar research by establishing a connection between the Earth Science Women\u0027s Network (ESWN), an organization PI Hastings helped to establish, and the Association of Polar Early Career Scientists (APECS). Finally, results of all measurements will be presented at relevant conferences, made available publicly and published in peer-reviewed journals.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hastings, Meredith", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Investigating Source, Chemistry and Climate changes using the Isotopic Composition of Nitrate in Antarctic Snow and Ice", "uid": "p0000399", "west": -112.1115}, {"awards": "1443260 Conway, Howard", "bounds_geometry": "POLYGON((159 -76.68,159.03 -76.68,159.06 -76.68,159.09 -76.68,159.12 -76.68,159.15 -76.68,159.18 -76.68,159.21 -76.68,159.24 -76.68,159.27 -76.68,159.3 -76.68,159.3 -76.697,159.3 -76.714,159.3 -76.731,159.3 -76.748,159.3 -76.765,159.3 -76.782,159.3 -76.799,159.3 -76.816,159.3 -76.833,159.3 -76.85,159.27 -76.85,159.24 -76.85,159.21 -76.85,159.18 -76.85,159.15 -76.85,159.12 -76.85,159.09 -76.85,159.06 -76.85,159.03 -76.85,159 -76.85,159 -76.833,159 -76.816,159 -76.799,159 -76.782,159 -76.765,159 -76.748,159 -76.731,159 -76.714,159 -76.697,159 -76.68))", "dataset_titles": "2015-2016 GPR Field Report for Allan Hills Shallow Ice Coring; Ground-based ice-penetrating radar profiles collected on the Allan Hills blue ice region", "datasets": [{"dataset_uid": "601005", "doi": "10.15784/601005", "keywords": "Allan Hills; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Navigation; Radar", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Ground-based ice-penetrating radar profiles collected on the Allan Hills blue ice region", "url": "https://www.usap-dc.org/view/dataset/601005"}, {"dataset_uid": "601668", "doi": "10.15784/601668", "keywords": "Allan Hills; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; GPR; Ice Core; Report", "people": "MacKay, Sean; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "2015-2016 GPR Field Report for Allan Hills Shallow Ice Coring", "url": "https://www.usap-dc.org/view/dataset/601668"}], "date_created": "Tue, 02 May 2017 00:00:00 GMT", "description": "Marine paleoclimate archives show that approximately one million years ago Earth\u0027s climate transitioned from 40,000-year glacial /interglacial cycles to 100,000-year cycles. This award will support a study designed to map the distribution of one million year-old ice in the Allan Hills Blue Ice Area, Antarctica using state-of-the-art ground penetrating radar. The Allen Hills was demonstrated to contain a continuous record of the past 400,000 years and is also the collection location of the oldest ice samples (990,000 years) yet recovered. The maps resulting from this study will be used to select an ice-core drilling site at which a million-plus year-old continuous record of climate could be recovered. Ice cores contain the only kind of record to directly capture atmospheric gases and aerosols, but no ice-core-based climate record yet extends continuously beyond the past 800,000 years. A million-plus year-old record will allow better understanding of the major mechanisms and driving forces of natural climate variability in a world with 100,000-year glacial/interglacial cycles. The project will support two early career scientists in collaboration with senior scientists, as well as a graduate student, and will conduct outreach to schools and the public. The Allan Hills Blue Ice Area preserves a continuous climate record covering the last 400,000 years along an established glaciological flow line. Two kilometers to the east of this flow line, the oldest ice on Earth (~1 million years old) is found only 120 m below the surface. Meteorites collected in the area are reported to be as old as 1.8 million years, suggesting still older ice may be present. Combined, these data strongly suggest that the Allen Hills area could contain a continuous, well-resolved environmental record, spanning at least the last million years. As such, this area has been selected as an upcoming target for the new Intermediate Depth Ice Core Drill by the US Ice Core Working Group. This drill will recover a higher-quality core than previous dry drilling attempts. This project will conduct a comprehensive ground penetrating radar survey aimed at tracing the signature of the million-year-old ice layer throughout the region. The resulting map will be used to select a drill site from which an ice core containing the million-plus year-old continuous climate record will be collected. The proposed activities are a necessary precursor to the collection of the oldest known ice on Earth. Ice cores provide a robust reconstruction of past climate and extending this record beyond the 800,000 years currently available will open new opportunities to study the climate system. The data collected will also be used to investigate the bedrock and ice flow parameters favorable to the preservation of old ice, which may allow targeted investigation of other blue ice areas in Antarctica.", "east": 159.3, "geometry": "POINT(159.15 -76.765)", "instruments": null, "is_usap_dc": true, "keywords": "Allan Hills; FIELD SURVEYS; ICE SHEETS", "locations": "Allan Hills", "north": -76.68, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.85, "title": "Collaborative Research: Allan HILLs Englacial Site (AHILLES) Selection", "uid": "p0000385", "west": 159.0}, {"awards": "1245283 Passchier, Sandra", "bounds_geometry": "POLYGON((66 -68,67.3 -68,68.6 -68,69.9 -68,71.2 -68,72.5 -68,73.8 -68,75.1 -68,76.4 -68,77.7 -68,79 -68,79 -68.2,79 -68.4,79 -68.6,79 -68.8,79 -69,79 -69.2,79 -69.4,79 -69.6,79 -69.8,79 -70,77.7 -70,76.4 -70,75.1 -70,73.8 -70,72.5 -70,71.2 -70,69.9 -70,68.6 -70,67.3 -70,66 -70,66 -69.8,66 -69.6,66 -69.4,66 -69.2,66 -69,66 -68.8,66 -68.6,66 -68.4,66 -68.2,66 -68))", "dataset_titles": "Antarctic Geochemistry Data and Mean Annual Temperature Reconstruction through the Eocene-Oligocene Transition; GSA Data Repository Item 2016298 - Passchier, S., Ciarletta, D.J., Miriagos, T.E., Bijl, P.K., and Bohaty, S.M., 2016, An Antarctic stratigraphic record of step-wise ice growth through the Eocene-Oligocene transition: GSA Bulletin, doi:10.1130/B31482.1.; Particle-size distributions of Eocene-Oligocene sediment from ODP Site 739, Prydz Bay; Particle-size distributions of Eocene-Oligocene sediment from ODP Site 742, Prydz Bay; Particle-size distributions of Eocene sediment from ODP Site 1166, Prydz Bay", "datasets": [{"dataset_uid": "601454", "doi": "10.15784/601454", "keywords": "Antarctica; Eocene; Marine Geoscience; ODP742; Oligocene; Particle Size; Prydz Bay; Sediment Core Data", "people": "Ciarletta, Daniel; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 742, Prydz Bay", "url": "https://www.usap-dc.org/view/dataset/601454"}, {"dataset_uid": "000192", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Antarctic Geochemistry Data and Mean Annual Temperature Reconstruction through the Eocene-Oligocene Transition", "url": "https://www.ncdc.noaa.gov/paleo-search/study/21770"}, {"dataset_uid": "200200", "doi": "10.1130/2016298", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": " GSA Data Repository Item 2016298 - Passchier, S., Ciarletta, D.J., Miriagos, T.E., Bijl, P.K., and Bohaty, S.M., 2016, An Antarctic stratigraphic record of step-wise ice growth through the Eocene-Oligocene transition: GSA Bulletin, doi:10.1130/B31482.1.", "url": "https://gsapubs.figshare.com/articles/journal_contribution/Supplemental_material_An_Antarctic_stratigraphic_record_of_step-wise_ice_growth_through_the_Eocene-Oligocene_transition/12534185"}, {"dataset_uid": "601455", "doi": "10.15784/601455", "keywords": "Antarctica; Eocene; Marine Geoscience; ODP1166; Particle Size; Prydz Bay; Sediment Core Data", "people": "Passchier, Sandra; Ciarletta, Daniel", "repository": "USAP-DC", "science_program": null, "title": "Particle-size distributions of Eocene sediment from ODP Site 1166, Prydz Bay", "url": "https://www.usap-dc.org/view/dataset/601455"}, {"dataset_uid": "601453", "doi": "10.15784/601453", "keywords": "Antarctica; Eocene; Marine Geoscience; ODP739; Oligocene; Particle Size; Prydz Bay; Sediment Core Data", "people": "Ciarletta, Daniel; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 739, Prydz Bay", "url": "https://www.usap-dc.org/view/dataset/601453"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "Intellectual Merit: This project will investigate glacial advance and retreat of the East Antarctic Ice Sheet through the Eocene-Oligocene transition, a major episode of ice growth. In Prydz Bay, East Antarctica, a 130-170 m thick Eocene-Oligocene transition interval of glaciomarine sediments was cored in drillholes of the Ocean Drilling Program at Sites 739, 742 and 1166. Correlations between the Prydz Bay drillholes have recently been made through well-log and multichannel seismic interpretations. Recent drilling on the Wilkes Land margin of East Antarctica recovered earliest Oligocene sediments overlying a major regional unconformity in two drillholes. The PI will study the lithostratigraphy and weathering history of cores in the five drillholes, to establish a unique Eocene-Oligocene transition record within Antarctic continental margin sediments of glacial advance and retreat cycles, the onset of physical weathering, and glacio-isostasy and self-gravitation processes with implications for the margin architecture, sediment routing, and off-shore sediment dispersal. Cores from the five drillholes will be re-examined through detailed core description using an updated classification scheme, so that lithofacies can be compared between drillholes. Samples will be collected for detailed laser particle size and bulk major element geochemistry via ICP-AES to determine the degree of chemical alteration of the sediments. Phases of major ice growth will be recognized as marker beds of physically eroded sediment and will be correlated to isotopic records documenting Antarctic ice growth offshore in the Southern Ocean. Broader impacts: This project will benefit a large minority undergraduate student population through the availability of up to two paid laboratory internships, a classroom exercise, and the availability of research equipment supported by this award. The project also allows support and training of a graduate student.", "east": 79.0, "geometry": "POINT(72.5 -69)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Not provided; Prydz Bay; SEDIMENTS", "locations": "Prydz Bay", "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "NCEI; Publication; USAP-DC", "science_programs": null, "south": -70.0, "title": "The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin", "uid": "p0000309", "west": 66.0}, {"awards": "0538427 McConnell, Joseph", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "Gas measurement from Higgins et al., 2015 - PNAS; WAIS Divide Ice-Core Aerosol Records from 1.5 to 577 m; WAIS Divide Ice-Core Aerosol Records from Intermediate Core WDC05A; WAIS Divide Ice-Core Aerosol Records from Intermediate Core WDC05Q; WAIS Divide Ice-Core Chronology from Intermediate Core WDC05A; WAIS Divide Ice-Core Chronology from Intermediate Core WDC05Q", "datasets": [{"dataset_uid": "601013", "doi": "10.15784/601013", "keywords": "Antarctica; Depth-Age-Model; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Chronology from Intermediate Core WDC05Q", "url": "https://www.usap-dc.org/view/dataset/601013"}, {"dataset_uid": "601010", "doi": "10.15784/601010", "keywords": "Aerosol; Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Aerosol Records from Intermediate Core WDC05A", "url": "https://www.usap-dc.org/view/dataset/601010"}, {"dataset_uid": "601014", "doi": "10.15784/601014", "keywords": "Allan Hills; Antarctica; Argon; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope", "people": "Higgins, John", "repository": "USAP-DC", "science_program": null, "title": "Gas measurement from Higgins et al., 2015 - PNAS", "url": "https://www.usap-dc.org/view/dataset/601014"}, {"dataset_uid": "601012", "doi": "10.15784/601012", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Snow Accumulation; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Chronology from Intermediate Core WDC05A", "url": "https://www.usap-dc.org/view/dataset/601012"}, {"dataset_uid": "601009", "doi": "10.15784/601009", "keywords": "Aerosol; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Aerosol Records from 1.5 to 577 m", "url": "https://www.usap-dc.org/view/dataset/601009"}, {"dataset_uid": "601011", "doi": "10.15784/601011", "keywords": "Aerosol; Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Aerosol Records from Intermediate Core WDC05Q", "url": "https://www.usap-dc.org/view/dataset/601011"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "0538427\u003cbr/\u003eMcConnell \u003cbr/\u003eThis award supports a project to use unique, high-depth-resolution records of a range of elements, chemical species, and ice properties measured in two WAIS Divide shallow ice cores and one shallow British ice core from West Antarctic to address critical paleoclimate, environmental, and ice-sheet mass-balance questions. Recent development of the CFA-TE method for ice-core analysis presents the opportunity to develop high-resolution, broad-spectrum glaciochemical records at WAIS Divide at relatively modest cost. Together with CFA-TE measurements from Greenland and other Antarctic sites spanning recent decades to centuries, these rich data will open new avenues for using glaciochemical data to investigate environmental and global changes issues ranging from anthropogenic and volcanic-trace-element fallout to changes in hemispheric-scale circulation, biogeochemistry, rapid-climate-change events, long-term climate change, and ice-sheet mass balance. As part of the proposed research, collaborations with U.S., Argentine, and British researchers will be initiated and expanded to directly address three major IPY themes (i.e., present environmental status, past and present environmental and human change, and polar-global interactions). Included in the contributions from these international collaborators will be ice-core samples, ice-core and meteorological model data, and extensive expertise in Antarctic glaciology, climatology, meteorology, and biogeochemistry. The broader impacts of the work include the training of students. The project will partially support one Ph.D. student and hourly undergraduate involvement. Every effort will be made to attract students from underrepresented groups to these positions. To address the challenge of introducing results of scientific research to the public policy debate, we will continue efforts to publish findings in high visibility journals, provide research results to policy makers, and work with the NSF media office to reach the public through mass-media programs. K-12 teacher and classroom involvement will be realized through outreach to local schools and NSF\u0027s Teachers Experiencing the Antarctic and Arctic (or similar) program in collaboration with WAIS Divide and other polar researchers.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bender, Michael; McConnell, Joseph", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Trace and Ultra-Trace Chemistry Measurements of the WAIS Divide Ice Core", "uid": "p0000148", "west": -112.1115}, {"awards": "1142166 McConnell, Joseph", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "WAIS Divide Ice-Core Aerosol Records from 1300 to 3404 m", "datasets": [{"dataset_uid": "601008", "doi": "10.15784/601008", "keywords": "Aerosol; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Aerosol Records from 1300 to 3404 m", "url": "https://www.usap-dc.org/view/dataset/601008"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "McConnell/1142166 This award supports a project to use unprecedented aerosol and continuous gas (methane, carbon monoxide) measurements of the deepest section of the West Antarctic Ice Sheet (WAIS) Divide ice core to investigate rapid climate changes in Antarctica during the ~60,000 year long Marine Isotope Stage 3 period of the late Pleistocene. These analyses, combined with others, will take advantage of the high snow accumulation of the WAIS Divide ice core to yield the highest time resolution glaciochemical and gas record of any deep Antarctic ice core for this time period. The research will expand already funded discrete gas measurements and extend currently funded continuous aerosol measurements on the WAIS Divide ice core from ~25,000 to ~60,000 years before present, spanning Heinrich events 3 to 6 and Antarctic Isotope Maximum (AIM, corresponding to the Northern Hemisphere Dansgaard-Oeschger) events 3 to 14. With other high resolution Greenland cores and lower resolution Antarctic cores, the combined record will yield new insights into worldwide climate dynamics and abrupt change. The intellectual merit of the work is that it will be used to address the science goals of the WAIS Divide project including the identification of dust and biomass burning tracers such as black carbon and carbon monoxide which reflect mid- and low-latitude climate and atmospheric circulation patterns, and fallout from these sources affects marine and terrestrial biogeochemical cycles. Similarly, sea salt and ocean productivity tracers reflect changes in sea ice extent, marine primary productivity, wind speeds above the ocean, and atmospheric circulation. Volcanic tracers address the relationship between northern, tropical, and southern climates as well as stability of the West Antarctic ice sheet and sea level change. When combined with other gas records from WAIS Divide, the records developed here will transform understanding of mid- and low-latitude drivers of Antarctic, Southern Hemisphere, and global climate rapid changes and the timing of such changes. The broader impacts of the work are that it will enhance infrastructure through expansion of continuous ice core analytical techniques, train students and support collaboration between two U.S. institutions (DRI and OSU). All data will be made available to the scientific community and the public and will include participation the WAIS Divide Outreach Program. Extensive graduate and undergraduate student involvement is planned. Student recruitment will be made from under-represented groups building on a long track record. Broad outreach will be achieved through collaborations with the global and radiative modeling communities, NESTA-related and other educational outreach efforts, and public lectures. This proposed project does not require field work in the Antarctic.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McConnell, Joseph", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Collaborative Research: Investigating Upper Pleistocene Rapid Climate Change using Continuous, Ultra-High-Resolution Aerosol and Gas Measurements in the WAIS Divide Ice Core", "uid": "p0000287", "west": -112.1115}, {"awards": "0538049 Steig, Eric; 0538520 Thiemens, Mark", "bounds_geometry": "POINT(-112.085 -79.5)", "dataset_titles": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core; WAIS Divide sulfate and nitrate isotopes; WAIS ice core isotope data #387, 385 (full data link not provided)", "datasets": [{"dataset_uid": "609479", "doi": "10.7265/N5BG2KXH", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Thiemens, Mark H.", "repository": "USAP-DC", "science_program": null, "title": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/609479"}, {"dataset_uid": "601007", "doi": "10.15784/601007", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrate; Oxygen Isotope; Sulfate; WAIS Divide; WAIS Divide Ice Core", "people": "Steig, Eric J.; Alexander, Becky", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide sulfate and nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601007"}, {"dataset_uid": "002512", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "WAIS ice core isotope data #387, 385 (full data link not provided)", "url": "http://www.waisdivide.unh.edu/"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "0538520\u003cbr/\u003eThiemens\u003cbr/\u003eThis award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions.", "east": -112.085, "geometry": "POINT(-112.085 -79.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Isotope Ratios; Temperature; Sulfate; West Antarctic; Paleoatmosphere; LABORATORY; Ice Core; Ice Core Data; Mass Independent Fractionation; FIELD SURVEYS; Not provided; Accumulation Rate; Oxygen Isotope; FIELD INVESTIGATION; Ice Core Chemistry; Isotope", "locations": "West Antarctic", "north": -79.5, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky; Steig, Eric J.; Thiemens, Mark H.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "Project website; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.5, "title": "Collaborative Research: Multiple-isotope Analysis of Nitrate and Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000020", "west": -112.085}, {"awards": "0944197 Waddington, Edwin; 0944191 Taylor, Kendrick", "bounds_geometry": "POLYGON((-180 -79,-173.3 -79,-166.6 -79,-159.9 -79,-153.2 -79,-146.5 -79,-139.8 -79,-133.1 -79,-126.4 -79,-119.7 -79,-113 -79,-113 -79.1,-113 -79.2,-113 -79.3,-113 -79.4,-113 -79.5,-113 -79.6,-113 -79.7,-113 -79.8,-113 -79.9,-113 -80,-119.7 -80,-126.4 -80,-133.1 -80,-139.8 -80,-146.5 -80,-153.2 -80,-159.9 -80,-166.6 -80,-173.3 -80,180 -80,150.9 -80,121.8 -80,92.7 -80,63.6 -80,34.5 -80,5.4 -80,-23.7 -80,-52.8 -80,-81.9 -80,-111 -80,-111 -79.9,-111 -79.8,-111 -79.7,-111 -79.6,-111 -79.5,-111 -79.4,-111 -79.3,-111 -79.2,-111 -79.1,-111 -79,-81.9 -79,-52.8 -79,-23.7 -79,5.4 -79,34.5 -79,63.6 -79,92.7 -79,121.8 -79,150.9 -79,-180 -79))", "dataset_titles": "Accumulation Rates from the WAIS Divide Ice Core; WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica; WAIS Divide Multi Track Electrical Measurements; WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "datasets": [{"dataset_uid": "601172", "doi": "10.15784/601172", "keywords": "Antarctic; Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; Wais Project; West Antarctic Ice Sheet", "people": "Fudge, T. J.; Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": null, "title": "WAIS Divide Multi Track Electrical Measurements", "url": "https://www.usap-dc.org/view/dataset/601172"}, {"dataset_uid": "601015", "doi": "10.15784/601015", "keywords": "Antarctica; Depth-Age-Model; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "url": "https://www.usap-dc.org/view/dataset/601015"}, {"dataset_uid": "609591", "doi": "10.7265/N5B56GPJ", "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Fudge, T. J.; Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609591"}, {"dataset_uid": "601004", "doi": "10.15784/601004", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Snow Accumulation; WAIS Divide Ice Core", "people": "Fudge, T. J.; Conway, Howard; Buizert, Christo; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Accumulation Rates from the WAIS Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/601004"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "This award supports a project to help to establish the depth-age chronology and the histories of accumulation and ice dynamics for the WAIS Divide ice core. The depth-age relationship and the histories of accumulation and ice dynamics are coupled. An accurate age scale is needed to infer histories of accumulation rate and ice-thickness change using ice-flow models. In turn, the accumulation-rate history is needed to calculate the age difference of ice to determine the age of the trapped gases. The accumulation history is also needed to calculate atmospheric concentrations of impurities trapped in the ice and is an important characteristic of climate. The history of ice-thickness change is also fundamental to understanding the stability of the WAIS. The primary goals of the WAIS Divide ice core project are to investigate climate forcing by greenhouse gases, the initiation of climate changes, and the stability of the West Antarctic Ice Sheet (WAIS). An accurate age scale is fundamental for achieving these goals. The first objective of this project is to establish an annually resolved depth-age relationship for the past 40,000 years. This will be done by measuring variations in electrical conductivity along the ice core, which are caused by seasonal variations in chemistry. We expect to be able to resolve annual layers back to 40,000 years before present (3,000 m depth) using this method. The second objective is to search for stratigraphic disturbances in the core that would compromise the paleoclimate record. Irregular layering will be identified by measuring the electrical conductivity of the ice in a vertical plan through the core. The third objective is to derive a preliminary chronology for the entire core. For the deeper ice we will use an ice-flow model to interpolate between known age markers, such as dated volcanic horizons and tie points from the methane gas chronology. The fourth objective is to derive a refined chronology simultaneously with histories of accumulation and ice-sheet thickness. An ice-flow model and all available data will be used to formulate an inverse problem, in which we infer the most appropriate histories of accumulation and ice-thickness, together with estimates of uncertainties. The flow model associated with those preferred histories then produces the best estimate of the chronology. The research contributes directly to the primary goals of the West Antarctic Ice Sheet Initiative. The project will help develop the next generation of scientists through the education and training of one Ph.D. student and several undergraduate students. This project will result in instrumentation for measuring the electrical conductivity of ice cores being available at the National Ice Core Lab for other researchers to use on other projects. All collaborators are committed to fostering diversity and currently participate in scientific outreach and most participate in undergraduate education. Outreach will be accomplished through regularly scheduled community and K-12 outreach events at UW, talks and popular writing by the PIs, as well as through our respective press offices.", "east": -111.0, "geometry": "POINT(-112 -79.5)", "instruments": null, "is_usap_dc": true, "keywords": "Ice Core Depth; National Ice Core Lab; Electrical Conductivity; FIELD INVESTIGATION; Not provided", "locations": null, "north": -79.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Conway, Howard; Fudge, T. J.; Taylor, Kendrick C.; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -80.0, "title": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core", "uid": "p0000026", "west": -113.0}, {"awards": "0539578 Alley, Richard; 0539232 Cuffey, Kurt", "bounds_geometry": "POINT(112.083 -79.467)", "dataset_titles": "Grain Size Full Population Dataset from WDC06A Core; Temperature Profile of the West Antarctic Ice Sheet Divide Deep Borehole; Temperature Reconstruction at the West Antarctic Ice Sheet Divide; Updated (2017) bubble number-density, size, shape, and modeled paleoclimate data; WAIS Divide Ice Core Vertical Thin Section Low-resolution Digital Imagery; WAIS Divide Surface and Snow-pit Data, 2009-2013; WDC 06A Mean Grain Size Data", "datasets": [{"dataset_uid": "601079", "doi": "10.15784/601079", "keywords": "Antarctica; Atmosphere; AWS; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Meteorology; Physical Properties; Snow Pit; Temperature; WAIS Divide; WAIS Divide Ice Core; Weatherstation", "people": "Alley, Richard; Fegyveresi, John", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Surface and Snow-pit Data, 2009-2013", "url": "https://www.usap-dc.org/view/dataset/601079"}, {"dataset_uid": "609656", "doi": "10.7265/N5MC8X08", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Fitzpatrick, Joan; Cravens, Eric D.", "repository": "USAP-DC", "science_program": null, "title": "WDC 06A Mean Grain Size Data", "url": "https://www.usap-dc.org/view/dataset/609656"}, {"dataset_uid": "600377", "doi": "10.15784/600377", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrogen; Paleoclimate; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Cuffey, Kurt M.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Temperature Reconstruction at the West Antarctic Ice Sheet Divide", "url": "https://www.usap-dc.org/view/dataset/600377"}, {"dataset_uid": "609655", "doi": "10.7265/N5VX0DG0", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Cravens, Eric D.; Fitzpatrick, Joan", "repository": "USAP-DC", "science_program": null, "title": "Grain Size Full Population Dataset from WDC06A Core", "url": "https://www.usap-dc.org/view/dataset/609655"}, {"dataset_uid": "609550", "doi": "10.7265/N5V69GJW", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Clow, Gary D.; Cuffey, Kurt M.", "repository": "USAP-DC", "science_program": null, "title": "Temperature Profile of the West Antarctic Ice Sheet Divide Deep Borehole", "url": "https://www.usap-dc.org/view/dataset/609550"}, {"dataset_uid": "609654", "doi": "10.7265/N5GM858X", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Photo/video; Photo/Video; Thin Sections; WAIS Divide; WAIS Divide Ice Core", "people": "Cravens, Eric D.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Vertical Thin Section Low-resolution Digital Imagery", "url": "https://www.usap-dc.org/view/dataset/609654"}, {"dataset_uid": "601224", "doi": "10.15784/601224", "keywords": "Antarctic; Antarctica; Bubble Number Density; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; NSF-ICF Microtome and Photography Stage; Paleoclimate; Physical Properties; Snow/ice; Snow/Ice; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Voigt, Donald E.; Fegyveresi, John; Fitzpatrick, Joan; Spencer, Matthew; Alley, Richard", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Updated (2017) bubble number-density, size, shape, and modeled paleoclimate data", "url": "https://www.usap-dc.org/view/dataset/601224"}], "date_created": "Thu, 12 Jan 2017 00:00:00 GMT", "description": "0539578\u003cbr/\u003eAlley \u003cbr/\u003eThis award supports a five-year collaborative project to study the physical-properties of the planned deep ice core and the temperature of the ice in the divide region of the West Antarctic Ice Sheet. The intellectual merit of the proposed research is to provide fundamental information on the state of the ice sheet, to validate the integrity of the climate record, to help reconstruct the climate record, and to understand the flow state and history of the ice sheet. This information will initially be supplied to other investigators and then to the public and to appropriate databases, and will be published in the refereed scientific literature. The objectives of the proposed research are to aid in dating of the core through counting of annual layers, to identify any exceptionally warm intervals in the past through counting of melt layers, to learn as much as possible about the flow state and history of the ice through measurement of size, shape and arrangements of bubbles, clathrate inclusions, grains and their c-axes, to identify any flow disturbances through these indicators, and to learn the history of snow accumulation and temperature from analyses of bubbles and borehole temperatures combined with flow modeling and use of data from other collaborators. These results will then be synthesized and communicated. Failure to examine cores can lead to erroneous identification of flow features as climate changes, so careful examination is required. Independent reconstruction of accumulation rate provides important data on climate change, and improves confidence in interpretation of other climate indicators. Borehole temperatures are useful recorders of temperature history. Flow state and history are important in understanding climate history and potential contribution of ice to sea-level change. By contributing to all of these and additional issues, the proposed research will be of considerable value. The broader impacts of the research include making available to the public improved knowledge on societally central questions involving abrupt climate change and sea-level rise. The project will also contribute to the education of advanced students, will utilize results in education of introductory students, and will make vigorous efforts in outreach, informal science education, and supplying information to policy-makers as requested, thus contributing to a more-informed society.", "east": 112.083, "geometry": "POINT(112.083 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS", "is_usap_dc": true, "keywords": "LABORATORY; WAIS Divide; Ice Core; Temperature Profiles; FIELD SURVEYS; Bubble Number Density; GROUND-BASED OBSERVATIONS; Wais Divide-project", "locations": "WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Fitzpatrick, Joan; Alley, Richard; Fegyveresi, John; Clow, Gary D.; Cuffey, Kurt M.; Cravens, Eric D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Physical Properties of the WAIS Divide Deep Core", "uid": "p0000038", "west": 112.083}, {"awards": "0944671 Wiens, Douglas; 0944794 Winberry, J. Paul", "bounds_geometry": "POLYGON((-163 -83.7,-161.9 -83.7,-160.8 -83.7,-159.7 -83.7,-158.6 -83.7,-157.5 -83.7,-156.4 -83.7,-155.3 -83.7,-154.2 -83.7,-153.1 -83.7,-152 -83.7,-152 -83.8,-152 -83.9,-152 -84,-152 -84.1,-152 -84.2,-152 -84.3,-152 -84.4,-152 -84.5,-152 -84.6,-152 -84.7,-153.1 -84.7,-154.2 -84.7,-155.3 -84.7,-156.4 -84.7,-157.5 -84.7,-158.6 -84.7,-159.7 -84.7,-160.8 -84.7,-161.9 -84.7,-163 -84.7,-163 -84.6,-163 -84.5,-163 -84.4,-163 -84.3,-163 -84.2,-163 -84.1,-163 -84,-163 -83.9,-163 -83.8,-163 -83.7))", "dataset_titles": "Geophysical Study of Ice Stream Stick Slip; Whillans Ice Stream Stick-slip", "datasets": [{"dataset_uid": "000169", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Geophysical Study of Ice Stream Stick Slip", "url": "http://ds.iris.edu/mda/2C/?timewindow=2010-2011"}, {"dataset_uid": "609632", "doi": "10.7265/N5PC309V", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Whillans Ice Stream", "people": "Anandakrishnan, Sridhar; Winberry, Paul; Wiens, Douglas; Alley, Richard", "repository": "USAP-DC", "science_program": null, "title": "Whillans Ice Stream Stick-slip", "url": "https://www.usap-dc.org/view/dataset/609632"}], "date_created": "Wed, 16 Nov 2016 00:00:00 GMT", "description": "This award supports a three-year study of the ongoing deceleration and stick-slip motion of Whillans Ice Stream (WIS), West Antarctica. Understanding the dynamic behavior of ice streams is essential for predicting the future of the West Antarctic Ice Sheet (WAIS). Despite being one of the best-studied ice streams in Antarctica, the surprising flow characteristics of WIS continue to demand interdisciplinary research. Recent estimates indicate that the WIS may stagnate within 50 years, resulting in a significant change to the mass balance of the Siple Coast sector of West Antarctica. The reasons for the ongoing stagnation are not well known, and are possibly linked (causally or coincidentally) to the stick-slip behavior. Our recent work on WIS stick-slip motion suggest that all slip events nucleate from a common location on the ice stream, suggesting that a relatively small (approximately 10 km in diameter) region of the exerts fundamental control over the flow of this large ice stream (100s of km long and 100 kilometers wide). We hypothesize that this is a region of increased bed strength and our measurements will address that hypothesis. We will deploy a series of GPS receivers and seismometers on the ice stream to accurately locate the nucleation region so that a comprehensive ground based geophysical survey can be conducted to determine the physical properties of bed at the nucleation point. The ground geophysical program will consist of reflection seismic and ice-penetrating radar studies that will better constrain the properties of both the hypothesized higher-friction nucleation zone and the surrounding regions. Slip events also generate seismic energy that can be recorded 100s of km away from the ice stream, thus, the GPS and seismometer deployment will also aid us in relating seismic waveforms directly with the rapid motion that occurs during slip events. The increased ability to relate rupture processes with seismic emissions will allow us to use archived seismic records to explore changes in the behavior of WIS during the later half of the 20th century. Broader impacts of this study include improved knowledge ice sheet dynamics, which remain a poorly constrained component of the climate system, thus, limiting our ability to predict the Earth\u0027s response to climate change. The scientific work includes the education of two graduate students and continued training of one post-doctoral scholar, thus helping to train the next generation of polar scientists. We will expose the broader public to polar science through interactions with the media and by take advantaging of programs to include K-12 educators in our field work.", "east": -152.0, "geometry": "POINT(-157.5 -84.2)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "West Antarctic Ice Sheet; Geodesy; GROUND-BASED OBSERVATIONS; Not provided; Seismic; Geodetic Gps Data", "locations": "West Antarctic Ice Sheet", "north": -83.7, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Winberry, Paul; Anandakrishnan, Sridhar; Alley, Richard; Wiens, Douglas", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided", "repo": "IRIS", "repositories": "IRIS; USAP-DC", "science_programs": null, "south": -84.7, "title": "Collaborative Research: Geophysical Study of Ice Stream Stick-slip Dynamics", "uid": "p0000053", "west": -163.0}, {"awards": "1043554 Willenbring, Jane", "bounds_geometry": "POINT(161.5 -77.5)", "dataset_titles": "Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "datasets": [{"dataset_uid": "600379", "doi": "10.15784/600379", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Cosmogenic Radionuclides; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope; Sample/collection Description; Sample/Collection Description; Transantarctic Mountains", "people": "Willenbring, Jane", "repository": "USAP-DC", "science_program": null, "title": "Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "url": "https://www.usap-dc.org/view/dataset/600379"}], "date_created": "Wed, 09 Nov 2016 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to address the question of whether ice surface melting zones developed at high elevations during warm climatic phases in the Transantarctic Mountains. Evidence from sediment cores drilled by the ANDRILL program indicates that open water in the Ross Sea could have been a source of warmth during Pliocene and Pleistocene. The question is whether marine warmth penetrated inland to the ice sheet margins. The glacial record may be ill suited to answer this question, as cold-based glaciers may respond too slowly to register brief warmth. Questions also surround possible orbital controls on regional climate and ice sheet margins. Northern Hemisphere insolation at obliquity and precession timescales is thought to control Antarctic climate through oceanic or atmospheric connections, but new thinking suggests that the duration of Southern Hemisphere summer may be more important. The PIs propose to use high elevation alluvial deposits in the Transantarctic Mountains as a proxy for inland warmth. These relatively young fans, channels, and debris flow levees stand out as visible evidence for the presence of melt water in an otherwise ancient, frozen landscape. Based on initial analyses of an alluvial fan in the Olympus Range, these deposits are sensitive recorders of rare melt events that occur at orbital timescales. For their study they will 1) map alluvial deposits using aerial photography, satellite imagery and GPS assisted field surveys to establish water sources and to quantify parameters effecting melt water production, 2) date stratigraphic sequences within these deposits using OSL, cosmogenic nuclide, and interbedded volcanic ash chronologies, 3) use paired nuclide analyses to estimate exposure and burial times, and rates of deposition and erosion, and 4) use micro and regional scale climate modeling to estimate paleoenvironmental conditions associated with melt events. Broader impacts: This study will produce a record of inland melting from sites adjacent to ice sheet margins to help determine controls on regional climate along margins of the East Antarctic Ice Sheet to aid ice sheet and sea level modeling studies. The proposal will support several graduate and undergraduates. A PhD student will be supported on existing funding. The PIs will work with multiple K 12 schools to conduct interviews and webcasts from Antarctica and they will make follow up visits to classrooms after the field season is complete.", "east": 161.5, "geometry": "POINT(161.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Willenbring, Jane", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.5, "title": "Collaborative Research: Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "uid": "p0000429", "west": 161.5}, {"awards": "1043018 Pollard, David; 1043485 Curtice, Josh; 1043517 Clark, Peter", "bounds_geometry": "POLYGON((163.5 -77.57,163.685 -77.57,163.87 -77.57,164.055 -77.57,164.24 -77.57,164.425 -77.57,164.61 -77.57,164.795 -77.57,164.98 -77.57,165.165 -77.57,165.35 -77.57,165.35 -77.645,165.35 -77.72,165.35 -77.795,165.35 -77.87,165.35 -77.945,165.35 -78.02,165.35 -78.095,165.35 -78.17,165.35 -78.245,165.35 -78.32,165.165 -78.32,164.98 -78.32,164.795 -78.32,164.61 -78.32,164.425 -78.32,164.24 -78.32,164.055 -78.32,163.87 -78.32,163.685 -78.32,163.5 -78.32,163.5 -78.245,163.5 -78.17,163.5 -78.095,163.5 -78.02,163.5 -77.945,163.5 -77.87,163.5 -77.795,163.5 -77.72,163.5 -77.645,163.5 -77.57))", "dataset_titles": "A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea; Ice Sheet Model Output, West Antarctic Ice Sheet Deglaciation", "datasets": [{"dataset_uid": "600123", "doi": "10.15784/600123", "keywords": "Antarctica; Cosmogenic Dating; Ross Sea; Sample/collection Description; Sample/Collection Description; Southern Ocean; WAIS", "people": "Kurz, Mark D.; Curtice, Josh", "repository": "USAP-DC", "science_program": null, "title": "A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea", "url": "https://www.usap-dc.org/view/dataset/600123"}, {"dataset_uid": "609639", "doi": "10.7265/N5NC5Z53", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model", "people": "Pollard, David", "repository": "USAP-DC", "science_program": null, "title": "Ice Sheet Model Output, West Antarctic Ice Sheet Deglaciation", "url": "https://www.usap-dc.org/view/dataset/609639"}], "date_created": "Sat, 15 Oct 2016 00:00:00 GMT", "description": "1043517/Clark This award supports a project to develop a better understanding of the response of the WAIS to climate change. The timing of the last deglaciation of the western Ross Sea will be improved using in situ terrestrial cosmogenic nuclides (3He, 10Be, 14C, 26Al, 36Cl) to date glacial erratics at key areas and elevations along the western Ross Sea coast. A state-of-the art ice sheet-shelf model will be used to identify mechanisms of deglaciation of the Ross Sea sector of WAIS. The model results and forcing will be compared with observations including the new cosmogenic data proposed here, with the aim of better determining and understanding the history and causes of WAIS deglaciation in the Ross Sea. There is considerable uncertainty, however, in the history of grounding line retreat from its last glacial maximum position, and virtually nothing is known about the timing of ice- surface lowering prior to ~10,000 years ago. Given these uncertainties, we are currently unable to assess one of the most important questions regarding the last deglaciation of the global ice sheets, namely as to whether the Ross Sea sector of WAIS contributed significantly to meltwater pulse 1A (MWP-1A), an extraordinarily rapid (~500-year duration) episode of ~20 m sea-level rise that occurred ~14,500 years ago. The intellectual merit of this project is that recent observations of startling changes at the margins of the Greenland and Antarctic ice sheets indicate that dynamic responses to warming may play a much greater role in the future mass balance of ice sheets than considered in current numerical projections of sea level rise. The broader impacts of this work are that it has direct societal relevance to developing an improved understanding of the response of the West Antarctic ice sheet to current and possible future environmental changes including the sea-level response to glacier and ice sheet melting due to global warming. The PI will communicate results from this project to a variety of audiences through the publication of peer-reviewed papers and by giving talks to public audiences. Finally the project will support a graduate student and undergraduate students in all phases of field-work, laboratory work and data interpretation.", "east": 165.35, "geometry": "POINT(164.425 -77.945)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e DATA ANALYSIS \u003e ENVIRONMENTAL MODELING \u003e COMPUTER", "is_usap_dc": true, "keywords": "Ocean Depth; Not provided; Bed Elevation; Model Output; Sea Level Rise; Surface Accumulation Rate; Surface Melt Rate; Ocean Melt Rate; Total Ice Volume; Modeling; Calving Rate; Total Ice Area; LABORATORY", "locations": null, "north": -77.57, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pollard, David; Curtice, Josh; Clark, Peter; Kurz, Mark D.", "platforms": "Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.32, "title": "Collaborative Research: A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea", "uid": "p0000194", "west": 163.5}, {"awards": "1043092 Steig, Eric; 1043167 White, James", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "Resampling of Deep Polar Ice Cores using Information Theory; Seasonal temperatures in West Antarctica during the Holocene ; Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core; WAIS Divide Ice Core Discrete CH4 (80-3403m)", "datasets": [{"dataset_uid": "600169", "doi": "10.15784/600169", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; Snow Accumulation; WAIS Divide; WAIS Divide Ice Core", "people": "Morris, Valerie; Jones, Tyler R.; White, James; Vaughn, Bruce", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/600169"}, {"dataset_uid": "601741", "doi": "10.15784/601741", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; WAIS", "people": "Brook, Edward J.; Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Discrete CH4 (80-3403m)", "url": "https://www.usap-dc.org/view/dataset/601741"}, {"dataset_uid": "601603", "doi": "10.15784/601603", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Seasonality; Seasonal Temperatures; Temperature; Water Isotopes; West Antarctic Ice Sheet", "people": "Jones, Tyler R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal temperatures in West Antarctica during the Holocene ", "url": "https://www.usap-dc.org/view/dataset/601603"}, {"dataset_uid": "601365", "doi": "10.15784/601365", "keywords": "Antarctica; Delta 18O; Isotope; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Jones, Tyler R.; Vaughn, Bruce; White, James; Morris, Valerie; Garland, Joshua", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Resampling of Deep Polar Ice Cores using Information Theory", "url": "https://www.usap-dc.org/view/dataset/601365"}, {"dataset_uid": "601274", "doi": "10.15784/601274", "keywords": "Antarctica; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Jones, Tyler R.; Bradley, Elizabeth; Morris, Valerie; Price, Michael; White, James; Vaughn, Bruce; Garland, Joshua", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/601274"}], "date_created": "Thu, 15 Sep 2016 00:00:00 GMT", "description": "Steig/1043092 This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY", "locations": null, "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "White, James; Vaughn, Bruce; Jones, Tyler R.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "uid": "p0000078", "west": -112.08}, {"awards": "1141877 Aronson, Richard", "bounds_geometry": "POLYGON((-111.18 -49.98,-105.429 -49.98,-99.678 -49.98,-93.927 -49.98,-88.176 -49.98,-82.425 -49.98,-76.674 -49.98,-70.923 -49.98,-65.172 -49.98,-59.421 -49.98,-53.67 -49.98,-53.67 -52.826,-53.67 -55.672,-53.67 -58.518,-53.67 -61.364,-53.67 -64.21,-53.67 -67.056,-53.67 -69.902,-53.67 -72.748,-53.67 -75.594,-53.67 -78.44,-59.421 -78.44,-65.172 -78.44,-70.923 -78.44,-76.674 -78.44,-82.425 -78.44,-88.176 -78.44,-93.927 -78.44,-99.678 -78.44,-105.429 -78.44,-111.18 -78.44,-111.18 -75.594,-111.18 -72.748,-111.18 -69.902,-111.18 -67.056,-111.18 -64.21,-111.18 -61.364,-111.18 -58.518,-111.18 -55.672,-111.18 -52.826,-111.18 -49.98))", "dataset_titles": "Climate Change and Predatory Invasion of the Antarctic Benthos; Expedition Data; Material properties of the exoskeleton of Paralomis birsteini", "datasets": [{"dataset_uid": "001417", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1310"}, {"dataset_uid": "601109", "doi": "10.15784/601109", "keywords": "Antarctica; Biota; Callinectes; Exoskeleton; Fish; Glaciers/ice Sheet; Glaciers/Ice Sheet; Paralomis", "people": "Steffel, Brittan", "repository": "USAP-DC", "science_program": null, "title": "Material properties of the exoskeleton of Paralomis birsteini", "url": "https://www.usap-dc.org/view/dataset/601109"}, {"dataset_uid": "600385", "doi": "10.15784/600385", "keywords": "Antarctica; Antarctic Peninsula; Anvers Island; Benthos; Biota; Camera Tow; LMG1502; Marguerite Bay; NBP1002; NBP1310; Oceans; Photo/video; Photo/Video; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Aronson, Richard", "repository": "USAP-DC", "science_program": null, "title": "Climate Change and Predatory Invasion of the Antarctic Benthos", "url": "https://www.usap-dc.org/view/dataset/600385"}, {"dataset_uid": "600171", "doi": "10.15784/600171", "keywords": "Antarctica; Antarctic Peninsula; Anvers Island; Benthos; Biota; Camera Tow; LMG1502; Marguerite Bay; NBP1002; NBP1310; Oceans; Photo/video; Photo/Video; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Aronson, Richard", "repository": "USAP-DC", "science_program": null, "title": "Climate Change and Predatory Invasion of the Antarctic Benthos", "url": "https://www.usap-dc.org/view/dataset/600171"}], "date_created": "Wed, 14 Sep 2016 00:00:00 GMT", "description": "Elevated temperatures and ocean acidification are both threatening the Southern Ocean. The effects of these environmental changes are poorly understood, but preliminary data suggest that they are driving a biological invasion. Specifically, large populations of skeleton-crushing king crabs, Paralomis birsteini, have been detected off Marguerite Bay on the West Antarctic Peninsula. These crabs appear to be invading the continental shelf region where benthic communities have evolved in the absence of such top-predators. Thus, this invasion could result in a wholesale restructuring of the Antarctic benthic ecosystem. The proposed work seeks to document this invasion and better understand the effects of the introduction of P. birsteini on the ecology of this region. A towed underwater vehicle will be used to photographically image communities, and communities with and without P. birsteini will be compared quantitatively. Additionally, crabs will trapped and various aspects of their morphology and physiology will be assessed. This research is unique in that it will document a biological invasion in real-time and it will therefore enhance our general understandings of the drivers of invasion and resilience in biological communities. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. This project will support the research and training of undergraduate and graduate students and will foster an international collaboration with British scientists. Researchers on this project will participate in outreach thorough the development of K-12 curricular materials.", "east": -53.67, "geometry": "POINT(-82.425 -64.21)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "R/V NBP; Not provided", "locations": null, "north": -49.98, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Aronson, Richard", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -78.44, "title": "Collaborative Research: Climate Change and Predatory Invasion of the Antarctic Benthos", "uid": "p0000303", "west": -111.18}, {"awards": "1043580 Reusch, David", "bounds_geometry": "POLYGON((-180 -47,-144 -47,-108 -47,-72 -47,-36 -47,0 -47,36 -47,72 -47,108 -47,144 -47,180 -47,180 -51.3,180 -55.6,180 -59.9,180 -64.2,180 -68.5,180 -72.8,180 -77.1,180 -81.4,180 -85.7,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.7,-180 -81.4,-180 -77.1,-180 -72.8,-180 -68.5,-180 -64.2,-180 -59.9,-180 -55.6,-180 -51.3,-180 -47))", "dataset_titles": "Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "datasets": [{"dataset_uid": "600166", "doi": "10.15784/600166", "keywords": "Antarctica; Atmosphere; Climate Model; Meteorology; Surface Melt", "people": "Reusch, David", "repository": "USAP-DC", "science_program": null, "title": "Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "url": "https://www.usap-dc.org/view/dataset/600166"}, {"dataset_uid": "600386", "doi": "10.15784/600386", "keywords": "Antarctica; Atmosphere; Atmospheric Model; Climate Model; Meteorology; Paleoclimate", "people": "Reusch, David", "repository": "USAP-DC", "science_program": null, "title": "Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "url": "https://www.usap-dc.org/view/dataset/600386"}], "date_created": "Thu, 28 Jul 2016 00:00:00 GMT", "description": "The presence of ice ponds from surface melting of glacial ice can be a significant threshold in assessing the stability of ice sheets, and their overall response to a warming climate. Snow melt has a much reduced albedo, leading to additional seasonal melting from warming insolation. Water run-off not only contributes to the mass loss of ice sheets directly, but meltwater reaching the glacial ice bed may lubricate faster flow of ice sheets towards the ocean. Surficial meltwater may also reach the grounding lines of glacial ice through the wedging open of existing crevasses. The occurrence and amount of meltwater refreeze has even been suggested as a paleo proxy of near-surface atmospheric temperature regimes. Using contemporary remote sensing (microwave) satellite assessment of surface melt occurrence and extent, the predictive skill of regional meteorological models and reanalyses (e.g. WRF, ERA-Interim) to describe the synoptic conditions favourable to surficial melt is to be investigated. Statistical approaches and pattern recognition techniques are argued to provide a context for projecting future ice sheet change. The previous Intergovernmental Panel on Climate Change (IPCC AR4) commented on our lack of understanding of ice-sheet mass balance processes in polar regions and the potential for sea-level change. The IPPC suggested that the forthcoming AR5 efforts highlight regional cryosphere modeling efforts, such as is proposed here.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -47.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Reusch, David; Lampkin, Derrick", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "uid": "p0000447", "west": -180.0}, {"awards": "1141973 Tedesco, Marco", "bounds_geometry": "POLYGON((-94.7374 -56.9464,-89.23679 -56.9464,-83.73618 -56.9464,-78.23557 -56.9464,-72.73496 -56.9464,-67.23435 -56.9464,-61.73374 -56.9464,-56.23313 -56.9464,-50.73252 -56.9464,-45.23191 -56.9464,-39.7313 -56.9464,-39.7313 -59.19838,-39.7313 -61.45036,-39.7313 -63.70234,-39.7313 -65.95432,-39.7313 -68.2063,-39.7313 -70.45828,-39.7313 -72.71026,-39.7313 -74.96224,-39.7313 -77.21422,-39.7313 -79.4662,-45.23191 -79.4662,-50.73252 -79.4662,-56.23313 -79.4662,-61.73374 -79.4662,-67.23435 -79.4662,-72.73496 -79.4662,-78.23557 -79.4662,-83.73618 -79.4662,-89.23679 -79.4662,-94.7374 -79.4662,-94.7374 -77.21422,-94.7374 -74.96224,-94.7374 -72.71026,-94.7374 -70.45828,-94.7374 -68.2063,-94.7374 -65.95432,-94.7374 -63.70234,-94.7374 -61.45036,-94.7374 -59.19838,-94.7374 -56.9464))", "dataset_titles": "Enhanced Spatial Resolution Surface Melting over the Antarctic Peninsula (1958 - to date) from a Regional Climate Model Validated through Remote Sensing Observations", "datasets": [{"dataset_uid": "600160", "doi": "10.15784/600160", "keywords": "Antarctica; Atmosphere; Climate; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meteorology; Model", "people": "Tedesco, Marco", "repository": "USAP-DC", "science_program": null, "title": "Enhanced Spatial Resolution Surface Melting over the Antarctic Peninsula (1958 - to date) from a Regional Climate Model Validated through Remote Sensing Observations", "url": "https://www.usap-dc.org/view/dataset/600160"}], "date_created": "Fri, 10 Jun 2016 00:00:00 GMT", "description": "1141973/Tedesco This award supports a project to generate first-time validated enhanced spatial resolution (5-10 km) maps of surface melting over the Antarctic Peninsula for the period 1958 - to date from the outputs of a regional climate model and different downscaling techniques. These maps will be assessed and validated through new high spatial resolution (2.25 km) surface melting maps obtained from the QuikSCAT satellite for the period 1999 - 2009. The intellectual merit of this work is that it would be the first time that the outputs of a regional climate model would be used to study surface melting over Antarctica at such high spatial resolution and the first time that such results are validated by means of an observational tool that has such a large spatial coverage and high spatial resolution. The results generated in this study would also provide a first-time opportunity to study the melt distribution over the Peninsula and its correlation with climate drivers, such as the Southern Annual Mode (SAM) and the El Nino-Southern Oscillation (ENSO) at these unprecedented spatial scales. The enhanced resolution melting maps will also offer a unique opportunity to study melting trends and patterns over specific regions of the Peninsula, such as the Wilkins and the Larsen A and B ice shelves and evaluate whether the extreme melting observed during the recent collapses was unprecedented over the + 50 years. The broader impacts of the project are that it will integrate research and education by fully supporting one female undergrad student, a PhD student and partially supporting a PostDoc. The work will be done at a minority-serving institution and the PhD student who worked on the development of the high-resolution melting data set from QuikSCAT will become the PostDoc who will work on this project. Teaching and learning will be supported by incorporating research results into graduate and undergrad level courses and will be disseminated over the web and through appropriate channels. Results from this project will also benefit the society at large as they will improve our understanding of the links between atmospheric patterns and surface melting and they will contribute to improving estimates of sea level rise from the Antarctica continent.", "east": -39.7313, "geometry": "POINT(-67.23435 -68.2063)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -56.9464, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Tedesco, Marco", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.4662, "title": "Enhanced Spatial Resolution Surface Melting over the Antarctic Peninsula (1958 - to date) from a Regional Climate Model Validated through Remote Sensing Observations", "uid": "p0000313", "west": -94.7374}, {"awards": "1043750 Chen, Jianli", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "datasets": [{"dataset_uid": "600159", "doi": "10.15784/600159", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; GRACE; Potential Field; Satellite Data", "people": "Chen, Jianli", "repository": "USAP-DC", "science_program": null, "title": "Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "url": "https://www.usap-dc.org/view/dataset/600159"}], "date_created": "Fri, 13 May 2016 00:00:00 GMT", "description": "1043750/Chen This award supports a project to improve the estimate of long-term and inter-annual variability of Antarctic ice sheet mass balance at continental, regional, and catchment scales, using satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and other geodetic measurements. The work will improve the quantification of long-term mass change rates over Antarctica using GRACE gravity data with a longer record and newer generation(s) of products and will develop advanced numerical forward modeling techniques that can accurately correct leakage effects associated with GRACE data processing, and significantly improve spatial resolution of GRACE mass rate estimates over Antarctica. The work will also contribute to a better understanding of crustal uplift rates due to postglacial rebound (PGR) and present day ice load change over Antarctica via PGR models, GPS measurements, and combined analysis of GRACE and ICESat elevation changes. Inter-annual variations of ice mass over Antarctica will be investigated at continental and catchment scales and connections to regional climate change will be studied. The major deliverables from this study will be improved assessments of ice mass balance for the entire Antarctic ice sheet and potential contribution to global mean sea level rise. The work will also provide estimates of regional ice mass change rates over Antarctica, with a focus along the coast in the Amundsen Sea Embayment, the Peninsula in West Antarctica, and in Wilkes Land and Victoria Land in East Antarctica. Estimates of inter-annual ice mass change over Antarctica at various spatial scales, and assessments of uncertainty of GRACE ice rate estimates and PGR models errors over Antarctica will also be made. The intellectual merits of the proposed investigation include 1) providing improved assessments of Antarctic ice mass balance at different temporal and spatial scales with unprecedented accuracy, an important contribution to broad areas of polar science research; 2) combining high accuracy GPS vertical uplift measurements and PGR models to better quantify long-term crust uplift effects that are not distinguishable from ice mass changes by GRACE; and 3) unifying the work of several investigations at the forefront of quantifying ice sheet and glacier mass balance and crustal uplift based on a variety of modern space geodetic observations. The broader impacts include the fact that the project will actively involve student participation and training, through the support of two graduate students. In addition the project will contribute to general education and public outreach (E/PO) activities and the results from this investigation will help inspire future geoscientists and promote public awareness of significant manifestations of climate change.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e LASER RANGING \u003e GRACE LRR", "is_usap_dc": true, "keywords": "SATELLITES; GRACE; Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Chen, Jianli; Wilson, Clark; Blankenship, Donald D.; Tapley, Byron", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e NASA EARTH SYSTEM SCIENCE PATHFINDER \u003e GRACE; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "uid": "p0000415", "west": -180.0}, {"awards": "0838936 Brook, Edward J.; 0839031 Severinghaus, Jeffrey", "bounds_geometry": "POINT(161.75 -77.75)", "dataset_titles": "Measurements of 14C-methane for the Younger Dryas - Preboreal Transition from Taylor Glacier, Antarctica; Measurements of in situ cosmogenic 14C from Taylor Glacier, Antarctica; Taylor Glacier chemistry data and Taylor Dome TD2015 time scale; Taylor Glacier CO2 record; Taylor Glacier Gas Isotope Data", "datasets": [{"dataset_uid": "601029", "doi": "10.15784/601029", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Critical Zone; Geochemistry; Methane; Paleoclimate; Sample/collection Description; Sample/Collection Description; Solid Earth; Taylor Glacier; Transantarctic Mountains; Younger Dryas", "people": "Severinghaus, Jeffrey P.; Petrenko, Vasilii", "repository": "USAP-DC", "science_program": null, "title": "Measurements of 14C-methane for the Younger Dryas - Preboreal Transition from Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601029"}, {"dataset_uid": "601103", "doi": "10.15784/601103", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Horizontal Ice Core; Ice Core Records; Taylor Dome; Taylor Dome Ice Core", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Taylor Glacier chemistry data and Taylor Dome TD2015 time scale", "url": "https://www.usap-dc.org/view/dataset/601103"}, {"dataset_uid": "600165", "doi": "10.15784/600165", "keywords": "Antarctica; Cosmogenic; Geochemistry; Ice Core Records; Paleoclimate; Radiocarbon; Taylor Glacier; Transantarctic Mountains", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Measurements of in situ cosmogenic 14C from Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600165"}, {"dataset_uid": "601033", "doi": "10.15784/601033", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciology; Ice Core Records; Isotope; Solid Earth; Taylor Glacier; Transantarctic Mountains", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Taylor Glacier Gas Isotope Data", "url": "https://www.usap-dc.org/view/dataset/601033"}, {"dataset_uid": "000158", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Taylor Glacier CO2 record", "url": "ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/taylor/taylor2016d13co2.txt"}], "date_created": "Tue, 29 Mar 2016 00:00:00 GMT", "description": "Severinghaus/0839031 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to develop a precise gas-based chronology for an archive of large-volume samples of the ancient atmosphere, which would enable ultra-trace gas measurements that are currently precluded by sample size limitations of ice cores. The intellectual merit of the proposed work is that it will provide a critical test of the \"clathrate hypothesis\" that methane clathrates contributed to the two abrupt atmospheric methane concentration increases during the last deglaciation 15 and 11 kyr ago. This approach employs large volumes of ice (\u003e1 ton) to measure carbon-14 on past atmospheric methane across the abrupt events. Carbon-14 is an ideal discriminator of fossil sources of methane to the atmosphere, because most methane sources (e.g., wetlands, termites, biomass burning) are rich in carbon-14, whereas clathrates and other fossil sources are devoid of carbon-14. The proposed work is a logical extension to Taylor Glacier, Antarctica, of an approach pioneered at the margin of the Greenland ice sheet over the past 7 years. The Greenland work found higher-than-expected carbon-14 values, likely due in part to contaminants stemming from the high impurity content of Greenland ice and the interaction of the ice with sediments from the glacier bed. The data also pointed to the possibility of a previously unknown process, in-situ cosmogenic production of carbon-14 methane (radiomethane) in the ice matrix. Antarctic ice in Taylor Glacier is orders of magnitude cleaner than the ice at the Greenland site, and is much colder and less stratigraphically disturbed, offering the potential for a clear resolution of this puzzle and a definitive test of the cosmogenic radiomethane hypothesis. Even if cosmogenic radiomethane in ice is found, it still may be possible to reconstruct atmospheric radiomethane with a correction enabled by a detailed understanding of the process, which will be sought by co-measuring carbon-14 in carbon monoxide and carbon dioxide. The broader impacts of the proposed work are that the clathrate test may shed light on the stability of the clathrate reservoir and its potential for climate feedbacks under human-induced warming. Development of Taylor Glacier as a \"horizontal ice core\" would provide a community resource for other researchers. Education of one postdoc, one graduate student, and one undergraduate, would add to human resources. This award has field work in Antarctica.", "east": 161.75, "geometry": "POINT(161.75 -77.75)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; Not provided; USAP-DC", "locations": null, "north": -77.75, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Brook, Edward J.; Severinghaus, Jeffrey P.", "platforms": "Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "NCEI; USAP-DC", "science_programs": null, "south": -77.75, "title": "Collaborative Research: A \"Horizontal Ice Core\" for Large-Volume Samples of the Past Atmosphere, Taylor Glacier, Antarctica", "uid": "p0000099", "west": 161.75}, {"awards": "1142162 Stone, John", "bounds_geometry": "POLYGON((-104.14 -81.07,-102.24 -81.07,-100.34 -81.07,-98.44 -81.07,-96.54 -81.07,-94.64 -81.07,-92.74 -81.07,-90.84 -81.07,-88.94 -81.07,-87.04 -81.07,-85.14 -81.07,-85.14 -81.207,-85.14 -81.344,-85.14 -81.481,-85.14 -81.618,-85.14 -81.755,-85.14 -81.892,-85.14 -82.029,-85.14 -82.166,-85.14 -82.303,-85.14 -82.44,-87.04 -82.44,-88.94 -82.44,-90.84 -82.44,-92.74 -82.44,-94.64 -82.44,-96.54 -82.44,-98.44 -82.44,-100.34 -82.44,-102.24 -82.44,-104.14 -82.44,-104.14 -82.303,-104.14 -82.166,-104.14 -82.029,-104.14 -81.892,-104.14 -81.755,-104.14 -81.618,-104.14 -81.481,-104.14 -81.344,-104.14 -81.207,-104.14 -81.07))", "dataset_titles": "Cosmogenic nuclide data at ICE-D; Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "datasets": [{"dataset_uid": "200299", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "600162", "doi": "10.15784/600162", "keywords": "Antarctica; Be-10; Chemistry:rock; Chemistry:Rock; Cosmogenic Dating; Glaciology; Nunataks; Sample/collection Description; Sample/Collection Description; Solid Earth; Whitmore Mountains", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "url": "https://www.usap-dc.org/view/dataset/600162"}], "date_created": "Wed, 16 Mar 2016 00:00:00 GMT", "description": "1142162/Stone This award supports a project to conduct a reconnaissance geological and radar-sounding study of promising sites in West Antarctica as a prelude to a future project to conduct subglacial cosmogenic nuclide measurements. Field work will take place in the Whitmore Mountains, close to the WAIS divide, and on the Nash and Pirrit Hills, downflow from the divide in the Weddell Sea drainage. At each site geological indicators of higher (and lower) ice levels in the past will be mapped and evidence of subglacial erosion or its absence will be documented. Elevation transects of both glacial erratics and adjacent bedrock samples will be collected to establish the timing of recent deglaciation at the sites and provide a complement to similar measurements on material from depth transects obtained by future subglacial drilling. At each site, bedrock ridges will be traced into the subsurface with closely-spaced ice-penetrating radar surveys, using a combination of instruments and frequencies to obtain meter-scale surface detail, using synthetic aperture techniques. Collectively the results will define prospective sites for subglacial sampling, and maximize the potential information to be obtained from such samples in future studies. The intellectual merit of this project is that measurements of cosmogenic nuclides in subglacial bedrock hold promise for resolving the questions of whether the West Antarctic ice sheet collapsed completely in the past, whether it is prone to repeated large deglaciations, and if so, what is their magnitude and frequency. Such studies will require careful choice of targets, to locate sites where bedrock geology is favorable, cosmogenic nuclide records are likely to have been protected from subglacial erosion, and the local ice-surface response is indicative of large-scale ice sheet behavior. The broader impacts of this work include helping to determine whether subglacial surfaces in West Antarctica were ever exposed to cosmic rays, which will provide unambiguous evidence for or against a smaller ice sheet in the past. This is an important step towards establishing whether the WAIS is vulnerable to collapse in future, and will ultimately help to address uncertainty in forecasting sea level change. The results will also provide ground truth for models of ice-sheet dynamics and long-term ice sheet evolution, and will help researchers use these models to identify paleoclimate conditions responsible for WAIS deglaciation. The education and training of students (both undergraduate and graduate students) will play an important role in the project, which will involve Antarctic fieldwork, technically challenging labwork, data collection and interpretation, and communication of the outcome to scientists and the general public.", "east": -85.14, "geometry": "POINT(-94.64 -81.755)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided; Antarctica; ICE SHEETS", "locations": "Antarctica", "north": -81.07, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John; Conway, Howard; Winebrenner, Dale", "platforms": "Not provided", "repo": "ICE-D", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -82.44, "title": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "uid": "p0000335", "west": -104.14}, {"awards": "1043649 Hock, Regine", "bounds_geometry": null, "dataset_titles": "King George and Livingston Islands: Velocities and Digital Elevation Model", "datasets": [{"dataset_uid": "609667", "doi": "10.7265/N5R49NR1", "keywords": "Antarctica; Antarctic Peninsula; Digital Elevation Model; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness; Ice Velocity", "people": "Hock, Regine; Osmanoglu, Batuhan", "repository": "USAP-DC", "science_program": null, "title": "King George and Livingston Islands: Velocities and Digital Elevation Model", "url": "https://www.usap-dc.org/view/dataset/609667"}], "date_created": "Wed, 17 Feb 2016 00:00:00 GMT", "description": "1043649/Braun This award supports a project to determine the current mass balance of selected glaciers of the Western Antarctic Peninsula (WAP) and adjacent islands, including King George Island and Livingston Island. A major goal is to discriminate the climatic and dynamic components of the current mass budget. The dynamic component will be assessed using a flux gate approach. Glacier velocity fields will be derived by offset tracking on repeat SAR satellite imagery, and ice thicknesses across grounding lines or near terminus will be approximated from a new methods based on mass continuity. The surface mass balance will be computed from a spatially distributed temperature-index mass-balance model forced by temperature and precipitation data from regional climate models. Our results will provide improved mass budget estimates of Western Antarctic Peninsula glaciers and a more thorough understanding of the ratio between the climatic and dynamic components. The techniques to be developed will be applicable to other glaciers in the region allowing regional scale mass budgets to be derived. The broader impacts of this work are that glacier wastage is currently the most important contributor to global sea level rise and the Antarctic Peninsula has been identified as one of the largest single contributors. Future sea-level rise has major societal, economic and ecological implications. The activity will foster new partnerships through collaboration with European and South American colleagues. The project will form the base of of a postdoctoral research fellowship. It will also provide training of undergraduate and graduate students through inclusion of data and results in course curriculums.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e PALSAR", "is_usap_dc": true, "keywords": "ALOS; Digital Elevation Model", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology", "paleo_time": null, "persons": "Hock, Regine; Osmanoglu, Batuhan", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e ADVANCED LAND OBSERVING SATELLITE (ALOS) \u003e ALOS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Contribution of Western Antarctic Peninsula glaciers to sea level rise: Separation of the dynamic and climatic components", "uid": "p0000054", "west": null}, {"awards": "1043518 Brook, Edward J.", "bounds_geometry": "POINT(-112.08648 -79.46763)", "dataset_titles": "Continuous, Ultra-high Resolution WAIS-Divide Ice Core Methane Record 9.8-67.2 ka BP; Early Holocene methane records from Siple Dome, Antarctica; Methan record", "datasets": [{"dataset_uid": "601055", "doi": "10.15784/601055", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Yang, Ji-Woong; Ahn, Jinho", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Early Holocene methane records from Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601055"}, {"dataset_uid": "609628", "doi": "10.7265/N5JM27K4", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph; Brook, Edward J.; Rhodes, Rachel", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Continuous, Ultra-high Resolution WAIS-Divide Ice Core Methane Record 9.8-67.2 ka BP", "url": "https://www.usap-dc.org/view/dataset/609628"}, {"dataset_uid": "000176", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Methan record", "url": "https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/ice-core"}, {"dataset_uid": "601055", "doi": "10.15784/601055", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Ahn, Jinho; Yang, Ji-Woong", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Early Holocene methane records from Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601055"}], "date_created": "Tue, 12 Jan 2016 00:00:00 GMT", "description": "1043500/Sowers This award supports a project to develop a 50 yr resolution methane data set that will play a pivotal role in developing the WAIS Divide timescale as well as providing a common stratigraphic framework for comparing climate records from Greenland and West Antarctica. Even higher resolution data are proposed for key intervals to assist in precisely defining the phasing of abrupt climate change between the hemispheres. Concurrent analysis of a suit of samples from both the WAIS Divide and GISP-2 cores throughout the last 110,000 years is also proposed, to establish the interpolar methan (CH4) gradient that will be used to identify geographic areas responsible for the climate related methane emission changes. The intellectual merit of the proposed work is that it will provide chronological control needed to examine the timing of changes in climate proxies, and critical chronological ties to the Greenland ice core records via methane variations. One main objective is to understand the interpolar timing of millennial-scale climate change. This is an important scientific goal relevant to understanding climate change mechanisms in general. The proposed work will help establish a chronological framework for addressing these issues. In addition, this proposal addresses the question of what methane sources were active during the ice age, through the work on the interpolar methane gradient. This work is directed at the fundamental question of what part of the biosphere controlled past methane variations, and is important for developing more sophisticated understanding of those variations. The broader impacts of the work are that the ultra-high resolution CH4 record will directly benefit all ice core paleoclimate research and the chronological refinements will impact paleoclimate studies that rely on ice core timescales for correlation purposes. The project will support both graduate and undergraduate students and the PIs will participate in outreach to the public.", "east": -112.08648, "geometry": "POINT(-112.08648 -79.46763)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e INFRARED LASER SPECTROSCOPY", "is_usap_dc": true, "keywords": "WAIS Divide; Not provided; LABORATORY; Wais Divide-project; Methane Concentration", "locations": "WAIS Divide", "north": -79.46763, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Rhodes, Rachel; Brook, Edward J.; McConnell, Joseph", "platforms": "Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "NCEI; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.46763, "title": "Collaborative Research: Completing an ultra-high resolution methane record from the WAIS Divide ice core", "uid": "p0000185", "west": -112.08648}, {"awards": "0948247 Pettit, Erin", "bounds_geometry": "POINT(-123.35 -75.1)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 06 Jan 2016 00:00:00 GMT", "description": "Pettit/0948247\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study of the relationship between fabric and climate for the ice near the EPICA Dome C ice core site, East Antarctica. The work builds on an ongoing study at Siple Dome, West Antarctica and takes advantage of collaborations with European scientists and access to the Dome C borehole to make measurements of sonic velocity. The intellectual merit of the project is that a better understanding of how fabric preserves past climate information can improve models of the ice flow near ice core sites and the interpreta-tion of ice core data (particularly paleo-accumulation), and it may allow us to extract climate information directly from fabric data. In addition, because ice deformation is sensitive to the orientation of crystals, ice flow patterns are sensitive to the fabric. Thus, variations in the fabric between glacial and interglacial ice can affect how ice deforms and how fabric in the ice sheet develops. The Dome C site is particularly important for answering these questions, because the ice core shows evidence of eight glacial cycles, not just one as found at Siple Dome or the Greenland sites. The research will improve the understanding of the proxy relationship between sonic-velocity data and fabric; will help to model the pattern of ice flow caused by the fabric variation between glacial and interglacial time periods using these data, existing ice core chemistry and existing and new thin section data, improved surface strain data, and borehole deformation data; and will help to better understand the positive feedback mechanism that enhances fabric (and corresponding rheological) variability through a focused study of several climate transitions and the associated fabric changes. Borehole compressional-wave sonic-velocity will be measured which will complement the sonic-velocity data that already exist for boreholes in Greenland and West Antarctica. These will be the first sonic-velocity measurements in East Antarctica and the first measurements that extend for more than a single glacial/interglacial transition. The project will ultimately contribute to better interpretation of ice core records for both paleoclimate studies and for ice flow history, both of which connect to the broader questions of the role of ice in the climate system. This project will also strengthen the international collaborations within the paleoclimate and ice sheet modeling communities. This project will partially support a graduate student at the University of Alaska Fairbanks who is currently working on modeling ice including anisotropy and it will support the growth of a young scientist through a Post-Doc position. This Post Doc will gain important experience collaborating with the EPICA scientists in studying the climate-fabric relationship. Erin Pettit is active in field-science education for high school students, under-graduates, teachers, and adults. This project will help support the continued development and enhancement of Girls on Ice a program that encourages young women to explore science and the natural world.", "east": -123.35, "geometry": "POINT(-123.35 -75.1)", "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY; Crystals; Deformation; FIELD INVESTIGATION; Model; Sonic Logger; Ice Flow; Rheology; FIELD SURVEYS; Borehole; Climate; Ice Fabric; Antarctica; Interglacial", "locations": "Antarctica", "north": -75.1, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Hansen, Sharon", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -75.1, "title": "The Relationship between Climate and Ice Rheology at Dome C, East Antarctica", "uid": "p0000708", "west": -123.35}, {"awards": "1043761 Young, Duncan", "bounds_geometry": "POLYGON((-145 -74,-141.6 -74,-138.2 -74,-134.8 -74,-131.4 -74,-128 -74,-124.6 -74,-121.2 -74,-117.8 -74,-114.4 -74,-111 -74,-111 -74.6,-111 -75.2,-111 -75.8,-111 -76.4,-111 -77,-111 -77.6,-111 -78.2,-111 -78.8,-111 -79.4,-111 -80,-114.4 -80,-117.8 -80,-121.2 -80,-124.6 -80,-128 -80,-131.4 -80,-134.8 -80,-138.2 -80,-141.6 -80,-145 -80,-145 -79.4,-145 -78.8,-145 -78.2,-145 -77.6,-145 -77,-145 -76.4,-145 -75.8,-145 -75.2,-145 -74.6,-145 -74))", "dataset_titles": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE) Airborne VHF Radar Transects: 2012/2013 and 2014/2015; Gravity disturbance data over central Marie Byrd Land, West Antarctica (GIMBLE.GGCMG2); Ice thickness and related data over central Marie Byrd Land, West Antarctica (GIMBLE.GR2HI2); Magnetic anomaly data over central Marie Byrd Land, West Antarctica (GIMBLE.GMGEO2)", "datasets": [{"dataset_uid": "601002", "doi": "10.15784/601002", "keywords": "Antarctica; Gimble; Glaciers/ice Sheet; Glaciers/Ice Sheet; Magnetic; Marie Byrd Land; Navigation; Potential Field; Solid Earth", "people": "Holt, John W.; Blankenship, Donald D.; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "Magnetic anomaly data over central Marie Byrd Land, West Antarctica (GIMBLE.GMGEO2)", "url": "https://www.usap-dc.org/view/dataset/601002"}, {"dataset_uid": "601001", "doi": "10.15784/601001", "keywords": "Airborne Radar; Antarctica; Gimble; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness; Marie Byrd Land; Navigation; Radar", "people": "Holt, John W.; Young, Duncan A.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "Ice thickness and related data over central Marie Byrd Land, West Antarctica (GIMBLE.GR2HI2)", "url": "https://www.usap-dc.org/view/dataset/601001"}, {"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Muldoon, Gail R.; Blankenship, Donald D.; Jackson, Charles; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}, {"dataset_uid": "601003", "doi": "10.15784/601003", "keywords": "Antarctica; Gimble; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravity; Marie Byrd Land; Navigation; Potential Field; Solid Earth", "people": "Blankenship, Donald D.; Holt, John W.; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "Gravity disturbance data over central Marie Byrd Land, West Antarctica (GIMBLE.GGCMG2)", "url": "https://www.usap-dc.org/view/dataset/601003"}, {"dataset_uid": "200407", "doi": "10.18738/T8/BMXUHX", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE) Airborne VHF Radar Transects: 2012/2013 and 2014/2015", "url": "https://doi.org/10.18738/T8/BMXUHX"}], "date_created": "Tue, 01 Dec 2015 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to use airborne geophysics to provide detailed geophysical mapping over the Marie Byrd Land dome of West Antarctica. They will use a Basler equipped with advanced ice penetrating radar, a magnetometer, an airborne gravimeter and laser altimeter. They will test models of Marie Byrd Land lithospheric evolution in three ways: 1) constrain bedrock topography and crustal structure of central Marie Byrd Land for the first time; 2) map subglacial geomorphology of Marie Byrd Land to constrain landscape evolution; and 3) map the distribution of subglacial volcanic centers and identify active sources. Marie Byrd Land is one of the few parts of West Antarctica whose bedrock lies above sea level; as such, it has a key role to play in the formation and decay of the West Antarctic Ice Sheet (WAIS), and thus on eustatic sea level change during the Neogene. Several lines of evidence suggest that the topography of Marie Byrd Land has changed over the course of the Cenozoic, with significant implications for the origin and evolution of the ice sheet. Broader impacts: This work will have important implications for both the cryospheric and geodynamic communities. These data will also leverage results from the POLENET project. The PIs will train both graduate and undergraduate students in the interpretation of large geophysical datasets providing them with the opportunity to co-author peer-reviewed papers and present their work to the broader science community. This research will also support a young female researcher. The PIs will conduct informal education using their Polar Studies website and contribute formally to K-12 curriculum development. The research will incorporate microblogging and data access to allow the project?s first-order hypothesis to be confirmed or denied in public.", "east": -111.0, "geometry": "POINT(-128 -77)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e HICARS1; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e LIDAR ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e NUCLEAR PRECESSION MAGNETOMETER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e CMG-GT-1A", "is_usap_dc": false, "keywords": "BT-67; Marie Byrd Land; ICE SHEETS", "locations": "Marie Byrd Land", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Young, Duncan A.; Holt, John W.; Blankenship, Donald D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e BT-67", "repo": "USAP-DC", "repositories": "Texas Data Repository; USAP-DC", "science_programs": null, "south": -80.0, "title": "Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE)", "uid": "p0000435", "west": -145.0}, {"awards": "1039982 Anandakrishnan, Sridhar", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Seismological Data at IRIS (full data link not provided)", "datasets": [{"dataset_uid": "000170", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismological Data at IRIS (full data link not provided)", "url": "http://ds.iris.edu/"}], "date_created": "Mon, 23 Nov 2015 00:00:00 GMT", "description": "Intellectual Merit: Knowledge of englacial and subglacial conditions are critical for ice sheet models and predictions of sea-level change. Some of the critical variables that are poorly known but essential for improving flow models and predictions of sea-level change are: basal roughness, subglacial sedimentary and hydrologic conditions, and the temporal and spatial variability of the ice sheet flow field. Seismic reflection and refraction imaging and dense arrays of continuously operating GPS receivers can determine these parameters. The PIs propose to develop a network of wirelessly interconnected geophysical sensors (geoPebble) that will allow glaciologists to carry out these experiments simultaneously. This sensor web will provide a new way of imaging the ice sheet that is not possible with current instruments. With this sensor web, the PIs will extend the range of existing instruments from 2D to 3D, from low resolution to high resolution, but more importantly, all the geophysical measurements will be conducted synchronously. By the end of the proposal period the PIs will produce a network of 150-200 geoPebbles that will be available for NSF-sponsored glaciology research projects. Broader impacts: Improved knowledge of the flow law of ice, the sliding of glaciers and ice streams, and paleoclimate history will contribute to assessments of the potential for abrupt ice-sheet mass change, with consequent sea-level effects and significant societal impacts. This improved modeling ability will be a direct consequence of better knowledge of the physical properties of ice sheets, which this project will facilitate. The development effort will be integrated with the undergraduate education program via the capstone design classes in EE and the senior thesis requirement in Geoscience. The PIs will also form a cohort of first-year and sophomore students who will work in their labs from the beginning of the project to develop specifications through the commissioning of the network.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anandakrishnan, Sridhar; Bilen, Sven; Urbina, Julio", "platforms": "Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -90.0, "title": "MRI: Development of a Wirelessly-Connected Network of Seismometers and GPS Instruments for Polar and Geophysical Research", "uid": "p0000405", "west": -180.0}, {"awards": "0944653 Forster, Richard", "bounds_geometry": "POLYGON((-119.4 -78.1,-118.46000000000001 -78.1,-117.52000000000001 -78.1,-116.58 -78.1,-115.64 -78.1,-114.7 -78.1,-113.76 -78.1,-112.82000000000001 -78.1,-111.88 -78.1,-110.94 -78.1,-110 -78.1,-110 -78.28999999999999,-110 -78.47999999999999,-110 -78.67,-110 -78.86,-110 -79.05,-110 -79.24,-110 -79.42999999999999,-110 -79.62,-110 -79.81,-110 -80,-110.94 -80,-111.88 -80,-112.82000000000001 -80,-113.76 -80,-114.7 -80,-115.64 -80,-116.58 -80,-117.52000000000001 -80,-118.46000000000001 -80,-119.4 -80,-119.4 -79.81,-119.4 -79.62,-119.4 -79.42999999999999,-119.4 -79.24,-119.4 -79.05,-119.4 -78.86,-119.4 -78.67,-119.4 -78.47999999999999,-119.4 -78.28999999999999,-119.4 -78.1))", "dataset_titles": "Annual Satellite Era Accumulation Patterns Over WAIS Divide: A Study Using Shallow Ice Cores, Near-Surface Radars and Satellites", "datasets": [{"dataset_uid": "600146", "doi": "10.15784/600146", "keywords": "Airborne Radar; Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar; WAIS Divide; WAIS Divide Ice Core", "people": "Forster, Richard", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Annual Satellite Era Accumulation Patterns Over WAIS Divide: A Study Using Shallow Ice Cores, Near-Surface Radars and Satellites", "url": "https://www.usap-dc.org/view/dataset/600146"}], "date_created": "Fri, 20 Nov 2015 00:00:00 GMT", "description": "This award supports a project to broaden the knowledge of annual accumulation patterns over the West Antarctic Ice Sheet by processing existing near-surface radar data taken on the US ITASE traverse in 2000 and by gathering and validating new ultra/super-high-frequency (UHF) radar images of near surface layers (to depths of ~15 m), expanding abilities to monitor recent annual accumulation patterns from point source ice cores to radar lines. Shallow (15 m) ice cores will be collected in conjunction with UHF radar images to confirm that radar echoed returns correspond with annual layers, and/or sub-annual density changes in the near-surface snow, as determined from ice core stable isotopes. This project will additionally improve accumulation monitoring from space-borne instruments by comparing the spatial-radar-derived-annual accumulation time series to the passive microwave time series dating back over 3 decades and covering most of Antarctica. The intellectual merit of this project is that mapping the spatial and temporal variations in accumulation rates over the Antarctic ice sheet is essential for understanding ice sheet responses to climate forcing. Antarctic precipitation rate is projected to increase up to 20% in the coming century from the predicted warming. Accumulation is a key component for determining ice sheet mass balance and, hence, sea level rise, yet our ability to measure annual accumulation variability over the past 5 decades (satellite era) is mostly limited to point-source ice cores. Developing a radar and ice core derived annual accumulation dataset will provide validation data for space-born remote sensing algorithms, climate models and, additionally, establish accumulation trends. The broader impacts of the project are that it will advance discovery and understanding within the climatology, glaciology and remote sensing communities by verifying the use of UHF radars to monitor annual layers as determined by visual, chemical and isotopic analysis from corresponding shallow ice cores and will provide a dataset of annual to near-annual accumulation measurements over the past ~5 decades across WAIS divide from existing radar data and proposed radar data. By determining if temporal changes in the passive microwave signal are correlated with temporal changes in accumulation will help assess the utility of passive microwave remote sensing to monitor accumulation rates over ice sheets for future decades. The project will promote teaching, training and learning, and increase representation of underrepresented groups by becoming involved in the NASA History of Winter project and Thermochron Mission and by providing K-12 teachers with training to monitor snow accumulation and temperature here in the US, linking polar research to the student?s backyard. The project will train both undergraduate and graduate students in polar research and will encouraging young investigators to become involved in careers in science. In particular, two REU students will participate in original research projects as part of this larger project, from development of a hypothesis to presentation and publication of the results. The support of a new, young woman scientist will help to increase gender diversity in polar research.", "east": -110.0, "geometry": "POINT(-114.7 -79.05)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -78.1, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Forster, Richard", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -80.0, "title": "Collaborative Research: Annual satellite era accumulation patterns over WAIS Divide: A study using shallow ice cores, near-surface radars and satellites", "uid": "p0000079", "west": -119.4}, {"awards": "1141936 Foreman, Christine", "bounds_geometry": "POINT(112.085 -79.467)", "dataset_titles": "Molecular Level Characterization of Dissolved Organic Carbon and Microbial Diversity in the WAIS Divide Replicate Core", "datasets": [{"dataset_uid": "600133", "doi": "10.15784/600133", "keywords": "Antarctica; Biota; Genetic Sequences; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Foreman, Christine", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Molecular Level Characterization of Dissolved Organic Carbon and Microbial Diversity in the WAIS Divide Replicate Core", "url": "https://www.usap-dc.org/view/dataset/600133"}], "date_created": "Thu, 05 Nov 2015 00:00:00 GMT", "description": "This award supports a detailed, molecular level characterization of dissolved organic carbon and microbes in Antarctic ice cores. Using the most modern biological (genomic), geochemical techniques, and advanced chemical instrumentation researchers will 1) optimize protocols for collecting, extracting and amplifying DNA from deep ice cores suitable for use in next generation pyrosequencing; 2) determine the microbial diversity within the ice core; and 3) obtain and analyze detailed molecular characterizations of the carbon in the ice by ultrahigh resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS). With this pilot study investigators will be able to quantify the amount of material (microbial biomass and carbon) required to perform these characterizations, which is needed to inform future ice coring projects. The ultimate goal will be to develop protocols that maximize the yield, while minimizing the amount of ice required. The broader impacts include education and outreach at both the local and national levels. As a faculty mentor with the American Indian Research Opportunities and BRIDGES programs at Montana State University, Foreman will serve as a mentor to a Native American student in the lab during the summer months. Susan Kelly is an Education and Outreach Coordinator with a MS degree in Geology and over 10 years of experience in science outreach. She will coordinate efforts for comprehensive educational collaboration with the Hardin School District on the Crow Indian Reservation in South-central Montana.", "east": 112.085, "geometry": "POINT(112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ADS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Dissolved Organic Carbon; Microbes; Ice Core; Not provided; Pyrosequencing; Microbial Diversity; Molecular; WAIS Divide; LABORATORY; FIELD SURVEYS; Antarctic; FIELD INVESTIGATION; DNA", "locations": "Antarctic; WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Foreman, Christine", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Molecular Level Characterization of Dissolved Organic Carbon and Microbial Diversity in the WAIS Divide Replicate Core", "uid": "p0000342", "west": 112.085}, {"awards": "1142173 Bay, Ryan; 1142010 Talghader, Joseph", "bounds_geometry": "POINT(112.085 -79.467)", "dataset_titles": "Optical Fabric and Fiber Logging of Glacial Ice (1142010)", "datasets": [{"dataset_uid": "600172", "doi": "10.15784/600172", "keywords": "Antarctica; Ash Layer; Borehole Camera; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Talghader, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Optical Fabric and Fiber Logging of Glacial Ice (1142010)", "url": "https://www.usap-dc.org/view/dataset/600172"}], "date_created": "Thu, 05 Nov 2015 00:00:00 GMT", "description": "1142010/Talghader This award supports a project to combine the expertise of both glaciologists and optical engineers to develop polarization- preserving optical scattering techniques for borehole tools to identify changes in high-resolution crystal structure (fabric) and dust content of glacial ice. The intellectual merit of this work is that the fabric and impurity content of the ice contain details on climate, volcanic activity and ice flow history. Such fabric measurements are currently taken by slicing an ice core into sections after it has started to depressurize which is an extremely time-intensive process that damages the core and does not always preserve the properties of ice in its in-situ state. In addition the ice core usually must be consumed in order to measure the components of the dust. The fabric measurements of this study utilize the concept that singly-scattered light in ice preserves most of its polarization when it is backscattered once from bubbles or dust; therefore, changes to the polarization of singly-backscattered light must originate with the birefringence. Measurements based on this concept will enable this program to obtain continuous records of fabric and correlate them to chronology and dust content. The project will also develop advanced borehole instruments to replace current logging tools, which require optical sources, detectors and power cables to be submerged in borehole fluid and lowered into the ice sheet at temperatures of -50oC. The use of telecommunications fiber will allow all sources and detectors to remain at the surface and enable low-noise signal processing techniques such as lock-in amplification that increase signal integrity and reduce needed power. Further, fiber logging systems would be much smaller and more flexible than current tools and capable of navigating most boreholes without a heavy winch. In order to assess fabric in situ and test fiber-optic borehole tools, field measurements will be made at WAIS Divide and a deep log will also be made at Siple Dome, both in West Antarctica. If successful, the broader impacts of the proposed research would include the development of new analytical methods and lightweight logging tools for ice drilling research that can operate in boreholes drilled in ice. Eventually the work could result in the development of better prehistoric records of glacier flow, atmospheric particulates, precipitation, and climate forcing. The project encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training graduate students and advanced undergraduates. Collaboration with schools and classroom teachers will help bring aspects of optics, climate, and polar science to an existing Middle School curriculum.", "east": 112.085, "geometry": "POINT(112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e OPTICAL DUST LOGGERS", "is_usap_dc": true, "keywords": "Fabric; Optical Scattering; Not provided; FIELD SURVEYS; Ice Core; Siple Dome; Antarctic; Dust; WAIS Divide; LABORATORY; Crystal Structure; Chronology; FIELD INVESTIGATION; Borehole", "locations": "Antarctic; WAIS Divide; Siple Dome", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Talghader, Joseph; Bay, Ryan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.467, "title": "Optical Fabric and Fiber Logging of Glacial Ice", "uid": "p0000339", "west": 112.085}, {"awards": "1043780 Aydin, Murat", "bounds_geometry": null, "dataset_titles": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core; Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "datasets": [{"dataset_uid": "609659", "doi": "10.7265/N5CV4FPK", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "url": "https://www.usap-dc.org/view/dataset/609659"}, {"dataset_uid": "601361", "doi": "10.15784/601361", "keywords": "Antarctica; Carbonyl Sulfide; Trace Gases", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/601361"}], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "Aydin/1043780 This award supports the analysis of the trace gas carbonyl sulfide (COS) in a deep ice core from West Antarctic Ice Sheet Divide (WAIS-D), Antarctica. COS is the most abundant sulfur gas in the troposphere and a precursor of stratospheric sulfate. It has a large terrestrial COS sink that is tightly coupled to the photosynthetic uptake of atmospheric carbon dioxide (CO2). The primary goal of this project is to develop high a resolution Holocene record of COS from the WAIS-D 06A ice core. The main objectives are 1) to assess the natural variability of COS and the extent to which its atmospheric variability was influenced by climate variability, and 2) to examine the relationship between changes in atmospheric COS and CO2. This project also includes low-resolution sampling and analysis of COS from 10,000-30,000 yrs BP, covering the transition from the Last Glacial Maximum into the early Holocene. The goal of this work is to assess the stability of COS in ice core air over long time scales and to establish the COS levels during the last glacial maximum and the magnitude of the change between glacial and interglacial conditions. The results of this work will be disseminated via peer-review publications and will contribute to environmental assessments such as the WMO Stratospheric Ozone Assessment and IPCC Climate Assessment. This project will support a PhD student and undergraduate researcher in the Department of Earth System Science at the University of California, Irvine, and will create summer research opportunities for undergraduates from non-research active Universities.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ethane; LABORATORY; N-Butane; Carbonyl Sulfide; Propane; Methyl Bromide; Methyl Chloride; Carbon Disulfide", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat; Saltzman, Eric", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Carbonyl Sulfide Measurements in the Deep West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000055", "west": null}, {"awards": "1042883 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "LA-ICP-MS Results: 3 Siple Dome A Glacial Age Archives; Roosevelt Island Climate Evolution Ice Core ICP-MS data", "datasets": [{"dataset_uid": "609621", "doi": "10.7265/N52J68SQ", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; ICP-MS; Roosevelt Island; Ross Ice Shelf", "people": "Mayewski, Paul A.; Kurbatov, Andrei V.; Beers, Thomas M.", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Climate Evolution Ice Core ICP-MS data", "url": "https://www.usap-dc.org/view/dataset/609621"}, {"dataset_uid": "609636", "doi": "10.7265/N5WS8R6H", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; ICP-MS; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Kurbatov, Andrei V.; Haines, Skylar; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "LA-ICP-MS Results: 3 Siple Dome A Glacial Age Archives", "url": "https://www.usap-dc.org/view/dataset/609636"}], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "1042883/Mayewski This award supports a project to analyze a deep ice core which will be drilled by a New Zealand research team at Roosevelt Island. The objectives are to process the ice core at very high resolution to (a) better understand phasing sequences in Arctic/Antarctic abrupt climate change, even at the level of individual storm events; (b) determine the impact of changes in the Westerlies and the Amundsen Sea Low on past/present/future climate change; (c) determine how sea ice extent has varied in the area; (d) compare the response of West Antarctica climate to other regions during glacial/interglacial cycles; and (e) determine how climate of the Ross Sea Embayment changed during the transition from Ross Ice Sheet to Ross Ice Shelf. The intellectual merit of the RICE deep ice core project is that it is expected to provide a 30kyr long (and possibly 150kyr long) extremely high-resolution view of climate change in the Ross Sea Embayment Region and data essential to test and understand critical questions that have emerged as a consequence of the recent synthesis of Antarctic and Southern Ocean climate change presented in the Scientific Commission for Antarctic Research document: Antarctic Climate Change and the Environment (ACCE, 2009). Ice core processing and analysis will be performed jointly by University of Maine and the collaborators from New Zealand. Co-registered sampling for all chemical analyses will be accomplished by a joint laboratory effort at the IGNS NZ ice core facility using a continuous melter system developed by the University of Maine. The RICE deep ice core record will provide information necessary in unraveling the significance of multi-millennial underpinning for climate change and in the understanding of observed and projected climate change in light of current dramatic human impact on Antarctica and the Southern Ocean. The broader impacts of the project include the fact that two CCI graduate students will be funded through the project, and will be involved in all aspects of field research, core sampling, sample processing, analytical and numerical analyses, data interpretation, writing of manuscripts, and presentation of results at national and international conferences. Data and ideas developed in this project and associated work will be used in several courses taught at the University of Maine. Innovative cyberinfrastructure will be incorporated into this work and ground breaking analytical technologies, and data access/storage tools will be used.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e LA-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS", "is_usap_dc": true, "keywords": "LABORATORY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Haines, Skylar; Kurbatov, Andrei V.; Mayewski, Paul A.; Beers, Thomas M.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Roosevelt Island Climate Evolution Project (RICE): US Deep Ice Core Glaciochemistry Contribution (2011- 2014)", "uid": "p0000193", "west": null}, {"awards": "1144224 Marchant, David", "bounds_geometry": "POLYGON((160 -71.5,161 -71.5,162 -71.5,163 -71.5,164 -71.5,165 -71.5,166 -71.5,167 -71.5,168 -71.5,169 -71.5,170 -71.5,170 -72.15,170 -72.8,170 -73.45,170 -74.1,170 -74.75,170 -75.4,170 -76.05,170 -76.7,170 -77.35,170 -78,169 -78,168 -78,167 -78,166 -78,165 -78,164 -78,163 -78,162 -78,161 -78,160 -78,160 -77.35,160 -76.7,160 -76.05,160 -75.4,160 -74.75,160 -74.1,160 -73.45,160 -72.8,160 -72.15,160 -71.5))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 23 Oct 2015 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose a two-year project to map the distribution of climate-sensitive landforms throughout Northern Victoria Land between the Convoy Range and Cape Adare. This work will produce geospatial products to aid their geomorphic work on ice sheet stability and landscape evolution. Specifically, the PI will investigate the potential for extensive surface melting and ice-sheet retreat with modest warming in areas north of the Convoy Range in Northern Victoria Land. The hypothesis is that if key landform elements of the Dry Valleys assemblage are lacking in NVL it suggests a major variation in current climate conditions, and perhaps changes in climate evolution. The proposed work will also benefit the broader research community, as it will demonstrate the potential for using geospatial imagery in geomorphic research and produce geospatial products that can be used by other researchers. Broader impacts: This work will help the research community better leverage the investment being made in the Polar Geospatial Center (PGC) and will help further demonstrate the significance of satellite imagery for doing ?virtual? field work in the Polar regions. More effective use of satellite imagery by field scientists in Antarctica will help reduce the logistical footprint on the Continent. The proposed research will support one graduate student at Boston University who will be trained in image analysis, map production, Antarctic geomorphology, and geospatial technologies. The proposed work will help to forge stronger links between PGC and Boston University?s Digital Image Analyses Lab (DIAL).", "east": 170.0, "geometry": "POINT(165 -74.75)", "instruments": null, "is_usap_dc": false, "keywords": "Bu/es Data Repository; Not provided", "locations": null, "north": -71.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Marchant, David", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -78.0, "title": "Geomorphic investigations of Northern Victoria Land, Antarctica", "uid": "p0000231", "west": 160.0}, {"awards": "0632282 Jacobs, Stanley", "bounds_geometry": "POLYGON((-129.6 -54.2,-124.44 -54.2,-119.28 -54.2,-114.12 -54.2,-108.96 -54.2,-103.8 -54.2,-98.64 -54.2,-93.48 -54.2,-88.32 -54.2,-83.16 -54.2,-78 -54.2,-78 -56.29,-78 -58.38,-78 -60.47,-78 -62.56,-78 -64.65,-78 -66.74,-78 -68.83,-78 -70.92,-78 -73.01,-78 -75.1,-83.16 -75.1,-88.32 -75.1,-93.48 -75.1,-98.64 -75.1,-103.8 -75.1,-108.96 -75.1,-114.12 -75.1,-119.28 -75.1,-124.44 -75.1,-129.6 -75.1,-129.6 -73.01,-129.6 -70.92,-129.6 -68.83,-129.6 -66.74,-129.6 -64.65,-129.6 -62.56,-129.6 -60.47,-129.6 -58.38,-129.6 -56.29,-129.6 -54.2))", "dataset_titles": "Amundsen Sea Continental Shelf Mooring Data (2006-2007); Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901; NBP07-09 cruise data; NBP07-09 processed CTD data; NBP09-01 cruise data; NBP09-01 processed CTD data; Processed Temperature, Salinity, and Current Measurement Data from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "datasets": [{"dataset_uid": "000128", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP07-09 processed CTD data", "url": "http://accession.nodc.noaa.gov/0120761"}, {"dataset_uid": "000130", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP09-01 processed CTD data", "url": "http://accession.nodc.noaa.gov/0071179"}, {"dataset_uid": "000129", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP09-01 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0901"}, {"dataset_uid": "000127", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP07-09 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0709"}, {"dataset_uid": "601350", "doi": null, "keywords": "Amundsen Sea; Antarctic; Antarctica; CTD; CTD Data; Current Measurements; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; Pine Island Glacier; R/v Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Jacobs, Stanley; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed Temperature, Salinity, and Current Measurement Data from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601350"}, {"dataset_uid": "601809", "doi": "10.15784/601809", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Mooring; Ocean Currents; Pressure; Salinity; Temperature", "people": "Giulivi, Claudia F.; Jacobs, Stanley", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Continental Shelf Mooring Data (2006-2007)", "url": "https://www.usap-dc.org/view/dataset/601809"}, {"dataset_uid": "601349", "doi": null, "keywords": "Amundsen Sea; Antarctica; Current Measurements; LADCP; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; R/v Nathaniel B. Palmer; Southern Ocean", "people": "Thurnherr, Andreas", "repository": "USAP-DC", "science_program": null, "title": "Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601349"}], "date_created": "Fri, 25 Sep 2015 00:00:00 GMT", "description": "The Office of Polar Programs, Antarctic Science Division, Ocean \u0026 Climate Systems Program has made this award to support a multidisciplinary effort to study the upwelling of relatively warm deep water onto the Amundsen Sea continental shelf and how it relates to atmospheric forcing and bottom bathymetry and how the warm waters interact with both glacial and sea ice. This study constitutes a contribution of a coordinated research effort in the region known as the Amundsen Sea Embayment Project or ASEP. Previous work by the PI and others has shown that the West Antarctic Ice Sheet has been found to be melting faster, perhaps by orders of magnitude, than ice sheets elsewhere around Antarctica, excluding those on the Peninsula. Submarine channels that incise the continental shelf are thought to provide fairly direct access of relatively warm circum polar deep water to the cavity under the floating extension of the ice shelf. Interactions with sea ice en route can modify the upwelled waters. The proposed investigations build on previous efforts by the PI and colleagues to use hydrographic measurements to put quantitative bounds on the rate of glacial ice melt by relatively warm seawater. \u003cbr/\u003eThe region can be quite difficult to access due to sea ice conditions and previous hydrographic measurements have been restricted to the austral summer time frame. In this project it was proposed to obtain the first austral spring hydrographic data via CTD casts and XBT drops (September-October 2007) as part of a separately funded cruise (PI Steve Ackley) the primary focus of which is sea-ice conditions to be studied while the RV Nathanial B Palmer (RV NBP) drifts in the ice pack. This includes opportunistic sampling for pCO2 and TCO2. A dedicated cruise in austral summer 2009 will follow this opportunity. The principal objectives of the dedicated field program are to deploy a set of moorings with which to characterize temporal variability in warm water intrusions onto the shelf and to conduct repeat hydrographic surveying and swath mapping in targeted areas, ice conditions permitting. Automatic weather stations are to be deployed in concert with the program, sea-ice observations will be undertaken from the vessel and the marine cavity beneath the Pine Island may be explored pending availability of the British autonomous underwater vehicle Autosub 3. These combined ocean-sea ice-atmosphere observations are aimed at a range of model validations. A well-defined plan for making data available as well as archiving in a timely fashion should facilitate a variety of modeling efforts and so extend the value of the spatially limited observations. \u003cbr/\u003eBroader impacts: This project is relevant to an International Polar Year research emphasis on ice sheet dynamics focusing in particular on the seaward ocean-ice sheet interactions. Such interactions must be clarified for understanding the potential for sea level rise by melt of the West Antarctic ice Sheet. The project entails substantive international partnerships (British Antarctic Survey and Alfred Wegner Institute) and complements other Amundsen Sea Embayment Project proposals covering other elements of ice sheet dynamics. The proposal includes partial support for 2 graduate students and 2 post docs. Participants from the Antarctic Artists and Writers program are to take part in the cruise and so aid in outreach. In addition, the project is to be represented in the Lamont-Doherty annual open house.", "east": -78.0, "geometry": "POINT(-103.8 -64.65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "Not provided; R/V NBP", "locations": null, "north": -54.2, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley; Hellmer, Hartmut; Jenkins, Adrian", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "NCEI", "repositories": "NCEI; R2R; USAP-DC", "science_programs": null, "south": -75.1, "title": "Collaborative International Research: Amundsen Sea Influence on West Antarctic Ice Sheet Stability and Sea Level Rise - IPY/ASEP", "uid": "p0000332", "west": -129.6}, {"awards": "1043421 Severinghaus, Jeffrey; 1043522 Brook, Edward J.", "bounds_geometry": "POINT(-112.09 -79.47)", "dataset_titles": "WAIS Divide Replicate Core Methane Isotopic Data Set", "datasets": [{"dataset_uid": "601059", "doi": "10.15784/601059", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Replicate Core Methane Isotopic Data Set", "url": "https://www.usap-dc.org/view/dataset/601059"}], "date_created": "Mon, 13 Jul 2015 00:00:00 GMT", "description": "1043421/Severinghaus This award supports a project to obtain samples of ice in selected intervals for replication and verification of the validity and spatial representativeness of key results in the WAIS Divide ice core, and to obtain additional ice samples in areas of intense scientific interest where demand is high. The US Ice Core Working Group recommended in 2003 that NSF pursue the means to take replicate samples, termed \"replicate coring\". This recommendation was part of an agreement to reduce the diameter of the (then) new drilling system (the DISC drill) core to 12.2 cm to lighten logistics burdens, and the science community accepted the reduction in ice sample with the understanding that replicate coring would be able to provide extra sample volume in key intervals. The WAIS Divide effort would particularly benefit from replicate coring, because of the unique quality of the expected gas record and the large samples needed for gases and gas isotopes; thus this proposal to employ replicate coring at WAIS Divide. In addition, scientific demand for ice samples has been, and will continue to be, very unevenly distributed, with the ice core archive being completely depleted in depth intervals of high scientific interest (abrupt climate changes, volcanic sulfate horizons, meteor impact horizons, for example). The broader impacts of the proposed research may include identification of leads and lags between Greenland, tropical, and Antarctic climate change, enabling critical tests of hypotheses for the mechanism of abrupt climate change. Improved understanding of volcanic impacts on atmospheric chemistry and climate may also emerge. This understanding may ultimately help improve climate models and prediction of the Earth System feedback response to ongoing human perturbation in coming centuries. Outreach and public education about climate change are integral components of the PIs\u0027 activities and the proposed work will enhance these efforts. Broader impacts also include education and training of 2 postdoctoral scholars and 1 graduate student, and invaluable field experience for the graduate and undergraduate students who will likely make up the core processing team at WAIS Divide.", "east": -112.09, "geometry": "POINT(-112.09 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": false, "keywords": "Ice Core Gas Records; Firn Air Isotopes; LABORATORY; FIELD SURVEYS; Mass Spectrometry; Not provided; FIELD INVESTIGATION; Ice Core; WAIS Divide", "locations": "WAIS Divide", "north": -79.47, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.47, "title": "Collaborative Research: Replicate Coring at WAIS Divide to Obtain Additional Samples at Events of High Scientific Interest", "uid": "p0000751", "west": -112.09}, {"awards": "1143619 Severinghaus, Jeffrey", "bounds_geometry": "POINT(-112.09 -79.47)", "dataset_titles": null, "datasets": null, "date_created": "Mon, 13 Jul 2015 00:00:00 GMT", "description": "1143619/Severinghaus This award supports a project to extend the study of gases in ice cores to those gases whose small molecular diameters cause them to escape rapidly from ice samples (the so-called \"fugitive gases\"). The work will employ helium, neon, argon, and oxygen measurements in the WAIS Divide ice core to better understand the mechanism of the gas close-off fractionation that occurs while air bubbles are incorporated into ice. The intellectual merit of the proposed work is that corrections for this fractionation using neon (which is constant in the atmosphere) may ultimately enable the first ice core-based atmospheric oxygen and helium records. Neon may also illuminate the mechanistic link between local insolation and oxygen used for astronomical dating of ice cores. Helium measure-ments in the deepest ~100 m of the core will also shed light on the stratigraphic integrity of the basal ice, and serve as a probe of solid earth-ice interaction at the base of the West Antarctic ice sheet. Past atmospheric oxygen records, currently unavailable prior to 1989 CE, would reveal changes in the size of the terrestrial biosphere carbon pool that accompany climate variations and place constraints on the biogeochemical feedback response to future warming. An atmospheric helium-3/helium-4 record would test the hypothesis that the solar wind (which is highly enriched in helium-3) condensed directly into Earth?s atmosphere during the collapse of the geomagnetic field that occurred 41,000 years ago, known as the Laschamp Event. Fugitive-gas samples will be taken on-site immediately after recovery of the ice core by the PI and one postdoctoral scholar, under the umbrella of an existing project to support replicate coring and borehole deepening. This work will add value to the scientific return from field work activity with little additional cost to logistical resources. The broader impacts of the work on atmospheric oxygen are that it may increase understanding of how terrestrial carbon pools and atmospheric greenhouse gas sources will respond in a feedback sense to the coming warming. Long-term atmospheric oxygen trends are also of interest for understanding biogeochemical regulatory mechanisms and the impact of atmospheric evolution on life. Helium records have value in understanding the budget of this non-renewable gas and its implications for space weather and solar activity. The project will train one graduate student and one postdoctoral scholar. The fascination of linking solid earth, cryosphere, atmosphere, and space weather will help to entrain and excite young scientists and efforts to understand the Earth as a whole interlinked system will provide fuel to outreach efforts at all ages.", "east": -112.09, "geometry": "POINT(-112.09 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": false, "keywords": "WAIS Divide; Not provided; Tracers; FIELD INVESTIGATION; Past Biospheric Carbon Storage; LABORATORY; Fugitive Gases; Basal Processes; Neon; Helium; FIELD SURVEYS; Antarctica", "locations": "WAIS Divide; Antarctica", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -79.47, "title": "Fugitive Gases (Helium, Neon, and Oxygen) in the WAIS Divide Ice Core as Tracers of Basal Processes and Past Biospheric Carbon Storage", "uid": "p0000441", "west": -112.09}, {"awards": "1245659 Petrenko, Vasilii; 1246148 Severinghaus, Jeffrey; 1245821 Brook, Edward J.", "bounds_geometry": "POINT(162.167 -77.733)", "dataset_titles": "Gas and Dust Measurements for Taylor Glacier and Taylor Dome Ice Cores; Last Interglacial Mean Ocean Temperature; Mean Ocean Temperature in Marine Isotope Stage 4; Measurements of 14CH4 and 14CO in ice from Taylor Glacier: Last Deglaciation; N2O Concentration and Isotope Data for 74-59 ka from Taylor Glacier, Antarctica; Taylor Glacier CO2 Isotope Data 74-59 kyr; Taylor Glacier Noble Gases - Younger Dryas; The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "datasets": [{"dataset_uid": "601398", "doi": "10.15784/601398", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Gas Records; Ice Core Records; Marine Isotope Stage 4; MIS 4; Nitrous Oxide; Pleistocene; Taylor Dome Ice Core; Taylor Glacier", "people": "Shackleton, Sarah; Petrenko, Vasilii; Severinghaus, Jeffrey P.; Dyonisius, Michael; Schilt, Adrian; Brook, Edward J.; Menking, James", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "N2O Concentration and Isotope Data for 74-59 ka from Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601398"}, {"dataset_uid": "601176", "doi": "10.15784/601176", "keywords": "Antarctica; CO2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; Noble Gas; Noble Gas Isotopes; Snow/ice; Snow/Ice; Taylor Glacier; Younger Dryas", "people": "Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Taylor Glacier Noble Gases - Younger Dryas", "url": "https://www.usap-dc.org/view/dataset/601176"}, {"dataset_uid": "601198", "doi": "10.15784/601198", "keywords": "Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; CO2; Dust; Gas; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Mass Spectrometer; Methane; Nitrogen Isotopes; Oxygen Isotope; Paleoclimate; Snow/ice; Snow/Ice; Taylor Dome; Taylor Dome Ice Core", "people": "Severinghaus, Jeffrey P.; Bauska, Thomas; Rhodes, Rachel; McConnell, Joseph; Petrenko, Vasilii; Dyonisius, Michael; Shackleton, Sarah; Barker, Stephen; Baggenstos, Daniel; Marcott, Shaun; Brook, Edward J.; Menking, James", "repository": "USAP-DC", "science_program": null, "title": "Gas and Dust Measurements for Taylor Glacier and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/601198"}, {"dataset_uid": "601218", "doi": "10.15784/601218", "keywords": "Antarctica; Carbon-14; Carbon Dioxide; Chemistry:ice; Chemistry:Ice; CO2; Dome C Ice Core; Epica; Epica Dome C; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Chemistry; Ice Core Data; Ice Core Gas Records; Ice Core Records; Isotope Data; Last Interglacial; Mass Spectrometer; Mass Spectrometry; Methane; Oxygen; Oxygen Isotope; Paleotemperature; Pleistocene; Snow/ice; Snow/Ice; Taylor Dome Ice Core; Taylor Glacier", "people": "Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Last Interglacial Mean Ocean Temperature", "url": "https://www.usap-dc.org/view/dataset/601218"}, {"dataset_uid": "601218", "doi": "10.15784/601218", "keywords": "Antarctica; Carbon-14; Carbon Dioxide; Chemistry:ice; Chemistry:Ice; CO2; Dome C Ice Core; Epica; Epica Dome C; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Chemistry; Ice Core Data; Ice Core Gas Records; Ice Core Records; Isotope Data; Last Interglacial; Mass Spectrometer; Mass Spectrometry; Methane; Oxygen; Oxygen Isotope; Paleotemperature; Pleistocene; Snow/ice; Snow/Ice; Taylor Dome Ice Core; Taylor Glacier", "people": "Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Last Interglacial Mean Ocean Temperature", "url": "https://www.usap-dc.org/view/dataset/601218"}, {"dataset_uid": "601260", "doi": "10.15784/601260", "keywords": "Antarctica; Carbon-14; Cosmogenic; Ice Core; Methane", "people": "Petrenko, Vasilii; Dyonisius, Michael", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Measurements of 14CH4 and 14CO in ice from Taylor Glacier: Last Deglaciation", "url": "https://www.usap-dc.org/view/dataset/601260"}, {"dataset_uid": "601600", "doi": "10.15784/601600", "keywords": "Antarctica; Taylor Glacier", "people": "Barker, Stephen; Menking, James; Petrenko, Vasilii; Dyonisius, Michael; Severinghaus, Jeffrey P.; Menking, Andy; Buffen, Aron; Brook, Edward J.; Shackleton, Sarah; Bauska, Thomas", "repository": "USAP-DC", "science_program": null, "title": "Taylor Glacier CO2 Isotope Data 74-59 kyr", "url": "https://www.usap-dc.org/view/dataset/601600"}, {"dataset_uid": "600163", "doi": "10.15784/600163", "keywords": "Antarctica; Atmosphere; Geochemistry; Ice Core Records; Isotope; Paleoclimate; Taylor Glacier; Transantarctic Mountains", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": null, "title": "The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "url": "https://www.usap-dc.org/view/dataset/600163"}, {"dataset_uid": "601415", "doi": "10.15784/601415", "keywords": "Antarctica; Glaciology; Ice Core Data; Ice Core Records; Paleoclimate; Paleotemperature; Taylor Glacier", "people": "Shackleton, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Mean Ocean Temperature in Marine Isotope Stage 4", "url": "https://www.usap-dc.org/view/dataset/601415"}], "date_created": "Mon, 13 Jul 2015 00:00:00 GMT", "description": "1245659/Petrenko This award supports a project to use the Taylor Glacier, Antarctica, ablation zone to collect ice samples for a range of paleoenvironmental studies. A record of carbon-14 of atmospheric methane (14CH4) will be obtained for the last deglaciation and the Early Holocene, together with a supporting record of CH4 stable isotopes. In-situ cosmogenic 14C content and partitioning of 14C between different species (14CH4, C-14 carbon monoxide (14CO) and C-14 carbon dioxide (14CO2)) will be determined with unprecedented precision in ice from the surface down to ~67 m. Further age-mapping of the ablating ice stratigraphy will take place using a combination of CH4, CO2, \u0026#948;18O of oxygen gas and H2O stable isotopes. High precision, high-resolution records of CO2, \u0026#948;13C of CO2, nitrous oxide (N2O) and N2O isotopes will be obtained for the last deglaciation and intervals during the last glacial period. The potential of 14CO2 and Krypton-81 (81Kr) as absolute dating tools for glacial ice will be investigated. The intellectual merit of proposed work includes the fact that the response of natural methane sources to continuing global warming is uncertain, and available evidence is insufficient to rule out the possibility of catastrophic releases from large 14C-depleted reservoirs such as CH4 clathrates and permafrost. The proposed paleoatmospheric 14CH4 record will improve our understanding of the possible magnitude and timing of CH4 release from these reservoirs during a large climatic warming. A thorough understanding of in-situ cosmogenic 14C in glacial ice (production rates by different mechanisms and partitioning between species) is currently lacking. Such an understanding will likely enable the use of in-situ 14CO in ice at accumulation sites as a reliable, uncomplicated tracer of the past cosmic ray flux and possibly past solar activity, as well as the use of 14CO2 at both ice accumulation and ice ablation sites as an absolute dating tool. Significant gaps remain in our understanding of the natural carbon cycle, as well as in its responses to global climate change. The proposed high-resolution, high-precision records of \u0026#948;13C of CO2 would provide new information on carbon cycle changes both during times of rising CO2 in a warming climate and falling CO2 in a cooling climate. N2O is an important greenhouse gas that increased by ~30% during the last deglaciation. The causes of this increase are still largely uncertain, and the proposed high-precision record of N2O concentration and isotopes would provide further insights into N2O source changes in a warming world. The broader impacts of proposed work include an improvement in our understanding of the response of these greenhouse gas budgets to global warming and inform societally important model projections of future climate change. The continued age-mapping of Taylor Glacier ablation ice will add value to this high-quality, easily accessible archive of natural environmental variability. Establishing 14CO as a robust new tracer for past cosmic ray flux would inform paleoclimate studies and constitute a valuable contribution to the study of the societally important issue of climate change. The proposed work will contribute to the development of new laboratory and field analytical systems. The data from the study will be made available to the scientific community and the broad public through the NSIDC and NOAA Paleoclimatology data centers. 1 graduate student each will be trained at UR, OSU and SIO, and the work will contribute to the training of a postdoc at OSU. 3 UR undergraduates will be involved in fieldwork and research. The work will support a new, junior UR faculty member, Petrenko. All PIs have a strong history of and commitment to scientific outreach in the forms of media interviews, participation in filming of field projects, as well as speaking to schools and the public about their research, and will continue these activities as part of the proposed work. This award has field work in Antarctica.", "east": 162.167, "geometry": "POINT(162.167 -77.733)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Not provided; USAP-DC; FIELD INVESTIGATION; Stratigraphy; FIELD SURVEYS; Antarctica; Paleoenvironment; Methane; Ice Core; Carbon Dioxide; FIXED OBSERVATION STATIONS; Stable Isotopes; Ablation Zone; Taylor Glacier; Nitrous Oxide; USA/NSF; LABORATORY; AMD; Cosmogenic; Amd/Us", "locations": "Taylor Glacier; Antarctica", "north": -77.733, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Petrenko, Vasilii; Brook, Edward J.; Severinghaus, Jeffrey P.; PETRENKO, VASILLI", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e FIXED OBSERVATION STATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": -77.733, "title": "Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "uid": "p0000283", "west": 162.167}, {"awards": "1043217 Zagorodnov, Victor", "bounds_geometry": null, "dataset_titles": "Fiber-Optic Distributed Temperature Sensing at Windless Bight", "datasets": [{"dataset_uid": "609604", "doi": "10.7265/N5V122QS", "keywords": "Antarctica; Ice Shelf; McMurdo Sound; Mooring; Oceans; Physical Oceanography; Ross Ice Shelf; Southern Ocean", "people": "Holland, David; Zagorodnov, Victor; Tyler, Scott W.", "repository": "USAP-DC", "science_program": null, "title": "Fiber-Optic Distributed Temperature Sensing at Windless Bight", "url": "https://www.usap-dc.org/view/dataset/609604"}], "date_created": "Tue, 05 May 2015 00:00:00 GMT", "description": "Abstract Researchers will explore the use of a distributed temperature sensing monitoring system (DTS), using fiber-optical (FO) technology, as the basis of a sustainable, sub-ice cavity sensing array. FO cable systems, such as may be deployed through a hot-water drilled hole through an ice shelf, passing through the underlying cavity to the sea floor, are capable of measuring temperatures down fiber at 1 meter intervals, and at time frequencies as high as 15 seconds. DTS FO systems operate via optical time domain reflectometry along the fiber waveguide using inelastic backscatter of coherent laser light as a probe beam in the FO environment. The introduction of new technologies to the harsh environmental conditions of the Antarctic are often associated with high risk. However, the potential rewards of this approach (e.g. multiyear capability, minimal submerged mechanical or electrical components that may fail, relative simplicity of deployment and measurement principle, yet yielding distributed real time and spatial observation) are attractive enough to conduct a pilot project at a field-ready location (McMurdo). Current indications are that the instability of some of the world\u0027s largest ice sheets located around the Antarctic and Greenland may be caused by the presence of warming, deep ocean waters, shoaling over continental shelves, and melting the underside of floating ice shelves. Additional knowledge of the temporal and spatial variability of the temperature fields underneath terminal ice shelves, such as those draining the West Antarctic Ice Sheet, are needed to accurately project future global climate effects on ice-shelf ocean interactions, and in order to inform societal and technological aspects of adaption to changing sea-level.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e TEMPERATURE LOGGERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e TEMPERATURE SENSORS", "is_usap_dc": true, "keywords": "GROUND STATIONS; Not provided; Conservative Temperature; MOORINGS; Ice Shelf Temperature; Ocean Temperature", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Zagorodnov, Victor; Holland, David; Tyler, Scott W.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED \u003e MOORINGS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Application of Distributed Temperature Sensors (DTS) for Antarctic Ice Shelves and Cavities", "uid": "p0000183", "west": null}, {"awards": "1146554 Rack, Frank", "bounds_geometry": "POLYGON((153.694 -77.89028,155.025433 -77.89028,156.356866 -77.89028,157.688299 -77.89028,159.019732 -77.89028,160.351165 -77.89028,161.682598 -77.89028,163.014031 -77.89028,164.345464 -77.89028,165.676897 -77.89028,167.00833 -77.89028,167.00833 -78.525252,167.00833 -79.160224,167.00833 -79.795196,167.00833 -80.430168,167.00833 -81.06514,167.00833 -81.700112,167.00833 -82.335084,167.00833 -82.970056,167.00833 -83.605028,167.00833 -84.24,165.676897 -84.24,164.345464 -84.24,163.014031 -84.24,161.682598 -84.24,160.351165 -84.24,159.019732 -84.24,157.688299 -84.24,156.356866 -84.24,155.025433 -84.24,153.694 -84.24,153.694 -83.605028,153.694 -82.970056,153.694 -82.335084,153.694 -81.700112,153.694 -81.06514,153.694 -80.430168,153.694 -79.795196,153.694 -79.160224,153.694 -78.525252,153.694 -77.89028))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 27 Apr 2015 00:00:00 GMT", "description": "This award provides support for \"EAGER: Handbook of Hot Water Drill System (HWDS) Design Considerations and Best Practices\" from the Antarctic Integrated System Science within the Office of Polar Programs. More and more science projects are proposing to use hot-water drilling systems (HWDS) to rapidly and/or cleanly access glacial and subglacial systems. To date the hot-water drill systems have been developed in isolation, and no attempt has been made to gather information about the different systems in one place. This proposal requests funds to document existing HWDS, and to then assess the design, testing, and development of a hot-water drill system that will be integrated with the evolving over-ice traverse capability of the USAP program. Intellectual Merit: A working handbook of best practices for hot-water drill design systems, including safety considerations, is long overdue, and will 1) provide suggestions for optimizing current systems; 2) contribute in the very near term to already funded projects such as WISSARD (Whillans Ice Stream Subglacial Access and Research Drilling); and 3) fit the long-term needs of the Antarctic science community who have identified rapid and clean access to glacial and subglaical environments as a top priority for the next decades. The collected information will be used for community education and training, will discuss potential design and operational trade-offs, and will identify ways to optimize the capabilities of an integrated USAP traverse and HWDS infrastructure. EAGER funding for this project is warranted because such a handbook has not been tried before, and needs to be shown to be doable prior to larger investments in such compilations. It fits the AISS (Antarctic Integrated System Science) program as an optimized HWDS will meet the needs of many different Antarctic research disciplines including biology, geology, glaciology, and oceanography. Broader Impacts: The proposed work is being done on behalf of the Antarctic research community, and will seek to capture the knowledge of experienced hot-water drill engineers who are nearing retirement, and to educate the next generation of hot-water drillers and engineers. The PI indicates he will work with the owners of such systems both within the US and abroad. Identification of best practices in hot-water drilling will save several different Antarctic research communities significant time, effort, and funding in the future.", "east": 167.00833, "geometry": "POINT(160.351165 -81.06514)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e GRAVITY CORER; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE TRANSDUCERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e NISKIN BOTTLES; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e FSI; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS", "is_usap_dc": false, "keywords": "Hot Water Drill; Subglacial Lake; Ross Ice Shelf; West Antarctic Ice Sheet; FIELD SURVEYS; TRAVERSE; Clean Access Drilling; Drilling Parameters; FIELD INVESTIGATION; DRILLING PLATFORMS; Not provided; Antarctica; WISSARD; Whillans Ice Stream; FIXED OBSERVATION STATIONS", "locations": "Antarctica; West Antarctic Ice Sheet; Whillans Ice Stream; Ross Ice Shelf", "north": -77.89028, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Rack, Frank", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e FIXED OBSERVATION STATIONS; LAND-BASED PLATFORMS \u003e VEHICLES \u003e TRAVERSE; Not provided; WATER-BASED PLATFORMS \u003e FIXED PLATFORMS \u003e SURFACE \u003e DRILLING PLATFORMS", "repositories": null, "science_programs": null, "south": -84.24, "title": "EAGER: Handbook of Hot Water Drill System (HWDS) Design Considerations and Best Practices.", "uid": "p0000729", "west": 153.694}, {"awards": "0229314 Stone, John", "bounds_geometry": null, "dataset_titles": "Reedy Glacier Exposure Ages, Antarctica", "datasets": [{"dataset_uid": "609601", "doi": "10.7265/N5MG7MF1", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Cosmogenic; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Reedy Glacier; Sample/collection Description; Sample/Collection Description", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Reedy Glacier Exposure Ages, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609601"}], "date_created": "Mon, 30 Mar 2015 00:00:00 GMT", "description": "The stability of the marine West Antarctic Ice Sheet (WAIS) remains an important, unresolved problem for predicting future sea level change. Recent studies indicate that the mass balance of the ice sheet today may be negative or positive. The apparent differences may stem in part from short-term fluctuations in flow. By comparison, geologic observations provide evidence of behavior over much longer time scales. Recent work involving glacial-geologic mapping, dating and ice-penetrating radar surveys suggests that deglaciation of both the Ross Sea Embayment and coastal Marie Byrd Land continued into the late Holocene, and leaves open the possibility of ongoing deglaciation and grounding-line retreat. However, previous work in the Ross Sea Embayment was based on data from just three locations that are all far to the north of the present grounding line. Additional data from farther south in the Ross Sea Embayment are needed to investigate whether recession has ended, or if the rate and pattern of deglaciation inferred from our previous study still apply to the present grounding line. This award provides support to reconstruct the evolution of Reedy Glacier, in the southern Transantarctic Mountains, since the Last Glacial Maximum (LGM). Because Reedy Glacier emerges from the mountains above the grounding line, its surface slope and elevation should record changes in thickness of grounded ice in the Ross Sea up to the present day. The deglaciation chronology of Reedy Glacier therefore can indicate whether Holocene retreat of the WAIS ended thousands of years ago, or is still continuing at present. This integrated glaciologic, glacial-geologic, and cosmogenic-isotope exposure- dating project will reconstruct past levels of Reedy Glacier. Over two field seasons, moraines will be mapped, dated and correlated at sites along the length of the glacier. Radar and GPS measurements will be made to supplement existing ice thickness and velocity data, which are needed as input for a model of glacier dynamics. The model will be used to relate geologic measurements to the grounding-line position downstream. Ultimately, the mapping, dating and ice-modeling components of the study will be integrated into a reconstruction that defines changes in ice thickness in the southern Ross Sea since the LGM, and relates these changes to the history of grounding-line retreat. This work directly addresses key goals of the West Antarctic Ice Sheet Initiative, which are to understand the dynamics, recent history and possible future behavior of the West Antarctic Ice Sheet.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "Surface Exposure Dates; FIELD SURVEYS; Aluminum-26; Erosion; Rock Samples; Beryllium-10; Exposure Age", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Late Quaternary History of Reedy Glacier", "uid": "p0000029", "west": null}, {"awards": "1246484 Balco, Gregory", "bounds_geometry": "POLYGON((-62 -63.5,-61.8 -63.5,-61.6 -63.5,-61.4 -63.5,-61.2 -63.5,-61 -63.5,-60.8 -63.5,-60.6 -63.5,-60.4 -63.5,-60.2 -63.5,-60 -63.5,-60 -63.6,-60 -63.7,-60 -63.8,-60 -63.9,-60 -64,-60 -64.1,-60 -64.2,-60 -64.3,-60 -64.4,-60 -64.5,-60.2 -64.5,-60.4 -64.5,-60.6 -64.5,-60.8 -64.5,-61 -64.5,-61.2 -64.5,-61.4 -64.5,-61.6 -64.5,-61.8 -64.5,-62 -64.5,-62 -64.4,-62 -64.3,-62 -64.2,-62 -64.1,-62 -64,-62 -63.9,-62 -63.8,-62 -63.7,-62 -63.6,-62 -63.5))", "dataset_titles": "Data repositories for UC-Berkeley/BGC thermochronometry and thermochronology research", "datasets": [{"dataset_uid": "001232", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Data repositories for UC-Berkeley/BGC thermochronometry and thermochronology research", "url": "http://noblegas.berkeley.edu/~noblegas/datarepository.html"}], "date_created": "Mon, 02 Mar 2015 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to use the (U-Th)/He system in apatite to investigate the exhumation history, development of the present topography, and pattern of glacial erosion in the central Antarctic Peninsula. The Antarctic Peninsula has been glaciated since the Eocene and Pleistocene climate cooling is hypothesized to have suppressed, rather than enhanced, glacial erosion. To achieve these goals, the PIs will use a thermochronometric record of when and how the present glacial valley relief formed. A challenge to the proposed research is that, unlike Pleistocene glacial landscapes in temperate areas, the Peninsula is ice-covered and it is not possible to directly sample the bedrock surface. The PIs hope to learn about the timing and process of glacial valley formation through apatite (U-Th)/He and 4He/3He measurements on glacial sediment collected near the grounding lines of major glaciers draining the Peninsula. Learning how the Antarctic Peninsula landscape formed is important to discern how the mechanics of glacial erosion operate on long time scales, and to understand how glaciers mediate the interaction between climate change and orogenic mass balance. This work addresses a fundamental question in Antarctic earth science of how to infer geologic and geomorphic processes active on an ice-covered and inaccessible landscape. Broader impacts: This proposal will bring new researchers into the Antarctic research community. A proposed collaboration with British Antarctic Survey researchers will build an international collaboration. The outcomes of this project have ancillary importance to other fields and addresses fundamental challenges in Antarctic Earth Science.", "east": -60.0, "geometry": "POINT(-61 -64)", "instruments": null, "is_usap_dc": false, "keywords": "Antarctica; Not provided; ICE SHEETS; Antarctic Peninsula", "locations": "Antarctica; Antarctic Peninsula", "north": -63.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Shuster, David; Balco, Gregory", "platforms": "Not provided", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -64.5, "title": "Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-temperature Detrital Thermochronometry", "uid": "p0000067", "west": -62.0}, {"awards": "0944087 Hamilton, Gordon", "bounds_geometry": "POLYGON((145 -80,147 -80,149 -80,151 -80,153 -80,155 -80,157 -80,159 -80,161 -80,163 -80,165 -80,165 -80.035,165 -80.07,165 -80.105,165 -80.14,165 -80.175,165 -80.21,165 -80.245,165 -80.28,165 -80.315,165 -80.35,163 -80.35,161 -80.35,159 -80.35,157 -80.35,155 -80.35,153 -80.35,151 -80.35,149 -80.35,147 -80.35,145 -80.35,145 -80.315,145 -80.28,145 -80.245,145 -80.21,145 -80.175,145 -80.14,145 -80.105,145 -80.07,145 -80.035,145 -80))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 23 Jan 2015 00:00:00 GMT", "description": "This award supports a project to understand the flow dynamics of large, fast-moving outlet glaciers that drain the East Antarctic Ice Sheet. The project includes an integrated field, remote sensing and modeling study of Byrd Glacier which is a major pathway for the discharge of mass from the East Antarctic Ice Sheet (EAIS) to the ocean. Recent work has shown that the glacier can undergo short-lived but significant changes in flow speed in response to perturbations in its boundary conditions. Because outlet glacier speeds exert a major control on ice sheet mass balance and modulate the ice sheet contribution to sea level rise, it is essential that their sensitivity to a range of dynamic processes is properly understood and incorporated into prognostic ice sheet models. The intellectual merit of the project is that the results from this study will provide critically important information regarding the flow dynamics of large EAIS outlet glaciers. The proposed study is designed to address variations in glacier behavior on timescales of minutes to years. A dense network of global positioning satellite (GPS) instruments on the grounded trunk and floating portions of the glacier will provide continuous, high-resolution time series of horizontal and vertical motions over a 26-month period. These results will be placed in the context of a longer record of remote sensing observations covering a larger spatial extent, and the combined datasets will be used to constrain a numerical model of the glacier\u0027s flow dynamics. The broader impacts of the work are that this project will generate results which are likely to be a significant component of next-generation ice sheet models seeking to predict the evolution of the Antarctic Ice Sheet and future rates of sea level rise. The most recent report from the Intergovernmental Panel on Climate Change (IPCC) highlights the imperfect understanding of outlet glacier dynamics as a major obstacle to the production of an accurate sea level rise projections. This project will provide significant research opportunities for several early-career scientists, including the lead PI for this proposal (she is both a new investigator and a junior faculty member at a large research university) and two PhD-level graduate students. The students will be trained in glaciology, geodesy and numerical modeling, contributing to society\u0027s need for experts in those fields. In addition, this project will strengthen international collaboration between polar scientists and geodesists in the US and Spain. The research team will work closely with science educators in the Center for Remote Sensing of Ice Sheets (CReSIS) outreach program to disseminate project results to non-specialist audiences.", "east": 165.0, "geometry": "POINT(155 -80.175)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "Sea Level Rise; FIELD INVESTIGATION; Glacier; LABORATORY; Outlet Glaciers; Boundary Conditions; Model; Numerical Model; FIELD SURVEYS; Antarctica; COMPUTERS; Not provided; Flow Dynamics", "locations": "Antarctica", "north": -80.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stearns, Leigh; Hamilton, Gordon S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -80.35, "title": "Collaborative Research: Byrd Glacier Flow Dynamics", "uid": "p0000319", "west": 145.0}, {"awards": "0632136 Nyblade, Andrew; 0632322 Wilson, Terry", "bounds_geometry": "POLYGON((-20 -70,-1 -70,18 -70,37 -70,56 -70,75 -70,94 -70,113 -70,132 -70,151 -70,170 -70,170 -72,170 -74,170 -76,170 -78,170 -80,170 -82,170 -84,170 -86,170 -88,170 -90,151 -90,132 -90,113 -90,94 -90,75 -90,56 -90,37 -90,18 -90,-1 -90,-20 -90,-20 -88,-20 -86,-20 -84,-20 -82,-20 -80,-20 -78,-20 -76,-20 -74,-20 -72,-20 -70))", "dataset_titles": "Incorporated Research Institutions for Seismology (IRIS); University NAVSTAR Consortium (UNAVCO)", "datasets": [{"dataset_uid": "000132", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Incorporated Research Institutions for Seismology (IRIS)", "url": "http://www.iris.edu/mda/YT?timewindow=2007-2018"}, {"dataset_uid": "000131", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "University NAVSTAR Consortium (UNAVCO)", "url": "http://www.unavco.org/data/gps-gnss/data-access-methods/dai2/app/dai2.html#groupingMod=contains;grouping=POLENET%20-%20ANET;scope=Station;sampleRate=normal"}], "date_created": "Thu, 22 Jan 2015 00:00:00 GMT", "description": "This project constructs POLENET a network of GPS and seismic stations in West Antarctica to understand how the mass of the West Antarctic ice sheet (WAIS) changes with time. The information is ultimately used to predict sea level rise accompanying global warming and interpret climate change records. The GPS (global positioning system) stations measure vertical and horizontal movements of bedrock, while the seismic stations characterize physical properties of the ice/rock interface, lithosphere, and mantle. Combined with satellite data, this project offers a more complete picture of the ice sheet\u0027s current state, its likely change in the near future, and its overall size during the last glacial maximum. This data will also be used to infer sub-ice sheet geology and the terrestrial heat flux, critical inputs to models of glacier movement. As well, this project improves tomographic models of the earth\u0027s deep interior and core through its location in the Earth\u0027s poorly instrumented southern hemisphere. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eBroader impacts of this project are varied. The work is relevant to society for improving our understanding of the impacts of global warming on sea level rise. It also supports education at the postdoctoral, graduate, and undergraduate levels, and outreach to groups underrepresented in the sciences. As an International Polar Year contribution, this project establishes a legacy of infrastructure for polar measurements. It also involves an international collaboration of twenty four countries. For more information see IPY Project #185 at IPY.org. NSF is supporting a complementary Arctic POLENET array being constructed in Greenland under NSF Award #0632320.", "east": 170.0, "geometry": "POINT(75 -80)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "Antarctica; Bedrock; Ice/Rock Interface; Climate Change; Seismic; West Antarctic Ice Sheet; FIELD SURVEYS; LABORATORY; Not provided; FIELD INVESTIGATION; Mass Balance; COMPUTERS; Sub-Ice Sheet Geology; Sea Level; Terrestrial Heat Flux", "locations": "Antarctica; West Antarctic Ice Sheet", "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wilson, Terry; Bevis, Michael; Anandakrishnan, Sridhar; Wiens, Douglas; Aster, Richard; Smalley, Robert; Nyblade, Andrew; Winberry, Paul; Hothem, Larry; Dalziel, Ian W.; Huerta, Audrey D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "IRIS", "repositories": "IRIS; UNAVCO", "science_programs": null, "south": -90.0, "title": "Collaborative Research: IPY: POLENET-Antarctica: Investigating Links Between Geodynamics and Ice Sheets", "uid": "p0000315", "west": -20.0}, {"awards": "0732804 McPhee, Miles; 0732730 Truffer, Martin; 0732869 Holland, David; 0732906 Nowicki, Sophie", "bounds_geometry": "POINT(-100.728 -75.0427)", "dataset_titles": "Automatic Weather Station Pine Island Glacier; Borehole Temperatures at Pine Island Glacier, Antarctica; Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "datasets": [{"dataset_uid": "600072", "doi": "10.15784/600072", "keywords": "Antarctica; Atmosphere; McMurdo; Meteorology; Oceans; Ross Island; Southern Ocean", "people": "McPhee, Miles G.", "repository": "USAP-DC", "science_program": null, "title": "Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "url": "https://www.usap-dc.org/view/dataset/600072"}, {"dataset_uid": "601216", "doi": "10.15784/601216", "keywords": "Antarctica; Atmosphere; Automated Weather Station; Flux; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meteorology; Pine Island Glacier; Weather Station Data", "people": "Mojica Moncada, Jhon F.; Holland, David", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Automatic Weather Station Pine Island Glacier", "url": "https://www.usap-dc.org/view/dataset/601216"}, {"dataset_uid": "609627", "doi": "10.7265/N5T151MV", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Pine Island Glacier; Temperature", "people": "Truffer, Martin; Stanton, Timothy", "repository": "USAP-DC", "science_program": null, "title": "Borehole Temperatures at Pine Island Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609627"}], "date_created": "Tue, 30 Dec 2014 00:00:00 GMT", "description": "Collaborative With: McPhee 0732804, Holland 0732869, Truffer 0732730, Stanton 0732926, Anandakrishnan 0732844 \u003cbr/\u003eTitle: Collaborative Research: IPY: Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica\u003cbr/\u003e\u003cbr/\u003eThe Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the \"Multidisciplinary Study of the Amundsen Sea Embayment\" proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded \"Polar Palooza\" education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project.", "east": -100.728, "geometry": "POINT(-100.728 -75.0427)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": true, "keywords": "West Antarctica; Seismic; LABORATORY; Amundsen Sea; Ocean-Ice Interaction; Remote Sensing; COMPUTERS; FIELD SURVEYS; LANDSAT-8; FIELD INVESTIGATION; Ocean Profiling; AUVS; Sea Level Rise; Stability; Not provided; Deformation; SATELLITES; Ice Movement; GROUND-BASED OBSERVATIONS; Ice Temperature; International Polar Year; Borehole", "locations": "West Antarctica; Amundsen Sea", "north": -75.0427, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Truffer, Martin; Stanton, Timothy; Bindschadler, Robert; Behar, Alberto; Nowicki, Sophie; Anandakrishnan, Sridhar; Holland, David; McPhee, Miles G.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-8; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES; WATER-BASED PLATFORMS \u003e UNCREWED VEHICLES \u003e SUBSURFACE \u003e AUVS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0427, "title": "Collaborative Research; IPY: Ocean-Ice Interaction in the Amundsen Sea sector of West Antarctica", "uid": "p0000043", "west": -100.728}, {"awards": "0838849 Bender, Michael; 0838843 Kurbatov, Andrei", "bounds_geometry": "POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667))", "dataset_titles": "Allan Hills Stable Water Isotopes; Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)", "datasets": [{"dataset_uid": "609541", "doi": "10.7265/N5NP22DF", "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope", "people": "Kurbatov, Andrei V.; Introne, Douglas; Mayewski, Paul A.; Spaulding, Nicole", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills Stable Water Isotopes", "url": "https://www.usap-dc.org/view/dataset/609541"}, {"dataset_uid": "600099", "doi": "10.15784/600099", "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Ice Core Records; Paleoclimate; Solid Earth", "people": "Bender, Michael", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)", "url": "https://www.usap-dc.org/view/dataset/600099"}], "date_created": "Wed, 10 Dec 2014 00:00:00 GMT", "description": "This award supports a project to generate an absolute timescale for the Allan Hills Blue Ice Area (BIA), and then to reconstruct details of past climate changes and greenhouse gas concentrations for certain time periods back to 2.5 Ma. Ice ages will be determined by applying emerging methods for absolute and relative dating of trapped air bubbles (based on Argon-40/Argon-38, delta-18O of O2, and the O2/N2 ratio). To demonstrate the potential of the Allan Hills BIAs as a paleoclimate archive trenches and ice cores will be collected for age intervals corresponding to 110-140 ka, 1 Ma, and 2.5 Ma. During the proposed two field seasons a total of 6x100 m and additional 15 m cores will be combined with trenching. The intellectual merit of the proposed activity is that the results of this work will extend the landmark work of EPICA and other deep ice coring efforts, which give records dating back to 0.8 Ma, and will complement work planned by IPICS to drill a continuous Antarctic ice core extending to 1.5 Ma. The results will help to advance understanding of major climate regimes and transitions that took place between 0-2.5 Ma, including the 40 kyr world and the mid-Pleistocene climate transition. A major long-term scientific goal is to provide a transformative approach to the collection of paleoclimate records by establishing an \"International Climate Park\" in the Allan Hills BIA that would enable sampling of large quantities of known age ice as old as 2.5 Ma, by any interested American or foreign investigator. The broader impacts resulting from the proposed activity include training students who are well versed in advanced field, laboratory and numerical modeling methods combining geochemistry, glaciology, and paleoclimatology. We will include material relevant to our proposed research in our ongoing efforts in local education and in our outreach efforts for media. The University of Maine already has cyberinfrastructure, using state of the art web-based technology, which can provide a wide community of scientists with fast access to the results of our research. The work will contribute to the broad array of climate change studies that is informing worldwide understanding of natural and anthropogenic forced climate change, and the options for responding. This award has field work in Antarctica.", "east": 159.41667, "geometry": "POINT(159.29167 -76.7)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "GROUND-BASED OBSERVATIONS; LABORATORY; Deuterium Isotopes; Not provided; Oxygen Isotope", "locations": null, "north": -76.66667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Spaulding, Nicole; Introne, Douglas; Bender, Michael; Kurbatov, Andrei V.; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.73333, "title": "Collaborative Research: Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)", "uid": "p0000046", "west": 159.16667}, {"awards": "1043092 Steig, Eric; 1043167 White, James", "bounds_geometry": null, "dataset_titles": "17O excess from WAIS Divide, 0 to 25 ka BP; WAIS Divide Ice Core Discrete CH4 (80-3403m); WAIS Divide WDC06A Oxygen Isotope Record", "datasets": [{"dataset_uid": "601741", "doi": "10.15784/601741", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; WAIS", "people": "Brook, Edward J.; Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Discrete CH4 (80-3403m)", "url": "https://www.usap-dc.org/view/dataset/601741"}, {"dataset_uid": "601413", "doi": "10.15784/601413", "keywords": "Antarctica; Ice Core; Oxygen Isotope; WAIS Divide", "people": "Schoenemann, Spruce; Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "17O excess from WAIS Divide, 0 to 25 ka BP", "url": "https://www.usap-dc.org/view/dataset/601413"}, {"dataset_uid": "609629", "doi": "10.7265/N5GT5K41", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide WDC06A Oxygen Isotope Record", "url": "https://www.usap-dc.org/view/dataset/609629"}], "date_created": "Sat, 06 Dec 2014 00:00:00 GMT", "description": "This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e INFRARED LASER SPECTROSCOPY; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e INFRARED LASER SPECTROSCOPY", "is_usap_dc": true, "keywords": "AMD; ANALYTICAL LAB; USAP-DC; Amd/Us; LABORATORY; ICE CORE RECORDS; Antarctica; Wais Divide-project; FIELD SURVEYS; USA/NSF", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "uid": "p0000010", "west": null}, {"awards": "1241574 Hemming, Sidney; 1241460 Barbeau, David", "bounds_geometry": "POLYGON((-67 -63.2,-65.97 -63.2,-64.94 -63.2,-63.91 -63.2,-62.88 -63.2,-61.85 -63.2,-60.82 -63.2,-59.79 -63.2,-58.76 -63.2,-57.73 -63.2,-56.7 -63.2,-56.7 -63.54,-56.7 -63.88,-56.7 -64.22,-56.7 -64.56,-56.7 -64.9,-56.7 -65.24,-56.7 -65.58,-56.7 -65.92,-56.7 -66.26,-56.7 -66.6,-57.73 -66.6,-58.76 -66.6,-59.79 -66.6,-60.82 -66.6,-61.85 -66.6,-62.88 -66.6,-63.91 -66.6,-64.94 -66.6,-65.97 -66.6,-67 -66.6,-67 -66.26,-67 -65.92,-67 -65.58,-67 -65.24,-67 -64.9,-67 -64.56,-67 -64.22,-67 -63.88,-67 -63.54,-67 -63.2))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 03 Dec 2014 00:00:00 GMT", "description": "Intellectual Merit: Recent geochemical, sequence stratigraphic, and integrated investigations of marine strata from several continental margins and ocean basins suggest that ephemeral ice sheets may have existed on Antarctica during parts of the Cretaceous and early Paleogene. However, atmospheric carbon dioxide estimates for this time are as much as four times modern levels. With such greenhouse conditions, the presence of Antarctic ice sheets would imply that our current understanding of Earth?s climate system, and specifically the interpreted thresholds of Antarctic glaciation and deglaciation should be reconsidered. The proposed research will compare the quantity and provenance of Cretaceous sediments in the Larsen basin of the eastern Antarctic Peninsula with the exhumation chronology and composition of potential sediment source terranes on the peninsula and in adjacent regions. New outcrop stratigraphic analyses with improvements in the age models from radioisotopic approaches will be integrated to determine the amount of detrital sediment fluxed to the Larsen basin between key chronostratigraphic surfaces. Microtextural analysis of quartz sand and silt grains will help determine whether the Larsen basin detrital sediment originated from glacial weathering. These preliminary results will test the viability of the proposed approach to assess the controversial Cretaceous Antarctic glaciation hypothesis. Broader impacts: The proposed work will partially support a PhD, a MSc, and three undergraduate students at the University of South Carolina. The PIs will publicize this work through volunteer speaking engagements and the development of videos and podcasts. They also commit to prompt publication of the results and timely submission of data to archives. The development/improvement of the Larsen basin age model will benefit ongoing research in paleobiology, paleoclimate and biogeography. Development of the glauconite K-Ar and Rb-Sr chronometers could be an important outcome beyond the direct scope of the proposed research.", "east": -56.7, "geometry": "POINT(-61.85 -64.9)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e LA-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MC-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e IRMS", "is_usap_dc": true, "keywords": "Not provided; Noble-Gas Mass Spectrometer; Antarctic Peninsula", "locations": "Antarctic Peninsula", "north": -63.2, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PROTEROZOIC; PHANEROZOIC \u003e PALEOZOIC; PHANEROZOIC \u003e MESOZOIC; PHANEROZOIC \u003e CENOZOIC; PHANEROZOIC \u003e MESOZOIC \u003e CRETACEOUS; PHANEROZOIC \u003e CENOZOIC \u003e PALEOGENE", "persons": "Barbeau, David; Hemming, Sidney R.; Barbeau, David Jr", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -66.6, "title": "Collaborative Research: EAGER: Evaluating the Larsen basin\u0027s suitability for testing the Cretaceous Glaciation Hypothesis", "uid": "p0000369", "west": -67.0}, {"awards": "0838970 Foreman, Christine", "bounds_geometry": "POINT(161.667 -77.117)", "dataset_titles": "The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "datasets": [{"dataset_uid": "600104", "doi": "10.15784/600104", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Microbiology", "people": "Foreman, Christine", "repository": "USAP-DC", "science_program": null, "title": "The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600104"}], "date_created": "Fri, 10 Oct 2014 00:00:00 GMT", "description": "Dissolved organic matter (DOM) comprises a significant pool of Earth\u0027s organic carbon that dwarfs the amount present in living aquatic organisms. The properties and reactivity of DOM are not well defined, and the evolution of autochthonous DOM from its precursor materials in freshwater has not been observed. Recent sampling of a supraglacial stream formed on the Cotton Glacier in the Transantarctic Mountains revealed DOM that more closely resembles an assemblage of recognizable precursor organic compounds, based upon its UV-VIS and fluorescence spectra. It is suggested that the DOM from this water evolved over time to resemble materials present in marine and many inland surface waters. The transient nature of the system i.e., it reforms seasonally, also prevents any accumulation of the refractory DOM present in most surface waters. Thus, the Cotton Glacier provides us with a unique environment to study the formation of DOM from precursor materials. An interdisciplinary team will study the biogeochemistry of this progenitor DOM and how microbes modify it. By focusing on the chemical composition of the DOM as it shifts from precursor material to the more humified fractions, the investigators will relate this transition to bioavailability, enzymatic activity, community composition and microbial growth efficiency. This project will support education at all levels, K-12, high school, undergraduate, graduate and post-doc and will increase participation by under-represented groups in science. Towards these goals, the investigators have established relationships with girls\u0027 schools and Native American programs. Additional outreach will be carried out in coordination with PolarTREC, PolarPalooza, and if possible, an Antarctic Artist and Writer.", "east": 161.667, "geometry": "POINT(161.667 -77.117)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.117, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Foreman, Christine", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "Collaborative Research: The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "uid": "p0000458", "west": 161.667}, {"awards": "0944199 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": "WAIS Divide Sonic Log Data", "datasets": [{"dataset_uid": "609592", "doi": "10.7265/N5T72FD2", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; Sonic Log; WAIS Divide; WAIS Divide Ice Core", "people": "Kluskiewicz, Dan; Waddington, Edwin D.; McCarthy, Michael; Anandakrishnan, Sridhar; Matsuoka, Kenichi", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Sonic Log Data", "url": "https://www.usap-dc.org/view/dataset/609592"}], "date_created": "Wed, 03 Sep 2014 00:00:00 GMT", "description": "0944199/Matsuoka\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to test the hypothesis that abrupt changes in fabric exist and are associated with both climate transitions and volcanic eruptions. It requires depth-continuous measurements of the fabric. By lowering a new logging tool into the WAIS Divide borehole after the completion of the core drilling, this project will measure acoustic-wave speeds as a function of depth and interpret it in terms of ice fabrics. This interpretation will be guided by ice-core-measured fabrics at sparse depths. This project will apply established analytical techniques for the ice-sheet logging and estimate depth profiles of both compressional- and shear-wave speeds at short intervals (~ 1 m). Previous logging projects measured only compressional-wave speeds averaged over typically 5-7 m intervals. Thus the new logger will enable more precise fabric interpretations. Fabric measurements using thin sections have revealed distinct fabric patterns separated by less than several meters; fabric measurements over a shorter period are crucial. At the WAIS Divide borehole, six two-way logging runs will be made with different observational parameters so that multiple wave-propagation modes will be identified, yielding estimates of both compressional- and shear-wave speeds. Each run takes approximately 24 hours to complete; we propose to occupy the boreholes in total eight days. The logging at WAIS Divide is temporarily planned in December 2011, but the timing is not critical. This project?s scope is limited to the completion of the logging and fabric interpretations. Results will be immediately shared with other WAIS Divide researchers. Direct benefits of this data sharing include guiding further thin-section analysis of the fabric, deriving a precise thinning function that retrieves more accurate accumulation history and depth-age scales. The PIs of this project have conducted radar and seismic surveys in this area and this project will provide a ground truth for these regional remote-sensing assessments of the ice interior. In turn, these remote sensing means can extend the results from the borehole to larger parts of the central West Antarctica. This project supports education for two graduate students for geophysics, glaciology, paleoclimate, and polar logistics. The instrument that will be acquired in this project can be used at other boreholes for ice-fabric characterizations and for englacial hydrology (wetness of temperate ice).", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e PROBES", "is_usap_dc": true, "keywords": "WAIS Divide; GROUND STATIONS; Western Divide Core; Antarctic Ice Sheet", "locations": "Antarctic Ice Sheet; WAIS Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Matsuoka, Kenichi; Kluskiewicz, Dan; Anandakrishnan, Sridhar; McCarthy, Michael; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Collaborative research: acoustic logging of the WAIS Divide borehole", "uid": "p0000051", "west": null}, {"awards": "1043700 Harry, Dennis", "bounds_geometry": "POLYGON((-180 -70,-176.5 -70,-173 -70,-169.5 -70,-166 -70,-162.5 -70,-159 -70,-155.5 -70,-152 -70,-148.5 -70,-145 -70,-145 -71,-145 -72,-145 -73,-145 -74,-145 -75,-145 -76,-145 -77,-145 -78,-145 -79,-145 -80,-148.5 -80,-152 -80,-155.5 -80,-159 -80,-162.5 -80,-166 -80,-169.5 -80,-173 -80,-176.5 -80,180 -80,177.5 -80,175 -80,172.5 -80,170 -80,167.5 -80,165 -80,162.5 -80,160 -80,157.5 -80,155 -80,155 -79,155 -78,155 -77,155 -76,155 -75,155 -74,155 -73,155 -72,155 -71,155 -70,157.5 -70,160 -70,162.5 -70,165 -70,167.5 -70,170 -70,172.5 -70,175 -70,177.5 -70,-180 -70))", "dataset_titles": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History; Ross Sea post-middle Miocene seismic interpretation", "datasets": [{"dataset_uid": "600128", "doi": "10.15784/600128", "keywords": "Andrill; Antarctica; Continental Rift; Geology/Geophysics - Other; Lithosphere; Model; Ross Sea; Solid Earth; Tectonic; Transantarctic Mountains", "people": "Harry, Dennis L.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "url": "https://www.usap-dc.org/view/dataset/600128"}, {"dataset_uid": "601227", "doi": "10.15784/601227", "keywords": "Andrill; Antarctica; Marine Geoscience; Ross Sea; Seismic Interpretation; Seismic Reflection; Stratigraphy; Subsidence; Victoria Land Basin", "people": "Harry, Dennis L.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Ross Sea post-middle Miocene seismic interpretation", "url": "https://www.usap-dc.org/view/dataset/601227"}], "date_created": "Sun, 31 Aug 2014 00:00:00 GMT", "description": "Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.", "east": -145.0, "geometry": "POINT(-175 -75)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; MARINE GEOPHYSICS; Antarctica; NOT APPLICABLE", "locations": "Antarctica", "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harry, Dennis L.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -80.0, "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "uid": "p0000467", "west": 155.0}, {"awards": "1354231 Kowalewski, Douglas", "bounds_geometry": "POLYGON((-180 -70,-174 -70,-168 -70,-162 -70,-156 -70,-150 -70,-144 -70,-138 -70,-132 -70,-126 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,178 -85,176 -85,174 -85,172 -85,170 -85,168 -85,166 -85,164 -85,162 -85,160 -85,160 -83.5,160 -82,160 -80.5,160 -79,160 -77.5,160 -76,160 -74.5,160 -73,160 -71.5,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "datasets": [{"dataset_uid": "600140", "doi": "10.15784/600140", "keywords": "Antarctica; Atmosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Model Data; Paleoclimate; Transantarctic Mountains", "people": "Kowalewski, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/600140"}], "date_created": "Thu, 28 Aug 2014 00:00:00 GMT", "description": "Intellectual Merit: Neogene sediment records recovered by ANDRILL suggest multiple events of open water conditions and elevated sea surface temperatures at times when terrestrial data from the McMurdo Dry Valleys indicate hyper arid, cold, desert conditions. Interpretation of the ANDRILL data suggests the West Antarctic Ice Sheet is highly sensitive to changes in Pliocene sea surface temperatures and this conclusion has been supported by recent Global Circulation Model results for the early to mid Pliocene. The PIs propose to model paleo-ice configurations and warm orbits associated with a WAIS collapse to assess potential climate change in East Antarctica. During such episodes of polar warmth they propose to answer: What is the limit of ablation along the East Antarctic Ice Sheet?; Are relict landforms in the Dry Valleys susceptible to modification from increase in maximum summertime temperatures?; and Is there sufficient increase in minimum wintertime temperatures to sustain a tundra environment in the Dry Valleys? Integration of depositional records and model outputs have the potential to test the performance of numerical models currently under development as part of ANDRILL; reconcile inconsistencies between marine and terrestrial paleoclimate records in high Southern Latitudes; and improve understanding of Antarctic climate and ice volume sensitivity to forcing for both the East Antarctic and West Antarctic Ice Sheets. Broader impacts: Results from this study have the potential to be used widely by the research community. Outreach to local elementary schools from other funded efforts will continue and be extended to homeschooled students. A Post Doc will be supported as part of this award.", "east": -120.0, "geometry": "POINT(-160 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kowalewski, Douglas", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "uid": "p0000463", "west": 160.0}, {"awards": "0944078 Albert, Mary", "bounds_geometry": "POINT(112.05 79.28)", "dataset_titles": "Firn Permeability and Density at WAIS Divide", "datasets": [{"dataset_uid": "609602", "doi": "10.7265/N57942NT", "keywords": "Antarctica; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Albert, Mary R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Firn Permeability and Density at WAIS Divide", "url": "https://www.usap-dc.org/view/dataset/609602"}], "date_created": "Fri, 15 Aug 2014 00:00:00 GMT", "description": "This award supports a project to investigate the transformations from snow to firn to ice and the underlying physics controlling firn\u0027s ability to store atmospheric samples from the past. Senior researchers, a graduate student, and several undergraduates will make high-resolution measurements of both the diffusivity and permeability profiles of firn cores from several sites in Antarctica and correlate the results with their microstructures quantified using advanced materials characterization techniques (scanning electron microscopy and x-ray computed tomography). The use of cores from different sites will enable us to examine the influence of different local climate conditions on the firn structure. We will use the results to help interpret existing measurements of firn air chemical composition at several sites where firn air measurements exist. There are three closely-linked goals of this project: to quantify the dependence of interstitial transport properties on firn microstructure from the surface down to the pore close-off depth, to determine at what depths bubbles form and entrap air, and investigate the extent to which these features exhibit site-to-site differences, and to use the measurements of firn air composition and firn structure to better quantify the differences between atmospheric composition (present and past), and the air trapped in both the firn and in air bubbles within ice by comparing the results of the proposed work with firn air measurements that have been made at the WAIS Divide and Megadunes sites. The broader impacts of this project are that the study will this study will enable us to elucidate the fundamental controls on the metamorphism of firn microstructure and its impact on processes of gas entrapment that are important to understanding ice core evidence of past atmospheric composition and climate change. The project will form the basis for the graduate research of a PhD student at Dartmouth, with numerous opportunities for undergraduate involvement in cold room measurements and outreach. The investigators have a track record of successfully mentoring women students, and will build on this experience. In conjunction with local earth science teachers, and graduate and undergraduate students will design a teacher-training module on the role of the Polar Regions in climate change. Once developed and tested, this module will be made available to the broader polar research community for their use with teachers in their communities.", "east": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e MICROTOMOGRAPHY; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": true, "keywords": "Firn Air; FIELD SURVEYS; Physics; GROUND-BASED OBSERVATIONS; Antarctica; Megadunes; Tomography; Wais Divide-project; Firn Core; FIELD INVESTIGATION; Not provided; Firn Permeability; LABORATORY; Visual Observations; Ice; Firn; WAIS Divide; Microstructure; Density", "locations": "Antarctica; WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Albert, Mary R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.28, "title": "Firn Metamorphism: Microstructure and Physical Properties", "uid": "p0000049", "west": -112.05}, {"awards": "0539578 Alley, Richard", "bounds_geometry": null, "dataset_titles": "Bubble Number-density Data and Modeled Paleoclimates", "datasets": [{"dataset_uid": "609538", "doi": "10.7265/N5JW8BTJ", "repository": "USAP-DC", "science_program": null, "title": "Bubble Number-density Data and Modeled Paleoclimates", "url": "http://www.usap-dc.org/view/dataset/609538"}], "date_created": "Thu, 14 Aug 2014 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Air Bubbles; Antarctica; Camera; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fegyveresi, John; Alley, Richard", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "0944489 Williams, Trevor", "bounds_geometry": "POLYGON((-55 -58,-33.2 -58,-11.4 -58,10.4 -58,32.2 -58,54 -58,75.8 -58,97.6 -58,119.4 -58,141.2 -58,163 -58,163 -60,163 -62,163 -64,163 -66,163 -68,163 -70,163 -72,163 -74,163 -76,163 -78,141.2 -78,119.4 -78,97.6 -78,75.8 -78,54 -78,32.2 -78,10.4 -78,-11.4 -78,-33.2 -78,-55 -78,-55 -76,-55 -74,-55 -72,-55 -70,-55 -68,-55 -66,-55 -64,-55 -62,-55 -60,-55 -58))", "dataset_titles": "History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris", "datasets": [{"dataset_uid": "600116", "doi": "10.15784/600116", "keywords": "Geochronology; George V Land; IODP U1356; IODP U1361; Marine Sediments; ODP1165; Prydz Bay; Solid Earth; Southern Ocean; Wilkes Land", "people": "Williams, Trevor; Hemming, Sidney R.", "repository": "USAP-DC", "science_program": null, "title": "History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris", "url": "https://www.usap-dc.org/view/dataset/600116"}], "date_created": "Wed, 13 Aug 2014 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThe PIs propose to study the stability and dynamics of the East Antarctic ice sheet during the Pliocene in the area of the Wilkes and Aurora subglacial basins. Models indicate the ice sheet is most sensitive to warming in these low-lying areas. This study is important as there is very little direct evidence about which parts of the East Antarctic ice sheet became unstable under warm conditions. In a pilot study the PIs have shown that the isotopic geochemical signature of downcore ice-rafted debris (IRD) can be linked to continental source areas indicating which parts of the ice sheet reached the coast and calved IRD-bearing icebergs. Their initial results suggest rapid iceberg discharge from the Wilkes Land and Ad\u00e9lie Land coastal areas at times in the late Miocene and early Pliocene. In this study the PIs will analyze IRD from IODP sediment cores collected on the continental rise off East Antarctica. By analyzing 40Ar/39Ar ages of hornblende IRD grains, U-Pb ages of zircons, and Sm-Nd isotopes of the fine fraction of several IRD-rich layers for each core, they will be able to fingerprint continental source areas that will indicated ice extent and dynamics on East Antarctica. The PIs will also carry out detailed studies across a few of these layers to characterize the anatomy of the ice-rafting event and better understand the mechanism of ice destabilization.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThe data collected will be important for scientists in a broad variety of fields. The project will involve one undergraduate student and one summer intern at LDEO, and a graduate student at Imperial College London. The project will expose to cutting edge methodologies as well as an international research team. Data from the project will be deposited in the online databases (SedDB) and all results and methods will be made available to the scientific community through publications in peer-reviewed journals and attendance at international conferences.", "east": 163.0, "geometry": "POINT(54 -68)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -58.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Williams, Trevor; Hemming, Sidney R.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris", "uid": "p0000353", "west": -55.0}, {"awards": "0944475 Kaplan, Michael", "bounds_geometry": "POLYGON((-149.7 -84.1,-118.61 -84.1,-87.52 -84.1,-56.43 -84.1,-25.34 -84.1,5.75 -84.1,36.84 -84.1,67.93 -84.1,99.02 -84.1,130.11 -84.1,161.2 -84.1,161.2 -84.43,161.2 -84.76,161.2 -85.09,161.2 -85.42,161.2 -85.75,161.2 -86.08,161.2 -86.41,161.2 -86.74,161.2 -87.07,161.2 -87.4,130.11 -87.4,99.02 -87.4,67.93 -87.4,36.84 -87.4,5.75 -87.4,-25.34 -87.4,-56.43 -87.4,-87.52 -87.4,-118.61 -87.4,-149.7 -87.4,-149.7 -87.07,-149.7 -86.74,-149.7 -86.41,-149.7 -86.08,-149.7 -85.75,-149.7 -85.42,-149.7 -85.09,-149.7 -84.76,-149.7 -84.43,-149.7 -84.1))", "dataset_titles": "Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "datasets": [{"dataset_uid": "600115", "doi": "10.15784/600115", "keywords": "Antarctica; Cosmogenic Dating; Sample/collection Description; Sample/Collection Description; Solid Earth; Transantarctic Mountains", "people": "Kaplan, Michael", "repository": "USAP-DC", "science_program": null, "title": "Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "url": "https://www.usap-dc.org/view/dataset/600115"}], "date_created": "Thu, 17 Jul 2014 00:00:00 GMT", "description": "The proposed work will investigate changes in the compositional variation of glacial tills over time across two concentric sequences of Pleistocene moraines located adjacent to the heads of East Antarctic outlet glaciers in the Transantarctic Mountains (TAM). The chronologic framework for this work will be generated from cosmogenic exposure ages of boulders on prominent morainal ridges. The PIs hypothesize that variations in till composition may indicate a change in ice flow direction or a change in the composition of the original source area, while ages of the moraines provide a long-term terrestrial perspective on ice sheet dynamics. Both results are vital for modeling experiments that aim to reconstruct the East Antarctic Ice Sheet and assess its role in the global climate system and its potential impact on global sea level rise. The variation of till compositions through time also allows for a more accurate interpretation of sediment cores from the Ross Sea and the Southern Ocean. Additionally, till exposures at the head of some East Antarctic outlet glaciers have been shown to contain subglacial material derived from East Antarctic bedrock, providing a window through the ice to view East Antarctica?s inaccessible bedrock. Till samples will be collected from two well-preserved sequences of moraine crests at Mt. Howe (head of Scott Glacier) and Mt. Achernar (between Beardmore and Nimrod Glaciers). Each size fraction in glacial till provides potentially valuable information, and the PIs will measure the petrography of the clast and sand fractions, quantitative X-ray diffraction on the crushed \u003c2mm fraction, elemental abundance of the silt/clay fraction, and U/Pb of detrital zircons in the sand fraction. Data collection will rely on established methods previously used in this region and the PIs will also explore new methods to assess their efficacy. On the same moraines crests sampled for provenance studies, the PIs will sample for cosmogenic surface exposure analyses to provide a chronologic framework at the sites for provenance changes through time. \u003cbr/\u003e\u003cbr/\u003eBroader Impact \u003cbr/\u003eThe proposed research involves graduate and undergraduate training in a diverse array of laboratory methods. Students and PIs will be make presentations to community and campus groups, as well as conduct interviews with local news outlets. The proposed work also establishes a new, potentially long-term, collaboration between scientists at IUPUI and LDEO and brings a new PI (Kaplan) into the field of Antarctic Earth Sciences.", "east": 161.2, "geometry": "POINT(5.75 -85.75)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION", "locations": null, "north": -84.1, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kaplan, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.4, "title": "Collaborative Research: Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "uid": "p0000459", "west": -149.7}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "MODIS Mosaic of Antarctica 2008-2009 (MOA2009) Image Map", "datasets": [{"dataset_uid": "609593", "doi": "10.7265/N5KP8037", "repository": "USAP-DC", "science_program": null, "title": "MODIS Mosaic of Antarctica 2008-2009 (MOA2009) Image Map", "url": "http://www.usap-dc.org/view/dataset/609593"}], "date_created": "Thu, 17 Jul 2014 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MODIS; Satellite Remote Sensing", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bohlander, Jennifer; Haran, Terry; Scambos, Ted; Painter, Thomas; Fahnestock, Mark", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "1139739 Hansen, Samantha", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "A New Approach to Investigate the Seismic Velocity Structure beneath Antarctica", "datasets": [{"dataset_uid": "600132", "doi": "10.15784/600132", "keywords": "Antarctica; Geology/Geophysics - Other; Lithosphere; Seismic Tomography; Solid Earth", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "A New Approach to Investigate the Seismic Velocity Structure beneath Antarctica", "url": "https://www.usap-dc.org/view/dataset/600132"}], "date_created": "Mon, 14 Jul 2014 00:00:00 GMT", "description": "Intellectual Merit: Numerous candidate models for the geologic processes that have shaped the Antarctic continent have been proposed. To discriminate between them, detailed images of the upper mantle structure are required; however, the only existing continental-scale images of seismic structure beneath Antarctica lack sufficient resolution to delineate important, diagnostic features. Using newly available data from various Antarctic seismic networks, the PI will employ the adaptively parameterized tomography method to develop a high-resolution, continental-scale seismic velocity model for all of Antarctica. The proposed tomography method combines regional seismic travel-time datasets in the context of a global model to create a composite continental-scale model of upper mantle structure. The proposed method allows for imaging of finer structure in areas with better seismic ray coverage while simultaneously limiting the resolution of features in regions with less coverage. This research will help advance understanding of important global processes, such as craton formation, mountain building, continental rifting and associated magmatism. Additionally, the proposed research will have important impacts on other fields of Antarctic science. Constraints provided by tomographic results can be used to develop thermal models of the lithosphere needed to characterize the history and dynamics of ice sheets. Also, further constraints on lithospheric structure are required by climate-ice models, which are focused on understanding the cooling history of the Antarctic continent. Broader impacts: The PI is a new faculty member at the University of Alabama after having been funded as a National Science Foundation Postdoctoral Fellow in Polar Regions Research. The graduate student supported by this project is new to polar research. Through the UA-Tuscaloosa Magnet School partnership program, the PI will educate K-12 students about the Antarctic environment and associated career opportunities through various online and hands-on activities. University of Alabama dedicates a significant percentage of its enrollment space to underrepresented groups.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Hansen, Samantha", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "New Approach to Investigate the Seismic Velocity Structure beneath Antarctica", "uid": "p0000354", "west": -180.0}, {"awards": "0839093 McConnell, Joseph; 0839075 Priscu, John; 0839122 Saltzman, Eric", "bounds_geometry": "POINT(112.05 -79.28)", "dataset_titles": "Fluorescence spectroscopy data from the West Antarctic Ice Sheet (WAIS) Divide ice core, WDC06A; Holocene Black Carbon in Antarctica; Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core; Prokaryotic cell concentration record from the WAIS Divide ice core", "datasets": [{"dataset_uid": "601006", "doi": "10.15784/601006", "keywords": "Antarctica; Fluorescence Spectroscopy; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "D\u0027Andrilli, Juliana; Priscu, John", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Fluorescence spectroscopy data from the West Antarctic Ice Sheet (WAIS) Divide ice core, WDC06A", "url": "https://www.usap-dc.org/view/dataset/601006"}, {"dataset_uid": "601034", "doi": "10.15784/601034", "keywords": "Antarctica; Atmosphere; Black Carbon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph; Arienzo, Monica", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Holocene Black Carbon in Antarctica", "url": "https://www.usap-dc.org/view/dataset/601034"}, {"dataset_uid": "601072", "doi": "10.15784/601072", "keywords": "Antarctica; Biota; Cell Counts; Glaciology; Microbiology; WAIS Divide; WAIS Divide Ice Core", "people": "Santibanez, Pamela; Priscu, John", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Prokaryotic cell concentration record from the WAIS Divide ice core", "url": "https://www.usap-dc.org/view/dataset/601072"}, {"dataset_uid": "601361", "doi": "10.15784/601361", "keywords": "Antarctica; Carbonyl Sulfide; Trace Gases", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/601361"}], "date_created": "Fri, 30 May 2014 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to use the WAIS Divide deep core to investigate the Last Deglaciation at sub-annual resolution through an integrated set of chemical and biological analyses. The intellectual merit of the project is that these analyses, combined with others, will take advantage of the high snow accumulation WAIS Divide site yielding the highest time resolution glacio-biogeochemical and gas record of any deep Antarctic ice core. With other high resolution Greenland cores (GISP2 and GRIP) and lower resolution Antarctic cores, the combined record will yield new insights into worldwide climate dynamics and abrupt change. The proposed chemical, biological, and elemental tracer measurements will also be used to address all of the WAIS Divide science themes. The broader impacts of the project include education and outreach activities such as numerous presentations to local K-12 students; opportunities for student and teacher involvement in the laboratory work; a teacher training program in Earth sciences in the heavily minority Santa Ana, Compton, and Costa Mesa, California school districts; and development of high school curricula. Extensive graduate and undergraduate student involvement also is planned and will include one post doctoral associate, one graduate student, and undergraduate hourly involvement at DRI; a graduate student and undergraduates at University of California, Irvine (UCI); and a post doctoral fellow at MSU. Student recruitment will be made from underrepresented groups building on a long track record of involvement and will include the NSF funded California Alliance for Minority Participation (CAMP) and the Montana American Indian Research Opportunities (AIRO).\u003cbr/\u003e\u003cbr/\u003eThis award does not involve field work in Antarctica.", "east": 112.05, "geometry": "POINT(112.05 -79.28)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e CARBON ANALYZERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e WAS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e ICE CORE MELTER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Bacteria Ice Core; LABORATORY; Ice Core; FIELD INVESTIGATION; West Antarctica; Not provided; Dissolved Organic Carbon", "locations": "West Antarctica", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Foreman, Christine; Skidmore, Mark; Saltzman, Eric; McConnell, Joseph; Priscu, John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.28, "title": "Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core", "uid": "p0000273", "west": 112.05}, {"awards": "0839066 Cole-Dai, Jihong", "bounds_geometry": null, "dataset_titles": "Major Ion Chemistry Data of WAIS Divide Ice Core Brittle Ice", "datasets": [{"dataset_uid": "609546", "doi": "10.7265/N5RF5S0D", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ion Chromatograph; WAIS Divide; WAIS Divide Ice Core", "people": "Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Major Ion Chemistry Data of WAIS Divide Ice Core Brittle Ice", "url": "https://www.usap-dc.org/view/dataset/609546"}], "date_created": "Wed, 19 Mar 2014 00:00:00 GMT", "description": "Cole-Dai/0839066\u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to make continuous major ion analyses in the West Antarctica Ice Sheet Divide (WAIS Divide) ice core by sampling the brittle ice zone (approximately from 500 m to 1500 m). The intellectual merit of the project is that these will likely be the only chemical measurements on the brittle ice zone and, therefore, will bridge the gap in the expected continuous records of climate, ice sheet dynamics and biological evolution based on chemical measurements. High resolution sampling and analysis, probably on selected portions and depth intervals in the brittle ice zone, will help with the independent, high-precision dating of the WAIS Divide core and contribute to the achievement of the major objectives of the WAIS Divide project?development of high resolution climate records with which to investigate issues of climate forcing by greenhouse gases and the role of Antarctica and Southern Hemisphere in the global climate system. Planned collaboration with other WAIS Divide investigators will develop the longest and most detailed volcanic record from Antarctica ice cores. The broader impacts of this project include a contribution to enhancing our knowledge of the climate system. Such improvements in understanding of the global climate system and the ability to predict the magnitude and uncertainty of future changes are highly relevant to the global community. The project will support post-doctoral scientists and graduate students, including those from under-represented groups, will contribute to education, an help to train future scientists and promote diversity in research and education. Public outreach activities of this project will contribute to informal science education of school age children in the Eastern South Dakota region.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Paleoclimate; LABORATORY; Ions; GROUND-BASED OBSERVATIONS; WAISCORES; Ion Chromatograph; Not provided; Ice Core", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "NOT APPLICABLE", "persons": "Cole-Dai, Jihong", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Major Ion Chemical Analysis of Brittle Ice in the WAIS Divide Ice Core", "uid": "p0000047", "west": null}, {"awards": "1043619 Hemming, Sidney; 1043572 Licht, Kathy", "bounds_geometry": "POLYGON((-177.982 -63.997,-149.64107 -63.997,-121.30014 -63.997,-92.95921 -63.997,-64.61828 -63.997,-36.27735 -63.997,-7.93642 -63.997,20.40451 -63.997,48.74544 -63.997,77.08637 -63.997,105.4273 -63.997,105.4273 -66.3324,105.4273 -68.6678,105.4273 -71.0032,105.4273 -73.3386,105.4273 -75.674,105.4273 -78.0094,105.4273 -80.3448,105.4273 -82.6802,105.4273 -85.0156,105.4273 -87.351,77.08637 -87.351,48.74544 -87.351,20.40451 -87.351,-7.93642 -87.351,-36.27735 -87.351,-64.61828 -87.351,-92.95921 -87.351,-121.30014 -87.351,-149.64107 -87.351,-177.982 -87.351,-177.982 -85.0156,-177.982 -82.6802,-177.982 -80.3448,-177.982 -78.0094,-177.982 -75.674,-177.982 -73.3386,-177.982 -71.0032,-177.982 -68.6678,-177.982 -66.3324,-177.982 -63.997))", "dataset_titles": "East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "datasets": [{"dataset_uid": "600124", "doi": "10.15784/600124", "keywords": "Antarctica; East Antarctica; Geochemistry; Ross Sea; Sample/collection Description; Sample/Collection Description; Solid Earth; Southern Ocean; West Antarctica", "people": "Hemming, Sidney R.", "repository": "USAP-DC", "science_program": null, "title": "East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "url": "https://www.usap-dc.org/view/dataset/600124"}], "date_created": "Tue, 18 Feb 2014 00:00:00 GMT", "description": "Intellectual Merit: The PIs proposed a provenance study of glacial deposits in the Ross Embayment that will provide a broad scale geochronologic survey of detrital minerals in till to help characterize bedrock beneath the East Antarctic ice sheet and constrain Antarctica?s glacial history. This project capitalizes on previous investments in field sampling. Analytical tools applied to single mineral grains extracted from existing collections of glacial till will generate ?fingerprints? of East Antarctic outlet glaciers and West Antarctic till to refine paleo-ice flow models for the Ross Embayment during the last glacial maximum, older records from ANDRILL cores, and to assess IRD sources in the Southern Ocean. New provenance tracers will include a suite of geochronological methods that together provide greater insights into the orogenic and erosional history the region. This project will include U/Pb of detrital zircons, (U-Th)/He on a subset of the U/Pb dated zircons, as well as Ar-Ar of detrital hornblende, mica and feldspars. Broader impacts: This research will train one M.S. student at IUPUI, a Ph.D. student at Columbia, and several undergraduates at both institutions. Graduate students involved in the project will be involved in mentoring undergraduate researchers. Incorporation of research discoveries will be brought into the classroom by providing concrete examples and exercises at the appropriate level. Licht and Columbia graduate student E. Pierce are developing outreach projects with local secondary school teachers to investigate the provenance of glacial materials in their local areas. The research will have broad applicability to many fields.", "east": 105.4273, "geometry": "POINT(-36.27735 -75.674)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e LA-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e PETROGRAPHIC MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS", "is_usap_dc": true, "keywords": "Not provided; FIELD SURVEYS", "locations": null, "north": -63.997, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Licht, Kathy; Hemming, Sidney R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.351, "title": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "uid": "p0000333", "west": -177.982}, {"awards": "0934534 Sergienko, Olga", "bounds_geometry": "POLYGON((-106 -70,-105.4 -70,-104.8 -70,-104.2 -70,-103.6 -70,-103 -70,-102.4 -70,-101.8 -70,-101.2 -70,-100.6 -70,-100 -70,-100 -70.6,-100 -71.2,-100 -71.8,-100 -72.4,-100 -73,-100 -73.6,-100 -74.2,-100 -74.8,-100 -75.4,-100 -76,-100.6 -76,-101.2 -76,-101.8 -76,-102.4 -76,-103 -76,-103.6 -76,-104.2 -76,-104.8 -76,-105.4 -76,-106 -76,-106 -75.4,-106 -74.8,-106 -74.2,-106 -73.6,-106 -73,-106 -72.4,-106 -71.8,-106 -71.2,-106 -70.6,-106 -70))", "dataset_titles": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "datasets": [{"dataset_uid": "609626", "doi": "10.7265/N5XS5SBW", "keywords": "Antarctica; Arctic; Bindschadler Ice Stream; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland; Lambert Ice Stream; Macayeal Ice Stream; Pine Island Glacier; Thwaites Glacier", "people": "Sergienko, Olga", "repository": "USAP-DC", "science_program": null, "title": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "url": "https://www.usap-dc.org/view/dataset/609626"}], "date_created": "Thu, 06 Feb 2014 00:00:00 GMT", "description": "Funds are provided to enable applications of powerful mathematical concepts and computational tools for rigorous sensitivity analysis, pseudo-spectra and generalized stability theory, and advanced state estimation in the context of large-scale ice sheet modeling. At the center of the proposal is the generation and application of adjoint model (ADM) and tangent linear model (TLM) components of the new Community Ice Sheet Model (CISM). The goal will be achieved through rigorous use of automatic differentiation (AD) to ensure synchronicity between the ongoing model development and improvement in terms of better representation of higher-order stress terms (which account for crucial fast flow regimes) of the nonlinear forward model (NLM) code and the derivative codes. The adjoint enables extremely efficient computation of gradients of scalar-valued functions in very high-dimensional control spaces. A hierarchy of applications is envisioned: (1) sensitivity calculations in support of the Intergovernmental Panel on Climate Change (IPCC) in order to determine to which control variables the polar ice sheet volumes are most sensitive; based on adjoint sensitivity maps, to establish quantitative estimates of ice sheet volume changes for relevant forcing scenarios; and to assess how sensitivities change when including higher-order stress terms; (2) coupling of the ADM and TLM to calculate pseudo-spectra or singular vectors (SV?s) of relevant ice sheet norms; SV?s provide perturbation patterns which lead to non-normal growth, optimally amplifying norm kernels over finite times; among the many applications of SV?s are optimal initialization of ensembles to assess uncertainties; SV?s are calculated through matrix-free iterative solution of a generalized eigenvalue problem via Lanczos or Arnoldi implicit restart algorithms; (3) a long-term goal is the development of an ice sheet state estimation system based on the adjoint or Lagrange Multiplier Method (LMM) in order to synthesize, in a formal manner, the increasing number and heterogeneous types of observations with a three-dimensional, state-of-the-art ice sheet model; an important requirement is that the adjoint incorporate new schemes that are being developed for CISM to capture crucial, but as yet unrepresented physical processes.", "east": -100.0, "geometry": "POINT(-103 -73)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e VISUAL OBSERVATIONS", "is_usap_dc": true, "keywords": "Not provided; Inverse Modeling; GROUND-BASED OBSERVATIONS; Basal Shear Stress", "locations": null, "north": -70.0, "nsf_funding_programs": "Arctic Natural Sciences", "paleo_time": null, "persons": "Sergienko, Olga", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.0, "title": "COLLABORATIVE RESEARCH: Enabling ice sheet sensitivity and stability analysis with a large-scale higher-order ice sheet model\u0027s adjoint to support sea level change assessment", "uid": "p0000048", "west": -106.0}, {"awards": "0944248 MacAyeal, Douglas", "bounds_geometry": "POLYGON((-63.72 -63.73,-62.893 -63.73,-62.066 -63.73,-61.239 -63.73,-60.412 -63.73,-59.585 -63.73,-58.758 -63.73,-57.931 -63.73,-57.104 -63.73,-56.277 -63.73,-55.45 -63.73,-55.45 -64.0876,-55.45 -64.4452,-55.45 -64.8028,-55.45 -65.1604,-55.45 -65.518,-55.45 -65.8756,-55.45 -66.2332,-55.45 -66.5908,-55.45 -66.9484,-55.45 -67.306,-56.277 -67.306,-57.104 -67.306,-57.931 -67.306,-58.758 -67.306,-59.585 -67.306,-60.412 -67.306,-61.239 -67.306,-62.066 -67.306,-62.893 -67.306,-63.72 -67.306,-63.72 -66.9484,-63.72 -66.5908,-63.72 -66.2332,-63.72 -65.8756,-63.72 -65.518,-63.72 -65.1604,-63.72 -64.8028,-63.72 -64.4452,-63.72 -64.0876,-63.72 -63.73))", "dataset_titles": "Go to the NSIDC and search for the data.; Standing Water Depth on Larsen B Ice Shelf", "datasets": [{"dataset_uid": "609584", "doi": "10.7265/N500002K", "keywords": "Antarctica; Antarctic Peninsula; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Larsen B Ice Shelf; Sample/collection Description; Sample/Collection Description; Supraglacial Meltwater", "people": "MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Standing Water Depth on Larsen B Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/609584"}, {"dataset_uid": "001996", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Go to the NSIDC and search for the data.", "url": "http://nsidc.org"}], "date_created": "Sat, 21 Dec 2013 00:00:00 GMT", "description": "MacAyeal/0944248\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to develop a better understanding of the processes and conditions that trigger ice shelf instability and explosive disintegration. A significant product of the proposed research will be the establishment of parameterizations of micro- and meso-scale ice-shelf surface processes needed in large scale ice-sheet models designed to predict future sea level rise. The proposed research represents a 3-year effort to conduct numerical model studies of 6 aspects of surface-water evolution on Antarctic ice shelves. These 6 model-study areas include energy balance models of melting ice-shelf surfaces, with treatment of surface ponds and water-filled crevasses, distributed, Darcian water flow modeling to simulate initial firn melting, brine infiltration, pond drainage and crevasse filling, ice-shelf surface topography evolution modeling by phase change (surface melting and freezing), surface-runoff driven erosion and seepage flows, mass loading and flexure effects of ice-shelf and iceberg surfaces; feedbacks between surface-water loads and flexure stresses; possible seiche phenomena of the surface water, ice and underlying ocean that constitute a mechanism for, inducing surface crevassing., surface pond and crevasse convection, and basal crevasse thermohaline convection (as a phenomena related to area 5 above). The broader impacts of the proposed work bears on the socio-environmental concerns of climate change and sea-level rise, and will contribute to the important goal of advising public policy. The project will form the basis of a dissertation project of a graduate student whose training will contribute to the scientific workforce of the nation and the PI and graduate student will additionally participate in a summer science-enrichment program for high-school teachers organized by colleagues at the University of Chicago.", "east": -55.45, "geometry": "POINT(-59.585 -65.518)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e ETM+; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS", "is_usap_dc": true, "keywords": "Supraglacial Lake; LANDSAT-7; Melt Ponds; Standing Water Depth; Ice Shelf Stability", "locations": null, "north": -63.73, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-7", "repo": "USAP-DC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": -67.306, "title": "Model Studies of Surface Water Behavior on Ice Shelves", "uid": "p0000052", "west": -63.72}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Heard Island Glacier Fluctuations and Climatic Change - 2003/04 Fieldwork", "datasets": [{"dataset_uid": "609582", "doi": "", "repository": "USAP-DC", "science_program": null, "title": "Heard Island Glacier Fluctuations and Climatic Change - 2003/04 Fieldwork", "url": "http://www.usap-dc.org/view/dataset/609582"}], "date_created": "Thu, 19 Dec 2013 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Heard Island Glacier", "locations": "Heard Island Glacier; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Truffer, Martin", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "0537371 Nyblade, Andrew", "bounds_geometry": "POLYGON((40 -76,50 -76,60 -76,70 -76,80 -76,90 -76,100 -76,110 -76,120 -76,130 -76,140 -76,140 -76.8,140 -77.6,140 -78.4,140 -79.2,140 -80,140 -80.8,140 -81.6,140 -82.4,140 -83.2,140 -84,130 -84,120 -84,110 -84,100 -84,90 -84,80 -84,70 -84,60 -84,50 -84,40 -84,40 -83.2,40 -82.4,40 -81.6,40 -80.8,40 -80,40 -79.2,40 -78.4,40 -77.6,40 -76.8,40 -76))", "dataset_titles": "Data at IRIS Data Management Center (full data link not provided)", "datasets": [{"dataset_uid": "000233", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Data at IRIS Data Management Center (full data link not provided)", "url": "http://www.iris.edu/dms/"}], "date_created": "Wed, 04 Dec 2013 00:00:00 GMT", "description": "Abstract\u003cbr/\u003eThis award supports a seismological study of the Gamburtsev Subglacial Mountains (GSM), a Texas-sized mountain range buried beneath the ice sheets of East Antarctica. The project will perform a passive seismic experiment deploying twenty-three seismic stations over the GSM to characterize the structure of the crust and upper mantle, and determine the processes driving uplift. The outcomes will also offer constraints on the terrestrial heat flux, a key variable in modeling ice sheet formation and behavior. Virtually unexplored, the GSM represents the largest unstudied area of crustal uplift on earth. As well, the region is the starting point for growth of the Antarctic ice sheets. \u003cbr/\u003eBecause of these outstanding questions, the GSM has been identified by the international Antarctic science community as a research focus for the International Polar Year (2007-2009). In addition to this seismic experiment, NSF is also supporting an aerogeophysical survey of the GSM under award number 0632292. Major international partners in the project include Germany, China, Australia, and the United Kingdom. For more information see IPY Project #67 at IPY.org. In terms of broader impacts, this project also supports postdoctoral and graduate student research, and various forms of outreach.", "east": 140.0, "geometry": "POINT(90 -80)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Nyblade, Andrew", "platforms": "Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -84.0, "title": "Collaborative Research: A Broadband Seismic Experiment to Image the Lithosphere Beneath the Gamburtsev Mountains and Surrounding Areas, East Antarctica", "uid": "p0000657", "west": 40.0}, {"awards": "1240707 Fahnestock, Mark; 0632292 Bell, Robin", "bounds_geometry": "POLYGON((65 -77.5,67.4 -77.5,69.8 -77.5,72.2 -77.5,74.6 -77.5,77 -77.5,79.4 -77.5,81.8 -77.5,84.2 -77.5,86.6 -77.5,89 -77.5,89 -78.25,89 -79,89 -79.75,89 -80.5,89 -81.25,89 -82,89 -82.75,89 -83.5,89 -84.25,89 -85,86.6 -85,84.2 -85,81.8 -85,79.4 -85,77 -85,74.6 -85,72.2 -85,69.8 -85,67.4 -85,65 -85,65 -84.25,65 -83.5,65 -82.75,65 -82,65 -81.25,65 -80.5,65 -79.75,65 -79,65 -78.25,65 -77.5))", "dataset_titles": "Data Access Tool; Processed Ice Penetrating Radar Altimeter data (SEGY format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT; Processed Ice Penetrating Radar Data (jpeg images) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ; Processed Ice Penetrating Radar Data (Matlab format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ; Processed Ice Penetrating Radar Data (Netcdf format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ", "datasets": [{"dataset_uid": "601286", "doi": "10.15784/601286", "keywords": "AGAP; Airborne Radar; Airplane; Antarctica; East Antarctica; Gamburtsev Mountains; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Radar; Radar Echo Sounder", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Processed Ice Penetrating Radar Data (jpeg images) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ", "url": "https://www.usap-dc.org/view/dataset/601286"}, {"dataset_uid": "001489", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Data Access Tool", "url": "http://www.marine-geo.org/tools/search/entry.php?id=AGAP_GAMBIT"}, {"dataset_uid": "601284", "doi": null, "keywords": "Airborne Radar; Airplane; Antarctica; East Antarctica; Gamburtsev Mountains; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Radar; Radar Echo Sounder", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Processed Ice Penetrating Radar Data (Matlab format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ", "url": "https://www.usap-dc.org/view/dataset/601284"}, {"dataset_uid": "601285", "doi": null, "keywords": "Airborne Radar; Airplane; Antarctica; East Antarctica; Gamburtsev Mountains; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Radar Echo Sounder", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Processed Ice Penetrating Radar Data (Netcdf format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ", "url": "https://www.usap-dc.org/view/dataset/601285"}, {"dataset_uid": "601283", "doi": "10.1594/IEDA/318208", "keywords": "Aerogeophysics; AGAP; Airborne Radar; Airplane; Antarctica; East Antarctica; Gamburtsev Mountains; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Radar; Radar Echo Sounder", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "Processed Ice Penetrating Radar Altimeter data (SEGY format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT", "url": "https://www.usap-dc.org/view/dataset/601283"}], "date_created": "Sun, 29 Sep 2013 00:00:00 GMT", "description": "This award supports an aerogeophysical study of the Gamburtsev Subglacial Mountains (GSM), a Texas-sized mountain range buried beneath the ice sheets of East Antarctica. The project would perform a combined gravity, magnetics, and radar study to achieve a range of goals including: advancing our understanding of the origin and evolution of the polar ice sheets and subglacial lakes; defining the crustal architecture of East Antarctica, a key question in the earth\u0027s history; and locating the oldest ice in East Antarctica, which may ultimately help find ancient climate records. Virtually unexplored, the GSM represents the largest unstudied area of crustal uplift on earth. As well, the region is the starting point for growth of the Antarctic ice sheets. Because of these outstanding questions, the GSM has been identified by the international Antarctic science community as a research focus for the International Polar Year (2007-2009). In addition to this study, NSF is also supporting a seismological survey of the GSM under award number 0537371. Major international partners in the project include Germany, China, Australia, and the United Kingdom. For more information see IPY Project #67 at IPY.org. In terms of broader impacts, this project also supports postdoctoral and graduate student research, and various forms of outreach including a focus on groups underrepresented in the earth sciences.", "east": 89.0, "geometry": "POINT(77 -81.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e AIRBORNE LASER SCANNER; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": false, "keywords": "GRAVITY; East Antarctica; GLACIERS/ICE SHEETS; ICE SHEETS; DHC-6; MAGNETIC FIELD; Not provided; Gamburtsev Mountains", "locations": "East Antarctica; Gamburtsev Mountains", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Studinger, Michael S.; Fahnestock, Mark", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; Not provided", "repo": "USAP-DC", "repositories": "MGDS; USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: IPY: GAMBIT: Gamburtsev Aerogeophysical Mapping of Bedrock and Ice Targets", "uid": "p0000114", "west": 65.0}, {"awards": "0838615 Hall, Brenda", "bounds_geometry": "POLYGON((-177.13 -84.55,-177.074 -84.55,-177.018 -84.55,-176.962 -84.55,-176.906 -84.55,-176.85 -84.55,-176.794 -84.55,-176.738 -84.55,-176.682 -84.55,-176.626 -84.55,-176.57 -84.55,-176.57 -84.615,-176.57 -84.68,-176.57 -84.745,-176.57 -84.81,-176.57 -84.875,-176.57 -84.94,-176.57 -85.005,-176.57 -85.07,-176.57 -85.135,-176.57 -85.2,-176.626 -85.2,-176.682 -85.2,-176.738 -85.2,-176.794 -85.2,-176.85 -85.2,-176.906 -85.2,-176.962 -85.2,-177.018 -85.2,-177.074 -85.2,-177.13 -85.2,-177.13 -85.135,-177.13 -85.07,-177.13 -85.005,-177.13 -84.94,-177.13 -84.875,-177.13 -84.81,-177.13 -84.745,-177.13 -84.68,-177.13 -84.615,-177.13 -84.55))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 05 Sep 2013 00:00:00 GMT", "description": "Stone/0838818 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). \u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study the former thickness and retreat history of Shackleton and Beardmore Glaciers which flow through the Transantarctic Mountains (TAMs) into the southern Ross Sea. Lateral moraine deposits along the lower reaches of these major outlet glaciers will be mapped and dated and the results will help to date the LGM and constrain the thickness of ice where it left the Transantarctic Mountains and flowed into the Ross Sea. The intellectual merit of the project is that the results will allow scientists to distinguish between models of ice retreat, which have important implications for former ice configuration and dynamics, and to constrain the contribution from Ross Sea deglaciation to global sea level through the late Holocene. In addition, this will make a significant contribution to a better understanding of the magnitude and timing of postglacial sea-level change and the potential contribution of Antarctica to sea-level rise in future. The broader impacts of the project are that the work will help quantify changes in grounded ice volume since the LGM, improve understanding of the ice dynamics responsible, and examine their implications for future sea level change. The project will train future scientists through participation of two graduate students and undergraduates who will develop self-contained research projects. As in previous Antarctic projects, there will be interaction with K-12 students through classroom visits, web-based expedition journals, letters from the field, and discussions with teachers and will allow the project to be shared with a wide audience. This award has field work in Antarctica.", "east": -176.57, "geometry": "POINT(-176.85 -84.875)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -84.55, "nsf_funding_programs": "Antarctic Instrumentation and Support", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Hall, Brenda", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -85.2, "title": "Collaborative Research: Constraints on the last Ross Ice Sheet from Glacial Deposits in the Southern Transantarctic Mountains", "uid": "p0000094", "west": -177.13}, {"awards": "0838811 Sergienko, Olga", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -87,180 -84,180 -81,180 -78,180 -75,180 -72,180 -69,180 -66,180 -63,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,-180 -60))", "dataset_titles": "Interaction of Ice Stream Flow with Heterogeneous Beds", "datasets": [{"dataset_uid": "609583", "doi": "10.7265/N53R0QS6", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Ice Thickness; Ice Velocity", "people": "Sergienko, Olga", "repository": "USAP-DC", "science_program": null, "title": "Interaction of Ice Stream Flow with Heterogeneous Beds", "url": "https://www.usap-dc.org/view/dataset/609583"}], "date_created": "Tue, 27 Aug 2013 00:00:00 GMT", "description": "Sergienko/0838811 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to conduct a modeling study of the ice stream ? sub-glacial water system. A suite of numerical models of various dimensionality and complexity will be constructed in a sequential, hierarchical fashion to formulate and test hypotheses regarding how sub-glacial lakes form under ice streams, determine the effect of sub-glacial lakes on ice-stream flow and mass balance, and to determine feedback effects whereby the ice stream ? sub-glacial water system can elicit both stable and unstable responses to environmental perturbations. This research will address one of the only observationally verified fast-time-scale processes apparent within the Antarctic Ice Stream system. The intellectual merit of the project is that understanding the origins and consequences of near-grounding-line sub-glacial lakes is a priority in glaciological research designed to predict short-term variations in Antarctica?s near-term future mass balance. The broader impacts of the proposed work are that it will contribute to better understanding of a system that has important societal relevance through contribution to sea level rise. Participation of a graduate student in the project will provide the student?s training and education in application of the numerical modeling in geosciences.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Subglacial And Supraglacial Water Depth; Not provided; Basal Stress; Ice Stream; Direct Numerical Simulation", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Sergienko, Olga; Hulbe, Christina", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Model Investigation of Ice Stream/Subglacial Lake Systems", "uid": "p0000045", "west": 180.0}, {"awards": "0724929 Simms, Alexander", "bounds_geometry": null, "dataset_titles": "Optically Stimulated Luminescence Ages of Raised Beaches; Optically stimulated luminescence-dated raised beaches from the western Antarctic Peninsula; Relative sea-level history of Marguerite Bay, Antarctic Peninsula derived from optically stimulated luminescence-dated beach cobbles.", "datasets": [{"dataset_uid": "000231", "doi": "", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Optically stimulated luminescence-dated raised beaches from the western Antarctic Peninsula", "url": "https://doi.pangaea.de/10.1594/PANGAEA.818518"}, {"dataset_uid": "000232", "doi": "", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Relative sea-level history of Marguerite Bay, Antarctic Peninsula derived from optically stimulated luminescence-dated beach cobbles.", "url": "https://doi.org/10.1594/PANGAEA.818537"}, {"dataset_uid": "600026", "doi": "10.15784/600026", "keywords": "Antarctica; Antarctic Peninsula; Sample/collection Description; Sample/Collection Description; Solid Earth", "people": "Simms, Alexander", "repository": "USAP-DC", "science_program": null, "title": "Optically Stimulated Luminescence Ages of Raised Beaches", "url": "https://www.usap-dc.org/view/dataset/600026"}], "date_created": "Fri, 23 Aug 2013 00:00:00 GMT", "description": "This Small Grant for Exploratory Research explores the possibility of dating beach deposits on the Antarctic Peninsula using Optical Stimulated Luminescence (OSL). This area is undergoing uplift in response to glacial retreat, and dating these deposits will allow for estimations of ice sheet thickness during the last glacial maximum through the creation of new sea level curves. Accurate reconstructions of ice sheet size are critical to predicting sea level rise in response to global warming. In terms of other broader impacts, this project supports a graduate student, who is learning cutting edge analytical techniques while applying them to questions of global climate change.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Sea Level; Not provided; Paleoclimate", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Simms, Alexander", "platforms": "Not provided", "repo": "PANGAEA", "repositories": "PANGAEA; USAP-DC", "science_programs": null, "south": null, "title": "SGER: Testing the use of OSL dating of beach deposits along the Antarctic Peninsula", "uid": "p0000266", "west": null}, {"awards": "0944764 Brook, Edward J.", "bounds_geometry": null, "dataset_titles": "Abrupt Change in Atmospheric CO2 During the Last Ice Age; High-resolution Atmospheric CO2 during 7.4-9.0 ka", "datasets": [{"dataset_uid": "609527", "doi": "10.7265/N5QF8QT5", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core; South Pole; WAISCORES", "people": "Ahn, Jinho; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "High-resolution Atmospheric CO2 during 7.4-9.0 ka", "url": "https://www.usap-dc.org/view/dataset/609527"}, {"dataset_uid": "609539", "doi": "10.7265/N5F47M23", "keywords": "Antarctica; Arctic; Byrd; Chemistry:fluid; Chemistry:Fluid; CO2; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome Ice Core; Taylor Dome; Taylor Dome Ice Core", "people": "Brook, Edward J.; Ahn, Jinho", "repository": "USAP-DC", "science_program": "Byrd Ice Core", "title": "Abrupt Change in Atmospheric CO2 During the Last Ice Age", "url": "https://www.usap-dc.org/view/dataset/609539"}, {"dataset_uid": "609539", "doi": "10.7265/N5F47M23", "keywords": "Antarctica; Arctic; Byrd; Chemistry:fluid; Chemistry:Fluid; CO2; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome Ice Core; Taylor Dome; Taylor Dome Ice Core", "people": "Brook, Edward J.; Ahn, Jinho", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Abrupt Change in Atmospheric CO2 During the Last Ice Age", "url": "https://www.usap-dc.org/view/dataset/609539"}, {"dataset_uid": "609539", "doi": "10.7265/N5F47M23", "keywords": "Antarctica; Arctic; Byrd; Chemistry:fluid; Chemistry:Fluid; CO2; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome Ice Core; Taylor Dome; Taylor Dome Ice Core", "people": "Ahn, Jinho; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Abrupt Change in Atmospheric CO2 During the Last Ice Age", "url": "https://www.usap-dc.org/view/dataset/609539"}], "date_created": "Thu, 08 Aug 2013 00:00:00 GMT", "description": "This award supports a project to create new, unprecedented high-resolution atmospheric carbon dioxide (CO2) records spanning intervals of abrupt climate changes during the last glacial period and the early Holocene. The proposed work will utilize high-precision methods on existing ice cores from high accumulation sites such as Siple Dome and Byrd Station, Antarctica and will improve our understanding of how fast CO2 can change naturally, how its variations are linked with climate, and, combined with a coupled climate-carbon cycle model, will clarify the role of terrestrial and oceanic processes during past abrupt changes of climate and CO2. The intellectual merit of this work is that CO2 is the most important anthropogenic greenhouse gas and understanding its past variations, its sources and sinks, and how they are linked to climate change is a major goal of the climate research community. This project will produce high quality data on centennial to multi-decadal time scales. Such high-resolution work has not been conducted before because of insufficient analytical precision, slow experimental procedures in previous studies, or lack of available samples. The proposed research will complement future high-resolution studies from WAIS Divide ice cores and will provide ice core CO2 records for the target age intervals, which are in the zone of clathrate formation in the WAIS ice cores. Clathrate hydrate is a phase composed of air and ice. CO2 analyses have historically been less precise in clathrate ice than in ?bubbly ice? such as the Siple Dome ice core that will be analyzed in the proposed project. High quality, high-resolution results from specific intervals in Siple Dome that we propose to analyze will provide important data for verifying the WAIS Divide record. The broader impacts of the work are that current models show a large uncertainty of future climate-carbon cycle interactions. The results of this proposed work will be used for testing coupled carbon cycle-climate models and may contribute to reducing this uncertainty. The project will contribute to the training of several undergraduate students and a full-time technician. Both will learn analytical techniques and the basic science involved. Minorities and female students will be highly encouraged to participate in this project. Outreach efforts will include participation in news media interviews, at a local festival celebrating art, science and technology, and giving seminar presentations in the US and foreign countries. The OSU ice core laboratory has begun a collaboration with a regional science museum and is developing ideas to build an exhibition booth to make public be aware of climate change and ice core research. All data will be archived at the National Snow and Ice Data Center and at other similar archives per the OPP data policy.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e CO2 ANALYZERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "GROUND-BASED OBSERVATIONS; CO2 Concentrations; Ice Core Gas Age; CO2 Uncertainty; LABORATORY; Ice Core Depth; Not provided; CH4 Concentrations", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "NOT APPLICABLE; NOT APPLICABLE", "persons": "Ahn, Jinho; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Atmospheric CO2 and Abrupt Climate Change", "uid": "p0000179", "west": null}, {"awards": "9725057 Mayewski, Paul", "bounds_geometry": "POLYGON((-76.1 -77.68,-53.253 -77.68,-30.406 -77.68,-7.559 -77.68,15.288 -77.68,38.135 -77.68,60.982 -77.68,83.829 -77.68,106.676 -77.68,129.523 -77.68,152.37 -77.68,152.37 -78.912,152.37 -80.144,152.37 -81.376,152.37 -82.608,152.37 -83.84,152.37 -85.072,152.37 -86.304,152.37 -87.536,152.37 -88.768,152.37 -90,129.523 -90,106.676 -90,83.829 -90,60.982 -90,38.135 -90,15.288 -90,-7.559 -90,-30.406 -90,-53.253 -90,-76.1 -90,-76.1 -88.768,-76.1 -87.536,-76.1 -86.304,-76.1 -85.072,-76.1 -83.84,-76.1 -82.608,-76.1 -81.376,-76.1 -80.144,-76.1 -78.912,-76.1 -77.68))", "dataset_titles": "US International Trans-Antarctic Scientific Expedition (US ITASE) Glaciochemical Data; US International Trans-Antarctic Scientific Expedition (US ITASE) Glaciochemical Data, Version 1", "datasets": [{"dataset_uid": "601559", "doi": null, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; ITASE; Paleoclimate; Solid Earth; Wais Project", "people": "Dixon, Daniel A.; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": "ITASE", "title": "US International Trans-Antarctic Scientific Expedition (US ITASE) Glaciochemical Data, Version 1", "url": "https://www.usap-dc.org/view/dataset/601559"}, {"dataset_uid": "609273", "doi": "10.7265/N51V5BXR", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; ITASE; Paleoclimate; Solid Earth; WAIS", "people": "Mayewski, Paul A.; Dixon, Daniel A.", "repository": "USAP-DC", "science_program": "ITASE", "title": "US International Trans-Antarctic Scientific Expedition (US ITASE) Glaciochemical Data", "url": "https://www.usap-dc.org/view/dataset/609273"}], "date_created": "Thu, 11 Jul 2013 00:00:00 GMT", "description": "9725057 Mayewski This award is for support for a Science Management Office (SMO) for the United States component of the International Trans-Antarctic Scientific Expedition (US ITASE). The broad aim of US ITASE is to develop an understanding of the last 200 years of past West Antarctic climate and environmental change. ITASE is a multidisciplinary program that integrates remote sensing, meteorology, ice coring, surface glaciology and geophysics. In addition to the formation of a science management office, this award supports a series of annual workshops to coordinate the science projects that will be involved in ITASE and the logistics base needed to undertake ground-based sampling in West Antarctica.", "east": 152.37, "geometry": "POINT(38.135 -83.84)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "US ITASE; Not provided; ITASE; GROUND STATIONS; GROUND-BASED OBSERVATIONS", "locations": null, "north": -77.68, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Dixon, Daniel A.; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -90.0, "title": "Science Management for the United States Component of the International Trans-Antarctic Expedition", "uid": "p0000221", "west": -76.1}, {"awards": "0838810 Hulbe, Christina", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 01 Jul 2013 00:00:00 GMT", "description": "Hulbe/0838810 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a modeling study of the processes in West Antarctic grounding zones, the transition from ice resting on bedrock to ice floating on the ocean surface with an eye toward understanding the interrelated causes of rapid change in grounding line configuration and outlet flow. A combination of satellite remote sensing and numerical modeling will be used to investigate both past and ongoing patterns of change. New high-resolution surface elevation maps made from a novel combination of satellite laser altimetry and remotely observed surface shape provide a unique view of grounding zones. These data will be used to diagnose events associated with the shutdown of Kamb Ice Stream, to investigate a recent discharge event on Institute Ice Stream and to investigate ongoing change at the outlet of Whillans Ice Stream, along with other modern processes around the West Antarctic. An existing numerical model of coupled ice sheet, ice stream, and ice shelf flow will be used and improved as part of the research project. The broader impacts of the project relate to the importance of understanding the role of polar ice sheets in global sea level rise. The work will contribute to the next round of deliberations for the Intergovernmental Panel on Climate Change (IPCC). Improved views, interpretations, and insights into the physical processes that govern variability in ice sheet outlet streams will help correct the shortcomings of the last IPCC report that didn?t include the role of ice sheets in sea level rise. The PIs have a strong record of public outreach, involvement in the professional community, and student training.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY; Kamb Ice Stream; Grounding Line; FIELD INVESTIGATION; SATELLITES; Transition Zone; Ice Shelf Flow; Outlet Flow; Ice Sheet; Modeling; COMPUTERS; Antarctica", "locations": "Antarctica; Kamb Ice Stream", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hulbe, Christina; Fahnestock, Mark", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Mass Transit: Controls on Grounding and Ungrounding at Marine Ice Sheet Outlets", "uid": "p0000371", "west": null}, {"awards": "0636883 Bell, Robin", "bounds_geometry": "POLYGON((20 -75,23 -75,26 -75,29 -75,32 -75,35 -75,38 -75,41 -75,44 -75,47 -75,50 -75,50 -76.5,50 -78,50 -79.5,50 -81,50 -82.5,50 -84,50 -85.5,50 -87,50 -88.5,50 -90,47 -90,44 -90,41 -90,38 -90,35 -90,32 -90,29 -90,26 -90,23 -90,20 -90,20 -88.5,20 -87,20 -85.5,20 -84,20 -82.5,20 -81,20 -79.5,20 -78,20 -76.5,20 -75))", "dataset_titles": "Data portal at Lamont for airborne data", "datasets": [{"dataset_uid": "000111", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Data portal at Lamont for airborne data", "url": "http://wonder.ldeo.columbia.edu/wordpress/"}], "date_created": "Tue, 02 Apr 2013 00:00:00 GMT", "description": "Bell/0636883\u003cbr/\u003e\u003cbr/\u003eThis award support a project to study the role that subglacial water plays in the overall stability of major ice sheets. An estimated 22,000 km3 of water is currently stored within Antarctica\u0027s subglacial lakes. Movement of this water occurs through a complex and largely inferred drainage system in both East and West Antarctica. Geomorphic evidence for the catastrophic drainage of subglacial lakes documents repeated events. These major flood events appear to have drained the largest subglacial lakes situated in the relatively stable interior of the East Antarctic ice sheet. Emerging evidence suggests there is a close connection between significant subglacial lakes and the onset of the Recovery Ice Stream one of the largest in East Antarctica. Our preliminary analysis of the Recovery Lakes region, East Antarctica suggests a direct linkage between lakes and streaming ice flow, specifically the 800 km long Recovery Ice Stream and its tributaries. Located just upslope of the Recovery Ice Stream, the Recovery Lakes Region is composed of 3 well-defined lakes and a fourth, ambiguous, \u0027lake-like\u0027 feature. While other large lakes have a localized impact on ice surface slope, the Recovery Lakes Region lakes are coincident with an abrupt regional change in the ice sheet surface slope. Satellite imagery demonstrates that the downslope margin of this lake area contains distinct flow strips and crevasses: both indicative of increasing ice velocities. The discovery of a series of large lakes coincident with the onset of rapid ice flow in East Antarctica clearly links subglacial lakes and ice sheet dynamics for the first time. The evidence linking the onset of streaming in the Recovery Drainage Ice Stream to the series of large subglacial lakes raises the fundamental question: How can subglacial lakes trigger the onset of ice streaming? We advance two possible mechanisms: (i) Subglacial lakes can produce accelerated ice flow through the drainage of lake water beneath the ice sheet downslope of the lakes. (ii) Subglacial lakes can produce accelerated ice flow accelerated ice flow by modifying the basal thermal gradient via basal accretion over the lakes so when the ice sheet regrounds basal melting dominates. To evaluate the contribution of lake water and the changing basal thermal gradient, we propose an integrated program incorporating satellite imagery analysis, a series of reconnaissance aerogeophysical profiles over the Recovery Lake Region and the installation of continuous GPS sites over the Recovery Lakes. This analysis and new data will enable us (1) to produce a velocity field over the Recovery Lakes Region, (2) to map the ice thickness changes over the lakes due to acceleration triggered thinning, basal melting and freezing, (3) determine the depth and possible the tectonic origin of the Recovery Lakes and (4) determine the stability of these lakes over time. These basic data sets will enable us to advance our understanding of how subglacial lakes trigger the onset of streaming. The intellectual merit of this project is that it will be the first systematic analysis of ice streams triggering the onset of ice streams. This work has profound implications for the modeling of ice sheet behavior in the future, the geologic record of abrupt climate changes and the longevity of subglacial lakes. The broader impacts of the project are programs that will reach students of all ages through undergraduates involved in the research, formal presentations in teacher education programs and ongoing public outreach efforts at major science museums. Subglacial Antarctic lake environments are emerging as a premier, major frontier for exploration during the IPY 2007-2009.", "east": 50.0, "geometry": "POINT(35 -82.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e AEM; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e LIDAR ALTIMETERS", "is_usap_dc": false, "keywords": "DHC-6; Basal Melting; Ice Stream; Ice Thickness; Velocity; Ice Stream Stability; Basal Freezing; Antarctica; Drainage; Aerogeophysical; Subglacial Lake; Flood Event", "locations": "Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bell, Robin; Studinger, Michael S.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -90.0, "title": "Subglacial Lakes and the Onset of Ice Streaming: Recovery Lakes", "uid": "p0000702", "west": 20.0}, {"awards": null, "bounds_geometry": null, "dataset_titles": "Depths to Ice-cemented Soils in High-elevation Quartermain Mountains, Dry Valleys, Antarctica", "datasets": [{"dataset_uid": "609529", "doi": "10.7265/N5VX0DFJ", "repository": "USAP-DC", "science_program": null, "title": "Depths to Ice-cemented Soils in High-elevation Quartermain Mountains, Dry Valleys, Antarctica", "url": "http://www.usap-dc.org/view/dataset/609529"}], "date_created": "Mon, 18 Mar 2013 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Critical Zone; Dry Valleys; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Permafrost; Soil", "locations": "Antarctica; Dry Valleys", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Marinova, Margarita M.; McKay, Christopher P.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "9615420 Kamb, Barclay", "bounds_geometry": "POINT(-136.404633 -82.39955)", "dataset_titles": "Temperature of the West Antarctic Ice Sheet; Videos of Basal Ice in Boreholes on the Kamb Ice Stream in West Antarctica", "datasets": [{"dataset_uid": "609537", "doi": "10.7265/N5PN93J8", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Temperature", "people": "Engelhardt, Hermann", "repository": "USAP-DC", "science_program": null, "title": "Temperature of the West Antarctic Ice Sheet", "url": "https://www.usap-dc.org/view/dataset/609537"}, {"dataset_uid": "609528", "doi": "10.7265/N5028PFH", "keywords": "Antarctica; Borehole Video; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Kamb Ice Stream; Photo/video; Photo/Video", "people": "Engelhardt, Hermann", "repository": "USAP-DC", "science_program": null, "title": "Videos of Basal Ice in Boreholes on the Kamb Ice Stream in West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609528"}], "date_created": "Thu, 14 Feb 2013 00:00:00 GMT", "description": "This award is for support for a four year program to study the basal conditions of ice stream D using techniques previously applied to ice stream B. The objective is to determine whether the physical conditions and processes to be observed by borehole geophysics at the base of this large ice stream are consistent with what has been observed at ice stream B and to point to a common basal mechanism of ice streaming. This project includes a comparison between two parts of ice stream D, an upstream reach where flow velocities are modest (about 80 meters/year) and a downstream reach of high velocity (about 400 meters/year). The comparison will help to reveal what physical variable or combination of variables is mainly responsible for the streaming flow. The variables to be monitmred by borehole observation include basal water pressure, basal sliding velocity, flow properties and sedimentological characteristics of subglacial till if present, ice temperature profile including basal water transport velocity, connection time to the basal water system, basal melting rate and others.", "east": -136.404633, "geometry": "POINT(-136.404633 -82.39955)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS", "is_usap_dc": true, "keywords": "Raymond Ridge; Kamb Ice Stream; Engelhardt Ridge; Basal Ice; Unicorn; Alley Ice Stream; Borehole Video; Basal Freeze-on; Ice Stream Flow; Basal Freezing; West Antarctic Ice Sheet Instability; GROUND-BASED OBSERVATIONS; Whillans Ice Stream; Basal Debris; Simple Dome; Basal Water; Bindschadler Ice Stream; West Antarctic Ice Sheet", "locations": "Kamb Ice Stream; Alley Ice Stream; Bindschadler Ice Stream; Engelhardt Ridge; Raymond Ridge; Simple Dome; Unicorn; West Antarctic Ice Sheet; Whillans Ice Stream", "north": -82.39955, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kamb, Barclay; Engelhardt, Hermann", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -82.39955, "title": "Basal Conditions of Ice Stream D and Related Borehole Studies of Antarctic Ice Stream Mechanics", "uid": "p0000181", "west": -136.404633}, {"awards": "0739444 Rice, James", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 16 Jan 2013 00:00:00 GMT", "description": "Rice 0739444\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study the mode of formation and causes of glacial earthquakes. The paradigm for glacial flow has been that glaciers flow in a viscous manner, with major changes in the force balance occurring on the decade timescale or longer. The recent discovery of a number of even shorter timescale events has challenged this paradigm. In 2003, it was discovered that Whillans Ice Stream in West Antarctica displays stick-slip behavior on the 10-30 minute timescale, with ice stream speed increasing by a factor of 30 from already high speeds. In the past year, the minimum timescale has been pushed shorter by recognition that a class of recently discovered 50-second-long, magnitude-5 earthquakes are closely associated with changes in the force balance near the calving fronts of large outlet glaciers in both Greenland and East Antarctica. With no adequate theory existing to explain these relatively large earthquakes associated with outlet glaciers, we have begun to investigate the physical mechanisms that must be involved in allowing such a response in a system traditionally not thought capable of generating large variations in forces over timescales less than 100 seconds. The intellectual merit of the work is that large-amplitude, short-timescale variability of glaciers is an important mode of glacier dynamics that has not yet been understood from a first-principles physics perspective. The proposed research addresses this gap in understanding, tying together knowledge from numerous disciplines including glaciology, seismology and fault rupture dynamics, laboratory rock physics, granular flow, fracture mechanics, and hydrogeology. The broader impacts of the work are that there is societal as well as general scientific interest in the stability of the major ice sheets. However, without an understanding of the physical processes governing short time scale variability, it is unlikely that we will be able accurately predict the future of these ice sheets and their impact on sea level changes. The project will also contribute to the development and education of young scientists.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Rapid Glacial Motions; Not provided; Hydrogeology; Fracture Mechanics; Glacier Dynamics; Glacial Earthquakes; Granular Flow; Glacial Underflooding; Glaciology; Ice Stream Margins; Outlet Glaciers", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Rice, James; Platt, John; Suckale, Jenny; Perol, Thibaut; Tsai, Victor", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Transient and Rapid Glacial Motions, including Glacial Earthquakes", "uid": "p0000709", "west": null}, {"awards": "0739781 Blythe, Ann", "bounds_geometry": "POLYGON((155.77667 -79.793335,156.208836 -79.793335,156.641002 -79.793335,157.073168 -79.793335,157.505334 -79.793335,157.9375 -79.793335,158.369666 -79.793335,158.801832 -79.793335,159.233998 -79.793335,159.666164 -79.793335,160.09833 -79.793335,160.09833 -79.8578345,160.09833 -79.922334,160.09833 -79.9868335,160.09833 -80.051333,160.09833 -80.1158325,160.09833 -80.180332,160.09833 -80.2448315,160.09833 -80.309331,160.09833 -80.3738305,160.09833 -80.43833,159.666164 -80.43833,159.233998 -80.43833,158.801832 -80.43833,158.369666 -80.43833,157.9375 -80.43833,157.505334 -80.43833,157.073168 -80.43833,156.641002 -80.43833,156.208836 -80.43833,155.77667 -80.43833,155.77667 -80.3738305,155.77667 -80.309331,155.77667 -80.2448315,155.77667 -80.180332,155.77667 -80.1158325,155.77667 -80.051333,155.77667 -79.9868335,155.77667 -79.922334,155.77667 -79.8578345,155.77667 -79.793335))", "dataset_titles": "Thermochronologic and modelling test for a Mesozoic West Antarctic Plateau", "datasets": [{"dataset_uid": "600082", "doi": "10.15784/600082", "keywords": "Antarctica; Fission Track Thermochronology; Geochemistry; Solid Earth; Transantarctic Mountains", "people": "Huerta, Audrey D.; Blythe, Ann Elizabeth", "repository": "USAP-DC", "science_program": null, "title": "Thermochronologic and modelling test for a Mesozoic West Antarctic Plateau", "url": "https://www.usap-dc.org/view/dataset/600082"}], "date_created": "Fri, 07 Dec 2012 00:00:00 GMT", "description": "This project studies formation of the TransAntarctic Mountains (TAM) through numerical modeling based on cooling histories of apatite mineral grains. The TAM are the highest and longest rift-related mountain range in the world. Various models for their uplift have been proposed, the most provocative of which is that they are not uplifted, but instead are the eroded remnant of a plateau. This project evaluates that hypothesis by collecting apatites from around Byrd Glacier for fission track thermochronology. Results will be combined with a kinematic and thermal model to determine the TAM?s structural evolution. The plateau model, if correct, implies that the Byrd Glacier originated not as a glacier-carved valley through the TAM, but as a river system flowing in the opposite direction. Given that the Byrd Glacier is a key drainage for the East Antarctic ice sheet, this result has important implications for ice sheet models and interpretation of both regional geology and sediment records.\u003cbr/\u003e\u003cbr/\u003eThe main broader impacts are undergraduate research and a new collaboration between a primarily undergraduate and a research institution. Students will be involved in the field program, sample analyses, and numerical modeling.", "east": 160.09833, "geometry": "POINT(157.9375 -80.1158325)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.793335, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blythe, Ann Elizabeth; Huerta, Audrey D.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.43833, "title": "Collaborative Research: Thermochronologic and modelling test for a Mesozoic West Antarctic Plateau", "uid": "p0000677", "west": 155.77667}, {"awards": "0738975 Baker, Ian", "bounds_geometry": null, "dataset_titles": "Siple Dome A (SDMA) Grain Orientation 640 - 790 Meters", "datasets": [{"dataset_uid": "609526", "doi": "10.7265/N53T9F5X", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Sample/collection Description; Sample/Collection Description; Siple Dome; Siple Dome Ice Core; South Pole; WAISCORES", "people": "Obbard, Rachel; Sieg, Katherine; Baker, Ian", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome A (SDMA) Grain Orientation 640 - 790 Meters", "url": "https://www.usap-dc.org/view/dataset/609526"}], "date_created": "Mon, 26 Nov 2012 00:00:00 GMT", "description": "This award supports a project to fully characterize the microstructure in ice cores, in particular the microstructural locations of impurities, grain orientations and strain gradients. This work will complement the optical observations, electrical conductivity measurement, and precise, detailed measurements of the soluble ion and gas contents that are performed by others. Linking the concentrations of soluble ions and gases, measured to a few parts per billion, to the optically determined annual layer structure and the stable isotope data in ice cores has enabled a great deal to be established about the concentrations and depth/age distributions of particles, trace gases and impurities for several polar ice cores. Ice core studies carried out by several groups contribute immensely to our understanding of paleoclimate and, to our ability to predict future climate change. The work will build on previous measurements and technique development in this area, as well as focusing on new techniques to characterize ice cores. The work will use both scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDS) and confocal scanning optical microscopy coupled with Raman spectroscopy (RS) to determine the microstructural locations of impurities and correlate this information with depth/age, and impurity type and concentration for several polar ice cores. The Broader Impacts of the proposed work are that knowledge of the location of impurities coupled with the grain orientation (both c- and a-axis) and grain misorientation information will allow paleoclimatologists to better interpret ice core data and other scientists to understand and model the physical and mechanical properties of natural ice sheets. Other Broader Impacts of the work are that the work will be performed and lead to the education of a Ph.D. student. At the end of the project, as well as the knowledge gained from coursework, the graduate student will have experience in ice core specimen preparation and characterization using scanning electron microscopy, x-ray microanalysis, confocal scanning microscopy, Raman spectroscopy and ion chromatography. Results from the research will be published in refereed journals, presented at conferences, and placed on a web page.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": true, "keywords": "FEI Xl30 Environmental Scanning Electron Microscope - Field Emission Gun (esem - Feg); LABORATORY; Electron Backscatter Diffraction", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Obbard, Rachel; Sieg, Katherine", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Advanced Microstructural Characterization of Polar Ice Cores", "uid": "p0000178", "west": null}, {"awards": "0838914 Wannamaker, Philip", "bounds_geometry": "POLYGON((141.01732 -82.13,144.910279 -82.13,148.803238 -82.13,152.696197 -82.13,156.589156 -82.13,160.482115 -82.13,164.375074 -82.13,168.268033 -82.13,172.160992 -82.13,176.053951 -82.13,179.94691 -82.13,179.94691 -82.351835,179.94691 -82.57367,179.94691 -82.795505,179.94691 -83.01734,179.94691 -83.239175,179.94691 -83.46101,179.94691 -83.682845,179.94691 -83.90468,179.94691 -84.126515,179.94691 -84.34835,176.053951 -84.34835,172.160992 -84.34835,168.268033 -84.34835,164.375074 -84.34835,160.482115 -84.34835,156.589156 -84.34835,152.696197 -84.34835,148.803238 -84.34835,144.910279 -84.34835,141.01732 -84.34835,141.01732 -84.126515,141.01732 -83.90468,141.01732 -83.682845,141.01732 -83.46101,141.01732 -83.239175,141.01732 -83.01734,141.01732 -82.795505,141.01732 -82.57367,141.01732 -82.351835,141.01732 -82.13))", "dataset_titles": "Agglutinated Foraminifera, genome sequencing data; Rift Mechanisms and Thermal Regime of the Lithosphere across Beardmore Glacier Region, Central Transantarctic Mountains, from Magnetotelluric Measurements", "datasets": [{"dataset_uid": "000211", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Agglutinated Foraminifera, genome sequencing data", "url": "http://www.ncbi.nlm.nih.gov/sites/myncbi/collections/public/1vwfrm7rJme2hrzl6smGVhpk-/"}, {"dataset_uid": "600102", "doi": "10.15784/600102", "keywords": "Antarctica; Magnetotelluric; Potential Field; Solid Earth; Transantarctic Mountains", "people": "Wannamaker, Philip", "repository": "USAP-DC", "science_program": null, "title": "Rift Mechanisms and Thermal Regime of the Lithosphere across Beardmore Glacier Region, Central Transantarctic Mountains, from Magnetotelluric Measurements", "url": "https://www.usap-dc.org/view/dataset/600102"}], "date_created": "Mon, 12 Nov 2012 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The investigators will examine competing hypotheses for the mechanism of extension and creation of the Transantarctic Mountains, and evolution of the thermal regimes of rifted West Antarctica and stable East Antarctica using magnetotelluric (MT) profiles. Surrounded almost entirely by ocean ridges, Antarctica is a special tectonic situation because of the need to make accommodation space for rifting in the Transantarctic region. In the MT method, temporal variations in the Earth\u0027s natural electromagnetic field are used as source fields to probe the electrical resistivity structure in the depth range of 1 to 200 km, or more. Geophysical methods, such as MT, are appropriate in Antarctica because of the predominance of thick ice cover over most of the Continent and the difficult operating environment. The proposed effort will consist of approximately 50 sites over a distance approaching 500 km with a 10 km average spacing, oriented normal to the Transantarctic Mountains (TAM), in the Beardmore glacier area. High quality MT soundings will be collected over thick ice sheets using a custom electrode preamp design, updated from previous Antarctic projects. Data acquisition will take place over two field seasons. The primary goals are three-fold: to establish the location of the deeper tectonic transition between East and West Antarctica that may be offset from the physiographic transition at the surface, using deep resistivity structure distinguish between modes of extensional upwelling and magmatism that may be vertically non-uniform, depth and magnitude of quasi-layered deep crustal low resistivity, particularly below West Antarctica, will be used to estimate crustal heat flux into the ice sheet base.", "east": 179.94691, "geometry": "POINT(160.482115 -83.239175)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -82.13, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bowser, Samuel; Wannamaker, Philip", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "NCBI GenBank; USAP-DC", "science_programs": null, "south": -84.34835, "title": "Rift Mechanisms and Thermal Regime of the Lithosphere across Beardmore Glacier Region, Central Transantarctic Mountains, from Magnetotelluric Measurements", "uid": "p0000247", "west": 141.01732}, {"awards": "0732946 Steffen, Konrad", "bounds_geometry": null, "dataset_titles": "Larsen C automatic weather station data 2008\u20132011; Mean surface mass balance over Larsen C ice shelf, Antarctica (1979-2014), assimilated to in situ GPR and snow height data", "datasets": [{"dataset_uid": "601056", "doi": "10.15784/601056", "keywords": "Antarctica; Antarctic Peninsula; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Larsen C Ice Shelf; Radar", "people": "McGrath, Daniel; Kuipers Munneke, Peter; Steffen, Konrad", "repository": "USAP-DC", "science_program": null, "title": "Mean surface mass balance over Larsen C ice shelf, Antarctica (1979-2014), assimilated to in situ GPR and snow height data", "url": "https://www.usap-dc.org/view/dataset/601056"}, {"dataset_uid": "601445", "doi": "10.15784/601445", "keywords": "Antarctica; Atmosphere; AWS; Foehn Winds; Ice Shelf; Larsen C Ice Shelf; Larsen Ice Shelf; Meteorology; Weather Station Data", "people": "Bayou, Nicolas; Steffen, Konrad; McGrath, Daniel", "repository": "USAP-DC", "science_program": null, "title": "Larsen C automatic weather station data 2008\u20132011", "url": "https://www.usap-dc.org/view/dataset/601445"}], "date_created": "Wed, 03 Oct 2012 00:00:00 GMT", "description": "This award supports a field experiment, with partners from Chile and the Netherlands, to determine the state of health and stability of Larsen C ice shelf in response to climate change. Significant glaciological and ecological changes are taking place in the Antarctic Peninsula in response to climate warming that is proceeding at 6 times the global average rate. Following the collapse of Larsen A ice shelf in 1995 and Larsen B in 2002, the outlet glaciers that nourished them with land ice accelerated massively, losing a disproportionate amount of ice to the ocean. Further south, the much larger Larsen C ice shelf is thinning and measurements collected over more than a decade suggest that it is doomed to break up. The intellectual merit of the project will be to contribute to the scientific knowledge of one of the Antarctic sectors where the most significant changes are taking place at present. The project is central to a cluster of International Polar Year activities in the Antarctic Peninsula. It will yield a legacy of international collaboration, instrument networking, education of young scientists, reference data and scientific analysis in a remote but globally relevant glaciological setting. The broader impacts of the project will be to address the contribution to sea level rise from Antarctica and to bring live monitoring of climate and ice dynamics in Antarctica to scientists, students, the non-specialized public, the press and the media via live web broadcasting of progress, data collection, visualization and analysis. Existing data will be combined with new measurements to assess what physical processes are controlling the weakening of the ice shelf, whether a break up is likely, and provide baseline data to quantify the consequences of a breakup. Field activities will include measurements using the Global Positioning System (GPS), installation of automatic weather stations (AWS), ground penetrating radar (GPR) measurements, collection of shallow firn cores and temperature measurements. These data will be used to characterize the dynamic response of the ice shelf to a variety of phenomena (oceanic tides, iceberg calving, ice-front retreat and rifting, time series of weather conditions, structural characteristics of the ice shelf and bottom melting regime, and the ability of firn to collect melt water and subsequently form water ponds that over-deepen and weaken the ice shelf). This effort will complement an analysis of remote sensing data, ice-shelf numerical models and control methods funded independently to provide a more comprehensive analysis of the ice shelf evolution in a changing climate.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e TEMPERATURE PROFILERS", "is_usap_dc": false, "keywords": "Climate Warming; Firn; COMPUTERS; Ice Dynamic; USAP-DC; Glaciological; Thinning; Sea Level Rise; FIELD SURVEYS; FIELD INVESTIGATION; USA/NSF; AMD; Ice Edge Retreat; LABORATORY; Climate Change; Antarctic Peninsula; Amd/Us; Melting", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steffen, Konrad", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "IPY: Stability of Larsen C Ice Shelf in a Warming Climate", "uid": "p0000087", "west": null}, {"awards": "0733025 Blankenship, Donald", "bounds_geometry": "POLYGON((95 -65,103.5 -65,112 -65,120.5 -65,129 -65,137.5 -65,146 -65,154.5 -65,163 -65,171.5 -65,180 -65,180 -66.7,180 -68.4,180 -70.1,180 -71.8,180 -73.5,180 -75.2,180 -76.9,180 -78.6,180 -80.3,180 -82,171.5 -82,163 -82,154.5 -82,146 -82,137.5 -82,129 -82,120.5 -82,112 -82,103.5 -82,95 -82,95 -80.3,95 -78.6,95 -76.9,95 -75.2,95 -73.5,95 -71.8,95 -70.1,95 -68.4,95 -66.7,95 -65))", "dataset_titles": "Gravity anomaly data; Gravity raw data; ICECAP Basal Interface Specularity Content Profiles: IPY and OIB; ICECAP flight reports; ICECAP ice thickness data over the Darwin and Hatherton Glaciers, Transantarctic Mountains, Antarctica; ICECAP radargrams (HiCARS 1); ICECAP radargrams (HiCARS 2); Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau; Ice thickness and bed reflectivity data (HiCARS 1); Ice thickness and bed reflectivity data (HiCARS 2); Laser altimetry raw data; Laser surface elevation data; Magnetic anomaly data; Magnetic raw data", "datasets": [{"dataset_uid": "601411", "doi": "10.15784/601411", "keywords": "Antarctica; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ICECAP; Ice Penetrating Radar; Internal Reflecting Horizons", "people": "Tozer, Carly; Ritz, Catherine; Blankenship, Donald D.; Schroeder, Dustin; Mulvaney, Robert; Roberts, Jason; Frezzotti, Massimo; Paden, John; Muldoon, Gail R.; Quartini, Enrica; Kempf, Scott D.; Ng, Gregory; Greenbaum, Jamin; Cavitte, Marie G. P; Young, Duncan A.", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau", "url": "https://www.usap-dc.org/view/dataset/601411"}, {"dataset_uid": "601605", "doi": "10.15784/601605", "keywords": "Airborne Radar; Antarctica; Basler; Darwin Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hatherton Glacier; Hicars; ICECAP; Ice Penetrating Radar; Ice Thickness; Transantarctic Mountains", "people": "Young, Duncan A.; Holt, John W.; Greenbaum, Jamin; Schroeder, Dustin; Gillespie, Mette; Blankenship, Donald D.; Siegert, Martin", "repository": "USAP-DC", "science_program": null, "title": "ICECAP ice thickness data over the Darwin and Hatherton Glaciers, Transantarctic Mountains, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601605"}, {"dataset_uid": "200114", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Ice thickness and bed reflectivity data (HiCARS 2)", "url": "https://nsidc.org/data/IR2HI2/versions/1"}, {"dataset_uid": "200115", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Magnetic raw data", "url": "https://nsidc.org/data/imgeo1b"}, {"dataset_uid": "200116", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Magnetic anomaly data", "url": "https://nsidc.org/data/imgeo2"}, {"dataset_uid": "200117", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Gravity raw data", "url": "https://nsidc.org/data/igbgm1b/"}, {"dataset_uid": "200118", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Gravity anomaly data", "url": "https://nsidc.org/data/igbgm2/"}, {"dataset_uid": "200119", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Laser altimetry raw data", "url": "https://nsidc.org/data/ilutp1b"}, {"dataset_uid": "200120", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Laser surface elevation data", "url": "https://nsidc.org/data/ilutp2"}, {"dataset_uid": "200121", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "ICECAP flight reports", "url": "https://nsidc.org/data/ifltrpt"}, {"dataset_uid": "200111", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "ICECAP radargrams (HiCARS 1)", "url": "https://nsidc.org/data/IR1HI1B/versions/1"}, {"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Young, Duncan A.; Roberts, Jason; Greenbaum, Jamin; Blankenship, Donald D.; Schroeder, Dustin; Siegert, Martin; van Ommen, Tas", "repository": "USAP-DC", "science_program": null, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "url": "https://www.usap-dc.org/view/dataset/601371"}, {"dataset_uid": "200112", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "ICECAP radargrams (HiCARS 2)", "url": "https://nsidc.org/data/IR2HI1B/versions/1"}, {"dataset_uid": "200113", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Ice thickness and bed reflectivity data (HiCARS 1)", "url": "https://nsidc.org/data/IR1HI2/versions/1"}], "date_created": "Tue, 04 Sep 2012 00:00:00 GMT", "description": "This project is an aerogeophysical survey to explore unknown terrain in East Antarctica to answer questions of climate change and earth science. The methods include ice-penetrating radar, gravity, and magnetic measurements. The project?s main goal is to investigate the stability and migration of ice divides that guide flow of the East Antarctic ice sheet, the world?s largest. The project also maps ice accumulation over the last interglacial, identifies subglacial lakes, and characterizes the catchment basins of the very largest glacial basins, including Wilkes and Aurora. The outcomes contribute to ice sheet models relevant to understanding sea level rise in a warming world. The work will also help understand the regional geology. Buried beneath miles-thick ice, East Antarctica is virtually uncharacterized, but is considered a keystone for tectonic reconstructions and other geologic questions. The region also hosts subglacial lakes, whose geologic histories are unknown. \u003cbr/\u003e\u003cbr/\u003eThe broader impacts are extensive, and include societal relevance for understanding sea level rise, outreach in various forms, and education at the K12 through postdoctoral levels. The project contributes to the International Polar Year (2007-2009) by addressing key IPY themes on frontiers in polar exploration and climate change. It also includes extensive international collaboration with the United Kingdom, Australia, France and other nations; and offers explicit opportunities for early career scientists.", "east": 180.0, "geometry": "POINT(137.5 -73.5)", "instruments": null, "is_usap_dc": false, "keywords": "DOME C; Aurora Subglacial Basin; BT-67; East Antarctica; Wilkes Land; Totten Glacier; ICE SHEETS; Byrd Glacier; Wilkes Subglacial Basin", "locations": "East Antarctica; DOME C; Byrd Glacier; Totten Glacier; Aurora Subglacial Basin; Wilkes Subglacial Basin; Wilkes Land", "north": -65.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Earth Sciences", "paleo_time": null, "persons": "Siegert, Martin; Roberts, Jason; Van Ommen, Tas; Warner, Roland; Richter, Thomas; Greenbaum, Jamin; Holt, John W.; Young, Duncan A.; Blankenship, Donald D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e BT-67", "repo": "USAP-DC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": -82.0, "title": "IPY Research: Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP)", "uid": "p0000719", "west": 95.0}, {"awards": "0632198 Anandakrishnan, Sridhar", "bounds_geometry": "POINT(110 -74)", "dataset_titles": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Blankenship, Donald D.; Dupont, Todd K.; Parizek, Byron R.; Holt, John W.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}], "date_created": "Wed, 29 Aug 2012 00:00:00 GMT", "description": "This award supports a project to study ice sheet history and dynamics on the Thwaites Glacier and Pine Island Glacier in the Amundsen Sea sector of the West Antarctic Ice Sheet. The international collaboration that has been established with the British Antarctic Survey will enable a fuller suite of geophysical experiments with more-efficient use of people and logistics than we could achieve individually. This project is one of a number of projects to characterize the Amundsen Sea Embayment, which has been identified in numerous planning documents as perhaps the most important target for ice-dynamical research. Taken together, this \"pulse of activity\" will result in a better understanding of this important part of the global system. Field work will measure the subglacial environment of Thwaites and Pine Island Glaciers using three powerful, but relatively simple tools: reflection seismic imaging, GPS motion monitoring of the tidal forcing, and passive seismic monitoring of the seismicity associated with motion. The results of the field work will feed into ice-sheet modeling efforts that are tuned to the case of an ocean-terminating glacier and will assess the influence of these glaciers on current sea level and project into the future. The broader impacts of the project involve the inclusion of a film- and audio-professional to document the work for informal outreach (public radio and TV; museums). In addition, we will train graduate students in polar geophysical and glaciological research and in numerical modeling techniques. The ultimate goal of this project, of assessing the role of Thwaites Glacier in global sea level change, has broad societal impact in coastal regions and small islands.", "east": -110.0, "geometry": "POINT(-110 -74)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": false, "keywords": "Pine Island Glacier; Bed Reflectivity; Tidal Forcing; FIELD INVESTIGATION; Not provided; Position; Thwaites; Thickness; Amundsen Sea; LABORATORY; FIELD SURVEYS; Subglacial; Ice Dynamic; Ice Sheet Modeling", "locations": "Thwaites; Pine Island Glacier; Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "IPY: Flow Dynamics of the Amundsen Sea Glaciers: Thwaites and Pine Island.", "uid": "p0000699", "west": -110.0}, {"awards": "0537752 Creyts, Timothy; 0538674 Winebrenner, Dale", "bounds_geometry": null, "dataset_titles": "Millennially Averaged Accumulation Rates for Lake Vostok; Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica", "datasets": [{"dataset_uid": "609500", "doi": "10.7265/N5F769HV", "keywords": "Accumulation Rate; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok", "people": "Matsuoka, Kenichi; Waddington, Edwin D.; Winebrenner, Dale; Studinger, Michael S.; Macgregor, Joseph A.", "repository": "USAP-DC", "science_program": null, "title": "Millennially Averaged Accumulation Rates for Lake Vostok", "url": "https://www.usap-dc.org/view/dataset/609500"}, {"dataset_uid": "609501", "doi": "10.7265/N59K485D", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Radar Attenuation Rate; Vostok Ice Core", "people": "Matsuoka, Kenichi; Macgregor, Joseph A.; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609501"}], "date_created": "Thu, 09 Aug 2012 00:00:00 GMT", "description": "0538674\u003cbr/\u003eMatsuoka\u003cbr/\u003eThis award supports a project to evaluate radio-echo intensities in the available SOAR ice-penetrating radar data along grids covering Lake Vostok, and along four regional tracks from Ridge B toward the lake. The project has two objectives; first, it will examine the upper surface of the lake and reflectors hypothesized to be a boundary between the meteoric and accreted ice. They will provide crucial knowledge on the dynamic evolution of the lake. Second, this project will examine a poorly understood echo-free zone within the deep ice in central East Antarctica. This zone may consist of distorted stagnant ice, while its upper boundary may be a shear zone. The SOAR radar data provide a unique resource to examine spatiotemporal water circulation patterns that should be understood in order to select the best direct-sampling strategy to the lake. The Vostok ice core provides a unique opportunity to do this work. First, the path effects, i.e. propagation loss and birefringence, will be derived at the ice-core site using ice temperature, chemistry, and fabric data. Second, lateral variations of the propagation loss will be estimated by tracking chemistry associated with radar-detected isochronous layers, and by inferring temperatures from an ice-flow model that can replicate those layers. Ice-fabric patterns will be inferred from anisotropy in the reflectivity at about 100 radar-track cross-over sites. In terms of broader impacts, a graduate student will be trained to interpret the radar data in the light of radar theory and glaciological context of Lake Vostok and summer workshops for K-12 teachers will be provided in Seattle and New York. This project will contribute to ongoing efforts to study Lake Vostok and will complement the site selection for a North Vostok ice core, which has been proposed by Russia and France as an IPY program.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LASERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Airborne Radar Sounding; DHC-6; Salinity; Lake Vostok; Antarctic Ice Sheet; Modeling; FIELD SURVEYS; Model Output; Accumulation Rate; MODELS; Numerical Model; Ice Sheet; Not provided; Hydrostatic; Aerogeophysical; Subglacial; Attenuation Rate; Radar; FIELD INVESTIGATION; Model; Circulation; LABORATORY", "locations": "Lake Vostok; Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Matsuoka, Kenichi; Winebrenner, Dale; Creyts, Timothy; Macgregor, Joseph A.; Studinger, Michael S.; Waddington, Edwin D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e MODELS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data", "uid": "p0000090", "west": null}, {"awards": "0636584 Creyts, Timothy", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 07 Aug 2012 00:00:00 GMT", "description": "Studinger/0636584\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to estimate the salinity of subglacial Lake Vostok, Lake Concordia and the 90 deg.E lake using existing airborne ice-penetrating radar and laser altimeter data. These lakes have been selected because of the availability of modern aerogeophysical data and because they are large enough for the floating ice to be unaffected by boundary stresses near the grounding lines. The proposed approach is based on the assumption that the ice sheet above large subglacial lakes is in hydrostatic equilibrium and the density and subsequently salinity of the lake\u0027s water can be estimated from the (linear) relationship between ice surface elevation and ice thickness of the floating ice. The goal of the proposed work is to estimate the salinity of Lake Vostok and determine spatial changes and to compare the salinity estimates of 3 large subglacial lakes in East Antarctica. The intellectual merits of the project are that this work will contribute to the knowledge of the physical and chemical processes operating within subglacial lake environments. Due to the inaccessibility of subglacial lakes numerical modeling of the water circulation is currently the only way forward to develop a conceptual understanding of the circulation and melting and freezing regimes in subglacial lakes. Numerical experiments show that the salinity of the lake\u0027s water is a crucial input parameter for the 3-D fluid dynamic models. Improved numerical models will contribute to our knowledge of water circulation in subglacial lakes, its effects on water and heat budgets, stratification, melting and freezing, and the conditions that support life in such extreme environments. The broader impacts of the project are that subglacial lakes have captured the interest of many people, scientists and laymen. The national and international press frequently reports about the research of the Principal Investigator. His Lake Vostok illustrations have been used in math and earth science text books. Lake Vostok will be used for education and outreach in the Earth2Class project. Earth2Class is a highly successful science/math/technology learning resource for K-12 students, teachers, and administrators in the New York metropolitan area. Earth2Class is created through collaboration by research scientists at the Lamont- Doherty Earth Observatory; curriculum and educational technology specialists from Teachers College, Columbia University; and classroom teachers in the New York metropolitan area.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LASERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS", "is_usap_dc": false, "keywords": "Subglacial; Hydrostatic; Not provided; LABORATORY; Aerogeophysical; Numerical Model; FIELD SURVEYS; Salinity; Circulation", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Creyts, Timothy; Studinger, Michael S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Estimating the Salinity of Subglacial Lakes From Existing Aerogeophysical Data", "uid": "p0000704", "west": null}, {"awards": "0631973 Joughin, Ian; 0632031 Das, Sarah", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 20 Jun 2012 00:00:00 GMT", "description": "Joughin 0631973\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to gather data to better understand the mass balance of the West Antarctic Ice Sheet, in the Pine Island and Thwaites region, through the combination of radar altimetry and surface-based ice-core measurements of accumulation. The intellectual merit of the project is that the results of the field work will provide information on decadal-scale average accumulation extending back through the last century and will help constrain a modeling effort to determine how coastal changes propagate inland, to allow better prediction of future change. Comparison of the basin averaged accumulation with ice discharge determined using Interferometric Synthetic Aperture Radar (InSAR) velocity data will provide improved mass-balance estimates. Study of changes in flow speed will produce a record of mass balance over the last three decades. Analysis of the satellite altimeter record in conjunction with annual accumulation estimates also will provide estimates of changes and variability in mass balance. The broader impacts of the work are that it will make a significant contribution to future IPCC estimates of sea level, which are important for projection of the impacts of increased sea level on coastal communities. The research will contribute to the graduate education of students at the Universities of Washington and Kansas and will enrich K-12 education through the direct participation of the PIs in classroom activities. Informal science education includes 4-day glacier flow demonstrations at the Polar Science Weekend held annually at the Pacific Science Center in Seattle. The project also will communicate results through Center for the Remote Sensing of Ice Sheets (CReSIS) outreach effort. All field and remotely-sensed data sets will be archived and distributed by the National Snow and Ice Data Center. This project is relevant to IPY in that the West Antarctic Ice Sheet is losing mass, in large part because of rapid thinning of the Amundsen Coast glaciers so, it will directly address the NSF IPY emphasis on \"ice sheet history and dynamics.\" The project is also international in scope.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": false, "keywords": "Not provided; FIELD INVESTIGATION; Flow Speed; Antarctic; LABORATORY; Ice Sheet Accumulation Rate; Mass Balance; Accumulation; Insar; SATELLITES; FIELD SURVEYS; Ice Core; Radar Altimetry; Ice Velocity", "locations": "Antarctic", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Joughin, Ian; Medley, Brooke; Das, Sarah", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repositories": null, "science_programs": null, "south": null, "title": "IPY: Collaborative Proposal: Constraining the Mass-Balance Deficit of the Amundsen Coast\u0027s Glaciers", "uid": "p0000542", "west": null}, {"awards": "0738658 Price, P. Buford", "bounds_geometry": "POINT(112.1125 -79.4638)", "dataset_titles": "Access to data; data from one of three optical logs we made at WAIS Divide; WAIS Divide Laser Dust Logger Data", "datasets": [{"dataset_uid": "001349", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to data", "url": "http://icecube.berkeley.edu/~bay/wdc/"}, {"dataset_uid": "609540", "doi": "10.7265/N5C53HSG", "keywords": "Antarctica; Atmosphere; Chemistry:ice; Chemistry:Ice; Dust; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Laser Dust Logger; WAIS Divide Ice Core", "people": "Bay, Ryan", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Laser Dust Logger Data", "url": "https://www.usap-dc.org/view/dataset/609540"}, {"dataset_uid": "000188", "doi": "", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "data from one of three optical logs we made at WAIS Divide", "url": "http://icecube.berkeley.edu/~bay/wdc/"}], "date_created": "Tue, 19 Jun 2012 00:00:00 GMT", "description": "This award supports a project to use two new scanning fluorimeters to map microbial concentrations vs depth in the WAIS Divide ice core as portions of it become available at NICL, and selected portions of the GISP2 ice core for inter-hemispheric comparison. Ground-truth calibrations with microbes in ice show that the instruments are sensitive to a single cell and can scan the full length of a 1-meter core at 300-micron intervals in two minutes. The goals of these studies will be to exploit the discovery that microbes are transported onto ice, in clumps, several times per year and that at rare intervals (not periodically) of ~104 years, a much higher flux, sometimes lasting \u003e1 decade, reaches the ice. From variations ranging from seasonal to millennial to glacial scale in the arrival time distribution of phototrophs, methanogens, and total microbes in the Antarctic and Arctic ice, the investigators will attempt to determine oceanic and terrestrial sources of these microbes and will look for correlations of microbial bursts with dust concentration and temperature proxies. In addition the project will follow up on the discovery that the rare instances of very high microbial flux account for some of the\"gas artifacts\" in ice cores - isolated spikes of excess CH4 and N2O that have been discarded by others in previous climate studies. The intellectual merit of this project is that it will exploit scanning fluorimetry of microbes as a powerful new tool for studies ranging from meteorology to climatology to biology, especially when combined with mapping of dust, gases, and major element chemistry in ice cores. In 2010-11 the WAIS Divide borehole will be logged with the latest version of the dust logger. The log will provide mm-scale depth resolution of dust concentration and of volcanic ash layers down the entire depth of the borehole. The locations of ash layers in the ice will be determined and chemical analyses of the ash will be analyzed in order to determine provenance. By comparing data from the WAIS Divide borehole with data from other boreholes and with chemical data (obtained by others) on volcanic layers, the researchers will examine the relationship between the timing of volcanic eruptions and abrupt climate change. Results from this project with the scanning fluorimeters and the dust logger could have applications to planetary missions, borehole oceanography, limnology, meteorology, climate, volcanology, and ancient life in ice. A deeper understanding of the causes of abrupt climate change, including a causal relationship with volcanic explosivity, would enable a better understanding of the adverse effects on climate. The broader impact of the project is that it will provide training to students and post-docs from the U. S. and other countries.", "east": 112.1125, "geometry": "POINT(112.1125 -79.4638)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e OPTICAL DUST LOGGERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e OPTICAL DUST LOGGERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS", "is_usap_dc": true, "keywords": "Dust Loggers; Dust Concentration; Ice Core; West Antarctic Ice Sheet; LABORATORY; Microbial; Fluorimetry; GROUND-BASED OBSERVATIONS; Meteorology; Climatologymeteorologyatmosphere; Ice", "locations": "West Antarctic Ice Sheet", "north": -79.4638, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bay, Ryan; Price, Buford; Souney, Joseph Jr.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "PI website", "repositories": "PI website; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.4638, "title": "Climatology, Meteorology, and Microbial Metabolism in Ice with Dust Loggers and Fluorimetry", "uid": "p0000009", "west": 112.1125}, {"awards": "1043313 Spencer, Matthew; 1043528 Alley, Richard", "bounds_geometry": "POINT(112.1166 -79.4666)", "dataset_titles": "Average Annual Layer Thickness of the WAIS Divide Ice Core from Visual Stratigraphy; C-axis Fabric from Physical Properties Samples of the WAIS Divide Ice Core; Updated (2017) bubble number-density, size, shape, and modeled paleoclimate data; WAIS Divide 580m Bubble and Grain Hybrid Data; WAIS Divide Surface and Snow-pit Data, 2009-2013", "datasets": [{"dataset_uid": "601224", "doi": "10.15784/601224", "keywords": "Antarctic; Antarctica; Bubble Number Density; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; NSF-ICF Microtome and Photography Stage; Paleoclimate; Physical Properties; Snow/ice; Snow/Ice; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Voigt, Donald E.; Fegyveresi, John; Fitzpatrick, Joan; Spencer, Matthew; Alley, Richard", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Updated (2017) bubble number-density, size, shape, and modeled paleoclimate data", "url": "https://www.usap-dc.org/view/dataset/601224"}, {"dataset_uid": "609605", "doi": "10.7265/N5W093VM", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Voigt, Donald E.; Alley, Richard; Fitzpatrick, Joan", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "C-axis Fabric from Physical Properties Samples of the WAIS Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/609605"}, {"dataset_uid": "601079", "doi": "10.15784/601079", "keywords": "Antarctica; Atmosphere; AWS; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Meteorology; Physical Properties; Snow Pit; Temperature; WAIS Divide; WAIS Divide Ice Core; Weatherstation", "people": "Alley, Richard; Fegyveresi, John", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Surface and Snow-pit Data, 2009-2013", "url": "https://www.usap-dc.org/view/dataset/601079"}, {"dataset_uid": "601087", "doi": "10.15784/601087", "keywords": "Air Bubbles; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Strain; Physical Ice Properties; Snow/ice; Snow/Ice; Strain", "people": "Fegyveresi, John; Alley, Richard", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide 580m Bubble and Grain Hybrid Data", "url": "https://www.usap-dc.org/view/dataset/601087"}, {"dataset_uid": "609603", "doi": "10.7265/N53J39X3", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Spencer, Matthew", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Average Annual Layer Thickness of the WAIS Divide Ice Core from Visual Stratigraphy", "url": "https://www.usap-dc.org/view/dataset/609603"}], "date_created": "Tue, 19 Jun 2012 00:00:00 GMT", "description": "1043528/Alley This award supports a project to complete the physical-properties studies of the WAIS Divide deep ice core, now being collected in West Antarctica. Ongoing work funded by NSF, under a grant that is ending, has produced visible stratigraphy dating, inspection of the core for any melt layers, volcanic horizons, flow disturbances or other features, analysis of bubble number-densities allowing reconstruction of a two-millennial cooling trend in the latter Holocene at the site, characterization of other bubble characteristics (size, etc.), density studies, characterization of snow-surface changes at the site, preliminary c-axis studies, and more. The current proposal seeks to complete this work, once the rest of the core is recovered. The intellectual merit of the proposed activity starts with quality assurance for the core, by visual detection of any evidence of flow disturbances that would disrupt the integrity of the climate record. Inspection will also reveal any melt layers, volcanic horizons, etc. Annual-layer dating will be conducted; thus far, the visible strata have not been as useful as some other indicators, but the possibility (based on experience in Greenland) that visible examination will allow detection of thinner annual layers than other techniques motivates the effort. Bubble number-density will be used to reconstruct temperature changes through the rest of the bubbly part of the core, providing important paleoclimatic data for earlier parts of the Holocene. Coordinated interpretation of c-axis fabrics, grain sizes and shapes, and bubble characteristics will be used to learn about the history of ice flow, the processes of ice flow, and the softness of the ice for additional deformation. Analysis of surface data already collected will improve interpretation of the layering of the core. It is possible that the annual-layer dating will not be sufficiently successful, and that the core will be undisturbed with no melt layers; if so, then these efforts will not yield major publications. However, success of the other efforts should produce improved understanding of the history and stability of the ice sheet, and key processes controlling these, and the quality assurance provided by the visual examination is important for the project as a whole. The broader impacts of the proposed activity include education of a PhD student and multiple undergraduates, and research opportunities for a junior faculty member at an undergraduate institution. The proposed activity will help support an especially vigorous education and outreach effort providing undergraduate instruction for over 1000 students per year, reaching thousands more citizens and many policymakers, and preparing educational materials used at many levels.", "east": 112.1166, "geometry": "POINT(112.1166 -79.4666)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e VISUAL OBSERVATIONS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ACFA; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Antarctic; Antarctica; Annual Layer Thickness; Ice Core; Visual Observations; Bubble; LABORATORY; Bubble Density; FIELD INVESTIGATION; Physical Properties; Stratigraphy; Climate Record; Annual Layers; Ice Fabric; C-axis; Model; WAIS Divide; GROUND-BASED OBSERVATIONS; FIELD SURVEYS; Melt Layers; Wais Divide-project; Not provided", "locations": "WAIS Divide; Antarctica; Antarctic", "north": -79.4666, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Spencer, Matthew; Alley, Richard; Fitzpatrick, Joan; Voigt, Donald E.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.4666, "title": "Collaborative Research: Continued Study of Physical Properties of the WAIS Divide Deep Core", "uid": "p0000027", "west": 112.1166}, {"awards": "0636767 Dunbar, Nelia; 0636740 Kreutz, Karl", "bounds_geometry": "POINT(112.11666 -79.46666)", "dataset_titles": "Microparticle, Conductivity, and Density Measurements from the WAIS Divide Deep Ice Core, Antarctica; Snowpit Chemistry - Methods Comparison, WAIS Divide, Antarctica; Snowpit evidence of the 2011 Puyehue-Cordon Caulle (Chile) eruption in West Antarctica; WAIS Divide Microparticle Concentration and Size Distribution, 0-2400 ka; WAIS Divide Snowpit Chemical and Isotope Measurements, Antarctica; WAIS Divide WDC06A Discrete ICP-MS Chemistry", "datasets": [{"dataset_uid": "609620", "doi": "10.7265/N5Q81B1X", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Trace Elements; WAIS Divide; WAIS Divide Ice Core", "people": "Kreutz, Karl; Koffman, Bess", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Snowpit Chemistry - Methods Comparison, WAIS Divide, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609620"}, {"dataset_uid": "601036", "doi": "10.15784/601036", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Intracontinental Magmatism; IntraContinental Magmatism; Snow Pit; Tephra; WAIS Divide; WAIS Divide Ice Core", "people": "Koffman, Bess; Kreutz, Karl", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Snowpit evidence of the 2011 Puyehue-Cordon Caulle (Chile) eruption in West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601036"}, {"dataset_uid": "601023", "doi": "10.15784/601023", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; ICP-MS; Isotope; WAIS Divide; WAIS Divide Ice Core", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide WDC06A Discrete ICP-MS Chemistry", "url": "https://www.usap-dc.org/view/dataset/601023"}, {"dataset_uid": "609506", "doi": "10.7265/N5SJ1HHN", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Isotope; Microparticle Concentration; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core", "people": "Koffman, Bess; Kreutz, Karl", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Snowpit Chemical and Isotope Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609506"}, {"dataset_uid": "609616", "doi": "10.7265/N5KK98QZ", "keywords": "Antarctica; Dust; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Particle Size; WAIS Divide; WAIS Divide Ice Core", "people": "Koffman, Bess; Kreutz, Karl", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Microparticle Concentration and Size Distribution, 0-2400 ka", "url": "https://www.usap-dc.org/view/dataset/609616"}, {"dataset_uid": "609499", "doi": "10.7265/N5K07264", "keywords": "Antarctica; Density; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Microparticle Concentration; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Kreutz, Karl; Hamilton, Gordon S.; Koffman, Bess; Breton, Daniel", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Microparticle, Conductivity, and Density Measurements from the WAIS Divide Deep Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609499"}], "date_created": "Tue, 19 Jun 2012 00:00:00 GMT", "description": "This award supports a project to perform continuous microparticle concentration and size distribution measurements (using coulter counter and state-of-the-art laser detector methods), analysis of biologically relevant trace elements associated with microparticles (Fe, Zn, Co, Cd, Cu), and tephra measurements on the WAIS Divide ice core. This initial three-year project includes analysis of ice core spanning the instrumental (~1850-present) to mid- Holocene (~5000 years BP) period, with sample resolution ranging from subannual to decadal. The intellectual merit of the project is that it will help in establishing the relationships among climate, atmospheric aerosols from terrestrial and volcanic sources, ocean biogeochemistry, and greenhouse gases on several timescales which remain a fundamental problem in paleoclimatology. The atmospheric mineral dust plays an important but uncertain role in direct radiative forcing, and the microparticle datasets produced in this project will allow us to examine changes in South Pacific aerosol loading, atmospheric dynamics, and dust source area climate. The phasing of changes in aerosol properties within Antarctica, throughout the Southern Hemisphere, and globally is unclear, largely due to the limited number of annually dated records extending into the glacial period and the lack of a\u003cbr/\u003etephra framework to correlate records. The broader impacts of the proposed research are an interdisciplinary approach to climate science problems, and will contribute to several WAIS Divide science themes as well as the broader paleoclimate and oceanographic communities. Because the research topics have a large and direct societal relevance, the project will form a centerpiece of various outreach efforts at UMaine and NMT including institution websites, public speaking, local K-12 school interaction, media interviews and news releases, and popular literature. At least one PhD student and one MS student will be directly supported by this project, including fieldwork, core processing, laboratory analysis, and data interpretation/publication. We expect that one graduate student per year will apply for a core handler/assistant driller position through the WAIS Divide Science Coordination Office, and that undergraduate student involvement will result in several Capstone experience projects (a UMaine graduation requirement). Data and ideas generated from the project will be integrated into undergraduate and graduate course curricula at both institutions.", "east": 112.11666, "geometry": "POINT(112.11666 -79.46666)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PARTICLE DETECTORS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e LOPC-PMS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e ICE CORE MELTER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PARTICLE DETECTORS", "is_usap_dc": true, "keywords": "Ice Core Dust; Tephra; Radiative Forcing; Greenhouse Gas; West Antarctica; Atmospheric Aerosols; Oxygen Isotope; Not provided; WAIS Divide; Snow Pit; Ice Core Chemistry; Microparticle; Wais Divide-project; Microparticles Size; Paleoclimate; LABORATORY; Ice Core Data; Atmospheric Dynamics; Antarctica; FIELD SURVEYS; Ice Core; Trace Elements; FIELD INVESTIGATION; Holocene; Isotope; Snow Chemistry", "locations": "Antarctica; WAIS Divide; West Antarctica", "north": -79.46666, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Koffman, Bess; Kreutz, Karl; Breton, Daniel; Dunbar, Nelia; Hamilton, Gordon S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.46666, "title": "Collaborative Research: Microparticle/tephra analysis of the WAIS Divide ice core", "uid": "p0000040", "west": 112.11666}, {"awards": "0440819 Taylor, Kendrick", "bounds_geometry": "POINT(112.1 -79.46667)", "dataset_titles": null, "datasets": null, "date_created": "Tue, 19 Jun 2012 00:00:00 GMT", "description": "This award supports a project that is part of the West Antarctic Ice Sheet Divide (WAIS Divide) program; which is a multi-disciplinary multi-institutional program to investigate the causes of natural changes in climate, the influence of the West Antarctic ice sheet on sea level, and the biology of deep ice. The WAIS Divide core will be unique among Antarctic ice cores in that it will have discernable annual layers for the last 40,000 years. A critical element of the program is to determine the age of the ice so that the climate proxies measured on the core can be interpreted in terms of age, not just depth. This project will make electrical measurements that can identify the annual layers. This information will be combined with information from other investigators to develop an annually resolved timescale over the last 40,000 years. This timescale will be the foundation on which the recent climate records are interpreted. Electrical measurements will also be used to produce two-dimensional images of the ice core stratigraphy; allowing sections of the core with abnormal stratigraphy to be identified. The broader impacts of this project include exposing a diverse group of undergraduate and graduate students to ice core research and assisting the Smithsonian National Museum of Natural History in Washington, D.C to develop a paleoclimate/ice core display.", "east": 112.1, "geometry": "POINT(112.1 -79.46667)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": false, "keywords": "Annual Layers; Time Scale; FIELD INVESTIGATION; Stratigraphy; FIELD SURVEYS; Glaciology; Electrical Measurements; Antarctic; Not provided; Ice Sheet; Ice Core; LABORATORY; Climate Proxies", "locations": "Antarctic", "north": -79.46667, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Taylor, Kendrick C.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -79.46667, "title": "Investigation of the Stratigraphy and Time Scale of the WAIS Divide Ice Core Using Electrical Methods", "uid": "p0000373", "west": 112.1}, {"awards": "0739654 Catania, Ginny; 0739372 Conway, Howard", "bounds_geometry": null, "dataset_titles": "Coastal and Terminus History of the Eastern Amundsen Sea Embayment, West Antarctica, 1972 - 2011; Ice Flow History of the Thwaites Glacier, West Antarctica", "datasets": [{"dataset_uid": "609522", "doi": "10.7265/N5CC0XNK", "keywords": "Amundsen Sea; Antarctica; Climate Change; Coastline; GIS Data; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Satellite Data Interpretation", "people": "Andrews, Alan G.; Catania, Ginny; Markowski, Michael; Macgregor, Joseph A.", "repository": "USAP-DC", "science_program": null, "title": "Coastal and Terminus History of the Eastern Amundsen Sea Embayment, West Antarctica, 1972 - 2011", "url": "https://www.usap-dc.org/view/dataset/609522"}, {"dataset_uid": "609463", "doi": "10.7265/N5RR1W6X", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Flow Lines; Thwaites Glacier", "people": "Catania, Ginny; Conway, Howard; Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Ice Flow History of the Thwaites Glacier, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609463"}], "date_created": "Wed, 30 May 2012 00:00:00 GMT", "description": "Catania 0739654\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study the Amundsen Sea drainage system and improve understanding of the impact of recent glaciological changes as an aid to predicting how this region will change in the future. The intellectual merit of the work is that the Amundsen Sea drainage system has been a recent focus for glaciological research because of rapid changes occurring there as a result of grounding line retreat. The work will focus on the regions of flow transition and will map the internal stratigraphy of the ice sheet across the Thwaites Glacier shear margins and use the age and geometry of radar-detected internal layers to interpret ice flow history. Thwaites Glacier (one of the main pathways for ice drainage in the region) has recently widened and may continue to do so in the near future. Thwaites Glacier may be particularly vulnerable to grounding line retreat because it lacks a well-defined subglacial channel. The subglacial environment exerts strong control on ice flow and flow history will be mapped in the context of bed topography and bed reflectivity. The plan is to use existing ice-penetrating radar data and coordinate with planned upcoming surveys to reduce logistical costs. The work proposed here will take three years to complete but no additional fieldwork in Antarctica is required. More detailed ground-based geophysical (radar and seismic) experiments will be needed at key locations to achieve our overall goal and the work proposed here will aid in identifying those regions. The broader impacts of the project are that it will initiate a new collaboration among radar communities within the US including those that are on the forefront of radar systems engineering and those that are actively involved in radar-derived internal layer and bed analysis. The project will also provide support for a postdoctoral researcher and a graduate student, thus giving them exposure to a variety of methodologies and scientific issues. Finally, there are plans to further develop the \"Wired Antarctica\" website designed by Ginny Catania with the help of a student-teacher. This will allow for the existing lesson plans to be updated to Texas State standards so that they can be used more broadly within state middle and high schools.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e TM; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": true, "keywords": "ERS-1; Coastal; Terminus; LABORATORY; Subglacial; Glacier; Not provided; Thwaites Glacier; Antarctica; LANDSAT; Internal Stratigraphy; West Antarctica; Internal Layers; Amundsen Sea; FIELD INVESTIGATION; FIELD SURVEYS; Glaciers; LANDSAT-5; Radar; Seismic", "locations": "Coastal; Antarctica; Thwaites Glacier; Amundsen Sea; West Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Catania, Ginny; Markowski, Michael; Macgregor, Joseph A.; Andrews, Alan G.; Fudge, T. J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e EUROPEAN REMOTE SENSING SATELLITE (ERS) \u003e ERS-1; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-5", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Ice-flow history of the Thwaites Glacier, West Antarctica", "uid": "p0000143", "west": null}, {"awards": "0739766 Brook, Edward J.", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "WAIS Divide Ice Core CO2", "datasets": [{"dataset_uid": "609651", "doi": "10.7265/N5DV1GTZ", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Brook, Edward J.; Marcott, Shaun", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core CO2", "url": "https://www.usap-dc.org/view/dataset/609651"}], "date_created": "Wed, 30 May 2012 00:00:00 GMT", "description": "Brook 0739766\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to create a 25,000-year high-resolution record of atmospheric CO2 from the WAIS Divide ice core. The site has high ice accumulation rate, relatively cold temperatures, and annual layering that should be preserved back to 40,000 years, all prerequisite for preserving a high quality, well-dated CO2 record. The new record will be used to examine relationships between Antarctic climate, Northern Hemisphere climate, and atmospheric CO2 on glacial-interglacial to centennial time scales, at unprecedented temporal resolution. The intellectual merit of the proposed work is simply that CO2 is the most important greenhouse gas that humans directly impact, and understanding the sources, sinks, and controls of atmospheric CO2 is a major goal for the global scientific community. Accurate chronology and detailed records are primary requirements for developing and testing models that explain and predict CO2 variability. The proposed work has several broader impacts. It contributes to the training of a post-doctoral researcher, who will transfer to a research faculty position during the award period and who will participate in graduate teaching and guest lecture in undergraduate courses. An undergraduate researcher will gain valuable lab training and conduct independent research. Bringing the results of\u003cbr/\u003ethe proposed work to the classroom will enrich courses taught by the PI. Outreach efforts will expose pre-college students to ice core research. The proposed work will enhance the laboratory facilities for ice core research at OSU, insuring that the capability for CO2 measurements exists for future projects. All data will be archived at the National Snow and Ice Data Center and other similar archives, per OPP policy. Highly significant results will be disseminated to the news media through OSU?s very effective News and Communications group. Carbon dioxide is the most important greenhouse gas that humans are directly changing. Understanding how CO2 and climate are linked on all time scales is necessary for predicting the future behavior of the carbon cycle and climate system, primarily to insure that the appropriate processes are represented in carbon cycle/climate models. Part of the proposed work emphasizes the relationship of CO2 and abrupt climate change. Understanding how future abrupt change might impact the carbon cycle is an important issue for society.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Carbon Dioxide; FIELD INVESTIGATION; CO2; Wais Divide-project; Ice Core; Antarctica; Climate; Gas Chromatography; Antarctic Ice Core; LABORATORY", "locations": "Antarctica", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Marcott, Shaun; Ahn, Jinho; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Atmospheric Carbon Dioxide and Climate Change: The WAIS Divide Ice Core Record", "uid": "p0000044", "west": -112.08}, {"awards": "0758274 Parizek, Byron; 0636724 Blankenship, Donald", "bounds_geometry": "POLYGON((-110.058 -74.0548,-109.57993 -74.0548,-109.10186 -74.0548,-108.62379 -74.0548,-108.14572 -74.0548,-107.66765 -74.0548,-107.18958 -74.0548,-106.71151 -74.0548,-106.23344 -74.0548,-105.75537 -74.0548,-105.2773 -74.0548,-105.2773 -74.31383,-105.2773 -74.57286,-105.2773 -74.83189,-105.2773 -75.09092,-105.2773 -75.34995,-105.2773 -75.60898,-105.2773 -75.86801,-105.2773 -76.12704,-105.2773 -76.38607,-105.2773 -76.6451,-105.75537 -76.6451,-106.23344 -76.6451,-106.71151 -76.6451,-107.18958 -76.6451,-107.66765 -76.6451,-108.14572 -76.6451,-108.62379 -76.6451,-109.10186 -76.6451,-109.57993 -76.6451,-110.058 -76.6451,-110.058 -76.38607,-110.058 -76.12704,-110.058 -75.86801,-110.058 -75.60898,-110.058 -75.34995,-110.058 -75.09092,-110.058 -74.83189,-110.058 -74.57286,-110.058 -74.31383,-110.058 -74.0548))", "dataset_titles": "Access to data; AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica; Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica; ICECAP Basal Interface Specularity Content Profiles: IPY and OIB; Subglacial water flow paths under Thwaites Glacier, West Antarctica; Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Young, Duncan A.; Roberts, Jason; Greenbaum, Jamin; Blankenship, Donald D.; Schroeder, Dustin; Siegert, Martin; van Ommen, Tas", "repository": "USAP-DC", "science_program": null, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "url": "https://www.usap-dc.org/view/dataset/601371"}, {"dataset_uid": "609518", "doi": "10.7265/N5RJ4GC8", "keywords": "AGASEA; Airborne Radar; Antarctica; Elevation; Flow Paths; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Young, Duncan A.; Blankenship, Donald D.; Carter, Sasha P.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial water flow paths under Thwaites Glacier, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609518"}, {"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Blankenship, Donald D.; Dupont, Todd K.; Parizek, Byron R.; Holt, John W.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}, {"dataset_uid": "000248", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Access to data", "url": "http://nsidc.org/data/netcdf/tools.html"}, {"dataset_uid": "609334", "doi": "10.7265/N5HD7SK8", "keywords": "AGASEA; Airborne Altimetry; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Blankenship, Donald D.; Holt, John W.; Morse, David L.; Young, Duncan A.; Kempf, Scott D.", "repository": "USAP-DC", "science_program": null, "title": "Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609334"}, {"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Muldoon, Gail R.; Blankenship, Donald D.; Jackson, Charles; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}, {"dataset_uid": "609517", "doi": "10.7265/N5W95730", "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness", "people": "Kempf, Scott D.; Holt, John W.; Young, Duncan A.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609517"}, {"dataset_uid": "002536", "doi": "", "keywords": null, "people": null, "repository": "NASA", "science_program": null, "title": "Access to data", "url": "http://www.giss.nasa.gov/tools/panoply/"}], "date_created": "Tue, 15 May 2012 00:00:00 GMT", "description": "This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program\u0027s emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: \"investigation of the physics of fast glacier flow with emphasis on processes at glacier beds\"; \"investigation of ice-shelf stability\"; and \"identification and quantification of the feedback between ice dynamics and climate change\". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations.", "east": -105.2773, "geometry": "POINT(-107.66765 -75.34995)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e RADIO \u003e INS", "is_usap_dc": true, "keywords": "Ice Sheet Thickness; Ice Sheet Elevation; Glacier Dynamics; Ice Stream; Numerical Model; West Antarctic; Surface Elevation; Basal Rheology; Ice Surface Velocity; Embayment Geometry; Amundsen Sea; Hydrology; FIELD SURVEYS; Antarctic Ice Sheet; Glacier; Subglacial; DHC-6; West Antarctic Ice Sheet; Model Output; Surface Climate; Glaciers; Basal Topography; Grounding Zone; Model Input Data; Airborne Laser Altimeters; FIELD INVESTIGATION; Thwaites Glacier; Airborne Laser Altimetry; Diagnostic; Ice-Shelf Buttressing; Ice Sheet; Prognostic; Glacier Surface; Airborne Radar Sounding; Digital Elevation Model; Ice Dynamic; Antarctica; Altimetry; Antarctica (agasea); Bed Elevation; Basal Stress; LABORATORY", "locations": "Antarctica; Thwaites Glacier; West Antarctic Ice Sheet; Antarctic Ice Sheet; West Antarctic; Amundsen Sea", "north": -74.0548, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Carter, Sasha P.; Dupont, Todd K.; Holt, John W.; Morse, David L.; Parizek, Byron R.; Young, Duncan A.; Kempf, Scott D.; Blankenship, Donald D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "NASA; NSIDC; USAP-DC", "science_programs": null, "south": -76.6451, "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "uid": "p0000174", "west": -110.058}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Antarctic Peninsula 100 m Digital Elevation Model Derived from ASTER GDEM", "datasets": [{"dataset_uid": "609516", "doi": "10.7265/N58K7711", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Peninsula 100 m Digital Elevation Model Derived from ASTER GDEM", "url": "http://www.usap-dc.org/view/dataset/609516"}], "date_created": "Mon, 30 Apr 2012 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Antarctic Peninsula; ASTER; Digital Elevation Model; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Solid Earth", "locations": "Antarctica; Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cook, Allison", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "0538538 Sowers, Todd; 0538578 Brook, Edward J.", "bounds_geometry": null, "dataset_titles": "Late Holocene Methane Concentrations from WAIS Divide and GISP2; Methane Concentrations from the WAIS Divide Ice Core (WDC06A), 60 to 11,300 ybp; The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "datasets": [{"dataset_uid": "609586", "doi": "10.7265/N5W66HQQ", "keywords": "Antarctica; Arctic; Chemistry:fluid; Chemistry:Fluid; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Mitchell, Logan E", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Late Holocene Methane Concentrations from WAIS Divide and GISP2", "url": "https://www.usap-dc.org/view/dataset/609586"}, {"dataset_uid": "609509", "doi": "10.7265/N5J1013R", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Methane Concentrations from the WAIS Divide Ice Core (WDC06A), 60 to 11,300 ybp", "url": "https://www.usap-dc.org/view/dataset/609509"}, {"dataset_uid": "001303", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "url": "https://nsidc.org/data/agdc"}], "date_created": "Thu, 19 Apr 2012 00:00:00 GMT", "description": "Sowers/Brook\u003cbr/\u003e0538538\u003cbr/\u003eThis award supports a project to develop a high-resolution (every 50 yr) methane data set that will play a pivotal role in developing the timescale for the new deep ice core being drilled at the West Antarctic Ice Sheet Divide (WAIS Divde) site as well as providing a common stratigraphic framework for comparing climate records from Greenland and WAIS Divide. Certain key intervals will be measured at even higher resolution to assist in precisely defining the phasing of abrupt climate change between the northern and southern hemispheres. Concurrent analysis of a suit of samples from both the WAIS Divide and GISP2 ice cores throughout the last 110kyr is also proposed, to establish the inter-hemispheric methane gradient which will be used to identify geographic areas responsible for the climate-related methane emission changes. A large gas measurement inter-calibration of numerous laboratories, utilizing both compressed air cylinders and WAIS Divide ice core samples, will also be performed. The intellectual merit of the proposed work is that it will provide the chronological control needed to examine the timing of changes in climate proxies, and critical chronological ties to the Greenland ice core records via methane variations. In addition, the project addresses the question of what methane sources were active during the ice age and will help to answer the fundamental question of what part of the biosphere controlled past methane variations. The broader impact of the proposed work is that it will directly benefit all ice core paleoclimate research and will impact the paleoclimate studies that rely on ice core timescales for correlation purposes. The project will also support a Ph.D. student at Oregon State University who will have the opportunity to be involved in a major new ice coring effort with international elements. Undergraduates at Penn State will gain valuable laboratory experience and participate fully in the project. The proposed work will underpin the WAIS Divide chronology, which will be fundamental to all graduate student projects that involve the core. The international inter-calibration effort will strengthen ties between research institutions on four continents and will be conducted as part of the International Polar Year research agenda.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Antarctica; Ch4; West Antarctica; Wais Divide-project; GROUND-BASED OBSERVATIONS; FIELD INVESTIGATION; FIELD SURVEYS; Methane Concentration; Methane; Ice Core; WAIS Divide; Antarctic; LABORATORY", "locations": "Antarctic; WAIS Divide; Antarctica; West Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Organisms and Ecosystems; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; NOT APPLICABLE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Lee, James; Buizert, Christo; Brook, Edward J.; Mitchell, Logan E; Sowers, Todd A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "NSIDC; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Collaborative Research: Constructing an Ultra-high Resolution Atmospheric Methane Record for the Last 140,000 Years from WAIS Divide Core.", "uid": "p0000025", "west": null}, {"awards": "0087521 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": "Annual Layers at Siple Dome, Antarctica, from Borehole Optical Stratigraphy", "datasets": [{"dataset_uid": "609515", "doi": "10.7265/N5DB7ZRZ", "keywords": "Antarctica; Borehole Optical Stratigraphy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Siple Dome; Siple Dome Ice Core; Snow/ice; Snow/Ice", "people": "Alley, Richard; Waddington, Edwin D.; Taylor, Kendrick C.; Hawley, Robert L.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Annual Layers at Siple Dome, Antarctica, from Borehole Optical Stratigraphy", "url": "https://www.usap-dc.org/view/dataset/609515"}], "date_created": "Sun, 15 Apr 2012 00:00:00 GMT", "description": "This award supports a two year project to develop a new method for measuring vertical strain rates in polar firn. Vertical strain rate measurements in the firn are important because they can aid in the understanding of the dynamics of firn compaction, a key factor in determining ice age/gas age difference estimates for ice cores. Vertical strain rate measurements also determine ice advection for borehole paleothermometry models, and most importantly can be used to date the shallow sections of ice cores where ambiguities in chemical dating or counting of annual layers hinder dating by traditional methods. In this project a video logging tool will be used to create a unique \"optical fingerprint\" of variations in the optical properties of the firn with depth, and track the movement and deformation of the features of this fingerprint. Preliminary work at Siple Dome, Antarctica using an improvised logging system shows a series of optically bright and dark zones as the tool transits up or down the hole. Borehole fingerprinting has the potential to improve measurements of vertical strain in firn holes. This project represents a unique opportunity to interface with an existing field program where a borehole vertical strain rate project is already underway. A graduate student will be supported to conduct the work on this project as part of a PhD. dissertation on climate and physical processes in polar firn.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS", "is_usap_dc": true, "keywords": "Antarctica; Stratigraphy; Layers; Ice Core Stratigraphy; Siple Dome; Borehole; FIELD INVESTIGATION; Borehole Camera; Ice Stratigraphy", "locations": "Antarctica; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard; Taylor, Kendrick C.; Waddington, Edwin D.; Hawley, Robert L.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Borehole Fingerprinting: Vertical Strain, Firn Compaction, and Firn Depth-Age Scales", "uid": "p0000173", "west": null}, {"awards": "0537930 Steig, Eric; 0537661 Cuffey, Kurt; 0537593 White, James", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "Stable Isotope Lab at INSTAAR, University of Colorado; WAIS ice core isotope data #342, 347, 348, 349, 350, 351 (full data link not provided)", "datasets": [{"dataset_uid": "000140", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "WAIS ice core isotope data #342, 347, 348, 349, 350, 351 (full data link not provided)", "url": "http://www.waisdivide.unh.edu/"}, {"dataset_uid": "002561", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Stable Isotope Lab at INSTAAR, University of Colorado", "url": "http://instaar.colorado.edu/sil/about/index.php"}], "date_created": "Mon, 09 Apr 2012 00:00:00 GMT", "description": "This award supports analyses of stable isotopes of water, dD, d18O and deuterium excess in the proposed West Antarctic Ice Sheet Divide (WAIS) deep ice core. The project will produce a continuous and high-resolution reconstruction of stable isotope ratios for the new core. dD and d18O values provide estimates of temperature change at the ice core site. Deuterium excess provides estimates of ocean surface conditions, such as sea surface temperature, at the moisture source areas. This new ice core is ideally situated to address questions ranging from ice sheet stability to abrupt climate change. WAIS Divide has high enough snowfall rates to record climate changes on annual to decadal time scales. It should also have ice old enough to capture the last interglacial period in detail. The West Antarctic ice sheet is the subject of great scrutiny as our modern climate warms and sea level rises. What are the prospects for added sea level rise from ice released by this ice sheet? Understanding how this ice sheet has responded to climate change in the past, which the data collected in this project will help to assess, is critical to answering this question. The high temporal resolution available in the WAIS Divide core will provide the best available basis for inter-comparison of millennial-scale climate changes between the poles, and thus a better understanding of the spatial expression and dynamics of rapid climate change events. Finally, the location of this core in the Pacific sector of West Antarctica makes it well situated for examining the influence of the tropical Pacific on Antarctica climate, on longer timescales than are available from the instrumental climate record. Analyses will include the measurement of sub-annually resolved isotope variations in the uppermost parts of the core, measurements at annual resolution throughout the last 10,000 years and during periods of rapid climate change prior to that, and measurements at 50-year resolution throughout the entire length of the core that is collected and processed during the period of this grant. We anticipate that this will be about half of the full core expected to be drilled. In terms of broader impacts, the PIs will share the advising of two graduate students, who will make this ice core the focus of their thesis projects. It will be done in an innovative multi-campus approach designed to foster a broader educational experience. As noted above, the data and interpretations generated by this proposal will address climate change questions not only of direct and immediate scientific interest, but also of direct and immediate policy interest.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES", "is_usap_dc": true, "keywords": "West Antarctic Ice Sheet Divide; Not provided; Ice Core; WAIS Divide; LABORATORY; FIELD SURVEYS; Isotope; FIELD INVESTIGATION; Antarctica; West Antarctica; Stable Isotope Ratios; Antarctic; Ice Sheet; Deuterium", "locations": "WAIS Divide; West Antarctica; Antarctic; Antarctica; West Antarctic Ice Sheet Divide", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "White, James; Steig, Eric J.; Cuffey, Kurt M.; Souney, Joseph Jr.; Vaughn, Bruce", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "Project website", "repositories": "Project website", "science_programs": null, "south": -79.47, "title": "Collaborative Research: Stable Isotopes of Ice in the WAIS Divide Deep Ice Core", "uid": "p0000294", "west": -112.08}, {"awards": "0739769 Fricker, Helen", "bounds_geometry": "POLYGON((-57.22 74.58,-55.343 74.58,-53.466 74.58,-51.589 74.58,-49.712 74.58,-47.835 74.58,-45.958 74.58,-44.081 74.58,-42.204 74.58,-40.327 74.58,-38.45 74.58,-38.45 73.822,-38.45 73.064,-38.45 72.306,-38.45 71.548,-38.45 70.79,-38.45 70.032,-38.45 69.274,-38.45 68.516,-38.45 67.758,-38.45 67,-40.327 67,-42.204 67,-44.081 67,-45.958 67,-47.835 67,-49.712 67,-51.589 67,-53.466 67,-55.343 67,-57.22 67,-57.22 67.758,-57.22 68.516,-57.22 69.274,-57.22 70.032,-57.22 70.79,-57.22 71.548,-57.22 72.306,-57.22 73.064,-57.22 73.822,-57.22 74.58))", "dataset_titles": "Amery Ice Shelf metadata (IRIS); Columbia Glacier metadata (IRIS); Greenland Ice Sheet Seismic Network metadata (IRIS)", "datasets": [{"dataset_uid": "000100", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Amery Ice Shelf metadata (IRIS)", "url": "http://www.iris.edu/mda/X9?timewindow=2004-2007"}, {"dataset_uid": "000103", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Greenland Ice Sheet Seismic Network metadata (IRIS)", "url": "http://www.iris.edu/mda/_GLISN"}, {"dataset_uid": "000101", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Columbia Glacier metadata (IRIS)", "url": "http://www.iris.edu/mda/YM?timewindow=2004-2005"}], "date_created": "Thu, 22 Mar 2012 00:00:00 GMT", "description": "This award supports a project to strengthen collaborations between the various research groups working on iceberg calving. Relatively little is known about the calving process, especially the physics that governs the initiation and propagation of fractures within the ice. This knowledge gap exists in part because of the diverse range in spatial and temporal scales associated with calving (ranging from less than one meter to over a hundred kilometers in length scale). It is becoming increasingly clear that to predict the future behavior of the Antarctic Ice Sheet and its contribution to sea level rise, it is necessary to improve our understanding of iceberg calving processes. Further challenges stem from difficulties in monitoring and quantifying short-time and spatial-scale processes associated with ice fracture, including increased fracturing events in ice shelves or outlet glaciers that may be a precursor to disintegration, retreat or increased calving rates. Coupled, these fundamental problems currently prohibit the inclusion of iceberg calving into numerical ice sheet models and hinder our ability to accurately forecast changes in sea level in response to climate change. Seismic data from four markedly different environmental regimes forms the basis of the proposed research, and researchers most familiar with the datasets will perform all analyses. Extracting the similarities and differences across the full breadth of calving processes embodies the core of the proposed work, combining and improving methods previously developed by each group. Techniques derived from solid Earth seismology, including waveform cross-correlation and clustering will be applied to each data set allowing quantitative process comparisons on a significantly higher level than previously possible. This project will derive catalogues of glaciologically produced seismic events; the events will then be located and categorized based on their location, waveform and waveform spectra both within individual environments and between regions. The intellectual merit of this work is that it will lead to a better understanding of iceberg calving and the teleconnections between seismic events and other geophysical processes around the globe. The broader impacts of this work are that it relates directly to socio-environmental impacts of global change and sea level rise. Strong collaborations will form as a result of this research, including bolstered collaborations between the glacier and ice sheet communities, as well as the glaciology and seismology communities. Outreach and public dissemination of findings will be driven by SIO\u0027s Visualization Center, and Birch Aquarium, hosting presentations devoted to the role of the cryosphere in global change. Time-lapse movies of recent changes at Columbia Glacier will be used to engage potential young scientists. A program of presentations outside the university setting to at-risk and gifted youth will be continued. This study will also involve undergraduates in analyses and interpretation and presentation of the seismic data assembled. The work will also support two junior scientists who will be supported by this project.", "east": 72.949097, "geometry": "POINT(72.8836975 -69.008701)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS", "is_usap_dc": false, "keywords": "PASSCAL; Not provided; Antarctic; SEISMOLOGICAL STATIONS; Iceberg; Seismology; Calving", "locations": "Antarctic", "north": -68.993301, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fricker, Helen", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e PASSCAL; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS; Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -69.024101, "title": "An Investigation into the Seismic Signatures Generated by Iceberg Calving and Rifting", "uid": "p0000683", "west": 72.818298}, {"awards": "0636997 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 20 Mar 2012 00:00:00 GMT", "description": "Waddington/0636997\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to integrate three lines of glaciology research, previously treated independently. First, internal layers in ice sheets, detected by ice-penetrating radar, retain information about past spatial and temporal patterns of ice accumulation. Ice-flow modelers can recover this information, using geophysical inverse methods; however, the ages of the layers must be known, through interpolation where they intersect a well-dated ice core. \u003cbr/\u003eSecond, concentrations of methane and some other atmospheric constituents vary through time as climate changes. However, the atmosphere is always well mixed, and concentrations are similar world-wide at any one time, so gas variations from an undated core can be correlated with those in a well-dated core such as GISP2. Because air in near-surface firn mixes readily with the atmosphere above, the air that is trapped in bubbles deep in the firn is typically hundreds to thousands of years younger than that firn. Gas geochemists must calculate this age difference, called delta-age, with a firn-densification model before the ice enclosing the gas can be dated accurately. To calculate delta-age, they must know the temperature and the snow accumulation rate at the time and place where the snow fell. Third, gases can be correlated between cores only at times when the atmosphere changed, so ice-core dates must be interpolated at depths between the sparse dated points. Simplistic interpolation schemes can create undesirable artifacts in the depth-age profile. The intellectual merit of this project is that it will develop new interpolation methods that calculate layer thinning over time due to ice-flow mechanics. Accurate interpolation also requires a spatial and temporal accumulation history. These three issues are coupled through accumulation patterns and ice-core dates. This project will develop an integrated inversion procedure to solve all three problems simultaneously. The new method will incorporate ice-penetrating radar profile data and ice-core data, and will find self-consistent: spatial/temporal accumulation patterns; delta-age profiles for ice cores; and reliably interpolated depth-age profiles. The project will then: recalculate the depth-age profile at Byrd Station, Antarctica; provide a preliminary depth-age at the West Antarctic Ice Sheet (WAIS) in the initial stages of drilling, using radar layers with estimated ages traced from Byrd Station; and generate a self-consistent depth-age relationship for Taylor Dome, Antarctica over the past 20ka, where low accumulation has created uncertainty in dating, accumulation, and controversy over delta-age estimates. The broader impacts of the project are that it will support the PhD research of a female graduate student, and her continued outreach work with Making Connections, a non-profit program through the University of Washington Women\u0027s Center, which matches professional women mentors with minority high-school women interested in mathematics and science, disciplines where they are traditionally under-represented. The graduate student will also work with Girls on Ice, a ten-day glacier field program, taught by women scientist instructors, emphasizing scientific observation through immersion, leadership skills and safety awareness.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Internal Layers; LABORATORY; Ice Core; FIELD SURVEYS; Firn; FIELD INVESTIGATION; Accumulation; Glaciology; Climate Change; Ice Sheet", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Carns, Regina; Hay, Mike; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Self-consistent Ice Dynamics, Accumulation, Delta-age, and Interpolation of Sparse Age Data using an Inverse Approach", "uid": "p0000376", "west": null}, {"awards": "9527571 Whillans, Ian", "bounds_geometry": "POLYGON((158.25 -76.66667,158.325 -76.66667,158.4 -76.66667,158.475 -76.66667,158.55 -76.66667,158.625 -76.66667,158.7 -76.66667,158.775 -76.66667,158.85 -76.66667,158.925 -76.66667,159 -76.66667,159 -76.683336,159 -76.700002,159 -76.716668,159 -76.733334,159 -76.75,159 -76.766666,159 -76.783332,159 -76.799998,159 -76.816664,159 -76.83333,158.925 -76.83333,158.85 -76.83333,158.775 -76.83333,158.7 -76.83333,158.625 -76.83333,158.55 -76.83333,158.475 -76.83333,158.4 -76.83333,158.325 -76.83333,158.25 -76.83333,158.25 -76.816664,158.25 -76.799998,158.25 -76.783332,158.25 -76.766666,158.25 -76.75,158.25 -76.733334,158.25 -76.716668,158.25 -76.700002,158.25 -76.683336,158.25 -76.66667))", "dataset_titles": "GPS Ice Flow Measurements, Allan Hills, Antarctica", "datasets": [{"dataset_uid": "609507", "doi": "10.7265/N5NS0RSX", "keywords": "Allan Hills; Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity", "people": "Hamilton, Gordon S.; Spikes, Vandy Blue; Kurbatov, Andrei V.; Spaulding, Nicole", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "GPS Ice Flow Measurements, Allan Hills, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609507"}], "date_created": "Tue, 20 Dec 2011 00:00:00 GMT", "description": "Whillans, Wilson, Goad OPP 9527571 Abstract This award supports a project to initiate Global Positioning System (GPS) measurements for rock motions in South Victoria Land and vicinity. The results will be used to test some of the leading models for ice-sheet change and tectonism, in particular, whether the continent is rebounding due to reduced ice load from East or West Antarctica and whether there is tectonic motion due to Terror Rift or uplift of the Transantarctic Mountains. A modest program to measure ice motion will be conducted as well. The motive is to test models for ice flow in the Allan Hills meteorite concentration region and to determine whether small glaciers in the Dry Valleys are thickening or thinning. Monuments will be set into rock and ice and GPS receivers used to determine their locations. Repeats in later years will determine motion. Field activities will involve close cooperation with the USGS.", "east": 159.0, "geometry": "POINT(158.625 -76.75)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; LABORATORY; Not provided; Ice Movement; GPS Data; Vertical Motions; GPS; FIELD INVESTIGATION", "locations": null, "north": -76.66667, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Whillans, Ian; Spaulding, Nicole; Hamilton, Gordon S.; Spikes, Vandy Blue; Kurbatov, Andrei V.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.83333, "title": "GPS Measurements of Rock and Ice Motions in South Victoria Land", "uid": "p0000523", "west": 158.25}, {"awards": "0636898 Winckler, Gisela", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 30 Nov 2011 00:00:00 GMT", "description": "Winckler/0636898\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study dust sources in Antarctic ice cores. Atmospheric aerosols play an important role both in global biogeochemical cycles as well as in the climate system of the Earth. Records extracted from Antarctic ice cores inform us that dust deposition from the atmosphere to the ice sheet was 15-20 times greater during glacial periods than during interglacials, which raises the possibility that dust may be a key player in climate change on glacial-interglacial timescales. By characterizing potential source areas from South America, South Africa, and Australia as well as fresh glacial flour from Patagonia, the project will determine if the interglacial dust was mobilized from a distinct geographical region (e.g., Australia) or from a more heavily weathered source region in South America. The intellectual merit of the project is that it will contribute to reconstructing climate-related changes in the rate of dust deposition, and in the provenance of the dust, it will provide critical constraints on hydrology and vegetation in the source regions, as well as on the nature of the atmospheric circulation transporting dust to the archive location. In a recent pilot study it was found that there is a dramatic glacial to Holocene change in the 4He/Ca ratio in the dust extracted from ice from Dronning Maud Land, Antarctica, indicating a shift in the source of dust transported to Antarctica. The broader impacts of the project are that Helium isotopes and calcium measurements provide a wealth of information that can then be turned into critical input for dust-climate models. Improved models, which are able to accurately reconstruct paleo dust distribution, will help us to predict changes in dust in response to future climate variability. This information will contribute to an improvement of our integrated understanding of the Earth\u0027s climate system and, in turn, will better inform policy makers of those processes and conditions most susceptible to perturbation by climate change, thereby leading to more meaningful climate-change policy. The project will support a graduate student in the dual masters Earth and Environmental Science Journalism program. The lead-PI manages the rock noble gas laboratory at Lamont. Her leadership role in this facility impacts the training of undergraduate and graduate students as well as visiting scientists.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": false, "keywords": "Deposition; LABORATORY; Dust; Climate; Not provided; Climate Change; Helium Isotopes; FIELD INVESTIGATION; Biogeochemical Cycles", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Winckler, Gisela", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Tracing Glacial-interglacial Changes in the Dust Source to Antarctica using Helium Isotopes", "uid": "p0000265", "west": null}, {"awards": "0840979 Adams, Byron; 0840705 Wall, Diana", "bounds_geometry": "POLYGON((165.35155 -83.71592,166.143133 -83.71592,166.934716 -83.71592,167.726299 -83.71592,168.517882 -83.71592,169.309465 -83.71592,170.101048 -83.71592,170.892631 -83.71592,171.684214 -83.71592,172.475797 -83.71592,173.26738 -83.71592,173.26738 -83.894053,173.26738 -84.072186,173.26738 -84.250319,173.26738 -84.428452,173.26738 -84.606585,173.26738 -84.784718,173.26738 -84.962851,173.26738 -85.140984,173.26738 -85.319117,173.26738 -85.49725,172.475797 -85.49725,171.684214 -85.49725,170.892631 -85.49725,170.101048 -85.49725,169.309465 -85.49725,168.517882 -85.49725,167.726299 -85.49725,166.934716 -85.49725,166.143133 -85.49725,165.35155 -85.49725,165.35155 -85.319117,165.35155 -85.140984,165.35155 -84.962851,165.35155 -84.784718,165.35155 -84.606585,165.35155 -84.428452,165.35155 -84.250319,165.35155 -84.072186,165.35155 -83.894053,165.35155 -83.71592))", "dataset_titles": "Genetic Sequences: JN819273 tardsubmission.sqn 354_18S6 JN819274 tardsubmission.sqn 354_ITS JN819275 tardsubmission.sqn 553_18S5_and_18S6 JN819276 tardsubmission.sqn 556_18S6; McMurdo Dry Valleys Long-Term Ecological Research", "datasets": [{"dataset_uid": "000217", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Genetic Sequences: JN819273 tardsubmission.sqn 354_18S6 JN819274 tardsubmission.sqn 354_ITS JN819275 tardsubmission.sqn 553_18S5_and_18S6 JN819276 tardsubmission.sqn 556_18S6", "url": "http://www.ncbi.nlm.nih.gov/genbank/"}, {"dataset_uid": "000157", "doi": "", "keywords": null, "people": null, "repository": "LTER", "science_program": null, "title": "McMurdo Dry Valleys Long-Term Ecological Research", "url": "http://www.mcmlter.org/"}], "date_created": "Mon, 03 Oct 2011 00:00:00 GMT", "description": "Ice sheet models of the Last Glacial Maximum, and previous glaciation events in the Miocene, suggest that current low altitude, ice-free surfaces in Antarctica were completely covered with ice. If so, the terrestrial biota of Antarctica today would result from recolonization events after each glacial maximum. However, there is emerging evidence that much of the terrestrial Antarctic biota are of ancient origin and have somehow survived these glaciation events. The Transantarctic Mountains TRANsition Zone (TAM-TRANZ) plays a pivotal role in understanding the evolution and biogeographic history of today\u0027s Antarctic terrestrial biota, primarily because it contains numerous inland areas that could have served as refugia during glacial maxima. Due to its remote location, the TAM-TRANZ has not been systematically surveyed for animal biodiversity. Although an exhaustive survey of the region requires a multi-discipline, multi-year and multi-region effort, the research herein combines ecological, evolutionary and geophysical expertise to conduct an exploratory investigation of the extreme southern limits of biotic communities. The project will examine the historical geophysical requirements for the colonization and maintenance of functional ecosystems by multicellular organisms, and the feasibility and desirability to implement more systematic biogeographic studies in the future. Broader impacts include graduate and undergraduate student ownership of important subprojects that will provide research, presentation and publication opportunities. The investigators also will contribute to ongoing public education efforts through relationships with K-12 teachers and administrators in the public school districts where the project personnel reside. Finally, the project is leveraged by opportunistic collaboration with scientists associated with Antarctica New Zealand.", "east": 173.26738, "geometry": "POINT(169.309465 -84.606585)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -83.71592, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Adams, Byron; Wall, Diana", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "LTER; NCBI GenBank", "science_programs": "LTER", "south": -85.49725, "title": "Collaborative Research: Limits and Drivers of Metazoan Distributions in the Transantarctic Mountains", "uid": "p0000517", "west": 165.35155}, {"awards": "0538033 Panter, Kurt", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 14 Sep 2011 00:00:00 GMT", "description": "This project studies glaciovolcanic deposits at Minna Bluff in the western Ross Embayment of Antarctica. Its goal is to determine the history of the Ross Ice Shelf, which is fed by the major ice sheets from both East and West Antarctica. Apart from determining how these ice sheets waxed and waned during a period of dynamic climate change, glaciovolcanic sequences may constrain ice sheet parameters that are critical to numerical models such as thickness, hydrology, and basal thermal regime. This three-year study would map, analyze, and determine the age of key units using 40Ar/39Ar dating. Pilot studies would also be conducted for 36Cl dating of glacial deposits and stable isotope evaluations of alteration. The project offers a complementary record of Ross Ice Shelf behavior to that sampled by ANDRILL. It also improves the general record of McMurdo area volcanostratigraphy, which is important to interpreting landforms, glacial deposits, and ancient ice found in the Dry Valleys.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this project include improving society\u0027s understanding of global climate change, sea level rise, and graduate and undergraduate student education. Outreach efforts include educational programs for public schools and community groups, exhibits for a local science museum, and a project website.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Panter, Kurt", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Proposal: Late Cenozoic Volcanism and Glaciation at Minna Bluff, Antarctica: Implications for Antarctic Cryosphere History", "uid": "p0000252", "west": null}, {"awards": "0440847 Raymond, Charles", "bounds_geometry": null, "dataset_titles": "GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica; Polarimetric Radar Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "datasets": [{"dataset_uid": "609503", "doi": "10.7265/N5222RQ8", "keywords": "Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity; Ross-Amundsen Divide; Strain", "people": "Matsuoka, Kenichi; Power, Donovan; Rasmussen, Al", "repository": "USAP-DC", "science_program": null, "title": "GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609503"}, {"dataset_uid": "609496", "doi": "10.7265/N5TH8JNG", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Ross-Amundsen Divide", "people": "Power, Donovan; Fujita, Shuji; Raymond, Charles; Matsuoka, Kenichi", "repository": "USAP-DC", "science_program": null, "title": "Polarimetric Radar Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609496"}], "date_created": "Mon, 29 Aug 2011 00:00:00 GMT", "description": "This award supports a project to investigate fabrics with ground-based radar measurements near the Ross/Amundsen Sea ice-flow divide where a deep ice core will be drilled. The alignment of crystals in ice (crystal-orientation fabric) has an important effect on ice deformation. As ice deforms, anisotropic fabrics are produced, which, in turn, influence further deformation. Measurement of ice fabric variations can help reveal the deformation history of the ice and indicate how the ice will deform in the future. Ice cores provide opportunities to determine a vertical fabric profile, but horizontal variations of fabrics remain unknown. Remote sensing with ice-penetrating radar is the only way to do that over large areas. Preliminary results show that well-established polarimetric methods can detect the degree of horizontal anisotropy of fabrics and their orientation, even when they are nearly vertical-symmetric fabrics. In conjunction with ice deformation history, our first mapping of ice fabrics will contribute to modeling ice flow near the future ice core site. The project will train a graduate student and provide research experiences for two under graduate students both in field and laboratory. The project will contribute to ongoing West Antarctic ice sheet program efforts to better understand the impact of the ice sheet on global sea level rise. This project also supports an international collaboration between US and Japanese scientists.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "GPS; FIELD SURVEYS; Antarctic; Radar; Antarctica; FIELD INVESTIGATION; Ice Sheet; Not provided; Ross-Amundsen Divide; West Antarctica; West Antarctic Ice Sheet", "locations": "Antarctica; Ross-Amundsen Divide; West Antarctica; Antarctic; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Matsuoka, Kenichi; Power, Donovan; Fujita, Shuji; Raymond, Charles; Rasmussen, Al", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods", "uid": "p0000024", "west": null}, {"awards": "0739598 Aydin, Murat; 0739491 Sowers, Todd", "bounds_geometry": null, "dataset_titles": "Alkanes in Firn Air Samples, Antarctica and Greenland; Methane Isotopes in South Pole Firn Air, 2008", "datasets": [{"dataset_uid": "609504", "doi": "10.7265/N5X9287C", "keywords": "Antarctica; Arctic; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Greenland; Snow/ice; Snow/Ice; South Pole; WAIS Divide", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "Alkanes in Firn Air Samples, Antarctica and Greenland", "url": "https://www.usap-dc.org/view/dataset/609504"}, {"dataset_uid": "609502", "doi": "10.7265/N55T3HFP", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Isotope; Paleoclimate; Snow/ice; Snow/Ice; South Pole", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": null, "title": "Methane Isotopes in South Pole Firn Air, 2008", "url": "https://www.usap-dc.org/view/dataset/609502"}], "date_created": "Thu, 18 Aug 2011 00:00:00 GMT", "description": "This award supports a project to make measurements of methane and other trace gases in firn air collected at South Pole, Antarctica. The analyses will include: methane isotopes (delta-13CH4 and delta-DCH4), light non-methane hydrocarbons (ethane, propane, and n-butane), sulfur gases (COS, CS2), and methyl halides (CH3Cl and CH3Br). The atmospheric burdens of these trace gases reflect changes in atmospheric OH, biomass burning, biogenic activity in terrestrial, oceanic, and wetland ecosystems, and industrial/agricultural activity. The goal of this project is to develop atmospheric histories for these trace gases over the last century through examination of depth profiles of these gases in South Pole firn air. The project will involve two phases: 1) a field campaign at South Pole, Antarctica to drill two firn holes and fill a total of ~200 flasks from depths reaching 120 m, 2) analysis of firn air at University of California, Irvine, Penn State University, and several other collaborating laboratories. Atmospheric histories will be inferred from the measurements using a one dimensional advective/diffusive model of firn air transport. This study will provide new information about the recent changes in atmospheric levels of these gases, providing about a 90 year long time series record that connects the earlier surface and firn air measurements to present day. The project will also explore the possibility of in- situ production of light non-methane hydrocarbons in firn air that is relevant to the interpretation of ice core records. The broader impacts of this research are that it has the potential for significant societal impact by improving our understanding of climate change and man\u0027s input to the atmosphere. The results of this work will be disseminated through the peer review process, and will contribute to environmental assessments, such as the Inter-governmental Panel on Climate Change (IPCC) Climate Assessment and the Word Meteorological Organization (WMO) Stratospheric Ozone Assessment. This research will provide educational opportunities for graduate and undergraduate students, and will contribute to a teacher training program for K-12 teachers in minority school districts.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GC-MS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; Isotope; Firn Air Chemistry; Firn Air Isotope Measurements; Not provided; LABORATORY; South Pole; Firn; Delta 13C; Carbon-13; Mass Spectrometer; Deuterium; Mass Spectrometry; Firn Air Samples; Carbon; Gas Chromatography; Polar Firn Air; GROUND-BASED OBSERVATIONS; Methane; Antarctica; Firn Air Isotopes; Delta Deuterium; FIELD SURVEYS; Firn Air; Chromatography; Methane Isotopes; Carbon Isotopes; Stable Isotopes", "locations": "Antarctica; South Pole", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat; Saltzman, Eric; Sowers, Todd A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Methane Isotopes, Hydrocarbons, and other Trace Gases in South Pole Firn Air", "uid": "p0000162", "west": null}, {"awards": "0842639 Soreghan, Gerilyn", "bounds_geometry": "POLYGON((162.44835 -77.41693,162.51638 -77.41693,162.58441 -77.41693,162.65244 -77.41693,162.72047 -77.41693,162.7885 -77.41693,162.85653 -77.41693,162.92455999999999 -77.41693,162.99259 -77.41693,163.06062 -77.41693,163.12865 -77.41693,163.12865 -77.445495,163.12865 -77.47406,163.12865 -77.502625,163.12865 -77.53119,163.12865 -77.559755,163.12865 -77.58832,163.12865 -77.616885,163.12865 -77.64545,163.12865 -77.674015,163.12865 -77.70258,163.06062 -77.70258,162.99259 -77.70258,162.92455999999999 -77.70258,162.85653 -77.70258,162.7885 -77.70258,162.72047 -77.70258,162.65244 -77.70258,162.58441 -77.70258,162.51638 -77.70258,162.44835 -77.70258,162.44835 -77.674015,162.44835 -77.64545,162.44835 -77.616885,162.44835 -77.58832,162.44835 -77.559755,162.44835 -77.53119,162.44835 -77.502625,162.44835 -77.47406,162.44835 -77.445495,162.44835 -77.41693))", "dataset_titles": "Development of Quantitative Weathering Indicators in Proximal Alluvial Sediments to Assess Glacial Activity in the Rock Record", "datasets": [{"dataset_uid": "600110", "doi": "10.15784/600110", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Chemistry:rock; Chemistry:Rock; Chemistry:sediment; Chemistry:Sediment; Critical Zone; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet", "people": "Elwood Madden, Megan; Soreghan, Gerilyn", "repository": "USAP-DC", "science_program": null, "title": "Development of Quantitative Weathering Indicators in Proximal Alluvial Sediments to Assess Glacial Activity in the Rock Record", "url": "https://www.usap-dc.org/view/dataset/600110"}], "date_created": "Fri, 12 Aug 2011 00:00:00 GMT", "description": "The proposed research seeks to test the hypothesis that chemical and physical weathering in proximal alluvial systems will show systematic and measurable variations between glacial and nonglacial systems. To accomplish this, the investigation will attempt to quantify the natural variation of chemical and physical weathering in granitoid-sourced proximal alluvial sediments in end-member glacial and nonglacial systems, when other, \"non-climatic\" factors (e.g. provenance, drainage basin area and relief, sample grain size, sediment facies) are controlled. If chemical weathering in the proposed hot-humid, hot-arid, hot semi-arid nonglacial systems and the cool-wet, cold semi-arid, and cold-arid glacial systems show systematic variations, then chemical indices may be used to help differentiate paleoclimatic conditions. Continued reliance on students provides a broader impact of this proposed research and firmly grounds this effort in its educational mission.", "east": 163.12865, "geometry": "POINT(162.7885 -77.559755)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.41693, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Soreghan, Gerilyn; Elwood Madden, Megan", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.70258, "title": "Development of Quantitative Weathering Indicators in Proximal Alluvial Sediments to Assess Glacial Activity in the Rock Record", "uid": "p0000518", "west": 162.44835}, {"awards": "0636818 Stone, John", "bounds_geometry": "POLYGON((-157 -85,-156 -85,-155 -85,-154 -85,-153 -85,-152 -85,-151 -85,-150 -85,-149 -85,-148 -85,-147 -85,-147 -85.3,-147 -85.6,-147 -85.9,-147 -86.2,-147 -86.5,-147 -86.8,-147 -87.1,-147 -87.4,-147 -87.7,-147 -88,-148 -88,-149 -88,-150 -88,-151 -88,-152 -88,-153 -88,-154 -88,-155 -88,-156 -88,-157 -88,-157 -87.7,-157 -87.4,-157 -87.1,-157 -86.8,-157 -86.5,-157 -86.2,-157 -85.9,-157 -85.6,-157 -85.3,-157 -85))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Aug 2011 00:00:00 GMT", "description": "Hall/0636687\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to investigate late Pleistocene and Holocene changes in Scott Glacier, a key outlet glacier that flows directly into the Ross Sea just west of the present-day West Antarctic Ice Sheet (WAIS) grounding line. The overarching goals are to understand changes in WAIS configuration in the Ross Sea sector at and since the last glacial maximum (LGM) and to determine whether Holocene retreat observed in the Ross Embayment has ended or if it is still ongoing. To address these goals, moraine and drift sequences associated with Scott Glacier will be mapped and dated and ice thickness, surface velocity and surface mass balance will be measured to constrain an ice-flow model of the glacier. This model will be used to help interpret the dated geologic sequences. The intellectual merit of the project relates to gaining a better understanding of the West Antarctic Ice Sheet and how changing activity of fast-flowing outlet glaciers and ice streams exerts strong control on the mass balance of the ice sheet. Previous work suggests that grounding-line retreat in the Ross Sea continued into the late Holocene and left open the possibility of ongoing deglaciation as part of a long-term trend. Results from Reedy Glacier, an outlet glacier just behind the grounding line, suggest that retreat may have slowed substantially over the past 2000 years and perhaps even stopped. By coupling the work on Scott Glacier with recent data from Reedy Glacier, the grounding-line position will be bracketed and it should be possible to establish whether the retreat has truly ended or if it is ongoing. The broader impacts of the work relate to the societal relevance of an improved understanding of the West Antarctic ice sheet to establish how it will respond to current and possible future environmental changes. The work addresses this key goal of the West Antarctic Ice Sheet Initiative, as well as the International Polar Year focus on ice sheet history and dynamics. The work will develop future scientists through the education and training of one undergraduate and two Ph.D. students, interaction with K-12 students through classroom visits, web-based \u0027expedition\u0027 journals, letters from the field, and discussions with teachers. Results from this project will be posted with previous exposure dating results from Antarctica, on the University of Washington Cosmogenic Nuclide Lab website, which also provides information about chemical procedures and calculation methods to other scientists working with cosmogenic nuclides.", "east": -147.0, "geometry": "POINT(-152 -86.5)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -85.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John; Conway, Howard", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -88.0, "title": "Collaborative Research:Grounding-line Retreat in the Southern Ross Sea - Constraints from Scott Glacier", "uid": "p0000149", "west": -157.0}, {"awards": "0636719 Joughin, Ian; 0636970 Tulaczyk, Slawek", "bounds_geometry": null, "dataset_titles": "Antarctic Active Subglacial Lake Inventory from ICESat Altimetry", "datasets": [{"dataset_uid": "601439", "doi": "10.15784/601439", "keywords": "Altimetry; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Icesat; Laser Altimetry; Subglacial Lake", "people": "Fricker, Helen; Smith, Ben; Joughin, Ian; Tulaczyk, Slawek", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Active Subglacial Lake Inventory from ICESat Altimetry", "url": "https://www.usap-dc.org/view/dataset/601439"}], "date_created": "Wed, 27 Jul 2011 00:00:00 GMT", "description": "Tulaczyk/0636970\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study elevation change anomalies (henceforth ECAs), which are oval-shaped, 5-to-10 km areas observed in remote sensing images in several locations within the Ross Sea sector of the West Antarctic Ice Sheet (WAIS). Within these anomalies, surface elevation changes at rates of up to ~1 to ~2 cm per day, significantly faster than in surrounding regions. These anomalies are thought to result from filling and draining of multi-kilometer-scale subglacial water pockets. The intellectual merit of this project is that these ECA\u0027s represent an unprecedented window into the elusive world of water drainage dynamics beneath the modern Antarctic ice sheet. Although subglacial water fluxes are small compared to normal terrestrial conditions, they play an important role in controlling fast ice streaming and, potentially, stability of the ice sheet. The dearth of observational constraints on sub-ice sheet water dynamics represents one of the most important limitations on progress in quantitative modeling of ice streams and ice sheets. Such models are necessary to assess future ice sheet mass balance and to reconstruct the response of ice sheets to past climate changes. The dynamic sub-ice sheet water transport indicated by the ECAs may have also implications for studies of subglacial lakes and other subglacial environments, which may harbor life adapted to such extreme conditions. The broader impacts of this project are that it will provide advanced training opportunities to one postdoctoral fellow (UW), two female doctoral students (UCSC), who will enhance diversity in polar sciences, and at least three undergraduate students (UCSC). Project output will be relevant to broad scientific and societal interests, such as the future global sea level changes and the response of Polar Regions to climate changes. Douglas Fox, a freelance science journalist, is interested in joining the first field season to write feature articles to popular science magazines and promote the exposure of this project, and Antarctic Science in general, to mass media.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e GLAS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e GLAS", "is_usap_dc": false, "keywords": "ICESAT; Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Smith, Ben; Joughin, Ian; Tulaczyk, Slawek; SMITH, BENJAMIN", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e ICE, CLOUD AND LAND ELEVATION SATELLITE (ICESAT) \u003e ICESAT", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Elevation Change Anomalies in West Antarctica and Dynamics of Subglacial Water Transport Beneath Ice Streams and their Tributaries", "uid": "p0000115", "west": null}, {"awards": "0636929 Bales, Roger", "bounds_geometry": null, "dataset_titles": "Measurements of Air and Snow Photochemical Species at WAIS Divide, Antarctica", "datasets": [{"dataset_uid": "609585", "doi": "10.7265/N5GX48HW", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Bales, Roger", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Measurements of Air and Snow Photochemical Species at WAIS Divide, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609585"}], "date_created": "Thu, 14 Jul 2011 00:00:00 GMT", "description": "This award supports a project to understand how recent changes in atmospheric chemistry, and historical changes as recorded in snow, firn and ice, have affected atmospheric photochemistry over Antarctica. Atmospheric, snow and firn core measurements of selected gas, meteorological and snow physical properties will be made and modeling of snow-atmosphere exchange will be carried out. The intellectual merit of the project is that it will lead to a better an understanding of the atmospheric chemistry in West Antarctica, its bi-directional linkages with the snowpack, and how it responds to regional influences. There are at least four broader impacts of this work. First is education of university students at both the graduate and undergraduate levels. One postdoctoral researcher and one graduate student will carry out much of the work, and a number of undergraduates will be involved. Second, involvement with the WAIS-Divide coring program will be used to help recruit under-represented groups as UC Merced students. As part of UC Merced\u0027s outreach efforts in the San Joaquin Valley, whose students are under-represented in the UC system, the PI and co-PI give short research talks to groups of prospective students, community college and high school educators and other groups. They will develop one such talk highlighting this project. Including high-profile research in these recruiting talks has proven to be an effective way to promote dialog, and interest students in UC Merced. Third, talks such as this also contribute to the scientific literacy of the general public. The PI and grad student will all seek opportunities to share project information with K-14 and community audiences. Fourth, results of the research will be disseminated broadly to the scientific community, and the researchers will seek additional applications for the transfer functions as tools to improve interpretation of ice-cores. This research is highly collaborative, and leverages the expertise and data from a number of other groups.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e CHEMILUMINESCENCE", "is_usap_dc": true, "keywords": "Snow; Atmospheric Chemistry; Not provided; LABORATORY; Antarctica; FIELD SURVEYS; Snow Physical Properties; Meteorology; Wais Divide-project; Firn; Atmosphere Exchange; WAIS Divide; FIELD INVESTIGATION", "locations": "Antarctica; WAIS Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bales, Roger", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Atmospheric, Snow and Firn Chemistry Studies for Interpretation of WAIS-Divide Cores", "uid": "p0000041", "west": null}, {"awards": "0538120 Catania, Ginny; 0538015 Hulbe, Christina", "bounds_geometry": "POLYGON((154.71 -82.78,154.79000000000002 -82.78,154.87 -82.78,154.95 -82.78,155.03 -82.78,155.11 -82.78,155.19 -82.78,155.26999999999998 -82.78,155.35 -82.78,155.43 -82.78,155.51 -82.78,155.51 -82.788,155.51 -82.796,155.51 -82.804,155.51 -82.812,155.51 -82.82,155.51 -82.828,155.51 -82.836,155.51 -82.844,155.51 -82.852,155.51 -82.86,155.43 -82.86,155.35 -82.86,155.26999999999998 -82.86,155.19 -82.86,155.11 -82.86,155.03 -82.86,154.95 -82.86,154.87 -82.86,154.79000000000002 -82.86,154.71 -82.86,154.71 -82.852,154.71 -82.844,154.71 -82.836,154.71 -82.828,154.71 -82.82,154.71 -82.812,154.71 -82.804,154.71 -82.796,154.71 -82.788,154.71 -82.78))", "dataset_titles": "Grounding Line Strain Grid Surveys, Kamb Ice Stream, Antarctica; Ice-Penetrating Radar Data Across Siple Coast Grounding Lines", "datasets": [{"dataset_uid": "609474", "doi": "10.7265/N5M043BH", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; GPR; Grounding Line; Radar; Siple Coast", "people": "Catania, Ginny; Hulbe, Christina", "repository": "USAP-DC", "science_program": null, "title": "Ice-Penetrating Radar Data Across Siple Coast Grounding Lines", "url": "https://www.usap-dc.org/view/dataset/609474"}, {"dataset_uid": "609494", "doi": "10.7265/N5Z899C6", "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Grounding Line; Kamb Ice Stream; Strain", "people": "Hulbe, Christina", "repository": "USAP-DC", "science_program": null, "title": "Grounding Line Strain Grid Surveys, Kamb Ice Stream, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609494"}], "date_created": "Sat, 02 Jul 2011 00:00:00 GMT", "description": "0538120\u003cbr/\u003eCatania\u003cbr/\u003eThis award supports a project to identify and map ice surface and internal features that chronicle the sequence of events leading to the shut-down of Kamb ice stream. In particular, the project will study past grounding line migration and the relationship between that process and ice stream shutdown. The intellectual merits of the project include the fact that an understanding of such processes has important implications for our ability to accurately predict mass balance changes in this region. Currently, one of the five major West Antarctic ice streams, Kamb, is quiescent, and another, Whillans, is slowing in its downstream reaches. The Kamb shutdown appears to have begun at its downstream end but beyond that simple observation, it is not possible, yet, to draw meaningful comparisons between the two adjacent streams. We do not know if current events on Whillans Ice Stream are similar to what transpired during the Kamb shut-down. The work proposed here intends to bridge that gap. It is expected that this effort will yield useful insights into the influence of grounding line dynamics on ice stream flow. The work will involve a combination of field investigations using radio-echo sounding and GPS combined with computational efforts involving the interpretation of ice-surface features such as relict flow traces and crevasses. The broader impacts of the project will be in addressing a global environmental problem with critical societal implications, training the next generation of scientists and engineers to serve the nation, and encouraging women to pursue scientific or engineering careers. Participants from both institutions are involved in a range of public outreach activities.", "east": 155.51, "geometry": "POINT(155.11 -82.82)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": true, "keywords": "Not provided; Ice Sheet Elevation; West Antarctic Ice Stream; MODELS; Ice Sheet Thickness; West Antarctic Ice Sheet; Kamb Ice Stream; Antarctic Ice Sheet; Ice Sheet; Ice Stream Motion; Antarctica; Siple Dome; Grounding Line; FIELD INVESTIGATION; GPS; FIELD SURVEYS; West Antarctica; Ice Stream; Radar", "locations": "Antarctica; Kamb Ice Stream; West Antarctic Ice Stream; Antarctic Ice Sheet; West Antarctica; West Antarctic Ice Sheet; Siple Dome", "north": -82.78, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Hulbe, Christina; Catania, Ginny", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e MODELS; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -82.86, "title": "Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region", "uid": "p0000019", "west": 154.71}, {"awards": "0424589 Gogineni, S. Prasad", "bounds_geometry": "POLYGON((-137 -74,-132.1 -74,-127.2 -74,-122.3 -74,-117.4 -74,-112.5 -74,-107.6 -74,-102.7 -74,-97.8 -74,-92.9 -74,-88 -74,-88 -74.65,-88 -75.3,-88 -75.95,-88 -76.6,-88 -77.25,-88 -77.9,-88 -78.55,-88 -79.2,-88 -79.85,-88 -80.5,-92.9 -80.5,-97.8 -80.5,-102.7 -80.5,-107.6 -80.5,-112.5 -80.5,-117.4 -80.5,-122.3 -80.5,-127.2 -80.5,-132.1 -80.5,-137 -80.5,-137 -79.85,-137 -79.2,-137 -78.55,-137 -77.9,-137 -77.25,-137 -76.6,-137 -75.95,-137 -75.3,-137 -74.65,-137 -74))", "dataset_titles": "Airborne radar profiles of the Whillans, Bindschadler, and Kamb Ice Streams; Archive of data; Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau; Ku-band Radar Echograms; Radar Depth Sounder Echograms and Ice Thickness; Snow Radar Echograms", "datasets": [{"dataset_uid": "601048", "doi": "10.15784/601048", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ku-Band; Navigation; Radar", "people": "Leuschen, Carl; Rodriguez, Fernando; Li, Jilu; Allen, Chris; Gogineni, Prasad; Paden, John", "repository": "USAP-DC", "science_program": null, "title": "Ku-band Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601048"}, {"dataset_uid": "002497", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Archive of data", "url": "https://www.cresis.ku.edu/data/accumulation"}, {"dataset_uid": "601049", "doi": "10.15784/601049", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Navigation; Radar; Snow", "people": "Paden, John; Leuschen, Carl; Rodriguez, Fernando; Li, Jilu; Allen, Chris; Gogineni, Prasad", "repository": "USAP-DC", "science_program": null, "title": "Snow Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601049"}, {"dataset_uid": "600384", "doi": "10.15784/600384", "keywords": "Airborne Radar; Antarctica; Basler; Glaciers/ice Sheet; Glaciers/Ice Sheet; Kamb Ice Stream; Radar; Siple Coast; Whillans Ice Stream", "people": "Paden, John; Hale, Richard", "repository": "USAP-DC", "science_program": null, "title": "Airborne radar profiles of the Whillans, Bindschadler, and Kamb Ice Streams", "url": "https://www.usap-dc.org/view/dataset/600384"}, {"dataset_uid": "601411", "doi": "10.15784/601411", "keywords": "Antarctica; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ICECAP; Ice Penetrating Radar; Internal Reflecting Horizons", "people": "Tozer, Carly; Ritz, Catherine; Blankenship, Donald D.; Schroeder, Dustin; Mulvaney, Robert; Roberts, Jason; Frezzotti, Massimo; Paden, John; Muldoon, Gail R.; Quartini, Enrica; Kempf, Scott D.; Ng, Gregory; Greenbaum, Jamin; Cavitte, Marie G. P; Young, Duncan A.", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau", "url": "https://www.usap-dc.org/view/dataset/601411"}, {"dataset_uid": "601047", "doi": "10.15784/601047", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MCoRDS; Navigation; Radar", "people": "Rodriguez, Fernando; Leuschen, Carl; Li, Jilu; Allen, Chris; Gogineni, Prasad; Paden, John", "repository": "USAP-DC", "science_program": null, "title": "Radar Depth Sounder Echograms and Ice Thickness", "url": "https://www.usap-dc.org/view/dataset/601047"}], "date_created": "Wed, 01 Jun 2011 00:00:00 GMT", "description": "This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbr\u00e6. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.\u003cbr/\u003e\u003cbr/\u003eThe intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. \u003cbr/\u003e\u003cbr/\u003eAs lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets.", "east": -88.0, "geometry": "POINT(-112.5 -77.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Remote Sensing; Not provided; Pine Island; Ice Sheet; DHC-6; Antarctic; Thwaites Region; Antarctica; Mass Balance; Accumulation; Velocity; Insar", "locations": "Antarctica; Antarctic; Pine Island; Thwaites Region", "north": -74.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Glaciology", "paleo_time": null, "persons": "Braaten, David; Joughin, Ian; Steig, Eric J.; Das, Sarah; Paden, John; Gogineni, Prasad", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; Not provided", "repo": "USAP-DC", "repositories": "Project website; USAP-DC", "science_programs": null, "south": -80.5, "title": "Center for Remote Sensing of Ice Sheets (CReSIS)", "uid": "p0000102", "west": -137.0}, {"awards": "0739780 Taylor, Kendrick", "bounds_geometry": "POINT(-112.117 -79.666)", "dataset_titles": "WAIS DIVIDE - High Temporal Resolution Black Carbon Record of Southern Hemisphere Biomass Burning", "datasets": [{"dataset_uid": "600142", "doi": "10.15784/600142", "keywords": "Antarctica; Atmosphere; Black Carbon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS DIVIDE - High Temporal Resolution Black Carbon Record of Southern Hemisphere Biomass Burning", "url": "https://www.usap-dc.org/view/dataset/600142"}], "date_created": "Thu, 28 Apr 2011 00:00:00 GMT", "description": "Edwards/0739780\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to develop a 2,000-year high-temporal resolution record of biomass burning from the analysis of black carbon in the WAIS Divide bedrock ice core. Pilot data for the WAIS WD05A core demonstrates that we now have the ability to reconstruct this record with minimal impact on the amount of ice available for other projects. The intellectual merit of this project is that black carbon (BC) aerosols result solely from combustion and play a critical but poorly quantified role in global climate forcing and the carbon cycle. When incorporated into snow and ice, BC increases absorption of solar radiation making seasonal snow packs, mountain glaciers, polar ice sheets, and sea ice much more vulnerable to climate warming. BC emissions in the Southern Hemisphere are dominated by biomass burning in the tropical regions of Southern Africa, South America and South Asia. Biomass burning, which results from both climate and human activities, alters the atmospheric composition of greenhouse gases, aerosols and perturbs key biogeochemical cycles. A long-term record of biomass burning is needed to aid in the interpretation of ice core gas composition and will provide important information regarding human impacts on the environment and climate before instrumental records. The broader impacts of the project are that it represents a paradigm shift in our ability to reconstruct the history of fire from ice core records and to understand its impact on atmospheric chemistry and climate over millennial time scales. This type of data is especially needed to drive global circulation model simulations of black carbon aerosols, which have been found to be an important component of global warming and which may be perturbing the hydrologic cycle. The project will also employ undergraduate students and is committed to attracting underrepresented groups to the physical sciences. The project?s outreach component will be conducted as part of the WAIS project outreach program and will reach a wide audience.", "east": -112.117, "geometry": "POINT(-112.117 -79.666)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Ice Core Chemistry; Not provided; Gas Record; Ice Core; Gas Measurement; Ice Core Gas Composition; Antarctica; LABORATORY; Bedrock Ice Core; Ice Core Gas Records; Wais Project; Greenhouse Gas; Atmospheric Chemistry; FIELD INVESTIGATION; Black Carbon; Biomass Burning; WAIS Divide; FIELD SURVEYS; West Antarctica; Methane", "locations": "Antarctica; West Antarctica; WAIS Divide", "north": -79.666, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.; McConnell, Joseph; Mitchell, Logan E; Sowers, Todd A.; Taylor, Kendrick C.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.666, "title": "WAIS DIVIDE - High Temporal Resolution Black Carbon Record of Southern Hemisphere Biomass Burning", "uid": "p0000022", "west": -112.117}, {"awards": "9909734 Anderson, John", "bounds_geometry": "POLYGON((-73.80311 -52.35021,-71.817373 -52.35021,-69.831636 -52.35021,-67.845899 -52.35021,-65.860162 -52.35021,-63.874425 -52.35021,-61.888688 -52.35021,-59.902951 -52.35021,-57.917214 -52.35021,-55.931477 -52.35021,-53.94574 -52.35021,-53.94574 -53.954842,-53.94574 -55.559474,-53.94574 -57.164106,-53.94574 -58.768738,-53.94574 -60.37337,-53.94574 -61.978002,-53.94574 -63.582634,-53.94574 -65.187266,-53.94574 -66.791898,-53.94574 -68.39653,-55.931477 -68.39653,-57.917214 -68.39653,-59.902951 -68.39653,-61.888688 -68.39653,-63.874425 -68.39653,-65.860162 -68.39653,-67.845899 -68.39653,-69.831636 -68.39653,-71.817373 -68.39653,-73.80311 -68.39653,-73.80311 -66.791898,-73.80311 -65.187266,-73.80311 -63.582634,-73.80311 -61.978002,-73.80311 -60.37337,-73.80311 -58.768738,-73.80311 -57.164106,-73.80311 -55.559474,-73.80311 -53.954842,-73.80311 -52.35021))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001803", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0201"}], "date_created": "Thu, 03 Mar 2011 00:00:00 GMT", "description": "9909734 Anderson This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research on the glaciomarine geology of the continental shelves of West Antarctica and the Antarctic Peninsula. It is hypothesized that the different glacial systems of the Antarctic Peninsula region have been more responsive to climate change and sea-level rise than either the West Antarctic or East Antarctic ice sheets. This is due mainly to the smaller size of these ice masses and the higher latitude location of the peninsula. Indeed, ice shelves of the Antarctic Peninsula are currently retreating at rates of up to a kilometer per year. But are these changes due to recent atmospheric warming in the region or are they simply the final phase of retreat since the last glacial maximum? This project hypothesizes that the deglacial history of the Antarctic Peninsula region has been quite complex, with different glacial systems retreating at different rates and at different times. This complex recessional history reflects the different sizes as well as different climatic and physiographic settings of glacial systems in the region. An understanding of the Late Pleistocene to Holocene glacial history of the Antarctic Peninsula glacial systems is needed to address how these systems responded to sea-level and climate change during that time interval. This investigation acquire new marine geological and geophysical data from the continental shelf to determine if and when different glacial systems were grounded on the shelf, to establish the extent of grounded ice, and to examine the history of glacial retreat. The project will build on an extensive seismic data set and hundreds of sediment cores collected along the Peninsula during earlier (1980\u0027s) cruises. Key to this investigation is the acquisition of swath bathymetry, side-scan sonar and very high-resolution sub-bottom (chirp) profiles from key drainage outlets. These new data will provide the necessary geomorphologic and stratigraphic framework for reconstructing the Antarctic Peninsula glacial record. Anticipated results will help constrain models for future glacier and ice sheet activity.", "east": -53.94574, "geometry": "POINT(-63.874425 -60.37337)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.35021, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John; Anderson, Jason", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -68.39653, "title": "LGM Late Pleistocene to Holocene Glacial History of West Antarctica", "uid": "p0000600", "west": -73.80311}, {"awards": "0732467 Domack, Eugene", "bounds_geometry": null, "dataset_titles": "Cosmogenic-Nuclide Data at ICe-D; Expedition data of LMG0903; Expedition data of NBP1001; NBP1001 cruise data; Processed CTD Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001; Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001", "datasets": [{"dataset_uid": "000142", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1001 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP1001"}, {"dataset_uid": "002651", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1001", "url": "https://www.rvdata.us/search/cruise/NBP1001"}, {"dataset_uid": "200297", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic-Nuclide Data at ICe-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "601346", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Current Measurements; LADCP; Larsen Ice Shelf; NBP1001; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer", "people": "Huber, Bruce; Gordon, Arnold", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601346"}, {"dataset_uid": "601345", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; CTD; CTD Data; LARISSA; Larsen Ice Shelf; NBP1001; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Temperature", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Processed CTD Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601345"}, {"dataset_uid": "002715", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0903", "url": "https://www.rvdata.us/search/cruise/LMG0903"}], "date_created": "Thu, 03 Mar 2011 00:00:00 GMT", "description": "This award supports a research cruise to perform geologic studies in the area under and surrounding the former Larsen B ice shelf, on the Antarctic Peninsula. The ice shelf\u0027s disintegration in 2002 coupled with the unique marine geology of the area make it possible to understand the conditions leading to ice shelf collapse. Bellwethers of climate change that reflect both oceanographic and atmospheric conditions, ice shelves also hold back glacial flow in key areas of the polar regions. Their collapse results in glacial surging and could cause rapid rise in global sea levels. This project characterizes the Larsen ice shelf\u0027s history and conditions leading to its collapse by determining: 1) the size of the Larsen B during warmer climates and higher sea levels back to the Eemian interglacial, 125,000 years ago; 2) the configuration of the Antarctic Peninsula ice sheet during the LGM and its subsequent retreat; 3) the causes of the Larsen B\u0027s stability through the Holocene, during which other shelves have come and gone; 4) the controls on the dynamics of ice shelf margins, especially the roles of surface melting and oceanic processes, and 5) the changes in sediment flux, both biogenic and lithogenic, after large ice shelf breakup. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThe broader impacts include graduate and undergraduate education through research projects and workshops; outreach to the general public through a television documentary and websites, and international collaboration with scientists from Belgium, Spain, Argentina, Canada, Germany and the UK. The work also has important societal relevance. Improving our understanding of how ice shelves behave in a warming world will improve models of sea level rise.\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThe project is supported under NSF\u0027s International Polar Year (IPY) research emphasis area on \"Understanding Environmental Change in Polar Regions\".", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG; Larsen Ice Shelf; R/V NBP; Antarctic Peninsula; ICE SHEETS", "locations": "Antarctic Peninsula; Larsen Ice Shelf", "north": null, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Domack, Eugene Walter; Blanchette, Robert", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "ICE-D; R2R; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach - Marine and Quaternary Geosciences", "uid": "p0000841", "west": null}, {"awards": "9909367 Leventer, Amy", "bounds_geometry": "POLYGON((26.27227 -42.81742,38.414467 -42.81742,50.556664 -42.81742,62.698861 -42.81742,74.841058 -42.81742,86.983255 -42.81742,99.125452 -42.81742,111.267649 -42.81742,123.409846 -42.81742,135.552043 -42.81742,147.69424 -42.81742,147.69424 -45.454494,147.69424 -48.091568,147.69424 -50.728642,147.69424 -53.365716,147.69424 -56.00279,147.69424 -58.639864,147.69424 -61.276938,147.69424 -63.914012,147.69424 -66.551086,147.69424 -69.18816,135.552043 -69.18816,123.409846 -69.18816,111.267649 -69.18816,99.125452 -69.18816,86.983255 -69.18816,74.841058 -69.18816,62.698861 -69.18816,50.556664 -69.18816,38.414467 -69.18816,26.27227 -69.18816,26.27227 -66.551086,26.27227 -63.914012,26.27227 -61.276938,26.27227 -58.639864,26.27227 -56.00279,26.27227 -53.365716,26.27227 -50.728642,26.27227 -48.091568,26.27227 -45.454494,26.27227 -42.81742))", "dataset_titles": "Diatom assemblages from Edward VIII Gulf, Kemp Coast, East Antarctica; NB0101 Expedition Data; Quantitative Diatom Assemblage Data from Iceberg Alley, Mac. Robertson Shelf, East Antarctica acquired during expedition NBP0101", "datasets": [{"dataset_uid": "601177", "doi": "10.15784/601177", "keywords": "Antarctica; Biota; Diatom; East Antarctica; Microscopy; NBP0101; Oceans; Paleoceanography; Paleoclimate; R/v Nathaniel B. Palmer; Sediment Corer", "people": "Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "Diatom assemblages from Edward VIII Gulf, Kemp Coast, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601177"}, {"dataset_uid": "601307", "doi": null, "keywords": "Antarctica; Biota; Diatom; East Antarctica; Mac. Robertson Shelf; Marine Geoscience; Microscope; NBP0101; Paleoclimate; Piston Corer; R/v Nathaniel B. Palmer; Sediment Core; Species Abundance", "people": "Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "Quantitative Diatom Assemblage Data from Iceberg Alley, Mac. Robertson Shelf, East Antarctica acquired during expedition NBP0101", "url": "https://www.usap-dc.org/view/dataset/601307"}, {"dataset_uid": "001879", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NB0101 Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0101"}], "date_created": "Thu, 03 Mar 2011 00:00:00 GMT", "description": "9909367 Leventer This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a multi-institutional, international (US - Australia) marine geologic and geophysical investigation of Prydz Bay and the MacRobertson Shelf, to be completed during an approximately 60-day cruise aboard the RVIB N.B. Palmer. The primary objective is to develop a record of climate and oceanographic change during the Quaternary, using sediment cores collected via kasten and jumbo piston coring. Core sites will be selected based on seismic profiling (Seabeam 2112 and Bathy2000). Recognition of the central role of the Antarctic Ice Sheet to global oceanic and atmospheric systems is based primarily on data collected along the West Antarctic margin, while similar extensive and high resolution data sets from the much more extensive East Antarctic margin are sparse. Goals of this project include (1) development of a century- to millennial-scale record of Holocene paleoenvironments, and (2) testing of hypotheses concerning the sedimentary record of previous glacial and interglacial events on the shelf, and evaluation of the timing and extent of maximum glaciation along this 500 km stretch of the East Antarctic margin. High-resolution seismic mapping and coring of sediments deposited in inner shelf depressions will be used to reconstruct Holocene paleoenvironments. In similar depositional settings in the Antarctic Peninsula and Ross Sea, sedimentary records demonstrate millennial- and century- scale variability in primary production and sea-ice extent during the Holocene, which have been linked to chronological periodicities in radiocarbon distribution, suggesting the possible role of solar variability in driving some changes in Holocene climate. Similar high-resolution Holocene records from the East Antarctic margin will be used to develop a circum-Antarctic suite of data regarding the response of southern glacial and oceanographic systems to late Quaternary climate change. In addition, these data will help us to evaluate the response of the East Antarctic margin to global warming. Initial surveys of the Prydz Channel - Amery Depression region reveal sequences deposited during previous Pleistocene interglacials. The upper Holocene and lower (undated) siliceous units can be traced over 15,000 km2 of the Prydz Channel, but more sub-bottom seismic reflection profiling in conjunction with dense coring over this region is needed to define the spatial distribution and extent of the units. Chronological work will determine the timing and duration of previous periods of glacial marine sedimentation on the East Antarctic margin during the late Pleistocene. Analyses will focus on detailed sedimentologic, geochemical, micropaleontological, and paleomagnetic techniques. This multi-parameter approach is the most effective way to extract a valuable paleoenvironmental signal in these glacial marine sediments. These results are expected to lead to a significant advance in understanding of the behavior of the Antarctic ice-sheet and ocean system in the recent geologic past. The combination of investigators, all with many years of experience working in high latitude marine settings, will provide an effective team to complete the project. University and College faculty (Principal Investigators on this project) will supervise a combination of undergraduate and post-graduate students involved in all stages of the project so that educational objectives will be met in tandem with the research goals of the project.", "east": 147.69424, "geometry": "POINT(86.983255 -56.00279)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": false, "keywords": "R/V NBP; USAP-DC", "locations": null, "north": -42.81742, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Leventer, Amy", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -69.18816, "title": "Quaternary Glacial History and Paleoenvironments of the East Antarctic Margin", "uid": "p0000609", "west": 26.27227}, {"awards": "0538495 Albert, Mary; 0537532 Liston, Glen; 0963924 Steig, Eric; 0538416 McConnell, Joseph; 0538103 Scambos, Ted; 0538422 Hamilton, Gordon", "bounds_geometry": "POLYGON((-180 -72.01667,-161.74667 -72.01667,-143.49334 -72.01667,-125.24001 -72.01667,-106.98668 -72.01667,-88.73335 -72.01667,-70.48002 -72.01667,-52.22669 -72.01667,-33.97336 -72.01667,-15.72003 -72.01667,2.5333 -72.01667,2.5333 -73.815003,2.5333 -75.613336,2.5333 -77.411669,2.5333 -79.210002,2.5333 -81.008335,2.5333 -82.806668,2.5333 -84.605001,2.5333 -86.403334,2.5333 -88.201667,2.5333 -90,-15.72003 -90,-33.97336 -90,-52.22669 -90,-70.48002 -90,-88.73335 -90,-106.98668 -90,-125.24001 -90,-143.49334 -90,-161.74667 -90,180 -90,162.25333 -90,144.50666 -90,126.75999 -90,109.01332 -90,91.26665 -90,73.51998 -90,55.77331 -90,38.02664 -90,20.27997 -90,2.5333 -90,2.5333 -88.201667,2.5333 -86.403334,2.5333 -84.605001,2.5333 -82.806668,2.5333 -81.008335,2.5333 -79.210002,2.5333 -77.411669,2.5333 -75.613336,2.5333 -73.815003,2.5333 -72.01667,20.27997 -72.01667,38.02664 -72.01667,55.77331 -72.01667,73.51998 -72.01667,91.26665 -72.01667,109.01332 -72.01667,126.75999 -72.01667,144.50666 -72.01667,162.25333 -72.01667,-180 -72.01667))", "dataset_titles": "Ice Core Chemistry from the Norwegian-U.S. Scientific Traverse of East Antarctica, IPY 2007-2009; Norwegian-U.S. Scientific Traverse of East Antarctica; This data set contains data from the publication Steig et al., Nature Geoscience, vol. 6, pages 372\u00e2\u20ac\u201c375 (doi:10.1038/ngeo1778), which includes isotope data from the Norway-US traverse in East Antarctica.", "datasets": [{"dataset_uid": "001305", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "This data set contains data from the publication Steig et al., Nature Geoscience, vol. 6, pages 372\u00e2\u20ac\u201c375 (doi:10.1038/ngeo1778), which includes isotope data from the Norway-US traverse in East Antarctica.", "url": "http://nsidc.org/data/nsidc-0536.html"}, {"dataset_uid": "609520", "doi": "10.7265/N5H41PC9", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; East Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Chemistry from the Norwegian-U.S. Scientific Traverse of East Antarctica, IPY 2007-2009", "url": "https://www.usap-dc.org/view/dataset/609520"}, {"dataset_uid": "000112", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Norwegian-U.S. Scientific Traverse of East Antarctica", "url": "http://traverse.npolar.no/"}], "date_created": "Wed, 23 Feb 2011 00:00:00 GMT", "description": "This award supports a project of scientific investigations along two overland traverses in East Antarctica: one going from the Norwegian Troll Station (72deg. S, 2deg. E) to the United States South Pole Station (90deg. S, 0deg. E) in 2007-2008; and a return traverse starting at South Pole Station and ending at Troll Station by a different route in 2008-2009. The project will investigate climate change in East Antarctica, with the goals of understanding climate variability in Dronning Maud Land of East Antarctica on time scales of years to centuries and determining the surface and net mass balance of the ice sheet in this sector to understand its impact on sea level. The project will also investigate the impact of atmospheric and oceanic variability and human activities on the chemical composition of firn and ice in the region, and will revisit areas and sites first explored by traverses in the 1960\u0027s, for detection of possible changes and to establish benchmark datasets for future research efforts. In terms of broader impacts, the results of this study will add to understanding of climate variability in East Antarctica and its contribution to global sea level change. The project includes international exchange of graduate students between the institutions involved and international education of undergraduate students through classes taught by the PI\u0027s at UNIS in Svalbard. It involves extensive outreach to the general public both in Scandinavia and North America through the press, television, science museums, children\u0027s literature, and web sites. Active knowledge sharing and collaboration between pioneers in Antarctic glaciology from Norway and the US, with the international group of scientists and students involved in this project, provide a unique opportunity to explore the changes that half a century have made in climate proxies from East Antarctica, scientific tools, and the culture and people of science. The project is relevant to the International Polar Year (IPY) since it is a genuine collaboration between nations: the scientists involved have complementary expertise, and the logistics involved relies on assets unique to each nation. It is truly an endeavor that neither nation could accomplish alone. This project is a part of the Trans- Antarctic Scientific Traverse Expeditions Ice Divide of East Antarctica (TASTE-IDEA) which is also part of IPY.", "east": 2.5333, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; East Antarctic Plateau; FIXED OBSERVATION STATIONS; Glaciology; LABORATORY; FIELD SURVEYS; Permeability; Ice Core; Climate Variability; Firn; Accumulation Rate; Mass Balance; Snow; Gravity; Ice Sheet; GROUND-BASED OBSERVATIONS; Traverse; Not provided; Antarctic; Ice Core Chemistry; Antarctica; Density", "locations": "Antarctica; Antarctic; East Antarctic Plateau", "north": -72.01667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Courville, Zoe; Bell, Eric; Liston, Glen; Scambos, Ted; Hamilton, Gordon S.; McConnell, Joseph; Albert, Mary R.; Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e FIXED OBSERVATION STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NSIDC", "repositories": "NSIDC; Project website; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Norwegian-United States IPY Scientific Traverse: Climate Variability and Glaciology in East Antarctica", "uid": "p0000095", "west": 2.5333}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "High-resolution Image-derived Grounding and Hydrostatic Lines for the Antarctic Ice Sheet", "datasets": [{"dataset_uid": "609489", "doi": "10.7265/N56T0JK2", "repository": "USAP-DC", "science_program": null, "title": "High-resolution Image-derived Grounding and Hydrostatic Lines for the Antarctic Ice Sheet", "url": "http://www.usap-dc.org/view/dataset/609489"}], "date_created": "Sun, 20 Feb 2011 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; ASAID; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Grounding Line Hydrostatic Line; Oceans", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bindschadler, Robert; Choi, Hyeungu", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "0636705 Marchant, David; 0636731 Bender, Michael", "bounds_geometry": "POLYGON((160.48705 -77.84513,160.501913 -77.84513,160.516776 -77.84513,160.531639 -77.84513,160.546502 -77.84513,160.561365 -77.84513,160.576228 -77.84513,160.591091 -77.84513,160.605954 -77.84513,160.620817 -77.84513,160.63568 -77.84513,160.63568 -77.8515624,160.63568 -77.8579948,160.63568 -77.8644272,160.63568 -77.8708596,160.63568 -77.877292,160.63568 -77.8837244,160.63568 -77.8901568,160.63568 -77.8965892,160.63568 -77.9030216,160.63568 -77.909454,160.620817 -77.909454,160.605954 -77.909454,160.591091 -77.909454,160.576228 -77.909454,160.561365 -77.909454,160.546502 -77.909454,160.531639 -77.909454,160.516776 -77.909454,160.501913 -77.909454,160.48705 -77.909454,160.48705 -77.9030216,160.48705 -77.8965892,160.48705 -77.8901568,160.48705 -77.8837244,160.48705 -77.877292,160.48705 -77.8708596,160.48705 -77.8644272,160.48705 -77.8579948,160.48705 -77.8515624,160.48705 -77.84513))", "dataset_titles": "Dating and Paleoenvironmental Studies on Ancient Ice in the Dry Valleys, Antarctica; Measurements of Trapped Air from Mullins Valley, Dry Valleys, Antarctica", "datasets": [{"dataset_uid": "609597", "doi": "10.7265/N50R9MBM", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Dry Valleys; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; Radar Interferometer", "people": "Bender, Michael; Yau, Audrey M.", "repository": "USAP-DC", "science_program": null, "title": "Measurements of Trapped Air from Mullins Valley, Dry Valleys, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609597"}, {"dataset_uid": "600069", "doi": "10.15784/600069", "keywords": "Antarctica; Dry Valleys; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Record; Lake Vostok; Paleoclimate", "people": "Bender, Michael", "repository": "USAP-DC", "science_program": null, "title": "Dating and Paleoenvironmental Studies on Ancient Ice in the Dry Valleys, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600069"}], "date_created": "Thu, 03 Feb 2011 00:00:00 GMT", "description": "This project studies ancient ice buried in the Dry Valleys of Antarctica. The ice, which may approach ten million years in age, will be dated using argon and uranium radioisotope techniques. High-risk work, if successful it will offer the first and perhaps only samples of the Earth\u0027s atmosphere from millions of years in the past. These samples could offer critically important tests of paleoclimate records and proxies, as well as a glimpse into the characteristics of a past world much like the predicted future, warmer Earth. The broader impacts are graduate student education, and potentially contributing to society\u0027s understanding of global climate change and sea level rise.", "east": 160.63568, "geometry": "POINT(160.561365 -77.877292)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Elemental Ratios; Oxygen Isotope; Not provided; Nitrogen Isotopes; LABORATORY; Argon Isotopes; FIELD INVESTIGATION", "locations": null, "north": -77.84513, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Bender, Michael; Yau, Audrey M.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.909454, "title": "Collaborative Research: Dating and Paleoenvironmental Studies on Ancient Ice in the Dry Valleys, Antarctica", "uid": "p0000039", "west": 160.48705}, {"awards": "0619708 Simpson, David", "bounds_geometry": "POINT(180 90)", "dataset_titles": "IRIS data management center: seismic data and metadata for the engineering testing of these designs can be found under the XD network code (Polar Equipment Development) at stations PMC01, PMC02, PSP01, PSP02, and PSP03.", "datasets": [{"dataset_uid": "001460", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IRIS data management center: seismic data and metadata for the engineering testing of these designs can be found under the XD network code (Polar Equipment Development) at stations PMC01, PMC02, PSP01, PSP02, and PSP03.", "url": "http://ds.iris.edu/ds/nodes/dmc/"}], "date_created": "Mon, 20 Dec 2010 00:00:00 GMT", "description": "This project develops power and communications systems to support the operation of seismometers and GPS receivers in Antarctica throughout the polar night. In terms of intellectual merit, this system would allow a new class of geophysical questions to be approached, in areas as varied as ice sheet movement, plate tectonics, and deep earth structure. In terms of broader impacts, this project represents research infrastructure of potential use to many scientific disciplines. In addition, the results will improve society\u0027s understanding of the Antarctic ice sheet and its behavior in response to global warming.", "east": -180.0, "geometry": "POINT(-180 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": false, "keywords": "IRIS-GSN; PASSCAL; SEISMOLOGICAL STATIONS; Not provided; GSN", "locations": null, "north": -90.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, Kent; Parker, Tim", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GSN; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e IRIS-GSN; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e PASSCAL; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS; Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Development of a Power and Communication System for Remote Autonomous GPS and Seismic Stations in Antarctica", "uid": "p0000691", "west": -180.0}, {"awards": "0337567 Jacobel, Robert", "bounds_geometry": "POLYGON((130 -78,133 -78,136 -78,139 -78,142 -78,145 -78,148 -78,151 -78,154 -78,157 -78,160 -78,160 -79.2,160 -80.4,160 -81.6,160 -82.8,160 -84,160 -85.2,160 -86.4,160 -87.6,160 -88.8,160 -90,157 -90,154 -90,151 -90,148 -90,145 -90,142 -90,139 -90,136 -90,133 -90,130 -90,130 -88.8,130 -87.6,130 -86.4,130 -85.2,130 -84,130 -82.8,130 -81.6,130 -80.4,130 -79.2,130 -78))", "dataset_titles": "Glaciological Investigations of the Bulge and Trunk of Kamb Ice Stream, West Antarctica; Radar Studies of Internal Stratigraphy and Bed Topography along the US ITASE-II Traverse", "datasets": [{"dataset_uid": "609380", "doi": "10.7265/N5ZC80SH", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Kamb Ice Stream", "people": "Jacobel, Robert", "repository": "USAP-DC", "science_program": null, "title": "Glaciological Investigations of the Bulge and Trunk of Kamb Ice Stream, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609380"}, {"dataset_uid": "609475", "doi": "10.7265/N5G73BMS", "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness; ITASE; South Pole; Taylor Dome", "people": "Jacobel, Robert", "repository": "USAP-DC", "science_program": "ITASE", "title": "Radar Studies of Internal Stratigraphy and Bed Topography along the US ITASE-II Traverse", "url": "https://www.usap-dc.org/view/dataset/609475"}], "date_created": "Wed, 20 Oct 2010 00:00:00 GMT", "description": "This award supports a project to test whether Kamb Ice Stream (formerly Ice Stream C (ISC)), an ice stream\u003cbr/\u003ethat is thought to have stopped ~150 years ago, may be already in the process of restarting. If yes, it will help establish what is the rate of ice stream reactivation and what mechanisms are controlling this rate. If there is no evidence for ongoing ice stream reactivation, the physical controls that are preventing it will be examined and alternative scenarios for near-future evolution of this ice stream will be explored. One such scenario is an increase in ice diversion toward the neighboring Whillans Ice Stream. Such diversion may help prevent a complete stoppage of Whillans Ice Stream,which has been slowing down for at least the last 24 years. This project will consist of two components: (1) field observations of bed properties,geometry of internal radar reflectors, as well as surface strain rates and velocity/topography changes using Ice-Penetrating Radar and differential Global Positioning System, (2) numerical modeling study of near future(~100-1000 years) evolution of Kamb Ice Stream. The field component will be focused on the bulge-to-trunk transition, which is located at the present time just downstream of the so-called camp UpC. Reactivation of Kamb Ice Stream should be reflected in a downstream migration of the bulge-trunk transition at possibly high rates (bulge migration rates of ~km/yr occur on surging mountain glaciers). The modeling\u003cbr/\u003ecomponent will be used to generate predictions regarding the near-future behavior of Kamb Ice Stream. This project will provide training opportunities for at least two undergraduate students (per year) at St. Olaf College and for one\u003cbr/\u003eundergraduate student (per year) at UCSC. This collaboration will bring together scientists from three different types of US institutions: (1) a liberal arts college (St.Olaf College), (2) a public research university (UCSC) and (3) a NASA research laboratory (JPL). The project will also help build a new glaciological research program at UCSC. Project results will be incorporated into undergraduate and graduate courses at UCSC and will be made available\u003cbr/\u003eto the general public and educators through downloadable graphics and animations posted on the research website of the UCSC PI. Field data resulting from the project will be posted in the Antarctic Glaciological Data Center for use by other investigators.", "east": 160.0, "geometry": "POINT(145 -84)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": true, "keywords": "Ice; Antarctic Glaciations; Radar; Antarctic Ice Sheet; Radar Echo Sounder; Ice Sheet Thickness; Ice Stream; Ice Sheet Elevation; Not provided; Radar Echo Sounding; Ice Stratigraphy; Antarctica; West Antarctic Ice Sheet; Continental Ice Sheet; Ice Cap; Antarctic; US ITASE; FIELD SURVEYS; Ice Thickness; FIELD INVESTIGATION", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; West Antarctic Ice Sheet", "north": -78.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobel, Robert", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -90.0, "title": "Collaborative Research: Is Ice Stream C Restarting? Glaciological Investigations of the \u0027Bulge\u0027 and the Trunk of Ice Stream C, West Antartica", "uid": "p0000192", "west": 130.0}, {"awards": "0737168 Prentice, Michael; 0541054 Sletten, Ronald", "bounds_geometry": "POLYGON((162.2335 -77.5047,162.3803 -77.5047,162.5271 -77.5047,162.6739 -77.5047,162.8207 -77.5047,162.9675 -77.5047,163.1143 -77.5047,163.2611 -77.5047,163.4079 -77.5047,163.5547 -77.5047,163.7015 -77.5047,163.7015 -77.52814,163.7015 -77.55158,163.7015 -77.57502,163.7015 -77.59846,163.7015 -77.6219,163.7015 -77.64534,163.7015 -77.66878,163.7015 -77.69222,163.7015 -77.71566,163.7015 -77.7391,163.5547 -77.7391,163.4079 -77.7391,163.2611 -77.7391,163.1143 -77.7391,162.9675 -77.7391,162.8207 -77.7391,162.6739 -77.7391,162.5271 -77.7391,162.3803 -77.7391,162.2335 -77.7391,162.2335 -77.71566,162.2335 -77.69222,162.2335 -77.66878,162.2335 -77.64534,162.2335 -77.6219,162.2335 -77.59846,162.2335 -77.57502,162.2335 -77.55158,162.2335 -77.52814,162.2335 -77.5047))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 06 Oct 2010 00:00:00 GMT", "description": "This award supports a project to examine the stratigraphy of near-surface sediments in Taylor Valley, Antarctica. Two contrasting hypotheses have been proposed for surface sediments in lower Taylor Valley, which have important and very different implications for how the West Antarctic Ice Sheet (WAIS) responded to the sea-level rise of the last deglaciation and Holocene environmental changes. One hypothesis holds that the sediments, designated Ross I drift, directly reflect \u003e10,000 14C-years of WAIS shrinkage in the Ross Sea during and perhaps driven by deglacial sea-level rise. The other hypothesis, holds that the Taylor sediments have little significance for WAIS change during the deglaciation. These two hypotheses reflect fundamentally different interpretations of the sediment record. Over the course of two field seasons and a third year at the home institutions, the project will test these two hypotheses using glacial geology, geochemistry, ground penetrating radar (GPR) at both 100 MHz and 400 MHz, and portable sediment coring. The intellectual merit of the proposed work is that it will test these two hypotheses and make novel use of the subsurface record that may result in new insights into WAIS sensitivity during the deglaciation. The study will also directly test the conclusion that Glacial Lake Washburn was much larger than previously proposed during the Last Glacial Maximum (LGM). This occurrence, if real, represents a stunning climate anomaly. Answers to these local ice sheet and lake questions directly pertain to larger scale issues concerning the influences of sea-level rise, climate change, and internal ice-sheet dynamics on the recession of the WAIS since the LGM. There are numerous broader impacts to this project. Understanding the glacial and lake history in the McMurdo Sound region has important implications for the role that the WAIS will play in future sea-level and global climate change. Moreover, the history of Taylor Valley has significance for the ecosystem studies currently being conducted by the LTER group. Lastly, during the course of the proposed research, the project will train two graduate and undergraduate students and the research will be featured prominently in the teaching of students.", "east": 163.7015, "geometry": "POINT(162.9675 -77.6219)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": false, "keywords": "Not provided; Salt", "locations": null, "north": -77.5047, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Prentice, Michael; Sletten, Ronald S.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -77.7391, "title": "Collaborative Research: Fluctuations of the West Antarctic Ice Sheet in Relation to Lake History in Taylor Valley, Antarctica, Since the Last Glacial Maximum", "uid": "p0000656", "west": 162.2335}, {"awards": "0636974 Verosub, Kenneth", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 01 Oct 2010 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThis project performs a paleomagnetic survey of sediment cores from Antarctica\u0027s continental margin. Its goal is to refine the magnetostratigraphy to improve regional stratigraphic correlations, help date cores that lack biostratigraphic indicators, and understand paleoenvironmental conditions and climate change. As well, these cores record the earth\u0027s magnetic field near the magnetic pole, which may offer important information to scientists modeling the geodynamo.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this work include postdoctoral and undergraduate education. There are also implications for society\u0027s understanding of global climate change, since these techniques offer a different perspective on climate change from Antarctic marine sediment cores, which are critical to understanding the behavior of the ice sheets and their links to the global climate.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Verosub, Kenneth", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "New Paleomagnetic and Environmental Magnetic Studies of Old Cores from the Ross Sea Sector, Antarctica", "uid": "p0000367", "west": null}, {"awards": "0838842 Passchier, Sandra", "bounds_geometry": "POLYGON((-180 -68,-177 -68,-174 -68,-171 -68,-168 -68,-165 -68,-162 -68,-159 -68,-156 -68,-153 -68,-150 -68,-150 -69,-150 -70,-150 -71,-150 -72,-150 -73,-150 -74,-150 -75,-150 -76,-150 -77,-150 -78,-153 -78,-156 -78,-159 -78,-162 -78,-165 -78,-168 -78,-171 -78,-174 -78,-177 -78,180 -78,178 -78,176 -78,174 -78,172 -78,170 -78,168 -78,166 -78,164 -78,162 -78,160 -78,160 -77,160 -76,160 -75,160 -74,160 -73,160 -72,160 -71,160 -70,160 -69,160 -68,162 -68,164 -68,166 -68,168 -68,170 -68,172 -68,174 -68,176 -68,178 -68,-180 -68))", "dataset_titles": "Particle-size measurements for diamictites AND-2A sediment core, McMurdo Sound", "datasets": [{"dataset_uid": "601452", "doi": "10.15784/601452", "keywords": "Antarctica; McMurdo Sound; Miocene; Particle Size; Pleistocene; Pliocene", "people": "Passchier, Sandra; Hansen, Melissa A.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Particle-size measurements for diamictites AND-2A sediment core, McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601452"}], "date_created": "Fri, 27 Aug 2010 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The project aims on studying sediment cores collected from Prydz Bay and the Ross Sea to unravel the Neogene paleoclimatic history of the East Antarctic ice sheet. In the light of current measurements and predictions of a substantial rise in global temperature, investigations into the sensitivity of the East Antarctic ice sheet to climate change and its role in the climate system are essential. Geological records of former periods of climate change provide an opportunity to ground truth model predictions. The scientific objective of this project is to identify a previously proposed middle Miocene transition from a more dynamic wet-based East Antarctic ice sheet to the present semi-permanent ice sheet that is partially frozen to its bed. The timing and significance of this transition is controversial due to a lack of quantitative studies on well-dated ice-proximal sedimentary sequences. This project partially fills that gap using the composition and physical properties of diamictites and sandstones to establish shifts in ice-sheet drainage pathways, paleoenvironments and basal ice conditions. The results from the two key areas around the Antarctic continental margin will provide insight into the behavior of the East Antarctic ice sheet across the middle Miocene transition and through known times of warming in the late Miocene and Pliocene.", "east": -150.0, "geometry": "POINT(-175 -73)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples", "uid": "p0000147", "west": 160.0}, {"awards": "0538553 Cole-Dai, Jihong", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Major Ion Concentrations in WDC05Q and WDC06A Ice Cores (WAIS Divide)", "datasets": [{"dataset_uid": "609544", "doi": "10.7265/N54M92H3", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ion Chromatograph; WAIS Divide; WAIS Divide Ice Core", "people": "Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Major Ion Concentrations in WDC05Q and WDC06A Ice Cores (WAIS Divide)", "url": "https://www.usap-dc.org/view/dataset/609544"}], "date_created": "Wed, 25 Aug 2010 00:00:00 GMT", "description": "Cole-Dai\u003cbr/\u003e0538553\u003cbr/\u003e\u003cbr/\u003eThis award supports a project that will contribute to the US West Antarctica Ice Sheet Ice Divide ice core (WAIS Divide) project by developing new instrumentation and analytical procedures to measure concentrations of major ions (Cl-, NO3-, SO42-, Na+, K+, NH4+, Mg2+, Ca2+). A melter-based, continuous flow, multi-ion-chromatograph technique (CFA-IC) has been developed recently at South Dakota State University (SDSU). This project will further expand and improve the CFA-IC technique and instrumentation and develop procedures for routine analysis of major ions in ice cores. In addition, training of personnel (operators) to perform continuous, high resolution major ion analysis of the deep core will be accomplished through this project. The temporal resolution of the major ion measurement will be as low as 0.5 cm with the fully developed CFA-IC technique. At this resolution, it will be possible to use annual cycles of sulfate and sea-salt ion concentrations to determine annual layers in the WAIS Divide ice core. Annual layer counting using CFA-IC chemical measurements and other high resolution measurements will contribute significantly to the major WAIS Divide project objective of producing precisely (i.e., annually) dated climate records. The project will support the integration of research and education, train future scientists and promote human resource development through the participation of graduate and undergraduate students. In particular, undergraduate participation will contribute to a current REU (Research Experience for Undergraduates) chemistry site program at SDSU. Development and utilization of multi-user instrumentation will promote research collaboration and advance environmental science. NSF support for SDSU will contribute to the economic development and strengthen the infrastructure for research and education in South Dakota.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "LABORATORY; WAIS Divide; Ice Core; West Antarctic Ice Sheet; Ion Chromatograph; GROUND-BASED OBSERVATIONS; Not provided; Major Ion; Ions", "locations": "WAIS Divide; West Antarctic Ice Sheet", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cole-Dai, Jihong", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Major Ion Chemistry of WAIS Divide Ice Core", "uid": "p0000035", "west": -112.085}, {"awards": "0636506 Mayewski, Paul", "bounds_geometry": "POLYGON((-137.7 -75.7,-137.4 -75.7,-137.1 -75.7,-136.8 -75.7,-136.5 -75.7,-136.2 -75.7,-135.9 -75.7,-135.6 -75.7,-135.3 -75.7,-135 -75.7,-134.7 -75.7,-134.7 -75.773,-134.7 -75.846,-134.7 -75.919,-134.7 -75.992,-134.7 -76.065,-134.7 -76.138,-134.7 -76.211,-134.7 -76.284,-134.7 -76.357,-134.7 -76.43,-135 -76.43,-135.3 -76.43,-135.6 -76.43,-135.9 -76.43,-136.2 -76.43,-136.5 -76.43,-136.8 -76.43,-137.1 -76.43,-137.4 -76.43,-137.7 -76.43,-137.7 -76.357,-137.7 -76.284,-137.7 -76.211,-137.7 -76.138,-137.7 -76.065,-137.7 -75.992,-137.7 -75.919,-137.7 -75.846,-137.7 -75.773,-137.7 -75.7))", "dataset_titles": "Ion Concentrations from SPRESSO Ice Core, Antarctica; Mt. Moulton Ice Trench Mass Spectrometry Data, Antarctica", "datasets": [{"dataset_uid": "609471", "doi": "10.7265/N508638J", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; ITASE; Paleoclimate; South Pole; SPRESSO Ice Core", "people": "Mayewski, Paul A.; Korotkikh, Elena", "repository": "USAP-DC", "science_program": null, "title": "Ion Concentrations from SPRESSO Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609471"}, {"dataset_uid": "609472", "doi": "10.7265/N5VH5KSV", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mt Moulton; Paleoclimate", "people": "Mayewski, Paul A.; Korotkikh, Elena", "repository": "USAP-DC", "science_program": null, "title": "Mt. Moulton Ice Trench Mass Spectrometry Data, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609472"}], "date_created": "Thu, 29 Jul 2010 00:00:00 GMT", "description": "This award supports a project to examine an existing ice core of opportunity from South Pole (SPRESO core) to develop a 2000+ year long climate record. SPRESO ice core will be an annually dated, sub-annually-resolved reconstruction of past climate (atmospheric circulation, temperature, precipitation rate, and atmospheric chemistry) utilizing continuous, co-registered measurements (n=45) of: major ions, trace elements, and stable isotope series, plus selected sections for microparticle size and composition. The intellectual merit of this project relates to the fact that few 2000+ year records of this quality exist in Antarctica despite increasing scientific interest in this critical time period as the framework within which to understand modern climate. The scientific impact of this ice core investigation are that it will provide an in-depth understanding of climate variability; a baseline for assessing modern climate variability in the context of human activity; and a contribution to the prediction of future climate variability. The broader impact of this work is that the proposed research addresses important questions concerning the role of Antarctica in past, present, and future global change. Results will be translated into publicly accessible information through public lectures, media appearances, and an extensive outreach activity housed in our Institute. Our ice core activities provide a major basis for curriculum in K-12 and University plus a basis for several field and laboratory based graduate theses and undergraduate student projects. The project will support one PhD student for 3 years and undergraduate salaries. The Climate Change Institute has a long history of gender and ethnically diverse student and staff involvement in research.", "east": -134.7, "geometry": "POINT(-136.2 -76.065)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Ice Core Interpretation; Ions; US ITASE; Explorations; LABORATORY; Ice Core Data; Ice Core; Ice Analysis; Ice; Not provided; Antarctic Ice Sheet; Laboratory Investigation; Field Investigations; Ice Core Chemistry; Horizontal Ice Core; Ice Chemistry; Ice Sheet", "locations": "Antarctic Ice Sheet", "north": -75.7, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Korotkikh, Elena; Kreutz, Karl; Kurbatov, Andrei V.; Mayewski, Paul A.", "platforms": "Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.43, "title": "Collaborative Proposal: 2000+ Year Detailed, Calibrated Climate Reconstruction from a South Pole Ice Core Set in an Antarctic - Global Scale Context", "uid": "p0000209", "west": -137.7}, {"awards": "0538657 Severinghaus, Jeffrey", "bounds_geometry": null, "dataset_titles": "Borehole Temperature Measurement in WDC05A in January 2008 and January 2009; d15N and d18O of air in the WAIS Divide ice core; Low-res d15N and d18O of O2 in the WAIS Divide 06A Deep Core; Ultra-High Resolution LA-ICP-MS Results: DO-21 Rapid Warming Event; WAIS Divide d18Oatm and Siple Dome/WAIS Divide composite and individual delta epsilon LAND", "datasets": [{"dataset_uid": "609635", "doi": "10.7265/N51J97PS", "keywords": "Arctic; Geochemistry; GISP; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate", "people": "Haines, Skylar; Mayewski, Paul A.; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": null, "title": "Ultra-High Resolution LA-ICP-MS Results: DO-21 Rapid Warming Event", "url": "https://www.usap-dc.org/view/dataset/609635"}, {"dataset_uid": "601747", "doi": "10.15784/601747", "keywords": "Antarctica; Delta 15N; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Gas Records; Ice Core Records; Isotope; Nitrogen; Nitrogen Isotopes; Oxygen; Oxygen Isotope; Snow/ice; Snow/Ice; WAIS; WAIS Divide", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "d15N and d18O of air in the WAIS Divide ice core", "url": "https://www.usap-dc.org/view/dataset/601747"}, {"dataset_uid": "609637", "doi": "10.7265/N5B27S7S", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Severinghaus, Jeffrey P.; Orsi, Anais J.", "repository": "USAP-DC", "science_program": null, "title": "Borehole Temperature Measurement in WDC05A in January 2008 and January 2009", "url": "https://www.usap-dc.org/view/dataset/609637"}, {"dataset_uid": "609660", "doi": "10.7265/N5S46PWD", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Low-res d15N and d18O of O2 in the WAIS Divide 06A Deep Core", "url": "https://www.usap-dc.org/view/dataset/609660"}, {"dataset_uid": "601041", "doi": "10.15784/601041", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Gas; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; WAIS Divide Ice Core", "people": "Severinghaus, Jeffrey P.; Seltzer, Alan", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide d18Oatm and Siple Dome/WAIS Divide composite and individual delta epsilon LAND", "url": "https://www.usap-dc.org/view/dataset/601041"}], "date_created": "Thu, 08 Jul 2010 00:00:00 GMT", "description": "0538657\u003cbr/\u003eSeveringhaus\u003cbr/\u003eThis award supports a project to develop high-resolution (20-yr) nitrogen and oxygen isotope records on trapped gases in the WAIS Divide ice core (Antarctica), with a comparison record for chronological purposes in the GISP2 (Greenland) ice core. The main scientific objective is to provide an independent temperature-change record for the past 100,000 years in West Antarctica that is not subject to the uncertainty inherent in ice isotopes (18O and deuterium), the classical paleothermometer. Nitrogen isotopes (Delta 15N) in air bubbles in glacial ice record rapid surface temperature change because of thermal fractionation of air in the porous firn layer, and this isotopic anomaly is recorded in bubbles as the firn becomes ice. Using this gas-based temperature-change record, in combination with methane data as interpolar stratigraphic markers, the proposed work will define the precise relative timing of abrupt warming in Greenland and abrupt cooling at the WAIS Divide site during the millennial-scale climatic oscillations of Marine Isotopic Stage 3 (30-70 kyr BP) and the last glacial termination. The nitrogen isotope record also provides constraints on past firn thickness, which inform temperature and accumulation rate histories from the ice core. A search for possible solar-related cycles will be conducted with the WAIS Divide Holocene (Delta 15N.) Oxygen isotopes of O2 (Delta 18Oatm) are obtained as a byproduct of the (Delta 15N) measurement. The gas-isotopic records will enhance the value of other atmospheric gas measurements in WAIS Divide, which are expected to be of unprecedented quality. The high-resolution (Delta 18Oatm) records will provide chronological control for use by the international ice coring community and for surface glacier ice dating. Education of a graduate student, and training of a staff member in the laboratory, will contribute to the nation\u0027s human resource base. Outreach activities in the context of the International Polar Year will be enhanced. International collaboration is planned with the laboratory of LSCE, University of Paris.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e LA-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Borehole Temperature; LABORATORY; Depth; Not provided; GROUND-BASED OBSERVATIONS; Wais Divide-project; Ice Core; WAIS Divide", "locations": "WAIS Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Haines, Skylar; Mayewski, Paul A.; Orsi, Anais J.; Kurbatov, Andrei V.; Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate", "uid": "p0000036", "west": null}, {"awards": "0632346 Tulaczyk, Slawek; 0632161 Johnson, Jesse; 0632168 Hulbe, Christina; 0632325 Seals, Cheryl", "bounds_geometry": "POLYGON((-180 -50.05,-144 -50.05,-108 -50.05,-72 -50.05,-36 -50.05,0 -50.05,36 -50.05,72 -50.05,108 -50.05,144 -50.05,180 -50.05,180 -54.045,180 -58.04,180 -62.035,180 -66.03,180 -70.025,180 -74.02,180 -78.015,180 -82.01,180 -86.005,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -86.005,-180 -82.01,-180 -78.015,-180 -74.02,-180 -70.025,-180 -66.03,-180 -62.035,-180 -58.04,-180 -54.045,-180 -50.05))", "dataset_titles": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields; Wiki containing the data and provenance.", "datasets": [{"dataset_uid": "609396", "doi": "10.7265/N5K64G1S", "keywords": "Antarctica; Community Ice Sheet Model; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Daescu, Dacian N.; Hulbe, Christina", "repository": "USAP-DC", "science_program": null, "title": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields", "url": "https://www.usap-dc.org/view/dataset/609396"}, {"dataset_uid": "001499", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Wiki containing the data and provenance.", "url": "http://websrv.cs.umt.edu/isis/index.php/Present_Day_Antarctica"}], "date_created": "Fri, 02 Jul 2010 00:00:00 GMT", "description": "Johnson/0632161\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to create a \"Community Ice Sheet Model (CISM)\". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating \"a new generation\" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MODELS; International Polar Year; Derived Basal Temperature Evolution; Ice Sheet; Community Ice Sheet Model; Ice Sheet Model; LABORATORY; Amundsen Sea; Eismint; Modeling; Basal Temperature; Numerical Model; Antarctic Ice Sheet; Environmental Modeling; IPY; Antarctica; Model; Not provided; Ice Dynamic", "locations": "Antarctic Ice Sheet; Antarctica; Amundsen Sea", "north": -50.05, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Hulbe, Christina; Seals, Cheryl; Johnson, Jesse; Daescu, Dacian N.", "platforms": "Not provided; OTHER \u003e MODELS \u003e MODELS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "PI website; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: IPY, The Next Generation: A Community Ice Sheet Model for Scientists and Educators With Demonstration Experiments in Amundsen Sea Embayment Region", "uid": "p0000756", "west": -180.0}, {"awards": "0839042 Caffee, Marc", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Cosmogenic 10Be in WAIS Divide Ice core, 1190-2453 m; Cosmogenic Radionuclides in the WAIS Divide Ice Core", "datasets": [{"dataset_uid": "601466", "doi": "10.15784/601466", "keywords": "Antarctica; West Antarctic Ice Sheet", "people": "Welten, Kees; Woodruff, T. E.; Caffee, M. W.; Nishiizumi, Kunihiko", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Cosmogenic 10Be in WAIS Divide Ice core, 1190-2453 m", "url": "https://www.usap-dc.org/view/dataset/601466"}, {"dataset_uid": "600383", "doi": "10.15784/600383", "keywords": "Antarctica; Cosmogenic Radionuclides; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrothermal Vent; WAIS Divide; WAIS Divide Ice Core", "people": "Welten, Kees", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Cosmogenic Radionuclides in the WAIS Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/600383"}], "date_created": "Thu, 01 Jul 2010 00:00:00 GMT", "description": "Caffee/0839042 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to measure the concentration of the cosmogenic radionuclide, Beryllium-10 in the deep WAIS divide ice core. Since cosmogenic radionuclides are one of the key parameters used for absolute dating of the ice core and deriving paleoaccumulation rates, it is essential that these measurements be made quickly and efficiently, and that the information is disseminated as soon as the results are available. The intellectual merit of the project is that it will allow a comparison to be made between the core from WAIS Divide and previously measured cosmogenic radionuclide records from Arctic ice cores, particularly GISP2 and GRIP This project will enable scientists to delineate those processes acting at a local level from those that produce global effects and will provide independent chronological markers to aid in the reconstruction of the WAIS Divide ice core chronology. The cosmogenic 10Be profile can also be used to investigate the possible role of solar activity on climate. The direct comparison of radionuclide concentrations with paleoclimate records in ice cores from different sites will provide more insight in the timing and magnitude of solar forcing of climate. The broader impacts of this project include: (i) the formation of a multi-disciplinary team of collaborators for the interpretation of future analyses of cosmogenic radionuclide data from the WAIS divide and other ice cores. (ii) the involvement and training of graduate and undergraduate students in the large scale project of climate research through detailed studies of ice samples. (iii) the opportunity to highlight to a wide range of lab visitors and students from local K-12 schools the importance of ice core and climate change studies.\u003cbr/\u003e\u003cbr/\u003eThis award does not involve field work in Antarctica.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS", "is_usap_dc": false, "keywords": "Ice Core; WAIS Divide; Antarctica; Not provided; Radionulides; Accelerator Mass Spectrometry; Cosmogenic", "locations": "WAIS Divide; Antarctica", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Welten, Kees; Nishiizumi, Kunihiko; Caffee, Marc; Woodruff, Thomas", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Cosmogenic Radionuclides in the Deep WAIS Divide Core", "uid": "p0000103", "west": -112.085}, {"awards": "0538494 Meese, Debra", "bounds_geometry": null, "dataset_titles": "Microstructural Location and Composition of Impurities in Polar Ice Cores", "datasets": [{"dataset_uid": "609436", "doi": "10.7265/N5DF6P5P", "keywords": "Antarctica; Arctic; Byrd Glacier; Byrd Ice Core; Chemistry:ice; Chemistry:Ice; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Lake Vostok; Paleoclimate; Vostok Ice Core", "people": "Baker, Ian; Obbard, Rachel", "repository": "USAP-DC", "science_program": null, "title": "Microstructural Location and Composition of Impurities in Polar Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609436"}], "date_created": "Thu, 03 Jun 2010 00:00:00 GMT", "description": "0538494\u003cbr/\u003eMeese\u003cbr/\u003eThis award supports a project for physical properties research on snow pits and firn/ice cores with specific objectives that include stratigraphic analysis including determination of accumulation rates, annual layers, depth hoar, ice and wind crusts and rates of grain growth with depth. Studies of firn densification rates and how these parameters relate to the meteorology and climatology over the last 200 years of snow accumulation in Antarctica will also be investigated. The project will also determine the seasonality of accumulation by co-registration of stratigraphy and chemistry and determination of chemical species at the grain boundaries, how these may change with depth/densification (and therefore temperature), precipitation, and may affect grain growth. Fabric analyses will be made, including variation with depth, location on undulations and if any variation exists with climate/chemistry. The large spatial coverage of the US ITASE program offers the opportunity to determine how these parameters are affected by a large range of temperature, precipitation and topographic effects. The intellectual merit of the project includes the fact that ITASE is the terrestrial equivalent of a polar research vessel that provides a unique, logistically efficient, multi-dimensional (x, y, z and time) view of the atmosphere, ice sheet and their histories. Physical properties measurements/ analyses are an integral part of understanding the dynamic processes to which the accumulated snow is subjected. Recent advancements in the field along with multiple core sites provide an excellent opportunity to gain a much broader understanding of the spatial, temporal and physical variables that impact firnification and the possible resultant impact on climatic interpretation. In terms of broader impacts, the data collected by US ITASE and its international ITASE partners is available to a broad scientific community. US ITASE has an extensive program of public outreach and provides significant opportunities for many students to experience multidisciplinary Antarctic research. A graduate student, a post-doctoral fellow and at least one undergraduate would be funded by this work. Dr. Meese is also a member of the New England Science Collaborative, an organization that educates the public on climate change based on recent scientific advancements.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": false, "keywords": "LABORATORY; Grain Growth; FIELD SURVEYS; Accumulation Rate; Firn Core; FIELD INVESTIGATION; Chemistry; Snow Pit; Depth Hoar; Firn Density; Ice Core; Not provided; Stratigraphic Analysis; Firn; US ITASE; Annual Layers", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Meese, Deb; MEESE, DEBRA", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "The Physical Properties of the US ITASE Firn and Ice Cores from South Pole to Taylor Dome", "uid": "p0000289", "west": null}, {"awards": "0338151 Raymond, Charles", "bounds_geometry": "POINT(-112.086 -79.468)", "dataset_titles": "Englacial Layers and Attenuation Rates across the Ross and Amundsen Sea Ice-Flow Divide (WAIS Divide), West Antarctica; Surface Elevation and Ice Thickness, Western Marie Byrd Land, Antarctica", "datasets": [{"dataset_uid": "609119", "doi": "10.7265/N5BZ63ZH", "keywords": "Airborne Radar; Airplane; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marie Byrd Land", "people": "Wilson, Douglas S.; Luyendyk, Bruce P.", "repository": "USAP-DC", "science_program": null, "title": "Surface Elevation and Ice Thickness, Western Marie Byrd Land, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609119"}, {"dataset_uid": "609470", "doi": "10.7265/N5416V0W", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar; WAIS Divide", "people": "Raymond, Charles; Matsuoka, Kenichi", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Englacial Layers and Attenuation Rates across the Ross and Amundsen Sea Ice-Flow Divide (WAIS Divide), West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609470"}], "date_created": "Tue, 11 May 2010 00:00:00 GMT", "description": "This award supports an investigation of spatial variations of ice temperature and subglacial conditions using available ice-penetrating radar data around a future deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet. Besides geometry of reflection layers the focus will be on intensities of radar echoes from within ice deeper than several hundred meters and will also examine echoes from the bed. Preliminary studies on theory and comparison with Japanese radar data from East Antarctica suggest that large spatial variations of the vertical gradient of radar echoes from within ice exist and are caused primarily by ice temperature and secondarily by crystal-orientation fabric. The hypothesis that the vertical gradient is a proxy of ice temperature will be tested. The project will utilize an existing data set from the Support Office for Aerogeophysical Research in Antarctica (SOAR) and will complement work already underway at University of Texas to analyze the radar data. The project will provide undergraduate research experience with an emphasis on computer analysis of time series and large data sets as well as development of web-based resource of results and methods and will support an international collaboration between US and Japan through discussions on the preliminary results from their study sites. Practical procedures developed through this study will be downloadable from the project\u0027s web site in the third year and will allow investigation of other ice sheets using existing radar data sets. This project will contribute to the interpretation of the future inland West Antarctic ice core and will help in the understanding of ice sheet history and climate change.", "east": -112.086, "geometry": "POINT(-112.086 -79.468)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LASERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": true, "keywords": "SOAR; Ice Sheet Elevation; Antarctic Ice Sheet; Layers; USAP-DC; West Antarctic; FIELD INVESTIGATION; Amundsen; Ice Sheet; Airborne Laser Altimetry; Ice Surface; Not provided; Ice Penetrating Radar; Ice Sheet Thickness; Ice Extent; Ice Surface Elevation; Ice Cover; Ice Deformation; FIELD SURVEYS; Antarctica; Ground Ice; Subglacial; Reflection Layers; West Antarctic Ice Sheet; Ice Surface Temperature; LABORATORY; Amundsen Flow Divide; Radar Echo Sounding; Internal Layering; Radar Altimetry; Ice; Radar Echoes; Englacial; Crystal Orientation Fabric; Ice Thickness; Altimetry; Ice Temperature; Radar Echo Sounder; Ice Thickness Distribution", "locations": "Antarctic Ice Sheet; Antarctica; West Antarctic; Amundsen; Amundsen Flow Divide; West Antarctic Ice Sheet", "north": -79.468, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Raymond, Charles; Matsuoka, Kenichi; Luyendyk, Bruce P.; Wilson, Douglas S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.468, "title": "Glaciological Characteristics of the Ross/Amundsen Sea Ice-flow Divide Deduced by a New Analysis of Ice-penetrating Radar Data", "uid": "p0000017", "west": -112.086}, {"awards": "0003060 Domack, Eugene", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP0107", "datasets": [{"dataset_uid": "002656", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0107", "url": "https://www.rvdata.us/search/cruise/NBP0107"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports project to test and develop approaches for using thermoluminescence techniques to determine the age of Antarctic marine sediments. \u003cbr/\u003e\u003cbr/\u003eQuaternary (last 2 million yrs) marine sediments surrounding Antarctica record the waxing and waning of ice shelves and ice sheets, and also other paleoclimatic information, yet accurate chronologies of these sediments are difficult to obtain. Such chronologies provide the essential foundation for study of geological processes in the past. Within the range of radiocarbon (14C) dating (less than 30-40 thousand yrs, note - \"ka\" below means 1000 yrs) 14C dates can be inaccurate because of a variable 14C reservoir effect, and beyond 30-40 ka few methods are applicable. Photon-stimulated-luminescence sediment dating (photonic dating) of eolian and waterlain deposits in temperate latitudes spans the range from decades to hundreds of ka, but marine sediments in and around Antarctica pose special difficulty because of the potentially restricted exposure to daylight (the clock-zeroing process) of most detrital grains before deposition. This proposal will test the clock-zeroing assumption in representative Antarctic glaciomarine depositional settings, and thereby determine the potential reliability of photonic dating of Antarctic marine sediments.\u003cbr/\u003e\u003cbr/\u003eLimited luminescence dating and signal-zeroing tests using glaciomarine and marine deposits have been conducted in the northern temperate and polar latitudes, but the effects on luminescence of the different glaciomarine depositional processes have never been studied in detail. Furthermore, the depositional settings around Antarctica are almost entirely polar, with consequent specific processes operating there. For example, transport of terrigenous suspensions by neutrally buoyant \"cold-tongue\" (mid-water) plumes may be common around Antarctica, yet the effect of such transport on luminescence zeroing is unknown. Typical marine cores near Antarctica may contain an unknown fraction of detrital grains from cold-tongue and near-bottom suspensions. Thus the extent to which the polar glaciomarine depositional processes around Antarctica may limit the potential accuracy of photonic dating of marine cores is unknown (age overestimates would result if grains are not exposed to daylight before deposition).\u003cbr/\u003e\u003cbr/\u003eThis project will collect detrital grains from a variety of \"zero-age\" (modern) marine depositional settings within the Antarctic Peninsula, where representative Antarctic depositional processes have been documented and where logistics permit access. Suspensions will be collected from four fjords representing a transect from polar through subpolar conditions. Suspensions will be collected from two stations and from up to 3 depths (surface and 2 deep plumes) at each station. Sediment traps will be deployed at two of these fjord settings. As well, core-top sediments will be collected from several sites. All samples will be shielded from light and transported to Reno, Nevada, for luminescence analyses.\u003cbr/\u003e\u003cbr/\u003eSystematic study of the effectiveness of luminescence-clock-zeroing in Antarctic glaciomarine settings will determine if photonic dating can be reliable for future applications to Antarctic marine sediments. Refined sedimentological criteria for the selection of future samples for photonic dating are expected from this project. A photonic-dating capability would provide a numeric geochronometer extending well beyond the age range of 14C dating. Such a capability would permit answering a number of broader questions about the timing and extent of past glaciations near and on the Antarctic shelves.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "Palmer Deep; Hugo Island; R/V NBP", "locations": "Hugo Island", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Domack, Eugene Walter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Development of a Luminescence Dating Capability for Antarctic Glaciomarine Sediments: Tests of Signal Zeroing at the Antarctic Peninsula", "uid": "p0000845", "west": null}, {"awards": "0732995 Barbeau, David", "bounds_geometry": "POLYGON((-67.9988 -52.7596,-66.83756 -52.7596,-65.67632 -52.7596,-64.51508 -52.7596,-63.35384 -52.7596,-62.1926 -52.7596,-61.03136 -52.7596,-59.87012 -52.7596,-58.70888 -52.7596,-57.54764 -52.7596,-56.3864 -52.7596,-56.3864 -54.15258,-56.3864 -55.54556,-56.3864 -56.93854,-56.3864 -58.33152,-56.3864 -59.7245,-56.3864 -61.11748,-56.3864 -62.51046,-56.3864 -63.90344,-56.3864 -65.29642,-56.3864 -66.6894,-57.54764 -66.6894,-58.70888 -66.6894,-59.87012 -66.6894,-61.03136 -66.6894,-62.1926 -66.6894,-63.35384 -66.6894,-64.51508 -66.6894,-65.67632 -66.6894,-66.83756 -66.6894,-67.9988 -66.6894,-67.9988 -65.29642,-67.9988 -63.90344,-67.9988 -62.51046,-67.9988 -61.11748,-67.9988 -59.7245,-67.9988 -58.33152,-67.9988 -56.93854,-67.9988 -55.54556,-67.9988 -54.15258,-67.9988 -52.7596))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001520", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0717"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project studies the relationship between opening of the Drake Passage and formation of the Antarctic ice sheet. Its goal is to answer the question: What drove the transition from a greenhouse to icehouse world thirty-four million years ago? Was it changes in circulation of the Southern Ocean caused by the separation of Antarctica from South America or was it a global effect such as decreasing atmospheric CO2 content? This study constrains the events and timing through fieldwork in South America and Antarctica and new work on marine sediment cores previously collected by the Ocean Drilling Program. It also involves an extensive, multidisciplinary analytical program. Compositional analyses of sediments and their sources will be combined with (U-Th)/He, fission-track, and Ar-Ar thermochronometry to constrain uplift and motion of the continental crust bounding the Drake Passage. Radiogenic isotope studies of fossil fish teeth found in marine sediment cores will be used to trace penetration of Pacific seawater into the Atlantic. Oxygen isotope and trace metal measurements on foraminifera will provide additional information on the timing and magnitude of ice volume changes. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThe broader impacts include graduate and undergraduate education; outreach to the general public through museum exhibits and presentations, and international collaboration with scientists from Argentina, Ukraine, UK and Germany.\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThe project is supported under NSF\u0027s International Polar Year (IPY) research emphasis area on \"Understanding Environmental Change in Polar Regions\". This project is also a key component of the IPY Plates \u0026 Gates initiative (IPY Project #77), focused on determining the role of tectonic gateways in instigating polar environmental change.", "east": -56.3864, "geometry": "POINT(-62.1926 -59.7245)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": -52.7596, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "MacPhee, Ross", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -66.6894, "title": "Collaborative Research: IPY: Testing the Polar Gateway Hypothesis: An Integrated Record of Drake Passage Opening \u0026 Antarctic Glaciation", "uid": "p0000120", "west": -67.9988}, {"awards": "0125562 Zachos, James", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0602A", "datasets": [{"dataset_uid": "001571", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}, {"dataset_uid": "002617", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0602A", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Proposal: SHALDRIL - A Demonstration Drilling Cruise to the James Ross Basin", "uid": "p0000829", "west": null}, {"awards": "9527876 Anderson, John", "bounds_geometry": "POLYGON((-179.9996 -70.29238,-143.99968 -70.29238,-107.99976 -70.29238,-71.99984 -70.29238,-35.99992 -70.29238,0 -70.29238,35.99992 -70.29238,71.99984 -70.29238,107.99976 -70.29238,143.99968 -70.29238,179.9996 -70.29238,179.9996 -71.048723,179.9996 -71.805066,179.9996 -72.561409,179.9996 -73.317752,179.9996 -74.074095,179.9996 -74.830438,179.9996 -75.586781,179.9996 -76.343124,179.9996 -77.099467,179.9996 -77.85581,143.99968 -77.85581,107.99976 -77.85581,71.99984 -77.85581,35.99992 -77.85581,0 -77.85581,-35.99992 -77.85581,-71.99984 -77.85581,-107.99976 -77.85581,-143.99968 -77.85581,-179.9996 -77.85581,-179.9996 -77.099467,-179.9996 -76.343124,-179.9996 -75.586781,-179.9996 -74.830438,-179.9996 -74.074095,-179.9996 -73.317752,-179.9996 -72.561409,-179.9996 -71.805066,-179.9996 -71.048723,-179.9996 -70.29238))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002067", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9902"}, {"dataset_uid": "002125", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9801"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Anderson OPP 9527876 Abstract This award supports continuation of a long term investigation of the continental shelf sediments that is aimed at examining the configuration of the West Antarctic Ice Sheet during the last glacial maximum, the events and mechanisms involved in its retreat, and the timing of retreat. The project involves: 1) characterizing variations in the ice sheet grounding zone in a latitudinal transect extending from Ross Sea to Bransfield Basin, 2) reconstructing conditions at the ice/bed interface prior to and after ice sheet retreat, and 3) radiometrically dating ice sheet retreat along this transect. Detailed sea floor imagery (multibeam and deep-tow side-scan sonar), high resolution seismic reflection profiles, and sediment cores will be used to map and characterize prior grounding zones. Of particular concern are features that indicate the amount and organization (channelization) of basal meltwater and the extent of bed deformation that occurred in different ice streams. The timing of ice sheet retreat provides information about the link between Northern and Southern hemisphere ice expansion, and the role of eustasy in ice sheet decoupling. This research should lead to better predictive models to determine which ice streams are most unstable and likely, therefore, to serve as Oweak linksO in the long term behavior of West Antarctic Ice Sheet.", "east": 179.9996, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -70.29238, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -77.85581, "title": "Mechanism and Timing of West Antarctic Ice Sheet Retreat at the End of the Last Glacial Maximum", "uid": "p0000624", "west": -179.9996}, {"awards": "9725024 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0001; Expedition data of NBP0008; Summer Oceanographic Measurements near the Mertz Polynya NBP0008", "datasets": [{"dataset_uid": "002598", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0001", "url": "https://www.rvdata.us/search/cruise/NBP0001"}, {"dataset_uid": "001885", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "601161", "doi": "10.15784/601161 ", "keywords": "Antarctica; CTD; CTD Data; Mertz Polynya; NBP0008; Oceans; Oxygen; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Mortlock, R. A.; Smethie, William M; Jacobs, Stanley; Mele, Phil", "repository": "USAP-DC", "science_program": null, "title": "Summer Oceanographic Measurements near the Mertz Polynya NBP0008", "url": "https://www.usap-dc.org/view/dataset/601161"}, {"dataset_uid": "002599", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0008", "url": "https://www.rvdata.us/search/cruise/NBP0008"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "*** 9725024 Jacobs This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999. ***", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "Circumpolar Deep Water and the West Antarctic Ice Sheet", "uid": "p0000815", "west": null}, {"awards": "9220848 Bartek, Louis", "bounds_geometry": "POLYGON((-179.9996 -52.35472,-143.99968 -52.35472,-107.99976 -52.35472,-71.99984 -52.35472,-35.99992 -52.35472,0 -52.35472,35.99992 -52.35472,71.99984 -52.35472,107.99976 -52.35472,143.99968 -52.35472,179.9996 -52.35472,179.9996 -54.916322,179.9996 -57.477924,179.9996 -60.039526,179.9996 -62.601128,179.9996 -65.16273,179.9996 -67.724332,179.9996 -70.285934,179.9996 -72.847536,179.9996 -75.409138,179.9996 -77.97074,143.99968 -77.97074,107.99976 -77.97074,71.99984 -77.97074,35.99992 -77.97074,0 -77.97074,-35.99992 -77.97074,-71.99984 -77.97074,-107.99976 -77.97074,-143.99968 -77.97074,-179.9996 -77.97074,-179.9996 -75.409138,-179.9996 -72.847536,-179.9996 -70.285934,-179.9996 -67.724332,-179.9996 -65.16273,-179.9996 -62.601128,-179.9996 -60.039526,-179.9996 -57.477924,-179.9996 -54.916322,-179.9996 -52.35472))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002245", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9407"}, {"dataset_uid": "002265", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9307"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award supports an integrated seismic, sedimentologic, and paleontologic investigation of glacio-marine stratigraphy of the Ross Sea continental shelf. The purpose of this work is to acquire seismic images and sediment cores of the glacial sediments toward a better understanding of the Cenozoic history of glaciation in the Ross Sea region. This investigation will utilize high resolution seismic profiling data to locate regions where the Pleistocene glacial till is thin or perhaps absent. Piston coring at these locations, if the till is penetrated, will provide sedimentary records of Cenozoic depositional environments and could provide important clues to fluctuations of the Antarctic Ice Sheets. The seismic profiling will provide a direct record of the grounding history of the Ross Ice Shelf during the Pleistocene and it will also allow first order correlations of Cenozoic sedimentary units that are represented by sediments recovered in the piston cores. This work will provide important proxy records of the history of both the West Antarctic Ice Sheet and the East Antarctic Ice Sheet and this, in turn, will provide important constraints to climate models.", "east": 179.9996, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.35472, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bartek, Louis", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -77.97074, "title": "Integrated Biostratigraphy and High Resolution Seismic Stratigraphy of the Ross Sea: Implications for Cenozoic Eustatic and Climatic Change", "uid": "p0000643", "west": -179.9996}, {"awards": "0125922 Anderson, John", "bounds_geometry": "POLYGON((-69.84264 -52.35215,-68.086508 -52.35215,-66.330376 -52.35215,-64.574244 -52.35215,-62.818112 -52.35215,-61.06198 -52.35215,-59.305848 -52.35215,-57.549716 -52.35215,-55.793584 -52.35215,-54.037452 -52.35215,-52.28132 -52.35215,-52.28132 -53.546701,-52.28132 -54.741252,-52.28132 -55.935803,-52.28132 -57.130354,-52.28132 -58.324905,-52.28132 -59.519456,-52.28132 -60.714007,-52.28132 -61.908558,-52.28132 -63.103109,-52.28132 -64.29766,-54.037452 -64.29766,-55.793584 -64.29766,-57.549716 -64.29766,-59.305848 -64.29766,-61.06198 -64.29766,-62.818112 -64.29766,-64.574244 -64.29766,-66.330376 -64.29766,-68.086508 -64.29766,-69.84264 -64.29766,-69.84264 -63.103109,-69.84264 -61.908558,-69.84264 -60.714007,-69.84264 -59.519456,-69.84264 -58.324905,-69.84264 -57.130354,-69.84264 -55.935803,-69.84264 -54.741252,-69.84264 -53.546701,-69.84264 -52.35215))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001602", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0502"}, {"dataset_uid": "001571", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.", "east": -52.28132, "geometry": "POINT(-61.06198 -58.324905)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.35215, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John; Wellner, Julia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.29766, "title": "Collaborative Research: SHALDRIL - A Demonstration Drilling Cruise to the James Ross Basin", "uid": "p0000571", "west": -69.84264}, {"awards": "0125526 Wise, Sherwood", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0602A", "datasets": [{"dataset_uid": "002616", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0602A", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}, {"dataset_uid": "001571", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Proposal: SHALDRIL - A Demonstration Drilling Cruise to the James Ross Basin", "uid": "p0000828", "west": null}, {"awards": "0094078 Bart, Philip", "bounds_geometry": "POLYGON((-179.99992 -72.00044,-143.999984 -72.00044,-108.000048 -72.00044,-72.000112 -72.00044,-36.000176 -72.00044,-0.000239999999991 -72.00044,35.999696 -72.00044,71.999632 -72.00044,107.999568 -72.00044,143.999504 -72.00044,179.99944 -72.00044,179.99944 -72.574101,179.99944 -73.147762,179.99944 -73.721423,179.99944 -74.295084,179.99944 -74.868745,179.99944 -75.442406,179.99944 -76.016067,179.99944 -76.589728,179.99944 -77.163389,179.99944 -77.73705,143.999504 -77.73705,107.999568 -77.73705,71.999632 -77.73705,35.999696 -77.73705,-0.000240000000019 -77.73705,-36.000176 -77.73705,-72.000112 -77.73705,-108.000048 -77.73705,-143.999984 -77.73705,-179.99992 -77.73705,-179.99992 -77.163389,-179.99992 -76.589728,-179.99992 -76.016067,-179.99992 -75.442406,-179.99992 -74.868745,-179.99992 -74.295084,-179.99992 -73.721423,-179.99992 -73.147762,-179.99992 -72.574101,-179.99992 -72.00044))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001648", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0301A"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "PROPOSAL NO.: 0094078\u003cbr/\u003ePRINCIPAL INVESTIGATOR: Bart, Philip\u003cbr/\u003eINSTITUTION NAME: Louisiana State University \u0026 Agricultural and Mechanical College\u003cbr/\u003eTITLE: CAREER: Relative frequency and phase of extreme expansions of the Antarctic Ice Sheets during the late Neogene\u003cbr/\u003eNSF RECEIVED DATE: 07/27/2000\u003cbr/\u003e\u003cbr/\u003ePROJECT SUMMARY\u003cbr/\u003e\u003cbr/\u003eExpansions and contractions of the Antarctic Ice Sheets (AISs) have undoubtedly had a profound influence on Earth\u0027s climate and global sea-level. However, rather than being a single entity, the Antarctic cryosphere consists of three primary elements: 1) the East Antarctic Ice Sheet (EAIS); 2) the West Antarctic Ice Sheet (WAIS); and 3) the Antarctic Peninsula Ice Cap (APIC). The distinguishing characteristics include significant differences in: 1) ice volume; 2) substratum elevation; 3) ice-surface elevation; and 4) location with respect to latitude. Various lines of evidence indicate that the AISs have undergone significant fluctuations in the past and that fluctuations will continue to occur in the future. The exact nature of the fluctuations has been the subject of many lively debates. According to one line of reasoning, the land-based EAIS has been relatively stable, experiencing only minor fluctuations since forming in the middle Miocene, whereas the marine-based WAIS has been dynamic, waxing and waning frequently since the late Miocene. According to an alternate hypothesis, the ice sheets advanced and retreated synchronously. These two views are incompatible. \u003cbr/\u003e\u003cbr/\u003eThe first objective of this proposal is to compare the long-term past behavior of the WAIS to that of the EAIS and APIC. The fluctuations of the AISs involve many aspects (the frequency of changes, the overall magnitude of ice-volume change, etc.), and the activities proposed here specifically concern the frequency and phase of extreme advances of the ice sheet to the continental shelf. The project will build upon previous seismic-stratigraphic investigations of the continental shelves. These studies have clarified many issues concerning the minimum frequency of extreme expansions for the individual ice sheets, but some important questions remain. During the course of the project, the following questions will be evaluated.\u003cbr/\u003e\u003cbr/\u003eQuestion 1) Were extreme advances of the EAIS and WAIS across the shelf of a similar frequency and coeval? This evaluation is possible because the western Ross Sea continental shelf (Northern Basin) receives drainage from the EAIS, and the eastern Ross Sea (Eastern Basin) receives drainage from the WAIS. Quantitative analyses of the extreme advances from these two areas have been conducted by Alonso et al. (1992) and Bart et al. (2000), respectively. However, the existing single-channel seismic grids are incomplete and can not be used to determine the stratigraphic correlations from Northern Basin to Eastern Basin. It is proposed that high-resolution seismic data (~2000 kms) be acquired to address this issue.\u003cbr/\u003e\u003cbr/\u003eQuestion 2) Were extreme advances of the APIC across the shelf as frequent as inferred by Bart and Anderson (1995)? Bart and Anderson (1995) inferred that the APIC advanced across the continental shelf at least 30 times since the middle Miocene. This is significant because it suggests that the advances of the small APIC were an order of magnitude more frequent than the advances of the EAIS and WAIS. Others contest the Bart and Anderson (1995) glacial-unconformity interpretation of seismic reflections, and argue that the advances of the APIC were far fewer (i.e., Larter et al., 1997). The recent drilling on the Antarctic Peninsula outer continental shelf has sampled some but not all of the glacial units, but the sediment recovery was poor, and thus, the glacial history interpretation is still ambiguous. The existing high-resolution seismic grids from the Antarctic Peninsula contain only one regional strike line on the outer continental shelf. This is inadequate to address the controversy of the glacial-unconformity interpretation and the regional correlation of the recent ODP results. It is proposed that high-resolution seismic data (~1000 kms) be acquired in a forthcoming (January 2002) cruise to the Antarctic Peninsula to address these issues.\u003cbr/\u003e\u003cbr/\u003eThe second objective of this project is 1) to expand the PI\u0027s effort to integrate his ongoing and the proposed experiments into a graduate-level course at LSU, and 2) to develop a pilot outreach program with a Baton Rouge public high school. The Louisiana Department of Education has adopted scientific standards that apply to all sciences. These standards reflect what 9th through 12th grade-level students should be able to do and know. The PI will target one of these standards, the Science As Inquiry Standard 1 Benchmark. The PI will endeavor to share with the students the excitement of conducting scientific research as a way to encourage the students to pursue earth science as a field of study at the university level.", "east": 179.99944, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -72.00044, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bart, Philip", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -77.73705, "title": "PECASE: Relative frequency and phase of extreme expansions of the Antarctic Ice Sheets during the late Neogene", "uid": "p0000593", "west": -179.99992}, {"awards": "0132032 Detrich, H. William", "bounds_geometry": "POLYGON((-68.84315 -42.87167,-61.576321 -42.87167,-54.309492 -42.87167,-47.042663 -42.87167,-39.775834 -42.87167,-32.509005 -42.87167,-25.242176 -42.87167,-17.975347 -42.87167,-10.708518 -42.87167,-3.441689 -42.87167,3.82514 -42.87167,3.82514 -44.482708,3.82514 -46.093746,3.82514 -47.704784,3.82514 -49.315822,3.82514 -50.92686,3.82514 -52.537898,3.82514 -54.148936,3.82514 -55.759974,3.82514 -57.371012,3.82514 -58.98205,-3.441689 -58.98205,-10.708518 -58.98205,-17.975347 -58.98205,-25.242176 -58.98205,-32.509005 -58.98205,-39.775834 -58.98205,-47.042663 -58.98205,-54.309492 -58.98205,-61.576321 -58.98205,-68.84315 -58.98205,-68.84315 -57.371012,-68.84315 -55.759974,-68.84315 -54.148936,-68.84315 -52.537898,-68.84315 -50.92686,-68.84315 -49.315822,-68.84315 -47.704784,-68.84315 -46.093746,-68.84315 -44.482708,-68.84315 -42.87167))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001655", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0404"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Notothenioid fish are a major group of fish in the Southern Ocean. The ancestral notothenioid fish stock of Antarctica probably arose as a sluggish, bottom-dwelling perciform species that evolved some 40-60 million years ago in the then temperate shelf waters of the Antarctic continent. The grounding of the ice sheet on the continental shelf and changing trophic conditions may have eliminated the taxonomically diverse late Eocene fauna and initiated the original diversification of notothenioids. On the High Antarctic shelf, notothenioids today dominate the ichthyofauna in terms of species diversity, abundance and biomass, the latter two at levels of 90-95%. Since the International Geophysical Year of 1957-58, fish biologists from the Antarctic Treaty nations have made impressive progress in understanding the notothenioid ichthyofauna of the cold Antarctic marine ecosystem. However, integration of this work into the broader marine context has been limited, largely due to lack of access to, and analysis of, specimens of Sub-Antarctic notothenioid fishes. Sub-Antarctic fishes of the notothenioid suborder are critical for a complete understanding of the evolution, population dynamics, eco-physiology, and eco-biochemistry of their Antarctic relatives. This project will support an international, collaborative research cruise to collect and study fish indigenous to sub-antarctic habitats. The topics included in the research plans of the international team of researchers includes Systematics and Evolutionary Studies; Life History Strategies and Population Dynamics; Physiological, Biochemical, and Molecular Biological Investigations of Major Organ and Tissue Systems; Genomic Resources for the Sub-Antarctic Notothenioids; and Ecological Studies of Transitional Benthic Invertebrates. In a world that is experiencing changes in global climate, the loss of biological diversity, and the depletion of marine fisheries, the Antarctic, Sub-Antarctic, and their biota offer compelling natural laboratories for understanding the evolutionary impacts of these processes. The proposed work will contribute to development of a baseline understanding of these sensitive ecosystems, one against which future changes in species distribution and survival may be evaluated judiciously.", "east": 3.82514, "geometry": "POINT(-32.509005 -50.92686)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -42.87167, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Detrich, H. William", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -58.98205, "title": "International Collaborative Expedition to Collect and Study Fish Indigenous to Sub-Antarctic Habitats", "uid": "p0000584", "west": -68.84315}, {"awards": "0440775 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "Amundsen Sea Continental Shelf Mooring Data (2006-2007); Expedition data of NBP0702; NBP0702 surface sediment sample information and images", "datasets": [{"dataset_uid": "002645", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0702", "url": "https://www.rvdata.us/search/cruise/NBP0702"}, {"dataset_uid": "601809", "doi": "10.15784/601809", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Mooring; Ocean Currents; Pressure; Salinity; Temperature", "people": "Giulivi, Claudia F.; Jacobs, Stanley", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Continental Shelf Mooring Data (2006-2007)", "url": "https://www.usap-dc.org/view/dataset/601809"}, {"dataset_uid": "601473", "doi": "10.15784/601473", "keywords": "Amundsen Sea; Antarctica; Marine Geoscience; Marine Sediments; NBP0702; Photo; R/v Nathaniel B. Palmer; Seafloor Sampling; Sediment Description; Smith-Mcintyre Grab", "people": "Jacobs, Stanley; Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "NBP0702 surface sediment sample information and images", "url": "https://www.usap-dc.org/view/dataset/601473"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This collaborative study between Columbia University and the Southampton Oceanography Centre will investigate the dynamics of warm water intrusions under antarctic floating ice shelves. The study will focus on the Amundsen Sea and Pine Island Glacier, and will document how this water gains access to the continental shelf, transports heat into the ice shelf cavities via deep, glacially-scoured troughs, and rises beneath the ice to drive basal melting. The resulting seawater-meltwater mixtures upwell near the ice fronts, contributing to the formation of atypical coastal polynyas with strong geochemical signatures. Multidecadal freshening downstream is consistent with thinning ice shelves, which may be triggering changes inland, increasing the flow of grounded ice into the sea. This work will be carried out in combination with parallel modeling, remote sensing and data based projects, in an effort to narrow uncertainties about the response of West Antarctic Ice Sheet to climate change. Using state-of-the-art facilities and instruments, this work will enhance knowledge of water mass production and modification, and the understanding of interactions between the ocean circulation, sea floor and ice shelves. The data and findings will be reported to publicly accessible archives and submitted for publication in the scientific literature. The information obtained should prove invaluable for the development and validation of general circulation models, needed to predict the future role of the Antarctic Ice Sheet in sea level change.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "AMD; Amd/Us; R/V NBP; NSF/USA; Amundsen Sea; USAP-DC", "locations": "Amundsen Sea", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "The Amundsen Continental Shelf and the Antarctic Ice Sheet", "uid": "p0000836", "west": null}, {"awards": "0003619 Dalziel, Ian", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG9810", "datasets": [{"dataset_uid": "002092", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG9810"}, {"dataset_uid": "002678", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9810", "url": "https://www.rvdata.us/search/cruise/LMG9810"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program to initiate a Global Positioning System (GPS) network to measure crustal motions in the bedrock surrounding and underlying the West Antarctic Ice Sheet (WAIS). Evaluation of the role of both tectonic and ice-induced crustal motions of the WAIS bedrock is a critical goal for understanding past, present, and future dynamics of WAIS and its potential role in future global change scenarios, as well as improving our understanding of the role of Antarctica in global plate motions. The extent of active tectonism in West Antarctica is largely speculative, as few data exist that constrain its geographic distribution, directions, or rates of deformation. Active tectonism and the influence of bedrock on the WAIS have been highlighted recently by geophysical data indicating active subglacial volcanism and control of ice streaming by the presence of sedimentary basins. The influence of bedrock crustal motion on the WAIS and its future dynamics is a fundamental issue. Existing GPS projects are located only on the fringe of the ice sheet and do not address the regional picture. It is important that baseline GPS measurements on the bedrock around and within the WAIS be started so that a basis is established for detecting change.\u003cbr/\u003e\u003cbr/\u003eTo measure crustal motions, this project will build a West Antarctica GPS Network (WAGN) of at least 15 GPS sites across the interior of West Antarctica (approximately the size of the contiguous United States from the Rocky Mountains to the Pacific coast) over a two-year period beginning in the Antarctic field season 2001-2002. The planned network is designed using the Multi-modal Occupation Strategy (MOST), in which a small number of independent GPS \"roving\" receivers make differential measurements against a network of continuous GPS stations for comparatively short periods at each site. This experimental strategy, successfully implemented by a number of projects in California, S America, the SW Pacific and Central Asia, minimizes logistical requirements, an essential element of application of GPS geodesy in the scattered and remote outcrops of the WAIS bedrock.\u003cbr/\u003e\u003cbr/\u003eThe WAGN program will be integrated with the GPS network that has been established linking the Antarctic Peninsula with South America through the Scotia arc (Scotia Arc GPS Project (SCARP)). It will also interface with stations currently measuring motion across the Ross Embayment, and with the continent-wide GIANT program of the Working Group on Geodesy and Geographic Information Systems of the Scientific Committee on Antarctic Research (SCAR). The GPS network will be based on permanent monuments set in solid rock outcrops that will have near-zero set-up error for roving GPS occupations, and that can be directly converted to a continuous GPS site when future technology makes autonomous operation and satellite data linkage throughout West Antarctica both reliable and economical. The planned network both depends on and complements the existing and planned continuous networks. It is presently not practical, for reasons of cost and logistics, to accomplish the measurements proposed herein with either a network of continuous stations or traditional campaigns.\u003cbr/\u003e\u003cbr/\u003eThe proposed WAGN will complement existing GPS projects by filling a major gap in coverage among several discrete crustal blocks that make up West Antarctica, a critical area of potential bedrock movements. If crustal motions are relatively slow, meaningful results will only begin to emerge within the five-year maximum period of time for an individual funded project. Hence this proposal is only to initiate the network and test precision and velocities at the most critical sites. Once built, however, the network will yield increasingly meaningful results with the passage of time. Indeed, the slower the rates turn out to be, the more important an early start to measuring. It is anticipated that the results of this project will initiate an iterative process that will gradually resolve into an understanding of the contributions from plate rotations and viscoelastic and elastic motions resulting from deglaciation and ice mass changes. Velocities obtained from initial reoccupation of the most critical sites will dictate the timing of a follow-up proposal for reoccupation of the entire network when detectable motions have occurred.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Dalziel, Ian W.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: A GPS Network to Determine Crustal Motions in the Bedrock of the West Antarctic Ice Sheet: Phase I - Installation", "uid": "p0000859", "west": null}, {"awards": "9814692 Kellogg, Thomas", "bounds_geometry": "POLYGON((-179.99342 -58.74225,-143.994734 -58.74225,-107.996048 -58.74225,-71.997362 -58.74225,-35.998676 -58.74225,0.000010000000003 -58.74225,35.998696 -58.74225,71.997382 -58.74225,107.996068 -58.74225,143.994754 -58.74225,179.99344 -58.74225,179.99344 -60.716231,179.99344 -62.690212,179.99344 -64.664193,179.99344 -66.638174,179.99344 -68.612155,179.99344 -70.586136,179.99344 -72.560117,179.99344 -74.534098,179.99344 -76.508079,179.99344 -78.48206,143.994754 -78.48206,107.996068 -78.48206,71.997382 -78.48206,35.998696 -78.48206,0.000010000000003 -78.48206,-35.998676 -78.48206,-71.997362 -78.48206,-107.996048 -78.48206,-143.994734 -78.48206,-179.99342 -78.48206,-179.99342 -76.508079,-179.99342 -74.534098,-179.99342 -72.560117,-179.99342 -70.586136,-179.99342 -68.612155,-179.99342 -66.638174,-179.99342 -64.664193,-179.99342 -62.690212,-179.99342 -60.716231,-179.99342 -58.74225))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001992", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0001"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a marine geological investigation of the Amundsen Sea region toward a better understanding of the deglaciation history of the West Antarctic Ice Sheet (WAIS). The WAIS may be inherently unstable because it is the last marine-based ice sheet in the world. Unlike other embayments in West Antarctica, major ice streams draining into the Amundsen Sea from the interior of the WAIS lack buttressing ice shelves. Mass balance data for the distal portions of these ice streams (Pine Island and Thwaites glaciers) appear to be in balance or may be becoming negative. Because both ice streams have beds that slope downward toward the center of the ice sheet, grounding-line recession resulting from either continued thinning or sea-level rise could trigger irreversible grounding-line retreat, leading to ice-sheet disintegration and consequent global sea-level rise. The limited marine geological and geophysical data available from the Amundsen Sea suggest that grounded ice or an ice shelf occupied the inner Amundsen Sea embayment until perhaps as recently as 1000 to 2000 years ago, and this ice may have retreated rapidly in historic time. This project, a study of the marine geology and geophysics of the Amundsen Sea continental shelf from 100 degrees W to 130 degrees W, is designed to address the Amundsen Sea part of WAIS Science Plan Priority Goal H2: \"What is the deglaciation history in the eastern Ross, the Bellingshausen and Amundsen Seas?\" This project will examine bathymetric data of the Amundsen Sea continental shelf to determine the positions of former ice-steam channels, and to aid in choosing sites for sediment coring. Single-channel seismic reflection studies will be conducted in order to determine sediment-thickness patterns, to aid in choice of coring sites, and to locate and identify morphologic features indicative of former grounded ice (e.g., moraines, scours, flutes, striations, till wedges and deltas, etc.). Coring will be concentrated along former ice flow-lines. Core samples will be analyzed in the laboratory for sedimentology, to determine whether of not basal tills are present (indicating former grounded ice and its former extent), and for calcareous and siliceous microfossils. The chronology of grounding-line and ice-shelf retreat from a presumed Last Glacial Maximum position near the shelf break will be established using accelerator mass spectrometry (AMS) carbon-14 dates of acid-insoluble particulate organic carbon. This project will share ship time in the Amundsen Sea with a physical oceanographic project. Marine geologic data and samples collected will be integrated with findings of other investigators toward developing a comprehensive interpretation of the history of the WAIS.", "east": 179.99344, "geometry": "POINT(0.000010000000003 -68.612155)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -58.74225, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kellogg, Thomas; Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -78.48206, "title": "Glacial History of the Amundsen Sea Shelf", "uid": "p0000620", "west": -179.99342}, {"awards": "0088143 Luyendyk, Bruce; 0087392 Bartek, Louis", "bounds_geometry": "POLYGON((-179.99786 -75.91667,-143.99852 -75.91667,-107.99918 -75.91667,-71.99984 -75.91667,-36.0005 -75.91667,-0.00115999999997 -75.91667,35.99818 -75.91667,71.99752 -75.91667,107.99686 -75.91667,143.9962 -75.91667,179.99554 -75.91667,179.99554 -76.183531,179.99554 -76.450392,179.99554 -76.717253,179.99554 -76.984114,179.99554 -77.250975,179.99554 -77.517836,179.99554 -77.784697,179.99554 -78.051558,179.99554 -78.318419,179.99554 -78.58528,143.9962 -78.58528,107.99686 -78.58528,71.99752 -78.58528,35.99818 -78.58528,-0.00116000000003 -78.58528,-36.0005 -78.58528,-71.99984 -78.58528,-107.99918 -78.58528,-143.99852 -78.58528,-179.99786 -78.58528,-179.99786 -78.318419,-179.99786 -78.051558,-179.99786 -77.784697,-179.99786 -77.517836,-179.99786 -77.250975,-179.99786 -76.984114,-179.99786 -76.717253,-179.99786 -76.450392,-179.99786 -76.183531,-179.99786 -75.91667))", "dataset_titles": "Expedition Data; NBP0301 data; NBP0306 data", "datasets": [{"dataset_uid": "000105", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0306 data", "url": "https://www.rvdata.us/search/cruise/NBP0306"}, {"dataset_uid": "001724", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0301"}, {"dataset_uid": "001668", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0306"}, {"dataset_uid": "000104", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0301 data", "url": "https://www.rvdata.us/search/cruise/NBP0301"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Luyendyk et.al.: OPP 0088143\u003cbr/\u003eBartek: OPP 0087392\u003cbr/\u003eDiebold: OPP 0087983\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program in marine geology and geophysics in the southern central and eastern Ross Sea. The project will conduct sites surveys for drilling from the Ross Ice Shelf into the seafloor beneath it. Many of the outstanding problems concerning the evolution of the East and West Antarctic Ice Sheets, Antarctic climate, global sea level, and the tectonic history of the West Antarctic Rift System can be addressed by drilling into the seafloor of the Ross Sea. Climate data for Cretaceous and Early Cenozoic time are lacking for this sector of Antarctica. Climate questions include: Was there any ice in Late Cretaceous time? What was the Antarctic climate during the Paleocene-Eocene global warming? When was the Cenozoic onset of Antarctic glaciation, when did glaciers reach the coast and when did they advance out onto the margin? Was the Ross Sea shelf non-marine in Late Cretaceous time; when did it become marine? Tectonic questions include: What was the timing of the Cretaceous extension in the Ross Sea rift; where was it located? What is the basement composition and structure? Where are the time and space limits of the effects of Adare Trough spreading? Another drilling objective is to sample and date the sedimentary section bounding the mapped RSU6 unconformity in the Eastern Basin and Central Trough to resolve questions about its age and regional extent. Deep Sea Drilling Project (DSDP) Leg 28 completed sampling at four drill sites in the early 1970\u0027s but had low recovery and did not sample the Early Cenozoic. Other drilling has been restricted to the McMurdo Sound area of the western Ross Sea and results can be correlated into the Victoria Land Basin but not eastward across basement highs. Further, Early Cenozoic and Cretaceous rocks have not been sampled. A new opportunity is developing to drill from the Ross Ice Shelf. This is a successor program to the Cape Roberts Drilling Project. One overriding difficulty is the need for site surveys at drilling locations under the ice shelf. This project will overcome this impediment by conducting marine geophysical drill site surveys at the front of the Ross Ice Shelf in the Central Trough and Eastern Basin. The surveys will be conducted a kilometer or two north of the ice shelf front where recent calving events have resulted in a southerly position of the ice shelf edge. In several years the northward advance of the ice shelf will override the surveyed locations and drilling could be accomplished. Systems to be used include swath bathymetry, gravity, magnetics, chirp sonar, high resolution seismic profiling, and 48 fold seismics. Cores will be collected to obtain samples for geotechnical properties, to study sub-ice shelf modern sedimentary processes, and at locations where deeper section is exposed.\u003cbr/\u003e\u003cbr/\u003eThis survey will include long profiles and detailed grids over potential drill sites. Survey lines will be tied to existing geophysical profiles and DSDP 270. A recent event that makes this plan timely is the calving of giant iceberg B-15 (in March, 2000) and others from the ice front in the eastern Ross Sea. This new calving event and one in 1987 have exposed 16,000 square kilometers of seafloor that had been covered by ice shelf for decades and is not explored. Newly exposed territory can now be mapped by modern geophysical methods. This project will map geological structure and stratigraphy below unconformity RSU6 farther south and east, study the place of Roosevelt Island in the Ross Sea rifting history, and determine subsidence history during Late Cenozoic time (post RSU6) in the far south and east. Finally the project will observe present day sedimentary processes beneath the ice shelf in the newly exposed areas.", "east": 179.99554, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "R/V NBP", "locations": null, "north": -75.91667, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bartek, Louis; Luyendyk, Bruce P.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -78.58528, "title": "Collaborative Research: Antarctic Cretaceous-Cenozoic Climate, Glaciation, and Tectonics: Site surveys for drilling from the edge of the Ross Ice Shelf", "uid": "p0000425", "west": -179.99786}, {"awards": "9119683 Anderson, John", "bounds_geometry": "POLYGON((-179.999 -72.1543,-143.9991 -72.1543,-107.9992 -72.1543,-71.9993 -72.1543,-35.9994 -72.1543,0.000500000000017 -72.1543,36.0004 -72.1543,72.0003 -72.1543,108.0002 -72.1543,144.0001 -72.1543,180 -72.1543,180 -72.72384,180 -73.29338,180 -73.86292,180 -74.43246,180 -75.002,180 -75.57154,180 -76.14108,180 -76.71062,180 -77.28016,180 -77.8497,144.0001 -77.8497,108.0002 -77.8497,72.0003 -77.8497,36.0004 -77.8497,0.000499999999988 -77.8497,-35.9994 -77.8497,-71.9993 -77.8497,-107.9992 -77.8497,-143.9991 -77.8497,-179.999 -77.8497,-179.999 -77.28016,-179.999 -76.71062,-179.999 -76.14108,-179.999 -75.57154,-179.999 -75.002,-179.999 -74.43246,-179.999 -73.86292,-179.999 -73.29338,-179.999 -72.72384,-179.999 -72.1543))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002241", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9501"}, {"dataset_uid": "002258", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9401"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Marine geological and geophysical studies of the Ross Sea and Weddell Sea continental shelves provide evidence that the ice sheet grounded near the shelf edge in these areas during the late Wisconsinan, and that the retreat of the ice sheet to its present position was rapid and probably episodic. This Award supports a project which will establish the most recent (late Wisconsin- Holocene) history of ice sheet advance and retreat in Ross Sea. The objectives include: 1) reconstruction the late Wisconsin paleodrainage regime, including ice stream divides; 2) reconstruction of former grounding zone positions; 3) constraint of the timing of ice sheet retreat from the shelf; and 4) acquisition of geophysical, sedimentological, and paleontological data which may provide indicators the environmental factors that may have influenced to ice sheet retreat. This is a joint effort between Rice University, the University of Colorado, and Hamilton College. The project involves experts in a wide variety of fields, and will interface with glaciologists, physical oceanographers and climatologists who will address the problem of ice sheet stability and the record of climatic and glaciological change.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -72.1543, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -77.8497, "title": "Geologic Record of Late Wisconsinan/Holocene Ice Sheet Advance and Retreat from Ross Sea", "uid": "p0000641", "west": -179.999}, {"awards": "0125480 Manley, Patricia", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0602A", "datasets": [{"dataset_uid": "001571", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}, {"dataset_uid": "002618", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0602A", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: SHALDRIL - A Demonstration Drilling Cruise to the James Ross Basin", "uid": "p0000830", "west": null}, {"awards": "9316710 Bartek, Louis", "bounds_geometry": "POLYGON((-179.9993 -75.77948,-143.99945 -75.77948,-107.9996 -75.77948,-71.99975 -75.77948,-35.9999 -75.77948,-0.000049999999987 -75.77948,35.9998 -75.77948,71.99965 -75.77948,107.9995 -75.77948,143.99935 -75.77948,179.9992 -75.77948,179.9992 -76.012273,179.9992 -76.245066,179.9992 -76.477859,179.9992 -76.710652,179.9992 -76.943445,179.9992 -77.176238,179.9992 -77.409031,179.9992 -77.641824,179.9992 -77.874617,179.9992 -78.10741,143.99935 -78.10741,107.9995 -78.10741,71.99965 -78.10741,35.9998 -78.10741,-0.000050000000016 -78.10741,-35.9999 -78.10741,-71.99975 -78.10741,-107.9996 -78.10741,-143.99945 -78.10741,-179.9993 -78.10741,-179.9993 -77.874617,-179.9993 -77.641824,-179.9993 -77.409031,-179.9993 -77.176238,-179.9993 -76.943445,-179.9993 -76.710652,-179.9993 -76.477859,-179.9993 -76.245066,-179.9993 -76.012273,-179.9993 -75.77948))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002168", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9601"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award supports a collaborative marine geological and geophysical project between the University of California, Santa Barbara, and the University of Alabama to study the glacial and tectonic history of the eastern Ross Sea and the Marie Byrd Land margin of West Antarctica. The goals of the project are (1) to conduct seismic imaging and piston coring to begin unraveling the history of the West Antarctic ice Sheet as recorded in the recent sediments of the continental shelf of the region, and (2) to acquire seismic images of the acoustic basement beneath the Cenozoic glacial deposits toward an understanding of the relationship between rift structure of the continental crust and Cenozoic glacial deposits of the region. This research will result in bathymetric, structural, sediment isopach, gravity and magnetic maps of the eastern Ross Sea and the Marie Byrd Land margin. This information will be integrated into an interpretation of the major glacial and structural features of the region. This project will result in a better understanding of the glacio-marine stratigraphy and glacial history of the eastern Ross Sea and Marie Byrd Land margin and, consequently, it will represent a significant contribution to the goals of the West Antarctic Ice Sheet initiative.", "east": 179.9992, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -75.77948, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bartek, Louis; Luyendyk, Bruce P.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -78.10741, "title": "Collaborative Research: Glacial Marine Stratigraphy in the Eastern Ross Sea and Western Marie Byrd Land, and Shallow Structure of the West Antarctic Rift", "uid": "p0000639", "west": -179.9993}, {"awards": "0837988 Steig, Eric", "bounds_geometry": "POLYGON((-180 -65,-144 -65,-108 -65,-72 -65,-36 -65,0 -65,36 -65,72 -65,108 -65,144 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.5,-180 -85,-180 -82.5,-180 -80,-180 -77.5,-180 -75,-180 -72.5,-180 -70,-180 -67.5,-180 -65))", "dataset_titles": "West Antarctica Ice Core and Climate Model Data", "datasets": [{"dataset_uid": "609536", "doi": "10.7265/N5QJ7F8B", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Paleoclimate; WAIS Divide", "people": "Steig, Eric J.", "repository": "USAP-DC", "science_program": null, "title": "West Antarctica Ice Core and Climate Model Data", "url": "https://www.usap-dc.org/view/dataset/609536"}], "date_created": "Fri, 30 Apr 2010 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). \u003cbr/\u003e\u003cbr/\u003eThis award supports a project to reconstruct the past physical and chemical climate of Antarctica, with an emphasis on the region surrounding the Ross Sea Embayment, using \u003e60 ice cores collected in this region by US ITASE and by Australian, Brazilian, Chilean, and New Zealand ITASE teams. The ice core records are annually resolved and exceptionally well dated, and will provide, through the analyses of stable isotopes, major soluble ions and for some trace elements, instrumentally calibrated proxies for past temperature, precipitation, atmospheric circulation, chemistry of the atmosphere, sea ice extent, and volcanic activity. These records will be used to understand the role of solar, volcanic, and human forcing on Antarctic climate and to investigate the character of recent abrupt climate change over Antarctica in the context of broader Southern Hemisphere and global climate variability. The intellectual merit of the project is that ITASE has resulted in an array of ice core records, increasing the spatial resolution of observations of recent Antarctic climate variability by more than an order of magnitude and provides the basis for assessment of past and current change and establishes a framework for monitoring of future climate change in the Southern Hemisphere. This comes at a critical time as global record warming and other impacts are noted in the Southern Ocean, the Antarctic Peninsula, and on the Antarctic ice sheet. The broader impacts of the project are that Post-doctoral and graduate students involved in the project will benefit from exposure to observational and modeling approaches to climate change research and working meetings to be held at the two collaborating institutions plus other prominent climate change institutions. The results are of prime interest to the public and the media Websites hosted by the two collaborating institutions contain climate change position papers, scientific exchanges concerning current climate change issues, and scientific contribution series.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Deuterium Isotopes; Deuterium Excess; Not provided; GROUND-BASED OBSERVATIONS; Wais Divide-project", "locations": null, "north": -65.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Antarctic Climate Reconstruction Utilizing the US ITASE Ice Core Array (2009- 2012)", "uid": "p0000180", "west": -180.0}, {"awards": "0632250 Cary, Stephen", "bounds_geometry": "POLYGON((-38.5 -72.6,-23.963 -72.6,-9.426 -72.6,5.111 -72.6,19.648 -72.6,34.185 -72.6,48.722 -72.6,63.259 -72.6,77.796 -72.6,92.333 -72.6,106.87 -72.6,106.87 -73.185,106.87 -73.77,106.87 -74.355,106.87 -74.94,106.87 -75.525,106.87 -76.11,106.87 -76.695,106.87 -77.28,106.87 -77.865,106.87 -78.45,92.333 -78.45,77.796 -78.45,63.259 -78.45,48.722 -78.45,34.185 -78.45,19.648 -78.45,5.111 -78.45,-9.426 -78.45,-23.963 -78.45,-38.5 -78.45,-38.5 -77.865,-38.5 -77.28,-38.5 -76.695,-38.5 -76.11,-38.5 -75.525,-38.5 -74.94,-38.5 -74.355,-38.5 -73.77,-38.5 -73.185,-38.5 -72.6))", "dataset_titles": "Metagenomic Data Lake Vostok Microbial Community", "datasets": [{"dataset_uid": "000136", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Metagenomic Data Lake Vostok Microbial Community", "url": "http://www.ncbi.nlm.nih.gov/genbank/"}], "date_created": "Fri, 30 Apr 2010 00:00:00 GMT", "description": "This project brings together researchers with expertise in molecular microbial ecology, Antarctic and deep sea environments, and metagenomics to address the overarching question: how do ecosystems dominated by microorganisms adapt to conditions of continuous cold and dark over evolutionarily and geologically relevant time scales? Lake Vostok, buried for at least 15 million years beneath approximately 4 km of ice that has prevented any communication with the external environment for as much as 1.5 million years, is an ideal system to study this question. Water from the lake that has frozen on to the bottom of the ice sheet (accretion ice) is available for study. Several studies have indicated the presence of low abundance, but detectable microbial communities in the accretion ice. Our central hypothesis maintains that Lake Vostok microbes are specifically adapted to life in conditions of extreme cold, dark, and oligotrophy and that signatures of those adaptations can be observed in their genome sequences at the gene, organism, and community levels. To address this hypothesis, we propose to characterize the metagenome (i.e. the genomes of all members of the community) of the accretion ice. using whole genome amplification (WGA), which can provide micrograms of unbiased metagenomic DNA from only a few cells. The results of this project have relevance to evolutionary biology and ecology, subglacial Antarctic lake exploration, biotechnology, and astrobiology. The project directly addresses priorities and themes in the International Polar Year at the national and international levels. A legacy of DNA sequence data and the metagenomic library will be created and maintained. Press releases and a publicly available web page will facilitate communication with the public. K-12 outreach will be the focus of a new, two-tiered program targeting the 7th grade classroom and on site visits to the Joint Genome Institute Production Sequencing Facility by high school juniors and seniors and community college level students. Minority undergraduate researchers will be recruited for research on this project, and support and training are provided to two graduate students, a postdoctoral scholar, and a technician.", "east": 106.87, "geometry": "POINT(34.185 -75.525)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -72.6, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cary, Stephen", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -78.45, "title": "IPY: Collaborative Research: A Metagenomic Investigation of Adaptation to Prolonged Cold and Dark Conditions of the Lake Vostok Microbial Community", "uid": "p0000201", "west": -38.5}, {"awards": "0335330 Waddington, Edwin", "bounds_geometry": "POLYGON((-60 83,-55.8 83,-51.6 83,-47.4 83,-43.2 83,-39 83,-34.8 83,-30.6 83,-26.4 83,-22.2 83,-18 83,-18 80.5,-18 78,-18 75.5,-18 73,-18 70.5,-18 68,-18 65.5,-18 63,-18 60.5,-18 58,-22.2 58,-26.4 58,-30.6 58,-34.8 58,-39 58,-43.2 58,-47.4 58,-51.6 58,-55.8 58,-60 58,-60 60.5,-60 63,-60 65.5,-60 68,-60 70.5,-60 73,-60 75.5,-60 78,-60 80.5,-60 83))", "dataset_titles": "Borehole Optical Stratigraphy Modeling, Antarctica", "datasets": [{"dataset_uid": "609468", "doi": "10.7265/N5H70CR5", "keywords": "Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Modeling Code", "people": "Waddington, Edwin D.; Fudge, T. J.; Hawley, Robert L.; Smith, Ben", "repository": "USAP-DC", "science_program": null, "title": "Borehole Optical Stratigraphy Modeling, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609468"}], "date_created": "Thu, 01 Apr 2010 00:00:00 GMT", "description": "This award supports a study of the physical nature and environmental origin of optical features (light and dark zones) observed by video in boreholes in polar ice. These features appear to include an annual signal, as well as longer period signals. Borehole logs exist from a previous project, and in this lab-based project the interpretation of these logs will be improved. The origin of the features is of broad interest to the ice-core community. If some components relate to changes in the depositional environment beyond seasonality, important climatic cycles may be seen. If some components relate to post-depositional reworking, insights will be gained into the physical processes that change snow and firn, and the implications for interpretation of the chemical record in terms of paleoclimate. In order to exploit these features to best advantage in future ice-core and climate-change research, the two principal objectives of this project are to determine what physically causes the optical differences that we see and to determine the environmental processes that give rise to these physical differences. In the laboratory at NICL the conditions of a log of a borehole wall will be re-created as closely as possible by running the borehole video camera along sections of ice core, making an optical log of light reflected from the core. Combinations of physical variables that are correlated with optical features will be identified. A radiative-transfer model will be used to aid in the interpretation of these measurements, and to determine the optimum configuration for an improved future logging tool. An attempt will be made to determine the origin of the features. Two broad possibilities exist: 1) temporal changes in the depositional environment, and 2) post-depositional reworking. This project represents an important step toward a new way of learning about paleoclimate with borehole optical methods. Broader impacts include enhancing the infrastructure for research and education, since this instrument will complement high-resolution continuous-melter chemistry techniques and provide a rapid way to log physical variables using optical features as a proxy for climate signals. Since no core is required for this method, it can be used in rapidly drilled access holes or where core quality is poor. This project will support a graduate student who will carry out this project under the direction of the Principal Investigator. K-12 education will be enhanced through an ongoing collaboration with a science and math teacher from a local middle school. International collaboration will be expanded through work on this project with colleagues at the Norwegian Polar Institute and broad dissemination of results will occur through a project website for the general public.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e OPTICAL DUST LOGGERS", "is_usap_dc": true, "keywords": "Ice; Stratigraphy; Optical; Glaciers; Polar Ice; Ice Microphysics; Snow; Firn; Climate Change; LABORATORY; Snow Stratigraphy; Borehole", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Smith, Ben; Waddington, Edwin D.; Hawley, Robert L.; Fudge, T. J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Borehole Optical Stratigraphy: Ice Microphysics, Climate Change, and the Optical Properties of Firn", "uid": "p0000016", "west": -180.0}, {"awards": "0440666 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": "Histories of Accumulation, Thickness, and WAIS Divide Location, Antarctica", "datasets": [{"dataset_uid": "609473", "doi": "10.7265/N5QR4V2J", "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; WAIS Divide; WAIS Divide Ice Core", "people": "Koutnik, Michelle; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Histories of Accumulation, Thickness, and WAIS Divide Location, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609473"}], "date_created": "Thu, 04 Mar 2010 00:00:00 GMT", "description": "This award supports development of a new modeling approach that will extract information about past snow accumulation rate in both space and time in the vicinity of the future ice core near the Ross-Amundsen divide of the West Antarctic Ice Sheet (WAIS). Internal layers, detected by ice-penetrating radar, are isochrones, or former ice-sheet surfaces that have been buried by subsequent snowfall, and distorted by ice flow. Extensive ice-penetrating radar data are available over the inland portion of the WAIS. Layers have been dated back to 17,000 years before present. The radar data add the spatial dimension to the temporally resolved accumulation record from ice cores. Accumulation rates are traditionally derived from the depths of young, shallow layers, corrected for strain using a local 1-D ice-flow model. Older, deeper layers have been more affected by flow over large horizontal distances. However, it is these deeper layers that contain information on longer-term climate patterns. This project will use geophysical inverse theory and a 2.5D flow-band ice-flow forward model comprising ice-surface and layer-evolution modules, to extract robust transient accumulation patterns by assimilating multiple deeper, more-deformed layers that have previously been intractable. Histories of divide migration, geothermal flux, and surface evolution will also be produced. The grant will support the PhD research of a female graduate student who is a mentor to female socio-economically disadvantaged high-school students interested in science, through the University of Washington Women\u0027s Center. It will also provide a research\u003cbr/\u003eexperience for an undergraduate student, and contribute to a freshman seminar on Scientific Research.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS", "is_usap_dc": true, "keywords": "Ross-Amundsen Divide; FIELD SURVEYS; Internal Layers; Ice Flow Model; West Antarctic Ice Sheet; Accumulation; Glacier; Ice Penetrating Radar; Model; MODELS; Snow Accumulation; GPS; Antarctica; Isochron; Not provided; Snowfall; Radar", "locations": "West Antarctic Ice Sheet; Antarctica; Ross-Amundsen Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e MODELS; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach", "uid": "p0000018", "west": null}, {"awards": "9980379 Baker, Ian", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 15 Feb 2010 00:00:00 GMT", "description": "This award is for support for three years of funding to study the effects of impurities on the flow of poly- crystalline ice. It has been known for thirty years that both hydrofluoric acid (HF) and hydrochloric acid (HCl) dramatically decrease the strength of ice and recent work by the author\u0027s group has shown that sulfuric acid (H2SO4) produces a similar reduction in strength. However, these data are for single crystals at strain rates and stresses that far exceed those found in glaciers and ice sheets, and often at concentrations that far exceed those in natural ice. Therefore, it is not known how impurities found in nature affect the flow of polycrystalline ice at slow strain rates. In this research, the effects of nitric acid and sulfuric acid (which are naturally occurring impurities in ice) on the microstructure (dislocation structure, grain boundary structure and location of the acids) and creep of polycrystalline ice (at a range of temperatures and stresses) will be determined. The ice\u0027s response to creep deformation will be studied using a combination of x-ray topography, optical microscopy and scanning electron microscopy. X-ray microanalysis in an environmental scanning electron microscope will be used to study the location of impurities. The structure and creep behavior of the acid-doped ice will be compared with those of both high-purity laboratory-grown ice and ice from Byrd Station, Antarctica. The end-result of this project will be to elucidate the effects of naturally-occurring acid impurities on the mechanical properties of polycrystalline ice under conditions relevant to the deformation of glaciers and ice sheets, including and understanding of how impurities affect the underlying deformation mechanisms.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PARTICLE DETECTORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": true, "keywords": "Ice Core Data; Ice Core; Microstructure; Ice Sheet; Ice Core Chemistry; Antarctic Ice Sheet; LABORATORY", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Obbard, Rachel", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "The Effects of Impurities on the Flow of Polycrystalline Ice", "uid": "p0000015", "west": null}, {"awards": "0440817 Taylor, Kendrick", "bounds_geometry": null, "dataset_titles": "WAIS Divide Ice Core Images, Antarctica", "datasets": [{"dataset_uid": "609375", "doi": "10.7265/N5348H8T", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Optical Images; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "McGwire, Kenneth C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Images, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609375"}], "date_created": "Wed, 10 Feb 2010 00:00:00 GMT", "description": "This award supports the coordination of an interdisciplinary and multi institutional deep ice coring program in West Antarctica. The program will develop interrelated climate, ice dynamics, and biologic records focused on understanding interactions of global earth systems. The records will have a year-by-year chronology for the most recent 40,000 years. Lower temporal resolution records will extend to 100,000 years before present. The intellectual activity of this project includes enhancing our understanding of the natural mechanisms that cause climate change. The study site was selected to obtain the best possible material, available from anywhere, to determine the role of greenhouse gas in the last series of major climate changes. The project will study the how natural changes in greenhouse gas concentrations influence climate. The influence of sea ice and atmospheric circulation on climate changes will also be investigated. Other topics that will be investigated include the influence of the West Antarctic ice sheet on changes in sea level and the biology deep in the ice sheet. The broader impacts of this project include developing information required by other science communities to improve predictions of future climate change. The \u003cbr/\u003eproject will use mass media to explain climate, glaciology, and biology issues to a broad audience. The next generation of ice core investigators will be trained and there will be an emphasis on exposing a diverse group of students to climate, glaciology and biology research.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Antarctica; Not provided; Ice Core Data; West Antarctica; LABORATORY; Ice Core; FIELD INVESTIGATION", "locations": "Antarctica; West Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McGwire, Kenneth C.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Investigation of Climate, Ice Dynamics and Biology using a Deep Ice Core from the West Antarctic Ice Sheet Ice Divide", "uid": "p0000182", "west": null}, {"awards": "0230285 Wilson, Terry", "bounds_geometry": "POLYGON((152.833 -75.317,154.4897 -75.317,156.1464 -75.317,157.8031 -75.317,159.4598 -75.317,161.1165 -75.317,162.7732 -75.317,164.4299 -75.317,166.0866 -75.317,167.7433 -75.317,169.4 -75.317,169.4 -75.9186,169.4 -76.5202,169.4 -77.1218,169.4 -77.7234,169.4 -78.325,169.4 -78.9266,169.4 -79.5282,169.4 -80.1298,169.4 -80.7314,169.4 -81.333,167.7433 -81.333,166.0866 -81.333,164.4299 -81.333,162.7732 -81.333,161.1165 -81.333,159.4598 -81.333,157.8031 -81.333,156.1464 -81.333,154.4897 -81.333,152.833 -81.333,152.833 -80.7314,152.833 -80.1298,152.833 -79.5282,152.833 -78.9266,152.833 -78.325,152.833 -77.7234,152.833 -77.1218,152.833 -76.5202,152.833 -75.9186,152.833 -75.317))", "dataset_titles": null, "datasets": null, "date_created": "Sat, 12 Dec 2009 00:00:00 GMT", "description": "OPP-0230285/OPP-0230356\u003cbr/\u003ePIs: Wilson, Terry J./Hothem, Larry D.\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to conduct GPS measurements of bedrock crustal motions in an extended Transantarctic Mountains Deformation network (TAMDEF) to document neotectonic displacements due to tectonic deformation within the West Antarctic rift and/or to mass change of the Antarctic ice sheets. Horizontal displacements related to active neotectonic rifting, strike-slip translations, and volcanism will be tightly constrained by monitoring the combined TAMDEF and Italian VLNDEF networks of bedrock GPS stations along the Transantarctic Mountains and on offshore islands in the Ross Sea. Glacio-isostatic adjustments due to deglaciation since the Last Glacial Maximum and to modern mass change of the ice sheets will be modeled from GPS-derived crustal motions together with new information from other programs on the configurations, thicknesses, deglaciation history and modern mass balance of the ice sheets. Tectonic and rheological information from ongoing structural and seismic investigations in the Victoria Land region will also be integrated in the modeling. The integrative and iterative modeling will yield a holistic interpretation of neotectonics and ice sheet history that will help us to discriminate tectonic crustal displacements from viscoelastic/elastic glacio-isostatic motions. These results will provide key information to interpret broad, continental-scale crustal motion patterns detected by sparse, regionally distributed GPS continuous trackers and by spaceborne instruments. This study will contribute to international programs focused on Antarctic neotectonic and global change issues.\u003cbr/\u003e\u003cbr/\u003eStrategies to meet these science objectives include repeat surveys of key sites in the existing TAMDEF network, extension of the array of TAMDEF sites southward about 250 km along the Transantarctic Mountains, linked measurements with the VLNDEF network, and integration of quasi-continuous trackers within the campaign network. By extending the array of bedrock sites southward, these measurements will cross gradients in predicted vertical motion due to viscoelastic rebound. The southward extension will also allow determination of the southern limit of the active Terror Rift and will provide a better baseline for constraints on any ongoing tectonic displacements across the West Antarctic rift system as a whole that might be possible using GPS data collected by the West Antarctic GPS Network. This project will also investigate unique aspects of GPS geodesy in Antarctica to determine how the error spectrum compares to mid-latitude regions and to identify the optimum measurement and data processing schemes for Antarctic conditions. The geodetic research will improve position accuracies within our network and will also yield general recommendations for deformation monitoring networks in polar regions.\u003cbr/\u003e\u003cbr/\u003eAn education and outreach program is planned and will be targeted at non-science-major undergraduate students taking Earth System Science at Ohio State University. The objective will be to illuminate the research process for nonscientists. This effort will educate students on the process of science and inform them about Antarctica and how it relates to global science issues.", "east": 169.4, "geometry": "POINT(161.1165 -78.325)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "GPS", "locations": null, "north": -75.317, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wilson, Terry", "platforms": "SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repositories": null, "science_programs": null, "south": -81.333, "title": "Collaborative Research: Transantarctic Mountains Deformation Network: GPS Measurements of Neotectonic Motion in the Antarctic Interior", "uid": "p0000574", "west": 152.833}, {"awards": "0520523 Brook, Edward J.", "bounds_geometry": null, "dataset_titles": "Methane Measurements from the GISP2 and Siple Dome Ice Cores", "datasets": [{"dataset_uid": "609440", "doi": "10.7265/N58P5XFZ", "keywords": "Antarctica; Arctic; Chemistry:fluid; Chemistry:Fluid; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Methane Measurements from the GISP2 and Siple Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609440"}], "date_created": "Wed, 09 Dec 2009 00:00:00 GMT", "description": "Not Available", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Methane; Greenland Ice Cap; Ice Core Data; Siple Dome; Not provided; Ice Core Gas Records; DRILLING PLATFORMS; LABORATORY; Ice Core; Ice Core Chemistry; Antarctica; Greenland Ice Sheet Project 2", "locations": "Antarctica; Greenland Ice Cap; Siple Dome", "north": null, "nsf_funding_programs": "Arctic Natural Sciences", "paleo_time": null, "persons": "Brook, Edward J.", "platforms": "Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e FIXED PLATFORMS \u003e SURFACE \u003e DRILLING PLATFORMS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Collaborative Research: New insights into the Holocene methane budget from dual isotope systematics and a high resolution record of the interpolar gradient", "uid": "p0000131", "west": null}, {"awards": "0196105 Steig, Eric", "bounds_geometry": null, "dataset_titles": "US ITASE Stable Isotope Data, Antarctica", "datasets": [{"dataset_uid": "609425", "doi": "10.7265/N5NZ85MD", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; ITASE; Paleoclimate; WAIS", "people": "Steig, Eric J.", "repository": "USAP-DC", "science_program": "ITASE", "title": "US ITASE Stable Isotope Data, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609425"}], "date_created": "Thu, 01 Oct 2009 00:00:00 GMT", "description": "Not Available", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e LIDAR/LASER SPECTROMETERS \u003e PALMS", "is_usap_dc": true, "keywords": "Isotope; Depth; Ice Core Gas Records; Ice Core; Ice Core Data; Ice Core Chemistry; LABORATORY; Firn Isotopes; FIELD SURVEYS; Deuterium; Ice Age; Oxygen Isotope; Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": null, "title": "Stable Isotope Studies at West Antarctic ITASE Sites", "uid": "p0000013", "west": null}, {"awards": "0440414 Steig, Eric", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Stable Isotope Studies at East Antarctic US ITASE Sites", "datasets": [{"dataset_uid": "600042", "doi": "10.15784/600042", "keywords": "Antarctica; Atmosphere; Climate; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; ITASE; Meteorology; Paleoclimate; Satellite Remote Sensing; Weather Station Data", "people": "Steig, Eric J.", "repository": "USAP-DC", "science_program": "ITASE", "title": "Stable Isotope Studies at East Antarctic US ITASE Sites", "url": "https://www.usap-dc.org/view/dataset/600042"}], "date_created": "Mon, 14 Sep 2009 00:00:00 GMT", "description": "This award supports a project to obtain stable isotope profiles from shallow (\u003c100 m) ice cores from East Antarctica, to add to the growing database of environmental proxy data collected under the auspices of the \"ITASE\" (International TransAntarctic Scientific Expedition) program. In Antarctica, the instrumental record of climate is particularly short (~40 years except in a few isolated locations on the coast), and ice core proxy data are the only means available for extending this record into the past. The use of stable isotopes of water (18-O/16-O and D/H ratios) from ice cores as proxies for temperature is well established for both very short (i.e. seasonal) and long timescales (centuries, millennia). Using multivariate regression methods and shallow ice cores from West Antarctica, a reconstruction of Antarctic climate over the last ~150 years has been developed which suggests the continent has been warming, on average, at a rate of ~0.2 K/century. Further improving these reconstructions is the chief motivation for further extending the US ITASE project. Ten to fifteen shallow (~ 100 m) from Victoria Land, East Antarctica will be obtained and analyzed. The core will be collected along a traverse route beginning at Taylor Dome and ending at the South Pole. Age-depth relationships for the cores will be determined through a combination of stable isotopes, visual stratigraphy and seasonal chemical signatures and marker horizons. Reconstructions of Antarctic climate obtained from these cores will be incorporated into the global network of paleoclimate information, which has been important in science, policy and educational contexts. The project will include graduate student and postdoctoral training and field experience.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -90.0, "title": "Stable Isotope Studies at East Antarctic US ITASE Sites", "uid": "p0000202", "west": -180.0}, {"awards": "0086645 Fountain, Andrew", "bounds_geometry": "POLYGON((161.04 -77.3,161.239 -77.3,161.438 -77.3,161.637 -77.3,161.836 -77.3,162.035 -77.3,162.234 -77.3,162.433 -77.3,162.632 -77.3,162.831 -77.3,163.03 -77.3,163.03 -77.378,163.03 -77.456,163.03 -77.534,163.03 -77.612,163.03 -77.69,163.03 -77.768,163.03 -77.846,163.03 -77.924,163.03 -78.002,163.03 -78.08,162.831 -78.08,162.632 -78.08,162.433 -78.08,162.234 -78.08,162.035 -78.08,161.836 -78.08,161.637 -78.08,161.438 -78.08,161.239 -78.08,161.04 -78.08,161.04 -78.002,161.04 -77.924,161.04 -77.846,161.04 -77.768,161.04 -77.69,161.04 -77.612,161.04 -77.534,161.04 -77.456,161.04 -77.378,161.04 -77.3))", "dataset_titles": "McMurdo Dry Valleys Long-Term Ecological Research (MCM LTER) Core Glacier Mass Balance Data, Antarctica", "datasets": [{"dataset_uid": "609421", "doi": "", "keywords": "Antarctica; Dry Valleys; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; LTER; LTER Mcmurdo Dry Valleys", "people": "Basagic, Hassan; Nylen, Thomas; Lyons, W. Berry; Langevin, Paul; Fountain, Andrew", "repository": "USAP-DC", "science_program": null, "title": "McMurdo Dry Valleys Long-Term Ecological Research (MCM LTER) Core Glacier Mass Balance Data, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609421"}], "date_created": "Mon, 31 Aug 2009 00:00:00 GMT", "description": "0086645\u003cbr/\u003eFountain\u003cbr/\u003e\u003cbr/\u003eThis award supports a Small Grant for Exploratory Research (SGER) to study glaciological change in the McMurdo Dry Valleys, Antarctica under the category of \"application of new expertise or new approaches to established research topics\". The purpose of the project is to assess the application of classified imagery to the study of the magnitude and rate of change of glacier extent and lake area as an indicator of climate change. Because the rate of change of both glacier extent and lake area is small compared to the resolution of unclassified imagery, the increased resolution of classified imagery is clearly needed. Access to classified imagery with 1 meter or better resolution will provide a baseline measurement against which future changes can be compared. Maximum use will be made of archived imagery but if necessary, one request will be made for new imagery to supplement the existing archive. This work will support on-going field measurements which are part of the Long-Term Ecological Research (LTER) site in the McMurdo Dry Valleys but which are limited by logistic constraints to only a few measurements during limited times of the year. If successful, the information gained in this project will enable researchers to better direct their efforts to identify the important physical processes controlling the changes in the valleys. The information acquired in conducting this project will be made available to the public, using appropriate security procedures to declassify the data. The \"exploratory\" and \"high risk\" nature of the proposed work and its \"potential\" to make an important \"impact\" on the field of Antarctic glacier studies are all reasons that this work is appropriate to support as an SGER.", "east": 163.03, "geometry": "POINT(162.035 -77.69)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SNOW DENSITY CUTTER", "is_usap_dc": true, "keywords": "Glacier Surface; Antarctic; LABORATORY; Byrd Polar Research Center; FIELD INVESTIGATION; FIELD SURVEYS; Antarctica; Not provided; Glacier; Mass Balance; Snow Density; Ice Core; Taylor Glacier", "locations": "Antarctic; Antarctica; Taylor Glacier", "north": -77.3, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Nylen, Thomas; Basagic, Hassan; Langevin, Paul; Lyons, W. Berry; Fountain, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.08, "title": "SGER Proposal:Glaciological change in the McMurdo Dry Valleys, Antarctica", "uid": "p0000541", "west": 161.04}, {"awards": "0636747 Warny, Sophie", "bounds_geometry": "POINT(-54.44917 -63.86)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 26 Aug 2009 00:00:00 GMT", "description": "Abstract\u003cbr/\u003eThis project studies microfossils of plants and algae to understand climate during the earliest glaciations of Antarctica. The microfossils are from marine sediment cores collected by the 2006 SHALDRIL campaign to the Antarctic Peninsula. The work will offer constraints on sea surface temperature, ocean salinity, and terrestrial vegetation to help answer questions such as: What were conditions like on the Antarctic Peninsula during the initial formation of Antarctica\u0027s ice sheets? How rapidly did the ice sheets grow? Was their growth driven by global factors such as low atmospheric CO2 or local events like opening of the Drake Passage? \u003cbr/\u003e\u003cbr/\u003eThe broader impacts include postdoctoral fellow research and outreach via a museum exhibit and a web-based activity book for children.", "east": -54.44917, "geometry": "POINT(-54.44917 -63.86)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -63.86, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Warny, Sophie", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -63.86, "title": "Past Environmental Conditions on the Antarctic Peninsula: a Palynological Characterization of In-situ Sediments recovered during the 2006 SHALDRIL campaign", "uid": "p0000484", "west": -54.44917}, {"awards": "0125794 Price, P. Buford", "bounds_geometry": null, "dataset_titles": "Optical Logging for Dust and Microbes in Boreholes in Glacial Ice", "datasets": [{"dataset_uid": "609403", "doi": "10.7265/N59P2ZKB", "keywords": "Antarctica; Dust; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Microbiology; Optical Backscatter", "people": "Bay, Ryan", "repository": "USAP-DC", "science_program": null, "title": "Optical Logging for Dust and Microbes in Boreholes in Glacial Ice", "url": "https://www.usap-dc.org/view/dataset/609403"}], "date_created": "Wed, 29 Jul 2009 00:00:00 GMT", "description": "0125794\u003cbr/\u003ePrice\u003cbr/\u003e\u003cbr/\u003eThis award supports research in climatology, geosciences, and life in extreme environments to be carried out with a newly developed optical borehole logger. The logger fits into a fluid-filled borehole in glacial ice. It emits light at 370 nm in a horizontal plane in order to probe optical properties of particles embedded in the ice out to several meters from the borehole. After leaving the borehole, the light is partially absorbed and scattered by dust, biomolecules, or microbes. A fraction of the light is scattered back into the borehole and is detected by a system of seven phototubes, each of which collects light with high efficiency in a separate wavelength band. One of them collects light that scatters off of dust and air bubbles without wavelength shift, and serves as a dust logger. The other six are covered with notch filters that measure six different wavelength bands and measure the shape of the fluorescence spectrum of microbes and biomolecules. Thus, the same instrument serves as both a dust logger and a microbe logger. Applications include: 1) Precise chronologies and long-period solar variability. With a resolution of 1 to 2 cm for both GISP2 and Siple Dome, the logger will record annual dust maxima and evaluate claims of modulations of dust concentration with periods ranging from 11 yrs (the solar cycle) to 2300 yrs; 2) Volcanism and age-depth markers. Dozens of volcanic ash bands will be detectable and will serve as primary age-depth markers for other boreholes; 3) Microorganisms and biomolecules. The vertical distribution of living, dormant, and dead microbes can be logged, and searches for archaea and aeolian polyaromatic hydrocarbons can be made. The logging experiments will be carried out at Siple Dome and Dome C in Antarctica and at GISP2 and GRIP in Greenland.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e OPTICAL DUST LOGGERS", "is_usap_dc": true, "keywords": "Ice Core Data; Not provided; Climate Research; Climate; FIELD INVESTIGATION; Climate Change; FIELD SURVEYS; LABORATORY; Paleoclimate; Ice Core; Volcanic", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Bay, Ryan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Optical Logging for Dust and Microbes in Boreholes in Glacial Ice", "uid": "p0000156", "west": null}, {"awards": "0619457 Bell, Robin", "bounds_geometry": "POLYGON((-51 72.5,-49.5 72.5,-48 72.5,-46.5 72.5,-45 72.5,-43.5 72.5,-42 72.5,-40.5 72.5,-39 72.5,-37.5 72.5,-36 72.5,-36 71.85,-36 71.2,-36 70.55,-36 69.9,-36 69.25,-36 68.6,-36 67.95,-36 67.3,-36 66.65,-36 66,-37.5 66,-39 66,-40.5 66,-42 66,-43.5 66,-45 66,-46.5 66,-48 66,-49.5 66,-51 66,-51 66.65,-51 67.3,-51 67.95,-51 68.6,-51 69.25,-51 69.9,-51 70.55,-51 71.2,-51 71.85,-51 72.5))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 20 Jul 2009 00:00:00 GMT", "description": "This project develops a system of airborne instruments to explore the polar ice sheets and their underlying environments. The instrument suite includes an ice-penetrating radar, laser altimeter, gravimeter and magnetometer. Airborne geophysical measurements are key to understanding the 99% of Antarctica and 85% of Greenland covered by ice, which have thus far been studied at the postage stamp level. Projects linking ice sheet behavior to underlying geology will immediately benefit from this system, but even more exciting are the system\u0027s potential uses for work at the frontiers of polar science, such as: 1) exploring subglacial lakes, recently discovered and potentially the most unique sites on Earth for understanding life in extreme environments; 2) locating the deepest, oldest ice, which would offer million year and older samples of the atmosphere and 3) interpreting Antarctica\u0027s subglacial geology, which contains unique and unstudied volcanoes, mountains, and tectonic provinces. In terms of broader impacts, this project constructs research infrastructure critical to society\u0027s understanding of sea level rise, and supports a project involving domestic, international, and private sector collaborations.", "east": -36.0, "geometry": "POINT(-43.5 69.25)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": 72.5, "nsf_funding_programs": null, "paleo_time": null, "persons": "Bell, Robin; Studinger, Michael S.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": 66.0, "title": "Development of a Polar Multidisciplinary Airborne Imaging System for the International Polar Year 2007-2009", "uid": "p0000205", "west": -51.0}, {"awards": "0440975 Severinghaus, Jeffrey", "bounds_geometry": "POINT(-119.533333 -80.016667)", "dataset_titles": "Nitrogen and Oxygen Gas Isotopes in the Siple Dome and Byrd Ice Cores, Antarctica", "datasets": [{"dataset_uid": "609407", "doi": "10.7265/N55X26V0", "keywords": "Antarctica; Arctic; Atmosphere; Byrd Glacier; Byrd Ice Core; Chemistry:fluid; Chemistry:Fluid; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Nitrogen and Oxygen Gas Isotopes in the Siple Dome and Byrd Ice Cores, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609407"}], "date_created": "Fri, 17 Jul 2009 00:00:00 GMT", "description": "The award supports the development of high-resolution nitrogen and oxygen isotope records on trapped gases in the Byrd and Siple Dome ice cores, and the Holocene part of the GISP2 ice core. The primary scientific goals of this work are to understand the enigmatic d15N anomalies seen thus far in the Siple Dome record at 15.3 ka and 35 ka, and to find other events that may occur in both cores. At these events, d15N of trapped air approaches zero, implying little or no gravitational fractionation of gases in the firn layer at the time of formation of the ice. These events may represent times of low accumulation rate and arid meteorological conditions, and thus may contain valuable information about the climatic history of West Antarctica. Alternatively, they may stem from crevassing and thus may reveal ice-dynamical processes. Finding the events in the Byrd core, which is located 500 km from Siple Dome, would place powerful constraints on their origin and significance. A second major goal is to explore the puzzling absence of the abrupt warming event at 22 ka (seen at Siple Dome) in the nearby Byrd 18O/16O record in the ice (d18Oice), and search for a possible correlative signal in Byrd d15N. A third goal takes advantage of the fact that precise measurements of the oxygen isotopic composition of atmospheric O2 (d18Oatm) are obtained as a byproduct of the d15N measurement. The proposed gas-isotopic measurements will underpin an integrated suite of West Antarctic climate and atmospheric gas records, which will ultimately include the WAIS Divide core. These records will help separate regional from global climate signals, and may place constraints on the cause of abrupt climate change. Education of two graduate students, and training of two staff members in the laboratory, contribute to the nation\u0027s human resource base. Education and outreach will be an important component of the project.", "east": -119.533333, "geometry": "POINT(-119.533333 -80.016667)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Antarctica; Firn Air Isotopes; Not provided; Nitrogen Isotopes; LABORATORY; Firn Isotopes; Paleoclimate; FIELD SURVEYS; Ice Core; Oxygen Isotope; FIELD INVESTIGATION; Siple Dome", "locations": "Antarctica; Siple Dome", "north": -80.016667, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -80.016667, "title": "Nitrogen and oxygen gas isotopes in the Siple Dome and Byrd ice cores", "uid": "p0000450", "west": -119.533333}, {"awards": "0739496 Miller, Molly; 0739583 Bowser, Samuel; 0739512 Walker, Sally", "bounds_geometry": "POLYGON((163.41667 -77.33333,163.46667 -77.33333,163.51667 -77.33333,163.56667 -77.33333,163.61667 -77.33333,163.66667 -77.33333,163.71667 -77.33333,163.76667 -77.33333,163.81667 -77.33333,163.86667 -77.33333,163.91667 -77.33333,163.91667 -77.369997,163.91667 -77.406664,163.91667 -77.443331,163.91667 -77.479998,163.91667 -77.516665,163.91667 -77.553332,163.91667 -77.589999,163.91667 -77.626666,163.91667 -77.663333,163.91667 -77.7,163.86667 -77.7,163.81667 -77.7,163.76667 -77.7,163.71667 -77.7,163.66667 -77.7,163.61667 -77.7,163.56667 -77.7,163.51667 -77.7,163.46667 -77.7,163.41667 -77.7,163.41667 -77.663333,163.41667 -77.626666,163.41667 -77.589999,163.41667 -77.553332,163.41667 -77.516665,163.41667 -77.479998,163.41667 -77.443331,163.41667 -77.406664,163.41667 -77.369997,163.41667 -77.33333))", "dataset_titles": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores; Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.; Sequence Data", "datasets": [{"dataset_uid": "601764", "doi": "10.15784/601764", "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Walker, Sally; Camarra, Steve; Verheyden, Anouk; Puhalski, Emma; Gillikin, David; Cronin, Kelly", "repository": "USAP-DC", "science_program": null, "title": "Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.", "url": "https://www.usap-dc.org/view/dataset/601764"}, {"dataset_uid": "600076", "doi": "10.15784/600076", "keywords": "Biota; Geochronology; Marine Sediments; Oceans; Southern Ocean", "people": "Miller, Molly; Furbish, David", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600076"}, {"dataset_uid": "600077", "doi": "10.15784/600077", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; McMurdo Sound; Oceans; Sample/collection Description; Sample/Collection Description", "people": "Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600077"}, {"dataset_uid": "000144", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Sequence Data", "url": "http://www.ncbi.nlm.nih.gov/sites/myncbi/collections/public/1rMU2lBNcxWAsa9h9WyD8rzA8/"}], "date_created": "Wed, 15 Jul 2009 00:00:00 GMT", "description": "This project answers a simple question: why are there so few fossils in sediment cores from Antarctica?s continental shelf? Antarctica?s benthos are as biologically rich as those of the tropics. Shell-secreting organisms should have left a trail throughout geologic time, but have not. This trail is particularly important because these organisms record regional climate in ways that are critical to interpreting the global climate record. This study uses field experiments and targeted observations of modern benthic systems to examine the biases inflicted by fossil preservation. By examining a spectrum of ice-affected habitats, this project provides paleoenvironmental insights into carbonate preservation, sedimentation rates, and burial processes; and will provide new approaches to reconstructing the Cenozoic history of Antarctica. Broader impacts include graduate and undergraduate research and education, development of undergraduate curricula to link art and science, K12 outreach, public outreach via the web, and societal relevance through improved understanding of records of global climate change.", "east": 163.91667, "geometry": "POINT(163.66667 -77.516665)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.33333, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walker, Sally; Bowser, Samuel; Miller, Molly; Furbish, David", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "NCBI GenBank; USAP-DC", "science_programs": null, "south": -77.7, "title": "Collaborative Research: Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "uid": "p0000203", "west": 163.41667}, {"awards": "0122520 Gogineni, S. Prasad", "bounds_geometry": "POLYGON((-110 -62,-105 -62,-100 -62,-95 -62,-90 -62,-85 -62,-80 -62,-75 -62,-70 -62,-65 -62,-60 -62,-60 -63.5,-60 -65,-60 -66.5,-60 -68,-60 -69.5,-60 -71,-60 -72.5,-60 -74,-60 -75.5,-60 -77,-65 -77,-70 -77,-75 -77,-80 -77,-85 -77,-90 -77,-95 -77,-100 -77,-105 -77,-110 -77,-110 -75.5,-110 -74,-110 -72.5,-110 -71,-110 -69.5,-110 -68,-110 -66.5,-110 -65,-110 -63.5,-110 -62))", "dataset_titles": "Antarctic Radar Echograms and Derived Ice Thickness Data from CReSIS", "datasets": [{"dataset_uid": "609414", "doi": "", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar", "people": "Gogineni, Prasad", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Radar Echograms and Derived Ice Thickness Data from CReSIS", "url": "https://www.usap-dc.org/view/dataset/609414"}], "date_created": "Wed, 01 Jul 2009 00:00:00 GMT", "description": "0122520\u003cbr/\u003eGogineni\u003cbr/\u003e\u003cbr/\u003eSea level has been rising over the last century. Although the immediate impact of sea level rise may be less severe than other effects of global climate change, the long-term consequences can be much more devastating since nearly 60% of the world population lives in coastal regions. Scientists have postulated that excess water is being released from polar ice sheets due to long-term, global climate change, but there are insufficient data to confirm these theories. Understanding the interactions between the ice sheets, oceans and atmosphere is essential to quantifying the role of ice sheets in sea level rise. Toward that end, this research project involves the innovative application of information technology in the development and deployment of intelligent radar sensors for measuring key glaciological parameters. \u003cbr/\u003e\u003cbr/\u003eRadar instrumentation will consist of a synthetic aperture radar (SAR) that can operate in bistatic or monostatic mode. One important application of the SAR will be in the determination of basal conditions, particularly the presence and distribution of basal water. Basal water lubricates the ice/bed interface, enhancing flow, and increasing the amount of ice discharged into the ocean. Another application of the SAR will be to measure ice thickness and map internal layers in both shallow and deep ice. Information on near-surface internal layers will be used to estimate the average, recent accumulation rate, while the deeper layers provide a history of past accumulation and flow rates. A tracked vehicle and an automated snowmobile will be used to test and demonstrate the utility of an intelligent radar in glaciological investigations.\u003cbr/\u003e\u003cbr/\u003eThe system will be developed to collect, process and analyze data in real time and in conjunction with a priori information derived from archived sources. The combined real time and archived information will be used onboard the vehicles to select and generate an optimum sensor configuration. This project thus involves innovative research in intelligent systems, sounding radars and ice sheet modeling. In addition it has a very strong public outreach and education program, which include near-real-time image broadcasts via the world wide web", "east": -60.0, "geometry": "POINT(-85 -69.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e AIRSAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR", "is_usap_dc": true, "keywords": "Radar Echo Sounding; Not provided; FIELD SURVEYS; Airborne Radar Sounding; Radar Echo Sounder; Antarctic Ice Sheet; LABORATORY; Antarctica; Ice Sheet Thickness; Antarctic; Ice Sheet; Synthetic Aperture Radar Imagery; Radar Altimetry; Ice Sheet Elevation; FIELD INVESTIGATION; Radar", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet", "north": -62.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Gogineni, Prasad", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "ITR/SI+AP: A Mobile Sensor Web for Polar Ice Sheet Measurements", "uid": "p0000583", "west": -110.0}, {"awards": "0440711 Marchant, David", "bounds_geometry": "POLYGON((160 -76.5,160.45 -76.5,160.9 -76.5,161.35 -76.5,161.8 -76.5,162.25 -76.5,162.7 -76.5,163.15 -76.5,163.6 -76.5,164.05 -76.5,164.5 -76.5,164.5 -76.7,164.5 -76.9,164.5 -77.1,164.5 -77.3,164.5 -77.5,164.5 -77.7,164.5 -77.9,164.5 -78.1,164.5 -78.3,164.5 -78.5,164.05 -78.5,163.6 -78.5,163.15 -78.5,162.7 -78.5,162.25 -78.5,161.8 -78.5,161.35 -78.5,160.9 -78.5,160.45 -78.5,160 -78.5,160 -78.3,160 -78.1,160 -77.9,160 -77.7,160 -77.5,160 -77.3,160 -77.1,160 -76.9,160 -76.7,160 -76.5))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 01 Jul 2009 00:00:00 GMT", "description": "This project studies ancient lake deposits from the western Dry Valleys of Antarctica. These deposits are particularly exciting because they preserve flora and fauna over seven million years in age that represent the last vestiges of ecosystems that dominated this area before formation of the modern East Antarctic ice sheet. Their unique nature offers a chance to bridge modern and ancient ecology. Formed along the margin of ancient alpine glaciers, these deposits contain layers of silt, clay, and volcanic ash; as well as freeze-dried remnants of mosses, insects, and diatoms. Geological and biological analyses provide a view of the ecological and environmental conditions during mid-to-late Miocene--seven to seventeen million years ago--which spans the critical period when the East Antarctic ice sheet transitioned to its present stable form. The results place the modern lakes of the Dry Valleys into a long-term evolutionary framework, and allow for correlation and dating comparisons with other fossil-rich deposits from the Transantarctic Mountains. Chemical fingerprinting and dating of volcanic glass shards will also help date fossil- and ash-bearing horizons in nearby marine cores, such as those to be collected under the ANDRILL program. \u003cbr/\u003e\u003cbr/\u003eThe broader impacts are education at the postdoctoral, graduate, and undergraduate levels; and collaboration between a research institution and primarily undergraduate institution. The work also improves our understanding of global climate change during a critical period in the Earth\u0027s history.", "east": 164.5, "geometry": "POINT(162.25 -77.5)", "instruments": null, "is_usap_dc": false, "keywords": "Paleoclimate; Not provided; Lacustrine; Tundra; Middle Miocene; McMurdo Dry Valleys; Vegetation; Fossil; Antarctica", "locations": "Antarctica; McMurdo Dry Valleys", "north": -76.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Marchant, David", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -78.5, "title": "Collaborative Research: Deducing Late Neogene Antarctic Climate from Fossil-Rich Lacustrine Sediments in the Dry Valleys", "uid": "p0000186", "west": 160.0}, {"awards": "0739693 Ashworth, Allan; 0739700 Marchant, David", "bounds_geometry": "POLYGON((160 -77,160.2 -77,160.4 -77,160.6 -77,160.8 -77,161 -77,161.2 -77,161.4 -77,161.6 -77,161.8 -77,162 -77,162 -77.1,162 -77.2,162 -77.3,162 -77.4,162 -77.5,162 -77.6,162 -77.7,162 -77.8,162 -77.9,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,160.8 -78,160.6 -78,160.4 -78,160.2 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))", "dataset_titles": "Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "datasets": [{"dataset_uid": "600081", "doi": "10.15784/600081", "keywords": "Antarctica; Geochronology; Geology/Geophysics - Other; GPS; Solid Earth", "people": "Ashworth, Allan; Lewis, Adam", "repository": "USAP-DC", "science_program": null, "title": "Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/600081"}], "date_created": "Mon, 22 Jun 2009 00:00:00 GMT", "description": "This project studies the last vestiges of life in Antarctica from exceptionally well-preserved fossils of tundra life--mosses, diatoms, ostracods, Nothofagus leaves, wood, and insect remains recently discovered in ancient lake sediments from the McMurdo Dry Valleys. The area will be studied by an interdisciplinary team to elucidate information about climate and biogeography. These deposits offer unique and direct information about the characteristics of Antarctica during a key period in its history, the time when it was freezing. This information is critical for correlation with indirect proxies, such as though obtained from drill cores, for climate and state of the ice sheet. The results will also help understand the origin and migration of similar organisms found in South America, India and Australia.\u003cbr/\u003e\u003cbr/\u003eIn terms of broader impacts, this project supports an early career researcher, undergraduate and graduate student research, various forms of outreach to K12 students, and extensive international collaboration. The work also has societal relevance in that the outcomes will offer direct constraints on Antarctica\u0027s ice sheet during a time with atmospheric CO2 contents similar to those of the earth in the coming centuries, and thus may help predictive models of sea level rise.", "east": 162.0, "geometry": "POINT(161 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided; Antarctica; Vegetation; Paleoclimate; Middle Miocene; Tundra; Bu/es Data Repository; McMurdo Dry Valleys; Lacustrine; Fossil", "locations": "Antarctica; McMurdo Dry Valleys", "north": -77.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Ashworth, Allan; Lewis, Adam", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research: Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "uid": "p0000188", "west": 160.0}, {"awards": "0538195 Marone, Chris", "bounds_geometry": "POLYGON((-147.75896 -61.77943,-147.758362 -61.77943,-147.757764 -61.77943,-147.757166 -61.77943,-147.756568 -61.77943,-147.75597 -61.77943,-147.755372 -61.77943,-147.754774 -61.77943,-147.754176 -61.77943,-147.753578 -61.77943,-147.75298 -61.77943,-147.75298 -61.779665,-147.75298 -61.7799,-147.75298 -61.780135,-147.75298 -61.78037,-147.75298 -61.780605,-147.75298 -61.78084,-147.75298 -61.781075,-147.75298 -61.78131,-147.75298 -61.781545,-147.75298 -61.78178,-147.753578 -61.78178,-147.754176 -61.78178,-147.754774 -61.78178,-147.755372 -61.78178,-147.75597 -61.78178,-147.756568 -61.78178,-147.757166 -61.78178,-147.757764 -61.78178,-147.758362 -61.78178,-147.75896 -61.78178,-147.75896 -61.781545,-147.75896 -61.78131,-147.75896 -61.781075,-147.75896 -61.78084,-147.75896 -61.780605,-147.75896 -61.78037,-147.75896 -61.780135,-147.75896 -61.7799,-147.75896 -61.779665,-147.75896 -61.77943))", "dataset_titles": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "datasets": [{"dataset_uid": "609460", "doi": "10.7265/N5WH2MX7", "keywords": "Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Shear Stress; Solid Earth; Strain", "people": "Marone, Chris; Anandakrishnan, Sridhar", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "url": "https://www.usap-dc.org/view/dataset/609460"}, {"dataset_uid": "600054", "doi": "10.15784/600054", "keywords": "Antarctica; Glacial Till; Glaciers/ice Sheet; Glaciers/Ice Sheet; Lab Experiment; Marine Sediments; Physical Properties; Solid Earth", "people": "Marone, Chris; Anandakrishnan, Sridhar", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "url": "https://www.usap-dc.org/view/dataset/600054"}], "date_created": "Thu, 18 Jun 2009 00:00:00 GMT", "description": "0538195\u003cbr/\u003eMarone\u003cbr/\u003eThis award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.", "east": -147.75298, "geometry": "POINT(-147.75597 -61.780605)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE TRANSDUCERS", "is_usap_dc": true, "keywords": "Subglacial Observations; Laboratory Investigation; LABORATORY; Subglacial", "locations": null, "north": -61.77943, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Marone, Chris; Anandakrishnan, Sridhar", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -61.78178, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "uid": "p0000554", "west": -147.75896}, {"awards": "9814810 Bales, Roger", "bounds_geometry": "POLYGON((-124 -76,-120 -76,-116 -76,-112 -76,-108 -76,-104 -76,-100 -76,-96 -76,-92 -76,-88 -76,-84 -76,-84 -77.4,-84 -78.8,-84 -80.2,-84 -81.6,-84 -83,-84 -84.4,-84 -85.8,-84 -87.2,-84 -88.6,-84 -90,-88 -90,-92 -90,-96 -90,-100 -90,-104 -90,-108 -90,-112 -90,-116 -90,-120 -90,-124 -90,-124 -88.6,-124 -87.2,-124 -85.8,-124 -84.4,-124 -83,-124 -81.6,-124 -80.2,-124 -78.8,-124 -77.4,-124 -76))", "dataset_titles": "Atmospheric Mixing Ratios of Hydroperoxides above the West Antarctic Ice Sheet; Twenty-Three Century-scale Ice Core Records of Hydrogen Peroxide (H2O2) from West Antarctica", "datasets": [{"dataset_uid": "609392", "doi": "10.7265/N5TM7826", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; WAIS", "people": "Frey, Markus; Bales, Roger; McConnell, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Twenty-Three Century-scale Ice Core Records of Hydrogen Peroxide (H2O2) from West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609392"}, {"dataset_uid": "609394", "doi": "10.7265/N5PZ56RS", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; ITASE; WAIS", "people": "Bales, Roger; Frey, Markus; McConnell, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Atmospheric Mixing Ratios of Hydroperoxides above the West Antarctic Ice Sheet", "url": "https://www.usap-dc.org/view/dataset/609394"}], "date_created": "Mon, 01 Jun 2009 00:00:00 GMT", "description": "This award supports a project to improve understanding of atmospheric photochemistry over West Antarctica, as recorded in snow, firn and ice. Atmospheric and firn sampling will be undertaken as part of the U.S. International Trans-Antarctic Scientific Expedition (US ITASE) traverses. Measurements of hydrogen peroxide (H2O2) and formaldehyde (HCHO) will be made on these samples and a recently developed, physically based atmosphere-to-snow transfer model will be used to relate photochemical model estimates of these components to the concentrations of these parameters in the atmosphere and snow. The efficiency of atmosphere-to-snow transfer and the preservation of these components is strongly related to the rate and timing of snow accumulation. This information will be obtained by analyzing the concentration of seasonally dependent species such as hydrogen peroxide, nitric acid and stable isotopes of oxygen. Collection of samples along the US ITASE traverses will allow sampling at a wide variety of locations, reflecting both a number of different depositional environments and covering much of the West Antarctic region.", "east": -84.0, "geometry": "POINT(-104 -83)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUORESCENCE SPECTROSCOPY; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS SENSORS", "is_usap_dc": true, "keywords": "Ice Core; Ice Core Chemistry; FIELD INVESTIGATION; FIELD SURVEYS; Antarctica; West Antarctica; Antarctic; LABORATORY; Ice Core Gas Records; Not provided; Ice Core Data; Polar Firn Air; Hydrogen Peroxide; West Antarctic Ice Sheet; Shallow Firn Air; US ITASE; Antarctic Ice Sheet; Snow Chemistry", "locations": "Antarctica; West Antarctica; Antarctic; Antarctic Ice Sheet; West Antarctic Ice Sheet", "north": -76.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Bales, Roger; Frey, Markus; McConnell, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Hydrogen Peroxide, Formaldehyde, and Sub-Annual Snow Accumulation in West Antarctica: Participation in West Antarctic Traverse", "uid": "p0000253", "west": -124.0}, {"awards": "0817163 Reiners, Peter; 0816934 Thomson, Stuart", "bounds_geometry": "POLYGON((72 -66,72.3 -66,72.6 -66,72.9 -66,73.2 -66,73.5 -66,73.8 -66,74.1 -66,74.4 -66,74.7 -66,75 -66,75 -66.3,75 -66.6,75 -66.9,75 -67.2,75 -67.5,75 -67.8,75 -68.1,75 -68.4,75 -68.7,75 -69,74.7 -69,74.4 -69,74.1 -69,73.8 -69,73.5 -69,73.2 -69,72.9 -69,72.6 -69,72.3 -69,72 -69,72 -68.7,72 -68.4,72 -68.1,72 -67.8,72 -67.5,72 -67.2,72 -66.9,72 -66.6,72 -66.3,72 -66))", "dataset_titles": "Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "datasets": [{"dataset_uid": "600089", "doi": "10.15784/600089", "keywords": "Antarctica; Fission Track Thermochronology; Gamburtsev Mountains; Geochronology; Solid Earth", "people": "Thomson, Stuart", "repository": "USAP-DC", "science_program": null, "title": "Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "url": "https://www.usap-dc.org/view/dataset/600089"}, {"dataset_uid": "600090", "doi": "10.15784/600090", "keywords": "Antarctica; Gamburtsev Mountains; Geochronology; Marine Sediments; NBP0101; ODP1166; Prydz Bay; Solid Earth; Southern Ocean", "people": "Reiners, Peter; Gehrels, George", "repository": "USAP-DC", "science_program": null, "title": "Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "url": "https://www.usap-dc.org/view/dataset/600090"}], "date_created": "Thu, 30 Apr 2009 00:00:00 GMT", "description": "This Small Grant for Exploratory Research investigates the origin and evolution of the Gamburtsev subglacial mountains (GSM). These mountains are considered the nucleation point for Antarctica\u0027s largest ice sheets; however, being of indeterminate age, they may postdate ice sheet formation. As well, their formation could reflect tectonic events during the breakup of Gondwana. The project studies GSM-derived detrital zircon and apatite crystals from Prydz Bay obtained by the Ocean Drilling Program. Analytical work includes triple-dating thermochronometry by U/Pb, fission track, and (U/Th)/He methods. The combined technique offers insight into both high and low temperature processes, and is potentially sensitive to both the orogenic events and the subsequent cooling and exhumation due to erosion. In terms of broader impacts, this project supports research for a postdoctoral fellow and an", "east": 75.0, "geometry": "POINT(73.5 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Thompson, Stuart; Reiners, Peter; Gehrels, George", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.0, "title": "Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains", "uid": "p0000210", "west": 72.0}, {"awards": "0636850 Dalziel, Ian", "bounds_geometry": "POLYGON((-70 -52,-66.5 -52,-63 -52,-59.5 -52,-56 -52,-52.5 -52,-49 -52,-45.5 -52,-42 -52,-38.5 -52,-35 -52,-35 -53,-35 -54,-35 -55,-35 -56,-35 -57,-35 -58,-35 -59,-35 -60,-35 -61,-35 -62,-38.5 -62,-42 -62,-45.5 -62,-49 -62,-52.5 -62,-56 -62,-59.5 -62,-63 -62,-66.5 -62,-70 -62,-70 -61,-70 -60,-70 -59,-70 -58,-70 -57,-70 -56,-70 -55,-70 -54,-70 -53,-70 -52))", "dataset_titles": "Expedition Data; NBP0805", "datasets": [{"dataset_uid": "001510", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0805"}, {"dataset_uid": "000139", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0805", "url": "https://www.rvdata.us/search/cruise/NBP0805"}], "date_created": "Wed, 15 Apr 2009 00:00:00 GMT", "description": "This project studies the opening of the Drake Passage between South America and Antarctica through a combined marine geophysical survey and geochemical study of dredged ocean floor basalts. Dating the passage\u0027s opening is key to understanding the formation of the circum-Antarctic current, which plays a major role in worldwide ocean circulation, and whose formation is connected with growth of the Antarctic ice sheet. Dredge samples will undergo various geochemical studies to determine their age and constrain mantle flow beneath the region. \u003cbr/\u003e\u003cbr/\u003eBroader impacts include support for graduate education, as well as undergraduate and K12 teacher involvement in a research cruise. The project also involves international collaboration with the UK and is part of IPY Project #77: Plates\u0026Gates, which aims to reconstruct the geologic history of polar ocean basins and gateways for computer simulations of climate change. See http://www.ipy.org/index.php?/ipy/detail/plates_gates/ for more information.", "east": -35.0, "geometry": "POINT(-52.5 -57)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "R/V NBP; Not provided", "locations": null, "north": -52.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Lawver, Lawrence; Dalziel, Ian W.", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -62.0, "title": "Central Scotia Seafloor and the Drake Passage Deep Ocean Current Gateway", "uid": "p0000208", "west": -70.0}, {"awards": "0739452 Mukhopadhyay, Sujoy", "bounds_geometry": "POLYGON((161 -76,161.2 -76,161.4 -76,161.6 -76,161.8 -76,162 -76,162.2 -76,162.4 -76,162.6 -76,162.8 -76,163 -76,163 -76.2,163 -76.4,163 -76.6,163 -76.8,163 -77,163 -77.2,163 -77.4,163 -77.6,163 -77.8,163 -78,162.8 -78,162.6 -78,162.4 -78,162.2 -78,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,161 -77.8,161 -77.6,161 -77.4,161 -77.2,161 -77,161 -76.8,161 -76.6,161 -76.4,161 -76.2,161 -76))", "dataset_titles": "Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica", "datasets": [{"dataset_uid": "600074", "doi": "10.15784/600074", "keywords": "Antarctica; Cosmogenic Dating; Dry Valleys; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Paleoclimate; Sample/collection Description; Sample/Collection Description; Solid Earth", "people": "Mukhopadhyay, Sujoy", "repository": "USAP-DC", "science_program": null, "title": "Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica", "url": "https://www.usap-dc.org/view/dataset/600074"}], "date_created": "Mon, 30 Mar 2009 00:00:00 GMT", "description": "This project seeks to answer a simple question: how old are potholes and related geomorphic features found in the uplands of the McMurdo Dry Valleys, Antarctica? Some research suggests that they are over ten million years old and date the growth of the East Antarctic Ice Sheet, the world?s largest. However, some evidence suggests that these are young, erosional features that continuing to evolve to this day. This project uses cosmogenic nuclide dating to determine the age of the pothole floors. The results are important for determining the ice sheet?s history and interpreting the O-isotope record from the marine sediment cores, key records of global climate. Broader impacts include K12 outreach and incorporation of outcomes into university courses.", "east": 163.0, "geometry": "POINT(162 -77)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Mukhopadhyay, Sujoy", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica", "uid": "p0000461", "west": 161.0}, {"awards": "0538683 Lal, Devendra", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Solar activity during the last millennium, estimated from cosmogenic in-situ C14 in South Pole and GISP2 ice cores", "datasets": [{"dataset_uid": "600058", "doi": "10.15784/600058", "keywords": "Antarctica; Carbon-14; Cosmos; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Solar Activity; South Pole", "people": "Lal, Devendra", "repository": "USAP-DC", "science_program": null, "title": "Solar activity during the last millennium, estimated from cosmogenic in-situ C14 in South Pole and GISP2 ice cores", "url": "https://www.usap-dc.org/view/dataset/600058"}], "date_created": "Fri, 20 Feb 2009 00:00:00 GMT", "description": "0538683\u003cbr/\u003eLal\u003cbr/\u003eThis award supports a project to continue development of a new method for estimating solar activity in the past. It is based on measurements of the concentrations of in-situ produced C-14 in polar ice by cosmic rays, which depend only on (i) the cosmic ray flux, and (ii) ice accumulation rate. This is the only direct method available to date polar ice, since it does not involve any uncertain climatic transfer functions as are encountered in the applications of cosmogenic C-14 data in tree rings, or of Be-10 in ice and sediments. An important task is to improve on the temporal resolution during identified periods of high/low solar activity in the past 32 Kyr. The plan is to undertake a study of changes in the cosmic ray flux during the last millennium (1100-1825 A.D.), during which time 4 low and 1 high solar activity epoch has been identified from historical records. Sunspot data during most of these periods are sparse. Adequate ice samples are available from ice cores from the South Pole and from Summit, Greenland and a careful high resolution study of past solar activity levels during this period will be undertaken. The intellectual merit of the work includes providing independent verification of estimated solar activity levels from the two polar ice records of cosmic ray flux and greatly improve our understanding of solar-terrestrial relationships. \u003cbr/\u003eThe broader impacts include collaboration with other scientists who are experts in the application of the atmospheric cosmogenic C-14 and student training. Both undergraduates and a graduate student will be involved in the proposed research. Various forms of outreach will also be used to disseminate the results of this project, including public presentations and interactions with the media.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Lal, Devendra", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Solar Activity during the Last Millennium, Estimated from Cosmogenic in-situ 14C in South Pole and GISP2 Ice Cores", "uid": "p0000555", "west": -180.0}, {"awards": "9911617 Blankenship, Donald; 9319379 Blankenship, Donald", "bounds_geometry": null, "dataset_titles": "Antarctic Aerogeophysics Data; Antarctic Subglacial Lake Classification Inventory; RBG - Robb Glacier Survey; SOAR-Lake Vostok Survey airborne radar data; SOAR-Lake Vostok Survey bed elevation data; SOAR-Lake Vostok Survey Gravity data; SOAR-Lake Vostok Survey ice thickness data; SOAR-Lake Vostok survey magnetic anomaly data; SOAR-Lake Vostok Survey surface elevation data", "datasets": [{"dataset_uid": "601295", "doi": "10.1594/IEDA/306563", "keywords": "Airborne Gravity; Airplane; Antarctica; East Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Lake Vostok; Potential Field; Solid Earth", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey Gravity data", "url": "https://www.usap-dc.org/view/dataset/601295"}, {"dataset_uid": "601296", "doi": " 10.1594/IEDA/306564", "keywords": "Airborne Magnetic; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Lake Vostok; Magnetic; Magnetic Anomaly; Magnetometer; Potential Field; SOAR; Solid Earth", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok survey magnetic anomaly data", "url": "https://www.usap-dc.org/view/dataset/601296"}, {"dataset_uid": "601300", "doi": "10.1594/IEDA/306568", "keywords": "Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Navigation; Radar; SOAR; Subglacial Lakes", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey airborne radar data", "url": "https://www.usap-dc.org/view/dataset/601300"}, {"dataset_uid": "601604", "doi": "10.15784/601604", "keywords": "Airborne Radar; Antarctica; Bed Elevation; Geophysics; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Surface Elevation; Ice Thickness; Robb Glacier; Transantarctic Mountains", "people": "Bell, Robin; Buck, W. Roger; Young, Duncan A.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "RBG - Robb Glacier Survey", "url": "https://www.usap-dc.org/view/dataset/601604"}, {"dataset_uid": "601297", "doi": "10.1594/IEDA/306567", "keywords": "Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Sheet; Ice Stratigraphy; Ice Thickness; Ice Thickness Distribution; Lake Vostok; Radar; Radar Altimetry; Radar Echo Sounder; SOAR; Subglacial Lake", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey ice thickness data", "url": "https://www.usap-dc.org/view/dataset/601297"}, {"dataset_uid": "601298", "doi": "10.1594/IEDA/306566", "keywords": "Airborne Altimetry; Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Sheet Elevation; Ice Surface; Lake Vostok; Radar Echo Sounder; SOAR; Surface Elevation", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey surface elevation data", "url": "https://www.usap-dc.org/view/dataset/601298"}, {"dataset_uid": "609240", "doi": "", "keywords": "Airborne Radar; Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Navigation; Potential Field; SOAR; Solid Earth", "people": "Morse, David L.; Blankenship, Donald D.; Holt, John W.; Dalziel, Ian W.", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Aerogeophysics Data", "url": "https://www.usap-dc.org/view/dataset/609240"}, {"dataset_uid": "601299", "doi": "10.1594/IEDA/306565", "keywords": "Airborne Laser Altimeters; Airborne Laser Altimetry; Airborne Radar; Airplane; Antarctica; Bed Elevation; Bedrock Elevation; Digital Elevation Model; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Lake Vostok; Radar; Radar Echo Sounder; SOAR", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey bed elevation data", "url": "https://www.usap-dc.org/view/dataset/601299"}, {"dataset_uid": "609336", "doi": "10.7265/N5CN71VX", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Subglacial Lake", "people": "Holt, John W.; Carter, Sasha P.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Subglacial Lake Classification Inventory", "url": "https://www.usap-dc.org/view/dataset/609336"}], "date_created": "Fri, 06 Feb 2009 00:00:00 GMT", "description": "9911617 Blankenship This award, provided jointly by the Antarctic Geology and Geophysics Program, the Antarctic Glaciology Program, and the Polar Research Support Section of the Office of Polar Programs, provides funds for continuation of the Support Office for Aerogeophysical Research (SOAR). From July 1994 to July 2000, SOAR served as a facility to accomplish aerogeophysical research in Antarctica under an agreement between the University of Texas at Austin and the National Science Foundation\u0027s Office of Polar Programs (NSF/OPP). SOAR operated and maintained an aerogeophysical instrument package that consists of an ice-penetrating radar sounder, a laser altimeter, a gravimeter and a magnetometer that are tightly integrated with each other as well as with the aircraft\u0027s avionics and power packages. An array of aircraft and ground-based GPS receivers supported kinematic differential positioning using carrier-phase observations. SOAR activities included: developing aerogeophysical research projects with NSF/OPP investigators; upgrading of the aerogeophysical instrumentation package to accommodate new science projects and advances in technology; fielding this instrument package to accomplish SOAR-developed projects; and management, reduction, and analysis of the acquired aerogeophysical data. In pursuit of 9 NSF-OPP funded aerogeophysical research projects (involving 14 investigators from 9 institutions), SOAR carried out six field campaigns over a six-year period and accomplished approximately 200,000 line kilometers of aerogeophysical surveying over both East and West Antarctica in 377 flights. This award supports SOAR to undertake a one year and 8 month program of aerogeophysical activities that are consistent with continuing U.S. support for geophysical research in Antarctica. - SOAR will conduct an aerogeophysical campaign during the 200/01 austral summer to accomplish surveys for two SOAR-developed projects: \"Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Studies\" (Co-PI\u0027s Bell and Studinger, LDEO); and \"Collaborative Research: Seismic Investigation of the Deep Continental Structure Across the East-West Antarctic Boundary\" (Co-PI\u0027s Weins, Washington U. and Anandakrishnan, U. Alabama). After configuration and testing of the survey aircraft in McMurdo, SOAR will conduct survey flights from an NSF-supported base adjacent to the Russian Station above Lake Vostok and briefly occupy one or two remote bases on the East Antarctic ice sheet. - SOAR will reduce these aerogeophysical data and produce profiles and maps of surface elevation, bed elevation, gravity and magnetic field intensity. These results will be provided to the respective project investigators within nine months of conclusion of field activities. We will also submit a technical manuscript that describes these results to a refereed scientific journal and distribute these results to appropriate national geophysical data centers within approximately 24 months of completion of field activities. - SOAR will standardize all previously reduced SOAR data products and transfer them to the appropriate national geophysical data centers by the end of this grant. - SOAR will convene a workshop to establish a community consensus for future U.S. Antarctic aerogeophysical research. This workshop will be co-convened by Ian Dalziel and Richard Alley and will take place during the spring of 2001. - SOAR will upgrade the existing SOAR in-field quality control procedures to serve as a web-based interface for efficient browsing of many low-level SOAR data streams. - SOAR will repair and/or refurbish equipment that was used during the 2000/01 field campaign. Support for SOAR is essential for accomplishing major geophysical investigations in Antarctica. Following data interpretation by the science teams, these data will provide valuable insights to the structure and evolution of the Antarctic continent.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LIDAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e PROTON MAGNETOMETER", "is_usap_dc": true, "keywords": "Ice Sheet; Ice Sheet Elevation; Surface Winds; Snow Temperature; Atmospheric Pressure; Antarctic; West Antarctic Ice Sheet; Surface Temperature Measurements; FIELD INVESTIGATION; Surface Wind Speed Measurements; Subglacial Topography; Atmospheric Humidity Measurements; Not provided; Aerogeophysics; FIELD SURVEYS; GROUND STATIONS; Antarctica; SOAR; Snow Temperature Measurements; West Antarctica; Antarctic Ice Sheet; East Antarctic Plateau", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; West Antarctica; West Antarctic Ice Sheet; East Antarctic Plateau", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Carter, Sasha P.; Holt, John W.; Blankenship, Donald D.; Morse, David L.; Dalziel, Ian W.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Continuation of Activities for the Support Office for Aerogeophysical Research (SOAR)", "uid": "p0000125", "west": null}, {"awards": "0440759 Sowers, Todd; 0440498 White, James; 0440602 Saltzman, Eric; 0440509 Battle, Mark; 0440701 Severinghaus, Jeffrey; 0440615 Brook, Edward J.", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Gases in Firn Air and Shallow Ice at the WAIS Drilling Site, Antarctica; Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core; Methane Isotopes from the WAIS Divide Ice Core; Surface Temperature Reconstruction from Borehole Temperature Measurement in WDC05A; WAIS ice core Methane Data, Carbon Dioxide Data", "datasets": [{"dataset_uid": "609493", "doi": "10.7265/N5319SV3", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Sowers, Todd A.; McConnell, Joseph; Brook, Edward J.; Mitchell, Logan E; Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS ice core Methane Data, Carbon Dioxide Data", "url": "https://www.usap-dc.org/view/dataset/609493"}, {"dataset_uid": "609435", "doi": "10.7265/N5J67DW0", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Methane Isotopes from the WAIS Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/609435"}, {"dataset_uid": "609638", "doi": "10.7265/N56971HF", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Orsi, Anais J.; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Surface Temperature Reconstruction from Borehole Temperature Measurement in WDC05A", "url": "https://www.usap-dc.org/view/dataset/609638"}, {"dataset_uid": "609412", "doi": "10.7265/N5251G40", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core", "people": "Saltzman, Eric", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Gases in Firn Air and Shallow Ice at the WAIS Drilling Site, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609412"}, {"dataset_uid": "601357", "doi": "10.15784/601357", "keywords": "Antarctica; Atmospheric Gases; Gas Measurement; Ice Core; Ice Core Gas Records; Trace Gases", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core", "url": "https://www.usap-dc.org/view/dataset/601357"}], "date_created": "Tue, 03 Feb 2009 00:00:00 GMT", "description": "This award supports a project to measure the elemental and isotopic composition of firn air and occluded air in shallow boreholes and ice cores from the WAIS Divide site, the location of a deep ice-coring program planned for 2006-07 and subsequent seasons. The three primary objectives are: 1) to establish the nature of firn air movement and trapping at the site to aid interpretations of gas data from the deep core; 2) to expand the suite of atmospheric trace gas species that can be measured in ice and replicate existing records of other species; and 3) to inter-calibrate all collaborating labs to insure that compositional and isotopic data sets are inter-comparable. The program will be initiated with a shallow drilling program during the 05/06 field season which will recover two 300+m cores and firn air samples. The ice core and firn air will provide more than 700 years of atmospheric history that will be used to address a number of important questions related to atmospheric change over this time period. The research team consists of six US laboratories that also plan to participate in the deep core program. This collaborative research program has a number of advantages. First, the scientists will be able to coordinate sample allocation a priori to maximize the resolution and overlap of records of interrelated species. Second, sample registration will be exact, allowing direct comparison of all records. Third, a coherent data set will be produced at the same time and all PI.s will participate in interpreting and publishing the results. This will insure that the best possible understanding of gas records at the WAIS Divide site will be achieved, and that all work necessary to interpret the deep core is conducted in a timely fashion. The collaborative structure created by the proposal will encourage sharing of techniques, equipment, and ideas between the laboratories. The research will identify impacts of various industrial/agricultural activities and help to distinguish them from natural variations, and will include species for which there are no long records of anthropogenic impact. The work will also help to predict future atmospheric loadings. The project will contribute to training scientists at several levels, including seven undergraduates, two graduate students and one post doctoral fellow.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GC-MS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e SPECTROMETERS \u003e SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e FLASKS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS", "is_usap_dc": true, "keywords": "Ice Core Chemistry; WAIS Divide; Firn; LABORATORY; Ice Core; Firn Air Isotope Measurements; Shallow Firn Air; FIELD INVESTIGATION; Ice Core Gas Records; GROUND-BASED OBSERVATIONS; Firn Isotopes; Wais Divide-project; Gas Data; Polar Firn Air; Not provided; Trace Gas Species; Trapped Gases; West Antarctic Ice Sheet; Deep Core; Ice Sheet; Gas; Firn Air Isotopes; FIELD SURVEYS; Air Samples; Atmospheric Gases; Isotope; Cores; Atmosphere; Ice Core Data; Surface Temperatures; Firn Air; Borehole; Antarctica", "locations": "West Antarctic Ice Sheet; Antarctica; WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Battle, Mark; Mischler, John; Saltzman, Eric; Aydin, Murat; White, James; Brook, Edward J.; Orsi, Anais J.; Severinghaus, Jeffrey P.; Sowers, Todd A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Gases in Firn Air and Shallow Ice at the Proposed WAIS Divide Drilling Site", "uid": "p0000368", "west": -112.085}, {"awards": "0636629 Kurz, Mark", "bounds_geometry": "POLYGON((160.7 -77.8,161.06 -77.8,161.42 -77.8,161.78 -77.8,162.14 -77.8,162.5 -77.8,162.86 -77.8,163.22 -77.8,163.58 -77.8,163.94 -77.8,164.3 -77.8,164.3 -77.86,164.3 -77.92,164.3 -77.98,164.3 -78.04,164.3 -78.1,164.3 -78.16,164.3 -78.22,164.3 -78.28,164.3 -78.34,164.3 -78.4,163.94 -78.4,163.58 -78.4,163.22 -78.4,162.86 -78.4,162.5 -78.4,162.14 -78.4,161.78 -78.4,161.42 -78.4,161.06 -78.4,160.7 -78.4,160.7 -78.34,160.7 -78.28,160.7 -78.22,160.7 -78.16,160.7 -78.1,160.7 -78.04,160.7 -77.98,160.7 -77.92,160.7 -77.86,160.7 -77.8))", "dataset_titles": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "datasets": [{"dataset_uid": "600066", "doi": "10.15784/600066", "keywords": "Antarctica; Cosmogenic Radionuclides; Dry Valleys; Geology/Geophysics - Other; Glaciology; LIDAR; Navigation; Sample/collection Description; Sample/Collection Description", "people": "Soule, S. Adam; Kurz, Mark D.", "repository": "USAP-DC", "science_program": null, "title": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "url": "https://www.usap-dc.org/view/dataset/600066"}], "date_created": "Sun, 01 Feb 2009 00:00:00 GMT", "description": "This project uses cosmogenic nuclide dating and LIDAR studies of surface roughness to understand weathering and landscape evolution in the Dry Valleys of Antarctica. The work focuses on two processes: cryoturbation of frozen soils and the development of patterned, frozen ground on ancient lava flows. The approach includes innovative uses of He3 profiling. Results will also be applied to understanding the glacial history of the Dry Valleys. There are potential applications to understanding the history of the East Antarctic Ice Sheet and the formation of Martian landscapes. The broader impacts include graduate student education. As well, the work may contribute to our understanding of the history of the Antarctic ice sheets, which is important to modeling their behavior during global climate change.", "east": 164.3, "geometry": "POINT(162.5 -78.1)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION", "locations": null, "north": -77.8, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Soule, Samuel; Kurz, Mark D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.4, "title": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "uid": "p0000559", "west": 160.7}, {"awards": "0126057 Brook, Edward J.; 0512971 Brook, Edward J.", "bounds_geometry": null, "dataset_titles": "Antarctic and Greenland Climate Change Comparison; GISP2 (B and D Core) Methane Concentrations; GISP2 (D Core) Helium Isotopes from Interplanetary Dust; GISP2 (D Core) Methane Concentration Data; Siple Dome Methane Record", "datasets": [{"dataset_uid": "609125", "doi": "", "keywords": "Arctic; Chemistry:fluid; Chemistry:Fluid; Chemistry:ice; Chemistry:Ice; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland; Ice Core Records; Methane; Paleoclimate", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": null, "title": "GISP2 (B and D Core) Methane Concentrations", "url": "https://www.usap-dc.org/view/dataset/609125"}, {"dataset_uid": "609361", "doi": "", "keywords": "Antarctica; Arctic; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Lake Vostok; Paleoclimate; Vostok Ice Core", "people": "Brook, Edward J.; Kurz, Mark D.", "repository": "USAP-DC", "science_program": null, "title": "GISP2 (D Core) Helium Isotopes from Interplanetary Dust", "url": "https://www.usap-dc.org/view/dataset/609361"}, {"dataset_uid": "609253", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Vostok Ice Core", "people": "Brook, Edward J.; Stauffer, Bernhard; Blunier, Thomas; Chappellaz, Jerome", "repository": "USAP-DC", "science_program": null, "title": "Antarctic and Greenland Climate Change Comparison", "url": "https://www.usap-dc.org/view/dataset/609253"}, {"dataset_uid": "609124", "doi": "10.7265/N5KH0K8R", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Methane Record", "url": "https://www.usap-dc.org/view/dataset/609124"}, {"dataset_uid": "609360", "doi": "", "keywords": "Antarctica; Arctic; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Methane; Paleoclimate; Taylor Dome", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": null, "title": "GISP2 (D Core) Methane Concentration Data", "url": "https://www.usap-dc.org/view/dataset/609360"}], "date_created": "Tue, 16 Dec 2008 00:00:00 GMT", "description": "This award supports work on trapped gases in Antarctic and other ice cores for paleoenvironmental and chronological purposes. The project will complete a ~ 100,000 year, high-resolution record of atmospheric methane from the Siple Dome ice core and use these data to construct a precise chronology for climate events recorded by the Siple Dome record. In addition, the resolution of the GISP2 (Greenland) ice core record will be increased in some critical intervals to help with the Siple Dome chronology and that of future ice cores. Finally, an upgrade to the analytical capabilities of the laboratory, including increasing precision and throughput and decreasing sample size needed for ice core methane measurements will be an important goal of this work. The proposed work will contribute to the understanding of the timing of rapid climate change in the Northern and Southern hemispheres during the last glacial period, the evolution of the global methane budget in the late Quaternary, and the late Quaternary climate history of Antarctica. It will also improve our ability to generate methane records for future ice coring projects, and inform and enrich the educational and outreach activities of our laboratory.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Isotope; Siple Coast; WAISCORES; GROUND-BASED OBSERVATIONS; Interplanetary Dust; FIELD SURVEYS; Not provided; Ice Sheet; Snow; GROUND STATIONS; Gas Measurement; Ice Core; Siple; Antarctica; Methane; Glaciology; Stratigraphy; Siple Dome", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Glaciology; Antarctic Organisms and Ecosystems; Antarctic Glaciology", "paleo_time": null, "persons": "Blunier, Thomas; Chappellaz, Jerome; Stauffer, Bernhard; Kurz, Mark D.; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "High Resolution Records of Atmospheric Methane in Ice Cores and Implications for Late Quaternary Climate Change", "uid": "p0000034", "west": null}, {"awards": "0636953 Saltzman, Eric", "bounds_geometry": "POINT(-148.82 -81.66)", "dataset_titles": "Carbonyl Sulfide Measurements in the Taylor Dome M3C1 Ice Core; Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core; Methyl Bromide Measurements in the Taylor Dome M3C1 Ice Core; Methyl Chloride Measurements from the Siple Dome A Deep Core, Antarctica; Methyl Chloride Measurements in the Taylor Dome M3C1 Ice Core", "datasets": [{"dataset_uid": "609598", "doi": "10.7265/N5X0650D", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Taylor Dome; Taylor Dome Ice Core", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Methyl Bromide Measurements in the Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/609598"}, {"dataset_uid": "609356", "doi": "10.7265/N56W9807", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Saltzman, Eric; Williams, Margaret; Aydin, Murat", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Methyl Chloride Measurements from the Siple Dome A Deep Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609356"}, {"dataset_uid": "609600", "doi": "10.7265/N5PG1PPB", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Taylor Dome; Taylor Dome Ice Core", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Methyl Chloride Measurements in the Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/609600"}, {"dataset_uid": "601361", "doi": "10.15784/601361", "keywords": "Antarctica; Carbonyl Sulfide; Trace Gases", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/601361"}, {"dataset_uid": "609599", "doi": "10.7265/N5S75D8P", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Taylor Dome; Taylor Dome Ice Core", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Carbonyl Sulfide Measurements in the Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/609599"}], "date_created": "Wed, 22 Oct 2008 00:00:00 GMT", "description": "Saltzman/0636953\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to measure methyl chloride, methyl bromide, and carbonyl sulfide in air extracted from Antarctic ice cores. Previous measurements in firn air and shallow ice cores suggest that the ice archive contains paleo-atmospheric signals for these gases. The goal of this study is to extend these records throughout the Holocene and into the last Glacial period to examine the behavior of these trace gases over longer time scales and a wider range of climatic conditions. These studies are exploratory, and both the stability of these trace gases and the extent to which they may be impacted by in situ processes will be assessed. This project will involve sampling and analyzing archived ice core samples from the Siple Dome, Taylor Dome, Byrd, and Vostok ice cores. The ice core samples will be analyzed by dry extraction, with gas chromatography/mass spectrometry with isotope dilution. The ice core measurements will generate new information about the range of natural variability of these trace gases in the atmosphere. The intellectual merit of this project is that this work will provide an improved basis for assessing the impact of anthropogenic activities on biogeochemical cycles, and new insight into the climatic sensitivity of the biogeochemical processes controlling atmospheric composition. The broader impact of this project is that there is a strong societal interest in understanding how man\u0027s activities impact the atmosphere, and how atmospheric chemistry may be altered by future climate change. The results of this study will contribute to the development of scenarios used for future projections of stratospheric ozone and climate change. In terms of human development, this project will support the doctoral dissertation of a graduate student in Earth System Science, and undergraduate research on polar ice core chemistry. This project will also contribute to the development of an Earth Sciences teacher training curriculum for high school teachers in the Orange County school system in collaboration with an established, NSF-sponsored Math and Science Partnership program (FOCUS).", "east": -148.82, "geometry": "POINT(-148.82 -81.66)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Antarctica; Methyl Bromide; Antarctic; Ice Core Gas Records; Ice Core Data; Carbonyl Sulfide; Methyl Chloride; Antarctic Ice Sheet; Siple Dome; Trace Gases; Ice Core Chemistry; Biogeochemical; Atmospheric Chemistry; West Antarctic Ice Sheet; LABORATORY; Ice Core; West Antarctica", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; Siple Dome; West Antarctica; West Antarctic Ice Sheet", "north": -81.66, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Saltzman, Eric; Aydin, Murat; Williams, Margaret", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core; Siple Dome Ice Core", "south": -81.66, "title": "Methyl Chloride, Methyl Bromide, and Carbonyl Sulfide in Deep Antarctic Ice Cores", "uid": "p0000042", "west": -148.82}, {"awards": "0228052 Kreutz, Karl", "bounds_geometry": "POLYGON((161.0434 -77.3002,161.241645 -77.3002,161.43989 -77.3002,161.638135 -77.3002,161.83638 -77.3002,162.034625 -77.3002,162.23287 -77.3002,162.431115 -77.3002,162.62936 -77.3002,162.827605 -77.3002,163.02585 -77.3002,163.02585 -77.3784846,163.02585 -77.4567692,163.02585 -77.5350538,163.02585 -77.6133384,163.02585 -77.691623,163.02585 -77.7699076,163.02585 -77.8481922,163.02585 -77.9264768,163.02585 -78.0047614,163.02585 -78.083046,162.827605 -78.083046,162.62936 -78.083046,162.431115 -78.083046,162.23287 -78.083046,162.034625 -78.083046,161.83638 -78.083046,161.638135 -78.083046,161.43989 -78.083046,161.241645 -78.083046,161.0434 -78.083046,161.0434 -78.0047614,161.0434 -77.9264768,161.0434 -77.8481922,161.0434 -77.7699076,161.0434 -77.691623,161.0434 -77.6133384,161.0434 -77.5350538,161.0434 -77.4567692,161.0434 -77.3784846,161.0434 -77.3002))", "dataset_titles": "Late Holocene Climate Variability, Dry Valleys, Antarctica", "datasets": [{"dataset_uid": "609399", "doi": "10.7265/N5FF3Q92", "keywords": "Antarctica; Borehole Temperature; Chemistry:ice; Chemistry:Ice; Dry Valleys; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Mass Balance; Paleoclimate; Physical Properties", "people": "Mayewski, Paul A.; Kreutz, Karl", "repository": "USAP-DC", "science_program": null, "title": "Late Holocene Climate Variability, Dry Valleys, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609399"}], "date_created": "Tue, 21 Oct 2008 00:00:00 GMT", "description": "This award supports a project to collect and develop high-resolution ice core records from the Dry Valleys region of Antarctica, and provide interpretations of interannual to decadal-scale climate variability during the last 2000 years (late Holocene). The project will test hypotheses related to ocean/atmosphere teleconnections (e.g., El Nino Southern Oscillation, Antarctic Oscillation) that may be responsible for major late Holocene climate events such as the Little Ice Age in the Southern Hemisphere. Conceptual and quantitative models of these processes in the Dry Valleys during the late Holocene are critical for understanding recent climate changes, and represent the main scientific merit of the project. We plan to collect intermediate-length ice cores (100-200m) at four sites along transects in Taylor Valley and Wright Valley, and analyze each core at high resolution for stable isotopes (d18O, dD), major ions (Na+, Mg2+, Ca2+, K+, NH4+, Cl-, NO3-, SO42-, MSA), and trace elements (Al, Fe, S, Sr, B). A suite of statistical techniques will be applied to the multivariate glaciochemical dataset to identify chemical associations and to calibrate the time-series records with available instrumental data. Broader impacts of the project include: 1) contributions to several ongoing interdisciplinary Antarctic research programs; 2) graduate and undergraduate student involvement in field, laboratory, and data interpretation activities; 3) use of project data and ideas in several UMaine courses and outreach activities; and 4) data dissemination through peer-reviewed publications, UMaine and other paleoclimate data archive websites, and presentations at national and international meetings.", "east": 163.02585, "geometry": "POINT(162.034625 -77.691623)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MC-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e HUMIDITY SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e TEMPERATURE SENSORS", "is_usap_dc": true, "keywords": "Holocene; Climate Research; AWS Climate Data; Paleoclimate; Climate Variation; Dry Valleys; Wright Valley; Little Ice Age; Stable Isotopes; Glaciochemical; Ice Core; FIELD INVESTIGATION; Enso; Antarctic Oscillation; Climate; GPS; El Nino-Southern Oscillation; LABORATORY; Not provided; Climate Change; Ice Core Records; Antarctica; Taylor Valley; FIELD SURVEYS; Variability", "locations": "Antarctica; Dry Valleys; Taylor Valley; Wright Valley", "north": -77.3002, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Kreutz, Karl; Arcone, Steven; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.083046, "title": "Dry Valleys Late Holocene Climate Variability", "uid": "p0000155", "west": 161.0434}, {"awards": "0440670 Hulbe, Christina; 0440636 Fahnestock, Mark", "bounds_geometry": "POLYGON((-180 -70,-175 -70,-170 -70,-165 -70,-160 -70,-155 -70,-150 -70,-145 -70,-140 -70,-135 -70,-130 -70,-130 -71.6,-130 -73.2,-130 -74.8,-130 -76.4,-130 -78,-130 -79.6,-130 -81.2,-130 -82.8,-130 -84.4,-130 -86,-135 -86,-140 -86,-145 -86,-150 -86,-155 -86,-160 -86,-165 -86,-170 -86,-175 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -84.4,180 -82.8,180 -81.2,180 -79.6,180 -78,180 -76.4,180 -74.8,180 -73.2,180 -71.6,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,-180 -70))", "dataset_titles": "MOA-derived Structural Feature Map of the Ronne Ice Shelf; MOA-derived Structural Feature Map of the Ross Ice Shelf; Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "datasets": [{"dataset_uid": "609497", "doi": "10.7265/N5PR7SXR", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MOA; MODIS; Ronne Ice Shelf", "people": "Ledoux, Christine; Hulbe, Christina", "repository": "USAP-DC", "science_program": null, "title": "MOA-derived Structural Feature Map of the Ronne Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/609497"}, {"dataset_uid": "601432", "doi": "10.15784/601432", "keywords": "Antarctica", "people": "Ledoux, Christine; Hulbe, Christina; Forbes, Martin", "repository": "USAP-DC", "science_program": null, "title": "MOA-derived Structural Feature Map of the Ross Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601432"}, {"dataset_uid": "600024", "doi": "", "keywords": null, "people": "Fahnestock, Mark", "repository": "USAP-DC", "science_program": null, "title": "Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "url": "https://www.usap-dc.org/view/dataset/600024"}], "date_created": "Thu, 25 Sep 2008 00:00:00 GMT", "description": "This award supports a three year project to develop the tools required to interpret complex patterns of flow features on the Ross Ice Shelf, which record the discharge history the ice streams flowing east off of the West Antarctic Ice Sheet. This work builds on previous research that used flow features visible in satellite image mosaics and numerical models of ice shelf flow to detect changes in grounding zone dynamics and redirection of ice stream outlets over hundreds of years. Recently observed changes on Whillans Ice Stream fit within this framework. The pattern of redirection is driven by the influence of rapid downstream thinning on the basal thermal gradient in the ice and associated \"sticky spot\" (ice rise) formation. In pursuing this work, the investigators recognized other records of discharge variation on the shelf that can be used to build a more complete history and understanding of ice-stream discharge variability. The intellectual merit of the proposed work lies in the fact that these records, including fracture patterns and spatial variation in ice thickness, when understood in the proper context, will yield quantitative information about the timing and dynamics of ice stream slowdowns, grounding line retreat, and the relative history of discharge between the ice streams. New tools will help further constrain this history. The laser altimeter on NASA\u0027s IceSAT has improved our knowledge of the surface elevation of Antarctic ice. IceSAT surface elevations provide a high-resolution map of ice-shelf thickness that, along with provenance maps from ice-shelf image mosaics, will be used to estimate the volumes of ice involved in past ice-stream discharge events (slowdowns, redirections, and so on). This project will develop new numerical models for fracture propagation; these will allow past variations in ice-shelf stress state to be investigated. Together, the dynamic and volume-flux histories will provide a powerful set of observations for understanding past variations in ice stream discharge and the underlying physical processes. The broader impacts of this project center on how it contributes to the ability to estimate West Antarctic contributions to global sea level rise and to answer outstanding questions about the causes of millennial and longer-scale evolution of ice streams. This work will provide a history of the most complex record of ice discharge known. In addition to the incorporation of this research into graduate student advising and normal teaching duties, the investigators are involved in other avenues of civic engagement and education. Outreach to high school students and the community at large is promoted on an annual basis by the investigators at both institutions. New outreach projects at Portland State University are developed with the assistance of researchers with expertise in student learning and achievement in science and mathematics. The collaborative research team includes two glaciologists with experience in the pairing of high resolution satellite imagery and a variety of ice-flow models and a geologist whose focus is the mechanics of rock deformation.", "east": -130.0, "geometry": "POINT(-155 -78)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e MODIS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e MODIS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; Fracture Patterns; Ross Ice Shelf; West Antarctic Ice Sheet; Not provided; Antarctica; TERRA; Ice Sheet; Ice Rise; LABORATORY; Ice-Stream Discharge; West Antarctica; Fracture Propagation; SATELLITES; Ice Stream Motion; Grounding Line; Ice Movement; Ice Stream; Whillans Ice Stream; Ice Stream Outlets; Basal Temperature Gradient; Numerical Model; Ice Thickness; Flow Features; Kamb Ice Stream; Antarctic Ice Sheet; Satellite Image Mosaics; Icesat; Grounding Line Migration; ICESAT", "locations": "Kamb Ice Stream; Whillans Ice Stream; Antarctica; Ross Ice Shelf; West Antarctic Ice Sheet; Antarctic Ice Sheet; West Antarctica", "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Hulbe, Christina; Ledoux, Christine; Fahnestock, Mark", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e ICE, CLOUD AND LAND ELEVATION SATELLITE (ICESAT) \u003e ICESAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e TERRA", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.0, "title": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "uid": "p0000096", "west": 180.0}, {"awards": "0229546 MacAyeal, Douglas", "bounds_geometry": "POINT(-178 -78)", "dataset_titles": "collection of nascent rift images and description of station deployment; Continuous GPS (static) Data from the Ross Ice Shelf, Antarctica; Giant Icebergs of the Ross Sea, in situ Drift and Weather Measurements, Antarctica; Iceberg Firn Temperatures, Antarctica; Iceberg Harmonic Tremor, Seismometer Data, Antarctica; Iceberg Satellite imagery from stations and ice shelves (full data link not provided); Iceberg Tiltmeter Measurements, Antarctica; Ice Shelf Rift Time-Lapse Photography, Antarctica; Incorporated Research Institutions for Seismology; Nascent Iceberg Webcam Images available during the deployment period; Ross Ice Shelf Firn Temperature, Antarctica; The files contain a short header (number of data samples, sample rate, start time, stop time, channel title)The time series data then follow the header above.; This site mirrors the NSIDC website archive.", "datasets": [{"dataset_uid": "609352", "doi": "10.7265/N5M61H55", "keywords": "Glaciology; Iceberg; Oceans; Ross Ice Shelf; Sea Ice; Snow/ice; Snow/Ice; Southern Ocean; Temperature", "people": "MacAyeal, Douglas; Sergienko, Olga; Thom, Jonathan", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Firn Temperatures, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609352"}, {"dataset_uid": "609350", "doi": "10.7265/N5VM496K", "keywords": "AWS; Glaciology; GPS; Iceberg; Meteorology; Oceans; Ross Sea; Sea Ice; Southern Ocean; Weatherstation", "people": "Bassis, Jeremy; Aster, Richard; Okal, Emile; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Giant Icebergs of the Ross Sea, in situ Drift and Weather Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609350"}, {"dataset_uid": "609351", "doi": "10.7265/N5QV3JGV", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Photo/video; Photo/Video; Ross Ice Shelf", "people": "Brunt, Kelly; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Ice Shelf Rift Time-Lapse Photography, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609351"}, {"dataset_uid": "609347", "doi": "10.7265/N57W694M", "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ross Ice Shelf; Southern Ocean", "people": "Brunt, Kelly; MacAyeal, Douglas; King, Matthew", "repository": "USAP-DC", "science_program": null, "title": "Continuous GPS (static) Data from the Ross Ice Shelf, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609347"}, {"dataset_uid": "001684", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "This site mirrors the NSIDC website archive.", "url": "http://uwamrc.ssec.wisc.edu/"}, {"dataset_uid": "609353", "doi": "10.7265/N5GF0RFF", "keywords": "Glaciology; Iceberg; Oceans; Ross Ice Shelf; Sea Ice; Southern Ocean; Tiltmeter", "people": "Kim, Young-Jin; MacAyeal, Douglas; Bliss, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Tiltmeter Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609353"}, {"dataset_uid": "609354", "doi": "10.7265/N5BP00Q3", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ross Ice Shelf; Snow/ice; Snow/Ice; Temperature", "people": "Scambos, Ted; Sergienko, Olga; Muto, Atsu; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Ross Ice Shelf Firn Temperature, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609354"}, {"dataset_uid": "002568", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Iceberg Satellite imagery from stations and ice shelves (full data link not provided)", "url": "http://amrc.ssec.wisc.edu/"}, {"dataset_uid": "001598", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "The files contain a short header (number of data samples, sample rate, start time, stop time, channel title)The time series data then follow the header above.", "url": "http://nsidc.org"}, {"dataset_uid": "002504", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Nascent Iceberg Webcam Images available during the deployment period", "url": "https://amrc.ssec.wisc.edu/data/iceberg.html"}, {"dataset_uid": "001639", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "collection of nascent rift images and description of station deployment", "url": "http://thistle.org/nascent/index.shtml"}, {"dataset_uid": "609349", "doi": "10.7265/N5445JD6", "keywords": "Geology/Geophysics - Other; Glaciology; Iceberg; Oceans; Ross Sea; Sea Ice; Seismometer; Southern Ocean", "people": "Bassis, Jeremy; Aster, Richard; Okal, Emile; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Harmonic Tremor, Seismometer Data, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609349"}, {"dataset_uid": "001685", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Incorporated Research Institutions for Seismology", "url": "http://www.iris.edu/data/sources.htm"}], "date_created": "Fri, 19 Sep 2008 00:00:00 GMT", "description": "This award supports the study of the drift and break-up of Earth\u0027s largest icebergs, which were recently released into the Ross Sea of Antarctica as a result of calving from the Ross Ice Shelf. The scientific goals of the study are to determine the physics of iceberg motion within the dynamic context of ocean currents, winds, and sea ice, which determine the forces that drive iceberg motion, and the relationship between the iceberg and geographically and topographically determined pinning points on which the iceberg can ground. In addition, the processes by which icebergs influence the local environments (e.g., sea ice conditions near Antarctica, access to penguin rookeries, air-sea heat exchange and upwelling at iceberg margins, nutrient fluxes) will be studied. The processes by which icebergs generate globally far-reaching ocean acoustic signals that are detected within the global seismic (earthquake) sensing networks will also be studied. A featured element of the scientific research activity will be a field effort to deploy automatic weather stations, seismometer arrays and GPS-tracking stations on several of the largest icebergs presently adrift, or about to be adrift, in the Ross Sea. Data generated and relayed via satellite to home institutions in the Midwest will motivate theoretical analysis and computer simulation; and will be archived on an \"iceberg\" website (http://amrc.ssec.wisc.edu/amrc/iceberg.html) for access by scientists and the general public. At the most broad level, the study is justified by the fact that icebergs released by the Antarctic ice sheet represent the largest movements of fresh water within the natural environment (e.g., several of the icebergs to be studied, B15, C19 and others calved since 2000 CE, represent over 6000 cubic kilometers of fresh water-an amount roughly equivalent to 100 years of the flow of the Nile River). A better understanding of the impact of iceberg drift through the environment, and particularly the impact on ocean stratification and mixing, is essential to the understanding of the abrupt global climate changes witnessed by proxy during the ice age and of concern under conditions of future greenhouse warming. On a more specific level, the study will generate a knowledge base useful for the better management of Antarctic logistical resources (e.g., the shipping lanes to McMurdo Station) that can occasionally be influenced by adverse effects icebergs have on sea ice conditions.", "east": -178.0, "geometry": "POINT(-178 -78)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e HUMIDITY SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e TEMPERATURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e MMS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e TEMPERATURE LOGGERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e TEMPERATURE PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e TEMPERATURE SENSORS", "is_usap_dc": true, "keywords": "SEISMOLOGICAL STATIONS; Pressure; AWS; Velocity Measurements; Firn Temperature Measurements; Ice Velocity; Seismology; Ice Sheet Elevation; Harmonic Tremor; Ice Shelf Temperature; Wind Speed; Iceberg; Ice Surface Elevation; Non-Volcanic Tremor; Not provided; Antarctic; Iceberg Tremor; Solar Radiation; Antarctic Ice Sheet; Ross Ice Shelf; Elevation; GPS; Temperature Profiles; Ice Shelf Rift Camera; GROUND STATIONS; Latitude; GROUND-BASED OBSERVATIONS; Ice Shelf Weather; FIELD INVESTIGATION; ARWS; Surface Elevation; Ice Shelf Flow; Antarctica; FIELD SURVEYS; Camera; Seismometer; Iceberg Weather (aws); Ice Movement; Photo; Wind Direction; Iceberg Snow Accumulation; Tremor And Slow Slip Events; AWS Climate Data; Location; Iceberg Drift; Iceberg Collisions; Iceberg Tilt; Atmospheric Pressure; Iceberg Seismicity; Firn Temperature", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; Ross Ice Shelf", "north": -78.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Okal, Emile; Aster, Richard; Bassis, Jeremy; Kim, Young-Jin; Bliss, Andrew; Sergienko, Olga; Thom, Jonathan; Scambos, Ted; Muto, Atsu; Brunt, Kelly; King, Matthew; Parker, Tim; Okal, Marianne; Cathles, Mac; MacAyeal, Douglas", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e ARWS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS; Not provided; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "AMRDC; IRIS; NSIDC; Project website; USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research of Earth\u0027s Largest Icebergs", "uid": "p0000117", "west": -178.0}, {"awards": "0536870 Rogers, Scott", "bounds_geometry": "POINT(-106.8 -72.4667)", "dataset_titles": "Comprehensive Biological Study of Vostok Accretion Ice", "datasets": [{"dataset_uid": "600052", "doi": "10.15784/600052", "keywords": "Antarctica; Biota; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrothermal Vent; Lake Vostok; Microbes; Subglacial Lake", "people": "Rogers, Scott O.", "repository": "USAP-DC", "science_program": null, "title": "Comprehensive Biological Study of Vostok Accretion Ice", "url": "https://www.usap-dc.org/view/dataset/600052"}], "date_created": "Tue, 02 Sep 2008 00:00:00 GMT", "description": "The large subglacial Lake Vostok in Antarctica is unique ecological site with a novel microbial biota. The temperatures, pressures and lack of light all select for organisms that may not exist anywhere else on Earth. The accretion ice (lake water frozen to the bottom of the lower surface of the glacier) has preserved microbial samples from each region of Lake Vostok as the glacier passes over and into the lake. Thus, without contaminating the lake with microorganisms from the surface, microbes originating from the lake can be collected, transported to the laboratory and studied. Two of the deepest ice cores sections in this project are part of the international allocation. The will be shared between four researchers (Sergey Bulat from Russia, Jean-Robert Petit and Daniel Prieur from France, Scott Rogers from USA). The United States team will study, isolate, and characterize bacteria, fungi, and viruses that have been sampled from the lake through the process of ice accretion to the lower surface of 3500+m thick glacier overriding the lake. The project will involve a suite of methods, including molecular, morphological, and cultural. This includes observation and description by fluorescence, light, and electron microscopy, isolation on thirteen separate cultural media, polymerase chain reaction amplification, DNA sequencing, and phylogenetic analyses. Eleven accretion ice core sections, as well as two glacial ice core sections. As well as two glacial ice core sections will be studied. The accretion ice core sections, as well as two glacial ice core sections will be studied. The accretion ice core sections represent all of the major regions of the lake that have been sampled by the accretion process in the vicinity of the Vostok 5G ice core. The broader impacts of the work relate to the impact the results will have on the filed. These long=isolated lakes, deep below the Antarctic ice sheet may contain novel uniquely adapted organisms. Glacial ice contains an enormous diversity of entrapped microbes, some of which may be metabolically active in the ice. The microbes from Lake Vostok are of special interest, since they are adapted to cold, dark, and high pressure. Thus, their enzyme systems and biochemical pathways may be significantly different from those in the microbes that are the subject of current studies. As such, these organisms may form compounds that may have useful applications. Also, study of the accretion ice, and eventually the water, from Lake Vostok will provide a basis for the study of other subglacial lakes. Additionally, study of the microbes in the accretion ice will be useful to those planning to study analogous systems on ice-covered planets and moons.", "east": -106.8, "geometry": "POINT(-106.8 -72.4667)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -72.4667, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Rogers, Scott O.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.4667, "title": "Comprehensive Biological Study of Vostok Accretion Ice", "uid": "p0000566", "west": -106.8}, {"awards": "0440447 Spencer, Matthew; 0917509 Spencer, Matthew", "bounds_geometry": "POINT(-148.81 -81.65)", "dataset_titles": "Firn depth and bubble density for Siple Ice Core and other sites", "datasets": [{"dataset_uid": "601746", "doi": "10.15784/601746", "keywords": "Antarctica; Density; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Data; Ice Core Records; Siple Dome; Snow/ice; Snow/Ice", "people": "Spencer, Matthew", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Firn depth and bubble density for Siple Ice Core and other sites", "url": "https://www.usap-dc.org/view/dataset/601746"}], "date_created": "Mon, 19 May 2008 00:00:00 GMT", "description": "This award supports a two-year collaborative effort to more fully understand the climatic history and physical properties of the Siple Dome, Antarctica deep ice core, to develop a new paleoclimatic technique based on bubble number-density, and to improve the U.S. capability to analyze ice-core physical properties rapidly and accurately. The Siple Dome ice core from West Antarctica is yielding important paleoclimatic insights, but has proven more difficult than some cores to interpret owing to the large iceflow effects on the paleoclimatic record. Paleoclimatic indicators that do not rely on iceflow corrections thus would be of value. The bubble number-density offers one such indicator, because it preserves information on mean temperature and accumulation rate during the transformation of firn to ice. We will focus on thin-section characteristics that are important to ice flow and the interpretation of the ice-core history, such as c-axis fabrics, and will use indicators that we have been developing, such as the correlation between grain elongation and the c-axis orientation, to gain additional information. To achieve this quickly and accurately, and to prepare for future projects, we propose to upgrade the automatic caxis- fabric analyzer that Wilen has built and housed at the National Ice Core Laboratory. The intellectual merit of the proposed activity includes improved estimates of paleoclimatic conditions in an important region, improved understanding of a new paleoclimatic research tool, greater understanding of ice flow and of linkages to physical properties, and a better instrument for further U.S. research in ice-core physical properties at the National Ice Core Laboratory. The broader impacts resulting from the proposed activity include providing better understanding of abrupt climate change and of ice flow, which eventually should help policy-makers, as well as an improved U.S. capability to analyze ice cores. The proposed research will assist the studies of two promising young scientists. Results of the research will be incorporated into courses and public outreach reaching at least hundreds or thousands of people per year.", "east": -148.81, "geometry": "POINT(-148.81 -81.65)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided; Ice Core; Ice Flow; Bubble Number Density; LABORATORY; Thin Sections; Paleoclimate; FIELD INVESTIGATION; Fabric; Siple Dome; Climate; Antarctica; Antarctic; FIELD SURVEYS", "locations": "Siple Dome; Antarctica; Antarctic", "north": -81.65, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Spencer, Matthew; Wilen, Larry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.65, "title": "Collaborative Research: Combined Physical Property Measurements at Siple Dome", "uid": "p0000658", "west": -148.81}, {"awards": "0338224 Putkonen, Jaakko", "bounds_geometry": "POLYGON((161 -77,161.3 -77,161.6 -77,161.9 -77,162.2 -77,162.5 -77,162.8 -77,163.1 -77,163.4 -77,163.7 -77,164 -77,164 -77.1,164 -77.2,164 -77.3,164 -77.4,164 -77.5,164 -77.6,164 -77.7,164 -77.8,164 -77.9,164 -78,163.7 -78,163.4 -78,163.1 -78,162.8 -78,162.5 -78,162.2 -78,161.9 -78,161.6 -78,161.3 -78,161 -78,161 -77.9,161 -77.8,161 -77.7,161 -77.6,161 -77.5,161 -77.4,161 -77.3,161 -77.2,161 -77.1,161 -77))", "dataset_titles": "Cosmogenic nucilde data at ICE-D", "datasets": [{"dataset_uid": "200298", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nucilde data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Tue, 20 Nov 2007 00:00:00 GMT", "description": "This work will study cosmogenic isotope profiles of rock and sediment in the Dry Valleys of Antarctica to understand their origin. The results will provide important constraints on the history of the East Antarctic Ice Sheet. The near-perfect preservation of volcanic ash and overlying sediments suggests that hyperarid cold conditions have prevailed in the Dry Valleys for over 10 Myr. The survival of these sediments also suggests that warm-based ice has not entered the valley system and ice sheet expansion has been minimal. Other evidence, however, suggests that the Dry Valleys have experienced considerably more sediment erosion than generally believed: 1) the cosmogenic exposure ages of boulders and bedrock in the Valleys all show generally younger ages than volcanic ash deposits used to determine minimum ages of moraines and drifts, 2) there appears to be a discrepancy between the suggested extreme preservation of unconsolidated slope deposits (\u003e10 Myr) and adjacent bedrock that has eroded 2.6-6 m during the same time interval. The fact that the till and moraine exposure ages generally post date the overlying volcanic ash deposits could reflect expansion of continental ice sheet into the Dry Valleys with cold-based ice, thus both preserving the landscape and shielding the surfaces from cosmic radiation. Another plausible explanation of the young cosmogenic exposure ages is erosion of the sediments and gradual exhumation of formerly buried boulders to the surface. Cosmogenic isotope systematics are especially well suited to address these questions. We will measure multiple cosmogenic isotopes in profiles of rock and sediment to determine the minimum exposure ages, the degree of soil stability or mixing, and the shielding history of surfaces by cold based ice. We expect to obtain unambiguous minimum ages for deposits. In addition, we should be able to identify areas disturbed by periglacial activity, constrain the timing of such activity, and account for the patchy preservation of important stratigraphic markers such as volcanic ash. The broader impacts of this project include graduate and undergraduate education, and improving our understanding of the dynamics of Southern Hemisphere climate on timescales of millions of years, which has major implications for understanding the controls and impacts of global climate change.", "east": 164.0, "geometry": "POINT(162.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Dry Valleys; Not provided", "locations": "Dry Valleys", "north": -77.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Putkonen, Jaakko", "platforms": "Not provided", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -78.0, "title": "Stability of Landscapes and Ice Sheets in Dry Valleys, Antarctica: A Systematic Study of Exposure Ages of Soils and Surface Deposits", "uid": "p0000575", "west": 161.0}, {"awards": "0337891 Brook, Edward J.", "bounds_geometry": "POINT(158 -77.666667)", "dataset_titles": "Atmospheric CO2 and Climate: Byrd Ice Core, Antarctica; Atmospheric CO2 and Climate: Taylor Dome Ice Core, Antarctica", "datasets": [{"dataset_uid": "609314", "doi": "10.7265/N58W3B80", "keywords": "Antarctica; Atmosphere; Byrd Glacier; Byrd Ice Core; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate", "people": "Brook, Edward J.; Ahn, Jinho", "repository": "USAP-DC", "science_program": "Byrd Ice Core", "title": "Atmospheric CO2 and Climate: Byrd Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609314"}, {"dataset_uid": "609315", "doi": "10.7265/N5542KJK", "keywords": "Antarctica; Atmosphere; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "people": "Brook, Edward J.; Ahn, Jinho", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Atmospheric CO2 and Climate: Taylor Dome Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609315"}], "date_created": "Mon, 05 Nov 2007 00:00:00 GMT", "description": "This award supports the development of a new laboratory capability in the U.S. to measure CO2 in ice cores and investigate millennial-scale changes in CO2 during the last glacial period using samples from the Byrd and Siple Dome ice cores. Both cores have precise relative chronologies based on correlation of methane and the isotopic composition of atmospheric oxygen with counterpart records from Greenland ice cores. The proposed work will therefore allow comparison of the timing of CO2 change, Antarctic temperature change, and Greenland temperature change on common time scales. Such comparisons are vital for evaluating models that explain changes in atmospheric CO2. The techniques being developed will also be available for future projects, specifically the proposed Inland WAIS ice core, for which a highly detailed CO2 record is a major objective, and studies greenhouse and other atmospheric gases and their isotopic composition for which dry extraction is necessary (stable isotopes in CO2, for example). There are many broad impacts of the proposed work. Ice core greenhouse gas records are central contributions of paleoclimatology to research and policy-making concerning global change. The proposed work will enhance those contributions by improving our understanding of the natural cycling of the most important greenhouse gas. It will contribute to the training of a postdoctoral researcher, who will be an integral part of an established research group and benefit from the diverse paleoclimate and geochemistry community at OSU. The PI teaches major and non-major undergraduate and graduate courses on climate and global change. The proposed work will enrich those courses and the courses will provide an opportunity for the postdoctoral researcher to participate in teaching by giving guest lectures. The PI also participates in a summer climate workshop for high school teachers at Washington State University and the proposed work will enrich that contribution. The extraction device that is built and the expertise gained in using it will be resources for the ice core community and available for future projects. Data will be made available through established national data center and the equipment designs will also be made available to other researchers.", "east": 158.0, "geometry": "POINT(158 -77.666667)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Core; Climate Change; CO2; Atmospheric Chemistry; Atmospheric CO2; LABORATORY; Not provided; Ice Core Data; Climate; Ice Core Chemistry; Atmospheric Gases; Ice Core Gas Records; GROUND STATIONS; Climate Research", "locations": null, "north": -77.666667, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Ahn, Jinho; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": -77.666667, "title": "Developing Dry Extraction of Ice Core Gases and Application to Millennial-Scale Variability in Atmospheric CO2", "uid": "p0000268", "west": 158.0}, {"awards": "9909665 Berger, Glenn", "bounds_geometry": "POLYGON((-67.25 -62,-66.025 -62,-64.8 -62,-63.575 -62,-62.35 -62,-61.125 -62,-59.9 -62,-58.675 -62,-57.45 -62,-56.225 -62,-55 -62,-55 -62.525,-55 -63.05,-55 -63.575,-55 -64.1,-55 -64.625,-55 -65.15,-55 -65.675,-55 -66.2,-55 -66.725,-55 -67.25,-56.225 -67.25,-57.45 -67.25,-58.675 -67.25,-59.9 -67.25,-61.125 -67.25,-62.35 -67.25,-63.575 -67.25,-64.8 -67.25,-66.025 -67.25,-67.25 -67.25,-67.25 -66.725,-67.25 -66.2,-67.25 -65.675,-67.25 -65.15,-67.25 -64.625,-67.25 -64.1,-67.25 -63.575,-67.25 -63.05,-67.25 -62.525,-67.25 -62))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001707", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0303"}, {"dataset_uid": "001818", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0107"}], "date_created": "Wed, 10 Oct 2007 00:00:00 GMT", "description": "9909665 Berger This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports project to test and develop approaches for using thermoluminescence techniques to determine the age of Antarctic marine sediments. Quaternary (last 2 million yrs) marine sediments surrounding Antarctica record the waxing and waning of ice shelves and ice sheets, and also other paleoclimatic information, yet accurate chronologies of these sediments are difficult to obtain. Such chronologies provide the essential foundation for study of geological processes in the past. Within the range of radiocarbon (14C) dating (less than 30-40 thousand yrs, note - \"ka\" below means 1000 yrs) 14C dates can be inaccurate because of a variable 14C reservoir effect, and beyond 30-40 ka few methods are applicable. Photon-stimulated-luminescence sediment dating (photonic dating) of eolian and waterlain deposits in temperate latitudes spans the range from decades to hundreds of ka, but marine sediments in and around Antarctica pose special difficulty because of the potentially restricted exposure to daylight (the clock-zeroing process) of most detrital grains before deposition. This proposal will test the clock-zeroing assumption in representative Antarctic glaciomarine depositional settings, and thereby determine the potential reliability of photonic dating of Antarctic marine sediments. Limited luminescence dating and signal-zeroing tests using glaciomarine and marine deposits have been conducted in the northern temperate and polar latitudes, but the effects on luminescence of the different glaciomarine depositional processes have never been studied in detail. Furthermore, the depositional settings around Antarctica are almost entirely polar, with consequent specific processes operating there. For example, transport of terrigenous suspensions by neutrally buoyant \"cold-tongue\" (mid-water) plumes may be common around Antarctica, yet the effect of such transport on luminescence zeroing is unknown. Typical marine cores near Antarctica may contain an unknown fraction of detrital grains from cold-tongue and near-bottom suspensions. Thus the extent to which the polar glaciomarine depositional processes around Antarctica may limit the potential accuracy of photonic dating of marine cores is unknown (age overestimates would result if grains are not exposed to daylight before deposition). This project will collect detrital grains from a variety of \"zero-age\" (modern) marine depositional settings within the Antarctic Peninsula, where representative Antarctic depositional processes have been documented and where logistics permit access. Suspensions will be collected from four fjords representing a transect from polar through subpolar conditions. Suspensions will be collected from two stations and from up to 3 depths (surface and 2 deep plumes) at each station. Sediment traps will be deployed at two of these fjord settings. As well, core-top sediments will be collected from several sites. All samples will be shielded from light and transported to Reno, Nevada, for luminescence analyses. Systematic study of the effectiveness of luminescence-clock-zeroing in Antarctic glaciomarine settings will determine if photonic dating can be reliable for future applications to Antarctic marine sediments. Refined sedimentological criteria for the selection of future samples for photonic dating are expected from this project. A photonic-dating capability would provide a numeric geochronometer extending well beyond the age range of 14C dating. Such a capability would permit answering a number of broader questions about the timing and extent of past glaciations near and on the Antarctic shelves.", "east": -55.0, "geometry": "POINT(-61.125 -64.625)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": false, "keywords": "R/V LMG; Not provided; Luminescence; Hugo Island; Geochronology; R/V NBP; Palmer Deep", "locations": "Hugo Island", "north": -62.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Berger, Glenn; Domack, Eugene Walter", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -67.25, "title": "Collaborative Research: Development of a Luminescence Dating Capability for Antarctic Glaciomarine Sediments: Tests of Signal Zeroing at the Antarctic Pennisula", "uid": "p0000592", "west": -67.25}, {"awards": "0540915 Scambos, Ted", "bounds_geometry": "POLYGON((-57.9857 -48.444,-55.95557 -48.444,-53.92544 -48.444,-51.89531 -48.444,-49.86518 -48.444,-47.83505 -48.444,-45.80492 -48.444,-43.77479 -48.444,-41.74466 -48.444,-39.71453 -48.444,-37.6844 -48.444,-37.6844 -50.12802,-37.6844 -51.81204,-37.6844 -53.49606,-37.6844 -55.18008,-37.6844 -56.8641,-37.6844 -58.54812,-37.6844 -60.23214,-37.6844 -61.91616,-37.6844 -63.60018,-37.6844 -65.2842,-39.71453 -65.2842,-41.74466 -65.2842,-43.77479 -65.2842,-45.80492 -65.2842,-47.83505 -65.2842,-49.86518 -65.2842,-51.89531 -65.2842,-53.92544 -65.2842,-55.95557 -65.2842,-57.9857 -65.2842,-57.9857 -63.60018,-57.9857 -61.91616,-57.9857 -60.23214,-57.9857 -58.54812,-57.9857 -56.8641,-57.9857 -55.18008,-57.9857 -53.49606,-57.9857 -51.81204,-57.9857 -50.12802,-57.9857 -48.444))", "dataset_titles": "Atlas of the Cryosphere - View dynamic maps of snow, sea ice, glaciers, ice sheets, permafrost, and more.; Climate, Drift, and Image Data from Antarctic Icebergs A22A and UK211, 2006-2007; MODIS Mosaic of Antarctica (MOA)", "datasets": [{"dataset_uid": "000189", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Atlas of the Cryosphere - View dynamic maps of snow, sea ice, glaciers, ice sheets, permafrost, and more.", "url": "http://nsidc.org/MMS/atlas/cryosphere_atlas_north.html"}, {"dataset_uid": "000190", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "MODIS Mosaic of Antarctica (MOA)", "url": "http://nsidc.org/data/nsidc-0280.html"}, {"dataset_uid": "609466", "doi": "10.7265/N5N014GW", "keywords": "Ablation; Atmosphere; Glaciology; GPS; Meteorology; Oceans; Photo/video; Photo/Video; Sea Ice; Southern Ocean; Temperature", "people": "Thom, Jonathan; Scambos, Ted; Yermolin, Yevgeny; Bohlander, Jennifer; Bauer, Rob", "repository": "USAP-DC", "science_program": null, "title": "Climate, Drift, and Image Data from Antarctic Icebergs A22A and UK211, 2006-2007", "url": "https://www.usap-dc.org/view/dataset/609466"}], "date_created": "Thu, 16 Aug 2007 00:00:00 GMT", "description": "This award supports a small grant for exploratory research to study the processes that contribute to the melting and break-up of tabular polar icebergs as they drift north. This work will enable the participation of a group of U.S. scientists in this international project which is collaborative with the Instituto Antartico Argentino. The field team will place weather instruments, firn sensors, and a video camera on the iceberg to measure the processes that affect it as it drifts north. In contrast to icebergs in other sectors of Antarctica, icebergs in the northwestern Weddell Sea drift northward along relatively predictable paths, and reach climate and ocean conditions that lead to break-up within a few years. The timing of this study is critical due to the anticipated presence of iceberg A43A, which broke off the Ronne Ice Shelf in February 2000 and which is expected to be accessible from Marambio Station in early 2006. It has recently been recognized that the end stages of break-up of these icebergs can imitate the rapid disintegrations due to melt ponding and surface fracturing observed for the Larsen A and Larsen B ice shelves. However, in some cases, basal melting may play a significant role in shelf break-up. Resolving the processes (surface ponding/ fracturing versus basal melt) and observing other processes of iceberg drift and break up in-situ are of high scientific interest. An understanding of the mechanisms that lead to the distintegration of icebergs as they drift north may enable scientists to use icebergs as proxies for understanding the processes that could cause ice shelves to disintegrate in a warming climate. A broader impact would thus be an ability to predict ice shelf disintegration in a warming world. Glacier mass balance and ice shelf stability are of critical importance to sea level change, which also has broader societal relevance.", "east": -37.6844, "geometry": "POINT(-47.83505 -56.8641)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ICE AUGERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SNOW DENSITY CUTTER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e MODIS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e MMS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Air Temperature; Weddell Sea; Edge-Wasting; Ice Shelf Meltwater; TERRA; Antarctic; GPS; Iceberg; Ice Breakup; South Atlantic Ocean; AQUA; Tabular; Photo; Not provided; Icetrek; HELICOPTER; Antarctica", "locations": "Antarctic; Weddell Sea; Antarctica; South Atlantic Ocean", "north": -48.444, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted; Bohlander, Jennifer; Bauer, Rob; Yermolin, Yevgeny; Thom, Jonathan", "platforms": "AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER \u003e HELICOPTER; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e AQUA; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e TERRA; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "NSIDC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": -65.2842, "title": "Investigating Iceberg Evolution During Drift and Break-Up: A Proxy for Climate-Related Changes in Antarctic Ice Shelves", "uid": "p0000003", "west": -57.9857}, {"awards": "0337948 Bromwich, David", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Access to data", "datasets": [{"dataset_uid": "001778", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to data", "url": "http://polarmet.mps.ohio-state.edu/PolarMet/ant_hindcast.html"}], "date_created": "Thu, 02 Aug 2007 00:00:00 GMT", "description": "This award supports a comprehensive investigation of the spatial and temporal characteristics of the surface mass balance of the Antarctic ice sheet and the governing mechanisms that affect it. A mesoscale atmospheric model, adapted for Antarctic conditions (Polar MM5), will be used in conjunction with the newly available reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) to resolve the surface mass balance of Antarctica at a time resolution of 3 hours and a spatial resolution of 60 km from 1957 to 2001. Polar MM5 will be upgraded to account for key processes in the simulation, including explicit consideration of blowing snow transport and sublimation as well as surface melting/runoff. The proposed 45-y hindcast of all Antarctic surface mass balance components with a limited area model has not previously been attempted and will provide a dataset of unprecedented scope to complement existing ice core measurements of recent climate, especially those collected by the International Transantarctic Scientific Expedition (ITASE). The trends and variability in space and time over 4.5 decades will be resolved and the impact of the dominant modes of atmospheric variability (Antarctic Oscillation, El Nino-Southern Oscillation, etc.) will be isolated. Hypotheses concerning the Antarctic surface mass balance response to climate change will be tested. The research will provide a sound basis for evaluating the impact of future climate change on Antarctic surface mass balance and its contribution to global sea level change as well as providing an important perspective for the interpretation of Antarctic ice core records. The broader impacts include the education of a Ph.D. student, the development of material for use in university classes, and construction of an interactive educational webpage on Antarctic surface mass balance.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e MMS", "is_usap_dc": false, "keywords": "El Nino-Southern Oscillation; ITASE; Atmospheric Model; Enso; Not provided; Antarctic Oscillation; Mesoscale; Antarctic; Polar Mm5; Climate", "locations": "Antarctic", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bromwich, David; Monaghan, Andrew", "platforms": "Not provided", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -90.0, "title": "A 45-Y Hindcast of Antarctic Surface Mass Balance Using Polar MM5", "uid": "p0000722", "west": -180.0}, {"awards": "9909436 Farley, Kenneth", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 11 Jul 2007 00:00:00 GMT", "description": "9909436 Farley This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an investigation of the uplift history of the Dry Valleys segment of the Transantarctic Mountains. The overall goal is to further constrain the exhumation history of the Transantarctic Mountains by using the newly developed apatite (U-Th)/He dating method on samples collected in vertical profiles. This approach, combined with existing apatite fission track information will constrain the rate and patterns of exhumation across the Transantarctic Mountains since their inception as a rift-flank uplift in the early Cenozoic. This project will complement other projects and build on previous interpretations of the exhumation and tectonic history determined using apatite fission track thermochronology. It will bridge the gap between information on erosion rates determined from fission track thermochronology and from cosmogenic surface exposure dating and integrate the exhumation history of the mountains with their landscape evolution. As such, the results from this project will address an outstanding problem in Antarctic science; namely the stability of the East Antarctic Ice Sheet, and the timing of the transition from a \"warm\" dynamic ice sheet to a cold polar ice sheet. Highly relevant to this issue is the landscape evolution of the Transantarctic Mountains because many diverse lines of evidence for the rate of landscape evolution have been used to argue for a dynamic ice sheet up until either the Pliocene (the \"dynamic\" ice sheet model) or the middle Miocene (the \"stable\" ice sheet model). Understanding the past stability or dynamic fluctuations of the East Antarctic ice sheet with respect to the climate record is, of course, important for understanding how the present ice sheet may respond to global warming. The specific objective of this project is to determine apatite (U-Th)/He age versus elevation trends for a number of vertical profiles from locations within the Transantarctic Mountain front and across the structural grain of the range. Fission track data already exist for all of these profiles, with apatite fission track ages ranging from 150-30 Ma. The greater precision of the (U-Th)/He technique and the fact it records information at lower temperatures (closure temperature of ~70 degrees Celsius; limits of 40-85 degrees Celsius for the He partial retention zone) will allow examination of the exhumation history of the TAM in more detail from ca 130 Ma to ~20 Ma. Another facet is to examine areas where Cretaceous exhumation is recorded and areas where the fission track profiles indicate periods of thermal and tectonic stability and minimal erosion throughout the Cretaceous. The variation of timing of the onset of more rapid exhumation accompanying uplift and formation of the Transantarctic Mountains in the early Cenozoic will also be examined.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Farley, Kenneth", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Exhumation of the Transantarctic Mountains: Constraints from (U-Th)/He Dating of Apatites", "uid": "p0000281", "west": null}, {"awards": "9526556 Sowers, Todd", "bounds_geometry": "POINT(-148.3023 -81.403)", "dataset_titles": "Carbon-13 Isotopic Composition of Atmospheric Methane in Firn Air, South Pole and Siple Dome, Antarctica", "datasets": [{"dataset_uid": "609310", "doi": "10.7265/N5ST7MR2", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Siple Dome; Snow/ice; Snow/Ice; South Pole", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Carbon-13 Isotopic Composition of Atmospheric Methane in Firn Air, South Pole and Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609310"}], "date_created": "Mon, 09 Jul 2007 00:00:00 GMT", "description": "This award is for support for a program to reconstruct records of the isotopic composition of paleoatmospheric methane and nitrous oxide covering the last 200,000 years. High resolution measurements of the carbon-13 isotopic composition of methane from shallow ice cores will help to determine the relative contributions of biogenic (wetlands, rice fields and ruminants) and abiogenic (biomass burning and natural gas) methane emissions which have caused the concentrations of this gas to increase at an exponential rate during the anthropogenic period. Isotopic data on methane and nitrous oxide over glacial/interglacial timescales will help determine the underlying cause of the large concentration variations that are known to occur. This project will make use of a new generation mass spectrometer which is capable of generating precise isotopic information on nanomolar quantities of methane and nitrous oxide, which means that samples can be 1000 times smaller than those needed for a standard isotope ratio instrument. The primary objective of the work is to further our understanding of the biogeochemical cycles of these two greenhouse gases throughout the anthropogenic period as well as over glacial interglacial timescales.", "east": -148.3023, "geometry": "POINT(-148.3023 -81.403)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Ice Core; Firn Air Isotope Measurements; Ice Core Chemistry; Firn Isotopes; Stable Isotopes; Methane; Carbon; Paleoclimate; LABORATORY; Siple Dome; Antarctica; Ice Core Data; Firn Air Isotopes; Antarctic Ice Sheet", "locations": "Antarctica; Antarctic Ice Sheet; Siple Dome", "north": -81.403, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Sowers, Todd A.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.403, "title": "Constructing Paleoatmospheric Records of the Isotopic Composition of Methane and Nitrous Oxide", "uid": "p0000611", "west": -148.3023}, {"awards": "0233303 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 09 Jul 2007 00:00:00 GMT", "description": "Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.\u003cbr/\u003eThis award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.\u003cbr/\u003eA better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Ice Sheet; Basal Melting; Ice Shelf Meltwater; Not provided; Oceanography; Ice Velocity; Glaciology; Sea Level Rise; Ice Sheet Stability; Mass; Ross Ice Sheet; Numerical Model; Basal Freezing; Ice Cavity Circulations; George VI Ice Shelf; Outflow", "locations": "Ross Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Melting and Calving of Antarctic Ice Shelves", "uid": "p0000730", "west": null}, {"awards": "9725882 Raymond, Charles", "bounds_geometry": "POLYGON((-141.6722 -80.1678,-141.34195 -80.1678,-141.0117 -80.1678,-140.68145 -80.1678,-140.3512 -80.1678,-140.02095 -80.1678,-139.6907 -80.1678,-139.36045 -80.1678,-139.0302 -80.1678,-138.69995 -80.1678,-138.3697 -80.1678,-138.3697 -80.4863,-138.3697 -80.8048,-138.3697 -81.1233,-138.3697 -81.4418,-138.3697 -81.7603,-138.3697 -82.0788,-138.3697 -82.3973,-138.3697 -82.7158,-138.3697 -83.0343,-138.3697 -83.3528,-138.69995 -83.3528,-139.0302 -83.3528,-139.36045 -83.3528,-139.6907 -83.3528,-140.02095 -83.3528,-140.3512 -83.3528,-140.68145 -83.3528,-141.0117 -83.3528,-141.34195 -83.3528,-141.6722 -83.3528,-141.6722 -83.0343,-141.6722 -82.7158,-141.6722 -82.3973,-141.6722 -82.0788,-141.6722 -81.7603,-141.6722 -81.4418,-141.6722 -81.1233,-141.6722 -80.8048,-141.6722 -80.4863,-141.6722 -80.1678))", "dataset_titles": "Radar Investigations of Antarctic Ice Stream Margins, Siple Dome, 1998", "datasets": [{"dataset_uid": "609303", "doi": "10.7265/N52B8VZP", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Siple Dome", "people": "Nereson, Nadine A.; Raymond, Charles", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Radar Investigations of Antarctic Ice Stream Margins, Siple Dome, 1998", "url": "https://www.usap-dc.org/view/dataset/609303"}], "date_created": "Fri, 06 Jul 2007 00:00:00 GMT", "description": "9725882 Raymond This award is for support for a program of surface-based radio echo sounding to examine the geometry of the internal layering and the presence or absence of thawed zones outside the margins of active Ice Streams B and E and across the flow band feeding Ice Stream D. Melting in the marginal shear zone and/or on the bed outside an ice stream relates to the amount of support of the ice stream from the sides compared to the bed and the conditions that limit expansion of its width. Radar observations will be extended over the crest of adjacent inter-ice-stream ridges (B/C and D/E) and areas next to the flow band in the onset of D. The purpose is to examine internal layering indicative of the histories of these areas adjacent to ice streams and to determine whether ice streams have expanded into these presently stable areas in the past. These goals concerning the physical controls and history of ice stream width relate to how the discharge of ice streams has changed in the past and could change in the future to affect sea level.", "east": -138.3697, "geometry": "POINT(-140.02095 -81.7603)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS", "is_usap_dc": true, "keywords": "Ice Stream; Antarctica; Bed Geometry; GROUND-BASED OBSERVATIONS; Internal Layering; Internal Layer Geometry; Siple Dome; Shabtaie Ridge; Not provided; Engelhardt Ridge; Ice Stream Margins; Radar; Whillans Ice Stream; GPS; Bed Reflectivity; Macayeal Ice Stream; Surface Geometry", "locations": "Antarctica; Engelhardt Ridge; Macayeal Ice Stream; Shabtaie Ridge; Siple Dome; Whillans Ice Stream", "north": -80.1678, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Raymond, Charles; Nereson, Nadine A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -83.3528, "title": "Internal Stratigraphy and Basal Conditions at the Margins ofActive Ice Streams of the Siple Coast, Antarctica", "uid": "p0000626", "west": -141.6722}, {"awards": "0548918 van de Flierdt, Christina-Maria", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 07 Jun 2007 00:00:00 GMT", "description": "This Small Grant for Exploratory Research supports development of a geochemical technique to time the onset of glacial erosion from Antarctica\u0027s continental ice sheets. The technique pairs neodymium (Nd) and hafnium (Hf) isotope proxies from the authigenic (seawater-derived) ferromanganese phase precipitated in marine sediments. This technique promises to be a sensitive indicator of glacial erosion. Non-radiogenic Hf is contained in the mineral zircon, which can only be released by the abrasive grinding that accompanies glacial erosion. Previous attempts to develop this technique encountered difficulty due to the minute amounts of Hf involved and the difficulty in its extraction. The PIs have developed a new chemical protocol that should allow them to selectively extract authigenic Hf from bulk sediments. If successful, studies of the Eocene-Oligocene boundary from two drill cores the Weddell Sea and Kerguelen Plateau will be carried out. This boundary is considered the initiation point for formation of Antarctica\u0027s current ice sheets. If successful, this method will benefit scientists with interests as diverse as continental weathering, ocean circulation, Cenozoic paleoceanography and paleoclimate, and Antarctic geology. \u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this work are development of a new analytical technique that may improve society\u0027s understanding of the potential for global climate change from the perspective of the deep time record.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Van De Flierdt, Christina-Maria", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "SGER: Development of the Paired Authigenic Neodymium-Hafnium Isotope Weathering Tracer From Marine Sediments in the Circum Antarctic Realm", "uid": "p0000130", "west": null}, {"awards": "0125754 Hulbe, Christina", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 07 Jun 2007 00:00:00 GMT", "description": "This award supports a project to develop computational models to simulate ice-shelf rift propagation using a combination of well-established ice-shelf creep-flow models and new crevasse models, based on linear elastic fracture mechanics (LEFM). The overall objective of the proposed work is to simulate rift propagation and eventual large iceberg calving,and place those processes within a larger ice sheet and climate context. The work will proceed in stages, first developing models of single-and multiple-crevasse propagation; then using those models to evaluate propagation sensitivity to various environmental conditions; and third developing models that incorporate both crevasse propagation and advection within an ice- shelf system. Model development will be guided by and evaluated according to satellite observations of rift propagation in several characteristic locations on Antarctic ice shelves. New numerical models of fracture in ice will have applications to many problems in glaciology. The research proposed here is directed toward large rift formation in ice shelves and subsequent iceberg calving. It is motivated by the need to understand observed changes in modern ice shelves,and their connection to climate. Where it has been sampled, the sedimentary record of the Weddell Sea sector implies Peninsular ice shelf variability on millennial time scales. The ability to simulate iceberg calving in a credible way will improve our ability to reproduce such events and place the complete cycle of ice shelf advance and retreat in an ice-dynamics context. That will, in turn, enable us to place ice-shelf cycles within the climate cycles that ultimately drive ice-sheet mass balance.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hulbe, Christina", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Ice-Shelf Rift Propagation: Computational Simulation Using a Fracture Fracture Mechanics Approach", "uid": "p0000270", "west": null}, {"awards": "0337858 Goodge, John", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 05 Jun 2007 00:00:00 GMT", "description": "This work will determine the age and provenance of glacially derived marine sediments from the coastal regions of Wilkes Land, Antarctica. These deposits may offer insight into the history of the East Antarctic Shield (EAS), which is amongst the oldest sections of continental crust on Earth, but cannot be studied directly because of nearly complete ice sheet coverage. The study will use Australian National University\u0027s SHRIMP ion microprobe to date zircon and monazite found in the sediments. Samples of interest include polymictic pebble and cobble clasts obtained from dredge hauls of tills, as well as sand-matrix fractions from cores of glacial diamicts on the continental margin. Individual clasts of igneous and metamorphic rocks from tills will be selected for zircon and/or monazite age dating, whereas detrital zircons from stratified and non-stratified diamictons will be analyzed for composite zircon provenance analysis. In addition, detrital zircon ages will be determined for Beacon Supergroup sandstones to evaluate recycling of zircon in Phanerozoic basins. Integration of ages obtained from both sources will provide a good representation of the EAS terrains underlying the Wilkes Land ice sheet. This project will allow us to learn more about the remote continental interior and improve our ability to interpret past ice-flow patterns without further environmental impact on Antarctica. The results will improve our understanding of Precambrian tectonics and crustal evolution, and help target future over-ice geophysical surveys and basement drilling projects currently under consideration. In terms of broader impacts, the project will provide educational and training opportunities for undergraduate students in Earth science.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Goodge, John", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Glacial proxies of East Antarctic shield basement in Wilkes Land, Antarctica", "uid": "p0000725", "west": null}, {"awards": "0229490 Conway, Howard", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 30 Apr 2007 00:00:00 GMT", "description": "This award supports a project to improve understanding of post-glacial retreat and thinning of the Siple Coast region. Research has shown how age-depth relationships from ice cores can be extrapolated over wide areas by tracking continuous radar layers. By comparing radar-derived timescales with one from a model of ice- flow, glacial conditions over regional scales were inferred. High-resolution radar profiles have been collected across most of the inter-stream ridges in the Siple Coast region, and an age- depth relationship has been established from the Siple Dome ice core. Application of the techniques used by others is problematic because the ice streams that surround Siple Dome have disrupted the continuity of the internal layers. A specific goal of this project is to search for other less direct ways to match radar layers between unconnected profiles. The correspondence between radar reflections and measurements of electrical conductivity and volcanic sulfates along the Siple Dome core will be investigated. The strategy is to search for distinctive patterns in the echoes that will facilitate layer matching. Preliminary results are encouraging: at least four distinct echoes at Siple Dome can be matched to spikes in the conductivity profile and the signature of one (at 210m depth, which is ~1,800 yrs BP) closely resembles that of a layer at ~200m on Ridge BC. Matching layers (and hence timescales) across the ice streams will allow reconstruction of spatial patterns of past flow, thinning and accumulation rate in the Siple Coast region, which is needed to predict future possible changes of the West Antarctic Ice Sheet. Data necessary for the proposed work are already available; additional fieldwork in Antarctica is not required. The project will take two years to complete and will provide core education for a doctoral student in Earth and Space Sciences, with an emphasis on radioglaciology.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Sylvester, John; Winebrenner, Dale", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Investigation of the Glacial History of the Siple Coast Using Radar-Detected Internal Layers and the Ice Core from Siple Dome", "uid": "p0000723", "west": null}, {"awards": "0229573 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Antarctic Mean Annual Temperature Map", "datasets": [{"dataset_uid": "609318", "doi": "10.7265/N51C1TTV", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Temperature", "people": "Dixon, Daniel A.", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Mean Annual Temperature Map", "url": "https://www.usap-dc.org/view/dataset/609318"}], "date_created": "Wed, 04 Apr 2007 00:00:00 GMT", "description": "This award supports a science management office for a pilot ice-core drilling and analysis program to test the feasibility of obtaining well-dated, high-resolution isotope and chemistry records from East Antarctica. Shallow ice cores will be obtained from two locations: 1) ~100 km from South Pole towards the Pole of Inaccessibility, as an extension of the Byrd Station-to-South Pole ITASE traverse [International Trans Antarctic Scientific Expedition]; 2) at Taylor Dome, near the original deep coring site, and (3) possibly at AGO 3 and AGO 4 as part of a logistics traverse to these sites. All of the cores collected will be sampled at very high resolution (~1/2 cm) and analyzed for major ions. Results from this calibration work, along with those from another project that is analyzing stable isotopes will be used to help plan a program of larger scope, with the objective of mapping the spatial expression of climate variability in East Antarctica. Funds are also provided to organize a community workshop for coordination of the second phase of US ITASE and for one workshop per year for two years dedicated to writing and preparation of scientific papers from phase one of US ITASE. In addition, route selection activities for the follow-on traverse activities in East Antarctica will be conducted using satellite image mapping. A summary document will be produced and made available to the community to help with planning of related field programs (e.g. deep ice radar, firn radar profiling, atmospheric chemistry, ice coring, snow surface properties for satellite observations, ice surface elevation and mass balance).", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOCOUPLES \u003e THERMOCOUPLES; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; West Antarctica; FIELD INVESTIGATION; West Antarctic Ice Sheet; Antarctic; Temperature; East Antarctic Plateau; FIELD SURVEYS; Antarctica; Not provided", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; West Antarctica; West Antarctic Ice Sheet; East Antarctic Plateau", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Dixon, Daniel A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "A Science Management Office for the U. S. Component of the International Trans Antarctic Expedition (US ITASE SMO)A Collaborative Pgrm of Research from S. Pole to N. Victoria Land", "uid": "p0000199", "west": null}, {"awards": "0538475 Bart, Philip", "bounds_geometry": "POLYGON((-180 -75,-178 -75,-176 -75,-174 -75,-172 -75,-170 -75,-168 -75,-166 -75,-164 -75,-162 -75,-160 -75,-160 -75.3,-160 -75.6,-160 -75.9,-160 -76.2,-160 -76.5,-160 -76.8,-160 -77.1,-160 -77.4,-160 -77.7,-160 -78,-162 -78,-164 -78,-166 -78,-168 -78,-170 -78,-172 -78,-174 -78,-176 -78,-178 -78,-180 -78,-180 -77.7,-180 -77.4,-180 -77.1,-180 -76.8,-180 -76.5,-180 -76.2,-180 -75.9,-180 -75.6,-180 -75.3,-180 -75))", "dataset_titles": "NBP0802 and NBP0803 Sediment samples (full data link not provided); NBP0802 data; NBP0803 data", "datasets": [{"dataset_uid": "000138", "doi": "", "keywords": null, "people": null, "repository": "AMGRF", "science_program": null, "title": "NBP0802 and NBP0803 Sediment samples (full data link not provided)", "url": "http://www.arf.fsu.edu/"}, {"dataset_uid": "000123", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0803 data", "url": "https://www.rvdata.us/search/cruise/NBP0803"}, {"dataset_uid": "000122", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0802 data", "url": "https://www.rvdata.us/search/cruise/NBP0802"}], "date_created": "Thu, 29 Mar 2007 00:00:00 GMT", "description": "This project determines the recent history of the West Antarctic Ice Sheet (WAIS) through a multidisciplinary study of the seabed in the Ross Sea of Antarctica. WAIS is perhaps the world\u0027s most critical ice sheet to sea level rise dut to near-future global warming. its history has been a key focus for the past decade, but there are significant questions as to whether WAIS was stable during the last glacial maximum--about 20,000 years ago--or undergoing advance and retreat. This project studies grounding zone translantions in Eastern Basin to constrain WAIS movements using a multidisciplinary approach that integrates multibeam bathymetry, seismic stratigraphy, sedimentology, diatom biostratigraphy, radiocarbon dating, 10Be concentration analyses, and numerical modeling.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts include improving society\u0027s understanding of sea level rise linked to global warming; postdoctoral, graduate, and undergraduate education; and expanding the participation of groups underrepresented in Earth sciences through links with LSU\u0027s Geoscience Alliance to Encourage Minority Participation.", "east": -160.0, "geometry": "POINT(-170 -76.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e WATERGUNS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES", "is_usap_dc": true, "keywords": "Ross Sea; R/V NBP; Ice Sheet; Last Glacial Maximum; Seismic Stratigraphy", "locations": "Ross Sea", "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Bart, Philip; Tomkin, Jonathan", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "AMGRF", "repositories": "AMGRF; R2R", "science_programs": null, "south": -78.0, "title": "WAIS grounding-zone migrations in Eastern Basin, Ross Sea and the LGM dilemma: New strategies to resolve the style and timing of outer continental shelf grounding events", "uid": "p0000539", "west": -180.0}, {"awards": "0230288 Anastasio, Cort", "bounds_geometry": "POLYGON((123.30014 -75.093445,123.307404 -75.093445,123.314668 -75.093445,123.321932 -75.093445,123.329196 -75.093445,123.33646 -75.093445,123.343724 -75.093445,123.350988 -75.093445,123.358252 -75.093445,123.365516 -75.093445,123.37278 -75.093445,123.37278 -75.0952669,123.37278 -75.0970888,123.37278 -75.0989107,123.37278 -75.1007326,123.37278 -75.1025545,123.37278 -75.1043764,123.37278 -75.1061983,123.37278 -75.1080202,123.37278 -75.1098421,123.37278 -75.111664,123.365516 -75.111664,123.358252 -75.111664,123.350988 -75.111664,123.343724 -75.111664,123.33646 -75.111664,123.329196 -75.111664,123.321932 -75.111664,123.314668 -75.111664,123.307404 -75.111664,123.30014 -75.111664,123.30014 -75.1098421,123.30014 -75.1080202,123.30014 -75.1061983,123.30014 -75.1043764,123.30014 -75.1025545,123.30014 -75.1007326,123.30014 -75.0989107,123.30014 -75.0970888,123.30014 -75.0952669,123.30014 -75.093445))", "dataset_titles": "Light Absorption Coefficients for Soluble Species in Snow, Dome C, Antarctica", "datasets": [{"dataset_uid": "609519", "doi": "10.7265/N5MS3QP0", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Dome C Ice Core; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice", "people": "Robles, Tony; Anastasio, Cort", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Light Absorption Coefficients for Soluble Species in Snow, Dome C, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609519"}], "date_created": "Wed, 07 Mar 2007 00:00:00 GMT", "description": "Photochemical reactions in snow can have important effects on the chemistry and composition of the snowpack as well as the overlying atmosphere. For example, recent measurements in the Antarctic and Arctic have revealed that sunlit snow releases a number of important pollutants to the atmosphere. Our ability to understand and model this chemistry is currently limited, in part because we lack fundamental photochemical information for a number of important chemical species in snow. This award supports research that will help fill this gap by characterizing the low-temperature photochemistry of three of these key species: nitrite (NO2-), nitrous acid (HNO2), and hydrogen peroxide (HOOH). We will measure quantum yields for these reactions on ice using a sensitive technique that we recently developed during a study of nitrate (NO3-) photochemistry. In addition to this basic research, we will also measure the rates of formation of hydroxyl radical (OH), nitrogen oxides (NOx), and HOOH in illuminated Antarctic snow samples. These measurements will be important inputs for future models, and will allow us to test whether known species (e.g., NO3-, NO2- and HNO2) are responsible for most of snowpack reactivity (e.g., OH formation). Overall, results from this award will significantly improve our ability to understand snowpack chemistry, and the resulting effects on the atmosphere, both in the Antarctic as well as in the many other regions with permanent or seasonal snow. These results will also strengthen efforts to use ice core records to monitor global change. In addition to these impacts, this award will help train students and a postdoctoral fellow, and results from this work will be integrated into two classes in order to expose students to some of the important issues facing polar regions.", "east": 123.37278, "geometry": "POINT(123.33646 -75.1025545)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e HPLC; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Snow Chemistry; Antarctica; Snowpack Chemistry; Snow Samples; Hydrogen Peroxide; Snow Properties; Pollutants; Chemistry; Light Absorption; Antarctic; Chemical Species; Snow; East Antarctica; Organic Compounds; Photochemistry; LABORATORY", "locations": "Antarctica; East Antarctica; Antarctic", "north": -75.093445, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anastasio, Cort; Robles, Tony", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Dome C Ice Core", "south": -75.111664, "title": "Laboratory Studies of Photochemistry in Antarctic Snow and Ice", "uid": "p0000175", "west": 123.30014}, {"awards": "0229292 Cressie, Noel", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 28 Feb 2007 00:00:00 GMT", "description": "Ice streams are believed to play a major role in determining the response of their parent ice sheet to climate change, and in determining global sea level by serving as regulators on the fresh water stored in the ice sheets. Ice streams are characterized by rapid, laterally confined flow which makes them uniquely identifiable within the body of the more slowly and more homogeneously flowing ice sheet. But while these characteristics enable the identification of ice streams, the processes which control ice-stream motion and evolution, and differences among ice streams in the polar regions, are only partially understood. Understanding the relative importance of lateral and basal drags, as well as the role of gradients in longitudinal stress, is essential for developing models for future evolution of the polar ice\u003cbr/\u003esheets. In this project, physical statistical models will be used to explore the processes that control ice-stream flow, and to compare these processes between seemingly different ice-stream systems. In particular, Whillans Ice Stream draining into the Ross Ice Shelf, will be compared with Recovery and RAMP glaciers draining into the Ronne-Filchner Ice Shelf, and the Northeast Ice Stream in Greenland. Geophysical models lie at the core of the approach, but are embellished by modeling various components of variability statistically. One important component comes from the uncertainty in observations on basal elevation, surface elevation, and surface velocity. In this project new observational data collected using remote-sensing techniques will be used. The various components, some of which are spatial, are combined hierarchically using Bayesian statistical methodology. All these components will be combined mathematically into a physical statistical model that yields the posterior distribution for basal, longitudinal, and lateral stress fields, and velocity fields, conditional on the data. Inference based on this distribution will be carried out via Markov chain Monte Carlo techniques, to obtain estimates of these unknown fields along with uncertainty measures associated with them.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Surface Elevation; Stress Field; Basal Elevation; DHC-6", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cressie, Noel; Jezek, Kenneth; Berliner, L.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6", "repositories": null, "science_programs": null, "south": null, "title": "Dynamics of Ice Streams: A Physical Statistical Approach", "uid": "p0000711", "west": null}, {"awards": "9615502 Harrison, William", "bounds_geometry": "POINT(-148.822 -81.655)", "dataset_titles": "Vertical Strain at Siple Dome, Antarctica, 1999-2002", "datasets": [{"dataset_uid": "609214", "doi": "10.7265/N5HH6H00", "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Siple Dome; Siple Dome Ice Core; Strain; WAISCORES", "people": "Harrison, William; Elsberg, Daniel; Zumberge, Mark; Pettit, Erin; Waddington, Edwin D.; Morack, James", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Vertical Strain at Siple Dome, Antarctica, 1999-2002", "url": "https://www.usap-dc.org/view/dataset/609214"}], "date_created": "Thu, 22 Feb 2007 00:00:00 GMT", "description": "This award is for support for a three year project to measure the vertical strain rate as a function of depth at two sites on Siple Dome Antarctica. Ice flow near a divide such as Siple Dome is unique in that it is predominantly vertical. As a consequence, the component of ice deformation in the vertical direction, the \"vertical strain rate\" is dominant. Its measurement is therefore important for the calibration of dynamic models of ice flow. Two different, relatively new, high resolution systems for its measurement in hot water drilled holes will be employed. The ice flow model resulting from the measurements and flow law determination will be used to interpret the shapes of radar internal layering in terms of the dynamic history and accumulation patterns of Siple Dome over the past 10,000 years. The resulting improved model will also be applied to the interpretation of annual layers thicknesses (to produce annual accumulation rates) and borehole temperatures from the ice core to be drilled at Siple Dome during the 1997/98 field season. The results should permit an improved analysis of the ice core, relative to what was possible at recent coring sites in central Greenland. This is a collaborative project between the University of Alaska, the University of California, San Diego and the University of Washington.", "east": -148.822, "geometry": "POINT(-148.822 -81.655)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e STRAIN GAUGE WHEATSTONE BRIDGE", "is_usap_dc": true, "keywords": "Ice Core Data; GROUND-BASED OBSERVATIONS; Antarctica; USAP-DC; Ice Core; Ice Analysis; Ice Flow; Ice Deformation; Antarctic Ice Sheet; West Antarctic Ice Sheet; Vertical Strain Rate; Ice Sheet; Glaciology; West Antarctica; Ice; Ice Movement", "locations": "Antarctica; Antarctic Ice Sheet; West Antarctica; West Antarctic Ice Sheet", "north": -81.655, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Harrison, William; Morack, James; Pettit, Erin; Zumberge, Mark; Elsberg, Daniel; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.655, "title": "Ice Dynamics, the Flow Law, and Vertical Strain at Siple Dome", "uid": "p0000601", "west": -148.822}, {"awards": "0125579 Cuffey, Kurt; 0126202 Blankenship, Donald", "bounds_geometry": "POLYGON((160 -77.6,160.25 -77.6,160.5 -77.6,160.75 -77.6,161 -77.6,161.25 -77.6,161.5 -77.6,161.75 -77.6,162 -77.6,162.25 -77.6,162.5 -77.6,162.5 -77.63,162.5 -77.66,162.5 -77.69,162.5 -77.72,162.5 -77.75,162.5 -77.78,162.5 -77.81,162.5 -77.84,162.5 -77.87,162.5 -77.9,162.25 -77.9,162 -77.9,161.75 -77.9,161.5 -77.9,161.25 -77.9,161 -77.9,160.75 -77.9,160.5 -77.9,160.25 -77.9,160 -77.9,160 -77.87,160 -77.84,160 -77.81,160 -77.78,160 -77.75,160 -77.72,160 -77.69,160 -77.66,160 -77.63,160 -77.6))", "dataset_titles": "Ablation Rates of Taylor Glacier, Antarctica; Stable Isotopes of Ice on the Surface of Taylor Glacier, Antarctica; Surface Velocities of Taylor Glacier, Antarctica", "datasets": [{"dataset_uid": "609324", "doi": "10.7265/N5RV0KM7", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Velocity; Taylor Glacier", "people": "Kavanaugh, Jeffrey; Cuffey, Kurt M.; Bliss, Andrew; Aciego, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Surface Velocities of Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609324"}, {"dataset_uid": "609326", "doi": "10.7265/N5N29TW8", "keywords": "Ablation Poles; Ablation Rates; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Taylor Glacier", "people": "Cuffey, Kurt M.; Kavanaugh, Jeffrey; Bliss, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Ablation Rates of Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609326"}, {"dataset_uid": "609323", "doi": "10.7265/N5WM1BBZ", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Isotope; Taylor Glacier", "people": "Cuffey, Kurt M.; Bliss, Andrew; Kavanaugh, Jeffrey; Aciego, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Stable Isotopes of Ice on the Surface of Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609323"}], "date_created": "Tue, 13 Feb 2007 00:00:00 GMT", "description": "This award supports a project to significantly improve our understanding of how Taylor Glacier flows and responds to climate changes. Taylor Glacier drains the Taylor Dome region of the East Antarctic Ice Sheet and terminates in Taylor Valley, one of the Dry Valleys of Victoria Land. It provides a crucial and unique link between two intensively studied Antarctic environments: the Taylor Dome, from which a 130 kyr ice core paleoclimate record has recently been extracted, and the Dry Valleys, a pivotal Long-Term Ecological Research (LTER) site and a focus of research on geomorphology and glacial geology. The proposed work will thus make an important contribution to ongoing efforts to exploit the Taylor Dome - Dry Valleys system to build a uniquely comprehensive view of regional long-term environmental changes. The proposed work has two complementary components: field research and numerical modelling. Two field seasons will be used to measure velocity, surface strain rate, mass balance, ice thickness, glacier bed reflectance, and subglacial topography, along a nearly complete longitudinal transect of the Taylor Glacier, and along select cross-valley transects. This information will be used to constrain numerical models of ice and heat flow for the Taylor Dome - Taylor Glacier system. These calibrated models will be used to analyze the time-dependent response of the Taylor Glacier to climate changes. The synthesis of results will be aimed to improve understanding of the glacial geomorphology of Taylor Valley, and to illuminate impacts on the Taylor Valley lakes ecosystem. The project will have a major role in furthering the careers of a doctoral-level graduate student and a post-doctoral researcher.", "east": 162.5, "geometry": "POINT(161.25 -77.75)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Glacier; Glacier Surface; Glacier Surface Ablation; Ice Velocity; Velocity Measurements; Taylor Glacier; Isotope; GPS; Ice Sheet Elevation; Not provided; FIELD INVESTIGATION; Ice Surface Elevation; Ablation; Oxygen Isotope; Elevation; Deuterium; GROUND-BASED OBSERVATIONS; Glacier Surface Ablation Rate; Surface Elevation", "locations": "Taylor Glacier", "north": -77.6, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Bliss, Andrew; Kavanaugh, Jeffrey; Aciego, Sarah; Cuffey, Kurt M.; Morse, David L.; Blankenship, Donald D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.9, "title": "Collaborative Research: Dynamics and Climatic Response of the Taylor Glacier System", "uid": "p0000084", "west": 160.0}, {"awards": "9814816 Blankenship, Donald", "bounds_geometry": "POLYGON((-129 -80.5,-128.4 -80.5,-127.8 -80.5,-127.2 -80.5,-126.6 -80.5,-126 -80.5,-125.4 -80.5,-124.8 -80.5,-124.2 -80.5,-123.6 -80.5,-123 -80.5,-123 -80.55,-123 -80.6,-123 -80.65,-123 -80.7,-123 -80.75,-123 -80.8,-123 -80.85,-123 -80.9,-123 -80.95,-123 -81,-123.6 -81,-124.2 -81,-124.8 -81,-125.4 -81,-126 -81,-126.6 -81,-127.2 -81,-127.8 -81,-128.4 -81,-129 -81,-129 -80.95,-129 -80.9,-129 -80.85,-129 -80.8,-129 -80.75,-129 -80.7,-129 -80.65,-129 -80.6,-129 -80.55,-129 -80.5))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 13 Feb 2007 00:00:00 GMT", "description": "9814816 Blankenship This award supports a four year project to develop of better understanding the ice streams of the Ross Sea Embayment (A--F) which drain the interior West Antarctic Ice Sheet (WAIS) by rapidly moving vast quantities of ice to the calving front of the Ross Ice Shelf. The project will examine the role of these ice streams as buffers between the interior ice and the floating ice shelves. The reasons for their fast flow, the factors controlling their current grounding-line-, margin-, and head-positions are crucial to any attempt at modeling the WAIS system and predicting the future of the ice sheet. For the Antarctic ice streams of the Siple Coast, the transition from no-sliding (or all internal deformation) to motion dominated by sliding is defined as the \"onset-region\". To fully understand (and adequately model) the WAIS, this onset region must be better understood. The lateral margins of the ice streams are also a transition that need better explanation. Hypotheses on controls of the location of the onset region range from the \"purely-glaciologic\" to the \"purely-geologic. Thus, to model the ice sheet accurately, the basal boundary conditions (roughness, wetness, till properties) and a good subglacial geologic map, showing the distribution, thickness, and properties of the sedimentary basins, are required. These parameters can be estimated from seismic, radar, and other geophysical methods. The transition region of ice stream D will be studied in detail with this coupled geophysical experiment. In addition, selected other locations on ice streams C \u0026 D will be made, to compare and contrast conditions with the main site on ice stream D. Site-selection for the main camp will be based on existing radar, GPS, and satellite data as well as input from the modeling community.", "east": -123.0, "geometry": "POINT(-126 -80.75)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -80.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Blankenship, Donald D.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -81.0, "title": "Collaborative Research: Characterizing the Onset of Ice Stream Flow: A Ground Geophysical Field Program", "uid": "p0000603", "west": -129.0}, {"awards": "0230197 Holt, John", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; Amundsen Sea Sector Data Set; Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "datasets": [{"dataset_uid": "609292", "doi": "10.7265/N59W0CDC", "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Solid Earth", "people": "Corr, Hugh F. J.; Holt, John W.; Blankenship, Donald D.; Morse, David L.; Vaughan, David G.; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609292"}, {"dataset_uid": "609312", "doi": "10.7265/N5J9649Q", "keywords": "Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Fastook, James L.", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Sector Data Set", "url": "https://www.usap-dc.org/view/dataset/609312"}, {"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Muldoon, Gail R.; Blankenship, Donald D.; Jackson, Charles; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}], "date_created": "Mon, 01 Jan 2007 00:00:00 GMT", "description": "This award supports a comprehensive aerogeophysical survey of the Amundsen Sea Embayment (ASE) in West Antarctica. The University of Texas will join forces with the British Antarctic Survey to use both US and UK aircraft and instrumentation to achieve this survey. Analyses of the new aerogeophysical\u003cbr/\u003edata will result in the generation of maps of ice sheet surface, volume and bottom-interface characteristics. These maps will support the efforts of a community of US and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE.\u003cbr/\u003eThe West Antarctic ice sheet has been the subject of intensive interdisciplinary study by both the European and U.S. scientific communities since it was recognized to be a potential source for up to 5 meters of sea\u003cbr/\u003elevel rise, possibly on short timescales. In terms of ice discharge, the ASE is the largest drainage system in West Antarctica. Yet it has been comparatively unstudied, primarily due to its remoteness from logistical\u003cbr/\u003ecenters. The ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change.\u003cbr/\u003eThe results from our surveys are required to achieve the fundamental research objectives outlined by the US scientific community in an ASE Science Plan. The surveys and analyses will be achieved through international collaboration and will involve graduate students, undergraduates and high school apprentices.\u003cbr/\u003eThrough its potential for influencing sea level, the future behavior of the ASE is of primary societal importance. Given the substantial public and scientific interest that recent reports of change in West Antarctica have generated, we expect fundamental research in the Amundsen Sea Embayment, enabled by our surveys, will have widespread impact.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS", "is_usap_dc": true, "keywords": "Thwaites Glacier; Ice Velocity; Ablation; Amundsen Sea; Pine Island Glacier; Elevation; Antarctica (agasea); Ice Sheet Elevation; West Antarctic Ice Sheet; Ice Temperature; Amundsen Basin; Subglacial Topography; Ice Melt; West Antarctica; Velocity Measurements; Snow Accumulation; Antarctica; Bedrock Elevation; Modeling", "locations": "Antarctica; West Antarctica; Amundsen Basin; Pine Island Glacier; Thwaites Glacier; West Antarctic Ice Sheet; Amundsen Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Blankenship, Donald D.; Fastook, James L.; Corr, Hugh F. J.; Holt, John W.; Morse, David L.; Vaughan, David G.; Young, Duncan A.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)", "uid": "p0000243", "west": -180.0}, {"awards": "9526566 Bindschadler, Robert", "bounds_geometry": null, "dataset_titles": "Decadal-Length Composite West Antarctic Air Temperature Records", "datasets": [{"dataset_uid": "609097", "doi": "10.7265/N55D8PS0", "keywords": "Antarctica; Atmosphere; Automated Weather Station; Meteorology; Temperature; West Antarctica", "people": "Stearns, Charles R.; Shuman, Christopher A.", "repository": "USAP-DC", "science_program": null, "title": "Decadal-Length Composite West Antarctic Air Temperature Records", "url": "https://www.usap-dc.org/view/dataset/609097"}], "date_created": "Tue, 28 Nov 2006 00:00:00 GMT", "description": "This award is for support for a research program involving the use of passive microwave data to validate key paleoclimate indicators used in glaciologic research. The specific contributions of this research are: 1) to define the timing and spatial extent of hoar complexes, which may serve as visible, annual stratigraphic markers in ice cores, through a combination of satellite passive microwave data and field observations; and 2) to monitor temperature trends at the site with calibrated passive microwave brightness temperatures and to correlate these trends to proxy temperatures provided by oxygen and hydrogen stable isotope ratio profiles from snow pits and/or ice cores. The work will take place at Siple Dome, Antarctica as part of the field activities associated with the ice core drilling program there.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SMMR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SSM/I", "is_usap_dc": true, "keywords": "West Antarctica; Near-Surface Air Temperatures; Surface Temperatures; Special Sensor Microwave/imager; Passive Microwave Brightness Temperatures; Scanning Multichannel Microwave Radiometer; SSM/I; SSMR; AWS Byrd Station; NIMBUS-7; Emissivity Modeling; Antarctica; West Antarctic Ice Sheet; Not provided; DMSP; AWS Siple; Automated Weather Station; AWS Lynn; AWS Lettau; AWS", "locations": "Antarctica; West Antarctica; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bindschadler, Robert; Shuman, Christopher A.; Stearns, Charles R.", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e DEFENSE METEOROLOGICAL SATELLITE PROGRAM (DMSP) \u003e DMSP; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e NIMBUS \u003e NIMBUS-7", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Passive Microwave Remote Sensing for Paleoclimate Indicators at Siple Dome, Antarctica", "uid": "p0000191", "west": null}, {"awards": "0230378 Kanagaratnam, Pannirselvam", "bounds_geometry": "POLYGON((-112.224 -79.3385,-112.1245 -79.3385,-112.025 -79.3385,-111.9255 -79.3385,-111.826 -79.3385,-111.7265 -79.3385,-111.627 -79.3385,-111.5275 -79.3385,-111.428 -79.3385,-111.3285 -79.3385,-111.229 -79.3385,-111.229 -79.35475,-111.229 -79.371,-111.229 -79.38725,-111.229 -79.4035,-111.229 -79.41975,-111.229 -79.436,-111.229 -79.45225,-111.229 -79.4685,-111.229 -79.48475,-111.229 -79.501,-111.3285 -79.501,-111.428 -79.501,-111.5275 -79.501,-111.627 -79.501,-111.7265 -79.501,-111.826 -79.501,-111.9255 -79.501,-112.025 -79.501,-112.1245 -79.501,-112.224 -79.501,-112.224 -79.48475,-112.224 -79.4685,-112.224 -79.45225,-112.224 -79.436,-112.224 -79.41975,-112.224 -79.4035,-112.224 -79.38725,-112.224 -79.371,-112.224 -79.35475,-112.224 -79.3385))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 18 Oct 2006 00:00:00 GMT", "description": "This award supports a project to build and test a 12-18 GHz radar system with a plane wave antenna. This is a wideband radar operating over a frequency range of 12 to 18 GHz to detect near-surface internal firn layers of the ice sheet with better than 10 cm resolution to a depth of approximately 7 m. These measurements will allow determination of spatially continuous snow accumulation rate in the firn, which would be useful along a traverse and is of critical importance to the validation of CryoSat and ICESAT satellite missions aimed at assessing the current state of mass balance of the polar ice sheets. The antenna system planned for the radar is relatively compact, and will be located on the sledge carrying the radar systems. The broad scientific focus of this project will be to investigate important glacial processes relevant to ice sheet mass balance. The new radar will allow the characterization (with high depth resolution) of the spatial variability of snow accumulation rate along a traverse route for interpreting data from CryoSat and ICESAT missions. As part of this project, we will institute a strong outreach program involving K-12 education and a minority institution of higher education. We currently work closely with the Advanced Learning Technology Program (ALTec) at the University of Kansas to develop interactive, resource-based lessons for use on-line by students of all grade levels, and we will develop new resources related to this project. We currently have an active research and education collaboration with faculty and undergraduate students at neighboring Haskell Indian Nations University, in Lawrence, Kansas, and we will expand our collaboration to include this project.", "east": -111.229, "geometry": "POINT(-111.7265 -79.41975)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": false, "keywords": "Firn; Cryosat; Plane Wave Antenna; Glacial Processes; GROUND-BASED OBSERVATIONS; Not provided; Icesat; FIELD INVESTIGATION; Radar; LABORATORY; Snow Accumulation; Mass Balance; FIELD SURVEYS", "locations": null, "north": -79.3385, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Kanagaratnam, Pannirselvam; Braaten, David; Bauer, Rob", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -79.501, "title": "High Resolution Ice Thickness and Plane Wave Mapping of Near-Surface Layers", "uid": "p0000731", "west": -112.224}, {"awards": "0230190 Goldsby, David", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 14 Aug 2006 00:00:00 GMT", "description": "This award supports a project to conduct laboratory experiments to investigate textures formed in ice during superplastic flow. Superplastic flow has recently been discovered in the laboratory and can be considered a new flow mechanism for ice. A simple extrapolation of these new data for superplastic flow from laboratory to natural conditions suggests that glaciers and ice sheets flow via this mechanism. Furthermore, several grain-scale features in ice (e.g., crystal shape) produced during superplastic flow in the laboratory are remarkably similar to those observed in glaciers and ice sheets. Despite this exciting discovery, however, important questions remain before we can apply with full confidence these new flow data in mathematical models of glacier and ice sheet flow. The textures seen in laboratory studies will be compared with those observed in field studies of glaciers and ice sheets. These comparisons, coupled with comparisons of the new superplastic flow data from the laboratory with flow measurements from field studies, will provide a powerful method for further assessing the importance of superplastic flow in nature and thereby improve our understanding of glacier and ice sheet dynamics and global climate change. Experiments will be conducted by the PI and an undergraduate research assistant. Experimental results will be published in relevant refereed journals, presented at glaciology meetings and incorporated into coursework.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": false, "keywords": "LABORATORY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Goldsby, David", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "A Laboratory Study of Texture Development During Grain Size Sensitive Creep of Ice, with Applications to the Flow of Glaciers and Ice Sheets", "uid": "p0000288", "west": null}, {"awards": "0338363 Thiemens, Mark; 0337933 Cole-Dai, Jihong", "bounds_geometry": null, "dataset_titles": "Major Ion Concentrations in 2004 South Pole Ice Core", "datasets": [{"dataset_uid": "609542", "doi": "10.7265/N5HX19N8", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ion Chromatograph; South Pole", "people": "Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": null, "title": "Major Ion Concentrations in 2004 South Pole Ice Core", "url": "https://www.usap-dc.org/view/dataset/609542"}], "date_created": "Fri, 11 Aug 2006 00:00:00 GMT", "description": "This award supports a collaborative study between South Dakota State University (SDSU) and University of California, San Diego (UCSD) to investigate the oxygen and sulfur isotope composition of sulfates from a number of large volcanic eruptions in the past 1000 years. The project aims to drill a number of shallow ice cores at South Pole and return them to SDSU and UCSD lab for chemical and isotope analysis. Preliminary results from measurements of isotopes in sulfate samples from several volcanic eruptions in Antarctic snow and ice indicate that isotopic composition of volcanic sulfate contains abundant valuable information on atmospheric chemical and dynamic processes that have not been previously investigated. One tentative conclusion is that mass-independently fractionated sulfur isotopes reveal that atmospheric photolysis of sulfur compounds occurs at longer UV wavelengths than those in the Archean atmosphere, possibly reflecting the atmospheric ozone and/or oxygen concentration. This suggests that isotopic composition of atmospheric sulfate may be used to understand the role of UV radiation in sulfur dioxide conversion in the atmosphere and to track the evolution (i.e., oxygenation) of the atmosphere and the origin of life on Earth. Other major research objectives include understanding what impact massive volcanic eruptions have on the oxidative capacity of the atmosphere, what oxidants and mechanisms are involved in the oxidation or conversion of volcanic sulfur dioxide to sulfate in the stratosphere and what isotopic criteria may be used to differentiate ice core signals of stratospheric eruptions from those of tropospheric eruptions. By providing educational and research opportunities to graduate and undergraduate students at both SDSU and UCSD, the proposed project will promote the integration of research and education and contribute to human resource development in science and engineering. The project will contribute to a proposed REU chemistry site program at SDSU. This collaboration will utilize the complementary strengths of both labs and promote exchange between the two institutions. International collaboration will enhance scientific cooperation between France and US.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Not provided; Ion Chromatograph; Ions; LABORATORY; GROUND-BASED OBSERVATIONS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Cole-Dai, Jihong", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Investigating Atmospheric Chemistry and Dynamics through Oxygen and Sulfur Isotopes in Volcanic Sulfate from South Pole Ice Cores", "uid": "p0000031", "west": null}, {"awards": "0230316 White, James; 0230021 Sowers, Todd; 0230348 Dunbar, Nelia", "bounds_geometry": "POINT(135.1333 -76.05)", "dataset_titles": "Mount Moulton Isotopes and Other Ice Core Data", "datasets": [{"dataset_uid": "609640", "doi": "10.7265/N5FT8J0N", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Epica Dome C; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Lake Vostok; Mount Moulton; Paleoclimate; Talos Dome; Taylor Dome", "people": "Steig, Eric J.; White, James; Popp, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Mount Moulton Isotopes and Other Ice Core Data", "url": "https://www.usap-dc.org/view/dataset/609640"}], "date_created": "Tue, 01 Aug 2006 00:00:00 GMT", "description": "The summit crater of Mt. Moulton, in West Antarctica, contains a 600-m thick horizontally-exposed section of ice with intercalated tephra layers from nearby Mt Berlin. Argon-40/Argon-39 dating of the thick, near-source tephra indicates that the age of the horizontal ice section ranges between 15,000 and 492,000 years. Thus, the Mt Moulton site offers an unparalleled repository of ancient West Antarctic snow and trapped air that can be used to investigate West Antarctic climate over much of the past 500,000 years. The planar nature and consistent dips of the tephra layers suggests that, although the ice section has thinned, it is otherwise undeformed. The Mt. Moulton site was visited during the 1999/2000 field season, at which time a horizontal ice core representing approximately 400 meters of ice was collected, ranging in age from 15,000 to older than 480,000 years. In addition to this horizontal core, samples of ice at a range of depths were collected in order to test the quality of the climate record in the ice. Forty tephra layers intercalated in the ice were also collected in order to provide chronology for the ice section. The results of this first effort are extremely encouraging. Based on the d?18 O of ice, for example, there is clearly a useable record of past climate at Mt. Moulton extending back beyond 140,000 years. There is work to do, however, to realize the full potential of this horizontal ice core. The elemental and isotopic composition of trapped gases suggest some contamination with modern air, for example. As gas cross-dating of ice cores is the current standard by which climate records are intercompared, we need to understand why and how the gas record is compromised before adding Moulton to our arsenal of ice core paleoclimate records. This award supports a collaborative effort between three institutions with following objectives: 1) to evaluate more thoroughly the integrity of the climatic record through shallow drilling of the blue ice area, as well as the snow field upslope from the blue ice; 2) to improve the radioisotopic dating of specific tephra layers; 3) to obtain baseline information about modern snowfall deposition, mean annual temperature, and wind pumping around the summit of Mt. Moulton; and 4) to study how firn densification differs when surface accumulation changes from net accumulation to net ablation.", "east": 135.1333, "geometry": "POINT(135.1333 -76.05)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES", "is_usap_dc": true, "keywords": "LABORATORY; Climate; Argon-40; 40Ar; Argon-39; FIELD SURVEYS; Chronology; Ice Core Gas Age; Gas Record; Ice Core; FIELD INVESTIGATION; Tephra; Mount Moulton; Not provided; Caldera; 39Ar; Stratigraphy; Ice Core Depth", "locations": "Mount Moulton", "north": -76.05, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "White, James; Popp, Trevor; Dunbar, Nelia; Sowers, Todd A.; Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.05, "title": "Collaborative Research: Refining a 500-kry Climate Record From the Moulton Blue Ice Field in West Antarctica", "uid": "p0000755", "west": 135.1333}, {"awards": "0126343 Nishiizumi, Kunihiko", "bounds_geometry": "POINT(-148.812 -81.6588)", "dataset_titles": "Cosmogenic Radionuclides in the Siple Dome A Ice Core", "datasets": [{"dataset_uid": "609307", "doi": "10.7265/N5XK8CGS", "keywords": "Antarctica; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Nishiizumi, Kunihiko; Finkel, R. C.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Cosmogenic Radionuclides in the Siple Dome A Ice Core", "url": "https://www.usap-dc.org/view/dataset/609307"}], "date_created": "Mon, 12 Jun 2006 00:00:00 GMT", "description": "This award supports a three-year renewal project to complete measurement of cosmogenic nuclides in the Siple Dome ice core as part of the West Antarctic ice core program. The investigators will continue to measure profiles of Beryllium-10 (half-life = 1.5x10 6 years) and Chlorine-36 (half-life = 3.0x10 5 years) in the entire ice core which spans the time period from the present to about 100 kyr. It will be particularly instructive to compare the Antarctic record with the detailed Arctic record that was measured by these investigators as part of the GISP2 project. This comparison will help separate global from local effects at the different drill sites. Cosmogenic radionuclides in polar ice cores have been used to study the long-term variations in several important geophysical variables, including solar activity, geomagnetic field strength, atmospheric circulation, snow accumulation rates, and others. The time series of nuclide concentrations resulting from this work will be applied to several problem areas: perfecting the ice core chronology, deducing the history of solar activity, deducing the history of variations in the geomagnetic field, and studying the possible role of solar variations on climate. Comparison of Beryllium-10 and Chlorine-36 profiles in different cores will allow us to improve the ice core chronology and directly compare ice cores from different regions of the globe. Additional comparison with the Carbon-14 record will allow correlation of the ice core paleoenvironment record to other, Carbon-14 dated, paleoclimate records.", "east": -148.812, "geometry": "POINT(-148.812 -81.6588)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Core Chemistry; Antarctica; Ice Core; Cosmogenic Radionuclides; Chlorine-36; GROUND STATIONS; Beryllium-10; Siple Dome; West Antarctica", "locations": "Antarctica; Siple Dome; West Antarctica", "north": -81.6588, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Finkel, R. C.; Nishiizumi, Kunihiko", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.6588, "title": "Cosmogenic Radionuclides in the Siple Dome Ice Core", "uid": "p0000358", "west": -148.812}, {"awards": "0126187 Alley, Richard", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 11 Apr 2006 00:00:00 GMT", "description": "0126187\u003cbr/\u003eAlley\u003cbr/\u003e\u003cbr/\u003eThis award provides support for a 2 year modeling effort to study the dynamics of Pine Island Glacier (PIG). The discharge from the PIG constitutes the largest mass loss from any single West Antarctic ice stream. Satellite observations indicate that this outlet glacier is experiencing ongoing thinning and acceleration. The emphasis of this work will be on understanding the cause and the near-term projection of the observed thinning of PIG. Model experiments will address the hypothesis that the observed changes were caused by the loss of a buttressing ice shelf, and that the changes will continue in the form of an upglacier propagating wave of thinning and acceleration. To perform this work a numerical model of the coupled mass, energy, and momentum balance of Pine Island Glacier basin will be developed. The model will comprise four modular components, which will be coupled and then benchmarked against the European Ice Sheet Modeling Inititative (EISMINT) model intercomparison. The model will then be applied to the thinning of Pine Island Glacier using likely ice-shelf histories and possible basal boundary conditions to learn which may be accurate and to assess possible future behavior. The primary expected result will be an improved understanding of the importance of ice-shelf buttressing and the potential for inland thinning due to the reduction of ice-shelf drag.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard; Dupont, Todd K.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "The Thinning of Pine Island Glacier: Model Development and Study of the Importance of Ice-Shelf Drag on Inland Ice", "uid": "p0000715", "west": null}, {"awards": "0230448 Severinghaus, Jeffrey; 0230260 Bender, Michael", "bounds_geometry": "POLYGON((-75.34 86.6,-68.742 86.6,-62.144 86.6,-55.546 86.6,-48.948 86.6,-42.35 86.6,-35.752 86.6,-29.154 86.6,-22.556 86.6,-15.958 86.6,-9.36 86.6,-9.36 83.618,-9.36 80.636,-9.36 77.654,-9.36 74.672,-9.36 71.69,-9.36 68.708,-9.36 65.726,-9.36 62.744,-9.36 59.762,-9.36 56.78,-15.958 56.78,-22.556 56.78,-29.154 56.78,-35.752 56.78,-42.35 56.78,-48.948 56.78,-55.546 56.78,-62.144 56.78,-68.742 56.78,-75.34 56.78,-75.34 59.762,-75.34 62.744,-75.34 65.726,-75.34 68.708,-75.34 71.69,-75.34 74.672,-75.34 77.654,-75.34 80.636,-75.34 83.618,-75.34 86.6))", "dataset_titles": "Firn Air Inert Gas and Oxygen Observations from Siple Dome, 1996, and the South Pole, 2001; Trapped Gas Composition and Chronology of the Vostok Ice Core", "datasets": [{"dataset_uid": "609311", "doi": "10.7265/N5P26W12", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Lake Vostok; Paleoclimate; Vostok; Vostok Ice Core", "people": "Bender, Michael; Suwa, Makoto", "repository": "USAP-DC", "science_program": null, "title": "Trapped Gas Composition and Chronology of the Vostok Ice Core", "url": "https://www.usap-dc.org/view/dataset/609311"}, {"dataset_uid": "609290", "doi": "10.7265/N5FJ2DQC", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciology; Paleoclimate; Siple Dome; Snow/ice; Snow/Ice; South Pole", "people": "Bender, Michael; Battle, Mark; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Firn Air Inert Gas and Oxygen Observations from Siple Dome, 1996, and the South Pole, 2001", "url": "https://www.usap-dc.org/view/dataset/609290"}], "date_created": "Wed, 18 Jan 2006 00:00:00 GMT", "description": "High latitude deep ice cores contain fundamental records of polar temperatures, atmospheric dust loads (and continental aridity), greenhouse gas concentrations, the status of the biosphere, and other essential properties of past environments. An accurate chronology for these records is needed if their significance is to be fully realized. The dating challenge has stimulated efforts at orbital tuning. In this approach, one varies a timescale, within allowable limits, to optimize the match between a paleoenvironmental property and a curve of insolation through time. The ideal property would vary with time due to direct insolation forcing. It would be unaffected by complex climate feedbacks and teleconnections, and it would give a clean record with high signal/noise ratio. It is argued strongly that the O2/N2 ratio of ice core trapped gases is such a property, and evidence is presented that this property, whose atmospheric ratio is nearly constant, is tied to local summertime insolation. This award will support a project to analyze the O2/N2 ratios at 1 kyr intervals from ~ 115-400 ka in the Vostok ice core. Ancillary measurements will be made of Ar/N2, and Ne/N2 and heavy noble gas ratios, in order to understand bubble close-off fractionation and its manifestation in the Vostok trapped gas record. O2/N2 variations will be matched with summertime insolation at Vostok to achieve a high-accuracy chronology for the Vostok core. The Vostok and other correlatable climate records will then be reexamined to improve our understanding of the dynamics of Pleistocene climate change.", "east": 106.8, "geometry": "POINT(106.8 -72.4667)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e FLASKS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Paleoclimate; Siple Dome; Ice Age; Shallow Firn Air; Firn Air Isotope Measurements; Polar Firn Air; Ice Sample Gas Integrity; Oxygen Isotope; Noble Gas; Ice Core Gas Records; Atmospheric Gases; Trapped Gases; Not provided; LABORATORY; Vostok; Firn Air Isotopes; Thermal Fractionation; Ice Core Chemistry; Trapped Air Bubbles; Ice Core; Antarctica; South Pole; Ice Core Data; GROUND-BASED OBSERVATIONS; Gas Age; Firn Isotopes", "locations": "Antarctica; Vostok; Siple Dome; South Pole", "north": -72.4667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Battle, Mark; Bender, Michael; Suwa, Makoto; Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -72.4667, "title": "Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core", "uid": "p0000257", "west": 106.8}, {"awards": "0125570 Scambos, Ted; 0125276 Albert, Mary", "bounds_geometry": null, "dataset_titles": "Access AGDC data online by navigating to Data Sets. Data sets are arranged by Principal Investigators. Access data that are combined into multiple data sets, or compiled products.; AWS Data: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation; GPR and GPS Data: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation; Snow and Firn Permeability: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation; The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "datasets": [{"dataset_uid": "609282", "doi": "10.7265/N5Q23X5F", "keywords": "Antarctica; East Antarctic Plateau; Glaciology; GPR; GPS; Navigation; Paleoclimate; Snow/ice; Snow/Ice", "people": "Scambos, Ted; Bauer, Rob", "repository": "USAP-DC", "science_program": null, "title": "GPR and GPS Data: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation", "url": "https://www.usap-dc.org/view/dataset/609282"}, {"dataset_uid": "609283", "doi": "10.7265/N5K935F3", "keywords": "Antarctica; Atmosphere; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meteorology; Snow/ice; Snow/Ice", "people": "Bauer, Rob; Fahnestock, Mark; Scambos, Ted; Haran, Terry", "repository": "USAP-DC", "science_program": null, "title": "AWS Data: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation", "url": "https://www.usap-dc.org/view/dataset/609283"}, {"dataset_uid": "001669", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Access AGDC data online by navigating to Data Sets. Data sets are arranged by Principal Investigators. Access data that are combined into multiple data sets, or compiled products.", "url": "http://nsidc.org/data/agdc_investigators.html"}, {"dataset_uid": "609299", "doi": "10.7265/N5639MPD", "keywords": "Antarctica; East Antarctic Plateau; Glaciology; Physical Properties; Snow/ice; Snow/Ice", "people": "Albert, Mary R.; Courville, Zoe; Cathles, Mac", "repository": "USAP-DC", "science_program": null, "title": "Snow and Firn Permeability: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation", "url": "https://www.usap-dc.org/view/dataset/609299"}, {"dataset_uid": "001343", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "url": "https://nsidc.org/data/agdc/"}], "date_created": "Wed, 04 Jan 2006 00:00:00 GMT", "description": "This award supports a program of field surveys of an area within the large, well-developed megadune field southeast of Vostok station. The objectives are to determine the physical characteristics of the firn across the dunes, including typical climate indicators such as stable isotopes and major chemical species, and to install instruments to measure the time variation of near-surface wind and temperature with depth, to test and refine hypotheses for megadune formation. Field study will consist of surface snowpit and shallow core sampling, ground penetrating radar (GPR) profiling, GPS topographic and ice motion surveys, AWS installation, accumulation/ ablation measurements, subsurface temperature, and firn permeability studies. Field work in two successive seasons is proposed. Continent-wide remote sensing studies of the dunes will be continued, using the new group of instruments that are now, or will shortly be available (e.g., MODIS, MISR, GLAS, AMSR). The earlier study of topographic, passive microwave, and SAR characteristics will be extended, with the intent of determining the relationships of dune amplitude and wavelength to climate parameters, and further development of models of dune formation. Diffusion, ventilation, and vapor transport processes within the dune firn will be modeled as well. A robust program of outreach is planned and reporting to inform both the public and scientists of the fundamental in-situ and remote sensing characteristics of these uniquely Antarctic features will be an important part of the work. Because of their extreme nature, their broad extent, and their potential impact on the climate record, it is important to improve our current understanding of these. Megadunes are a manifestation of an extreme terrestrial climate and may provide insight on past terrestrial climate, or to processes active on other planets. Megadunes are likely to represent an end-member in firn diagenesis, and as such, may have much to teach us about the processes involved.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ICE AUGERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e SNOWPACK TEMPERATURE PROBE; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e PERMEAMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e CURRENT/WIND METERS \u003e ANEMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e AIR PERMEAMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CURRENT/WIND METERS \u003e ANEMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e RADIO \u003e ARGOS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e WIND PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e DENSIOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e BALANCE", "is_usap_dc": true, "keywords": "Internal Layering; ICESAT; Vapor-Redeposition; Antarctic; Wind Speed; FIELD INVESTIGATION; Surface Morphology; Antarctica; GROUND-BASED OBSERVATIONS; ARWS; Polar Firn Air; Microstructure; Gas Diffusivity; WEATHER STATIONS; Surface Temperatures; RADARSAT-2; Ice Core; Wind Direction; AWS; Ice Sheet; Snow Pit; Dunefields; Climate Record; Megadunes; GROUND STATIONS; METEOROLOGICAL STATIONS; Antarctic Ice Sheet; Density; Atmospheric Pressure; Firn Permeability; FIELD SURVEYS; Radar; Permeability; Field Survey; Firn Temperature Measurements; Snow Megadunes; Thermal Conductivity; LANDSAT; Firn; Ice Core Interpretation; East Antarctic Plateau; Not provided; Surface Winds; Sublimation; Snow Density; Ice Climate Record; Glaciology; Snow Permeability; Air Temperature; Paleoenvironment; Automated Weather Station", "locations": "Antarctica; Antarctic Ice Sheet; Antarctic; East Antarctic Plateau", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Courville, Zoe; Cathles, Mac; Scambos, Ted; Bauer, Rob; Fahnestock, Mark; Haran, Terry; Shuman, Christopher A.; Albert, Mary R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e ARWS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e METEOROLOGICAL STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e WEATHER STATIONS; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e ICE, CLOUD AND LAND ELEVATION SATELLITE (ICESAT) \u003e ICESAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e RADARSAT \u003e RADARSAT-2", "repo": "USAP-DC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation", "uid": "p0000587", "west": null}, {"awards": "0338359 Saltzman, Eric", "bounds_geometry": "POINT(-148.81 -81.65)", "dataset_titles": "Analysis of Siple Dome Ice Core: Carbonyl Sulfide (COS), Methyl Chloride (CH3Cl), and Methyl Bromide (CH3Br); Antarctic Ice Cores: Methyl Chloride and Methyl Bromide; Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core; Methane and Carbonyl Sulfide Analysis of Siple Dome Ice Core Subsamples", "datasets": [{"dataset_uid": "609279", "doi": "10.7265/N53B5X3G", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Analysis of Siple Dome Ice Core: Carbonyl Sulfide (COS), Methyl Chloride (CH3Cl), and Methyl Bromide (CH3Br)", "url": "https://www.usap-dc.org/view/dataset/609279"}, {"dataset_uid": "609131", "doi": "10.7265/N5P848VP", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Methane and Carbonyl Sulfide Analysis of Siple Dome Ice Core Subsamples", "url": "https://www.usap-dc.org/view/dataset/609131"}, {"dataset_uid": "601357", "doi": "10.15784/601357", "keywords": "Antarctica; Atmospheric Gases; Gas Measurement; Ice Core; Ice Core Gas Records; Trace Gases", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core", "url": "https://www.usap-dc.org/view/dataset/601357"}, {"dataset_uid": "609313", "doi": "10.7265/N5DN430Q", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; ITASE; Paleoclimate; Siple Dome Ice Core; South Pole; SPRESSO; SPRESSO Ice Core", "people": "Williams, Margaret; Tatum, Cheryl; Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Cores: Methyl Chloride and Methyl Bromide", "url": "https://www.usap-dc.org/view/dataset/609313"}], "date_created": "Wed, 16 Nov 2005 00:00:00 GMT", "description": "This award supports the analysis, in Antarctic ice cores, of the ozone depleting substances methyl bromide (CH3Br) and methyl chloride (CH3Cl), and the sulfur-containing gas, carbonyl sulfide (OCS). The broad scientific goal is to assess the level and variability of these gases in the preindustrial atmosphere. This information will allow testing of current models for sources and sinks of these gases from the atmosphere, and to indirectly assess the impact of anthropogenic activities on their biogeochemical cycles. Longer-term records will shed light on the climatic sensitivity of the atmospheric burden of these gases, and ultimately on the biogeochemical processes controlling them. These gases are present in ice at parts per trillion levels, and the current database consists entirely of a small number of measurements made in from a shallow ice core from Siple Dome, Antarctica. This project will involve studies of ice core samples from three Antarctic sites: Siple Station, Siple Dome, and South Pole. The sampling strategy is designed to accomplish several objectives: 1) to verify the atmospheric mixing ratios previously observed in shallow Siple Dome ice for OCS, CH3Br, and CH3Cl at sites with very different accumulation rates and surface temperatures; 2) to obtain a well-dated, high resolution record from a high accumulation rate site (Siple Station), that can provide overlap in mean gas age with Antarctic firn air samples; 3) explore Holocene variability in trace gas mixing ratios; and 4) to make the first measurements of these trace gases in Antarctic glacial ice. In terms of broader impact on society, this research will help to provide a stronger scientific basis for policy decisions regulating the production and use of ozone-depleting and climate-active gases. Specifically, the methyl bromide results will contribute to the current debate on the impact of recent regulation (via the Montreal Protocol and its Amendments) on atmospheric levels. Determination of pre-industrial atmospheric variability of ozone-depleting substances will help place more realistic constraints on scenarios used for future projections of stratospheric ozone and its climatic impacts. This research will involve the participation of both graduate and undergraduate students.", "east": -148.81, "geometry": "POINT(-148.81 -81.65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Ice Core Gas Records; Carbonyl Sulfide; Siple Coast; Chloride; Trapped Gases; Snow; Ice Core Chemistry; Chromatography; Siple; GROUND STATIONS; Atmospheric Gases; Ozone Depletion; AWS Siple; Ice Sheet; Ice Core Data; Antarctica; Glaciology; West Antarctica; Atmospheric Chemistry; Ice Core; Stratigraphy; LABORATORY; Methane; Mass Spectrometer; GROUND-BASED OBSERVATIONS; WAISCORES; Msa; Mass Spectrometry; Not provided; Siple Dome; Gas Measurement", "locations": "Antarctica; Siple Coast; Siple Dome; West Antarctica; Siple", "north": -81.65, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Saltzman, Eric; Aydin, Murat; Williams, Margaret; Tatum, Cheryl", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.65, "title": "Methyl chloride and methyl bromide in Antarctic ice cores", "uid": "p0000032", "west": -148.81}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "MODIS Mosaic of Antarctica 2003-2004 (MOA2004) Image Map", "datasets": [{"dataset_uid": "609280", "doi": "10.7265/N5ZK5DM5", "repository": "USAP-DC", "science_program": null, "title": "MODIS Mosaic of Antarctica 2003-2004 (MOA2004) Image Map", "url": "http://www.usap-dc.org/view/dataset/609280"}], "date_created": "Wed, 02 Nov 2005 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MODIS; Sample/collection Description; Sample/Collection Description; Solid Earth", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bohlander, Jennifer; Scambos, Ted; Painter, Thomas; Fahnestock, Mark; Haran, Terry", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "9909518 Raymond, Charles", "bounds_geometry": "POLYGON((-154 -80,-152 -80,-150 -80,-148 -80,-146 -80,-144 -80,-142 -80,-140 -80,-138 -80,-136 -80,-134 -80,-134 -80.5,-134 -81,-134 -81.5,-134 -82,-134 -82.5,-134 -83,-134 -83.5,-134 -84,-134 -84.5,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-152 -85,-154 -85,-154 -84.5,-154 -84,-154 -83.5,-154 -83,-154 -82.5,-154 -82,-154 -81.5,-154 -81,-154 -80.5,-154 -80))", "dataset_titles": "Compilation of Antarctic Radar Data, Siple Coast, 2000-2002", "datasets": [{"dataset_uid": "609274", "doi": "10.7265/N5736NTS", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Siple Coast", "people": "Raymond, Charles; Conway, Howard; Catania, Ginny", "repository": "USAP-DC", "science_program": null, "title": "Compilation of Antarctic Radar Data, Siple Coast, 2000-2002", "url": "https://www.usap-dc.org/view/dataset/609274"}], "date_created": "Fri, 03 Jun 2005 00:00:00 GMT", "description": "9909518 Raymond This award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide \"shutdown\" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time.", "east": -134.0, "geometry": "POINT(-144 -82.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e AVHRR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": true, "keywords": "Ice Stream; West Antarctic Ice Sheet; Radarsat; Siple Dome; Radar; Ice Floe; Not provided; AVHRR; Siple Coast; Ice Stratigraphy; Margin Scars; NOAA POES; RAMP; GROUND-BASED OBSERVATIONS; Ice Flow; Accumulation Rate; Antarctic Ice Sheet; RADARSAT-1", "locations": "Siple Coast; Antarctic Ice Sheet; Siple Dome; West Antarctic Ice Sheet", "north": -80.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Raymond, Charles; Conway, Howard; Catania, Ginny", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e POLAR ORBITING ENVIRONMENTAL SATELLITES (POES) \u003e NOAA POES; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e RADARSAT \u003e RADARSAT-1", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research:History and Evolution of the Siple Coast Ice Stream Systems as Recorded by Former Shear-Margin Scars", "uid": "p0000275", "west": -154.0}, {"awards": "0125981 Sowers, Todd", "bounds_geometry": "POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 05 May 2005 00:00:00 GMT", "description": "0125981\u003cbr/\u003eSowers\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to construct an isotopic record of atmospheric methane and nitrous oxide over the last century from South Pole firn air. Over the last 150 years, atmospheric methane and nitrous oxide concentrations have risen in response to increased emissions from various anthropogenic activities. As this trend is liable to continue in the foreseeable future, it is important to understand the biogeochemical processes that contribute to the emissions of these two greenhouse gases. In this context, records of the variations in the atmospheric loading of trace gases found in ice cores and interstitial spaces in the snow near the surface of the ice sheet (firn air) provide fundamental boundary conditions for reconstructing historical emission records. One way to improve our understanding of the cycling of bioactive trace gases and their emission records is to use stable isotope tracers, which have been recorded in the ice cores and firn air. This project will develop records of carbon-13 and deuterium isotope ratios of methane, as well as the nitrogen-15, oxygen-18 and the isotopomer composition of nitrous oxide trapped in firn air samples collected in January 2001 at the South Pole. These measurements will allow isotopic records of these atmospheric gases to be reconstructed throughout the 20th century. Such records will help to establish the relative contribution of individual sources with a higher degree of confidence than is currently available.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -62.83, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Sowers, Todd A.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -90.0, "title": "Generating an Isotopic Record of Atmospheric Methane and Nitrous Oxide Over the Last Century from South Pole Firn Air", "uid": "p0000086", "west": -180.0}, {"awards": "0088035 Arcone, Steven", "bounds_geometry": "POLYGON((-135 -75,-130.5 -75,-126 -75,-121.5 -75,-117 -75,-112.5 -75,-108 -75,-103.5 -75,-99 -75,-94.5 -75,-90 -75,-90 -76.5,-90 -78,-90 -79.5,-90 -81,-90 -82.5,-90 -84,-90 -85.5,-90 -87,-90 -88.5,-90 -90,-94.5 -90,-99 -90,-103.5 -90,-108 -90,-112.5 -90,-117 -90,-121.5 -90,-126 -90,-130.5 -90,-135 -90,-135 -88.5,-135 -87,-135 -85.5,-135 -84,-135 -82.5,-135 -81,-135 -79.5,-135 -78,-135 -76.5,-135 -75))", "dataset_titles": "US International Trans-Antarctic Scientific Expedition 400 MHz Subsurface Radar Profiles; US International Trans-Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping", "datasets": [{"dataset_uid": "609269", "doi": "10.7265/N5GH9FV6", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; ITASE; WAIS", "people": "Mayewski, Paul A.; Arcone, Steven; Kaspari, Susan; Hamilton, Gordon S.; Spikes, Vandy Blue", "repository": "USAP-DC", "science_program": "ITASE", "title": "US International Trans-Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping", "url": "https://www.usap-dc.org/view/dataset/609269"}, {"dataset_uid": "609254", "doi": "10.7265/N58050J7", "keywords": "Airborne Radar; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ITASE; Radar; WAIS", "people": "Arcone, Steven", "repository": "USAP-DC", "science_program": null, "title": "US International Trans-Antarctic Scientific Expedition 400 MHz Subsurface Radar Profiles", "url": "https://www.usap-dc.org/view/dataset/609254"}], "date_created": "Sun, 01 May 2005 00:00:00 GMT", "description": "This award supports continued acquisition of high resolution, radar reflection profiles of the snow and ice stratigraphy between core sites planned along traverse routes of the U.S. component of the International\u003cbr/\u003eTrans-Antarctic Scientific Expedition (U.S.-ITASE). The purpose is to use the profiles to establish the structure and continuity of firn stratigraphic horizons over hundreds of kilometers and to quantitatively\u003cbr/\u003eassess topographic and ice movement effects upon snow deposition. Other objectives are to establish the climatic extent that a single site represents and to investigate the cause of firn reflections. The radar\u003cbr/\u003ewill also be used to identify crevasses ahead of the traverse vehicles in order to protect the safety of the scientists and support personnel on the traverse. Collaboration with other ITASE investigators will use the radar horizons as continuous isochronic references fixed by the core dating to calculate historical snow accumulation rates. The primary radar system uses 400-MHz (center frequency) short-pulse antennas, which (with processing) gives the penetration of 50-70 meters. This is the depth which is required to exceed the 200-year deposition horizon along the traverse routes. Profiles at 200 MHz will also be recorded if depths greater than 70 meters are of interest. Processing will be accomplished by data compression (stacking) to reveal long distance stratigraphic deformation, range gain corrections to give proper weight to signal amplitudes, and GPS corrections to adjust the records for the present ice sheet topography. Near surface stratigraphy will allow topographic and ice movement effects to be separated. This work is critical to the success of the U.S.-ITASE program.", "east": -90.0, "geometry": "POINT(-112.5 -82.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": true, "keywords": "Ice; Radar Echo Sounder; USAP-DC; US ITASE; Ice Cover; West Antarctic Ice Sheet; Snow Accumulation; CRREL; Antarctic Ice Sheet; Radar; Ice Surveys; ITASE; Ice Sheet; Radar Echo Sounding; GROUND-BASED OBSERVATIONS; Ice Thickness; Mass Balance", "locations": "Antarctic Ice Sheet; West Antarctic Ice Sheet", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Spikes, Vandy Blue; Arcone, Steven; Kaspari, Susan; Hamilton, Gordon S.; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -90.0, "title": "High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet", "uid": "p0000146", "west": -135.0}, {"awards": "0088054 Goldstein, Steven", "bounds_geometry": "POLYGON((-180 -39.57,-144 -39.57,-108 -39.57,-72 -39.57,-36 -39.57,0 -39.57,36 -39.57,72 -39.57,108 -39.57,144 -39.57,180 -39.57,180 -42.967,180 -46.364,180 -49.761,180 -53.158,180 -56.555,180 -59.952,180 -63.349,180 -66.746,180 -70.143,180 -73.54,144 -73.54,108 -73.54,72 -73.54,36 -73.54,0 -73.54,-36 -73.54,-72 -73.54,-108 -73.54,-144 -73.54,-180 -73.54,-180 -70.143,-180 -66.746,-180 -63.349,-180 -59.952,-180 -56.555,-180 -53.158,-180 -49.761,-180 -46.364,-180 -42.967,-180 -39.57))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 26 Apr 2005 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the sediment core from the Southern Ocean for paleoenvironmental research. The polar regions are susceptible to the largest changes in climate and are among the least accessible places on Earth. Current concern about the instability of the West Antarctic Ice Sheet has heightened awareness of the vulnerability of polar regions. This proposal seeks to gain a basic understanding of the isotopic characteristics of terrigenous sediment sources derived from Antarctica in the Holocene and Last Glacial Maximum, and their dispersal into the Southern Ocean. Terrigenous clastic sediments are brought to the ocean from continental sources via rivers, ice and wind, and distributed within the ocean by surface and deep currents. At present there are virtually no isotopic data on circumpolar detritus, save a few strontium (Sr) isotopic ratios in the Atlantic sector. This project will fill part of this gap. From the large range in geological ages of crustal provinces of Antarctica, we would predict that there are large isotopic differences in detritus around the continent. The main objectives are to (1) characterize the strontium-neodymium-lead-argon (Sr-Nd-Pb-Ar) isotope compositions of sediment sources derived from Antarctica, (2) to identify the composition and source ages of major ice rafted detritus (IRD) contributions by analyzing individual grains of hornblende and feldspar in conjunction with bulk isotopic analysis, and (3) track sediment dispersal into the Antarctic Circumpolar Current (ACC) during the Holocene and Last Glacial Maximum.\u003cbr/\u003e\u003cbr/\u003eBecause of the paucity of circumpolar data, this research necessarily has a large exploratory component. Consequently, it will provide a basic database for future studies. Nevertheless there are important hypothesis-driven questions that will be addressed in this primary pass. Can lessons learned in North Atlantic IRD studies be applied toward understanding the history of Antarctic ice sheets? Can the large geological variability around the Antarctic margin be treated as a series of natural tracer injections into the ACC, and thus characterize its trajectory, speed, and interaction with other current systems today and in the past? The proposed study is motivated by an exciting set of results from the South Atlantic, showing that detrital Sr isotope ratios are a sensitive current tracer in that region. This research should serve a basic need across many Earth Science disciplines if the use of long-lived radiogenic isotopes (Sr-Nd-Pb-Ar) as tracers of marine sediment sources is successful in elucidating processes related to changing climatic conditions. The results of this study will fill a basic gap in our knowledge of an important region of the Earth. At the same time, it will provide an essential basis for attempting reconstruction of the ACC during the LGM, as well as for future studies of Antarctic geology, ice sheet history, and the Southern Ocean circulation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -39.57, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Roy, Martin; Hemming, Sidney R.; Goldstein, Steven L.; Van De Flierdt, Christina-Maria", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -73.54, "title": "Establishing the Pattern of Holocene-LGM Changes in Sediment Contributions from Antarctica to the Southern Ocean", "uid": "p0000724", "west": -180.0}, {"awards": "9814574 Jacobel, Robert", "bounds_geometry": "POLYGON((-120 -80,-115.6 -80,-111.2 -80,-106.8 -80,-102.4 -80,-98 -80,-93.6 -80,-89.2 -80,-84.8 -80,-80.4 -80,-76 -80,-76 -81,-76 -82,-76 -83,-76 -84,-76 -85,-76 -86,-76 -87,-76 -88,-76 -89,-76 -90,-80.4 -90,-84.8 -90,-89.2 -90,-93.6 -90,-98 -90,-102.4 -90,-106.8 -90,-111.2 -90,-115.6 -90,-120 -90,-120 -89,-120 -88,-120 -87,-120 -86,-120 -85,-120 -84,-120 -83,-120 -82,-120 -81,-120 -80))", "dataset_titles": "Ice Thickness and Internal Layer Depth Along the 2001 and 2002 US ITASE Traverses", "datasets": [{"dataset_uid": "609264", "doi": "10.7265/N5R20Z9T", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ITASE; WAIS", "people": "Welch, Brian; Jacobel, Robert", "repository": "USAP-DC", "science_program": "ITASE", "title": "Ice Thickness and Internal Layer Depth Along the 2001 and 2002 US ITASE Traverses", "url": "https://www.usap-dc.org/view/dataset/609264"}], "date_created": "Fri, 08 Apr 2005 00:00:00 GMT", "description": "This award supports a program of radar studies of internal stratigraphy and bedrock topography along the traverses for the U.S. component of the International Trans-Antarctic Scientific Expedition (US ITASE). The radar will provide information immediately available in the field on ice thickness and internal layer structure to help in the selection of core sites as the traverse proceeds. These data will also be useful in siting deeper millennial scale cores planned at less frequent intervals along the traverse, and in the selection of the location for the deep inland core planned for the future. In addition to continuous coverage along the traverse route, more detailed studies on a grid surrounding each of the core locations will be made to better characterize accumulation and bedrock topography in each area. This proposal is complimentary to the one submitted by the Cold Regions Research and Engineering Laboratory (CRREL), which proposes a high frequency radar to examine the shallower portion of the record down to approximately 60 meters, including the presence of near-surface crevasses. The radar proposed herein is most sensitive at depths below 60 meters and can depict deep bedrock and internal layers to a substantial fraction of the ice thickness.", "east": -76.0, "geometry": "POINT(-98 -85)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "US ITASE; Traverses; West Antarctica; Radar Echo Sounder; GROUND-BASED OBSERVATIONS; Radar Echo Sounding; Antarctica; Depth; Ice Thickness; Radar", "locations": "Antarctica; West Antarctica", "north": -80.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Jacobel, Robert; Welch, Brian", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -90.0, "title": "Radar Studies of Internal Stratigraphy and Bedrock Topography along the US ITASE Traverse", "uid": "p0000595", "west": -120.0}, {"awards": "0086997 Truffer, Martin", "bounds_geometry": null, "dataset_titles": "Margin Migration Rates and Dynamics: Siple Coast Ice Streams", "datasets": [{"dataset_uid": "609263", "doi": "10.7265/N50K26HH", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Siple Coast", "people": "Truffer, Martin; Echelmeyer, Keith A.", "repository": "USAP-DC", "science_program": null, "title": "Margin Migration Rates and Dynamics: Siple Coast Ice Streams", "url": "https://www.usap-dc.org/view/dataset/609263"}], "date_created": "Thu, 17 Mar 2005 00:00:00 GMT", "description": "0086997\u003cbr/\u003eTruffer\u003cbr/\u003e\u003cbr/\u003eThis award supports a two year project to investigate the dynamics of the marginal zone of the Siple Coast ice streams using existing velocity and temperature profiles. The flow and stress fields will be modeled using finite element methods and a thermo-mechanical model will be used to investigate the coupling of the flow and temperature fields. Direct comparison of these models with the observed velocity profiles will lead to estimates of the structure of the margins and the softening of the marginal ice. The distribution of basal and marginal shear stress will be investigated, leading to an estimate of the relative roles of the bed and the margins in the overall force balance of the ice streams.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e SURVEYING TOOLS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e THEODOLITE", "is_usap_dc": true, "keywords": "GROUND-BASED OBSERVATIONS; Ice Movement; Siple Dome; Ice Stream; USAP-DC; Ice Velocity", "locations": "Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Truffer, Martin; Echelmeyer, Keith A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Margin Migration Rates and Margin Dynamics of the Siple Coast Ice Streams", "uid": "p0000144", "west": null}, {"awards": "0135989 Wilen, Larry", "bounds_geometry": null, "dataset_titles": "Ice Fabric Characteristics: Siple Dome, A Core", "datasets": [{"dataset_uid": "609255", "doi": "10.7265/N54B2Z7V", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core", "people": "Wilen, Larry", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Ice Fabric Characteristics: Siple Dome, A Core", "url": "https://www.usap-dc.org/view/dataset/609255"}], "date_created": "Wed, 02 Mar 2005 00:00:00 GMT", "description": "0135989\u003cbr/\u003eWilen\u003cbr/\u003e\u003cbr/\u003eThis is a collaborative proposal by Principal Investigators at the University of Washington and Ohio University. Detailed knowledge about the interactions between micro-structure of ice and its deformation is needed to assess the integrity of stratigraphic layering and the depth-age relationship in ice cores, which is essential for interpreting the paleoclimate record. The Principal Investigators will use micro-structure to study fabric, the orientation distribution of crystal c-axes, and texture, the size and shape of crystals. Numerical modeling of ice deformation is a useful tool in understanding these interactions. Accurate modeling of ice deformation is complicated by factors, such as the fabric, grain size, dynamic recrystallization, stress level, and precise knowledge of initial conditions. For example, ice fabric evolves as the ice is strained and the deformation depends on the fabric. This complicated feedback mechanism must be understood to correctly model ice deformation. In another example, the usual assumption is that the initial fabric is isotropic or random, but there are excellent examples of near-surface ice in the ice cores that are apparently not isotropic. One must know the initial fabric to calculate the deformation rate in ice sheets. Dr. Wilen will combine results of his new automatic fabric analyzer (AFA) with predictions of detailed ice deformation models (Dr. Thorsteinsson) to refine and better constrain such models. The AFA gives new information in thin sections because the precision and number of measured c-axis orientations are greatly improved. The Principal Investigators will analyze existing data and collect new data on fabric and texture from ice cores to address questions regarding near-surface fabric, deformation mechanisms, dynamic recrystallization, and potential sources of layer disturbances. The data will be used to constrain models of fabric evolution and recrystallization processes. With the more refined models, scientists can address different questions and important problems related to ice deformation and ice cores. For example, the recent agreement between the climate records from the Greenland Ice Core Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) ice cores of the upper-90%, and the disagreement in the lower-10% emphasizes the need to understand and predict the mechanisms and probable depths of disruption in these and future deep ice cores. Evidence suggests that the stratigraphic disturbances arise from the anisotropic nature of ice crystals at a variety of scales. To properly model the deformation of anisotropic ice, the influence of fabric on deformation must be well known.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GROUND-BASED OBSERVATIONS; Ice Core Data; Siple Dome; Ice Fabric; Ice Core; USAP-DC", "locations": "Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Wilen, Larry", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Collaborative Research: Fabric and Texture Characteristics of Micro-Physical Processes in Ice", "uid": "p0000134", "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Talos Dome Ice Core Deuterium Isotope Data", "datasets": [{"dataset_uid": "609252", "doi": "", "repository": "USAP-DC", "science_program": null, "title": "Talos Dome Ice Core Deuterium Isotope Data", "url": "http://www.usap-dc.org/view/dataset/609252"}], "date_created": "Fri, 27 Aug 2004 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Paleoclimate; Talos Dome", "locations": "Antarctica; Talos Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stenni, Barbara; Jouzel, Jean", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Dronning Maud Land Ice Core Chemistry Data", "datasets": [{"dataset_uid": "609250", "doi": "", "repository": "USAP-DC", "science_program": null, "title": "Dronning Maud Land Ice Core Chemistry Data", "url": "http://www.usap-dc.org/view/dataset/609250"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Dronning Maud Land; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate", "locations": "Dronning Maud Land; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Isaksson, Elisabeth; Whitlow, Sallie", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Vostok Ice Core Chemistry, Timescale, Isotope, and Temperature Data", "datasets": [{"dataset_uid": "609242", "doi": "", "repository": "USAP-DC", "science_program": null, "title": "Vostok Ice Core Chemistry, Timescale, Isotope, and Temperature Data", "url": "http://www.usap-dc.org/view/dataset/609242"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Lake Vostok; Paleoclimate; Physical Properties; Temperature; Vostok Ice Core", "locations": "Lake Vostok; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Blunier, Thomas; Petit, Jean Robert; Barnola, J. M.; Lal, Devendra; Ruddiman, William; Jouzel, Jean; Chappellaz, Jerome; Fishcer, Hubertus; Brook, Edward J.; Sowers, Todd A.; Lorius, Claude; Raymo, Maureen; Bender, Michael", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "European Project for Ice Coring in Antarctica (EPICA) Dome C Ice Core Data", "datasets": [{"dataset_uid": "609244", "doi": "", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "European Project for Ice Coring in Antarctica (EPICA) Dome C Ice Core Data", "url": "http://www.usap-dc.org/view/dataset/609244"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Dome C Ice Core; Epica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Physical Properties", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fluckiger, Jacqueline; Wolff, Eric W.; Monnin, Eric", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Dome C Ice Core", "south": null, "title": null, "uid": null, "west": null}, {"awards": "9714687 Brook, Edward J.", "bounds_geometry": null, "dataset_titles": "Byrd Ice Core Microparticle and Chemistry Data", "datasets": [{"dataset_uid": "609247", "doi": "", "keywords": "Antarctica; Byrd; Byrd Ice Core; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate", "people": "Blunier, Thomas; Brook, Edward J.; Thompson, Lonnie G.; Fluckiger, Jacqueline", "repository": "USAP-DC", "science_program": "Byrd Ice Core", "title": "Byrd Ice Core Microparticle and Chemistry Data", "url": "https://www.usap-dc.org/view/dataset/609247"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": "This award is for support for a program to make high resolution studies of variations in the concentration of methane, the oxygenisotope composition of paleoatmospheric oxygen, and the total gas content of deep Antarctic ice cores. Studies of the concentration and isotopic composition of air in the firn of the Antarctic ice sheet will also be continued. One objective of this work is to use the methane concentration and oxygen-isotope composition of oxygen of air in ice as time-stratigraphic markers for the precise intercorrelation of Greenland and Antarctic ice cores as well as the correlation of ice cores to other climatic records. A second objective is to use variations in the concentration and interhemispheric gradient of methane measured in Greenland and Antarctic ice cores to deduce changes in continental climates and biogeochemistry on which the atmospheric methane distribution depends. A third objective is to use data on the variability of total gas content in the Siple Dome ice core to reconstruct aspects of the glacial history of West Antarctica during the last glacial maximum. The fourth objective is to participate in collaborative studies of firn air chemistry at Vostok, Siple Dome, and South Pole which will yield much new information about gas trapping in ice as well as the concentration history and isotopic composition of greenhouse gases, oxygen, trace biogenic gases and trace anthropogenic gases during the last 100 years.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "GROUND STATIONS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Blunier, Thomas; Fluckiger, Jacqueline; Thompson, Lonnie G.; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Studies of Trapped Gases in Firn and Ice from Antarctic Deep Ice Cores", "uid": "p0000168", "west": null}, {"awards": "9316564 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Ross Ice Drainage System (RIDS) Glaciochemical Analysis; Siple Dome Ice Core Chemistry and Ion Data", "datasets": [{"dataset_uid": "609266", "doi": "10.7265/N5M906KG", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; Snow Pit", "people": "Kreutz, Karl; Mayewski, Paul A.; Twickler, Mark; Whitlow, Sallie; Meeker, Loren D.", "repository": "USAP-DC", "science_program": null, "title": "Ross Ice Drainage System (RIDS) Glaciochemical Analysis", "url": "https://www.usap-dc.org/view/dataset/609266"}, {"dataset_uid": "609251", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Severinghaus, Jeffrey P.; Dunbar, Nelia; Mayewski, Paul A.; Kreutz, Karl; Brook, Edward J.; Blunier, Thomas", "repository": "NCEI", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Ice Core Chemistry and Ion Data", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/2461"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": "9316564 Mayewski This award is for support for a three year program to provide a high resolution record of the Antarctic climate through the acquisition, analysis, and interpretation of records of atmospheric chemical deposition taken from three ice cores located at sites within or immediately adjacent to the Ross Ice Drainage System (RIDS). These cores include one from Taylor Dome, and two from West Antarctic locations identified as potential deep drilling sites for the WAISCORES program. Collection of the two West Antarctic cores is intended to be a lightweight dry-drilling operation to depths of ~ 200 m, which will provide records of \u003e 2 kyr. Glaciochemical analyses will focus on the major cations and anions found in the antarctic atmosphere, plus methanesulfonic acid and selected measurements of the hydrogen ion, aluminum, iron, and silica. These analyses, and companion stable isotope and particle measurements to be carried out by other investigators require \u003c 7% by volume of each core, leaving \u003e 90% for other investigators and storage at the U.S. National Ice Core Laboratory. These records are intended to solve a variety of scientific objectives while also providing spatial sampling and reconnaissance for future U.S. efforts in West Antarctica. ***", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Magnesium; GROUND STATIONS; Nitrate; Methane Sulfonic Acid; Sodium; Ice Core Chemistry; Ammonium (NH4); Sulfate; Ice Core; Chloride; Potassium (k); Calcium (ca)", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Kreutz, Karl; Twickler, Mark; Whitlow, Sallie; Blunier, Thomas; Dunbar, Nelia; Brook, Edward J.; Mayewski, Paul A.; Meeker, Loren D.; Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "NCEI; USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Ross Ice Drainage System (RIDS) Late Holocene Climate Variability", "uid": "p0000145", "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Law Dome Ice Cores Chemistry Data", "datasets": [{"dataset_uid": "609245", "doi": "", "repository": "USAP-DC", "science_program": null, "title": "Law Dome Ice Cores Chemistry Data", "url": "http://www.usap-dc.org/view/dataset/609245"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Law Dome; Paleoclimate", "locations": "Antarctica; Law Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Barnola, J. M.; Etheridge, David; Morgan, Vin", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "8411018 Frisic, David", "bounds_geometry": null, "dataset_titles": "Dominion Range Ice Core Beta Profiles, Chemistry, and Density Data; Newall Glacier Ice Core and Snow Pit Beta Profiles, Chemistry, and Stratigraphy; Newall Glacier Snow Pit and Ice Core, 1987 to 1989", "datasets": [{"dataset_uid": "609088", "doi": "10.7265/N5JM27JP", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Newall Glacier; Paleoclimate; Snow/ice; Snow/Ice", "people": "Mayewski, Paul A.; Whitlow, Sallie", "repository": "USAP-DC", "science_program": null, "title": "Newall Glacier Snow Pit and Ice Core, 1987 to 1989", "url": "https://www.usap-dc.org/view/dataset/609088"}, {"dataset_uid": "609249", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Newall Glacier; Paleoclimate; Physical Properties; Snow/ice; Snow/Ice; Statigraphy", "people": "Mayewski, Paul A.; Welch, Kathy A.", "repository": "USAP-DC", "science_program": null, "title": "Newall Glacier Ice Core and Snow Pit Beta Profiles, Chemistry, and Stratigraphy", "url": "https://www.usap-dc.org/view/dataset/609249"}, {"dataset_uid": "609248", "doi": "", "keywords": "Antarctica; Beta Profiles; Chemistry:ice; Chemistry:Ice; Density; Dominion Range; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Physical Properties", "people": "Mayewski, Paul A.; Watson, M. Scott; Saltzman, Eric; Sowers, Todd A.; Grootes, Pieter; Meese, Deb; Gow, Tony", "repository": "USAP-DC", "science_program": null, "title": "Dominion Range Ice Core Beta Profiles, Chemistry, and Density Data", "url": "https://www.usap-dc.org/view/dataset/609248"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": "Not available", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "GROUND STATIONS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Frisic, David; Meese, Deb; Gow, Tony; Saltzman, Eric; Mayewski, Paul A.; Sowers, Todd A.; Welch, Kathy A.; Grootes, Pieter; Watson, M. Scott; Grootes, Peiter", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Characterization of Climatic Events for the Last 2 x 103y through the Retrieval of Ice Cores from the Transantarctic Mountains, Antarctica", "uid": "p0000169", "west": null}, {"awards": "9017827 Lal, Devendra", "bounds_geometry": null, "dataset_titles": "Dome C Ice Core Chemistry and Depth and Age Scale Data", "datasets": [{"dataset_uid": "609243", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Depth-Age-Model; Dome C Ice Core; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate", "people": "Lal, Devendra; Lorius, Claude", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Dome C Ice Core Chemistry and Depth and Age Scale Data", "url": "https://www.usap-dc.org/view/dataset/609243"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": "This award is for support of a study to establish a quantitative nuclear method for determination of Antarctic ablation and accumulation rates and to provide correction factors for the carbon 14 ages of ice samples dated using trapped carbon 14. Recent studies have established the presence of cosmogenic in-situ produced carbon 14 in polar ice. In conjunction with estimated carbon 14 production rates, measured concentrations of carbon 14 per gram of ice yield, ablation rates which are in good agreement with the values determined from stake measurements. Similar studies to determine accumulation rates have been tested and the estimates are consistent with previous studies. This study will expand the preliminary work done to date in order to improve the 14CO and 14CO2 vacuum extraction techniques, by lowering blank levels and by obtaining more complete separation of 14CO and 14CO2.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "GROUND STATIONS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Lal, Devendra; Lorius, Claude; Lal, Devendra", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Dome C Ice Core", "south": null, "title": "Nuclear Studies of Accumulating and Ablation Ice Using Cosmogenic 14c", "uid": "p0000152", "west": null}, {"awards": "0087390 Grunow, Anne", "bounds_geometry": "POLYGON((-170 -79,-164 -79,-158 -79,-152 -79,-146 -79,-140 -79,-134 -79,-128 -79,-122 -79,-116 -79,-110 -79,-110 -79.5,-110 -80,-110 -80.5,-110 -81,-110 -81.5,-110 -82,-110 -82.5,-110 -83,-110 -83.5,-110 -84,-116 -84,-122 -84,-128 -84,-134 -84,-140 -84,-146 -84,-152 -84,-158 -84,-164 -84,-170 -84,-170 -83.5,-170 -83,-170 -82.5,-170 -82,-170 -81.5,-170 -81,-170 -80.5,-170 -80,-170 -79.5,-170 -79))", "dataset_titles": "Polar Rock Repository; Rock Magnetic Clast data are at this website", "datasets": [{"dataset_uid": "001970", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Rock Magnetic Clast data are at this website", "url": "http://bprc.osu.edu/"}, {"dataset_uid": "200243", "doi": "", "keywords": null, "people": null, "repository": "PRR", "science_program": null, "title": "Polar Rock Repository", "url": "https://prr.osu.edu/"}], "date_created": "Mon, 23 Aug 2004 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research project between the University of California-Santa Cruz, the University of Texas-Austin, and the Ohio State University to investigate sediment samples recovered from the base of the West Antarctic Ice Sheet (WAIS). West Antarctica is a remote polar region but its dynamic ice sheet, complicated tectonic history, and the sedimentary record of Cenozoic glaciation make it of particular interest to glaciologists and geologists. Glaciologists are concerned with the possibility of significant near-future changes in mass balance of the WAIS that may contribute to the ongoing global sea level rise. Geologists are investigating in West Antarctica the fundamental process of continental extension and are constructing models of a polar marine depositional system using this region as the prime modern example. The subglacial part of West Antarctica has escaped direct geological investigations and all that is known about subglacial geology comes from geophysical remote sensing. Recent acquisitions of new, high-quality geophysical data have led to generation of several enticing models. For instance, subglacial presence of high-magnitude, short-wavelength magnetic anomalies has prompted the proposition that there may be voluminous (\u003e1 million cubic km), Late Cenozoic flood basalts beneath the ice sheet. Another important model suggests that the patterns of fast ice streaming (~100 meters/year) and slow ice motion (~1-10 meters/year) observed within the WAIS are controlled by subglacial distribution of sedimentary basins and resistant bedrock. These new geophysics-based models should be tested with direct observations because they are of such great importance to our understanding of the West Antarctic tectonic history and to our ability to predict the future behavior of the WAIS.\u003cbr/\u003e\u003cbr/\u003eThis research is designed as a pilot study to provide new geologic data, which may help to test the recent models inferred from geophysical observations. The new constraints on subglacial geology and on its interactions with the WAIS will be obtained through petrological and geochemical analyses of basal and subglacial sediments collected previously from seven localities. This investigation will take place in the context of testing the following three hypotheses: (A) the provenance of bedrock clasts in the glacial sediment samples is primarily from West Antarctica, (B) some clasts and muds from the West Antarctic subglacial sediments have been derived by erosion of the (inferred) subglacial Late Cenozoic flood basalts, and (C) the sediments underlying the West Antarctic ice streams were generated by glacial erosion of preglacial sedimentary basins but the sediments recovered from beneath the slow-moving parts of the WAIS were produced through erosion of resistant bedrock.\u003cbr/\u003e\u003cbr/\u003eThe individual hypotheses will be tested by collecting data on: (A) petrology, geochemistry and age of granitoid clasts, (B) petrology, geochemistry and age of basaltic clasts combined with mud geochemistry, and (C) clay mineralogy/paragenesis combined with textural maturity of sand and silt grains. The results of these tests will help evaluate the interesting possibility that subglacial geology may have first-order control on the patterns of fast ice flow within the WAIS. The new data will also help to determine whether the subglacial portion of West Antarctica is a Late Cenozoic flood basalt province. By combining glaciological and geological aspects of West Antarctic research the proposed collaborative project will add to the ongoing U.S. effort to create a multidisciplinary understanding of this polar region.", "east": -110.0, "geometry": "POINT(-140 -81.5)", "instruments": null, "is_usap_dc": false, "keywords": "Till; Subglacial; Clasts; Magnetic Properties; Rock Magnetics; FIELD INVESTIGATION; West Antarctic Ice Sheet", "locations": "West Antarctic Ice Sheet", "north": -79.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Grunow, Anne; Vogel, Stefan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "PI website", "repositories": "PI website; PRR", "science_programs": null, "south": -84.0, "title": "Collaborative Research: Relationship Between Subglacial Geology and Glacial Processes in West Antarctica: Petrological and Geochemical Analyses of Subglacial and Basal Sediments", "uid": "p0000740", "west": -170.0}, {"awards": "0126286 McConnell, Joseph", "bounds_geometry": "POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83))", "dataset_titles": "Siple Shallow Core Density Data", "datasets": [{"dataset_uid": "609129", "doi": "10.7265/N52F7KCD", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Lamorey, Gregg W.", "repository": "USAP-DC", "science_program": null, "title": "Siple Shallow Core Density Data", "url": "https://www.usap-dc.org/view/dataset/609129"}], "date_created": "Mon, 19 Apr 2004 00:00:00 GMT", "description": "This award provides one year of support to use newly developed technology in which an ice-core melter is coupled with both an Inductively Coupled Plasma - Mass Spectrometer (ICP-MS) and a traditional Continuous Flow Analysis (CFA) system, to measure a continuous time series of chemical and trace element deposition on the Siple Dome ice core from West Antarctica. A coupled ice-core melter, ICP-MS, and CFA system will be used to measure concentrations of a number of elements, isotopes and chemical species at very high depth resolution (~2-cm) in the top 54 m of the Siple Dome A-core. Pilot data from analyses of ~6 m from the nearby but much lower accumulation J-core site at Siple Dome, together with more extensive results from Summit, Greenland, indicate that it will be possible to obtain exactly co-registered, high-quality records of at least 12 seasonally varying elements (sodium, magnesium, aluminum, potassium, calcium, iron, manganese, rubidium, strontium, zirconium, barium, lead) and three other chemical species and ions (ammonium, nitrate, calcium ion) with this system. Under this proposed research, we will also add continuous measurements of sulfate to our system. Because more than sufficient core from Siple Dome for these depths is archived at the National Ice Core Laboratory, the proposed research will require no fieldwork. The continuous, very high-resolution, ~350-y record of these elemental tracers will enhance the value of previous chemical and isotopic measurements that have been made on the Siple Dome core and will be particularly valuable for comparisons between ice-core proxies and modern instrumental data related to El Nino-Southern Oscillation (ENSO) as well as for validation of model simulations of atmospheric circulation. These data, and the expertise gained through this research, will be invaluable when this novel chemical analysis technology is eventually applied to deep ice-core records for the study of rapid climate-change events.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "WAISCORES; Siple Coast; Glaciology; Not provided; GROUND-BASED OBSERVATIONS; Ice Core; Siple; Antarctica; Density; Snow; Ice Sheet; Siple Dome; Shallow Core; GROUND STATIONS; Stratigraphy", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": -62.83, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Lamorey, Gregg W.; McConnell, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -90.0, "title": "Continuous High Resolution Ice-Core Chemistry using ICP-MS at Siple Dome", "uid": "p0000159", "west": -180.0}, {"awards": "0087151 Cole-Dai, Jihong", "bounds_geometry": null, "dataset_titles": "Sulfate-Based Volcanic Record from South Pole Ice Core", "datasets": [{"dataset_uid": "609215", "doi": "10.7265/N5CR5R88", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Solid Earth; South Pole", "people": "Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": null, "title": "Sulfate-Based Volcanic Record from South Pole Ice Core", "url": "https://www.usap-dc.org/view/dataset/609215"}], "date_created": "Fri, 09 Apr 2004 00:00:00 GMT", "description": "This award supports a two year project to analyze shallow (~150 m) ice cores from South Pole in order to construct an annually resolved, sulfate-based volcanic record covering the last 1400 years. Two shallow ice cores will be recovered at the South Pole during the 00/01 field season and will be used for this work. Volcanic records from polar ice cores provide valuable information for studies of the connection between volcanism and climate. The new records are expected to be continuous and to cover at least the last 1400 years. The information from these records will verify the volcanic events found in the few existing Antarctic records and resolve discrepancies in the timing and magnitude of major explosive eruptions \u003cbr/\u003edetermined from those earlier records. In order to achieve the objectives of the proposed research, funds are provided to assist with the construction of an analytical laboratory for ice core and environmental \u003cbr/\u003echemistry research.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Core; Snow Chemistry; West Antarctica; GROUND-BASED OBSERVATIONS; Antarctica; Ice Core Gas Records; Ion Chemistry; Ice Core Data", "locations": "West Antarctica; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cole-Dai, Jihong", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "A Sulfate-based Volcanic Record from South Pole Ice Cores", "uid": "p0000167", "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Antarctic Ice Velocity Data", "datasets": [{"dataset_uid": "609070", "doi": "10.7265/N5KS6PH5", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Velocity Data", "url": "http://www.usap-dc.org/view/dataset/609070"}], "date_created": "Tue, 23 Mar 2004 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Velocity; Sample/collection Description; Sample/Collection Description", "locations": "Antarctica; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bindschadler, Robert; Raymond, Charles", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "8919147 Elliot, David", "bounds_geometry": null, "dataset_titles": "Ice Thickness and Surface Elevation, Southeastern Ross Embayment, West Antarctica", "datasets": [{"dataset_uid": "609099", "doi": "10.7265/N5WW7FKC", "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ross Embayment; West Antarctica", "people": "Peters, M. E.; Bell, Robin; Studinger, Michael S.; Morse, David L.; Blankenship, Donald D.; Brozena, J. M.; Finn, C. A.; Behrendt, J. C.; Hodge, S. M.; Kempf, Scott D.", "repository": "USAP-DC", "science_program": null, "title": "Ice Thickness and Surface Elevation, Southeastern Ross Embayment, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609099"}], "date_created": "Wed, 17 Mar 2004 00:00:00 GMT", "description": "This award will support a combined airborne radar and aeromagnetic survey of two 220 x 330 km regions between the Transantarctica Mountains and Marie Byrd Land during the 1990-91 and 1991-92 field seasons. These efforts will address significant problems identified in the Ross Transect Zone (RTZ) by the National Academy of Sciences (1986) report \"Antarctic Solid Earth Sciences Research,\" and by the report to NSF \"A Plan for a United States Program to Study the Structure and Evolution of the Antarctic Lithosphere (SEAL).\" The surveys will be flown using the NSF/TUD radar and an areomagnetics system mounted in a light aircraft. The grid spacing will be 5 km and navigation will be by radiopositioning. In addition to maps of subglacial topography and magnetic intensity, attempts will be made to reconstruct the position of subglacial diffractors in three dimensions. This reconstruction should give new information about the distribution of escarpments and therefore the tectonic relationships within the region, especially when combined with the magnetic results. These experiments will be conducted by the Byrd Polar Research Center of the Ohio State University and the Water Resources and Geological Divisions of the U.S. Geological Survey.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Subglacial Topography; SOAR; Airborne Laser Altimeters; Ross Embayment; West Antarctica; Ice Stream; Surface Morphology; Airborne Laser Altimetry; Aerogeophysics; Ice Sheet Thickness; Airborne Radar Sounding; Ice Thickness; West Antarctic Ice Sheet; Ice Surface Elevation; Casertz", "locations": "Ross Embayment; West Antarctica; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Elliot, David; Bell, Robin; Blankenship, Donald D.; Brozena, J. M.; Finn, C. A.; Hodge, S. M.; Kempf, Scott D.; Behrendt, J. C.; Morse, David L.; Peters, M. E.; Studinger, Michael S.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Corridor Aerogeophysics of the Southeastern Ross Transect Zone (CASERTZ), Antarctica", "uid": "p0000056", "west": null}, {"awards": "9615333 Saltzman, Eric", "bounds_geometry": "POINT(-148.8 -81.7)", "dataset_titles": "Biogenic Sulfur in the Siple Dome Ice Core", "datasets": [{"dataset_uid": "609201", "doi": "10.7265/N5S180F1", "keywords": "Antarctica; Biota; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Saltzman, Eric; Dioumaeva, Irina; Finley, Brandon", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Biogenic Sulfur in the Siple Dome Ice Core", "url": "https://www.usap-dc.org/view/dataset/609201"}], "date_created": "Tue, 09 Mar 2004 00:00:00 GMT", "description": "This award is for support for four years of funding for a program of biogenic sulfur measurements on the Siple Dome ice core. Biogenic sulfur is a major aerosol-forming constituent of the atmosphere and has potentially important links to the earth\u0027s radiation budget. Previous work on the Vostok ice core has demonstrated a remarkable climate-related variability in biogenic sulfur, suggesting that the sulfur cycle may act to stabilize climate (keep the glacial atmosphere cool and the interglacial atmosphere warm) in the Southern Hemisphere. In this study, methane-sulfonate (MSA) will be measured on the Siple Dome ice core as part of the West Antarctic ice sheet program (WAIS). Siple Dome is located in a region which is strongly impacted by the incursion of marine air onto the Antarctic plateau. Because of its proximity to the coast and meteorological setting, it is expected that variability in high-latitude marine biogenic sulfur emissions should dominate the MSA record at this site. In addition to the deep ice core record, samples from shallow cores will also be analyzed to provide information about regional variability and decadal-to-centennial scale variability in the deposition of sulfur-containing aerosols from high latitude source regions over the past 200 years.", "east": -148.8, "geometry": "POINT(-148.8 -81.7)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Siple Dome; GROUND-BASED OBSERVATIONS; Biogenic Sulfur; FIELD INVESTIGATION; Not provided; LABORATORY; Methane Sulfonate", "locations": "Siple Dome", "north": -81.7, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Saltzman, Eric; Dioumaeva, Irina; Finley, Brandon", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.7, "title": "Biogenic Sulfur in the Siple Dome Ice Core", "uid": "p0000251", "west": -148.8}, {"awards": "9980691 Wahlen, Martin", "bounds_geometry": null, "dataset_titles": "Atmospheric CO2 Trapped in the Ice Core from Siple Dome, Antarctica", "datasets": [{"dataset_uid": "609202", "doi": "10.7265/N5N877Q9", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; CO2; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Wahlen, Martin; Ahn, Jinho; Deck, Bruce", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Atmospheric CO2 Trapped in the Ice Core from Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609202"}], "date_created": "Thu, 11 Dec 2003 00:00:00 GMT", "description": "9980691 Wahlen This award is for support for three years of funding to reconstruct the atmospheric carbon dioxide (CO2) and carbon-13 isotope (d13C) concentration in ice cores from Antarctica over several climatic periods. Samples from the Holocene, the Last Glacial Maximum (LGM)-Holocene transition and glacial stadial/interstadial episodes will be examined. Samples from the Siple Dome ice core drilled in 1998/99 will be made, in addition to measurements from the Taylor Dome and Vostok ice cores. The major objectives are to investigate the phase relationships between variations in the concentration of atmospheric CO2, its carbon isotope composition, and temperature changes (indicated by 18dO and dD of the ice) during deglaciations as well as across rapid climate change events (e.g. Dansgaard-Oeschger events). This will help to determine systematic changes in the global carbon cycle during and between different climatic periods, and to ascertain if the widely spread northern hemisphere temperature stadial/interstadial events produced a global atmospheric carbon dioxide signal. Proven experimental techniques will be used.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Siple Dome; Ice Core; USAP-DC; Carbon Dioxide", "locations": "Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Wahlen, Martin; Ahn, Jinho; Deck, Bruce", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "CO2 and Delta 13CO2 in Antarctic Ice Cores", "uid": "p0000166", "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Central West Antarctic Glaciochemistry from Ice Cores", "datasets": [{"dataset_uid": "609093", "doi": "10.7265/N5959FHQ", "repository": "USAP-DC", "science_program": null, "title": "Central West Antarctic Glaciochemistry from Ice Cores", "url": "http://www.usap-dc.org/view/dataset/609093"}], "date_created": "Thu, 16 Oct 2003 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Accumulation Rate; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; West Antarctica", "locations": "West Antarctica; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Reusch, David", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "9420648 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": "Siple Dome Ice Core Age-Depth Scales", "datasets": [{"dataset_uid": "609130", "doi": "10.7265/N5T151KD", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Nereson, Nadine A.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Ice Core Age-Depth Scales", "url": "https://www.usap-dc.org/view/dataset/609130"}], "date_created": "Tue, 09 Sep 2003 00:00:00 GMT", "description": "This award is for support for a three year program to investigate the response of ice domes, such as Siple Dome in West Antarctica, to changing boundary conditions, for example as arising from fluctuations in thickness or position of bounding ice streams. A range of models will be used, from simple one-dimensional analytical models to coupled dynamic-thermodynamic flow models, to investigate the response of the ice dome to boundary forcing, and the record that boundary forcing can leave in the ice core record. Using radar, temperature, and ice core data from the currently funded field programs on Siple Dome, and ice flux and thickness values from the map view model as boundary conditions, a flow line across Siple Dome will be studied and possible ranges of time scales, the likely origin of ice near the bed, and the basal temperature conditions that exist now and existed in the past will be determined.The response of internal stratigraphy patterns to climate and dynamic forcing effects will be investigated and observed internal layers from ice cores will be used to infer the forcing history.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Ice Sheet; Snow; Not provided; Stratigraphy; Shallow Core; Siple Coast; Antarctica; Ice Core; Siple Dome; Glaciology; Density; Siple; WAISCORES; GROUND STATIONS; GROUND-BASED OBSERVATIONS", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Nereson, Nadine A.; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Ice Modelling Study of Siple Dome: WAIS Ice Dynamics, WAISCORES Paleoclimate and Ice Stream/Ice Dome Interactions", "uid": "p0000058", "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Taylor Dome Ice Core Data", "datasets": [{"dataset_uid": "609132", "doi": "10.7265/N5JH3J4C", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Taylor Dome Ice Core Data", "url": "http://www.usap-dc.org/view/dataset/609132"}], "date_created": "Mon, 18 Aug 2003 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "locations": "Antarctica; Taylor Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.; White, James", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": null, "title": null, "uid": null, "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Siple Dome Highlights: Stable isotopes", "datasets": [{"dataset_uid": "609134", "doi": "10.7265/N59021PM", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Highlights: Stable isotopes", "url": "http://www.usap-dc.org/view/dataset/609134"}], "date_created": "Mon, 18 Aug 2003 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; Siple Dome; Siple Dome Ice Core; WAISCORES", "locations": "Antarctica; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.; White, James", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": null, "uid": null, "west": null}, {"awards": "9909469 Scambos, Ted", "bounds_geometry": null, "dataset_titles": "Ice Motion and Topography Near Margin Areas of Kamb Ice Stream, Antarctica", "datasets": [{"dataset_uid": "609141", "doi": "10.7265/N5WS8R52", "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Kamb Ice Stream", "people": "Scambos, Ted; Raymond, Charles; Gades, Anthony; Conway, Howard; Catania, Ginny", "repository": "USAP-DC", "science_program": null, "title": "Ice Motion and Topography Near Margin Areas of Kamb Ice Stream, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609141"}], "date_created": "Fri, 01 Aug 2003 00:00:00 GMT", "description": "9909469 Scambos This award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide \"shutdown\" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Ice Velocity; Ice Acceleration; Ice Sheet Elevation; GROUND-BASED OBSERVATIONS; Ice Stream; Antarctic Ice Sheet; Ice Sheet; Ice Surface Elevation; Ice Position; Ice Surface; Ice Stream C Velocities; Ice Movement; Ice; Cryosphere", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted; Catania, Ginny; Conway, Howard; Gades, Anthony; Raymond, Charles", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: History and Evolution of the Siple Coast Ice Stream System as Recorded by Former Shear-Margin Scars", "uid": "p0000165", "west": null}, {"awards": "9526979 White, James", "bounds_geometry": null, "dataset_titles": "Siple Dome Core Date from Measurement of the d18O of Paleoatmospheric Oxygen", "datasets": [{"dataset_uid": "609123", "doi": "10.7265/N5TX3C95", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "White, James; Bender, Michael", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Core Date from Measurement of the d18O of Paleoatmospheric Oxygen", "url": "https://www.usap-dc.org/view/dataset/609123"}], "date_created": "Mon, 16 Jun 2003 00:00:00 GMT", "description": "This award is for support for a program to measure the stable isotope (deuterium to hydrogen and oxygen-18 to oxygen-16) concentrations of ice cores retrieved from Siple Dome as part of the West Antarctic ice sheet program. In addition, the deuterium excess of samples from the Taylor Dome ice core will be determined. This project will approach the question of rapid climate change using ice cores to determine the history of temperature changes, moisture source changes, and elevational changes in the West Antarctic ice sheet. Results from ice cores taken to date in the interior of Antarctica (East and West) are surprisingly lacking in indications of abrupt climate changes, such as those that have been observed in the GISP2 ice core from Summit, Greenland. This work will address the question of whether rapid climate changes, which are known to have occurred in other parts of the southern hemi-sphere, may have also occurred in the coastal regions of West Antarctica. There is some indication from existing records of isotopes in ice cores that the West Antarctic ice sheet may have flushed ice in the past (as evidenced by large changes in elevation of the ice sheet).", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Antarctica; LABORATORY; WAISCORES; GROUND STATIONS; Siple Coast; Glaciology; Snow; D18O; Isotope; Thermometry; Ice Sheet; Siple; Accumulation; Ice Core; Siple Dome; Stratigraphy; Densification; GROUND-BASED OBSERVATIONS; Not provided", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "White, James; Bender, Michael", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Isotopic Measurements on the WAIS/Siple Dome Ice Cores", "uid": "p0000063", "west": null}, {"awards": "9615347 Conway, Howard", "bounds_geometry": null, "dataset_titles": "Roosevelt Island Bedrock and Surface Elevations; Roosevelt Island Ice Core Density and Beta Count Data", "datasets": [{"dataset_uid": "609139", "doi": "10.7265/N55718ZW", "keywords": "Antarctica; Beta Count; Density; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Roosevelt Island", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Ice Core Density and Beta Count Data", "url": "https://www.usap-dc.org/view/dataset/609139"}, {"dataset_uid": "609140", "doi": "10.7265/N51J97NB", "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Roosevelt Island; Solid Earth", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Bedrock and Surface Elevations", "url": "https://www.usap-dc.org/view/dataset/609140"}], "date_created": "Fri, 23 May 2003 00:00:00 GMT", "description": "This award is for two years of support to perform radar investigations across former shear margins at Roosevelt Island and Ice Stream C in order to measure changes in the configuration and continuity of internal layers and the bed. The broad goal of these investigations is to gain an understanding of ice stream flow and the timing and mechanisms of ice stream shutdown. A high-resolution short-pulse radar system will be used for detailed examination of the uppermost hundred meters of the firn and ice, and a monopulse sounding-radar system will be used to image the rest of the ice column (including internal layers) and the bed. Changes in the shape and continuity of layers will be used to interpret mechanisms and modes of ice stream flow including the possible migration of stagnation fronts and rates of shut-down. Variations in bed reflectivity will be used to deduce basal hydrology conditions across lineations. Accumulation rates deduced from snow pits and shallow cores will be used to estimate near-surface depth-age profiles. Improved understanding of ice stream history opens the possibility of linking changes in the West Antarctic ice sheet with the geologic evidence from Northern Victoria Land and the ocean record of the retreat of the grounding line in the Ross Sea.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RA; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Radioactive Decay; Radar Echo Sounder; Antarctica; Radar Altimetry; Densification; Bedrock Elevation; Ice Sheet Elevation; Satellite Radar Data; GROUND-BASED OBSERVATIONS; Radar; Ice Core; Snow Stratigraphy; Terrain Elevation; Antarctic Ice Sheet; Stable Isotopes; Ice Surface Elevation; Surface Elevation; Glaciology; Snow Densification; Ice Core Data; GROUND STATIONS; Not provided; Altimetry; Antarctic; Ice Core Stratigraphy; Ice Stratigraphy", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Radar Investigations of Former Shear Margins: Roosevelt Island and Ice Stream C", "uid": "p0000164", "west": null}, {"awards": "9615554 Fitzpatrick, Joan", "bounds_geometry": null, "dataset_titles": "Digital Images of Thin Sections from Siple Dome; Digital Imaging for Siple Dome Ice Core Analysis, Antarctica", "datasets": [{"dataset_uid": "609127", "doi": "10.7265/N59Z92T4", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Photo/video; Photo/Video; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Fitzpatrick, Joan", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Digital Images of Thin Sections from Siple Dome", "url": "https://www.usap-dc.org/view/dataset/609127"}, {"dataset_uid": "609413", "doi": "10.7265/N5XG9P2G", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Photo/video; Photo/Video; Siple Dome; Siple Dome Ice Core", "people": "Alley, Richard; Spencer, Matthew; Fitzpatrick, Joan", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Digital Imaging for Siple Dome Ice Core Analysis, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609413"}], "date_created": "Wed, 14 May 2003 00:00:00 GMT", "description": "This award is for support for two years to develop the technology and methodology for digitizing the photographs and analyzing the thin sections from ice cores. In addition, the application of digital technology for whole-core stratigraphy, using digital photography, image enhancement and image processing will be investigated. The thin section analysis will be piloted with samples already in hand from the Taylor Dome ice core. If successful, these techniques will be applied to samples from the Siple Dome ice core, in cooperation with Principal Investigators already funded to retrieve and examine these sections. The original digital images with all original data annotation files will be distributed to Siple Dome principal investigators for their use in the interpretation of their own data. All software and hardware acquired for this project will become part of the permanent equipment inventory at the U.S. National Ice Core Laboratory and will be available for use by clients at the facility.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Antarctica; Glaciology; Ice Sheet; Siple; Ice Core; Stratigraphy; GROUND STATIONS; Siple Dome; WAISCORES; Trapped Air Bubbles; Photo; Snow; Density; Volcanic Deposits; Not provided; Ice Core Data; GROUND-BASED OBSERVATIONS; Siple Coast; Chemical Composition", "locations": "Siple Dome; Antarctica; Siple; Siple Coast", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fitzpatrick, Joan; Alley, Richard; Spencer, Matthew", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Digital Imaging for Ice Core Analysis", "uid": "p0000011", "west": null}, {"awards": "9527262 Gow, Anthony", "bounds_geometry": null, "dataset_titles": "Physical and Structural Properties of the Siple Dome Ice Cores", "datasets": [{"dataset_uid": "609128", "doi": "10.7265/N5668B34", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Photo/video; Photo/Video; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Meese, Deb; Gow, Tony", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Physical and Structural Properties of the Siple Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609128"}], "date_created": "Wed, 14 May 2003 00:00:00 GMT", "description": "This award is for support for a program to investigate the visual stratigraphy, index physical properties, relaxation characteristics and crystalline structure of ice cores from Siple Dome, West Antarctica. This investigation will include measurements of a time-priority nature that must be initiated at the drill site on freshly-drilled cores. This will be especially true of cores from the brittle ice zone, which is expected to comprise a significant fraction of the ice core. The brittle zone includes ice in which relaxation , resulting from the release of confining pressure is maximized and leads to significant changes in the mechanical condition of the core that must be considered in relation to the processing and analysis of ice samples for entrapped gas and chemical studies. This relaxation will be monitored via precision density measurements made initially at the drill site and repeated at intervals back in the U.S. Other studies will include measurement of the annual layering in the core to as great a depth as visual stratigraphy can be deciphered, crystal size measurements as a function of depth and age, c-axis fabric studies, and analysis of the physical properties of any debris-bearing basal ice and its relationship to the underlying bedrock. Only through careful documentation and analysis of these key properties can we hope to accurately assess the dynamic state of the ice and the age-depth relationships essential to deciphering the paleoclimate record at this location.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Siple Dome; Antarctica; Stratigraphy; Ice Sheet; GROUND-BASED OBSERVATIONS; Density; Siple; Chemical Composition; Volcanic Deposits; Siple Coast; WAISCORES; Not provided; GROUND STATIONS; Pico; Ice Core; Tephra; Fabric; Glaciology; Snow", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Gow, Tony; Meese, Deb", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Physical and Structural Properties of the Siple Dome Core", "uid": "p0000064", "west": null}, {"awards": "9526420 Taylor, Kendrick", "bounds_geometry": null, "dataset_titles": "Siple Dome Cores Electrical Measurement Data", "datasets": [{"dataset_uid": "609133", "doi": "10.7265/N5DR2SDN", "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Cores Electrical Measurement Data", "url": "https://www.usap-dc.org/view/dataset/609133"}], "date_created": "Thu, 08 May 2003 00:00:00 GMT", "description": "This award is for support for the measurement of electrical and optical properties of the Siple Dome ice core. The electrical methods can be used to determine the concentration of the hydrogen ions and the concentration of a weighted sum of all ions. The electrical measurements can resolve features as small as 1 cm. The albedo of the core is also measured with a laser system that can resolve features as small as 0.5 cm. The high spatial resolution of these methods makes them ideal for resolving narrow features in the core, which can be missed in larger composite samples. The measurements will be particularly useful for assisting to date the core and to identify short duration features in the record, such as volcanic eruptions. These measurements will also provide useful information for assessing the temporal variability of Holocene accumulation rate and atmospheric circulation.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Densification; Siple Dome; Glaciology; Snow; Thermometry; WAISCORES; Electrical; Isotope; GROUND STATIONS; GROUND-BASED OBSERVATIONS; Not provided; Ice Sheet; Siple Coast; Ice Core; Siple; Antarctica", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Taylor, Kendrick C.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Electrical and Optical Measurements on the Siple Dome Ice Core", "uid": "p0000163", "west": null}, {"awards": "0096302 Tulaczyk, Slawek", "bounds_geometry": "POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 06 May 2003 00:00:00 GMT", "description": "Not Available", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided; Centerline Ice Stream Velocity; Till Void Ratio; Basal Temperature Gradient; Surface Elevation; Till Strength", "locations": null, "north": -62.83, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas; Tulaczyk, Slawek", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -90.0, "title": "Control of Ice-Till Interactions on Evolution and Stability of Ice Streams and Ice Sheets", "uid": "p0000743", "west": -180.0}, {"awards": "9526572 Bales, Roger", "bounds_geometry": null, "dataset_titles": "Snow-atmosphere Transfer Function for Reversibly Deposited Chemical Species in West Antarctica", "datasets": [{"dataset_uid": "609122", "doi": "10.7265/N5ZP441W", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Snow/ice; Snow/Ice; WAISCORES", "people": "Bales, Roger; McConnell, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Snow-atmosphere Transfer Function for Reversibly Deposited Chemical Species in West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609122"}], "date_created": "Thu, 11 Jul 2002 00:00:00 GMT", "description": "This award is for support for a program of measurements to improve our understanding of the relationship between formaldehyde (HCHO) and hydrogen peroxide (H2O2) in the atmosphere and the concentrations of the same species in Antarctic snow, firn and ice. This work aims to relate changes in concentrations in the snow, firn and ice to corresponding changes in tropospheric chemistry. Atmospheric and firn sampling for formaldehyde and hydrogen peroxide at one or more of the WAIS ice core drilling sites will be undertaken and controlled laboratory studies to estimate thermodynamic and rate parameters will be performed. In addition, this work will involve modeling of atmosphere-snow exchange processes to infer the \"transfer function\" for reactive species at the sites and atmospheric photochemical modeling to relate changes in concentrations of formaldehyde and hydrogen peroxide in snow, firn and ice to atmospheric oxidation capacity. This work will contribute to a better understanding of the relationship between atmospheric concentrations of various species and those same species measured in snow and ice samples.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Siple Dome; Antarctica; Isotope; WAISCORES; GROUND-BASED OBSERVATIONS; GROUND STATIONS; Snow; Glaciology; LABORATORY; Siple; Siple Coast; Thermometry; Hydrogen Peroxide; Ice Sheet", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bales, Roger; McConnell, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Snow-Atmosphere Transfer Function for Reversibly Deposited Chemical Species in West Antarctica", "uid": "p0000060", "west": null}, {"awards": "9526449 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "WAISCORES Snow Pit Chemistry, Antarctica", "datasets": [{"dataset_uid": "609420", "doi": "10.7265/N5SQ8XBR", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; Snow Pit; WAIS; WAISCORES", "people": "Kreutz, Karl; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": null, "title": "WAISCORES Snow Pit Chemistry, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609420"}], "date_created": "Thu, 11 Jul 2002 00:00:00 GMT", "description": "This award is for support for a program of glaciochemical analyses of shallow and deep ice cores from Siple Dome, West Antarctica. Measurements that have been proposed include chloride, nitrate, sulfate, calcium, magnesium, sodium, potassium, ammonium and methansulfonic acid. These measurements will provide information about past volcanic events, biomass source strength, sea ice fluctuations, atmospheric circulation, changes in ice-free areas and the environmental response to Earth orbit insolation changes and solar variability. The glaciochemical records from the Siple Dome core will be developed at a resolution sufficient to compare with the Summit, Greenland record, thus allowing a bipolar comparison of climate change event timing and magnitude. As part of this award, an international workshop will be held during the first year to formulate a science plan for the International Transantarctic Scientific Expedition (ITASE), a program of regional surveys documenting the spatial distribution of properties measured in ice cores .", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Ion Chemistry; Antarctic; Snow Chemistry; Stable Isotopes; Snow Density; Siple Dome; GROUND-BASED OBSERVATIONS", "locations": "Antarctic; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kreutz, Karl; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Siple Dome Deep Ice Core Glaciochemistry and Regional Survey - A Contribution to the WAIS Initiative", "uid": "p0000012", "west": null}, {"awards": "9615167 Dunbar, Nelia; 9527373 Dunbar, Nelia", "bounds_geometry": null, "dataset_titles": "Blue Ice Tephra II - Brimstone Peak; Blue Ice Tephra II - Mt. DeWitt; Tephra in Siple and Taylor Dome Ice Cores; Volcanic Records in the Siple and Taylor Dome Ice Cores", "datasets": [{"dataset_uid": "609110", "doi": "10.7265/N50P0WXF", "keywords": "Antarctica; Backscattered Electron Images; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core; Taylor Dome Ice Core; WAIS", "people": "Dunbar, Nelia", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Tephra in Siple and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609110"}, {"dataset_uid": "609126", "doi": "10.7265/N5FQ9TJG", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome Ice Core; Taylor Dome Ice Core; Tephra; WAIS; WAISCORES", "people": "Zielinski, Gregory; Dunbar, Nelia", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Volcanic Records in the Siple and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609126"}, {"dataset_uid": "609126", "doi": "10.7265/N5FQ9TJG", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome Ice Core; Taylor Dome Ice Core; Tephra; WAIS; WAISCORES", "people": "Zielinski, Gregory; Dunbar, Nelia", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Volcanic Records in the Siple and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609126"}, {"dataset_uid": "609114", "doi": "10.7265/N5MG7MDK", "keywords": "Antarctica; Blue Ice; Brimstone Peak; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Petrography; Tephra", "people": "Dunbar, Nelia", "repository": "USAP-DC", "science_program": null, "title": "Blue Ice Tephra II - Brimstone Peak", "url": "https://www.usap-dc.org/view/dataset/609114"}, {"dataset_uid": "609115", "doi": "10.7265/N5GQ6VPV", "keywords": "Antarctica; Blue Ice; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mount Dewitt; Petrography; Tephra", "people": "Dunbar, Nelia", "repository": "USAP-DC", "science_program": null, "title": "Blue Ice Tephra II - Mt. DeWitt", "url": "https://www.usap-dc.org/view/dataset/609115"}, {"dataset_uid": "609110", "doi": "10.7265/N50P0WXF", "keywords": "Antarctica; Backscattered Electron Images; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core; Taylor Dome Ice Core; WAIS", "people": "Dunbar, Nelia", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Tephra in Siple and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609110"}], "date_created": "Sat, 01 Jun 2002 00:00:00 GMT", "description": "Dunbar/Kyle OPP 9527373 Zielinski OPP 9527824 Abstract The Antarctic ice sheets are ideal places to preserve a record the volcanic ash (tephra) layers and chemical aerosol signatures of volcanic eruptions. This record, which is present both in areas of bare blue ice, as well as in deep ice cores, consists of a combination of local eruptions, as well as eruptions from more distant volcanic sources from which glassy shards can be chemically fingerprinted and related to a source volcano. Field work carried out during the 1994/1995 Antarctic field season in the Allan Hills area of Antarctica, and subsequent microbeam chemical analysis and 40Ar/39Ar dating has shown that tephra layers in deep Antarctic ice preserve a coherent, systematic stratigraphy, and can be successfully mapped, dated, chemically fingerprinted and tied to source volcanoes. The combination of chemical fingerprinting of glass shards, and chemical analysis of volcanic aerosols associated with ash layers will allow establishment of a high-resolution chronology of local and distant volcanism that can help understand patterns of significant explosive volcanisms and atmospheric loading and climactic effects associated with volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas, which have been identified in many places the Transantarctic Mountains, will allow the geometry of ice flow in these areas to be better understood and will provide a useful basis for interpreting ice core records.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES", "is_usap_dc": true, "keywords": "USAP-DC; Siple Coast; Sulfur Dioxide; Siple Dome; Taylor Dome; Chlorine; WAISCORES; Ice Core; Tephra; Geochemistry; Volcanic Deposits; GROUND STATIONS; Brimstone Peak; GROUND-BASED OBSERVATIONS; Magnesium Oxide; Glaciology; Mount Dewitt; Silicon Dioxide; Glass Shards; Ice Sheet; Siple; Nickel Oxide; Potassium Dioxide; Not provided; Manganese Oxide; Volcanic; Snow; Nitrogen; Iron Oxide; Titanium Dioxide; Stratigraphy; Antarctica", "locations": "Antarctica; Siple; Siple Coast; Siple Dome; Taylor Dome; Brimstone Peak; Mount Dewitt", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Dunbar, Nelia; Zielinski, Gregory", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": null, "title": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region", "uid": "p0000065", "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "WAISCORES: Deep Ice Coring in West Antarctica", "datasets": [{"dataset_uid": "609120", "doi": "10.7265/N5765C7H", "repository": "USAP-DC", "science_program": null, "title": "WAISCORES: Deep Ice Coring in West Antarctica", "url": "http://www.usap-dc.org/view/dataset/609120"}], "date_created": "Tue, 01 Jan 2002 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; WAIS; WAISCORES", "locations": "WAIS; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Lamorey, Gregg W.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "9615292 Wahlen, Martin", "bounds_geometry": null, "dataset_titles": "Carbon-Isotopic Composition of Atmospheric CO2 since the Last Glacial Maximum; Taylor Dome Ice Core Chemistry, Ion, and Isotope Data", "datasets": [{"dataset_uid": "609246", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "people": "Brook, Edward J.; Indermuhle, A.; Steig, Eric J.; Mayewski, Paul A.; Smith, Jesse; Sowers, Todd A.", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Taylor Dome Ice Core Chemistry, Ion, and Isotope Data", "url": "https://www.usap-dc.org/view/dataset/609246"}, {"dataset_uid": "609108", "doi": "10.7265/N54F1NN5", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "people": "Wahlen, Martin", "repository": "USAP-DC", "science_program": null, "title": "Carbon-Isotopic Composition of Atmospheric CO2 since the Last Glacial Maximum", "url": "https://www.usap-dc.org/view/dataset/609108"}], "date_created": "Tue, 01 Jan 2002 00:00:00 GMT", "description": "This award is for support of a program to reconstruct the record of atmospheric carbon dioxide (and the carbon-13 isotopes of carbon dioxide) over several intervals, including the Last Glacial Maximum-Holocene transition, interstadial episodes, the mid-Holocene, the last 1000 years and the penultimate glacial period, using ice from the Taylor Dome and Vostok ice cores. The major objective of this study is to investigate the phase relationship between variations of the greenhouse gases occluded in the ice cores and temperature changes (indicated by oxygen and deuterium isotopes) during the last deglaciation. In addition, the concentration of atmospheric carbon dioxide over the past 1000 years and during the mid-Holocene will be determined in these cores.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "USAP-DC; Ice Core; GROUND-BASED OBSERVATIONS; Carbon; Trapped Gases; Glaciology; GROUND STATIONS; Taylor Dome; Carbon Dioxide; Isotope; Antarctica; Nitrogen", "locations": "Antarctica; Taylor Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.; Wahlen, Martin; Smith, Jesse; Brook, Edward J.; Indermuhle, A.; Mayewski, Paul A.; Sowers, Todd A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": null, "title": "Carbon Dioxide and Carbon Isotopes in the Taylor Dome and Vostok Ice Cores", "uid": "p0000153", "west": null}, {"awards": "9222121 Dalziel, Ian", "bounds_geometry": null, "dataset_titles": "Concentration and Isotopic Composition of O2 and N2 in Trapped Gases of the Vostok Ice Core", "datasets": [{"dataset_uid": "609107", "doi": "10.7265/N5862DCW", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciology; Ice Core Records; Lake Vostok; Paleoclimate; UPLC-Q-TOF; Vostok Ice Core", "people": "Bender, Michael", "repository": "USAP-DC", "science_program": null, "title": "Concentration and Isotopic Composition of O2 and N2 in Trapped Gases of the Vostok Ice Core", "url": "https://www.usap-dc.org/view/dataset/609107"}], "date_created": "Tue, 01 Jan 2002 00:00:00 GMT", "description": "This award supports an in situ and short traverse seismic reflection/refraction and magnetotelluric experiment in West Antarctica. This collaborative experiment involves four awards at four institutions. The four-fold purpose is 1) to investigate part of the Byrd Subglacial Basin, 2) to test techniques for this work that could be done in a long traverse, 3) to determine the viability of the magnetotelluric method on a thick (electrically resistive) ice sheet, and 4) to evaluate the relative merits of refraction with wide reflection versus reflection with narrow refraction seismic studies in imaging the lithosphere. The geophysical techniques that will be employed are capable of imaging the ice sheet, the continental lithosphere, and the upper mantle, as well as determining physical properties of parts of the lithosphere and mantle. Investigations of outcrop geology over the last thirty years in West Antarctica and the Transantarctic Mountains have lead to recent interpretations that the crust is made up of many different lithospheric blocks. Seismic reflection work is the only way to image the crust in detail and the refraction work is the only way to determine physical properties of the layers and blocks defined by the reflection work. The magnetotelluric work is scientifically risky because it may not yield useful information when used over the electrically resistive ice sheet; however, if it works it has the potential to image molten rock in the crust and upper mantle. In a continental rift region such as West Antarctica, the presence of melt in the lithosphere is likely and, if documented, has very important ramifications to ice sheet dynamics. Research work supported by this award is expected to provide constraints to models of a range of crustal processes from models of ice sheet dynamics to tectonic and kinematic models of lithospheric thinning and rifting.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Isotope; Vostok; USAP-DC; Antarctica; Trapped Gases; Ice Core; Glaciology; Nitrogen; GROUND STATIONS", "locations": "Antarctica; Vostok", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bender, Michael; Dalziel, Ian W.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Seismic Traverse of the Byrd Subglacial Basin-Field Test", "uid": "p0000150", "west": null}, {"awards": "9318121 Anandakrishnan, Sridhar", "bounds_geometry": null, "dataset_titles": "Ice Velocity Data from Ice Stream C, West Antarctica", "datasets": [{"dataset_uid": "609106", "doi": "10.7265/N5CZ3539", "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; WAIS", "people": "Anandakrishnan, Sridhar", "repository": "USAP-DC", "science_program": null, "title": "Ice Velocity Data from Ice Stream C, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609106"}], "date_created": "Sat, 01 Dec 2001 00:00:00 GMT", "description": "9318121 Anandakrishnan This award is for support for a three year project to test the hypothesis that a controlling parameter of fast ice-stream flow is the hydrologic state of discrete zones of high friction (\"sticky spots\") at the bed of the ice streams. Previous work has discovered an enormous difference in basal microearthquake activity between fast-flowing ice stream B and ice stream C, which stopped flowing within the last 200 years. It is hypothesized that the basal water system is lubricating the sticky spots under the fast ice stream and thus inhibiting microearthquake activity, and at the same time permitting fast ice flow. This experiment is intended to collect a continuous record of wide-bandwidth microearthquake data from a variety of sites, on the ice streams, in the transition zone, and on the inland ice. ***", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS", "is_usap_dc": true, "keywords": "Glaciology; USAP-DC; Ice Stream; Velocity Measurements; Ice Velocity; GROUND-BASED OBSERVATIONS; Ice Sheet; West Antarctic Ice Sheet; Ice Stream C Velocities; GPS; Antarctica", "locations": "Antarctica; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Microearthquake Monitoring of Ice Stream C, West Antarctica: A Sensor for Sticky Spots", "uid": "p0000161", "west": null}, {"awards": "9526601 Albert, Mary", "bounds_geometry": null, "dataset_titles": "Snow and Firn Temperature and Permeability Measurements from Siple Dome, Antarctica", "datasets": [{"dataset_uid": "609100", "doi": "10.7265/N5S46PVZ", "keywords": "Antarctica; Glaciology; Permeability; Siple Dome; Siple Dome Ice Core; Snow/ice; Snow/Ice; Temperature", "people": "Albert, Mary R.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Snow and Firn Temperature and Permeability Measurements from Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609100"}], "date_created": "Sat, 01 Dec 2001 00:00:00 GMT", "description": "This award supports a project to examine the physical processes that affect the manner in which heat, vapor and chemical species in air are incorporated into snow and polar firn. The processes include advection, diffusion, and the effects of solar radiation penetration into the snow. An understanding of these processes is important because they control the rate at which reactive and non-reactive chemical species in the atmosphere become incorporated into the snow, firn, and polar ice, and thus will affect interpretation of polar ice core data. Currently, the interpretation of polar ice core data assumes that diffusion controls the rate at which chemical species are incorporated into firn. This project will determine whether ventilation, or advection of the species by air movement in the firn, and radiation penetration processes have a significant effect. Field studies at the two West Antarctic ice sheet deep drilling sites will be conducted to determine the spatial and temporal extent for key parameters, and boundary conditions needed to model the advection, conduction, and radiation transmission/absorption processes. An existing multidimensional numerical model is being expanded to simulate the processes and to serve as the basis for ongoing and future work in transport and distribution of reactive chemical species.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e PERMEAMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Glaciology; Antarctica; Snow Permeability; Firn Permeability; USAP-DC; GROUND-BASED OBSERVATIONS; Not provided; GROUND STATIONS; Snow Properties; Snow Temperature; Siple Dome; Firn Temperature", "locations": "Antarctica; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Albert, Mary R.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Near-Surface Processes Affecting Gas Exchange: West Antarctic Ice Sheet", "uid": "p0000061", "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Images of Antarctic Ice Shelves", "datasets": [{"dataset_uid": "609102", "doi": "10.7265/N5NC5Z4N", "repository": "USAP-DC", "science_program": null, "title": "Images of Antarctic Ice Shelves", "url": "http://www.usap-dc.org/view/dataset/609102"}], "date_created": "Mon, 01 Jan 2001 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; AVHRR; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Sample/collection Description; Sample/Collection Description; Sea Ice", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bohlander, Jennifer; Raup, Bruce H.; Scambos, Ted", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "9316338 Jacobel, Robert", "bounds_geometry": null, "dataset_titles": "Siple Dome Glaciology and Ice Stream History 1994, 1996", "datasets": [{"dataset_uid": "609085", "doi": "10.7265/N5Z31WJQ", "keywords": "Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Sample/collection Description; Sample/Collection Description; Siple Dome; Siple Dome Ice Core", "people": "Jacobel, Robert", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Glaciology and Ice Stream History 1994, 1996", "url": "https://www.usap-dc.org/view/dataset/609085"}], "date_created": "Fri, 01 Jan 1999 00:00:00 GMT", "description": "9316338 Jacobel This award is for support for a program of glaciological studies of Siple Dome and its surroundings between Ice Streams C and D. The purpose of the work is to characterize the dynamic environment and ice stratigraphy to aid in the assessment of Siple Dome as a potential deep ice core site, and to determine whether the configuration of ice stream flow in the region was different in the past than now. The work involves measurements of the configuration and continuity of internal layers in the ice, using radar echo sounding and determination of velocity field, based on standard GPS surveying. The goals of the work are relevant to understanding the dynamics of the West Antarctic Ice Sheet (WAIS), its past history and its potential future behavior, including possible effects on global sea level. This work is a collaborative project between the University of Washington, the University of Colorado and St. Olaf College. ***", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": true, "keywords": "Siple Dome; Antarctic; Glaciology; Radar; GROUND-BASED OBSERVATIONS; Ice Stream", "locations": "Antarctic; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobel, Robert", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Siple Dome Glaciology and Ice Stream History", "uid": "p0000190", "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Dronning Maud Land, Antarctica, Ice Core, 1991 and 1992", "datasets": [{"dataset_uid": "609089", "doi": "10.7265/N5DZ067P", "repository": "USAP-DC", "science_program": null, "title": "Dronning Maud Land, Antarctica, Ice Core, 1991 and 1992", "url": "http://www.usap-dc.org/view/dataset/609089"}], "date_created": "Fri, 01 Jan 1999 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Dronning Maud Land; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice", "locations": "Antarctica; Dronning Maud Land", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Whitlow, Sallie", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "9526374 Alley, Richard", "bounds_geometry": null, "dataset_titles": "Visible Stratigraphic Dating, Siple Dome and Upstream C Cores", "datasets": [{"dataset_uid": "609121", "doi": "10.7265/N53F4MHS", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Sample/collection Description; Sample/Collection Description; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Alley, Richard", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Visible Stratigraphic Dating, Siple Dome and Upstream C Cores", "url": "https://www.usap-dc.org/view/dataset/609121"}], "date_created": "Wed, 01 Jan 1997 00:00:00 GMT", "description": "This award is for support for a program of physical and visible studies on the shallow and deep ice cores to be retrieved from Siple Dome, West Antarctica. Visible examination of ice cores has proven to be a powerful technique for dating and paleoclimatic interpretation. Recent examination of a shallow core from Siple Dome indicates that annual-layer dating is possible and that visible examination will contribute significantly to the dating effort at Siple Dome. Once ages are obtained, distances between layers provide snow accumulation after correction for density variations and ice flow thinning. Thin- section examination of the core will contribute to understanding the visible stratigraphy, and will reveal c-axis fabrics which are related to past ice deformation. The results of this study should include a better understanding of rapid climate change in the Antarctic and should contribute to knowledge of the stability of the West Antarctic ice sheet.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Ice Core; GROUND-BASED OBSERVATIONS; Siple; Ice Sheet; Isotope; Stratigraphy; GROUND STATIONS; Accumulation; Siple Dome; WAISCORES; Densification; Antarctica; Siple Coast; Thermometry; Snow; Not provided; Bubble; Glaciology", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Physical Properties of the Siple Dome Deep Ice Core", "uid": "p0000059", "west": null}, {"awards": "0838834 Lazzara, Matthew", "bounds_geometry": "POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83))", "dataset_titles": "Access all real-time datasets; Access Antarctic Composite Images.; Access Antarctic Synoptic and METAR Observations.; Access McMurdo Radiosonde Observations; Access South Pole Radiosonde Observations; Archived METAR observational data; We have observations from three ships near Antarctica, the R/V Polar Duke the R/V Nathaniel B. Palmer and the R/V Laurence M. Gould. Data from 23 August 1993 are available via ftp and the files are updated with the most recent observations every 7-10 days as we receive the information. The AMRC has been archiving general ship and buoy observational data for the Antarctic and surrounding regions since 2 December 1998.", "datasets": [{"dataset_uid": "001285", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "Access Antarctic Composite Images.", "url": "http://amrc.ssec.wisc.edu/data/view-data.php?action=list\u0026amp;amp;product=satellite/composite"}, {"dataset_uid": "001288", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "Access South Pole Radiosonde Observations", "url": "ftp://amrc.ssec.wisc.edu/pub/southpole/radiosonde/"}, {"dataset_uid": "001289", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "Access McMurdo Radiosonde Observations", "url": "ftp://amrc.ssec.wisc.edu/pub/mcmurdo/radiosonde/"}, {"dataset_uid": "001290", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "We have observations from three ships near Antarctica, the R/V Polar Duke the R/V Nathaniel B. Palmer and the R/V Laurence M. Gould. Data from 23 August 1993 are available via ftp and the files are updated with the most recent observations every 7-10 days as we receive the information. The AMRC has been archiving general ship and buoy observational data for the Antarctic and surrounding regions since 2 December 1998.", "url": "ftp://amrc.ssec.wisc.edu/pub/shipobs/"}, {"dataset_uid": "001299", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "Access Antarctic Synoptic and METAR Observations.", "url": "ftp://amrc.ssec.wisc.edu/"}, {"dataset_uid": "001300", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "Access all real-time datasets", "url": "http://amrc.ssec.wisc.edu/"}, {"dataset_uid": "001382", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "Access Antarctic Synoptic and METAR Observations.", "url": "ftp://amrc.ssec.wisc.edu"}, {"dataset_uid": "001386", "doi": "", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "Archived METAR observational data", "url": "ftp://amrc.ssec.wisc.edu/archive/"}], "date_created": "Thu, 01 Jan 1970 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003eThe Antarctic Meteorological Research Center (AMRC), located at the University of Wisconsin, Madison, serves several communities by maintaining and extending the stewardship of meteorological data pertinent to the Antarctic continent, its surrounding islands, ice sheets and ice margins and the adjacent Southern Ocean. This data will continue to be made freely available to interested researchers and the general public. Activities of particular interest for the current award include the development of an enhanced data portal to provide improved data and analysis tools to the research community, and to continue to add to the evolution of the Antarctic-Internet Data Distribution system, which is meant to overcome the costly and generally low bandwidth internet connectivity to and from the Antarctic continent. Operational forecasting for logistical activities in the Antarctic, as well as active Antarctic meteorological research programs, are clearly in need of a dependable, steady flow of meteorological observations, model output, and related data in what must be a collaborative environment in order to overcome the otherwise distributed nature of Antarctic meteorological and climatological observations.\u003cbr/\u003e\u003cbr/\u003eAMRC interaction with the public through answering e-mail questions, giving informal public lectures and presentations to K-12 education institutions through visits to schools will help to raise science literacy with regards to meteorology and of the Antarctic and polar regions. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\"", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e AVHRR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e GOES I-M IMAGER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e OLS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e VISSR; IN SITU/LABORATORY INSTRUMENTS \u003e CURRENT/WIND METERS \u003e ANEMOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e BAROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e WET BULB THERMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADIOSONDES; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e AMSU-A; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e AVHRR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e HIRS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e HIRS/2; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e MSU; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e TOVS", "is_usap_dc": false, "keywords": "Shortwave Composite Satellite Images; Radiosonde Data; Antarctic; Noaa Hrpt Raw Data; Synoptic Data; Water Vapor Composite Satellite Images; SATELLITES; Satellite Imagery; Infrared Imagery; NOAA POES; Visible Composite Satellite Images; BUOYS; Antarctica; Ship/buoy Data; FIXED OBSERVATION STATIONS; Longwave Composite Satellite Images; Not provided; COASTAL STATIONS; Metar Weather Observations", "locations": "Antarctic; Antarctica", "north": -62.83, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Lazzara, Matthew; Costanza, Carol", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e COASTAL STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e FIXED OBSERVATION STATIONS; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e POLAR ORBITING ENVIRONMENTAL SATELLITES (POES) \u003e NOAA POES; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED \u003e BUOYS", "repo": "AMRDC", "repositories": "AMRDC", "science_programs": null, "south": -90.0, "title": "Antarctic Meteorological Research Center (2009-2011)", "uid": "p0000264", "west": -180.0}]
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Non-Technical Abstract The deep world ocean is flooded with near 0°C water, drawn from the margins of Antarctica. Antarctic Bottom Water, as it is referred to, is mainly derived from cold water formed the over the continental shelves of the Weddell and Ross Seas, where the coastal water is exposed to frigid polar air masses spreading off the Antarctic ice sheet. Antarctic Bottom Water is a key component of the global ocean overturning system, which is fundamental to the global ocean heat, carbon and nutrient inventories, and hence the climate and marine ecosystem. The processes producing the dense shelf waters involve small scale factors associated with ocean/atmosphere/sea and glacial ice interaction. What is lacking from previous work is a coordinated, synchronous observational study of the seaward spreading, from formation, to export across the continental shelf edge, to its descent into the deep ocean. This work fills the gap, by investigating the characteristics of dense shelf water formed within Terra Nova Bay, Ross Sea, its transformation, modification and northward spreading within the Drygalski Trough in the western Ross Sea, feeding into the spill-over at the continental slope into the deep boundary current adjacent to Cape Adare. The sequence of events will be observed with a series of instrumented moorings along the pathway from Terra Nova Bay, along the Drygalski Trough and onto the boundary current adjacent to Cape Adare. The project is an international collaboration that involves the USA (this proposal), S. Korea, New Zealand and Italy. Technical Abstract The lower kilometer or two of the world ocean is flooded with near 0°C water derived from the Southern Ocean, the Antarctic Bottom Water (AABW). The cold end-member of AABW is formed over various sectors of the continental shelf of Antarctica, notable in the Weddell and Ross Seas. The governing processes producing the dense shelf waters involve small scale spatial and temporal factors associated with ocean/sea ice interaction, often related to coastal polynyas and katabatic winds, along with further modification by ocean-glacial ice interaction. There have been studies of the formation of dense shelf water, of export of shelf water over the shelf/slope, the descent of gravity currents into the AABW realm, and of flow paths of AABW spreading across the deep ocean well into the northern hemisphere. What is lacking is a coordinated, synchronous observational study of the seaward spreading, from formation of the dense shelf water to its spreading to the shelf/slope break and descent into the deep ocean. This program fills the gap, by investigating the characteristics of dense shelf water formed within Terra Nova Bay (TNB), Ross Sea, its transformation, modification and northward spreading within the Drygalski Trough in the western Ross Sea, feeding into the spill-over at the continental slope and the deep boundary current adjacent to Cape Adare. The team will deploy a series of moorings – two heavily instrumented full water column moorings within TNB to capture high-salinity shelf water (HSSW) production and a series of bottom-focused moorings to evaluate the transformation and northward spreading of the dense saline water. The broad science goals of the project will be addressed by this program through a coordinated analysis of these mooring measurements. The project is an international collaboration that involves the USA (this proposal), S. Korea, New Zealand and Italy. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The ice shelves around the perimeter Antarctica hold back inland ice that has the potential to raise global sea level by meters. By how much and how rapidly this could occur is a central question in glaciology. The underside of these ice shelves is in contact with the ocean, and there are signs that warming of ocean water is causing melting and retreat of these shelves, with direct implications for sea-level rise. This project will seize an emergent opportunity to work with Australian and South Korean colleagues to acquire snapshot profiles of ocean temperature, salinity, and velocity, and improve bathymetric knowledge, where no prior data exist. The team will work near three glaciers draining ice with substantial sea-level potential from the East and West Antarctic Ice Sheets. The targets are Shackleton and Cook Ice Shelves in East Antarctica, and Thwaites Glacier in West Antarctica. An undergraduate student will be engaged through the Scripps Undergraduate Research Fellowship program and the team will work through the Scripps Educational Alliances program to identify educational outreach opportunities through which to build community engagement in this project. The team will use high-resolution general circulation model simulations to optimize sensor targeting (to be deployed from helicopter and fixed-wing aircraft) and evaluate the relative roles of subglacial freshwater discharge and ocean forcing on subglacial melt rates. The aim is to better understand why grounding-line melt rates are higher at the East Antarctic sites despite data indicating warmer ambient ocean temperatures at the West Antarctic sites. Such behavior could be explained by discharge of subglacial freshwater into ice-shelf cavities, but insufficient data currently exist to test this hypothesis. The team aims to build on ongoing international, collaborative airborne oceanographic sampling with colleagues in the Republic of Korea, Australia, and the United States. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Goodge, John; Kylander-Clark, Andrew; Bell, Elizabeth; Pecha, Mark
No dataset link provided
Non-Technical Abstract This project will examine ancient Antarctic rocks to understand the continent’s early history, including how Antarctica was once connected to other continents. By studying rock samples from the Nimrod Complex, the project will gather data on the age and makeup of these rocks, showing how Antarctica's crust formed and changed over time. This work will not only expand scientific knowledge about Earth's history but also provide valuable training for college students at multiple universities, helping to grow a diverse community of researchers who can tackle big questions in Earth science. Technical Abstract This project seeks to unravel the origin, evolution, and geological significance of the Nimrod Complex in Antarctica’s East Antarctic craton through detailed age and isotopic analysis of its igneous and metamorphic rocks. Using U-Pb zircon geochronology along with O-isotope, Hf-isotope, and trace element analyses, we will construct a comprehensive petrochronological profile of these Mesoarchean to Paleoproterozoic rocks to reveal their magmatic sources, metamorphic history, and role in the broader tectonic framework. The project aims to trace sediment sources and tectonic influences across sedimentary units spanning the Paleoproterozoic to lower Paleozoic eras, adding crucial data to supercontinent reconstructions (Columbia, Rodinia, and Gondwana) and Antarctic tectonic models. Broader impacts include collaborations between universities to develop a diverse STEM workforce, inter-laboratory partnerships, and a robust isotopic dataset that will contribute to models of Antarctic crustal evolution and its implications for ice sheet stability. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Non-Technical The future response of the East Antarctic Ice Sheet (EAIS) to climate change and its consequent effect on global sea level remains a pressing problem, with implications for societal well-being, the economy, and national security. Projections of future ice-sheet behavior rely in part on understanding gained from ice-sheet response to past climate change, which can be found in geologic records. This project uses geologic features produced at the base of the ice sheet to examine a large change in EAIS behavior and to place ages on when this change occurred. By comparison to climate records from the same time, the project results will allow assessment of ice-sheet response to a climate that likely was warmer than at present. Such information will improve understanding of possible ice-sheet responses to a warming climate, as well as the underlying mechanisms. A better assessment of the likely EAIS response to future warming climate will aid in setting national and international policy and improve public welfare, by promoting more accurate predictions of the amounts and rates of sea-level rise. This project will contribute to the education of young scientists, thereby increasing the STEM workforce, which is in the national interest. A general-audience book will be produced to explain the importance of Antarctica to the public. Technical Accurate, well-dated reconstructions of the behavior of the East Antarctic Ice Sheet (EAIS) afford insight into its response to future climate change. This project uses new insights in subglacial hydrology and erosion to identify and date a major missing piece of Antarctic glacial history, involving massive expansion of the EAIS over the Transantarctic Mountains. This expansion led to formation of an extensive erosional landscape that was characterized by subglacial meltwater and represents a significant shift in ice-sheet behavior. Understanding the age and reasons for such an expansion are important in part, because the subglacial meltwater must have been linked to the Wilkes Subglacial Basin – an area thought to be susceptible to large-scale ice collapse under warm climates. The project will constrain the extent and age of this surface through 1) detailed geomorphological mapping from imagery, 2) reassessment of existing chronologic data, and 3) new surface exposure dating of existing samples. Results will test the hypothesis that the scoured surface and the ice-sheet behavior that it represents is much younger than its traditionally assigned age of ≥14 Ma and thus relevant to current investigations into ice-sheet behavior under warmer-than-present climates. The work affords mentoring opportunities for students of all ages and will include the production of a book on the landscapes of the Transantarctic Mountains designed to introduce the public to the importance of Antarctica. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Glaciers move in response to gravity pulling them downhill and much of the resistance to this motion is supplied by the bedrock that they sit on. For fast moving glaciers this motion is largely the result of basal ice sliding over and around bedrock bumps, and the specific processes at the ice-bed interface that facilitate this sliding play a dominant role in setting the glacier speed. Sliding atop the ice-bed interface is known to create cavities (pockets of water) downstream of bedrock bumps. These cavities facilitate water flow, control areas of ice-bed contact, regulate basal drag, dictate subglacial erosion, and affect ice mechanics in general. Thus, the length and shape of cavities (geometry) as they separate from the bed is of fundamental importance in glaciology. This project will determine the fundamental processes that set the shapes of those cavities. This work will benefit the scientific community by producing improved estimates to basal sliding and subglacial hydrology which are two of the main uncertainties in glacier-flow modeling. It will also lead to a better understanding of subglacial erosion which effectively controls the basal bump geometries. This in turn will lead to improved understanding of the fundamentals of glacier and ice-sheet dynamics. Therefore, the outcome of the project could ultimately improve future projections of sea-level rise, benefitting society at large. In addition, this project will train a postdoctoral researcher and undergraduate students from tribal institutions. This project will: 1) Use a novel experimental device to generate a cavity geometry data set for a range of independent controls; and 2) Use the results from part one to constrain numerical models that will allow for the exploration of a greater range of parameter space than is possible in the physical experiments alone. Using a novel cryogenic ring-shear device, this project will systematically assess three likely controls on cavity geometry: effective stress, sliding speed, and bump geometry, while simultaneously tracking strain indicators within the ice and the geometry of the cavity through the transparent walls of the device. These experiments will be conducted with the University of Wisconsin-Madison, state-of-the-art ring-shear device and represent the first instance where all three parameters’ effects on the resultant cavity geometry can be measured simultaneously. The lab experiment findings of cavity geometry and strain rates within the ice will be used to help constrain the process-based numerical modeling of cavity formation. The numerical simulations of ice flow around obstacles will provide information about the stress and strain distribution within the ice, and from this data we can explore the ability of existing theories to predict cavity geometry for fast-flowing ice. The physics within the numerical model will be updated as needed to incorporate processes such as a stress dependent ice rheology or changes in the ice-bed contact physics that are currently unaccounted for. Outcomes will be 1) a detailed understanding of the physics that govern cavity geometry and 2) a simple parameterization of the lab and modeling results that can be easily incorporated into glaciological models for improved estimates of subglacial sliding, hydrology, and erosion. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
MacAyeal, Douglas; Banwell, Alison; Campbell, Seth; Schild, Kristin; Cassoto, Ryan
No dataset link provided
Non-Technical Abstract: This project explores the areas or crash-zones where floating ice shelves in Antarctica compressively flow against obstructions such as islands and plugs of stagnant ice frozen to the sea bed. The significance of these crash-zones is that they are responsible for generating the resistive forces that allow ice shelves to slow down the flow of ice farther inland into the ocean. Ice conditions within these boundaries thus determine how Antarctica’s ice sheets contribute to sea-level rise. The research will feature on-the-ice glaciological and geophysical field measurements near pressure ridges near Scott Base and the transition to the ice road where large wave-like pressure ridges form on the ice-shelf surface. This field area is along the coast of Ross Island adjacent to major logistical stations of the US and New Zealand Antarctic programs. Thus the research will help station managers better preserve one of the key roadways that connects the stations to the major runway used to fly to virtually all other parts of Antarctica. The research will also interact with educational programs such as featured in the long-standing Juneau Icefield Research Project as well as potential involvement of an artist from the US Antarctic Program’s Polar STEAM in the second field season. Technical Abstract: This project explores the dynamics of boundaries where ice shelves compressively flow against obstructions such as islands and areas of grounded ice. The significance of these boundaries is that they are responsible for generating the resistive forces that allow ice shelves to impede or slow down the flow of grounded inland ice into the ocean. Ice conditions within these boundaries thus determine how Antarctica’s ice sheets contribute to sea-level rise. The research will feature glaciological and geophysical field surveys in a compressive boundary area near pressure ridges adjacent to Scott Base and the transition to the ice road along the coast of Ross Island, an area affecting access to major logistical hubs of the US and New Zealand Antarctic programs. Field data will be combined with remote sensing, numerical modeling and theory development to answer key questions about the dynamics of compressive boundaries such as: is there a limit to compressive stress due to ice fracture and the bending of the ice shelf into sinusoidal pressure ridges? Over what time scales does this compressive stress build, fluctuate and decay, and how is it related to the processes that form rumples? Are there ways in which the ridges actually protect the compressive boundary from damage such as by setting up a means to scatter ocean swell impinging from the open ocean? How should compressive ice-shelf boundaries be represented in large scale ice-sheet/shelf models for the prediction of future sea-level rise? A variety of broader impact work will be done both specifically targeting the research field area and more broadly addressing scientific and societal concerns. The field area contains a critical logistics roadway that connects McMurdo Station, Scott Base and a runway essential for continent-wide air logistics. The project will inform how to stabilize the roadway against excessive damage from summer ablation and other factors. Other broader impacts include: (a) Open-Science evaluation of climate systems engineering strategies for glacial geoengineering mitigation of sea-level rise, (b) cooperation with the Juneau Icefield Research Program (JIRP) education component, (c) support and facilitation of an online FieldSafe workshop and associated panel discussion to support early-career Antarctic field teams to mitigate environmental and interpersonal risks in remote field sites, and (d) potential involvement of an artist from the US Antarctic Program’s Polar STEAM in the second field season. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Ice sheets lose ice mass through gravity-driven flow to the ocean where ice breaks into icebergs and melts, contributing to global sea level rise. Water commonly found at the base of ice sheets facilitates this process by lubricating the ice-rock interface. The recent discovery of vast, kilometer-thick groundwater reservoirs beneath the Antarctic Ice Sheet thus raises important questions about the potential impact of groundwater on ice flow. It has been hypothesized that groundwater flow to the ice-sheet bed may accelerate ice flow as the ice sheet shrinks in response to global warming. Evaluating this hypothesis is challenging due to poorly understood interactions between water, ice, and rock, but is crucial for anticipating the response of ice sheets and sea level to climate change. Understanding how groundwater responds to a changing ice sheet also has important implications for the heat, chemical elements, and microorganisms it stores and transports. To assess the impact of groundwater processes on ice dynamics, a new idealized modeling framework will be developed, incorporating several novel hydromechanical couplings between ice sheets, subglacial drainage systems, and groundwater aquifers. This framework will enable testing the hypotheses that (1) aquifers decelerate ice mass loss in the absence of a well-developed subglacial drainage system, but that (2) an efficient, channelized drainage system can reduce and even reverse this decelerating effect, and that (3) the impact of these phenomena is most pronounced for steep ice flowing rapidly over thick sedimentary basins and depends in a complex way on aquifer permeability. Existing geodetic, seismic, and other geophysical datasets at well-studied Thwaites Glacier and Whillans Ice Stream will be used to constrain model parameters and investigate the impact of groundwater processes in contrasting glaciologic settings. This work will help rule out or highlight subglacial groundwater as one of the next major challenges for efforts to predict the future of the Antarctic Ice Sheet and sea-level rise on decadal to millennial timescales. The project will contribute to educating the next generation of scientists by supporting an early-career PI and a graduate student, as well as participation in a field and research educational program in Alaska and the production of chapters for an online, open-source, free interactive textbook. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Marine ice sheets are low-pass filters of climate variability that take centuries to adjust to interior and near-terminus changes in mass balance. Constraining these century-scale changes from satellite observations that span only the last 40 years is challenging. Here, we take a different approach of carefully synthesizing different data sets to infer changes in the configurations of van der Veen and Mercer Ice Streams on the Siple Coast over the past 3000 years from englacial features encoded in ice-penetrating radar data. Englacial radar data from Conway Ridge reveal smooth, surface conformal layers overlying disrupted stratigraphy that suggest the van der Veen Ice Stream was 40 km wider over 3000 years ago. Englacial layer dating indicates that the ice stream narrowed to its present configuration between $\sim3000$ and $\sim1000$ years ago. Similarly disrupted stratigraphy and buried crevasses suggest that ice flowing from Mercer to Whillans Ice Stream across the northwestern tip of the ridge slowed shortly after. Using an ice-flow model capable of simulating shear margin migration, we evaluate whether small changes in ice thickness can lead to large changes in shear margin location. Our results suggest that the tip of Conway Ridge is sensitive to thinning and thickening, and that when the basal strength at the tip of the ridge increases with the height above flotation, the ice sheet shear margins can change quickly.
Ice penetrating radar is one of the primary tools that researchers use to study ice sheets and glaciers. With radar, it is possible to see a cross-section of the ice, revealing internal layers and the shape of the rocks under the ice. Among other things, this is important for calculating how much potential sea level change is locked up in the polar ice sheets, and how stable the ice sheets are likely to be in a warming world. This type of data is logistically challenging and expensive to collect. Historically, individual research groups have obtained funding to collect these data sets, and then the data largely stayed within that institution. There has been a recent push to make more and more data openly available, enabling the same datasets to be used by multiple research groups. However, it is still difficult to figure out what data is available because there is no centralized index. Additionally, each group releases data in a different format, which creates an additional hurdle to its use. This project addresses both of those challenges to data reuse by providing a unified tool for discovering where ice penetrating radar data already exists, then allowing the researcher to download and visualize the data. It is integrated into open-source mapping software that many in the research community already use, and makes it possible for non-experts to explore these datasets. This is particularly valuable for early-career researchers and for enabling interdisciplinary work. The US alone has spent many tens of millions of dollars on direct grants to enable the acquisition and analysis of polar ice penetrating radar data, and even more on the associated infrastructure and support costs. Unfortunately, much of these data is not publicly released, and even the data that has been released is not easily accessible. There is significant technical work involved in figuring out how to locate, download and view the data. This project is developing a tool that will both lower the barrier to entry for using this data and improve the workflows of existing users. Quantarctica and QGreenland have rapidly become indispensable tools for the polar research community, making diverse data sets readily available to researchers. However, ice penetrating radar is a major category of data that is not currently supported – it is possible to see the locations of existing survey lines, and the ice thickness maps that have been interpreted from their data, but it is not readily possible to see the radargrams themselves in context with all of the other information. This capability is important because there is far more visual information contained in a radargram than simply its interpreted basal elevation or ice thickness. This project is developing software that will enable researchers to to view radargram images and interpreted surface and basal horizons in context with the existing map-view datasets in Quantarctica and QGreenland. A data layer shows the locations of all known ice penetrating radar surveys, color-coded based on availability. This layer enables data discovery and browsing. The plugin itself interacts with the data layer, first to download selected data, then to visualize the radargrams along with a cursor that moves simultaneously along the radargram and along the map view, making it straightforward to determine the precise geolocation of radar features. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Lamont-Doherty Earth Observatory of Columbia University was awarded a multi-year grant (May 1, 2010- April 30, 2015) to develop an ice imaging system, or "IcePod," for use in measuring the surface and subsurface topography of ice sheets. IcePod will enable research on the effects of global climate change on ice sheets and the effects of sub-glacial water on potential sea-level rise. IcePod sensors are contained in a Common Science Support Pod and operated on NYANG LC-130 aircraft during routine and targeted missions over Greenland and Antarctica. The IcePod instrument package consists of ice-penetrating radar, infrared and visible cameras, laser altimeter, inertial measurement unit, GPS receiver and data acquisition system. IcePod will also enable other instruments to be used in the modular Common Science Support Pod, and will become a shared community research facility providing data to the science community. Funding will support activities in both Greenland and Antarctica needed to commission IcePod, to develop a data reduction flow and data delivery system for IcePod data, and to engineer a UPS to provide IcePod with clean, reliable power for system operation.
Non-technical abstract Earth’s climatic changes have been recorded in the ice core collected from the Antarctic ice sheet. While these records provide a high resolution view of how polar temperatures changed through time, it is not always clear what Earth process influence Antarctic climate. One likely contributor to Antarctic temperature changes is the cyclic changes in Earth’s orientation as it orbits the sun. These so-called Milankovitch cycles control the amount and pattern of sunlight reaching the polar regions, that in turn result in periods of climatic warming or cooling. While the orbital variations and control on incoming solar energy remain well understood, how they influence Antarctic climate remains unresolved. It is the goal of this project to determine how variations in Earth’s orbit may be locally influencing Antarctic temperatures. The researchers on this project are pursing this goal by identifying periods of past ice melting on the surface of Antarctica using minerals that precipitate from the meltwaters that resulted from past warm periods. The timing of this past melting will be determined by radioisotopic dating of the minerals using the natural radioactive decay of uranium to thorium. By dating numerous samples, collected in past scientific expeditions throughout the Antarctic continent, these researchers aim to reconstruct the frequency and spatial pattern of past warming and in doing so, determine what aspect of Earth’s orbital variations influences Antarctic ice loss. Technical abstract Antarctic ice cores provide high resolution records of Pleistocene Southern Hemisphere temperatures that show an overall coherence with Northern Hemisphere temperature variations. One explanation for this bi-hemispheric temperature covariance relies on changes in atmospheric CO2 that result from varying northern hemisphere insolation. An alternative posits that the apparent coherence of polar temperatures is due to the misleading covariance between northern hemisphere summer insolation and, the southern hemisphere summer duration. At present there is an insufficient understanding of the role that local insolation plays in Antarctic climate. The goal of this research project is to identify the temporal spatial patterns of solar forcing in Antarctica. To reach this goal, the project team will: 1) develop a way to identify periods of past surface melt production in Antarctica using U-Th dating of pedogenic carbonates; and 2) utilize the evidence of past surface melting to calibrate energy balance models and interrogate past Antarctic surface temperatures and; 3) compare the timing of Antarctic warm periods to potential solar forcing mechanisms such as peak summer insolation or summer duration. A means of identifying the spatial and temporal pattern at which local insolation influences Antarctic temperature would provide a transformative solution to the contradiction in current climate records. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Much of our understanding of ice sheet behavior due to warming temperatures is based on how past ice sheets responded to warming associated with the end of the last ice age, 20,000 years ago. These studies rely on accurate dating of features left behind by the past ice sheets. The most commonly used method for determining the age of these features over the last ~40,000 years is radiocarbon dating. However, radiocarbon dating is not without its nuances, which are particularly pronounced around Antarctica. One of these nuances is determining the offset between the materials measured radiocarbon age and its true age. The purpose of this research is to use historically harvested whale bones from the Antarctic Peninsula, whose age is independently known, to determine that offset. A better understanding of that offset will allow more accurate estimates of past rates of ice sheet and sea-level changes across the Antarctic Peninsula over the last ~40,000 years. Much of our understanding of how the Antarctic Ice Sheet will respond to future climate changes is based on studies of its past behavior. Those studies often rely on reconstructing its evolution since the Last Glacial Maximum, 20,000 years ago. Radiocarbon dating is the most commonly used method of dating Quaternary deposits for these reconstructions. However, the use of radiocarbon in Antarctica is hampered by some of the largest and least constrained radiocarbon reservoirs on the planet. The purpose of this research is to determine the radiocarbon reservoir for whale bones. This research will leverage an existing collection of 25 whale bones used for prior DNA research to determine the late Holocene radiocarbon reservoir for the Antarctic Peninsula. The whale bones are from specimens harvested at the turn of the 20th century prior to nuclear testing in the 1950s. Thus, their radiocarbon age will provide valuable new constraints on the radiocarbon reservoir for shallow waters around Antarctica. An added benefit of this approach is that given the DNA determination, we will also be able to determine if that radiocarbon reservoir varies across three species of whales, thus testing the common assumption that the radiocarbon reservoir does not vary significantly across different species. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Kreutz, Karl; Mukhopadhyay, Sharmila M; Allen, Katherine A; Mayewski, Paul A.; Kurbatov, Andrei V.
No dataset link provided
This award is for acquisition of new instrumentation to support acquisition of the new LA-HR-ICPMS instrumentation for the trace-element analysis of various environmental samples. This instrumentation will replace the original (and heavily used over two decades) ThermoScientific Element2 ICP-MS installed at the University of Maine’s Climate Change Institute (CCI). The new acquisition will significantly expand research capabilities of the CCI/ICP-MS Facility to improve the analysis of aqueous samples, supplemented with a laser ablation (LA) front end for ice, biological, and other solid materials. The current ICP-MS Facility was established in 2002 with an NSF/MRI award, which since then has served as a vital resource for climate, environmental, ecosystem, and engineering research and training at the U. Maine, across the state of Maine and beyond. The routine use and primary support of the Facility come from the Principal Investigators and their collaborators that group under three research areas: glaciochemistry and climate/environmental reconstruction; paleoceanography and marine biogeochemistry; and environmental sensor development and material science engineering. The U. Maine is the State’s Land & Sea Grant university and only PhD granting institution, so the campus is the de facto academic research and research training hub of the state of Maine. The proposed advances of this research & training instrumentation will immediately impact current and future NSF-funded research projects that support extensive national and international collaborations. Specific to this proposal are collaborations with the University of Venice (Italy) and the University of Cambridge/British Antarctic Survey to develop laser ablation ICP-MS imaging of ice cores, and collaborations with New Zealand, Swiss, Chinese, Canadian, and Brazilian colleagues to analyze ice, thereby maintaining our leadership role in global ice core and climate change research. Likewise, the enhanced carbonate analysis capacity of the Element XR will have an immediate impact on NSF-funded research projects in the Gulf of Maine and in the South Pacific. The proposed instrumentation will facilitate new and important collaborations between academic colleges (College of Natural Science, Forestry, and Agriculture and the College of Engineering) and research units - the CCI and the Frontier Institute for Research in Sensor Technology - across the campus, as well as enabling new and broader scientific collaborations with other academic and scientific institutions across Maine. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The snow that falls on Antarctica compresses to ice that flows toward the coast as a large sheet, returning it to the ocean over periods of centuries to millennia. In many places around Antarctica, the ice sheet extends from the land to over the ocean, forming floating ice shelves on the periphery. If this cycle is in balance, the ice sheets help maintain a stable sea level. When the climate cools or warms, however, sea level falls or rises as the ice sheet gains or loses ice. The peripheral ice shelves are important for regulating sea level because they help hold back the flow of ice to the ocean. Warming ocean waters thin ice shelves by melting their undersides, allowing ice to flow faster to the ocean, and raising sea level globally. Thus, an important question is how much sea level will rise in response to warming ocean temperatures over the next century(s) that further thin Antarctica’s ice shelves. Currently, West Antarctica produces the majority of the continent’s contribution to sea level. Albeit with large uncertainty, ice-sheet models indicate that Totten and Denman glaciers in East Antarctica could also produce substantial sea-level rise in the next century(s). This international study will focus on improving understanding of how much these glaciers will contribute to sea level under various warming scenarios. The project will use numerical models constrained by oceanographic and remote sensing observations to determine how Totten and Denman glaciers will respond to increased melting. Remote sensing data will provide updated and improved estimates of the melt rate for each ice shelf. Two float profilers will be deployed from aircraft by British and Australian partners in front of each ice shelf to repeatedly measure the temperature and salinity of the water column, with the results telemetered back via satellite link. The melt and oceanographic data will be used to constrain parameterized transfer functions for ice-shelf cavity melting in response to ocean temperature, improving on current parameterizations based on limited data. These melt functions will be used with ocean temperatures from climate models to force an open-source ice-flow numerical model for each glacier to determine the century-scale response for a variety of scenarios, helping to reduce uncertainty in sea level contributions from this part of Antarctica. Processes other than melt that might further alter the contribution to sea level over the next few centuries will also be examined. On the observational side, the demonstrated deployment of float profilers from a sonobuoy launch tube in polar settings would help raise the technology readiness of operational in-situ monitoring of the rapidly changing polar shelf seas, paving the way for an expansion of observations of ocean hydrographic properties from remote areas that currently are poorly understood. In addition to being of scientific value, reduced uncertainty in sea-level rise projections has strong societal benefit to coastal communities struggling with long-range planning to mitigate the effects of sea-level rise over the coming decades to centuries. Outreach activities by team members will help raise public awareness of Antarctica's dramatic changes and the resulting consequences. This is a project jointly funded by the National Science Foundation’s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part I, Non-technical Abstract Concerns that the West Antarctic Ice Sheet (WAIS) might be susceptible to releasing its ice as giant icebergs into the Southern Ocean due to a warming climate, raising global sea level, were first expressed more than 40 years ago. To best-assess this threat, scientists need to know whether such events occurred in the geologically recent past, during warm intervals of past glacial-interglacial cycles. Ocean drilling near the most vulnerable sector of the WAIS, in 2019, yielded seafloor geologic records demonstrating times when icebergs dropped large volumes of sands and pebbles, called ice-rafted detritus (IRD) in deep water of the Amundsen Sea. Occurring together with IRD that was eroded from bedrock beneath the ice sheets, there are abundant microfossils of diatoms (algal plankton), which indicate high biological productivity in the open ocean. The new sediment cores provide a complete, uninterrupted record of a time of dramatic fluctuations of ice sheet extent that occurred over the last 3 million years. Therefore, they provide the means to obtain clear answers to the question whether ice sheet collapse occurred in the past and offering clues to its potential future. This project will investigate sediment intervals where IRD coincides with evidence of high diatom production, to test whether these two criteria indicate rapid ice sheet collapse. Geochemical analysis of IRD pebbles will help trace the source of the icebergs to likely on-land sites. By analyzing conditions of high diatom and IRD accumulation in deep ocean sediment, where local coastal influences can be avoided, we will assess oceanographic and climatic conditions associated with past ice sheet collapse events. Diatoms provide powerful evidence of temperature and ocean productivity changes in the past, that, when linked to time, can translate into rates of ice sheet drawdown. These results will provide critical data for designing, constraining and testing the next suite computer models that can determine the likelihood and timing of future ice sheet collapse in a warming world. The project will include training of undergraduate and graduate students from diverse backgrounds, and the public will be introduced to Antarctic science and engaged through several different outreach efforts. Part 2, Technical Abstract New drillcores from the Amundsen Sea, Antarctica (IODP Expedition 379) contain a continuous record of oceanographic changes and iceberg rafted debris (IRD) spanning the last 5 million years. This study aims to identify the signature of retreat/collapse of the West Antarctic Ice Sheet (WAIS) in these continental margin, deep-sea sediments by quantitatively analyzing, in detail, diatom and IRD records across glacial-interglacial lithostratigraphic transitions to establish the timing and frequency of Late Pliocene and Pleistocene WAIS collapse events. The investigators will secure age constraints and diagnostic observations of marine paleoenvironmental conditions for selected interglacial intervals of cores from sites U1532 and U1533, using high resolution micropaleontology of diatom assemblages coupled with microstratigraphic analysis of IRD depositional events, while petrography, geochronology and thermochronology of iceberg rafted clasts will provide evidence of iceberg sources and pathways. Depositional paleotemperatures will be assessed via a new paleotemperature proxy based on quantitative assessment of morphologic changes in the dominant Southern Ocean diatom Fragilariopsis kerguelensis. Their results will contribute to parameterization of new ice sheet models that seek to reconstruct and forecast West Antarctic Ice Sheet behavior. This project will directly contribute to undergraduate education at an undergraduate-only college and at a public university that serves a demographic typified by first generation university students and underrepresented groups. Spanning geology, geochemistry, sedimentology, paleontology and paleoceanography, the proposed work will allow undergraduate students to develop diverse skills through hands-on research within a collaborative team that is dedicated to societally relevant research. The two graduate students will conduct original research and work alongside/mentor undergraduates, making for a well-rounded research experience that prepares them for success in future academic or employment sectors. The discoveries that come from this deep-sea record from West Antarctica will be communicated by students and investigators at national and international conferences and an array of public science outreach events. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The evolution of surface and shallow subsurface meltwater across Antarctic ice shelves has important implications for their (in)stability, as demonstrated by the 2002 rapid collapse of the Larsen B Ice Shelf. It is vital to understand the causes of ice-shelf (in)stability because ice shelves buttress against the discharge of inland ice and therefore influence ice-sheet contributions to sea-level rise. Ice-shelf break-up may be triggered by stress variations associated with surface meltwater movement, ponding, and drainage. These variations may cause an ice shelf to flex and fracture. This four-year project will provide key geophysical observations to improve understanding of ice-shelf meltwater and its effects on (in)stability. The work will be conducted on the George VI Ice Shelf on the Antarctic Peninsula, where hundreds of surface lakes form each summer. Over a 27-month period, global positioning systems, seismometers, water pressure transducers, automatic weather stations, and in-ice thermistor strings will be deployed to record ice shelf flexure, fracture seismicity, water depths, and surface and subsurface melting, respectively, in and around several surface lakes on the George VI Ice Shelf, within roughly 20 km of the British Antarctic Survey's Fossil Bluff Station. Field data will be used to validate and extend the team's approach to modelling ice-shelf flexure and stress, and possible "Larsen-B style" ice-shelf instability and break-up. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Satellite observations of Earth’s surface gravity and elevation changes indicate rapid melting of ice sheets in recent decades in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica. This rapid melting may lead to significant global sea level rise which is a major societal concern. Measurements from the Global Positioning System (GPS) show rapid land uplift in these regions as the ice sheets melt. When an ice sheet melts, the melt water flows to oceans, causing global sea level to rise. However, the sea level change at a given geographic location is also influenced by two other factors associated with the ice melting process: 1) the vertical motion of the land and 2) gravitational attraction. The vertical motion of the land is caused by the change of pressure force on the surface of the solid Earth. For example, the removal of ice mass reduces the pressure force on the land, leading to uplift of the land below the ice sheet, while the addition of water in oceans increases the pressure force on the seafloor, causing it to subside. The sea level always follows the equipotential surface of the gravity which changes as the mass on the Earth’s surface (e.g., the ice and water) or/and in its interiors (e.g., at the crust-mantle boundary) is redistributed. Additionally, the vertical motion of the land below an ice sheet has important effects on the evolution and stability of the ice sheet and may determine whether the ice sheet will rapidly collapse or gradually stabilize. The main goal of this project is to build an accurate and efficient computer model to study the displacement and deformation of the Antarctic crust and mantle in response to recent ice melting. The project will significantly improve existing and publicly available computer code, CitcomSVE. The horizontal and vertical components of the Earth’s surface displacement depends on mantle viscosity and elastic properties of the Earth. Although seismic imaging studies demonstrate that the Antarctica mantle is heterogeneous, most studies on the ice-melting induced deformation in Antarctica have assumed that mantle viscosity and elastic properties only vary with the depth due to computational limitations. In this project, the new computational method in CitcomSVE avoids such assumptions and makes it possible to include realistic 3-D mantle viscosity and elastic properties in computing the Antarctica crustal and mantle displacement. This project will interpret the GPS measurements of the surface displacements in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica and use the observations to place constraints on mantle viscosity and deformation mechanisms. The project will also seek to predict the future land displacement Antarctica, which will lead to a better understand of Antarctica ice sheets. Finally, the project has direct implications for the study of global sea level change and the dynamics of the Greenland ice sheet. Technical Description Glacial isostatic adjustment (GIA) is important for understanding not only fundamental science questions including mantle viscosity, mantle convection and lithospheric deformation but also societally important questions of global sea-level change, polar ice melting, climate change, and groundwater hydrology. Studies of rock deformation in laboratory experiments, post-seismic deformation, and mantle dynamics indicate that mantle viscosity is temperature- and stress-dependent. Although the effects of stress-dependent (i.e., non-Newtonian) viscosity and transient creep rheology on GIA process have been studied, observational evidence remains elusive. There has been significant ice mass loss in recent decades in northern Antarctica Peninsula (NAP) and Amundsen Sea Embayment (ASE) of West Antarctica. The ice mass loss has caused rapid bedrock uplift as measured by GPS techniques which require surprisingly small upper mantle viscosity of ~1018 Pas. The rapid uplifts may have important feedback effects on ongoing ice melting because of their influence on grounding line migration, and the inferred small viscosity may have implications for mantle rheology and deformation on decadal time scales. The main objective of the project is to test hypotheses that the GPS observations in NAP and ASE regions are controlled by 3-D non-Newtonian or/and transient creep viscosity by developing new GIA modeling capability based on finite element package CitcomSVE. The project will carry out the following three tasks: Task 1 is to build GIA models for the NAP and ASE regions to examine the effects of 3-D temperature-dependent mantle viscosity on the surface displacements and to test hypothesis that the 3-D mantle viscosity improves the fit to the GPS observations. Task 2 is to test the hypothesis that non-Newtonian or/and transient creep rheology controls GIA process on decadal time scales by computing GIA models and comparing model predictions with GPS observations for the NAP and ASE regions. Task 3 is to implement transient creep (i.e., Burgers model) rheology into finite element package CitcomSVE for modeling the GIA process on global and regional scales and to make the package publicly available to the scientific community. The project will develop the first numerical GIA model with Burgers transient rheology and use the models to examine the effects of 3-D temperature-dependent viscosity, non-Newtonian viscosity and transient rheology on GIA-induced surface displacements in Antarctica. The project will model the unique GPS observations of unusually large displacement rates in the NAP and ASE regions to place constraints on mantle rheology and to distinguish between 3-D temperature-dependent, non-Newtonian and transient mantle viscosity. The project will expand the capability of the publicly available software package CitcomSVE for modeling viscoelastic deformation and tidal deformation on global and regional scales. The project will advance our understanding in lithospheric deformation and mantle rheology on decadal time scales, which helps predict grounding line migration and understand ice sheet stability in West Antarctica. The project will strengthen the open science practice by improving the publicly available code CitcomSVE at github. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Non-technical Abstract The McMurdo Dry Valleys LTER seeks to understand how changes in the temporal variability of ecological connectivity interact with existing landscape legacies to alter the structure and functioning of this extreme polar desert ecosystem. This research has broad implications, as it will help us to understand how natural ecosystems respond to ongoing anthropogenic global change. At the same time, this project also serves an important educational and outreach function, providing immersive research and educational experiences to students and artists from diverse backgrounds, and helping to ensure a diverse and well-trained next generation of leaders in polar ecosystem science and stewardship. Ultimately, the results of this project will help us to better understand and prepare for the effects of climate change and develop scientific insights that are relevant far beyond Antarctic ecosystems. The McMurdo Dry Valleys (MDVs) make up an extreme polar desert ecosystem in the largest ice-free region of Antarctica. The organisms in this ecosystem are generally small. Bacteria, microinvertebrates, cyanobacterial mats, and phytoplankton can be found across the streams, soils, glaciers, and ice-covered lakes. These organisms have adapted to the cold and arid conditions that prevail outside of lakes for all but a brief period in the austral summer when the ecosystem is connected by liquid water. In the summer when air temperatures rise barely above freezing, soils warm and glacial meltwater flows through streams into the open moats of lakes. Most biological activity across the landscape occurs in summer. Through the winter, or polar night (6 months of darkness), glaciers, streams, and soil biota are inactive until sufficient light, heat, and liquid water return, while lake communities remain active all year. Over the past 30 years, the MDVs have been disturbed by cooling, heatwaves, floods, rising lake levels, as well as permafrost and lake ice thaw. Considering the clear ecological responses to this variation in physical drivers, and climate models predicting further warming and more precipitation, the MDV ecosystem sits at a threshold between the current extreme cold and dry conditions and an uncertain future. This project seeks to determine how important the legacy of past events and conditions versus current physical and biological interactions shape the current ecosystem. Four hypotheses will be tested, related to 1) whether the status of specific organisms are indicative ecosystem stability, 2) the relationship between legacies of past events to current ecosystem resilience (resistance to big changes), 3) carryover of materials between times of high ecosystem connectivity and activity help to maintain ecosystem stability, and 4) changes in disturbances affect how this ecosystem persists through the annual polar night (i.e., extended period of dark and cold). Technical Abstract In this iteration of the McMurdo LTER project (MCM6), the project team will test ecological connectivity and stability theory in a system subject to strong physical drivers (geological legacies, extreme seasonality, and contemporary climate change) and driven by microbial organisms. Since microorganisms regulate most of the world’s critical biogeochemical functions, these insights will be relevant far beyond polar ecosystems and will inform understanding and expectations of how natural and managed ecosystems respond to ongoing anthropogenic global change. MCM6 builds on previous foundational research, both in Antarctica and within the LTER network, to consider the temporal aspects of connectivity and how it relates to ecosystem stability. The project will examine how changes in the temporal variability of ecological connectivity interact with the legacies of the existing landscape that have defined habitats and biogeochemical cycling for millennia. The project team hypothesizes that the structure and functioning of the MDV ecosystem is dependent upon legacies and the contemporary frequency, duration, and magnitude of ecological connectivity. This hypothesis will be tested with new and continuing monitoring, experiments, and analyses of long-term datasets to examine: 1) the stability of these ecosystems as reflected by sentinel taxa, 2) the relationship between ecological legacies and ecosystem resilience, 3) the importance of material carryover during periods of low connectivity to maintaining biological activity and community stability, and 4) how changes in disturbance dynamics disrupt ecological cycles through the polar night. Tests of these hypotheses will occur in field and modeling activities using new and long-term datasets already collected. New datasets resulting from field activities will be made freely available via widely-known online databases (MCM LTER and EDI). The project team has also developed six Antarctic Core Ideas that encompass themes from data literacy to polar food webs and form a consistent thread across the education and outreach activities. Building on past success, collaborations will be established with teachers and artists embedded within the science teams, who will work to develop educational modules with science content informed by direct experience and artistic expression. Undergraduate mentoring efforts will incorporate computational methods through a new data-intensive scientific training program for MCM REU students. The project will also establish an Antarctic Research Experience for Community College Students at CU Boulder, to provide an immersive educational and research experience for students from diverse backgrounds in community colleges. MCM LTER will continue its mission of training and mentoring students, postdocs, and early career scientists as the next generation of leaders in polar ecosystem science and stewardship. Historically underrepresented participation will be expanded at each level of the project. To aid in these efforts, the project has established Education & Outreach and Diversity, Equity, and Inclusion committees to lead, coordinate, support, and integrate these activities through all aspects of MCM6. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Bassis/1149085 This CAREER award supports a project to develop physically based bounds on the amount ice sheets can contribute to sea level rise in the coming centuries. To simulate these limits, a three-dimensional discrete element model will be developed and applied to simulate regions of interest in the Greenland and Antarctic ice sheets. These regions will include Helheim Glacier, Jakobshavn Isbräe, Pine Island Glacier and sections of the Larsen Ice Shelf. In the discrete element model the ice will be discretized into distinct blocks or boulders of ice that interact through inelastic collisions, frictional forces and bonds. The spectrum of best to worst case scenarios will be examined by varying the strength and number of bonds between neighboring blocks of ice. The worst case scenario corresponds to completely disarticulated ice that behaves in a manner akin to a granular material while the best case scenario corresponds to completely intact ice with no preexisting flaws or fractures. Results from the discrete element model will be compared with those from analogous continuum models that incorporate a plastic yield stress into the more traditional viscous flow approximations used to simulate ice sheets. This will be done to assess if a fracture permitting plastic rheology can be efficiently incorporated into large-scale ice sheet models to simulate the evolution of ice sheets over the coming centuries. This award will also support to forge a partnership with two science teachers in the Ypsilanti school district in southeastern Michigan. The Ypsilanti school district is a low income, resource- poor region with a population that consists of ~70% underrepresented minorities and ~69% of students qualify for a free or reduced cost lunch. The cornerstone of the proposed partnership is the development of lesson plans and content associated with a hands-on ice sheet dynamics activity for 6th and 7th grade science students. The activity will be designed so that it integrates into existing classroom lesson plans and is aligned with State of Michigan Science Technology, Engineering and Math (STEM) curriculum goals. The aim of this program is to not only influence the elementary school students, but also to educate the teachers to extend the impact of the partnership beyond the duration of this study. Graduate students will be mentored and engaged in outreach activities and assist in supervising undergraduate students. Undergraduates will play a key role in developing an experimental, analogue ice dynamics lab designed to illustrate how ice sheets and glaciers flow and allow experimental validation of the proposed research activities. The research program advances ice sheet modeling infrastructure by distributing results through the community based Community Ice Sheet Model.
Kingslake, Jonathan; Sole, Andrew; Livingstone, Stephen; Winter, Kate; Ely, Jeremy
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When ice sheets and glaciers lose ice faster than it accumulates from snowfall, they shrink and contribute to sea-level rise. This has consequences for coastal communities around the globe by, for example, increasing the frequency of damaging storm surges. Sea-level rise is already underway and a major challenge for the geoscience community is improving predictions of how this will evolve. The Antarctic Ice Sheet is the largest potential contributor to sea-level rise and its future is highly uncertain. It loses ice through two main mechanisms: the formation of icebergs and melting at the base of floating ice shelves on its periphery. Ice flows under gravity towards the ocean and the rate of ice flow controls how fast ice sheets and glaciers shrink. In Greenland and Antarctica, ice flow is focused into outlet glaciers and ice streams, which flow much faster than surrounding areas. Moreover, parts of the Greenland Ice Sheet speed up and slow down substantially on hourly to seasonal time scales, particularly where meltwater from the surface reaches the base of the ice. Meltwater reaching the base changes ice flow by altering basal water pressure and consequently the friction exerted on the ice by the rock and sediment beneath. This phenomenon has been observed frequently in Greenland but not in Antarctica. Recent satellite observations suggest this phenomenon also occurs on outlet glaciers in the Antarctic Peninsula. Meltwater reaching the base of the Antarctic Ice Sheet is likely to become more common as air temperature and surface melting are predicted to increase around Antarctica this century. This project aims to confirm the recent satellite observations, establish a baseline against which to compare future changes, and improve understanding of the direct influence of meltwater on Antarctic Ice Sheet dynamics. This is a project jointly funded by the National Science Foundation’s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries. This project will include a field campaign on Flask Glacier, an Antarctic Peninsula outlet glacier, and a continent-wide remote sensing survey. These activities will allow the team to test three hypotheses related to the Antarctic Ice Sheet’s dynamic response to surface meltwater: (1) short-term changes in ice velocity indicated by satellite data result from surface meltwater reaching the bed, (2) this is widespread in Antarctica today, and (3) this results in a measurable increase in mean annual ice discharge. The project is a collaboration between US- and UK-based researchers and will be supported logistically by the British Antarctic Survey. The project aims to provide insights into both the drivers and implications of short-term changes in ice flow velocity caused by surface melting. For example, showing conclusively that meltwater directly influences Antarctic ice dynamics would have significant implications for understanding the response of Antarctica to atmospheric warming, as it did in Greenland when the phenomenon was first detected there twenty years ago. This work will also potentially influence other fields, as surface meltwater reaching the bed of the Antarctic Ice Sheet may affect ice rheology, subglacial hydrology, submarine melting, calving, ocean circulation, and ocean biogeochemistry. The project aims to have broader impacts on science and society by supporting early-career scientists, UK-US collaboration, education and outreach, and adoption of open data science approaches within the glaciological community. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The fastest-changing regions of the Antarctic and Greenland Ice Sheets that contribute most to sea-level rise are underlain by soft sediments that facilitate glacier motion. Glacier ice can infiltrate several meters into these sediments, depending on the temperature and water pressure at the base of the glacier. To understand how ice infiltration into subglacial sediments affects glacier slip, the team will conduct laboratory experiments under relevant temperature and pressure conditions and compare the results to state-of-the-art mathematical models. Through an undergraduate research exchange between University of Wisconsin-Madison, Dartmouth College, and the College of Menominee Nation, Native American students will work on laboratory experiments in one summer and mathematical theory in the following summer. Ice-sediment interactions are a central component of ice-sheet and landform-development models. Limited process understanding poses a key uncertainty for ice-sheet models that are used to forecast sea-level rise. This uncertainty underscores the importance of developing experimentally validated, theoretically robust descriptions of processes at the ice-sediment interface. To achieve this, the team aims to build on long-established theoretical, experimental, and field investigations that have elucidated the central role of premelting and surface-energy effects in controlling the dynamics of frost heave in soils. Project members will theoretically describe and experimentally test the role of premelting at the basal ice-sediment interface. The experiments are designed to provide quantitative insight into the impact of ice infiltration into sediments on glacier sliding, erosion, and subglacial landform evolution. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
1. A non-technical explanation of the project's broader significance and importance, that serves as a public justification for NSF funding. This part should be understandable to an educated reader who is not a scientist or engineer. Katabatic or drainage winds, carry high-density air from a higher elevation down a slope under the force of gravity. Although katabatic flows are ubiquitous in alpine and polar regions, a surface-layer similarity theory is currently lacking for these flows, undermining the accuracy of numerical weather and climate prediction models. This project is interdisciplinary, and will give graduate and undergraduate students valuable experience interacting with researchers outside their core discipline. Furthermore, this project will broaden participating in science through recruitment of students from under-represented groups at OU and CU through established programs. The Antarctic Ice Sheet drives many processes in the Earth system through its modulation of regional and global atmospheric and oceanic circulations, storage of fresh water, and effects on global albedo and climate. An understanding of the surface mass balance of the ice sheets is critical for predicting future sea level rise and for interpreting ice core records. Yet, the evolution of the ice sheets through snow deposition, erosion, and transport in katabatic winds (which are persistent across much of the Antarctic) remains poorly understood due to the lack of an overarching theoretical framework, scarcity of in situ observational datasets, and a lack of accurate numerical modeling tools. Advances in the fundamental understanding and modeling capabilities of katabatic transport processes are urgently needed in view of the future climatic and snowfall changes that are projected to occur within the Antarctic continent. This project will leverage the expertise of a multidisciplinary team of investigators (with backgrounds spanning cryospheric science, environmental fluid mechanics, and atmospheric science) to address these knowledge gaps. 2. A technical description of the project that states the problem to be studied, the goals and scope of the research, and the methods and approaches to be used. In many cases, the technical project description may be a modified version of the project summary submitted with the proposal. Using field observations and direct numerical simulations of katabatic flow, this project is expected--- for the first time---to lead to a surface-layer similarity theory for katabatic flows relating turbulent fluxes to mean vertical gradients. The similarity theory will be used to develop surface boundary conditions for large eddy simulations (LES), enabling the first accurate LES of katabatic flow. The numerical tools that the PIs will develop will allow them to investigate how the partitioning between snow redistribution, transport, and sublimation depends on the environmental parameters typically encountered in Antarctica (e.g. atmospheric stratification, surface sloping angles, and humidity profiles), and to develop simple models to infer snow transport based on satellite remote sensing and regional climate models This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The unique Antarctic environment offers insight into processes and records not seen anywhere else on Earth, and is critical to understanding our planet’s history and future. The remoteness and logistics of Antarctic science brings together researchers from diverse disciplines who otherwise wouldn’t be presented with opportunities for collaboration, and often rarely attend the same academic conferences. The Interdisciplinary Antarctic Earth Science (IAES) conference is a biennial gathering that supports the collaboration of U.S. bio-, cryo-, geo-, and atmospheric science researchers working in the Antarctic. This proposal will support the next two IAES conferences to be held in 2022 and 2024, as well as a paired deep-field camp planning workshop. The IAES conference is important to the mission of the NSF in supporting interdisciplinary collaboration in the Antarctic Earth sciences, but also fulfills recommendations by the National Academy for improving cross-disciplinary awareness, data sharing, and early career researcher mentoring and development. The size and scope of the IAES conference allow it to serve as a hub for novel, interdisciplinary collaboration, as well as help develop the next generation of Antarctic Earth scientists. The goals of the IAES conference are to develop and deepen scientific collaborations across the Antarctic Earth science community, and create a framework for future deep-field, as well as non-field-based research. Across a 2.5 day hybrid conference, the IAES themes will include 1) connecting surficial processes, geology, and the deep earth; 2) landscape, ice sheet, ocean and atmospheric interactions; 3) exploring the hidden continent; and 4) evolution and ecology of ancient and modern organisms, ecosystems, and environments. The conference will share science through presentations of current research and keynote talks, broaden participation through welcoming new researchers from under-represented communities and disciplines, and deepen collaboration through interdisciplinary networking highlighting potential research connections, novel mentorship activities, and promoting data re-use, and application of remote sensing and modeling. Discussions resulting from the IAES conference will be used to develop white papers on future Antarctic collaborative research and deep-field camps based on community-driven research priorities. Community surveys and feedback will be solicited throughout the project to guide the future development of the IAES conference. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Antarctic animals face tremendous threats as Antarctic ice sheets melt and temperatures rise. About 34 million years ago, when Antarctica began to cool, most species of fish became locally extinct. A group called the notothenioids, however, survived due to the evolution of antifreeze. The group eventually split into over 120 species. Why did this group of Antarctic fishes evolve into so many species? One possible reason why a single population splits into two species relates to sex genes and sex chromosomes. Diverging species often have either different sex determining genes (genes that specify whether an individual’s gonads become ovaries or testes) or have different sex chromosomes (chromosomes that differ between males and females within a species, like the human X and Y chromosomes). We know the sex chromosomes of only a few notothenioid species and know the genetic basis for sex determination in none of them. The aims of this research are to: 1) identify sex chromosomes in species representing every major group of Antarctic notothenioid fish; 2) discover possible sex determining genes in every major group of Antarctic notothenioid fish; and 3) find sex chromosomes and possible sex determining genes in two groups of temperate, warmer water, notothenioid fish. These warmer water fish include groups that never experienced the frigid Southern Ocean and groups that had ancestors inhabiting Antarctic oceans that later adjusted to warmer waters. This project will help explain the mechanisms that led to the division of a group of species threatened by climate change. This information is critical to conserve declining populations of Antarctic notothenioids, which are major food sources for other Antarctic species such as bird and seals. The project will offer a diverse group of undergraduates the opportunity to develop a permanent exhibit at the Eugene Science Center Museum. The exhibit will describe the Antarctic environment and explain its rapid climate change. It will also introduce the continent’s bizarre fishes that live below the freezing point of water. The project will collaborate with the university’s Science and Comics Initiative and students in the English Department’s Comics Studies Minor to prepare short graphic novels explaining Antarctic biogeography, icefish specialties, and the science of this project as it develops. As Antarctica cooled, most species disappeared from the continent’s waters, but cryonotothenioid fish radiated into a species flock. What facilitated this radiation? Coyne’s “two rules of speciation” offer explanations for why species diverge: 1) the dysgenic sex in an interspecies hybrid is the one with two different sex chromosomes (i.e., in humans, it would be XY males and not XX females); and 2) “sex chromosomes play an outsized role in speciation”. These ideas propel the project’s main hypothesis: new sex chromosomes and new sex determination genes associate with cryonotothenioid speciation events. The main objective of the research is to identify notothenioid sex chromosomes and candidate sex-determination genes in many notothenioid species. The project’s first aim is to identify Antarctic fish sex chromosomes, asking the question: Did new sex chromosomes accompany speciation events? Knowledge gaps include: which species have cryptic sex chromosomes; which have newly evolved sex chromosomes; and which are chromosomally XX/XY or ZZ/ZW. Methods involve population genomics (RAD-seq and Pool-seq) for more than 20 Antarctic cryonotothenioids. The prediction is frequent turnover of sex chromosomes. The project’s second aim is to Identify candidate Antarctic cryonotothenioid sex-determination genes, asking the question: Did new sex-determination genes accompany Antarctic cryonotothenioid speciation events? A knowledge gap is the identity of sex determination genes in any notothenioid. Preliminary data show that three sex-linked loci are in or adjacent to three different candidate sex determination genes: 1) a duplicate of bmpr1ba in blackfin icefish; 2) a tandem duplicate of gsdf in South Georgia icefish; and 3) a transposed duplicate of gsdf in striped notothen. Methods involve annotating the genomic neighborhoods of cryonotothenioid sex linked loci for anomalies in candidate sex genes, sequencing sex chromosomes, and testing sex gene variants by CRISPR mutagenesis in zebrafish. The prediction is frequent turnover of sex determination genes. The project’s third aim is to identify sex chromosomes and sex-determination genes in temperate notothenioids. Basally diverging temperate notothenioids (‘basals’) lack identifiable sex chromosomes, consistent with temperature-cued sex determination, and one ‘basal’ species is a hermaphrodite. The constantly cold Southern Ocean rules out temperature, a common sex determination cue in many temperate fish, favoring genetic sex determination. Some cryonotothenioids re-invaded temperate waters (‘returnees’). Knowledge gaps include whether basals and returnees have strong sex determination genes. Methods employ pool-seq. The prediction is that genetic sex determination is weak in basals and that returnees have the same, but weaker, sex-linked loci as their Antarctic sister clade. A permanent exhibit will be established at the Eugene Science Center Museum tentatively entitled: The Antarctic: its fishes and climate change. Thousands of visitors, especially school children will be exposed, to the science of Antarctic ecosystems and the impacts of climate change. The research team will collaborate with the university’s Science and Comics Initiative to produce short graphic novels explaining Antarctic biogeography, icefish specialties, and this project. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The seaward motion of ice sheets and glaciers is primarily controlled by basal sliding at the base of the ice sheet and internal viscous flow within the ice mass. The latter of these — viscous flow — is dependent on various factors, including temperature, stress, grain size, and the alignment of ice crystals during flow to produce a "crystal orientation fabric" (COF). Historically, ice flow has been modeled using an equation, termed “Glen’s law”, that describes ice-flow rate as a function of temperature and stress. Glen’s law was constrained under relatively high-stress conditions and is often attributed to the motion of crystal defects within ice grains. More recently, however, grain boundary sliding (GBS) has been invoked as the rate-controlling process under low-stress, “superplastic” conditions. The grain boundary sliding hypothesis is contentious because GBS is not thought to produce a COF, whereas geophysical measurements and polar ice cores demonstrate strong COFs in polar ice masses. However, very few COF measurements have been conducted on ice samples subjected to superplastic flow conditions in the laboratory. This project would measure the evolution of ice COF across the transition from superplastic to Glen-type creep. Results will be used to interrogate the role of superplastic GBS creep within polar ice masses, and thereby provide constraints on polar ice discharge models. Polycrystalline ice samples with grain sizes ranging from 5 µm to 1000 µm will be fabricated and deformed in a laboratory, using a 1-atm cryogenic axial-torsion apparatus. Experiments will be conducted at temperatures of -30°C to -10°C, and at a constant uniaxial strain rate. Under these conditions, 5% to 99.99% of strain should be accommodated by superplastic, GBS-limited creep, depending on the sample grain size. The deformed samples will then be imaged using cryogenic electron backscatter diffraction (cryo-EBSD) and high-angular-resolution electron backscatter diffraction (HR-EBSD) to quantify COF, grain size, grain shape, and crystal defect (dislocation) densities, among other microstructural properties. These measurements will be used to decipher the rate-controlling mechanisms operating within different thermomechanical regimes, and resolve a long-standing debate over whether superplastic creep can produce a COF in ice. In addition to the polycrystal experiments, ice bicrystals will be fabricated and deformed to investigate the micromechanical behavior of individual grain boundaries under superplastic conditions. Ultimately, these results will be used to provide a microstructural toolbox for identifying superplastic creep using geophysical (e.g., seismic, radar) and glaciological (e.g., ice core) observations. This project will support one graduate student, one or more undergraduate summer students, and an early-career researcher. In addition, this project will support a workshop aimed at bringing together experimentalists, glaciologists, and ice modelers to facilitate cross-disciplinary knowledge sharing and collaborative problem solving. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Ice flow is resisted by frictional forces that keep a glacier from immediately sliding into the ocean. Friction comes in two varieties: internal friction within the ice column which resists ice deformation and basal friction which resists ice sliding over its bedrock substrate. Partitioning between internal and basal friction is difficult since both have similar expressions at the most common target for data collection—the ice-sheet surface. However, understanding this partitioning is important because the physical processes that control internal and basal friction act and evolve at different timescales. This project combines spaceborne remote sensing observations from the ice-sheet surface with ice-penetrating radar data that images the internal structure of the ice sheet in order to partition the contribution of each source of friction. Results will advance the fundamental understanding of ice flow and will strengthen projections of future sea-level rise. Broader Impacts of the project include facilitating data reuse for the ice-sheet research community; the strategy for distributing the software toolkit includes student mentorship and hackathon teaching. The researcher will expand the impact of existing ice-penetrating datasets by 1) developing new open-source algorithms for extraction of englacial stratigraphy; 2) creating stratigraphy data products that can be assimilated into future studies of ice motion; and 3) using statistical analyses to integrate radar datasets into larger-scale interpretations with remote sensing datasets of ice-surface velocity, altimetry, climate variables, and model-derived basal friction. The computational tools developed as part of this effort will be integrated and released as a reusable software toolkit for ice-penetrating radar data analysis. The toolkit will be validated and tested by deployment to cloud-hosted JupyterHub instances, which will serve as a singular interface to access radar and remote sensing data, load them into a unified framework, step through a predefined processing flow, and carry out statistical analyses. In some areas, the imaged englacial stratigraphy will deviate from the ice-dynamic setting expected based on surface measurements alone. There, the internal dynamics (or ice-dynamic history) are inconsistent with the surface dynamics, likely because internal friction is poorly constrained and misattributed to basal friction instead. This work will develop the data and statistical tools for constraining internal friction from ice-penetrating radar, making those data products and tools available for future work. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica’s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica’s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth's most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica’s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Iceberg calving is a complex natural fracture process and a dominant cause of mass loss from the floating ice shelves on the margins of the Antarctic ice sheet. There is concern that rapid changes at these ice shelves can destabilize parts of the ice sheet and accelerate their contribution to sea-level rise. The goal of this project is to understand and simulate the fracture mechanics of calving and to develop physically-consistent calving schemes for ice-sheet models. This would enable more reliable estimation of Antarctic mass loss by reducing the uncertainty in projections. The research plan is integrated with an education and outreach plan that aims to (1) enhance computational modeling skills of engineering and Earth science students through a cross-college course and a high-performance computing workshop and (2) increase participation and diversity in engineering and sciences by providing interdisciplinary research opportunities to undergraduates and by deploying new cyberlearning tools to engage local K-12 students in the Metro Nashville Public Schools in computational science and engineering, and glaciology. This project aims to provide fundamental understanding of iceberg calving by advancing the frontiers in computational fracture mechanics and nonlinear continuum mechanics and translating it to glaciology. The project investigates crevasse propagation using poro-damage mechanics models for hydrofracture that are consistent with nonlinear viscous ice rheology, along with the thermodynamics of refreezing in narrow crevasses at meter length scales. It will develop a fracture-physics based scheme to better represent calving in ice-sheet models using a multiscale method. The effort will also address research questions related to calving behavior of floating ice shelves and glaciers, with the goal of enabling more reliable prediction of calving fronts in whole-Antarctic ice-sheet simulations over decadal-to-millennial time scales. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Melting of snow and ice at the surface of the Antarctic ice sheet can lead to the formation of meltwater lakes, an important precursor to ice-shelf collapse and accelerated ice-sheet mass loss. Understanding the present state of Antarctic surface melt provides a baseline to gauge how quickly melt impacts could evolve in the future and to reduce uncertainties in estimates of future sea-level rise. This project will use a suite of complimentary measurements from Earth-observing satellites, ground observations, and numerical climate and ice-shelf models to enhance understanding of surface melt and lakes, as well as the processes linking these systems. The project directly supports the scientific training of a postdoctoral associate and several undergraduate researchers. In addition, it will promote public scientific literacy and the broadening of quantitative skills for high-school students through the development and implementation of an educational unit in a partnership with an education and outreach expert and two high school teachers. Accurate prediction of sea-level contributions from Antarctica critically requires understanding current melting and supraglacial lake conditions. This project will quantify Antarctic surface melt and supraglacial lakes, and the linkages between the two phenomena. Scatterometer data will enable generation of a 19-year multi-sensor melt time series. Synthetic aperture radar data will document melt conditions across all Antarctic ice shelves at the highest spatial resolution to date (40 m). Multispectral satellite imagery will be used to delineate and measure the depth of supraglacial lakes--for the first time studying the spatial and temporal variations of Antarctic supraglacial lakes. Melt and lake observations will be compared to identify agreement and disagreement. Melt observations will be used to evaluate biases in a widely used, reanalysis-driven, regional climate model. This model will then be used to examine climatic and glaciological variables associated with supraglacial lakes. Finally, in situ observations and climate model output will drive a numerical model that simulates the entire lifecycle of surface melt and possible subsequent lake formation.
Ice cores from glaciers and ice sheets provide detailed archives of past environmental conditions, furthering our understanding of Earth’s climate. Microorganisms in the West Antarctic Ice Sheet are buried over glaciological time and form a stratigraphy record providing the opportunity of analysis of the order and position of layers of geological events, with potential links to Southern Hemisphere climate. However, microbial cells that land on the ice sheet are subject to the stresses of changing habitat conditions due to burial and conditions associated with long-term isolation in ice. These processes may lead to a loss of fidelity within the stratigraphic record of microbial cells. We know little about how and if microorganisms survive burial and remain alive over glacial-interglacial time periods within an ice sheet. This analysis will identify the viable and preserved community of microorganisms and core genomic adaptation that permit cell viability, which will advance knowledge in the areas of microbiology and glaciology while increasing fidelity of ice core measurements relevant to past climate and potential future global climate impacts. This exploratory endeavor has the potential to be a transformative step toward understanding the ecology of one of the most understudied environments on Earth. The project will partner with the Museum of Science, Boston, to increase public scientific literacy via education and outreach. Additionally, this project will support two early-career scientists and two undergraduates in interdisciplinary research at the intersection of microbiology and climate science. Results from this project will provide the first DNA data based on single-cell whole genomic sequencing from the Antarctic Ice Sheet and inform whether post-depositional processes impact the interpretations of paleoenvironmental conditions from microbes. The goals to determine the taxonomic identity of viable and preserved microbial cells, and decode the genetic repertoire that confers survival of burial and long-term viability within glacial ice, will be achieved by utilizing subsamples from a ~60,000 year old record of the West Antarctic Ice Sheet Divide (WD) Ice Core. WD samples will be melted using the Desert Research Institute’s ice core melting system that is optimized for glaciobiological sampling. Microbial cells from the meltwater will be sorted using fluorescence-activated cell sorting, and individually sorted cells will have their genomes sequenced. The fluorescence-based methods will discern the viable (metabolically active) cells from those cells that are non-viable but preserved in the ice (DNA-containing). The genomic analysis will identify the taxonomy of each cell, presence of known genes that confer survival in permanently frozen environments, and comparatively analyze genomes to determine the core set of genes required by viable cells to persist in an ice sheet. The outcomes of this work will expand the potential for biological measurements and contamination control from archived ice cores. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This project will develop methods to measure the ratios of carbon-13 to carbon-12, and heavy to light hydrogen in methane in air trapped in ice cores. The ratios of the different forms of carbon and hydrogen are "fingerprints" of different sources of this gas in the past--for example wetlands in the tropics versus methane frozen in the sea floor. Once the analysis method is developed, the measurements will be used to examine why methane changed abruptly in the past, both during the last ice age, and during previous warm periods. The data will be used to understand how methane sources like wildfires, methane hydrates, and wetlands respond to climate change. This information is needed to understand future risks of large changes in methane in the atmosphere as Earth warms. The project involves two tasks. First, the investigators will build and test a gas extraction system for methane isotopic measurements using continuous flow methods, with the goal of equaling or bettering the precision attained by the few other laboratories that make these measurements. The system will be interfaced with existing mass spectrometers at Oregon State University. The system consists of a vacuum chamber and sequence of traps, purification columns, and furnaces that separate methane from other gases and convert it to carbon dioxide or hydrogen for mass spectrometry. Second, the team will measure the isotopic composition of methane across large changes in concentration associated with two past interglacial periods and during abrupt methane changes of the last ice age. These measurements will be used to understand if the main reason for these concentration changes is climate-driven changes in emissions from wetlands, or whether other sources are involved, for example methane hydrates or wildfires. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Understanding ice structure, depth, internal velocity, and basal conditions is key to understanding current and future glacier and ice sheet behavior in Greenland and Antarctica. Most radio glaciology research projects are limited to whatever airborne ice-penetrating radar (IPR) data happens to already exist in the area of interest. Collecting new IPR data is a long and slow process, usually well outside the scope of individual research teams, especially in resource-intensive Antarctic glaciology research. This proposal seeks to field-test and validate two community-driven instruments that help address this gap in Antarctic research: a snowmobile-towed radar as well as a UAV (uncrewed aerial vehicle) system. Both systems are based off a common software control system and share the same code and post-processing tools. As part of this proposal, this code will be made available under an open-source license for other researchers to use and adapt, along with instructions for creating compatible hardware setups from commercially available parts, in order for them to be able to study glaciers and ice sheets at higher capacity and lower cost. The snowmobile-towed radar will be a multi-frequency, polarimetric chirped radar system designed to illuminate thermal, material, and roughness properties at the ice-bed interface. The PEREGRINE UAV system is a chirped radar with 56 MHz of bandwidth built into a small fixed-wing uncrewed aircraft that packs away into a single Pelican case for rapid small-scale surveys. The variables to be measured by these systems are critical observational data for projecting future behavior of the Antarctic ice sheet. The project spans two years and incorporates two seasons of field testing planned for Summit Station, Greenland, due to the need to test on a thick, cold ice sheet as well as the lower cost and risk of supporting instrument testing in the Arctic compared to Antarctica. The period between the field seasons will be used to initiate or continue conversations with researchers interested in incorporating our instruments into future fieldwork or adapting our core radar system into new instruments. This will give us an opportunity to develop new capabilities in response to this feedback and conduct relevant system tests during the second field season. A period after the second field season is reserved for the development of detailed documentation and preparation for the open release of code and systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Hock/1543432 Over the last half century the Antarctic Peninsula has been among the most rapidly warming regions in the world. This has led to increased glacier melt, widespread glacier retreat, ice-shelf collapses, and glacier speed-ups. Many of these changes are driven by changing precipitation and increased melt due to warmer air temperatures. This project will use a combination of two models - a regional atmospheric model and a model of processes at the glacier surface - to simulate future changes in temperature and snowfall, and the resulting changes in glacier mass. The combination of models will be tested against the observational record (since 1979 when satellite observations became available), to verify that it can reproduce observed change, and then run to the year 2100. Results will provide better estimates of the impacts of future climate changes over the Antarctic Pensinsula and the expected glacier mass changes driven by the evolving climate. The project will use the large changes observed on the Peninsula to validate a model framework suitable for understanding the impact of these changes on the glaciers and ice shelves there, with the goal of developing optimally constrained future climate and surface mass change scenarios for the region. The framework will provide both a coherent picture of the impacts of past changes on the region's ice cover, and also the best available constraints on forcings that will determine ice mass loss from this region going forward under a standard scenario. The Weather Forecasting and Research (WRF) Model will be used over the domain of the Antarctic Peninsula and neighboring islands to quantify trends in spatio-temporal patterns of mass change with a focus on surface melt. The WRF model will be enhanced to account for the specific conditions of glacier surfaces, and the modified model will be used to simulate climate conditions and resulting surface mass budgets and melt over the period 1979-2100. Tying modeled past climate changes to the surface and satellite-based observational record will provide a foundation for interpreting projected future change. Results will be validated using available weather station observations, surface mass-balance data, and satellite-derived records of melt. The activity will foster partnerships through collaboration with colleagues in Spain, Germany and The Netherlands and will support an early-career postdoctoral researcher and two graduate students, introduce undergraduate and high-school students to original research and provide training of students through inclusion of data and results in course curriculums.
Prothro, Lindsay; Venturelli, Ryan A; Miller, Lauren
No dataset link provided
Sediments that collect on the seafloor provide a wealth of information about past and present environmental change. Around Antarctica, these seafloor sediments are influenced by an ice sheet that grinds and transports sediments from the continent’s interior into the surrounding ocean. Since the Last Glacial Maximum (about 20,000 years ago) when the ice sheet extended hundreds to thousands of kilometers seaward, ice has retreated inland to the configuration we observe today and left behind signatures of its growth and decline, as well as indicators of ocean change, in the seafloor sediments. Ongoing glacial and ocean processes are reflected in the characteristics of contemporary sediments, whereas older sediments beneath the seafloor offer a longer temporal perspective of changes to the ice sheet and surrounding ocean. Using data generated from archived sediment cores that are predominantly housed in the Antarctic Core Collection at Oregon State University, we aim to confirm if recent sediments clearly reflect the specific instrumental and historical field-based observations of ocean and glacial change seen in different regions of Antarctica. These modern changes will be placed into context with those recorded by sediments deposited on the seafloor hundreds to thousands of years ago. This project will explore interlinked physical, biological, and geochemical properties of seafloor sediments to address the influence of glacial and oceanographic processes on ice-proximal marine sedimentation during the 20th and 21st centuries and since the Last Glacial Maximum, with a focus on sediment fluxes, meltwater drainage, ice-rafted debris deposition, and radiocarbon chronologies. We will integrate multi-proxy analyses to interrogate the seafloor sediment record around Antarctica, targeting regions offshore of relatively fast-flowing and fast-changing glacial systems today and regions offshore of slower flowing, more stable (i.e., unchanging or relatively minimally changing) parts of the ice sheet. This work will leverage the application of new techniques and knowledge to legacy sediment cores that NSF has invested greatly in collecting and archiving. This project is led by three early-career women project investigators who seek to foster collaborative and open research practices and professional growth of the project team which will include three graduate students, numerous undergraduate students, and a postdoctoral research associate. The project team will co-produce educational materials with Math4Science, an organization that connects STEM professionals with public secondary education students and their math and science teachers through curricula; and develop and implement best practices in working with marine sediment core data through a collaboration with the Oregon State University Marine and Geology Repository and the United States Antarctic Program - Data Center. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Earth's atmosphere is a highly oxidizing medium. The abundance of oxidants such as ozone in the atmosphere strongly influences the concentrations of pollutants and greenhouse gases, with implications for human health and welfare. Because oxidants are not preserved in geological archives, knowledge of how oxidants have varied in the past under changing climate conditions is extremely limited. This award will measure a proxy for oxidant concentrations in a West Antarctic ice core over several major climate transitions over the past 50,000 years. These measurements will complement similar measurements from a Greenland ice core, which showed significant changes in atmospheric oxidants over major climate transitions covering this same time period. The addition of measurements from Antarctica will allow researchers to examine if the oxidant changes suggested by the Greenland ice core record are regional or global in scale. Knowledge of how oxidants vary naturally with climate will better inform predictions of the composition of the future atmosphere under a warming climate. This award will support measurements of the isotopic composition of nitrate in a West Antarctic ice core as a proxy for oxidant concentrations in the past atmosphere. The nitrogen isotopes of nitrate provide information on the degree of preservation of nitrate in the ice core record, and thus aid in the interpretation of the observed variability in the observed nitrate concentrations and oxygen isotopes in ice core records. By providing information about the spatial scale of oxidant changes over abrupt climate change events during the last glacial period, this project may also improve our understanding of mechanisms driving these abrupt events. Insight from this project will prove valuable for forecasting the response of stratospheric circulation to climate change, which has large implications for climate feedbacks and tropospheric composition. In addition, the information gleaned from this project on the mechanisms and feedbacks during abrupt climate change events will help determine the likelihood of such rapid events occurring in the future, which would have dramatic impacts on humankind. This award will provide training for one graduate and one undergraduate student, and will support the development of a hands-on activity related to rapid climate change to be used at the annual Polar Science Weekend at the Pacific Science Center in Seattle, WA.
The goal of this project is to drill and recover an ice core from Hercules Dome, Antarctica. The geographic setting of Hercules Dome makes it well-situated to investigate changes in the size of the West Antarctic ice sheet over long time periods. The base of the West Antarctic ice sheet lies below sea level, which makes this part of Antarctica vulnerable to melting from the relatively warm deep water of the Southern Ocean. An important research question is whether the West Antarctic Ice Sheet collapsed during Earth's last prolonged warm period, about 125,000 years ago, when the ocean was warmer and sea level was several meters higher than today. Evidence for or against such a collapse will be recorded in the chemistry and physical properties of the ice. The Hercules Dome ice core will be obtained over three to four field seasons in Antarctica using efficient drilling technology. This grant includes support for project management, pre-drilling science community engagement, ice-core recovery, and education and outreach activities. Hercules Dome is located at the edge of the East Antarctic ice sheet, south of the Transantarctic Mountains at 86 degrees South, 105 degrees West. Glaciological conditions at Hercules Dome are simple, with well-defined layering to the bed, optimal for the recovery of a deep ice core reaching to the last interglacial period at depths between 1600 and 2800 meters. An ice core from Hercules Dome will provide a research opportunity for ice-core analysts and others to make progress on a number of science priorities, including the environmental conditions of the last interglacial period, the history of gases and aerosols, and the magnitude and timing of changes in temperature and snow accumulation over the last 150,000 years. Together with the network of ice cores obtained by U.S. and international researchers over the last few decades, results from Hercules Dome will yield improved estimates of the boundary conditions necessary for the implementation and validation of ice-sheet models critical to the projection of future Antarctic ice-sheet change and sea level. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites Glacier has been accelerating and widening over the past three decades. How fast Thwaites will disintegrate or how quickly it will find a new stable state have become some of the most important questions of the future of the West Antarctic Ice Sheet and its contribution to sea-level rise over the next decades to centuries and beyond. This project will rely on three independent numerical models of ice flow, coupled to an ocean circulation model to (1) improve our understanding of the interactions between the ice and the underlying bedrock, (2) analyze how sensitive the glacier is to external changes, (3) assess the processes that may lead to a collapse of Thwaites, and, most importantly, (4) forecast future ice loss of Thwaites. By providing predictions based on a suite of coupled ice-ocean models, this project will also assess the uncertainty in model projections. The project will use three independent ice-sheet models: Ice Sheet System Model, Ua, and STREAMICE, coupled to the ocean circulation model of the MIT General Circulation Model. The team will first focus on the representation of key physical processes of calving, ice damage, and basal slipperiness that have either not been included, or are poorly represented, in previous ice-flow modelling work. The team will then quantify the relative role of different proposed external drivers of change (e.g., ocean-induced ice-shelf thinning, loss of ice-shelf pinning points) and explore the stability regime of Thwaites Glacier with the aim of identifying internal thresholds separating stable and unstable grounding-line retreat. Using inverse methodology, the project will produce new physically consistent high-resolution (300-m) data sets on ice-thicknesses from available radar measurements. Furthermore, the team will generate new remote sensing data sets on ice velocities and rates of elevation change. These will be used to constrain and validate the numerical models, and will also be valuable stand-alone data sets. This process will allow the numerical models to be constrained more tightly by data than has previously been possible. The resultant more robust model predictions of near-future impact of Thwaites Glacier on global sea levels can inform policy-relevant decision-making. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Reconstructions of past changes in thickness and extent of the Antarctic ice sheet are important for evaluating past and present sea-level change, and for validating numerical models necessary to make realistic predictions of changes under future climate and ocean conditions. Models estimate that the Ross Sea sector was one of the largest contributors to sea-level rise from Antarctica as the ice sheet adjusted during the past ten thousand years from the glacial period to the Holocene. In this sector, ice flow into the embayment comes through West Antarctic ice streams and through East Antarctic outlet glaciers that flow through the Transantarctic Mountains. Observational data constrain the last glacial maximum and the Holocene retreat, but models are necessary to understand the environmental conditions needed for outlet glaciers to reach observed high stands, to fit the observed patterns of retreat, and to understand how the contribution of ice from West Antarctica and from East Antarctica changed over time. The investigators will use available geological and geophysical data in combination with forward ice-flow models and inverse models to investigate the evolution of the four Transantarctic outlet glaciers where sufficient data exist. The objectives of this new modeling are to constrain the glaciological conditions necessary for these glaciers to thicken during the last glacial, thin during the Holocene, and reach their present-day state. By testing specific hypotheses this work contributes to an interdisciplinary effort to understand Holocene deglaciation of the Ross Sea Embayment. In addition, the modeling will address the resolving power of the available data to answer key questions for each target glacier. Broader impacts include mentoring a graduate student, public outreach, incorporation of research into high-school and university classes, and support of an early-career investigator.
Anandakrishnan/1643961 This award supports a project to study conditions under the Rutford Ice Stream, a large glacier that flows from the interior of the West Antarctic Ice Sheet to the Filchner Ronne Ice Shelf and then on to the ocean. The speed and volume of ice delivered to the ocean by this and similar glaciers is central to the question of sea-level change in the coming decades: if the volume of ice carried by Rutford to the ocean increases, then it will contribute to a rise in sea level. Numerical models of glacier flow that are used to forecast future conditions must include a component that accounts for the sliding of the ice over its bed. The sliding process is poorly modeled because of lack of detailed information about the bottom of glaciers, leading to increased uncertainty in the ice-flow models. Data from this project will provide such information. During this project, in collaboration with researchers at the British Antarctic Survey, a detailed survey of the properties of the bed of Rutford Ice Stream will be carried out. These surveys include using seismic instruments (which are sensitive to naturally occurring earthquakes within glaciers--called icequakes) to monitor the distribution of those icequakes at the bed. The locations, size, and timing of icequakes are controlled by the properties of the bed such as porosity, water pressure, and stress. As part of this project, a hole will be drilled to the bed of the glacier to monitor water pressures and to extract a sample of the basal material. By comparing the pressure variations with icequake production, the properties of the basal material over a large area can be better determined. Those results will aid in the application of numerical models by informing their description of the sliding process. This award requires field work in Antarctica. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Current networking capacity at McMurdo Station is insufficient to even be considered “broadband,” with a summer population of up to 1000 people sharing what is equivalent to the connection enjoyed by a typical family of three in the United States. The changing Antarctic ice sheets and Southern Ocean are large, complex systems that require cutting edge technology to do cutting edge research, with remote technology becoming increasingly useful and even necessary to monitor changes at sufficient spatial and temporal scales. Antarctic science also often involves large data-transfer needs not currently met by existing satellite communication infrastructure. This workshop will gather representatives from across Antarctic science disciplines—from astronomy to zoology—as well as research and education networking experts to explore the scientific advances that would be enabled through dramatically increased real-time network connectivity, and also consider opportunities for subsea cable instrumentation. This workshop will assess the importance of a subsea fiber optic cable for high-capacity real-time connectivity in the US Antarctic Program, which is at the forefront of some of the greatest climate-related challenges facing our planet. The workshop will: (1) document unmet or poorly met current scientific and logistic needs for connectivity; (2) explore connectivity needs for planned future research and note the scientific advances that would be possible if the full value of modern cyberinfrastructure-empowered research could be brought to the Antarctic research community; and (3) identify scientific opportunities in planning a fully instrumented communication cable as a scientific observatory. Due to the ongoing COVID-19 pandemic, the workshop will be hosted and streamed online. While the workshop will be limited to invited personnel in order to facilitate a collaborative working environment, broad community input will be sought via survey and via comment on draft outputs. A workshop summary document and report will be delivered to NSF. Increasing US Antarctic connectivity by orders of magnitude will be transformative for science and logistics, and it may well usher in a new era of Antarctic science that is more accessible, efficient and sustainable. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Siddoway, Christine; Thomson, Stuart; Teyssier, Christian
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in progress
No project link provided
in progress
Sediment records off the coast of Marie Byrd Land (MBL), Antarctica suggest frequent and dramatic changes in the size of the West Antarctic Ice Sheet (WAIS) over short (tens of thousands of years) and long (millions of years) time frames in the past. WAIS currently overrides much of MBL and covers the rugged and scoured bedrock landscape. The ice sheet carved narrow linear troughs that reach depths of two to three thousand meters below sea level as outlet glaciers flowed from the interior of the continent to the oceans. As a result, large volumes of fragmented continental bedrock were carried out to the seabed. The glaciers cut downward into a region of crystalline rocks (i.e. granite) whose temperature change as a function of rock depth happens to be significant. This strong geothermal gradient in the bedrock is favorable for determining when the bedrock experienced rapid exhumation or "uncovering". Analyzing the chemistry of minerals (zircon and apatite) within the eroded rocks will provide information about the rate and timing of the glacier removal of bedrock from the Antarctic continent. The research addresses the following questions: When did the land become high enough for a large ice sheet to form? What was the regional pre-glacial topography? Under what climate conditions, and at what point in the growth of an ice sheet, did glaciers begin to cut sharply into bedrock to form the narrow troughs that flow seaward? The research will lead to greater understanding of past Antarctic ice sheet fluctuations and identify precise timing of glacial incision. These results will refine ice sheet history and aid the international societal response to contemporary ice sheet change and its global consequences. The project will contribute to the training of two graduate and two undergraduate students in STEM. The objective is to clarify the onset of WAIS glacier incision and assess the evolution of Cenozoic paleo-topography. Low-temperature (T) thermochronology and Pecube 3-D thermo-kinematic modeling will be applied to date and characterize episodes of glacial erosional incision. Single-grain double- and triple-dating of zircon and apatite will reveal the detailed crustal thermal evolution of the region enabling the research team to determine the comparative topographic influences on glaciation versus bedrock uplift induced by Eocene to present tectonism/magmatism. High-T mineral thermochronometers across Marie Byrd Land (MBL) record rapid extension-related cooling at ~100 Ma from temperatures of >800 degrees C to ≤ 300 degrees C. This signature forms a reference horizon, or paleogeotherm, through which the Cenozoic landscape history using low-T thermochronometers can be explored. MBL's elevated geothermal gradient, sustained during the Cenozoic, created favorable conditions for sensitive apatite and zircon low-T thermochronometers to record bedrock cooling related to glacial incision. Students will be trained to use state-of-the-art analytical facilities in Arizona and Minnesota, expanding the geo- and thermochronologic history of MBL from bedrock samples and offshore sedimentary deposits. The temperature and time data they acquire will provide constraints on paleotopography, isostasy, and the thermal evolution of MBL that will be modeled in 3D using Pecube model simulations. Within hot crust, less incision is required to expose bedrock containing the distinct thermochronometric profile; a prediction that will be tested with inverse Pecube 3-D models of the thermal field through which bedrock and detrital samples cooled. Using results from Pecube, the ICI-Hot team will examine time-varying topography formed in response to changes in erosion rates, topographic relief, geothermal gradient and/or flexural isostatic rigidity. These effects are manifestations of dynamic processes in the WAIS, including ice sheet loading, ice volume fluctuations, relative motion upon crustal faults, and magmatism-related elevation increase across the MBL dome. The project makes use of pre-existing sample collections housed at the US Polar Rock Repository, IODP's Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
van der Veen, Cornelis; Stearns, Leigh; Paden, John
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Van der Veen/1543530 The objective of this research is to gain better understanding of the West Antarctic ice flow in the transition region from grounded ice to floating ice shelves and investigate the conditions that can initiate and sustain major retreat of these glaciers. Several major Antarctic outlet glaciers and ice streams will be investigated using a suite of observational techniques and modeling tools. Glaciers include Thwaites Glacier, which has become a focal point in the discussion of West Antarctic retreat, Whillans Ice Stream as an example of the archetype ice stream, and Byrd Glacier, a major outlet glacier draining East Antarctica through the Transantarctic Mountains into the Ross Ice Shelf. This study will investigate whether the ongoing changes in these glaciers will lead to long-term mass loss (the onset of ice sheet collapse), or whether these glaciers will quickly stabilize with a new geometry. To adequately incorporate the dynamic behavior of outlet glaciers and ice streams requires inclusion of the relevant physical processes, and the development of regional models that employ a numerical grid with a horizontal grid spacing sufficiently refined to capture smaller-scale bed topographic features that may control the flow of these glaciers. This award revisits the issue of stability of marine-terminating glaciers whose grounding line is located on a retrograded bed slope. In particular, an attempt will be made to resolve the question whether observed rapid changes are the result of perturbations at the terminus or grounding line, or whether these changes reflect ice-dynamical forcing over the grounded reaches. High-resolution satellite imagery will be used to investigate ice-flow perturbations on smaller spatial scales than has been done before, to evaluate the importance of localized sites of high basal resistance on grounding-line stability. This collaborative project involves a range of modeling strategies including force-budget analysis, flow-band modeling, Full Stokes modeling for local studies, and using the Ice Sheet System Model developed at JPL for regional modeling. Broader Impacts include training two graduate students in computer simulations and ice sheet modeling algorithms. The work will also expand on a web-based interactive flowline model, so that it includes more realistic grounding line dynamics.
Estimating Antarctic ice sheet growth or loss is important to predicting future sea level rise. Such estimates rely on field measurements or remotely sensed based observations of the ice sheet surface, ice margins, and or ice shelves. This work examines the introduction of freshwater into the ocean to surrounding Antarctica to track meltwater from continental ice. Polar ice is depleted in two stable isotopes, 18O and D, deuterium, relative to Southern Ocean seawater and precipitation. Measurements of seawater isotopic composition in conjunction with precise observations of seawater temperature and salinity, will permit discrimination of freshwater derived from melting glacial ice from that derived from regional precipitation or sea ice melt. This research describes an accepted method for determining rates and locations of meltwater entering the oceans from polar ice sheets. As isotopic and salinity perturbations are cumulative in many Antarctic coastal seas, the method allows for the detection of any marked acceleration in meltwater introduction in specific regions, using samples collected and analyzed over a period of years to decades. Impact of the project derives from use of an independent method capable of constraining knowledge about current ice sheet melt rates, their stability and potential impact on sea level rise. The project allows for sample collection taken from foreign vessels of opportunity sailing in Antarctic waters, and subsequent sharing and interpretation of data. Research partners include the U.S., Korea, China, New Zealand, the United Kingdom, and Germany. Participating collaborators will collect seawater samples for isotopic and salinity analysis at Stanford University. USAP cruises will concentrate on sampling the Ross Sea, and the West Antarctic. The work plan includes interpretation of isotopic data using box model and mixing curve analyses as well as using isotope enabled ROMS (Regional Ocean Modeling System) models. The broader impacts of the research will include development of an educational module that illustrates the scientific method and how ocean observations help society understand how Earth is changing.
Ice cores are a vital source of information about past climate. Research that utilizes ice cores benefits from an undamaged ice-core record. There is often a zone within ice sheets where the ice is brittle upon extraction in a core. Brittle-ice behavior occurs when the rapid decompression of the core as it is being extracted from the ice-sheet results in extensive fracturing. Ice from this zone can compromise the undamaged record. This project seeks to improve our understanding of the mechanisms involved in brittle-ice behavior and onset, with the goal of helping to guide field-site operations, core handling preparation, and planned laboratory measurement techniques for future ice-coring projects, including the upcoming work at Hercules Dome. This project requires no field work, as it will use existing observations and existing ice cores to gain an understanding of brittle ice. This is a high-risk and timely proposal that is early-concept and exploratory in nature, making it appropriate for the EAGER solicitation. The project will support an early-career researcher and provide training for a master’s student who is a woman. And, finally, the project will develop educational and outreach materials for graduate and undergraduate courses and elementary schools. This project will examine and catalog brittle ice from several existing ice-core samples to specifically assess various ice physical properties affecting brittleness potential, including bubble size and number-density, ice fabric, grain statistics, fracture characteristics, and the location and properties of grain and subgrain boundaries. End members of this sample assessment have been identified and include Siple Dome, which exhibited major brittle behavior and damage, and South Pole ice core, which exhibited very-minor brittle behavior and almost no damage. Output datasets will include calibrated relationships for bubble number-density, mean grain and bubble sizes, subgrain prevalence and orientation, and a usable indicator for estimating brittle-ice onset and magnitude. There is an immediate applicability of results from this effort for the Hercules Dome drilling project. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The goal of this study is to identify and distinguish different source areas of glacial sediment in the McMurdo Dry Valleys, Antarctica to determine past glacial flow direction. Understanding ice flow is critical for determining how the Antarctic Ice Sheets have behaved in the past. Such insight is fundamental for allowing scientists to predict how the Antarctic Ice Sheets will evolve and, in turn, forecast how much and how fast sea level may rise. The project study site, the McMurdo Dry Valleys, contain a tremendous record of glacial deposits on land that extends back at least 14 million years. Chemistry of the rocks within the glacial deposits hold clues to the sources of ice that deposited the material. The chemical analyses of the glacial deposits will allow mapping of the former extent of glaciations providing a better understand of ice flow history. The mapping of the largest ice sheet expansion of the past 14 million years in the McMurdo Dry Valleys is of broad interest to the global climate change community. Undergraduate students comprise the majority of the field teams and will be responsible for sample preparation and analysis in the laboratory. This project utilizes new geochemical techniques to test hypotheses about the source, extent, and flow patterns of the glacier ice that deposited glacial tills in the McMurdo Dry Valleys, Antarctica (MDV). The MDV contain an unparalleled terrestrial archive of glacial deposits, which record multiple sources of ice that deposited them. These include the northeast flowing ice that overrode the Transantarctic Mountains, the eastward expansion of the East Antarctic Ice Sheet, the westward extension of the Ross Ice Shelf representing an expansion of the West Antarctic Ice Sheet, and the growth of local alpine glaciers. The glacial tills and drifts in the Antarctic are typically isolated in patches or disjointed outcrop patterns making it difficult to correlate tills and determine their source. This project will undertake a systematic study of the tills in the McMurdo Dry Valleys to determine their provenance with a variety of geochemical techniques including major and minor element analyses with X-ray fluorescence, heavy mineral composition, soil salt concentration, and determining the uranium-lead (U-Pb) ages of zircon sands contained in these tills. The primary tool will be the age distribution of the population of detrital zircon in a glacial drift because it reflects the source of the tills and provides a unique geochemical "fingerprint" used to distinguish source areas while correlating units across different sites. A deliverable from this project will be a community available library of zircon fingerprints for mapped glacial tills from archived samples at the Polar Rock Repository and the systematic collection of samples in the MDV. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Walker, Catherine; Zhang, Weifeng; Seroussi, Helene
No dataset link provided
Most of the mass loss from the Antarctic Ice Sheet, a major contributor to sea level rise, occurs at its margins, where ice meets the ocean. Glaciers and ice streams flow towards the coast and can go afloat over the water, forming ice shelves. Ice shelves make up almost half of the entire Antarctic coastline, and hold back the flow of inland ice in Antarctica continent; thus they are integral to the overall stability of the Antarctic Ice Sheet. Ice shelves lose mass by two main processes: iceberg calving and basal melting. Temporal and spatial fluctuations in both are driven by various processes; a major driver of ice shelf melt is the heat provided by the neighboring Southern Ocean. Ocean heat, in turn, is driven by various aspects of the ice shelf environment. One of the most significant contributors to changes in the ocean’s heat content is the presence of sea ice. This research will focus on the effects of coastal polynyas (areas of open water amidst sea ice), how they modulate the local ocean environment, and how that environment drives ice shelf basal melting. To date, the relationship between polynyas and ice shelf melt has not been characterized on an Antarctic-wide scale. Understanding the feedbacks between polynya size and duration, ocean stratification, and ice shelf melt, and the strength of those feedbacks, will improve the ability to characterize influences on the long-term stability of ice shelves, and in turn, the Antarctic Ice Sheet as a whole. A critical aspect of this study is that it will provide a framework for understanding ice shelf-ocean interaction across a diverse range of geographic settings. This, together with improvements of various models, will help interpret the impacts of future climate change on these systems, as their responses are likely quite variable and, overall, different from the large-scale response of the ice sheet. This project will also provide a broader context to better design future observational studies of specific coastal polynya and ice shelf processes. This study focuses on four main hypotheses: 1) Variations of coastal polynya extent are correlated with those of the ice shelf melt rates, and this correlation varies around Antarctica; 2) Polynya extent modulates a feedback between ice shelf melt and accretion regimes through stratification of local waters; 3) Polynya extent together with seafloor bathymetry regulate the volume of warm offshore waters that reach ice margins; and 4) The strength of the feedback between polynya and glacier ice varies with geographic setting and influences the long-term stability of the glacial system. Observational data, including ice-penetrating radar, radar and laser altimetry, and in situ hydrographic data, and derived data sets from the Southern Ocean State Estimate (SOSE) project and BedMachine Antarctica, will be used in conjunction with ocean (MIT global circulation model, MITgcm) and ice sheet (Ice sheet and Sea-level System Model, ISSM) models to reveal underlying dynamics. The joint analysis of the observational data enables an investigation of polynya, ocean, and ice shelf signals and their interplay over time across a range of settings. The results of this data analysis also provide inputs and validation data for the modeling tasks, which will allow for characterization of the feedbacks in our observations. The coupled modeling will enable us to examine the interaction between polynya circulation and ice shelves in different dynamical regimes and to understand ice and ocean feedback over time. Diagnosing and interpreting the pan-Antarctic spatial variability of the polynya-ice shelf interaction are the main objectives of this research and separates this study from other projects targeted at the interactive processes in specific regions. As such, this research focuses on seven preliminary target sites around the Antarctic coast to establish a framework for interpreting coupled ice shelf-ocean variability across a diverse range of geographic settings. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Ice cores provide valuable records of past climate such as atmospheric concentrations of greenhouse gasses and unmatched evidence of past abrupt climate change. Key to understanding past climate changes are the measurements of annual layers that are used to determine the age of the ice, and the timing and pace of major climate events. The current measurement limit for annual layers in ice cores is at the centimeter scale. This project aims to improve the depth resolution of measurements of the chemical impurities in ice using measurements such as electrical conductivity, hyperspectral imaging, major elements measured with laser ablation, and ice grain properties. This will advance understanding of the preservation and layering in ice cores and improve the accuracy and length of annual timescales for existing ice cores. Most of the past time preserved in an ice core is near the bed where the layers have been thinned to only a fraction of their original thickness. Interpreting highly compressed portions of ice cores is increasingly important as projects target climate records in basal ice, and old ice recovered from blue-ice areas. This project will integrate precisely co-registered electrical conductivity measurements, hyperspectral imaging, laser ablation mass spectrometer measurements of impurities, and ice physical properties to investigate sub-centimeter chemical and physical variations in polar ice. Critical to resolving thin ice layers is understanding the across-core variations that may obscure or distort the vertical layering. Analyses will be focused on samples from the WDC-06A (WAIS Divide), SPC-14 (South Pole), and GISP2 (Greenland Ice Sheet Project 2) ice cores that have well-established seasonal cycles that yielded benchmark timescales, as well a large-diameter ice core from the Allan Hills blue ice area. This work will develop state-of-the-art instrumentation and FAIR (findable, accessible, interoperable, and reusable) data handling workflow at the National Science Foundation Ice Core Facility available to the community both to enhance understanding of existing ice cores, and for use in future projects. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Non-Technical Description: Snow accumulation in the interior of the Antarctic Ice Sheet, and how much snow is redistributed by wind are important components of the climate system of Antarctica, yet remain largely unknown. Because of the extreme meteorological conditions found in Antarctica, direct observations of snowfall and related weather are few, leaving a gap in the regional climate records in the continent. Snow accumulation across the Antarctic Ice Sheet is a critical component for the assessment of the contribution of Antarctica to sea level rise, and accurate measurements are required to evaluate results from regional climate models, used to reconstruct climate trends of the recent past for the whole ice sheet. Owing to the size of Antarctica alone, small fluctuations in the total snow accumulation at the surface have a significant effect on the mass budget of the ice sheet and thus on global sea level. In this work will develop an instrument suite for deployment at the South Pole research station in Antarctica. The monitoring station will have new state-of-the-art sensors will record measurements of weather, snow accumulation, and structural conditions within the layer of packed snow. The autonomous system will be tested in the coldest and darkest winter on the planet, and will provide the first continuous measurements of snow accumulation processes in the interior of the ice sheet, which will be used to validate atmospheric and regional climate models. Technical Description: The overarching goal of the proposed work is to improve our understanding of the spatiotemporal variability in ice-sheet surface mass balance and densification rates within the layer of firn, a layer roughly 100 m thick consisting of the buried and compacted snow that has yet to densify into solid ice. For this, we will A) design and install a cost-efficient, reliable, and easily deployable surface mass balance and firn monitoring system for Antarctica; B) adapt the system to operate autonomously for long periods of time under the harshest meteorological conditions; C) use observations for evaluation of surface mass balance simulated by atmospheric reanalyzes and regional climate model; and D) measure the surface mass balance, surface density, and firn compaction rates to derive ice sheet surface elevation change in areas with low ice dynamics. The set up of the monitoring station is unique in that it is able to monitor separately height change due to surface mass balance variability and absolute surface mass balance, the latter in units of water equivalence, and differentiation of the two is crucial for understanding the role of surface processes in ice sheet mass balance. An installed sonic ranger will provide hourly measurements of surface height change that is due to snow accumulation. Surface height change alone is not sufficient to evaluate atmospheric models of surface mass balance, which is measured in in units of mass; a key variable missing is density. To overcome this, the system will be equipped with a SnowFox sensor that is able to capture the variations in surface mass balance in terms of mass through time. Combining the height change with mass change will allow us to determine the density of the material as well, which is very important for conversion of observed height changes due to surface processes into mass changes. Therefore, we aim to better evaluate the short-term variability in surface height and mass fluctuations due to surface mass balance to improve our understanding of the total mass change and to evaluate atmospheric models, which are typically used for ice sheet-wide mass balance studies.
The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington's annual Polar Science Weekend in Seattle, and art-science collaboration. This project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a "Raymond Bump") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). An important part of understanding future climate change is predicting changes in how fast the ice in Antarctica is moving. If ice flows more quickly towards the ocean, it will have a direct impact on sea level rise. One of the things that can influence the ice flow is the type of rock below the ice coverage in Antarctica. Sedimentary basins are large regions where sedimentary rocks accumulated in the past, often under ancient seas. It has been observed that where there are sediments below the ice, the ice can flow faster. This project seeks to understand what is below the ice and how the underlying rock influences the ice flow. Is it hard, crystalline rock? Is it a sedimentary basin? What is the relationship between sediments and ice flow? The answers to these questions will be addressed by using a combination of available data and geophysical methods. Information from well-known rock-types will be used to train the computer to recognize these features by using an application of artificial intelligence known as machine learning, which will help the characterization and identification of unknown sedimentary basins beneath the ice. The results of this project will be disseminated to a broad audience by holding workshops for teacher and students to explain our findings under the ice and to introduce the machine learning technique. Open-source codes used during this project will be made available for use in higher-level classrooms as well as in further studies. To date, no comprehensive distribution of onshore and offshore sedimentary basins over Antarctica has been developed. A combination of large-scale datasets will be used to characterize known basins and identify new sedimentary basins to produce the first continent-wide mapping of sedimentary basins and provide improved basal parametrizations conditions that have the potential to support more realistic ice sheet models. Available geophysical compilations of data and the location of well-known sedimentary basins will be used to apply an ensemble machine learning algorithm. The machine learning algorithm will learn complex relationships by voting among a collection of randomized decision trees. The gravity signal related to sedimentary basins known from other (e.g. seismic) techniques will be evaluated and unknown basins from aerogravity data regression analyses will be proposed by calculating a gravity residual that reflects density inhomogeneities. The gravimetric sedimentary basins identified from the regression analyses will be compared with an independent method of identifying sedimentary distribution, the Werner deconvolution method of estimating depth to magnetic sources. The hypothesis, which is sedimentary basins are correlated to fast ice flow behavior, will be tested by comparing the location of the sedimentary basins with locations of high ice flow by using available ice velocity observations. A relationship between sedimentary basins and ice streams will be defined qualitatively and quantitatively, aiming to evaluate if there are ice streams where no sedimentary basins are reported, or sedimentary basins with no ice streams related. The findings of these project can confirm if the presence of abundant sediments is a pre-requisite for ice streaming. Analyzing previously known sedimentary basins and identifying new ones in Antarctica is central to evaluating the influence of subglacial sediments on the ice sheet flow. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Aschwanden/1644277 This award supports a project to study the phenomenon of the rain shadow (technically called orographic precipitation) in the Antarctic Peninsula and its interaction with a mountain range covered in ice and snow. Orographic precipitation gives rise to the largest climatic and ecological gradients on Earth. Air ascending on the windward side of the mountain range expands and cools, condensing the water vapor it carries and producing heavy rain- or snow-fall. As the air descends on the leeward flank, the air warms and dries out, leaving little-to-no precipitation. This pattern of snowfall, caused by the interaction of winds and the landscape, is hypothesized to control the shape of the ice cap itself. The investigators hypothesize that feedbacks between precipitation and topography control ice flux and temperature, impacting basal conditions (frozen versus wet) and motion, which over long time scales can affect basal topography via erosion. The authors propose to investigate the feedbacks between orographically driven precipitation, ice dynamics, thermodynamics, and basal erosion and uplift over the northern Antarctic Peninsula by coupling an orographic precipitation model to the Parallel Ice Sheet Model (PISM). Using idealized and more realistic geometries, they will begin with a 2-D flow band model, which will be expanded into three dimensions to determine the strength of the feedbacks as a function of bedrock geometry and the intensity of the orographic precipitation gradient. The Antarctic Peninsula is targeted as the ideal case study, in the context of its rapid modern and future change as well as its deflation since the Last Glacial Maximum. The broader impacts of the work include the strengthening of predictive models by capturing feedbacks related to orographic precipitation not included in current models. This is likely to provide a more realistic assessment of the impacts of orographic precipitation in a regime of changing climate. The project will support an early career scientist and a female mid-career scientist and will support one PhD student, and provide summer research experience for one undergraduate student as an REU supplement. The project does not require field work in the Antarctic.
This project will conduct basic research into geological dating techniques that are useful for determining the age of glacial deposits in polar regions, Antarctica in particular. These techniques are necessary for determining how large the polar ice sheets were in the geologic past, including during past periods of warm climate that likely resemble present and near-future conditions. Thus, they represent an important technical capability needed for estimating the response of polar ice sheets to climate warming. Because changes in the size of polar ice sheets are the largest potential contribution to future global sea-level change, this capability is also relevant to understanding likely sea-level impacts of future climate change. The research in this project comprises several observational and experimental approaches to improving the speed, efficiency, cost, and accuracy of these techniques, as well as a scientific outreach program aimed at making the resulting capabilities more broadly available to other researchers. The project supports a postdoctoral scholar and contributes to human resources development in polar and climate science. The project focuses on several areas of cosmogenic-nuclide geochemistry, which is a geochemical dating method that relies on the production and decay of cosmic-ray-produced radionuclides in surface rocks. Measurements of these nuclides can be used to quantify the duration of surface exposure and ice cover at locations in Antarctica that are covered and uncovered by changes in the size of the Antarctic ice sheets, thus providing a means of reconstructing past ice-sheet change. The first proposed set of experiments are aimed at implementing a 'virtual mineral separation' approach to cosmogenic noble gas analysis that may allow measurement of nuclide concentrations in certain minerals without physically separating the minerals from the host rock. If feasible, this would realize significant speed and cost improvements for this type of analysis. A second set of experiments will focus on means of identifying and quantifying non-cosmogenic background inventories of some relevant nuclides, which is intended to improve the measurement sensitivity and precision for cosmic-ray-produced inventories of these nuclides. A third focus area aims to improve capabilities to measure multiple cosmic-ray-produced nuclides in the same sample, which has the potential to improve the accuracy of dating methods based on these nuclides and to expand the situations in which these methods can be applied. If successful, these experiments are likely to improve a number of applications of cosmogenic-nuclide geochemistry relevant to Antarctic research, including subglacial bedrock exposure dating, dating of multimillion-year-old glacial deposits, and surface-process studies useful in understanding landform evolution and ecosystem dynamics. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The purpose of this project is to use geological data that record past changes in the Antarctic ice sheets to test computer models for ice sheet change. The geologic data mainly consist of dated glacial deposits that are preserved above the level of the present ice sheet, and range in age from thousands to millions of years old. These provide information about the size, thickness, and rate of change of the ice sheets during past times when the ice sheets were larger than present. In addition, some of these data are from below the present ice surface and therefore also provide some information about past warm periods when ice sheets were most likely smaller than present. The primary purpose of the computer model is to predict future ice sheet changes, but because significant changes in the size of ice sheets are slow and likely occur over hundreds of years or longer, the only way to determine whether these models are accurate is to test their ability to reproduce past ice sheet changes. The primary purpose of this project is to carry out such a test. The research team will compile relevant geologic data, in some cases generate new data by dating additional deposits, and develop methods and software to compare data to model simulations. In addition, this project will (i) contribute to building and sustaining U.S. science capacity through postdoctoral training in geochronology, ice sheet modeling, and data science, and (ii) improve public access to geologic data and model simulations relevant to ice sheet change through online database and website development. Technical aspects of this project are primarily focused on the field of cosmogenic-nuclide exposure-dating, which is a method that relies on the production of rare stable and radio-nuclides by cosmic-ray interactions with rocks and minerals exposed at the Earth's surface. Because the advance and retreat of ice sheets results in alternating cosmic-ray exposure and shielding of underlying bedrock and surficial deposits, this technique is commonly used to date and reconstruct past ice sheet changes. First, this project will contribute to compiling and systematizing a large amount of cosmogenic-nuclide exposure age data collected in Antarctica during the past three decades. Second, it will generate additional geochemical data needed to improve the extent and usefulness of measurements of stable cosmogenic nuclides, cosmogenic neon-21 in particular, that are useful for constraining ice-sheet behavior on million-year timescales. Third, it will develop a computational framework for comparison of the geologic data set with existing numerical model simulations of Antarctic ice sheet change during the past several million years, with particular emphasis on model simulations of past warm periods, for example the middle Pliocene ca. 3-3.3 million years ago, during which the Antarctic ice sheets are hypothesized to have been substantially smaller than present. Fourth, guided by the results of this comparison, it will generate new model simulations aimed at improving agreement between model simulations and geologic data, as well as diagnosing which processes or parameterizations in the models are or are not well constrained by the data. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Hydroxyl radicals are responsible for removal of most atmospheric trace gases, including pollutants and important greenhouse gases. They have been called the "detergent of the atmosphere". Changes in hydroxyl radical concentration in response to large changes in reactive trace gas emissions, which may happen in the future, are uncertain. This project aims to provide the first estimates of the variability of atmospheric hydroxyl radicals since about 1880 AD when anthropogenic emissions of reactive trace gases were minimal. This will improve understanding of their stability in response to large changes in emissions. The project will also investigate whether ice cores record past changes in Southern Hemisphere westerly winds. These winds are a key component of the global climate system, and have an important influence on ocean circulation and possibly on atmospheric carbon dioxide concentrations. The project team will include three early career scientists, a postdoctoral researcher, and graduate and undergraduate students, working in collaboration with senior scientists and Australian collaborators. Firn air and shallow ice to a depth of about 233 m will be sampled at the Law Dome high-accumulation coastal site in East Antarctica. Trapped air will be extracted from the ice cores on site immediately after drilling. Carbon-14 of carbon monoxide (14CO) will be analyzed in firn and ice-core air samples. Corrections will be made for the in situ cosmogenic 14CO component in the ice, allowing for the atmospheric 14CO history to be reconstructed. This 14CO history will be interpreted with the aid of a chemistry-transport model to place the first observational constraints on the variability of Southern Hemisphere hydroxyl radical concentration after about 1880 AD. An additional component of the project will analyze Krypton-86 in the firn-air and ice-core samples. These measurements will explore whether ice-core Krypton-86 acts as a proxy for barometric pressure variability, and whether this proxy can be used in Antarctic ice cores to infer past movement of the Southern Hemisphere westerly winds. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The western portion of the Antarctic continent is very active in terms of plate tectonic processes that can produce significant variations in the Earths mantle temperature as well as partial melting of the mantle. In addition to these internal processes, the ice sheet in western Antarctica is melting due to Earths warming climate and adding water to the ocean. These changes in ice mass cause adjustments in rocks within the Earth's crust, allowing the surface to rebound in some locations and fall in others, altering the geographical pattern of sea-level change. However, the solid Earth response depends strongly on the strength of the rocks at a wide range of timescales which is not well-known and varies with temperature and other rock properties. This project has three primary goals. (1) It will assess how processes such as rifting, mantle upwelling and lithospheric instability have altered the lithosphere and underlying asthenosphere of western Antarctica, contributing to a planet-wide understanding of these processes. (2) It will use new measurements of mantle and crust properties to estimate the rate at which heat from the solid Earth flows into the base of the ice, which is important for modeling the rates at which the ice melts and flows. (3) It will places bounds on mantle viscosity, which is key for modeling the interaction of the solid Earth with changing ice and water masses and their implications for sea-level rise. To accomplish these goals, new resolution of crust and mantle structure will be obtained by analyzing seismic waves from distant earthquakes that have been recorded at numerous seismic stations in Antarctica. These analyses will include new combinations of seismic wave data that provide complementary information about mantle temperature, heat flow and viscosity. This project will provide educational and career opportunities to a Brown University graduate student, undergraduates from groups underrepresented in science who will come to Brown University for a summer research program, and other undergraduates. The project will bring together faculty and students for a seminar at Brown that explores the connections between the solid Earth and ice processes in Antarctica. Project research will be incorporated in outreach to local public elementary schools and high schools. This research addresses key questions about mantle processes and properties in western Antarctica. What are the relative impacts of rifting, mantle plumes, and lithospheric delamination in the evolution of the lithosphere and asthenosphere? Where is topography isostatically compensated, and where are dynamic processes such as plate flexure or tractions from 3-D mantle flow required? What are the bounds on heat flow and mantle viscosity, which represent important inputs to models of ice sheet evolution and its feedback from the solid Earth? To address these questions, this project will measure mantle and crust properties using seismic tools that have not yet been applied in Antarctica: regional-scale measurement of mantle attenuation from surface waves; Sp body wave phases to image mantle velocity gradients such as the lithosphere-asthenosphere boundary; and surface wave amplification and ellipticity. The resulting models of seismic attenuation and velocity will be jointly interpreted to shed new light on temperature, bulk composition, volatile content, and partial melt, using a range of laboratory-derived constitutive laws, while considering data from mantle xenoliths. To test the relative roles of rifting, mantle plumes, and delamination, and to assess isostatic support for Antarctic topography, the predictions of these processes will be compared to the new models of crust and mantle properties. To improve bounds on western Antarctic heat flow, seismic attenuation and velocity will be used in empirical comparisons and in direct modeling of vertical temperature gradients. To better measure mantle viscosity at the timescales of glacial isostatic adjustment, frequency-dependent viscosity will be estimated from the inferred mantle conditions. This project will contribute to the education and career development of the following: a Brown University Ph.D. student, Brown undergraduates, and undergraduates from outside the university will be involved through the Department of Earth, Environmental and Planetary Sciences (DEEPS) Leadership Alliance NSF Research Experience for Undergraduates (REU) Site which focuses on geoscience summer research experiences for underrepresented students. The project will be the basis for a seminar at Brown that explores the connections between the solid Earth and cryosphere in Antarctica and will contribute to outreach in local public elementary and high schools. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Nontechnical abstract Presently, Antarctica’s glaciers are melting as Earth’s atmosphere and the Southern Ocean warm. Not much is known about how Antarctica’s ice sheets might respond to ongoing and future warming, but such knowledge is important because Antarctica’s ice sheets might raise global sea levels significantly with continued melting. Over time, mud accumulates on the sea floor around Antarctica that is composed of the skeletons and debris of microscopic marine organisms and sediment from the adjacent continent. As this mud is deposited, it creates a record of past environmental and ecological changes, including ocean depth, glacier advance and retreat, ocean temperature, ocean circulation, marine ecosystems, ocean chemistry, and continental weathering. Scientists interested in understanding how Antarctica’s glaciers and ice sheets might respond to ongoing warming can use a variety of physical, biological, and chemical analyses of these mud archives to determine how long ago the mud was deposited and how the ice sheets, oceans, and marine ecosystems responded during intervals in the past when Earth’s climate was warmer. In this project, researchers from the University of South Florida, University of Massachusetts, and Northern Illinois University will reconstruct the depth, ocean temperature, weathering and nutrient input, and marine ecosystems in the central Ross Sea from ~17 to 13 million years ago, when the warm Miocene Climate Optimum transitioned to a cooler interval with more extensive ice sheets. Record will be generated from new sediments recovered during the International Ocean Discovery Program (IODP) Expedition 374 and legacy sequences recovered in the 1970’s during the Deep Sea Drilling Program. Results will be integrated into ice sheet and climate models to improve the accuracy of predictions. The research provides experience for three graduate students and seven undergraduate students via a multi-institutional REU program focused on increasing diversity in Antarctic Earth Sciences. Technical Abstract Deep-sea sediments reveal that the Miocene Climatic Optimum (MCO) was the warmest climate interval of the last ~20 Ma, was associated with global carbon cycle changes and ice growth, and immediately preceded the Middle Miocene Climate Transition (MMCT; ~14 Ma), one of three major intervals of Antarctic ice expansion and global cooling. Ice-proximal studies are required to assess: where and when ice grew, ice sheet extent, continental shelf geometry, high-latitude heat and moisture supply, oceanic and/or atmospheric temperature influence on ice dynamics, regional sea ice extent, meltwater input, and regions of bottom water formation. Existing studies indicate that ice expanded beyond the Transantarctic Mountains and onto the prograding Ross Sea continental shelf multiple times between ~17 and 13.5 Ma. However, these records are either too ice-proximal/terrestrial to adequately assess ocean-ice interactions or under-studied. To address this data gap, this work will: 1) generate micropaleontologic and geochemical records of oceanic and atmospheric temperature, water depth, ocean circulation, and paleoproductivity from existing Ross Sea marine sedimentary sequences, and 2) use these proxy records to test the hypothesis that dynamic glacial expansion in the Ross Sea sector during the MCO was driven by heat and moisture transport to the high latitudes during an interval of enhanced climate sensitivity. Downcore geochemical and micropaleontologic studies will focus on an expanded (120 m/my) early to middle Miocene (~17-16 Ma) diatom-bearing/rich mudstone/diatomite unit from IODP Site U1521, drilled on the Ross Sea continental shelf. A hiatus (~16-14.6 Ma) suggests ice expansion during the MCO, followed by diamictite to mudstone unit indicative of slight retreat (14.6 -14 Ma) immediately preceding the MMCT. Data from Site U1521 will be integrated with foraminiferal geochemical and micropaleontologic data from DSDP Leg 28 (1972/73) and RISP J-9 (1978-79) to develop a MCO to late Miocene regional view of ocean-ice sheet interactions using legacy core material previously processed for foraminifera. This integrated record will: 1) document the timing and extent of glacial advances and retreats across the prograding Ross Sea shelf during the middle and late Miocene, 2) provide orbital-scale paleotemperature reconstructions (TEX86, Mg/Ca, δ18O, MBT/CBT) to establish atmosphere-ocean-ice interactions during an extreme high-latitude warm interval, and 3) provide orbital-scale nutrient/paleoproductivity, ocean circulation, and paleoenvironmental data required to assess climate feedbacks associated with Miocene Antarctic ice sheet and global climate system development. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Non-Technical abstract The physical state of the mantle beneath the Antarctic Ice Sheet plays a key role in the interaction between the Antarctic ice cover and the solid earth, strongly influencing the glacial system's evolution. Generally, mantle temperature profiles are determined by analyzing rock samples from the mantle to determine pressure-temperature conditions, and/or by conversion of seismic velocity anomalies to temperature anomalies. However, mantle rocks have been found only in a very few places in Antarctica, and seismic anomalies reflect not only thermal anomalies but also compositional variations. In this project, the investigators will (1) use the most recent geophysical datasets sensitive to temperature and composition (high-resolution seismic velocity model, topography, satellite gravity), (2) Combine the sensitivity of these datasets in a to retrieve the most reliable model of thermal and compositional structure, (3) translate the results into 2-dimensional maps of temperature slices and the composition of iron in the mantle,(4) compare the results with results from other continents to better understand Antarctic geological history, and (5) use the new thermal model along with established rock relationships to estimate mantle viscosity. Technical abstract The thermochemical structure of the lithosphere beneath Antarctica is fundamental for understanding the geological evolution of the continent and its relationship to surrounding Gondwana continents. In addition, the thermal structure controls the solid earth response to glacial unloading, with important implications for ice sheet models and the future of the West Antarctic Ice Sheet. However, it is challenging to get an accurate picture of temperature and composition from only sparse petrological/geochemical analysis, and most previous attempts to solve this problem geophysically have relied on seismic or gravity data alone. Here, we propose to use a probabilistic joint inversion (high resolution regional seismic data, satellite gravity data, topography) and petrological modelling approach to determine the 3D thermochemical structure of the mantle. The inversion will be carried out using a Markov-chain Bayesian Monte Carlo methodology, providing quantitative estimates of uncertainties. Mapping the 3-dimensional thermochemical structure (thermal and composition) will provide a comprehensive view of the horizontal (50-100 km resolution) and vertical (from the surface down to 380 km) variations. This new model will give us the temperature variation from the surface down to 380 km and the degree of depletion of the lithospheric mantle and the sub-lithospheric mantle. This new model will also be compared to recent models of Gondwana terranes 200 Myrs to build a new model of the thermochemical evolution of the cratonic mantle. The new thermal and chemical structures can be used to better understand the geothermal heat flux beneath the ice sheet as well as improve glacial isostatic adjustment and ice sheet models. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth’s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth’s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community. Knowledge of Earth’s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth’s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Understanding and being able to more reliably forecast ice mass loss from Antarctica is a critical research priority for Antarctic Science. Massive ice shelves buttress marine terminating glaciers, slowing the rate that land ice reaches the sea and, in turn, restraining the rate of sea level rise. To date, most work has focused on the destabilizing impacts of warmer air and water temperatures, resulting in melting that thins and weakens ice shelves. However, recent findings indicate that sea ice does not protect ice shelves from wave impacts as much as previously thought, which has raised the possibility that tsunamis and other ocean waves could affect shelf stability. This project will assess the potential for increased shelf fracturing from the impact of tsunamis and from heightened wave activity due to climate-driven changes in storm patterns and reduced sea-ice extent by developing models to investigate how wave impacts damage ice shelves. The modeling effort will allow for regional comparisons between large and small ice shelves, and provide an evaluation of the impacts of changing climate and storm patterns on ice shelves, ice sheets, glaciers, and, ultimately, sea level rise. This project will train graduate students in mathematical modeling and interdisciplinary approaches to Earth and ocean sciences. This project takes a four-pronged approach to estimating the impact of vibrations on ice shelves at the grounding zone due to tsunamis, very long period, infragravity, and storm-driven waves. First, the team will use high-resolution tsunami modeling to investigate the response of ice shelves along the West Antarctic coast to waves originating in different regions of the Pacific Ocean. Second, it will compare the response to wave impacts on grounding zones of narrow and wide ice shelves. Third, it will assess the exposure risk due to storm forcing through a reanalysis of weather and wave model data; and, finally, the team will model the propagation of ocean-wave-induced vibrations in the ice from the shelf front to and across the grounding zone. In combination, this project aims to identify locations along the Antarctic coast that are subject to enhanced, bathymetrically-focused, long-period ocean-wave impacts. Linkages between wave impacts and climate arise from potential changes in sea-ice extent in front of shelves, and changes in the magnitude, frequency, and tracks of storms. Understanding the effects of ocean waves and climate on ice-shelf integrity is critical to anticipate their contribution to the amplitude and timing of sea-level rise. Wave-driven reductions in ice-shelf stability may enhance shelf fragmentation and iceberg calving, reducing ice shelf buttressing and eventually accelerating sea-level rise. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The West Antarctic Ice Sheet contains enough ice to raise global sea levels by 3-4 meters. Ice-sheet volume falls, and sea level increases, when more ice is lost to the ocean by glacier flow than is replaced by snowfall. Glacier speed is reduced when ice shelves, which are the floating extensions of the ice sheets, are present. Processes that affect ice shelf thickness and extent therefore influence the rates of grounded ice loss and sea-level rise. West Antarctica is currently losing ice, at an accelerating rate, with most loss occurring in the Amundsen Sea region via discharge from Pine Island and Thwaites glaciers. This loss was initiated by increased circulation of relatively warm ocean water beneath these glacier's ice shelves, causing them to thin by melting. However, this melting also depends on how the changing shape of the ice shelves affects the ocean circulation beneath them and the speeds of the grounded glaciers upstream. Limited understanding of these processes leads to uncertainties in estimates of future ice loss. This interdisciplinary project brings together glaciologists and oceanographers from three US institutions to study the interactions between changing glacier flow, ice shelf shape and extent, and ocean circulation. Data and numerical models will be used to identify the key processes that determine how rapidly this region can shed ice. The project team will train postdocs and graduate students in cutting-edge modeling techniques, and educate the public about Antarctic ice loss through talks, school science fairs, and Seattle Science Center's annual Polar Science Weekend. The project team will conduct simulations, using a combination of ice-sheet and ocean models, to reduce uncertainties in projected ice loss from Pine Island and Thwaites glaciers by: (i) assessing how ice-shelf melt rates will change as the ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of sub-shelf melt rates to changes in ocean state on the nearby continental shelf. These studies will reduce uncertainty on ice loss and sea-level rise estimates, and lay the groundwork for development of future fully-coupled ice-sheet/ocean models. The project will first develop high-resolution ice-shelf-cavity circulation models driven by modern observed regional ocean state and validated with estimates of melt derived from satellite observations. Next, an ice-flow model will be used to estimate the future grounding retreat. An iterative process with the ocean-circulation and ice-flow models will then simulate melt rates at each stage of retreat. These results will help assess the validity of the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway, which was based on simplified models of melt rate. These models will also provide a better understanding of the sensitivity of melt to regional forcing such as changes in Circumpolar Deep Water temperature and wind-driven changes in thermocline height. Finally, several semi-coupled ice-ocean simulations will help determine the influence of the ocean-circulation driven melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response.
Melt from the Greenland and Antarctic ice sheets is increasingly contributing to sea-level rise. This ice sheet mass loss is primarily driven by the thinning, retreat, and acceleration of glaciers in contact with the ocean. Observations from the field and satellites indicate that glaciers are sensitive to changes at the ice-ocean interface and that the increase in submarine melting is likely to be driven by the discharge of meltwater from underneath the glacier known as subglacial meltwater plumes. The melting of glacier ice also directly adds a large volume of freshwater into the ocean, potentially causing significant changes in the circulation of ocean waters that regulate global heat transport, making ice-ocean interactions an important potential factor in climate change and variability. The ability to predict, and hence adequately respond to, climate change and sea-level rise therefore depends on our knowledge of the small-scale processes occurring in the vicinity of subglacial meltwater plumes at the ice-ocean interface. Currently, understanding of the underlying physics is incomplete; for example, different models of glacier-ocean interaction could yield melting rates that vary over a factor of five for the same heat supply from the ocean. It is then very difficult to assess the reliability of predictive models. This project will use comprehensive laboratory experiments to study how the melt rates of glaciers in the vicinity of plumes are affected by the ice roughness, ice geometry, ocean turbulence, and ocean density stratification at the ice-ocean interface. These experiments will then be used to develop new and improved predictive models of ice-sheet melting by the ocean. This project builds bridges between modern experimental fluid mechanics and glaciology with the goal of leading to advances in both fields. As a part of this work, two graduate students will receive interdisciplinary training and each year two undergraduate students will be trained in experimental fluid mechanics to assist in this work and develop their own research projects. This project consists of a comprehensive experimental program designed for studying the melt rates of glacier ice under the combined influences of (1) turbulence occurring near and at the ice-ocean interface, (2) density stratification in the ambient water column, (3) irregularities in the bottom topology of an ice shelf, and (4) differing spatial distributions of multiple meltwater plumes. The objective of the experiments is to obtain high-resolution data of the velocity, density, and temperature near/at the ice-ocean interface, which will then be used to improve understanding of melt processes down to scales of millimeters, and to devise new, more robust numerical models of glacier evolution and sea-level rise. Specially, laser-based, optical techniques in experimental fluid mechanics (particle image velocity and laser-induced fluorescence) will be used to gather the data, and the experiments will be conducted using refractive-index matching techniques to eliminate changes in refractive indices that could otherwise bias the measurements. The experiments will be run inside a climate-controlled cold room to mimic field conditions (ocean temperature from 0-10 degrees C). The project will use 3D-printing to create different casting molds for making ice blocks with different types of roughness. The goal is to investigate how ice melt rate changes as a function of the properties of the plume, the ambient ocean water, and the geometric properties of the ice interface. Based on the experimental findings, this project will develop and test a new integral-plume-model coupled to a regional circulation model (MITgcm) that can be used to predict the effects of glacial melt on ocean circulation and sea-level rise. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Dunbar/1543454 Antarctic ice cores offer unparalleled records of earth?s climate back to almost one million years and perhaps beyond. Layers of volcanic ash (tephra) embedded in glacial ice can be used to establish an accurate ice core chronology. In order to use a visible or ultrafine volcanic ash layer as a time-stratigraphic marker, a unique geochemical fingerprint must be established, and this forms the basis of our research. This award will investigate the volcanic record in the 1751 m ice core that was completed at the South Pole during the 2015/16 field season. The core is in an ideal location to link the existing, established, volcanic records in East and West Antarctica, and therefore to connect and integrate those records, allowing the climate records of ice cores to be directly compared, as well as to focus research on the most widespread and significant volcanic eruptions from West Antarctica. Tephra derived from well-dated, large, tropical volcanic eruptions that may have had an impact on climate will also be studied. Recent success in identifying and analyzing very fine ash particles from these types of eruptions makes it likely that we will be able to pinpoint some of these eruptions, which will allow the sulfate peaks associated with these layers to be positively identified and dated. Volcanic forcing time series developed from earlier South Pole ice cores based on preserved sulfate were crucial for testing climate models, but without tephra analysis, the origin of these layers remains uncertain. Work on the tephra layers in the South Pole ice core has a number of significant specific objectives, some with practical applications to the basic science goals of Antarctic ice coring, and others that represent independent scientific contributions in their own right. These include: (1) providing independently dated time-intervals in the core, particularly for the deepest ice, (2) quantitatively linking tephra records across Antarctica with the goal of allowing direct and robust climate comparisons between these different parts of the continent, (3) providing information for large local eruptions, that will lead to direct estimates of eruption magnitude and dispersal patterns of Antarctic volcanoes, several of which will likely erupt again. The initial stages of the work will be carried out by identifying silicate-bearing horizons in the ice core, using several methods. Once found, silicate particles will be imaged so that morphological characteristics of the particles can be used to identify volcanic origin. Particles identified as tephra will then be chemically analyzed using electron microprobe and laser ablation ICP-MS. Samples that yield a robust chemical fingerprint will be statistically correlated to known eruptions, and this will be used to address the goals described above. Broader impacts of this project fall into the areas of education of future generation of researchers, outreach and international cooperation. These activities will continue to promote forward progress in integrating the Antarctic tephra record and more broadly tying it to the global volcanic record.
This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth's climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area.
Hall/1643248 This award supports a project to reconstruct the behavior of a portion of the East Antarctic Ice Sheet (the Ross Ice Sheet), using glacial geologic mapping and radiocarbon dating of algal deposits contained in glacial moraines, at the end of the last glacial period. The results will be compared with other dating methods that will be used on alpine glaciers that terminated in the mountains of the Royal Society Range in East Antarctica during the last glacial maximum and whose landforms intersect with those of the Ross Ice Sheet. Results from this comparison will contribute to a better understanding of the Antarctic ice sheet during the most recent global warming that ended the last ice age. This period is of interest since it will help inform our understanding of Antarctic ice sheet behavior in a future climate warming. Such data also will help inform models that attempt to simulate not only the behavior of the ice sheet during the end of the last ice age, but also its future response to elevated atmospheric carbon dioxide. The work will contribute to the education and training of both graduate and undergraduate students and results from the work will be incorporated in classes at the University of Maine. Results derived from the research will be disseminated to the public through lectures and visits to K-12 classrooms and data from this project will be downloadable from a University of Maine web site, as well as from public data repositories. The Antarctic Ice Sheet exerts a key control on global sea levels, both past and future, and strongly influences Southern Hemisphere and even global climate and ocean circulation. And yet a complete understanding of the evolution of the ice sheet over the last glacial cycle and of the mechanisms that caused it to advance and retreat is still lacking. Of particular interest is the response of the Antarctic Ice Sheet to the global warming that ended the last ice age, because it yields important clues about likely future ice-sheet behavior under a warming climate. In this project, scientists will reconstruct the thinning history of the Antarctic Ice Sheet in the Ross Sea sector during the last glacial/interglacial transition on the headlands of the southern Royal Society Range. They will use a combination of glacial geomorphological mapping and radiocarbon dating of algal deposits enclosed within recessional moraines. Finally, this record will be compared with a beryllium- and radiocarbon-dated chronology that will be produced of adjacent independent alpine glaciers that terminated on land during the last glacial maximum and whose deposits show cross-cutting relationships with those of the ice sheet. Results from this comparison will bear on the behavior of the Antarctic Ice Sheet during the termination of the last ice age. This work will support six students, including at least three undergraduates, and involves field work in the Antarctic.
The Antarctic ice sheet is underlain by a dynamic water system that lubricates the flow of ice streams and outlet glaciers, provides a habitat for a diverse microbial ecosystem, and delivers freshwater and nutrients to the Southern Ocean. However, imaging this subglacial environment is difficult: Antarctica is a vast continent with ice up to four kilometers (2.5 miles) thick. To detect water at the ice-bed interface and in deeper groundwater reservoirs, this project will adapt a technique called electromagnetic sounding that is well-established on land and in the ocean for imaging fluids beneath the surface. Groundwater is estimated to be a significant part of the subglacial water budget in Antarctica, yet previous observational approaches have been unable to characterize its volume and distribution. This project will thus yield critical information about how ice-rock-water-ocean systems interact and inform our understanding of ice-sheet processes, global nutrient cycles, and freshwater flux to the ocean. The project will provide cross-disciplinary training for a graduate student and postdoctoral scientist, and develop an educational outreach program through the Birch Aquarium. Standard geophysical surveying techniques used in glaciology to image subglacial water (radio-echo sounding and active-source seismology) are not directly sensitive to water content. In contrast, ground-based electromagnetic (EM) methods are sensitive to water content through its impact on bulk conductivity. Although EM methods are well-established for high-precision mapping of hydrology in other geological environments, their application on ice sheets is in its infancy. The proposed work will adapt both passive- and active-source EM techniques to glaciological questions to quantify the three-dimensional structure of subglacial water beneath an ice stream and in a grounding zone. The project will perform a suite of synthetic inversion studies to determine the range of applications of EM techniques in glaciology and execute a field experiment on the Whillans Ice Plain to investigate two hypotheses about the subglacial water system based on previous observational and modeling results: (1) Subglacial Lake Whillans is underlain by a deep, saline groundwater reservoir; and (2) there is an estuary-like zone of mixing between fresh subglacial water and seawater near, and possibly landward, of the grounding line.
ANDRILL is a scientific drilling program to investigate Antarctica's role in global climate change over the last sixty million years. The approach integrates geophysical surveys, new drilling technology, multidisciplinary core analysis, and ice sheet modeling to address four scientific themes: (1) the history of Antarctica's climate and ice sheets; (2) the evolution of polar biota and ecosystems; (3) the timing and nature of major tectonic and volcanic episodes; and (4) the role of Antarctica in the Earth's ocean-climate system. <br/><br/>This award initiates what may become a long-term program with drilling of two previously inaccessible sediment records beneath the McMurdo Ice Shelf and in South McMurdo Sound. These stratigraphic records cover critical time periods in the development of Antarctica's major ice sheets. The McMurdo Ice Shelf site focuses on the Ross Ice Shelf, whose size is a sensitive indicator of global climate change. It has recently undergone major calving events, and there is evidence of a thousand-kilometer contraction since the last glacial maximum. As a generator of cold bottom water, the shelf may also play a key role in ocean circulation. The core obtained from this site will also offer insight into sub-ice shelf sedimentary, biologic, and oceanographic processes; the history of Ross Island volcanism; and the flexural response of the lithosphere to volcanic loading, which is important for geophysical and tectonic studies of the region.<br/><br/>The South McMurdo Sound site is located adjacent to the Dry Valleys, and focuses on the major ice sheet overlying East Antarctica. A debate persists regarding the stability of this ice sheet. Evidence from the Dry Valleys supports contradictory conclusions; a stable ice sheet for at least the last fifteen million years or an active ice sheet that cycled through expansions and contractions as recently as a few millions of years ago. Constraining this history is critical to deep-time models of global climate change. The sediment cores will be used to construct an overall glacial and interglacial history for the region; including documentation of sea-ice coverage, sea level, terrestrial vegetation, and melt-water discharge events. The core will also provide a general chronostratigraphic framework for regional seismic studies and help unravel the area's complex tectonic history.<br/><br/>The broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society's understanding of global climate change. Education is supported at the postdoctoral, graduate, undergraduate, and K-12 levels. Teachers and curriculum specialists are integrated into the research program, and a range of video resources will be produced, including a science documentary for television release. New research infrastructure includes equipment for core analysis and ice sheet modeling, as well as development of a unique drilling system to penetrate ice shelves. Drill development and the overall project are co-supported by international collaboration with scientists and the National Antarctic programs of New Zealand, Germany, and Italy. The program also forges new collaborations between research and primarily undergraduate institutions within the United States. <br/><br/>As key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica's ice sheets are important to society's understanding of global climate change. ANDRILL offers new data on marine and terrestrial temperatures, and changes our understanding of extreme climate events like the formation of polar ice caps. Such data are critical to developing accurate models of the Earth's climatic future.
Atmospheric warming has been a major factor in the loss of ice shelves on the Antarctic Peninsula. In West Antarctica, oceanic warming is presently regarded as the largest source of stress on both the ice-shelves and at the grounding lines of the ice sheets. The loss of ice shelf buttressing and grounding line retreat may have already induced irreversible loss of Thwaites Glacier. To advance predictive models more data is needed regarding both water-induced fracturing on an ice shelf and marine ice cliff instability near the grounding line. This project will help advance understanding of atmospheric circulation and solar radiation over West Antarctica and the Ross Ice Shelf that lead to surface melting. In support of this project, and incorporating Antarctic science from this work, UCSD educators will sponsor a workshop series for exemplary middle and/or high school science teachers designed to address this need. Teacher participants will be carefully selected for their demonstrated leadership skills and will eventually become part of an cadre of "master" science teachers who will serve as local leaders in disseminating strategies and tools for addressing the NGSS (Ca Next Gen. of Sci. Eng. Stds.) to teachers throughout the county. For the summer field seasons requested, UCSD scientists will deploy a suite instruments to measure downwelling and net shortwave and longwave fluxes, sensible and latent heat fluxes, and near-surface meteorology. This suite of instruments will be self-reliant with power requirements and will be supportable in the field with a single Twin Otter aircraft. The investigators plan to deploy this suite as a remote ice camp with a field party of 2-3 personnel, making measurements for at up to one month during each of the sampled summer field seasons. These measurements will be analyzed and interpreted to determine mesoscale conditions that govern surface melt in West Antarctica, in the context of improving coupled climate model parameterizations. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Correlating ecosystem responses to past climate forcing is highly dependent on the use of reliable techniques for establishing the age of events (dating techniques). In Antarctic dry regions (land areas without glaciers), carbon-14 dating has been used to assess the ages of organic deposits left behind by ancient lakes. However, the reliability of the ages is debatable because of possible contamination with "old carbon" from the surrounding landscape. The proposed research will attempt to establish two alternate dating techniques, in situ carbon-14 cosmogenic radionuclide exposure dating and optically stimulated luminescence (OSL), as reliable alternate dating methods for lake history in Antarctic dry areas that are not contaminated by the old carbon. The end goal will be to increase scientific understanding of lake level fluctuation in the lakes of Taylor Valley, Antarctica so that inference about past climate, glacier, and ecosystem response can be inferred. The results of this study will provide a coarse-scale absolute chronology for lake level history in Taylor Valley, demonstrate that exposure dating and OSL are effective means to understand the physical dynamics of ancient water bodies, and increase the current understanding of polar lacustrine and ice sheet responses to past and present climatic changes. These chronologies will allow polar lake level fluctuations to be correlated with past changes in global and regional climate, providing information critical for understanding and modeling the physical responses of these environments to modern change. This research supports a PhD student; the student will highlight this work with grade school classes in the United States. This research aims to establish in situ carbon-14 exposure dating and OSL as reliable alternate (to carbon-14 of organic lake deposits) geochronometers that can be used to settle the long-disputed lacustrine history and chronology of Taylor Valley, Antarctica and elsewhere. Improved lake level history will have significant impacts for the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) site as the legacy of fluctuating lake levels of the past affects the distribution of organic matter and nutrients, and impacts biological connectivity valley-wide. This work will provide insight into the carbon reservoir of large glacial lakes in the late Holocene and have implications for previously reported radiocarbon chronologies. OSL samples will be analyzed in the Desert Research Institute Luminescence Laboratory in Reno, NV. For the in situ carbon-14 work, rock samples extracted from boulders and bedrock surfaces will be prepared at Tulane University. The prepared in situ carbon-14 samples will be analyzed at the National Ocean Sciences Accelerator Mass Spectrometry laboratory in Woods Hole, MA. The two datasets will be combined to produce a reliable, coarse scale chronology for late Quaternary lake level fluctuations in Taylor Valley. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Welten/1644128 This award supports a project to use existing samples from the West Antarctic Ice Sheet (WAIS) Divide ice core to align its timescale with that of the Greenland ice cores using common chronological markers. The upper 2850 m of the WAIS Divide core, which was drilled to a depth of 3405 m, has been dated with high precision. The timescale of the remaining (bottom) 550 m of the core has larger uncertainties, limiting our understanding of the timing of abrupt climate events in Antarctica relative to those in Greenland during the last ice age. The intellectual merit of this project is to further constrain the relative timing of these abrupt climate events in Greenland and Antarctica to obtain crucial insight into the underlying mechanism. The main objective of this project is to improve the current timescale of the WAIS Divide core from 31,000 to 65,000 years ago by synchronizing this core with the Greenland ice cores using common signals in Beryllium-10, a radioactive isotope of Be that is produced in the atmosphere by cosmic rays and is deposited onto the snow within 1-2 years of its production. The 10Be flux is largely independent of climate signals since its production varies with solar activity and the geomagnetic field. This project will further strengthen collaborations between the PI's in Berkeley and Purdue with ice core researchers in the US and Europe, involve undergraduate students in many aspects of its research, and continue outreach to under-represented students. The direct ice-to-ice synchronization of the WAIS Divide ice core with the Greenland Ice Core Chronology (GICC05) using cosmogenic 10Be is expected to reduce the uncertainty in the relative timing of more than 20 abrupt climate events in Greenland and Antarctica to a few decades. To achieve this goal the investigators will obtain a continuous high-resolution record of 10Be in the WAIS Divide core from 2850 to 3390 m depth, and compare the obtained 10Be record with existing 10Be records of the Greenland ice cores, including GISP2 and NGRIP. The scientists will separate 10Be from ~1000 ice samples of the WAIS Divide core and measure the 10Be concentration in each sample using accelerator mass spectrometry (AMS). Broader impacts of the 10Be measurements are that they will also provide information on the Laschamp event, a ~2000 year long period of low geomagnetic field strength around 41,000 years ago, and improve the calibration of the 14C dating method for organic samples older than 30,000 years. The broader impacts of the project include (1) the involvement and training of undergraduate students in ice core research and accelerator mass spectrometry measurements, (2) the incorporation of ice core and climate research into ongoing outreach programs at Purdue University and Berkeley SSL, (3) better understanding of abrupt climate changes in the past will improve our ability to predict future climate change, (4) evaluating the possible threat of a future geomagnetic excursion in the next few hundred years. This award does not require support in Antarctica.
Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.
Geologic data provide crucial insights into Antarctic Ice Sheet dynamics; for example, progressive exposure of mountain peaks emerging from the ice sheet reveal ice elevation changes, and the past ‘footprint’ of marine-based ice sheets is imprinted on the seafloor. Numerical ice sheet simulations can link these geologic records in space and time to make larger-scale inferences about continent-wide ice sheet evolution. This work integrates both marine and terrestrial geologic datasets with numerical simulations to investigate Antarctic Ice Sheet behavior (and contribution to global sea level) throughout the last deglaciation, ~20,000 years ago until present. Specifically, this research addresses two issues regarding the relationship between simulations and data and their use in reconstructing past ice-sheet behavior: (1) Geologic records from the modern seafloor suggest significantly earlier retreat of marine-based ice compared to terrestrial records of mountain peak exposure (ice thinning). Computer experiments investigate several hypotheses for this mismatch in timing. (2) Exposure age data (terrestrial measurements recording ice elevation changes) are often interpreted to reflect ice dynamics hundreds of kilometers away from the study site. This work uses simulations to explore the linkage between ice elevation changes ‘upstream’ as glaciers flow through mountainous regions and ice dynamics further ‘downstream’ where ice contacts the ocean. This work will produce a publicly available, customizable, and easily accessible toolkit for comparing simulations and data, including a database of geologic records to use as constraints. The project is interdisciplinary, bridging a communication gap between the ice-sheet simulations and geologic data-collecting communities. This project combines numerical simulations and geologic data to explore fundamental knowledge gaps regarding the interpretation and use of marine and terrestrial datasets. This work will produce an ensemble of continent-wide coupled ice sheet and glacial isostatic adjustment simulations, constrained with comprehensive existing geologic data, to reproduce a history of deglacial Antarctic Ice Sheet evolution that is compatible with the geologic record as well as glaciologically and gravitationally self-consistent. Comparison between simulations and data is improved through high-resolution nested ice sheet modeling techniques, which provide unprecedented context for exposure age data generally located in regions of complex topography. Numerical simulations will be performed with systematically varied parameters and boundary conditions, and can thus support an investigation of (1) chronological mismatches between terrestrial thinning and marine ice sheet retreat during the mid-Holocene, and (2) how marine grounding-line dynamics are propagated upstream to coastal outlet glaciers and further interior under a variety of different scenarios. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Climate change is promoting increased melting in Greenland and Antarctica, contributing to the global sea level rise. Understanding what drives the increase and the amount of meltwater from the ice sheets is paramount to improve our skills to project future sea level rise and associated consequences. Melting in Antarctica mostly occurs along ice shelves (tongues of ice floating in the water). They do not contribute directly to sea level when they melt but their disappearance allows the glaciers at the top to flow faster towards the ocean, increasing the contribution of Antarctica to sea level rise. Satellite data can only offer a partial view of what is happening, either because of limited coverage or because of the presence of clouds, which often obstruct the view in this part of the world. Models, on the other hand, can provide estimates but the spatial detail they can provide is still limited by many factors. This project will use artificial intelligence to overcome these problems and to merge satellite data and model outputs to generate daily maps of surface melting with unprecedented detail. These techniques are similar to those used in cell phones to sharpen images or to create landscapes that look “real” but are only existing in the “computer world,” but they have never been applied to melting in Antarctica for improving estimates of sea level rise. Meltwater in Antarctica has been shown to impact ice shelf stability through the fracturing and flexural processes. Image scarcity has often forced the community to use general climate and regional climate models to explore hydrological features. Notwithstanding models having been considerably refined over the past years, they still require improvements in capturing the processes driving the energy balance and, most importantly, the feedback among the drivers and the energy balance terms that drive the hydrological processes. Moreover, spatial resolution is still too coarse to properly capture hydrological processes, especially over ice shelves. Machine learning (ML) tools can help in this regard, especially when it is computationally infeasible to run physics-based models at desired resolutions in space and time, like in the case of ice shelf surface hydrology. This project will train Generative Adversarial Networks (GANs) with the outputs of a regional climate model and remote sensing data to generate unprecedented, high-resolution (100 m) maps of surface melting. Beside improving the spatial resolution, and hence providing a long-needed and crucial dataset to the polar community, the tool here proposed will be able to provide satellite-like maps on a daily basis, hence addressing also those issues related to the lack of spatial coverage. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Icebergs influence climate by controlling how freshwater from ice sheets is distributed into the ocean, where roughly half of ice sheet mass loss is attributed to iceberg calving in the current climate. The freshwater deposited by icebergs as they drift and melt can affect ocean circulation, sea-ice formation, and biological primary productivity. Furthermore, calving of icebergs from ice shelves, the floating extensions of ice sheets, can influence ice sheet evolution and sea-level rise by reducing the resistive stresses provided by ice shelves on the seaward flow of upstream grounded ice. The majority of mass calved from ice shelves occurs in the form of tabular icebergs, which are typically hundreds of meters thick and on the order of tens to hundreds of kilometers in length and width. Tabular calving occurs when full-thickness ice shelf fractures known as rifts propagate to the edges of the ice shelf. These calving events are infrequent, often with decades between events on an individual ice shelf. Changes in tabular calving behavior, i.e., the size and frequency of calving events, can strongly influence climate and ice sheet evolution. However, tabular calving behavior, and how it responds to changes in climate, is neither well understood nor accurately represented in climate models. In this project, a tabular calving parameterization for climate models will be developed. The parameterization will be derived according to data generated from a series of realistic and idealized century-scale tabular calving simulations, which will be performed with a novel ice flow and damage framework that can be applied at the scale of individual ice sheet-ice shelf systems: the CD-MPM-SSA (Continuum Damage Material Point Method for Shelfy-Stream Approximation). During these simulations, the geometry of the ice shelf, mechanical/rheological properties of the ice, and climate forcings such as ocean temperature will be varied to determine the rifting and calving response. The calving parameterization derived from these experiments will be implemented in a Geophysical Fluid Dynamics Laboratory (GFDL) climate model, where it will be coupled with a bonded-particle iceberg model. Then, experiments will be run to study the feedback between changes in iceberg calving behavior and climate. Success of this project will improve our understanding and representation of the ice mass budget, ice sheet evolution, and ocean freshwater fluxes, and will improve projections of climate change and sea-level rise. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Carbotte, Suzanne; Tinto, Kirsty; Nitsche, Frank O.
No dataset link provided
Samples and data obtained by researchers working in Antarctica are valuable, unique assets which typically require a substantial and expensive logistical effort to acquire. Preservation of these data increases the return on the significant public investment for acquisition, enabling future re-use for new analyses, and ensure that data behind scientific publications are available for others to review. The US Antarctic Program Data Center (USAP-DC) will provide an open-disciplinary hybrid repository for project metadata and the diverse research data obtained from the Antarctic region by NSF funded researchers for which other data repositories do not exist. In addition, a Project Catalog will provide a single online resource for the US Antarctic scientific community to manage information about their research activities and will link project metadata to the various distributed repositories where Antarctic data resides. In doing so, the USAP-DC will follow community best practices and standards to ensure data are citable, shareable, and discoverable. It will also facilitate registration of data descriptions into the Antarctic Master Directory to meet US goals for data sharing under the International Antarctic Treaty. With full open access to interfaces to search for and download data, USAP-DC will make a wide range of data products resulting from NSF funded research in Antarctica available not only to the research community but also to the broader public. The data center is operated using community standards for metadata and data access which helps ensure data re-usability into the future. The new Project catalog, which is designed to support consolidation of information on research products of USAP awards over the lifetime of a project, will make it simpler for NSF program managers, but also for individual researchers and especially larger collaborative research groups to keep track of datasets and related information produced as part of their projects. Through tutorials and meetings at conferences USAP-DC will contribute to raise awareness and inform the research community, especially new investigators about data management best practices. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Antarctic Ice Sheet stability remains a large uncertainty in predicting future sea level. Presently, the greatest ice mass loss is observed in locations where relatively warm water comes into contact with glaciers and ice shelves, melting them from below. This has led researchers to hypothesize that the interactions that occur between the ocean and the ice are important for determining ice sheet stability and that increased warm water presence will accelerate Antarctic ice mass loss and lead to greater sea level rise in the coming century. To better predict future ice sheet behavior, it is critical to understand past ice-ocean interactions around Antarctica, especially during warm periods and at times when Earth’s climate was undergoing major changes. Past Antarctic ice mass and environmental conditions like ocean temperature can be reconstructed using sediments, which capture an environmental record as they accumulate on the ocean floor. By looking at sediment composition and by analyzing geochemical signatures within the sediment, it is possible to piece together a record of climate change on hundred- to million-year timescales. This project will reconstruct upper ocean temperatures and Antarctic ice retreat/advance cycles from 2.6 to 0.7 million years ago, which encompasses the Mid-Pleistocene Transition, a time in Earth’s history that marks the shift from 41-thousand year glacial cycles to 100-thousand year glacial cycles. A record will be generated from existing sediment cores collected from the Scotia Sea during International Ocean Discovery Program Expedition 382. The Mid-Pleistocene Transition (MPT; ~1.25–0.7 Ma) marks the shift from glacial-interglacial cycles paced by obliquity (~41 kyr cycles) to those paced by eccentricity (~100-kyr cycles). This transition occurred despite little variation in Earth’s orbital parameters, suggesting a role for internal climate feedbacks. The MPT was accompanied by decreasing atmospheric pCO2, increasing deep ocean carbon storage, and changes in deep water formation and distribution, all of which are linked to Antarctic margin atmosphere-ice-ocean interactions. However, Pleistocene records that document such interactions are rarely preserved on the shelf due to repeated Antarctic Ice Sheet (AIS) advance; instead, they are preserved in deep Southern Ocean basins. This project takes advantage of the excellent preservation and recovery of continuous Pleistocene sediment sequences collected from the Scotia Sea during International Ocean Discovery Program Expedition 382 to test the following hypotheses: 1) Southern Ocean upper ocean temperatures vary on orbital timescales during the early to middle Pleistocene (2.6–0.7 Ma), and 2) Southern Ocean temperatures co-vary with AIS advance/retreat cycles. Paleotemperatures will be reconstructed using the TetraEther indeX of 86 carbons (TEX86), a proxy that utilizes marine archaeal biomarkers. The Scotia Sea TEX86-based paleotemperature record will be compared to records of AIS variability, including ice rafted debris. Expedition 382 records will be compared to orbitally paced climatic time series and the benthic oxygen isotope record of global ice volume and bottom water temperature to determine if a correlation exists between upper ocean temperature, AIS retreat/advance, and orbital climate forcing. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This study will collect a novel dataset to determine how the West Antarctic Ice Sheet (WAIS) responded to a warmer climate during the last interglacial period (~125,000 years ago) by reconstructing the glacial history at the Mt. Waesche volcano. Reconstructing WAIS geometry when the ice sheet was smaller than present is difficult and data are lacking because the evidence lies beneath the present ice sheet. This study will drill through the ice sheet and recover bedrock that can be analyzed for its surface exposure history to help determine when the surface became overridden by the ice sheet. This study will provide constraints on the past maximum and minimum spatial extent of WAIS during the last glacial-interglacial cycle. Understanding the geometry of a reduced WAIS during intervals when the planet was warmer than present may provide a possible analogue for future environmental conditions given predicted temperature trends. A reduction of WAIS results in rising sea levels which threatens coastal communities across the globe. The data will help improve numerical ice sheet models to better predict WAIS response to current and future climate trends. The project supports a teacher educational workshop and the training of graduate and undergraduate students. The goal of this project is to obtain rock samples from beneath the WAIS through shallow (<80 m) drilling at Mt. Waesche, a volcano in Marie Byrd Land, near an ice dome of WAIS (2000 m elevation). The lithologies of lava flows exposed on the flank of the volcano are well-suited for cosmogenic 3He and 36Cl as well as 40Ar/39Ar measurements which will establish eruption and exposure age. Existing 40Ar/39Ar data indicate basaltic lava flows on the volcano flank as young as 350 ka. Thus, measured cosmogenic nuclides measured in rock cores from beneath the ice surface will be indicative of relatively recent exposure during periods of reduced ice elevation, most likely, during the last interglacial. The first field season is focused on identifying appropriate locations for drilling and a ground penetrating radar (GPR) survey of the subglacial topography <100m under the blue ice area. Mapping and dating the adjacent exposed lava flows will allow tracing of lava flows of known age and composition below the ice margin that will be targeted for drilling the following year. The second field season activities include drilling 8 boreholes (two transects) through blue ice with the Winkie drill near the ice margin to 80 m depth to obtain rock cores from the sub-ice lava flows. 3He exposure ages will constrain the duration and minimum extent of past surface lowering of the WAIS in Marie Byrd Land. Deeper GPR imaging (up to 700 m) will hope to reveal additional evidence of lava/ice interactions that would independently place constraints on lower ice levels during past eruptions. Results from this study will be compared with the modeled ice elevation histories at Mt. Waesche to validate ice sheet modeling efforts. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Predicting the response of ice sheets to changing climate and their contribution to sea level requires accurate representation in numerical models of basal conditions under the ice. There remain large data gaps for these basal boundary conditions under the East Antarctic Ice Sheet as well as in West Antarctica, including basal melt rates under ice shelves. This project will develop and test a prototype ground-based radar system to sound and image ice more than 4km thick, detect thin water films at the ice bed, and determine basal melt rates under ice shelves. The team will work with European partners (France, Italy, Germany) at Dome C to conduct deep-field Antarctic testing of the new radar. The project will build and test an L-band radar system (1.2-1.4GHz) with peak transmit power of 2kW. In addition to sounding and imaging thick ice, detection goals include resolving thin water films (>0.5mm). Such a system would target glaciological problems including site selection for ice in the 1.5-million-year age range, basal stress boundary conditions under grounded ice, and melt rates under floating shelves. By demonstrating feasibility, the project aims to influence sensor selection for satellite missions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The spatial extent of the West Antarctic Ice Sheet during the last interglacial period (129,000 to 116,000 years ago) is currently unknown, yet this information is fundamental to projections of the future stability of the ice sheet in a warming climate. Paleoclimate records and proxy evidence such as dust can inform on past environmental conditions and ice-sheet coverage. This project will combine new, high-sensitivity geochemical measurements of dust from Antarctic ice collected at Allan Hills with existing water isotope records to document climate and environmental changes through the last interglacial period. These changes will then be compared with Earth-system model simulations of dust and water isotopes to determine past conditions and constrain the sensitivity of the West Antarctic Ice Sheet to warming. The project will test the hypothesis that the uncharacteristically volcanic dust composition observed at another peripheral ice core site at Taylor Glacier during the last interglacial period is related to changes in the spatial extent of the West Antarctic Ice Sheet. This project aims to characterize mineral dust transport during the penultimate glacial-interglacial transition. The team will apply high-precision geochemical techniques to the high-volume, high-resolution ice core drilled at the Allan Hills site in combination with Earth system model simulations to: (1) determine if the volcanic dust signature found in interglacial ice from Taylor Glacier is also found at Allan Hills, (2) determine the likely dust source(s) to this site during the last interglacial, and (3) probe the atmospheric and environmental changes during the last interglacial with a diminished West Antarctic Ice Sheet. The team will develop a suite of measurements on previously drilled ice from Allan Hills, including isotopic compositions of Strontium and Neodymium, trace element concentrations, dust-size distribution, and imaging of ice-core dust to confirm the original signal observed and provide a broader spatial reconstruction of dust transport. In tandem, the team will conduct Earth system modeling with prognostic dust and water-isotope capability to test the sensitivity of dust transport under several plausible ice-sheet and freshwater-flux configurations. By comparing dust reconstruction and model simulations, the team aims to elucidate the driving mechanisms behind dust transport during the last interglacial period. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Current ice mass loss in Antarctica is largely driven by changes at glacier grounding lines, where inland ice transitions from being grounded to floating in the ocean. The rate and pattern of glacier retreat in these circumstances is thought to be controlled by the terrain under the ice. This project incorporates evidence of past ice-retreat events and other field data, such as grounding-line positions and dates, subglacial topography, and meltwater features, into numerical models of ice flow to investigate the influence that grounding-line processes and subglacial topography have on glacier retreat rates over the past 15,000 years. Recent observations suggest that Antarctic ice mass loss is largely driven by perturbations at or near the grounding line. However, the lack of information on subglacial and grounding-line environments causes large uncertainties in projections of mass loss and sea-level rise. This project will integrate geologic data from the deglaciated continental shelf into numerical models of varying complexity from one to three-dimensions. Rarely do numerical ice-sheet models of Antarctica have multiple constraints on dynamics over the past ~15,000 years (a period that spans the deglaciation of the Antarctic continental shelf since the Last Glacial Maximum). The geologic constraints include grounding-line positions, deglacial chronologies, and information on grounding line-ice shelf processes. The models will be used to investigate necessary perturbations and controls that meet the geological constraints. The multidisciplinary approach of merging geologic reconstructions of paleo-ice behavior with numerical models of ice response will allow the research team to test understanding of subglacial controls on grounding-line dynamics and assess the stability of modern grounding lines. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Antarctica is among the most rapidly warming places on the planet, and some reports suggest the Antarctic environment is approaching, or possibly beyond, the tipping point for ice shelf collapse. The loss of ice around Antarctica is dramatically changing habitat availability for marine fauna, particularly benthic marine invertebrate species. Building on past studies, this research will provide insights into how changing climate impacts species distribution and community structure. Geological data suggests that during periods when ice extent was much reduced relative to modern levels, marine seaways connected the Ross and Weddell Seas on either side of Antarctica. However, most theories about the origins of current marine invertebrate distribution patterns fail to consider this transantarctic connection. This research will use molecular genomic tools to probe the DNA of Antarctic marine invertebrates and explore alternative hypotheses about factors that may have shaped current patterns of animal biodiversity in the Southern Ocean. Research will inform predictions about how species distributions may change as Antarctic ice sheets continue to deteriorate and provide critical information on how organisms adjust their ranges in response to environmental change. This work includes several specific outreach activities including presentations in K-8 classrooms, several short-format videos on Antarctic genomics and field work, and two 3-day workshops on bioinformatics approaches. A minimum of 4 graduate students, a postdoc and several undergraduates will also be trained during this project. The overarching goal of this research is to understand environmental factors that have shaped patterns of present-day diversity in Antarctic benthic marine invertebrates. Evidence from sediment cores and modeling suggests ice shelf collapses have occurred multiple times in the last few million years. During these periods, transantarctic seaways connected the Ross and Weddell Seas. This research will assess whether the presence of transantarctic waterways helps explain observed similarities between the Ross and Weddell Seas benthic marine invertebrate fauna better than other current hypotheses (e.g., dispersal by the Antarctic Circumpolar Current, or expansion from common glacial refugia). Seven Antarctic benthic invertebrate taxa will be targeted to test alternative hypothesis about the origins of population genetic structure in the Southern Ocean using Single Nucleotide Polymorphism (SNP) markers that sample thousands of loci across the genome. Additionally, research will test the current paradigm that divergence between closely related, often cryptic, species is the result of population bottlenecks caused by glaciation. Specifically, SNP data will be mapped on to draft genomes of three of our target taxa to assess the degree of genetic divergence and look for signs of selection. Research findings may be applicable to other marine ecosystems around the planet. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Ice shelves play a critical role in restricting the seaward flow of grounded glacier ice by providing buttressing at their bases and sides. Processes that affect the long-term stability of ice shelves can therefore influence the future contribution of the Antarctic Ice Sheet to global sea-level rise. The Ross Ice Shelf is the largest ice shelf on Earth, and it buttresses massive areas of West and East Antarctica. Previous studies of modern ice velocity indicated that the Ross Ice Shelf’s mass loss is roughly balanced by its mass gain. However, more recent work that extends further back in time reveals the ice shelf is likely not in steady state, with possible long-term thinning since the late 1990s. Consequently, to accurately interpret modern-day ice-shelf changes, long-term observations are critical to evaluate how these recent variations fit into the historical context of ice-shelf variability. This project will examine more than four decades of historical and modern airborne radar sounding observations of the Ross Ice Shelf (spanning 1971 to 2017) to investigate ice-shelf changes on decadal timescales. The team will process, calibrate, and analyze radar data collected during 1971-79 field campaigns and compare them against modern observations collected between 2011-17. They will estimate basal melt rates by examining changes in ice-shelf thickness, and will determine other important metrics for melt, including ice-shelf roughness, englacial temperature, and marine-ice formation. The project will support the education of a Ph.D. student at each of the three participating institutions. In addition, the project will support the training of undergraduate and high-school researchers in radioglaciology and Antarctic sciences. The project will test the hypothesis that, over decadal timescales, the basal melt rates beneath the Ross Ice Shelf have been low, particularly under shallow ice drafts, leading to overall thickening and increased buttressing potential. The team aims to provide a direct estimate of basal melt rates based on changes in ice-shelf thickness that occurred between 1971 and 2017. This project will extend similar work completed at Thwaites Glacier and improve the calibration methods on the vertical scaling for fast-time and depth conversion. The work will also leverage the dense modern surveys to improve the geolocation of radar film collected on earlier field campaigns to produce a more precise comparison of local shelf thickness with the modern data. In addition, the team will conduct englacial attenuation analysis to calculate englacial temperature to infer the trends in local basal melting. They will also examine the radiometric and scatterometric character of bed echoes at the ice-ocean boundary to characterize changes in ice-shelf basal roughness, marine-ice formation related to local basal freezing, and structural damage from fracture processes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Schmittner, Andreas; Haight, Andrew ; Clark, Peter
No dataset link provided
This project investigates Antarctic ice-ocean interactions of the last 20,000 years. The Antarctic ice sheet is an important component of Earth’s climate system, as it interacts with the atmosphere, the surrounding Southern Ocean, and the underlaying solid Earth. The ice sheet is also the largest potential contributor to future sea-level rise and a major uncertainty in climate projections. Climate change may trigger instabilities that may lead to fast and irreversible collapse of parts of the ice sheet. However, little is known about how interactions between the Antarctic ice sheet and the rest of the climate system affect its behavior, climate, and sea level, partly because most climate models currently do not have fully-interactive ice-sheet components. The project team will construct a numerical climate model that includes an interactive Antarctic ice sheet, improving computational infrastructure for research. The model code will be made freely available to the public on a code-sharing site. In addition, the team will synthesize paleoclimate data and compare these with model simulations. This model-data comparison will test three scientific hypotheses regarding past changes in deep-ocean circulation, ice sheet, carbon, and sea level. The project will contribute to a better understanding of ice-ocean interactions and past climate variability. The project will test ideas that ice-ocean interactions have been important for setting deep ocean circulation and carbon storage during the Last Glacial Maximum and subsequent deglaciation. The new model will consist of three existing and well-tested components: (1) an isotope-enabled climate-carbon cycle model of intermediate complexity; (2) a model of the combined Antarctic ice sheet, solid Earth, and sea level; and (3) an iceberg model. The coupling will include ocean-temperature effects on basal melting of ice shelves; freshwater fluxes from the ice sheet to the ocean; and calving, transport and melting of icebergs. Once constructed and optimized, the model will be applied to simulate the Last Glacial Maximum and subsequent deglaciation. Differences between model versions with full, partial, or no coupling will be used to investigate the effects of ice-ocean interactions on the Meridional Overturning Circulation, deep ocean carbon storage, and ice-sheet fluctuations. Paleoclimate data synthesis will include temperature, carbon and nitrogen isotopes, radiocarbon ages, protactinium-thorium ratios, neodymium isotopes, carbonate ion, dissolved oxygen, relative sea level, and terrestrial cosmogenic ages into one multi-proxy database with a consistent updated chronology. The project will support an early-career scientist, one graduate student, undergraduate students, and new and ongoing national and international collaborations. Outreach activities in collaboration with a local science museum will benefit rural communities in Oregon by improving their climate literacy. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica’s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica’s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth's most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica’s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The overall goal of this project is to determine the effect of past changes in the size of the Antarctic Ice Sheet on global sea level. At the peak of the last ice age 25,000 years ago, sea level was 120 meters (400 feet) lower than it is at present because water that is now part of the ocean was instead part of expanded glaciers and ice sheets in North America, Eurasia, and Antarctica. Between then and now, melting and retreat of this land ice caused sea level to rise. In this project, we aim to improve our understanding of how changes in the size of the Antarctic Ice Sheet contributed to this process. The overall strategy to accomplish this involves (i) visiting areas in Antarctica that are not now covered by ice; (ii) looking for geological evidence, specifically rock surface and sediment deposits, that indicates that these areas were covered by thicker ice in the past; and (iii) determining the age of these geological surfaces and deposits. This project addresses the final part of this strategy -- determining the age of Antarctic glacial rock surfaces or sediment deposits -- using a relatively new technique that involves measuring trace elements in rock surfaces that are produced by cosmic-ray bombardment after the rock surfaces are exposed by ice retreat. By applying this method to rock samples collected in previous visits to Antarctica, the timing of past expansion and contraction of the ice sheet can be determined. The main scientific outcomes expected from this project are (i) improved understanding of how Antarctic Ice Sheet changes contributed to past global sea level rise; and (ii) improved understanding of modern observed Antarctic Ice Sheet changes in a longer-term context. This second outcome will potentially improve predictions of future ice sheet behavior. Other outcomes of the project include training of individual undergraduate and graduate students, as well as the development of a new course on sea level change to be taught at Tulane University in New Orleans, a city that is being affected by sea level change today. This project will use measurements of in-situ-produced cosmogenic carbon-14 in quartz from existing samples collected at several sites in Antarctica to resolve major ambiguities in existing Last Glacial Maximum to present ice sheet reconstructions. This project is important because of the critical nature of accurate reconstructions of ice sheet change in constraining reconstructions of past sea level change. Although carbon-14 is most commonly exploited as a geochronometer through its production in the upper atmosphere and incorporation into organic materials, it is also produced within the crystal lattice of rocks and minerals that are exposed to the cosmic-ray flux at the Earth's surface. In this latter case, its concentration is proportional to the duration of surface exposure, and measurements of in-situ-produced carbon-14 can be used to date geological events that form or expose rock surfaces, for example, ice sheet expansion and retreat. Although carbon-14 is one of several trace radionuclides that can be used for this purpose, it is unique among them in that its half-life is short relative to the time scale of glacial-interglacial variations. Thus, in cases where rock surfaces in polar regions have been repeatedly covered and uncovered by ice sheet change during many glacial-interglacial cycles, carbon-14 measurements are uniquely suited to accurately dating the most recent episode of ice sheet advance and retreat. We aim to use this property to improve our understanding of Antarctic Ice Sheet change at a number of critically located sites at which other surface exposure dating methods have yielded ambiguous results. Geographically, these are focused in the Weddell Sea embayment of Antarctica, which is an area where the geometry of the Antarctic continent potentially permits large glacial-interglacial changes in ice volume but where existing geologic records of ice sheet change are particularly ambiguous. In addition, in-situ carbon-14 measurements, applied where independently constrained deglaciation chronologies already exist, can potentially allow us to date the last period of ice sheet advance as well as the most recent retreat.
Bubbles of ancient air trapped in ice cores have been used to directly reconstruct atmospheric composition, and its links to Antarctic and global climate, over the last 800,000 years. Previous field expeditions to the Allan Hills Blue Ice Area, Antarctica, have recovered ice cores that extend as far back as 2.7 million years, by far the oldest polar ice samples yet recovered. These ice cores extend direct observations of atmospheric carbon dioxide and methane concentrations and indirect records of Antarctic climate into a period of Earth's climate history that represents a plausible geologic analogue to future anthropogenic climate change. The results demonstrate a smaller glacial-interglacial variability of climate and greenhouse gases, and a persistent linkage between Antarctic climate and atmospheric carbon dioxide, between 1 and 2 million years ago. Through this project, the team will return to the Allan Hills Blue Ice Area to recover additional ice cores that date to 2 million years or older. The climate records developed from these ice cores will provide new insights into the chemical composition of the atmosphere and Antarctic climate during times of comparable or even greater warmth than the present day. Project results will help answer questions about issues associated with anthropogenic change including the relationship between temperature change and the mass balance of Antarctic ice and the relationship between atmospheric greenhouse gases and global climate change. Earth has been cooling, and ice sheets expanding, over the past ~52 million years. Superimposed on this cooling are periodic changes in Earth's climate system driven by variations in the eccentricity, precession, and obliquity of Earth's orbit around the Sun. Climate reconstructions based on measurements of oxygen isotopes in foraminiferal calcite indicate that, from ~2.8 to 1.2 million years before present (Ma), Earth's climate system oscillated between glacial and interglacial states every ~40,000 years (the "40k world"). Between 1.2-0.8 Ma and continuing to the present, the period of glacial cycles increased in amplitude and lengthened to ~100,000 years (the "100k world"). Ice cores preserve ancient air that allows direct reconstructions of atmospheric carbon dioxide and methane. They also archive proxy records of regional climate, mean ocean temperature, global oxygen cycling, and the aridity of nearby continents. Studies of stratigraphically continuous ice cores, extending to 800,000 years before present, have demonstrated that atmospheric carbon dioxide is strongly linked to climate, and it is of great interest to extend the ice-core record into the 40k world. Recent discoveries of well-preserved ice dating from 1.0 to 2.7 Ma from ice cores drilled in the Allan Hills Blue Ice Area (BIA), Antarctica, demonstrate the potential to retrieve stratigraphically discontinuous old ice at shallow depths (<200 meters). This project will continue this work by retrieving new large-volume ice cores and measuring paleoclimate properties in both new and existing ice from the Allan Hills BIA. The experimental objectives are to more fully characterize fundamental properties of the climate system and the carbon cycle during the 40k world. Project results will have implications for Pleistocene climate change, and will provide new constraints on the processes that regulate atmospheric carbon dioxide, methane, and oxygen on geologic timescales. Given a demonstrated age of the ice at the Allan Hills BIA of at least 2 million years, the team will drill additional cores to prospect for ice that predates the initiation of Northern Hemisphere glaciation at the Plio-Pleistocene transition (~2.8 Ma). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The West Antarctic Ice Sheet is the most vulnerable polar ice mass to warming and already a major contributor to global mean sea level rise. Its fate in the light of prolonged warming is a topic of major uncertainty. Accelerated sea level rise from ice mass loss in the polar regions is a major concern as a cause of increased coastal flooding affecting millions of people. This project will disclose a unique geological archive buried beneath the seafloor off the Amundsen Sea, Antarctica, which will reveal how the West Antarctic Ice Sheet behaved in a warmer climate in the past. The data and insights can be used to inform ice-sheet and ocean modeling used in coastal policy development. The project will also support the development of a competitive U.S. STEM workforce. Online class exercises for introductory geology classes will provide a gateway for qualified students into undergraduate research programs and this project will enhance the participation of women in science by funding the education of current female Ph.D. students. The project targets the long-term variability of the West Antarctic Ice Sheet over several glacial-interglacial cycles in the early Pliocene sedimentary record drilled by the International Ocean Discovery Program (IODP) Expedition 379 in the Amundsen Sea. Data collection includes 1) the sand provenance of ice-rafted debris and shelf diamictites and its sources within the Amundsen Sea and Antarctic Peninsula region; 2) sedimentary structures and sortable silt calculations from particle size records and reconstructions of current intensities and interactions; and 3) the bulk provenance of continental rise sediments compared to existing data from the Amundsen Sea shelf with investigations into downslope currents as pathways for Antarctic Bottom Water formation. The results are analyzed within a cyclostratigraphic framework of reflectance spectroscopy and colorimetry (RSC) and X-ray fluorescence scanner (XRF) data to gain insight into orbital forcing of the high-latitude processes. The early Pliocene Climatic Optimum (PCO) ~4.5-4.1 Ma spans a major warm period recognized in deep-sea stable isotope and sea-surface temperature records. This period also coincides with a global mean sea level highstand of > 20 m requiring contributions in ice mass loss from Antarctica. The following hypotheses will be tested: 1) that the West Antarctic Ice Sheet retreated from the continental shelf break through an increase in sub iceshelf melt and iceberg calving at the onset of the PCO ~4.5 Ma, and 2) that dense shelf water cascaded down through slope channels after ~4.5 Ma as the continental shelf became exposed during glacial terminations. The project will reveal for the first time how the West Antarctic Ice Sheet operated in a warmer climate state prior to the onset of the current “icehouse” period ~3.3 Ma. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part I: Non-technical summary: The Amundsen Sea is adjacent to the West Antarctic Ice Sheet (WAIS) and hosts the most productive coastal ecosystem in all of Antarctica, with vibrant green waters visible from space and an atmospheric carbon dioxide uptake rate ten times higher than the Southern Ocean average. The region is also an area highly impacted by climate change and glacier ice loss. Upwelling of warm deep water is causing melt under the ice sheet, which is contributing to sea level rise and added nutrient inputs to the region. This is a project that is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own country. In this collaboration, the US team will undertake biogeochemical sampling alongside a UK-funded physical oceanographic program to evaluate the contribution of micronutrients such as iron from glacial meltwater to ecosystem productivity and carbon cycling. Measurements will be incorporated into computer simulations to examine ecosystem responses to further glacial melting. Results will help predict future impacts on the region and determine whether the climate sensitivity of the Amundsen Sea ecosystem represents the front line of processes generalizable to the greater Antarctic. This study is aligned with the large International Thwaites Glacier Collaboration (ITGC) and will make data available to the full scientific community. The program will provide training for undergraduate, graduate, post-doctoral, and early-career scientists in both science and communication. The team will also develop out-of-school science experiences for middle and high schoolers related to climate change and Antarctica. Part II: Technical summary: The Amundsen Sea hosts the most productive polynya in all of Antarctica, with atmospheric carbon dioxide uptake rates ten times higher than the Southern Ocean average. The region is vulnerable to climate change, experiencing rapid losses in sea ice, a changing icescape and some of the fastest melting glaciers flowing from the West Antarctic Ice Sheet, a process being studied by the International Thwaites Glacier Collaboration. The biogeochemical composition of the outflow from the glaciers surrounding the Amundsen Sea is largely unstudied. In collaboration with a UK-funded physical oceanographic program, ARTEMIS is using shipboard sampling for trace metals, carbonate system, nutrients, organic matter, and microorganisms, with biogeochemical sensors on autonomous vehicles to gather data needed to understand the impact of the melting ice sheet on both the coastal ecosystem and the regional carbon cycle. These measurements, along with access to the advanced physical oceanographic measurements will allow this team to 1) bridge the gap between biogeochemistry and physics by adding estimates of fluxes and transport of limiting micronutrients; 2) provide biogeochemical context to broaden understanding of the global significance of ocean-ice shelf interactions; 3) determine processes and scales of variability in micronutrient supply that drive the ten-fold increase in carbon dioxide uptake, and 4) identify small-scale processes key to iron and carbon cycling using optimized field sampling. Observations will be integrated into an ocean model to enhance predictive capabilities of regional ocean function. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The geologic record reveals that volcanic activity increases when glaciers retreat and major ice sheets thin. This relationship produces a positive feedback mechanism where the uptick in volcanism increases greenhouse gasses concentrations, leading to climate warming and further deglaciation. Although the pattern between volcanism and deglaciation is observed in the geologic record, the exact mechanism(s) by which glaciers impact a volcanic plumbing system is unknown. This project focuses on Mount Waesche, a volcano in West Antarctica, that frequently erupts during warm, interglacial periods and undergoes a period of less activity during cold, glacial periods. This project will examine compositions of the rocks and minerals from Mount Waesche to determine magma storage depths, allowing the investigators to understand how magma plumbing systems change in response to glacial cycles. These results will be compared with geodynamic simulations to understand the physics behind the effects of deglaciation on the magmatic plumbing systems within Earth’s crust. The investigators will additionally partner with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online. Isotopic and sedimentary datasets reveal that volcanic activity typically increases during interglacial periods. However, the physical mechanisms through which changes in the surface loading affect volcanic magmatic plumbing systems remain unconstrained. Recently generated 40Ar/39Ar eruption ages indicate that 86% of the dated samples from Mt. Waesche, a late Quaternary volcano in Marie Byrd land, correlate with interglacial periods, suggesting this volcano uniquely responds to changes in the West Antarctic Ice Sheet. We propose to combine the petrology of Mount Waesche’s volcanic record, constraints on changing ice loads through time, and geodynamic modelling to: (1) Determine how pre-eruptive storage conditions change during glacial and interglacial periods using whole rock and mineral compositions of volcanic rocks; (2) Conduct geodynamic modeling to elucidate the relationship between lithospheric structure, temporal variations in ice sheet thickness, and subsequent changes in crustal stresses and magmatic transport and, therefore, the mechanism(s) by which deglaciation impacts magmatic plumbing systems; (3) Use the outcomes of objectives (1) and (2) to provide new constraints on the changes in ice sheet thickness through time that could plausibly trigger future volcanic and magmatic activity in West Antarctica. This collaborative approach will provide a novel methodology to determine prior magnitudes and rates of ice load changes within the Marie Byrd Land region of Antarctica. Lastly, estimates of WAIS elevation changes from this study will be compared to ongoing studies at Mount Waesche focused on constraining last interglacial ice sheet draw down using cosmogenic exposure ages obtained from shallow drilling. The scope of work also includes a partnership with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
A nontechnical description of the project The primary scientific goal of the project is to test whether Taylor Valley, Antarctica has been eroded significantly by glaciers in the last ~2 million years (Ma). Taylor Valley is one of the Dry Valleys of the Transantarctic Mountains, which are characterized by low mean annual temperatures, low precipitation, and limited erosion. These conditions have allowed fragile glacial landforms to be preserved for up to 15 Ma. Sediment eroded and deposited by glaciers is found on the valley walls and floors, with progressively younger deposits preserved at lower elevations. Scientists can date glacial deposits to understand the process and timing of past glacial erosion. Previous work in the Dry Valleys region suggested that extremely cold glaciers like Taylor Glacier, a major outlet glacier entering the valleys, were not erosive during the last several million years. This research will test a new hypothesis that glacial erosion and sediment production beneath Taylor Glacier have been active in the last few million years. This hypothesis will be tested using a new isotopic dating method called "comminution dating' which determines when fine-grained sediment particles called silt were formed. If the sediment age is young, then the results will suggest that glacial processes have been more dynamic than previously thought. Overall, this study will increase our understanding of the nature and extent of past glaciations in Antarctica. Because the silt produced by erosion sediment is a nutrient for local ecosystems, the results will also shed light on delivery of nutrients to soils, streams, and coastal zones in high polar regions. This project will be led by an early career scientist and includes training of a Ph.D. student. A technical description of the project There is a long-standing scientific controversy about the stability of the East Antarctic Ice Sheet with much evidence centered in the Dry Valleys region of South Victoria Land. A prevailing view of geomorphologists is that the landscape has been very stable and that the effects of glaciation have been minimal for the past ~15 Ma. This project will distinguish between two end-member scenarios of glacial erosion and deposition by Taylor Glacier, an outlet glacier of the East Antarctic Ice Sheet that terminates in Taylor Valley in the Dry Valleys region of Antarctica. In the first scenario, all valley relief is generated prior to 15 Ma when non-polar climates enabled warm-based glaciers to incise and widen ancient river channels. In this case, younger glacial deposits record advances of cold-based glaciers of decreasing ice volume and limited glacial erosion, and sediment generation resulted in glacial deposits composed primarily of older recycled sediments. In the second scenario, selective erosion of the valley floor has continued to deepen Taylor Valley but has not affected the adjacent peaks over the last 2 Ma. In this scenario, the "bathtub rings" of Quaternary glacial deposits situated at progressively lower elevations through time could be due to the lowering of the valley floor by subglacial erosion and with it, production of new sediment which is now incorporated into these deposits. While either scenario would result in the present-day topography, they differ in the implied evolution of regional glacial ice volume over time and the timing of both valley relief production and generation of fine-grained particles. The two scenarios will be tested by placing time constraints on fine particle production using U-series comminution dating. This new geochronologic tool exploits the loss of 234U due to alpha-recoil. The deficiency in 234U only becomes detectable in fine-grained particles with a sufficiently high surface-area-to-volume ratio which can incur appreciable 234U loss. The timing of comminution and particle size controls the magnitude of 234U loss. While this geochronologic tool is in its infancy, the scientific goal of this proposal can be achieved by resolving between ancient and recently comminuted fine particles, a binary question that the preliminary modeling and measured data show is readily resolved.
The goal of this project is to discover whether the Antarctic scallop, Adamussium colbecki, provides a guide to sea-ice conditions in nearshore Antarctica today and in the past. Scallops may grow slower and live longer in habitats where sea ice persists for many years, limited by food, compared to habitats where sea ice melts out annually. Also, the chemicals retained in the shell during growth may provide crucial habitat information related to not only changing sea-ice conditions but also the type of food, whether it is recycled from the seafloor or produced by algae blooming when sea ice has melted. Unlocking the ecological imprint captured within the shell of the Antarctic Scallop will increase our understanding of changing sea-ice conditions in Antarctica. Further, because the Antarctic scallop had relatives living at the time when the Antarctic ice sheet first appeared, the scallop shell record may contain information on the stability of the ice sheet and the history of Antarctic shallow seas. Funding will also be integral for training a new generation of geoscientists in fossil and chemical forensics related to shallow sea habitats in Antarctica. Scallops are worldwide in distribution, are integral for structuring marine communities have an extensive fossil record dating to the late Devonian, and are increasingly recognized as important paleoenvironmental proxies because they are generally well preserved in the sediment and rock record. The primary goal of this project is to assess the differences in growth, lifespan, and chemistry (stable isotopes, trace elements) archived in the shell of the Antarctic scallop that may be indicative of two ice states: persistent (multiannual) sea ice at Explorers Cove (EC) and annual sea ice (that melts out every year) at Bay of Sails (BOS), western McMurdo Sound, Antarctica. This project will investigate growth and lifespan proxies (physical and geochemical) and will use high-resolution records of stable oxygen isotopes to determine if a melt-water signal is archived in A. colbecki shells and whether that signal captures the differing ice behavior at two sites (EC versus BOS). Stable isotopes of carbon and nitrogen in association with trace elements will be used to examine subannual productivity spikes indicative of phytoplankton blooms, which are predicted to be more pronounced during open ocean conditions. Small growth increments in the outer calcite layer will be assessed to determine if they represent fortnightly growth, if so, they could provide a high-resolution proxy for monthly environmental processes. Unlocking the environmental archive preserved in A. colbecki shells may prove to be an important proxy for understanding changing sea-ice conditions in Antarctica's past. Funding will support a Ph.D. student and undergraduates from multiple institutions working on independent research projects. Web content focused on Antarctic marine communities will be designed for museum outreach, reaching thousands of middle-school children each year. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Antarctic Ice Sheet (AIS) is sensitive to and an indicator of climate change. While ice loss is largely driven by ocean warming, this might be mitigated by enhanced snowfall on the ice sheet. By developing an understanding of the processes governing snowfall variability and change on the AIS, this project will contribute to understanding the long-term role of the AIS as a contributor to sea-level rise. This project is strongly embedded in the collaborative, open-source framework of the Community Earth System Model version 2 (CESM2) and will deliver new datasets of Antarctic precipitation for use by the research community. The project will help to build a diverse geoscience workforce by recruiting and training a student to be directly involved in the research through the Significant Opportunities in Atmospheric Research and Science (SOARS) program. The project will leverage the Climate Model Intercomparison Project 6 climate model ensemble as a whole, and CESM2 in particular, to disentangle the major sources of uncertainty and to elucidate the underlying mechanisms of Antarctic precipitation change, with a particular focus on the role of atmospheric circulation changes relative to the role of atmospheric warming. Using the variable resolution capabilities of CESM2, the team will provide the community with precipitation estimates at a very high horizontal resolution. The analyses will also use a forthcoming 100-member large ensemble. The project seeks to answer the following questions: 1) How well does the CESM2 represent the present-day Antarctic surface climate, precipitation, and surface mass balance, including the mean and its variability? 2) What is the sensitivity of simulated Antarctic precipitation to model resolution in present-day and future climates? 3) What are the roles of thermodynamics (warming atmosphere and ocean) and dynamics (changes in atmospheric circulation) in observed and projected snowfall changes? How do these break down into forced and internal variability? In particular, is there a significant forced precipitation trend due to circulation changes driven by stratospheric ozone depletion and recovery and increases in greenhouse gas concentration? 4) What processes and boundary conditions drive the ensemble spread of Antarctic precipitation in single-model and multi-model ensembles? How does the spread driven by initial surface conditions (including sea ice cover, surface fluxes, inversion strength) compare with the irreducible uncertainty due to internal climate system variability? This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Putkonen/1445205 This award supports the study of a large body of ice that is buried beneath approximately a meter of debris in the Ong Valley of the Transantarctic Mountains of East Antarctica. Preliminary analyses of this material suggest that it could be over a million years old. Most glacial ice contains tiny air bubbles that have trapped the atmospheric gases and other atmospherically transported materials existing at the time that the ice was deposited such as plant pollen, microbes and mineral dust. Samples will be collected from this buried ice mass, down to a depth of 10 meters, and cosmogenic nuclide concentrations both in the overlying debris and in the till contained in the ice will be measured. This site could contain some of the oldest ice on Earth and studies of the material contained within it may help researchers to better understand the processes involved in its survival for such long periods of time. This work will also help inform scientists about the processes involved in the development of landforms here on earth as well as those on Mars where similar dirt covered glaciers are found today. Samples of the buried ice will be collected in Ong Valley and analyzed to determine the cosmogenic nuclide concentrations in both the overlying debris and in the mineral matter suspended in the ice. The combined analysis of the target cosmogenic nuclides (Beryllium-10, Aluminum-26, and Neon-21) will allow the age of the ice to be uniquely determined and will enable determination of the rate that the ice is sublimating. The intellectual merit of this research is to unequivocally determine the age of the ice and the sublimation rate of the ice in Ong Valley, Antarctica and to better understand if this an uniquely Antarctic process or whether it could exist elsewhere on earth or on other planets. The work may also lead to the recognition of the oldest buried ice ever found on Earth and would provide a source from which direct information about the atmospheric chemistry, ancient life forms, and geology of that time could be measured. The broader impacts of this work are that it will be relevant to researchers in a number of different fields including glaciology, paleoclimatology, planetary geology, and biology. Several students will also participate in the project, conducting Antarctic field work, making measurements in the lab, attending meetings, participating in outreach activities, and producing videos. A graduate student will also write a thesis on this research. The results will be published in scientific journals and presented at conferences. The project requires field work in Antarctica.
The near surface atmosphere over West Antarctica is one of the fastest warming locations on the planet. This atmospheric warming, along with oceanic forcing, is contributing to ice sheet melt and hence rising global sea levels. An observational campaign, focused on the atmospheric boundary layer over the West Antarctic ice sheet, is envisioned. A robust set of year-round, autonomous, atmospheric and surface measurements, will be made using an instrumented 30-m tall tower at the West Antarctic ice sheet divide field camp. An additional unmanned aerial system field campaign will be conducted during the second year of this project and will supplement the West Antarctic ice sheet tall tower observations by sampling the depths of the boundary layer. The broader subject of the Antarctic ABL clearly supports a range of research activities ranging from the physics of turbulent mixing, its parameterization and constraints on meteorological forecasts, and even climatological effects, such as surface mass and energy balances. With the coming of the Thwaites WAIS program, a suite of metrological observables would be a welcome addition to the joint NSF/NERC (UK) Thwaites field campaigns. The meteorologists of this proposal have pioneered 30-m tall tower (TT) and unmanned aerial system (UAS) development in the Antarctic, and are well positioned to successfully carry out and analyze this work. In turn, the potential for these observations to advance our understanding of how the atmosphere exchanges heat with the ice sheet is high. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part I: Non-technical description: Predicting how polar ice sheets will respond to future global warming is difficult because all the processes that contribute to their melting are not well understood. This is important because the more ice on land that melts, the higher sea levels will rise. The most significant uncertainty in current estimates of sea-level rise in the coming decades is the potential contribution from the Antarctic Ice Sheet. One way to increase our knowledge about how large ice sheets respond to climate change in response to natural factors is to examine the geologic past. Natural global warming (and cooling) events in Earth’s history provide examples that we can use to better understand processes, interactions, and responses we can’t directly observe today. One such time period, approximately three million years ago (known as the Pliocene), was the last time atmospheric carbon dioxide levels were as high as they are today and, therefore, represents a time period to study to better understand the ice sheet response to a warming climate. Specifically, this project is interested in understanding how ocean currents near Antarctica, which transport heat and store carbon, behaved during these past climate events. The history of past ice sheet-ocean interactions are recorded in sediments that were deposited, layer upon layer, in the deep sea offshore Antarctica. In January-February 2018, a team of scientists and crew set sail to the Ross Sea, offshore west Antarctica, on the scientific ocean drilling vessel JOIDES Resolution to recover such sediment archives. This project focuses on a sediment core from that expedition, which captures the relatively warm Pliocene time interval, as well as the subsequent transition into cooler climates typical of the past two million years. The researchers will analyze the sediment with multiple complementary measurements, including: grain size, composition, chemistry of organic matter, physical structures, microfossil type and abundance, and more. These analyses will be done by the research team, including several students, at their respective laboratories and will then integrated into a unified record of ice sheet-ocean interactions. Ultimately, the results will be used to improve modeled projections of how the Antarctic Ice Sheet could respond to future climate change. Part II: Technical description: Geological records from the Antarctic Ice Sheet (AIS) margin demonstrate that the ice sheet oscillated in response to orbital variations in insolation (i.e., ~400, 100, 41, and 20 kyr), and it appears to be more sensitive to specific frequencies that regulate mean annual insolation (i.e., 41-kyr obliquity), particularly when the ice sheet extends into marine environments and is impacted by ocean circulation. However, the relationship between orbital forcing and the production of Antarctic Bottom Water (AABW) is unconstrained. Thus, a knowledge gap exists in understanding how changing insolation impacts ice marginal and Southern Ocean conditions that directly influence ventilation of the global ocean. The researchers hypothesize that insolation-driven changes directly affected the production and export of AABW to the Southern Ocean from the Pliocene through the Pleistocene. For example, obliquity amplification during the warmer Pliocene may have led to enhanced production and export of dense waters from the shelf due to reduced AIS extent, which, in turn, led to greater AABW outflow. To determine the relationship of AABW production to orbital regime, they plan to reconstruct both from a single, continuous record from the levee of Hillary Canyon, a major conduit of AABW outflow, on the Ross Sea continental rise. To test their hypothesis, they will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) They will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. They will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) They will use grain-size data, physical properties, XRF core scanning, CT imaging, and hyperspectral imaging to guide lithofacies analysis to infer processes occurring during glacial, deglacial, and interglacial periods. Statistical techniques and optimization methods will be applied to test for astronomical forcing of sedimentary packages in order to provide a cyclostratigraphic framework and interpret the orbital-forcing regime. (3) They will use bulk sedimentary carbon and nitrogen abundance and isotope data to determine how relative contributions of terrigenous and marine organic matter change in response to orbital forcing. All of these data will be integrated with sedimentological records to deconvolve organic matter production from its deposition or remobilization due to AABW outflow as a function of the oscillating extent of the AIS. These data sets will be integrated into a unified chronostratigraphy to determine the relationship between AABW outflow and orbital-forcing scenarios under the varying climate regimes of the Plio-Pleistocene. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Uncertainty in projections of future sea level rise comes, in part, from ice-sheet melting under the influence of unpredictable variations in ocean and atmospheric temperature near ice sheets. Using state-of-the-art modeling techniques, the Antarctic Ice Sheet Large Ensemble (AISLENS) Project will estimate the range of possible Antarctic Ice Sheet melt during the recent past and over the next several centuries that could result from such climate variations. The AISLENS Project will also facilitate research by providing modeling output as an open product to the broader climate and glaciology communities. The project will support an early career faculty member, and interdisciplinary training for a graduate student, postdoctoral fellow and undergraduate student. As a part of this project, an undergraduate course on "Sea Level Rise and Coastal Engineering" will be also developed, bringing together Earth Science and Civil Engineering students in an interdisciplinary setting and contributing to their education in sea level science and coastal adaptation. This will be done in the geographic context of the Southeastern US, the region of most concentrated vulnerability to sea-level rise in the US. The primary goal of the proposed research is to understand and quantify the role of internal climate variability in driving ice loss from the Antarctic Ice Sheet over the recent past and into the future. The AISLENS Project will encompass hundreds of simulations of Antarctic ice sheet evolution from 1950 to 2300 forced by realistic variations in climate, including snowfall and melt from fluctuating oceanic and atmospheric temperatures. Plausible realizations of Antarctic climate forcing will be generated from stochastic emulation of output from the Energy Exascale Earth System Model (E3SM) under past and future emissions scenarios. These realizations of variable climate will be used to force the MPAS Albany Land Ice (MALI) model, a state-of-the-art model of ice flow in the Antarctic Ice Sheet. In this project, AISLENS will be used to conduct uncertainty and attribution analyses. In the uncertainty analysis, the evolution of ensemble spread in simulations of the future evolution of the Antarctic Ice Sheet will be systematically decomposed to determine which temporal and spatial scales of climate variability contribute the most to future ice-sheet projection uncertainty. In the attribution analysis, a range of satellite-based observations of recent Antarctic ice loss will be compared to the envelope of internal variability of Antarctic ice loss simulated in AISLENS simulations encompassing the recent past. This analysis will provide context to recent observations indicating significant variability of Antarctic climate forcing and provide a possible path forward for conducting robust statistical inference studies for observed ice-sheet changes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This project will take initial development steps toward a laser-cut ice-sampling capability in glaciers and ice sheets. The collection of ice samples from the Polar Ice Sheets involves large amounts of time, effort, and expense. However, the most important science data are often retrieved from small sections of an ice core and, while replicate coring can supplement this section of ice core, there is often a need to retrieve additional ice samples based on subsequent scientific findings or borehole logging at a research site. In addition, there are currently no easy methods of extracting ice samples from a borehole drilled by non-coring mechanical drills that are faster, lighter, and less expensive to operate. There are numerous science applications that could potentially benefit from laser-cut ice samples, including sampling ice overlying buried impact craters and bolides, filling critical gaps in chemical records retrieved from damaged ice cores, and obtaining ice samples from sites where coring drills apply stresses that may fracture the ice. This award will explore a laser cutting technology to rapidly extract high-quality ice samples from a borehole wall. The project will investigate and validate the existing technology of laser ice sampling and will use a fiberoptic cable to deliver light pulses to a borehole instrument rather than attempting to assemble a complete laser system in an instrument deployed in a borehole. This offers a new way of retrieving ice samples from a polar ice sheet without the need to drill a borehole to collect ice-core samples (i.e., the hole could be mechanically drilled). This technology could also be used in existing boreholes or those that are made by augering through ice (i.e., not coring) or made with hot water. If successful, this technique would create the ability to rapidly retrieve ice samples with a small logistical footprint and enable science that might not be supportable otherwise. The proposed technology could eventually provide better access to ice-core samples to study past atmospheric composition for understanding past climate and inform on future potential for ice-sheet change. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This EAGER award will explore the Distributed Acoustic Sensing emerging technology that transforms a single optical fiber into a massively multichannel seismic array. This technology may provide a scalable and affordable way to deploy dense seismic networks. Experimental Distributed Acoustic Sensing equipment will be tested in the Antarctic exploiting unused (dark) strands in the existing fiber-optic cable that connects the U.S. Amundsen-Scott South Pole Station to the Remote Earth Science and Seismological Observatory (SPRESSO) located about 7.5-km from the main station. Upon processing the seismic signals, the Distributed Acoustic Sensing may provide a new tool to structurally image firn, glacial ice, and glacial bedrock. Learning how Distributed Acoustic Sensing would work on the ice sheet, scientists can then check seismological signals propagating through the Earth's crust and mantle variously using natural icequakes and earthquakes events in the surrounding area. The investigators propose to convert at least 8 km of pre-existing fiber optic cable at the Amundsen-Scott South Pole station into more than 8000 sensors to explore the potential of Distributed acoustic sensing (DAS) as a breakthrough data engine for polar seismology. The DAS array will operate for about one year, allowing them to (1) evaluate and calibrate the performance of the DAS technology in the extreme cold, very low noise (including during the exceptionally quiet austral winter) polar plateau environment; (2) record and analyze local ambient and transient signals from ice, anthropogenic signals, ocean microseism, atmospheric and other processes, as well as to study local, regional, and teleseismic tectonic events; (3) structurally image the firn, glacial ice, glacial bed, crust, and mantle, variously using active sources, ambient seismic noise, and natural icequake and earthquake events. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This project will develop a new ice-penetrating radar system that can simultaneously map glacier geometry and glacier flow along repeat profiles. Forecasting an ice-sheet’s contribution to sea level requires an estimate for the initial ice-sheet geometry and the parameters that govern ice flow and slip across bedrock. Existing ice-sheet models cannot independently determine this information from conventional observations of ice-surface velocities and glacier geometry. This introduces substantial uncertainty into simulations of past and future ice-sheet behavior. Thus, this new radar capability is conceived to provide the needed data to support higher-fidelity simulations of past and future ice-sheet behavior and more accurate projections of future sea level. The new radar system will integrate two existing radars (the multi-channel coherent radio-echo depth sounder and the accumulation radar) developed by the Center for the Remote Sensing of Ice Sheets, as well as adding new capabilities. An eight-element very high frequency (VHF; 140-215 MHz) array will have sufficient cross-track aperture to swath map internal layers and the ice-sheet base in three dimensions. A single ultra high frequency (UHF; 600-900 MHz) antenna will have the range and phase resolution to map internal layer displacement with 0.25-mm precision. The VHF array will create 3D mappings of layer geometry that enable measurements of vertical velocities by accounting for spatial offsets between repeat profiles and changing surface conditions. The vertical displacement measurement will then be made by determining the difference in radar phase response recorded by the UHF antenna for radar profiles collected at the same locations at different times. The UHF antenna will be dual-polarized and thus capable of isolating both components of complex internal reflections. This should enable inferences of ice crystal orientation fabric and widespread mapping of ice viscosity. Initial field testing of the radar will occur on the McMurdo Ice Shelf and then progress to Thwaites Glacier, Antarctica. The dual-band radar system technology and processing algorithms will be developed with versatile extensible hardware and user-friendly software so that this system will serve as a prototype for a future community radar system. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The ice of the polar ice sheets is among the purest substances on Earth, yet the small amount of impurities --such as acids-- are important to how the ice flows and what can be learned from ice cores about past climate. The goal of this project is to understand the role of such acids on the deformation of polycrystalline ice by comparing the deformation behavior of pure and sulfuric acid-doped samples. Sulfuric acid was chosen both because of its importance for interpreting past climate and because it can lead to water veins in ice at low temperatures. This work will focus on the location, movement, and impact of acids in polycrystalline ice that are more complex than in single crystals of ice. By deforming samples and performing microstructural characterization, the role of acids on deformation rate, grain evolution, and the movement of the acids themselves, will be assessed. The work will lead to the education of a Ph.D. student at Dartmouth College, introduce undergraduate students to research at both the University of Washington and Dartmouth College. Despite the ubiquitous use of the constitutive relation for ice commonly referred to as "Glen's Flow Law", significant uncertainty exists particularly with regard to the role of impurities and the development of oriented fabrics. The aim of this project is to improve the constitutive relationship for ice by performing deformation tests and microstructural characterization of pure and sulfuric acid-doped ice. The project will focus on sulfuric acid's impact on ice viscosity, fabric evolution, and diffusivity. Sulfuric acid can have both direct and indirect effects on the mechanical properties of polycrystalline ice. The direct effects change the dislocation velocity and/or density, and the indirect effects change the grain size and fabric. The complexity and interaction of these effects means that it is not possible to understand the effects of sulfuric acid by simply examining ice core specimens. In this project, the team will deform four types of ice: lab-grown ice samples doped with similar-to-natural concentrations of sulfuric acid, lab-grown high-purity ice, layered doped and pure ice, and natural ice from Antarctic ice cores. Deformation will be performed in both uniaxial compression and simple shear. The addition of simple shear tests is critical for relating the laboratory-observed deformation behavior to the behavior of polar ice sheets where the shear strain dominates ice motion in basal ice. After deformation to strains from 5 percent up to 25 percent, the microstructural development will be assessed with methods including a variety of scanning electron microscope techniques, Raman microscopy, synchrotron-based Nano-X-ray fluorescence, and ion chromatography. These analysis techniques will allow the determination of 1) the segregation and movement of impurities, 2) the rate of grain-boundary migration, 3) the number of recrystallized grains; and 4) the full orientation of the ice crystals. The results will enable both microstructural modeling of the effects of sulfuric acid and numerical modeling of diffusion in ice cores. The net result will be a better understanding of ice deformation that improves ice-core interpretation and ice-sheet modeling. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Enderlin/1643455 This award supports a project that will use a novel remote sensing method, which was initially developed to investigate melting of icebergs around Greenland, to examine spatial and temporal variations in ocean forcing around the Antarctic ice sheet periphery. Nearly three-quarters of the Antarctic ice sheet is fringed by regions of floating glacier ice called ice shelves. These ice shelves play an important role in modulating the flow of ice from the ice sheet interior towards the coast, similar to how dams regulate the downstream flow of water from reservoirs. Therefore, a reduction in ice shelf size due to changing air and ocean temperatures can have serious implications for the flux of glacier ice reaching the Antarctic coast, and thus, sea level change. Observations of recent ocean warming in the Amundsen Sea, thinning of the ice shelves, and increased ice flux from the West Antarctic ice sheet interior suggests that ice shelf destabilization triggered by ocean warming may already be underway in some regions. Although detailed observations are available in the Amundsen Sea region, our understanding of spatial and temporal variations in ocean conditions and their influence on ice shelf stability is limited by the scarceness of observations spanning the ice sheet periphery. The project will yield insights into variability in the submarine melting of ice shelves and will help advance the career of a female early-career scientist in a male-dominated field. The project will use repeat, very high-resolution (~0.5 m pixel width and length) satellite images acquired by the WorldView satellites, to estimate rates of iceberg melting in key coastal regions around Antarctica. The satellite images will be used to construct maps of iceberg surface elevation, which will be differenced in time to derive time series of iceberg volume change and area-averaged melt rates. Where ocean data are available, the melt rates will be compared to these data to assess whether variations in ocean temperature can explain observed iceberg melt variability. Large spatial gradients in melt rates will be compared to estimates of iceberg drift rates, which will be inferred from the repeat satellite images as well as numerically modeled drift rates produced by (unfunded) collaborators, to quantify the effects of water shear on iceberg melt rates. Spatial and temporal patterns in iceberg melting will also be compared to independently derived ice shelf thickness datasets. Overall, the analysis should yield insights into the effects of changes in ocean forcing on the submarine melting of Antarctic ice shelves and icebergs. The project does not require field work in Antarctica.
This project will test the hypothesis that physical and thermal properties of Antarctic firn--partially compacted granular snow in an intermediate stage between snow and glacier ice--can be remotely measured from space. Although these properties, such as internal temperature, density, grain size, and layer thickness, are highly relevant to studies of Antarctic climate, ice-sheet dynamics, and mass balance, their measurement currently relies on sparse in-situ surveys under challenging weather conditions. Sensors on polar-orbiting satellites can observe the entire Antarctic every few days during their years-long lifetime. Consequently, the approaches developed in this study, when coupled with the advancing technologies of small and low-cost CubeSats, aim to contribute to Antarctic science and lead to cost-effective, convenient, and accurate long-term analyses of the Antarctic system while reducing the human footprint on the continent. Moreover, the project will be solely based on publicly-available datasets; thus, while contributing to interdisciplinary undergraduate and graduate research and education at the grantee's institution, the project will also encourage engagement of citizen scientists through its website. The overarching goal of this project is to characterize Antarctic firn layers in terms of their thickness, physical temperature, density, and grain size through multi-frequency microwave radiometer measurements from space. Electromagnetic penetration depth changes with frequency in ice; thus, multi-frequency radiometers are able to profile firn layer properties versus depth. To achieve its objective, the project will utilize the Global Precipitation Measurement (GPM) satellite constellation as a single multi-frequency microwave radiometer system with 11 frequency channels observing the Antarctic Ice Sheet. Archived in-situ measurements of Antarctic firn density, grain size, temperature, and layer thickness will be collected and separated into training and test datasets. Microwave emissions simulated using the training data will be compared to GPM constellation measurements to evaluate and improve state-of-the-art forward microwave emission models. Based on these models, the project will develop numerical retrieval algorithms for the thermal and physical properties of Antarctic firn. Results of retrievals will be validated using the test dataset, and uncertainty and error analyses will be conducted. Lastly, changes in the thermal and physical characteristics of Antarctic firn will be examined through long-term retrieval studies exploiting GPM constellation measurements. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part I: Nontechnical Earths warming climate has the potential to drive widespread collapse of glaciers and ice sheets across the planet, driving global sea-level rise. Understanding both the rate and magnitude of such changes is essential for predicting future sea-level and how it will impact infrastructure and property. Collapse of the ice sheets of Antarctica has the potential to raise global sea-level by up to 60 meters. However, not all regions of Antarctica are equally suspectable to collapse. One area with potential for collapse is the Wilkes Subglacial Basin in East Antarctica, a region twice the size of California's Central Valley. Geologic evidence indicates that the ice-sheet in this region has retreated significantly in response to past global warming events. While the geologic record clearly indicates ice-sheets in this area are vulnerable, the rate and magnitude of any future retreat will be influenced significantly by geology of the region. In particular, ice-sheets sitting above warm Earth will collapse more quickly during warming climate. Constraining the geologic controls on the stability of the ice-sheets of the Wilkes Subglacial Basin remains challenging since the ice-sheet hides the geology beneath kilometers of ice. As a step in understanding the potential for future ice loss in the Wilkes Subglacial Basin this project will conduct geophysical analysis of existing data to better constrain the geology of the region. These results will constrain new models designed to understand the tectonics that control the behavior of the ice-sheets in the region. These new models will highlight the geological properties that exert the most significant control on the future of the ice-sheets of the Wilkes Subglacial Basin. Such insights are critical to guide future efforts aimed at collecting in-situ observations needed to more fully constrain Antarctica's potential for future sea-level. Part II: Technical Description In polar environments, inward-sloping marine basins are susceptible to an effect known as the marine ice-sheet instability (MISI): run-away ice stream drainage caused by warm ocean water eroding the ice shelf from below. The magnitude and time-scale of the ice-sheet response strongly depend on the physical conditions along the ice-bed interface, which are, to a first order, controlled by the tectonic evolution of the basin. Topography, sedimentology, geothermal heat flux, and mantle viscosity all play critical roles in ice-sheet stability. However, in most cases, these solid-Earth parameters for regions susceptible to the MISI are largely unknown. One region with potential susceptibility to MISI is the Wilkes Subglacial Basin of East Antarctica. The project will provide an integrated investigation of the Wilkes Subglacial Basin, combining geophysical analyses with both mantle flow and ice-sheet modeling to understand the stability of the ice sheet in this region, and the associated potential sea level rise. The work will be focused on four primary objectives: (1) to develop an improved tectonic model for the region based on existing seismic observations as well as existing geophysical and geological data; (2) to use the new tectonic model and seismic data to estimate the thermal, density, and viscosity structure of the upper mantle and to develop a heat flow map for the WSB; (3) to simulate mantle flow and to assess paleotopography based on our density and viscosity constraints; and (4) to assess ice-sheet behavior by modeling (a) past ice-sheet stability using our paleotopography estimates and (b) future ice-sheet stability using our heat flow and mantle viscosity estimates. Ultimately, the project will generate improved images of the geophysical structure beneath the WSB that will allow us to assess the geodynamic origin for this region and to assess the influence of geologic parameters on past, current, and future ice-sheet behavior. These efforts will then highlight areas and geophysical properties that should be the focus of future geophysical deployments. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Overview and Intellectual merit: This project extends and combines historical and recent ocean data sets to investigate ice-ocean-interactions along the Pacific continental margin of the West Antarctic Ice Sheet. The synthesis focuses on the strikingly different environments on and near the cold Ross Sea and warm Amundsen Sea continental shelves, where available measurements reach back to ~1958 and 1994, respectively. On the more extensively covered Ross Sea continental shelf, multiple reoccupations of ocean stations and transects are used to extend our knowledge of long-term ocean freshening and the mass balance of the world?s largest ice shelf. On the more rugged Amundsen Sea continental shelf, which contains the earth?s fastest melting ice shelves, continuing research on observed thermohaline variability also pursues connections between outer shelf shoals and vulnerable ice shelf grounding zones. This interdisciplinary work updates a prior study of ice shelf response to ocean thermal forcing, and uses chemical tracers to measure changes in shelf, deep and bottom water transformations and production rates. Broader Impacts : Recent and potential future rates of sea level rise are the primary broad-scale impacts of the ice and ocean changes revealed by observations in the study area. The overriding question is whether global and regional sea levels will accelerate gradually, allowing carbon usage reductions to head off the worst consequences, or so rapidly that they will contribute to major social and economic upheavals. Collaborations and data acquired by foreign vessels are also utilized to better understand the causes of rapid change in these shelf seas and ice shelves, along with associated wider implications. Data that are re-gridded, re-edited or newly collated will be archived, and results made available via presentations, publications, and press releases if warranted. This proposal does not require fieldwork in the Antarctic This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Collapse of the West Antarctic Ice Sheet (WAIS) could raise the global sea level by about 5 meters (16 feet) and the scientific community considers it the most significant risk for coastal environments and cities. The risk arises from the deep, marine setting of WAIS. Although scientists have been aware of the precarious setting of this ice sheet since the early 1970s, it is only now that the flow of ice in several large drainage basins is undergoing dynamic change consistent with a potentially irreversible disintegration. Understanding WAIS stability and enabling more accurate prediction of sea-level rise through computer simulation are two of the key objectives facing the polar science community today. This project will directly address both objectives by: (1) using state-of-the-art technologies to observe rapidly deforming parts of Thwaites Glacier that may have significant control over the future evolution of WAIS, and (2) using these new observations to improve ice-sheet models used to predict future sea-level rise. This project brings together a multidisciplinary team of UK and US scientists. This international collaboration will result in new understanding of natural processes that may lead to the collapse of the WAIS and will boost infrastructure for research and education by creating a multidisciplinary network of scientists. This team will mentor three postdoctoral researchers, train four Ph.D. students and integrate undergraduate students in this research project. The project will test the overarching hypothesis that shear-margin dynamics may exert powerful control on the future evolution of ice flow in Thwaites Drainage Basin. To test the hypothesis, the team will set up an ice observatory at two sites on the eastern shear margin of Thwaites Glacier. The team argues that weak topographic control makes this shear margin susceptible to outward migration and, possibly, sudden jumps in response to the drawdown of inland ice when the grounding line of Thwaites retreats. The ice observatory is designed to produce new and comprehensive constraints on englacial properties, including ice deformation rates, ice crystal fabric, ice viscosity, ice temperature, ice water content and basal melt rates. The ice observatory will also establish basal conditions, including thickness and porosity of the till layer and the deeper marine sediments, if any. Furthermore, the team will develop new knowledge with an emphasis on physical processes, including direct assessment of the spatial and temporal scales on which these processes operate. Seismic surveys will be carried out in 2D and 3D using wireless geophones. A network of broadband seismometers will identify icequakes produced by crevassing and basal sliding. Autonomous radar systems with phased arrays will produce sequential images of rapidly deforming internal layers in 3D while potentially also revealing the geometry of a basal water system. Datasets will be incorporated into numerical models developed on different spatial scales. One will focus specifically on shear-margin dynamics, the other on how shear-margin dynamics can influence ice flow in the whole drainage basin. Upon completion, the project aims to have confirmed whether the eastern shear margin of Thwaites Glacier can migrate rapidly, as hypothesized, and if so what the impacts will be in terms of sea-level rise in this century and beyond. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Iverson/1643120 This award supports a project to study temperate ice, using both experimental methods and modeling, in order to determine the effect of water on its flow resistance and structure and to study the mobility of water within the ice. A new mathematical model of ice stream flow and temperature is developed in conjunction with these experiments. The model includes water production, storage, and movement in deforming ice and their effects on flow resistance at ice stream margins and on water availability for lubrication of ice stream beds. Results will improve estimates of the evolution of ice stream speed and geometry in a warming climate, and so improve the accuracy of assessments of the contribution of the Antarctic ice sheet to sea level rise over the next century. Ice streams are zones of rapid flow within the Antarctic ice sheet and are primarily responsible for its discharge of ice to the ocean and major effect on sea-level rise. Water plays a central role in the flow of ice streams. It lubricates their bases and softens their margins, where flow speeds abruptly transition from rapid to slow. Within ice stream margins some ice is "temperate", meaning that it is at its melting temperature and thus contains intercrystalline water that significantly softens the ice. Two postdoctoral researchers will be supported, trained, and mentored for academic careers, and three undergraduates will be introduced to research in the geosciences. This award is part the NSF/GEO-UK NERC lead agency opportunity (NSF 14-118) and is a collaboration between Iowa State University in the United States and Oxford University in the United Kingdom. The two-phase deformation of temperate ice will be studied, with the objective of determining its effect on the flow of Antarctic ice streams. The project has two components that reinforce each other. First there will be laboratory experiments in which a rotary device at Iowa State University will be used to determine relationships between the water content of temperate ice and its rheology and permeability. The second component will involve the development at Oxford University of a two-phase, fluid-dynamical theory of temperate ice and application of this theory in models of ice-stream dynamics. Results of the experiments will guide the constitutive rules and parameter ranges considered in the theory, and application of elements of the theory will improve interpretations of the experimental results. The theory and resultant models will predict the coupled distributions of temperate ice, water, stress, deformation, and basal slip that control the evolution of ice-stream speed and geometry. The modeling will result in parameterizations that allow ice streaming to be included in continental-scale models of ice sheets in a simplified but physically defensible way.
Glacial retreat in West Antarctica is correlated with ocean warming; however, less is known about the ocean's effect on East Antarctica's glaciers including Totten Glacier located on the Sabrina Coast. The retreat of Totten Glacier has global significance as the glacier drains a sector of the East Antarctic Ice Sheet that contains enough ice to raise global sea levels by as much as 3.5 meters. This study looks to determine the influence of ocean temperatures on East Antarctic glaciers, including Totten Glacier, over the last ~18,000 years by studying seafloor sediment around Antarctica. These sediments, or muds, include the remains of microscopic marine organisms as well as tiny particles originating from eroded Antarctic bedrock. These muds provide a record of past environmental changes including ocean temperatures and the advance and retreat of glaciers. Scientists use a variety of physical and chemical analyses to determine how long ago this mud was deposited, the temperature of the ocean at that location through time, and the relative location of glacial ice. In this project, researchers will refine and test new methods for measuring ocean temperature from the sediments to better understand the influence of ocean temperatures on East Antarctic glacier response. Results will be integrated into ice sheet and climate models to improve the accuracy of ice sheet modeling efforts and subsequent sea level predictions. Results from this project will be disseminated at scientific conferences, in the scientific literature, and more broadly to the general public via the St. Petersburg Science Festival and at the Oceanography Camp for Girls. The influence of ocean temperatures on East Antarctic glaciers is largely unknown. This research focuses on ice-proximal Antarctic margin paleoceanographic proxy calibration and validation, which will improve understanding of past ocean-ice sheet interactions on a variety of timescales. In this project, researchers from the University of South Florida will (1) further develop and refine two ocean temperature proxies, foraminifer Mg/Ca and TEX86, for use in ice-proximal Antarctic continental margin sediments and (2) investigate deglacial to present (~18-0 ka) ocean-ice interactions at the outlet of the climatically sensitive Aurora Subglacial Basin. The proposed research utilizes sediment trap, sediment core, and physical oceanographic data previously collected from the Sabrina Coast continental shelf during NSF-funded cruise NBP14-02. Studies of existing sediment cores will integrate multiple paleotemperature, meltwater/salinity, nutrient, bottom water oxygen, and sea ice proxies with geophysical and lithologic data to understand past regional ocean-ice interactions. While the recent international Antarctic research focus has been on understanding the drivers of West Antarctic Ice Sheet retreat, models suggest it would be imprudent to ignore the East Antarctic Ice Sheet, which is proving more sensitive to climate perturbations than previously realized. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Worldwide publicity surrounding the calving of an iceberg the size of Delaware in July 2017 from the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula presents a unique and time-sensitive opportunity for research and education on polar ecosystems in a changing climate. The goal of this project is to convene a workshop, drawing from the large fund of intellectual capital in the US and international Antarctic research communities. The two-day workshop will be held at Florida State University where a consortium of researchers with expertise in Antarctic biological, ecological, and ecosystem sciences will be gathered to share knowledge, identify important research knowledge gaps, and outline strategic plans for research. The workshop will help advance scientific and public understanding of the continent-wide changes that Antarctic ice shelves and surrounding ecosystems experience as ice shelves change. The primary products will be reports focusing on synthesizing, coordinating and integrating research efforts to understand the ecological impacts of ice-shelf collapses and large iceberg calving along the Antarctic Peninsula. The workshop will also provide an immediate, interactive experience for K-12 school children with a hands-on ?Saturday Polar Academy?, a children?s poster session, and question-answer session during the workshop. Children will have the opportunity to interact with Antarctic researchers and become familiar with Antarctic science, organisms, ecosystems and current issues, feeding their scientific curiosity. The calving of A-68, the 5,800-km2 iceberg shed in July 2017 from the Larsen C Ice Shelf presents a unique and time-sensitive research opportunity. The scientific momentum and public interest created by this most recent event will be leveraged to convene a workshop at the earliest opportunity, drawing from the large intellectual capital in the US and international Antarctic research communities. The two-day workshop will be held at Florida State University, Coastal and Marine Laboratory on the Gulf Coast organized by Jeroen Ingels (Florida State University; FSU), Richard Aronson (Florida Institute of Technology; FIT), and Craig Smith (University of Hawaii at Manoa; UHM). A consortium of researchers with a diversity of expertise in Antarctic biological, ecological, and ecosystem sciences will be gathered to share knowledge, identify important research priorities and knowledge gaps, and outline strategic plans for research to advance understanding of the continent-wide changes that Antarctic ice shelves and surrounding ecosystems experience as ice shelves change.
Over the past century, climate science has constructed an extensive record of Earth’s ice age cycles through the chemical and isotopic characterization of various geologic archives such as polar ice cores, deep-ocean sediments, and cave speleothems. These climatic archives provide an insightful picture of ice age cycles and of the related large global sea level fluctuations triggered by these significant climate rhythms. However, such records still provide limited insight as to how or which of Earth’s ice sheets contributed to higher sea levels during past warm climate periods. This is of particular importance for our modern world: the Antarctic ice sheet is currently the world’s largest freshwater reservoir, which, if completely melted, would raise the global sea level by over 60 meters (200 feet). Yet, geologic records of Antarctic ice sheet sensitivity to warm climates are particularly limited and difficult to obtain, because the direct records of ice sheet geometry smaller than the modern one are still buried beneath the mile-thick ice covering the continent. Therefore, it remains unclear how much this ice sheet contributed to past sea level rise during warm climate periods or how it will respond to the anticipated near-future climate warming. In the proposed research we seek to develop sub-ice chemical precipitates—minerals that form in lakes found beneath the ice sheet—as a climatic archive, one that records how the Antarctic ice sheet responded to past climatic change. These sub-ice mineral formations accumulated beneath the ice for over a hundred thousand years, recording the changes in chemical and isotopic subglacial properties that occur in response to climate change. Eventually these samples were eroded by the ice sheet and moved to the Antarctic ice margin where they were collected and made available to study. This research will utilize advanced geochemical, isotopic and geochronologic techniques to develop record of the Antarctica ice sheet’s past response to warm climate periods, directly informing efforts to understand how Antarctica will response to future warming. Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth’s past warm periods. Large uncertainties, however, in reconstructions of past and future sea levels, result from the poorly constrained climate sensitivity of the Antarctic Ice sheet (AIS). This research project aims to develop the use of subglacial precipitates as an archive the Antarctic ice sheet (AIS) past response to climate change. The subglacial precipitates from East Antarctica form in water bodies beneath Antarctic ice and in doing so provide an entirely new and unique measure of how the AIS responds to climate change. In preliminary examination of these precipitates, we identified multiple samples consisting of cyclic opal and calcite that spans hundreds of thousands of years in duration. Our preliminary geochemical characterization of these samples indicates that the observed mineralogic changes result from a cyclic change in subglacial water compositions between isotopically and chemically distinct waters. Opal-forming waters are reduced (Ce* <1 and high Fe/Mn) and exhibit elevated 234U/238U compositions similar to the saline groundwater brines found at the periphery of the AIS. Calcite-forming waters, are rather, oxidized and exhibit δ18O compositions consistent with derivation from the depleted polar plateau (< -50 ‰). 234U-230Th dates permit construction of a robust timeseries describing these mineralogic and compositional changes through time. Comparisons of these time series with other Antarctic climate records (e.g., ice core records) reveal that calcite forming events align with millennial scale changes in local temperature or “Antarctic isotopic maximums”, which represent Southern Hemisphere warm periods resulting in increased Atlantic Meridional overturing circulation. Ultimately, this project seeks to develop a comprehensive model as to how changes in the thermohaline cycle induce a glaciologic response which in turn induces a change in the composition of subglacial waters and the mineralogic phase recorded within the precipitate archive. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Antarctica is almost entirely covered by ice, in places over two miles thick. This ice hides a landscape that is less well known than the surface of Mars and represents one of Earth's last unexplored frontiers. Ice-penetrating radar images provide a remote glimpse of this landscape including ice-buried mountains larger than the European Alps and huge fjords twice as deep as the Grand Canyon. The goal of this project is to collect sediment samples derived from these landscapes to determine when and under what conditions these features formed. Specifically, the project seeks to understand the landscape in the context of the history and dynamics of the overlying ice sheet and past mountain-building episodes. This project accomplishes this goal by analyzing sand collected during previous sea-floor drilling expeditions off the coast of Antarctica. This sand was supplied from the continent interior by ancient rivers when it was ice-free over 34 million year ago, and later by glaciers. The project will also study bedrock samples from rare ice-free parts of the Transantarctic Mountains. The primary activity is to apply multiple advanced dating techniques to single mineral grains contained within this sand and rock. Different methods and minerals yield different dates that provide insight into how Antarctica?s landscape has eroded over the many tens of millions of years during which sand was deposited offshore. The dating techniques that are being developed and enhanced for this study have broad application in many branches of geoscience research and industry. The project makes cost-effective use of pre-existing sample collections housed at NSF facilities including the US Polar Rock Repository, the Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. The project will contribute to the STEM training of two graduate and two undergraduate students, and includes collaboration among four US universities as well as international collaboration between the US and France. The project also supports outreach in the form of a two-week open workshop giving ten students the opportunity to visit the University of Arizona to conduct STEM-based analytical work and training on Antarctic-based projects. Results from both the project and workshop will be disseminated through presentations at professional meetings, peer-reviewed publications, and through public outreach and media. The main objective of this project is to reconstruct a chronology of East Antarctic subglacial landscape evolution to understand the tectonic and climatic forcing behind landscape modification, and how it has influenced past ice sheet inception and dynamics. Our approach focuses on acquiring a record of the cooling and erosion history contained in East Antarctic-derived detrital mineral grains and clasts in offshore sediments deposited both before and after the onset of Antarctic glaciation. Samples will be taken from existing drill core and marine sediment core material from offshore Wilkes Land (100°E-160°E) and the Ross Sea. Multiple geo- and thermo-chronometers will be employed to reconstruct source region cooling history including U-Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar. This offshore record will be augmented and tested by applying the same methods to onshore bedrock samples in the Transantarctic Mountains obtained from the US Polar Rock Repository and through fieldwork. The onshore work will additionally address the debated incision history of the large glacial troughs that cut the range, now occupied by glaciers draining the East Antarctic Ice Sheet. This includes collection of samples from several age-elevation transects, apatite 4He/3He thermochronometry, and Pecube thermo-kinematic modeling. Acquiring an extensive geo- and thermo-chronologic database will also provide valuable new information on the poorly known ice-hidden geology and tectonics of subglacial East Antarctica that has implications for improving supercontinent reconstructions and understanding continental break-up.
1245871/McCarthy This award supports a project to conduct laboratory experiments with a new, custom-fabricated cryo-friction apparatus to explore ice deformation oscillatory stresses like those experienced by tidewater glaciers in nature. The experimental design will explore the dynamic frictional properties of periodically loaded ice sliding on rock. Although the frictional strength of ice has been studied in the past these studies have all focused on constant rates of loading and sliding. The results of this work will advance understanding of ice stream dynamics by improving constraints on key material and frictional properties and allowing physics-based predictions of the amplitude and phase of glacier strain due to tidally induced stress variations. The intellectual merit of this work is that it will result in a better understanding of dynamic rheological parameters and will provide better predictive tools for dynamic glacier flow. The proposed experiments will provide dynamic material properties of ice and rock deformation at realistic frequencies experienced by Antarctic glaciers. The PIs will measure the full spectrum of material response from elastic to anelastic to viscous. The study will provide better constraints to improve predictive capability for glacier and ice-stream response to external forcing. The broader impacts of the work include providing estimates of material properties that can be used to broaden our understanding of glacier flow and that will ultimately be used for models of sea level rise and ice sheet stability. The ability to predict sea level in the near future is contingent on understanding of the processes responsible for flow of Antarctic ice streams and glaciers. Modulation of glacier flow by ocean tides represents a natural experiment that can be used to improve knowledge of ice and bed properties, and of the way in which these properties depend on time-varying forcings. Presently, the influence of tidal forcing on glacier movement is poorly understood, and knowledge of ice properties under tidal loading conditions is limited. The study will generate results of interest beyond polar science by examining phenomena that are of interest to seismology, glaciology and general materials science. The project will provide valuable research and laboratory experience for two undergraduate interns and will provide experience for the PI (currently a postdoc) in leading a scientific project. The three PIs are early career scientists. This proposal does not require fieldwork in the Antarctic.
The ice sheets of Antarctica and Greenland are losing mass and contributing to accelerating global sea-level rise. Satellite altimetry provides precise measurement of ice-sheet volume change, but computing ice-sheet mass change—the quantity relevant for estimating the ice sheet’s sea-level contribution—requires knowing the density of the ice sheet. The density near the ice-sheet surface also affects age estimates of air bubbles recovered in ice cores, which are a key source of information on past climate changes. Ice-sheet density is primarily controlled by the rate at which firn (snow that has persisted for a year or more on ice sheets) compacts into ice, but there is currently no widely accepted theory of how this compaction occurs. The goal of this project is thus to advance understanding of how firn densifies. The team will conduct laboratory experiments and analyze ice-penetrating radar and ice-core data from Antarctica. A key desired outcome of the project is a new model of firn densification that can be used to improve satellite-based altimetry measurements of present-day ice-sheet change and reconstructions of past climate changes from ice cores. This project will combine laboratory experiments, numerical modeling, and geophysical techniques to determine the rheology of firn as it compacts to form ice. The team will use two methods to measure firn compaction: (1) lab-based experiments and (2) analysis of ice-core and radar data. For the lab-based work, the team will conduct a suite of compaction experiments on synthetic firn samples under uni-axial strain and constant temperature and axial stress. They will also measure the grain-size evolution. By running a large number of experiments (> 25), the team will constrain key parameters that determine how firn compaction rate depends on density, temperature, grain size, and axial stress. The experiments will be conducted in a table-top apparatus at temperatures as low as -40 degrees C and axial stresses up to 4 MPa. For the field-data-based component, the team will analyze ice-core and ice-penetrating radar data to produce the first coincident set of radar-derived firn compaction rates, borehole temperatures, firn densities, and firn grain sizes. Results from lab and field data will be tied together using a numerical firn compaction model. This model is formulated using conservation of mass, momentum, and energy, along with an explicit description of firn rheology and grain-size evolution. Constraints on firn rheology will be incorporated into this model and the team will use it to examine fundamental questions about how changes in the climate affect firn density. This is a crucial unknown that contributes significant measurement uncertainty in estimates of past and present climate change. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Ice shelves slow the movement of the grounded ice sheets that feed them. This reduces the rate at which ice sheets lose mass to the oceans and contribute to sea-level rise. But ice shelves can be susceptible to collapse, particularly when surface meltwater accumulates in vulnerable areas. Meltwater lakes can create and enlarge fractures within the ice shelves, thereby triggering or hastening ice-shelf collapse. Also, water refreezing within ice shelves warms the ice and could affect the flow of the ice by changing its viscosity, which depends on temperature. The drainage of water across the surface of Antarctica and where it accumulates has received little attention. This drainage was assumed to be insignificant, but recent work shows that meltwater can drain for tens of kilometers across ice-shelf surfaces and access areas that would otherwise not accumulate meltwater. Surface meltwater drainage could play a major role in the future stability of ice sheets. This drainage is the focus of this project. The team will develop and test physics-based mathematical models of water flow and ice-shelf flow, closely informed by remote sensing observations, to ask (1) how drainage systems will grow in response to the increased melt rates that are predicted for this century, (2) how this drainage is influenced by ice dynamics and (3) whether enlarged drainage systems could deliver meltwater to areas of ice shelves that are vulnerable to water-driven collapse. The team hypothesizes that refreezing of meltwater in snow and firn will prove important for hydrology by impacting the permeability of the snow/firn and for ice-shelf dynamics by releasing latent heat within the ice and lowering ice viscosity. The project will examine these issues by (1) conducting a remote sensing survey of the structure and temporal evolution of meltwater systems around Antarctica, (2) developing and analyzing mathematical models of water flow across ice shelves, and (3) examining idealized and realistic models of ice-shelf flow. This project will support a first-time NSF PI, a post-doctoral researcher and a graduate student. An outreach activity will make use of the emerging technology of Augmented Reality to visualize the dynamics of ice sheets in three dimensions to excite the public about glaciology at outreach events around New York City. This approach will be made publicly available for wider use as Augmented Reality continues to grow in popularity. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.
The continent of Antarctica has approximately the same surface area as the continental United States, though we know significantly less about its underlying geology and seismic activity. Multinational investments in geophysical infrastructure over the last few decades, especially broadband seismometers operating for several years, are allowing us to observe many interesting natural phenomena, including iceberg calving, ice stream slip, and tectonic earthquakes. To specifically leverage those past investments, we will analyze past and current data to gain a better understanding of Antarctic seismicity. Our recent research revealed that certain large earthquakes occurring elsewhere in the world triggered ice movement near various stations throughout Antarctica. We plan to conduct an exhaustive search of the terabytes of available data, using cutting-edge computational techniques, to uncover additional evidence for ice crevassing, ice stream slip, and earth movement during earthquakes. One specific focus of our research will include investigating whether some of these phenomena may be triggered by external influences, including passing surface waves from distant earthquakes, ocean tides, or seasonal melt. We plan to produce a catalog of the identified activity and share it publicly, so the public and researchers can easily access it. To reach a broader audience, we will present talks to high school classes, including Advanced Placement classes, in the Austin, Texas and Atlanta, Georgia metropolitan areas with emphasis on general aspects of seismic hazard, climate variability, and the geographies of Antarctica. This project will provide research opportunities for undergraduates, training for graduate students, and support for an early-career scientist. In recent years, a new generation of geodetic and seismic instrumentation has been deployed as permanent stations throughout Antarctica (POLENET), in addition to stations deployed for shorter duration (less than 3 years) experiments (e.g. AGAP/TAMSEIS). These efforts are providing critical infrastructure needed to address fundamental questions about both crustal-scale tectonic structures and ice sheets, and their interactions. We plan to conduct a systematic detection of tectonic and icequake activities in Antarctica, focusing primarily on background seismicity, remotely-triggered seismicity, and glacier slip events. Our proposed tasks include: (1) Identification of seismicity throughout the Antarctic continent for both tectonic and ice sources. (2) An exhaustive search for additional triggered events in Antarctica during the last ~15 years of global significant earthquakes. (3) Determination of triggered source mechanisms and whether those triggered events also occur at other times, by analyzing years of data using a matched-filter analysis (where the triggered local event is used to detect similar events). (4) Further analysis of GPS measurements over a ~5.5 year period from Whillans Ice Plain, which suggests that triggering of stick-slip events occurred after the largest earthquakes. An improved knowledge of how the Antarctic ice sheet responds to external perturbations such as dynamic stresses from large distant earthquakes and recent ice unloading could lead to a better understanding of ice failure and related dynamic processes. By leveraging the vast logistical investment to install seismometers in Antarctica over the last decade, our project will build an exhaustive catalog of tectonic earthquakes, icequakes, calving events, and any other detectable near-surface seismic phenomena.
Howat/1543501 This award will provide support to map the topography of the Antarctic continent at high spatial resolution and precision to measure ice sheet change, constrain models, correct satellite observations and support logistics. Antarctica remains the most poorly mapped landmass on Earth, yet, accurate and complete surface topography is essential for a wide range of scientific and logistical activities. The group will use a combination of very high-resolution satellite imagery, existing ground and airborne survey data and the NSF's supercomputer infrastructure to construct the Reference Elevation Model of Antarctica (REMA): a continuous, time-stamped reference surface that will be one to two orders of magnitude higher resolution than currently available. REMA will be constructed from stereoscopic, submeter resolution imagery collected by the WorldView satellite constellation, obtained at no cost in partnership with the National Geospatial Intelligence Agency and the NSF-supported Polar Geospatial Center (PGC). The high spatial and radiometric resolution of the imagery enables photogrammetric digital elevation model (DEM) extraction over low contrast terrains such as snow, ice and shadows. These DEM's have horizontal and vertical offsets of up to several meters that can be reduced to the DEM relative accuracy of 0.2 meter with a single ground control point. We will use available control points from ground and lidar surveys to register individual DEMs and optimized, least-squares co-registration to provide control between overlapping DEM's over large regions. REMA will have a posting of 10 meters and accuracy better than 1 meter. It will be distributed openly by the Polar Geospatial Center. This project will involve substantial undergraduate participation, providing training in geospatial science and remote sensing, and REMA will be used extensively for the outreach programs of the Byrd Polar and Climate Research Center. This project does not require field work in Antarctica.
Coastal waters surrounding Antarctica represent some of the most biologically rich and most untouched ecosystems on Earth. In large part, this biological richness is concentrated within the numerous openings that riddle the expansive sea ice (these openings are known as polynyas) near the Antarctic continent. These polynyas represent regions of enhanced production known as hot-spots and support the highest animal densities in the Southern Ocean. Many of them are also located adjacent to floating extensions of the vast Antarctic Ice Sheet and receive a substantial amount of meltwater runoff each year during the summer. However, little is known about the specific processes that make these ecosystems so biologically productive. Of the 46 Antarctic coastal polynyas that are presently known, only a handful have been investigated in detail. This project will develop ecosystem models for the Ross Sea polynya, Amundsen polynya, and Pine Island polynya; three of the most productive Antarctic coastal polynyas. The primary goal is to use these models to better understand the fundamental physical, chemical, and biological interacting processes and differences in these processes that make these systems so biologically productive yet different in some respects (e.g. size and productivity) during the present day settings. Modeling efforts will also be extended to potentially assess how these ecosystems may have functioned in the past and how they might change in the future under different physical and chemical and climatic settings. The project will advance the education of underrepresented minorities through Stanford?s Summer Undergraduate Research in Geoscience and Engineering (SURGE) Program. SURGE will provide undergraduates the opportunity to gain mentored research experiences at Stanford University in engineering and the geosciences. Old Dominion University also will utilize an outreach programs for local public and private schools as well as an ongoing program supporting the Boy Scout Oceanography merit badge program to create outreach and education impacts. Polynyas (areas of open water surrounded by sea ice) are disproportionately productive regions of polar ecosystems, yet controls on their high rates of production are not well understood. This project will provide quantitative assessments of the physical and chemical processes that control phytoplankton abundance and productivity within polynyas, how these differ for different polynyas, and how polynyas may change in the future. Of particular interest are the interactions among processes within the polynyas and the summertime melting of nearby ice sheets, including the Thwaites and Pine Island glaciers. In this proposed study, we will develop a set of comprehensive, high resolution coupled physical-biological models and implement these for three major, but diverse, Antarctic polynyas. These polynyas, the Ross Sea polynya, the Amundsen polynya, and Pine Island polynya, account for >50% of the total Antarctic polynya production. The research questions to be addressed are: 1) What environmental factors exert the greatest control of primary production in polynyas around Antarctica? 2) What are the controlling physics that leads to the heterogeneity of dissolved iron (dFe) supply to the euphotic zone in polynyas around the Antarctic continental shelf? What effect does this have on local rates of primary production? 3) What are the likely changes in the supply of dFe to the euphotic zone in the next several decades due to climate-induced changes in the physics (winds, sea-ice, ice shelf basal melt, cross-shelf exchange, stratification and vertical mixing) and how will this affect primary productivity around the continent? The Ross Sea, Amundsen, and Pine Island polynyas are some of the best-sampled polynyas in Antarctica, facilitating model parameterization and validation. Furthermore, these polynyas differ widely in their size, location, sea ice dynamics, relationship to melting ice shelves, and distance from the continental shelf break, making them ideal case studies. For comparison, the western Antarctic Peninsula (wAP), a productive continental shelf where polynyas are a relatively minor contributor to biological production, will also be modeled. Investigating specific processes within different types Antarctic coastal waters will provide a better understand of how these important biological oases function and how they might change under different environmental conditions.
Accurately measuring precipitation in Antarctica is important for purposes such as calculating Antarctica?s mass balance and contribution to global sea level rise, interpreting ice core records, and validating model- and satellite-based precipitation estimates. There is a critical need for reliable, autonomous, long-term measurements of Antarctic precipitation in order to better understand its variability in space in time. Such records over time are essentially absent from the continent, despite their importance. This project will deploy and test instrumentation to measure and record rates of snowfall and blowing snow in Antarctica. Project goals are based on installation of four low-power, autonomous Antarctic precipitation systems (APS) co-located at automatic weather station (AWS) sites in the Ross Island region of Antarctica. The APSs are designed with an integrated sensor approach to provide multiple types of observations of snow accumulation types at the test sites. The APSs are designed to construct an accurate timeline of snow accumulation, and to distinguish the water equivalent of fallen precipitation from surface blowing (lofted) snow, a prime confounding factor. The standard suite of instruments to be deployed includes: precipitation gauge with double Alter windshield, laser disdrometer, laser snow height sensor, optical precipitation detector, anemometer at gauge height, and a visible /infrared webcam. These instruments have previously been shown to work well in cold regions applications.
Bromirski/1246151 This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is "locally" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.
This award funds the continued management and operations (M&O) of the IceCube Neutrino Observatory (ICNO) located at the South Pole Station. The core team of researchers and engineers maintain the existing ICNO infrastructure at the South Pole and home institution, guaranteeing an uninterrupted stream of scientifically unique, high-quality data. The M&O activities are built upon eight highly successful years of managing the overall ICNO operations after the start of science operations in 2008. Construction of ICNO was supported by NSF's Major Research Equipment and Facilities Construction (MREFC) account and was completed on schedule and within budget in 2010. Effective coordination of efforts by the core M&O personnel and efforts by personnel within the IceCube Collaboration has yielded significant increases in the performance of this cubic-kilometer detector over time. The scientific output from the IceCube Collaboration during the past five years has been outstanding. The broader impacts of the ICNO/M&O activities are strong, involving postdoctoral, graduate, and (in some cases) undergraduate students in the day-today operation & calibration of the neutrino detector. The extraordinary physics results recently produced by ICNO and its extraordinary location at South Pole have a high potential to excite the imagination of high school children and the public in general at a national and international level. The current ICNO/M&O effort produces better energy and angular resolution information about detected neutrino events, has more efficient data filters and more accurate detector simulations, and enables continuous software development for systems that are needed to acquire and analyze data. This has produced data acquisition and data management systems with high robustness, traceability, and maintainability. The current ICNO/M&O effort includes: (1) resources for both distributed and centrally managed activities, and (2) additional accountability mechanisms for "in-kind" and institutional contributions. Both are necessary to ensure that the detector maintains its capability to produce quality scientific data at the level required to achieve the detector's scientific discovery objectives. Recent ICNO discoveries of cosmic high-energy neutrinos (some reaching energies close to and over 2.5 PeV) and oscillating atmospheric neutrinos in a previously unexplored energy range from 10 to 60 GeV became possible because of the "state-of-the-art" detector configuration, excellently supported infrastructure, and cutting-edge science analyses. The ICNO has set limits on Dark Matter annihilations, made precision measurements of the angular distribution of cosmic ray muons, and characterized in detail physical properties of the Antarctic 2.5-km thick ice sheet at South Pole. The discovery of high-energy cosmic neutrinos by IceCube with a flux at the level anticipated for those associated with high-energy gamma- and cosmic-ray accelerators brightens the prospect for identifying the sources of the highest energy particles.
This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Thwaites Glacier system dominates the contribution to sea-level rise from Antarctica. Predicting how this system will evolve in coming decades, and thereby its likely contribution to sea level, requires detailed understanding of how it has responded to changes in climate and oceanographic conditions in the past. This project will provide a record of regional sea-level change by establishing chronologies for raised marine beaches as well as the timing and duration of periods of retreat of Thwaites Glacier during the past 10,000 years by sampling and dating bedrock presently covered by Thwaites Glacier via subglacial drilling. Together with climatic and oceanographic conditions from other records, these will provide boundary conditions for past-to-present model simulations as well as those used to predict future glacier changes under a range of climate scenarios. Specifically, the project will test the hypothesis--implied by existing geological evidence from the region--that present rapid retreat of the Thwaites Glacier system is reversible. The team aims to utilize two approaches: 1. To reconstruct relative sea level during the Holocene, it will map and date raised marine and shoreline deposits throughout Pine Island Bay. Chronological constraints on sea-level change will be provided by radiocarbon dating of organic material in landforms and sediments that are genetically related to past sea level, such as shell fragments, bones of marine fauna, and penguin guano. 2. To obtain geological evidence for past episodes of grounding-line retreat, the team will apply cosmogenic-nuclide exposure-dating of subglacial bedrock. Using drill systems recently developed for subglacial bedrock recovery, the team will obtain subglacial bedrock from sites where ice thickness is dynamically linked to grounding-line position in the Thwaites system (specifically in the Hudson Mountains, and near Mount Murphy). Observation of significant cosmogenic-nuclide concentrations--the team will primarily measure Beryllium-10 and in situ Carbon-14--in these samples would provide direct, unambiguous evidence for past episodes of thinning linked to grounding-line retreat as well as constraints on their timing and duration. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Predictions of future changes of the Antarctic ice sheet are essential for understanding changes in the global sea level expected for the coming centuries. These predictions rely on models of ice-sheet flow that in turn rely on knowledge of the physical conditions of the Antarctic continent beneath the ice. Exploration of Antarctica by land, sea, and air has advanced our understanding of the geological material under the Antarctic ice sheet, but this information has not yet been fully integrated into ice-sheet models. This project will take advantage of existing data from decades of US and international investment in geophysical surveys to create a new understanding of the geology underlying the Amundsen Sea and the adjacent areas of the West Antarctic Ice Sheet—a portion of Antarctica that is considered particularly vulnerable to collapse. A series of new datasets called “Bed Classes” will be developed that will translate the geological properties of the Antarctic continent in ways that can be incorporated into ice-sheet models. This project will develop a new regional geologic/tectonic framework for the Amundsen Sea Embayment and its ice catchments using extensive marine and airborne geophysical data together with ground-based onshore geophysical and geological constraints to delineate sedimentary basins, bedrock ridges, faults, and volcanic structures. Using this new geologic interpretation of the region, several key issues regarding the geologic influence on ice-sheet stability will be addressed: whether the regional heat flow is dominated by localization along the faults or lithology; the role of geology on the sources, sinks, and flow-paths of subglacial water; the distribution of sediments that determine bed-character variability; and the extent of geologic control on the current Thwaites Glacier grounding line. The impact of improved geological knowledge on ice-sheet models will be tested with the development of a set of “Bed Class” grids to capture these new insights for use in the models. Bed Classes will be tested within the Parallel Ice Sheet Model framework with initial experiments to identify the sensitivity of model simulations to geological parameterizations. Through a series of workshops with ice-sheet modelers, the Bed Classes will be refined and made accessible to the broader modelling community. This work aims to ensure that the Bed-Class concept can be applied more broadly to ice-sheet models working in different geographic areas and on different timescales. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part I: Nontechnical Antarcticas ice sheets constitute the largest ice mass on Earth, with approximately 53 meters of sea level equivalent stored in the East Antarctic Ice Sheet alone. The history of the East Antarctic Ice Sheet is therefore important to understanding and predicting changes in sea level and Earths climate. There is conflicting evidence regarding long-term stability of the East Antarctic Ice Sheet, over the last twenty million years. To better understand past ice sheet changes, together with the history of the Transantarctic Mountains, accurate time scales are needed. One of the few dating methods applicable to the Antarctic glacial deposits, that record past ice sheet changes, is the measurement of rare isotopes produced by cosmic rays in surface rock samples, referred to as cosmogenic nuclides. Whenever a rock surface is exposed/free of cover, cosmic rays produce rare isotopes such as helium-3, beryllium-10, and neon-21within the minerals. This project will involve measurement of all three isotopes in some of the oldest glacial deposits found at high elevation in the Transantarctic Mountains. Because the amount of each isotope is directly linked to the exposure time, this can be used to calculate the age of a surface. This method requires knowledge of the rates that cosmic radiation produces each isotope, which depends upon mineral composition, and is presently a limitation of the method. The goal of this project is to advance and enhance existing measurement methods and expand the range of possibilities in surface dating with new measurements of all three isotopes in pyroxene, a mineral that is commonly found throughout the Transantarctic Mountains. This technological progress will allow a better application of the surface exposure dating method, which in turn will help to reconstruct Antarctic ice sheet history and provide valuable knowledge of former ice-extent. Understanding Antarcticas ice-sheet history is crucial to predict its influence on past and future sea level changes. Part II: Technical Description Measurements of in-situ produced cosmogenic nuclides in Antarctic surficial rock samples provide unique time scales for glacial and landscape evolution processes. However, due to analytical challenges, pyroxene-bearing and widely distributed lithologies like the Ferrar dolerite of the Transantarctic Mountains, are underutilized. This proposal aims to changes this and to improve the cosmogenic nuclide methodologies for stable isotopes (21Ne and 3He) and radioactive nuclides (10Be) in pyroxenes. Proposed methodological improvements will be directly applicable to erosion rates and deposition ages of important glacial deposits, such as the controversial Sirius Group tills, and also to younger glacial features. Bennett Platform is the focus of this study because it is one of the southern-most Sirius Group outcrops along the Transantarctic Mountains, where cosmogenic ages are sparse. Preliminary measurements demonstrate large discrepancies between 3He and 21Ne age determinations in Sirius Group pyroxenes. One possible explanation is composition dependence of the 21Ne production rates. Coupled measurements of 3He, 21Ne, and 10Be in well-characterized pyroxene mineral separates from Ferrar dolerite will be used to better constrain the production rates, major element and trace element dependencies, the assumptions of the method, and ultimately advance the application of cosmogenic nuclides to mafic Antarctic lithologies. The main goals of this study are to improve measurement protocols for 10Be in pyroxene, and the determination of the composition dependence of 21Ne production rates by measuring mineral compositions (by electron microprobe), and nuclide concentrations in mineral pairs from young lava flows. Further aims are the validation of the nucleogenic contributions and the effects of helium diffusive loss through measurements of 3He/21Ne production ratios, combined with measurements of shielded samples of the Ferrar dolerite. Combined measurements of 3He, 21Ne and 10Be in pyroxenes have rarely been published for individual samples in Antarctica. The new and unique measurements of this study will advance the applicability of in-situ produced cosmogenic nuclides to both young and ancient Antarctic surfaces. The study will be performed using existing samples: no field work is requested. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites and neighboring glaciers in the Amundsen Sea Embayment are rapidly losing mass in response to recent climate warming and related changes in ocean circulation. Mass loss from the Amundsen Sea Embayment could lead to the eventual collapse of the West Antarctic Ice Sheet, raising the global sea level by up to 2.5 meters (8 feet) in as short as 500 years. The processes driving the loss appear to be warmer ocean circulation and changes in the width and flow speed of the glacier, but a better understanding of these changes is needed to refine predictions of how the glacier will evolve. One highly sensitive process is the transitional flow of glacier ice from land onto the ocean to become a floating ice shelf. This flow of ice from grounded to floating is affected by changes in air temperature and snowfall at the surface; the speed and thickness of ice feeding it from upstream; and the ocean temperature, salinity, bathymetry, and currents that the ice flows into. The project team will gather new measurements of each of these local environmental conditions so that it can better predict how future changes in air, ocean, or the ice will affect the loss of ice to the ocean in this region. Current and anticipated near-future mass loss from Thwaites Glacier and nearby Amundsen Sea Embayment region is mainly attributed to reduction in ice-shelf buttressing due to sub-ice-shelf melting by intrusion of relatively warm Circumpolar Deep Water into sub-ice-shelf cavities. Such predictions for mass loss, however, still lack understanding of the dominant processes at and near grounding zones, especially their spatial and temporal variability, as well as atmospheric and oceanic drivers of these processes. This project aims to constrain and compare these processes for the Thwaites and the Dotson Ice Shelves, which are connected through upstream ice dynamics, but influenced by different submarine troughs. The team's specific objectives are to: 1) install atmosphere-ice-ocean multi-sensor remote autonomous stations on the ice shelves for two years to provide sub-daily continuous observations of concurrent oceanic, glaciologic, and atmospheric conditions; 2) measure ocean properties on the continental shelf adjacent to ice-shelf fronts (using seal tagging, glider-based and ship-based surveys, and existing moored and conductivity-temperature-depth-cast data), 3) measure ocean properties into sub-ice-shelf cavities (using autonomous underwater vehicles) to detail ocean transports and heat fluxes; and 4) constrain current ice-shelf and sub-ice-shelf cavity geometry, ice flow, and firn properties for the ice-shelves (using radar, active-source seismic, and gravimetric methods) to better understand the impact of ocean and atmosphere on the ice-sheet change. The team will also engage the public and bring awareness to this rapidly changing component of the cryosphere through a "Live from the Ice" social media campaign in which the public can follow the action and data collection from the perspective of tagged seals and autonomous stations. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Gerbi/1643301 This award supports a project to develop software that will allow researchers considering seismic or radar field surveys to test, ahead of time, whether the data they plan to collect will have sufficient resolution to measure the natural variations in the mechanical properties of ice, which determine the response of flowing ice to changing climatic conditions. The mechanical properties of ice depend largely on the temperature and the orientation of the crystals that make up the ice. The most accurate method for measuring ice crystal orientation and temperature is through drilling and direct analysis of an ice core. However, this method is very costly, time-consuming, and limited in spatial coverage. Geophysical techniques, such as seismic and radar, can cover much more area, but we have little knowledge about the practical limitations of these techniques as they relate to calculating mechanical properties. This project addresses that knowledge gap through construction of a computational toolbox that will allow accurate assessment of the ability of geophysical surveys to image crystal orientation and ice temperature. Researchers can then use these tools to adjust the field survey plans to maximize the return on investment. By working to improve the efficiency and effectiveness of future geophysical work related to glacial flow, this proposal will improve scientists? ability to quantify sea-level variations within the larger context of climate change. The project includes building new user-friendly, publicly accessible software and instructional modules. The work will provide training for graduate and undergraduate students, who will play a role in research and develop instructional materials. Ice viscosity, the resistance of ice to flow, exerts significant control over ice velocity. Therefore, mapping ice viscosity is important for understanding the current and future behavior of glaciers and ice sheets. To do so, scientists must determine the temperature and crystal orientation fabric throughout the ice. Seismic and radar techniques can survey large areas quickly, and thus are promising, yet not fully tested, methods to efficiently measure the thermal and mechanical structure of flowing ice. As part of this project, scientists will develop and use a computational framework to quantify the degree to which seismic and radar techniques can resolve the crystal orientation fabric and temperature of streaming ice, and then test how sensitive ice flow is to the attendant uncertainty. To meet these goals, a numerical toolbox will be built which will allow the glacier/ice stream geometry and physical properties (temperature, crystal orientation fabric, density and acidity) to be varied. The toolbox will be capable of both creating synthetic radar and seismic profiles through forward modeling and inverting synthetic profiles to allow evaluation of how well geophysical techniques can image the original thermal and mechanical structure. These simulated radar and seismic data will allow scientists to better quantify the influence of the variability in mechanical properties of the ice on flow velocities and patterns. The results of this work will guide planning for future field campaigns, making them more effective and efficient. This project does not require fieldwork in the Antarctic.
This project evaluates the role that water and rock/ice properties at the base of a fast moving glacier, or ice stream, play in controlling its motion. In Antarctica, where surface melting is limited, the speed of ice flow through the grounding zone (where ice on land detaches, and begins to float on ocean water) controls the rate at which glaciers contribute to sea level rise. The velocity of the ice stream is strongly dependent on resistance from the bed, so understanding the processes that control resistance to flow is critical in predicting ice sheet mass balance. In fact, the Intergovernmental Panel on Climate Change (IPCC) recognized this and stated in their 4th assessment report that reliable predictions of future global sea-level rise require improved understanding of ice sheet dynamics, which include basal controls on fast ice motion. Drilling to obtain direct observations of basal properties over substantial regions is prohibitively expensive. This project uses passive source seismology to "listen to" and analyze sounds generated by water flow and/or sticky spots at the ice/bed interface to evaluate the role that basal shear stress plays in ice flow dynamics. Because polar science is captivating to both scientists and the general public, it serves as an excellent topic to engage students at all levels with important scientific concepts and processes. In conjunction with this research, polar science educational materials will be developed to be used by students spanning middle school through the University level. Starting in summer 2015, a new polar science class for high school students in the California State Summer School for Mathematics and Science (COSMOS) will be offered at the University of California-Santa Cruz. This curriculum will be shared with the MESA Schools Program, a Santa Cruz and Monterey County organization that runs after-school science clubs led by teachers at several local middle and high schools with largely minority and underprivileged populations. This proposal extends the period of borehole and surface geophysical monitoring of the Whillians Ice Stream (WIS) established under a previous award for an additional 2 years. Data from the WIS network demonstrated that basal heterogeneity, revealed by microseismicity, shows variation over scales of 100's of meters. An extended observation period will allow detailed seismic characterization of ice sheet bed properties over a crucial length scale comparable to the local ice thickness. Due to the fast ice velocity (>300 m/year), a single instrumented location will move approximately 1 km during the extended 3 year operational period, allowing continuous monitoring of seismic emissions as the ice travels over sticky spots and other features in the bed (e.g., patches of till or subglacial water bodies). Observations over ~1km length scales will help to bridge a crucial gap in current observations of basal conditions between extremely local observations made in boreholes and remote observations of basal shear stress inferred from inversions of ice surface velocity data.
Non-technical description: Global sea-level rise is a significant long-term risk for human population and infrastructure. To mitigate and properly react to this threat, society needs accurate predictions of future sea-level variations. The largest uncertainty in these predictions comes from estimating the amount of ice that melts from polar ice sheets, especially from the West Antarctica ice sheet. Right now, scientists estimate the mass variations of ice sheets in two ways. The first way is using airplanes and repeated flybys to monitor the variation of ice sheet topography and estimate the gain or loss of ice. The second way is using satellite measurements to track gravity fluctuations that correlate with the variation of ice sheet volume. Both techniques work, but both have limitations including cost and resolution. This project uses a passive seismic monitoring method to estimate the change in weight of the ice pressing on the Earth's crust. One advantage of this seismic method is that vibrations are recorded continuously; therefore, it is possible to monitor the changes of the ice sheet with better temporal resolution. The sensitivity of the seismic waves also provides a picture of the structure of the interface between the ice and the rocks beneath the ice, where most of the dynamics and changes of the ice sheet take place. This information is difficult to obtain with other methods. In this project, the researchers will process and analyze previously acquired seismic data from the POLENET-ANET array, measuring variations in seismic wave speed through time to assess the amount of ice lost or gained. They will also determine important information about the mechanical properties at the ice-rock interface. The project will support a postdoctoral scholar to develop this new branch of seismological research and more generally the field of environmental seismology. This project will also support the education of a PhD student who will work in close collaboration with the postdoctoral scholar and the two researchers. Technical description: The researchers plan to monitor ice-mass variations in the West-Antarctic ice sheet by measuring and interpreting seismic velocity changes in crust beneath the ice sheet. This project will extend similar work already completed on the Greenland ice sheet, where ice-mass fluctuations were found to lead to poroelastic changes in the crust and modify the seismic-wave velocity. This investigation uses a passive seismology method, whereby repetitive seismic noise correlation functions are computed from records of Earth's ambient seismic noise field. Measurements of the temporal changes in the correlation functions are made and then related to variations of the poroelastic properties of the crust. The physical model for the relationship between ice-mass change and surface-wave velocity change has previously been verified using GRACE satellite data in Greenland. This project will specifically focus on the recent rapid ice loss in Western Antarctica using data from the POLENET-ANET seismic network. A comparison between the ice-sheet behaviors in Greenland and Antarctica will provide clarification about the underlying physical processes responsible for the observed seismic velocity changes. This new method will be a transformative approach to monitor ice sheets with the potential for much higher spatial and temporal resolution than existing methods. The fact that this method relies on seismic waves makes the approach completely independent from other modern ice-sheet monitoring techniques.
This investigation will reconstruct past behavior of the East Antarctic Ice Sheet during periods of warmer-than-present climate, such as the Pliocene, in order to better project the likely response of Earth's largest ice sheet to anthropogenic warming. Containing the equivalent of ~55 m sea-level rise, the future evolution of the East Antarctic Ice Sheet has clear societal ramifications on a global scale as temperatures continue to rise. Therefore, determining ice-sheet sensitivity to climate on the scale predicted for the next two centuries is a matter of increasing urgency, particularly in light of evidence suggesting the East Antarctic Ice Sheet is more dynamic than previously thought. This research will provide a terrestrial geologic record of long-term ice-sheet behavior from sites immediately adjacent the East Antarctic Ice Sheet in the Transantarctic Mountains, with which the project will help ascertain how the ice sheet responded to past warm periods. The project will focus primarily on the Pliocene warm period, 5 to 3 million years ago, as this represents the closest analogue to 21st Century climate conditions. The proposed research will investigate glacial deposits corresponding to the East Antarctic Ice Sheet in the central Transantarctic Mountains in order to expand the geologic record of past ice-sheet behavior. The overarching research objectives are to improve understanding of the East Antarctic Ice Sheet's configuration during periods of warmer-than-present climate, such as the Pliocene warm period, and to determine whether the ice sheet underwent significant volume changes or remained relatively stable in response to warming. To address these goals, the investigation will map and date glacial deposits preserved at mountain sites immediately adjacent the ice sheet. Specifically, we will: (i) employ multiple cosmogenic nuclides (10Be, 26Al, 21Ne) to establish more fully ice-thickness histories for the upper Shackleton and Beardmore Glaciers, where they exit the ice sheet; (ii) use this record to identify periods during which the East Antarctic Ice Sheet was at least as extensive as today; and (iii) use these data to assess long-term ice-sheet variability in East Antarctica, with particular emphasis on Pliocene warm episodes. This research will require Antarctic fieldwork, glacial-geologic mapping, and cosmogenic surface-exposure dating.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The proposed project will investigate the coldest and driest parts of the Transantarctic Mountains (Ong Valley at Nimrod Glacier and Moraine Canyon at Amundsen Glacier) where the lack of running water and biological activity in the modern environment is thought to have preserved the landscape, essentially unchanged, for millions of years. Contrary to this common belief, it is hypothesized that the landscape does evolve, perhaps as fast as many surfaces in the Dry Valleys area where both loose soil and bedrock surfaces have been degrading at a rate of about 1-2 m/Myrs for the past several million years. The research team will rely on analysis of the both stable and radioactive cosmogenic isotopes that accumulate in near surface soil and bedrock. Collectively these measurements allow comparison of the long term landscape evolution to current processes and environmental drivers such as wind speed. The results of this work will improve understanding of the evolution of the Earth's surface and directly aid in evaluating imagery of Martian geomorphology. Continued reliance on students provides a broader impact to this proposed research and firmly grounds this effort in its educational mission.
This award supports a project to find and date geologic evidence of past ice-marginal positions in the Pensacola Mountains, which border the Foundation Ice Stream at the head of the Weddell Sea embayment. The project will involve glacial geologic mapping and cosmogenic-nuclide surface exposure dating of glacially transported erratics. An ice-flow model will be used to link our exposure-dating results together in a glaciologically consistent way, and to relate them to regional LGM to Holocene elevation changes. A secondary focus of the project seeks to improve the effectiveness of exposure-dating methods in understanding ice sheet change. Changes in the location of the ice margin, and thus the exposure ages that record these changes, are controlled not only by regional ice sheet mass balance, but also by local effects on snow- and icefields immediately adjacent to the exposure-dating sites. This part of the project will combine glaciological observations near the present ice margin with targeted exposure- age sampling in an effort to better understand the processes controlling the ice margin location, and improve the interpretation of very recent exposure-age data as a record of latest Holocene to present ice sheet changes. The intellectual merit of the project is that it will provide direct geologic evidence of LGM-to-Holocene ice volume change in a region of Antarctica where no such evidence now exists. The broader impacts of the work involve both gathering information needed for accurate understanding of past and present global sea level change. Secondly, this project will help to develop and maintain the human and intellectual resources necessary for continued excellence in polar research and global change education, by linking experienced Antarctic researchers with early career scientists who seek to develop their expertise in both research and education. In addition, it brings together two early career scientists whose careers are focused at opposite ends of the research-education spectrum, thus facilitating better integration of research and education both in the careers of these scientists and in the outcome of this project. This award has field work in Antarctica.
The Siple Coast in West Antarctica has undergone significant glacier changes over the last millenium. Several ice streams--rapidly moving streams of ice bordered by slow-moving ice--exist in this region that feeds into the Ross Ice Shelf. A long-term slowdown of Whillans Ice Stream appears to be occurring, and this is affecting the zone between the Whillans and Mercer Ice Streams. However, the consistency of this slowdown and resulting changes to the shear margin between the two ice streams are unknown. The goal of this project is to quantify the observed changes over the past decade and understand the dynamic processes that cause them. A collateral benefit of and driver for this as a RAPID project is to test a method for assessing where crevassing will develop in this zone of steep velocity gradients. Such a method may benefit not only near-term field-project planning in the 2018-19 field season, but also planning for future fieldwork and traverses. The team will use remote sensing feature-tracking techniques to determine transient velocity patterns and shifts in the shear-zone location over the last 10-plus years. This velocity time series will be incorporated into a large-scale ice-sheet model to estimate ice-sheet susceptibility to changing boundary conditions over the next century based on likely regional ice-flux scenarios. This approach is an extension of recent work conducted by the team that shows promise for predicting areas of changing high strain rates indicative of an active glacier shear margin. The ultimate objectives are to characterize the flow field of merging ice streams over time and investigate lateral boundary migration. This will provide a better understanding of shear-margin control on ice-shelf and up-glacier stability. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The East Antarctic Ice Sheet holds the largest volume of freshwater on the planet, in total enough to raise sea level by almost two hundred feet. Even minor adjustments in the volume of ice stored have major implications for coastlines and climates around the world. The question motivating this project is how did the ice grow to cover the continent over thirty million years ago when Antarctica changed from a warmer environment to an ice-covered southern continent? The seafloor of Prydz Bay, a major drainage basin of the East Antarctic Ice Sheet (EAIS), has been drilled previously to recover sediments dating from millions of years prior to and across the time when inception of continental ice sheets occurred in Antarctica. The last remnants of plant material found as 'biomarkers' in the ocean sediments record the chemical signatures of rain and snowfall that fed the plants and later the expanding glaciers. Sediment carried by glaciers was also deposited on the seafloor and can be analyzed to discover how glaciers flowed across the landscape. Here, the researchers will identify precipitation changes that result from, and drive, ice sheet growth. This study will gather data and further analyze samples from the seafloor sediment archives of the International Ocean Discovery Program's (IODP) core repositories. Ultimately these findings can help inform temperature-precipitation-ice linkages within climate and ice sheet models. The project will support the training of three female, early career scientists (PhD & MS students, and research technician) and both PIs and the PhD student will continue their engagement with broadening participation efforts (e.g., Women in Science and Engineering Program; local chapters of Society for the advancement of Native Americans and Chicanos in Science and other access programs) to recruit undergraduate student participants from underrepresented minorities at both campuses and from local community colleges. Antarctic earth science education materials will be assisted by professional illustrations to be open access and used in public education and communication efforts to engage local communities in Los Angeles CA and Columbia SC. The researchers at the University of Southern California and the University of South Carolina will together study the penultimate moment of the early Cenozoic greenhouse climate state: the ~4 million years of global cooling that culminated in the Eocene/Oligocene transition (~34 Ma). Significant gaps remain in the understanding of the conditions that preceded ice expansion on Antarctica. In particular, the supply of raw material for ice sheets (i.e., moisture) and the timing, frequency, and duration of precursor glaciations is poorly constrained. This collaborative proposal combines organic and inorganic proxies to examine how Antarctic hydroclimate changed during the greenhouse to icehouse transition. The central hypothesis is that the hydrological cycle weakened as cooling proceeded. Plant-wax hydrogen and carbon isotopes (hydroclimate proxies) and Hf-Nd isotopes of lithogenous and hydrogenous sediments (mechanical weathering proxies) respond strongly and rapidly to precipitation and glacial advance. This detailed and sensitive combined approach will test whether there were hidden glaciations (and/or warm events) that punctuated the pre-icehouse interval. Studies will be conducted on Prydz Bay marine sediment cores in a depositional area for products of weathering and erosion that were (and are) transported through Lambert Graben from the center of Antarctica. The project will yield proxy information about the presence of plants and the hydroclimate of Antarctica and the timing of glacial advance, and is expected to show drying associated with cooling and ice-sheet growth. The dual approach will untangle climate signals from changes in fluvial versus glacial erosion of plant biomarkers. This proposal is potentially transformative because the combination of organic and inorganic proxies can reveal rapid transitions in aridity and glacial expansion, that may have been missed in slower-response proxies and more distal archives. The research is significant as hydroclimate seems to be a key player in the temperature-cryosphere hysteresis. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Nontechnical description of proposed research: This project will apply cutting-edge seismic imaging methods to existing seismic data to study the three-dimensional structure of the Earth beneath the ice-covered Antarctic continent. The study will improve understanding of Earth structure and hotspots and geologically recent and ancient rift systems. The results will be useful for models of ice movement and bedrock elevation changes due to variation in ice sheet thickness. The results will also help guide future seismic data collection. The researchers will transfer existing software from the high-performance computers at The University of Rhode Island to the Alabama supercomputer facilities. The project will also broaden public understanding of scientific research in Antarctica by engaging with the students and teachers in Socorro County, New Mexico to discuss career opportunities in science, technology, engineering, and mathematics (STEM), the Earth Sciences, and the importance of computers in scientific research. Project personnel from Alabama will visit Socorro and share research with students at New Mexico Tech and at the Socorro High School. The project will also train undergraduate and graduate students in the expanding field of computational seismology, by applying these approaches to study Antarctic geology. Technical description of proposed research: The project seeks to better resolve the three-dimensional Antarctic mantle structure and viscosity and to identify locations of ancient rifts within the stable East Antarctic lithosphere. To accomplish this, the researchers will utilize full-waveform tomographic inversion techniques that combine long-period ambient noise data with earthquake constraints to more accurately resolve structure than traditional tomographic approaches. The proposed research will be completed using the Alabama supercomputer facilities and the programs and methodology developed at The University of Rhode Island. The new tomographic results will be useful in assessing lithospheric structure beneath Dronning Maud Land as well as the Wilkes and Aurora Subglacial Basins in East Antarctica, where previous rifting episodes and mid-lithospheric discontinuities will be explored. In West Antarctica, the work will elucidate the easternmost extent of the West Antarctic Rift System as well as rifted structure and possible compositional variations within the Weddell Sea. The accuracy of existing Antarctic seismic models will be quantified through model validation approaches. The researchers will highlight regions of Antarctica where tomographic resolution is still lacking and where future deployments would improve resolution.
A profound transformation in ecosystem structure and function is occurring in coastal waters of the western Weddell Sea, with the collapse of the Larsen B ice shelf. This transformation appears to be yielding a redistribution of energy flow between chemoautotrophic and photosynthetic production, and to be causing the rapid demise of the extraordinary seep ecosystem discovered beneath the ice shelf. This event provides an ideal opportunity to examine fundamental aspects of ecosystem transition associated with climate change. We propose to test the following hypotheses to elucidate the transformations occurring in marine ecosystems as a consequence of the Larsen B collapse: (1) The biogeographic isolation and sub-ice shelf setting of the Larsen B seep has led to novel habitat characteristics, chemoautotrophically dependent taxa and functional adaptations. (2) Benthic communities beneath the former Larsen B ice shelf are fundamentally different from assemblages at similar depths in the Weddell sea-ice zone, and resemble oligotrophic deep-sea communities. Larsen B assemblages are undergoing rapid change. (3) The previously dark, oligotrophic waters of the Larsen B embayment now support a thriving phototrophic community, with production rates and phytoplankton composition similar to other productive areas of the Weddell Sea. To document rapid changes occurring in the Larsen B ecosystem, we will use a remotely operated vehicle, shipboard samplers, and moored sediment traps. We will characterize microbial, macrofaunal and megafaunal components of the seep community; evaluate patterns of surface productivity, export flux, and benthic faunal composition in areas previously covered by the ice shelf, and compare these areas to the open sea-ice zone. These changes will be placed within the geological, glaciological and climatological context that led to ice-shelf retreat, through companion research projects funded in concert with this effort. Together these projects will help predict the likely consequences of ice-shelf collapse to marine ecosystems in other regions of Antarctica vulnerable to climate change. The research features international collaborators from Argentina, Belgium, Canada, Germany, Spain and the United Kingdom. The broader impacts include participation of a science writer; broadcast of science segments by members of the Jim Lehrer News Hour (Public Broadcasting System); material for summer courses in environmental change; mentoring of graduate students and postdoctoral fellows; and showcasing scientific activities and findings to students and public through podcasts.
This project investigates a rapidly moving section of the West Antarctic Ice Sheet known as the Whillans Ice Stream. Ice streams and outlet glaciers are the major pathways for ice discharge from ice sheets into the ocean. Consequently, understanding ice stream dynamics, specifically the processes controlling the frictional resistance of ice sliding on sediments at its base, is essential for predictive modeling of how Earth's ice sheets will respond to a changing climate. Rather than flowing smoothly, Whillans Ice Stream advances in stick-slip cycles: brief periods of rapid sliding, equivalent to magnitude 7 earthquakes, alternating with much longer periods of repose. The PIs will perform simulations of these stick-slip cycles using computer codes originally developed for modeling tectonic earthquakes. By matching observed ice motions, the PIs will constrain the range of frictional processes acting at the base of the ice stream. An additional focus of the project is on brittle fracture processes in ice, expressed through seismic waves radiated by faulting and/or crevassing episodes that accompany the large-scale sliding events. An understanding of ice fracture provides a basis for assessing the susceptibility of ice shelves to rifting and catastrophic disintegration. Project results will be incorporated into outreach activities (from elementary school to community college events) as well as a polar science class for the California State Summer School for Mathematics and Science (COSMOS) program for high school students. Simulations of the stick-slip cycle will employ 3D dynamic rupture models that simultaneously solve for the seismic wavefield and rupture process, consistent with elastodynamic material response and friction laws on the ice stream bed. Stresses and frictional properties will be varied to achieve consistency with surface GPS and broadband seismic data as well as borehole seismograms from the WISSARD project. The results will be interpreted using laboratory till friction experiments, which link velocity-weakening/strengthening behavior to temperature and water content, and to related experiments quantifying basal drag from ice flow over rough beds. The source mechanism of seismicity accompanying the slip events (shear faulting versus crevassing) will be determined using 3D waveform modeling in conjunction with mechanical models of the seismic source processes. This proposal does not require fieldwork in the Antarctic.
Baker/1141411 This award supports a project to undertake a systematic examination of the effects of soluble impurities, particularly sulfuric acid, on the creep of polycrystalline ice as function of temperature, strain rate and impurity concentration. The working hypothesis is that soluble impurities will increase the flow rate of polycrystalline ice compared to high-purity ice, that this effect will be temperature dependent and that the impurities by affecting the re-crystallization and grain growth will change the fabric of the ice. Both H2SO4-doped and high-purity poly-crystalline ice will be produced by freezing sheets of ice, breaking them up, sieving the ice particles and then sintering them in a mold into fine-grained cylindrical specimens with at least ten grains across their diameter. The resulting microstructures (dislocation structure, grain size and shape, grain boundary character and micro-structural location of the acid) will be characterized using a variety of techniques including: optical microscopy, scanning electron microscopy, including secondary electron imaging, electron backscattered patterns, energy dispersive X-ray spectroscopy, electron channeling contrast imaging, and X-ray topography. The creep of both the H2SO4-doped and the high-purity polycrystalline ice will be undertaken at a range of temperatures and stresses. The ice?s response to the creep deformation (grain boundary sliding, dislocation motion, re-crystallization, grain boundary migration, impurity redistribution) will be studied using a combination of methods. The creep behavior will be modeled and related to the microstructure. Of particular interest is how impurities affect the activation energy for creep. The intellectual merit of the work is that it will lead to a better understanding of glacier ice and will enable glaciologists to model the influence of impurities on the flow and fabric development in polycrystalline ice. The broader impacts of the project include the knowledge that will be gained of the effects of impurities on the flow of ice which will allow paleoclimatologists to better interpret ice core data and will allow scientists developing predictive models to better address the flow of ice sheets under various climate change scenarios. The project will also lead to the education and training of a Ph.D. student, several undergraduates and some high school students. Results from the research will be published in refereed journals. Several undergraduates, typically two per year, will also perform the work. Dartmouth aggressively courts minority students at all degree levels, and we will seek women or minority group undergraduates for this project. The undergraduates will be supported by Dartmouth?s nationally-honored Women In Science Project or by REU funding. The undergraduates? research will integrate closely with the Ph.D. student?s studies. Hanover High School students will also be involved in the project and develop an educational kit to introduce students to the properties of ice. Results from the research will be published in refereed journals and presented at conferences.
Nontechnical Description Glacier ice loss from Antarctica has the potential to lead to a significant rise in global sea level. One line of evidence for accelerated glacier ice loss has been an increase in the rate at which the land has been rising across the Antarctic Peninsula as measured by GPS receivers. However, GPS observations of uplift are limited to the last two decades. One goal of this study is to determine how these newly observed rates of uplift compare to average rates of uplift across the Antarctic Peninsula over a longer time interval. Researchers will reconstruct past sea levels using the age and elevation of ancient beaches now stranded above sea level on the low-lying coastal hills of the Antarctica Peninsula to determine the rate of uplift over the last 5,000 years. The researchers will also analyze the structure of the beaches using ground-penetrating radar and the characteristics of beach sediments to understand how sea-level rise and past climate changes are recorded in beach deposits. The benefits of these new records will be threefold: (1) they will help determine the natural variability of the Antarctic Ice Sheet and relative sea level (2) they will provide new insight about uplift and the structure of the Earth's interior; and 3) they will help researchers refine the methods used to determine the age of geologic deposits. The study results will be shared in outreach events at K-12 schools and with visitors of the Santa Barbara Natural History Museum. Three graduate students will be supported through this project. Technical description Paleo sea-level data is critical for reconstructing the size and extent of past ice sheets, documenting increased uplift following glacial retreat, and correcting gravity-based measurements of ice-mass loss for the impacts of post-glacial rebound. However, there are only 14 sites with relative sea-level data for Antarctica compared to over 500 sites used in a recent study of the North American Ice-Sheet complex. The purpose of this project is to use optically stimulated luminescence to date a series of newly discovered raised beaches along the eastern Antarctic Peninsula and an already known, but only preliminarily dated, series of raised beaches in the South Shetland Islands. Data to be collected at the raised beaches include the age and elevation, ground-penetrating radar profiles, and the roundness of cobbles and the lithology of ice-rafted debris. The study will test three hypotheses: (1) uplift rates have increased in modern times relative to the late Holocene across the Antarctic Peninsula, (2) the sea-level history at the northern tip of the Antarctic Peninsula is distinctly different than that of the South Shetland Islands, and (3) cobble roundness and the source of ice-rafted debris on raised beaches varied systematically through time reflecting the climate history of the northern Antarctic Peninsula.
Licht/1443433 Sediments deposited by the Antarctic ice sheet are an archive of its history with time and help geologists to determine how the remote interior of the ice sheet has changed over the past several hundred thousand years. This project will focus on the formation and dynamics of moraines (accumulations of dirt and rocks that are incorporated in the glacier surface or have been pushed along by the glacier as it moves) near the blue ice area of Mt. Achernar in the central Transantarctic Mountains in Antarctica.. The study will improve basic understanding of the formation of these moraines. Fieldwork at the site will focus on imaging the internal structure of the moraine to determine the processes by which it, and others like it, form over time. Additional analyses will include measurements of ice flow and collection of rock samples to determine the timing of debris deposition and the changes in the sources of sediments from deep within the Antarctic continent. The project will provide both graduate and undergraduate students training in paleoclimate studies, geology, and numerical modeling approaches. The broader impacts of the proposed work include hands on training in the Earth Sciences for graduate and undergraduate students, collaboration with colleagues in New Zealand and Sweden to provide an international research experience for students from the US, and three educational modules to be delivered by student researchers regarding Antarctica's role in global environments. The research is societally relevant and multidisciplinary and the topics are ideal for sharing with the public. All research findings will be made publicly available to others via timely publication in high-impact, peer-reviewed journals and all data will be submitted to the National Snow and Ice Data Center, and excess samples will be provided to the U.S. Polar Rock Repository. Direct observations of ice sheet history from the margins of Antarctica's polar plateau are essential for testing numerical ice sheet models, and the laterally extensive, blue-ice moraines of the Mt. Achernar Moraine complex in the central Transantarctic Mountains contain a unique and nearly untapped direct, quasi-continuous record of ice sheet change over multiple glacial cycles. The project objectives include improved understanding of processes and rates of blue ice moraine formation, as well as identifying the topographic, glaciological, and climatic controls on their evolution. Data to be collected with fieldwork in Antarctica include: imaging of internal ice structure with ground-penetrating radar, measurement of ice flow velocity and direction with a global positioning system (GPS) array, analysis of debris concentration and composition in glacier ice, state-of-the-art cosmogenic multi-nuclide analyses to determine exposure ages of moraine debris, mapping of trimlines and provenance analysis. Numerical model simulations, constrained by field data, will be used to evaluate the factors influencing changes in glacier flow that potentially impact the accumulation of the moraine debris. All together, the new data and modeling efforts will improve conceptual models of blue ice moraine formation, and thereby make them a more valuable proxy for developing a better understanding of the history of the ice sheet.
In Antarctica, millions of years of freezing have led to the development of hundreds of meters of thick permafrost (i.e., frozen ground). Recent research demonstrated that this slow freezing has trapped and concentrated water into local and regional briny aquifers, many times more salty than seawater. Because salt depresses the freezing point of water, these saline brines are able to persist as liquid water at temperatures well below the normal freezing point of freshwater. Such unusual groundwater systems may support microbial life, supply nutrients to coastal ocean and ice-covered lakes, and influence motion of glaciers. These briny aquifers also represent potential terrestrial analogs for deep life habitats on other planets, such as Mars, and provide a testing ground for the search for extraterrestrial water. Whereas much effort has been invested in understanding the physics, chemistry, and biology of surface and near-surface waters in cold polar regions, it has been comparably difficult to investigate deep subsurface aquifers in such settings. Airborne ElectroMagnetics (AEM) subsurface imaging provides an efficient way for mapping salty groundwater. An international collaboration with the University of Aarhus in Denmark will enable knowledge and skill transfer in AEM techniques that will enhance US polar research capabilities and provide US undergraduates and graduate students with unique training experiences. This project will survey over 1000 km2 of ocean and land near McMurdo Station in Antarctica, and will reveal if cold polar deserts hide a subsurface pool of liquid water. This will have significant implications for understanding cold polar glaciers, ice-covered lakes, frozen ground, and polar microbiology as well as for predictions of their response to future change. Improvements in permafrost mapping techniques and understanding of permafrost and of underlying groundwaters will benefit human use of high polar regions in the Antarctic and the Arctic. The project will provide the first integrative system-scale overview of subsurface water distribution and hydrological connectivity in a partly ice-free coastal region of Antarctica, the McMurdo Dry Valleys. Liquid water is relatively scarce in this environment but plays an outsized role by influencing, and integrating, biological, biogeochemical, glaciological, and geological processes. Whereas surface hydrology and its role in ecosystem processes has been thoroughly studied over the last several decades, it has been difficult to map out and characterize subsurface water reservoirs and to understand their interactions with regional lakes, glaciers, and coastal waters. The proposed project builds on the "proof-of-concept" use of AEM technology in 2011. Improvements in sensor and data processing capabilities will result in about double the depth of penetration of the subsurface during the new data collection when compared to the 2011 proof-of-concept survey, which reached depths of 300-400m. The first field season will focus on collecting deep soundings with a ground-based system in key locations where: (i) independent constraints on subsurface structure exist from past drilling projects, and (ii) the 2011 resistivity dataset indicates the need for deeper penetration and high signal-to-noise ratios achievable only with a ground-based system. The regional airborne survey will take place during the second field season and will yield subsurface electrical resistivity data from across several valleys of different sizes and different ice cover fractions.
Abstract for the general public: The margins of the Antarctic ice sheet have advanced and retreated repeatedly over the past few million years. Melting ice from the last retreat, from 19,000 to 9,000 years ago, raised sea levels by 8 meters or more, but the extents of previous retreats are less well known. The main goal of this project is to understand how Antarctic ice retreats: fast or slow, stepped or steady, and which parts of the ice sheet are most prone to retreat. Antarctica loses ice by two main processes: melting of the underside of floating ice shelves and calving of icebergs. Icebergs themselves are ephemeral, but they carry mineral grains and rock fragments that have been scoured from Antarctic bedrock. As the icebergs drift and melt, this 'iceberg-rafted debris' falls to the sea-bed and is steadily buried in marine sediments to form a record of iceberg activity and ice sheet retreat. The investigators will read this record of iceberg-rafted debris to find when and where Antarctic ice destabilized in the past. This information can help to predict how Antarctic ice will behave in a warming climate. The study area is the Weddell Sea embayment, in the Atlantic sector of Antarctica. Principal sources of icebergs are the nearby Antarctic Peninsula and Weddell Sea embayment, where ice streams drain about a quarter of Antarctic ice. The provenance of the iceberg-rafted debris (IRD), and the icebergs that carried it, will be found by matching the geochemical fingerprint (such as characteristic argon isotope ages) of individual mineral grains in the IRD to that of the corresponding source area. In more detail, the project will: 1. Define the geochemical fingerprints of the source areas of the glacially-eroded material using samples from each major ice stream entering the Weddell Sea. Existing data indicates that the hinterland of the Weddell embayment is made up of geochemically distinguishable source areas, making it possible to apply geochemical provenance techniques to determine the origin of Antarctica icebergs. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till samples to characterize detritus supplied by the Recovery and Foundation ice streams. 2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information identifies which groups of ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents), and the stratigraphy of the cores shows the relative sequence of ice stream activity through time. A further dimension is added by determining the time lag between fine sediment erosion and deposition, using a new method of uranium-series isotope measurements in fine grained material. Technical abstract: The behavior of the Antarctic ice sheets and ice streams is a critical topic for climate change and future sea level rise. The goal of this proposal is to constrain ice sheet response to changing climate in the Weddell Sea during the three most recent glacial terminations, as analogues for potential future warming. The project will also examine possible contributions to Meltwater Pulse 1A, and test the relative stability of the ice streams draining East and West Antarctica. Much of the West Antarctic ice may have melted during the Eemian (130 to 114 Ka), so it may be an analogue for predicting future ice drawdown over the coming centuries. Geochemical provenance fingerprinting of glacially eroded detritus provides a novel way to reconstruct the location and relative timing of glacial retreat during these terminations in the Weddell Sea embayment. The two major objectives of the project are to: 1. Define the provenance source areas by characterizing Ar, U-Pb, and Nd isotopic signatures, and heavy mineral and Fe-Ti oxide compositions of detrital minerals from each major ice stream entering the Weddell Sea, using onshore tills and existing sediment cores from the Ronne and Filchner Ice Shelves. Pilot data demonstrate that detritus originating from the east and west sides of the Weddell Sea embayment can be clearly distinguished, and published data indicates that the hinterland of the embayment is made up of geochemically distinguishable source areas. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till to characterize detritus supplied by the Recovery and Foundation ice streams. 2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information will identify which ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents). The stratigraphy of the cores will show the relative sequence of ice stream activity through time. A further time dimension is added by determining the time lag between fine sediment erosion and deposition, using U-series comminution ages.
This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Science Coordination Office will facilitate planning and coordination of the science and broader impacts of several international research projects studying Thwaites Glacier--one of the largest glaciers in Antarctica. The glacier is located on the Pacific coast of the Antarctic continent. It is flowing almost twice as fast now as in the 1970s, and is one of the largest likely contributors to sea-level rise over the coming decades to centuries. Many of the factors that will affect the speed and retreat of Thwaites Glacier will be addressed by the set of projects funded by the Thwaites initiative. The Science Coordination Office comprises a US-UK science and communications team that will work with each project's scientists and students, logistics planners, and NSF and NERC to ensure the overall success of the project. The Office will maintain an informative website, and will produce content to explain the activities of the scientists and highlight the results of the work. The role of the Science Coordination Office will be to enhance integration and coordination among the science projects selected for the joint NSF-NERC Thwaites initiative to achieve maximum collective scientific and societal impact. The Office will facilitate scientific and logistical planning; facilitate data management, sharing, and discovery; and facilitate and support web content, outreach, and education for this high-profile research endeavor. The Office's role will be key to enabling the program to achieve its scientific goals and for the program to be broadly recognized and valued by scientists, the public, and policymakers. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Snow or firn aquifers are areas of subsurface meltwater storage that form in glaciated regions experiencing intense summer surface melting and high snowfall. Aquifers can induce hydrofracturing, and thereby accelerate flow or trigger ice-shelf instability leading to increased ice-sheet mass loss. Widespread aquifers have recently been discovered in Greenland. These have been modelled and mapped using new satellite and airborne remote-sensing techniques. In Antarctica, a series of catastrophic break-ups at the Wilkins Ice Shelf on the Antarctic Peninsula that was previously attributed to effects of surface melting and brine infiltration is now recognized as being consistent with a firn aquifer--possibly stimulated by long-period ocean swell--that enhanced ice-shelf hydrofracture. This project will verify inferences (from the same mapping approach used in Greenland) that such aquifers are indeed present in Antarctica. The team will survey two high-probability sites: the Wilkins Ice Shelf, and the southern George VI Ice Shelf. This two-year study will characterize the firn at the two field sites, drill shallow (~60 m maximum) ice cores, examine snow pits (~2 m), and install two AMIGOS (Automated Met-Ice-Geophysics Observing System) stations that include weather, GPS, and firn temperature sensors that will collect and transmit measurements for at least a year before retrieval. Ground-penetrating radar survey in areas surrounding the field sites will track aquifer extent and depth variations. Ice and microwave model studies will be combined with the field-observed properties to further explore the range of firn aquifers and related upper-snow-layer conditions. This study will provide valuable experience for three early-career scientists. An outreach effort through field blogging, social media posts, K-12 presentations, and public lectures is planned to engage the public in the team?s Antarctic scientific exploration and discovery. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Tremblay, Marissa; Granger, Darryl; Balco, Gregory; Lamp, Jennifer
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. ______________________________________________________________________________________________________________ Part I: Nontechnical Description Scientists study the Earth's past climate in order to understand how the climate will respond to ongoing global change in the future. One of the best analogs for future climate might the period that occurred approximately 3 million years ago, during an interval known as the mid-Pliocene Warm Period. During this period, the concentration of carbon dioxide in the atmosphere was similar to today's and sea level was 15 or more meters higher, due primarily to warming and consequent ice sheet melting in polar regions. However, the temperatures in polar regions during the mid-Pliocene Warm Period are not well determined, in part because we do not have records like ice cores that extend this far back in time. This project will provide constraints on surface temperatures in Antarctica during the mid-Pliocene Warm Period using a new type of climate substitute, known as cosmogenic noble gas paleothermometry. This project focuses on an area of Antarctica called the McMurdo Dry Valleys. In this area, climate models suggest that temperatures were more than 10 C warmer during the mid-Pliocene than they are today, but indirect geologic observations suggest that temperatures may have been similar to today. The McMurdo Dry Valleys are also a place where rocks have been exposed to Earth surface conditions for several million years, and where this new climate substitute can be readily applied. The team will reconstruct temperatures in the McMurdo Dry Valleys during the mid-Pliocene Warm Period in order to resolve the discrepancy between models and indirect geologic observations and provide much-needed constraints on the sensitivity of Antarctic ice sheets to warming temperatures. The temperature reconstructions generated in this project will have scientific impact in multiple disciplines, including climate science, glaciology, geomorphology, and planetary science. In addition, the project will (1) broaden the participation of underrepresented groups by supporting two early-career female principal investigators, (2) build STEM talent through the education and training of a graduate student, (3) enhance infrastructure for research via publication of a publicly-accessible, open-source code library, and (4) be broadly disseminated via social media, blog posts, publications, and conference presentations. Part II: Technical Description The mid-Pliocene Warm Period (3-3.3 million years ago) is the most recent interval of the geologic past when atmospheric CO2 concentrations exceeded 400 ppm and is widely considered an analog for how Earth’s climate system will respond to current global change. Climate models predict polar amplification - the occurrence of larger changes in temperatures at high latitudes than the global average due to a radiative forcing - both during the mid-Pliocene Warm Period and due to current climate warming. However, the predicted magnitude of polar amplification is highly uncertain in both cases. The magnitude of polar amplification has important implications for the sensitivity of ice sheets to warming and the contribution of ice sheet melting to sea level change. Proxy-based constraints on polar surface air temperatures during the mid-Pliocene Warm Period are sparse to non-existent. In Antarctica, there is only indirect evidence for the magnitude of warming during this time. This project will provide constraints on surface temperatures in the McMurdo Dry Valleys of Antarctica during the mid-Pliocene Warm Period using a newly developed technique called cosmogenic noble gas (CNG) paleothermometry. CNG paleothermometry utilizes the diffusive behavior of cosmogenic 3He in quartz to quantify the temperatures rocks experience while exposed to cosmic-ray particles within a few meters of the Earth’s surface. The very low erosion rates and subzero temperatures characterizing the McMurdo Dry Valleys make this region uniquely suited for the application of CNG paleothermometry for addressing the question: what temperatures characterized the McMurdo Dry Valleys during the mid-Pliocene Warm Period? To address this question, the team will collect bedrock samples at several locations in the McMurdo Dry Valleys where erosion rates are known to be low enough that cosmic ray exposure extends into the mid-Pliocene or earlier. They will pair cosmogenic 3He measurements, which will record the thermal histories of our samples, with measurements of cosmogenic 10Be, 26Al, and 21Ne, which record samples exposure and erosion histories. We will also make in situ measurements of rock and air temperatures at sample sites in order to quantify the effect of radiative heating and develop a statistical relationship between rock and air temperatures, as well as conduct diffusion experiments to quantify the kinetics of 3He diffusion specific to each sample. This suite of observations will be used to model permissible thermal histories and place constraints on temperatures during the mid-Pliocene Warm Period interval of cosmic-ray exposure. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Nontechnical Abstract Studies in Antarctica are, at present, severely limited by the costs of placing measurement instruments within and beneath thousands of meters of ice. Our aim is to enable dense, widespread measurement-networks by advancing development of low-cost ice melt probe technology to deploy instruments. Ice melt probes use electrical energy to descend through thick ice with little support structure on the ice surface. We are extending previous technology by using anti-freeze to maintain a partially open melt-hole above a descending probe, deploying as we go a new a new fiber-optic technology to measure ice temperature. Ice temperature measurements will reveal spatial patterns of heat welling up from the Earth beneath the ice, which in turn will contribute greatly to finding ancient ice that contains global climate records, and to understanding how ice flow may raise sea levels. Our immediate objective in this 1-year project is to test and refine our anti-freeze-based method in a 15 meter-tall ice column at the University of Wisconsin, so as to reduce technical risk in future field tests. Technical Abstract The overarching aim of our development is to enable widespread, spatially dense deployments of instruments within and beneath the Antarctic Ice Sheet for a variety of investigations, beginning with observations of basal temperature and geothermal flux at the base of the ice sheet. Dense, widespread deployment requires logistical costs far below current costs for ice drilling and coring. Our approach is to extend ice melt probe technology (which is inherently light, logistically) to allow the progressive deployment of cable for Distributed Temperature Sensing (DTS) from the ice surface as the probe descends, without greatly increasing logistical costs. Our extension is based on arresting refreezing of the melt-hole above the probe (at a diameter a few times the cable diameter) by injecting anti-freeze - specifically, ethanol at temperature near 0C - a few meters above the probe during descent. After thermal equilibration of the liquid ethanol/water column with the ice, DTS measurements yield the depth-profile of ice sheet temperature, from which basal temperature and (over frozen beds) geothermal flux can be inferred. We have carried out initial trials of our approach in a cold-room laboratory, but field work based only on such small-scale tests may still involve unnecessary risk. We therefore propose further testing at a facility of the Ice Drilling Design and Operations (IDDO) facility in Madison, WI. The new trials will test our approaches to melt-hole control and probe recovery in the taller column, will test cable and cable-tension-management methods more nearly approximating those needed to work on ice sheets, and will demonstrate the Distributed Temperature Sensing in its field configuration. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Antarctic subglacial environment remains one of the least explored regions on Earth. This project will examine the physical and biological characteristics of Subglacial Lake Mercer, a lake that lies 1200m beneath the West Antarctic Ice Sheet. This study will address key questions relating to the stability of the ice sheet, the subglacial hydrological system, and the deep-cold subglacial biosphere. The education and outreach component aims to widely disseminate results to the scientific community and to the general public through short films, a blog, and a website. Subglacial Lake Mercer is one of the larger hydrologically active lakes in the southern basin of the Whillans Ice Plain, West Antarctica. It receives about 25 percent of its water from East Antarctica with the remainder originating from West Antarctica, is influenced by drain/fill cycles in a lake immediately upstream (Subglacial Lake Conway), and lies about 100 km upstream of the present grounding line of the Ross Ice Shelf. This site will yield information on the history of the Whillans and Mercer Ice Streams, and on grounding line migration. The integrated study will include direct sampling of basal ice, water, and sediment from the lake in concert with surface geophysical surveys over a three-year period to define the hydrological connectivity among lakes on the Whillans Ice Plain and their flow paths to the sea. The geophysical surveys will furnish information on subglacial hydrology, aid the site selection for hot-water drilling, and provide spatial context for interpreting findings. The hot-water-drilled boreholes will be used to collect basal ice samples, provide access for direct measurement of subglacial physical, chemical, and biological conditions in the water column and sediments, and to explore the subglacial water cavities using a remotely operated vehicle equipped with sensors, cameras, and sampling equipment. Data collected from this study will address the overarching hypothesis "Contemporary biodiversity and carbon cycling in hydrologically-active subglacial environments associated with the Mercer and Whillans ice streams are regulated by the mineralization and cycling of relict marine organic matter and through interactions among ice, rock, water, and sediments". The project will be undertaken by a collaborative team of scientists, with expertise in microbiology, biogeochemistry, hydrology, geophysics, glaciology, marine geology, paleoceanography, and science communication.
Non-technical description: East Antarctica holds a vast, ancient ice sheet. The bedrock hidden beneath this ice sheet may provide clues to how today's continents formed, while the ice itself contains records of Earth's atmosphere from distant eras. New drilling technologies are now available to allow for direct sampling of these materials from more than two kilometers below the ice surface. However, getting this material will require knowing where to look. The Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP) project will use internationally collected airborne survey data to search East Antarctica near the South Pole for key locations that will provide insight into Antarctica's geology and for locating the oldest intact ice on Earth. Ultimately, scientists are interested in obtaining samples of the oldest ice to address fundamental questions about the causes of changes in the timing of ice-age conditions from 40,000 to 100,000 year cycles. SPICECAP data analysis will provide site survey data for future drilling and will increase the overall understanding of Antarctica's hidden ice and geologic records. The project involves international collaboration and leveraging of internationally collected data. The SPICECAP project will train new interdisciplinary scientists at the undergraduate, graduate, and postdoctoral levels. Technical description: This study focuses on processing and interpretation of internationally collected aerogeophysical data from the Southern Plateau of the East Antarctic Ice Sheet. The data include ice penetrating radar data, laser altimetry, gravity and magnetics. The project will provide information on geological trends under the ice, the topography and character of the ice/rock interface, and the stratigraphy of the ice. The project will also provide baseline site characterization for future drilling. Future drilling sites and deep ice cores for old ice require that the base of the ice sheet be frozen to the bed (i.e. no free water at the interface between rock and ice) and the assessment will map the extent of frozen vs. thawed areas. Specifically, three main outcomes are anticipated for this project. First, the study will provide an assessment of the viability of Titan Dome, a subglacial highland region located near South Pole, as a potential old ice drilling prospect. The assessment will include determining the hydraulic context of the bed by processing and interpreting the radar data, ice sheet mass balance through time by mapping englacial reflectors in the ice and connecting them to ice stratigraphy in the recent South Pole, and ice sheet geometry using laser altimetry. Second, the study will provide an assessment of the geological context of the Titan Dome region with respect to understanding regional geologic boundaries and the potential for bedrock sampling. For these two goals, we will use data opportunistically collected by China, and the recent PolarGAP dataset. Third, the study will provide an assessment of the risk posture for RAID site targeting in the Titan Dome region, and the Dome C region. This will use a high-resolution dataset the team collected previously at Dome C, an area similar to the coarser resolution data collected at Titan Dome, and will enable an understanding of what is missed by the wide lines spacing at Titan Dome. Specifically, we will model subglacial hydrology with and without the high resolution data, and statistically examine the detection of subglacial mountains (which could preserve old ice) and subglacial lakes (which could destroy old ice), as a function of line spacing.
The ocean tide is a large component of total variability of ocean surface height and currents in the seas surrounding Antarctica, including under the floating ice shelves. Maximum tidal height range exceeds 7 m (near the grounding line of Rutford Ice Stream) and maximum tidal currents exceed 1 m/s (near the shelf break in the northwest Ross Sea). Tides contribute to several important climate and ecosystems processes including: ocean mixing, production of dense bottom water, flow of warm Circumpolar Deep Water onto the continental shelves, melting at the bases of ice shelves, fracturing of the ice sheet near a glacier or ice stream’s grounding line, production and decay of sea ice, and sediment resuspension. Tide heights and, in particular, currents can change as the ocean background state changes, and as the geometry of the coastal margins of the Antarctic Ice Sheet varies through ice shelf thickness changes and ice-front and grounding-line advances or retreats. For satellite-based studies of ocean surface height and ice shelf thickness changes, tide heights are a source of substantial noise that must be removed. Similarly, tidal currents can also be a substantial noise signal when trying to estimate mean ocean currents from short-term measurements such as from acoustic Doppler current profilers mounted on ships and CTD rosettes. Therefore, tide models play critical roles in understanding current and future ocean and ice states, and as a method for removing tides in various measurements. A paper in Reviews of Geophysics (Padman, Siegfried and Fricker, 2018, see list of project-related publications below) provides a detailed review of tides and tidal processes around Antarctica.
This project provides a gateway to tide models and a database of tide height coefficients at the Antarctic Data Center, and links to toolboxes to work with these models and data.
Modeling fluctuations in the extent of the West Antarctic Ice Sheet (WAIS) over time is a principal goal of the glaciological community. These models will provide a critical basis for predictions of future sea level change, and therefore this work great societal relevance. The mid-Pliocene time interval is of particular interest, as it is the most recent period in which global temperatures were warmer and atmospheric CO2 concentrations may have been higher than current levels. However, observational constraints on fluctuations in the WAIS older than the last glacial maximum are rare. The investigators propose to collect geochemical data from the Ohio Range and Scott Glacier to quantify past variability in the height of the WAIS. Limited available cosmogenic nuclide data are broadly consistent with a model indicating that Pliocene WAIS elevations and volumes were smaller than at present, and that WAIS collapse was common. The PIs will use geologic observations and cosmogenic nuclide concentrations from bedrock samples at multiple locations and at multiple elevations, including sub-ice samples, to constrain WAIS ice volume changes in a "dipstick" like fashion. Data obtained from the proposed research will provide targets for data-ice sheet model comparisons to accurately characterize Plio-Pleistocene and future WAIS behavior. As part of this project, the investigators will work with the Natural History Museum and the Earth & Planetary Science department at Harvard to develop an exhibit that will become part of the Museum's recently opened Earth and Planetary Science Gallery. The project involves mentoring of a female graduate student as well as an undergraduate student.
Brook/1246465 This award supports a project to measure the carbon dioxide (CO2) concentration in the WAIS Divide ice core covering the time period 25,000 to 60,000 years before present, and to analyze the isotopic composition of CO2 in selected time intervals. The research will improve understanding of how and why atmospheric CO2 varied during the last ice age, focusing particularly on abrupt transitions in the concentration record that are associated with abrupt climate change. These events represents large perturbations to the global climate system and better information about the CO2 response should inform our understanding of carbon cycle-climate feedbacks and radiative forcing of climate. The research will also improve analytical methods in support of these goals, including completing development of sublimation methods to replace laborious mechanical crushing of ice to release air for analysis. The intellectual merit of the proposed work is that it will increase knowledge about the magnitude and timing of atmospheric CO2 variations during the last ice age, and their relationship to regional climate in Antarctica, global climate history, and the history of abrupt climate change in the Northern Hemisphere. The temporal resolution of the proposed record will in most intervals be ~ 4 x higher than previous data sets for this time period, and for selected intervals up to 8-10 times higher. Broader impacts of the proposed work include a significant addition to the amount of data documenting the history of the most important long-lived greenhouse gas in the atmosphere and more information about carbon cycle-climate feedbacks - important parameters for predicting future climate change. The project will contribute to training a postdoctoral researcher, research experience for an undergraduate and a high school student, and outreach to local middle school and other students. It will also improve the analytical infrastructure at OSU, which will be available for future projects.
Predictions of future sea level rise require better understanding of the changing dynamics of the Greenland and Antarctic ice sheets. One way to better understand the past history of the ice sheets is to obtain records from inland ice for past geological periods, particularly in Antarctica, the world?s largest remaining ice sheet. Such records are exceedingly rare, and can be acquired at volcanic outcrops in the La Gorce Mountains of the central Transantarctic Mountains. Volcanoes now exposed within the La Gorce Mountains erupted beneath the East Antarctic ice sheet and the data collected will record how thick the ice sheet was in the past. In addition, information will be used to determine the thermal conditions at the base of the ice sheet, which impacts ice sheet stability. The project will also investigate the origin of volcanic activity in Antarctica and links to the West Antarctic Rift System (WARS). The WARS is a broad area of extended (i.e. stretched) continental crust, similar to that found in East Africa, and volcanism is wide spread and long-lived (65 million years to currently active) and despite more than 50 years of research, the fundamental cause of volcanism and rifting in Antarctica is still vigorously debated. The results of this award therefore also potentially impact the study of oceanic volcanism in the entire southwestern Pacific region (e.g., New Zealand and Australia), where volcanic fields of similar composition and age have been linked by common magma sources and processes. The field program includes a graduate student who will work on the collection, analysis, and interpretation of petrological data as part of his/her Masters project. The experience and specialized analytical training being offered will improve the quality of the student?s research and optimize their opportunities for their future. The proposed work fosters faculty and student national and international collaboration, including working with multi-user facilities that provide advanced technological mentoring of science students. Results will be broadly disseminated in peer-reviewed journals, public presentations at science meetings, and in outreach activities. Petrologic and geochemical data will be disseminated to be the community through the Polar Rock Repository. The study of subglacially erupted volcanic rocks has been developed to the extent that it is now the most powerful proxy methodology for establishing precise ?snapshots? of ice sheets, including multiple critical ice parameters. Such data should include measurements of ice thickness, surface elevation and stability, which will be used to verify, or reject, published semi-empirical models relating ice dynamics to sea level changes. In addition to establishing whether East Antarctic ice was present during the formation of the volcanoes, data will be used to derive the coeval ice thicknesses, surface elevations and basal thermal regime(s) in concert with a precise new geochronology using the 40Ar/39Ar dating method. Inferences from measurement of standard geochemical characteristics (major, trace elements and Sr, Nd, Pb, O isotopes) will be used to investigate a possible relationship between the volcanoes and the recently discovered subglacial ridge under the East Antarctic ice, which may be a rift flank uplift. The ridge has never been sampled, is undated and its significance is uncertain. The data will provide important new information about the deep Earth and geodynamic processes beneath this mostly ice covered and poorly understood sector of the Antarctic continent.
The geological structure and history of Antarctica remains poorly understood because much of the continental crust is covered by ice. Here, the PIs will analyze over 15 years of seismic data recorded by numerous projects in Antarctica to develop seismic structural models of the continent. The seismic velocity models will reveal features including crustal thinning due to rifting in West Antarctica, the structures associated with mountain building, and the boundaries between different tectonic blocks. The models will be compared to continents that are better understood geologically to constrain the tectonic evolution of Antarctica. In addition, the work will provide better insight into how the solid earth interacts with and influences the development of the ice sheet. Surface heat flow will be mapped and used to identify regions in Antarctica with potential melting at the base of the ice sheet. This melt can lead to reduced friction and lower resistance to ice sheet movement. The models will help to determine whether the earth response to ice mass changes occurs over decades, hundreds, or thousands of years. Estimates of mantle viscosity calculated from the seismic data will be used to better understand the pattern and timescales of the response of the solid earth to changes in ice mass in various parts of Antarctica. The study will advance our knowledge of the structure of Antarctica by constructing two new seismic models and a thermal model using different but complementary methodologies. Because of the limitations of different seismic analysis methods, efforts will be divided between a model seeking the highest possible resolution within the upper 200 km depth in the well instrumented region (Bayesian Monte-Carlo joint inversion), and another model determining the structure of the entire continent and surrounding oceans extending through the mantle transition zone (adjoint full waveform inversion). The Monte-Carlo inversion will jointly invert Rayleigh wave group and phase velocities from earthquakes and ambient noise correlation along with P-wave receiver functions and Rayleigh H/V ratios. The inversion will be done in a Bayesian framework that provides uncertainty estimates for the structural model. Azimuthal anisotropy will be determined from Rayleigh wave velocities, providing constraints on mantle fabric and flow patterns. The seismic data will also be inverted for temperature structure, providing estimates of lithospheric thickness and surface heat flow. The larger-scale model will cover the entire continent as well as the surrounding oceans, and will be constructed using an adjoint inversion of phase differences between three component seismograms and synthetic seismograms calculated in a 3D earth model using the spectral element method. This model will fit the entire waveforms, including body waves and both fundamental and higher mode surface waves. Higher resolution results will be obtained by using double-difference methods and by incorporating Green's functions from ambient noise cross-correlation, and solving for both radial and azimuthal anisotropy. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Brook/1643722 This award supports a project to measure the concentration of the gas methane in air trapped in an ice core collected from the South Pole. The data will provide an age scale (age as a function of depth) by matching the South Pole methane changes with similar data from other ice cores for which the age vs. depth relationship is well known. The ages provided will allow all other gas measurements made on the South Pole core (by the PI and other NSF supported investigators) to be interpreted accurately as a function of time. This is critical because a major goal of the South Pole coring project is to understand the history of rare gases in the atmosphere like carbon monoxide, carbon dioxide, ethane, propane, methyl chloride, and methyl bromide. Relatively little is known about what controls these gases in the atmosphere despite their importance to atmospheric chemistry and climate. Undergraduate assistants will work on the project and be introduced to independent research through their work. The PI will continue visits to local middle schools to introduce students to polar science, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) as part of the project. Methane concentrations from a major portion (2 depth intervals, excluding the brittle ice-zone which is being measured at Penn State University) of the new South Pole ice core will be used to create a gas chronology by matching the new South Pole ice core record with that from the well-dated WAIS Divide ice core record. In combination with measurements made at Penn State, this will provide gas dating for the entire 50,000-year record. Correlation will be made using a simple but powerful mid-point method that has been previously demonstrated, and other methods of matching records will be explored. The intellectual merit of this work is that the gas chronology will be a fundamental component of this ice core project, and will be used by the PI and other investigators for dating records of atmospheric composition, and determining the gas age-ice age difference independently of glaciological models, which will constrain processes that affected firn densification in the past. The methane data will also provide direct stratigraphic markers of important perturbations to global biogeochemical cycles (e.g., rapid methane variations synchronous with abrupt warming and cooling in the Northern Hemisphere) that will tie other ice core gas records directly to those perturbations. A record of the total air content will also be produced as a by-product of the methane measurements and will contribute to understanding of this parameter. The broader impacts include that the work will provide a fundamental data set for the South Pole ice core project and the age scale (or variants of it) will be used by all other investigators working on gas records from the core. The project will employ an undergraduate assistant(s) in both years who will conduct an undergraduate research project which will be part of the student's senior thesis or other research paper. The project will also offer at least one research position for the Oregon State University Summer REU site program. Visits to local middle schools, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) will also be part of the project.
Ice cores contain detailed accounts of Earth's climate history. The collection of an ice core can be logistically challenging, and extraction of data from the core can be time-consuming as well as susceptible to both human and machine error. Furthermore, locked in measurements from ice cores is information that scientists have not yet found ways to recover. This project will apply techniques from information theory to ice-core data to unlock that information. The primary goal is to demonstrate that information theory can (a) identify regions of a specific ice-core record that are in need of further analysis and (b) provide some specific guidance for that analysis. A secondary goal is to demonstrate that information theory has practical and scientific utility for studies of past climate. This project aims to use information theory in two distinct ways: first, to identify regions of a core where information appears to be damaged or missing, perhaps due to human and/or machine error. In the segment of the West Antarctic Ice Sheet Divide core that is 5000-8000 years old, for instance, information-theoretic methods reveal significant levels of noise, probably due to a laboratory instrument, and something that was not visible in the raw data. This is a particularly important segment of the record, as it contains valuable clues about climatic shifts and the onset of the Holocene. Targeted re-sampling of this segment of the core and reanalysis with newer laboratory apparatus could resolve the data issues. The second way in which information theory can potentially aid in ice-core analysis is by extracting climate signals from the data--such as the accumulation rate at the core site over the period of its formation. This quantity usually requires significant time and effort to produce, but information theory could help to streamline that process. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Abstract (non-technical) Sea level rise is a problem of global importance and it is increasingly affecting the tens of millions of Americans living along coastlines. The melting of glaciers in mountain areas worldwide in response to global warming is a major cause of sea level rise and increases in nuisance coastal flooding. However, the world's largest land-based ice sheets are situated in the Polar Regions and their response under continued warming is very difficult to predict. One reason for this uncertainty is a lack of observations of ice behavior and melt under conditions of warming, as it is a relatively new global climate state lasting only a few generations so far. Researchers will investigate ice growth on Antarctica under past warm conditions using geological archives embedded in the layers of sand and mud under the sea floor near Antarctica. By peeling back at the layers beneath the seafloor investigators can read the history book of past events affecting the ice sheet. The Antarctic continent on the South Pole, carries the largest ice mass in the world. The investigator's findings will substantially improve scientists understanding of the response of ice sheets to global warming and its effect on sea level rise. Abstract (technical) The melt of land based ice is raising global sea levels with at present only minor contributions from polar ice sheets. However, the future role of polar ice sheets in climate change is one of the most critical uncertainties in predictions of sea level rise around the globe. The respective roles of oceanic and atmospheric greenhouse forcing on ice sheets are poorly addressed with recent measurements of polar climatology, because of the extreme rise in greenhouse forcing the earth is experiencing at this time. Data on the evolution of the West Antarctic ice sheet is particularly sparse. To address the data gap, researchers will reconstruct the timing and spatial distribution of Antarctic ice growth through the last greenhouse to icehouse climate transition around 37 to 33 Ma. They will collect sedimentological and geochemical data on core samples from a high-latitude paleoarchive to trace the shutdown of the chemical weathering system, the onset of glacial erosion, ice rafting, and sea ice development, as East and West Antarctic ice sheets coalesced in the Weddell Sea sector. Their findings will lead to profound increases in the understanding of the role of greenhouse forcing in ice sheet development and its effect on the global climate system. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The PIs will design and build a new rapid access ice drill (RAID) for use in Antarctica. This drill will have the ability to rapidly drill through ice up to 3300 m thick and then collect samples of the ice, ice-sheet bed interface, and bedrock substrate below. This drilling technology will provide a new way to obtain in situ measurements and samples for interdisciplinary studies in geology, glaciology, paleoclimatology, microbiology, and astrophysics. The RAID drilling platform will give the scientific community access to records of geologic and climatic change on a variety of timescales, from the billion-year rock record to thousand-year ice and climate histories. Successful development of the RAID system will provide a research tool that is currently unavailable. Development of this platform will enable scientists to address critical questions about the deep interface between the Antarctic ice sheets and the substrate below. Development of RAID will provide a way to address many of the unknowns associated with general stability of the Antarctic ice sheets in the face of changing climate and sea level rise. The scientific rationale for RAID was reviewed in a previous proposal (Goodge 1242027). The PIs were granted ?Phase I? funding to develop a more detailed conceptual design for the RAID drill that would provide a better understanding of construction costs as well as operation and maintenance costs for RAID once it is constructed. Phase I support also allowed the PIs to work with the research community to develop more detailed science requirements for the drill. This proposal requests continued funding (Phase II) to construct, assemble and test the RAID drilling platform, through to staging it in Antarctic for future scientific operations.
1142167/Pettit This award supports a project to develop a better understanding of the relation between ice microstructure, impurities, and ice flow and their connection to climate history for the West Antarctic Ice Sheet (WAIS) ice core site. This work builds on several ongoing studies at Siple Dome in West Antarctica and Dome C in East Antarctica. It is well known that the microstructure of ice evolves with depth and time in an ice sheet. This evolution of microstructure depends on the ice flow field, temperature, and impurity content. The ice flow field, in turn, depends on microstructure, leading to feedbacks that create layered variation in microstructure that relates to climate and flow history. The research proposed here focuses on developing a better understanding of: 1) how ice microstructure evolves with time and stress in an ice sheet and how that relates to impurity content, temperature, and strain rate; 2) how variations in ice microstructure and impurity content affect ice flow patterns near ice divides (on both small (1cm to 1m) and large (1m to 100km) scales); and 3) in what ways is the spatial variability of ice microstructure and its effect on ice flow important for interpretation of climate history in the WAIS Divide ice core. The study will integrate existing ice core and borehole data with a detailed study of ice microstructure using Electron Backscatter Diffraction (EBSD) techniques and measurements of borehole deformation through time using Acoustic Televiewers. This will be the first study to combine these two novel techniques for studying the relation between microstructure and deformation and it will build on other data being collected as part of other WAIS Divide borehole logging projects (e.g. sonic velocity, optical dust logging, temperature and other measurements on the ice core including fabric measurements from thin section analyses as well as studies of ice chemistry and stable isotopes. The intellectual merit of the work is that it will improve interpretation of ice core data (especially information on past accumulation) and overall understanding of ice flow. The broader impacts are that the work will ultimately contribute to a better interpretation of ice core records for both paleoclimate studies and for ice flow history, both of which connect to the broader questions of the role of ice in the climate system. The work will also advance the careers of two early-career female scientists, including one with a hearing impairment disability. This project will support a PhD student at the UAF and provide research and field experience for two or three undergraduates at Dartmouth. The PIs plan to include a teacher on their field team and collaborate with UAF's "From STEM to STEAM" toward enhancing the connection between art and science.
Blankenship: 9319369 Bell: 9319854 Behrendt: 9319877 This award supports a project to conduct an integrated geophysical survey over a large portion of the West Antarctic Ice Sheet (WAIS) toward an understanding of the dynamic behavior of the ice sheet and the nature of the lithosphere beneath the ice sheet. West Antarctica is characterized by two kinds of the Earth s most dynamic systems, a continental rift (the West Antarctic Rift System) and a marine based ice sheet (the WAIS). Active continental rift systems, caused by divergent plate motions, result in thinned continental crust. Associated with the thin crust are fault-bounded sedimentary basins, active volcanism, and elevated heat flow. Marine ice sheets are characterized by rapidly moving streams of ice, penetrating and draining a slowly moving ice reservoir. Evidence left by past marine ice sheets indicates that they may have a strongly non- linear response to long-term climate change which results in massive and rapid discharges of ice. Understanding the evolution of the ice stream system and its interaction with the interior ice is the key to understanding this non-linear response. Subglacial geology and ice dynamics are generally studied in isolation, but evidence is mounting that the behavior of the West Antarctic ice streams may be closely linked to the nature of the underlying West Antarctic rift system. The fast moving ice streams appear to glide on a lubricating layer of water-saturated till. This till requires easily eroded sediment and a source of water, both of which may be controlled by the geology of the rift system; the sediments from the fault-bounded basins and the water from the elevated heat flux associated with active lithospheric extension. This project represents an interdisciplinary aerogeophysical study to characterize the lithosphere of the West Antarctic rift system beneath critical regions of the WAIS. The objective is to determine the effects of the rift architect ure, as manifested by the distribution of sedimentary basins and volcanic constructs, on the ice stream system. The research tool is a unique geophysical aircraft with laser altimetry, ice penetrating radar, aerogravity, and aeromagnetic systems integrated with a high precision kinematic GPS navigation system. It is capable of imaging both the surface and bed of the ice sheet while simultaneously measuring the gravity and magnetic signature of the subglacial lithosphere. Work to be done under this award will build on work already completed in the southern sector of central West Antarctica and it will focus on the region of the Byrd Subglacial Basin and Ice Stream D. The ice sheet in these regions is completely covered by satellite imagery and so this project will be integrated with remote sensing studies of the ice stream. The changing dynamics of Ice Stream D, as with other West Antarctic ice streams, seem to be correlated with changes in the morphological provinces of the underlying rift system. The experimental targets proceed from the divide of the interior ice, downstream through the onset of streaming to the trunk of Ice Stream D. This study will be coordinated with surface glaciological investigations of Ice Stream D and will be used to guide cooperative over-snow seismic investigations of the central West Antarctic rift system. The data will also be used to select a site for future deep ice coring along the crest of the WAIS. These data represent baseline data for long term global change monitoring work and represent crucial boundary conditions for ice sheet modeling efforts.
OPP 9615281 Luyendyk OPP 9615282 Siddoway Abstract This award supports a collaborative project that combines air and ground geological-geophysical investigations to understand the tectonic and geological development of the boundary between the Ross Sea Rift and the Marie Byrd Land (MBL) volcanic province. The project will determine the Cenozoic tectonic history of the region and whether Neogene structures that localized outlet glacier flow developed within the context of Cenozoic rifting on the eastern Ross Embayment margin, or within the volcanic province in MBL. The geological structure at the boundary between the Ross Embayment and western MBL may be a result of: 1) Cenozoic extension on the eastern shoulder of the Ross Sea rift; 2) uplift and crustal extension related to Neogene mantle plume activity in western MBL; or a combination of the two. Faulting and volcanism, mountain uplift, and glacier downcutting appear to now be active in western MBL, where generally East-to-West-flowing outlet glaciers incise Paleozoic and Mesozoic bedrock, and deglaciated summits indicate a previous North-South glacial flow direction. This study requires data collection using SOAR (Support Office for Aerogeophysical Research, a facility supported by Office of Polar Programs which utilizes high precision differential GPS to support a laser altimeter, ice-penetrating radar, a towed proton magnetometer, and a Bell BGM-3 gravimeter). This survey requires data for 37,000 square kilometers using 5.3 kilometer line spacing with 15.6 kilometer tie lines, and 86,000 square kilometers using a grid of 10.6 by 10.6 kilometer spacing. Data will be acquired over several key features in the region including, among other, the eastern edge of the Ross Sea rift, over ice stream OEO, the transition from the Edward VII Peninsula plateau to the Ford Ranges, the continuation to the east of a gravity high known from previous reconnaissance mapping over the Fosdick Metamorphic Complex, an d the extent of the high-amplitude magnetic anomalies (volcanic centers?) detected southeast of the northern Ford Ranges by other investigators. SOAR products will include glaciology data useful for studying driving stresses, glacial flow and mass balance in the West Antarctic Ice Sheet (WAIS). The ground program is centered on the southern Ford Ranges. Geologic field mapping will focus on small scale brittle structures for regional kinematic interpretation, on glaciated surfaces and deposits, and on datable volcanic rocks for geochronologic control. The relative significance of fault and joint sets, the timing relationships between them, and the probable context of their formation will also be determined. Exposure ages will be determined for erosion surfaces and moraines. Interpretation of potential field data will be aided by on ground sampling for magnetic properties and density as well as ground based gravity measurements. Oriented samples will be taken for paleomagnetic studies. Combined airborne and ground investigations will obtain basic data for describing the geology and structure at the eastern boundary of the Ross Embayment both in outcrop and ice covered areas, and may be used to distinguish between Ross Sea rift- related structural activity from uplift and faulting on the perimeter of the MBL dome and volcanic province. Outcrop geology and structure will be extrapolated with the aerogeophysical data to infer the geology that resides beneath the WAIS. The new knowledge of Neogene tectonics in western MBL will contribute to a comprehensive model for the Cenozoic Ross rift and to understanding of the extent of plume activity in MBL. Both are important for determining the influence of Neogene tectonics on the ice streams and WAIS.
9978236 Bell Abstract This award, provided by the Office of Polar Programs under the Life in Extreme Environments (LExEn) Program, supports a geophysical study of Lake Vostok, a large lake beneath the East Antarctic Ice Sheet. Subglacial ecosystems, in particular subglacial lake ecosystems are extreme oligotrophic environments. These environments, and the ecosystems which may exist within them, should provide key insights into a range of fundamental questions about the development of Earth and other bodies in the Solar System including: 1) the processes associated with rapid evolutionary radiation after the extensive Neoproterozoic glaciations; 2) the overall carbon cycle through glacial and interglacial periods; and 3) the possible adaptations organisms may require to thrive in environments such as on Europa, the ice covered moon of Jupiter. Over 70 subglacial lakes have been identified beneath the 3-4 kilometer thick ice of Antarctica. One lake, Lake Vostok, is sufficiently large to be clearly identified from space with satellite altimetry. Lake Vostok is similar to Lake Ontario in area but with a much larger volume including measured water depths of 600 meters. The overlying ice sheet is acting as a conveyer belt continually delivering new water, nutrients, gas hydrates, sediments and microbes as the ice sheet flows across the lake. The goal of this program is to determine the fundamental boundary conditions for this subglacial lake as an essential first step toward understanding the physical processes within the lake. An aerogeophysical survey over the lake and into the surrounding regions will be acquired to meet this goal. This data set includes gravity, magnetic, laser altimetry and ice penetrating radar data and will be used to compile a basic set of ice surface elevation, subglacial topography, gravity and magnetic anomaly maps. Potential field methods widely used in the oil industry will be modified to estimate the subglacial topography from gravity data where the ice penetrating radar will be unable to recover the depth of the lake. A similar method can be modified to estimate the thickness of the sediments beneath the lake from magnetic data. These methods will be tested and applied to subglacial lakes near South Pole prior to the Lake Vostok field campaign and will provide valuable comparisons to the planned survey. Once the methods have been adjusted for the Lake Vostok application, maps of the water cavity and sediment thickness beneath the lake will be produced. These maps will become tools to explore the geologic origin of the lake. The two endmember models are, first, that the lake is an active tectonic rift such as Lake Baikal and, second, the lake is the result of glacial scouring. The distinct characteristics of an extensional rift can be easily identified with our aerogeophysical survey. The geological interpretation of the airborne geophysical survey will provide the first geological constraints of the interior of the East Antarctic continent based on modern data. In addition, the underlying geology will influence the ecosystem within the lake. One of the critical issues for the ecosystem within the lake will be the flux of nutrients. A preliminary estimation of the regions of freezing and melting based on the distance between distinctive internal layers observed on the radar data will be made. These basic boundary conditions will provide guidance for a potential international effort aimed at in situ exploration of the lake and improve the understanding of East Antarctic geologic structures.
Bell and Buck: OPP 9615704 Blankenship: OPP 9615832 Abstract Continental extension produces a great variety of structures from the linear narrow rifts of the East African Rift to the diffuse extension of the Basin and Range Province of the Western U.S. Rift shoulder uplift varies dramatically between rift flanks. The cause of variable rift width and crustal thinning is fairly well explained by variable initial heat flow and crustal thickness. Mechanical stretching of the lithosphere has been linked to rift shoulder uplift but the cause of variable rift flank uplift remains poorly understood. The Transantarctic Mountains (TAM) are an extreme example of rift flank uplift, extending over 3500 km across Antarctica and reaching elevations up to 4500 m and thus constitute a unique feature of EarthOs crust. The range was formed in the extensional environment associated with the Mesozoic and Cenozoic breakup of Gondwanaland. Geological and geophysical work has shown that the TAM developed along the long-lived lithospheric boundary between East and West Antarctica reactivated by a complex history of extensional and translational microplate motions. The TAM are not uniform along strike. Along the OWilkes FrontO, the northern segment of the rift extends from North Victoria Land to Byrd Glacier. The Wilkes Front architecture consists of (1) thin, extended crust forming the Victoria Land Basin in the Ross Sea, (2) the TAM rift shoulder, and (3) a long-wavelength down- ward forming the Wilkes Basin. Contrasting structures are mapped along the OPensacola/PoleO Front, the southern segment of the rift extending from the Nimrod Glacier to the Pensacola Mountains. Along this southern section no rift basin has been mapped to date and the down-ward along the East Antarctic, or ObacksideO, edge of the mountains is less pronounced. A flexural model linking the extension in the Ross Sea to the formation of both the mountains and the Wilkes Basin has been considered as a me chanism for uplift of the entire mountain range. The variability in fundamental architecture along the TAM indicates that neither a single event nor a sequence of identical events produced the rift flank uplift. The observation of variable architecture suggests complex mechanisms and possibly a fundamental limitation in maximum sustainable rift flank elevation. The motivation for studying the TAM is to try to understand the geodynamics of this extreme elevation rift flank. Are the geodynamics of the area unique, or does the history of glaciation and related erosion contribute to the extreme uplift? With the existing data sets it is difficult to confidently constrain the geological architecture across representative sections of the TAM. Any effort to refine geodynamic mechanisms requires this basic understanding of the TAM architecture. The goal of this project is to (1) constrain the architecture of the rift system as well as the distribution and structure of sedimentary basins, glacial erosion and mafic igneous rocks surrounding the rift flank by acquiring three long wavelength geophysical transects with integrated gravity, magnetics, ice- penetrating radar, and ice surface measurements, (2) quantify the contribution of various geodynamic mechanisms to understand the geological conditions which can lead to extreme rift flank uplift, and (3) use the improved understanding of architecture and geophysical data to test geodynamic models in order to improve our understanding both of the TAM geodynamics and the general problem of the geodynamics of rift flank uplift worldwide. This project will allow development of a generalized framework for understanding the development of rift flank uplift as well as address the question of the specific geodynamic evolution of the TAM.
In the past, Earth's climate underwent dramatic changes that influenced physical, chemical, geological, and biological processes on a global scale. Such changes left an imprint in Earth's atmosphere, as shown by the variability in abundances of trace gases like carbon dioxide and methane. In return, changes in the atmospheric trace gas composition affected Earth's climate. Studying compositional variations of the past atmosphere helps us understand the history of interactions between global biogeochemical cycles and Earth?s climate. The most reliable information on past atmospheric composition comes from analysis of air entrapped in polar ice cores. This project aims to generate ice-core records of relatively short-lived, very-low-abundance trace gases to determine the range of past variability in their atmospheric levels and investigate the changes in global biogeochemical cycles that caused this variability. This project measures three such gases: carbonyl sulfide, methyl chloride, and methyl bromide. Changes in carbonyl sulfide can indicate changes in primary productivity and photosynthetic update of carbon dioxide. Changes in methyl chloride and methyl bromide significantly impact natural variability in stratospheric ozone. In addition, the processes that control atmospheric levels of methyl chloride and methyl bromide are shared with those controlling levels of atmospheric methane. The measurements will be made in the new ice core from the South Pole, which is expected to provide a 40,000-year record. The primary focus of this project is to develop high-quality trace gas records for the entire Holocene period (the past 11,000 years), with additional, more exploratory measurements from the last glacial period including the period from 29,000-36,000 years ago when there were large changes in atmospheric methane. Due to the cold temperatures of the South Pole ice, the proposed carbonyl sulfide measurements are expected to provide a direct measure of the past atmospheric variability of this gas without the large hydrolysis corrections that are necessary for interpretation of measurements from ice cores in warmer settings. Furthermore, we will test the expectation that contemporaneous measurements from the last glacial period in the deep West Antarctic Ice Sheet Divide ice core will not require hydrolysis loss corrections. With respect to methyl chloride, we aim to verify and improve the existing Holocene atmospheric history from the Taylor Dome ice core in Antarctica. The higher resolution of our measurements compared with those from Taylor Dome will allow us to derive a more statistically significant relationship between methyl chloride and methane. With respect to methyl bromide, we plan to extend the existing 2,000-year database to 11,000 years. Together, the methyl bromide and methyl chloride records will provide strong measurement-based constraints on the natural variability of stratospheric halogens during the Holocene period. In addition, the methyl bromide record will provide insight into the correlation between methyl chloride and methane during the Holocene period due to common sources and sinks.
Melting of snow and ice at the surface of the Antarctic ice sheet can lead to the formation of meltwater lakes, an important precursor to ice-shelf collapse and accelerated ice-sheet mass loss. Understanding the present state of Antarctic surface melt provides a baseline to gauge how quickly melt impacts could evolve in the future and to reduce uncertainties in estimates of future sea-level rise. This project will use a suite of complimentary measurements from Earth-observing satellites, ground observations, and numerical climate and ice-shelf models to enhance understanding of surface melt and lakes, as well as the processes linking these systems. The project directly supports the scientific training of a postdoctoral associate and several undergraduate researchers. In addition, it will promote public scientific literacy and the broadening of quantitative skills for high-school students through the development and implementation of an educational unit in a partnership with an education and outreach expert and two high school teachers. Accurate prediction of sea-level contributions from Antarctica critically requires understanding current melting and supraglacial lake conditions. This project will quantify Antarctic surface melt and supraglacial lakes, and the linkages between the two phenomena. Scatterometer data will enable generation of a 19-year multi-sensor melt time series. Synthetic aperture radar data will document melt conditions across all Antarctic ice shelves at the highest spatial resolution to date (40 m). Multispectral satellite imagery will be used to delineate and measure the depth of supraglacial lakes--for the first time studying the spatial and temporal variations of Antarctic supraglacial lakes. Melt and lake observations will be compared to identify agreement and disagreement. Melt observations will be used to evaluate biases in a widely used, reanalysis-driven, regional climate model. This model will then be used to examine climatic and glaciological variables associated with supraglacial lakes. Finally, in situ observations and climate model output will drive a numerical model that simulates the entire lifecycle of surface melt and possible subsequent lake formation.
Part I: Nontechnical One of the most interesting historical records that science can provide is contained in the ice of Antarctica. Layer by layer over hundreds of thousands of years, snow has precipitated on the ice sheet, become compacted, and turned into additional ice. Any dust or other impurities in the air or snow have been precipitated as well and thus each snowfall leaves a snapshot record of the atmosphere that existed at or near the time of deposition. A detailed chronology of volcanic eruptions can be obtained from the ice layers where ash and other volcanic products were deposited. Normally, the analysis of volcanic layers requires the physical extraction of a core from the ice sheet; however, chronologies from cores have discontinuities and are difficult, time-consuming, and expensive to obtain. Borehole logging is a measurement method where one lowers instrumentation into a drilled hole in the ice, whether or not core has been retrieved. To date, this technology has only been used to measure optical systems to identify volcanic ash and other impurity layers. In this program, a profiling technology will be developed that measures the conductivity of the ice. A radio-frequency emitter lowered into the borehole will create a return signal that changes depending on the local conductivity, which depends on the concentration of dissolved ions. For example, dissolved sulfates are a critical marker of volcanic activity that may not be coincident with deposited ash. Other dissolved ions, such as chloride, can be indicative of other processes. It is expected that this borehole profiling instrument will be able to help rapidly identify volcanic eruptions that had potentially global impact, distinguish between different dissolved ions via their frequency dependencies, and assist in establishing chronologies between different ice cores and boreholes. Part II: Technical Description Borehole logging of the polar ice sheets is one of the most important methods that earth scientists have to identify and date volcanic eruptions. However, current technology only indicates the presence and depth of ash from an eruption. In order to extract more detailed information, one must obtain an ice core, and laboriously measure each section in the laboratory using electrical conductivity or dielectric measurements to determine the presence or absence of dissolved sulfate and its location relative to the corresponding ash, if any. This program will investigate and demonstrate a borehole logging-compatible radio-frequency dielectric sensor to detect and measure spikes in dissolved major ions chemistry in ice, particularly in intervals corresponding to volcanically produced sulfates. The sulfate layers are one of the primary signatures of volcanic products. However, other ions, such as chlorides, calcium, and others are also commonly seen in ice, and the dielectric logging technology of this program would also measure these. It is expected that certain sets of ions will be distinguishable by their frequency dependencies. This technique could guide other investigators, who are using conventional core scanning and sampling methods, to regions of special interest in corresponding core. We plan to construct a ring-based electrode system and test this system on a variety of artificial ice boreholes and ice cores. This unit will not include a pressure vessel or other borehole logger packing. We will test different means of applying electrical signals including short pulses and periodic waves. We will further utilize differential measurements with low noise circuits and filters to achieve maximum sensitivity. We will correlate the signals extracted with known molarities of sulfates and other ions and measured ECM records. We will perform scaled-down experiments using real ice cores stored in Bay?s lab at UC Berkeley. This will permit testing of different designs in ice with natural impurities and polycrystalline structure. This small collection includes cores from a variety of locations in Antarctica and Greenland, and a variety of ages as old as a million years.
Collapse of the West Antarctic ice sheet (WAIS) could raise global sea level by up to 3 meters, at a rate of up to ~1 meter per century, yielding major societal impacts. The goal of this project is to determine if such a collapse occurred in the recent past. This will include development of new geochemical tools to evaluate the sedimentary geologic record around the WAIS to evaluate WAIS behavior during past warm periods. The primary activities to be carried out by the research team are to: 1) characterize the chemistry and magnetic properties of sediments being discharged from different portions of the WAIS and use these properties to ?fingerprint? inputs from different sources on the continent; 2) measure these same properties in a marine sediment core to document major changes in the WAIS over the last 150,000 years. Determining if the WAIS has collapsed in the recent past can provide important information on WAIS potential to grow unstable in the future. The tools to be developed here can then be used on older records around the WAIS to examine the frequency of ice sheet instability in the past. The project will support a postdoctoral researcher as well as undergraduate students. This project will develop sediment provenance proxies to trace the sources of sediment discharged by the West Antarctic Ice Sheet (WAIS) to the continental rise. Specific questions to be addressed are: 1) the degree that sediment from different WAIS terranes can be geochemically and magnetically differentiated; 2) the ability of terrane provenance proxies to detect WAIS collapse in the late Quaternary. The WAIS erodes sediments from various West Antarctic geologic terranes that are deposited in adjacent drift sites. The geochemistry and magnetic properties of drift sediments reflect the tectonic and metamorphic history of their source terranes. Deglaciation of a terrane during WAIS collapse should be detectable by the loss of the terrane?s geochemical and magnetic signature in continental-rise detrital sediments. Continental shelf late-Holocene sediments from near the current WAIS groundling line will be analyzed for silt- and clay-size Sr-Nd-Pb isotopes, magnetic properties, and major-trace elements. The suite of cores includes the eastern Ross Sea to the northern tip of the Antarctic Peninsula and will establish provenance signatures of the Ross and Amundsen Provinces of Marie Byrd Land, Pine Island Bay, Thurston Island/Eight Coast Block, Ellsworth-Whitmore Crustal Block, and Antarctic Peninsula terranes. Many of these terranes have similar tectonic and metamorphic histories but Sr-Nd isotope data from detrital sediments suggest at least 3 distinct provenance signatures. An initial down core study of Ocean Drilling Program Site 1096 in the Bellingshausen Sea will be conducted to detect if the WAIS was unstable during the last interglacial period.
Intellectual Merit: Opening of Drake Passage and the West Scotia Sea south of Tierra del Fuego broke the final continental barrier to onset of a complete Antarctic Circumpolar Current (ACC). Initiation of the ACC has been associated in time with a major, abrupt, drop in global temperatures and the rapid expansion of the Antarctic ice sheets at 33-34 Ma. Events leading to the formation of the Drake Passage gateway are poorly known. Understanding the tectonic evolution of the floor of the Central Scotia Sea (CSS) and the North Scotia Ridge is a key to this understanding. Previous work has demonstrated that superimposed constructs formed a volcanic arc that likely blocked direct eastward flow from the Pacific to the Atlantic through the opening Drake Passage gateway as the active South Sandwich arc does today. The PIs propose a cruise to test, develop and refine, with further targeted mapping and dredging, their theory of CSS tectonics and the influence it had on the onset and development of the ACC. In addition they propose an installation of GPS receiver to test their paleogeographic reconstructions and determine whether South Georgia is moving as part of the South American plate. Broader impacts: A graduate student will be involved in all stages of the research. Undergraduate students will also be involved as watch-standers. A community college teacher will participate in the cruise. The PIs will have a website on which there will be images of the actual ocean floor dredging in operation. The teacher will participate with web and outreach support through PolarTREC. Results of the cruise are of broad interest to paleoceanographers, paleoclimate modelers and paleobiogeographers.
Current oceanographic interest in the interaction of relatively warm water of the Southern Ocean Circumpolar Deep Water ( CDW) as it moves southward to the frigid waters of the Antarctic continental shelves is based on the potential importance of heat transport from the global ocean to the base of continental ice shelves. This is needed to understand the longer term mass balance of the continent, the stability of the vast Antarctic ice sheets and the rate at which sea-level will rise in a warming world. Improved observational knowledge of the mechanisms of how warming CDW moves across the Antarctic Circumpolar Current (ACC) is needed. Understanding this dynamical transport, believed to take place by the eddy flux of time-varying mesoscale circulation features, will improve coupled ocean-atmospheric climate models. The development of the next generation of coupled ocean-ice- climate models help us understand future changes in atmospheric heat fluxes, glacial and sea-ice balance, and changes in the Antarctic ecosystems. A recurring obstacle to our understanding is the lack of data in this distant region. In this project, a number of subsurface profiling EM-APEX floats adapted to operate under sea ice will be launched on up to 4 cruises of opportunity to the Pacific sector during Austral summer. The floats will be launched south of the Polar Front and measure shear, turbulence, temperature, and salinity to 2000m depth for up to 2 year missions while following the CDW layer.
This project will develop a record of the stable-isotope ratios of water from an ice core at the South Pole, Antarctica. Water-isotope ratio measurements provide a means to determine variability in temperature through time. South Pole is distinct from most other locations in Antarctica in showing no warming in recent decades, but little is known about temperature variability in this location prior to the installation of weather stations in 1957. The measurements made as part of this project will result in a much longer temperature record, extending at least 40,000 years, aiding our ability to understand what controls Antarctic climate, and improving projections of future Antarctic climate change. Data from this project will be critical to other investigators working on the South Pole ice core, and of general interest to other scientists and the public. Data will be provided rapidly to other investigators and made public as soon as possible. This project will obtain records of the stable-isotope ratios of water on the ice core currently being obtained at South Pole. The core will reach a depth of 1500 m and an age of 40,000 years. The project will use laser spectroscopy to obtain both an ultra-high-resolution record of oxygen 18/16 and deuterium-hydrogen ratios, and a lower-resolution record of oxygen 17/16 ratios. The high-resolution measurements will be used to aid in dating the core, and to provide estimates of isotope diffusion that constrain the process of firn densification. The novel 17/16 measurement provides additional constraints on the isotope fractionation due to the temperature-dependent supersaturation ratio, which affects the fractionation of water during the liquid-solid condensate transition. Together, these techniques will allow for improved accuracy in the use of the water isotope ratios as proxies for ice-sheet temperature, sea-surface temperature, and atmospheric circulation. The result will be a record of decadal through centennial and millennial scale climate change in a climatically distinct region in East Antarctica that has not been previously sampled by deep ice coring. The project will support a graduate student who will be co-advised by faculty at the University of Washington and the University of Colorado, and will be involved in all aspects of the work.
This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Satellite observations extending over the last 25 years show that Thwaites Glacier is rapidly thinning and accelerating. Over this same period, the Thwaites grounding line, the point at which the glacier transitions from sitting on the seabed to floating, has retreated. Oceanographic studies demonstrate that the main driver of these changes is incursion of warm water from the deep ocean that flows beneath the floating ice shelf and causes basal melting. The period of satellite observation is not long enough to determine how a large glacier, such as Thwaites, responds to long-term and near-term changes in the ocean or the atmosphere. As a result, records of glacier change from the pre-satellite era are required to build a holistic understanding of glacier behavior. Ocean-floor sediments deposited at the retreating grounding line and further offshore contain these longer-term records of changes in the glacier and the adjacent ocean. An additional large unknown is the topography of the seafloor and how it influences interactions of landward-flowing warm water with Thwaites Glacier and affects its stability. Consequently, this project focuses on the seafloor offshore from Thwaites Glacier and the records of past glacial and ocean change contained in the sediments deposited by the glacier and surrounding ocean. Uncertainty in model projections of the future of Thwaites Glacier will be significantly reduced by cross-disciplinary investigations seaward of the current grounding line, including extracting the record of decadal to millennial variations in warm water incursion, determining the pre-satellite era history of grounding-line migration, and constraining the bathymetric pathways that control flow of warm water to the grounding line. Sedimentary records and glacial landforms preserved on the seafloor will allow reconstruction of changes in drivers and the glacial response to them over a range of timescales, thus providing reference data that can be used to initiate and evaluate the reliability of models. Such data will further provide insights on the influence of poorly understood processes on marine ice sheet dynamics. This project will include an integrated suite of marine and sub-ice shelf research activities aimed at establishing boundary conditions seaward of the Thwaites Glacier grounding line, obtaining records of the external drivers of change, improving knowledge of processes leading to collapse of Thwaites Glacier, and determining the history of past change in grounding line migration and conditions at the glacier base. These objectives will be achieved through high-resolution geophysical surveys of the seafloor and analysis of sediments collected in cores from the inner shelf seaward of the Thwaites Glacier grounding line using ship-based equipment, and from beneath the ice shelf using a corer deployed through the ice shelf via hot water drill holes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Bay/1443566 This award supports the deployment and analysis of data from an oriented laser dust logger in the South Pole ice core borehole to complement study of the ice core record. Before the core is even processed, data from the borehole probe will immediately determine the depth-age relationship, augment 3D mapping of South Pole stratigraphy, aid in searches for the oldest ice in Antarctica, and reveal layers of volcanic or extraterrestrial fallout. Regarding the intellectual merit, the oriented borehole log will be essential for investigating features in the ice sheet that may have implications for ice core chronology, ice flow, ice sheet physical properties and stability in response to climate change. The tools and techniques developed in this program have applications in glaciology, biogeoscience and exploration of other planetary bodies. The program aims for a deeper understanding of the consequences and causes of abrupt climate change. The broader impacts of the project are that it will include outreach and education, providing a broad training ground for students and post-docs. Data and metadata will be made available through data centers and repositories such as the National Snow and Ice Data Center web portal. The laser dust logger detects reproducible paleoclimate features at sub-centimeter depth scale. Dust logger data are being used for synchronizing records and dating any site on the continent, revealing accumulation anomalies and episodes of rapid ice sheet thinning, and discovering particulate horizons of special interest. In this project we will deploy a laser dust logger equipped with a magnetic compass to find direct evidence of preferentially oriented dust. Using optical scattering measurements from IceCube calibration studies at South Pole and borehole logs at WAIS Divide, we have detected a persistent anisotropy correlated with flow and crystal fabric which suggests that the majority of insoluble particulates must be located within ice grains. With typical concentrations of parts-per-billion, little is known about the location of impurities within the polycrystalline structure of polar ice. While soluble impurities are generally thought to concentrate at inter-grain boundaries and determine electrical conductivity, the fate of insoluble particulates is much less clear, and microscopic examinations are extremely challenging. These in situ borehole measurements will help to unravel intimate relationships between impurities, flow, and crystal fabric. Data from this project will further develop a unique record of South Pole surface roughness as a proxy for paleowind and provide new insights for understanding glacial radar propagation. This project has field work in Antarctica.
1142517/Saltzman This proposal requests support for a project to drill and recover a new ice core from South Pole, Antarctica. The South Pole ice core will be drilled to a depth of 1500 m, providing an environmental record spanning approximately 40 kyrs. This core will be recovered using a new intermediate drill, which is under development by the U.S. Ice Drilling Design and Operations (IDDO) group in collaboration with Danish scientists. This proposal seeks support to provide: 1) scientific management and oversight for the South Pole ice core project, 2) personnel for ice core drilling and core processing, 3) data management, and 3) scientific coordination and communication via scientific workshops. The intellectual merit of the work is that the analysis of stable isotopes, atmospheric gases, and aerosol-borne chemicals in polar ice has provided unique information about the magnitude and timing of changes in climate and climate forcing through time. The international ice core research community has articulated the goal of developing spatial arrays of ice cores across Antarctica and Greenland, allowing the reconstruction of regional patterns of climate variability in order to provide greater insight into the mechanisms driving climate change. The broader impacts of the project include obtaining the South Pole ice core will support a wide range of ice core science projects, which will contribute to the societal need for a basic understanding of climate and the capability to predict climate and ice sheet stability on long time scales. Second, the project will help train the next generation of ice core scientists by providing the opportunity for hands-on field and core processing experience for graduate students and postdoctoral researchers. A postdoctoral researcher at the University of Washington will be directly supported by this project, and many other young scientists will interact with the project through individual science proposals. Third, the project will result in the development of a new intermediate drill which will become an important resource to US ice core science community. This drill will have a light logistical footprint which will enable a wide range of ice core projects to be carried out that are not currently feasible. Finally, although this project does not request funds for outreach activities, the project will run workshops that will encourage and enable proposals for coordinated outreach activities involving the South Pole ice core science team.
Earth's geologic record shows that the great ice sheets have contributed to rates of sea-level rise that have been much higher than those observed today. That said, some sectors of the current Antarctic ice sheet are losing mass at large and accelerating rates. One of the primary challenges for placing these recent and ongoing changes in the context of geologically historic rates, and for making projections decades to centuries into the future, is the difficulty of observing conditions and processes beneath the ice sheet. Whereas satellite observations allow tracking of the ice-surface velocity and elevation on the scale of glacier catchments to ice sheets, airborne ice-penetrating radar has been the only approach for assessing conditions on this scale beneath the ice. These radar observations have been made since the late 1960s, but, because many different instruments have been used, it is difficult to track change in subglacial conditions through time. This project will develop the technical tools and approaches required to cross-compare among these measurements and thus open up opportunities for tracking and understanding changes in the critical subglacial environment. Intertwined with the research and student training on this project will be an outreach education effort to provide middle school and high school students with improved resources and enhanced exposure to geophysical, glaciological, and remote-sensing topics through partnership with the National Science Olympiad. The radar sounding of ice sheets is a powerful tool for glaciological science with broad applicability across a wide range of cryosphere problems and processes. Radar sounding data have been collected with extensive spatial and temporal coverage across the West Antarctic Ice Sheet, including areas where multiple surveys provide observations that span decades in time or entire cross-catchment ice-sheet sectors. However, one major obstacle to realizing the scientific potential of existing radar sounding observations in Antarctica is the lack of analysis approaches specifically developed for cross-instrument interpretation. This project aims to directly address these barriers to full utilization of the collective Antarctic radar sounding record by developing a suite of processing and interpretation techniques to enable the synthesis of radar sounding data sets collected with systems that range from incoherent to coherent, single-channel to swath-imaging, and digital to optically-recorded radar sounders. The approaches will be assessed for two target regions: the Amundsen Sea Embayment and the Siple Coast. All pre- and post-processed sounding data produced by this project will be publically hosted for use by the wider research community. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Stone/1341728 This award supports a project to determine if the West Antarctic Ice Sheet (WAIS) has thinned and collapsed in the past and if so, when did this occur. This topic is of interest to geologists who have long been studying the history and behavior of ice sheets (including the WAIS) in order to determine what climatic conditions allow an ice sheet to survive and what conditions have caused them to collapse in the past. The bulk of this research has focused on the last ice age, when climate conditions were far colder than the present; this project will focus on the response of ice sheets to warmer climates in the past. A new and potentially transformative approach that uses the analysis of atoms transformed by cosmic-rays in bedrock beneath the WAIS will allow a definitive test for ice free conditions in the past. This is because the cosmic rays capable of producing the necessary reactions can penetrate only a few meters through glacier ice. Therefore, if they are detected in samples from hundreds of meters below the current ice sheet surface this would provide definitive proof of mostly ice-free conditions in the past. The concentrations of different cosmic ray products in cores from different depths will help answer the question of how frequently bedrock has been exposed, how much the ice sheet has thinned, and which time periods in the past produced climatic conditions capable of making the ice sheet unstable. Short bedrock cores beneath the ice sheet near the Pirrit Hills in West Antarctica will be collected using a new agile sub-ice geological drill (capable of drilling up to 200 meters beneath the ice surface) that is being developed by the Ice Drilling Program Office (IDPO) to support this and other projects. Favorable drilling sites have already been identified based on prior reconnaissance mapping, sample analysis and radar surveys of the ice-sheet bed. The cores collected in this study will be analyzed for cosmic-ray-produced isotopes of different elements with a range of half-lives from 5700 yr (C-14) to 1.4 Myr (Be-10), as well as stable Ne-21. The presence or absence of these isotopes will provide a definitive test of whether bedrock surfaces were ice-free in the past and due to their different half-lives, ratios of the isotopes will place constraints on the age, frequency and duration of past exposure episodes. Results from bedrock surfaces at different depths will indicate the degree of past ice-sheet thinning. The aim is to tie evidence of deglaciation in the past to specific periods of warmer climate and thus to gauge the ice sheet's response to known climate conditions. This project addresses the broad question of ice-sheet sensitivity to climate warming, which previously has been largely determined indirectly from sea-level records. In contrast, this project will provide direct measurements that provide evidence of ice-sheet thinning in West Antarctica. Results from this work will help to identify the climatic factors and thresholds capable of endangering the WAIS in future. The project will make a significant contribution to the ongoing study of climate change, ice-sheet melting and associated sea-level rise. This project has field work in Antarctica.
Accurate reconstructions and predictions of glacier movement on timescales of human interest require a better understanding of available observations and the ability to model the key processes that govern ice flow. The fact that many of these processes are interconnected, are loosely constrained by data, and involve not only the ice, but also the atmosphere, ocean, and solid Earth, makes this a challenging endeavor, but one that is essential for Earth-system modeling and the resulting climate and sea-level forecasts that are provided to policymakers worldwide. Based on the amount of ice present in the West Antarctic Ice Sheet and its ability to flow and/or melt into the ocean, its complete collapse would result in a global sea-level rise of 3.3 to 5 meters, making its stability and rate of change scientific questions of global societal significance. Whether or not a collapse eventually occurs, a better understanding of the potential West Antarctic contribution to sea level over the coming decades and centuries is necessary when considering the fate of coastal population centers. Recent observations of the Amundsen Sea Embayment of West Antarctica indicate that it is experiencing faster mass loss than any other region of the continent. At present, the long-term stability of this embayment is unknown, with both theory and observations suggesting that collapse is possible. This study is focused on this critical region. We will test an ice-sheet model against existing observations, improve treatment of key processes in the model, and make projections with uncertainty assessments. This is a three-year modeling study using the open-source Ice Sheet System Model in coordination with other models to improve projections of future sea-level change. Project goals are to: 1. hindcast the past two-to-three decades of evolution of the Amundsen Sea Embayment sector to determine controlling processes, incorporate and test parameterizations, and assess and improve model initialization, spinup, and performance; 2. improve the model by utilizing sensitivity studies with regional process-oriented models to create numerically efficient parameterizations for key sub-grid-scale processes; 3. project a range of likely evolutions of the Amundsen Sea Embayment sector and their respective contributions to sea level in the next several centuries; 4. attribute sources of errors in the hindcast and provide an assessment of the uncertainties in the projections, including a range of likely outcomes given various forcings and inclusion or omission of physical processes in the model. At present, the long-term stability of the Amundsen Sea Embayment is unknown, with both theory (the "marine ice sheet instability hypothesis") and observations (rapid thinning and grounding-line retreat approaching regions where the bed deepens inland) suggesting that collapse is possible. But incompletely understood physical processes (e.g., basal hydrology, rheology, and sliding; tidal effects; ice-ocean interaction along the shelf and within the grounding zone) and lack of resolution in basal topography datasets making the ultimate outcome uncertain. Thus, there is a pressing need for high-resolution simulations of this region that include numerical representations of controlling physical processes (many of which are applicable elsewhere) within a higher-order ice-sheet model capable of assimilating recent observations and providing uncertainty analyses associated with model and data limitations. By focusing on the Amundsen Sea Embayment as a connected region across the 10-10,000-meter scales using a hierarchy of one, two, and three-dimensional models along with the sensitivity analysis tools built into the Ice Sheet System Model, this project aims to produce (1) the most reliable results to date when compared with studies that consider only one ice stream or the entire ice sheet and (2) estimates of differing dynamic responses arising from errors in data, model parameterizations, and forcings. Given the uncertainties, the project will produce a range of predictions with characteristic trends that can be recognized within future observational data sets. As new data become available, some predicted rates of change could be culled from the predictive paths generated by this study.
The response of the Antarctic Ice Sheet to future climatic changes is recognized as the greatest uncertainty in projections of future sea level. An understanding of past ice fluctuations affords insight into ice-sheet response to climate and sea-level change and thus is critical for improving sea-level predictions. This project will examine deglaciation of the southern Ross Sea over the past few thousand years to document oscillations in Antarctic ice volume during a period of relatively stable climate and sea level. We will help quantify changes in ice volume, improve understanding of the ice dynamics responsible, and examine the implications for future sea-level change. The project will train future scientists through participation of graduate students, as well as undergraduates who will develop research projects in our laboratories. Previous research indicates rapid Ross Sea deglaciation as far south as Beardmore Glacier early in the Holocene epoch (which began approximately 11,700 years before present), followed by more gradual recession. However, deglaciation in the later half of the Holocene remains poorly constrained, with no chronological control on grounding-line migration between Beardmore and Scott Glaciers. Thus, we do not know if mid-Holocene recession drove the grounding line rapidly back to its present position at Scott Glacier, or if the ice sheet withdrew gradually in the absence of significant climate forcing or eustatic sea level change. The latter possibility raises concerns for future stability of the Ross Sea grounding line. To address this question, we will map and date glacial deposits on coastal mountains that constrain the thinning history of Liv and Amundsen Glaciers. By extending our chronology down to the level of floating ice at the mouths of these glaciers, we will date their thinning history from glacial maximum to present, as well as migration of the Ross Sea grounding line southwards along the Transantarctic Mountains. High-resolution dating will come from Beryllium-10 surface-exposure ages of erratics collected along elevation transects, as well as Carbon-14 dates of algae within shorelines from former ice-dammed ponds. Sites have been chosen specifically to allow close comparison of these two dating methods, which will afford constraints on Antarctic Beryllium-10 production rates.
This collaborative project explores the signatures and causes of natural climate change in the region surrounding Antarctica over the last 40,000 years as the Earth transitioned from an ice age into the modern warm period. The researchers will investigate how the wind belts that surround Antarctica changed in their strength and position through time, and document explosive volcanic eruptions and CO2 cycling in the Southern Ocean as potential climate forcing mechanisms over this interval. Understanding how and why the climate varied naturally in the past is critical for improving understanding of modern climate change and projections of future climate under higher levels of atmospheric CO2. The investigators plan to conduct a suite of chemical measurements along the 1500m length of the South Pole Ice Core, including major ion and trace element concentrations, and microparticle (dust) concentrations and size distributions. These measurements will (1) extend the South Pole record of explosive volcanic eruptions to 40,000 years using sulfate and particle data; (2) establish the relative timing of climate changes in dust source regions of Patagonia, New Zealand, and Australia using dust flux data; (3) investigate changes in the strength and position of the westerly wind belt using dust size distribution data; and (4) quantify the flux of bioavailable trace metals deposited as dust to the Southern Ocean over time. These chemistry records will also be critical for creating the timescale that will be used by all researchers studying records from the South Pole core. The project will support four graduate students and several undergraduate students across three different institutions, and become a focus of the investigators' efforts to disseminate outcomes of climate change science to the broader community.
The Antarctic marine ecosystem is highly productive and supports a diverse range of ecologically and commercially important species. A key species in this ecosystem is Antarctic krill, which in addition to being commercially harvested, is the principle prey of a wide range of marine organisms including penguins, seals and whales. The aim of this study is to use penguins and other krill predators as sensitive indicators of past changes in the Antarctic marine food web resulting from climate variability and the historic harvesting of seals and whales by humans. Specifically this study will recover and analyze modern (<20 year old), historic (20-200 year old) and ancient (200-10,000 year old) penguin and other krill predator tissues to track their past diets and population movements relative to shifts in climate and the availability of Antarctic krill. Understanding how krill predators were affected by these factors in the past will allow us to better understand how these predators, the krill they depend on, and the Antarctic marine ecosystem as a whole will respond to current challenges such as global climate change and an expanding commercial fishery for Antarctic krill. The project will further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. This project will support the cross-institutional training of undergraduate and graduate students in advanced analytical techniques in the fields of ecology and biogeochemistry. In addition, this project includes educational outreach aimed encouraging participation in science careers by engaging K-12 students in scientific issues related to Antarctica, penguins, marine ecology, biogeochemistry, and global climate change. This research will help place recent ecological changes in the Southern Ocean into a larger historical context by examining decadal and millennial-scale shifts in the diets and population movements of Antarctic krill predators (penguins, seals, and squid) in concert with climate variability and commercial harvesting. This will be achieved by coupling advanced stable and radio isotope techniques, particularly compound-specific stable isotope analysis, with unprecedented access to modern, historical, and well-preserved paleo-archives of Antarctic predator tissues dating throughout the Holocene. This approach will allow the project to empirically test if observed shifts in Antarctic predator bulk tissue stable isotope values over the past millennia were caused by climate-driven shifts at the base of the food web in addition to, or rather than, shifts in predator diets due to a competitive release following the historic harvesting of krill eating whale and seals. In addition, this project will track the large-scale abandonment and reoccupation of penguin colonies around Antarctica in response to changes in climate and sea ice conditions over the past several millennia. These integrated field studies and laboratory analyses will provide new insights into the underlying mechanisms that influenced past shifts in the diets and population movements of charismatic krill predators such as penguins. This will allow for improved projections of the ecosystem consequences of future climate change and anthropogenic harvesting scenarios in the Antarctica that are likely to affect the availability of Antarctic krill.
Abstract During the Early Pliocene, 4.8 to 3.4 million years ago, warmer-than-present global temperatures resulted in a retreat of the Ross Ice Shelf and West Antarctic Ice Sheet. Understanding changes in ocean dynamics during times of reduced ice volume and increased temperatures in the geologic past will improve the predictive models for these conditions. The primary goal of the proposed research is to develop a new oxygen isotope record of Pliocene oceanographic conditions near the Antarctic continent. Oxygen isotope values from the carbonate tests of benthic foraminifera have become the global standard for paleo-oceanographic studies, but foraminifera are sparse in high-latitude sediment cores. This research will instead make use of oxygen isotope measurements from diatom silica preserved in a marine sediment core from the Ross Sea. The project is the first attempt at using this method and will advance understanding of global ocean dynamics and ice sheet-ocean interactions during the Pliocene. The project will foster the professional development of two early-career scientists and serve as training for graduate and undergraduate student researchers. The PIs will use this project to introduce High School students to polar/oceanographic research, as well as stable isotope geochemistry. Collaboration with teachers via NSTA and Polar Educators International will ensure the implementation of excellent STEM learning activities and curricula for younger students. Technical Description This project will produce a high-resolution oxygen isotope record from well-dated diatom rich sediments that have been cross-correlated with global benthic foraminifera oxygen isotope records. Diatom silica frustules deposited during the Early Pliocene and recovered by the ANDRILL Project (AND-1B) provide ideal material for this objective. Diatomite unites in the AND-1B core are nearly pure, with little evidence of opal formation. A diatom oxygen isotope record from this core offers the potential to constrain lingering uncertainties about Ross Sea and Southern Ocean paleoceanography and Antarctic Ice Sheet history during a time of high atmospheric carbon dioxide concentrations. Specifically, oxygen isotope variations will be used to constrain changes in the water temperature and/or freshwater flux in the Pliocene Ross Sea. Diatom species data from the AND-1B core have been used to infer variations in the extent and duration of seasonal sea ice coverage, sea surface temperatures, and mid-water advection onto the continental shelf. However, the diatom oxygen isotope record will provide the first direct measure of water/oxygen isotope values at the Antarctic continental margin during the Pliocene.
Brook 1543267 Approximately half of the human caused carbon dioxide emissions to the atmosphere are absorbed by the ocean, which reduces the amount of global warming associated with these emissions. Much of this carbon uptake occurs in the Southern Ocean around Antarctica, where water from the deep ocean comes to the surface. How much water "up-wells," and therefore how much carbon is absorbed, is believed to depend on the strength and location of the major westerly winds in the southern hemisphere. These wind patterns have been shifting southward in recent decades, and future changes could impact the global carbon cycle and promote the circulation of relatively warm water from the deep ocean on to the continental shelf, which contributes to enhanced Antarctic ice melt and sea level rise. Understanding of the westerly winds and their role in controlling atmospheric carbon dioxide levels and the circulation of ocean water is therefore very important. The work supported by this award will study past movement of the SH westerlies in response to natural climate variations. Of particular interest is the last deglaciation (20,000 to 10,000 years ago), when the global climate made a transition from an ice age climate to the current warm period. During this period, atmospheric carbon dioxide rose from about 180 ppm to 270 parts per million, and one leading hypothesis is that the rise in carbon dioxide was driven by a southward movement of the southern hemisphere westerlies. The broader impacts of the work include a perspective on past movement of the southern hemisphere westerlies and their link to atmospheric carbon dioxide, which could guide projections of future oceanic carbon dioxide uptake, with strong societal benefits; international collaboration with German scientists; training of a postdoctoral investigator; and outreach to public schools. This project will investigate whether the abundance of a noble gas, krypton-86, trapped in Antarctic ice cores, records atmospheric pressure variability, and whether or not this pressure variability can be used to infer past movement of the Southern Hemisphere westerly winds. The rationale for the project is that models of air movement in the snow pack (firn) in Antarctica indicate that pressure variations drive air movement that disturbs the normal enrichment in krypton-86 caused by gravitational settling of gases. Calculations predict that the krypton-86 deviation from gravitational equilibrium reflects the magnitude of pressure variations. In turn, atmospheric data show that pressure variability over Antarctica is linked to the position of the southern hemisphere westerly winds. Preliminary data from the West Antarctic Ice Sheet (WAIS) Divide ice core show a large excursion in krypton-86 during the transition from the last ice age to the current warm period. The investigators will perform krypton-86 analysis on ice core and firn air samples to establish whether the Kr-86 deviation is linked to pressure variability, refine the record of krypton isotopes from the WAIS Divide ice core, investigate the role of pressure variability in firn air transport using firn air models, and investigate how barometric pressure variability in Antarctica is linked to the position/strength of the SH westerlies in past and present climates.
The Ross Ice Shelf is the largest existing ice shelf in Antarctica, and is currently stabilizing significant portions of the land ice atop the Antarctic continent. An ice shelf begins where the land ice goes afloat on the ocean, and as such, the Ross Ice Shelf interacts with the ocean and seafloor below, and the land ice behind. Currently, the Ross Ice Shelf slows down, or buttresses, the fast flowing ice streams of the West Antarctic Ice Sheet (WAIS), a marine-based ice sheet, which if melted, would raise global sea level by 3-4 meters. The Ross Ice Shelf average ice thickness is approximately 350 meters, and it covers approximately 487,000 square kilometers, an area slightly larger than the state of California. The Ross Ice Shelf has disappeared during prior interglacial periods, suggesting in the future it may disappear again. Understanding the dynamics, stability and future of the West Antarctic Ice Sheet therefore requires in-depth knowledge of the Ross Ice Shelf. The ROSETTA-ICE project brings together scientists from 4 US institutions and from the Institute of Geological and Nuclear Sciences Limited, known as GNS Science, New Zealand. The ROSETTA-ICE data on the ice shelf, the water beneath the ice shelf, and the underlying rocks, will allow better predictions of how the Ross Ice Shelf will respond to changing climate, and therefore how the WAIS will behave in the future. The interdisciplinary ROSETTA-ICE team will train undergraduate and high school students in cutting edge research techniques, and will also work to educate the public via a series of vignettes integrating ROSETTA-ICE science with the scientific and human history of Antarctic research. The ROSETTA-ICE survey will acquire gravity and magnetics data to determine the water depth beneath the ice shelf. Radar, LIDAR and imagery systems will be used to map the Ross Ice Shelf thickness and fine structure, crevasses, channels, debris, surface accumulation and distribution of marine ice. The high resolution aerogeophysical data over the Ross Ice Shelf region in Antarctica will be acquired using the IcePod sensor suite mounted externally on an LC-130 aircraft operating from McMurdo Station, Antarctica. Field activities will include ~36 flights on LC-130 aircraft over two field seasons in Antarctica. The IcePod instrument suite leverages the unique experience of the New York Air National Guard operating in Antarctica for NSF scientific research as well as infrastructure and logistics. The project will answer questions about the stability of the Ross Ice Shelf in future climate, and the geotectonic evolution of the Ross Ice Shelf Region, a key component of the West Antarctic Rift system. The comprehensive benchmark data sets acquired will enable broad, interdisciplinary analyses and modeling, which will also be performed as part of the project. ROSETTA-ICE will illuminate Ross ice sheet-ice shelf-ocean dynamics as the system nears a critical juncture but still is intact. Through interacting with an online data visualization tool, and comparing the ROSETTA-ICE data and results from earlier studies, we will engage students and young investigators, equipping them with new capabilities for the study of critical earth systems that influence global climate.
Intellectual Merit: Evidence from the eastern Ross Sea continental shelf indicates that the West Antarctic Ice Sheet advanced and retreated during the last glacial cycle, but it is unclear whether the ice sheet advanced to the shelf edge or just to the middle shelf. These two end-member scenarios offer different interpretations as to why, how, and when the West Antarctic Ice Sheet oscillated. The PI proposes to acquire seismic, multibeam, and core data from Whales Deep, to evaluate the timing and duration of two advances of grounded ice to the outer and middle shelf of the Whales Deep Basin, a West Antarctic Ice Sheet paleo ice stream trough in eastern Ross Sea. Grounding events are represented by seismically resolvable Grounding Zone Wedges. The PI will collect radiocarbon dates on in situ benthic foraminifera from the grounding zone diamict as well as ramped pyrolysis radiocarbon dates on acid insoluble organics from open-marine mud overlying the grounding zone diamict. Using these data the PI will calculate the duration of the two grounding events. Furthermore, the PI will test a numerical model prediction that West Antarctic Ice Sheet retreat must have involved melting at the marine terminus of the ice sheet. Pore-water from the grounding zone diamict will be extracted from piston cores to determine salinity and δ18O values that should indicate if significant melting occurred at the grounding line. Broader impacts: The data collected will provide constraints on the timing and pattern of Last Glacial Maximum advance and retreat that can be incorporated into interpretations of ice-surface elevation changes. The proposed activities will provide valuable field and research training to undergraduate/graduate students and a Louisiana high-school science teacher. The research will be interactively shared with middle- and high-school science students and with visitors to the LSU Museum of Natural Science Weekend-Science Program.
Recent observations and model results suggest that collapse of the Amundsen Sea sector of West Antarctica may already be underway. However, the timeline of collapse and the effects of ongoing climatic and oceanographic changes are key unanswered questions. Complete disintegration of the ice sheet would raise global sea level by more than 3 m, which would have significant societal impacts. Improved understanding of the controls on ice-sheet evolution is needed to make better predictions of ice-sheet behavior. Results from numerical models show that buttressing from surrounding ice shelves and/or from small-scale grounded ice rises should act to slow the retreat and discharge of ice from the interior ice sheet. However, there are very few field observations with which to develop and validate models. Field observations conducted in the early 1980s on Crary Ice Rise in the Ross Sea Embayment are a notable exception. This project will revisit Crary Ice Rise with new tools to make a suite of measurements designed to address questions about how the ice rise affects ice discharge from the Ross Sea sector of West Antarctica. The team will include a graduate and undergraduate student, and will participate in a range of outreach activities. New tools including radar, seismic, and GPS instruments will be used to conduct targeted geophysical measurements both on Crary Ice Rise and across its grounding line. The project will use these new measurements, together with available ancillary data to inform a numerical model of grounding line dynamics. The model and measurements will be used to address the (1) How has the ice rise evolved over timescales ranging from: the past few decades; the past millennia after freeze-on; and through the deglaciation? (2) What history of ice dynamics is preserved in the radar-detected internal stratigraphy? (3) What dynamical effect does the presence/absence of the ice rise have on discharge of the Ross Ice Streams today? (4) How is it contributing to the slow-down of the proximal Whillans and Mercer ice streams? (5) What dynamical response will the ice rise have under future environmental change?
In order to understand what environmental conditions might look like for future generations, we need to turn to archives of past times when the world was indeed warmer, before anyone was around to commit them to collective memory. The geologic record of Earth's past offers a glimpse of what could be in store for the future. Research by Ivany and her team looks to Antarctica during a time of past global warmth to see how seasonality of temperature and rainfall in coastal settings are likely to change in the future. They will use the chemistry of fossils (a natural archive of these variables) to test a provocative hypothesis about near-monsoonal conditions in the high latitudes when the oceans are warm. If true, we can expect high-latitude shipping lanes to become more hazardous and fragile marine ecosystems adapted to constant cold temperatures to suffer. With growing information about how human activities are likely to affect the planet in the future, we will be able to make more informed decisions about policies today. This research involves an international team of scholars, including several women scientists, training of graduate students, and a public museum exhibit to educate children about how we study Earth's ancient climate and what we can learn from it. Antarctica is key to an understanding how Earth?s climate system works under conditions of elevated CO2. The poles are the most sensitive regions on the planet to climate change, and the equator-to-pole temperature gradient and the degree to which high-latitude warming is amplified are important components for climate models to capture. Accurate proxy data with good age control are therefore critical for testing numerical models and establishing global patterns. The La Meseta Formation on Seymour Island is the only documented marine section from the globally warm Eocene Epoch exposed in outcrop on the continent; hence its climate record is integral to studies of warming. Early data suggest the potential for strongly seasonal precipitation and runoff in coastal settings. This collaboration among paleontologists, geochemists, and climate modelers will test this using seasonally resolved del-18O data from fossil shallow marine bivalves to track the evolution of seasonality through the section, in combination with independent proxies for the composition of summer precipitation (leaf wax del-D) and local seawater (clumped isotopes). The impact of the anticipated salinity stratification on regional climate will be evaluated in the context of numerical climate model simulations. In addition to providing greater clarity on high-latitude conditions during this time of high CO2, the combination of proxy and model results will provide insights about how Eocene warmth may have been maintained and how subsequent cooling came about. As well, a new approach to the analysis of shell carbonates for 87Sr/86Sr will allow refinements in age control so as to allow correlation of this important section with other regions to clarify global climate gradients. The project outlined here will develop new and detailed paleoclimate records from existing samples using well-tuned as well as newer proxies applied here in novel ways. Seasonal extremes are climate parameters generally inaccessible to most studies but critical to an understanding of climate change; these are possible to resolve in this well-preserved, accretionary-macrofossil-bearing section. This is an integrated study that links marine and terrestrial climate records for a key region of the planet across the most significant climate transition in the Cenozoic.
Ice shelves are the floating portions of glaciers that terminate in the ocean. They are common around the periphery of Antarctica. The accumulation of surface meltwater on or near the surface of ice shelves can play a role in ice-shelf collapse, which leads to accelerated loss of grounded ice and sea-level rise. Recent studies have showed that present-day meltwater generation and movement across the surface of Antarctica is more widespread than previously thought and is expected to increase. Consequently, there is a growing need to address the role of surface water in forecasts of ice-shelf behavior. While much progress has been made, understanding of the role of water in ice-shelf collapse is still in its infancy. This award supports a workshop that will bring together experts from multiple disciplines that, together, can advance understanding of Antarctic surface hydrology and its role in the future stability of ice shelves. This workshop will bring together U.S. and international scientists with expertise in ice-sheet dynamics, glacial hydrology, climatology, and other disciplines to identify critical knowledge gaps and move the community towards answering fundamental questions such as: What climate dynamics are responsible for surface meltwater generation in Antarctica? What controls the spatiotemporal distribution of meltwater ponds on Antarctic ice shelves? Where is meltwater generated, where does it pond today, and how will this change this century? How will meltwater impact ice shelves? How will surface hydrology impact sea-level this century? The deliberations will be captured in a workshop report and review paper that will be broadly distributed.
Intellectual Merit: Ice free rock outcrops in the Transantarctic Mountains provide the only accessible windows into the interior of the ice covered Antarctic continent; they are extremely remote and difficult to study. This region also hosts the highest latitude ice-free valley systems on the planet. Based on two interdisciplinary workshops, the Transantarctic region near the Shackleton Glacier has been identified as a high priority site for further studies, with a field camp proposed for the 2015-2016 Antarctic field season. The geology of this region has been studied since the heroic era of Antarctic exploration, in the early 1900s, but geologic mapping has not been updated in more than forty years, and existing maps are at poor resolution (typically 1:250,000). This project would utilize the WorldView-2 multispectral orbital dataset to supplement original geologic mapping efforts near the proposed 2015-2016 Shackleton Glacier camp. The WorldView-2 satellite is the only multispectral orbiting sensor capable of imaging the entirety of the Transantarctic Mountains, and all necessary data are currently available to the Polar Geospatial Center. High-latitude atmospheric correction of multispectral data for geologic investigations has only recently been tested, but has never been applied to WorldView-2 data, and never for observations of this type. Therefore, this research will require technique refinements and methodological developements to accomplish the goals. Atmospheric correction refinements and spectral validation will be made possible by laboratory spectroscopic measurements of rock samples currently stored at the U.S. Polar Rock Repository, at the Ohio State University. This project will result in spectral unit identification and boundary mapping at a factor of four higher resolution (1:62,500) than previous geologic mapping efforts, and more detailed investigations (1:5,123) are possible at resolutions more than a factor of forty-eight improved over previous geologic maps. Validated spectral mapping at these improved resolutions will allow for detailed lithologic, and potentially biologic, mapping using existing satellite imagery. This will greatly enhance planning capabilities, thus maximizing the efficiency of the scientific research and support logistics associated with the Shackleton Glacier deep field camp. Broader impacts: The proposed work will have multiple impacts on the broader scientific community. First, the refinement of existing atmospheric correction methodologies, and the development of new spectral mapping techniques, may substantially improve our ability to remotely investigate geologic surfaces throughout Antarctica. The ability to validate this orbital dataset will be of use to both current and future geologic, environmental, and biologic studies, potentially across the entire continent. The project will yield a specific spectral mapping product (at a scale of 1:62,500) to the scientific community by a targeted date of 01 March 2014, in order to support proposals submitted to the National Science Foundation for the proposed 2015/2016 Shackleton Glacier camp. High-resolution spectral mapping products (up to a maximum resolution of 2 meters per pixel) will also be generated for regions of particular scientific interest. The use of community based resources, such as Polar Geospatial Center (PGC) imagery and U.S. Polar Rock Repository rock samples, will generate new synergistic and collaborative research possibilities within the Antarctic research community. In addition, the lead PI (Salvatore) is an early career scientist who is active in both Antarctic and planetary remote sensing. There are overlaps in the calibration, correction, and validation of remote spectral datasets for Antarctic and planetary applications which can lead to benefits and insights to an early career PI, as well as the two communities.
This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999.
This proposal would provide funding for continued operation of the Antarctic Marine Geology Research Facility (AMGRF) at Florida State University. This facility is the NSF repository of sediment cores from the ocean floor surrounding Antarctica, and makes sediment cores available to the entire scientific community, providing the equipment and knowledge necessary for scientists to collect samples for specialized measurements. The sediments provide a record of past climate, ocean circulation, and ice sheet history, and were recovered at great cost using piston cores deployed from research vessels and rotary coring from drilling platforms. The funding supports a curator, an assistant curator, and a student work force from FSU. This staff supports visiting scientists, manages the collections and the equipment used for core characterization and sampling, and maintain data bases. The AMGRF houses a unique collection of sediment cores from the Southern Oceans and has served in this role for the past 50 years. The Antarctic Marine Geology Research Facility (AMGRF) at Florida State University, the NSF repository of Southern Ocean piston- and drill-cores, has been conducting marine geological research and providing numerous services to the Antarctic and Earth Science Community in its present building for the past 50 years. This proposal requests operating funds to (a) continue provide these services, (b) manage archives and databases, (c) complete necessary upgrades of the AMGRF Cold-Room, and (d) continue our education and outreach programs for students and the general public. The AMGRF archives and curates more than 23,000 m of cored sediment (over 7,000 cores) collected by United States Antarctic Program (USAP) vessels. The Facility also archives and curates some 5,500 m of rotary-cored material from international programs such as ANDRILL. The standard core processing services include core splitting, Multi-Sensor Track analyses, core photography, whole-core x-rays, etc., core description publications (macroscopic and microscopic), and core sampling. Facility personnel also provide curatorial support services to field-based projects upon request. Analytical equipment at the AMGRF serves the research needs of Facility personnel (for the generation of detailed core descriptions), NSF Principal Investigators involved with the United States Antarctic Program (USAP), and qualified users from the scientific community in the U.S. and beyond. This equipment provides users of the Facility with the necessary tools to rapidly and objectively analyze the piston cores and drill cores sent to the Facility each year. The AMGRF maintains a core and sample database with the latest map-sample search capabilities that can be accessed through the continuously upgraded Facility website. This searchable database contains basic information about all the cores stored at the facility, as well as information on samples taken from 1964 to the present. In addition to the sediment core archives the AMGRF also keeps archives of ship and deck-logs, a collection of ca. 862,000 microscope slides, and a library of AMGRF related publications. Facility personnel routinely provide tours and lectures for students and the general public.
Intellectual Merit: The PIs propose to continue and expand GPS and seismic for ANET-POLENET Phase 2 to advance understanding of geodynamic processes and their influence on the West Antarctic Ice Sheet. ANET-POLENET science themes include: 1) determining ice mass change since the last glacial maximum, including modern ice mass balance; 2) solid earth influence on ice sheet dynamics; and 3) tectonic evolution of West Antarctica and feedbacks with ice sheet evolution. Nine new remote continuous GPS stations, to be deployed in collaboration with U.K. and Italian partners, will augment ANET-POLENET instrumentation deployed during Phase 1. Siting is designed to better constrain uplift centers predicted by GIA models and indicated by Phase 1 results. ANET-POLENET Phase 2 builds on Phase 1 scientific, technological, and logistical achievements including 1) seismic images of crust and mantle structure that resolve the highly heterogeneous thermal and viscosity structure of the Antarctic lithosphere and underlying mantle; 2) newly identified intraplate glacial, volcanic, and tectonic seismogenic processes; 3) improved estimates of intraplate vertical and horizontal crustal motions and refinement of the Antarctic GPS reference frame; and 4) elucidation of controls on glacial isostatic adjustment-induced crustal motions due to laterally varying earth structure. The PIs present a nominal plan to reduce ANET by approximately half to a longer-term community "backbone network" in the final 2 years of this project. Broader impacts: Monitoring and understanding mass change and dynamic behavior of the Antarctic ice sheet using in situ GPS and seismological studies will help improve understanding of how Antarctic ice sheets respond to a warming world and how will this response impacts sea-level and other global changes. Seismic and geodetic data collected by the backbone ANET-POLENET network are openly available to the scientific community. ANET-POLENET is integral in the development and realization of technological and logistical innovations for year-round operation of instrumentation at remote polar sites, helping to advance scientifically and geographically broad studies of the polar regions. The ANET-POLENET team will establish a training initiative to mentor young polar scientists in complex, multidisciplinary and internationally collaborative research. ANET-POLENET will continue the broad public outreach to the public about polar science through the polenet.org website, university lectures, and K-12 school visits. This research involves multiple international partners.
Worldwide publicity surrounding the calving of an iceberg the size of Delaware in July 2017 from the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula presents a unique and time-sensitive opportunity for research and education on polar ecosystems in a changing climate. The goal of this project was to convene a workshop, drawing from the large fund of intellectual capital in the US and international Antarctic research communities. The two-day workshop was designed to bring scientists with expertise in Antarctic biological, ecological, and ecosystem sciences to Florida State University to share knowledge, identify important research knowledge gaps, and outline strategic plans for research.
Major outcomes from the project were as follows. The international workshop to share and review knowledge concerning the response of Antarctic ecosystems to ice-shelf collapse was held at the Florida State University Coastal and Marine Laboratory (FSUCML) on 18-19 November 2017. Thirty-eight U.S. and international scientists attended the workshop, providing expertise in biological, ecological, geological, biogeographical, and glaciological sciences. Twenty-six additional scientists were either not able to attend or were declined because of having reached maximum capacity of the venue or for not responding to our invitation before the registration deadline.
The latest results of ice-shelf research were presented, providing an overview of the current scientific knowledge and understanding of the biological, ecological,
geological and cryospheric processes associated with ice-shelf collapse and its
ecosystem-level consequences. In addition, several presentations focused on future plans to investigate the impacts of the recent Larsen C collapse. The following presentations were given at the meeting:
1) Cryospheric dynamics and ice-shelf collapse – past and future (M. Truffer,
University of Alaska, Fairbanks)
2) The geological history and geological impacts of ice-shelf collapse on the Antarctic Peninsula (Scottt Ishman, Amy Leventer)
3) Pelagic ecosystem responses to ice-shelf collapse (Mattias Cape, Amy Leventer)
4) Benthic ecosystem response to ice-shelf collapse (Craig Smith, Pavica Sršen, Ann Vanreusel)
5) Larsen C and biotic homogenization of the benthos (Richard Aronson, James
McClintock, Kathryn Smith, Brittany Steffel)
6) British Antarctic Survey: plans for Larsen C investigations early 2018 and in the
future (Huw Griffiths)
7) Feedback on the workshop “Climate change impacts on marine ecosystems:
implications for management of living resources and conservation” held 19-22
September 2017, Cambridge, UK (Alex Rogers)
8) Past research activities and plans for Larsen field work by the Alfred Wegener
Institute, Germany (Charlotte Havermans, Dieter Piepenburg.
One of the salient points emerging from the presentations and ensuing discussions was that, given our poor abilities to predict ecological outcomes of ice-shelf collapses, major cross-disciplinary efforts are needed on a variety of spatial and temporal scales to achieve a broader, predictive understanding of ecosystem
consequences of climatic warming and ice-shelf failure. As part of the workshop, the FSUCML Polar Academy Team—Dr. Emily Dolan, Dr. Heidi Geisz, Barbara Shoplock, and Dr. Jeroen Ingels—initiated AntICE: "Antarctic Influences of Climate Change on Ecosystems" (AntICE). They reached out to various groups of school children in the local area (and continue to do so). The AntICE Team have been interacting with these children at Wakulla High School and Wakulla Elementary in Crawfordville; children from the Cornerstone Learning Community, Maclay Middle School, Gilchrist Elementary, and the School of Arts and Sciences in Tallahassee; and the Tallahassee-area homeschooling community to educate them about Antarctic ecosystems and ongoing climate change. The underlying idea was to
make the children aware of climatic changes in the Antarctic and their effect on
ecosystems so they, in turn, can spread this knowledge to their communities, family
and friends – acting as ‘Polar Ambassadors’. We collaborated with the Polar-ICE
project, an NSF-funded educational project that established the Polar Literacy
Initiative. This program developed the Polar Literacy Principles, which outline
essential concepts to improve public understanding of Antarctic and Arctic
ecosystems. In the Polar Academy work, we used the Polar Literacy principles, the
Polar Academy Team’s own Antarctic scientific efforts, and the experience of the FSU outreach and education program to engage with the children. We focused on the importance of Antarctic organisms and ecosystems, the uniqueness of its biota and the significance of its food webs, as well as how all these are changing and will
change further with climate change. Using general presentations, case studies,
scientific methodology, individual experiences, interactive discussions and Q&A
sessions, the children were guided through the many issues Antarctic ecosystems
are facing. Over 300 'Polar ambassadors' attended the interactive lectures and
afterwards took their creativity to high latitudes by creating welcome letters, displays, dioramas, sculptures, videos and online media to present at the scientific workshop. Over 50 projects were created by the children (Please see supporting files for images). We were also joined by a photographer, Ryan David Reines, to document the event. More information, media and links to online outreach products are available at https://marinelab.fsu.edu/labs/ingels/outreach/polar-academy/
Marine communities along the western Antarctic Peninsula are highly productive ecosystems which support a diverse assemblage of charismatic animals such as penguins, seals, and whales as well as commercial fisheries such as that on Antarctic krill. Fjords (long, narrow, deep inlets of the sea between high cliffs) along the central coast of the Peninsula appear to be intense, potentially climate sensitive, hotspots of biological production and biodiversity, yet the structure and dynamics of these fjord ecosystems are very poorly understood. Because of this intense biological activity and the charismatic fauna it supports, these fjords are also major destinations for a large Antarctic tourism industry. This project is an integrated field and modeling program to evaluate physical oceanographic processes, glacial inputs, water column community dynamics, and seafloor bottom community structure and function in these important yet little understood fjord systems. These Antarctic fjords have characteristics that are substantially different from well-studied Arctic fjords, likely yielding much different responses to climate warming. This project will provide major new insights into the dynamics and climate sensitivity of Antarctic fjord ecosystems, highlighting contrasts with Arctic sub-polar fjords, and potentially transforming our understanding of the ecological role of fjords in the rapidly warming west Antarctic coastal marine landscape. The project will also further the NSF goal of training new generations of scientists, providing scientific training for undergraduate, graduate, and postdoctoral students. This includes the unique educational opportunity for undergraduates to participate in research cruises in Antarctica and the development of a novel summer graduate course on fjord ecosystems. Internet based outreach activities will be enhanced and extended by the participation of a professional photographer who will produce magazine articles, websites, radio broadcasts, and other forms of public outreach on the fascinating Antarctic ecosystem. This project will involve a 15-month field program to test mechanistic hypotheses concerning oceanographic and glaciological forcing, and phytoplankton and benthic community response in the Antarctic fjords. Those efforts will be followed by a coupled physical/biological modeling effort to evaluate the drivers of biogeochemical cycles in the fjords and to explore their potential sensitivity to enhanced meltwater and sediment inputs. Fieldwork over two oceanographic cruises will utilize moorings, weather stations, and glacial, sea-ice and seafloor time-lapse cameras to obtain an integrated view of fjord ecosystem processes. The field team will also make multiple shipboard measurements and will use towed and autonomous underwater vehicles to intensively evaluate fjord ecosystem structure and function during spring/summer and autumn seasons. These integrated field and modeling studies are expected to elucidate fundamental properties of water column and sea bottom ecosystem structure and function in the fjords, and to identify key physical-chemical-glaciological forcing in these rapidly warming ecosystems.
There is compelling historical evidence that the West Antarctic Ice Sheet (WAIS) is vulnerable to rapid retreat and collapse. Recent observations, compared to observations made 20-30 years before, indicate that both ice shelves (thick ice with ocean below) and land ice (thick ice with land below), are now melting at a much faster rate. Some numerical models suggest that significant ice retreat may begin within many of our lifetimes, starting with the abrupt collapse of Pine Island and Thwaites Glaciers in the next 50 years. This may be followed by retreat of much of the WAIS and then the collapse of parts of the East Antarctic ice sheet (EAIS). This research project will assess the extent to which global ocean circulation and climate will be impacted if enormous volumes of fresh water and ice flow into the Southern Ocean. It will establish whether a rapid collapse of WAIS in the near-future poses any significant threat to the stability of modern-day climate and human society. This is a topic that has so far received little attention as most prior research has focused on the response of climate to melting the Greenland ice sheet. Yet model simulations predict that the volumes of fresh water and ice released from Antarctica in the next few centuries could be up at least ten-times larger than from Greenland. The Intellectual Merit of this project stems from its ability to establish a link between the physical Antarctic system (ice sheet dynamics, fresh water discharge and iceberg calving) and global climate. The PIs (Principal Investigators) will assess the sensitivity of ocean circulation and climate to increased ice sheet melt using a combination of ocean, iceberg, ice sheet and climate models. Results from this study will help identify areas of the ice sheet that are vulnerable to collapse and also regions of the ocean where a significant freshening will have a considerable impact on climate, and serve to guide the deployment of an observational monitoring system capable of warning us when ice and fresh water discharge start to approach levels capable of disrupting ocean circulation and global climate. This project will support and train two graduate students, and each PI will be involved with local primary and secondary schools, making presentations, mentoring science fair projects, and contributing to curriculum development. A novel, web-based, interactive, cryosphere learning tool will be developed to help make school children more aware of the importance of the Polar Regions in global climate, and this software will be introduced to science teachers at a half day workshop organized by the UMass STEM Education Institute. Recent numerical simulations using a continental ice sheet/shelf model show the potential for more rapid and greater Antarctic ice sheet retreat in the next 50-300 years (under the full range of IPCC RCP (Intergovernmental Panel on Climate Change, Representative Concentration Pathways) future warming scenarios) than previously projected. Exactly how the release of enormous volumes of ice and fresh water to the Southern Ocean will impact global ocean circulation and climate has yet to be accurately assessed. This is in part because previous model simulations were too coarse to accurately resolve narrow coastal boundary currents, shelf breaks, fronts, and mesoscale eddies that are all very important for realistically simulating fresh water transport in the ocean. In this award, future projections of fresh water discharge and iceberg calving from Antarctic will be used to force a high resolution eddy-resolving ocean model (MITgcm) coupled to a new iceberg module and a fully-coupled global climate model (CCSM4). High resolution ocean/iceberg simulations will determine the role of mesoscale eddies in freshwater transport and give new insight into how fresh water is advected to far-field locations, including deep water formation sites in the North Atlantic. These simulations will provide detailed information about subsurface temperatures and changes in ocean circulation close to the ice front and grounding line. An accompanying set of fully coupled climate model simulations (NCAR CCSM4) will identify multidecadal-to-centennial changes in the climate system triggered by increased high-latitude Southern Ocean freshwater forcing. Particular attention will be given to changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC), wind stress, sea ice formation, and global temperatures. In doing so, this project will more accurately determine whether abrupt and potentially catastrophic changes in global climate are likely to be triggered by changes in the Antarctic system in the near-future.
Gases trapped in ice cores have revealed astonishing things about the greenhouse gas composition of the past atmosphere, including the fact that carbon dioxide concentrations never rose above 300 parts per million during the last 800,000 years. This places today's concentration of 400 parts per million in stark contrast. Furthermore, these gas records show that natural sources of greenhouse gas such as oceans and ecosystems act as amplifiers of climate change by increasing emissions of gases during warmer periods. Such amplification is expected to occur in the future, adding to the human-produced gas burden. The South Pole ice core will build upon these prior findings by expanding the suite of gases to include, for the first time, those potent trace gases that both trapped heat and depleted ozone during the past 40,000 years. The present project on inert gases and methane in the South Pole ice core will improve the dating of this crucial record, to unprecedented precision, so that the relative timing of events can be used to learn about the mechanism of trace gas production and destruction, and consequent climate change amplification. Ultimately, this information will inform predictions of future atmospheric chemical cleansing mechanisms and climate in the context of our rapidly changing atmosphere. This award also engages young people in the excitement of discovery and polar research, helping to entrain the next generations of scientists and educators. Education of graduate students, a young researcher (Buizert), and training of technicians, will add to the nation?s human resource base. This award funds the construction of the gas chronology for the South Pole 1500m ice core, using measured inert gases (d15N and d40Ar--Nitrogen and Argon isotope ratios, respectively) and methane in combination with a next-generation firn densification model that treats the stochastic nature of air trapping and the role of impurities on densification. The project addresses fundamental gaps in scientific understanding that limit the accuracy of gas chronologies, specifically a poor knowledge of the controls on ice-core d15N and the possible role of layering and impurities in firn densification. These gaps will be addressed by studying the gas enclosure process in modern firn at the deep core site. The work will comprise the first-ever firn air pumping experiment that has tightly co-located measurements of firn structural properties on the core taken from the same borehole. The project will test the hypothesis that the lock-in horizon as defined by firn air d15N, CO2, and methane is structurally controlled by impermeable layers, which are in turn created by high-impurity content horizons in which densification is enhanced. Thermal signals will be sought using the inert gas measurements, which improve the temperature record with benefits to the firn densification modeling. Neon, argon, and oxygen will be measured in firn air and a limited number of deep core samples to test whether glacial period layering was enhanced, which could explain low observed d15N in the last glacial period. Drawing on separate volcanic and methane synchronization to well-dated ice cores to create independent ice and gas tie points, independent empirical estimates of the gas age-ice age difference will be made to check the validity of the firn densification model-inert gas approach to calculating the gas age-ice age difference. These points will also be used to test whether the anomalously low d15N seen during the last glacial period in east Antarctic ice cores is due to deep air convection in the firn, or a missing impurity dependence in the firn densification models. The increased physical understanding gained from these studies, combined with new high-precision measurements, will lead to improved accuracy of the gas chronology of the South Pole ice core, which will enhance the overall science return from this gas-oriented core. This will lead to clarification of timing of atmospheric gas variations and temperature, and aid in efforts to understand the biogeochemical feedbacks among trace gases. These feedbacks bear on the future response of the Earth System to anthropogenic forcing. Ozone-depleting substances will be measured in the South Pole ice core record, and a precise gas chronology will add value. Lastly, by seeking a better understanding of the physics of gas entrapment, the project aims to have an impact on ice-core science in general.
Recent discoveries of widespread liquid water and microbial ecosystems below the Antarctic ice sheets have generated considerable interest in studying Antarctic subglacial environments. Understanding subglacial hydrology, the persistence of life in extended isolation and the evolution and stability of subglacial habitats requires an integrated, interdisciplinary approach. The collaborative project, Minimally Invasive Direct Glacial Exploration (MIDGE) of the Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys will integrate geophysical measurements, molecular microbial ecology and geochemical analyses to explore a unique Antarctic subglacial system known as Blood Falls. Blood Falls is a hypersaline, subglacial brine that supports an active microbial community. The subglacial brine is released from a crevasse at the surface of the Taylor Glacier providing an accessible portal into an Antarctic subglacial ecosystem. Recent geochemical and molecular analyses support a marine source for the salts and microorganisms in Blood Falls. The last time marine waters inundated this part of the McMurdo Dry Valleys was during the Late Tertiary, which suggests the brine is ancient. Still, no direct samples have been collected from the subglacial source to Blood Falls and little is known about the origin of this brine or the amount of time it has been sealed below Taylor Glacier. Radar profiles collected near Blood Falls delineate a possible fault in the subglacial substrate that may help explain the localized and episodic nature of brine release. However it remains unclear what triggers the episodic release of brine exclusively at the Blood Falls crevasse or the extent to which the brine is altered as it makes its way to the surface. The MIDGE project aims to determine the mechanism of brine release at Blood Falls, evaluate changes in the geochemistry and the microbial community within the englacial conduit and assess if Blood Falls waters have a distinct impact on the thermal and stress state of Taylor Glacier, one of the most studied polar glaciers in Antarctica. The geophysical study of the glaciological structure and mechanism of brine release will use GPR, GPS, and a small passive seismic network. Together with international collaborators, the 'Ice Mole' team from FH Aachen University of Applied Sciences, Germany (funded by the German Aerospace Center, DLR), MIDGE will develop and deploy innovative, minimally invasive technologies for clean access and brine sample retrieval from deep within the Blood Falls drainage system. These technologies will allow for the collection of samples of the brine away from the surface (up to tens of meters) for geochemical analyses and microbial structure-function experiments. There is concern over the contamination of pristine subglacial environments from chemical and biological materials inherent in the drilling process; and MIDGE will provide data on the efficacy of thermoelectric probes for clean access and retrieval of representative subglacial samples. Antarctic subglacial environments provide an excellent opportunity for researching survivability and adaptability of microbial life and are potential terrestrial analogues for life habitats on icy planetary bodies. The MIDGE project offers a portable, versatile, clean alternative to hot water and mechanical drilling and will enable the exploration of subglacial hydrology and ecosystem function while making significant progress towards developing technologies for minimally invasive and clean sampling of icy systems.
Bubbles of ancient air trapped in ice cores permit the direct reconstruction of atmospheric composition and allow us to link greenhouse gases and global climate over the last 800,000 years. Previous field expeditions to the Allan Hills blue ice area, Antarctica, have recovered ice cores that date to one million years, the oldest ice cores yet recovered from Antarctica. These records have revealed that interglacial CO2 concentrations decreased by 800,000 years ago and that, in the warmer world 1 million years ago, CO2 and Antarctic temperature were linked as during the last 800,000 years. This project will return to the Allan Hills blue ice area to recover additional ice cores that date to 1 million years or older. The climate records developed from the drilled ice cores will provide new insights into the chemical composition of the atmosphere and Antarctic climate during times of comparable or even greater warmth than the present day. Our results will help answer questions about issues associated with anthropogenic change. These include the relationship between temperature change and the mass balance of Antarctic ice; precipitation and aridity variations associated with radiatively forced climate change; and the climate significance of sea ice extent. The project will entrain two graduate students and a postdoctoral scholar, and will conduct outreach including workshops to engage teachers in carbon science and ice cores. Between about 2.8-0.9 million years ago, Earth's climate was characterized by 40,000-year cycles, driven or paced by changes in the tilt of Earth's spin axis. Much is known about the "40,000-year" world from studies of deep-sea sediments, but our understanding of climate change during this period is incomplete because we lack records of Antarctic climate and direct records of atmospheric greenhouse gas concentrations. We propose to address these issues by building on our recent studies of ancient ice from the Main Ice Field, Allan Hills, Antarctica. During previous field seasons we recovered ice extending, discontinuously, from 0.1-1.0 million years old. Ice was dated by measuring the 40Ar/38Ar (Argon) ratio of the trapped gases. Our discovery of million year-old ice demonstrates that there is gas-record-quality ice from the 40,000-year world in the Allan Hills Main Ice Field. We have identified two different sites, each overlying bedrock at ~ 200 m depth, that are attractive targets for coring ice dating to 1 million years and older. This project aims to core the ice at these two sites, re-occupy a previous site with million year-old ice and drill it down to the bedrock, and generate 10-20 short (~10-meter) cores in areas where our previous work and terrestrial meteorite ages suggest ancient surface ice. We plan to date the ice using the 40Ar/38Ar ages of trapped Argon. We also plan to characterize the continuity of our cores by measuring the deuterium and oxygen isotope ratios in the ice, methane, ratios of Oxygen and Argon to Nitrogen in trapped gas, the Nitrogen-15 isotope (d15N) of Nitrogen, and the Oxygen-18 isotope (d18O) of Oxygen. As the ice may be stratigraphically disturbed, these measurements will provide diagnostic properties for assessing the continuity of the ice-core records. Successful retrieval of ice older than one million years will provide the opportunity for follow-up work to measure the CO2 concentration and other properties within the ice to inform on the temperature history of the Allan Hills region, dust sources and source-area aridity, moisture sources, densification conditions, global average ocean temperature, and greenhouse gas concentrations. We will analyze the data in the context of leading hypotheses of the 40,000-year world and the Mid-Pleistocene Transition to the 100,000-year world. We expect to advance understanding of climate dynamics during these periods.
Hamilton/1246400 This award supports an integrated field observation, remote sensing and numerical modeling study of the McMurdo Shear Zone (SZ). The SZ is a 5-10 km wide strip of heavily crevassed ice that separates the McMurdo and Ross ice shelves, and is an important region of lateral support for the Ross Ice Shelf. Previous radar and remote sensing studies reveal an enigmatic picture of the SZ in which crevasses detected at depth have no apparent surface expression, and have orientations which are possibly inconsistent with the observed flow field. In the proposed work, we seek to test the hypothesis that the SZ is a zone of chaotic Lagrangian mixing with (intersecting) buried crevasses which leads to rheological instability, potentially allowing large scale velocity discontinuities. The work will involve detailed field-based observations of crevasse distributions and structure using ground-penetrating radar, and GPS and remote sensing observations of the flow and stress field in the SZ. Because of the hazardous nature of the SZ, the radar surveys will be conducted largely with the aid of a lightweight robotic vehicle. Observations will be used to develop a finite element model of ice shelf shear margin behavior. The intellectual merit of this project is an increased understanding of ice shelf shear margin dynamics. Shear margins play a key role in ice shelf stability, and ice shelves in turn modulate the flux of ice from the ice sheet across the grounding line to the ocean. Insights from this project will improve large-scale models being developed to predict ice sheet evolution and future rates of sea level rise, which are topics of enormous societal concern. The broader impacts of the project include an improved basis for US Antarctic Program logistics planning as well as numerous opportunities to engage K-12 students in scientific discovery. Intensified crevassing in the shear zone between the Ross and McMurdo ice shelves would preclude surface crossing by heavy traverse vehicles which would lead to increased costs of delivering fuel to South Pole and a concomitant loss of flight time provided by heavy-lift aircraft for science missions on the continent. Our multidisciplinary research combining glaciology, numerical modeling, and robotics engineering is an engaging way to show how robotics can assist scientists in collecting hazardous field measurements. Our outreach activities will leverage Dartmouth's current NSF GK-12 program, build on faculty-educator relationships established during University of Maine's recent GK-12 program, and incorporate project results into University of Maine's IDEAS initiative, which integrates computational modeling with the existing science curriculum at the middle school level. This award has field work in Antarctica.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The LISSARD project (Lake and Ice Stream Subglacial Access Research Drilling) is one of three research components of the WISSARD integrative initiative (Whillans Ice Stream Subglacial Access Research Drilling) that is being funded by the Antarctic Integrated System Science Program of NSF's Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The LISSARD component of WISSARD focuses on the role of active subglacial lakes in determining how fast the West Antarctic ice sheet loses mass to the global ocean and influences global sea level changes. The importance of Antarctic subglacial lakes has only been recently recognized, and the lakes have been identified as high priority targets for scientific investigations because of their unknown contributions to ice sheet stability under future global warming scenarios. LISSARD has several primary science goals: A) To provide an observational basis for improving treatments of subglacial hydrological and mechanical processes in models of ice sheet mass balance and stability; B) To reconstruct the past history of ice stream stability by analyzing archives of past basal water and ice flow variability contained in subglacial sediments, porewater, lake water, and basal accreted ice; C) To provide background understanding of subglacial lake environments to benefit RAGES and GBASE (the other two components of the WISSARD project); and D) To synthesize data and concepts developed as part of this project to determine whether subglacial lakes play an important role in (de)stabilizing Antarctic ice sheets. We propose an unprecedented synthesis of approaches to studying ice sheet processes, including: (1) satellite remote sensing, (2) surface geophysics, (3) borehole observations and measurements and, (4) basal and subglacial sampling. <br/><br/>INTELLECTUAL MERIT: The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. <br/><br/>BROADER IMPACTS: Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars.
Conway/1141866 This award supports a project to conduct a suite of experiments to study spatial and temporal variations of basal conditions beneath Beardmore Glacier, an East Antarctic outlet glacier that discharges into the Ross Sea Embayment. The intellectual merit of the project is that it should help verify whether or not global warming will play a much larger role in the future mass balance of ice sheets than previously considered. Recent observations of rapid changes in discharge of fast-flowing outlet glaciers and ice streams suggest that dynamical responses to warming could affect that ice sheets of Greenland and Antarctica. Assessment of possible consequences of these responses is hampered by the lack of information about the basal boundary conditions. The leading hypothesis is that variations in basal conditions exert strong control on the discharge of outlet glaciers. Airborne and surface-based radar measurements of Beardmore Glacier will be made to map the ice thickness and geometry of the sub-glacial trough and active and passive seismic experiments, together with ground-based radar and GPS measurements will be made to map spatial and temporal variations of conditions at the ice-bed interface. The observational data will be used to constrain dynamic models of glacier flow. The models will be used to address the primary controls on the dynamics of Antarctic outlet glaciers, the conditions at the bed, their spatial and temporal variation, and how such variability might affect the sliding and flow of these glaciers. The work will also explore whether or not these outlet glaciers could draw down the interior of East Antarctica, and if so, how fast. The study will take three years including two field seasons to complete and results from the work will be disseminated through public and professional meetings and journal publications. All data and metadata will be made available through the NSIDC web portal. The broader impacts of the work are that it will help elucidate the fundamental physics of outlet glacier dynamics which is needed to improve predictions of the response of ice sheets to changing environmental conditions. The project will also provide support for early career investigators and will provide training and support for one graduate and two undergraduate students. All collaborators are currently involved in scientific outreach and graduate student education and they are committed to fostering diversity.
Meltwater lakes that sit on top of Antarctica's floating ice shelves have likely contributed to the dramatic changes seen in Antarctica's glacial ice cover over the past two decades. In 2002, the 1,600-square-kilometer Larsen B Ice Shelf located on the Eastern side of the Antarctic Peninsula, for example, broke into thousands of small icebergs, which subsequently floated away as a result of the formation of more than 2,000 meltwater lakes on its surface over the prior decade. Our research project addresses the reasons why surface lakes form on Antarctic ice shelves and how these surface lakes subsequently contribute to the forces that may contribute to ice-shelf breakup like that of the Larsen B. Our project focuses primarily on making precise global positioning system (GPS) measurements of ice-shelf bending in response to the filling and draining of a surface lake on the McMurdo Ice Shelf. The observed vertical displacements (on the order of tens of centimeters) in response to lake filling will be used to calibrate and test computer simulation models that predict the response of ice shelves to surface lakes more generally and in a variety of future climate conditions. Our project will make hourly measurements of both vertical ice-shelf movements (using GPS surveying instruments) and of temperature and sunlight conditions (that drive melting) around a surface lake located close to the McMurdo Station airfield. Following this initial data-gathering effort, computer simulations and other more theoretical analysis will be undertaken to determine the suitability of the chosen McMurdo Ice Shelf surface lake as a field-laboratory for continued study. Ultimately, the research will contribute to understanding of the glaciological processes that link climate change to rising sea level. A successful outcome of the research will allow glaciologists to better assess the processes that promote or erode the influence Antarctic ice shelves have in controlling the transfer of ice from the interior of Antarctica into the ocean. The project will undertake two outreach activities: (1) web-posting of a field-activity journal and (2) establishing an open-access glaciological teaching and outreach web-sharing site for the International Glaciological Society. The proposed project seeks to experimentally verify a theory of ice-shelf instability proposed to explain the explosive break-up of Larsen B Ice Shelf in 2002. This theory holds that the filling and draining of supraglacial lakes on floating ice shelves induces sufficient flexure stress within the ice to (a) induce upward/downward propagating fractures originating at the base/surface of the ice shelf that (b) dissect the ice shelf into fragments that tend to have widths less than about half the ice thickness. The significance of narrow widths is that they promote capsize of the ice-shelf fragments during the break-up process. This capsize releases large amounts of gravitational potential energy (comparable to thousands of kilotons of TNT for the Larsen B Ice Shelf) thereby promoting explosiveness of the Larsen B event. The observational motivation for experimentally verifying the surface-lake mechanism for ice-shelf breakup is based on the fact that >2,000 surface lakes developed on the Larsen B Ice Shelf in the decade prior to its break up, and that these lakes were observed (via satellite imagery) to drain in a coordinated fashion during the day prior to the initiation of the break up. The field-observation component of the project will focus on a supraglacial lake on the McMurdo Ice Shelf where there is persistent summer season surface melting. The lake will be studied during a single provisional field season to determine whether grooming of surrounding surface streams and shorelines with heavy construction equipment will allow surface water to be manually encouraged to fill the lake. If successfully encouraged to develop, the McMurdo Ice Shelf surface lake will allow measurements of key ice-shelf flexure and stress variables needed to develop the theory of ice-shelf surface lakes without having to access the much more logistically demanding surface lakes of ice-shelves located elsewhere in Antarctica. Data to be gathered during the 6-week provisional field season include: energy- and water-balance parameters determining how the surface lake grows and fills, and various global positioning system measurements of the vertical bending of the ice sheet in response to the changing meltwater load contained within the surface lake. These data will be used to (1) constrain a computer model of viscoelastic flexure and possible fracture of the ice shelf in response to the increasing load of meltwater in the lake, and (2) determine whether continued study of the incipient surface-meltwater lake features on the McMurdo Ice Shelf provides a promising avenue for constraining the more-general behavior of surface meltwater lakes on other ice shelves located in warmer parts of Antarctica. Computer models constrained by the observational data obtained from the field project will inform energy- and water-balance models of ice shelves in general, and allow more accurate forecasts of changing ice-shelf conditions surrounding the inland ice of Antarctica. The project will create the first-ever ground-based observations useful for spawning the development of models capable of predicting viscoelastic and fracture behavior of ice shelves in response to supraglacial lake evolution, including slow changes due to energy balance effects, as well as fast changes due to filling and draining.
Timmerman/1341311 This award supports a project to study the physical processes that synchronize glacial-scale variability between the Northern Hemisphere ice sheets and the Antarctic ice-sheet. Using a coupled numerical ice-sheet earth-system model, the research team will explore the cryospheric responses to past changes in greenhouse gas concentrations and variations in earth's orbit and tilt. First capturing the sensitivity of each individual ice-sheet to these forcings and then determining their joint variability induced by changes in sea level, ocean temperatures and atmospheric circulation, the researchers will quantify the relative roles of local versus remote effects on long-term ice volume variability. The numerical experiments will provide deeper physical insights into the underlying dynamics of past Antarctic ice-volume changes and their contribution to global sea level. Output from the transient earth system model simulations will be directly compared with ice-core data from previous and ongoing drilling efforts, such as West Antarctic Ice Sheet (WAIS) Divide. Specific questions that will be addressed include: 1) Did the high-latitude Southern Hemispheric atmospheric and oceanic climate, relevant to Antarctic ice sheet forcing, respond to local insolation variations, CO2, Northern Hemispheric changes, or a combination thereof?; 2) How did WAIS and East Antarctic Ice Sheet (EAIS) vary through the Last Glacial Termination and into the Holocene (21 ka- present)?; 3) Did the WAIS (or EAIS) contribute to rapid sea-level fluctuations during this period, such as Meltwater Pulse 1A? 4) Did WAIS collapse fully at Stage 5e (~ 125 ka), and what was its timing relative to the maximum Greenland retreat?; and 5) How did the synchronized behavior of Northern Hemisphere and Southern Hemisphere ice-sheet variations affect the strength of North Atlantic Deep Water and Antarctic Bottom Water formation and the respective overturning cells? The transient earth-system model simulations conducted as part of this project will be closely compared with paleo-climate reconstructions from ice cores, sediment cores and terrestrial data. This will generate an integrated understanding of the hemispheric contributions of deglacial climate change, the origin of meltwater pulses, and potential thresholds in the coupled ice-sheet climate system in response to different types of forcings. A well-informed long-term societal response to sea level rise requires a detailed understanding of ice-sheet sensitivities to external forcing. The proposed research will strongly contribute to this task through numerical modeling and paleo-data analysis. The research team will make the resulting model simulations available on the web-based data server at the Asia Pacific Data Research Center (APDRC) to enable further analysis by the scientific community. As part of this project a female graduate student and a postdoctoral researcher will receive training in earth-system and ice-sheet modeling and paleo-climate dynamics. This award has no field work in Antarctica.
Ice-core records are critical to understanding past climate variations. An Antarctic ice core currently being drilled at the South Pole will allow detailed investigation of atmospheric gases and fill an important gap in understanding the pattern of climate variability across Antarctica. Critical to the interpretation of any ice core are: 1) accurate chronologies for both the ice and the trapped gas and 2) demonstration that records from the ice core reliably reflect climate. The proposed research will improve the ice and gas chronologies by making measurements of snow compaction in the upstream catchment in order to constrain age models of the ice. These measurements will be a key data set needed for better understanding and predicting time-varying conditions in the upper part of the ice sheet. The research team will measure the modern spatial gradients in accumulation rate, surface temperature, and water stable isotopes from shallow ice cores in the upstream catchment in order to determine the climate history from the ice-core record. The new ice-flow measurements will make it possible to define the path of ice from upstream to the South Pole ice-core drill site to assess spatial gradients in snowfall and to infer histories of snowfall from internal layers within the ice sheet. The project will be led by an early-career scientist, provide broad training to graduate students, and engage in public outreach on polar science. Ice-core records of stable isotopes, aerosol-born particles, and atmospheric gases are critical to understanding past climate variations. The proposed research will improve the ice and gas chronologies in the South Pole ice core by making in situ measurements of firn compaction in the upstream catchment to constrain models of the gas-age ice-age difference. The firn measurements will be a key data set needed to form a constitutive relationship for firn, and will drive better understanding and prediction of transient firn evolution. The research team will measure the modern gradients in accumulation rate, surface temperature, and water stable isotopes in the upstream catchment to separate spatial (advection) variations from temporal (climate) variations in the ice-core records. The ice-flow measurements will define the flowline upstream of the drill site, assess spatial gradients in accumulation, and infer histories of accumulation from radar-observed internal layers. Results will directly enhance interpretation of South Pole ice-core records, and also advance understanding of firn densification and drive next-generation firn models.
Intellectual Merit: This project will produce a new compilation of Ross Sea seismic stratigraphy, including new interpretations, that can be used to provide boundary conditions on the tectonic and glacial evolution of West Antarctica and the Ross Sea. The principal goals include compilation of, and interpretation of, all available existing seismic reflection data for the Western Ross Sea, coupled with geophysical modeling to produce paleo-bathymetric reconstructions for the entire 800 km-wide Ross Sea. Specific tasks will include: extending existing work on mapping travel time to reflectors, identifying relations in the seismic data that indicate subsidence through sea level, constructing velocity models for converting travel time to thickness, and using the velocity models to estimate density and porosity of sediments for backstripping analysis. Modeling/backstripping efforts will be used to constrain past bathymetry. Digital interpretations and stratigraphic grids will be provided as supplements to publications. In that way the results of this study can be used in thermal subsidence modeling and restoration of eroded rock to other parts of Ross Embayment and Marie Byrd Land by others. Digital products may be provided in advance of publication to modelers in a way that will not hurt publication chances. Broader impacts: The results of this work will be important for paleo-geographic reconstructions of Antarctica and will therefore be of use to a broad range of researchers, particularly those working in the Ross Sea region. The digital products can be used to test models for the past fluctuations of West Antarctic ice sheets, and in planning for future sediment drilling projects. Two undergraduates to be chosen from applicants will be involved in summer internships held at the University of Rhode Island. Outreach will also include a new website and one or more Wikipedia entries related to Ross Sea sub-sea floor characteristics. The project includes an international collaboration with Dr. Chiara Sauli and others at Instituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Italy.
Ice cores record detailed histories of past climate variations. The South Pole ice core will allow investigation of atmospheric trace gases and fill an important gap in understanding the pattern of climate variability across Antarctica. An accurate timescale that assigns an age to the ice at each depth in the core is essential to interpretation of the ice-core records. This work will use electrical methods to identify volcanic eruptions throughout the past ~40,000 years in the core by detecting the enhanced electrical conductance in those layers due to volcanic impurities in the ice. These eruptions will be pattern-matched to other cores across Antarctica, synchronizing the timing of climate variations among cores and allowing the precise timescales developed for other Antarctic ice cores to be transferred to the South Pole ice core. The well-dated records of volcanic forcing will be combined with records of atmospheric gases, stable water-isotopes, and aerosols to better understand the large natural climate variations of the past 40,000 years. The electrical conductance method and dielectric profiling measurements will be made along the length of each section of the South Pole ice core at the National Ice Core Lab. These measurements will help to establish a timescale for the core. Electrical measurements will provide a continuous record of volcanic events for the entire core including through the brittle ice (550-1250m representing ~10,000-20,000 year-old ice) where the core quality and thin annual layers may prevent continuous melt analysis and cause discrete measurements to miss volcanic events. The electrical measurements also produce a 2-D image of the electrical layering on a longitudinal cut surface of each core. These data will be used to identify any irregular or absent layering that would indicate a stratigraphic disturbance in the core. A robust chronology is essential to interpretation of the paleoclimate records from the South Pole ice core. The investigators will engage teachers through talks and webinars with the National Science Teachers Association and will share information with the public at events such as Polar Science Weekend at the Pacific Science Center. Results will be disseminated through publications and conference presentations and the data will be archived and publicly available.
Waddington/1246045 This award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.
This award supports a project to use the Roosevelt Island ice core as a glaciological dipstick for the eastern Ross Sea. Recent attention has focused on the eastern Ross Embayment, where there are no geological constraints on ice thickness changes, due to the lack of protruding rock "dipsticks" where the ice sheet can leave datable records of high stands. Recent work has shown how dated ice cores can be used as dipsticks to derive ice-thickness histories. Partners from New Zealand and Denmark will extract an ice core from Roosevelt Island during the 2010-2011 and 2011-12 austral summers. Their science objective is to contribute to understanding of climate variability over the past 40kyr. The science goal of this project is not the climate record, but rather the history of deglaciation in the Ross Sea. The new history from the eastern Ross Sea will be combined with the glacial histories from the central Ross Sea (Siple Dome and Byrd) and existing and emerging histories from geologic and marine records along the western Ross Sea margin and will allow investigators to establish an updated, self-consistent model of the configuration and thickness of ice in the Ross Embayment during the LGM, and the timing of deglaciation. Results from this work will provide ground truth for new-generation ice-sheet models that incorporate ice streams and fast-flow dynamics. Realistic ice-sheet models are needed not only for predicting the response to future possible environments, but also for investigating past behaviors of ice sheets. This research contributes to the primary goals of the West Antarctic Ice Sheet Initiative as well as the IPY focus on ice-sheet history and dynamics. It also contributes to understanding spatial and temporal patterns of climate change and climate dynamics over the past 40kyr, one of the primary goals of the International Partnerships in Ice Core Sciences (IPICS). The project will help to develop the next generation of scientists and will contribute to the education and training of two Ph.D. students. All participants will benefit from the international collaboration, which will expose them to different field and laboratory techniques and benefit future collaborative work. All participants are involved in scientific outreach and undergraduate education, and are committed to fostering diversity. Outreach will be accomplished through regularly scheduled community and K-12 outreach events, talks and popular writing by the PIs, as well as through University press offices.
Intellectual Merit: The PI hypothesizes that bedforms found in the Central and Joides troughs can be interpreted as having been formed by rapid retreat, and possible collapse of an ice stream that occupied this area. To test this hypothesis, the PI proposes to conduct a detailed marine geological and geophysical survey of Central and Joides Troughs in the western Ross Sea. This project will bridge gaps between the small and isolated areas previously surveyed and will acquire a detailed sedimentological record of the retreating grounding line. The PI will reconstruct the retreat history of the Central and Joides troughs to century-scale resolution using radiocarbon dating methods and by looking at geomorphic features that are formed at regular time intervals. Existing multibeam, deep tow side-scan sonar, and core data will provide a framework for this research. The western Ross Sea is an ideal study area to investigate a single ice stream and the dynamics controlling its stability, including interactions between both East and West Antarctic Ice Sheets. Broader impacts: This proposal includes a post-doc, a graduate and two undergraduate students. The post-doc is involved with teaching an in-service K-12 teacher development and training course at Rice University for high-need teachers with a focus on curriculum enhancement. The project fosters collaboration for the PI and students with researchers at Louisiana State University and international colleagues at the Institute for Paleobiology at the Polish Academy of Sciences. The results from this project could lead to a better understanding of ice sheet and ice stream stability. This project will yield implications for society's understanding of climate change, as this work improves understanding of the behavior of ice sheets and their links to global climate.
This project will investigate the marine component of the Totten Glacier and Moscow University Ice Shelf, East Antarctica. This system is of critical importance because it drains one-eighth of the East Antarctic Ice Sheet and contains a volume equivalent to nearly 7 meters of potential sea level rise, greater than the entire West Antarctic Ice Sheet. This nearly completely unexplored region is the single largest and least understood marine glacial system that is potentially unstable. Despite intense scrutiny of marine based systems in the West Antarctic Ice Sheet, little is known about the Totten Glacier system. This study will add substantially to the meager oceanographic and marine geology and geophysics data available in this region, and will significantly advance understanding of this poorly understood glacial system and its potentially sensitive response to environmental change. Independent, space-based platforms indicate accelerating mass loss of the Totten system. Recent aerogeophysical surveys of the Aurora Subglacial Basin, which contains the deepest ice in Antarctica and drains into the Totten system, have provided the subglacial context for measured surface changes and show that the Totten Glacier has been the most significant drainage pathway for at least two previous ice flow regimes. However, the offshore context is far less understood. Limited physical oceanographic data from the nearby shelf/slope break indicate the presence of Modified Circumpolar Deep Water within a thick bottom layer at the mouth of a trough with apparent access to Totten Glacier, suggesting the possibility of sub-glacial bottom inflow of relatively warm water, a process considered to be responsible for West Antarctic Ice Sheet grounding line retreat. This project will conduct a ship-based marine geologic and geophysical survey of the region, combined with a physical oceanographic study, in order to evaluate both the recent and longer-term behavior of the glacial system and its relationship to the adjacent oceanographic system. This endeavor will complement studies of other Antarctic ice shelves, oceanographic studies near the Antarctic Peninsula, and ongoing development of ice sheet and other ocean models.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The West Antarctic Ice Sheet is believed to be vulnerable to climate change as it is grounded below sea level, is drained by rapidly flowing ice streams and is fringed by floating ice shelves subject to melting by incursions of relatively warm Antarctic circumpolar water. Currently, the most rapidly thinning glaciers in Antarctica occur in the Amundsen and Bellingshausen Sea sectors. This study seeks to place the present day observations into a longer-term geological context over a broad scale by high-resolution swath bathymetric mapping of continental shelf sea floor features that indicate past ice presence and behavior. Gaps in existing survey coverage of glacial lineations and troughs indicating ice flow direction and paleo-grounding zone wedges over the Ross, Amundsen and Bellingshausen Sea sectors are targeted. The surveys will be conducted as part of the 2010 Icebreaker Oden science opportunity and will take advantage of the vessel?s state-of-the-art swath mapping system.<br/><br/>Broader impacts:<br/>This activity will supplement and complement more focused regional studies by US, Swedish, UK, French, Japanese and Polish collaborators also sailing on the Oden. The PI will compile bathymetric data to be acquired by the Oden and other ships in the region over the duration of the project into the existing bathymetric data base. The compiled data set will be made publically available through the NSF founded Antarctic Multibeam Bathymetry and Geophysical Data Synthesis (AMBS) site. It will also be integrated into the GEBCO International Bathymetric Chart of the Southern Ocean (IBCSO) and so significantly improve the basis for ship navigation in the Pacific sector of the Southern Ocean. Undergraduate students will be involved in the research under supervision of the PI via the Lamont summer internship program. The PI is a young investigator and this will be his first NSF grant as a PI.
Intellectual Merit: The PIs propose to complement the ANDRILL marine record with a terrestrial project that will provide chronological control for past fluctuations of the West Antarctic Ice Sheet (WAIS) and alpine glaciers in McMurdo Sound. The project will develop high-resolution maps of drifts deposited from grounded marine-based ice and alpine glaciers on islands and peninsulas in McMurdo Sound. In addition, the PIs will acquire multi-clast/multi-nuclide cosmogenic analyses of these mapped drift sheets and alpine moraines and use regional climate modeling to shed light on the range of possible environmental conditions in the McMurdo region during periods of grounded ice expansion and recession. The PIs will make use of geological records for ice sheet and alpine glacier fluctuations preserved on the flanks of Mount Discovery, Black Island, and Brown Peninsula. Drifts deposited from grounded, marine-based ice will yield spatial constraints for former advances and retreats of the WAIS. Moraines from alpine glaciers, hypothesized to be of interglacial origin, could yield a first-order record of hydrologic change in the region. Synthesizing the field data, the team proposes to improve the resolution of existing regional-scale climate models for the Ross Embayment. The overall approach and anticipated results will provide the first steps towards linking the marine and terrestrial records in this critical sector of Antarctica. Broader impacts: Results from the proposed work will be integrated with outreach programs at Boston University, Columbia University, and Worcester State University. The team will actively collaborate with the American Museum of Natural History to feature this project prominently in museum outreach. The team will also include a PolarTREC teacher as a member of the research team. The geomorphological results will be presented in 3D at Boston University?s Antarctic Digital Image Analyses Lab. The research will form the basis of a PhD dissertation at Boston University.
Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project seeks to drive a transformative shift in our understanding of the crucial role of the Southern Ocean in taking up anthropogenic carbon and heat, and resupplying nutrients from the abyss to the surface. An observational program will generate vast amounts of new biogeochemical data that will provide a greatly improved view of the dynamics and ecosystem responses of the Southern Ocean. A modeling component will apply these observations to enhancing understanding of the current ocean, reducing uncertainty in projections of future carbon and nutrient cycles and climate. Because it serves as the primary gateway through which the intermediate, deep, and bottom waters of the ocean interact with the surface layers and thus the atmosphere, the Southern Ocean has a profound influence on the oceanic uptake of anthropogenic carbon and heat as well as nutrient resupply from the abyss to the surface. Yet it is the least observed and understood region of the world ocean. The oceanographic community is on the cusp of two major advances that have the potential to transform understanding of the Southern Ocean. The first is the development of new biogeochemical sensors mounted on autonomous profiling floats that allow sampling of ocean biogeochemistry and acidification in 3-dimensional space with a temporal resolution of five to ten days. The SOCCOM float program proposed will increase the average number of biogeochemical profiles measured per month in the Southern Ocean by ~10-30x. The second is that the climate modeling community now has the computational resources and physical understanding to develop fully coupled climate models that can represent crucial mesoscale processes in the Southern Ocean, as well as corresponding models that assimilate observations to produce a state estimate. Together with the observations, this new generation of models provides the tools to vastly improve understanding of Southern Ocean processes and the ability to quantitatively assess uptake of anthropogenic carbon and heat, as well as nutrient resupply, both today and into the future. In order to take advantage of the above technological and modeling breakthroughs, SOCCOM will implement the following research programs: * Theme 1: Observations. Scripps Institution of Oceanography will lead a field program to expand the number of Southern Ocean autonomous profiling floats and equip them with sensors to measure pH, nitrate, and oxygen. The University of Washington and Monterey Bay Aquarium Research Institute will design, build, and oversee deployment of the floats. Scripps will also develop a mesoscale eddying Southern Ocean state estimate that assimilates physical and biogeochemical data into the MIT ocean general circulation model. * Theme 2: Modeling. University of Arizona and Princeton University, together with NOAA's Geophysical Fluid Dynamics Laboratory (GFDL), will use SOCCOM observations to develop data/model assessment metrics and next-generation model analysis and evaluation, with the goal of improving process level understanding and reducing the uncertainty in projections of our future climate. Led by Climate Central, an independent, non-profit journalism and research organization that promotes understanding of climate science, SOCCOM will collaborate with educators and media professionals to inform policymakers and the public about the challenges of climate change and its impacts on marine life in the context of the Southern Ocean. In addition, the integrated team of SOCCOM scientists and educators will: * communicate data and results of the SOCCOM efforts quickly to the public through established data networks, publications, broadcast media, and a public portal; * train a new generation of diverse ocean scientists, including undergraduate students, graduate students, and postdoctoral fellows versed in field techniques, data calibration, modeling, and communication of research to non-scientists; * transfer new sensor technology and related software to autonomous instrument providers and manufacturers to ensure that they become widely useable.
The extreme mountain topographies of alpine landscapes at mid latitudes (e.g., European Alps, Patagonia, Alaska) are thought to have formed by the erosive action of glaciers, yet our understanding of exactly when and how those topographies developed is limited. If glacial ice was responsible for forming them, then those landscapes must have developed primarily over the last 2-3 million years when ice was present at those latitudes; this timing has only recently been confirmed by observations. In contrast, the Antarctic Peninsula, which contains similarly spectacular topographic relief, is known to have hosted alpine glaciers as early as 37 million years ago, and is currently covered by ice. Thus, if caused by glacial erosion, the high relief of the peninsula should have formed much earlier than what has been observed at mid latitude sites, yet we know nearly nothing about the timing of its development. The primary benefit of this research will be to study the timing of topography development along the Antarctic Peninsula by applying state of the art chemical analyses to sediments collected offshore. This research is important because studying a high latitude site will enable comparison with sites at mid latitudes and test current hypotheses on the development of glacial landscapes in general. This project aims to apply low-temperature thermochronometry based on the (U-Th)/He system in apatite to investigate the exhumation history, the development of the present topography, and the pattern of glacial erosion in the central Antarctic Peninsula. A number of recent studies have used this approach to study the dramatic, high-relief landscapes formed by Pleistocene alpine glacial erosion in temperate latitudes: New Zealand, the Alps, British Columbia, Alaska, and Patagonia. These studies have not only revealed when these landscapes formed, but have also provided new insights into the physical mechanisms of glacial erosion. The Antarctic Peninsula is broadly akin to temperate alpine landscapes in that the dominant landforms are massive glacial troughs. However, what we know about Antarctic glacial history suggests that the timing and history of glacial erosion was most likely very different from the temperate alpine setting: The Antarctic Peninsula has been glaciated since the Eocene, and Pleistocene climate cooling is hypothesized to have suppressed, rather than enhanced, glacial erosion. Our goal is to evaluate these hypotheses by developing a direct thermochronometric record of when and how the present glacial valley relief formed. We propose to learn about the timing and process of glacial valley formation through apatite (U-Th)/He and 4He/3He measurements on glacial sediment collected near the grounding lines of major glaciers draining the Peninsula. In effect, since we cannot sample bedrock directly that is currently covered by ice, we will rely on these glaciers to do it for us.
This project aims to identify which portions of the glacial cover in the Antarctic Peninsula are losing mass to the ocean. This is an important issue to resolve because the Antarctic Peninsula is warming at a faster rate than any other region across the earth. Even though glaciers across the Antarctic Peninsula are small, compared to the continental ice sheet, defining how rapidly they respond to both ocean and atmospheric temperature rise is critical. It is critical because it informs us about the exact mechanisms which regulate ice flow and melting into the ocean. For instance, after the break- up of the Larsen Ice Shelf in 2002 many glaciers began to flow rapidly into the sea. Measuring how much ice was involved is difficult and depends upon accurate estimates of volume and area. One way to increase the accuracy of our estimates is to measure how fast the Earth's crust is rebounding or bouncing back, after the ice has been removed. This rebound effect can be measured with very precise techniques using instruments locked into ice free bedrock surrounding the area of interest. These instruments are monitored by a set of positioning satellites (the Global Positioning System or GPS) in a continuous fashion. Of course the movement of the Earth's bedrock relates not only to the immediate response but also the longer term rate that reflects the long vanished ice masses that once covered the entire Antarctic Peninsula?at the time of the last glaciation. These rebound measurements can, therefore, also tell us about the amount of ice which covered the Antarctic Peninsula thousands of years ago. Glacial isostatic rebound is one of the complicating factors in allowing us to understand how much the larger ice sheets are losing today, something that can be estimated by satellite techniques but only within large errors when the isostatic (rebound) correction is unknown. The research proposed consists of maintaining a set of six rebound stations until the year 2016, allowing for a longer time series and thus more accurate estimates of immediate elastic and longer term rebound effects. It also involves the establishment of two additional GPS stations that will focus on constraining the "bull's eye" of rebound suggested by measurements over the past two years. In addition, several more geologic data points will be collected that will help to reconstruct the position of the ice sheet margin during its recession from the full ice sheet of the last glacial maximum. These will be based upon the coring of marine sediment sequences now recognized to have been deposited along the margins of retreating ice sheets and outlets. Precise dating of the ice margin along with the new and improved rebound data will help to constrain past ice sheet configurations and refine geophysical models related to the nature of post glacial rebound. Data management will be under the auspices of the UNAVCO polar geophysical network or POLENET and will be publically available at the time of station installation. This project is a small scale extension of the ongoing LARsen Ice Shelf, Antarctica Project (LARISSA), an IPY (International Polar Year)-funded interdisciplinary study aimed at understanding earth system connections related to the Larsen Ice Shelf and the northern Antarctic Peninsula.
Pettit/1565576 This award supports a Rapid Response Research (RAPID) project to observe the current weakened state of the Scar Inlet Ice Shelf, and potentially capture data during its anticipated disintegration. The Scar Inlet Ice Shelf (SIIS) is the southern remnant of the former Larsen B Ice Shelf, which disintegrated in March of 2002. Since then, the SIIS has weakened significantly but has not yet broken up. Cooler conditions than those seen prior to 2006 have reduced the chance of a disintegration in recent years, although a single warm season is likely to be enough to trigger such an event. The predicted "Super El Nino" for this austral summer may have significant effects on Antarctica's weather, potentially leading to a break-up or disintegration this year. Given the very weak state of the SIIS, it is urgent that we act now to better understand the processes involved in shelf disintegration or break-up of ice shelves. The goal of this work is to collect several key data sets, publish initial observations and preliminary conclusions, and then make the complete data record available to all scientists. Extreme changes in the stress conditions on the SIIS resulted from both the loss of the Larsen B ice plate and the continued inflow of ice from three large glaciers (Flask, Leppard, and Starbuck). The SIIS now has a number of large rifts and it is expected to break up or disintegrate in the very near future. Past research has made use of satellite data and weather instruments, establishing many of the current ideas regarding ice shelf break-ups and ice shelf weakening. Additional ground-based data to be collected under this study will test a number of hypotheses regarding pre-disintegration characteristics, triggering mechanisms, fracturing processes, runaway feedback effects, and stabilizing mechanisms. The project will collect extensive multi-instrument field observations of the SIIS and possibly capture a major disintegration event. In collaboration with the British Antarctic Survey, a team of 4 people will be deployed via Twin Otter for up to 4 weeks to a site with a broad view of the shelf and will install several temporary observing instruments there. The study derives its intellectual merit from the role of the Antarctic Peninsula as a microcosm of how other parts of Antarctica might evolve and de-glaciate in the next few centuries. The broader impacts include an opportunity to educate the public about the anticipated collapse of this remnant ice shelf and its relationship to future changes in Antarctica. The potential for wide media coverage (through a connection with the National Geographic) will underscore the critical changes scientists are observing in the crysophere driven by climate change. This proposal requires field work in Antarctica.
Previous studies of the Indo-Pacific region of Antarctica show that the margin of the ice sheet in this region has advanced and retreated into deep interior basins many times in the past. The apparent instability of this region makes it an important target for study in terms of understanding the future of the East Antarctic ice sheet and sea level rise. This project will study a number of processes that control the ice-shelf stability of this region, with the aim of improving projections of the rate and magnitude of future sea-level rise. This project will engage a range of students and train this next generation of scientists in the complex, interdisciplinary issue of ice-ocean interaction. The project will integrate geophysical data collected from aircraft over three critical sections of the East Antarctic grounding line (Totten Glacier, Denman Glacier, and Cook Ice Shelf) with an advanced ocean model. Using Australian and French assets, the team will collect new data around Denman Glacier and Cook Ice Shelf whereas analysis of Totten Glacier will be based on existing data. The project will assess three hypotheses to isolate the processes that drive the differences in observed grounding line thinning among these three glaciers: 1. bathymetry and large-scale ocean forcing control cavity circulation; 2. ice-shelf draft and basal morphology control cavity circulation; 3. subglacial freshwater input across the grounding line controls cavity circulation. The key outcomes of this new project will be to: 1. evaluate of ice-ocean coupling in areas of significant potential sea-level contribution; 2. relate volume changes of grounded and floating ice to regional oceanic heat transport and sub-ice shelf ocean dynamics in areas of significant potential sea-level and meridional overturning circulation impacts; and 3. improve boundary conditions to evaluate mass, heat, and freshwater budgets of East Antarctica's continental margins.
Intellectual Merit: The MCM-SkyTEM project mapped resistivity in the McMurdo Dry Valleys and at Cape Barne on the Ross Island during the 2011-12 austral season using an airborne transient electromagnetic method. The SkyTEM system is mounted to a helicopter enabling a broad geophysical survey of subsurface resistivity structure over terrain that is inaccessible to traditional ground-based methods. Resistivity measurements obtained distinguish between highly resistive geologic materials such as glacier ice, bedrock and permafrost, and conductive materials such as unfrozen sediments or permafrost with liquid brine to depths of about 300 m. The PIs request funding to derive data products relevant to physical and chemical conditions in potential subsurface microbial habitats of the McMurdo Dry Valleys, similar cold regions on Earth and other planetary bodies. They will use these data products to characterize the hydrologic history of McMurdo Dry Valleys as well as the subsurface hydrologic connectivity in the region to investigate the implications for nutrient and microbial transport. The PIs will make these data products accessible to the research community. Broader impacts: Polar microbial habitats are of high societal and scientific interest because they represent important testing grounds for the limits of life on Earth and other planetary bodies. Project deliverables will include teaching aids for undergraduate and graduate students. Two Ph.D. students will obtain advanced research training as part of this project. The PIs and students on this project will also engage in informal public outreach opportunities by presenting at local K-12 schools and reaching out to local media outlets on stories relating to SkyTEM research.
1043471/Kaplan This award supports a project to obtain the first set of isotopic-based provenance data from the WAIS divide ice core. A lack of data from the WAIS prevents even a basic knowledge of whether different sources of dust blew around the Pacific and Atlantic sectors of the southern latitudes. Precise isotopic measurements on dust in the new WAIS ice divide core are specifically warranted because the data will be synergistically integrated with other high frequency proxies, such as dust concentration and flux, and carbon dioxide, for example. Higher resolution proxies will bridge gaps between our observations on the same well-dated, well-preserved core. The intellectual merit of the project is that the proposed analyses will contribute to the WAIS Divide Project science themes. Whether an active driver or passive recorder, dust is one of the most important but least understood components of regional and global climate. Collaborative and expert discussion with dust-climate modelers will lead to an important progression in understanding of dust and past atmospheric circulation patterns and climate around the southern latitudes, and help to exclude unlikely air trajectories to the ice sheets. The project will provide data to help evaluate models that simulate the dust patterns and cycle and the relative importance of changes in the sources, air trajectories and transport processes, and deposition to the ice sheet under different climate states. The results will be of broad interest to a range of disciplines beyond those directly associated with the WAIS ice core project, including the paleoceanography and dust- paleoclimatology communities. The broader impacts of the project include infrastructure and professional development, as the proposed research will initiate collaborations between LDEO and other WAIS scientists and modelers with expertise in climate and dust. Most of the researchers are still in the early phase of their careers and hence the project will facilitate long-term relationships. This includes a graduate student from UMaine, an undergraduate student from Columbia University who will be involved in lab work, in addition to a LDEO Postdoctoral scientist, and possibly an additional student involved in the international project PIRE-ICETRICS. The proposed research will broaden the scientific outlooks of three PIs, who come to Antarctic ice core science from a variety of other terrestrial and marine geology perspectives. Outreach activities include interaction with the science writers of the Columbia's Earth Institute for news releases and associated blog websites, public speaking, and involvement in an arts/science initiative between New York City's arts and science communities to bridge the gap between scientific knowledge and public perception.
Intellectual Merit: Southern Ocean processes play an important role in Late Quaternary glacial-interglacial climate change. However, the direct influence of newly upwelled warm nutrient-rich Circumpolar Deep Water on the Antarctic cryosphere remains speculative. The PI proposes to test the hypothesis that Circumpolar Deep Water-derived ocean heat negatively impacts the mass-balance of Antarctica?s ice sheets during deglaciations using precisely dated late Quaternary paleoceanographic studies of Antarctic margin sediments and a suite of geochemical proxies measured on three existing glacial marine sediment cores from the Prydz Channel, Antarctica. Specifically, the PI will use these data to reconstruct the Late Quaternary history of the Lambert Glacier/Amery Ice Shelf system; evaluate the timing, speed, and style of retreat of the Lambert Glacier/Amery Ice Shelf system during the last deglaciation, and to assess the impact of Circumpolar Deep Water intrusions on the Lambert Glacier/Amery Ice Shelf system in the Late Quaternary. Diatom bound radiocarbon and optically stimulated luminescence techniques will be used to obtain precise stratigraphic age control for the Prydz Channel siliceous muddy ooze intervals. In addition, the PI will measure sedimentary 10Be concentrations to determine the origin of the siliceous muddy ooze units and to track past changes in the position of the ice shelf front. Broader impacts: This proposal will support an early career female scientist and will provide professional development and research experiences for women/minority graduate and undergraduate students. The PI will take advantage of USF?s Oceanography Camp for Girls.
Intellectual Merit: Southern Ocean processes play an important role in Late Quaternary glacial-interglacial climate change. However, the direct influence of newly upwelled warm nutrient-rich Circumpolar Deep Water on the Antarctic cryosphere remains speculative. The PI proposes to test the hypothesis that Circumpolar Deep Water-derived ocean heat negatively impacts the mass-balance of Antarctica?s ice sheets during deglaciations using precisely dated late Quaternary paleoceanographic studies of Antarctic margin sediments and a suite of geochemical proxies measured on three existing glacial marine sediment cores from the Prydz Channel, Antarctica. Specifically, the PI will use these data to reconstruct the Late Quaternary history of the Lambert Glacier/Amery Ice Shelf system; evaluate the timing, speed, and style of retreat of the Lambert Glacier/Amery Ice Shelf system during the last deglaciation, and to assess the impact of Circumpolar Deep Water intrusions on the Lambert Glacier/Amery Ice Shelf system in the Late Quaternary. Diatom bound radiocarbon and optically stimulated luminescence techniques will be used to obtain precise stratigraphic age control for the Prydz Channel siliceous muddy ooze intervals. In addition, the PI will measure sedimentary 10Be concentrations to determine the origin of the siliceous muddy ooze units and to track past changes in the position of the ice shelf front. Broader impacts: This proposal will support an early career female scientist and will provide professional development and research experiences for women/minority graduate and undergraduate students. The PI will take advantage of USF?s Oceanography Camp for Girls.
Hall/1246170 This award supports a project to reconstruct past ice-surface elevations from detailed glacial mapping and dating of moraines (using 14C dates of algae from former ice-marginal ponds and 10Be surface exposure ages) in the region of the Darwin-Hatherton Glaciers in Antarctica in order to try and resolve very different interpretations that currently exist about the glacial history in the region. The results will be integrated with existing climate and geophysical data into a flow-line model to gain insight into glacier response to climate and ice-dynamics perturbations during the Late Glacial Maximum (LGM) in Antarctica. The work will contribute to a better understanding of both LGM ice thickness and whether or not there is any evidence that Antarctica contributed to Meltwater Pulse (MWP)-1A a very controversial topic in Antarctic glacial geology. The intellectual merit of the work relates to the fact that reconstructing past fluctuations of the Antarctic Ice Sheet (AIS) is critical for understanding the sensitivity of ice volume to sea-level and climatic change. Constraints on past behavior help put ongoing changes into context and provide a basis for predicting future sea-level rise. Broader impacts include the support of two graduate and two undergraduate students, as well as a female early-career investigator. Graduate students will be involved in all stages of the project from planning and field mapping to geochronological analyses, interpretation, synthesis and reporting. Two undergraduates will work on lab-based research from the project. The project also will include visits to K-12 classrooms to talk about glaciers and climate change, correspondence with teachers and students from the field, and web-based outreach. This award has field work in Antarctica.
The investigators will map glacial deposits and date variations in glacier variability at several ice-free regions in northern Victoria Land, Antarctica. These data will constrain the nature and timing of past ice thickness changes for major glaciers that drain into the northwestern Ross Sea. This is important because during the Last Glacial Maximum (15,000 - 18,000 years ago) these glaciers were most likely flowing together with grounded ice from both the East and West Antarctic Ice Sheets that expanded across the Ross Sea continental shelf to near the present shelf edge. Thus, the thickness of these glaciers was most likely controlled in part by the extent and thickness of the Ross Sea ice sheet and ice shelf. The data the PIs propose to collect can provide constraints on the position of the grounding line in the western Ross Sea during the Last Glacial Maximum, the time that position was reached, and ice thickness changes that occurred after that time. The primary intellectual merit of this project will be to improve understanding of a period of Antarctic ice sheet history that is relatively unconstrained at present and also potentially important in understanding past ice sheet-sea level interactions. This proposal will support an early career researcher's ongoing program of undergraduate education and research that is building a socio-economically diverse student body with students from backgrounds underrepresented in the geosciences. This proposal will also bring an early career researcher into Antarctic research.
Many key questions in climate research (e.g. relative timing of climate events in different geographic areas, climate-forcing mechanisms, natural threshold levels in the climate system) are dependent on accurate reconstructions of the temporal and spatial distribution of past rapid climate change events in continental, atmospheric, marine and polar realms. This collaborative interdisciplinary research project aims to consolidate, into a single user-friendly database, information about volcanic products detected in Antarctica. By consolidating information about volcanic sources, and physical and geochemical characteristics of volcanic products, this systematic data collection approach will improve the ability of researchers to identify volcanic ash, or tephra, from specific volcanic eruptions that may be spread over large areas in a geologically instantaneous amount of time. Development of this database will assist in the identification and cross-correlation of time intervals in various paleoclimate archives that contain volcanic layers from often unknown sources. The AntT project relies on a cyberinfrastructure framework developed in house through NSF funded CDI-Type I: CiiWork for data assimilation, interpretation and open distribution model. In addition to collection and integration of existing information about volcanic products, this project will focus on filling the information gaps about unique physico-chemical characteristics of very fine (<3 micrometer) volcanic particles (cryptotephra) that are present in Antarctic ice cores. This component of research will involve improving analytical methodology for detecting cryptotephra layers in ice, and will train a new generation of scientists to apply an array of modern state?of?the-art instrumentation available to the project team. The recognized importance of tephra in establishing a chronological framework for volcanic and sedimentary successions has already resulted in the development of robust regional tephrochronological frameworks (e.g. Europe, Kamchatka, New Zealand, Western North America). The AntT project will provide this framework for Antarctic tephrochronology, as needed for precise correlation records between Antarctic ice cores (e.g. WAIS Divide, RICE, ITASE) and global paleoclimate archives. The results of AntT will be of particular significance to climatologists, paleoclimatologists, atmospheric chemists, geochemists, climate modelers, solar-terrestrial physicists, environmental statisticians, and policy makers for designing solutions to mitigate or cope with likely future impacts of climate change events on modern society.
Alley/1542778 This award supports a three-year effort to study physical properties of the South Pole ice core to help provide a high-time-resolution history of trace gases and other paleoclimatic indicators from an especially cold site with high preservation potential for important signals. The physical-properties studies include visual inspection to identify any flow disturbances and for identifying annual layers and other features, and combined bubble, grain and ice crystal orientation studies to better understand the processes occurring in the ice that affect the climate record and the ice-sheet behavior. Success of these efforts will provide necessary support for dating and quality control to others studying the ice core, as well as determining the climate history of the site, flow state, and key physical processes in ice. The intellectual merits of the project include better understanding of physical processes, paleoclimatic reconstruction, dating of the ice, and quality assurance. Visual inspection of the core will help identify evidence of flow disturbances that would disrupt the integrity of the climate record and will reveal volcanic horizons and other features of interest. Annual layer counting will be conducted to help estimate accumulation rate over time as recorded in the ice core. Measurements of C-axis fabric, grain size and shapes, and bubble characteristics will provide information about processes occurring in the ice sheet as well as the history of ice flow, current flow state and how the ice is flowing and how easily it will flow in the future. Analysis of this data in conjunction with microCT data will help to reveal grain-scale processes. The broader impacts of the project include support for an early-career, post-doctoral researcher, and improved paleoclimatic data of societal relevance. The results will be incorporated into the active program of education and outreach which have educated many students, members of the public and policy makers through the sharing of information and educational materials about all aspects of ice core science and paleoclimate.
Intellectual Merit: The PIs propose to investigate last glacial maximum through Holocene glacial change on the northeastern Antarctic Peninsula, an area distinguished by dramatic ice shelf collapses and retreat of upstream glaciers. However, there is a lack of long-term context to know the relative significance of recent events over longer time scales. The PIs will obtain data on former ice margin positions, ice thicknesses, glacier retreat and thinning rates, and Holocene glacier change in the James Ross Island Archipelago and areas near the former Larsen-A ice shelf. These data include maximum- and minimum-limiting 14C and cosmogenic-nuclide exposure dates integrated with geomorphology and stratigraphy. Understanding the extent, nature, and history of glacial events is important for placing current changes in glacial extent into a long-term context. This research will also contribute to understanding the sensitivity of ice shelves and glaciers in this region to climate change. Records of changes in land-terminating glaciers will also address outstanding questions related to climate change since the LGM and through the Holocene. The PIs will collect samples during cooperative field projects with scientists of the Instituto Antártico Argentino and the Korea Polar Research Institute planned as part of existing, larger, research projects. Broader impacts: The proposed work includes collaborations with Argentina and Korea. The PIs are currently involved in or are initiating education and outreach activities that will be incorporated into this project. These include interactions with the American Museum of Natural History, the United States Military Academy at West Point, and undergraduate involvement in their laboratories. This project provides a significant opportunity to engage the public as it focuses on an area where environmental changes are the object of attention in the popular media.
Alley/1142085 This award supports a project to continue the collection and analyses of firn temperature data from three automated firn thermal profiling units deployed in Dronning Maud Land sector of East Antarctica as part of the Norway-US IPY Traverse project between 2007 and 2009. The intellectual merits of this project are as follows: 1) to constrain and improve the parameterization of firn thermal properties (thermal conductivity and specific heat capacity) that are required for the borehole paleothermometry, 2) to study the change in firn temperature since the deployment of thermal profiling units ~5 years ago and derive the surface temperature trend for that time period, and 3) to compare and contrast the surface temperatures and their trends derived from the measured firn temperatures and satellite thermal infrared data for the past three decades. The project also involves acquiring and deploying an automated system to record transient temperatures at multiple depths in the top 16 meters of the shallow borehole at Dome Fuji, to provide useful data and to prepare for the possibility of conducting temperature-logging in the existing deep (3035 m) and shallow (112 m) boreholes at Dome Fuji in the near future. The preparation of the shallow borehole and the installation of the automated system will be carried out by collaborators from the Japanese Antarctic Research Expedition (JARE) in 2012-13 Antarctic field season. The data collected by this automated system will be used to constrain the thermal properties of upper firn layer at Dome Fuji, as well as comparing with data from other sites, increasing the geographic extent of these studies. The broader impacts of the project include presentation of results at scientific conferences and publication of results in peer-reviewed journals. Public outreach will include targeted work with science teachers and middle school students.
Intellectual Merit: This project will determine the potential vulnerability of key ice streams to incursions of warmer ocean water onto the continental shelf and if this mechanism could already explain any of the observed thinning of the ice sheet. It will provide important constrains on ice dynamic of the investigated section of the EAIS, and thus will be critical for future ice sheet models and provide mechanisms for EAIS contributions to past sea level high-stand. The PI proposes to investigate four key ice stream systems on the continental shelf between ~90°E and 160°E. They will use multibeam bathymetry to identify if and where cross-shelf troughs exist to help determine whether these troughs could provide potential pathways for warmer ocean water. Furthermore, detailed analysis of morphological features of these troughs could provide information on past ice dynamic, maximum extent, and flow direction of related paleo ice streams. The PIs will also conduct water column measurements along these troughs and on the continental slope to determine whether warmer ocean water could enter the shelf in the near future, or if such water has already entered any troughs, and thus might be causing the observed thinning of some ice streams. Broader impacts: This project includes the participation and support of undergraduate and graduate students in field work and data analysis. The possible involvement of a PolarTREC teacher and the Earth2Class teachers program will reach out to K-12 students.
Taylor/0944348<br/><br/>This award supports renewal of funding of the WAIS Divide Science Coordination Office (SCO). The Science Coordination Office (SCO) was established to represent the research community and facilitates the project by working with support organizations responsible for logistics, drilling, and core curation. During the last five years, 26 projects have been individually funded to work on this effort and 1,511 m of the total 3,470 m of ice at the site has been collected. This proposal seeks funding to continue the SCO and related field operations needed to complete the WAIS Divide ice core project. Tasks for the SCO during the second five years include planning and oversight of logistics, drilling, and core curation; coordinating research activities in the field; assisting in curation of the core in the field; allocating samples to individual projects; coordinating the sampling effort; collecting, archiving, and distributing data and other information about the project; hosting an annual science meeting; and facilitating collaborative efforts among the research groups. The intellectual merit of the WAIS Divide project is to better predict how human-caused increases in greenhouse gases will alter climate requires an improved understanding of how previous natural changes in greenhouse gases influenced climate in the past. Information on previous climate changes is used to validate the physics and results of climate models that are used to predict future climate. Antarctic ice cores are the only source of samples of the paleo-atmosphere that can be used to determine previous concentrations of carbon dioxide. Ice cores also contain records of other components of the climate system such as the paleo air and ocean temperature, atmospheric loading of aerosols, and indicators of atmospheric transport. The WAIS Divide ice core project has been designed to obtain the best possible record of greenhouse gases during the last glacial cycle (last ~100,000 years). The site was selected because it has the best balance of high annual snowfall (23 cm of ice equivalent/year), low dust Antarctic ice that does not compromise the carbon dioxide record, and favorable glaciology. The main science objectives of the project are to investigate climate forcing by greenhouse gases, initiation of climate changes, stability of the West Antarctic Ice Sheet, and cryobiology in the ice core. The project has numerous broader impacts. An established provider of educational material (Teachers? Domain) will develop and distribute web-based resources related to the project and climate change for use in K?12 classrooms. These resources will consist of video and interactive graphics that explain how and why ice cores are collected, and what they tell us about future climate change. Members of the national media will be included in the field team and the SCO will assist in presenting information to the general public. Video of the project will be collected and made available for general use. Finally, an opportunity will be created for cryosphere students and early career scientists to participate in field activities and core analysis. An ice core archive will be available for future projects and scientific discoveries from the project can be used by policy makers to make informed decisions.
Steig/1341360 This award supports a two-year project to develop a method for rapid and precise measurements of the difference in 18O/16O and 17O/16O isotope ratios in water, referred to as the 17O-excess. Measurement of 17O-excess is a recent innovation in geochemistry, complementing traditional measurements of the ratios of hydrogen (D/H) and oxygen (18O/16O). Conventional measurements of 17O/16O are limited in number because of the time-consuming and laborious nature of the analyses, which involves the conversion of water to oxygen via fluorination, followed by high-precision mass spectrometry. This project will use a novel cavity ring-down spectroscopy (CRDS) system developed by a joint effort of the University of Washington and Picarro, Inc. (Santa Clara, CA), along with the Centre for Ice and Climate (Neils Bohr Institute, Copenhagen). The primary intellectual merit of the research is the improvement of the CRDS method for measurements of 17Oexcess of discrete samples of water, to obtain precision and accuracy competitive with conventional methods using mass spectrometry. This will be achieved by quantification of the effects of water vapor concentration variability and instrument memory, precise calibration of the instrument against standard waters, and improvements to the spectroscopic analyses. The CRDS system will also be coupled to continuous-flow systems for ice core analysis, in collaboration with the University of Colorado, Boulder. The goal is to have an operational system available for ice core processing associated with the next major U.S.-led ice core project at South Pole, in 2015-2017. The broader impacts of the research include the ability to measure 17O-excess in ambient atmospheric water vapor, which can be used to improve understanding of convection, moisture transport, and condensation. The instrument development work proposed here is relevant to research supported by several NSF-GEO programs, including Hydrology, Climate and Large Scale Dynamics, Paleoclimate, Atmosphere Chemistry, and both the Arctic and Antarctic Programs. This proposal will support a postdoctoral researcher.
Intellectual Merit: To understand Antarctica's geodynamic development, origin of the Transantarctic Mountains (TAMs) and the Wilkes Subglacial Basin (WSB) must be determined. Current constraints on the crustal thickness and seismic velocity structure beneath the TAMs and the WSB are limited, leading to uncertainties over competing geologic models that have been suggested to explain their formation. The PI proposes to broaden the investigation of this region with a new seismic deployment, the Transantarctic Mountains Northern Network (TAMNNET), a 15-station array across the northern TAMs and the WSB that will fill a major gap in seismic coverage. Data from TAMNNET will be combined with that from other previous and ongoing seismic initiatives and will be analyzed using proven modeling techniques to generate a detailed image of the seismic structure beneath the TAMs and the WSB. These data will be used to test three fundamental hypotheses: the TAMs are underlain by thickened crust, the WSB is characterized by thin crust and thick sedimentary layers, and slow seismic velocities are prevalent along strike beneath the TAMs. Results from the proposed study will provide new information about the nature and formation of the Antarctic continent and will help to advance our understanding of important global processes, such as mountain building and basin formation. The proposed research also has important implications for other fields of Antarctic science. Constraints on the origin of the TAMs uplift are critical for climate and ice sheet models, and new information acquired about variations in the thermal and lithospheric structure beneath the TAMs and the WSB will be used to estimate critical ice sheet boundary conditions. Broader impacts: This project incorporates three educational strategies to promote the integration of teaching and research. Graduate students will be trained in Antarctic tectonics and seismic processing through hands-on fieldwork and data analysis techniques. Through NSF's PolarTREC program, the PI will work with K-12 educators. The PI will develop a three-week summer field program for recent high school graduates and early-career undergraduate students from Minority-Serving Institutions in Alabama. Teaching materials and participant experiences will be shared with individuals outside the program via a course website. Following the summer program, participants who were particularly engaged will be offered internship opportunities to analyze TAMNNET data. In successive years, the students could assist with fieldwork and could be recruited into the graduate program under the PI's supervision. Ultimately, this program would not only serve to educate undergraduates but would also generate a pipeline of underrepresented students into the geosciences.
Hastings/1246223 This award supports a project with the aim of distinguishing the sources of nitrate deposition to the West Antarctic Ice Sheet (WAIS) using isotopic ratios snow in archive snow and ice samples. The isotopic composition of nitrate has been shown to contain information about the source of the nitrate (i.e. nitrogen oxides = NOx = NO+NO2) and the oxidation processes that convert NOx to nitrate in the atmosphere prior to deposition. A difficulty in interpreting records in the context of NOx sources is that nitrate can be post-depositionally processed in surface snow, such that the archived record does not reflect the composition of the atmosphere. This intellectual merit of this work specifically aims to investigate variability in the isotopic composition of nitrate in snow and ice from the WAIS in the context of accumulation rate, NOx source emissions, and atmospheric chemistry. These records will be interpreted in the context of our understanding of biospheric (biomass burning, microbial processes in soils), atmospheric (lightning, transport, chemistry), and climate (temperature, accumulation rate) changes over time. A graduate student will be supported as part of this project, and both graduate student and PI will be involved in communicating the utility and results of polar research to elementary school students in the Providence, RI area. The broader impacts of the project also include making efforts to attract more young, female scientists to polar research by establishing a connection between the Earth Science Women's Network (ESWN), an organization PI Hastings helped to establish, and the Association of Polar Early Career Scientists (APECS). Finally, results of all measurements will be presented at relevant conferences, made available publicly and published in peer-reviewed journals.
Marine paleoclimate archives show that approximately one million years ago Earth's climate transitioned from 40,000-year glacial /interglacial cycles to 100,000-year cycles. This award will support a study designed to map the distribution of one million year-old ice in the Allan Hills Blue Ice Area, Antarctica using state-of-the-art ground penetrating radar. The Allen Hills was demonstrated to contain a continuous record of the past 400,000 years and is also the collection location of the oldest ice samples (990,000 years) yet recovered. The maps resulting from this study will be used to select an ice-core drilling site at which a million-plus year-old continuous record of climate could be recovered. Ice cores contain the only kind of record to directly capture atmospheric gases and aerosols, but no ice-core-based climate record yet extends continuously beyond the past 800,000 years. A million-plus year-old record will allow better understanding of the major mechanisms and driving forces of natural climate variability in a world with 100,000-year glacial/interglacial cycles. The project will support two early career scientists in collaboration with senior scientists, as well as a graduate student, and will conduct outreach to schools and the public. The Allan Hills Blue Ice Area preserves a continuous climate record covering the last 400,000 years along an established glaciological flow line. Two kilometers to the east of this flow line, the oldest ice on Earth (~1 million years old) is found only 120 m below the surface. Meteorites collected in the area are reported to be as old as 1.8 million years, suggesting still older ice may be present. Combined, these data strongly suggest that the Allen Hills area could contain a continuous, well-resolved environmental record, spanning at least the last million years. As such, this area has been selected as an upcoming target for the new Intermediate Depth Ice Core Drill by the US Ice Core Working Group. This drill will recover a higher-quality core than previous dry drilling attempts. This project will conduct a comprehensive ground penetrating radar survey aimed at tracing the signature of the million-year-old ice layer throughout the region. The resulting map will be used to select a drill site from which an ice core containing the million-plus year-old continuous climate record will be collected. The proposed activities are a necessary precursor to the collection of the oldest known ice on Earth. Ice cores provide a robust reconstruction of past climate and extending this record beyond the 800,000 years currently available will open new opportunities to study the climate system. The data collected will also be used to investigate the bedrock and ice flow parameters favorable to the preservation of old ice, which may allow targeted investigation of other blue ice areas in Antarctica.
Intellectual Merit: This project will investigate glacial advance and retreat of the East Antarctic Ice Sheet through the Eocene-Oligocene transition, a major episode of ice growth. In Prydz Bay, East Antarctica, a 130-170 m thick Eocene-Oligocene transition interval of glaciomarine sediments was cored in drillholes of the Ocean Drilling Program at Sites 739, 742 and 1166. Correlations between the Prydz Bay drillholes have recently been made through well-log and multichannel seismic interpretations. Recent drilling on the Wilkes Land margin of East Antarctica recovered earliest Oligocene sediments overlying a major regional unconformity in two drillholes. The PI will study the lithostratigraphy and weathering history of cores in the five drillholes, to establish a unique Eocene-Oligocene transition record within Antarctic continental margin sediments of glacial advance and retreat cycles, the onset of physical weathering, and glacio-isostasy and self-gravitation processes with implications for the margin architecture, sediment routing, and off-shore sediment dispersal. Cores from the five drillholes will be re-examined through detailed core description using an updated classification scheme, so that lithofacies can be compared between drillholes. Samples will be collected for detailed laser particle size and bulk major element geochemistry via ICP-AES to determine the degree of chemical alteration of the sediments. Phases of major ice growth will be recognized as marker beds of physically eroded sediment and will be correlated to isotopic records documenting Antarctic ice growth offshore in the Southern Ocean. Broader impacts: This project will benefit a large minority undergraduate student population through the availability of up to two paid laboratory internships, a classroom exercise, and the availability of research equipment supported by this award. The project also allows support and training of a graduate student.
0538427<br/>McConnell <br/>This award supports a project to use unique, high-depth-resolution records of a range of elements, chemical species, and ice properties measured in two WAIS Divide shallow ice cores and one shallow British ice core from West Antarctic to address critical paleoclimate, environmental, and ice-sheet mass-balance questions. Recent development of the CFA-TE method for ice-core analysis presents the opportunity to develop high-resolution, broad-spectrum glaciochemical records at WAIS Divide at relatively modest cost. Together with CFA-TE measurements from Greenland and other Antarctic sites spanning recent decades to centuries, these rich data will open new avenues for using glaciochemical data to investigate environmental and global changes issues ranging from anthropogenic and volcanic-trace-element fallout to changes in hemispheric-scale circulation, biogeochemistry, rapid-climate-change events, long-term climate change, and ice-sheet mass balance. As part of the proposed research, collaborations with U.S., Argentine, and British researchers will be initiated and expanded to directly address three major IPY themes (i.e., present environmental status, past and present environmental and human change, and polar-global interactions). Included in the contributions from these international collaborators will be ice-core samples, ice-core and meteorological model data, and extensive expertise in Antarctic glaciology, climatology, meteorology, and biogeochemistry. The broader impacts of the work include the training of students. The project will partially support one Ph.D. student and hourly undergraduate involvement. Every effort will be made to attract students from underrepresented groups to these positions. To address the challenge of introducing results of scientific research to the public policy debate, we will continue efforts to publish findings in high visibility journals, provide research results to policy makers, and work with the NSF media office to reach the public through mass-media programs. K-12 teacher and classroom involvement will be realized through outreach to local schools and NSF's Teachers Experiencing the Antarctic and Arctic (or similar) program in collaboration with WAIS Divide and other polar researchers.
McConnell/1142166 This award supports a project to use unprecedented aerosol and continuous gas (methane, carbon monoxide) measurements of the deepest section of the West Antarctic Ice Sheet (WAIS) Divide ice core to investigate rapid climate changes in Antarctica during the ~60,000 year long Marine Isotope Stage 3 period of the late Pleistocene. These analyses, combined with others, will take advantage of the high snow accumulation of the WAIS Divide ice core to yield the highest time resolution glaciochemical and gas record of any deep Antarctic ice core for this time period. The research will expand already funded discrete gas measurements and extend currently funded continuous aerosol measurements on the WAIS Divide ice core from ~25,000 to ~60,000 years before present, spanning Heinrich events 3 to 6 and Antarctic Isotope Maximum (AIM, corresponding to the Northern Hemisphere Dansgaard-Oeschger) events 3 to 14. With other high resolution Greenland cores and lower resolution Antarctic cores, the combined record will yield new insights into worldwide climate dynamics and abrupt change. The intellectual merit of the work is that it will be used to address the science goals of the WAIS Divide project including the identification of dust and biomass burning tracers such as black carbon and carbon monoxide which reflect mid- and low-latitude climate and atmospheric circulation patterns, and fallout from these sources affects marine and terrestrial biogeochemical cycles. Similarly, sea salt and ocean productivity tracers reflect changes in sea ice extent, marine primary productivity, wind speeds above the ocean, and atmospheric circulation. Volcanic tracers address the relationship between northern, tropical, and southern climates as well as stability of the West Antarctic ice sheet and sea level change. When combined with other gas records from WAIS Divide, the records developed here will transform understanding of mid- and low-latitude drivers of Antarctic, Southern Hemisphere, and global climate rapid changes and the timing of such changes. The broader impacts of the work are that it will enhance infrastructure through expansion of continuous ice core analytical techniques, train students and support collaboration between two U.S. institutions (DRI and OSU). All data will be made available to the scientific community and the public and will include participation the WAIS Divide Outreach Program. Extensive graduate and undergraduate student involvement is planned. Student recruitment will be made from under-represented groups building on a long track record. Broad outreach will be achieved through collaborations with the global and radiative modeling communities, NESTA-related and other educational outreach efforts, and public lectures. This proposed project does not require field work in the Antarctic.
0538520<br/>Thiemens<br/>This award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions.
This award supports a project to help to establish the depth-age chronology and the histories of accumulation and ice dynamics for the WAIS Divide ice core. The depth-age relationship and the histories of accumulation and ice dynamics are coupled. An accurate age scale is needed to infer histories of accumulation rate and ice-thickness change using ice-flow models. In turn, the accumulation-rate history is needed to calculate the age difference of ice to determine the age of the trapped gases. The accumulation history is also needed to calculate atmospheric concentrations of impurities trapped in the ice and is an important characteristic of climate. The history of ice-thickness change is also fundamental to understanding the stability of the WAIS. The primary goals of the WAIS Divide ice core project are to investigate climate forcing by greenhouse gases, the initiation of climate changes, and the stability of the West Antarctic Ice Sheet (WAIS). An accurate age scale is fundamental for achieving these goals. The first objective of this project is to establish an annually resolved depth-age relationship for the past 40,000 years. This will be done by measuring variations in electrical conductivity along the ice core, which are caused by seasonal variations in chemistry. We expect to be able to resolve annual layers back to 40,000 years before present (3,000 m depth) using this method. The second objective is to search for stratigraphic disturbances in the core that would compromise the paleoclimate record. Irregular layering will be identified by measuring the electrical conductivity of the ice in a vertical plan through the core. The third objective is to derive a preliminary chronology for the entire core. For the deeper ice we will use an ice-flow model to interpolate between known age markers, such as dated volcanic horizons and tie points from the methane gas chronology. The fourth objective is to derive a refined chronology simultaneously with histories of accumulation and ice-sheet thickness. An ice-flow model and all available data will be used to formulate an inverse problem, in which we infer the most appropriate histories of accumulation and ice-thickness, together with estimates of uncertainties. The flow model associated with those preferred histories then produces the best estimate of the chronology. The research contributes directly to the primary goals of the West Antarctic Ice Sheet Initiative. The project will help develop the next generation of scientists through the education and training of one Ph.D. student and several undergraduate students. This project will result in instrumentation for measuring the electrical conductivity of ice cores being available at the National Ice Core Lab for other researchers to use on other projects. All collaborators are committed to fostering diversity and currently participate in scientific outreach and most participate in undergraduate education. Outreach will be accomplished through regularly scheduled community and K-12 outreach events at UW, talks and popular writing by the PIs, as well as through our respective press offices.
0539578<br/>Alley <br/>This award supports a five-year collaborative project to study the physical-properties of the planned deep ice core and the temperature of the ice in the divide region of the West Antarctic Ice Sheet. The intellectual merit of the proposed research is to provide fundamental information on the state of the ice sheet, to validate the integrity of the climate record, to help reconstruct the climate record, and to understand the flow state and history of the ice sheet. This information will initially be supplied to other investigators and then to the public and to appropriate databases, and will be published in the refereed scientific literature. The objectives of the proposed research are to aid in dating of the core through counting of annual layers, to identify any exceptionally warm intervals in the past through counting of melt layers, to learn as much as possible about the flow state and history of the ice through measurement of size, shape and arrangements of bubbles, clathrate inclusions, grains and their c-axes, to identify any flow disturbances through these indicators, and to learn the history of snow accumulation and temperature from analyses of bubbles and borehole temperatures combined with flow modeling and use of data from other collaborators. These results will then be synthesized and communicated. Failure to examine cores can lead to erroneous identification of flow features as climate changes, so careful examination is required. Independent reconstruction of accumulation rate provides important data on climate change, and improves confidence in interpretation of other climate indicators. Borehole temperatures are useful recorders of temperature history. Flow state and history are important in understanding climate history and potential contribution of ice to sea-level change. By contributing to all of these and additional issues, the proposed research will be of considerable value. The broader impacts of the research include making available to the public improved knowledge on societally central questions involving abrupt climate change and sea-level rise. The project will also contribute to the education of advanced students, will utilize results in education of introductory students, and will make vigorous efforts in outreach, informal science education, and supplying information to policy-makers as requested, thus contributing to a more-informed society.
This award supports a three-year study of the ongoing deceleration and stick-slip motion of Whillans Ice Stream (WIS), West Antarctica. Understanding the dynamic behavior of ice streams is essential for predicting the future of the West Antarctic Ice Sheet (WAIS). Despite being one of the best-studied ice streams in Antarctica, the surprising flow characteristics of WIS continue to demand interdisciplinary research. Recent estimates indicate that the WIS may stagnate within 50 years, resulting in a significant change to the mass balance of the Siple Coast sector of West Antarctica. The reasons for the ongoing stagnation are not well known, and are possibly linked (causally or coincidentally) to the stick-slip behavior. Our recent work on WIS stick-slip motion suggest that all slip events nucleate from a common location on the ice stream, suggesting that a relatively small (approximately 10 km in diameter) region of the exerts fundamental control over the flow of this large ice stream (100s of km long and 100 kilometers wide). We hypothesize that this is a region of increased bed strength and our measurements will address that hypothesis. We will deploy a series of GPS receivers and seismometers on the ice stream to accurately locate the nucleation region so that a comprehensive ground based geophysical survey can be conducted to determine the physical properties of bed at the nucleation point. The ground geophysical program will consist of reflection seismic and ice-penetrating radar studies that will better constrain the properties of both the hypothesized higher-friction nucleation zone and the surrounding regions. Slip events also generate seismic energy that can be recorded 100s of km away from the ice stream, thus, the GPS and seismometer deployment will also aid us in relating seismic waveforms directly with the rapid motion that occurs during slip events. The increased ability to relate rupture processes with seismic emissions will allow us to use archived seismic records to explore changes in the behavior of WIS during the later half of the 20th century. Broader impacts of this study include improved knowledge ice sheet dynamics, which remain a poorly constrained component of the climate system, thus, limiting our ability to predict the Earth's response to climate change. The scientific work includes the education of two graduate students and continued training of one post-doctoral scholar, thus helping to train the next generation of polar scientists. We will expose the broader public to polar science through interactions with the media and by take advantaging of programs to include K-12 educators in our field work.
Intellectual Merit: The PIs propose to address the question of whether ice surface melting zones developed at high elevations during warm climatic phases in the Transantarctic Mountains. Evidence from sediment cores drilled by the ANDRILL program indicates that open water in the Ross Sea could have been a source of warmth during Pliocene and Pleistocene. The question is whether marine warmth penetrated inland to the ice sheet margins. The glacial record may be ill suited to answer this question, as cold-based glaciers may respond too slowly to register brief warmth. Questions also surround possible orbital controls on regional climate and ice sheet margins. Northern Hemisphere insolation at obliquity and precession timescales is thought to control Antarctic climate through oceanic or atmospheric connections, but new thinking suggests that the duration of Southern Hemisphere summer may be more important. The PIs propose to use high elevation alluvial deposits in the Transantarctic Mountains as a proxy for inland warmth. These relatively young fans, channels, and debris flow levees stand out as visible evidence for the presence of melt water in an otherwise ancient, frozen landscape. Based on initial analyses of an alluvial fan in the Olympus Range, these deposits are sensitive recorders of rare melt events that occur at orbital timescales. For their study they will 1) map alluvial deposits using aerial photography, satellite imagery and GPS assisted field surveys to establish water sources and to quantify parameters effecting melt water production, 2) date stratigraphic sequences within these deposits using OSL, cosmogenic nuclide, and interbedded volcanic ash chronologies, 3) use paired nuclide analyses to estimate exposure and burial times, and rates of deposition and erosion, and 4) use micro and regional scale climate modeling to estimate paleoenvironmental conditions associated with melt events. Broader impacts: This study will produce a record of inland melting from sites adjacent to ice sheet margins to help determine controls on regional climate along margins of the East Antarctic Ice Sheet to aid ice sheet and sea level modeling studies. The proposal will support several graduate and undergraduates. A PhD student will be supported on existing funding. The PIs will work with multiple K 12 schools to conduct interviews and webcasts from Antarctica and they will make follow up visits to classrooms after the field season is complete.
1043517/Clark This award supports a project to develop a better understanding of the response of the WAIS to climate change. The timing of the last deglaciation of the western Ross Sea will be improved using in situ terrestrial cosmogenic nuclides (3He, 10Be, 14C, 26Al, 36Cl) to date glacial erratics at key areas and elevations along the western Ross Sea coast. A state-of-the art ice sheet-shelf model will be used to identify mechanisms of deglaciation of the Ross Sea sector of WAIS. The model results and forcing will be compared with observations including the new cosmogenic data proposed here, with the aim of better determining and understanding the history and causes of WAIS deglaciation in the Ross Sea. There is considerable uncertainty, however, in the history of grounding line retreat from its last glacial maximum position, and virtually nothing is known about the timing of ice- surface lowering prior to ~10,000 years ago. Given these uncertainties, we are currently unable to assess one of the most important questions regarding the last deglaciation of the global ice sheets, namely as to whether the Ross Sea sector of WAIS contributed significantly to meltwater pulse 1A (MWP-1A), an extraordinarily rapid (~500-year duration) episode of ~20 m sea-level rise that occurred ~14,500 years ago. The intellectual merit of this project is that recent observations of startling changes at the margins of the Greenland and Antarctic ice sheets indicate that dynamic responses to warming may play a much greater role in the future mass balance of ice sheets than considered in current numerical projections of sea level rise. The broader impacts of this work are that it has direct societal relevance to developing an improved understanding of the response of the West Antarctic ice sheet to current and possible future environmental changes including the sea-level response to glacier and ice sheet melting due to global warming. The PI will communicate results from this project to a variety of audiences through the publication of peer-reviewed papers and by giving talks to public audiences. Finally the project will support a graduate student and undergraduate students in all phases of field-work, laboratory work and data interpretation.
Steig/1043092 This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.
Elevated temperatures and ocean acidification are both threatening the Southern Ocean. The effects of these environmental changes are poorly understood, but preliminary data suggest that they are driving a biological invasion. Specifically, large populations of skeleton-crushing king crabs, Paralomis birsteini, have been detected off Marguerite Bay on the West Antarctic Peninsula. These crabs appear to be invading the continental shelf region where benthic communities have evolved in the absence of such top-predators. Thus, this invasion could result in a wholesale restructuring of the Antarctic benthic ecosystem. The proposed work seeks to document this invasion and better understand the effects of the introduction of P. birsteini on the ecology of this region. A towed underwater vehicle will be used to photographically image communities, and communities with and without P. birsteini will be compared quantitatively. Additionally, crabs will trapped and various aspects of their morphology and physiology will be assessed. This research is unique in that it will document a biological invasion in real-time and it will therefore enhance our general understandings of the drivers of invasion and resilience in biological communities. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. This project will support the research and training of undergraduate and graduate students and will foster an international collaboration with British scientists. Researchers on this project will participate in outreach thorough the development of K-12 curricular materials.
The presence of ice ponds from surface melting of glacial ice can be a significant threshold in assessing the stability of ice sheets, and their overall response to a warming climate. Snow melt has a much reduced albedo, leading to additional seasonal melting from warming insolation. Water run-off not only contributes to the mass loss of ice sheets directly, but meltwater reaching the glacial ice bed may lubricate faster flow of ice sheets towards the ocean. Surficial meltwater may also reach the grounding lines of glacial ice through the wedging open of existing crevasses. The occurrence and amount of meltwater refreeze has even been suggested as a paleo proxy of near-surface atmospheric temperature regimes. Using contemporary remote sensing (microwave) satellite assessment of surface melt occurrence and extent, the predictive skill of regional meteorological models and reanalyses (e.g. WRF, ERA-Interim) to describe the synoptic conditions favourable to surficial melt is to be investigated. Statistical approaches and pattern recognition techniques are argued to provide a context for projecting future ice sheet change. The previous Intergovernmental Panel on Climate Change (IPCC AR4) commented on our lack of understanding of ice-sheet mass balance processes in polar regions and the potential for sea-level change. The IPPC suggested that the forthcoming AR5 efforts highlight regional cryosphere modeling efforts, such as is proposed here.
1141973/Tedesco This award supports a project to generate first-time validated enhanced spatial resolution (5-10 km) maps of surface melting over the Antarctic Peninsula for the period 1958 - to date from the outputs of a regional climate model and different downscaling techniques. These maps will be assessed and validated through new high spatial resolution (2.25 km) surface melting maps obtained from the QuikSCAT satellite for the period 1999 - 2009. The intellectual merit of this work is that it would be the first time that the outputs of a regional climate model would be used to study surface melting over Antarctica at such high spatial resolution and the first time that such results are validated by means of an observational tool that has such a large spatial coverage and high spatial resolution. The results generated in this study would also provide a first-time opportunity to study the melt distribution over the Peninsula and its correlation with climate drivers, such as the Southern Annual Mode (SAM) and the El Nino-Southern Oscillation (ENSO) at these unprecedented spatial scales. The enhanced resolution melting maps will also offer a unique opportunity to study melting trends and patterns over specific regions of the Peninsula, such as the Wilkins and the Larsen A and B ice shelves and evaluate whether the extreme melting observed during the recent collapses was unprecedented over the + 50 years. The broader impacts of the project are that it will integrate research and education by fully supporting one female undergrad student, a PhD student and partially supporting a PostDoc. The work will be done at a minority-serving institution and the PhD student who worked on the development of the high-resolution melting data set from QuikSCAT will become the PostDoc who will work on this project. Teaching and learning will be supported by incorporating research results into graduate and undergrad level courses and will be disseminated over the web and through appropriate channels. Results from this project will also benefit the society at large as they will improve our understanding of the links between atmospheric patterns and surface melting and they will contribute to improving estimates of sea level rise from the Antarctica continent.
1043750/Chen This award supports a project to improve the estimate of long-term and inter-annual variability of Antarctic ice sheet mass balance at continental, regional, and catchment scales, using satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and other geodetic measurements. The work will improve the quantification of long-term mass change rates over Antarctica using GRACE gravity data with a longer record and newer generation(s) of products and will develop advanced numerical forward modeling techniques that can accurately correct leakage effects associated with GRACE data processing, and significantly improve spatial resolution of GRACE mass rate estimates over Antarctica. The work will also contribute to a better understanding of crustal uplift rates due to postglacial rebound (PGR) and present day ice load change over Antarctica via PGR models, GPS measurements, and combined analysis of GRACE and ICESat elevation changes. Inter-annual variations of ice mass over Antarctica will be investigated at continental and catchment scales and connections to regional climate change will be studied. The major deliverables from this study will be improved assessments of ice mass balance for the entire Antarctic ice sheet and potential contribution to global mean sea level rise. The work will also provide estimates of regional ice mass change rates over Antarctica, with a focus along the coast in the Amundsen Sea Embayment, the Peninsula in West Antarctica, and in Wilkes Land and Victoria Land in East Antarctica. Estimates of inter-annual ice mass change over Antarctica at various spatial scales, and assessments of uncertainty of GRACE ice rate estimates and PGR models errors over Antarctica will also be made. The intellectual merits of the proposed investigation include 1) providing improved assessments of Antarctic ice mass balance at different temporal and spatial scales with unprecedented accuracy, an important contribution to broad areas of polar science research; 2) combining high accuracy GPS vertical uplift measurements and PGR models to better quantify long-term crust uplift effects that are not distinguishable from ice mass changes by GRACE; and 3) unifying the work of several investigations at the forefront of quantifying ice sheet and glacier mass balance and crustal uplift based on a variety of modern space geodetic observations. The broader impacts include the fact that the project will actively involve student participation and training, through the support of two graduate students. In addition the project will contribute to general education and public outreach (E/PO) activities and the results from this investigation will help inspire future geoscientists and promote public awareness of significant manifestations of climate change.
Severinghaus/0839031 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a project to develop a precise gas-based chronology for an archive of large-volume samples of the ancient atmosphere, which would enable ultra-trace gas measurements that are currently precluded by sample size limitations of ice cores. The intellectual merit of the proposed work is that it will provide a critical test of the "clathrate hypothesis" that methane clathrates contributed to the two abrupt atmospheric methane concentration increases during the last deglaciation 15 and 11 kyr ago. This approach employs large volumes of ice (>1 ton) to measure carbon-14 on past atmospheric methane across the abrupt events. Carbon-14 is an ideal discriminator of fossil sources of methane to the atmosphere, because most methane sources (e.g., wetlands, termites, biomass burning) are rich in carbon-14, whereas clathrates and other fossil sources are devoid of carbon-14. The proposed work is a logical extension to Taylor Glacier, Antarctica, of an approach pioneered at the margin of the Greenland ice sheet over the past 7 years. The Greenland work found higher-than-expected carbon-14 values, likely due in part to contaminants stemming from the high impurity content of Greenland ice and the interaction of the ice with sediments from the glacier bed. The data also pointed to the possibility of a previously unknown process, in-situ cosmogenic production of carbon-14 methane (radiomethane) in the ice matrix. Antarctic ice in Taylor Glacier is orders of magnitude cleaner than the ice at the Greenland site, and is much colder and less stratigraphically disturbed, offering the potential for a clear resolution of this puzzle and a definitive test of the cosmogenic radiomethane hypothesis. Even if cosmogenic radiomethane in ice is found, it still may be possible to reconstruct atmospheric radiomethane with a correction enabled by a detailed understanding of the process, which will be sought by co-measuring carbon-14 in carbon monoxide and carbon dioxide. The broader impacts of the proposed work are that the clathrate test may shed light on the stability of the clathrate reservoir and its potential for climate feedbacks under human-induced warming. Development of Taylor Glacier as a "horizontal ice core" would provide a community resource for other researchers. Education of one postdoc, one graduate student, and one undergraduate, would add to human resources. This award has field work in Antarctica.
1142162/Stone This award supports a project to conduct a reconnaissance geological and radar-sounding study of promising sites in West Antarctica as a prelude to a future project to conduct subglacial cosmogenic nuclide measurements. Field work will take place in the Whitmore Mountains, close to the WAIS divide, and on the Nash and Pirrit Hills, downflow from the divide in the Weddell Sea drainage. At each site geological indicators of higher (and lower) ice levels in the past will be mapped and evidence of subglacial erosion or its absence will be documented. Elevation transects of both glacial erratics and adjacent bedrock samples will be collected to establish the timing of recent deglaciation at the sites and provide a complement to similar measurements on material from depth transects obtained by future subglacial drilling. At each site, bedrock ridges will be traced into the subsurface with closely-spaced ice-penetrating radar surveys, using a combination of instruments and frequencies to obtain meter-scale surface detail, using synthetic aperture techniques. Collectively the results will define prospective sites for subglacial sampling, and maximize the potential information to be obtained from such samples in future studies. The intellectual merit of this project is that measurements of cosmogenic nuclides in subglacial bedrock hold promise for resolving the questions of whether the West Antarctic ice sheet collapsed completely in the past, whether it is prone to repeated large deglaciations, and if so, what is their magnitude and frequency. Such studies will require careful choice of targets, to locate sites where bedrock geology is favorable, cosmogenic nuclide records are likely to have been protected from subglacial erosion, and the local ice-surface response is indicative of large-scale ice sheet behavior. The broader impacts of this work include helping to determine whether subglacial surfaces in West Antarctica were ever exposed to cosmic rays, which will provide unambiguous evidence for or against a smaller ice sheet in the past. This is an important step towards establishing whether the WAIS is vulnerable to collapse in future, and will ultimately help to address uncertainty in forecasting sea level change. The results will also provide ground truth for models of ice-sheet dynamics and long-term ice sheet evolution, and will help researchers use these models to identify paleoclimate conditions responsible for WAIS deglaciation. The education and training of students (both undergraduate and graduate students) will play an important role in the project, which will involve Antarctic fieldwork, technically challenging labwork, data collection and interpretation, and communication of the outcome to scientists and the general public.
1043649/Braun This award supports a project to determine the current mass balance of selected glaciers of the Western Antarctic Peninsula (WAP) and adjacent islands, including King George Island and Livingston Island. A major goal is to discriminate the climatic and dynamic components of the current mass budget. The dynamic component will be assessed using a flux gate approach. Glacier velocity fields will be derived by offset tracking on repeat SAR satellite imagery, and ice thicknesses across grounding lines or near terminus will be approximated from a new methods based on mass continuity. The surface mass balance will be computed from a spatially distributed temperature-index mass-balance model forced by temperature and precipitation data from regional climate models. Our results will provide improved mass budget estimates of Western Antarctic Peninsula glaciers and a more thorough understanding of the ratio between the climatic and dynamic components. The techniques to be developed will be applicable to other glaciers in the region allowing regional scale mass budgets to be derived. The broader impacts of this work are that glacier wastage is currently the most important contributor to global sea level rise and the Antarctic Peninsula has been identified as one of the largest single contributors. Future sea-level rise has major societal, economic and ecological implications. The activity will foster new partnerships through collaboration with European and South American colleagues. The project will form the base of of a postdoctoral research fellowship. It will also provide training of undergraduate and graduate students through inclusion of data and results in course curriculums.
1043500/Sowers This award supports a project to develop a 50 yr resolution methane data set that will play a pivotal role in developing the WAIS Divide timescale as well as providing a common stratigraphic framework for comparing climate records from Greenland and West Antarctica. Even higher resolution data are proposed for key intervals to assist in precisely defining the phasing of abrupt climate change between the hemispheres. Concurrent analysis of a suit of samples from both the WAIS Divide and GISP-2 cores throughout the last 110,000 years is also proposed, to establish the interpolar methan (CH4) gradient that will be used to identify geographic areas responsible for the climate related methane emission changes. The intellectual merit of the proposed work is that it will provide chronological control needed to examine the timing of changes in climate proxies, and critical chronological ties to the Greenland ice core records via methane variations. One main objective is to understand the interpolar timing of millennial-scale climate change. This is an important scientific goal relevant to understanding climate change mechanisms in general. The proposed work will help establish a chronological framework for addressing these issues. In addition, this proposal addresses the question of what methane sources were active during the ice age, through the work on the interpolar methane gradient. This work is directed at the fundamental question of what part of the biosphere controlled past methane variations, and is important for developing more sophisticated understanding of those variations. The broader impacts of the work are that the ultra-high resolution CH4 record will directly benefit all ice core paleoclimate research and the chronological refinements will impact paleoclimate studies that rely on ice core timescales for correlation purposes. The project will support both graduate and undergraduate students and the PIs will participate in outreach to the public.
Pettit/0948247<br/><br/>This award supports a project to study of the relationship between fabric and climate for the ice near the EPICA Dome C ice core site, East Antarctica. The work builds on an ongoing study at Siple Dome, West Antarctica and takes advantage of collaborations with European scientists and access to the Dome C borehole to make measurements of sonic velocity. The intellectual merit of the project is that a better understanding of how fabric preserves past climate information can improve models of the ice flow near ice core sites and the interpreta-tion of ice core data (particularly paleo-accumulation), and it may allow us to extract climate information directly from fabric data. In addition, because ice deformation is sensitive to the orientation of crystals, ice flow patterns are sensitive to the fabric. Thus, variations in the fabric between glacial and interglacial ice can affect how ice deforms and how fabric in the ice sheet develops. The Dome C site is particularly important for answering these questions, because the ice core shows evidence of eight glacial cycles, not just one as found at Siple Dome or the Greenland sites. The research will improve the understanding of the proxy relationship between sonic-velocity data and fabric; will help to model the pattern of ice flow caused by the fabric variation between glacial and interglacial time periods using these data, existing ice core chemistry and existing and new thin section data, improved surface strain data, and borehole deformation data; and will help to better understand the positive feedback mechanism that enhances fabric (and corresponding rheological) variability through a focused study of several climate transitions and the associated fabric changes. Borehole compressional-wave sonic-velocity will be measured which will complement the sonic-velocity data that already exist for boreholes in Greenland and West Antarctica. These will be the first sonic-velocity measurements in East Antarctica and the first measurements that extend for more than a single glacial/interglacial transition. The project will ultimately contribute to better interpretation of ice core records for both paleoclimate studies and for ice flow history, both of which connect to the broader questions of the role of ice in the climate system. This project will also strengthen the international collaborations within the paleoclimate and ice sheet modeling communities. This project will partially support a graduate student at the University of Alaska Fairbanks who is currently working on modeling ice including anisotropy and it will support the growth of a young scientist through a Post-Doc position. This Post Doc will gain important experience collaborating with the EPICA scientists in studying the climate-fabric relationship. Erin Pettit is active in field-science education for high school students, under-graduates, teachers, and adults. This project will help support the continued development and enhancement of Girls on Ice a program that encourages young women to explore science and the natural world.
Intellectual Merit: The PIs propose to use airborne geophysics to provide detailed geophysical mapping over the Marie Byrd Land dome of West Antarctica. They will use a Basler equipped with advanced ice penetrating radar, a magnetometer, an airborne gravimeter and laser altimeter. They will test models of Marie Byrd Land lithospheric evolution in three ways: 1) constrain bedrock topography and crustal structure of central Marie Byrd Land for the first time; 2) map subglacial geomorphology of Marie Byrd Land to constrain landscape evolution; and 3) map the distribution of subglacial volcanic centers and identify active sources. Marie Byrd Land is one of the few parts of West Antarctica whose bedrock lies above sea level; as such, it has a key role to play in the formation and decay of the West Antarctic Ice Sheet (WAIS), and thus on eustatic sea level change during the Neogene. Several lines of evidence suggest that the topography of Marie Byrd Land has changed over the course of the Cenozoic, with significant implications for the origin and evolution of the ice sheet. Broader impacts: This work will have important implications for both the cryospheric and geodynamic communities. These data will also leverage results from the POLENET project. The PIs will train both graduate and undergraduate students in the interpretation of large geophysical datasets providing them with the opportunity to co-author peer-reviewed papers and present their work to the broader science community. This research will also support a young female researcher. The PIs will conduct informal education using their Polar Studies website and contribute formally to K-12 curriculum development. The research will incorporate microblogging and data access to allow the project?s first-order hypothesis to be confirmed or denied in public.
Intellectual Merit: Knowledge of englacial and subglacial conditions are critical for ice sheet models and predictions of sea-level change. Some of the critical variables that are poorly known but essential for improving flow models and predictions of sea-level change are: basal roughness, subglacial sedimentary and hydrologic conditions, and the temporal and spatial variability of the ice sheet flow field. Seismic reflection and refraction imaging and dense arrays of continuously operating GPS receivers can determine these parameters. The PIs propose to develop a network of wirelessly interconnected geophysical sensors (geoPebble) that will allow glaciologists to carry out these experiments simultaneously. This sensor web will provide a new way of imaging the ice sheet that is not possible with current instruments. With this sensor web, the PIs will extend the range of existing instruments from 2D to 3D, from low resolution to high resolution, but more importantly, all the geophysical measurements will be conducted synchronously. By the end of the proposal period the PIs will produce a network of 150-200 geoPebbles that will be available for NSF-sponsored glaciology research projects. Broader impacts: Improved knowledge of the flow law of ice, the sliding of glaciers and ice streams, and paleoclimate history will contribute to assessments of the potential for abrupt ice-sheet mass change, with consequent sea-level effects and significant societal impacts. This improved modeling ability will be a direct consequence of better knowledge of the physical properties of ice sheets, which this project will facilitate. The development effort will be integrated with the undergraduate education program via the capstone design classes in EE and the senior thesis requirement in Geoscience. The PIs will also form a cohort of first-year and sophomore students who will work in their labs from the beginning of the project to develop specifications through the commissioning of the network.
This award supports a project to broaden the knowledge of annual accumulation patterns over the West Antarctic Ice Sheet by processing existing near-surface radar data taken on the US ITASE traverse in 2000 and by gathering and validating new ultra/super-high-frequency (UHF) radar images of near surface layers (to depths of ~15 m), expanding abilities to monitor recent annual accumulation patterns from point source ice cores to radar lines. Shallow (15 m) ice cores will be collected in conjunction with UHF radar images to confirm that radar echoed returns correspond with annual layers, and/or sub-annual density changes in the near-surface snow, as determined from ice core stable isotopes. This project will additionally improve accumulation monitoring from space-borne instruments by comparing the spatial-radar-derived-annual accumulation time series to the passive microwave time series dating back over 3 decades and covering most of Antarctica. The intellectual merit of this project is that mapping the spatial and temporal variations in accumulation rates over the Antarctic ice sheet is essential for understanding ice sheet responses to climate forcing. Antarctic precipitation rate is projected to increase up to 20% in the coming century from the predicted warming. Accumulation is a key component for determining ice sheet mass balance and, hence, sea level rise, yet our ability to measure annual accumulation variability over the past 5 decades (satellite era) is mostly limited to point-source ice cores. Developing a radar and ice core derived annual accumulation dataset will provide validation data for space-born remote sensing algorithms, climate models and, additionally, establish accumulation trends. The broader impacts of the project are that it will advance discovery and understanding within the climatology, glaciology and remote sensing communities by verifying the use of UHF radars to monitor annual layers as determined by visual, chemical and isotopic analysis from corresponding shallow ice cores and will provide a dataset of annual to near-annual accumulation measurements over the past ~5 decades across WAIS divide from existing radar data and proposed radar data. By determining if temporal changes in the passive microwave signal are correlated with temporal changes in accumulation will help assess the utility of passive microwave remote sensing to monitor accumulation rates over ice sheets for future decades. The project will promote teaching, training and learning, and increase representation of underrepresented groups by becoming involved in the NASA History of Winter project and Thermochron Mission and by providing K-12 teachers with training to monitor snow accumulation and temperature here in the US, linking polar research to the student?s backyard. The project will train both undergraduate and graduate students in polar research and will encouraging young investigators to become involved in careers in science. In particular, two REU students will participate in original research projects as part of this larger project, from development of a hypothesis to presentation and publication of the results. The support of a new, young woman scientist will help to increase gender diversity in polar research.
This award supports a detailed, molecular level characterization of dissolved organic carbon and microbes in Antarctic ice cores. Using the most modern biological (genomic), geochemical techniques, and advanced chemical instrumentation researchers will 1) optimize protocols for collecting, extracting and amplifying DNA from deep ice cores suitable for use in next generation pyrosequencing; 2) determine the microbial diversity within the ice core; and 3) obtain and analyze detailed molecular characterizations of the carbon in the ice by ultrahigh resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS). With this pilot study investigators will be able to quantify the amount of material (microbial biomass and carbon) required to perform these characterizations, which is needed to inform future ice coring projects. The ultimate goal will be to develop protocols that maximize the yield, while minimizing the amount of ice required. The broader impacts include education and outreach at both the local and national levels. As a faculty mentor with the American Indian Research Opportunities and BRIDGES programs at Montana State University, Foreman will serve as a mentor to a Native American student in the lab during the summer months. Susan Kelly is an Education and Outreach Coordinator with a MS degree in Geology and over 10 years of experience in science outreach. She will coordinate efforts for comprehensive educational collaboration with the Hardin School District on the Crow Indian Reservation in South-central Montana.
1142010/Talghader This award supports a project to combine the expertise of both glaciologists and optical engineers to develop polarization- preserving optical scattering techniques for borehole tools to identify changes in high-resolution crystal structure (fabric) and dust content of glacial ice. The intellectual merit of this work is that the fabric and impurity content of the ice contain details on climate, volcanic activity and ice flow history. Such fabric measurements are currently taken by slicing an ice core into sections after it has started to depressurize which is an extremely time-intensive process that damages the core and does not always preserve the properties of ice in its in-situ state. In addition the ice core usually must be consumed in order to measure the components of the dust. The fabric measurements of this study utilize the concept that singly-scattered light in ice preserves most of its polarization when it is backscattered once from bubbles or dust; therefore, changes to the polarization of singly-backscattered light must originate with the birefringence. Measurements based on this concept will enable this program to obtain continuous records of fabric and correlate them to chronology and dust content. The project will also develop advanced borehole instruments to replace current logging tools, which require optical sources, detectors and power cables to be submerged in borehole fluid and lowered into the ice sheet at temperatures of -50oC. The use of telecommunications fiber will allow all sources and detectors to remain at the surface and enable low-noise signal processing techniques such as lock-in amplification that increase signal integrity and reduce needed power. Further, fiber logging systems would be much smaller and more flexible than current tools and capable of navigating most boreholes without a heavy winch. In order to assess fabric in situ and test fiber-optic borehole tools, field measurements will be made at WAIS Divide and a deep log will also be made at Siple Dome, both in West Antarctica. If successful, the broader impacts of the proposed research would include the development of new analytical methods and lightweight logging tools for ice drilling research that can operate in boreholes drilled in ice. Eventually the work could result in the development of better prehistoric records of glacier flow, atmospheric particulates, precipitation, and climate forcing. The project encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training graduate students and advanced undergraduates. Collaboration with schools and classroom teachers will help bring aspects of optics, climate, and polar science to an existing Middle School curriculum.
Aydin/1043780 This award supports the analysis of the trace gas carbonyl sulfide (COS) in a deep ice core from West Antarctic Ice Sheet Divide (WAIS-D), Antarctica. COS is the most abundant sulfur gas in the troposphere and a precursor of stratospheric sulfate. It has a large terrestrial COS sink that is tightly coupled to the photosynthetic uptake of atmospheric carbon dioxide (CO2). The primary goal of this project is to develop high a resolution Holocene record of COS from the WAIS-D 06A ice core. The main objectives are 1) to assess the natural variability of COS and the extent to which its atmospheric variability was influenced by climate variability, and 2) to examine the relationship between changes in atmospheric COS and CO2. This project also includes low-resolution sampling and analysis of COS from 10,000-30,000 yrs BP, covering the transition from the Last Glacial Maximum into the early Holocene. The goal of this work is to assess the stability of COS in ice core air over long time scales and to establish the COS levels during the last glacial maximum and the magnitude of the change between glacial and interglacial conditions. The results of this work will be disseminated via peer-review publications and will contribute to environmental assessments such as the WMO Stratospheric Ozone Assessment and IPCC Climate Assessment. This project will support a PhD student and undergraduate researcher in the Department of Earth System Science at the University of California, Irvine, and will create summer research opportunities for undergraduates from non-research active Universities.
1042883/Mayewski This award supports a project to analyze a deep ice core which will be drilled by a New Zealand research team at Roosevelt Island. The objectives are to process the ice core at very high resolution to (a) better understand phasing sequences in Arctic/Antarctic abrupt climate change, even at the level of individual storm events; (b) determine the impact of changes in the Westerlies and the Amundsen Sea Low on past/present/future climate change; (c) determine how sea ice extent has varied in the area; (d) compare the response of West Antarctica climate to other regions during glacial/interglacial cycles; and (e) determine how climate of the Ross Sea Embayment changed during the transition from Ross Ice Sheet to Ross Ice Shelf. The intellectual merit of the RICE deep ice core project is that it is expected to provide a 30kyr long (and possibly 150kyr long) extremely high-resolution view of climate change in the Ross Sea Embayment Region and data essential to test and understand critical questions that have emerged as a consequence of the recent synthesis of Antarctic and Southern Ocean climate change presented in the Scientific Commission for Antarctic Research document: Antarctic Climate Change and the Environment (ACCE, 2009). Ice core processing and analysis will be performed jointly by University of Maine and the collaborators from New Zealand. Co-registered sampling for all chemical analyses will be accomplished by a joint laboratory effort at the IGNS NZ ice core facility using a continuous melter system developed by the University of Maine. The RICE deep ice core record will provide information necessary in unraveling the significance of multi-millennial underpinning for climate change and in the understanding of observed and projected climate change in light of current dramatic human impact on Antarctica and the Southern Ocean. The broader impacts of the project include the fact that two CCI graduate students will be funded through the project, and will be involved in all aspects of field research, core sampling, sample processing, analytical and numerical analyses, data interpretation, writing of manuscripts, and presentation of results at national and international conferences. Data and ideas developed in this project and associated work will be used in several courses taught at the University of Maine. Innovative cyberinfrastructure will be incorporated into this work and ground breaking analytical technologies, and data access/storage tools will be used.
Intellectual Merit: The PIs propose a two-year project to map the distribution of climate-sensitive landforms throughout Northern Victoria Land between the Convoy Range and Cape Adare. This work will produce geospatial products to aid their geomorphic work on ice sheet stability and landscape evolution. Specifically, the PI will investigate the potential for extensive surface melting and ice-sheet retreat with modest warming in areas north of the Convoy Range in Northern Victoria Land. The hypothesis is that if key landform elements of the Dry Valleys assemblage are lacking in NVL it suggests a major variation in current climate conditions, and perhaps changes in climate evolution. The proposed work will also benefit the broader research community, as it will demonstrate the potential for using geospatial imagery in geomorphic research and produce geospatial products that can be used by other researchers. Broader impacts: This work will help the research community better leverage the investment being made in the Polar Geospatial Center (PGC) and will help further demonstrate the significance of satellite imagery for doing ?virtual? field work in the Polar regions. More effective use of satellite imagery by field scientists in Antarctica will help reduce the logistical footprint on the Continent. The proposed research will support one graduate student at Boston University who will be trained in image analysis, map production, Antarctic geomorphology, and geospatial technologies. The proposed work will help to forge stronger links between PGC and Boston University?s Digital Image Analyses Lab (DIAL).
The Office of Polar Programs, Antarctic Science Division, Ocean & Climate Systems Program has made this award to support a multidisciplinary effort to study the upwelling of relatively warm deep water onto the Amundsen Sea continental shelf and how it relates to atmospheric forcing and bottom bathymetry and how the warm waters interact with both glacial and sea ice. This study constitutes a contribution of a coordinated research effort in the region known as the Amundsen Sea Embayment Project or ASEP. Previous work by the PI and others has shown that the West Antarctic Ice Sheet has been found to be melting faster, perhaps by orders of magnitude, than ice sheets elsewhere around Antarctica, excluding those on the Peninsula. Submarine channels that incise the continental shelf are thought to provide fairly direct access of relatively warm circum polar deep water to the cavity under the floating extension of the ice shelf. Interactions with sea ice en route can modify the upwelled waters. The proposed investigations build on previous efforts by the PI and colleagues to use hydrographic measurements to put quantitative bounds on the rate of glacial ice melt by relatively warm seawater. <br/>The region can be quite difficult to access due to sea ice conditions and previous hydrographic measurements have been restricted to the austral summer time frame. In this project it was proposed to obtain the first austral spring hydrographic data via CTD casts and XBT drops (September-October 2007) as part of a separately funded cruise (PI Steve Ackley) the primary focus of which is sea-ice conditions to be studied while the RV Nathanial B Palmer (RV NBP) drifts in the ice pack. This includes opportunistic sampling for pCO2 and TCO2. A dedicated cruise in austral summer 2009 will follow this opportunity. The principal objectives of the dedicated field program are to deploy a set of moorings with which to characterize temporal variability in warm water intrusions onto the shelf and to conduct repeat hydrographic surveying and swath mapping in targeted areas, ice conditions permitting. Automatic weather stations are to be deployed in concert with the program, sea-ice observations will be undertaken from the vessel and the marine cavity beneath the Pine Island may be explored pending availability of the British autonomous underwater vehicle Autosub 3. These combined ocean-sea ice-atmosphere observations are aimed at a range of model validations. A well-defined plan for making data available as well as archiving in a timely fashion should facilitate a variety of modeling efforts and so extend the value of the spatially limited observations. <br/>Broader impacts: This project is relevant to an International Polar Year research emphasis on ice sheet dynamics focusing in particular on the seaward ocean-ice sheet interactions. Such interactions must be clarified for understanding the potential for sea level rise by melt of the West Antarctic ice Sheet. The project entails substantive international partnerships (British Antarctic Survey and Alfred Wegner Institute) and complements other Amundsen Sea Embayment Project proposals covering other elements of ice sheet dynamics. The proposal includes partial support for 2 graduate students and 2 post docs. Participants from the Antarctic Artists and Writers program are to take part in the cruise and so aid in outreach. In addition, the project is to be represented in the Lamont-Doherty annual open house.
1043421/Severinghaus This award supports a project to obtain samples of ice in selected intervals for replication and verification of the validity and spatial representativeness of key results in the WAIS Divide ice core, and to obtain additional ice samples in areas of intense scientific interest where demand is high. The US Ice Core Working Group recommended in 2003 that NSF pursue the means to take replicate samples, termed "replicate coring". This recommendation was part of an agreement to reduce the diameter of the (then) new drilling system (the DISC drill) core to 12.2 cm to lighten logistics burdens, and the science community accepted the reduction in ice sample with the understanding that replicate coring would be able to provide extra sample volume in key intervals. The WAIS Divide effort would particularly benefit from replicate coring, because of the unique quality of the expected gas record and the large samples needed for gases and gas isotopes; thus this proposal to employ replicate coring at WAIS Divide. In addition, scientific demand for ice samples has been, and will continue to be, very unevenly distributed, with the ice core archive being completely depleted in depth intervals of high scientific interest (abrupt climate changes, volcanic sulfate horizons, meteor impact horizons, for example). The broader impacts of the proposed research may include identification of leads and lags between Greenland, tropical, and Antarctic climate change, enabling critical tests of hypotheses for the mechanism of abrupt climate change. Improved understanding of volcanic impacts on atmospheric chemistry and climate may also emerge. This understanding may ultimately help improve climate models and prediction of the Earth System feedback response to ongoing human perturbation in coming centuries. Outreach and public education about climate change are integral components of the PIs' activities and the proposed work will enhance these efforts. Broader impacts also include education and training of 2 postdoctoral scholars and 1 graduate student, and invaluable field experience for the graduate and undergraduate students who will likely make up the core processing team at WAIS Divide.
1143619/Severinghaus This award supports a project to extend the study of gases in ice cores to those gases whose small molecular diameters cause them to escape rapidly from ice samples (the so-called "fugitive gases"). The work will employ helium, neon, argon, and oxygen measurements in the WAIS Divide ice core to better understand the mechanism of the gas close-off fractionation that occurs while air bubbles are incorporated into ice. The intellectual merit of the proposed work is that corrections for this fractionation using neon (which is constant in the atmosphere) may ultimately enable the first ice core-based atmospheric oxygen and helium records. Neon may also illuminate the mechanistic link between local insolation and oxygen used for astronomical dating of ice cores. Helium measure-ments in the deepest ~100 m of the core will also shed light on the stratigraphic integrity of the basal ice, and serve as a probe of solid earth-ice interaction at the base of the West Antarctic ice sheet. Past atmospheric oxygen records, currently unavailable prior to 1989 CE, would reveal changes in the size of the terrestrial biosphere carbon pool that accompany climate variations and place constraints on the biogeochemical feedback response to future warming. An atmospheric helium-3/helium-4 record would test the hypothesis that the solar wind (which is highly enriched in helium-3) condensed directly into Earth?s atmosphere during the collapse of the geomagnetic field that occurred 41,000 years ago, known as the Laschamp Event. Fugitive-gas samples will be taken on-site immediately after recovery of the ice core by the PI and one postdoctoral scholar, under the umbrella of an existing project to support replicate coring and borehole deepening. This work will add value to the scientific return from field work activity with little additional cost to logistical resources. The broader impacts of the work on atmospheric oxygen are that it may increase understanding of how terrestrial carbon pools and atmospheric greenhouse gas sources will respond in a feedback sense to the coming warming. Long-term atmospheric oxygen trends are also of interest for understanding biogeochemical regulatory mechanisms and the impact of atmospheric evolution on life. Helium records have value in understanding the budget of this non-renewable gas and its implications for space weather and solar activity. The project will train one graduate student and one postdoctoral scholar. The fascination of linking solid earth, cryosphere, atmosphere, and space weather will help to entrain and excite young scientists and efforts to understand the Earth as a whole interlinked system will provide fuel to outreach efforts at all ages.
1245659/Petrenko This award supports a project to use the Taylor Glacier, Antarctica, ablation zone to collect ice samples for a range of paleoenvironmental studies. A record of carbon-14 of atmospheric methane (14CH4) will be obtained for the last deglaciation and the Early Holocene, together with a supporting record of CH4 stable isotopes. In-situ cosmogenic 14C content and partitioning of 14C between different species (14CH4, C-14 carbon monoxide (14CO) and C-14 carbon dioxide (14CO2)) will be determined with unprecedented precision in ice from the surface down to ~67 m. Further age-mapping of the ablating ice stratigraphy will take place using a combination of CH4, CO2, δ18O of oxygen gas and H2O stable isotopes. High precision, high-resolution records of CO2, δ13C of CO2, nitrous oxide (N2O) and N2O isotopes will be obtained for the last deglaciation and intervals during the last glacial period. The potential of 14CO2 and Krypton-81 (81Kr) as absolute dating tools for glacial ice will be investigated. The intellectual merit of proposed work includes the fact that the response of natural methane sources to continuing global warming is uncertain, and available evidence is insufficient to rule out the possibility of catastrophic releases from large 14C-depleted reservoirs such as CH4 clathrates and permafrost. The proposed paleoatmospheric 14CH4 record will improve our understanding of the possible magnitude and timing of CH4 release from these reservoirs during a large climatic warming. A thorough understanding of in-situ cosmogenic 14C in glacial ice (production rates by different mechanisms and partitioning between species) is currently lacking. Such an understanding will likely enable the use of in-situ 14CO in ice at accumulation sites as a reliable, uncomplicated tracer of the past cosmic ray flux and possibly past solar activity, as well as the use of 14CO2 at both ice accumulation and ice ablation sites as an absolute dating tool. Significant gaps remain in our understanding of the natural carbon cycle, as well as in its responses to global climate change. The proposed high-resolution, high-precision records of δ13C of CO2 would provide new information on carbon cycle changes both during times of rising CO2 in a warming climate and falling CO2 in a cooling climate. N2O is an important greenhouse gas that increased by ~30% during the last deglaciation. The causes of this increase are still largely uncertain, and the proposed high-precision record of N2O concentration and isotopes would provide further insights into N2O source changes in a warming world. The broader impacts of proposed work include an improvement in our understanding of the response of these greenhouse gas budgets to global warming and inform societally important model projections of future climate change. The continued age-mapping of Taylor Glacier ablation ice will add value to this high-quality, easily accessible archive of natural environmental variability. Establishing 14CO as a robust new tracer for past cosmic ray flux would inform paleoclimate studies and constitute a valuable contribution to the study of the societally important issue of climate change. The proposed work will contribute to the development of new laboratory and field analytical systems. The data from the study will be made available to the scientific community and the broad public through the NSIDC and NOAA Paleoclimatology data centers. 1 graduate student each will be trained at UR, OSU and SIO, and the work will contribute to the training of a postdoc at OSU. 3 UR undergraduates will be involved in fieldwork and research. The work will support a new, junior UR faculty member, Petrenko. All PIs have a strong history of and commitment to scientific outreach in the forms of media interviews, participation in filming of field projects, as well as speaking to schools and the public about their research, and will continue these activities as part of the proposed work. This award has field work in Antarctica.
Abstract Researchers will explore the use of a distributed temperature sensing monitoring system (DTS), using fiber-optical (FO) technology, as the basis of a sustainable, sub-ice cavity sensing array. FO cable systems, such as may be deployed through a hot-water drilled hole through an ice shelf, passing through the underlying cavity to the sea floor, are capable of measuring temperatures down fiber at 1 meter intervals, and at time frequencies as high as 15 seconds. DTS FO systems operate via optical time domain reflectometry along the fiber waveguide using inelastic backscatter of coherent laser light as a probe beam in the FO environment. The introduction of new technologies to the harsh environmental conditions of the Antarctic are often associated with high risk. However, the potential rewards of this approach (e.g. multiyear capability, minimal submerged mechanical or electrical components that may fail, relative simplicity of deployment and measurement principle, yet yielding distributed real time and spatial observation) are attractive enough to conduct a pilot project at a field-ready location (McMurdo). Current indications are that the instability of some of the world's largest ice sheets located around the Antarctic and Greenland may be caused by the presence of warming, deep ocean waters, shoaling over continental shelves, and melting the underside of floating ice shelves. Additional knowledge of the temporal and spatial variability of the temperature fields underneath terminal ice shelves, such as those draining the West Antarctic Ice Sheet, are needed to accurately project future global climate effects on ice-shelf ocean interactions, and in order to inform societal and technological aspects of adaption to changing sea-level.
This award provides support for "EAGER: Handbook of Hot Water Drill System (HWDS) Design Considerations and Best Practices" from the Antarctic Integrated System Science within the Office of Polar Programs. More and more science projects are proposing to use hot-water drilling systems (HWDS) to rapidly and/or cleanly access glacial and subglacial systems. To date the hot-water drill systems have been developed in isolation, and no attempt has been made to gather information about the different systems in one place. This proposal requests funds to document existing HWDS, and to then assess the design, testing, and development of a hot-water drill system that will be integrated with the evolving over-ice traverse capability of the USAP program. Intellectual Merit: A working handbook of best practices for hot-water drill design systems, including safety considerations, is long overdue, and will 1) provide suggestions for optimizing current systems; 2) contribute in the very near term to already funded projects such as WISSARD (Whillans Ice Stream Subglacial Access and Research Drilling); and 3) fit the long-term needs of the Antarctic science community who have identified rapid and clean access to glacial and subglaical environments as a top priority for the next decades. The collected information will be used for community education and training, will discuss potential design and operational trade-offs, and will identify ways to optimize the capabilities of an integrated USAP traverse and HWDS infrastructure. EAGER funding for this project is warranted because such a handbook has not been tried before, and needs to be shown to be doable prior to larger investments in such compilations. It fits the AISS (Antarctic Integrated System Science) program as an optimized HWDS will meet the needs of many different Antarctic research disciplines including biology, geology, glaciology, and oceanography. Broader Impacts: The proposed work is being done on behalf of the Antarctic research community, and will seek to capture the knowledge of experienced hot-water drill engineers who are nearing retirement, and to educate the next generation of hot-water drillers and engineers. The PI indicates he will work with the owners of such systems both within the US and abroad. Identification of best practices in hot-water drilling will save several different Antarctic research communities significant time, effort, and funding in the future.
The stability of the marine West Antarctic Ice Sheet (WAIS) remains an important, unresolved problem for predicting future sea level change. Recent studies indicate that the mass balance of the ice sheet today may be negative or positive. The apparent differences may stem in part from short-term fluctuations in flow. By comparison, geologic observations provide evidence of behavior over much longer time scales. Recent work involving glacial-geologic mapping, dating and ice-penetrating radar surveys suggests that deglaciation of both the Ross Sea Embayment and coastal Marie Byrd Land continued into the late Holocene, and leaves open the possibility of ongoing deglaciation and grounding-line retreat. However, previous work in the Ross Sea Embayment was based on data from just three locations that are all far to the north of the present grounding line. Additional data from farther south in the Ross Sea Embayment are needed to investigate whether recession has ended, or if the rate and pattern of deglaciation inferred from our previous study still apply to the present grounding line. This award provides support to reconstruct the evolution of Reedy Glacier, in the southern Transantarctic Mountains, since the Last Glacial Maximum (LGM). Because Reedy Glacier emerges from the mountains above the grounding line, its surface slope and elevation should record changes in thickness of grounded ice in the Ross Sea up to the present day. The deglaciation chronology of Reedy Glacier therefore can indicate whether Holocene retreat of the WAIS ended thousands of years ago, or is still continuing at present. This integrated glaciologic, glacial-geologic, and cosmogenic-isotope exposure- dating project will reconstruct past levels of Reedy Glacier. Over two field seasons, moraines will be mapped, dated and correlated at sites along the length of the glacier. Radar and GPS measurements will be made to supplement existing ice thickness and velocity data, which are needed as input for a model of glacier dynamics. The model will be used to relate geologic measurements to the grounding-line position downstream. Ultimately, the mapping, dating and ice-modeling components of the study will be integrated into a reconstruction that defines changes in ice thickness in the southern Ross Sea since the LGM, and relates these changes to the history of grounding-line retreat. This work directly addresses key goals of the West Antarctic Ice Sheet Initiative, which are to understand the dynamics, recent history and possible future behavior of the West Antarctic Ice Sheet.
Intellectual Merit: The PIs propose to use the (U-Th)/He system in apatite to investigate the exhumation history, development of the present topography, and pattern of glacial erosion in the central Antarctic Peninsula. The Antarctic Peninsula has been glaciated since the Eocene and Pleistocene climate cooling is hypothesized to have suppressed, rather than enhanced, glacial erosion. To achieve these goals, the PIs will use a thermochronometric record of when and how the present glacial valley relief formed. A challenge to the proposed research is that, unlike Pleistocene glacial landscapes in temperate areas, the Peninsula is ice-covered and it is not possible to directly sample the bedrock surface. The PIs hope to learn about the timing and process of glacial valley formation through apatite (U-Th)/He and 4He/3He measurements on glacial sediment collected near the grounding lines of major glaciers draining the Peninsula. Learning how the Antarctic Peninsula landscape formed is important to discern how the mechanics of glacial erosion operate on long time scales, and to understand how glaciers mediate the interaction between climate change and orogenic mass balance. This work addresses a fundamental question in Antarctic earth science of how to infer geologic and geomorphic processes active on an ice-covered and inaccessible landscape. Broader impacts: This proposal will bring new researchers into the Antarctic research community. A proposed collaboration with British Antarctic Survey researchers will build an international collaboration. The outcomes of this project have ancillary importance to other fields and addresses fundamental challenges in Antarctic Earth Science.
This award supports a project to understand the flow dynamics of large, fast-moving outlet glaciers that drain the East Antarctic Ice Sheet. The project includes an integrated field, remote sensing and modeling study of Byrd Glacier which is a major pathway for the discharge of mass from the East Antarctic Ice Sheet (EAIS) to the ocean. Recent work has shown that the glacier can undergo short-lived but significant changes in flow speed in response to perturbations in its boundary conditions. Because outlet glacier speeds exert a major control on ice sheet mass balance and modulate the ice sheet contribution to sea level rise, it is essential that their sensitivity to a range of dynamic processes is properly understood and incorporated into prognostic ice sheet models. The intellectual merit of the project is that the results from this study will provide critically important information regarding the flow dynamics of large EAIS outlet glaciers. The proposed study is designed to address variations in glacier behavior on timescales of minutes to years. A dense network of global positioning satellite (GPS) instruments on the grounded trunk and floating portions of the glacier will provide continuous, high-resolution time series of horizontal and vertical motions over a 26-month period. These results will be placed in the context of a longer record of remote sensing observations covering a larger spatial extent, and the combined datasets will be used to constrain a numerical model of the glacier's flow dynamics. The broader impacts of the work are that this project will generate results which are likely to be a significant component of next-generation ice sheet models seeking to predict the evolution of the Antarctic Ice Sheet and future rates of sea level rise. The most recent report from the Intergovernmental Panel on Climate Change (IPCC) highlights the imperfect understanding of outlet glacier dynamics as a major obstacle to the production of an accurate sea level rise projections. This project will provide significant research opportunities for several early-career scientists, including the lead PI for this proposal (she is both a new investigator and a junior faculty member at a large research university) and two PhD-level graduate students. The students will be trained in glaciology, geodesy and numerical modeling, contributing to society's need for experts in those fields. In addition, this project will strengthen international collaboration between polar scientists and geodesists in the US and Spain. The research team will work closely with science educators in the Center for Remote Sensing of Ice Sheets (CReSIS) outreach program to disseminate project results to non-specialist audiences.
This project constructs POLENET a network of GPS and seismic stations in West Antarctica to understand how the mass of the West Antarctic ice sheet (WAIS) changes with time. The information is ultimately used to predict sea level rise accompanying global warming and interpret climate change records. The GPS (global positioning system) stations measure vertical and horizontal movements of bedrock, while the seismic stations characterize physical properties of the ice/rock interface, lithosphere, and mantle. Combined with satellite data, this project offers a more complete picture of the ice sheet's current state, its likely change in the near future, and its overall size during the last glacial maximum. This data will also be used to infer sub-ice sheet geology and the terrestrial heat flux, critical inputs to models of glacier movement. As well, this project improves tomographic models of the earth's deep interior and core through its location in the Earth's poorly instrumented southern hemisphere. <br/><br/><br/><br/>Broader impacts of this project are varied. The work is relevant to society for improving our understanding of the impacts of global warming on sea level rise. It also supports education at the postdoctoral, graduate, and undergraduate levels, and outreach to groups underrepresented in the sciences. As an International Polar Year contribution, this project establishes a legacy of infrastructure for polar measurements. It also involves an international collaboration of twenty four countries. For more information see IPY Project #185 at IPY.org. NSF is supporting a complementary Arctic POLENET array being constructed in Greenland under NSF Award #0632320.
Collaborative With: McPhee 0732804, Holland 0732869, Truffer 0732730, Stanton 0732926, Anandakrishnan 0732844 <br/>Title: Collaborative Research: IPY: Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica<br/><br/>The Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. <br/><br/>Broader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the "Multidisciplinary Study of the Amundsen Sea Embayment" proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded "Polar Palooza" education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project.
This award supports a project to generate an absolute timescale for the Allan Hills Blue Ice Area (BIA), and then to reconstruct details of past climate changes and greenhouse gas concentrations for certain time periods back to 2.5 Ma. Ice ages will be determined by applying emerging methods for absolute and relative dating of trapped air bubbles (based on Argon-40/Argon-38, delta-18O of O2, and the O2/N2 ratio). To demonstrate the potential of the Allan Hills BIAs as a paleoclimate archive trenches and ice cores will be collected for age intervals corresponding to 110-140 ka, 1 Ma, and 2.5 Ma. During the proposed two field seasons a total of 6x100 m and additional 15 m cores will be combined with trenching. The intellectual merit of the proposed activity is that the results of this work will extend the landmark work of EPICA and other deep ice coring efforts, which give records dating back to 0.8 Ma, and will complement work planned by IPICS to drill a continuous Antarctic ice core extending to 1.5 Ma. The results will help to advance understanding of major climate regimes and transitions that took place between 0-2.5 Ma, including the 40 kyr world and the mid-Pleistocene climate transition. A major long-term scientific goal is to provide a transformative approach to the collection of paleoclimate records by establishing an "International Climate Park" in the Allan Hills BIA that would enable sampling of large quantities of known age ice as old as 2.5 Ma, by any interested American or foreign investigator. The broader impacts resulting from the proposed activity include training students who are well versed in advanced field, laboratory and numerical modeling methods combining geochemistry, glaciology, and paleoclimatology. We will include material relevant to our proposed research in our ongoing efforts in local education and in our outreach efforts for media. The University of Maine already has cyberinfrastructure, using state of the art web-based technology, which can provide a wide community of scientists with fast access to the results of our research. The work will contribute to the broad array of climate change studies that is informing worldwide understanding of natural and anthropogenic forced climate change, and the options for responding. This award has field work in Antarctica.
This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.
Barbeau, David; Hemming, Sidney R.; Barbeau, David Jr
No dataset link provided
Intellectual Merit: Recent geochemical, sequence stratigraphic, and integrated investigations of marine strata from several continental margins and ocean basins suggest that ephemeral ice sheets may have existed on Antarctica during parts of the Cretaceous and early Paleogene. However, atmospheric carbon dioxide estimates for this time are as much as four times modern levels. With such greenhouse conditions, the presence of Antarctic ice sheets would imply that our current understanding of Earth?s climate system, and specifically the interpreted thresholds of Antarctic glaciation and deglaciation should be reconsidered. The proposed research will compare the quantity and provenance of Cretaceous sediments in the Larsen basin of the eastern Antarctic Peninsula with the exhumation chronology and composition of potential sediment source terranes on the peninsula and in adjacent regions. New outcrop stratigraphic analyses with improvements in the age models from radioisotopic approaches will be integrated to determine the amount of detrital sediment fluxed to the Larsen basin between key chronostratigraphic surfaces. Microtextural analysis of quartz sand and silt grains will help determine whether the Larsen basin detrital sediment originated from glacial weathering. These preliminary results will test the viability of the proposed approach to assess the controversial Cretaceous Antarctic glaciation hypothesis. Broader impacts: The proposed work will partially support a PhD, a MSc, and three undergraduate students at the University of South Carolina. The PIs will publicize this work through volunteer speaking engagements and the development of videos and podcasts. They also commit to prompt publication of the results and timely submission of data to archives. The development/improvement of the Larsen basin age model will benefit ongoing research in paleobiology, paleoclimate and biogeography. Development of the glauconite K-Ar and Rb-Sr chronometers could be an important outcome beyond the direct scope of the proposed research.
Dissolved organic matter (DOM) comprises a significant pool of Earth's organic carbon that dwarfs the amount present in living aquatic organisms. The properties and reactivity of DOM are not well defined, and the evolution of autochthonous DOM from its precursor materials in freshwater has not been observed. Recent sampling of a supraglacial stream formed on the Cotton Glacier in the Transantarctic Mountains revealed DOM that more closely resembles an assemblage of recognizable precursor organic compounds, based upon its UV-VIS and fluorescence spectra. It is suggested that the DOM from this water evolved over time to resemble materials present in marine and many inland surface waters. The transient nature of the system i.e., it reforms seasonally, also prevents any accumulation of the refractory DOM present in most surface waters. Thus, the Cotton Glacier provides us with a unique environment to study the formation of DOM from precursor materials. An interdisciplinary team will study the biogeochemistry of this progenitor DOM and how microbes modify it. By focusing on the chemical composition of the DOM as it shifts from precursor material to the more humified fractions, the investigators will relate this transition to bioavailability, enzymatic activity, community composition and microbial growth efficiency. This project will support education at all levels, K-12, high school, undergraduate, graduate and post-doc and will increase participation by under-represented groups in science. Towards these goals, the investigators have established relationships with girls' schools and Native American programs. Additional outreach will be carried out in coordination with PolarTREC, PolarPalooza, and if possible, an Antarctic Artist and Writer.
0944199/Matsuoka<br/><br/>This award supports a project to test the hypothesis that abrupt changes in fabric exist and are associated with both climate transitions and volcanic eruptions. It requires depth-continuous measurements of the fabric. By lowering a new logging tool into the WAIS Divide borehole after the completion of the core drilling, this project will measure acoustic-wave speeds as a function of depth and interpret it in terms of ice fabrics. This interpretation will be guided by ice-core-measured fabrics at sparse depths. This project will apply established analytical techniques for the ice-sheet logging and estimate depth profiles of both compressional- and shear-wave speeds at short intervals (~ 1 m). Previous logging projects measured only compressional-wave speeds averaged over typically 5-7 m intervals. Thus the new logger will enable more precise fabric interpretations. Fabric measurements using thin sections have revealed distinct fabric patterns separated by less than several meters; fabric measurements over a shorter period are crucial. At the WAIS Divide borehole, six two-way logging runs will be made with different observational parameters so that multiple wave-propagation modes will be identified, yielding estimates of both compressional- and shear-wave speeds. Each run takes approximately 24 hours to complete; we propose to occupy the boreholes in total eight days. The logging at WAIS Divide is temporarily planned in December 2011, but the timing is not critical. This project?s scope is limited to the completion of the logging and fabric interpretations. Results will be immediately shared with other WAIS Divide researchers. Direct benefits of this data sharing include guiding further thin-section analysis of the fabric, deriving a precise thinning function that retrieves more accurate accumulation history and depth-age scales. The PIs of this project have conducted radar and seismic surveys in this area and this project will provide a ground truth for these regional remote-sensing assessments of the ice interior. In turn, these remote sensing means can extend the results from the borehole to larger parts of the central West Antarctica. This project supports education for two graduate students for geophysics, glaciology, paleoclimate, and polar logistics. The instrument that will be acquired in this project can be used at other boreholes for ice-fabric characterizations and for englacial hydrology (wetness of temperate ice).
Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.
Intellectual Merit: Neogene sediment records recovered by ANDRILL suggest multiple events of open water conditions and elevated sea surface temperatures at times when terrestrial data from the McMurdo Dry Valleys indicate hyper arid, cold, desert conditions. Interpretation of the ANDRILL data suggests the West Antarctic Ice Sheet is highly sensitive to changes in Pliocene sea surface temperatures and this conclusion has been supported by recent Global Circulation Model results for the early to mid Pliocene. The PIs propose to model paleo-ice configurations and warm orbits associated with a WAIS collapse to assess potential climate change in East Antarctica. During such episodes of polar warmth they propose to answer: What is the limit of ablation along the East Antarctic Ice Sheet?; Are relict landforms in the Dry Valleys susceptible to modification from increase in maximum summertime temperatures?; and Is there sufficient increase in minimum wintertime temperatures to sustain a tundra environment in the Dry Valleys? Integration of depositional records and model outputs have the potential to test the performance of numerical models currently under development as part of ANDRILL; reconcile inconsistencies between marine and terrestrial paleoclimate records in high Southern Latitudes; and improve understanding of Antarctic climate and ice volume sensitivity to forcing for both the East Antarctic and West Antarctic Ice Sheets. Broader impacts: Results from this study have the potential to be used widely by the research community. Outreach to local elementary schools from other funded efforts will continue and be extended to homeschooled students. A Post Doc will be supported as part of this award.
This award supports a project to investigate the transformations from snow to firn to ice and the underlying physics controlling firn's ability to store atmospheric samples from the past. Senior researchers, a graduate student, and several undergraduates will make high-resolution measurements of both the diffusivity and permeability profiles of firn cores from several sites in Antarctica and correlate the results with their microstructures quantified using advanced materials characterization techniques (scanning electron microscopy and x-ray computed tomography). The use of cores from different sites will enable us to examine the influence of different local climate conditions on the firn structure. We will use the results to help interpret existing measurements of firn air chemical composition at several sites where firn air measurements exist. There are three closely-linked goals of this project: to quantify the dependence of interstitial transport properties on firn microstructure from the surface down to the pore close-off depth, to determine at what depths bubbles form and entrap air, and investigate the extent to which these features exhibit site-to-site differences, and to use the measurements of firn air composition and firn structure to better quantify the differences between atmospheric composition (present and past), and the air trapped in both the firn and in air bubbles within ice by comparing the results of the proposed work with firn air measurements that have been made at the WAIS Divide and Megadunes sites. The broader impacts of this project are that the study will this study will enable us to elucidate the fundamental controls on the metamorphism of firn microstructure and its impact on processes of gas entrapment that are important to understanding ice core evidence of past atmospheric composition and climate change. The project will form the basis for the graduate research of a PhD student at Dartmouth, with numerous opportunities for undergraduate involvement in cold room measurements and outreach. The investigators have a track record of successfully mentoring women students, and will build on this experience. In conjunction with local earth science teachers, and graduate and undergraduate students will design a teacher-training module on the role of the Polar Regions in climate change. Once developed and tested, this module will be made available to the broader polar research community for their use with teachers in their communities.
Intellectual Merit: <br/>The PIs propose to study the stability and dynamics of the East Antarctic ice sheet during the Pliocene in the area of the Wilkes and Aurora subglacial basins. Models indicate the ice sheet is most sensitive to warming in these low-lying areas. This study is important as there is very little direct evidence about which parts of the East Antarctic ice sheet became unstable under warm conditions. In a pilot study the PIs have shown that the isotopic geochemical signature of downcore ice-rafted debris (IRD) can be linked to continental source areas indicating which parts of the ice sheet reached the coast and calved IRD-bearing icebergs. Their initial results suggest rapid iceberg discharge from the Wilkes Land and Adélie Land coastal areas at times in the late Miocene and early Pliocene. In this study the PIs will analyze IRD from IODP sediment cores collected on the continental rise off East Antarctica. By analyzing 40Ar/39Ar ages of hornblende IRD grains, U-Pb ages of zircons, and Sm-Nd isotopes of the fine fraction of several IRD-rich layers for each core, they will be able to fingerprint continental source areas that will indicated ice extent and dynamics on East Antarctica. The PIs will also carry out detailed studies across a few of these layers to characterize the anatomy of the ice-rafting event and better understand the mechanism of ice destabilization.<br/><br/>Broader impacts: <br/>The data collected will be important for scientists in a broad variety of fields. The project will involve one undergraduate student and one summer intern at LDEO, and a graduate student at Imperial College London. The project will expose to cutting edge methodologies as well as an international research team. Data from the project will be deposited in the online databases (SedDB) and all results and methods will be made available to the scientific community through publications in peer-reviewed journals and attendance at international conferences.
The proposed work will investigate changes in the compositional variation of glacial tills over time across two concentric sequences of Pleistocene moraines located adjacent to the heads of East Antarctic outlet glaciers in the Transantarctic Mountains (TAM). The chronologic framework for this work will be generated from cosmogenic exposure ages of boulders on prominent morainal ridges. The PIs hypothesize that variations in till composition may indicate a change in ice flow direction or a change in the composition of the original source area, while ages of the moraines provide a long-term terrestrial perspective on ice sheet dynamics. Both results are vital for modeling experiments that aim to reconstruct the East Antarctic Ice Sheet and assess its role in the global climate system and its potential impact on global sea level rise. The variation of till compositions through time also allows for a more accurate interpretation of sediment cores from the Ross Sea and the Southern Ocean. Additionally, till exposures at the head of some East Antarctic outlet glaciers have been shown to contain subglacial material derived from East Antarctic bedrock, providing a window through the ice to view East Antarctica?s inaccessible bedrock. Till samples will be collected from two well-preserved sequences of moraine crests at Mt. Howe (head of Scott Glacier) and Mt. Achernar (between Beardmore and Nimrod Glaciers). Each size fraction in glacial till provides potentially valuable information, and the PIs will measure the petrography of the clast and sand fractions, quantitative X-ray diffraction on the crushed <2mm fraction, elemental abundance of the silt/clay fraction, and U/Pb of detrital zircons in the sand fraction. Data collection will rely on established methods previously used in this region and the PIs will also explore new methods to assess their efficacy. On the same moraines crests sampled for provenance studies, the PIs will sample for cosmogenic surface exposure analyses to provide a chronologic framework at the sites for provenance changes through time. <br/><br/>Broader Impact <br/>The proposed research involves graduate and undergraduate training in a diverse array of laboratory methods. Students and PIs will be make presentations to community and campus groups, as well as conduct interviews with local news outlets. The proposed work also establishes a new, potentially long-term, collaboration between scientists at IUPUI and LDEO and brings a new PI (Kaplan) into the field of Antarctic Earth Sciences.
Intellectual Merit: Numerous candidate models for the geologic processes that have shaped the Antarctic continent have been proposed. To discriminate between them, detailed images of the upper mantle structure are required; however, the only existing continental-scale images of seismic structure beneath Antarctica lack sufficient resolution to delineate important, diagnostic features. Using newly available data from various Antarctic seismic networks, the PI will employ the adaptively parameterized tomography method to develop a high-resolution, continental-scale seismic velocity model for all of Antarctica. The proposed tomography method combines regional seismic travel-time datasets in the context of a global model to create a composite continental-scale model of upper mantle structure. The proposed method allows for imaging of finer structure in areas with better seismic ray coverage while simultaneously limiting the resolution of features in regions with less coverage. This research will help advance understanding of important global processes, such as craton formation, mountain building, continental rifting and associated magmatism. Additionally, the proposed research will have important impacts on other fields of Antarctic science. Constraints provided by tomographic results can be used to develop thermal models of the lithosphere needed to characterize the history and dynamics of ice sheets. Also, further constraints on lithospheric structure are required by climate-ice models, which are focused on understanding the cooling history of the Antarctic continent. Broader impacts: The PI is a new faculty member at the University of Alabama after having been funded as a National Science Foundation Postdoctoral Fellow in Polar Regions Research. The graduate student supported by this project is new to polar research. Through the UA-Tuscaloosa Magnet School partnership program, the PI will educate K-12 students about the Antarctic environment and associated career opportunities through various online and hands-on activities. University of Alabama dedicates a significant percentage of its enrollment space to underrepresented groups.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a project to use the WAIS Divide deep core to investigate the Last Deglaciation at sub-annual resolution through an integrated set of chemical and biological analyses. The intellectual merit of the project is that these analyses, combined with others, will take advantage of the high snow accumulation WAIS Divide site yielding the highest time resolution glacio-biogeochemical and gas record of any deep Antarctic ice core. With other high resolution Greenland cores (GISP2 and GRIP) and lower resolution Antarctic cores, the combined record will yield new insights into worldwide climate dynamics and abrupt change. The proposed chemical, biological, and elemental tracer measurements will also be used to address all of the WAIS Divide science themes. The broader impacts of the project include education and outreach activities such as numerous presentations to local K-12 students; opportunities for student and teacher involvement in the laboratory work; a teacher training program in Earth sciences in the heavily minority Santa Ana, Compton, and Costa Mesa, California school districts; and development of high school curricula. Extensive graduate and undergraduate student involvement also is planned and will include one post doctoral associate, one graduate student, and undergraduate hourly involvement at DRI; a graduate student and undergraduates at University of California, Irvine (UCI); and a post doctoral fellow at MSU. Student recruitment will be made from underrepresented groups building on a long track record of involvement and will include the NSF funded California Alliance for Minority Participation (CAMP) and the Montana American Indian Research Opportunities (AIRO).<br/><br/>This award does not involve field work in Antarctica.
Cole-Dai/0839066<br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a project to make continuous major ion analyses in the West Antarctica Ice Sheet Divide (WAIS Divide) ice core by sampling the brittle ice zone (approximately from 500 m to 1500 m). The intellectual merit of the project is that these will likely be the only chemical measurements on the brittle ice zone and, therefore, will bridge the gap in the expected continuous records of climate, ice sheet dynamics and biological evolution based on chemical measurements. High resolution sampling and analysis, probably on selected portions and depth intervals in the brittle ice zone, will help with the independent, high-precision dating of the WAIS Divide core and contribute to the achievement of the major objectives of the WAIS Divide project?development of high resolution climate records with which to investigate issues of climate forcing by greenhouse gases and the role of Antarctica and Southern Hemisphere in the global climate system. Planned collaboration with other WAIS Divide investigators will develop the longest and most detailed volcanic record from Antarctica ice cores. The broader impacts of this project include a contribution to enhancing our knowledge of the climate system. Such improvements in understanding of the global climate system and the ability to predict the magnitude and uncertainty of future changes are highly relevant to the global community. The project will support post-doctoral scientists and graduate students, including those from under-represented groups, will contribute to education, an help to train future scientists and promote diversity in research and education. Public outreach activities of this project will contribute to informal science education of school age children in the Eastern South Dakota region.
Intellectual Merit: The PIs proposed a provenance study of glacial deposits in the Ross Embayment that will provide a broad scale geochronologic survey of detrital minerals in till to help characterize bedrock beneath the East Antarctic ice sheet and constrain Antarctica?s glacial history. This project capitalizes on previous investments in field sampling. Analytical tools applied to single mineral grains extracted from existing collections of glacial till will generate ?fingerprints? of East Antarctic outlet glaciers and West Antarctic till to refine paleo-ice flow models for the Ross Embayment during the last glacial maximum, older records from ANDRILL cores, and to assess IRD sources in the Southern Ocean. New provenance tracers will include a suite of geochronological methods that together provide greater insights into the orogenic and erosional history the region. This project will include U/Pb of detrital zircons, (U-Th)/He on a subset of the U/Pb dated zircons, as well as Ar-Ar of detrital hornblende, mica and feldspars. Broader impacts: This research will train one M.S. student at IUPUI, a Ph.D. student at Columbia, and several undergraduates at both institutions. Graduate students involved in the project will be involved in mentoring undergraduate researchers. Incorporation of research discoveries will be brought into the classroom by providing concrete examples and exercises at the appropriate level. Licht and Columbia graduate student E. Pierce are developing outreach projects with local secondary school teachers to investigate the provenance of glacial materials in their local areas. The research will have broad applicability to many fields.
Funds are provided to enable applications of powerful mathematical concepts and computational tools for rigorous sensitivity analysis, pseudo-spectra and generalized stability theory, and advanced state estimation in the context of large-scale ice sheet modeling. At the center of the proposal is the generation and application of adjoint model (ADM) and tangent linear model (TLM) components of the new Community Ice Sheet Model (CISM). The goal will be achieved through rigorous use of automatic differentiation (AD) to ensure synchronicity between the ongoing model development and improvement in terms of better representation of higher-order stress terms (which account for crucial fast flow regimes) of the nonlinear forward model (NLM) code and the derivative codes. The adjoint enables extremely efficient computation of gradients of scalar-valued functions in very high-dimensional control spaces. A hierarchy of applications is envisioned: (1) sensitivity calculations in support of the Intergovernmental Panel on Climate Change (IPCC) in order to determine to which control variables the polar ice sheet volumes are most sensitive; based on adjoint sensitivity maps, to establish quantitative estimates of ice sheet volume changes for relevant forcing scenarios; and to assess how sensitivities change when including higher-order stress terms; (2) coupling of the ADM and TLM to calculate pseudo-spectra or singular vectors (SV?s) of relevant ice sheet norms; SV?s provide perturbation patterns which lead to non-normal growth, optimally amplifying norm kernels over finite times; among the many applications of SV?s are optimal initialization of ensembles to assess uncertainties; SV?s are calculated through matrix-free iterative solution of a generalized eigenvalue problem via Lanczos or Arnoldi implicit restart algorithms; (3) a long-term goal is the development of an ice sheet state estimation system based on the adjoint or Lagrange Multiplier Method (LMM) in order to synthesize, in a formal manner, the increasing number and heterogeneous types of observations with a three-dimensional, state-of-the-art ice sheet model; an important requirement is that the adjoint incorporate new schemes that are being developed for CISM to capture crucial, but as yet unrepresented physical processes.
MacAyeal/0944248<br/><br/>This award supports a project to develop a better understanding of the processes and conditions that trigger ice shelf instability and explosive disintegration. A significant product of the proposed research will be the establishment of parameterizations of micro- and meso-scale ice-shelf surface processes needed in large scale ice-sheet models designed to predict future sea level rise. The proposed research represents a 3-year effort to conduct numerical model studies of 6 aspects of surface-water evolution on Antarctic ice shelves. These 6 model-study areas include energy balance models of melting ice-shelf surfaces, with treatment of surface ponds and water-filled crevasses, distributed, Darcian water flow modeling to simulate initial firn melting, brine infiltration, pond drainage and crevasse filling, ice-shelf surface topography evolution modeling by phase change (surface melting and freezing), surface-runoff driven erosion and seepage flows, mass loading and flexure effects of ice-shelf and iceberg surfaces; feedbacks between surface-water loads and flexure stresses; possible seiche phenomena of the surface water, ice and underlying ocean that constitute a mechanism for, inducing surface crevassing., surface pond and crevasse convection, and basal crevasse thermohaline convection (as a phenomena related to area 5 above). The broader impacts of the proposed work bears on the socio-environmental concerns of climate change and sea-level rise, and will contribute to the important goal of advising public policy. The project will form the basis of a dissertation project of a graduate student whose training will contribute to the scientific workforce of the nation and the PI and graduate student will additionally participate in a summer science-enrichment program for high-school teachers organized by colleagues at the University of Chicago.
Abstract<br/>This award supports a seismological study of the Gamburtsev Subglacial Mountains (GSM), a Texas-sized mountain range buried beneath the ice sheets of East Antarctica. The project will perform a passive seismic experiment deploying twenty-three seismic stations over the GSM to characterize the structure of the crust and upper mantle, and determine the processes driving uplift. The outcomes will also offer constraints on the terrestrial heat flux, a key variable in modeling ice sheet formation and behavior. Virtually unexplored, the GSM represents the largest unstudied area of crustal uplift on earth. As well, the region is the starting point for growth of the Antarctic ice sheets. <br/>Because of these outstanding questions, the GSM has been identified by the international Antarctic science community as a research focus for the International Polar Year (2007-2009). In addition to this seismic experiment, NSF is also supporting an aerogeophysical survey of the GSM under award number 0632292. Major international partners in the project include Germany, China, Australia, and the United Kingdom. For more information see IPY Project #67 at IPY.org. In terms of broader impacts, this project also supports postdoctoral and graduate student research, and various forms of outreach.
This award supports an aerogeophysical study of the Gamburtsev Subglacial Mountains (GSM), a Texas-sized mountain range buried beneath the ice sheets of East Antarctica. The project would perform a combined gravity, magnetics, and radar study to achieve a range of goals including: advancing our understanding of the origin and evolution of the polar ice sheets and subglacial lakes; defining the crustal architecture of East Antarctica, a key question in the earth's history; and locating the oldest ice in East Antarctica, which may ultimately help find ancient climate records. Virtually unexplored, the GSM represents the largest unstudied area of crustal uplift on earth. As well, the region is the starting point for growth of the Antarctic ice sheets. Because of these outstanding questions, the GSM has been identified by the international Antarctic science community as a research focus for the International Polar Year (2007-2009). In addition to this study, NSF is also supporting a seismological survey of the GSM under award number 0537371. Major international partners in the project include Germany, China, Australia, and the United Kingdom. For more information see IPY Project #67 at IPY.org. In terms of broader impacts, this project also supports postdoctoral and graduate student research, and various forms of outreach including a focus on groups underrepresented in the earth sciences.
Stone/0838818 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). <br/><br/>This award supports a project to study the former thickness and retreat history of Shackleton and Beardmore Glaciers which flow through the Transantarctic Mountains (TAMs) into the southern Ross Sea. Lateral moraine deposits along the lower reaches of these major outlet glaciers will be mapped and dated and the results will help to date the LGM and constrain the thickness of ice where it left the Transantarctic Mountains and flowed into the Ross Sea. The intellectual merit of the project is that the results will allow scientists to distinguish between models of ice retreat, which have important implications for former ice configuration and dynamics, and to constrain the contribution from Ross Sea deglaciation to global sea level through the late Holocene. In addition, this will make a significant contribution to a better understanding of the magnitude and timing of postglacial sea-level change and the potential contribution of Antarctica to sea-level rise in future. The broader impacts of the project are that the work will help quantify changes in grounded ice volume since the LGM, improve understanding of the ice dynamics responsible, and examine their implications for future sea level change. The project will train future scientists through participation of two graduate students and undergraduates who will develop self-contained research projects. As in previous Antarctic projects, there will be interaction with K-12 students through classroom visits, web-based expedition journals, letters from the field, and discussions with teachers and will allow the project to be shared with a wide audience. This award has field work in Antarctica.
Sergienko/0838811 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a project to conduct a modeling study of the ice stream ? sub-glacial water system. A suite of numerical models of various dimensionality and complexity will be constructed in a sequential, hierarchical fashion to formulate and test hypotheses regarding how sub-glacial lakes form under ice streams, determine the effect of sub-glacial lakes on ice-stream flow and mass balance, and to determine feedback effects whereby the ice stream ? sub-glacial water system can elicit both stable and unstable responses to environmental perturbations. This research will address one of the only observationally verified fast-time-scale processes apparent within the Antarctic Ice Stream system. The intellectual merit of the project is that understanding the origins and consequences of near-grounding-line sub-glacial lakes is a priority in glaciological research designed to predict short-term variations in Antarctica?s near-term future mass balance. The broader impacts of the proposed work are that it will contribute to better understanding of a system that has important societal relevance through contribution to sea level rise. Participation of a graduate student in the project will provide the student?s training and education in application of the numerical modeling in geosciences.
This Small Grant for Exploratory Research explores the possibility of dating beach deposits on the Antarctic Peninsula using Optical Stimulated Luminescence (OSL). This area is undergoing uplift in response to glacial retreat, and dating these deposits will allow for estimations of ice sheet thickness during the last glacial maximum through the creation of new sea level curves. Accurate reconstructions of ice sheet size are critical to predicting sea level rise in response to global warming. In terms of other broader impacts, this project supports a graduate student, who is learning cutting edge analytical techniques while applying them to questions of global climate change.
This award supports a project to create new, unprecedented high-resolution atmospheric carbon dioxide (CO2) records spanning intervals of abrupt climate changes during the last glacial period and the early Holocene. The proposed work will utilize high-precision methods on existing ice cores from high accumulation sites such as Siple Dome and Byrd Station, Antarctica and will improve our understanding of how fast CO2 can change naturally, how its variations are linked with climate, and, combined with a coupled climate-carbon cycle model, will clarify the role of terrestrial and oceanic processes during past abrupt changes of climate and CO2. The intellectual merit of this work is that CO2 is the most important anthropogenic greenhouse gas and understanding its past variations, its sources and sinks, and how they are linked to climate change is a major goal of the climate research community. This project will produce high quality data on centennial to multi-decadal time scales. Such high-resolution work has not been conducted before because of insufficient analytical precision, slow experimental procedures in previous studies, or lack of available samples. The proposed research will complement future high-resolution studies from WAIS Divide ice cores and will provide ice core CO2 records for the target age intervals, which are in the zone of clathrate formation in the WAIS ice cores. Clathrate hydrate is a phase composed of air and ice. CO2 analyses have historically been less precise in clathrate ice than in ?bubbly ice? such as the Siple Dome ice core that will be analyzed in the proposed project. High quality, high-resolution results from specific intervals in Siple Dome that we propose to analyze will provide important data for verifying the WAIS Divide record. The broader impacts of the work are that current models show a large uncertainty of future climate-carbon cycle interactions. The results of this proposed work will be used for testing coupled carbon cycle-climate models and may contribute to reducing this uncertainty. The project will contribute to the training of several undergraduate students and a full-time technician. Both will learn analytical techniques and the basic science involved. Minorities and female students will be highly encouraged to participate in this project. Outreach efforts will include participation in news media interviews, at a local festival celebrating art, science and technology, and giving seminar presentations in the US and foreign countries. The OSU ice core laboratory has begun a collaboration with a regional science museum and is developing ideas to build an exhibition booth to make public be aware of climate change and ice core research. All data will be archived at the National Snow and Ice Data Center and at other similar archives per the OPP data policy.
9725057 Mayewski This award is for support for a Science Management Office (SMO) for the United States component of the International Trans-Antarctic Scientific Expedition (US ITASE). The broad aim of US ITASE is to develop an understanding of the last 200 years of past West Antarctic climate and environmental change. ITASE is a multidisciplinary program that integrates remote sensing, meteorology, ice coring, surface glaciology and geophysics. In addition to the formation of a science management office, this award supports a series of annual workshops to coordinate the science projects that will be involved in ITASE and the logistics base needed to undertake ground-based sampling in West Antarctica.
Hulbe/0838810 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a modeling study of the processes in West Antarctic grounding zones, the transition from ice resting on bedrock to ice floating on the ocean surface with an eye toward understanding the interrelated causes of rapid change in grounding line configuration and outlet flow. A combination of satellite remote sensing and numerical modeling will be used to investigate both past and ongoing patterns of change. New high-resolution surface elevation maps made from a novel combination of satellite laser altimetry and remotely observed surface shape provide a unique view of grounding zones. These data will be used to diagnose events associated with the shutdown of Kamb Ice Stream, to investigate a recent discharge event on Institute Ice Stream and to investigate ongoing change at the outlet of Whillans Ice Stream, along with other modern processes around the West Antarctic. An existing numerical model of coupled ice sheet, ice stream, and ice shelf flow will be used and improved as part of the research project. The broader impacts of the project relate to the importance of understanding the role of polar ice sheets in global sea level rise. The work will contribute to the next round of deliberations for the Intergovernmental Panel on Climate Change (IPCC). Improved views, interpretations, and insights into the physical processes that govern variability in ice sheet outlet streams will help correct the shortcomings of the last IPCC report that didn?t include the role of ice sheets in sea level rise. The PIs have a strong record of public outreach, involvement in the professional community, and student training.
Bell/0636883<br/><br/>This award support a project to study the role that subglacial water plays in the overall stability of major ice sheets. An estimated 22,000 km3 of water is currently stored within Antarctica's subglacial lakes. Movement of this water occurs through a complex and largely inferred drainage system in both East and West Antarctica. Geomorphic evidence for the catastrophic drainage of subglacial lakes documents repeated events. These major flood events appear to have drained the largest subglacial lakes situated in the relatively stable interior of the East Antarctic ice sheet. Emerging evidence suggests there is a close connection between significant subglacial lakes and the onset of the Recovery Ice Stream one of the largest in East Antarctica. Our preliminary analysis of the Recovery Lakes region, East Antarctica suggests a direct linkage between lakes and streaming ice flow, specifically the 800 km long Recovery Ice Stream and its tributaries. Located just upslope of the Recovery Ice Stream, the Recovery Lakes Region is composed of 3 well-defined lakes and a fourth, ambiguous, 'lake-like' feature. While other large lakes have a localized impact on ice surface slope, the Recovery Lakes Region lakes are coincident with an abrupt regional change in the ice sheet surface slope. Satellite imagery demonstrates that the downslope margin of this lake area contains distinct flow strips and crevasses: both indicative of increasing ice velocities. The discovery of a series of large lakes coincident with the onset of rapid ice flow in East Antarctica clearly links subglacial lakes and ice sheet dynamics for the first time. The evidence linking the onset of streaming in the Recovery Drainage Ice Stream to the series of large subglacial lakes raises the fundamental question: How can subglacial lakes trigger the onset of ice streaming? We advance two possible mechanisms: (i) Subglacial lakes can produce accelerated ice flow through the drainage of lake water beneath the ice sheet downslope of the lakes. (ii) Subglacial lakes can produce accelerated ice flow accelerated ice flow by modifying the basal thermal gradient via basal accretion over the lakes so when the ice sheet regrounds basal melting dominates. To evaluate the contribution of lake water and the changing basal thermal gradient, we propose an integrated program incorporating satellite imagery analysis, a series of reconnaissance aerogeophysical profiles over the Recovery Lake Region and the installation of continuous GPS sites over the Recovery Lakes. This analysis and new data will enable us (1) to produce a velocity field over the Recovery Lakes Region, (2) to map the ice thickness changes over the lakes due to acceleration triggered thinning, basal melting and freezing, (3) determine the depth and possible the tectonic origin of the Recovery Lakes and (4) determine the stability of these lakes over time. These basic data sets will enable us to advance our understanding of how subglacial lakes trigger the onset of streaming. The intellectual merit of this project is that it will be the first systematic analysis of ice streams triggering the onset of ice streams. This work has profound implications for the modeling of ice sheet behavior in the future, the geologic record of abrupt climate changes and the longevity of subglacial lakes. The broader impacts of the project are programs that will reach students of all ages through undergraduates involved in the research, formal presentations in teacher education programs and ongoing public outreach efforts at major science museums. Subglacial Antarctic lake environments are emerging as a premier, major frontier for exploration during the IPY 2007-2009.
This award is for support for a four year program to study the basal conditions of ice stream D using techniques previously applied to ice stream B. The objective is to determine whether the physical conditions and processes to be observed by borehole geophysics at the base of this large ice stream are consistent with what has been observed at ice stream B and to point to a common basal mechanism of ice streaming. This project includes a comparison between two parts of ice stream D, an upstream reach where flow velocities are modest (about 80 meters/year) and a downstream reach of high velocity (about 400 meters/year). The comparison will help to reveal what physical variable or combination of variables is mainly responsible for the streaming flow. The variables to be monitmred by borehole observation include basal water pressure, basal sliding velocity, flow properties and sedimentological characteristics of subglacial till if present, ice temperature profile including basal water transport velocity, connection time to the basal water system, basal melting rate and others.
Rice, James; Platt, John; Suckale, Jenny; Perol, Thibaut; Tsai, Victor
No dataset link provided
Rice 0739444<br/><br/>This award supports a project to study the mode of formation and causes of glacial earthquakes. The paradigm for glacial flow has been that glaciers flow in a viscous manner, with major changes in the force balance occurring on the decade timescale or longer. The recent discovery of a number of even shorter timescale events has challenged this paradigm. In 2003, it was discovered that Whillans Ice Stream in West Antarctica displays stick-slip behavior on the 10-30 minute timescale, with ice stream speed increasing by a factor of 30 from already high speeds. In the past year, the minimum timescale has been pushed shorter by recognition that a class of recently discovered 50-second-long, magnitude-5 earthquakes are closely associated with changes in the force balance near the calving fronts of large outlet glaciers in both Greenland and East Antarctica. With no adequate theory existing to explain these relatively large earthquakes associated with outlet glaciers, we have begun to investigate the physical mechanisms that must be involved in allowing such a response in a system traditionally not thought capable of generating large variations in forces over timescales less than 100 seconds. The intellectual merit of the work is that large-amplitude, short-timescale variability of glaciers is an important mode of glacier dynamics that has not yet been understood from a first-principles physics perspective. The proposed research addresses this gap in understanding, tying together knowledge from numerous disciplines including glaciology, seismology and fault rupture dynamics, laboratory rock physics, granular flow, fracture mechanics, and hydrogeology. The broader impacts of the work are that there is societal as well as general scientific interest in the stability of the major ice sheets. However, without an understanding of the physical processes governing short time scale variability, it is unlikely that we will be able accurately predict the future of these ice sheets and their impact on sea level changes. The project will also contribute to the development and education of young scientists.
This project studies formation of the TransAntarctic Mountains (TAM) through numerical modeling based on cooling histories of apatite mineral grains. The TAM are the highest and longest rift-related mountain range in the world. Various models for their uplift have been proposed, the most provocative of which is that they are not uplifted, but instead are the eroded remnant of a plateau. This project evaluates that hypothesis by collecting apatites from around Byrd Glacier for fission track thermochronology. Results will be combined with a kinematic and thermal model to determine the TAM?s structural evolution. The plateau model, if correct, implies that the Byrd Glacier originated not as a glacier-carved valley through the TAM, but as a river system flowing in the opposite direction. Given that the Byrd Glacier is a key drainage for the East Antarctic ice sheet, this result has important implications for ice sheet models and interpretation of both regional geology and sediment records.<br/><br/>The main broader impacts are undergraduate research and a new collaboration between a primarily undergraduate and a research institution. Students will be involved in the field program, sample analyses, and numerical modeling.
This award supports a project to fully characterize the microstructure in ice cores, in particular the microstructural locations of impurities, grain orientations and strain gradients. This work will complement the optical observations, electrical conductivity measurement, and precise, detailed measurements of the soluble ion and gas contents that are performed by others. Linking the concentrations of soluble ions and gases, measured to a few parts per billion, to the optically determined annual layer structure and the stable isotope data in ice cores has enabled a great deal to be established about the concentrations and depth/age distributions of particles, trace gases and impurities for several polar ice cores. Ice core studies carried out by several groups contribute immensely to our understanding of paleoclimate and, to our ability to predict future climate change. The work will build on previous measurements and technique development in this area, as well as focusing on new techniques to characterize ice cores. The work will use both scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDS) and confocal scanning optical microscopy coupled with Raman spectroscopy (RS) to determine the microstructural locations of impurities and correlate this information with depth/age, and impurity type and concentration for several polar ice cores. The Broader Impacts of the proposed work are that knowledge of the location of impurities coupled with the grain orientation (both c- and a-axis) and grain misorientation information will allow paleoclimatologists to better interpret ice core data and other scientists to understand and model the physical and mechanical properties of natural ice sheets. Other Broader Impacts of the work are that the work will be performed and lead to the education of a Ph.D. student. At the end of the project, as well as the knowledge gained from coursework, the graduate student will have experience in ice core specimen preparation and characterization using scanning electron microscopy, x-ray microanalysis, confocal scanning microscopy, Raman spectroscopy and ion chromatography. Results from the research will be published in refereed journals, presented at conferences, and placed on a web page.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The investigators will examine competing hypotheses for the mechanism of extension and creation of the Transantarctic Mountains, and evolution of the thermal regimes of rifted West Antarctica and stable East Antarctica using magnetotelluric (MT) profiles. Surrounded almost entirely by ocean ridges, Antarctica is a special tectonic situation because of the need to make accommodation space for rifting in the Transantarctic region. In the MT method, temporal variations in the Earth's natural electromagnetic field are used as source fields to probe the electrical resistivity structure in the depth range of 1 to 200 km, or more. Geophysical methods, such as MT, are appropriate in Antarctica because of the predominance of thick ice cover over most of the Continent and the difficult operating environment. The proposed effort will consist of approximately 50 sites over a distance approaching 500 km with a 10 km average spacing, oriented normal to the Transantarctic Mountains (TAM), in the Beardmore glacier area. High quality MT soundings will be collected over thick ice sheets using a custom electrode preamp design, updated from previous Antarctic projects. Data acquisition will take place over two field seasons. The primary goals are three-fold: to establish the location of the deeper tectonic transition between East and West Antarctica that may be offset from the physiographic transition at the surface, using deep resistivity structure distinguish between modes of extensional upwelling and magmatism that may be vertically non-uniform, depth and magnitude of quasi-layered deep crustal low resistivity, particularly below West Antarctica, will be used to estimate crustal heat flux into the ice sheet base.
This award supports a field experiment, with partners from Chile and the Netherlands, to determine the state of health and stability of Larsen C ice shelf in response to climate change. Significant glaciological and ecological changes are taking place in the Antarctic Peninsula in response to climate warming that is proceeding at 6 times the global average rate. Following the collapse of Larsen A ice shelf in 1995 and Larsen B in 2002, the outlet glaciers that nourished them with land ice accelerated massively, losing a disproportionate amount of ice to the ocean. Further south, the much larger Larsen C ice shelf is thinning and measurements collected over more than a decade suggest that it is doomed to break up. The intellectual merit of the project will be to contribute to the scientific knowledge of one of the Antarctic sectors where the most significant changes are taking place at present. The project is central to a cluster of International Polar Year activities in the Antarctic Peninsula. It will yield a legacy of international collaboration, instrument networking, education of young scientists, reference data and scientific analysis in a remote but globally relevant glaciological setting. The broader impacts of the project will be to address the contribution to sea level rise from Antarctica and to bring live monitoring of climate and ice dynamics in Antarctica to scientists, students, the non-specialized public, the press and the media via live web broadcasting of progress, data collection, visualization and analysis. Existing data will be combined with new measurements to assess what physical processes are controlling the weakening of the ice shelf, whether a break up is likely, and provide baseline data to quantify the consequences of a breakup. Field activities will include measurements using the Global Positioning System (GPS), installation of automatic weather stations (AWS), ground penetrating radar (GPR) measurements, collection of shallow firn cores and temperature measurements. These data will be used to characterize the dynamic response of the ice shelf to a variety of phenomena (oceanic tides, iceberg calving, ice-front retreat and rifting, time series of weather conditions, structural characteristics of the ice shelf and bottom melting regime, and the ability of firn to collect melt water and subsequently form water ponds that over-deepen and weaken the ice shelf). This effort will complement an analysis of remote sensing data, ice-shelf numerical models and control methods funded independently to provide a more comprehensive analysis of the ice shelf evolution in a changing climate.
This project is an aerogeophysical survey to explore unknown terrain in East Antarctica to answer questions of climate change and earth science. The methods include ice-penetrating radar, gravity, and magnetic measurements. The project?s main goal is to investigate the stability and migration of ice divides that guide flow of the East Antarctic ice sheet, the world?s largest. The project also maps ice accumulation over the last interglacial, identifies subglacial lakes, and characterizes the catchment basins of the very largest glacial basins, including Wilkes and Aurora. The outcomes contribute to ice sheet models relevant to understanding sea level rise in a warming world. The work will also help understand the regional geology. Buried beneath miles-thick ice, East Antarctica is virtually uncharacterized, but is considered a keystone for tectonic reconstructions and other geologic questions. The region also hosts subglacial lakes, whose geologic histories are unknown. <br/><br/>The broader impacts are extensive, and include societal relevance for understanding sea level rise, outreach in various forms, and education at the K12 through postdoctoral levels. The project contributes to the International Polar Year (2007-2009) by addressing key IPY themes on frontiers in polar exploration and climate change. It also includes extensive international collaboration with the United Kingdom, Australia, France and other nations; and offers explicit opportunities for early career scientists.
This award supports a project to study ice sheet history and dynamics on the Thwaites Glacier and Pine Island Glacier in the Amundsen Sea sector of the West Antarctic Ice Sheet. The international collaboration that has been established with the British Antarctic Survey will enable a fuller suite of geophysical experiments with more-efficient use of people and logistics than we could achieve individually. This project is one of a number of projects to characterize the Amundsen Sea Embayment, which has been identified in numerous planning documents as perhaps the most important target for ice-dynamical research. Taken together, this "pulse of activity" will result in a better understanding of this important part of the global system. Field work will measure the subglacial environment of Thwaites and Pine Island Glaciers using three powerful, but relatively simple tools: reflection seismic imaging, GPS motion monitoring of the tidal forcing, and passive seismic monitoring of the seismicity associated with motion. The results of the field work will feed into ice-sheet modeling efforts that are tuned to the case of an ocean-terminating glacier and will assess the influence of these glaciers on current sea level and project into the future. The broader impacts of the project involve the inclusion of a film- and audio-professional to document the work for informal outreach (public radio and TV; museums). In addition, we will train graduate students in polar geophysical and glaciological research and in numerical modeling techniques. The ultimate goal of this project, of assessing the role of Thwaites Glacier in global sea level change, has broad societal impact in coastal regions and small islands.
0538674<br/>Matsuoka<br/>This award supports a project to evaluate radio-echo intensities in the available SOAR ice-penetrating radar data along grids covering Lake Vostok, and along four regional tracks from Ridge B toward the lake. The project has two objectives; first, it will examine the upper surface of the lake and reflectors hypothesized to be a boundary between the meteoric and accreted ice. They will provide crucial knowledge on the dynamic evolution of the lake. Second, this project will examine a poorly understood echo-free zone within the deep ice in central East Antarctica. This zone may consist of distorted stagnant ice, while its upper boundary may be a shear zone. The SOAR radar data provide a unique resource to examine spatiotemporal water circulation patterns that should be understood in order to select the best direct-sampling strategy to the lake. The Vostok ice core provides a unique opportunity to do this work. First, the path effects, i.e. propagation loss and birefringence, will be derived at the ice-core site using ice temperature, chemistry, and fabric data. Second, lateral variations of the propagation loss will be estimated by tracking chemistry associated with radar-detected isochronous layers, and by inferring temperatures from an ice-flow model that can replicate those layers. Ice-fabric patterns will be inferred from anisotropy in the reflectivity at about 100 radar-track cross-over sites. In terms of broader impacts, a graduate student will be trained to interpret the radar data in the light of radar theory and glaciological context of Lake Vostok and summer workshops for K-12 teachers will be provided in Seattle and New York. This project will contribute to ongoing efforts to study Lake Vostok and will complement the site selection for a North Vostok ice core, which has been proposed by Russia and France as an IPY program.
Studinger/0636584<br/><br/>This award supports a project to estimate the salinity of subglacial Lake Vostok, Lake Concordia and the 90 deg.E lake using existing airborne ice-penetrating radar and laser altimeter data. These lakes have been selected because of the availability of modern aerogeophysical data and because they are large enough for the floating ice to be unaffected by boundary stresses near the grounding lines. The proposed approach is based on the assumption that the ice sheet above large subglacial lakes is in hydrostatic equilibrium and the density and subsequently salinity of the lake's water can be estimated from the (linear) relationship between ice surface elevation and ice thickness of the floating ice. The goal of the proposed work is to estimate the salinity of Lake Vostok and determine spatial changes and to compare the salinity estimates of 3 large subglacial lakes in East Antarctica. The intellectual merits of the project are that this work will contribute to the knowledge of the physical and chemical processes operating within subglacial lake environments. Due to the inaccessibility of subglacial lakes numerical modeling of the water circulation is currently the only way forward to develop a conceptual understanding of the circulation and melting and freezing regimes in subglacial lakes. Numerical experiments show that the salinity of the lake's water is a crucial input parameter for the 3-D fluid dynamic models. Improved numerical models will contribute to our knowledge of water circulation in subglacial lakes, its effects on water and heat budgets, stratification, melting and freezing, and the conditions that support life in such extreme environments. The broader impacts of the project are that subglacial lakes have captured the interest of many people, scientists and laymen. The national and international press frequently reports about the research of the Principal Investigator. His Lake Vostok illustrations have been used in math and earth science text books. Lake Vostok will be used for education and outreach in the Earth2Class project. Earth2Class is a highly successful science/math/technology learning resource for K-12 students, teachers, and administrators in the New York metropolitan area. Earth2Class is created through collaboration by research scientists at the Lamont- Doherty Earth Observatory; curriculum and educational technology specialists from Teachers College, Columbia University; and classroom teachers in the New York metropolitan area.
Joughin 0631973<br/><br/>This award supports a project to gather data to better understand the mass balance of the West Antarctic Ice Sheet, in the Pine Island and Thwaites region, through the combination of radar altimetry and surface-based ice-core measurements of accumulation. The intellectual merit of the project is that the results of the field work will provide information on decadal-scale average accumulation extending back through the last century and will help constrain a modeling effort to determine how coastal changes propagate inland, to allow better prediction of future change. Comparison of the basin averaged accumulation with ice discharge determined using Interferometric Synthetic Aperture Radar (InSAR) velocity data will provide improved mass-balance estimates. Study of changes in flow speed will produce a record of mass balance over the last three decades. Analysis of the satellite altimeter record in conjunction with annual accumulation estimates also will provide estimates of changes and variability in mass balance. The broader impacts of the work are that it will make a significant contribution to future IPCC estimates of sea level, which are important for projection of the impacts of increased sea level on coastal communities. The research will contribute to the graduate education of students at the Universities of Washington and Kansas and will enrich K-12 education through the direct participation of the PIs in classroom activities. Informal science education includes 4-day glacier flow demonstrations at the Polar Science Weekend held annually at the Pacific Science Center in Seattle. The project also will communicate results through Center for the Remote Sensing of Ice Sheets (CReSIS) outreach effort. All field and remotely-sensed data sets will be archived and distributed by the National Snow and Ice Data Center. This project is relevant to IPY in that the West Antarctic Ice Sheet is losing mass, in large part because of rapid thinning of the Amundsen Coast glaciers so, it will directly address the NSF IPY emphasis on "ice sheet history and dynamics." The project is also international in scope.
This award supports a project to use two new scanning fluorimeters to map microbial concentrations vs depth in the WAIS Divide ice core as portions of it become available at NICL, and selected portions of the GISP2 ice core for inter-hemispheric comparison. Ground-truth calibrations with microbes in ice show that the instruments are sensitive to a single cell and can scan the full length of a 1-meter core at 300-micron intervals in two minutes. The goals of these studies will be to exploit the discovery that microbes are transported onto ice, in clumps, several times per year and that at rare intervals (not periodically) of ~104 years, a much higher flux, sometimes lasting >1 decade, reaches the ice. From variations ranging from seasonal to millennial to glacial scale in the arrival time distribution of phototrophs, methanogens, and total microbes in the Antarctic and Arctic ice, the investigators will attempt to determine oceanic and terrestrial sources of these microbes and will look for correlations of microbial bursts with dust concentration and temperature proxies. In addition the project will follow up on the discovery that the rare instances of very high microbial flux account for some of the"gas artifacts" in ice cores - isolated spikes of excess CH4 and N2O that have been discarded by others in previous climate studies. The intellectual merit of this project is that it will exploit scanning fluorimetry of microbes as a powerful new tool for studies ranging from meteorology to climatology to biology, especially when combined with mapping of dust, gases, and major element chemistry in ice cores. In 2010-11 the WAIS Divide borehole will be logged with the latest version of the dust logger. The log will provide mm-scale depth resolution of dust concentration and of volcanic ash layers down the entire depth of the borehole. The locations of ash layers in the ice will be determined and chemical analyses of the ash will be analyzed in order to determine provenance. By comparing data from the WAIS Divide borehole with data from other boreholes and with chemical data (obtained by others) on volcanic layers, the researchers will examine the relationship between the timing of volcanic eruptions and abrupt climate change. Results from this project with the scanning fluorimeters and the dust logger could have applications to planetary missions, borehole oceanography, limnology, meteorology, climate, volcanology, and ancient life in ice. A deeper understanding of the causes of abrupt climate change, including a causal relationship with volcanic explosivity, would enable a better understanding of the adverse effects on climate. The broader impact of the project is that it will provide training to students and post-docs from the U. S. and other countries.
1043528/Alley This award supports a project to complete the physical-properties studies of the WAIS Divide deep ice core, now being collected in West Antarctica. Ongoing work funded by NSF, under a grant that is ending, has produced visible stratigraphy dating, inspection of the core for any melt layers, volcanic horizons, flow disturbances or other features, analysis of bubble number-densities allowing reconstruction of a two-millennial cooling trend in the latter Holocene at the site, characterization of other bubble characteristics (size, etc.), density studies, characterization of snow-surface changes at the site, preliminary c-axis studies, and more. The current proposal seeks to complete this work, once the rest of the core is recovered. The intellectual merit of the proposed activity starts with quality assurance for the core, by visual detection of any evidence of flow disturbances that would disrupt the integrity of the climate record. Inspection will also reveal any melt layers, volcanic horizons, etc. Annual-layer dating will be conducted; thus far, the visible strata have not been as useful as some other indicators, but the possibility (based on experience in Greenland) that visible examination will allow detection of thinner annual layers than other techniques motivates the effort. Bubble number-density will be used to reconstruct temperature changes through the rest of the bubbly part of the core, providing important paleoclimatic data for earlier parts of the Holocene. Coordinated interpretation of c-axis fabrics, grain sizes and shapes, and bubble characteristics will be used to learn about the history of ice flow, the processes of ice flow, and the softness of the ice for additional deformation. Analysis of surface data already collected will improve interpretation of the layering of the core. It is possible that the annual-layer dating will not be sufficiently successful, and that the core will be undisturbed with no melt layers; if so, then these efforts will not yield major publications. However, success of the other efforts should produce improved understanding of the history and stability of the ice sheet, and key processes controlling these, and the quality assurance provided by the visual examination is important for the project as a whole. The broader impacts of the proposed activity include education of a PhD student and multiple undergraduates, and research opportunities for a junior faculty member at an undergraduate institution. The proposed activity will help support an especially vigorous education and outreach effort providing undergraduate instruction for over 1000 students per year, reaching thousands more citizens and many policymakers, and preparing educational materials used at many levels.
This award supports a project to perform continuous microparticle concentration and size distribution measurements (using coulter counter and state-of-the-art laser detector methods), analysis of biologically relevant trace elements associated with microparticles (Fe, Zn, Co, Cd, Cu), and tephra measurements on the WAIS Divide ice core. This initial three-year project includes analysis of ice core spanning the instrumental (~1850-present) to mid- Holocene (~5000 years BP) period, with sample resolution ranging from subannual to decadal. The intellectual merit of the project is that it will help in establishing the relationships among climate, atmospheric aerosols from terrestrial and volcanic sources, ocean biogeochemistry, and greenhouse gases on several timescales which remain a fundamental problem in paleoclimatology. The atmospheric mineral dust plays an important but uncertain role in direct radiative forcing, and the microparticle datasets produced in this project will allow us to examine changes in South Pacific aerosol loading, atmospheric dynamics, and dust source area climate. The phasing of changes in aerosol properties within Antarctica, throughout the Southern Hemisphere, and globally is unclear, largely due to the limited number of annually dated records extending into the glacial period and the lack of a<br/>tephra framework to correlate records. The broader impacts of the proposed research are an interdisciplinary approach to climate science problems, and will contribute to several WAIS Divide science themes as well as the broader paleoclimate and oceanographic communities. Because the research topics have a large and direct societal relevance, the project will form a centerpiece of various outreach efforts at UMaine and NMT including institution websites, public speaking, local K-12 school interaction, media interviews and news releases, and popular literature. At least one PhD student and one MS student will be directly supported by this project, including fieldwork, core processing, laboratory analysis, and data interpretation/publication. We expect that one graduate student per year will apply for a core handler/assistant driller position through the WAIS Divide Science Coordination Office, and that undergraduate student involvement will result in several Capstone experience projects (a UMaine graduation requirement). Data and ideas generated from the project will be integrated into undergraduate and graduate course curricula at both institutions.
This award supports a project that is part of the West Antarctic Ice Sheet Divide (WAIS Divide) program; which is a multi-disciplinary multi-institutional program to investigate the causes of natural changes in climate, the influence of the West Antarctic ice sheet on sea level, and the biology of deep ice. The WAIS Divide core will be unique among Antarctic ice cores in that it will have discernable annual layers for the last 40,000 years. A critical element of the program is to determine the age of the ice so that the climate proxies measured on the core can be interpreted in terms of age, not just depth. This project will make electrical measurements that can identify the annual layers. This information will be combined with information from other investigators to develop an annually resolved timescale over the last 40,000 years. This timescale will be the foundation on which the recent climate records are interpreted. Electrical measurements will also be used to produce two-dimensional images of the ice core stratigraphy; allowing sections of the core with abnormal stratigraphy to be identified. The broader impacts of this project include exposing a diverse group of undergraduate and graduate students to ice core research and assisting the Smithsonian National Museum of Natural History in Washington, D.C to develop a paleoclimate/ice core display.
Catania 0739654<br/><br/>This award supports a project to study the Amundsen Sea drainage system and improve understanding of the impact of recent glaciological changes as an aid to predicting how this region will change in the future. The intellectual merit of the work is that the Amundsen Sea drainage system has been a recent focus for glaciological research because of rapid changes occurring there as a result of grounding line retreat. The work will focus on the regions of flow transition and will map the internal stratigraphy of the ice sheet across the Thwaites Glacier shear margins and use the age and geometry of radar-detected internal layers to interpret ice flow history. Thwaites Glacier (one of the main pathways for ice drainage in the region) has recently widened and may continue to do so in the near future. Thwaites Glacier may be particularly vulnerable to grounding line retreat because it lacks a well-defined subglacial channel. The subglacial environment exerts strong control on ice flow and flow history will be mapped in the context of bed topography and bed reflectivity. The plan is to use existing ice-penetrating radar data and coordinate with planned upcoming surveys to reduce logistical costs. The work proposed here will take three years to complete but no additional fieldwork in Antarctica is required. More detailed ground-based geophysical (radar and seismic) experiments will be needed at key locations to achieve our overall goal and the work proposed here will aid in identifying those regions. The broader impacts of the project are that it will initiate a new collaboration among radar communities within the US including those that are on the forefront of radar systems engineering and those that are actively involved in radar-derived internal layer and bed analysis. The project will also provide support for a postdoctoral researcher and a graduate student, thus giving them exposure to a variety of methodologies and scientific issues. Finally, there are plans to further develop the "Wired Antarctica" website designed by Ginny Catania with the help of a student-teacher. This will allow for the existing lesson plans to be updated to Texas State standards so that they can be used more broadly within state middle and high schools.
Brook 0739766<br/><br/>This award supports a project to create a 25,000-year high-resolution record of atmospheric CO2 from the WAIS Divide ice core. The site has high ice accumulation rate, relatively cold temperatures, and annual layering that should be preserved back to 40,000 years, all prerequisite for preserving a high quality, well-dated CO2 record. The new record will be used to examine relationships between Antarctic climate, Northern Hemisphere climate, and atmospheric CO2 on glacial-interglacial to centennial time scales, at unprecedented temporal resolution. The intellectual merit of the proposed work is simply that CO2 is the most important greenhouse gas that humans directly impact, and understanding the sources, sinks, and controls of atmospheric CO2 is a major goal for the global scientific community. Accurate chronology and detailed records are primary requirements for developing and testing models that explain and predict CO2 variability. The proposed work has several broader impacts. It contributes to the training of a post-doctoral researcher, who will transfer to a research faculty position during the award period and who will participate in graduate teaching and guest lecture in undergraduate courses. An undergraduate researcher will gain valuable lab training and conduct independent research. Bringing the results of<br/>the proposed work to the classroom will enrich courses taught by the PI. Outreach efforts will expose pre-college students to ice core research. The proposed work will enhance the laboratory facilities for ice core research at OSU, insuring that the capability for CO2 measurements exists for future projects. All data will be archived at the National Snow and Ice Data Center and other similar archives, per OPP policy. Highly significant results will be disseminated to the news media through OSU?s very effective News and Communications group. Carbon dioxide is the most important greenhouse gas that humans are directly changing. Understanding how CO2 and climate are linked on all time scales is necessary for predicting the future behavior of the carbon cycle and climate system, primarily to insure that the appropriate processes are represented in carbon cycle/climate models. Part of the proposed work emphasizes the relationship of CO2 and abrupt climate change. Understanding how future abrupt change might impact the carbon cycle is an important issue for society.
This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program's emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: "investigation of the physics of fast glacier flow with emphasis on processes at glacier beds"; "investigation of ice-shelf stability"; and "identification and quantification of the feedback between ice dynamics and climate change". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations.
Sowers/Brook<br/>0538538<br/>This award supports a project to develop a high-resolution (every 50 yr) methane data set that will play a pivotal role in developing the timescale for the new deep ice core being drilled at the West Antarctic Ice Sheet Divide (WAIS Divde) site as well as providing a common stratigraphic framework for comparing climate records from Greenland and WAIS Divide. Certain key intervals will be measured at even higher resolution to assist in precisely defining the phasing of abrupt climate change between the northern and southern hemispheres. Concurrent analysis of a suit of samples from both the WAIS Divide and GISP2 ice cores throughout the last 110kyr is also proposed, to establish the inter-hemispheric methane gradient which will be used to identify geographic areas responsible for the climate-related methane emission changes. A large gas measurement inter-calibration of numerous laboratories, utilizing both compressed air cylinders and WAIS Divide ice core samples, will also be performed. The intellectual merit of the proposed work is that it will provide the chronological control needed to examine the timing of changes in climate proxies, and critical chronological ties to the Greenland ice core records via methane variations. In addition, the project addresses the question of what methane sources were active during the ice age and will help to answer the fundamental question of what part of the biosphere controlled past methane variations. The broader impact of the proposed work is that it will directly benefit all ice core paleoclimate research and will impact the paleoclimate studies that rely on ice core timescales for correlation purposes. The project will also support a Ph.D. student at Oregon State University who will have the opportunity to be involved in a major new ice coring effort with international elements. Undergraduates at Penn State will gain valuable laboratory experience and participate fully in the project. The proposed work will underpin the WAIS Divide chronology, which will be fundamental to all graduate student projects that involve the core. The international inter-calibration effort will strengthen ties between research institutions on four continents and will be conducted as part of the International Polar Year research agenda.
This award supports a two year project to develop a new method for measuring vertical strain rates in polar firn. Vertical strain rate measurements in the firn are important because they can aid in the understanding of the dynamics of firn compaction, a key factor in determining ice age/gas age difference estimates for ice cores. Vertical strain rate measurements also determine ice advection for borehole paleothermometry models, and most importantly can be used to date the shallow sections of ice cores where ambiguities in chemical dating or counting of annual layers hinder dating by traditional methods. In this project a video logging tool will be used to create a unique "optical fingerprint" of variations in the optical properties of the firn with depth, and track the movement and deformation of the features of this fingerprint. Preliminary work at Siple Dome, Antarctica using an improvised logging system shows a series of optically bright and dark zones as the tool transits up or down the hole. Borehole fingerprinting has the potential to improve measurements of vertical strain in firn holes. This project represents a unique opportunity to interface with an existing field program where a borehole vertical strain rate project is already underway. A graduate student will be supported to conduct the work on this project as part of a PhD. dissertation on climate and physical processes in polar firn.
This award supports analyses of stable isotopes of water, dD, d18O and deuterium excess in the proposed West Antarctic Ice Sheet Divide (WAIS) deep ice core. The project will produce a continuous and high-resolution reconstruction of stable isotope ratios for the new core. dD and d18O values provide estimates of temperature change at the ice core site. Deuterium excess provides estimates of ocean surface conditions, such as sea surface temperature, at the moisture source areas. This new ice core is ideally situated to address questions ranging from ice sheet stability to abrupt climate change. WAIS Divide has high enough snowfall rates to record climate changes on annual to decadal time scales. It should also have ice old enough to capture the last interglacial period in detail. The West Antarctic ice sheet is the subject of great scrutiny as our modern climate warms and sea level rises. What are the prospects for added sea level rise from ice released by this ice sheet? Understanding how this ice sheet has responded to climate change in the past, which the data collected in this project will help to assess, is critical to answering this question. The high temporal resolution available in the WAIS Divide core will provide the best available basis for inter-comparison of millennial-scale climate changes between the poles, and thus a better understanding of the spatial expression and dynamics of rapid climate change events. Finally, the location of this core in the Pacific sector of West Antarctica makes it well situated for examining the influence of the tropical Pacific on Antarctica climate, on longer timescales than are available from the instrumental climate record. Analyses will include the measurement of sub-annually resolved isotope variations in the uppermost parts of the core, measurements at annual resolution throughout the last 10,000 years and during periods of rapid climate change prior to that, and measurements at 50-year resolution throughout the entire length of the core that is collected and processed during the period of this grant. We anticipate that this will be about half of the full core expected to be drilled. In terms of broader impacts, the PIs will share the advising of two graduate students, who will make this ice core the focus of their thesis projects. It will be done in an innovative multi-campus approach designed to foster a broader educational experience. As noted above, the data and interpretations generated by this proposal will address climate change questions not only of direct and immediate scientific interest, but also of direct and immediate policy interest.
This award supports a project to strengthen collaborations between the various research groups working on iceberg calving. Relatively little is known about the calving process, especially the physics that governs the initiation and propagation of fractures within the ice. This knowledge gap exists in part because of the diverse range in spatial and temporal scales associated with calving (ranging from less than one meter to over a hundred kilometers in length scale). It is becoming increasingly clear that to predict the future behavior of the Antarctic Ice Sheet and its contribution to sea level rise, it is necessary to improve our understanding of iceberg calving processes. Further challenges stem from difficulties in monitoring and quantifying short-time and spatial-scale processes associated with ice fracture, including increased fracturing events in ice shelves or outlet glaciers that may be a precursor to disintegration, retreat or increased calving rates. Coupled, these fundamental problems currently prohibit the inclusion of iceberg calving into numerical ice sheet models and hinder our ability to accurately forecast changes in sea level in response to climate change. Seismic data from four markedly different environmental regimes forms the basis of the proposed research, and researchers most familiar with the datasets will perform all analyses. Extracting the similarities and differences across the full breadth of calving processes embodies the core of the proposed work, combining and improving methods previously developed by each group. Techniques derived from solid Earth seismology, including waveform cross-correlation and clustering will be applied to each data set allowing quantitative process comparisons on a significantly higher level than previously possible. This project will derive catalogues of glaciologically produced seismic events; the events will then be located and categorized based on their location, waveform and waveform spectra both within individual environments and between regions. The intellectual merit of this work is that it will lead to a better understanding of iceberg calving and the teleconnections between seismic events and other geophysical processes around the globe. The broader impacts of this work are that it relates directly to socio-environmental impacts of global change and sea level rise. Strong collaborations will form as a result of this research, including bolstered collaborations between the glacier and ice sheet communities, as well as the glaciology and seismology communities. Outreach and public dissemination of findings will be driven by SIO's Visualization Center, and Birch Aquarium, hosting presentations devoted to the role of the cryosphere in global change. Time-lapse movies of recent changes at Columbia Glacier will be used to engage potential young scientists. A program of presentations outside the university setting to at-risk and gifted youth will be continued. This study will also involve undergraduates in analyses and interpretation and presentation of the seismic data assembled. The work will also support two junior scientists who will be supported by this project.
Waddington/0636997<br/><br/>This award supports a project to integrate three lines of glaciology research, previously treated independently. First, internal layers in ice sheets, detected by ice-penetrating radar, retain information about past spatial and temporal patterns of ice accumulation. Ice-flow modelers can recover this information, using geophysical inverse methods; however, the ages of the layers must be known, through interpolation where they intersect a well-dated ice core. <br/>Second, concentrations of methane and some other atmospheric constituents vary through time as climate changes. However, the atmosphere is always well mixed, and concentrations are similar world-wide at any one time, so gas variations from an undated core can be correlated with those in a well-dated core such as GISP2. Because air in near-surface firn mixes readily with the atmosphere above, the air that is trapped in bubbles deep in the firn is typically hundreds to thousands of years younger than that firn. Gas geochemists must calculate this age difference, called delta-age, with a firn-densification model before the ice enclosing the gas can be dated accurately. To calculate delta-age, they must know the temperature and the snow accumulation rate at the time and place where the snow fell. Third, gases can be correlated between cores only at times when the atmosphere changed, so ice-core dates must be interpolated at depths between the sparse dated points. Simplistic interpolation schemes can create undesirable artifacts in the depth-age profile. The intellectual merit of this project is that it will develop new interpolation methods that calculate layer thinning over time due to ice-flow mechanics. Accurate interpolation also requires a spatial and temporal accumulation history. These three issues are coupled through accumulation patterns and ice-core dates. This project will develop an integrated inversion procedure to solve all three problems simultaneously. The new method will incorporate ice-penetrating radar profile data and ice-core data, and will find self-consistent: spatial/temporal accumulation patterns; delta-age profiles for ice cores; and reliably interpolated depth-age profiles. The project will then: recalculate the depth-age profile at Byrd Station, Antarctica; provide a preliminary depth-age at the West Antarctic Ice Sheet (WAIS) in the initial stages of drilling, using radar layers with estimated ages traced from Byrd Station; and generate a self-consistent depth-age relationship for Taylor Dome, Antarctica over the past 20ka, where low accumulation has created uncertainty in dating, accumulation, and controversy over delta-age estimates. The broader impacts of the project are that it will support the PhD research of a female graduate student, and her continued outreach work with Making Connections, a non-profit program through the University of Washington Women's Center, which matches professional women mentors with minority high-school women interested in mathematics and science, disciplines where they are traditionally under-represented. The graduate student will also work with Girls on Ice, a ten-day glacier field program, taught by women scientist instructors, emphasizing scientific observation through immersion, leadership skills and safety awareness.
Whillans, Wilson, Goad OPP 9527571 Abstract This award supports a project to initiate Global Positioning System (GPS) measurements for rock motions in South Victoria Land and vicinity. The results will be used to test some of the leading models for ice-sheet change and tectonism, in particular, whether the continent is rebounding due to reduced ice load from East or West Antarctica and whether there is tectonic motion due to Terror Rift or uplift of the Transantarctic Mountains. A modest program to measure ice motion will be conducted as well. The motive is to test models for ice flow in the Allan Hills meteorite concentration region and to determine whether small glaciers in the Dry Valleys are thickening or thinning. Monuments will be set into rock and ice and GPS receivers used to determine their locations. Repeats in later years will determine motion. Field activities will involve close cooperation with the USGS.
Winckler/0636898<br/><br/>This award supports a project to study dust sources in Antarctic ice cores. Atmospheric aerosols play an important role both in global biogeochemical cycles as well as in the climate system of the Earth. Records extracted from Antarctic ice cores inform us that dust deposition from the atmosphere to the ice sheet was 15-20 times greater during glacial periods than during interglacials, which raises the possibility that dust may be a key player in climate change on glacial-interglacial timescales. By characterizing potential source areas from South America, South Africa, and Australia as well as fresh glacial flour from Patagonia, the project will determine if the interglacial dust was mobilized from a distinct geographical region (e.g., Australia) or from a more heavily weathered source region in South America. The intellectual merit of the project is that it will contribute to reconstructing climate-related changes in the rate of dust deposition, and in the provenance of the dust, it will provide critical constraints on hydrology and vegetation in the source regions, as well as on the nature of the atmospheric circulation transporting dust to the archive location. In a recent pilot study it was found that there is a dramatic glacial to Holocene change in the 4He/Ca ratio in the dust extracted from ice from Dronning Maud Land, Antarctica, indicating a shift in the source of dust transported to Antarctica. The broader impacts of the project are that Helium isotopes and calcium measurements provide a wealth of information that can then be turned into critical input for dust-climate models. Improved models, which are able to accurately reconstruct paleo dust distribution, will help us to predict changes in dust in response to future climate variability. This information will contribute to an improvement of our integrated understanding of the Earth's climate system and, in turn, will better inform policy makers of those processes and conditions most susceptible to perturbation by climate change, thereby leading to more meaningful climate-change policy. The project will support a graduate student in the dual masters Earth and Environmental Science Journalism program. The lead-PI manages the rock noble gas laboratory at Lamont. Her leadership role in this facility impacts the training of undergraduate and graduate students as well as visiting scientists.
Ice sheet models of the Last Glacial Maximum, and previous glaciation events in the Miocene, suggest that current low altitude, ice-free surfaces in Antarctica were completely covered with ice. If so, the terrestrial biota of Antarctica today would result from recolonization events after each glacial maximum. However, there is emerging evidence that much of the terrestrial Antarctic biota are of ancient origin and have somehow survived these glaciation events. The Transantarctic Mountains TRANsition Zone (TAM-TRANZ) plays a pivotal role in understanding the evolution and biogeographic history of today's Antarctic terrestrial biota, primarily because it contains numerous inland areas that could have served as refugia during glacial maxima. Due to its remote location, the TAM-TRANZ has not been systematically surveyed for animal biodiversity. Although an exhaustive survey of the region requires a multi-discipline, multi-year and multi-region effort, the research herein combines ecological, evolutionary and geophysical expertise to conduct an exploratory investigation of the extreme southern limits of biotic communities. The project will examine the historical geophysical requirements for the colonization and maintenance of functional ecosystems by multicellular organisms, and the feasibility and desirability to implement more systematic biogeographic studies in the future. Broader impacts include graduate and undergraduate student ownership of important subprojects that will provide research, presentation and publication opportunities. The investigators also will contribute to ongoing public education efforts through relationships with K-12 teachers and administrators in the public school districts where the project personnel reside. Finally, the project is leveraged by opportunistic collaboration with scientists associated with Antarctica New Zealand.
This project studies glaciovolcanic deposits at Minna Bluff in the western Ross Embayment of Antarctica. Its goal is to determine the history of the Ross Ice Shelf, which is fed by the major ice sheets from both East and West Antarctica. Apart from determining how these ice sheets waxed and waned during a period of dynamic climate change, glaciovolcanic sequences may constrain ice sheet parameters that are critical to numerical models such as thickness, hydrology, and basal thermal regime. This three-year study would map, analyze, and determine the age of key units using 40Ar/39Ar dating. Pilot studies would also be conducted for 36Cl dating of glacial deposits and stable isotope evaluations of alteration. The project offers a complementary record of Ross Ice Shelf behavior to that sampled by ANDRILL. It also improves the general record of McMurdo area volcanostratigraphy, which is important to interpreting landforms, glacial deposits, and ancient ice found in the Dry Valleys.<br/><br/>The broader impacts of this project include improving society's understanding of global climate change, sea level rise, and graduate and undergraduate student education. Outreach efforts include educational programs for public schools and community groups, exhibits for a local science museum, and a project website.
This award supports a project to investigate fabrics with ground-based radar measurements near the Ross/Amundsen Sea ice-flow divide where a deep ice core will be drilled. The alignment of crystals in ice (crystal-orientation fabric) has an important effect on ice deformation. As ice deforms, anisotropic fabrics are produced, which, in turn, influence further deformation. Measurement of ice fabric variations can help reveal the deformation history of the ice and indicate how the ice will deform in the future. Ice cores provide opportunities to determine a vertical fabric profile, but horizontal variations of fabrics remain unknown. Remote sensing with ice-penetrating radar is the only way to do that over large areas. Preliminary results show that well-established polarimetric methods can detect the degree of horizontal anisotropy of fabrics and their orientation, even when they are nearly vertical-symmetric fabrics. In conjunction with ice deformation history, our first mapping of ice fabrics will contribute to modeling ice flow near the future ice core site. The project will train a graduate student and provide research experiences for two under graduate students both in field and laboratory. The project will contribute to ongoing West Antarctic ice sheet program efforts to better understand the impact of the ice sheet on global sea level rise. This project also supports an international collaboration between US and Japanese scientists.
This award supports a project to make measurements of methane and other trace gases in firn air collected at South Pole, Antarctica. The analyses will include: methane isotopes (delta-13CH4 and delta-DCH4), light non-methane hydrocarbons (ethane, propane, and n-butane), sulfur gases (COS, CS2), and methyl halides (CH3Cl and CH3Br). The atmospheric burdens of these trace gases reflect changes in atmospheric OH, biomass burning, biogenic activity in terrestrial, oceanic, and wetland ecosystems, and industrial/agricultural activity. The goal of this project is to develop atmospheric histories for these trace gases over the last century through examination of depth profiles of these gases in South Pole firn air. The project will involve two phases: 1) a field campaign at South Pole, Antarctica to drill two firn holes and fill a total of ~200 flasks from depths reaching 120 m, 2) analysis of firn air at University of California, Irvine, Penn State University, and several other collaborating laboratories. Atmospheric histories will be inferred from the measurements using a one dimensional advective/diffusive model of firn air transport. This study will provide new information about the recent changes in atmospheric levels of these gases, providing about a 90 year long time series record that connects the earlier surface and firn air measurements to present day. The project will also explore the possibility of in- situ production of light non-methane hydrocarbons in firn air that is relevant to the interpretation of ice core records. The broader impacts of this research are that it has the potential for significant societal impact by improving our understanding of climate change and man's input to the atmosphere. The results of this work will be disseminated through the peer review process, and will contribute to environmental assessments, such as the Inter-governmental Panel on Climate Change (IPCC) Climate Assessment and the Word Meteorological Organization (WMO) Stratospheric Ozone Assessment. This research will provide educational opportunities for graduate and undergraduate students, and will contribute to a teacher training program for K-12 teachers in minority school districts.
The proposed research seeks to test the hypothesis that chemical and physical weathering in proximal alluvial systems will show systematic and measurable variations between glacial and nonglacial systems. To accomplish this, the investigation will attempt to quantify the natural variation of chemical and physical weathering in granitoid-sourced proximal alluvial sediments in end-member glacial and nonglacial systems, when other, "non-climatic" factors (e.g. provenance, drainage basin area and relief, sample grain size, sediment facies) are controlled. If chemical weathering in the proposed hot-humid, hot-arid, hot semi-arid nonglacial systems and the cool-wet, cold semi-arid, and cold-arid glacial systems show systematic variations, then chemical indices may be used to help differentiate paleoclimatic conditions. Continued reliance on students provides a broader impact of this proposed research and firmly grounds this effort in its educational mission.
Hall/0636687<br/><br/>This award supports a project to investigate late Pleistocene and Holocene changes in Scott Glacier, a key outlet glacier that flows directly into the Ross Sea just west of the present-day West Antarctic Ice Sheet (WAIS) grounding line. The overarching goals are to understand changes in WAIS configuration in the Ross Sea sector at and since the last glacial maximum (LGM) and to determine whether Holocene retreat observed in the Ross Embayment has ended or if it is still ongoing. To address these goals, moraine and drift sequences associated with Scott Glacier will be mapped and dated and ice thickness, surface velocity and surface mass balance will be measured to constrain an ice-flow model of the glacier. This model will be used to help interpret the dated geologic sequences. The intellectual merit of the project relates to gaining a better understanding of the West Antarctic Ice Sheet and how changing activity of fast-flowing outlet glaciers and ice streams exerts strong control on the mass balance of the ice sheet. Previous work suggests that grounding-line retreat in the Ross Sea continued into the late Holocene and left open the possibility of ongoing deglaciation as part of a long-term trend. Results from Reedy Glacier, an outlet glacier just behind the grounding line, suggest that retreat may have slowed substantially over the past 2000 years and perhaps even stopped. By coupling the work on Scott Glacier with recent data from Reedy Glacier, the grounding-line position will be bracketed and it should be possible to establish whether the retreat has truly ended or if it is ongoing. The broader impacts of the work relate to the societal relevance of an improved understanding of the West Antarctic ice sheet to establish how it will respond to current and possible future environmental changes. The work addresses this key goal of the West Antarctic Ice Sheet Initiative, as well as the International Polar Year focus on ice sheet history and dynamics. The work will develop future scientists through the education and training of one undergraduate and two Ph.D. students, interaction with K-12 students through classroom visits, web-based 'expedition' journals, letters from the field, and discussions with teachers. Results from this project will be posted with previous exposure dating results from Antarctica, on the University of Washington Cosmogenic Nuclide Lab website, which also provides information about chemical procedures and calculation methods to other scientists working with cosmogenic nuclides.
Tulaczyk/0636970<br/><br/>This award supports a project to study elevation change anomalies (henceforth ECAs), which are oval-shaped, 5-to-10 km areas observed in remote sensing images in several locations within the Ross Sea sector of the West Antarctic Ice Sheet (WAIS). Within these anomalies, surface elevation changes at rates of up to ~1 to ~2 cm per day, significantly faster than in surrounding regions. These anomalies are thought to result from filling and draining of multi-kilometer-scale subglacial water pockets. The intellectual merit of this project is that these ECA's represent an unprecedented window into the elusive world of water drainage dynamics beneath the modern Antarctic ice sheet. Although subglacial water fluxes are small compared to normal terrestrial conditions, they play an important role in controlling fast ice streaming and, potentially, stability of the ice sheet. The dearth of observational constraints on sub-ice sheet water dynamics represents one of the most important limitations on progress in quantitative modeling of ice streams and ice sheets. Such models are necessary to assess future ice sheet mass balance and to reconstruct the response of ice sheets to past climate changes. The dynamic sub-ice sheet water transport indicated by the ECAs may have also implications for studies of subglacial lakes and other subglacial environments, which may harbor life adapted to such extreme conditions. The broader impacts of this project are that it will provide advanced training opportunities to one postdoctoral fellow (UW), two female doctoral students (UCSC), who will enhance diversity in polar sciences, and at least three undergraduate students (UCSC). Project output will be relevant to broad scientific and societal interests, such as the future global sea level changes and the response of Polar Regions to climate changes. Douglas Fox, a freelance science journalist, is interested in joining the first field season to write feature articles to popular science magazines and promote the exposure of this project, and Antarctic Science in general, to mass media.
This award supports a project to understand how recent changes in atmospheric chemistry, and historical changes as recorded in snow, firn and ice, have affected atmospheric photochemistry over Antarctica. Atmospheric, snow and firn core measurements of selected gas, meteorological and snow physical properties will be made and modeling of snow-atmosphere exchange will be carried out. The intellectual merit of the project is that it will lead to a better an understanding of the atmospheric chemistry in West Antarctica, its bi-directional linkages with the snowpack, and how it responds to regional influences. There are at least four broader impacts of this work. First is education of university students at both the graduate and undergraduate levels. One postdoctoral researcher and one graduate student will carry out much of the work, and a number of undergraduates will be involved. Second, involvement with the WAIS-Divide coring program will be used to help recruit under-represented groups as UC Merced students. As part of UC Merced's outreach efforts in the San Joaquin Valley, whose students are under-represented in the UC system, the PI and co-PI give short research talks to groups of prospective students, community college and high school educators and other groups. They will develop one such talk highlighting this project. Including high-profile research in these recruiting talks has proven to be an effective way to promote dialog, and interest students in UC Merced. Third, talks such as this also contribute to the scientific literacy of the general public. The PI and grad student will all seek opportunities to share project information with K-14 and community audiences. Fourth, results of the research will be disseminated broadly to the scientific community, and the researchers will seek additional applications for the transfer functions as tools to improve interpretation of ice-cores. This research is highly collaborative, and leverages the expertise and data from a number of other groups.
0538120<br/>Catania<br/>This award supports a project to identify and map ice surface and internal features that chronicle the sequence of events leading to the shut-down of Kamb ice stream. In particular, the project will study past grounding line migration and the relationship between that process and ice stream shutdown. The intellectual merits of the project include the fact that an understanding of such processes has important implications for our ability to accurately predict mass balance changes in this region. Currently, one of the five major West Antarctic ice streams, Kamb, is quiescent, and another, Whillans, is slowing in its downstream reaches. The Kamb shutdown appears to have begun at its downstream end but beyond that simple observation, it is not possible, yet, to draw meaningful comparisons between the two adjacent streams. We do not know if current events on Whillans Ice Stream are similar to what transpired during the Kamb shut-down. The work proposed here intends to bridge that gap. It is expected that this effort will yield useful insights into the influence of grounding line dynamics on ice stream flow. The work will involve a combination of field investigations using radio-echo sounding and GPS combined with computational efforts involving the interpretation of ice-surface features such as relict flow traces and crevasses. The broader impacts of the project will be in addressing a global environmental problem with critical societal implications, training the next generation of scientists and engineers to serve the nation, and encouraging women to pursue scientific or engineering careers. Participants from both institutions are involved in a range of public outreach activities.
This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbræ. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.<br/><br/>The intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. <br/><br/>As lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets.
Edwards/0739780<br/><br/>This award supports a project to develop a 2,000-year high-temporal resolution record of biomass burning from the analysis of black carbon in the WAIS Divide bedrock ice core. Pilot data for the WAIS WD05A core demonstrates that we now have the ability to reconstruct this record with minimal impact on the amount of ice available for other projects. The intellectual merit of this project is that black carbon (BC) aerosols result solely from combustion and play a critical but poorly quantified role in global climate forcing and the carbon cycle. When incorporated into snow and ice, BC increases absorption of solar radiation making seasonal snow packs, mountain glaciers, polar ice sheets, and sea ice much more vulnerable to climate warming. BC emissions in the Southern Hemisphere are dominated by biomass burning in the tropical regions of Southern Africa, South America and South Asia. Biomass burning, which results from both climate and human activities, alters the atmospheric composition of greenhouse gases, aerosols and perturbs key biogeochemical cycles. A long-term record of biomass burning is needed to aid in the interpretation of ice core gas composition and will provide important information regarding human impacts on the environment and climate before instrumental records. The broader impacts of the project are that it represents a paradigm shift in our ability to reconstruct the history of fire from ice core records and to understand its impact on atmospheric chemistry and climate over millennial time scales. This type of data is especially needed to drive global circulation model simulations of black carbon aerosols, which have been found to be an important component of global warming and which may be perturbing the hydrologic cycle. The project will also employ undergraduate students and is committed to attracting underrepresented groups to the physical sciences. The project?s outreach component will be conducted as part of the WAIS project outreach program and will reach a wide audience.
9909734 Anderson This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research on the glaciomarine geology of the continental shelves of West Antarctica and the Antarctic Peninsula. It is hypothesized that the different glacial systems of the Antarctic Peninsula region have been more responsive to climate change and sea-level rise than either the West Antarctic or East Antarctic ice sheets. This is due mainly to the smaller size of these ice masses and the higher latitude location of the peninsula. Indeed, ice shelves of the Antarctic Peninsula are currently retreating at rates of up to a kilometer per year. But are these changes due to recent atmospheric warming in the region or are they simply the final phase of retreat since the last glacial maximum? This project hypothesizes that the deglacial history of the Antarctic Peninsula region has been quite complex, with different glacial systems retreating at different rates and at different times. This complex recessional history reflects the different sizes as well as different climatic and physiographic settings of glacial systems in the region. An understanding of the Late Pleistocene to Holocene glacial history of the Antarctic Peninsula glacial systems is needed to address how these systems responded to sea-level and climate change during that time interval. This investigation acquire new marine geological and geophysical data from the continental shelf to determine if and when different glacial systems were grounded on the shelf, to establish the extent of grounded ice, and to examine the history of glacial retreat. The project will build on an extensive seismic data set and hundreds of sediment cores collected along the Peninsula during earlier (1980's) cruises. Key to this investigation is the acquisition of swath bathymetry, side-scan sonar and very high-resolution sub-bottom (chirp) profiles from key drainage outlets. These new data will provide the necessary geomorphologic and stratigraphic framework for reconstructing the Antarctic Peninsula glacial record. Anticipated results will help constrain models for future glacier and ice sheet activity.
This award supports a research cruise to perform geologic studies in the area under and surrounding the former Larsen B ice shelf, on the Antarctic Peninsula. The ice shelf's disintegration in 2002 coupled with the unique marine geology of the area make it possible to understand the conditions leading to ice shelf collapse. Bellwethers of climate change that reflect both oceanographic and atmospheric conditions, ice shelves also hold back glacial flow in key areas of the polar regions. Their collapse results in glacial surging and could cause rapid rise in global sea levels. This project characterizes the Larsen ice shelf's history and conditions leading to its collapse by determining: 1) the size of the Larsen B during warmer climates and higher sea levels back to the Eemian interglacial, 125,000 years ago; 2) the configuration of the Antarctic Peninsula ice sheet during the LGM and its subsequent retreat; 3) the causes of the Larsen B's stability through the Holocene, during which other shelves have come and gone; 4) the controls on the dynamics of ice shelf margins, especially the roles of surface melting and oceanic processes, and 5) the changes in sediment flux, both biogenic and lithogenic, after large ice shelf breakup. <br/><br/><br/><br/>The broader impacts include graduate and undergraduate education through research projects and workshops; outreach to the general public through a television documentary and websites, and international collaboration with scientists from Belgium, Spain, Argentina, Canada, Germany and the UK. The work also has important societal relevance. Improving our understanding of how ice shelves behave in a warming world will improve models of sea level rise.<br/><br/><br/><br/>The project is supported under NSF's International Polar Year (IPY) research emphasis area on "Understanding Environmental Change in Polar Regions".
9909367 Leventer This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a multi-institutional, international (US - Australia) marine geologic and geophysical investigation of Prydz Bay and the MacRobertson Shelf, to be completed during an approximately 60-day cruise aboard the RVIB N.B. Palmer. The primary objective is to develop a record of climate and oceanographic change during the Quaternary, using sediment cores collected via kasten and jumbo piston coring. Core sites will be selected based on seismic profiling (Seabeam 2112 and Bathy2000). Recognition of the central role of the Antarctic Ice Sheet to global oceanic and atmospheric systems is based primarily on data collected along the West Antarctic margin, while similar extensive and high resolution data sets from the much more extensive East Antarctic margin are sparse. Goals of this project include (1) development of a century- to millennial-scale record of Holocene paleoenvironments, and (2) testing of hypotheses concerning the sedimentary record of previous glacial and interglacial events on the shelf, and evaluation of the timing and extent of maximum glaciation along this 500 km stretch of the East Antarctic margin. High-resolution seismic mapping and coring of sediments deposited in inner shelf depressions will be used to reconstruct Holocene paleoenvironments. In similar depositional settings in the Antarctic Peninsula and Ross Sea, sedimentary records demonstrate millennial- and century- scale variability in primary production and sea-ice extent during the Holocene, which have been linked to chronological periodicities in radiocarbon distribution, suggesting the possible role of solar variability in driving some changes in Holocene climate. Similar high-resolution Holocene records from the East Antarctic margin will be used to develop a circum-Antarctic suite of data regarding the response of southern glacial and oceanographic systems to late Quaternary climate change. In addition, these data will help us to evaluate the response of the East Antarctic margin to global warming. Initial surveys of the Prydz Channel - Amery Depression region reveal sequences deposited during previous Pleistocene interglacials. The upper Holocene and lower (undated) siliceous units can be traced over 15,000 km2 of the Prydz Channel, but more sub-bottom seismic reflection profiling in conjunction with dense coring over this region is needed to define the spatial distribution and extent of the units. Chronological work will determine the timing and duration of previous periods of glacial marine sedimentation on the East Antarctic margin during the late Pleistocene. Analyses will focus on detailed sedimentologic, geochemical, micropaleontological, and paleomagnetic techniques. This multi-parameter approach is the most effective way to extract a valuable paleoenvironmental signal in these glacial marine sediments. These results are expected to lead to a significant advance in understanding of the behavior of the Antarctic ice-sheet and ocean system in the recent geologic past. The combination of investigators, all with many years of experience working in high latitude marine settings, will provide an effective team to complete the project. University and College faculty (Principal Investigators on this project) will supervise a combination of undergraduate and post-graduate students involved in all stages of the project so that educational objectives will be met in tandem with the research goals of the project.
This award supports a project of scientific investigations along two overland traverses in East Antarctica: one going from the Norwegian Troll Station (72deg. S, 2deg. E) to the United States South Pole Station (90deg. S, 0deg. E) in 2007-2008; and a return traverse starting at South Pole Station and ending at Troll Station by a different route in 2008-2009. The project will investigate climate change in East Antarctica, with the goals of understanding climate variability in Dronning Maud Land of East Antarctica on time scales of years to centuries and determining the surface and net mass balance of the ice sheet in this sector to understand its impact on sea level. The project will also investigate the impact of atmospheric and oceanic variability and human activities on the chemical composition of firn and ice in the region, and will revisit areas and sites first explored by traverses in the 1960's, for detection of possible changes and to establish benchmark datasets for future research efforts. In terms of broader impacts, the results of this study will add to understanding of climate variability in East Antarctica and its contribution to global sea level change. The project includes international exchange of graduate students between the institutions involved and international education of undergraduate students through classes taught by the PI's at UNIS in Svalbard. It involves extensive outreach to the general public both in Scandinavia and North America through the press, television, science museums, children's literature, and web sites. Active knowledge sharing and collaboration between pioneers in Antarctic glaciology from Norway and the US, with the international group of scientists and students involved in this project, provide a unique opportunity to explore the changes that half a century have made in climate proxies from East Antarctica, scientific tools, and the culture and people of science. The project is relevant to the International Polar Year (IPY) since it is a genuine collaboration between nations: the scientists involved have complementary expertise, and the logistics involved relies on assets unique to each nation. It is truly an endeavor that neither nation could accomplish alone. This project is a part of the Trans- Antarctic Scientific Traverse Expeditions Ice Divide of East Antarctica (TASTE-IDEA) which is also part of IPY.
This project studies ancient ice buried in the Dry Valleys of Antarctica. The ice, which may approach ten million years in age, will be dated using argon and uranium radioisotope techniques. High-risk work, if successful it will offer the first and perhaps only samples of the Earth's atmosphere from millions of years in the past. These samples could offer critically important tests of paleoclimate records and proxies, as well as a glimpse into the characteristics of a past world much like the predicted future, warmer Earth. The broader impacts are graduate student education, and potentially contributing to society's understanding of global climate change and sea level rise.
This project develops power and communications systems to support the operation of seismometers and GPS receivers in Antarctica throughout the polar night. In terms of intellectual merit, this system would allow a new class of geophysical questions to be approached, in areas as varied as ice sheet movement, plate tectonics, and deep earth structure. In terms of broader impacts, this project represents research infrastructure of potential use to many scientific disciplines. In addition, the results will improve society's understanding of the Antarctic ice sheet and its behavior in response to global warming.
This award supports a project to test whether Kamb Ice Stream (formerly Ice Stream C (ISC)), an ice stream<br/>that is thought to have stopped ~150 years ago, may be already in the process of restarting. If yes, it will help establish what is the rate of ice stream reactivation and what mechanisms are controlling this rate. If there is no evidence for ongoing ice stream reactivation, the physical controls that are preventing it will be examined and alternative scenarios for near-future evolution of this ice stream will be explored. One such scenario is an increase in ice diversion toward the neighboring Whillans Ice Stream. Such diversion may help prevent a complete stoppage of Whillans Ice Stream,which has been slowing down for at least the last 24 years. This project will consist of two components: (1) field observations of bed properties,geometry of internal radar reflectors, as well as surface strain rates and velocity/topography changes using Ice-Penetrating Radar and differential Global Positioning System, (2) numerical modeling study of near future(~100-1000 years) evolution of Kamb Ice Stream. The field component will be focused on the bulge-to-trunk transition, which is located at the present time just downstream of the so-called camp UpC. Reactivation of Kamb Ice Stream should be reflected in a downstream migration of the bulge-trunk transition at possibly high rates (bulge migration rates of ~km/yr occur on surging mountain glaciers). The modeling<br/>component will be used to generate predictions regarding the near-future behavior of Kamb Ice Stream. This project will provide training opportunities for at least two undergraduate students (per year) at St. Olaf College and for one<br/>undergraduate student (per year) at UCSC. This collaboration will bring together scientists from three different types of US institutions: (1) a liberal arts college (St.Olaf College), (2) a public research university (UCSC) and (3) a NASA research laboratory (JPL). The project will also help build a new glaciological research program at UCSC. Project results will be incorporated into undergraduate and graduate courses at UCSC and will be made available<br/>to the general public and educators through downloadable graphics and animations posted on the research website of the UCSC PI. Field data resulting from the project will be posted in the Antarctic Glaciological Data Center for use by other investigators.
This award supports a project to examine the stratigraphy of near-surface sediments in Taylor Valley, Antarctica. Two contrasting hypotheses have been proposed for surface sediments in lower Taylor Valley, which have important and very different implications for how the West Antarctic Ice Sheet (WAIS) responded to the sea-level rise of the last deglaciation and Holocene environmental changes. One hypothesis holds that the sediments, designated Ross I drift, directly reflect >10,000 14C-years of WAIS shrinkage in the Ross Sea during and perhaps driven by deglacial sea-level rise. The other hypothesis, holds that the Taylor sediments have little significance for WAIS change during the deglaciation. These two hypotheses reflect fundamentally different interpretations of the sediment record. Over the course of two field seasons and a third year at the home institutions, the project will test these two hypotheses using glacial geology, geochemistry, ground penetrating radar (GPR) at both 100 MHz and 400 MHz, and portable sediment coring. The intellectual merit of the proposed work is that it will test these two hypotheses and make novel use of the subsurface record that may result in new insights into WAIS sensitivity during the deglaciation. The study will also directly test the conclusion that Glacial Lake Washburn was much larger than previously proposed during the Last Glacial Maximum (LGM). This occurrence, if real, represents a stunning climate anomaly. Answers to these local ice sheet and lake questions directly pertain to larger scale issues concerning the influences of sea-level rise, climate change, and internal ice-sheet dynamics on the recession of the WAIS since the LGM. There are numerous broader impacts to this project. Understanding the glacial and lake history in the McMurdo Sound region has important implications for the role that the WAIS will play in future sea-level and global climate change. Moreover, the history of Taylor Valley has significance for the ecosystem studies currently being conducted by the LTER group. Lastly, during the course of the proposed research, the project will train two graduate and undergraduate students and the research will be featured prominently in the teaching of students.
Abstract<br/><br/><br/><br/>This project performs a paleomagnetic survey of sediment cores from Antarctica's continental margin. Its goal is to refine the magnetostratigraphy to improve regional stratigraphic correlations, help date cores that lack biostratigraphic indicators, and understand paleoenvironmental conditions and climate change. As well, these cores record the earth's magnetic field near the magnetic pole, which may offer important information to scientists modeling the geodynamo.<br/><br/>The broader impacts of this work include postdoctoral and undergraduate education. There are also implications for society's understanding of global climate change, since these techniques offer a different perspective on climate change from Antarctic marine sediment cores, which are critical to understanding the behavior of the ice sheets and their links to the global climate.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The project aims on studying sediment cores collected from Prydz Bay and the Ross Sea to unravel the Neogene paleoclimatic history of the East Antarctic ice sheet. In the light of current measurements and predictions of a substantial rise in global temperature, investigations into the sensitivity of the East Antarctic ice sheet to climate change and its role in the climate system are essential. Geological records of former periods of climate change provide an opportunity to ground truth model predictions. The scientific objective of this project is to identify a previously proposed middle Miocene transition from a more dynamic wet-based East Antarctic ice sheet to the present semi-permanent ice sheet that is partially frozen to its bed. The timing and significance of this transition is controversial due to a lack of quantitative studies on well-dated ice-proximal sedimentary sequences. This project partially fills that gap using the composition and physical properties of diamictites and sandstones to establish shifts in ice-sheet drainage pathways, paleoenvironments and basal ice conditions. The results from the two key areas around the Antarctic continental margin will provide insight into the behavior of the East Antarctic ice sheet across the middle Miocene transition and through known times of warming in the late Miocene and Pliocene.
Cole-Dai<br/>0538553<br/><br/>This award supports a project that will contribute to the US West Antarctica Ice Sheet Ice Divide ice core (WAIS Divide) project by developing new instrumentation and analytical procedures to measure concentrations of major ions (Cl-, NO3-, SO42-, Na+, K+, NH4+, Mg2+, Ca2+). A melter-based, continuous flow, multi-ion-chromatograph technique (CFA-IC) has been developed recently at South Dakota State University (SDSU). This project will further expand and improve the CFA-IC technique and instrumentation and develop procedures for routine analysis of major ions in ice cores. In addition, training of personnel (operators) to perform continuous, high resolution major ion analysis of the deep core will be accomplished through this project. The temporal resolution of the major ion measurement will be as low as 0.5 cm with the fully developed CFA-IC technique. At this resolution, it will be possible to use annual cycles of sulfate and sea-salt ion concentrations to determine annual layers in the WAIS Divide ice core. Annual layer counting using CFA-IC chemical measurements and other high resolution measurements will contribute significantly to the major WAIS Divide project objective of producing precisely (i.e., annually) dated climate records. The project will support the integration of research and education, train future scientists and promote human resource development through the participation of graduate and undergraduate students. In particular, undergraduate participation will contribute to a current REU (Research Experience for Undergraduates) chemistry site program at SDSU. Development and utilization of multi-user instrumentation will promote research collaboration and advance environmental science. NSF support for SDSU will contribute to the economic development and strengthen the infrastructure for research and education in South Dakota.
This award supports a project to examine an existing ice core of opportunity from South Pole (SPRESO core) to develop a 2000+ year long climate record. SPRESO ice core will be an annually dated, sub-annually-resolved reconstruction of past climate (atmospheric circulation, temperature, precipitation rate, and atmospheric chemistry) utilizing continuous, co-registered measurements (n=45) of: major ions, trace elements, and stable isotope series, plus selected sections for microparticle size and composition. The intellectual merit of this project relates to the fact that few 2000+ year records of this quality exist in Antarctica despite increasing scientific interest in this critical time period as the framework within which to understand modern climate. The scientific impact of this ice core investigation are that it will provide an in-depth understanding of climate variability; a baseline for assessing modern climate variability in the context of human activity; and a contribution to the prediction of future climate variability. The broader impact of this work is that the proposed research addresses important questions concerning the role of Antarctica in past, present, and future global change. Results will be translated into publicly accessible information through public lectures, media appearances, and an extensive outreach activity housed in our Institute. Our ice core activities provide a major basis for curriculum in K-12 and University plus a basis for several field and laboratory based graduate theses and undergraduate student projects. The project will support one PhD student for 3 years and undergraduate salaries. The Climate Change Institute has a long history of gender and ethnically diverse student and staff involvement in research.
0538657<br/>Severinghaus<br/>This award supports a project to develop high-resolution (20-yr) nitrogen and oxygen isotope records on trapped gases in the WAIS Divide ice core (Antarctica), with a comparison record for chronological purposes in the GISP2 (Greenland) ice core. The main scientific objective is to provide an independent temperature-change record for the past 100,000 years in West Antarctica that is not subject to the uncertainty inherent in ice isotopes (18O and deuterium), the classical paleothermometer. Nitrogen isotopes (Delta 15N) in air bubbles in glacial ice record rapid surface temperature change because of thermal fractionation of air in the porous firn layer, and this isotopic anomaly is recorded in bubbles as the firn becomes ice. Using this gas-based temperature-change record, in combination with methane data as interpolar stratigraphic markers, the proposed work will define the precise relative timing of abrupt warming in Greenland and abrupt cooling at the WAIS Divide site during the millennial-scale climatic oscillations of Marine Isotopic Stage 3 (30-70 kyr BP) and the last glacial termination. The nitrogen isotope record also provides constraints on past firn thickness, which inform temperature and accumulation rate histories from the ice core. A search for possible solar-related cycles will be conducted with the WAIS Divide Holocene (Delta 15N.) Oxygen isotopes of O2 (Delta 18Oatm) are obtained as a byproduct of the (Delta 15N) measurement. The gas-isotopic records will enhance the value of other atmospheric gas measurements in WAIS Divide, which are expected to be of unprecedented quality. The high-resolution (Delta 18Oatm) records will provide chronological control for use by the international ice coring community and for surface glacier ice dating. Education of a graduate student, and training of a staff member in the laboratory, will contribute to the nation's human resource base. Outreach activities in the context of the International Polar Year will be enhanced. International collaboration is planned with the laboratory of LSCE, University of Paris.
Johnson/0632161<br/><br/>This award supports a project to create a "Community Ice Sheet Model (CISM)". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating "a new generation" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities.
Caffee/0839042 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a project to measure the concentration of the cosmogenic radionuclide, Beryllium-10 in the deep WAIS divide ice core. Since cosmogenic radionuclides are one of the key parameters used for absolute dating of the ice core and deriving paleoaccumulation rates, it is essential that these measurements be made quickly and efficiently, and that the information is disseminated as soon as the results are available. The intellectual merit of the project is that it will allow a comparison to be made between the core from WAIS Divide and previously measured cosmogenic radionuclide records from Arctic ice cores, particularly GISP2 and GRIP This project will enable scientists to delineate those processes acting at a local level from those that produce global effects and will provide independent chronological markers to aid in the reconstruction of the WAIS Divide ice core chronology. The cosmogenic 10Be profile can also be used to investigate the possible role of solar activity on climate. The direct comparison of radionuclide concentrations with paleoclimate records in ice cores from different sites will provide more insight in the timing and magnitude of solar forcing of climate. The broader impacts of this project include: (i) the formation of a multi-disciplinary team of collaborators for the interpretation of future analyses of cosmogenic radionuclide data from the WAIS divide and other ice cores. (ii) the involvement and training of graduate and undergraduate students in the large scale project of climate research through detailed studies of ice samples. (iii) the opportunity to highlight to a wide range of lab visitors and students from local K-12 schools the importance of ice core and climate change studies.<br/><br/>This award does not involve field work in Antarctica.
0538494<br/>Meese<br/>This award supports a project for physical properties research on snow pits and firn/ice cores with specific objectives that include stratigraphic analysis including determination of accumulation rates, annual layers, depth hoar, ice and wind crusts and rates of grain growth with depth. Studies of firn densification rates and how these parameters relate to the meteorology and climatology over the last 200 years of snow accumulation in Antarctica will also be investigated. The project will also determine the seasonality of accumulation by co-registration of stratigraphy and chemistry and determination of chemical species at the grain boundaries, how these may change with depth/densification (and therefore temperature), precipitation, and may affect grain growth. Fabric analyses will be made, including variation with depth, location on undulations and if any variation exists with climate/chemistry. The large spatial coverage of the US ITASE program offers the opportunity to determine how these parameters are affected by a large range of temperature, precipitation and topographic effects. The intellectual merit of the project includes the fact that ITASE is the terrestrial equivalent of a polar research vessel that provides a unique, logistically efficient, multi-dimensional (x, y, z and time) view of the atmosphere, ice sheet and their histories. Physical properties measurements/ analyses are an integral part of understanding the dynamic processes to which the accumulated snow is subjected. Recent advancements in the field along with multiple core sites provide an excellent opportunity to gain a much broader understanding of the spatial, temporal and physical variables that impact firnification and the possible resultant impact on climatic interpretation. In terms of broader impacts, the data collected by US ITASE and its international ITASE partners is available to a broad scientific community. US ITASE has an extensive program of public outreach and provides significant opportunities for many students to experience multidisciplinary Antarctic research. A graduate student, a post-doctoral fellow and at least one undergraduate would be funded by this work. Dr. Meese is also a member of the New England Science Collaborative, an organization that educates the public on climate change based on recent scientific advancements.
This award supports an investigation of spatial variations of ice temperature and subglacial conditions using available ice-penetrating radar data around a future deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet. Besides geometry of reflection layers the focus will be on intensities of radar echoes from within ice deeper than several hundred meters and will also examine echoes from the bed. Preliminary studies on theory and comparison with Japanese radar data from East Antarctica suggest that large spatial variations of the vertical gradient of radar echoes from within ice exist and are caused primarily by ice temperature and secondarily by crystal-orientation fabric. The hypothesis that the vertical gradient is a proxy of ice temperature will be tested. The project will utilize an existing data set from the Support Office for Aerogeophysical Research in Antarctica (SOAR) and will complement work already underway at University of Texas to analyze the radar data. The project will provide undergraduate research experience with an emphasis on computer analysis of time series and large data sets as well as development of web-based resource of results and methods and will support an international collaboration between US and Japan through discussions on the preliminary results from their study sites. Practical procedures developed through this study will be downloadable from the project's web site in the third year and will allow investigation of other ice sheets using existing radar data sets. This project will contribute to the interpretation of the future inland West Antarctic ice core and will help in the understanding of ice sheet history and climate change.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports project to test and develop approaches for using thermoluminescence techniques to determine the age of Antarctic marine sediments. <br/><br/>Quaternary (last 2 million yrs) marine sediments surrounding Antarctica record the waxing and waning of ice shelves and ice sheets, and also other paleoclimatic information, yet accurate chronologies of these sediments are difficult to obtain. Such chronologies provide the essential foundation for study of geological processes in the past. Within the range of radiocarbon (14C) dating (less than 30-40 thousand yrs, note - "ka" below means 1000 yrs) 14C dates can be inaccurate because of a variable 14C reservoir effect, and beyond 30-40 ka few methods are applicable. Photon-stimulated-luminescence sediment dating (photonic dating) of eolian and waterlain deposits in temperate latitudes spans the range from decades to hundreds of ka, but marine sediments in and around Antarctica pose special difficulty because of the potentially restricted exposure to daylight (the clock-zeroing process) of most detrital grains before deposition. This proposal will test the clock-zeroing assumption in representative Antarctic glaciomarine depositional settings, and thereby determine the potential reliability of photonic dating of Antarctic marine sediments.<br/><br/>Limited luminescence dating and signal-zeroing tests using glaciomarine and marine deposits have been conducted in the northern temperate and polar latitudes, but the effects on luminescence of the different glaciomarine depositional processes have never been studied in detail. Furthermore, the depositional settings around Antarctica are almost entirely polar, with consequent specific processes operating there. For example, transport of terrigenous suspensions by neutrally buoyant "cold-tongue" (mid-water) plumes may be common around Antarctica, yet the effect of such transport on luminescence zeroing is unknown. Typical marine cores near Antarctica may contain an unknown fraction of detrital grains from cold-tongue and near-bottom suspensions. Thus the extent to which the polar glaciomarine depositional processes around Antarctica may limit the potential accuracy of photonic dating of marine cores is unknown (age overestimates would result if grains are not exposed to daylight before deposition).<br/><br/>This project will collect detrital grains from a variety of "zero-age" (modern) marine depositional settings within the Antarctic Peninsula, where representative Antarctic depositional processes have been documented and where logistics permit access. Suspensions will be collected from four fjords representing a transect from polar through subpolar conditions. Suspensions will be collected from two stations and from up to 3 depths (surface and 2 deep plumes) at each station. Sediment traps will be deployed at two of these fjord settings. As well, core-top sediments will be collected from several sites. All samples will be shielded from light and transported to Reno, Nevada, for luminescence analyses.<br/><br/>Systematic study of the effectiveness of luminescence-clock-zeroing in Antarctic glaciomarine settings will determine if photonic dating can be reliable for future applications to Antarctic marine sediments. Refined sedimentological criteria for the selection of future samples for photonic dating are expected from this project. A photonic-dating capability would provide a numeric geochronometer extending well beyond the age range of 14C dating. Such a capability would permit answering a number of broader questions about the timing and extent of past glaciations near and on the Antarctic shelves.
This project studies the relationship between opening of the Drake Passage and formation of the Antarctic ice sheet. Its goal is to answer the question: What drove the transition from a greenhouse to icehouse world thirty-four million years ago? Was it changes in circulation of the Southern Ocean caused by the separation of Antarctica from South America or was it a global effect such as decreasing atmospheric CO2 content? This study constrains the events and timing through fieldwork in South America and Antarctica and new work on marine sediment cores previously collected by the Ocean Drilling Program. It also involves an extensive, multidisciplinary analytical program. Compositional analyses of sediments and their sources will be combined with (U-Th)/He, fission-track, and Ar-Ar thermochronometry to constrain uplift and motion of the continental crust bounding the Drake Passage. Radiogenic isotope studies of fossil fish teeth found in marine sediment cores will be used to trace penetration of Pacific seawater into the Atlantic. Oxygen isotope and trace metal measurements on foraminifera will provide additional information on the timing and magnitude of ice volume changes. <br/><br/><br/><br/>The broader impacts include graduate and undergraduate education; outreach to the general public through museum exhibits and presentations, and international collaboration with scientists from Argentina, Ukraine, UK and Germany.<br/><br/><br/><br/>The project is supported under NSF's International Polar Year (IPY) research emphasis area on "Understanding Environmental Change in Polar Regions". This project is also a key component of the IPY Plates & Gates initiative (IPY Project #77), focused on determining the role of tectonic gateways in instigating polar environmental change.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.
Anderson OPP 9527876 Abstract This award supports continuation of a long term investigation of the continental shelf sediments that is aimed at examining the configuration of the West Antarctic Ice Sheet during the last glacial maximum, the events and mechanisms involved in its retreat, and the timing of retreat. The project involves: 1) characterizing variations in the ice sheet grounding zone in a latitudinal transect extending from Ross Sea to Bransfield Basin, 2) reconstructing conditions at the ice/bed interface prior to and after ice sheet retreat, and 3) radiometrically dating ice sheet retreat along this transect. Detailed sea floor imagery (multibeam and deep-tow side-scan sonar), high resolution seismic reflection profiles, and sediment cores will be used to map and characterize prior grounding zones. Of particular concern are features that indicate the amount and organization (channelization) of basal meltwater and the extent of bed deformation that occurred in different ice streams. The timing of ice sheet retreat provides information about the link between Northern and Southern hemisphere ice expansion, and the role of eustasy in ice sheet decoupling. This research should lead to better predictive models to determine which ice streams are most unstable and likely, therefore, to serve as Oweak linksO in the long term behavior of West Antarctic Ice Sheet.
*** 9725024 Jacobs This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999. ***
This award supports an integrated seismic, sedimentologic, and paleontologic investigation of glacio-marine stratigraphy of the Ross Sea continental shelf. The purpose of this work is to acquire seismic images and sediment cores of the glacial sediments toward a better understanding of the Cenozoic history of glaciation in the Ross Sea region. This investigation will utilize high resolution seismic profiling data to locate regions where the Pleistocene glacial till is thin or perhaps absent. Piston coring at these locations, if the till is penetrated, will provide sedimentary records of Cenozoic depositional environments and could provide important clues to fluctuations of the Antarctic Ice Sheets. The seismic profiling will provide a direct record of the grounding history of the Ross Ice Shelf during the Pleistocene and it will also allow first order correlations of Cenozoic sedimentary units that are represented by sediments recovered in the piston cores. This work will provide important proxy records of the history of both the West Antarctic Ice Sheet and the East Antarctic Ice Sheet and this, in turn, will provide important constraints to climate models.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.
PROPOSAL NO.: 0094078<br/>PRINCIPAL INVESTIGATOR: Bart, Philip<br/>INSTITUTION NAME: Louisiana State University & Agricultural and Mechanical College<br/>TITLE: CAREER: Relative frequency and phase of extreme expansions of the Antarctic Ice Sheets during the late Neogene<br/>NSF RECEIVED DATE: 07/27/2000<br/><br/>PROJECT SUMMARY<br/><br/>Expansions and contractions of the Antarctic Ice Sheets (AISs) have undoubtedly had a profound influence on Earth's climate and global sea-level. However, rather than being a single entity, the Antarctic cryosphere consists of three primary elements: 1) the East Antarctic Ice Sheet (EAIS); 2) the West Antarctic Ice Sheet (WAIS); and 3) the Antarctic Peninsula Ice Cap (APIC). The distinguishing characteristics include significant differences in: 1) ice volume; 2) substratum elevation; 3) ice-surface elevation; and 4) location with respect to latitude. Various lines of evidence indicate that the AISs have undergone significant fluctuations in the past and that fluctuations will continue to occur in the future. The exact nature of the fluctuations has been the subject of many lively debates. According to one line of reasoning, the land-based EAIS has been relatively stable, experiencing only minor fluctuations since forming in the middle Miocene, whereas the marine-based WAIS has been dynamic, waxing and waning frequently since the late Miocene. According to an alternate hypothesis, the ice sheets advanced and retreated synchronously. These two views are incompatible. <br/><br/>The first objective of this proposal is to compare the long-term past behavior of the WAIS to that of the EAIS and APIC. The fluctuations of the AISs involve many aspects (the frequency of changes, the overall magnitude of ice-volume change, etc.), and the activities proposed here specifically concern the frequency and phase of extreme advances of the ice sheet to the continental shelf. The project will build upon previous seismic-stratigraphic investigations of the continental shelves. These studies have clarified many issues concerning the minimum frequency of extreme expansions for the individual ice sheets, but some important questions remain. During the course of the project, the following questions will be evaluated.<br/><br/>Question 1) Were extreme advances of the EAIS and WAIS across the shelf of a similar frequency and coeval? This evaluation is possible because the western Ross Sea continental shelf (Northern Basin) receives drainage from the EAIS, and the eastern Ross Sea (Eastern Basin) receives drainage from the WAIS. Quantitative analyses of the extreme advances from these two areas have been conducted by Alonso et al. (1992) and Bart et al. (2000), respectively. However, the existing single-channel seismic grids are incomplete and can not be used to determine the stratigraphic correlations from Northern Basin to Eastern Basin. It is proposed that high-resolution seismic data (~2000 kms) be acquired to address this issue.<br/><br/>Question 2) Were extreme advances of the APIC across the shelf as frequent as inferred by Bart and Anderson (1995)? Bart and Anderson (1995) inferred that the APIC advanced across the continental shelf at least 30 times since the middle Miocene. This is significant because it suggests that the advances of the small APIC were an order of magnitude more frequent than the advances of the EAIS and WAIS. Others contest the Bart and Anderson (1995) glacial-unconformity interpretation of seismic reflections, and argue that the advances of the APIC were far fewer (i.e., Larter et al., 1997). The recent drilling on the Antarctic Peninsula outer continental shelf has sampled some but not all of the glacial units, but the sediment recovery was poor, and thus, the glacial history interpretation is still ambiguous. The existing high-resolution seismic grids from the Antarctic Peninsula contain only one regional strike line on the outer continental shelf. This is inadequate to address the controversy of the glacial-unconformity interpretation and the regional correlation of the recent ODP results. It is proposed that high-resolution seismic data (~1000 kms) be acquired in a forthcoming (January 2002) cruise to the Antarctic Peninsula to address these issues.<br/><br/>The second objective of this project is 1) to expand the PI's effort to integrate his ongoing and the proposed experiments into a graduate-level course at LSU, and 2) to develop a pilot outreach program with a Baton Rouge public high school. The Louisiana Department of Education has adopted scientific standards that apply to all sciences. These standards reflect what 9th through 12th grade-level students should be able to do and know. The PI will target one of these standards, the Science As Inquiry Standard 1 Benchmark. The PI will endeavor to share with the students the excitement of conducting scientific research as a way to encourage the students to pursue earth science as a field of study at the university level.
Notothenioid fish are a major group of fish in the Southern Ocean. The ancestral notothenioid fish stock of Antarctica probably arose as a sluggish, bottom-dwelling perciform species that evolved some 40-60 million years ago in the then temperate shelf waters of the Antarctic continent. The grounding of the ice sheet on the continental shelf and changing trophic conditions may have eliminated the taxonomically diverse late Eocene fauna and initiated the original diversification of notothenioids. On the High Antarctic shelf, notothenioids today dominate the ichthyofauna in terms of species diversity, abundance and biomass, the latter two at levels of 90-95%. Since the International Geophysical Year of 1957-58, fish biologists from the Antarctic Treaty nations have made impressive progress in understanding the notothenioid ichthyofauna of the cold Antarctic marine ecosystem. However, integration of this work into the broader marine context has been limited, largely due to lack of access to, and analysis of, specimens of Sub-Antarctic notothenioid fishes. Sub-Antarctic fishes of the notothenioid suborder are critical for a complete understanding of the evolution, population dynamics, eco-physiology, and eco-biochemistry of their Antarctic relatives. This project will support an international, collaborative research cruise to collect and study fish indigenous to sub-antarctic habitats. The topics included in the research plans of the international team of researchers includes Systematics and Evolutionary Studies; Life History Strategies and Population Dynamics; Physiological, Biochemical, and Molecular Biological Investigations of Major Organ and Tissue Systems; Genomic Resources for the Sub-Antarctic Notothenioids; and Ecological Studies of Transitional Benthic Invertebrates. In a world that is experiencing changes in global climate, the loss of biological diversity, and the depletion of marine fisheries, the Antarctic, Sub-Antarctic, and their biota offer compelling natural laboratories for understanding the evolutionary impacts of these processes. The proposed work will contribute to development of a baseline understanding of these sensitive ecosystems, one against which future changes in species distribution and survival may be evaluated judiciously.
This collaborative study between Columbia University and the Southampton Oceanography Centre will investigate the dynamics of warm water intrusions under antarctic floating ice shelves. The study will focus on the Amundsen Sea and Pine Island Glacier, and will document how this water gains access to the continental shelf, transports heat into the ice shelf cavities via deep, glacially-scoured troughs, and rises beneath the ice to drive basal melting. The resulting seawater-meltwater mixtures upwell near the ice fronts, contributing to the formation of atypical coastal polynyas with strong geochemical signatures. Multidecadal freshening downstream is consistent with thinning ice shelves, which may be triggering changes inland, increasing the flow of grounded ice into the sea. This work will be carried out in combination with parallel modeling, remote sensing and data based projects, in an effort to narrow uncertainties about the response of West Antarctic Ice Sheet to climate change. Using state-of-the-art facilities and instruments, this work will enhance knowledge of water mass production and modification, and the understanding of interactions between the ocean circulation, sea floor and ice shelves. The data and findings will be reported to publicly accessible archives and submitted for publication in the scientific literature. The information obtained should prove invaluable for the development and validation of general circulation models, needed to predict the future role of the Antarctic Ice Sheet in sea level change.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program to initiate a Global Positioning System (GPS) network to measure crustal motions in the bedrock surrounding and underlying the West Antarctic Ice Sheet (WAIS). Evaluation of the role of both tectonic and ice-induced crustal motions of the WAIS bedrock is a critical goal for understanding past, present, and future dynamics of WAIS and its potential role in future global change scenarios, as well as improving our understanding of the role of Antarctica in global plate motions. The extent of active tectonism in West Antarctica is largely speculative, as few data exist that constrain its geographic distribution, directions, or rates of deformation. Active tectonism and the influence of bedrock on the WAIS have been highlighted recently by geophysical data indicating active subglacial volcanism and control of ice streaming by the presence of sedimentary basins. The influence of bedrock crustal motion on the WAIS and its future dynamics is a fundamental issue. Existing GPS projects are located only on the fringe of the ice sheet and do not address the regional picture. It is important that baseline GPS measurements on the bedrock around and within the WAIS be started so that a basis is established for detecting change.<br/><br/>To measure crustal motions, this project will build a West Antarctica GPS Network (WAGN) of at least 15 GPS sites across the interior of West Antarctica (approximately the size of the contiguous United States from the Rocky Mountains to the Pacific coast) over a two-year period beginning in the Antarctic field season 2001-2002. The planned network is designed using the Multi-modal Occupation Strategy (MOST), in which a small number of independent GPS "roving" receivers make differential measurements against a network of continuous GPS stations for comparatively short periods at each site. This experimental strategy, successfully implemented by a number of projects in California, S America, the SW Pacific and Central Asia, minimizes logistical requirements, an essential element of application of GPS geodesy in the scattered and remote outcrops of the WAIS bedrock.<br/><br/>The WAGN program will be integrated with the GPS network that has been established linking the Antarctic Peninsula with South America through the Scotia arc (Scotia Arc GPS Project (SCARP)). It will also interface with stations currently measuring motion across the Ross Embayment, and with the continent-wide GIANT program of the Working Group on Geodesy and Geographic Information Systems of the Scientific Committee on Antarctic Research (SCAR). The GPS network will be based on permanent monuments set in solid rock outcrops that will have near-zero set-up error for roving GPS occupations, and that can be directly converted to a continuous GPS site when future technology makes autonomous operation and satellite data linkage throughout West Antarctica both reliable and economical. The planned network both depends on and complements the existing and planned continuous networks. It is presently not practical, for reasons of cost and logistics, to accomplish the measurements proposed herein with either a network of continuous stations or traditional campaigns.<br/><br/>The proposed WAGN will complement existing GPS projects by filling a major gap in coverage among several discrete crustal blocks that make up West Antarctica, a critical area of potential bedrock movements. If crustal motions are relatively slow, meaningful results will only begin to emerge within the five-year maximum period of time for an individual funded project. Hence this proposal is only to initiate the network and test precision and velocities at the most critical sites. Once built, however, the network will yield increasingly meaningful results with the passage of time. Indeed, the slower the rates turn out to be, the more important an early start to measuring. It is anticipated that the results of this project will initiate an iterative process that will gradually resolve into an understanding of the contributions from plate rotations and viscoelastic and elastic motions resulting from deglaciation and ice mass changes. Velocities obtained from initial reoccupation of the most critical sites will dictate the timing of a follow-up proposal for reoccupation of the entire network when detectable motions have occurred.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a marine geological investigation of the Amundsen Sea region toward a better understanding of the deglaciation history of the West Antarctic Ice Sheet (WAIS). The WAIS may be inherently unstable because it is the last marine-based ice sheet in the world. Unlike other embayments in West Antarctica, major ice streams draining into the Amundsen Sea from the interior of the WAIS lack buttressing ice shelves. Mass balance data for the distal portions of these ice streams (Pine Island and Thwaites glaciers) appear to be in balance or may be becoming negative. Because both ice streams have beds that slope downward toward the center of the ice sheet, grounding-line recession resulting from either continued thinning or sea-level rise could trigger irreversible grounding-line retreat, leading to ice-sheet disintegration and consequent global sea-level rise. The limited marine geological and geophysical data available from the Amundsen Sea suggest that grounded ice or an ice shelf occupied the inner Amundsen Sea embayment until perhaps as recently as 1000 to 2000 years ago, and this ice may have retreated rapidly in historic time. This project, a study of the marine geology and geophysics of the Amundsen Sea continental shelf from 100 degrees W to 130 degrees W, is designed to address the Amundsen Sea part of WAIS Science Plan Priority Goal H2: "What is the deglaciation history in the eastern Ross, the Bellingshausen and Amundsen Seas?" This project will examine bathymetric data of the Amundsen Sea continental shelf to determine the positions of former ice-steam channels, and to aid in choosing sites for sediment coring. Single-channel seismic reflection studies will be conducted in order to determine sediment-thickness patterns, to aid in choice of coring sites, and to locate and identify morphologic features indicative of former grounded ice (e.g., moraines, scours, flutes, striations, till wedges and deltas, etc.). Coring will be concentrated along former ice flow-lines. Core samples will be analyzed in the laboratory for sedimentology, to determine whether of not basal tills are present (indicating former grounded ice and its former extent), and for calcareous and siliceous microfossils. The chronology of grounding-line and ice-shelf retreat from a presumed Last Glacial Maximum position near the shelf break will be established using accelerator mass spectrometry (AMS) carbon-14 dates of acid-insoluble particulate organic carbon. This project will share ship time in the Amundsen Sea with a physical oceanographic project. Marine geologic data and samples collected will be integrated with findings of other investigators toward developing a comprehensive interpretation of the history of the WAIS.
Luyendyk et.al.: OPP 0088143<br/>Bartek: OPP 0087392<br/>Diebold: OPP 0087983<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program in marine geology and geophysics in the southern central and eastern Ross Sea. The project will conduct sites surveys for drilling from the Ross Ice Shelf into the seafloor beneath it. Many of the outstanding problems concerning the evolution of the East and West Antarctic Ice Sheets, Antarctic climate, global sea level, and the tectonic history of the West Antarctic Rift System can be addressed by drilling into the seafloor of the Ross Sea. Climate data for Cretaceous and Early Cenozoic time are lacking for this sector of Antarctica. Climate questions include: Was there any ice in Late Cretaceous time? What was the Antarctic climate during the Paleocene-Eocene global warming? When was the Cenozoic onset of Antarctic glaciation, when did glaciers reach the coast and when did they advance out onto the margin? Was the Ross Sea shelf non-marine in Late Cretaceous time; when did it become marine? Tectonic questions include: What was the timing of the Cretaceous extension in the Ross Sea rift; where was it located? What is the basement composition and structure? Where are the time and space limits of the effects of Adare Trough spreading? Another drilling objective is to sample and date the sedimentary section bounding the mapped RSU6 unconformity in the Eastern Basin and Central Trough to resolve questions about its age and regional extent. Deep Sea Drilling Project (DSDP) Leg 28 completed sampling at four drill sites in the early 1970's but had low recovery and did not sample the Early Cenozoic. Other drilling has been restricted to the McMurdo Sound area of the western Ross Sea and results can be correlated into the Victoria Land Basin but not eastward across basement highs. Further, Early Cenozoic and Cretaceous rocks have not been sampled. A new opportunity is developing to drill from the Ross Ice Shelf. This is a successor program to the Cape Roberts Drilling Project. One overriding difficulty is the need for site surveys at drilling locations under the ice shelf. This project will overcome this impediment by conducting marine geophysical drill site surveys at the front of the Ross Ice Shelf in the Central Trough and Eastern Basin. The surveys will be conducted a kilometer or two north of the ice shelf front where recent calving events have resulted in a southerly position of the ice shelf edge. In several years the northward advance of the ice shelf will override the surveyed locations and drilling could be accomplished. Systems to be used include swath bathymetry, gravity, magnetics, chirp sonar, high resolution seismic profiling, and 48 fold seismics. Cores will be collected to obtain samples for geotechnical properties, to study sub-ice shelf modern sedimentary processes, and at locations where deeper section is exposed.<br/><br/>This survey will include long profiles and detailed grids over potential drill sites. Survey lines will be tied to existing geophysical profiles and DSDP 270. A recent event that makes this plan timely is the calving of giant iceberg B-15 (in March, 2000) and others from the ice front in the eastern Ross Sea. This new calving event and one in 1987 have exposed 16,000 square kilometers of seafloor that had been covered by ice shelf for decades and is not explored. Newly exposed territory can now be mapped by modern geophysical methods. This project will map geological structure and stratigraphy below unconformity RSU6 farther south and east, study the place of Roosevelt Island in the Ross Sea rifting history, and determine subsidence history during Late Cenozoic time (post RSU6) in the far south and east. Finally the project will observe present day sedimentary processes beneath the ice shelf in the newly exposed areas.
Marine geological and geophysical studies of the Ross Sea and Weddell Sea continental shelves provide evidence that the ice sheet grounded near the shelf edge in these areas during the late Wisconsinan, and that the retreat of the ice sheet to its present position was rapid and probably episodic. This Award supports a project which will establish the most recent (late Wisconsin- Holocene) history of ice sheet advance and retreat in Ross Sea. The objectives include: 1) reconstruction the late Wisconsin paleodrainage regime, including ice stream divides; 2) reconstruction of former grounding zone positions; 3) constraint of the timing of ice sheet retreat from the shelf; and 4) acquisition of geophysical, sedimentological, and paleontological data which may provide indicators the environmental factors that may have influenced to ice sheet retreat. This is a joint effort between Rice University, the University of Colorado, and Hamilton College. The project involves experts in a wide variety of fields, and will interface with glaciologists, physical oceanographers and climatologists who will address the problem of ice sheet stability and the record of climatic and glaciological change.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.
This award supports a collaborative marine geological and geophysical project between the University of California, Santa Barbara, and the University of Alabama to study the glacial and tectonic history of the eastern Ross Sea and the Marie Byrd Land margin of West Antarctica. The goals of the project are (1) to conduct seismic imaging and piston coring to begin unraveling the history of the West Antarctic ice Sheet as recorded in the recent sediments of the continental shelf of the region, and (2) to acquire seismic images of the acoustic basement beneath the Cenozoic glacial deposits toward an understanding of the relationship between rift structure of the continental crust and Cenozoic glacial deposits of the region. This research will result in bathymetric, structural, sediment isopach, gravity and magnetic maps of the eastern Ross Sea and the Marie Byrd Land margin. This information will be integrated into an interpretation of the major glacial and structural features of the region. This project will result in a better understanding of the glacio-marine stratigraphy and glacial history of the eastern Ross Sea and Marie Byrd Land margin and, consequently, it will represent a significant contribution to the goals of the West Antarctic Ice Sheet initiative.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). <br/><br/>This award supports a project to reconstruct the past physical and chemical climate of Antarctica, with an emphasis on the region surrounding the Ross Sea Embayment, using >60 ice cores collected in this region by US ITASE and by Australian, Brazilian, Chilean, and New Zealand ITASE teams. The ice core records are annually resolved and exceptionally well dated, and will provide, through the analyses of stable isotopes, major soluble ions and for some trace elements, instrumentally calibrated proxies for past temperature, precipitation, atmospheric circulation, chemistry of the atmosphere, sea ice extent, and volcanic activity. These records will be used to understand the role of solar, volcanic, and human forcing on Antarctic climate and to investigate the character of recent abrupt climate change over Antarctica in the context of broader Southern Hemisphere and global climate variability. The intellectual merit of the project is that ITASE has resulted in an array of ice core records, increasing the spatial resolution of observations of recent Antarctic climate variability by more than an order of magnitude and provides the basis for assessment of past and current change and establishes a framework for monitoring of future climate change in the Southern Hemisphere. This comes at a critical time as global record warming and other impacts are noted in the Southern Ocean, the Antarctic Peninsula, and on the Antarctic ice sheet. The broader impacts of the project are that Post-doctoral and graduate students involved in the project will benefit from exposure to observational and modeling approaches to climate change research and working meetings to be held at the two collaborating institutions plus other prominent climate change institutions. The results are of prime interest to the public and the media Websites hosted by the two collaborating institutions contain climate change position papers, scientific exchanges concerning current climate change issues, and scientific contribution series.
This project brings together researchers with expertise in molecular microbial ecology, Antarctic and deep sea environments, and metagenomics to address the overarching question: how do ecosystems dominated by microorganisms adapt to conditions of continuous cold and dark over evolutionarily and geologically relevant time scales? Lake Vostok, buried for at least 15 million years beneath approximately 4 km of ice that has prevented any communication with the external environment for as much as 1.5 million years, is an ideal system to study this question. Water from the lake that has frozen on to the bottom of the ice sheet (accretion ice) is available for study. Several studies have indicated the presence of low abundance, but detectable microbial communities in the accretion ice. Our central hypothesis maintains that Lake Vostok microbes are specifically adapted to life in conditions of extreme cold, dark, and oligotrophy and that signatures of those adaptations can be observed in their genome sequences at the gene, organism, and community levels. To address this hypothesis, we propose to characterize the metagenome (i.e. the genomes of all members of the community) of the accretion ice. using whole genome amplification (WGA), which can provide micrograms of unbiased metagenomic DNA from only a few cells. The results of this project have relevance to evolutionary biology and ecology, subglacial Antarctic lake exploration, biotechnology, and astrobiology. The project directly addresses priorities and themes in the International Polar Year at the national and international levels. A legacy of DNA sequence data and the metagenomic library will be created and maintained. Press releases and a publicly available web page will facilitate communication with the public. K-12 outreach will be the focus of a new, two-tiered program targeting the 7th grade classroom and on site visits to the Joint Genome Institute Production Sequencing Facility by high school juniors and seniors and community college level students. Minority undergraduate researchers will be recruited for research on this project, and support and training are provided to two graduate students, a postdoctoral scholar, and a technician.
This award supports a study of the physical nature and environmental origin of optical features (light and dark zones) observed by video in boreholes in polar ice. These features appear to include an annual signal, as well as longer period signals. Borehole logs exist from a previous project, and in this lab-based project the interpretation of these logs will be improved. The origin of the features is of broad interest to the ice-core community. If some components relate to changes in the depositional environment beyond seasonality, important climatic cycles may be seen. If some components relate to post-depositional reworking, insights will be gained into the physical processes that change snow and firn, and the implications for interpretation of the chemical record in terms of paleoclimate. In order to exploit these features to best advantage in future ice-core and climate-change research, the two principal objectives of this project are to determine what physically causes the optical differences that we see and to determine the environmental processes that give rise to these physical differences. In the laboratory at NICL the conditions of a log of a borehole wall will be re-created as closely as possible by running the borehole video camera along sections of ice core, making an optical log of light reflected from the core. Combinations of physical variables that are correlated with optical features will be identified. A radiative-transfer model will be used to aid in the interpretation of these measurements, and to determine the optimum configuration for an improved future logging tool. An attempt will be made to determine the origin of the features. Two broad possibilities exist: 1) temporal changes in the depositional environment, and 2) post-depositional reworking. This project represents an important step toward a new way of learning about paleoclimate with borehole optical methods. Broader impacts include enhancing the infrastructure for research and education, since this instrument will complement high-resolution continuous-melter chemistry techniques and provide a rapid way to log physical variables using optical features as a proxy for climate signals. Since no core is required for this method, it can be used in rapidly drilled access holes or where core quality is poor. This project will support a graduate student who will carry out this project under the direction of the Principal Investigator. K-12 education will be enhanced through an ongoing collaboration with a science and math teacher from a local middle school. International collaboration will be expanded through work on this project with colleagues at the Norwegian Polar Institute and broad dissemination of results will occur through a project website for the general public.
This award supports development of a new modeling approach that will extract information about past snow accumulation rate in both space and time in the vicinity of the future ice core near the Ross-Amundsen divide of the West Antarctic Ice Sheet (WAIS). Internal layers, detected by ice-penetrating radar, are isochrones, or former ice-sheet surfaces that have been buried by subsequent snowfall, and distorted by ice flow. Extensive ice-penetrating radar data are available over the inland portion of the WAIS. Layers have been dated back to 17,000 years before present. The radar data add the spatial dimension to the temporally resolved accumulation record from ice cores. Accumulation rates are traditionally derived from the depths of young, shallow layers, corrected for strain using a local 1-D ice-flow model. Older, deeper layers have been more affected by flow over large horizontal distances. However, it is these deeper layers that contain information on longer-term climate patterns. This project will use geophysical inverse theory and a 2.5D flow-band ice-flow forward model comprising ice-surface and layer-evolution modules, to extract robust transient accumulation patterns by assimilating multiple deeper, more-deformed layers that have previously been intractable. Histories of divide migration, geothermal flux, and surface evolution will also be produced. The grant will support the PhD research of a female graduate student who is a mentor to female socio-economically disadvantaged high-school students interested in science, through the University of Washington Women's Center. It will also provide a research<br/>experience for an undergraduate student, and contribute to a freshman seminar on Scientific Research.
This award is for support for three years of funding to study the effects of impurities on the flow of poly- crystalline ice. It has been known for thirty years that both hydrofluoric acid (HF) and hydrochloric acid (HCl) dramatically decrease the strength of ice and recent work by the author's group has shown that sulfuric acid (H2SO4) produces a similar reduction in strength. However, these data are for single crystals at strain rates and stresses that far exceed those found in glaciers and ice sheets, and often at concentrations that far exceed those in natural ice. Therefore, it is not known how impurities found in nature affect the flow of polycrystalline ice at slow strain rates. In this research, the effects of nitric acid and sulfuric acid (which are naturally occurring impurities in ice) on the microstructure (dislocation structure, grain boundary structure and location of the acids) and creep of polycrystalline ice (at a range of temperatures and stresses) will be determined. The ice's response to creep deformation will be studied using a combination of x-ray topography, optical microscopy and scanning electron microscopy. X-ray microanalysis in an environmental scanning electron microscope will be used to study the location of impurities. The structure and creep behavior of the acid-doped ice will be compared with those of both high-purity laboratory-grown ice and ice from Byrd Station, Antarctica. The end-result of this project will be to elucidate the effects of naturally-occurring acid impurities on the mechanical properties of polycrystalline ice under conditions relevant to the deformation of glaciers and ice sheets, including and understanding of how impurities affect the underlying deformation mechanisms.
This award supports the coordination of an interdisciplinary and multi institutional deep ice coring program in West Antarctica. The program will develop interrelated climate, ice dynamics, and biologic records focused on understanding interactions of global earth systems. The records will have a year-by-year chronology for the most recent 40,000 years. Lower temporal resolution records will extend to 100,000 years before present. The intellectual activity of this project includes enhancing our understanding of the natural mechanisms that cause climate change. The study site was selected to obtain the best possible material, available from anywhere, to determine the role of greenhouse gas in the last series of major climate changes. The project will study the how natural changes in greenhouse gas concentrations influence climate. The influence of sea ice and atmospheric circulation on climate changes will also be investigated. Other topics that will be investigated include the influence of the West Antarctic ice sheet on changes in sea level and the biology deep in the ice sheet. The broader impacts of this project include developing information required by other science communities to improve predictions of future climate change. The <br/>project will use mass media to explain climate, glaciology, and biology issues to a broad audience. The next generation of ice core investigators will be trained and there will be an emphasis on exposing a diverse group of students to climate, glaciology and biology research.
OPP-0230285/OPP-0230356<br/>PIs: Wilson, Terry J./Hothem, Larry D.<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to conduct GPS measurements of bedrock crustal motions in an extended Transantarctic Mountains Deformation network (TAMDEF) to document neotectonic displacements due to tectonic deformation within the West Antarctic rift and/or to mass change of the Antarctic ice sheets. Horizontal displacements related to active neotectonic rifting, strike-slip translations, and volcanism will be tightly constrained by monitoring the combined TAMDEF and Italian VLNDEF networks of bedrock GPS stations along the Transantarctic Mountains and on offshore islands in the Ross Sea. Glacio-isostatic adjustments due to deglaciation since the Last Glacial Maximum and to modern mass change of the ice sheets will be modeled from GPS-derived crustal motions together with new information from other programs on the configurations, thicknesses, deglaciation history and modern mass balance of the ice sheets. Tectonic and rheological information from ongoing structural and seismic investigations in the Victoria Land region will also be integrated in the modeling. The integrative and iterative modeling will yield a holistic interpretation of neotectonics and ice sheet history that will help us to discriminate tectonic crustal displacements from viscoelastic/elastic glacio-isostatic motions. These results will provide key information to interpret broad, continental-scale crustal motion patterns detected by sparse, regionally distributed GPS continuous trackers and by spaceborne instruments. This study will contribute to international programs focused on Antarctic neotectonic and global change issues.<br/><br/>Strategies to meet these science objectives include repeat surveys of key sites in the existing TAMDEF network, extension of the array of TAMDEF sites southward about 250 km along the Transantarctic Mountains, linked measurements with the VLNDEF network, and integration of quasi-continuous trackers within the campaign network. By extending the array of bedrock sites southward, these measurements will cross gradients in predicted vertical motion due to viscoelastic rebound. The southward extension will also allow determination of the southern limit of the active Terror Rift and will provide a better baseline for constraints on any ongoing tectonic displacements across the West Antarctic rift system as a whole that might be possible using GPS data collected by the West Antarctic GPS Network. This project will also investigate unique aspects of GPS geodesy in Antarctica to determine how the error spectrum compares to mid-latitude regions and to identify the optimum measurement and data processing schemes for Antarctic conditions. The geodetic research will improve position accuracies within our network and will also yield general recommendations for deformation monitoring networks in polar regions.<br/><br/>An education and outreach program is planned and will be targeted at non-science-major undergraduate students taking Earth System Science at Ohio State University. The objective will be to illuminate the research process for nonscientists. This effort will educate students on the process of science and inform them about Antarctica and how it relates to global science issues.
This award supports a project to obtain stable isotope profiles from shallow (<100 m) ice cores from East Antarctica, to add to the growing database of environmental proxy data collected under the auspices of the "ITASE" (International TransAntarctic Scientific Expedition) program. In Antarctica, the instrumental record of climate is particularly short (~40 years except in a few isolated locations on the coast), and ice core proxy data are the only means available for extending this record into the past. The use of stable isotopes of water (18-O/16-O and D/H ratios) from ice cores as proxies for temperature is well established for both very short (i.e. seasonal) and long timescales (centuries, millennia). Using multivariate regression methods and shallow ice cores from West Antarctica, a reconstruction of Antarctic climate over the last ~150 years has been developed which suggests the continent has been warming, on average, at a rate of ~0.2 K/century. Further improving these reconstructions is the chief motivation for further extending the US ITASE project. Ten to fifteen shallow (~ 100 m) from Victoria Land, East Antarctica will be obtained and analyzed. The core will be collected along a traverse route beginning at Taylor Dome and ending at the South Pole. Age-depth relationships for the cores will be determined through a combination of stable isotopes, visual stratigraphy and seasonal chemical signatures and marker horizons. Reconstructions of Antarctic climate obtained from these cores will be incorporated into the global network of paleoclimate information, which has been important in science, policy and educational contexts. The project will include graduate student and postdoctoral training and field experience.
0086645<br/>Fountain<br/><br/>This award supports a Small Grant for Exploratory Research (SGER) to study glaciological change in the McMurdo Dry Valleys, Antarctica under the category of "application of new expertise or new approaches to established research topics". The purpose of the project is to assess the application of classified imagery to the study of the magnitude and rate of change of glacier extent and lake area as an indicator of climate change. Because the rate of change of both glacier extent and lake area is small compared to the resolution of unclassified imagery, the increased resolution of classified imagery is clearly needed. Access to classified imagery with 1 meter or better resolution will provide a baseline measurement against which future changes can be compared. Maximum use will be made of archived imagery but if necessary, one request will be made for new imagery to supplement the existing archive. This work will support on-going field measurements which are part of the Long-Term Ecological Research (LTER) site in the McMurdo Dry Valleys but which are limited by logistic constraints to only a few measurements during limited times of the year. If successful, the information gained in this project will enable researchers to better direct their efforts to identify the important physical processes controlling the changes in the valleys. The information acquired in conducting this project will be made available to the public, using appropriate security procedures to declassify the data. The "exploratory" and "high risk" nature of the proposed work and its "potential" to make an important "impact" on the field of Antarctic glacier studies are all reasons that this work is appropriate to support as an SGER.
Abstract<br/>This project studies microfossils of plants and algae to understand climate during the earliest glaciations of Antarctica. The microfossils are from marine sediment cores collected by the 2006 SHALDRIL campaign to the Antarctic Peninsula. The work will offer constraints on sea surface temperature, ocean salinity, and terrestrial vegetation to help answer questions such as: What were conditions like on the Antarctic Peninsula during the initial formation of Antarctica's ice sheets? How rapidly did the ice sheets grow? Was their growth driven by global factors such as low atmospheric CO2 or local events like opening of the Drake Passage? <br/><br/>The broader impacts include postdoctoral fellow research and outreach via a museum exhibit and a web-based activity book for children.
0125794<br/>Price<br/><br/>This award supports research in climatology, geosciences, and life in extreme environments to be carried out with a newly developed optical borehole logger. The logger fits into a fluid-filled borehole in glacial ice. It emits light at 370 nm in a horizontal plane in order to probe optical properties of particles embedded in the ice out to several meters from the borehole. After leaving the borehole, the light is partially absorbed and scattered by dust, biomolecules, or microbes. A fraction of the light is scattered back into the borehole and is detected by a system of seven phototubes, each of which collects light with high efficiency in a separate wavelength band. One of them collects light that scatters off of dust and air bubbles without wavelength shift, and serves as a dust logger. The other six are covered with notch filters that measure six different wavelength bands and measure the shape of the fluorescence spectrum of microbes and biomolecules. Thus, the same instrument serves as both a dust logger and a microbe logger. Applications include: 1) Precise chronologies and long-period solar variability. With a resolution of 1 to 2 cm for both GISP2 and Siple Dome, the logger will record annual dust maxima and evaluate claims of modulations of dust concentration with periods ranging from 11 yrs (the solar cycle) to 2300 yrs; 2) Volcanism and age-depth markers. Dozens of volcanic ash bands will be detectable and will serve as primary age-depth markers for other boreholes; 3) Microorganisms and biomolecules. The vertical distribution of living, dormant, and dead microbes can be logged, and searches for archaea and aeolian polyaromatic hydrocarbons can be made. The logging experiments will be carried out at Siple Dome and Dome C in Antarctica and at GISP2 and GRIP in Greenland.
This project develops a system of airborne instruments to explore the polar ice sheets and their underlying environments. The instrument suite includes an ice-penetrating radar, laser altimeter, gravimeter and magnetometer. Airborne geophysical measurements are key to understanding the 99% of Antarctica and 85% of Greenland covered by ice, which have thus far been studied at the postage stamp level. Projects linking ice sheet behavior to underlying geology will immediately benefit from this system, but even more exciting are the system's potential uses for work at the frontiers of polar science, such as: 1) exploring subglacial lakes, recently discovered and potentially the most unique sites on Earth for understanding life in extreme environments; 2) locating the deepest, oldest ice, which would offer million year and older samples of the atmosphere and 3) interpreting Antarctica's subglacial geology, which contains unique and unstudied volcanoes, mountains, and tectonic provinces. In terms of broader impacts, this project constructs research infrastructure critical to society's understanding of sea level rise, and supports a project involving domestic, international, and private sector collaborations.
The award supports the development of high-resolution nitrogen and oxygen isotope records on trapped gases in the Byrd and Siple Dome ice cores, and the Holocene part of the GISP2 ice core. The primary scientific goals of this work are to understand the enigmatic d15N anomalies seen thus far in the Siple Dome record at 15.3 ka and 35 ka, and to find other events that may occur in both cores. At these events, d15N of trapped air approaches zero, implying little or no gravitational fractionation of gases in the firn layer at the time of formation of the ice. These events may represent times of low accumulation rate and arid meteorological conditions, and thus may contain valuable information about the climatic history of West Antarctica. Alternatively, they may stem from crevassing and thus may reveal ice-dynamical processes. Finding the events in the Byrd core, which is located 500 km from Siple Dome, would place powerful constraints on their origin and significance. A second major goal is to explore the puzzling absence of the abrupt warming event at 22 ka (seen at Siple Dome) in the nearby Byrd 18O/16O record in the ice (d18Oice), and search for a possible correlative signal in Byrd d15N. A third goal takes advantage of the fact that precise measurements of the oxygen isotopic composition of atmospheric O2 (d18Oatm) are obtained as a byproduct of the d15N measurement. The proposed gas-isotopic measurements will underpin an integrated suite of West Antarctic climate and atmospheric gas records, which will ultimately include the WAIS Divide core. These records will help separate regional from global climate signals, and may place constraints on the cause of abrupt climate change. Education of two graduate students, and training of two staff members in the laboratory, contribute to the nation's human resource base. Education and outreach will be an important component of the project.
This project answers a simple question: why are there so few fossils in sediment cores from Antarctica?s continental shelf? Antarctica?s benthos are as biologically rich as those of the tropics. Shell-secreting organisms should have left a trail throughout geologic time, but have not. This trail is particularly important because these organisms record regional climate in ways that are critical to interpreting the global climate record. This study uses field experiments and targeted observations of modern benthic systems to examine the biases inflicted by fossil preservation. By examining a spectrum of ice-affected habitats, this project provides paleoenvironmental insights into carbonate preservation, sedimentation rates, and burial processes; and will provide new approaches to reconstructing the Cenozoic history of Antarctica. Broader impacts include graduate and undergraduate research and education, development of undergraduate curricula to link art and science, K12 outreach, public outreach via the web, and societal relevance through improved understanding of records of global climate change.
0122520<br/>Gogineni<br/><br/>Sea level has been rising over the last century. Although the immediate impact of sea level rise may be less severe than other effects of global climate change, the long-term consequences can be much more devastating since nearly 60% of the world population lives in coastal regions. Scientists have postulated that excess water is being released from polar ice sheets due to long-term, global climate change, but there are insufficient data to confirm these theories. Understanding the interactions between the ice sheets, oceans and atmosphere is essential to quantifying the role of ice sheets in sea level rise. Toward that end, this research project involves the innovative application of information technology in the development and deployment of intelligent radar sensors for measuring key glaciological parameters. <br/><br/>Radar instrumentation will consist of a synthetic aperture radar (SAR) that can operate in bistatic or monostatic mode. One important application of the SAR will be in the determination of basal conditions, particularly the presence and distribution of basal water. Basal water lubricates the ice/bed interface, enhancing flow, and increasing the amount of ice discharged into the ocean. Another application of the SAR will be to measure ice thickness and map internal layers in both shallow and deep ice. Information on near-surface internal layers will be used to estimate the average, recent accumulation rate, while the deeper layers provide a history of past accumulation and flow rates. A tracked vehicle and an automated snowmobile will be used to test and demonstrate the utility of an intelligent radar in glaciological investigations.<br/><br/>The system will be developed to collect, process and analyze data in real time and in conjunction with a priori information derived from archived sources. The combined real time and archived information will be used onboard the vehicles to select and generate an optimum sensor configuration. This project thus involves innovative research in intelligent systems, sounding radars and ice sheet modeling. In addition it has a very strong public outreach and education program, which include near-real-time image broadcasts via the world wide web
This project studies ancient lake deposits from the western Dry Valleys of Antarctica. These deposits are particularly exciting because they preserve flora and fauna over seven million years in age that represent the last vestiges of ecosystems that dominated this area before formation of the modern East Antarctic ice sheet. Their unique nature offers a chance to bridge modern and ancient ecology. Formed along the margin of ancient alpine glaciers, these deposits contain layers of silt, clay, and volcanic ash; as well as freeze-dried remnants of mosses, insects, and diatoms. Geological and biological analyses provide a view of the ecological and environmental conditions during mid-to-late Miocene--seven to seventeen million years ago--which spans the critical period when the East Antarctic ice sheet transitioned to its present stable form. The results place the modern lakes of the Dry Valleys into a long-term evolutionary framework, and allow for correlation and dating comparisons with other fossil-rich deposits from the Transantarctic Mountains. Chemical fingerprinting and dating of volcanic glass shards will also help date fossil- and ash-bearing horizons in nearby marine cores, such as those to be collected under the ANDRILL program. <br/><br/>The broader impacts are education at the postdoctoral, graduate, and undergraduate levels; and collaboration between a research institution and primarily undergraduate institution. The work also improves our understanding of global climate change during a critical period in the Earth's history.
This project studies the last vestiges of life in Antarctica from exceptionally well-preserved fossils of tundra life--mosses, diatoms, ostracods, Nothofagus leaves, wood, and insect remains recently discovered in ancient lake sediments from the McMurdo Dry Valleys. The area will be studied by an interdisciplinary team to elucidate information about climate and biogeography. These deposits offer unique and direct information about the characteristics of Antarctica during a key period in its history, the time when it was freezing. This information is critical for correlation with indirect proxies, such as though obtained from drill cores, for climate and state of the ice sheet. The results will also help understand the origin and migration of similar organisms found in South America, India and Australia.<br/><br/>In terms of broader impacts, this project supports an early career researcher, undergraduate and graduate student research, various forms of outreach to K12 students, and extensive international collaboration. The work also has societal relevance in that the outcomes will offer direct constraints on Antarctica's ice sheet during a time with atmospheric CO2 contents similar to those of the earth in the coming centuries, and thus may help predictive models of sea level rise.
0538195<br/>Marone<br/>This award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.
This award supports a project to improve understanding of atmospheric photochemistry over West Antarctica, as recorded in snow, firn and ice. Atmospheric and firn sampling will be undertaken as part of the U.S. International Trans-Antarctic Scientific Expedition (US ITASE) traverses. Measurements of hydrogen peroxide (H2O2) and formaldehyde (HCHO) will be made on these samples and a recently developed, physically based atmosphere-to-snow transfer model will be used to relate photochemical model estimates of these components to the concentrations of these parameters in the atmosphere and snow. The efficiency of atmosphere-to-snow transfer and the preservation of these components is strongly related to the rate and timing of snow accumulation. This information will be obtained by analyzing the concentration of seasonally dependent species such as hydrogen peroxide, nitric acid and stable isotopes of oxygen. Collection of samples along the US ITASE traverses will allow sampling at a wide variety of locations, reflecting both a number of different depositional environments and covering much of the West Antarctic region.
This Small Grant for Exploratory Research investigates the origin and evolution of the Gamburtsev subglacial mountains (GSM). These mountains are considered the nucleation point for Antarctica's largest ice sheets; however, being of indeterminate age, they may postdate ice sheet formation. As well, their formation could reflect tectonic events during the breakup of Gondwana. The project studies GSM-derived detrital zircon and apatite crystals from Prydz Bay obtained by the Ocean Drilling Program. Analytical work includes triple-dating thermochronometry by U/Pb, fission track, and (U/Th)/He methods. The combined technique offers insight into both high and low temperature processes, and is potentially sensitive to both the orogenic events and the subsequent cooling and exhumation due to erosion. In terms of broader impacts, this project supports research for a postdoctoral fellow and an
This project studies the opening of the Drake Passage between South America and Antarctica through a combined marine geophysical survey and geochemical study of dredged ocean floor basalts. Dating the passage's opening is key to understanding the formation of the circum-Antarctic current, which plays a major role in worldwide ocean circulation, and whose formation is connected with growth of the Antarctic ice sheet. Dredge samples will undergo various geochemical studies to determine their age and constrain mantle flow beneath the region. <br/><br/>Broader impacts include support for graduate education, as well as undergraduate and K12 teacher involvement in a research cruise. The project also involves international collaboration with the UK and is part of IPY Project #77: Plates&Gates, which aims to reconstruct the geologic history of polar ocean basins and gateways for computer simulations of climate change. See http://www.ipy.org/index.php?/ipy/detail/plates_gates/ for more information.
This project seeks to answer a simple question: how old are potholes and related geomorphic features found in the uplands of the McMurdo Dry Valleys, Antarctica? Some research suggests that they are over ten million years old and date the growth of the East Antarctic Ice Sheet, the world?s largest. However, some evidence suggests that these are young, erosional features that continuing to evolve to this day. This project uses cosmogenic nuclide dating to determine the age of the pothole floors. The results are important for determining the ice sheet?s history and interpreting the O-isotope record from the marine sediment cores, key records of global climate. Broader impacts include K12 outreach and incorporation of outcomes into university courses.
0538683<br/>Lal<br/>This award supports a project to continue development of a new method for estimating solar activity in the past. It is based on measurements of the concentrations of in-situ produced C-14 in polar ice by cosmic rays, which depend only on (i) the cosmic ray flux, and (ii) ice accumulation rate. This is the only direct method available to date polar ice, since it does not involve any uncertain climatic transfer functions as are encountered in the applications of cosmogenic C-14 data in tree rings, or of Be-10 in ice and sediments. An important task is to improve on the temporal resolution during identified periods of high/low solar activity in the past 32 Kyr. The plan is to undertake a study of changes in the cosmic ray flux during the last millennium (1100-1825 A.D.), during which time 4 low and 1 high solar activity epoch has been identified from historical records. Sunspot data during most of these periods are sparse. Adequate ice samples are available from ice cores from the South Pole and from Summit, Greenland and a careful high resolution study of past solar activity levels during this period will be undertaken. The intellectual merit of the work includes providing independent verification of estimated solar activity levels from the two polar ice records of cosmic ray flux and greatly improve our understanding of solar-terrestrial relationships. <br/>The broader impacts include collaboration with other scientists who are experts in the application of the atmospheric cosmogenic C-14 and student training. Both undergraduates and a graduate student will be involved in the proposed research. Various forms of outreach will also be used to disseminate the results of this project, including public presentations and interactions with the media.
9911617 Blankenship This award, provided jointly by the Antarctic Geology and Geophysics Program, the Antarctic Glaciology Program, and the Polar Research Support Section of the Office of Polar Programs, provides funds for continuation of the Support Office for Aerogeophysical Research (SOAR). From July 1994 to July 2000, SOAR served as a facility to accomplish aerogeophysical research in Antarctica under an agreement between the University of Texas at Austin and the National Science Foundation's Office of Polar Programs (NSF/OPP). SOAR operated and maintained an aerogeophysical instrument package that consists of an ice-penetrating radar sounder, a laser altimeter, a gravimeter and a magnetometer that are tightly integrated with each other as well as with the aircraft's avionics and power packages. An array of aircraft and ground-based GPS receivers supported kinematic differential positioning using carrier-phase observations. SOAR activities included: developing aerogeophysical research projects with NSF/OPP investigators; upgrading of the aerogeophysical instrumentation package to accommodate new science projects and advances in technology; fielding this instrument package to accomplish SOAR-developed projects; and management, reduction, and analysis of the acquired aerogeophysical data. In pursuit of 9 NSF-OPP funded aerogeophysical research projects (involving 14 investigators from 9 institutions), SOAR carried out six field campaigns over a six-year period and accomplished approximately 200,000 line kilometers of aerogeophysical surveying over both East and West Antarctica in 377 flights. This award supports SOAR to undertake a one year and 8 month program of aerogeophysical activities that are consistent with continuing U.S. support for geophysical research in Antarctica. - SOAR will conduct an aerogeophysical campaign during the 200/01 austral summer to accomplish surveys for two SOAR-developed projects: "Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Studies" (Co-PI's Bell and Studinger, LDEO); and "Collaborative Research: Seismic Investigation of the Deep Continental Structure Across the East-West Antarctic Boundary" (Co-PI's Weins, Washington U. and Anandakrishnan, U. Alabama). After configuration and testing of the survey aircraft in McMurdo, SOAR will conduct survey flights from an NSF-supported base adjacent to the Russian Station above Lake Vostok and briefly occupy one or two remote bases on the East Antarctic ice sheet. - SOAR will reduce these aerogeophysical data and produce profiles and maps of surface elevation, bed elevation, gravity and magnetic field intensity. These results will be provided to the respective project investigators within nine months of conclusion of field activities. We will also submit a technical manuscript that describes these results to a refereed scientific journal and distribute these results to appropriate national geophysical data centers within approximately 24 months of completion of field activities. - SOAR will standardize all previously reduced SOAR data products and transfer them to the appropriate national geophysical data centers by the end of this grant. - SOAR will convene a workshop to establish a community consensus for future U.S. Antarctic aerogeophysical research. This workshop will be co-convened by Ian Dalziel and Richard Alley and will take place during the spring of 2001. - SOAR will upgrade the existing SOAR in-field quality control procedures to serve as a web-based interface for efficient browsing of many low-level SOAR data streams. - SOAR will repair and/or refurbish equipment that was used during the 2000/01 field campaign. Support for SOAR is essential for accomplishing major geophysical investigations in Antarctica. Following data interpretation by the science teams, these data will provide valuable insights to the structure and evolution of the Antarctic continent.
This award supports a project to measure the elemental and isotopic composition of firn air and occluded air in shallow boreholes and ice cores from the WAIS Divide site, the location of a deep ice-coring program planned for 2006-07 and subsequent seasons. The three primary objectives are: 1) to establish the nature of firn air movement and trapping at the site to aid interpretations of gas data from the deep core; 2) to expand the suite of atmospheric trace gas species that can be measured in ice and replicate existing records of other species; and 3) to inter-calibrate all collaborating labs to insure that compositional and isotopic data sets are inter-comparable. The program will be initiated with a shallow drilling program during the 05/06 field season which will recover two 300+m cores and firn air samples. The ice core and firn air will provide more than 700 years of atmospheric history that will be used to address a number of important questions related to atmospheric change over this time period. The research team consists of six US laboratories that also plan to participate in the deep core program. This collaborative research program has a number of advantages. First, the scientists will be able to coordinate sample allocation a priori to maximize the resolution and overlap of records of interrelated species. Second, sample registration will be exact, allowing direct comparison of all records. Third, a coherent data set will be produced at the same time and all PI.s will participate in interpreting and publishing the results. This will insure that the best possible understanding of gas records at the WAIS Divide site will be achieved, and that all work necessary to interpret the deep core is conducted in a timely fashion. The collaborative structure created by the proposal will encourage sharing of techniques, equipment, and ideas between the laboratories. The research will identify impacts of various industrial/agricultural activities and help to distinguish them from natural variations, and will include species for which there are no long records of anthropogenic impact. The work will also help to predict future atmospheric loadings. The project will contribute to training scientists at several levels, including seven undergraduates, two graduate students and one post doctoral fellow.
This project uses cosmogenic nuclide dating and LIDAR studies of surface roughness to understand weathering and landscape evolution in the Dry Valleys of Antarctica. The work focuses on two processes: cryoturbation of frozen soils and the development of patterned, frozen ground on ancient lava flows. The approach includes innovative uses of He3 profiling. Results will also be applied to understanding the glacial history of the Dry Valleys. There are potential applications to understanding the history of the East Antarctic Ice Sheet and the formation of Martian landscapes. The broader impacts include graduate student education. As well, the work may contribute to our understanding of the history of the Antarctic ice sheets, which is important to modeling their behavior during global climate change.
This award supports work on trapped gases in Antarctic and other ice cores for paleoenvironmental and chronological purposes. The project will complete a ~ 100,000 year, high-resolution record of atmospheric methane from the Siple Dome ice core and use these data to construct a precise chronology for climate events recorded by the Siple Dome record. In addition, the resolution of the GISP2 (Greenland) ice core record will be increased in some critical intervals to help with the Siple Dome chronology and that of future ice cores. Finally, an upgrade to the analytical capabilities of the laboratory, including increasing precision and throughput and decreasing sample size needed for ice core methane measurements will be an important goal of this work. The proposed work will contribute to the understanding of the timing of rapid climate change in the Northern and Southern hemispheres during the last glacial period, the evolution of the global methane budget in the late Quaternary, and the late Quaternary climate history of Antarctica. It will also improve our ability to generate methane records for future ice coring projects, and inform and enrich the educational and outreach activities of our laboratory.
Saltzman/0636953<br/><br/>This award supports a project to measure methyl chloride, methyl bromide, and carbonyl sulfide in air extracted from Antarctic ice cores. Previous measurements in firn air and shallow ice cores suggest that the ice archive contains paleo-atmospheric signals for these gases. The goal of this study is to extend these records throughout the Holocene and into the last Glacial period to examine the behavior of these trace gases over longer time scales and a wider range of climatic conditions. These studies are exploratory, and both the stability of these trace gases and the extent to which they may be impacted by in situ processes will be assessed. This project will involve sampling and analyzing archived ice core samples from the Siple Dome, Taylor Dome, Byrd, and Vostok ice cores. The ice core samples will be analyzed by dry extraction, with gas chromatography/mass spectrometry with isotope dilution. The ice core measurements will generate new information about the range of natural variability of these trace gases in the atmosphere. The intellectual merit of this project is that this work will provide an improved basis for assessing the impact of anthropogenic activities on biogeochemical cycles, and new insight into the climatic sensitivity of the biogeochemical processes controlling atmospheric composition. The broader impact of this project is that there is a strong societal interest in understanding how man's activities impact the atmosphere, and how atmospheric chemistry may be altered by future climate change. The results of this study will contribute to the development of scenarios used for future projections of stratospheric ozone and climate change. In terms of human development, this project will support the doctoral dissertation of a graduate student in Earth System Science, and undergraduate research on polar ice core chemistry. This project will also contribute to the development of an Earth Sciences teacher training curriculum for high school teachers in the Orange County school system in collaboration with an established, NSF-sponsored Math and Science Partnership program (FOCUS).
This award supports a project to collect and develop high-resolution ice core records from the Dry Valleys region of Antarctica, and provide interpretations of interannual to decadal-scale climate variability during the last 2000 years (late Holocene). The project will test hypotheses related to ocean/atmosphere teleconnections (e.g., El Nino Southern Oscillation, Antarctic Oscillation) that may be responsible for major late Holocene climate events such as the Little Ice Age in the Southern Hemisphere. Conceptual and quantitative models of these processes in the Dry Valleys during the late Holocene are critical for understanding recent climate changes, and represent the main scientific merit of the project. We plan to collect intermediate-length ice cores (100-200m) at four sites along transects in Taylor Valley and Wright Valley, and analyze each core at high resolution for stable isotopes (d18O, dD), major ions (Na+, Mg2+, Ca2+, K+, NH4+, Cl-, NO3-, SO42-, MSA), and trace elements (Al, Fe, S, Sr, B). A suite of statistical techniques will be applied to the multivariate glaciochemical dataset to identify chemical associations and to calibrate the time-series records with available instrumental data. Broader impacts of the project include: 1) contributions to several ongoing interdisciplinary Antarctic research programs; 2) graduate and undergraduate student involvement in field, laboratory, and data interpretation activities; 3) use of project data and ideas in several UMaine courses and outreach activities; and 4) data dissemination through peer-reviewed publications, UMaine and other paleoclimate data archive websites, and presentations at national and international meetings.
This award supports a three year project to develop the tools required to interpret complex patterns of flow features on the Ross Ice Shelf, which record the discharge history the ice streams flowing east off of the West Antarctic Ice Sheet. This work builds on previous research that used flow features visible in satellite image mosaics and numerical models of ice shelf flow to detect changes in grounding zone dynamics and redirection of ice stream outlets over hundreds of years. Recently observed changes on Whillans Ice Stream fit within this framework. The pattern of redirection is driven by the influence of rapid downstream thinning on the basal thermal gradient in the ice and associated "sticky spot" (ice rise) formation. In pursuing this work, the investigators recognized other records of discharge variation on the shelf that can be used to build a more complete history and understanding of ice-stream discharge variability. The intellectual merit of the proposed work lies in the fact that these records, including fracture patterns and spatial variation in ice thickness, when understood in the proper context, will yield quantitative information about the timing and dynamics of ice stream slowdowns, grounding line retreat, and the relative history of discharge between the ice streams. New tools will help further constrain this history. The laser altimeter on NASA's IceSAT has improved our knowledge of the surface elevation of Antarctic ice. IceSAT surface elevations provide a high-resolution map of ice-shelf thickness that, along with provenance maps from ice-shelf image mosaics, will be used to estimate the volumes of ice involved in past ice-stream discharge events (slowdowns, redirections, and so on). This project will develop new numerical models for fracture propagation; these will allow past variations in ice-shelf stress state to be investigated. Together, the dynamic and volume-flux histories will provide a powerful set of observations for understanding past variations in ice stream discharge and the underlying physical processes. The broader impacts of this project center on how it contributes to the ability to estimate West Antarctic contributions to global sea level rise and to answer outstanding questions about the causes of millennial and longer-scale evolution of ice streams. This work will provide a history of the most complex record of ice discharge known. In addition to the incorporation of this research into graduate student advising and normal teaching duties, the investigators are involved in other avenues of civic engagement and education. Outreach to high school students and the community at large is promoted on an annual basis by the investigators at both institutions. New outreach projects at Portland State University are developed with the assistance of researchers with expertise in student learning and achievement in science and mathematics. The collaborative research team includes two glaciologists with experience in the pairing of high resolution satellite imagery and a variety of ice-flow models and a geologist whose focus is the mechanics of rock deformation.
This award supports the study of the drift and break-up of Earth's largest icebergs, which were recently released into the Ross Sea of Antarctica as a result of calving from the Ross Ice Shelf. The scientific goals of the study are to determine the physics of iceberg motion within the dynamic context of ocean currents, winds, and sea ice, which determine the forces that drive iceberg motion, and the relationship between the iceberg and geographically and topographically determined pinning points on which the iceberg can ground. In addition, the processes by which icebergs influence the local environments (e.g., sea ice conditions near Antarctica, access to penguin rookeries, air-sea heat exchange and upwelling at iceberg margins, nutrient fluxes) will be studied. The processes by which icebergs generate globally far-reaching ocean acoustic signals that are detected within the global seismic (earthquake) sensing networks will also be studied. A featured element of the scientific research activity will be a field effort to deploy automatic weather stations, seismometer arrays and GPS-tracking stations on several of the largest icebergs presently adrift, or about to be adrift, in the Ross Sea. Data generated and relayed via satellite to home institutions in the Midwest will motivate theoretical analysis and computer simulation; and will be archived on an "iceberg" website (http://amrc.ssec.wisc.edu/amrc/iceberg.html) for access by scientists and the general public. At the most broad level, the study is justified by the fact that icebergs released by the Antarctic ice sheet represent the largest movements of fresh water within the natural environment (e.g., several of the icebergs to be studied, B15, C19 and others calved since 2000 CE, represent over 6000 cubic kilometers of fresh water-an amount roughly equivalent to 100 years of the flow of the Nile River). A better understanding of the impact of iceberg drift through the environment, and particularly the impact on ocean stratification and mixing, is essential to the understanding of the abrupt global climate changes witnessed by proxy during the ice age and of concern under conditions of future greenhouse warming. On a more specific level, the study will generate a knowledge base useful for the better management of Antarctic logistical resources (e.g., the shipping lanes to McMurdo Station) that can occasionally be influenced by adverse effects icebergs have on sea ice conditions.
The large subglacial Lake Vostok in Antarctica is unique ecological site with a novel microbial biota. The temperatures, pressures and lack of light all select for organisms that may not exist anywhere else on Earth. The accretion ice (lake water frozen to the bottom of the lower surface of the glacier) has preserved microbial samples from each region of Lake Vostok as the glacier passes over and into the lake. Thus, without contaminating the lake with microorganisms from the surface, microbes originating from the lake can be collected, transported to the laboratory and studied. Two of the deepest ice cores sections in this project are part of the international allocation. The will be shared between four researchers (Sergey Bulat from Russia, Jean-Robert Petit and Daniel Prieur from France, Scott Rogers from USA). The United States team will study, isolate, and characterize bacteria, fungi, and viruses that have been sampled from the lake through the process of ice accretion to the lower surface of 3500+m thick glacier overriding the lake. The project will involve a suite of methods, including molecular, morphological, and cultural. This includes observation and description by fluorescence, light, and electron microscopy, isolation on thirteen separate cultural media, polymerase chain reaction amplification, DNA sequencing, and phylogenetic analyses. Eleven accretion ice core sections, as well as two glacial ice core sections. As well as two glacial ice core sections will be studied. The accretion ice core sections, as well as two glacial ice core sections will be studied. The accretion ice core sections represent all of the major regions of the lake that have been sampled by the accretion process in the vicinity of the Vostok 5G ice core. The broader impacts of the work relate to the impact the results will have on the filed. These long=isolated lakes, deep below the Antarctic ice sheet may contain novel uniquely adapted organisms. Glacial ice contains an enormous diversity of entrapped microbes, some of which may be metabolically active in the ice. The microbes from Lake Vostok are of special interest, since they are adapted to cold, dark, and high pressure. Thus, their enzyme systems and biochemical pathways may be significantly different from those in the microbes that are the subject of current studies. As such, these organisms may form compounds that may have useful applications. Also, study of the accretion ice, and eventually the water, from Lake Vostok will provide a basis for the study of other subglacial lakes. Additionally, study of the microbes in the accretion ice will be useful to those planning to study analogous systems on ice-covered planets and moons.
This award supports a two-year collaborative effort to more fully understand the climatic history and physical properties of the Siple Dome, Antarctica deep ice core, to develop a new paleoclimatic technique based on bubble number-density, and to improve the U.S. capability to analyze ice-core physical properties rapidly and accurately. The Siple Dome ice core from West Antarctica is yielding important paleoclimatic insights, but has proven more difficult than some cores to interpret owing to the large iceflow effects on the paleoclimatic record. Paleoclimatic indicators that do not rely on iceflow corrections thus would be of value. The bubble number-density offers one such indicator, because it preserves information on mean temperature and accumulation rate during the transformation of firn to ice. We will focus on thin-section characteristics that are important to ice flow and the interpretation of the ice-core history, such as c-axis fabrics, and will use indicators that we have been developing, such as the correlation between grain elongation and the c-axis orientation, to gain additional information. To achieve this quickly and accurately, and to prepare for future projects, we propose to upgrade the automatic caxis- fabric analyzer that Wilen has built and housed at the National Ice Core Laboratory. The intellectual merit of the proposed activity includes improved estimates of paleoclimatic conditions in an important region, improved understanding of a new paleoclimatic research tool, greater understanding of ice flow and of linkages to physical properties, and a better instrument for further U.S. research in ice-core physical properties at the National Ice Core Laboratory. The broader impacts resulting from the proposed activity include providing better understanding of abrupt climate change and of ice flow, which eventually should help policy-makers, as well as an improved U.S. capability to analyze ice cores. The proposed research will assist the studies of two promising young scientists. Results of the research will be incorporated into courses and public outreach reaching at least hundreds or thousands of people per year.
This work will study cosmogenic isotope profiles of rock and sediment in the Dry Valleys of Antarctica to understand their origin. The results will provide important constraints on the history of the East Antarctic Ice Sheet. The near-perfect preservation of volcanic ash and overlying sediments suggests that hyperarid cold conditions have prevailed in the Dry Valleys for over 10 Myr. The survival of these sediments also suggests that warm-based ice has not entered the valley system and ice sheet expansion has been minimal. Other evidence, however, suggests that the Dry Valleys have experienced considerably more sediment erosion than generally believed: 1) the cosmogenic exposure ages of boulders and bedrock in the Valleys all show generally younger ages than volcanic ash deposits used to determine minimum ages of moraines and drifts, 2) there appears to be a discrepancy between the suggested extreme preservation of unconsolidated slope deposits (>10 Myr) and adjacent bedrock that has eroded 2.6-6 m during the same time interval. The fact that the till and moraine exposure ages generally post date the overlying volcanic ash deposits could reflect expansion of continental ice sheet into the Dry Valleys with cold-based ice, thus both preserving the landscape and shielding the surfaces from cosmic radiation. Another plausible explanation of the young cosmogenic exposure ages is erosion of the sediments and gradual exhumation of formerly buried boulders to the surface. Cosmogenic isotope systematics are especially well suited to address these questions. We will measure multiple cosmogenic isotopes in profiles of rock and sediment to determine the minimum exposure ages, the degree of soil stability or mixing, and the shielding history of surfaces by cold based ice. We expect to obtain unambiguous minimum ages for deposits. In addition, we should be able to identify areas disturbed by periglacial activity, constrain the timing of such activity, and account for the patchy preservation of important stratigraphic markers such as volcanic ash. The broader impacts of this project include graduate and undergraduate education, and improving our understanding of the dynamics of Southern Hemisphere climate on timescales of millions of years, which has major implications for understanding the controls and impacts of global climate change.
This award supports the development of a new laboratory capability in the U.S. to measure CO2 in ice cores and investigate millennial-scale changes in CO2 during the last glacial period using samples from the Byrd and Siple Dome ice cores. Both cores have precise relative chronologies based on correlation of methane and the isotopic composition of atmospheric oxygen with counterpart records from Greenland ice cores. The proposed work will therefore allow comparison of the timing of CO2 change, Antarctic temperature change, and Greenland temperature change on common time scales. Such comparisons are vital for evaluating models that explain changes in atmospheric CO2. The techniques being developed will also be available for future projects, specifically the proposed Inland WAIS ice core, for which a highly detailed CO2 record is a major objective, and studies greenhouse and other atmospheric gases and their isotopic composition for which dry extraction is necessary (stable isotopes in CO2, for example). There are many broad impacts of the proposed work. Ice core greenhouse gas records are central contributions of paleoclimatology to research and policy-making concerning global change. The proposed work will enhance those contributions by improving our understanding of the natural cycling of the most important greenhouse gas. It will contribute to the training of a postdoctoral researcher, who will be an integral part of an established research group and benefit from the diverse paleoclimate and geochemistry community at OSU. The PI teaches major and non-major undergraduate and graduate courses on climate and global change. The proposed work will enrich those courses and the courses will provide an opportunity for the postdoctoral researcher to participate in teaching by giving guest lectures. The PI also participates in a summer climate workshop for high school teachers at Washington State University and the proposed work will enrich that contribution. The extraction device that is built and the expertise gained in using it will be resources for the ice core community and available for future projects. Data will be made available through established national data center and the equipment designs will also be made available to other researchers.
9909665 Berger This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports project to test and develop approaches for using thermoluminescence techniques to determine the age of Antarctic marine sediments. Quaternary (last 2 million yrs) marine sediments surrounding Antarctica record the waxing and waning of ice shelves and ice sheets, and also other paleoclimatic information, yet accurate chronologies of these sediments are difficult to obtain. Such chronologies provide the essential foundation for study of geological processes in the past. Within the range of radiocarbon (14C) dating (less than 30-40 thousand yrs, note - "ka" below means 1000 yrs) 14C dates can be inaccurate because of a variable 14C reservoir effect, and beyond 30-40 ka few methods are applicable. Photon-stimulated-luminescence sediment dating (photonic dating) of eolian and waterlain deposits in temperate latitudes spans the range from decades to hundreds of ka, but marine sediments in and around Antarctica pose special difficulty because of the potentially restricted exposure to daylight (the clock-zeroing process) of most detrital grains before deposition. This proposal will test the clock-zeroing assumption in representative Antarctic glaciomarine depositional settings, and thereby determine the potential reliability of photonic dating of Antarctic marine sediments. Limited luminescence dating and signal-zeroing tests using glaciomarine and marine deposits have been conducted in the northern temperate and polar latitudes, but the effects on luminescence of the different glaciomarine depositional processes have never been studied in detail. Furthermore, the depositional settings around Antarctica are almost entirely polar, with consequent specific processes operating there. For example, transport of terrigenous suspensions by neutrally buoyant "cold-tongue" (mid-water) plumes may be common around Antarctica, yet the effect of such transport on luminescence zeroing is unknown. Typical marine cores near Antarctica may contain an unknown fraction of detrital grains from cold-tongue and near-bottom suspensions. Thus the extent to which the polar glaciomarine depositional processes around Antarctica may limit the potential accuracy of photonic dating of marine cores is unknown (age overestimates would result if grains are not exposed to daylight before deposition). This project will collect detrital grains from a variety of "zero-age" (modern) marine depositional settings within the Antarctic Peninsula, where representative Antarctic depositional processes have been documented and where logistics permit access. Suspensions will be collected from four fjords representing a transect from polar through subpolar conditions. Suspensions will be collected from two stations and from up to 3 depths (surface and 2 deep plumes) at each station. Sediment traps will be deployed at two of these fjord settings. As well, core-top sediments will be collected from several sites. All samples will be shielded from light and transported to Reno, Nevada, for luminescence analyses. Systematic study of the effectiveness of luminescence-clock-zeroing in Antarctic glaciomarine settings will determine if photonic dating can be reliable for future applications to Antarctic marine sediments. Refined sedimentological criteria for the selection of future samples for photonic dating are expected from this project. A photonic-dating capability would provide a numeric geochronometer extending well beyond the age range of 14C dating. Such a capability would permit answering a number of broader questions about the timing and extent of past glaciations near and on the Antarctic shelves.
This award supports a small grant for exploratory research to study the processes that contribute to the melting and break-up of tabular polar icebergs as they drift north. This work will enable the participation of a group of U.S. scientists in this international project which is collaborative with the Instituto Antartico Argentino. The field team will place weather instruments, firn sensors, and a video camera on the iceberg to measure the processes that affect it as it drifts north. In contrast to icebergs in other sectors of Antarctica, icebergs in the northwestern Weddell Sea drift northward along relatively predictable paths, and reach climate and ocean conditions that lead to break-up within a few years. The timing of this study is critical due to the anticipated presence of iceberg A43A, which broke off the Ronne Ice Shelf in February 2000 and which is expected to be accessible from Marambio Station in early 2006. It has recently been recognized that the end stages of break-up of these icebergs can imitate the rapid disintegrations due to melt ponding and surface fracturing observed for the Larsen A and Larsen B ice shelves. However, in some cases, basal melting may play a significant role in shelf break-up. Resolving the processes (surface ponding/ fracturing versus basal melt) and observing other processes of iceberg drift and break up in-situ are of high scientific interest. An understanding of the mechanisms that lead to the distintegration of icebergs as they drift north may enable scientists to use icebergs as proxies for understanding the processes that could cause ice shelves to disintegrate in a warming climate. A broader impact would thus be an ability to predict ice shelf disintegration in a warming world. Glacier mass balance and ice shelf stability are of critical importance to sea level change, which also has broader societal relevance.
This award supports a comprehensive investigation of the spatial and temporal characteristics of the surface mass balance of the Antarctic ice sheet and the governing mechanisms that affect it. A mesoscale atmospheric model, adapted for Antarctic conditions (Polar MM5), will be used in conjunction with the newly available reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) to resolve the surface mass balance of Antarctica at a time resolution of 3 hours and a spatial resolution of 60 km from 1957 to 2001. Polar MM5 will be upgraded to account for key processes in the simulation, including explicit consideration of blowing snow transport and sublimation as well as surface melting/runoff. The proposed 45-y hindcast of all Antarctic surface mass balance components with a limited area model has not previously been attempted and will provide a dataset of unprecedented scope to complement existing ice core measurements of recent climate, especially those collected by the International Transantarctic Scientific Expedition (ITASE). The trends and variability in space and time over 4.5 decades will be resolved and the impact of the dominant modes of atmospheric variability (Antarctic Oscillation, El Nino-Southern Oscillation, etc.) will be isolated. Hypotheses concerning the Antarctic surface mass balance response to climate change will be tested. The research will provide a sound basis for evaluating the impact of future climate change on Antarctic surface mass balance and its contribution to global sea level change as well as providing an important perspective for the interpretation of Antarctic ice core records. The broader impacts include the education of a Ph.D. student, the development of material for use in university classes, and construction of an interactive educational webpage on Antarctic surface mass balance.
9909436 Farley This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an investigation of the uplift history of the Dry Valleys segment of the Transantarctic Mountains. The overall goal is to further constrain the exhumation history of the Transantarctic Mountains by using the newly developed apatite (U-Th)/He dating method on samples collected in vertical profiles. This approach, combined with existing apatite fission track information will constrain the rate and patterns of exhumation across the Transantarctic Mountains since their inception as a rift-flank uplift in the early Cenozoic. This project will complement other projects and build on previous interpretations of the exhumation and tectonic history determined using apatite fission track thermochronology. It will bridge the gap between information on erosion rates determined from fission track thermochronology and from cosmogenic surface exposure dating and integrate the exhumation history of the mountains with their landscape evolution. As such, the results from this project will address an outstanding problem in Antarctic science; namely the stability of the East Antarctic Ice Sheet, and the timing of the transition from a "warm" dynamic ice sheet to a cold polar ice sheet. Highly relevant to this issue is the landscape evolution of the Transantarctic Mountains because many diverse lines of evidence for the rate of landscape evolution have been used to argue for a dynamic ice sheet up until either the Pliocene (the "dynamic" ice sheet model) or the middle Miocene (the "stable" ice sheet model). Understanding the past stability or dynamic fluctuations of the East Antarctic ice sheet with respect to the climate record is, of course, important for understanding how the present ice sheet may respond to global warming. The specific objective of this project is to determine apatite (U-Th)/He age versus elevation trends for a number of vertical profiles from locations within the Transantarctic Mountain front and across the structural grain of the range. Fission track data already exist for all of these profiles, with apatite fission track ages ranging from 150-30 Ma. The greater precision of the (U-Th)/He technique and the fact it records information at lower temperatures (closure temperature of ~70 degrees Celsius; limits of 40-85 degrees Celsius for the He partial retention zone) will allow examination of the exhumation history of the TAM in more detail from ca 130 Ma to ~20 Ma. Another facet is to examine areas where Cretaceous exhumation is recorded and areas where the fission track profiles indicate periods of thermal and tectonic stability and minimal erosion throughout the Cretaceous. The variation of timing of the onset of more rapid exhumation accompanying uplift and formation of the Transantarctic Mountains in the early Cenozoic will also be examined.
This award is for support for a program to reconstruct records of the isotopic composition of paleoatmospheric methane and nitrous oxide covering the last 200,000 years. High resolution measurements of the carbon-13 isotopic composition of methane from shallow ice cores will help to determine the relative contributions of biogenic (wetlands, rice fields and ruminants) and abiogenic (biomass burning and natural gas) methane emissions which have caused the concentrations of this gas to increase at an exponential rate during the anthropogenic period. Isotopic data on methane and nitrous oxide over glacial/interglacial timescales will help determine the underlying cause of the large concentration variations that are known to occur. This project will make use of a new generation mass spectrometer which is capable of generating precise isotopic information on nanomolar quantities of methane and nitrous oxide, which means that samples can be 1000 times smaller than those needed for a standard isotope ratio instrument. The primary objective of the work is to further our understanding of the biogeochemical cycles of these two greenhouse gases throughout the anthropogenic period as well as over glacial interglacial timescales.
Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.<br/>This award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.<br/>A better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.
9725882 Raymond This award is for support for a program of surface-based radio echo sounding to examine the geometry of the internal layering and the presence or absence of thawed zones outside the margins of active Ice Streams B and E and across the flow band feeding Ice Stream D. Melting in the marginal shear zone and/or on the bed outside an ice stream relates to the amount of support of the ice stream from the sides compared to the bed and the conditions that limit expansion of its width. Radar observations will be extended over the crest of adjacent inter-ice-stream ridges (B/C and D/E) and areas next to the flow band in the onset of D. The purpose is to examine internal layering indicative of the histories of these areas adjacent to ice streams and to determine whether ice streams have expanded into these presently stable areas in the past. These goals concerning the physical controls and history of ice stream width relate to how the discharge of ice streams has changed in the past and could change in the future to affect sea level.
This Small Grant for Exploratory Research supports development of a geochemical technique to time the onset of glacial erosion from Antarctica's continental ice sheets. The technique pairs neodymium (Nd) and hafnium (Hf) isotope proxies from the authigenic (seawater-derived) ferromanganese phase precipitated in marine sediments. This technique promises to be a sensitive indicator of glacial erosion. Non-radiogenic Hf is contained in the mineral zircon, which can only be released by the abrasive grinding that accompanies glacial erosion. Previous attempts to develop this technique encountered difficulty due to the minute amounts of Hf involved and the difficulty in its extraction. The PIs have developed a new chemical protocol that should allow them to selectively extract authigenic Hf from bulk sediments. If successful, studies of the Eocene-Oligocene boundary from two drill cores the Weddell Sea and Kerguelen Plateau will be carried out. This boundary is considered the initiation point for formation of Antarctica's current ice sheets. If successful, this method will benefit scientists with interests as diverse as continental weathering, ocean circulation, Cenozoic paleoceanography and paleoclimate, and Antarctic geology. <br/><br/>The broader impacts of this work are development of a new analytical technique that may improve society's understanding of the potential for global climate change from the perspective of the deep time record.
This award supports a project to develop computational models to simulate ice-shelf rift propagation using a combination of well-established ice-shelf creep-flow models and new crevasse models, based on linear elastic fracture mechanics (LEFM). The overall objective of the proposed work is to simulate rift propagation and eventual large iceberg calving,and place those processes within a larger ice sheet and climate context. The work will proceed in stages, first developing models of single-and multiple-crevasse propagation; then using those models to evaluate propagation sensitivity to various environmental conditions; and third developing models that incorporate both crevasse propagation and advection within an ice- shelf system. Model development will be guided by and evaluated according to satellite observations of rift propagation in several characteristic locations on Antarctic ice shelves. New numerical models of fracture in ice will have applications to many problems in glaciology. The research proposed here is directed toward large rift formation in ice shelves and subsequent iceberg calving. It is motivated by the need to understand observed changes in modern ice shelves,and their connection to climate. Where it has been sampled, the sedimentary record of the Weddell Sea sector implies Peninsular ice shelf variability on millennial time scales. The ability to simulate iceberg calving in a credible way will improve our ability to reproduce such events and place the complete cycle of ice shelf advance and retreat in an ice-dynamics context. That will, in turn, enable us to place ice-shelf cycles within the climate cycles that ultimately drive ice-sheet mass balance.
This work will determine the age and provenance of glacially derived marine sediments from the coastal regions of Wilkes Land, Antarctica. These deposits may offer insight into the history of the East Antarctic Shield (EAS), which is amongst the oldest sections of continental crust on Earth, but cannot be studied directly because of nearly complete ice sheet coverage. The study will use Australian National University's SHRIMP ion microprobe to date zircon and monazite found in the sediments. Samples of interest include polymictic pebble and cobble clasts obtained from dredge hauls of tills, as well as sand-matrix fractions from cores of glacial diamicts on the continental margin. Individual clasts of igneous and metamorphic rocks from tills will be selected for zircon and/or monazite age dating, whereas detrital zircons from stratified and non-stratified diamictons will be analyzed for composite zircon provenance analysis. In addition, detrital zircon ages will be determined for Beacon Supergroup sandstones to evaluate recycling of zircon in Phanerozoic basins. Integration of ages obtained from both sources will provide a good representation of the EAS terrains underlying the Wilkes Land ice sheet. This project will allow us to learn more about the remote continental interior and improve our ability to interpret past ice-flow patterns without further environmental impact on Antarctica. The results will improve our understanding of Precambrian tectonics and crustal evolution, and help target future over-ice geophysical surveys and basement drilling projects currently under consideration. In terms of broader impacts, the project will provide educational and training opportunities for undergraduate students in Earth science.
This award supports a project to improve understanding of post-glacial retreat and thinning of the Siple Coast region. Research has shown how age-depth relationships from ice cores can be extrapolated over wide areas by tracking continuous radar layers. By comparing radar-derived timescales with one from a model of ice- flow, glacial conditions over regional scales were inferred. High-resolution radar profiles have been collected across most of the inter-stream ridges in the Siple Coast region, and an age- depth relationship has been established from the Siple Dome ice core. Application of the techniques used by others is problematic because the ice streams that surround Siple Dome have disrupted the continuity of the internal layers. A specific goal of this project is to search for other less direct ways to match radar layers between unconnected profiles. The correspondence between radar reflections and measurements of electrical conductivity and volcanic sulfates along the Siple Dome core will be investigated. The strategy is to search for distinctive patterns in the echoes that will facilitate layer matching. Preliminary results are encouraging: at least four distinct echoes at Siple Dome can be matched to spikes in the conductivity profile and the signature of one (at 210m depth, which is ~1,800 yrs BP) closely resembles that of a layer at ~200m on Ridge BC. Matching layers (and hence timescales) across the ice streams will allow reconstruction of spatial patterns of past flow, thinning and accumulation rate in the Siple Coast region, which is needed to predict future possible changes of the West Antarctic Ice Sheet. Data necessary for the proposed work are already available; additional fieldwork in Antarctica is not required. The project will take two years to complete and will provide core education for a doctoral student in Earth and Space Sciences, with an emphasis on radioglaciology.
This award supports a science management office for a pilot ice-core drilling and analysis program to test the feasibility of obtaining well-dated, high-resolution isotope and chemistry records from East Antarctica. Shallow ice cores will be obtained from two locations: 1) ~100 km from South Pole towards the Pole of Inaccessibility, as an extension of the Byrd Station-to-South Pole ITASE traverse [International Trans Antarctic Scientific Expedition]; 2) at Taylor Dome, near the original deep coring site, and (3) possibly at AGO 3 and AGO 4 as part of a logistics traverse to these sites. All of the cores collected will be sampled at very high resolution (~1/2 cm) and analyzed for major ions. Results from this calibration work, along with those from another project that is analyzing stable isotopes will be used to help plan a program of larger scope, with the objective of mapping the spatial expression of climate variability in East Antarctica. Funds are also provided to organize a community workshop for coordination of the second phase of US ITASE and for one workshop per year for two years dedicated to writing and preparation of scientific papers from phase one of US ITASE. In addition, route selection activities for the follow-on traverse activities in East Antarctica will be conducted using satellite image mapping. A summary document will be produced and made available to the community to help with planning of related field programs (e.g. deep ice radar, firn radar profiling, atmospheric chemistry, ice coring, snow surface properties for satellite observations, ice surface elevation and mass balance).
This project determines the recent history of the West Antarctic Ice Sheet (WAIS) through a multidisciplinary study of the seabed in the Ross Sea of Antarctica. WAIS is perhaps the world's most critical ice sheet to sea level rise dut to near-future global warming. its history has been a key focus for the past decade, but there are significant questions as to whether WAIS was stable during the last glacial maximum--about 20,000 years ago--or undergoing advance and retreat. This project studies grounding zone translantions in Eastern Basin to constrain WAIS movements using a multidisciplinary approach that integrates multibeam bathymetry, seismic stratigraphy, sedimentology, diatom biostratigraphy, radiocarbon dating, 10Be concentration analyses, and numerical modeling.<br/><br/>The broader impacts include improving society's understanding of sea level rise linked to global warming; postdoctoral, graduate, and undergraduate education; and expanding the participation of groups underrepresented in Earth sciences through links with LSU's Geoscience Alliance to Encourage Minority Participation.
Photochemical reactions in snow can have important effects on the chemistry and composition of the snowpack as well as the overlying atmosphere. For example, recent measurements in the Antarctic and Arctic have revealed that sunlit snow releases a number of important pollutants to the atmosphere. Our ability to understand and model this chemistry is currently limited, in part because we lack fundamental photochemical information for a number of important chemical species in snow. This award supports research that will help fill this gap by characterizing the low-temperature photochemistry of three of these key species: nitrite (NO2-), nitrous acid (HNO2), and hydrogen peroxide (HOOH). We will measure quantum yields for these reactions on ice using a sensitive technique that we recently developed during a study of nitrate (NO3-) photochemistry. In addition to this basic research, we will also measure the rates of formation of hydroxyl radical (OH), nitrogen oxides (NOx), and HOOH in illuminated Antarctic snow samples. These measurements will be important inputs for future models, and will allow us to test whether known species (e.g., NO3-, NO2- and HNO2) are responsible for most of snowpack reactivity (e.g., OH formation). Overall, results from this award will significantly improve our ability to understand snowpack chemistry, and the resulting effects on the atmosphere, both in the Antarctic as well as in the many other regions with permanent or seasonal snow. These results will also strengthen efforts to use ice core records to monitor global change. In addition to these impacts, this award will help train students and a postdoctoral fellow, and results from this work will be integrated into two classes in order to expose students to some of the important issues facing polar regions.
Ice streams are believed to play a major role in determining the response of their parent ice sheet to climate change, and in determining global sea level by serving as regulators on the fresh water stored in the ice sheets. Ice streams are characterized by rapid, laterally confined flow which makes them uniquely identifiable within the body of the more slowly and more homogeneously flowing ice sheet. But while these characteristics enable the identification of ice streams, the processes which control ice-stream motion and evolution, and differences among ice streams in the polar regions, are only partially understood. Understanding the relative importance of lateral and basal drags, as well as the role of gradients in longitudinal stress, is essential for developing models for future evolution of the polar ice<br/>sheets. In this project, physical statistical models will be used to explore the processes that control ice-stream flow, and to compare these processes between seemingly different ice-stream systems. In particular, Whillans Ice Stream draining into the Ross Ice Shelf, will be compared with Recovery and RAMP glaciers draining into the Ronne-Filchner Ice Shelf, and the Northeast Ice Stream in Greenland. Geophysical models lie at the core of the approach, but are embellished by modeling various components of variability statistically. One important component comes from the uncertainty in observations on basal elevation, surface elevation, and surface velocity. In this project new observational data collected using remote-sensing techniques will be used. The various components, some of which are spatial, are combined hierarchically using Bayesian statistical methodology. All these components will be combined mathematically into a physical statistical model that yields the posterior distribution for basal, longitudinal, and lateral stress fields, and velocity fields, conditional on the data. Inference based on this distribution will be carried out via Markov chain Monte Carlo techniques, to obtain estimates of these unknown fields along with uncertainty measures associated with them.
This award is for support for a three year project to measure the vertical strain rate as a function of depth at two sites on Siple Dome Antarctica. Ice flow near a divide such as Siple Dome is unique in that it is predominantly vertical. As a consequence, the component of ice deformation in the vertical direction, the "vertical strain rate" is dominant. Its measurement is therefore important for the calibration of dynamic models of ice flow. Two different, relatively new, high resolution systems for its measurement in hot water drilled holes will be employed. The ice flow model resulting from the measurements and flow law determination will be used to interpret the shapes of radar internal layering in terms of the dynamic history and accumulation patterns of Siple Dome over the past 10,000 years. The resulting improved model will also be applied to the interpretation of annual layers thicknesses (to produce annual accumulation rates) and borehole temperatures from the ice core to be drilled at Siple Dome during the 1997/98 field season. The results should permit an improved analysis of the ice core, relative to what was possible at recent coring sites in central Greenland. This is a collaborative project between the University of Alaska, the University of California, San Diego and the University of Washington.
This award supports a project to significantly improve our understanding of how Taylor Glacier flows and responds to climate changes. Taylor Glacier drains the Taylor Dome region of the East Antarctic Ice Sheet and terminates in Taylor Valley, one of the Dry Valleys of Victoria Land. It provides a crucial and unique link between two intensively studied Antarctic environments: the Taylor Dome, from which a 130 kyr ice core paleoclimate record has recently been extracted, and the Dry Valleys, a pivotal Long-Term Ecological Research (LTER) site and a focus of research on geomorphology and glacial geology. The proposed work will thus make an important contribution to ongoing efforts to exploit the Taylor Dome - Dry Valleys system to build a uniquely comprehensive view of regional long-term environmental changes. The proposed work has two complementary components: field research and numerical modelling. Two field seasons will be used to measure velocity, surface strain rate, mass balance, ice thickness, glacier bed reflectance, and subglacial topography, along a nearly complete longitudinal transect of the Taylor Glacier, and along select cross-valley transects. This information will be used to constrain numerical models of ice and heat flow for the Taylor Dome - Taylor Glacier system. These calibrated models will be used to analyze the time-dependent response of the Taylor Glacier to climate changes. The synthesis of results will be aimed to improve understanding of the glacial geomorphology of Taylor Valley, and to illuminate impacts on the Taylor Valley lakes ecosystem. The project will have a major role in furthering the careers of a doctoral-level graduate student and a post-doctoral researcher.
9814816 Blankenship This award supports a four year project to develop of better understanding the ice streams of the Ross Sea Embayment (A--F) which drain the interior West Antarctic Ice Sheet (WAIS) by rapidly moving vast quantities of ice to the calving front of the Ross Ice Shelf. The project will examine the role of these ice streams as buffers between the interior ice and the floating ice shelves. The reasons for their fast flow, the factors controlling their current grounding-line-, margin-, and head-positions are crucial to any attempt at modeling the WAIS system and predicting the future of the ice sheet. For the Antarctic ice streams of the Siple Coast, the transition from no-sliding (or all internal deformation) to motion dominated by sliding is defined as the "onset-region". To fully understand (and adequately model) the WAIS, this onset region must be better understood. The lateral margins of the ice streams are also a transition that need better explanation. Hypotheses on controls of the location of the onset region range from the "purely-glaciologic" to the "purely-geologic. Thus, to model the ice sheet accurately, the basal boundary conditions (roughness, wetness, till properties) and a good subglacial geologic map, showing the distribution, thickness, and properties of the sedimentary basins, are required. These parameters can be estimated from seismic, radar, and other geophysical methods. The transition region of ice stream D will be studied in detail with this coupled geophysical experiment. In addition, selected other locations on ice streams C & D will be made, to compare and contrast conditions with the main site on ice stream D. Site-selection for the main camp will be based on existing radar, GPS, and satellite data as well as input from the modeling community.
This award supports a comprehensive aerogeophysical survey of the Amundsen Sea Embayment (ASE) in West Antarctica. The University of Texas will join forces with the British Antarctic Survey to use both US and UK aircraft and instrumentation to achieve this survey. Analyses of the new aerogeophysical<br/>data will result in the generation of maps of ice sheet surface, volume and bottom-interface characteristics. These maps will support the efforts of a community of US and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE.<br/>The West Antarctic ice sheet has been the subject of intensive interdisciplinary study by both the European and U.S. scientific communities since it was recognized to be a potential source for up to 5 meters of sea<br/>level rise, possibly on short timescales. In terms of ice discharge, the ASE is the largest drainage system in West Antarctica. Yet it has been comparatively unstudied, primarily due to its remoteness from logistical<br/>centers. The ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change.<br/>The results from our surveys are required to achieve the fundamental research objectives outlined by the US scientific community in an ASE Science Plan. The surveys and analyses will be achieved through international collaboration and will involve graduate students, undergraduates and high school apprentices.<br/>Through its potential for influencing sea level, the future behavior of the ASE is of primary societal importance. Given the substantial public and scientific interest that recent reports of change in West Antarctica have generated, we expect fundamental research in the Amundsen Sea Embayment, enabled by our surveys, will have widespread impact.
This award is for support for a research program involving the use of passive microwave data to validate key paleoclimate indicators used in glaciologic research. The specific contributions of this research are: 1) to define the timing and spatial extent of hoar complexes, which may serve as visible, annual stratigraphic markers in ice cores, through a combination of satellite passive microwave data and field observations; and 2) to monitor temperature trends at the site with calibrated passive microwave brightness temperatures and to correlate these trends to proxy temperatures provided by oxygen and hydrogen stable isotope ratio profiles from snow pits and/or ice cores. The work will take place at Siple Dome, Antarctica as part of the field activities associated with the ice core drilling program there.
Kanagaratnam, Pannirselvam; Braaten, David; Bauer, Rob
No dataset link provided
This award supports a project to build and test a 12-18 GHz radar system with a plane wave antenna. This is a wideband radar operating over a frequency range of 12 to 18 GHz to detect near-surface internal firn layers of the ice sheet with better than 10 cm resolution to a depth of approximately 7 m. These measurements will allow determination of spatially continuous snow accumulation rate in the firn, which would be useful along a traverse and is of critical importance to the validation of CryoSat and ICESAT satellite missions aimed at assessing the current state of mass balance of the polar ice sheets. The antenna system planned for the radar is relatively compact, and will be located on the sledge carrying the radar systems. The broad scientific focus of this project will be to investigate important glacial processes relevant to ice sheet mass balance. The new radar will allow the characterization (with high depth resolution) of the spatial variability of snow accumulation rate along a traverse route for interpreting data from CryoSat and ICESAT missions. As part of this project, we will institute a strong outreach program involving K-12 education and a minority institution of higher education. We currently work closely with the Advanced Learning Technology Program (ALTec) at the University of Kansas to develop interactive, resource-based lessons for use on-line by students of all grade levels, and we will develop new resources related to this project. We currently have an active research and education collaboration with faculty and undergraduate students at neighboring Haskell Indian Nations University, in Lawrence, Kansas, and we will expand our collaboration to include this project.
This award supports a project to conduct laboratory experiments to investigate textures formed in ice during superplastic flow. Superplastic flow has recently been discovered in the laboratory and can be considered a new flow mechanism for ice. A simple extrapolation of these new data for superplastic flow from laboratory to natural conditions suggests that glaciers and ice sheets flow via this mechanism. Furthermore, several grain-scale features in ice (e.g., crystal shape) produced during superplastic flow in the laboratory are remarkably similar to those observed in glaciers and ice sheets. Despite this exciting discovery, however, important questions remain before we can apply with full confidence these new flow data in mathematical models of glacier and ice sheet flow. The textures seen in laboratory studies will be compared with those observed in field studies of glaciers and ice sheets. These comparisons, coupled with comparisons of the new superplastic flow data from the laboratory with flow measurements from field studies, will provide a powerful method for further assessing the importance of superplastic flow in nature and thereby improve our understanding of glacier and ice sheet dynamics and global climate change. Experiments will be conducted by the PI and an undergraduate research assistant. Experimental results will be published in relevant refereed journals, presented at glaciology meetings and incorporated into coursework.
This award supports a collaborative study between South Dakota State University (SDSU) and University of California, San Diego (UCSD) to investigate the oxygen and sulfur isotope composition of sulfates from a number of large volcanic eruptions in the past 1000 years. The project aims to drill a number of shallow ice cores at South Pole and return them to SDSU and UCSD lab for chemical and isotope analysis. Preliminary results from measurements of isotopes in sulfate samples from several volcanic eruptions in Antarctic snow and ice indicate that isotopic composition of volcanic sulfate contains abundant valuable information on atmospheric chemical and dynamic processes that have not been previously investigated. One tentative conclusion is that mass-independently fractionated sulfur isotopes reveal that atmospheric photolysis of sulfur compounds occurs at longer UV wavelengths than those in the Archean atmosphere, possibly reflecting the atmospheric ozone and/or oxygen concentration. This suggests that isotopic composition of atmospheric sulfate may be used to understand the role of UV radiation in sulfur dioxide conversion in the atmosphere and to track the evolution (i.e., oxygenation) of the atmosphere and the origin of life on Earth. Other major research objectives include understanding what impact massive volcanic eruptions have on the oxidative capacity of the atmosphere, what oxidants and mechanisms are involved in the oxidation or conversion of volcanic sulfur dioxide to sulfate in the stratosphere and what isotopic criteria may be used to differentiate ice core signals of stratospheric eruptions from those of tropospheric eruptions. By providing educational and research opportunities to graduate and undergraduate students at both SDSU and UCSD, the proposed project will promote the integration of research and education and contribute to human resource development in science and engineering. The project will contribute to a proposed REU chemistry site program at SDSU. This collaboration will utilize the complementary strengths of both labs and promote exchange between the two institutions. International collaboration will enhance scientific cooperation between France and US.
The summit crater of Mt. Moulton, in West Antarctica, contains a 600-m thick horizontally-exposed section of ice with intercalated tephra layers from nearby Mt Berlin. Argon-40/Argon-39 dating of the thick, near-source tephra indicates that the age of the horizontal ice section ranges between 15,000 and 492,000 years. Thus, the Mt Moulton site offers an unparalleled repository of ancient West Antarctic snow and trapped air that can be used to investigate West Antarctic climate over much of the past 500,000 years. The planar nature and consistent dips of the tephra layers suggests that, although the ice section has thinned, it is otherwise undeformed. The Mt. Moulton site was visited during the 1999/2000 field season, at which time a horizontal ice core representing approximately 400 meters of ice was collected, ranging in age from 15,000 to older than 480,000 years. In addition to this horizontal core, samples of ice at a range of depths were collected in order to test the quality of the climate record in the ice. Forty tephra layers intercalated in the ice were also collected in order to provide chronology for the ice section. The results of this first effort are extremely encouraging. Based on the d?18 O of ice, for example, there is clearly a useable record of past climate at Mt. Moulton extending back beyond 140,000 years. There is work to do, however, to realize the full potential of this horizontal ice core. The elemental and isotopic composition of trapped gases suggest some contamination with modern air, for example. As gas cross-dating of ice cores is the current standard by which climate records are intercompared, we need to understand why and how the gas record is compromised before adding Moulton to our arsenal of ice core paleoclimate records. This award supports a collaborative effort between three institutions with following objectives: 1) to evaluate more thoroughly the integrity of the climatic record through shallow drilling of the blue ice area, as well as the snow field upslope from the blue ice; 2) to improve the radioisotopic dating of specific tephra layers; 3) to obtain baseline information about modern snowfall deposition, mean annual temperature, and wind pumping around the summit of Mt. Moulton; and 4) to study how firn densification differs when surface accumulation changes from net accumulation to net ablation.
This award supports a three-year renewal project to complete measurement of cosmogenic nuclides in the Siple Dome ice core as part of the West Antarctic ice core program. The investigators will continue to measure profiles of Beryllium-10 (half-life = 1.5x10 6 years) and Chlorine-36 (half-life = 3.0x10 5 years) in the entire ice core which spans the time period from the present to about 100 kyr. It will be particularly instructive to compare the Antarctic record with the detailed Arctic record that was measured by these investigators as part of the GISP2 project. This comparison will help separate global from local effects at the different drill sites. Cosmogenic radionuclides in polar ice cores have been used to study the long-term variations in several important geophysical variables, including solar activity, geomagnetic field strength, atmospheric circulation, snow accumulation rates, and others. The time series of nuclide concentrations resulting from this work will be applied to several problem areas: perfecting the ice core chronology, deducing the history of solar activity, deducing the history of variations in the geomagnetic field, and studying the possible role of solar variations on climate. Comparison of Beryllium-10 and Chlorine-36 profiles in different cores will allow us to improve the ice core chronology and directly compare ice cores from different regions of the globe. Additional comparison with the Carbon-14 record will allow correlation of the ice core paleoenvironment record to other, Carbon-14 dated, paleoclimate records.
0126187<br/>Alley<br/><br/>This award provides support for a 2 year modeling effort to study the dynamics of Pine Island Glacier (PIG). The discharge from the PIG constitutes the largest mass loss from any single West Antarctic ice stream. Satellite observations indicate that this outlet glacier is experiencing ongoing thinning and acceleration. The emphasis of this work will be on understanding the cause and the near-term projection of the observed thinning of PIG. Model experiments will address the hypothesis that the observed changes were caused by the loss of a buttressing ice shelf, and that the changes will continue in the form of an upglacier propagating wave of thinning and acceleration. To perform this work a numerical model of the coupled mass, energy, and momentum balance of Pine Island Glacier basin will be developed. The model will comprise four modular components, which will be coupled and then benchmarked against the European Ice Sheet Modeling Inititative (EISMINT) model intercomparison. The model will then be applied to the thinning of Pine Island Glacier using likely ice-shelf histories and possible basal boundary conditions to learn which may be accurate and to assess possible future behavior. The primary expected result will be an improved understanding of the importance of ice-shelf buttressing and the potential for inland thinning due to the reduction of ice-shelf drag.
High latitude deep ice cores contain fundamental records of polar temperatures, atmospheric dust loads (and continental aridity), greenhouse gas concentrations, the status of the biosphere, and other essential properties of past environments. An accurate chronology for these records is needed if their significance is to be fully realized. The dating challenge has stimulated efforts at orbital tuning. In this approach, one varies a timescale, within allowable limits, to optimize the match between a paleoenvironmental property and a curve of insolation through time. The ideal property would vary with time due to direct insolation forcing. It would be unaffected by complex climate feedbacks and teleconnections, and it would give a clean record with high signal/noise ratio. It is argued strongly that the O2/N2 ratio of ice core trapped gases is such a property, and evidence is presented that this property, whose atmospheric ratio is nearly constant, is tied to local summertime insolation. This award will support a project to analyze the O2/N2 ratios at 1 kyr intervals from ~ 115-400 ka in the Vostok ice core. Ancillary measurements will be made of Ar/N2, and Ne/N2 and heavy noble gas ratios, in order to understand bubble close-off fractionation and its manifestation in the Vostok trapped gas record. O2/N2 variations will be matched with summertime insolation at Vostok to achieve a high-accuracy chronology for the Vostok core. The Vostok and other correlatable climate records will then be reexamined to improve our understanding of the dynamics of Pleistocene climate change.
This award supports a program of field surveys of an area within the large, well-developed megadune field southeast of Vostok station. The objectives are to determine the physical characteristics of the firn across the dunes, including typical climate indicators such as stable isotopes and major chemical species, and to install instruments to measure the time variation of near-surface wind and temperature with depth, to test and refine hypotheses for megadune formation. Field study will consist of surface snowpit and shallow core sampling, ground penetrating radar (GPR) profiling, GPS topographic and ice motion surveys, AWS installation, accumulation/ ablation measurements, subsurface temperature, and firn permeability studies. Field work in two successive seasons is proposed. Continent-wide remote sensing studies of the dunes will be continued, using the new group of instruments that are now, or will shortly be available (e.g., MODIS, MISR, GLAS, AMSR). The earlier study of topographic, passive microwave, and SAR characteristics will be extended, with the intent of determining the relationships of dune amplitude and wavelength to climate parameters, and further development of models of dune formation. Diffusion, ventilation, and vapor transport processes within the dune firn will be modeled as well. A robust program of outreach is planned and reporting to inform both the public and scientists of the fundamental in-situ and remote sensing characteristics of these uniquely Antarctic features will be an important part of the work. Because of their extreme nature, their broad extent, and their potential impact on the climate record, it is important to improve our current understanding of these. Megadunes are a manifestation of an extreme terrestrial climate and may provide insight on past terrestrial climate, or to processes active on other planets. Megadunes are likely to represent an end-member in firn diagenesis, and as such, may have much to teach us about the processes involved.
This award supports the analysis, in Antarctic ice cores, of the ozone depleting substances methyl bromide (CH3Br) and methyl chloride (CH3Cl), and the sulfur-containing gas, carbonyl sulfide (OCS). The broad scientific goal is to assess the level and variability of these gases in the preindustrial atmosphere. This information will allow testing of current models for sources and sinks of these gases from the atmosphere, and to indirectly assess the impact of anthropogenic activities on their biogeochemical cycles. Longer-term records will shed light on the climatic sensitivity of the atmospheric burden of these gases, and ultimately on the biogeochemical processes controlling them. These gases are present in ice at parts per trillion levels, and the current database consists entirely of a small number of measurements made in from a shallow ice core from Siple Dome, Antarctica. This project will involve studies of ice core samples from three Antarctic sites: Siple Station, Siple Dome, and South Pole. The sampling strategy is designed to accomplish several objectives: 1) to verify the atmospheric mixing ratios previously observed in shallow Siple Dome ice for OCS, CH3Br, and CH3Cl at sites with very different accumulation rates and surface temperatures; 2) to obtain a well-dated, high resolution record from a high accumulation rate site (Siple Station), that can provide overlap in mean gas age with Antarctic firn air samples; 3) explore Holocene variability in trace gas mixing ratios; and 4) to make the first measurements of these trace gases in Antarctic glacial ice. In terms of broader impact on society, this research will help to provide a stronger scientific basis for policy decisions regulating the production and use of ozone-depleting and climate-active gases. Specifically, the methyl bromide results will contribute to the current debate on the impact of recent regulation (via the Montreal Protocol and its Amendments) on atmospheric levels. Determination of pre-industrial atmospheric variability of ozone-depleting substances will help place more realistic constraints on scenarios used for future projections of stratospheric ozone and its climatic impacts. This research will involve the participation of both graduate and undergraduate students.
POINT(-148.81 -81.65)
POINT(-148.81 -81.65)
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None
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2005-11-02
Bohlander, Jennifer; Scambos, Ted; Painter, Thomas; Fahnestock, Mark; Haran, Terry
9909518 Raymond This award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide "shutdown" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time.
0125981<br/>Sowers<br/><br/>This award supports a project to construct an isotopic record of atmospheric methane and nitrous oxide over the last century from South Pole firn air. Over the last 150 years, atmospheric methane and nitrous oxide concentrations have risen in response to increased emissions from various anthropogenic activities. As this trend is liable to continue in the foreseeable future, it is important to understand the biogeochemical processes that contribute to the emissions of these two greenhouse gases. In this context, records of the variations in the atmospheric loading of trace gases found in ice cores and interstitial spaces in the snow near the surface of the ice sheet (firn air) provide fundamental boundary conditions for reconstructing historical emission records. One way to improve our understanding of the cycling of bioactive trace gases and their emission records is to use stable isotope tracers, which have been recorded in the ice cores and firn air. This project will develop records of carbon-13 and deuterium isotope ratios of methane, as well as the nitrogen-15, oxygen-18 and the isotopomer composition of nitrous oxide trapped in firn air samples collected in January 2001 at the South Pole. These measurements will allow isotopic records of these atmospheric gases to be reconstructed throughout the 20th century. Such records will help to establish the relative contribution of individual sources with a higher degree of confidence than is currently available.
This award supports continued acquisition of high resolution, radar reflection profiles of the snow and ice stratigraphy between core sites planned along traverse routes of the U.S. component of the International<br/>Trans-Antarctic Scientific Expedition (U.S.-ITASE). The purpose is to use the profiles to establish the structure and continuity of firn stratigraphic horizons over hundreds of kilometers and to quantitatively<br/>assess topographic and ice movement effects upon snow deposition. Other objectives are to establish the climatic extent that a single site represents and to investigate the cause of firn reflections. The radar<br/>will also be used to identify crevasses ahead of the traverse vehicles in order to protect the safety of the scientists and support personnel on the traverse. Collaboration with other ITASE investigators will use the radar horizons as continuous isochronic references fixed by the core dating to calculate historical snow accumulation rates. The primary radar system uses 400-MHz (center frequency) short-pulse antennas, which (with processing) gives the penetration of 50-70 meters. This is the depth which is required to exceed the 200-year deposition horizon along the traverse routes. Profiles at 200 MHz will also be recorded if depths greater than 70 meters are of interest. Processing will be accomplished by data compression (stacking) to reveal long distance stratigraphic deformation, range gain corrections to give proper weight to signal amplitudes, and GPS corrections to adjust the records for the present ice sheet topography. Near surface stratigraphy will allow topographic and ice movement effects to be separated. This work is critical to the success of the U.S.-ITASE program.
Roy, Martin; Hemming, Sidney R.; Goldstein, Steven L.; Van De Flierdt, Christina-Maria
No dataset link provided
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the sediment core from the Southern Ocean for paleoenvironmental research. The polar regions are susceptible to the largest changes in climate and are among the least accessible places on Earth. Current concern about the instability of the West Antarctic Ice Sheet has heightened awareness of the vulnerability of polar regions. This proposal seeks to gain a basic understanding of the isotopic characteristics of terrigenous sediment sources derived from Antarctica in the Holocene and Last Glacial Maximum, and their dispersal into the Southern Ocean. Terrigenous clastic sediments are brought to the ocean from continental sources via rivers, ice and wind, and distributed within the ocean by surface and deep currents. At present there are virtually no isotopic data on circumpolar detritus, save a few strontium (Sr) isotopic ratios in the Atlantic sector. This project will fill part of this gap. From the large range in geological ages of crustal provinces of Antarctica, we would predict that there are large isotopic differences in detritus around the continent. The main objectives are to (1) characterize the strontium-neodymium-lead-argon (Sr-Nd-Pb-Ar) isotope compositions of sediment sources derived from Antarctica, (2) to identify the composition and source ages of major ice rafted detritus (IRD) contributions by analyzing individual grains of hornblende and feldspar in conjunction with bulk isotopic analysis, and (3) track sediment dispersal into the Antarctic Circumpolar Current (ACC) during the Holocene and Last Glacial Maximum.<br/><br/>Because of the paucity of circumpolar data, this research necessarily has a large exploratory component. Consequently, it will provide a basic database for future studies. Nevertheless there are important hypothesis-driven questions that will be addressed in this primary pass. Can lessons learned in North Atlantic IRD studies be applied toward understanding the history of Antarctic ice sheets? Can the large geological variability around the Antarctic margin be treated as a series of natural tracer injections into the ACC, and thus characterize its trajectory, speed, and interaction with other current systems today and in the past? The proposed study is motivated by an exciting set of results from the South Atlantic, showing that detrital Sr isotope ratios are a sensitive current tracer in that region. This research should serve a basic need across many Earth Science disciplines if the use of long-lived radiogenic isotopes (Sr-Nd-Pb-Ar) as tracers of marine sediment sources is successful in elucidating processes related to changing climatic conditions. The results of this study will fill a basic gap in our knowledge of an important region of the Earth. At the same time, it will provide an essential basis for attempting reconstruction of the ACC during the LGM, as well as for future studies of Antarctic geology, ice sheet history, and the Southern Ocean circulation.
This award supports a program of radar studies of internal stratigraphy and bedrock topography along the traverses for the U.S. component of the International Trans-Antarctic Scientific Expedition (US ITASE). The radar will provide information immediately available in the field on ice thickness and internal layer structure to help in the selection of core sites as the traverse proceeds. These data will also be useful in siting deeper millennial scale cores planned at less frequent intervals along the traverse, and in the selection of the location for the deep inland core planned for the future. In addition to continuous coverage along the traverse route, more detailed studies on a grid surrounding each of the core locations will be made to better characterize accumulation and bedrock topography in each area. This proposal is complimentary to the one submitted by the Cold Regions Research and Engineering Laboratory (CRREL), which proposes a high frequency radar to examine the shallower portion of the record down to approximately 60 meters, including the presence of near-surface crevasses. The radar proposed herein is most sensitive at depths below 60 meters and can depict deep bedrock and internal layers to a substantial fraction of the ice thickness.
0086997<br/>Truffer<br/><br/>This award supports a two year project to investigate the dynamics of the marginal zone of the Siple Coast ice streams using existing velocity and temperature profiles. The flow and stress fields will be modeled using finite element methods and a thermo-mechanical model will be used to investigate the coupling of the flow and temperature fields. Direct comparison of these models with the observed velocity profiles will lead to estimates of the structure of the margins and the softening of the marginal ice. The distribution of basal and marginal shear stress will be investigated, leading to an estimate of the relative roles of the bed and the margins in the overall force balance of the ice streams.
0135989<br/>Wilen<br/><br/>This is a collaborative proposal by Principal Investigators at the University of Washington and Ohio University. Detailed knowledge about the interactions between micro-structure of ice and its deformation is needed to assess the integrity of stratigraphic layering and the depth-age relationship in ice cores, which is essential for interpreting the paleoclimate record. The Principal Investigators will use micro-structure to study fabric, the orientation distribution of crystal c-axes, and texture, the size and shape of crystals. Numerical modeling of ice deformation is a useful tool in understanding these interactions. Accurate modeling of ice deformation is complicated by factors, such as the fabric, grain size, dynamic recrystallization, stress level, and precise knowledge of initial conditions. For example, ice fabric evolves as the ice is strained and the deformation depends on the fabric. This complicated feedback mechanism must be understood to correctly model ice deformation. In another example, the usual assumption is that the initial fabric is isotropic or random, but there are excellent examples of near-surface ice in the ice cores that are apparently not isotropic. One must know the initial fabric to calculate the deformation rate in ice sheets. Dr. Wilen will combine results of his new automatic fabric analyzer (AFA) with predictions of detailed ice deformation models (Dr. Thorsteinsson) to refine and better constrain such models. The AFA gives new information in thin sections because the precision and number of measured c-axis orientations are greatly improved. The Principal Investigators will analyze existing data and collect new data on fabric and texture from ice cores to address questions regarding near-surface fabric, deformation mechanisms, dynamic recrystallization, and potential sources of layer disturbances. The data will be used to constrain models of fabric evolution and recrystallization processes. With the more refined models, scientists can address different questions and important problems related to ice deformation and ice cores. For example, the recent agreement between the climate records from the Greenland Ice Core Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) ice cores of the upper-90%, and the disagreement in the lower-10% emphasizes the need to understand and predict the mechanisms and probable depths of disruption in these and future deep ice cores. Evidence suggests that the stratigraphic disturbances arise from the anisotropic nature of ice crystals at a variety of scales. To properly model the deformation of anisotropic ice, the influence of fabric on deformation must be well known.
This award is for support for a program to make high resolution studies of variations in the concentration of methane, the oxygenisotope composition of paleoatmospheric oxygen, and the total gas content of deep Antarctic ice cores. Studies of the concentration and isotopic composition of air in the firn of the Antarctic ice sheet will also be continued. One objective of this work is to use the methane concentration and oxygen-isotope composition of oxygen of air in ice as time-stratigraphic markers for the precise intercorrelation of Greenland and Antarctic ice cores as well as the correlation of ice cores to other climatic records. A second objective is to use variations in the concentration and interhemispheric gradient of methane measured in Greenland and Antarctic ice cores to deduce changes in continental climates and biogeochemistry on which the atmospheric methane distribution depends. A third objective is to use data on the variability of total gas content in the Siple Dome ice core to reconstruct aspects of the glacial history of West Antarctica during the last glacial maximum. The fourth objective is to participate in collaborative studies of firn air chemistry at Vostok, Siple Dome, and South Pole which will yield much new information about gas trapping in ice as well as the concentration history and isotopic composition of greenhouse gases, oxygen, trace biogenic gases and trace anthropogenic gases during the last 100 years.
9316564 Mayewski This award is for support for a three year program to provide a high resolution record of the Antarctic climate through the acquisition, analysis, and interpretation of records of atmospheric chemical deposition taken from three ice cores located at sites within or immediately adjacent to the Ross Ice Drainage System (RIDS). These cores include one from Taylor Dome, and two from West Antarctic locations identified as potential deep drilling sites for the WAISCORES program. Collection of the two West Antarctic cores is intended to be a lightweight dry-drilling operation to depths of ~ 200 m, which will provide records of > 2 kyr. Glaciochemical analyses will focus on the major cations and anions found in the antarctic atmosphere, plus methanesulfonic acid and selected measurements of the hydrogen ion, aluminum, iron, and silica. These analyses, and companion stable isotope and particle measurements to be carried out by other investigators require < 7% by volume of each core, leaving > 90% for other investigators and storage at the U.S. National Ice Core Laboratory. These records are intended to solve a variety of scientific objectives while also providing spatial sampling and reconnaissance for future U.S. efforts in West Antarctica. ***
This award is for support of a study to establish a quantitative nuclear method for determination of Antarctic ablation and accumulation rates and to provide correction factors for the carbon 14 ages of ice samples dated using trapped carbon 14. Recent studies have established the presence of cosmogenic in-situ produced carbon 14 in polar ice. In conjunction with estimated carbon 14 production rates, measured concentrations of carbon 14 per gram of ice yield, ablation rates which are in good agreement with the values determined from stake measurements. Similar studies to determine accumulation rates have been tested and the estimates are consistent with previous studies. This study will expand the preliminary work done to date in order to improve the 14CO and 14CO2 vacuum extraction techniques, by lowering blank levels and by obtaining more complete separation of 14CO and 14CO2.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research project between the University of California-Santa Cruz, the University of Texas-Austin, and the Ohio State University to investigate sediment samples recovered from the base of the West Antarctic Ice Sheet (WAIS). West Antarctica is a remote polar region but its dynamic ice sheet, complicated tectonic history, and the sedimentary record of Cenozoic glaciation make it of particular interest to glaciologists and geologists. Glaciologists are concerned with the possibility of significant near-future changes in mass balance of the WAIS that may contribute to the ongoing global sea level rise. Geologists are investigating in West Antarctica the fundamental process of continental extension and are constructing models of a polar marine depositional system using this region as the prime modern example. The subglacial part of West Antarctica has escaped direct geological investigations and all that is known about subglacial geology comes from geophysical remote sensing. Recent acquisitions of new, high-quality geophysical data have led to generation of several enticing models. For instance, subglacial presence of high-magnitude, short-wavelength magnetic anomalies has prompted the proposition that there may be voluminous (>1 million cubic km), Late Cenozoic flood basalts beneath the ice sheet. Another important model suggests that the patterns of fast ice streaming (~100 meters/year) and slow ice motion (~1-10 meters/year) observed within the WAIS are controlled by subglacial distribution of sedimentary basins and resistant bedrock. These new geophysics-based models should be tested with direct observations because they are of such great importance to our understanding of the West Antarctic tectonic history and to our ability to predict the future behavior of the WAIS.<br/><br/>This research is designed as a pilot study to provide new geologic data, which may help to test the recent models inferred from geophysical observations. The new constraints on subglacial geology and on its interactions with the WAIS will be obtained through petrological and geochemical analyses of basal and subglacial sediments collected previously from seven localities. This investigation will take place in the context of testing the following three hypotheses: (A) the provenance of bedrock clasts in the glacial sediment samples is primarily from West Antarctica, (B) some clasts and muds from the West Antarctic subglacial sediments have been derived by erosion of the (inferred) subglacial Late Cenozoic flood basalts, and (C) the sediments underlying the West Antarctic ice streams were generated by glacial erosion of preglacial sedimentary basins but the sediments recovered from beneath the slow-moving parts of the WAIS were produced through erosion of resistant bedrock.<br/><br/>The individual hypotheses will be tested by collecting data on: (A) petrology, geochemistry and age of granitoid clasts, (B) petrology, geochemistry and age of basaltic clasts combined with mud geochemistry, and (C) clay mineralogy/paragenesis combined with textural maturity of sand and silt grains. The results of these tests will help evaluate the interesting possibility that subglacial geology may have first-order control on the patterns of fast ice flow within the WAIS. The new data will also help to determine whether the subglacial portion of West Antarctica is a Late Cenozoic flood basalt province. By combining glaciological and geological aspects of West Antarctic research the proposed collaborative project will add to the ongoing U.S. effort to create a multidisciplinary understanding of this polar region.
This award provides one year of support to use newly developed technology in which an ice-core melter is coupled with both an Inductively Coupled Plasma - Mass Spectrometer (ICP-MS) and a traditional Continuous Flow Analysis (CFA) system, to measure a continuous time series of chemical and trace element deposition on the Siple Dome ice core from West Antarctica. A coupled ice-core melter, ICP-MS, and CFA system will be used to measure concentrations of a number of elements, isotopes and chemical species at very high depth resolution (~2-cm) in the top 54 m of the Siple Dome A-core. Pilot data from analyses of ~6 m from the nearby but much lower accumulation J-core site at Siple Dome, together with more extensive results from Summit, Greenland, indicate that it will be possible to obtain exactly co-registered, high-quality records of at least 12 seasonally varying elements (sodium, magnesium, aluminum, potassium, calcium, iron, manganese, rubidium, strontium, zirconium, barium, lead) and three other chemical species and ions (ammonium, nitrate, calcium ion) with this system. Under this proposed research, we will also add continuous measurements of sulfate to our system. Because more than sufficient core from Siple Dome for these depths is archived at the National Ice Core Laboratory, the proposed research will require no fieldwork. The continuous, very high-resolution, ~350-y record of these elemental tracers will enhance the value of previous chemical and isotopic measurements that have been made on the Siple Dome core and will be particularly valuable for comparisons between ice-core proxies and modern instrumental data related to El Nino-Southern Oscillation (ENSO) as well as for validation of model simulations of atmospheric circulation. These data, and the expertise gained through this research, will be invaluable when this novel chemical analysis technology is eventually applied to deep ice-core records for the study of rapid climate-change events.
This award supports a two year project to analyze shallow (~150 m) ice cores from South Pole in order to construct an annually resolved, sulfate-based volcanic record covering the last 1400 years. Two shallow ice cores will be recovered at the South Pole during the 00/01 field season and will be used for this work. Volcanic records from polar ice cores provide valuable information for studies of the connection between volcanism and climate. The new records are expected to be continuous and to cover at least the last 1400 years. The information from these records will verify the volcanic events found in the few existing Antarctic records and resolve discrepancies in the timing and magnitude of major explosive eruptions <br/>determined from those earlier records. In order to achieve the objectives of the proposed research, funds are provided to assist with the construction of an analytical laboratory for ice core and environmental <br/>chemistry research.
Elliot, David; Bell, Robin; Blankenship, Donald D.; Brozena, J. M.; Finn, C. A.; Hodge, S. M.; Kempf, Scott D.; Behrendt, J. C.; Morse, David L.; Peters, M. E.; Studinger, Michael S.
This award will support a combined airborne radar and aeromagnetic survey of two 220 x 330 km regions between the Transantarctica Mountains and Marie Byrd Land during the 1990-91 and 1991-92 field seasons. These efforts will address significant problems identified in the Ross Transect Zone (RTZ) by the National Academy of Sciences (1986) report "Antarctic Solid Earth Sciences Research," and by the report to NSF "A Plan for a United States Program to Study the Structure and Evolution of the Antarctic Lithosphere (SEAL)." The surveys will be flown using the NSF/TUD radar and an areomagnetics system mounted in a light aircraft. The grid spacing will be 5 km and navigation will be by radiopositioning. In addition to maps of subglacial topography and magnetic intensity, attempts will be made to reconstruct the position of subglacial diffractors in three dimensions. This reconstruction should give new information about the distribution of escarpments and therefore the tectonic relationships within the region, especially when combined with the magnetic results. These experiments will be conducted by the Byrd Polar Research Center of the Ohio State University and the Water Resources and Geological Divisions of the U.S. Geological Survey.
This award is for support for four years of funding for a program of biogenic sulfur measurements on the Siple Dome ice core. Biogenic sulfur is a major aerosol-forming constituent of the atmosphere and has potentially important links to the earth's radiation budget. Previous work on the Vostok ice core has demonstrated a remarkable climate-related variability in biogenic sulfur, suggesting that the sulfur cycle may act to stabilize climate (keep the glacial atmosphere cool and the interglacial atmosphere warm) in the Southern Hemisphere. In this study, methane-sulfonate (MSA) will be measured on the Siple Dome ice core as part of the West Antarctic ice sheet program (WAIS). Siple Dome is located in a region which is strongly impacted by the incursion of marine air onto the Antarctic plateau. Because of its proximity to the coast and meteorological setting, it is expected that variability in high-latitude marine biogenic sulfur emissions should dominate the MSA record at this site. In addition to the deep ice core record, samples from shallow cores will also be analyzed to provide information about regional variability and decadal-to-centennial scale variability in the deposition of sulfur-containing aerosols from high latitude source regions over the past 200 years.
9980691 Wahlen This award is for support for three years of funding to reconstruct the atmospheric carbon dioxide (CO2) and carbon-13 isotope (d13C) concentration in ice cores from Antarctica over several climatic periods. Samples from the Holocene, the Last Glacial Maximum (LGM)-Holocene transition and glacial stadial/interstadial episodes will be examined. Samples from the Siple Dome ice core drilled in 1998/99 will be made, in addition to measurements from the Taylor Dome and Vostok ice cores. The major objectives are to investigate the phase relationships between variations in the concentration of atmospheric CO2, its carbon isotope composition, and temperature changes (indicated by 18dO and dD of the ice) during deglaciations as well as across rapid climate change events (e.g. Dansgaard-Oeschger events). This will help to determine systematic changes in the global carbon cycle during and between different climatic periods, and to ascertain if the widely spread northern hemisphere temperature stadial/interstadial events produced a global atmospheric carbon dioxide signal. Proven experimental techniques will be used.
This award is for support for a three year program to investigate the response of ice domes, such as Siple Dome in West Antarctica, to changing boundary conditions, for example as arising from fluctuations in thickness or position of bounding ice streams. A range of models will be used, from simple one-dimensional analytical models to coupled dynamic-thermodynamic flow models, to investigate the response of the ice dome to boundary forcing, and the record that boundary forcing can leave in the ice core record. Using radar, temperature, and ice core data from the currently funded field programs on Siple Dome, and ice flux and thickness values from the map view model as boundary conditions, a flow line across Siple Dome will be studied and possible ranges of time scales, the likely origin of ice near the bed, and the basal temperature conditions that exist now and existed in the past will be determined.The response of internal stratigraphy patterns to climate and dynamic forcing effects will be investigated and observed internal layers from ice cores will be used to infer the forcing history.
9909469 Scambos This award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide "shutdown" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time.
This award is for support for a program to measure the stable isotope (deuterium to hydrogen and oxygen-18 to oxygen-16) concentrations of ice cores retrieved from Siple Dome as part of the West Antarctic ice sheet program. In addition, the deuterium excess of samples from the Taylor Dome ice core will be determined. This project will approach the question of rapid climate change using ice cores to determine the history of temperature changes, moisture source changes, and elevational changes in the West Antarctic ice sheet. Results from ice cores taken to date in the interior of Antarctica (East and West) are surprisingly lacking in indications of abrupt climate changes, such as those that have been observed in the GISP2 ice core from Summit, Greenland. This work will address the question of whether rapid climate changes, which are known to have occurred in other parts of the southern hemi-sphere, may have also occurred in the coastal regions of West Antarctica. There is some indication from existing records of isotopes in ice cores that the West Antarctic ice sheet may have flushed ice in the past (as evidenced by large changes in elevation of the ice sheet).
This award is for two years of support to perform radar investigations across former shear margins at Roosevelt Island and Ice Stream C in order to measure changes in the configuration and continuity of internal layers and the bed. The broad goal of these investigations is to gain an understanding of ice stream flow and the timing and mechanisms of ice stream shutdown. A high-resolution short-pulse radar system will be used for detailed examination of the uppermost hundred meters of the firn and ice, and a monopulse sounding-radar system will be used to image the rest of the ice column (including internal layers) and the bed. Changes in the shape and continuity of layers will be used to interpret mechanisms and modes of ice stream flow including the possible migration of stagnation fronts and rates of shut-down. Variations in bed reflectivity will be used to deduce basal hydrology conditions across lineations. Accumulation rates deduced from snow pits and shallow cores will be used to estimate near-surface depth-age profiles. Improved understanding of ice stream history opens the possibility of linking changes in the West Antarctic ice sheet with the geologic evidence from Northern Victoria Land and the ocean record of the retreat of the grounding line in the Ross Sea.
This award is for support for two years to develop the technology and methodology for digitizing the photographs and analyzing the thin sections from ice cores. In addition, the application of digital technology for whole-core stratigraphy, using digital photography, image enhancement and image processing will be investigated. The thin section analysis will be piloted with samples already in hand from the Taylor Dome ice core. If successful, these techniques will be applied to samples from the Siple Dome ice core, in cooperation with Principal Investigators already funded to retrieve and examine these sections. The original digital images with all original data annotation files will be distributed to Siple Dome principal investigators for their use in the interpretation of their own data. All software and hardware acquired for this project will become part of the permanent equipment inventory at the U.S. National Ice Core Laboratory and will be available for use by clients at the facility.
This award is for support for a program to investigate the visual stratigraphy, index physical properties, relaxation characteristics and crystalline structure of ice cores from Siple Dome, West Antarctica. This investigation will include measurements of a time-priority nature that must be initiated at the drill site on freshly-drilled cores. This will be especially true of cores from the brittle ice zone, which is expected to comprise a significant fraction of the ice core. The brittle zone includes ice in which relaxation , resulting from the release of confining pressure is maximized and leads to significant changes in the mechanical condition of the core that must be considered in relation to the processing and analysis of ice samples for entrapped gas and chemical studies. This relaxation will be monitored via precision density measurements made initially at the drill site and repeated at intervals back in the U.S. Other studies will include measurement of the annual layering in the core to as great a depth as visual stratigraphy can be deciphered, crystal size measurements as a function of depth and age, c-axis fabric studies, and analysis of the physical properties of any debris-bearing basal ice and its relationship to the underlying bedrock. Only through careful documentation and analysis of these key properties can we hope to accurately assess the dynamic state of the ice and the age-depth relationships essential to deciphering the paleoclimate record at this location.
This award is for support for the measurement of electrical and optical properties of the Siple Dome ice core. The electrical methods can be used to determine the concentration of the hydrogen ions and the concentration of a weighted sum of all ions. The electrical measurements can resolve features as small as 1 cm. The albedo of the core is also measured with a laser system that can resolve features as small as 0.5 cm. The high spatial resolution of these methods makes them ideal for resolving narrow features in the core, which can be missed in larger composite samples. The measurements will be particularly useful for assisting to date the core and to identify short duration features in the record, such as volcanic eruptions. These measurements will also provide useful information for assessing the temporal variability of Holocene accumulation rate and atmospheric circulation.
This award is for support for a program of measurements to improve our understanding of the relationship between formaldehyde (HCHO) and hydrogen peroxide (H2O2) in the atmosphere and the concentrations of the same species in Antarctic snow, firn and ice. This work aims to relate changes in concentrations in the snow, firn and ice to corresponding changes in tropospheric chemistry. Atmospheric and firn sampling for formaldehyde and hydrogen peroxide at one or more of the WAIS ice core drilling sites will be undertaken and controlled laboratory studies to estimate thermodynamic and rate parameters will be performed. In addition, this work will involve modeling of atmosphere-snow exchange processes to infer the "transfer function" for reactive species at the sites and atmospheric photochemical modeling to relate changes in concentrations of formaldehyde and hydrogen peroxide in snow, firn and ice to atmospheric oxidation capacity. This work will contribute to a better understanding of the relationship between atmospheric concentrations of various species and those same species measured in snow and ice samples.
This award is for support for a program of glaciochemical analyses of shallow and deep ice cores from Siple Dome, West Antarctica. Measurements that have been proposed include chloride, nitrate, sulfate, calcium, magnesium, sodium, potassium, ammonium and methansulfonic acid. These measurements will provide information about past volcanic events, biomass source strength, sea ice fluctuations, atmospheric circulation, changes in ice-free areas and the environmental response to Earth orbit insolation changes and solar variability. The glaciochemical records from the Siple Dome core will be developed at a resolution sufficient to compare with the Summit, Greenland record, thus allowing a bipolar comparison of climate change event timing and magnitude. As part of this award, an international workshop will be held during the first year to formulate a science plan for the International Transantarctic Scientific Expedition (ITASE), a program of regional surveys documenting the spatial distribution of properties measured in ice cores .
Dunbar/Kyle OPP 9527373 Zielinski OPP 9527824 Abstract The Antarctic ice sheets are ideal places to preserve a record the volcanic ash (tephra) layers and chemical aerosol signatures of volcanic eruptions. This record, which is present both in areas of bare blue ice, as well as in deep ice cores, consists of a combination of local eruptions, as well as eruptions from more distant volcanic sources from which glassy shards can be chemically fingerprinted and related to a source volcano. Field work carried out during the 1994/1995 Antarctic field season in the Allan Hills area of Antarctica, and subsequent microbeam chemical analysis and 40Ar/39Ar dating has shown that tephra layers in deep Antarctic ice preserve a coherent, systematic stratigraphy, and can be successfully mapped, dated, chemically fingerprinted and tied to source volcanoes. The combination of chemical fingerprinting of glass shards, and chemical analysis of volcanic aerosols associated with ash layers will allow establishment of a high-resolution chronology of local and distant volcanism that can help understand patterns of significant explosive volcanisms and atmospheric loading and climactic effects associated with volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas, which have been identified in many places the Transantarctic Mountains, will allow the geometry of ice flow in these areas to be better understood and will provide a useful basis for interpreting ice core records.
This award is for support of a program to reconstruct the record of atmospheric carbon dioxide (and the carbon-13 isotopes of carbon dioxide) over several intervals, including the Last Glacial Maximum-Holocene transition, interstadial episodes, the mid-Holocene, the last 1000 years and the penultimate glacial period, using ice from the Taylor Dome and Vostok ice cores. The major objective of this study is to investigate the phase relationship between variations of the greenhouse gases occluded in the ice cores and temperature changes (indicated by oxygen and deuterium isotopes) during the last deglaciation. In addition, the concentration of atmospheric carbon dioxide over the past 1000 years and during the mid-Holocene will be determined in these cores.
This award supports an in situ and short traverse seismic reflection/refraction and magnetotelluric experiment in West Antarctica. This collaborative experiment involves four awards at four institutions. The four-fold purpose is 1) to investigate part of the Byrd Subglacial Basin, 2) to test techniques for this work that could be done in a long traverse, 3) to determine the viability of the magnetotelluric method on a thick (electrically resistive) ice sheet, and 4) to evaluate the relative merits of refraction with wide reflection versus reflection with narrow refraction seismic studies in imaging the lithosphere. The geophysical techniques that will be employed are capable of imaging the ice sheet, the continental lithosphere, and the upper mantle, as well as determining physical properties of parts of the lithosphere and mantle. Investigations of outcrop geology over the last thirty years in West Antarctica and the Transantarctic Mountains have lead to recent interpretations that the crust is made up of many different lithospheric blocks. Seismic reflection work is the only way to image the crust in detail and the refraction work is the only way to determine physical properties of the layers and blocks defined by the reflection work. The magnetotelluric work is scientifically risky because it may not yield useful information when used over the electrically resistive ice sheet; however, if it works it has the potential to image molten rock in the crust and upper mantle. In a continental rift region such as West Antarctica, the presence of melt in the lithosphere is likely and, if documented, has very important ramifications to ice sheet dynamics. Research work supported by this award is expected to provide constraints to models of a range of crustal processes from models of ice sheet dynamics to tectonic and kinematic models of lithospheric thinning and rifting.
9318121 Anandakrishnan This award is for support for a three year project to test the hypothesis that a controlling parameter of fast ice-stream flow is the hydrologic state of discrete zones of high friction ("sticky spots") at the bed of the ice streams. Previous work has discovered an enormous difference in basal microearthquake activity between fast-flowing ice stream B and ice stream C, which stopped flowing within the last 200 years. It is hypothesized that the basal water system is lubricating the sticky spots under the fast ice stream and thus inhibiting microearthquake activity, and at the same time permitting fast ice flow. This experiment is intended to collect a continuous record of wide-bandwidth microearthquake data from a variety of sites, on the ice streams, in the transition zone, and on the inland ice. ***
This award supports a project to examine the physical processes that affect the manner in which heat, vapor and chemical species in air are incorporated into snow and polar firn. The processes include advection, diffusion, and the effects of solar radiation penetration into the snow. An understanding of these processes is important because they control the rate at which reactive and non-reactive chemical species in the atmosphere become incorporated into the snow, firn, and polar ice, and thus will affect interpretation of polar ice core data. Currently, the interpretation of polar ice core data assumes that diffusion controls the rate at which chemical species are incorporated into firn. This project will determine whether ventilation, or advection of the species by air movement in the firn, and radiation penetration processes have a significant effect. Field studies at the two West Antarctic ice sheet deep drilling sites will be conducted to determine the spatial and temporal extent for key parameters, and boundary conditions needed to model the advection, conduction, and radiation transmission/absorption processes. An existing multidimensional numerical model is being expanded to simulate the processes and to serve as the basis for ongoing and future work in transport and distribution of reactive chemical species.
9316338 Jacobel This award is for support for a program of glaciological studies of Siple Dome and its surroundings between Ice Streams C and D. The purpose of the work is to characterize the dynamic environment and ice stratigraphy to aid in the assessment of Siple Dome as a potential deep ice core site, and to determine whether the configuration of ice stream flow in the region was different in the past than now. The work involves measurements of the configuration and continuity of internal layers in the ice, using radar echo sounding and determination of velocity field, based on standard GPS surveying. The goals of the work are relevant to understanding the dynamics of the West Antarctic Ice Sheet (WAIS), its past history and its potential future behavior, including possible effects on global sea level. This work is a collaborative project between the University of Washington, the University of Colorado and St. Olaf College. ***
This award is for support for a program of physical and visible studies on the shallow and deep ice cores to be retrieved from Siple Dome, West Antarctica. Visible examination of ice cores has proven to be a powerful technique for dating and paleoclimatic interpretation. Recent examination of a shallow core from Siple Dome indicates that annual-layer dating is possible and that visible examination will contribute significantly to the dating effort at Siple Dome. Once ages are obtained, distances between layers provide snow accumulation after correction for density variations and ice flow thinning. Thin- section examination of the core will contribute to understanding the visible stratigraphy, and will reveal c-axis fabrics which are related to past ice deformation. The results of this study should include a better understanding of rapid climate change in the Antarctic and should contribute to knowledge of the stability of the West Antarctic ice sheet.
Abstract<br/><br/>The Antarctic Meteorological Research Center (AMRC), located at the University of Wisconsin, Madison, serves several communities by maintaining and extending the stewardship of meteorological data pertinent to the Antarctic continent, its surrounding islands, ice sheets and ice margins and the adjacent Southern Ocean. This data will continue to be made freely available to interested researchers and the general public. Activities of particular interest for the current award include the development of an enhanced data portal to provide improved data and analysis tools to the research community, and to continue to add to the evolution of the Antarctic-Internet Data Distribution system, which is meant to overcome the costly and generally low bandwidth internet connectivity to and from the Antarctic continent. Operational forecasting for logistical activities in the Antarctic, as well as active Antarctic meteorological research programs, are clearly in need of a dependable, steady flow of meteorological observations, model output, and related data in what must be a collaborative environment in order to overcome the otherwise distributed nature of Antarctic meteorological and climatological observations.<br/><br/>AMRC interaction with the public through answering e-mail questions, giving informal public lectures and presentations to K-12 education institutions through visits to schools will help to raise science literacy with regards to meteorology and of the Antarctic and polar regions. <br/><br/><br/><br/>"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."