{"dp_type": "Project", "free_text": "Melt"}
[{"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 Stevens; Greenbaum, Jamin", "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": "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": "1841228 Lyons, W. Berry", "bounds_geometry": "POLYGON((163.37428 -77.558627,163.3922735 -77.558627,163.410267 -77.558627,163.4282605 -77.558627,163.446254 -77.558627,163.4642475 -77.558627,163.482241 -77.558627,163.5002345 -77.558627,163.518228 -77.558627,163.5362215 -77.558627,163.554215 -77.558627,163.554215 -77.56397510000001,163.554215 -77.5693232,163.554215 -77.5746713,163.554215 -77.5800194,163.554215 -77.5853675,163.554215 -77.59071560000001,163.554215 -77.5960637,163.554215 -77.60141180000001,163.554215 -77.6067599,163.554215 -77.612108,163.5362215 -77.612108,163.518228 -77.612108,163.5002345 -77.612108,163.482241 -77.612108,163.4642475 -77.612108,163.446254 -77.612108,163.4282605 -77.612108,163.410267 -77.612108,163.3922735 -77.612108,163.37428 -77.612108,163.37428 -77.6067599,163.37428 -77.60141180000001,163.37428 -77.5960637,163.37428 -77.59071560000001,163.37428 -77.5853675,163.37428 -77.5800194,163.37428 -77.5746713,163.37428 -77.5693232,163.37428 -77.56397510000001,163.37428 -77.558627))", "dataset_titles": "Commonwealth Stream Diel Water Chemistry; Hyporheic zone geochemistry of Wales Stream, Taylor Valley, Antarctica; isotopic signature of massive buried ice, eastern Taylor Valley, Antarctica", "datasets": [{"dataset_uid": "601848", "doi": "10.15784/601848", "keywords": "Antarctica; Buried Ice; Cryosphere; Stable Isotopes; Stable Water Isotopes; Taylor Valley", "people": "Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "isotopic signature of massive buried ice, eastern Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601848"}, {"dataset_uid": "601844", "doi": "10.15784/601844", "keywords": "Antarctica; Commonwealth Stream; Cryosphere; Diel; Inlandwaters; McMurdo Dry Valleys; Stream Chemistry; Water Chemisty", "people": "Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Commonwealth Stream Diel Water Chemistry", "url": "https://www.usap-dc.org/view/dataset/601844"}, {"dataset_uid": "601847", "doi": "10.15784/601847", "keywords": "Antarctica; Cryosphere; Nutrients; Stable Isotopes; Taylor Valley; Trace Elements", "people": "Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Hyporheic zone geochemistry of Wales Stream, Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601847"}], "date_created": "Wed, 16 Oct 2024 00:00:00 GMT", "description": "Phytoplankton, or microscopic marine algae, are an important part of the carbon cycle and can lower the rates of atmospheric carbon dioxide by transferring the atmospheric carbon into the oceans. The concentration of phytoplankton in the Southern Ocean is regularly limited by the availability of marine iron. This in turn influences the rate of carbon transfer from the atmosphere to the ocean. The primary source of iron in the Southern Ocean is eroded continental rock. Understanding the current and future sources of iron to the Southern Ocean as a result of increased melting of terrestrial glaciers is necessary for predicting future concentrations of Southern Ocean phytoplankton and the subsequent influence on the carbon cycle. A poorly understood source of iron to the Southern Ocean is stream input from ice-free regions such as the McMurdo Dry Valleys in Antarctica. This source of iron is likely to become larger if glaciers retreat. This study investigates the sources and amount of iron transported by McMurdo Dry Valley streams directly into the Southern Ocean. Because not all forms of iron can be used by phytoplankton, experiments will be performed to determine how available iron is to phytoplankton and how iron mixes with seawater. Immersive 360-degree video, infographics, and educational videos of findings from this project will be shared on social media, at schools and science events, and in an urban science center. In the Southern Ocean (SO) there is an excess of macronutrients but regional primary production is limited or co-limited due to iron. An addition of iron to the ocean will affect biochemical cycles, increase primary production, and affect the structure and composition of phytoplankton communities in the SO. Iron flux to the SO is globally significant, as increased Fe fertilization leads to increased carbon sequestration which acts as a negative feedback to increased atmospheric pCO2. One source of potentially bioavailable iron to the coastal regions of the SO is from direct sub-aerial stream discharge in ice-free areas of Antarctica, a source that may become more important if terrestrial glaciers retreat. It is imperative to understand the source, nature, potential fate, and flux of iron to the SO if better predictive models for the carbon cycle and atmospheric chemistry are to be developed. This project will investigate in-stream processes and characteristics controlling dissolved iron draining into the Ross Sea including photoreduction, temperature, and complexation with organic matter. The novel study will quantify bioavailability of particulate iron and bioavailability of dissolved iron in Antarctic in streams draining into the SO. On-site speciation measurements will be performed on dissolved iron species, particulate iron speciation will be determined using high-resolution spectroscopy, mixing experiments will be performed with coastal marine water, and the bioavailability of Fe will be determined through marine bioassays. This project will provide two students with valuable Antarctic field experience and reach thousands of individuals through existing partnerships with K-12 schools, public STEM events, an urban science center, and a strong social media presence. 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": 163.554215, "geometry": "POINT(163.4642475 -77.5853675)", "instruments": null, "is_usap_dc": true, "keywords": "SURFACE WATER CHEMISTRY; Iron Fertilization; McMurdo Dry Valleys; Weathering", "locations": "McMurdo Dry Valleys", "north": -77.558627, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Lyons, W. Berry; Gardner, Christopher B.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.612108, "title": "Fe Behavior and Bioavailability in Sub-aerial Runoff into the Ross Sea", "uid": "p0010483", "west": 163.37428}, {"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": "2336354 Juarez Rivera, Marisol", "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": "Lake Fryxell 2022-2023 benthic microbial mat thickness and number of laminae", "datasets": [{"dataset_uid": "601839", "doi": "10.15784/601839", "keywords": "Antarctica; Cryosphere; Dry Valleys; Lake Fryxell; Laminae; Microbial Mat; Thickness", "people": "Mackey, Tyler; Juarez Rivera, Marisol; Sumner, Dawn; Paul, Ann; Hawes, Ian", "repository": "USAP-DC", "science_program": null, "title": "Lake Fryxell 2022-2023 benthic microbial mat thickness and number of laminae", "url": "https://www.usap-dc.org/view/dataset/601839"}], "date_created": "Fri, 05 Jul 2024 00:00:00 GMT", "description": "Perennially ice-covered lakes in the McMurdo Dry Valleys of Antarctica contain abundant microbial mats, and the export of this mat material can fertilize the surrounding polar desert ecosystems. These desert soils are one of the most organic-poor on earth yet host a community of microorganisms. Microbial mat material is exported from the shallow, gas-supersaturated regions of the lakes when gas bubbles form in the mats, lifting them to the ice cover; the perennial ice cover maintains gas supersaturation. These mats freeze in and are exported to the surrounding soils through ice ablation. The largest seasonal decrease and thinnest ice cover in the history of Lake Fryxell was recorded during the 2022-2023 Austral summer. In this thin ice year, the water column dissolved oxygen increased over prior observations, and the lake bottom surface area with bubble-disrupted mat was more than double that observed in 1980-1981 and 2006-2007. This work will constrain mat mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning to understand how future changing regional climate and predicted seasonal loss of lake ice cover will affect nutrient transport in the McMurdo Dry Valleys. Exceptional years of mat export are hypothesized to have the most significant impact on nutrient export to soil communities; variability in mat liftoff may thus play a role in the McMurdo Dry Valleys ecosystem response to changing climate. The perennial ice cover of lakes in the McMurdo Dry Valleys of Antarctica modulates the transfer of gasses, organic and inorganic material, between the lakes and surrounding soils. The export of biomass in these lakes is driven by the supersaturation of atmospheric gasses in the shallow regions under perennial ice cover. Gas bubbles nucleate in the mats, producing buoyancy that lifts them to the bottom of the ice, where they freeze in and are exported to the surrounding soils through ice ablation. These mats represent a significant source of biomass and nutrients to the McMurdo Dry Valleys soils, which are among the most organic-poor on earth. Nevertheless, this biomass remains unaccounted for in organic carbon cycling models for the McMurdo Dry Valleys. Ice cover data from the McMurdo Dry Valleys Long Term Ecological Research Project shows that the ice thickness has undergone cyclical variation over the last 40 years, reaching the largest seasonal decrease and thinnest ice-cover in the recorded history of Lake Fryxell during the 2022-2023 austral summer. Preliminary work shows that the surface area with mat liftoff at Lake Fryxell is more than double that observed in 1980-1981 and 2006-2007, coinciding with this unprecedented thinning of the ice-cover and an increase in the water column dissolved O2. This research will constrain biomass mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning. The researchers hypothesize that a thinner ice cover promotes more biomass mobilization by 1) stimulating additional production of gas bubbles from the existing gas-supersaturated waters during summertime photosynthesis to create microbial mat liftoff and 2) promoting mat liftoff in deeper, thicker microbial mats, and 3) that this biomass can be traced into the soils by characterizing its chemistry and modeling the most likely depositional settings. This work will use microbial mat samples, lake dissolved oxygen and photosynthetically active radiation data and underwater drone footage documenting the depth distribution of liftoff mats in January 2023, and long-term ice cover thickness, photosynthetically active radiation, and lake level change data collected by the McMurdo Dry Valleys Long Term Ecological Research Project to test hypotheses 1-3. The dispersal of the liftoff mat exposed at Lake Fryxell surface will be modeled using a Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Exceptional liftoff years like the present are hypothesized to have the most significant impact on the soil communities as the rates of soil respiration increase with the addition of carbon. However, continued warming in the next 10 - 40 years may result in seasonal loss of the ice cover and cessation of liftoff mat export. 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": 164.5, "geometry": "POINT(162.25 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Stable Isotopes; MINERALS; LAKE/POND; ISOTOPES; Organic Matter; McMurdo Dry Valleys; SEDIMENTARY ROCKS", "locations": "McMurdo Dry Valleys", "north": -76.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Earth Sciences", "paleo_time": null, "persons": "Juarez Rivera, Marisol", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.5, "title": "RAPID: Is Biomass Mobilization at Ice-covered Lake Fryxell, Antarctica reaching a Critical Threshold?", "uid": "p0010467", "west": 160.0}, {"awards": null, "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 13 Jun 2024 00:00:00 GMT", "description": "The Amundsen Sea, near the fastest melting Antarctic glaciers, hosts one of the most productive polar ecosystems in the world. Phytoplankton serve as the base of the food chain, and their growth also removes carbon dioxide from the atmosphere. Phytoplankton growth is fertilized in this area by nutrient iron, which is only present at low concentrations in seawater. Prior studies have shown the seabed sediments may provide iron to the Amundsen Sea ecosystem. However, sediment sources of iron have never been studied here directly. This project fills this gap by analyzing sediments from the Amundsen Sea and investigating whether sediment iron fertilizes plankton growth. The results will help scientists understand the basic ecosystem drivers and predict the effects of climate change on this vibrant, vulnerable region. This project also emphasizes inclusivity and openness to the public. The researchers will establish a mentoring network for diverse polar scientists through the Polar Impact Network and communicate their results to the public through the website CryoConnect.org. \u003cbr/\u003e\u003cbr/\u003eThis project leverages samples already collected from the Amundsen Sea (NBP22-02) to investigate sediment iron (Fe) cycling and fluxes. The broad questions driving this research are 1) does benthic Fe fertilize Antarctic coastal primary productivity, and 2) what are the feedbacks between benthic Fe release and carbon cycling in the coastal Antarctic? To answer these questions, the researchers will analyze pore water Fe content and speciation and calculate fluxes of Fe across the sediment-water interface. These results will be compared to sediment characteristics (e.g., organic carbon content, reactive Fe content, proximity to glacial sources) to identify controls on benthic Fe release. This research dovetails with and expands on the science goals of the ?Accelerating Thwaites Ecosystem Impacts for the Southern Ocean? (ARTEMIS) project through which the field samples were collected. In turn, the findings of ARTEMIS regarding modeled and observed trace metal dynamics, surface water productivity, and carbon cycling will inform the conclusions of this project, allowing insight into the impact of benthic Fe in the whole system. This project represents a unique opportunity for combined study of the water column and sediment biogeochemistry which will be of great value to the marine biogeochemistry community and will inform future sediment-ocean studies in polar oceanography and beyond.\u003cbr/\u003e\u003cbr/\u003eThis 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": "SEDIMENT CHEMISTRY; TRACE ELEMENTS", "locations": null, "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": null, "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Benthic Iron Fluxes and Cycling in the Amundsen Sea", "uid": "p0010463", "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": "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": "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": "Banwell, Alison; Willis, Ian; Stevens, Laura; 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": "1443522 Wannamaker, Philip", "bounds_geometry": "POLYGON((166 -77.15,166.34 -77.15,166.68 -77.15,167.02 -77.15,167.36 -77.15,167.7 -77.15,168.04 -77.15,168.38 -77.15,168.72 -77.15,169.06 -77.15,169.4 -77.15,169.4 -77.22500000000001,169.4 -77.30000000000001,169.4 -77.375,169.4 -77.45,169.4 -77.525,169.4 -77.60000000000001,169.4 -77.67500000000001,169.4 -77.75,169.4 -77.825,169.4 -77.9,169.06 -77.9,168.72 -77.9,168.38 -77.9,168.04 -77.9,167.7 -77.9,167.36 -77.9,167.02 -77.9,166.68 -77.9,166.34 -77.9,166 -77.9,166 -77.825,166 -77.75,166 -77.67500000000001,166 -77.60000000000001,166 -77.525,166 -77.45,166 -77.375,166 -77.30000000000001,166 -77.22500000000001,166 -77.15))", "dataset_titles": "Erebus volcano/Ross Island Magnetotelluric (MT) data", "datasets": [{"dataset_uid": "601493", "doi": "10.15784/601493", "keywords": "Antarctica; Mantle Melting; Mount Erebus", "people": "Hill, Graham; Wannamaker, Philip", "repository": "USAP-DC", "science_program": null, "title": "Erebus volcano/Ross Island Magnetotelluric (MT) data", "url": "https://www.usap-dc.org/view/dataset/601493"}], "date_created": "Mon, 05 Feb 2024 00:00:00 GMT", "description": "General Description: This project is intended to reveal the magma source regions, staging areas, and eruptive pathways within the active volcano Mount Erebus. This volcano is an end-member type known as phonolitic, which refers to the lava composition, and is almost purely carbon-dioxide-bearing and occurs in continental rift settings. It is in contrast to the better known water-bearing volcanoes which occur at plate boundary settings (such as Mount St Helens or Mount Fuji). Phonolitic volcanic eruptions elsewhere such as Tamboro or Vesuvius have caused more than 50,000 eruption related fatalities. Phonolites are also associated with rare earth element deposits, giving them economic interest. To illuminate the inner workings of Mount Erebus, we will cover the volcano with a dense network of geophysical probes based on magnetotelluric (MT) measurements. MT makes use of naturally occurring electromagnetic (EM) waves generated mainly by the sun as sources to provide images of the electrical conductivity structure of the Earth\u0027s interior. Conductivity is sensitive to the presence of fluids and melts in the Earth and so is well suited to understanding volcanic processes. The project is a cooperative effort between scientists from the United States, New Zealand, Japan and Canada. It implements new technology developed by the lead investigator and associates that allows such measurements to be taken on snow-covered terrains. This has applicability for frozen environments generally, such as resource exploration in the Arctic. The project supports a new post-doctoral researcher, and leverages imaging and measurement methods developed through support by other agencies and interfaced with commercial platforms. Technical Description: The investigators propose to test magmatic evolution models for Mount Erebus volcano, Antarctica, using the magnetotelluric (MT) method. The phonolite lava flow compositions on Mount Erebus are uncommon, but provide a window into the range of upper mantle source compositions and melt differentiation paths. Explosive phonolite eruptions have been known worldwide for devastating eruptions such as Tambora and Vesuvius, and commonly host rare earth element deposits. In the MT method, temporal variations in the Earth\u0027s natural electromagnetic (EM) field are used as source fields to probe the electrical resistivity structure in the depth range of 1 to 100 kilometers. This effort will consist of approximately 100 MT sites, with some concentration in the summit area. Field acquisition will take place over two field seasons. The main goals are to 1) confirm the existence and the geometry of the uppermost magma chamber thought to reside at 5-10 kilometer depths; 2) attempt to identify, in the deeper resistivity structure, the magma staging area near the crust-mantle boundary; 3) image the steep, crustal-scale, near-vertical conduit carrying magma from the mantle; 4) infer the physical and chemical state from geophysical properties of a CO2-dominated mafic shield volcano; and 5) constrain the relationships between structural and magmatic/ hydrothermal activity related to the Terror Rift. Tomographic imaging of the interior resistivity will be performed using a new inversion platform developed at Utah, based on the deformable edge finite element method, that is the best available for accommodating the steep topography of the study area. The project is an international cooperation between University of Utah, GNS Science Wellington New Zealand (G. Hill, Co-I), and Tokyo Institute of Technology Japan (Y. Ogawa, Co-I), plus participation by University of Alberta (M. Unsworth) and Missouri State University (K. Mickus). Instrument deployments will be made exclusively by helicopter. The project implements new technology that allows MT measurements to be taken on snow-covered terrains. The project supports a new post-doctoral researcher, and leverages imaging and measurement methods developed through support by other agencies and interfaced with commercial platforms.", "east": 169.4, "geometry": "POINT(167.7 -77.525)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS", "is_usap_dc": true, "keywords": "MAGNETIC FIELD; FIELD SURVEYS; Ross Island; Magnetotelluric; Mount Erebus", "locations": "Ross Island; Mount Erebus", "north": -77.15, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wannamaker, Philip", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.9, "title": "Magma Sources, Residence and Pathways of Mount Erebus Phonolitic Volcano, Antarctica, from Magnetotelluric Resistivity Structure", "uid": "p0010444", "west": 166.0}, {"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 Integrated System Science; Antarctic Organisms and Ecosystems", "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": "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": "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"}, {"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"}], "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": null, "bounds_geometry": null, "dataset_titles": "Direct observations of melting, freezing, and ocean circulation in an ice shelf basal crevasse", "datasets": [{"dataset_uid": "601733", "doi": "10.15784/601733", "repository": "USAP-DC", "science_program": null, "title": "Direct observations of melting, freezing, and ocean circulation in an ice shelf basal crevasse", "url": "http://www.usap-dc.org/view/dataset/601733"}], "date_created": "Tue, 12 Sep 2023 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Basal Crevassing; Basal Freezing; Basal Melting; Ice Shelf; Kamb Ice Stream; Oceanography", "locations": "Kamb Ice Stream; Antarctica", "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": "Washam, Peter", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"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": "2142491 Young, Jodi", "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, 26 Jul 2023 00:00:00 GMT", "description": "Sea ice in Antarctic coastal waters shape ecosystems, both in the surface waters and at the bottom of the ocean, environments that depend on algae living in sea ice for their productivity. With high variability in sea ice formation and melt between years and as a response to climate change, it is of importance to obtain better understanding of the interaction of sea ice with algae, as well as provide better data for global climate models. This project will accomplish those goals by measuring phytoplankton growth and cellular properties in sea ice with experiments performed using an ice tank. Laboratory experiments will be based on previous observations in the Antarctic Peninsula coastal waters, providing realistic conditions to emulate. The scientific importance of the proposed work aligns with the National Science Foundation goals to understand the biological and chemical properties of sea ice bio-geo-chemistry and its feedbacks with seasonal sea ice dynamics and climate. The finding from this project will be of interest to a broad scientific community, including oceanographers, biologists, chemists, and ecosystem and ocean modelers. To address the scarcity of data on sea ice microbes that limits our ability to predict future Antarctic climate with accuracy, the principal investigator will develop an Antarctic Science Minor in order to train future scientists with an environmental perspective and prepare the future US workforce with a strong scientific background on Earth and Biological Sciences. There is a paucity of data to understand the processes underlying observed patters in sea ice quality and their interaction with the sea-ice microbial community. This project will provide a mechanistic understanding of primary production and physiology of sympagic algae over the seasonal cycle of formation and melt of Antarctic sea ice. Although sea ice is central to the Antarctic coastal ecosystems, little is known of how they affect, and are in turn affected, by sea-ice algae. This project concentrates on first-year sea ice, forming and melting each year, creating unique and very dynamic habitats. The study will be structured by 4 main objectives: 1) how different algal species adapt to the seasonal changes in sea ice conditions, 2) how different methods to measure primary production (carbon dioxide drawdown, oxygen production and variable fluorescence) relate in sea ice and differ from sea water measurements, 3) how sympagic algae influence the physical structure of sea ice, 4) how sympagic algae contribute to organic matter cycling during ice melt. Due to expected changes in sea ice due to climate change, this study is uniquely positioned to provide needed data on short-term and seasonal processes. Results from this study will be useful to refine models of algal production in Antarctic and Arctic ecosystems, data not available to date as sea ice and its biogeochemistry are often poorly represented in earth system models. This project will also provide education for graduate and undergraduate students as well as material to develop class curriculum for middle-school students. 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 ECOSYSTEMS", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Young, Jodi", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "CAREER: Experimentally Testing the Role of Sympagic Algae in Sea-ice Environments using a Laboratory Scale Ice-tank.", "uid": "p0010425", "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": "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": "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"}, {"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"}], "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": "2137378 Varsani, Arvind; 2137377 Bergstrom, Anna; 2137376 Porazinska, Dorota; 2137375 Schmidt, Steven", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 10 May 2023 00:00:00 GMT", "description": "Cryoconite holes are sediment-filled melt holes in the surface of glaciers that can be important sites of active microbial life in an otherwise mostly frozen and barren landscape. Previous studies in the McMurdo Dry Valleys, Antarctica suggest that viral infections of microbes, and a general lack of fertilizers (i.e., nutrients), may be important factors shaping the development and functioning of microbial communities in cryoconite holes. The researchers propose an experimental approach to understand how nutrient limitation affects diversity (number of species) and overall abundance of microbes, and how the diversity and abundance of microbes in turn affects the diversity, abundance, and infection type of viruses that parasitize the microbes in cryoconite sediments. The researchers will use sediments previously collected from Antarctic glaciers that have varying concentrations of viruses and nutrients, to set up a nutrient-addition experiment to determine how nutrients affect microbial and viral population dynamics. The results will deepen our understanding of how microbial communities in general are shaped by nutrients and viruses and give new insights into the functioning of viruses in extremely cold environments. The researchers will publish their findings in scientific journals and will share their discoveries with K-12 students from rural schools in collaboration with the Pinhead Institute and will connect undergraduate students from under-represented minorities to polar research through participation in the university\u2019s Science, Technology, Engineering \u0026 Mathematics Routes Uplift Research Program. Outreach will be achieved through videos produced and distributed by a professional science communicator. The research advances a National Science Foundation goal of expanding fundamental knowledge of Antarctic systems, biota, and processes by utilizing the unique characteristics of the Antarctic region as a science observing platform. The Principal Investigators propose an experimental approach to understand how nutrient limitation affects microbial diversity and abundances and their cascading effects on virus diversity, abundance, and mode of infection (lysis vs. lysogeny) in Antarctic cryoconite holes. Cryoconite holes are ideal natural microcosms for manipulative studies, not available in other cryospheric ecosystems. The PIs will use previously collected cryoconite from across a gradient of both viral diversity and nutrient levels to address questions about key limiting nutrients and microbial-viral community dynamics in cryoconite sediments. Nutrient manipulation experiments will be conducted in a growth chamber that closely approximates the light and temperature regime of in situ cryoconite holes to test three core hypotheses: (1) phosphorus availability limits microbial productivity and abundance in cryoconite holes; (2) relaxing nutrient limitation in cryoconite from low-diversity glaciers will increase species diversity, leading microbial communities to resemble those found on more nutrient-rich glaciers; (3) relaxing nutrient limitation will increase the diversity and abundance of viruses by increasing the availability of suitable hosts, and decrease the prevalence of lysogenic infections. By manipulating nutrient limitation within a realistic range, this project will help verify hypothesized phosphorus limitation of Antarctic cryoconite holes and will extend understanding of the connections between nutrients, diversity, and viral infection dynamics in the cryosphere more generally. A better understanding of these dynamics in cryoconite sediments improves the ability of scientists to forecast future impacts of environmental changes in the cryosphere. 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": "AQUATIC ECOSYSTEMS; Taylor Valley", "locations": "Taylor Valley", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Varsani, Arvind; Porazinska, Dorota; Schmidt, Steven; Bergstrom, Anna", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Role of Nutrient Limitation and Viral Interactions on Antarctic Microbial Community Assembly: A Cryoconite Microcosm Study", "uid": "p0010418", "west": null}, {"awards": "1739003 Holland, David", "bounds_geometry": null, "dataset_titles": "MELT 2018-2020 Accumulation Radar at Thwaites", "datasets": [{"dataset_uid": "601678", "doi": null, "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "MELT 2018-2020 Accumulation Radar at Thwaites", "url": "http://www.usap-dc.org/view/dataset/601678"}], "date_created": "Tue, 28 Mar 2023 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Ice Base; Ice Penetrating Radar; Ice Surface; Radar Echo Sounder; Thwaites Glacier", "locations": "Thwaites Glacier; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Paden, John", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": null, "title": null, "uid": null, "west": null}, {"awards": "2224679 Miller, Lauren; 2224681 Venturelli, Ryan; 2224680 Prothro, Lindsay", "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": "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": "Fahnestock, Mark; Johnson, Andrew; 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": "1841858 Souney, Joseph; 1841844 Steig, Eric; 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": "1644234 Phillips, Fred", "bounds_geometry": "POLYGON((166.17 -77.3,166.32799999999997 -77.3,166.486 -77.3,166.644 -77.3,166.802 -77.3,166.95999999999998 -77.3,167.118 -77.3,167.276 -77.3,167.434 -77.3,167.59199999999998 -77.3,167.75 -77.3,167.75 -77.34,167.75 -77.38,167.75 -77.42,167.75 -77.46,167.75 -77.5,167.75 -77.54,167.75 -77.58,167.75 -77.62,167.75 -77.66,167.75 -77.7,167.59199999999998 -77.7,167.434 -77.7,167.276 -77.7,167.118 -77.7,166.95999999999998 -77.7,166.802 -77.7,166.644 -77.7,166.486 -77.7,166.32799999999997 -77.7,166.17 -77.7,166.17 -77.66,166.17 -77.62,166.17 -77.58,166.17 -77.54,166.17 -77.5,166.17 -77.46,166.17 -77.42,166.17 -77.38,166.17 -77.34,166.17 -77.3))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "Nontechnical Description: The age of rocks and soils at the surface of the Earth can help answer multiple questions that are important for human welfare, including: when did volcanoes erupt and are they likely to erupt again? when did glaciers advance and what do they tell us about climate? what is the frequency of hazards such as landslides, floods, and debris flows? how long does it take soils to form and is erosion of soils going to make farming unsustainable? One method that is used thousands of times every year to address these questions is called \u0027cosmogenic surface-exposure dating\u0027. This method takes advantage of cosmic rays, which are powerful protons and neutrons produced by supernova that constantly bombard the Earth\u0027s atmosphere. Some cosmic rays reach Earth\u0027s surface and produce nuclear reactions that result in rare isotopes. Measuring the quantity of the rare isotopes enables the length of time that the rock or soil has been exposed to the atmosphere to be calculated. The distribution of cosmic rays around the globe depends on Earth\u0027s magnetic field, and this distribution must be accurately known if useful exposure ages are to be obtained. Currently there are two remaining theories, narrowed down from many, of how to calculate this distribution. Measurements from a site that is at both high altitude and high latitude (close to the poles) are needed to test the two theories. This study involves both field and lab research and includes a Ph.D. student and an undergraduate student. The research team will collect rocks from lava flows on an active volcano in Antarctica named Mount Erebus and measure the amounts of two rare isotopes: 36Cl and 3He. The age of eruption of the samples will be determined using a highly accurate method that does not depend on cosmic rays, called 40Ar/39Ar dating. The two cosmic-ray theories will be used to calculate the ages of the samples using the 36Cl and 3He concentrations and will then be compared to the ages calculated from the 40Ar/39Ar dating. The accurate cosmic-ray theory will be the one that gives the same ages as the 40Ar/39Ar dating. Identification of the accurate theory will enable use of the cosmogenic surface dating methods anywhere on earth. Technical Description: Nuclides produced by cosmic rays in rocks at the surface of the earth are widely used for Quaternary geochronology and geomorphic studies and their use is increasing every year. The recently completed CRONUS-Earth Project (Cosmic-Ray Produced Nuclides on Earth) has systematically evaluated the production rates and theoretical underpinnings of cosmogenic nuclides. However, the CRONUS-Earth Project was not able to discriminate between the two leading theoretical approaches: the original Lal model (St) and the new Lifton-Sato-Dunai model (LSD). Mathematical models used to scale the production of the nuclides as a function of location on the earth, elevation, and magnetic field configuration are an essential component of this dating method. The inability to distinguish between the two models was because the predicted production rates did not differ sufficiently at the location of the calibration sites. The cosmogenic-nuclide production rates that are predicted by the two models differ significantly from each other at Erebus volcano, Antarctica. Mount Erebus is therefore an excellent site for testing which production model best describes actual cosmogenic-nuclide production variations over the globe. The research team recently measured 3He and 36Cl in mineral separates extracted from Erebus lava flows. The exposure ages for each nuclide were reproducible within each flow (~2% standard deviation) and in very good agreement between the 3He and the 36Cl ages. However, the ages calculated by the St and LSD scaling methods differ by ~15-25% due to the sensitivity of the production rate to the scaling at this latitude and elevation. These results lend confidence that Erebus qualifies as a suitable high- latitude/high-elevation calibration site. The remaining component that is still lacking is accurate and reliable independent (i.e., non-cosmogenic) ages, however, published 40Ar/39Ar ages are too imprecise and typically biased to older ages due to excess argon contained in melt inclusions. The research team\u0027s new 40Ar/39Ar data show that previous problems with Erebus anorthoclase geochronology are now overcome with modern mass spectrometry and better sample preparation. This indicates a high likelihood of success for this proposal in defining an accurate global scaling model. Although encouraging, much remains to be accomplished. This project will sample lava flows over 3 km in elevation and determine their 40Ar/39Ar and exposure ages. These combined data will discriminate between the two scaling methods, resulting in a preferred scaling model for global cosmogenic geochronology. The LSD method contains two sub-methods, the \u0027plain\u0027 LSD scales all nuclides the same, whereas LSDn scales each nuclide individually. The project can discriminate between these models using 3He and 36Cl data from lava flows at different elevations, because the first model predicts that the production ratio for these two nuclides will be invariant with elevation and the second that there should be ~10% difference over the range of elevations to be sampled. Finally, the project will provide a local, finite-age calibration site for cosmogenic-nuclide investigations in Antarctica.", "east": 167.75, "geometry": "POINT(166.95999999999998 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "AGE DETERMINATIONS; Mount Erebus; VOLCANO", "locations": "Mount Erebus", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Phillips, Fred; Kyle, Philip; Heizler, Matthew T", "platforms": null, "repositories": null, "science_programs": null, "south": -77.7, "title": "A Test of Global and Antarctic Models for Cosmogenic-nuclide Production Rates using High-precision Dating of 40Ar/39Ar Lava Flows from Mount Erebus", "uid": "p0010397", "west": 166.17}, {"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": "1744562 Loose, Brice", "bounds_geometry": "POLYGON((-180 -71,-179.9 -71,-179.8 -71,-179.7 -71,-179.6 -71,-179.5 -71,-179.4 -71,-179.3 -71,-179.2 -71,-179.1 -71,-179 -71,-179 -71.7,-179 -72.4,-179 -73.1,-179 -73.8,-179 -74.5,-179 -75.2,-179 -75.9,-179 -76.6,-179 -77.3,-179 -78,-179.1 -78,-179.2 -78,-179.3 -78,-179.4 -78,-179.5 -78,-179.6 -78,-179.7 -78,-179.8 -78,-179.9 -78,180 -78,177.5 -78,175 -78,172.5 -78,170 -78,167.5 -78,165 -78,162.5 -78,160 -78,157.5 -78,155 -78,155 -77.3,155 -76.6,155 -75.9,155 -75.2,155 -74.5,155 -73.8,155 -73.1,155 -72.4,155 -71.7,155 -71,157.5 -71,160 -71,162.5 -71,165 -71,167.5 -71,170 -71,172.5 -71,175 -71,177.5 -71,-180 -71))", "dataset_titles": "Expedition Data of NBP1704; NBP1704 Expedition Data; PIPERS Noble Gases", "datasets": [{"dataset_uid": "200329", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Expedition Data of NBP1704", "url": "https://www.marine-geo.org/tools/entry/NBP1704"}, {"dataset_uid": "001363", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1704 Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1704"}, {"dataset_uid": "601609", "doi": "10.15784/601609", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Mass Spectrometer; NBP1704; Noble Gas; Oceans; Ross Sea; R/v Nathaniel B. Palmer", "people": "Loose, Brice", "repository": "USAP-DC", "science_program": null, "title": "PIPERS Noble Gases", "url": "https://www.usap-dc.org/view/dataset/601609"}], "date_created": "Wed, 14 Sep 2022 00:00:00 GMT", "description": "Near the Antarctic coast, polynyas are open-water regions where extreme heat loss in winter causes seawater to become cold, salty, and dense enough to sink into the deep sea. The formation of this dense water has regional and global importance because it influences the ocean current system. Polynya processes are also tied to the amount of sea ice formed, ocean heat lost to atmosphere, and atmospheric CO2 absorbed by the Southern Ocean. Unfortunately, the ocean-atmosphere interactions that influence the deep ocean water properties are difficult to observe directly during the Antarctic winter. This project will combine field measurements and laboratory experiments to investigate whether differences in the concentration of noble gasses (helium, neon, argon, xenon, and krypton) dissolved in ocean waters can be linked to environmental conditions at the time of their formation. If so, noble gas concentrations could provide insight into the mechanisms controlling shelf and bottom-water properties, and be used to reconstruct past climate conditions. Project results will contribute to the Southern Ocean Observing System (SOOS) theme of The Future and Consequences of Carbon Uptake in the Southern Ocean. The project will also train undergraduate and graduate students in environmental monitoring, and earth and ocean sciences methods. Understanding the causal links between Antarctic coastal processes and changes in the deep ocean system requires study of winter polynya processes. The winter period of intense ocean heat loss and sea ice production impacts two important Antarctic water masses: High-Salinity Shelf Water (HSSW), and Antarctic Bottom Water (AABW), which then influence the strength of the ocean solubility pump and meridional overturning circulation. To better characterize how sea ice cover, ocean-atmosphere exchange, brine rejection, and glacial melt influence the physical properties of AABW and HSSW, this project will analyze samples and data collected from two Ross Sea polynyas during the 2017 PIPERS winter cruise. Gas concentrations will be measured in seawater samples collected by a CTD rosette, from an underwater mass-spectrometer, and from a benchtop Membrane Inlet Mass Spectrometer. Noble gas concentrations will reveal the ocean-atmosphere (dis)equilibrium that exists at the time that surface water is transformed into HSSW and AABW, and provide a fingerprint of past conditions. In addition, nitrogen (N2), oxygen (O2), argon, and CO2 concentration will be used to determine the net metabolic balance, and to evaluate the efficacy of N2 as an alternative to O2 as glacial meltwater tracer. Laboratory experiments will determine the gas partitioning ratios during sea ice formation. Findings will be synthesized with PIPERS and related projects, and so provide an integrated view of the role of the wintertime Antarctic coastal system on deep water composition. 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": -179.0, "geometry": "POINT(168 -74.5)", "instruments": null, "is_usap_dc": true, "keywords": "Helium Isotopes; R/V NBP; DISSOLVED GASES; POLYNYAS; Ross Sea", "locations": "Ross Sea", "north": -71.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Loose, Brice", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "MGDS", "repositories": "MGDS; R2R; USAP-DC", "science_programs": null, "south": -78.0, "title": "Measuring Dissolved Gases to Reveal the Processes that Drive the Solubility Pump and Determine Gas Concentration in Antarctic Bottom Water", "uid": "p0010376", "west": 155.0}, {"awards": "2123491 John, Seth; 2123333 Fitzsimmons, Jessica; 2123354 Conway, Timothy", "bounds_geometry": "POLYGON((-135 -66,-131.5 -66,-128 -66,-124.5 -66,-121 -66,-117.5 -66,-114 -66,-110.5 -66,-107 -66,-103.5 -66,-100 -66,-100 -67,-100 -68,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-103.5 -76,-107 -76,-110.5 -76,-114 -76,-117.5 -76,-121 -76,-124.5 -76,-128 -76,-131.5 -76,-135 -76,-135 -75,-135 -74,-135 -73,-135 -72,-135 -71,-135 -70,-135 -69,-135 -68,-135 -67,-135 -66))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 08 Sep 2022 00:00:00 GMT", "description": "The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes (TEIs) in the oceans. Many trace metals such as iron are essential for life and thus considered nutrients for phytoplankton growth, with trace metal cycling being especially important for influencing carbon cycling in the iron-limited Southern Ocean, where episodic supply of iron from a range of different external sources is important. The primary goal of this project is to measure the dissolved concentrations, size partitioning, and dissolved isotope signature of Fe on a transect of water-column stations throughout the Amundsen Sea and surrounding region of the Antarctic Margin, as part of the GP17-ANT Expedition. The secondary goal of this project is to analyze the concentrations and size partitioning of the trace metals manganese, zinc, copper, cadmium, nickel, and lead in all water-column samples, measure the isotope ratios of zinc, cadmium, nickel, and copper in a subset of water column samples, and measure the Fe isotopic signature of aerosols, porewaters, and particles. Observations from this project will be incorporated into regional and global biogeochemistry models to assess TEI cycling within the Amundsen Sea and implications for the wider Southern Ocean. This project spans three institutions, four graduate students, undergraduate students, and will provide ultrafiltered samples and data to other PIs as service. The US GEOTRACES GP17 ANT expedition, planned for austral summer 2023/2024 aims to determine the distribution and cycling of trace elements and their isotopes in the Amundsen Sea Sector (100-135\u00b0W) of the Antarctic Margin. The cruise will follow the Amundsen Sea \u2018conveyor belt\u2019 by sampling waters coming from the Antarctic Circumpolar Current onto the continental shelf, including near the Dotson and Pine Island ice shelves, the productive Amundsen Sea Polynya (ASP), and outflowing waters. Episodic addition of dissolved Fe and other TEIs from dust, ice-shelves, melting ice, and sediments drive seasonal primary productivity and carbon export over the Antarctic shelf and offshore into Southern Ocean. Seasonal coastal polynyas such as the highly productive ASP thus act as key levers on global carbon cycling. However, field observations of TEIs in such regions remain scarce, and biogeochemical cycling processes are poorly captured in models of ocean biogeochemistry. The investigators will use their combined analytical toolbox, in collaboration with the diagnostic chemical tracers and regional models of other funded groups to address four main objectives: 1) What is the relative importance of different sources in supplying Fe and other TEIs to the ASP? 2) What is the physiochemical speciation of this Fe, and its potential for transport? 3) How do biological uptake, scavenging and regeneration in the ASP influence TEI distributions, stoichiometry, and nutrient limitation? 4) What is the flux and signature of TEIs transported offshore to the ACC and Southern Ocean? 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(-117.5 -71)", "instruments": null, "is_usap_dc": true, "keywords": "R/V NBP; Amundsen Sea; TRACE ELEMENTS; BIOGEOCHEMICAL CYCLES", "locations": "Amundsen Sea", "north": -66.0, "nsf_funding_programs": "Chemical Oceanography; Chemical Oceanography; Chemical Oceanography", "paleo_time": null, "persons": "Conway, Timothy; Fitzsimmons, Jessica; John, Seth", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repositories": null, "science_programs": null, "south": -76.0, "title": "Collaborative Research: US GEOTRACES GP17-ANT: Dissolved concentrations, isotopes, and colloids of the bioactive trace metals", "uid": "p0010374", "west": -135.0}, {"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": "2212904 Herbert, Lisa; 2407093 Herbert, Lisa", "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": null, "datasets": null, "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "The Amundsen Sea, near the fastest melting Antarctic glaciers, hosts one of the most productive polar ecosystems in the world. Phytoplankton serve as the base of the food chain, and their growth also removes carbon dioxide from the atmosphere. Phytoplankton growth is fertilized in this area by nutrient iron, which is only present at low concentrations in seawater. Prior studies have shown the seabed sediments may provide iron to the Amundsen Sea ecosystem. However, sediment sources of iron have never been studied here directly. This project fills this gap by analyzing sediments from the Amundsen Sea and investigating whether sediment iron fertilizes plankton growth. The results will help scientists understand the basic ecosystem drivers and predict the effects of climate change on this vibrant, vulnerable region. This project also emphasizes inclusivity and openness to the public. The researchers will establish a mentoring network for diverse polar scientists through the Polar Impact Network and communicate their results to the public through the website CryoConnect.org. This project leverages samples already collected from the Amundsen Sea (NBP22-02) to investigate sediment iron (Fe) cycling and fluxes. The broad questions driving this research are 1) does benthic Fe fertilize Antarctic coastal primary productivity, and 2) what are the feedbacks between benthic Fe release and carbon cycling in the coastal Antarctic? To answer these questions, the researchers will analyze pore water Fe content and speciation and calculate fluxes of Fe across the sediment-water interface. These results will be compared to sediment characteristics (e.g., organic carbon content, reactive Fe content, proximity to glacial sources) to identify controls on benthic Fe release. This research dovetails with and expands on the science goals of the \u201cAccelerating Thwaites Ecosystem Impacts for the Southern Ocean\u201d (ARTEMIS) project through which the field samples were collected. In turn, the findings of ARTEMIS regarding modeled and observed trace metal dynamics, surface water productivity, and carbon cycling will inform the conclusions of this project, allowing insight into the impact of benthic Fe in the whole system. This project represents a unique opportunity for combined study of the water column and sediment biogeochemistry which will be of great value to the marine biogeochemistry community and will inform future sediment-ocean studies in polar oceanography 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": -100.0, "geometry": "POINT(-110 -73)", "instruments": null, "is_usap_dc": true, "keywords": "TRACE ELEMENTS; SEDIMENT CHEMISTRY; Amundsen Sea", "locations": "Amundsen Sea", "north": -71.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Post Doc/Travel", "paleo_time": null, "persons": "Herbert, Lisa", "platforms": null, "repositories": null, "science_programs": null, "south": -75.0, "title": "OPP-PRF: Benthic Iron Fluxes and Cycling in the Amundsen Sea", "uid": "p0010362", "west": -120.0}, {"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": "Brown, Sarah; Fischer, Karen", "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": "1947646 Shevenell, Amelia; 1947657 Dodd, Justin; 1947558 Leckie, Robert", "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": "1945127 Moffat, Carlos", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "Freshwater discharges from melting high-latitude continental ice glacial reserves strongly control salt budgets, circulation and associated ocean water mass formation arising from polar ice shelves. These are different in nature than freshwater inputs associated with riverine coastal inputs. The PI proposes an observational deployment to measure a specific, previously-identified example of a coastal freshwater-driven current, the Antarctic Peninsula Coastal Current (APCC). The research component of this CAREER project aims to improve understanding of the dynamics of freshwater discharge around the Antarctic continent. Associated research questions pertain to the i) controls on the cross- and along-shelf spreading of fresh, buoyant coastal currents, ii) the role of distributed coastal freshwater sources (as opposed to \u0027point\u0027 source river outflow sources typical of lower latitudes), and iii) the contribution of these coastal currents to water mass transformation and heat transfer on the continental shelf. An educational CAREER program component leverages a series of field experiences and research outputs including data, model outputs, and theory, to bring polar science to the classroom and the general public, as well as training a new polar scientist. This combined strategy will allow the investigator to lay the foundation for a successful academic career as a researcher and teacher at the University of Delaware. The project will also provide the opportunity to train a PhD student. Informal outreach efforts will include giving public lectures at University of Deleware\u0027s sponsored events, including Coast Day, a summer event that attracts 8000-10000 people, and remote lectures from the field using an existing outreach network. This proposal requires 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": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; R/V LMG; TURBULENCE; USAP-DC; OCEAN CURRENTS; Antarctic Peninsula; AMD; USA/NSF; HEAT FLUX", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Moffat, Carlos", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repositories": null, "science_programs": null, "south": null, "title": "CAREER: The Transformation, Cross-shore Export, and along-shore Transport of Freshwater on Antarctic Shelves", "uid": "p0010330", "west": null}, {"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": "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": "Kempf, Scott D.; Ng, Gregory; Buhl, Dillon; Kerr, Megan; Greenbaum, Jamin; Blankenship, Donald D.; Young, Duncan A.; Chan, Kristian", "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": "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": "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": "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": "601819", "doi": "10.15784/601819", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Kuhl, Tanner; Morton, Elizabeth; Zajicek, Anna; Nesbitt, Ian; Carter, Austin; Morgan, Jacob; Shackleton, Sarah; Higgins, John; Epifanio, Jenna", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2019-2020 Allan Hills Field Report", "url": "https://www.usap-dc.org/view/dataset/601819"}, {"dataset_uid": "601824", "doi": "10.15784/601824", "keywords": "Allan Hills; Antarctica; Coldex; Cryosphere", "people": "Brook, Edward J.; Epifanio, Jenna; Mayo, Emalia; Goverman, Ashley; Jayred, Michael; Morton, Elizabeth; Banerjee, Asmita; Hudak, Abigail; Manos, John-Morgan; Carter, Austin; Shackleton, Sarah; Higgins, John; Marks Peterson, Julia", "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": "601826", "doi": "10.15784/601826", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Shaya, Margot; Manos, John-Morgan; Horlings, Annika; Epifanio, Jenna; Conway, Howard", "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": "601697", "doi": "10.15784/601697", "keywords": "Allan Hills; Antarctica; Apres; Ice Core; Ice Penetrating Radar; Temperature Profiles", "people": "Conway, Howard; Brook, Edward J.", "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": "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": "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": "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"}, {"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": "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": "601854", "doi": "10.15784/601854", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Kirkpatrick, Liam; Carter, Austin; Marks Peterson, Julia; Shackleton, Sarah; Fudge, T. J.", "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": "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": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Mayewski, Paul A.; Introne, Douglas; Severinghaus, Jeffrey P.; Kurbatov, Andrei V.; Higgins, John; Brook, Edward", "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": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Higgins, John; Introne, Douglas; Brook, Edward; Mayewski, Paul A.; Severinghaus, Jeffrey P.; 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": "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": "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": "601878", "doi": "10.15784/601878", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Cryosphere; Methane", "people": "Shackleton, Sarah; Severinghaus, Jeffrey P.; Hishamunda, Valens; Kalk, Michael; Brook, Edward; Marks Peterson, Julia", "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": "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": "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": "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": "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": "601912", "doi": "10.15784/601912", "keywords": "Antarctica; Coldex; Cryosphere; East Antarctica; East Antarctic Plateau; Glaciology; Radar Echo Sounder", "people": "Vega Gonzalez, Alejandra; Kerr, Megan; Young, Duncan A.; Yan, Shuai; Blankenship, Donald D.; Singh, Shivangini", "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"}], "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": "Antarctic Glaciology; Polar Special Initiatives", "paleo_time": null, "persons": "Brook, Edward J.; Neff, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "Texas Data Repository", "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; 1744958 Wei, Yong; 1744759 Dunham, Eric; 1246151 Bromirski, Peter", "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; Almquist, Martin; Dunham, Eric", "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": "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": "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": "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"}, {"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": "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": "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"}], "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": "1643285 Joughin, Ian; 1643174 Padman, Laurence", "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": "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"}, {"dataset_uid": "200314", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "icepack", "url": "https://github.com/icepack/icepack"}], "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 Glaciology; Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Joughin, Ian; Dutrieux, Pierre; Padman, Laurence; Springer, Scott", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "Uni. Washington ResearchWorks Archive", "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 Glaciology; Antarctic Ocean and Atmospheric Sciences", "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": "2046260 Salvatore, Mark; 2045880 Sokol, Eric", "bounds_geometry": "POLYGON((161.88 -77.47,162.075 -77.47,162.27 -77.47,162.465 -77.47,162.66 -77.47,162.855 -77.47,163.05 -77.47,163.245 -77.47,163.44 -77.47,163.635 -77.47,163.83 -77.47,163.83 -77.501,163.83 -77.532,163.83 -77.563,163.83 -77.594,163.83 -77.625,163.83 -77.656,163.83 -77.687,163.83 -77.718,163.83 -77.749,163.83 -77.78,163.635 -77.78,163.44 -77.78,163.245 -77.78,163.05 -77.78,162.855 -77.78,162.66 -77.78,162.465 -77.78,162.27 -77.78,162.075 -77.78,161.88 -77.78,161.88 -77.749,161.88 -77.718,161.88 -77.687,161.88 -77.656,161.88 -77.625,161.88 -77.594,161.88 -77.563,161.88 -77.532,161.88 -77.501,161.88 -77.47))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 21 Apr 2022 00:00:00 GMT", "description": "Part I: Non-technical description: Water is life and nowhere is it more notable than in deserts. Within the drylands on Earth, the Antarctic deserts, represented in this study by the McMurdo Dry Valleys, exemplify life in extreme environments with scarce water, low temperatures and long periods of darkness during the polar winter. There is a scarcity of methods to determine water availability, data necessary to predict which species are successful in the drylands, unless measurements are done manually or with field instruments. This project aims to develop a new method of determining soil moisture and use the new data to identify locations suitable for life. Combining these habitats with known species distributions in the McMurdo Dry Valleys, results from this project will predict which species should be present, and also what is the expected species distribution in a changing environment. In this way the project takes advantage of a combination of methods, from recent remote sensing products, ecological models and 30 years of field collections to bring a prediction of how life might change in the McMurdo Dry Valleys in a warmer, and possibly, moister future climate. This project benefits the National Science Foundation goals of expanding fundamental knowledge of Antarctic biota and the processes that sustain life in extreme environments. The knowledge acquired in this project will be disseminated to other drylands through training of high-school curricular programming in Native American communities of the SouthWest. Part II: Technical description: Terrestrial environments in Antarctica are characterized by low liquid water supply, sub-zero temperatures and the polar night in winter months. During summer, melting of snow patches, seasonal steams from glacial melt and vicinity to lakes provide a variety of environments that maintain life, not yet studied at landscape-scale level for habitat suitability and the processes that drive them. This project proposes to integrate remote sensing, hydrological models and ecological models to establish habitat suitability for species in the McMurdo Dry Valleys based on water availability. The approach is at a landscape level in order to establish present-day and future scenarios of species distribution. There are four main objectives: remote sensing development of moisture levels in soils, combining biological and soil data, building and calibrating models of habitat suitability by combining species distribution and environmental variability and applying statistical species distribution model. The field data to develop habitat suitability and calibration of models will leverage a the 30-year dataset collected by the McMurdo Long-Term Ecological Research program. Mechanistic models developed will be essential to predict species distribution in future climate scenarios. Training of post-doctoral researchers and a graduate student will prepare for the next generation of Antarctic scientists. Results from this project will train high-school students from native American communities in the SouthWest where similar desert conditions exist. 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": 163.83, "geometry": "POINT(162.855 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "ACTIVE LAYER; Taylor Valley; USAP-DC; Amd/Us; AMD; MODELS; USA/NSF", "locations": "Taylor Valley", "north": -77.47, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Salvatore, Mark; Gooseff, Michael N.; Sokol, Eric; Barrett, John", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -77.78, "title": "Collaborative Research: Moving Beyond the Margins: Modeling Water Availability and Habitable Terrestrial Ecosystems in the Polar Desert of the McMurdo Dry Valleys", "uid": "p0010316", "west": 161.88}, {"awards": "1932876 Ball, Becky", "bounds_geometry": "POLYGON((-59.666116 -62.15,-59.5128377 -62.15,-59.3595594 -62.15,-59.2062811 -62.15,-59.0530028 -62.15,-58.8997245 -62.15,-58.7464462 -62.15,-58.5931679 -62.15,-58.4398896 -62.15,-58.2866113 -62.15,-58.133333 -62.15,-58.133333 -62.1731502,-58.133333 -62.1963004,-58.133333 -62.2194506,-58.133333 -62.2426008,-58.133333 -62.265751,-58.133333 -62.2889012,-58.133333 -62.3120514,-58.133333 -62.3352016,-58.133333 -62.3583518,-58.133333 -62.381502,-58.2866113 -62.381502,-58.4398896 -62.381502,-58.5931679 -62.381502,-58.7464462 -62.381502,-58.8997245 -62.381502,-59.0530028 -62.381502,-59.2062811 -62.381502,-59.3595594 -62.381502,-59.5128377 -62.381502,-59.666116 -62.381502,-59.666116 -62.3583518,-59.666116 -62.3352016,-59.666116 -62.3120514,-59.666116 -62.2889012,-59.666116 -62.265751,-59.666116 -62.2426008,-59.666116 -62.2194506,-59.666116 -62.1963004,-59.666116 -62.1731502,-59.666116 -62.15))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 14 Apr 2022 00:00:00 GMT", "description": "Part I: Non-technical summary The Antarctic Peninsula warmed very rapidly in the late part of the 20th century, much faster than the global average, and this warming is predicted to resume and continue over the rest of the 21st century. One consequence of this rapid warming is the melting and subsequent retreat of glaciers, leading to an increase in newly-exposed land on the Peninsula that was previously covered with ice. Once new terrain is exposed, the process of ecological succession begins, with the arrival of early-colonizing plants, such as moss and lichens, and soil organisms - a process commonly referred to as the \u201cgreening\u201d of Antarctica. Early stages of succession will be an increasingly common feature on the Antarctic Peninsula, but the mechanisms by which they occur on the Antarctic continent is not well understood. Once the plants have established on the newly-exposed soil, they can change many important properties, such as water dynamics, nutrient recycling, soil development, and habitat for microscopic organisms, which will ultimately determine the structure and functioning of the future ecosystem as it develops. These relationships between vegetation, soil, and the associated microorganisms, referred to as \u201cplant-soil\u201d interactions, are something we know virtually nothing about. This project will be the first to make a comprehensive study of how the type of colonizing plant, and the expansion of those plants from climate change, will influence terrestrial ecosystems in Antarctica. Understanding these processes is critical to understanding how the greening Antarctica is occurring and how soil communities and processes are influenced by these expanding plant communities. Through this work the research team, will also be intensively training undergraduate and graduate students, including training of students from underrepresented groups and collaborative training of students from Chile and the US. Additionally, the research groups will continue their focus on scientific outreach with K-12 schools and the general public to expand awareness of the effects of climate change in Antarctica. Part II: Technical summary In this study, the researchers will use surveys across succession sites along the Antarctic Peninsula and Scotia Arc as well as a manipulative field experiment at glacier succession sites to test how species-specific plant functional traits impact soil properties and associated microbial and invertebrate communities in a greening Antarctica. In doing so, they will pursue three integrated aims to understand how Antarctic plant functional traits alter their soil environment and soil communities during succession after glacial retreat. AIM 1) Characterize six fundamental plant functional traits (thermal conductivity, water holding capacity, albedo, decomposability, tissue nutrient content, and secondary chemistry) among diverse Antarctica flora; AIM 2) Measure the relative effects of fundamental plant functional traits on soil physical properties and soil biogeochemistry across glacial succession gradients in Antarctica; and AIM 3) Measure the relative effects of fundamental plant functional traits on soil microbial and invertebrate communities across glacial succession gradients in Antarctica. They will explore how early-colonizing plants, especially mosses and lichens, alter soil physical, biogeochemical, and biological components, potentially impacting later patterns of succession. The researhcers will use intensive surveys of plant-soil interactions across succession sites and a manipulative transplant experiment in the South Shetland Islands, Antarctica to address their aims. The investigators will collect data on plant functional traits and their effects on soil physical properties, biogeochemistry, biotic abundance, and microbial metagenomics. The data collected will be the first comprehensive measures of the relative importance of plant functional types during glacial retreat and vegetative expansion from climate change in Antarctica, aiding our understanding of how plant functional group diversity and abundance are changing in a greening 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": -58.133333, "geometry": "POINT(-58.8997245 -62.265751)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; FIELD SURVEYS; ECOLOGICAL DYNAMICS; USA/NSF; SOIL CHEMISTRY; 25 De Mayo/King George Island; Antarctic Peninsula; PLANTS; Amd/Us; FUNGI; ANIMALS/INVERTEBRATES; USAP-DC; TERRESTRIAL ECOSYSTEMS; BACTERIA/ARCHAEA", "locations": "25 De Mayo/King George Island; Antarctic Peninsula", "north": -62.15, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ball, Becky", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -62.381502, "title": "Collaborative Research: Exploring the Functional Role of Antarctic Plants during Terrestrial Succession", "uid": "p0010315", "west": -59.666116}, {"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": "Candice, Falk; Passchier, Sandra", "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": "Ghiz, Madison; Lubin, Dan", "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": "2127633 ZOU, XUN; 2127632 Rowe, Penny", "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, 01 Feb 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). The Western Antarctic Peninsula (WAP; AP) has been warming faster than the global average since the mid-1960s. Concurrent mobilization of ice shelves has been associated with glacial discharge into the ocean, with important implications for global sea level rise. This work will enhance our understanding of the contributions of clouds, water vapor and surface radiation to warming over the WAP. Processes governing phase partitioning and amounts of supercooled liquid water are crucial for understanding surface melt, and will be explored. In addition, the role of clouds and moisture during foehn and atmospheric river (AR) events, will be characterized. Clouds and atmospheric water vapor have strong radiative signals that vary seasonally and with cloud properties. This work will lead to a better understanding of how clouds are impacting surface melt on the AP in the changing climate. In addition, the proposed work will include several undergraduate research projects. Finally, broader impacts include public outreach through participation in GeoWeek at Ohio State University and Polar Science Weekend at the Pacific Science Center in Seattle, WA. It is crucial to human welfare to understand mechanisms responsible for the rapid pace of Antarctic ice loss. This work will lead to a better understanding of how clouds are impacting surface melt on the WAP in the changing climate. The project will use surface- and satellite-based measurements to characterize clouds and humidity. The project maximizes value by using a variety of previous, ongoing, and planned measurements made by an international group of collaborators, along with measurements and model (AMPS, Polar-WRF) results. These will be used to quantify clouds, water vapor, and radiation and their effects on the surface energy balance at three strategically-located stations: Rothera (upwind of the WAP), Marambio (downwind of the WAP) and Escudero (north of the WAP), in order to provide a detailed characterization of cloud radiative and precipitation-formation properties and their role in surface warming and melt events. These mechanisms lead to the following hypotheses: 1) Through their effect on the surface energy balance, clouds play an important role in surface warming on the AP; this role is seasonally varying and sensitive to cloud thermodynamic phase, 2) Radiative heating during foehn events is an important contributor to warming at the northern AP, and 3) The radiative effects of clouds and water vapor have strong influences on heating before and during AR events, with significant differences on the two sides of the WAP. 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; FIELD SURVEYS; AMD; USA/NSF; SURFACE TEMPERATURE; Amd/Us; ATMOSPHERIC RADIATION; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Zou, Xun", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Cloud Radiative Impact on the Surface Energy Budget of the Antarctic Peninsula", "uid": "p0010295", "west": -180.0}, {"awards": "1744835 Wagner, Till; 1744800 Adcroft, Alistair", "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": "Model of iceberg drift and decay including breakup", "datasets": [{"dataset_uid": "601510", "doi": "10.15784/601510", "keywords": "Antarctica; Footloose Mechanism; Iceberg Breakup; Iceberg Decay; Model; Southern Ocean", "people": "England, Mark; Wagner, Till", "repository": "USAP-DC", "science_program": null, "title": "Model of iceberg drift and decay including breakup", "url": "https://www.usap-dc.org/view/dataset/601510"}], "date_created": "Tue, 18 Jan 2022 00:00:00 GMT", "description": "Icebergs are a component of the Antarctic climate system, yet a comprehensive representation of their dynamics in climate models has remained elusive. Representing the role of icebergs in global climate models (GCMs) poses a formidable challenge to the scientific community. The most striking shortcoming of current iceberg models is arguably that they do not represent giant tabular icebergs, even though giant icebergs carry most of the freshwater stored in icebergs in the Southern Ocean. This lack of large icebergs in models is mostly due to the difficulties associated with adequately modeling iceberg decay. In particular, fracturing and breakup are not typically considered in iceberg models, despite being dominant iceberg decay processes. Investigators are to address these issues using a hierarchy of iceberg models, ranging from an idealized analytical model to a comprehensive GCM, in concert with recent observational data. The main objective of this study is to develop a new iceberg model that: (i) accounts for iceberg breakup and fracturing processes that have been neglected to date, (ii) improves on the representation of iceberg decay processes that were considered in previous models, (iii) explicitly represents large tabular icebergs. The primary broader impact of the proposed work will be through a K-12 teacher workshop series showcasing this project as an example of how scientists develop physical models. Ongoing changes in the California K-12 science standards will enable the teachers to creatively use this material in their classrooms. 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; ICEBERGS; USA/NSF; Southern Ocean; AMD; USAP-DC; COMPUTERS", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Wagner, Till; Eisenman, Ian", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Modeling Giant Icebergs and Their Decay", "uid": "p0010290", "west": -180.0}, {"awards": "1847067 Levy, Joseph", "bounds_geometry": "POLYGON((161 -76,161.35 -76,161.7 -76,162.05 -76,162.4 -76,162.75 -76,163.1 -76,163.45 -76,163.8 -76,164.15 -76,164.5 -76,164.5 -76.2,164.5 -76.4,164.5 -76.6,164.5 -76.8,164.5 -77,164.5 -77.2,164.5 -77.4,164.5 -77.6,164.5 -77.8,164.5 -78,164.15 -78,163.8 -78,163.45 -78,163.1 -78,162.75 -78,162.4 -78,162.05 -78,161.7 -78,161.35 -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": "Biogeochemical measurements of water tracks and adjacent dry soils from the McMurdo Dry Valleys; Surface Water Geochemistry from the McMurdo Dry Valleys", "datasets": [{"dataset_uid": "601684", "doi": "10.15784/601684", "keywords": "Antarctica; Cation Exchange; Chemistry:soil; Chemistry:Soil; Dry Valleys; Organic Matter; Salt; Soil", "people": "Levy, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Biogeochemical measurements of water tracks and adjacent dry soils from the McMurdo Dry Valleys", "url": "https://www.usap-dc.org/view/dataset/601684"}, {"dataset_uid": "601703", "doi": "10.15784/601703", "keywords": "Antarctica; Dry Valleys", "people": "Levy, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Surface Water Geochemistry from the McMurdo Dry Valleys", "url": "https://www.usap-dc.org/view/dataset/601703"}], "date_created": "Fri, 24 Dec 2021 00:00:00 GMT", "description": "Antarctic groundwater drives the regional carbon cycle and can accelerate permafrost thaw shaping Antarctic surface features. However, groundwater extent, flow, and processes on a continent virtually locked in ice are poorly understood. The proposed work investigates the interplay between groundwater, sediment, and ice in Antarctica\u0027s cold desert landscape to determine when, where, and why Antarctic groundwater is flowing, and how it may evolve Antarctic frozen deserts from dry and stable to wet and dynamic. Mapping the changing extent of Antarctic near-surface groundwater requires the ability to measure soil moisture rapidly and repeatedly over large areas. The research will capture changes in near-surface groundwater distribution through an unmanned aerial vehicle (UAV) mapping approach. The project integrates a diverse range of sensors with new UAV technologies to provide a higher-resolution and more frequent assessment of Antarctic groundwater extent and composition than can be accomplished using satellite observations alone. To complement the research objectives, the PI will develop a new UAV summer field school, the Geosciences UAV Academy, focused on training undergraduate-level UAV pilots in conducting novel earth sciences research using cutting edge imaging tools. The integration of research and technology will prepare students for careers in UAV-related industries and research. The project will deliver new UAV tools and workflows for soil moisture mapping relevant to arid regions including Antarctica as well as temperate desert and dryland systems and will train student research pilots to tackle next generation airborne challenges. Water tracks are the basic hydrological unit that currently feeds the rapidly-changing permafrost and wetlands in the Antarctic McMurdo Dry Valleys (MDV). Despite the importance of water tracks in the MDV hydrologic cycle and their influence on biogeochemistry, little is known about how these water tracks control the unique brine processes operating in Antarctic ice-free areas. Both groundwater availability and geochemistry shape Antarctic microbial communities, connecting soil geology and hydrology to carbon cycling and ecosystem functioning. The objectives of this CAREER proposal are to 1) map water tracks to determine the spatial distribution and seasonal magnitude of groundwater impacts on the MDV near-surface environment to determine how near-surface groundwater drives permafrost thaw and enhances chemical weathering and biogeochemical cycling; 2) establish a UAV academy training earth sciences students to answer geoscience questions using drone-based platforms and remote sensing techniques; and 3) provide a formative step in the development of the PI as a teacher-scholar. UAV-borne hyperspectral imaging complemented with field soil sampling will determine the aerial extent and timing of inundation, water level, and water budget of representative water tracks in the MDV. Soil moisture will be measured via near-infrared reflectance spectroscopy while bulk chemistry of soils and groundwater will be analyzed via ion chromatography and soil x-ray fluorescence. Sedimentological and hydrological properties will be determined via analysis of intact core samples. These data will be used to test competing hypotheses regarding the origin of water track solutions and water movement through seasonal wetlands. The work will provide a regional understanding of groundwater sources, shallow groundwater flux, and the influence of regional hydrogeology on solute export to the Southern Ocean and on soil/atmosphere linkages in earth\u0027s carbon budget. The UAV school will 1) provide comprehensive instruction at the undergraduate level in both how and why UAVs can advance geoscience research and learning; and 2) provide educational infrastructure for an eventual self-sustaining summer program for undergraduate UAV education. 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": 164.5, "geometry": "POINT(162.75 -77)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Amd/Us; USA/NSF; AMD; USAP-DC; FROZEN GROUND; Taylor Valley", "locations": "Taylor Valley", "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Levy, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Linking Antarctic Cold Desert Groundwater to Thermokarst \u0026 Chemical Weathering in Partnership with the Geoscience UAV Academy", "uid": "p0010286", "west": 161.0}, {"awards": "2039419 Swanger, Kate", "bounds_geometry": "POLYGON((161 -77.3,161.2 -77.3,161.4 -77.3,161.6 -77.3,161.8 -77.3,162 -77.3,162.2 -77.3,162.4 -77.3,162.6 -77.3,162.8 -77.3,163 -77.3,163 -77.35,163 -77.4,163 -77.45,163 -77.5,163 -77.55,163 -77.6,163 -77.65,163 -77.7,163 -77.75,163 -77.8,162.8 -77.8,162.6 -77.8,162.4 -77.8,162.2 -77.8,162 -77.8,161.8 -77.8,161.6 -77.8,161.4 -77.8,161.2 -77.8,161 -77.8,161 -77.75,161 -77.7,161 -77.65,161 -77.6,161 -77.55,161 -77.5,161 -77.45,161 -77.4,161 -77.35,161 -77.3))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 16 Dec 2021 00:00:00 GMT", "description": "The McMurdo Dry Valleys are the largest ice-free region in Antarctica and home to a seasonally active hydrologic system, with streams and saline lakes. Streams are fed by summer meltwater from local glaciers and snowbanks. Therefore, streamflow is tied to summer climate conditions such as air temperatures, ground temperatures, winds, and incoming solar radiation. Based on 50 years of monitoring, summer stream activity has been observed to change, and it likely varied during the geologic past in response to regional climate change and fluctuating glaciers. Thus, deposits from these streams can address questions about past climate, meltwater, and lake level changes in this region. How did meltwater streamflow respond to past climate change? How did streamflow vary during periods of glacial advance and retreat? At what times did large lakes fill many of the valleys and what was their extent? The researchers plan to acquire a record of stream activity for the Dry Valleys that will span the three largest valleys and a time period of about 100,000 years. This record will come from a series of active and ancient alluvial fans that were deposited by streams as they flowed from valley sidewalls onto valley floors. The study will provide a long-term context with which to assess recent observed changes to stream activity and lake levels. The research will be led by two female mid-career investigators and contribute significantly to student research opportunities and education. The research will contribute to graduate and undergraduate education by including students in both field and laboratory research, as well as incorporating data and results into the classroom. The research will be disseminated to K-12 and non-scientific communities through outreach that includes professional development training for K-12 teachers in eastern Massachusetts, development of hands-on activities, visits to K-12 classrooms, and STEM education and literacy activities in North Carolina. The PIs propose to constrain rates of fluvial deposition and periods of increased fluvial activity in the McMurdo Dry Valleys during the Holocene and late Pleistocene. During 50 years of hydrologic monitoring in the Dry Valleys, scientists have observed that streams exhibit significant response to summer conditions. Previous studies of glacial and lacustrine deposits indicate regional glacier advance in the Dry Valleys during recent interglacial periods and high lake levels during and after the Last Glacial Maximum (LGM), with potentially significant low and high stands during the Holocene. However, the geologic record of meltwater activity is poorly constrained. The PIs seek to develop the first spatially-extensive record of stream deposition in the Dry Valleys by analyzing and dating alluvial fans. Given that alluvial fans are deposited by summer meltwater streams in a relatively stable tectonic setting, this record will serve as a proxy of regional summer climate conditions. Meltwater streams are an important component of the regional hydrologic system, connecting glaciers to lakes and affecting ecosystems and soils. A record of fluvial deposition is key to understanding the relationship between past climate change and regional hydrology. The proposed research will include remote- and field-based mapping of alluvial fans, stream channels, and meltwater sources as well as modeling potential incoming solar radiation to the fans and moisture sources during the austral summer. In the field, the PIs will document stratigraphy, collect near-surface sediments from 25 fans across four valleys (Taylor, Pearse, Wright, and Victoria), and collect 2- to 3-m vertical cores of ice-cemented sediments from three alluvial fan complexes. The PIs will then conduct depositional dating of fluvial sands via optically stimulated luminescence, and analyze mineralogy and bulk major element chemistry with X-ray powder diffraction and X-ray fluorescence. From these analyses, the PIs propose to (1) determine the timing of local- to regional-scale periods of high fluvial deposition, (2) calculate depositional rates, and (3) constrain depositional environments and sediment provenance. Given that many of the alluvial fans occur below the hypothesized maximum extents of glacially-dammed lakes in Wright and Victoria valleys, detailed stratigraphy, sediment provenance, and OSL dating of these fans could shed light on ongoing debates regarding the timing and extent of LGM and post-LGM lakes. The work will support a postdoctoral researcher, a PhD student, and many undergraduate and master\u2019s students in cross-disciplinary research that spans stratigraphy, geochemistry, paleoclimatology and physics. 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": 163.0, "geometry": "POINT(162 -77.55)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Amd/Us; SEDIMENTS; USA/NSF; AMD; Dry Valleys; USAP-DC", "locations": "Dry Valleys", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Swanger, Kate", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -77.8, "title": "Collaborative Research: Holocene and Late Pleistocene Stream Deposition in the McMurdo Dry Valleys, Antarctica as a Proxy for Glacial Meltwater and Paleoclimate", "uid": "p0010285", "west": 161.0}, {"awards": "1744785 Barrett, John", "bounds_geometry": "POLYGON((-180 -77.62,-145.683 -77.62,-111.366 -77.62,-77.049 -77.62,-42.732 -77.62,-8.415 -77.62,25.902 -77.62,60.219 -77.62,94.536 -77.62,128.853 -77.62,163.17 -77.62,163.17 -77.618,163.17 -77.616,163.17 -77.614,163.17 -77.612,163.17 -77.61,163.17 -77.608,163.17 -77.606,163.17 -77.604,163.17 -77.602,163.17 -77.6,128.853 -77.6,94.536 -77.6,60.219 -77.6,25.902 -77.6,-8.415 -77.6,-42.732 -77.6,-77.049 -77.6,-111.366 -77.6,-145.683 -77.6,180 -77.6,178.319 -77.6,176.638 -77.6,174.957 -77.6,173.276 -77.6,171.595 -77.6,169.914 -77.6,168.233 -77.6,166.552 -77.6,164.871 -77.6,163.19 -77.6,163.19 -77.602,163.19 -77.604,163.19 -77.606,163.19 -77.608,163.19 -77.61,163.19 -77.612,163.19 -77.614,163.19 -77.616,163.19 -77.618,163.19 -77.62,164.871 -77.62,166.552 -77.62,168.233 -77.62,169.914 -77.62,171.595 -77.62,173.276 -77.62,174.957 -77.62,176.638 -77.62,178.319 -77.62,-180 -77.62))", "dataset_titles": "McMurdo Dry Valleys LTER: Microbial mat biomass and Normalized Difference Vegetation Index (NDVI) values from Lake Fryxell Basin, Antarctica", "datasets": [{"dataset_uid": "200260", "doi": "doi:10.6073/pasta/9acbbde9abc1e013f8c9fd9c383327f4", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "McMurdo Dry Valleys LTER: Microbial mat biomass and Normalized Difference Vegetation Index (NDVI) values from Lake Fryxell Basin, Antarctica", "url": "https://doi.org/10.6073/pasta/9acbbde9abc1e013f8c9fd9c383327f4"}], "date_created": "Tue, 30 Nov 2021 00:00:00 GMT", "description": "Microbial mats are found throughout the McMurdo Dry Valleys where summer snowmelt provides liquid water that allows these mats to flourish. Researchers have long studied the environmental conditions microbial mats need to grow. Despite these efforts, it has been difficult to develop a broad picture of these unique ecosystems. Recent advances in satellite technology now provide researchers an exciting new tool to study these special Antarctic ecosystems from space using the unique spectral signatures associated with microbial mats. This new technology not only offers the promise that microbial mats can be mapped and studied from space, this research will also help protect these delicate environments from potentially harmful human impacts that can occur when studying them from the ground. This project will use satellite imagery and spectroscopic techniques to identify and map microbial mat communities and relate their properties and distributions to both field and lab-based measurements. This research provides an exciting new tool to help document and understand the distribution of a major component of the Antarctic ecosystem in the McMurdo Dry Valleys. The goal of this project is to establish quantitative relationships between spectral signatures derived from orbit and the physiological status and biogeochemical properties of microbial mat communities in Taylor Valley, Antarctica, as measured by field and laboratory analyses on collected samples. The goal wioll be met by (1) refining atmospheric correction techniques using in situ radiometric rectification to derive accurate surface spectra; (2) collecting multispectral orbital images concurrent with in situ sampling and spectral measurements in the field to ensure temporal comparability; (3) measuring sediment, water, and microbial mat samples for organic and inorganic carbon content, essential biogeochemical nutrients, and chlorophyll-a to determine relevant mat characteristics; and (4) quantitatively associating these laboratory-derived characteristics with field-derived and orbital spectral signatures and parameters. The result of this work will be a more robust quantitative link between the distribution of microbial mat communities and their biogeochemical properties to landscape-scale spectral signatures. 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": 163.19, "geometry": "POINT(-16.82 -77.61)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; ECOSYSTEM FUNCTIONS; FIELD SURVEYS; USAP-DC; USA/NSF; Taylor Valley; Amd/Us", "locations": "Taylor Valley", "north": -77.6, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Barrett, John; Salvatore, Mark", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "EDI", "repositories": "EDI", "science_programs": null, "south": -77.62, "title": "Collaborative Research: Remote characterization of microbial mats in Taylor Valley, Antarctica through in situ sampling and spectral validation", "uid": "p0010281", "west": 163.17}, {"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; 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 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": "Tedesco, Marco; Alexander, Patrick; Antwerpen, Raphael; Cervone, Guido; Fettweis, Xavier; L\u00fctjens, Bj\u00f6rn", "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": "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": "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": "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": "601489", "doi": "10.15784/601489", "keywords": "Antarctica", "people": "Gogineni, Prasad; O\u0027Neill, Charles; Taylor, Ryan; 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"}, {"dataset_uid": "601488", "doi": "10.15784/601488", "keywords": "Antarctica; Greenland", "people": "Gogineni, Prasad; Taylor, Drew; 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"}], "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 Science and Technology; Antarctic Glaciology", "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": "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": "601484", "doi": "10.15784/601484", "keywords": "Antarctica; Bed Roughness; Bed Slope; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pinning Points", "people": "Riverman, Kiya; Stearns, Leigh; 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": "Simkins, Lauren; Prothro, Lindsay; Anderson, John; Greenwood, Sarah; Eareckson, Elizabeth; Munevar Garcia, Santiago", "repository": "USAP-DC", "science_program": null, "title": "Pennell Trough, Ross Sea bathymetry and glacial landforms", "url": "https://www.usap-dc.org/view/dataset/601474"}, {"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"}], "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 Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; 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": "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": "2046240 Khan, Alia", "bounds_geometry": "POLYGON((-75 -62,-73.5 -62,-72 -62,-70.5 -62,-69 -62,-67.5 -62,-66 -62,-64.5 -62,-63 -62,-61.5 -62,-60 -62,-60 -62.85,-60 -63.7,-60 -64.55,-60 -65.4,-60 -66.25,-60 -67.1,-60 -67.95,-60 -68.8,-60 -69.65,-60 -70.5,-61.5 -70.5,-63 -70.5,-64.5 -70.5,-66 -70.5,-67.5 -70.5,-69 -70.5,-70.5 -70.5,-72 -70.5,-73.5 -70.5,-75 -70.5,-75 -69.65,-75 -68.8,-75 -67.95,-75 -67.1,-75 -66.25,-75 -65.4,-75 -64.55,-75 -63.7,-75 -62.85,-75 -62))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 10 Sep 2021 00:00:00 GMT", "description": "________________________________________________________________________________________________ Part I: Non-technical Summary The Antarctic Peninsula is one of the most rapidly warming regions on the planet. This 5-yr time-series program will build on an ongoing international collaboration with scientists from the Chilean Antarctic Program to evaluate the role of temperature, light absorbing particles, snow-algae growth, and their radiative forcing effects on snow and ice melt in the Western Antarctic Peninsula. There is strong evidence that these effects may be intensifying due to a warming climate. Rising temperatures can increase the growth rate of coastal snow algae as well as enhance the input of particles from sources such as the long-range transport of black carbon to the Antarctic continent from intensifying Southern Hemisphere wildfire seasons. Particle and algae feedbacks can have immediate local impacts on snow melt and long-term regional impacts on climate because reduced snow cover alters how the Antarctic continent interacts with the rest of the global climate. A variety of ground-based and remote sensing data collected across multiple spatial scales will be used. Ground measurements will be compared to satellite imagery to develop novel computer algorithms to map ice algal bloom effects under changing climates. The project is expected to fundamentally advance knowledge of the spatial and temporal snow algae growing season, which is needed to quantify impacts on regional snow and ice melt. The program also has a strong partnership with the International Association of Antarctic Tour Operators to involve cruise passengers as citizen scientists for sample collection. Antarctic research results will be integrated into undergraduate curricula and research opportunities through studies to LAPs and snow algae in the Pacific Northwest. The PI will recruit and train a diverse pool of students in cryosphere climate related research methods on Mt. Baker in Western Washington. Trained undergraduate will then serve as instructors for a local Snow School that takes middle school students to Mt. Baker to learn about snow science. Resulting datasets from Antarctica and Mt. Baker will be used in University classes to explore regional effects of climate change. Along with enhancing cryosphere-oriented place-based undergraduate field courses in the Pacific Northwest, the PI will recruit and train a diverse pool of undergraduate students to serve as instructors for the Mt. Baker Snow School program. This award will advance our understanding of cryosphere-climate feedbacks, which are likely changing and will continue to evolve in a warming world, while also increasing under-represented student engagement in the polar geosciences. Part 2: Technical Summary Rapid and persistent climate warming in the Western Antarctic Peninsula is likely resulting in intensified snow-algae growth and an extended bloom season in coastal areas. Similarly, deposition of light absorbing particles (LAPs) onto Antarctica cryosphere surfaces, such as black carbon from intensifying Southern Hemisphere wildfire seasons, and dust from the expansion of ice-free regions in the Antarctic Peninsula, may be increasing. The presence of snow algae blooms and LAPs enhance the absorption of solar radiation by snow and ice surfaces. This positive feedback creates a measurable radiative forcing, which can have immediate local and long-term regional impacts on albedo, snow melt and downstream ecosystems. This project will investigate the spatial and temporal distribution of snow algae, black carbon and dust across the Western Antarctica Peninsula region, their response to climate warming, and their role in regional snow and ice melt. Data will be collected across multiple spatial scales from in situ field measurements and sample collection to imagery from ground-based photos and high resolution multi-spectral satellite sensors. Ground measurements will inform development and application of novel algorithms to map algal bloom extent through time using 0.5-3m spatial resolution multi-spectral satellite imagery. Results will be used to improve snow algae parameterization in a new version of the Snow Ice Aerosol Radiation model (SNICARv3) that includes bio-albedo feedbacks, eventually informing models of ice-free area expansion through incorporation of SNICARv3 in the Community Earth System Model. Citizen scientists will be mentored and engaged in the research through an active partnership with the International Association of Antarctic Tour Operators that frequently visits the region. The cruise ship association will facilitate sampling to develop a unique snow algae observing network to validate remote sensing algorithms that map snow algae with high-resolution multi-spectral satellite imagery from space. These time-series will inform instantaneous and interannual radiative forcing calculations to assess impacts of snow algae and LAPs on regional snow melt. Quantifying the spatio-temporal growing season of snow algae and impacts from black carbon and dust will increase our ability to model their impact on snow melt, regional climate warming and ice-free expansion in the Antarctic Peninsula region. 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": -60.0, "geometry": "POINT(-67.5 -66.25)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Antarctic Peninsula; Amd/Us; AMD; SNOW/ICE CHEMISTRY; USA/NSF; USAP-DC; SNOW", "locations": "Antarctic Peninsula", "north": -62.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Khan, Alia", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -70.5, "title": "CAREER: Coastal Antarctic Snow Algae and Light Absorbing Particles: Snowmelt, Climate and Ecosystem Impacts", "uid": "p0010263", "west": -75.0}, {"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": "1542976 Balco, Gregory; 1542936 Goehring, Brent", "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": "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": "Mino-Moreira, Lisbeth; Passchier, Sandra", "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": "1941304 Sherrell, Robert; 1941308 Fitzsimmons, Jessica; 1941483 Yager, Patricia; 1941327 Stammerjohn, Sharon; 1941292 St-Laurent, Pierre", "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": "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": "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": "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": "USAP-DC", "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": "1745064 Perez-Huerta, Alberto; 1745057 Walker, Sally; 1745080 Gillikin, 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": "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": "601764", "doi": "10.15784/601764", "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Gillikin, David; Puhalski, Emma; Camarra, Steve; Cronin, Kelly; Verheyden, Anouk; Walker, Sally", "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": "601468", "doi": "10.15784/601468", "keywords": "Adamussium Colbecki; Antarctica; Growth; McMurdo Sound; Shell Fish", "people": "Walker, Sally; Cronin, Kelly", "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": "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": "601761", "doi": "10.15784/601761", "keywords": "Adamussium Colbecki; Antarctica; Bay Of Sails; Carbon; Explorers Cove; McMurdo Sound; Oxygen; Stable Isotopes", "people": "Walker, Sally; Cronin, Kelly; Puhalski, Emma; Perez-Huerta, Alberto; Bowser, Samuel S.; Verheyden, Anouk; Gillikin, David; Camarra, Steve; Andrus, Fred", "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": "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": "1746087 Tarrant, Ann", "bounds_geometry": "POLYGON((-80 -60,-77.5 -60,-75 -60,-72.5 -60,-70 -60,-67.5 -60,-65 -60,-62.5 -60,-60 -60,-57.5 -60,-55 -60,-55 -61,-55 -62,-55 -63,-55 -64,-55 -65,-55 -66,-55 -67,-55 -68,-55 -69,-55 -70,-57.5 -70,-60 -70,-62.5 -70,-65 -70,-67.5 -70,-70 -70,-72.5 -70,-75 -70,-77.5 -70,-80 -70,-80 -69,-80 -68,-80 -67,-80 -66,-80 -65,-80 -64,-80 -63,-80 -62,-80 -61,-80 -60))", "dataset_titles": "Calanoides acutus: Transcriptome and gene expression data; BioProject PRJNA757455; Calanus propinquus: Transcriptome and gene expression data; BioProject PRJNA669816; Expedition data of LMG1901; Rhincalanus gigas: Transcriptome and gene expression data; BioProject PRJNA666170", "datasets": [{"dataset_uid": "200283", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "Calanus propinquus: Transcriptome and gene expression data; BioProject PRJNA669816", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA669816"}, {"dataset_uid": "200125", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1901", "url": "https://www.rvdata.us/search/cruise/LMG1901"}, {"dataset_uid": "200284", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "Calanoides acutus: Transcriptome and gene expression data; BioProject PRJNA757455", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA757455"}, {"dataset_uid": "200239", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "Rhincalanus gigas: Transcriptome and gene expression data; BioProject PRJNA666170", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA666170"}], "date_created": "Fri, 06 Aug 2021 00:00:00 GMT", "description": "Animals in the polar oceans have adapted to dramatic seasonal changes in day length, food availability, and ice cover, as well as to consistently cold waters. This project focuses on the adaptations of copepods - small animals that live in the water column and are an important food source to many different predators. The field studies will take place in the western Antarctic Peninsula, an environment and ecosystem that is rapidly changing. Antarctic copepods have developed particular feeding and behavioral strategies to survive in their very seasonal environment, however it is not known how each of these species will respond to environmental change. The overall goal of this project is to examine and compare these adaptations across species and to understand how each species responds to short-term changes in food availability. The project contains three main objectives: the first objective is to compare the sets of genes across species, especially looking at genes related to storage of energy from food. The second objective is to measure and compare the responses of copepods to changes in food availability. The third objective is to determine how variation across the western Antarctic Pensinsula habitat affects the feeding condition of the copepods. To make the data more useful to the broader research community, a database will be developed enabling easy comparison of genetic information between copepod species. This project will provide hands-on training opportunities to graduate and undergraduate student and will seek to recruit students from underrepresented groups. Results and scientific concepts will be shared through outreach activities, including an expedition blog, a series of interactive animations, and public presentations. Polar marine organisms have adapted to dramatic seasonal changes in photoperiod, light intensity, and ice cover, as well as to cold but stable thermal environments. The western Antarctic Peninsula, the focal region for the field studies, has experienced rapid warming and ice melt. While it is difficult to predict exactly how physical conditions in this region will change, effects on species distributions have already been documented. Large Antarctic copepods in the families Calanidae and Rhincalanidae are dominant components of the mesozooplankton that use different metabolic and behavioral strategies to optimize their use of a highly seasonal food supply. The overall goal of this project is to leverage molecular approaches to examine the physiological and metabolic adaptations at the individual and species level. The project focuses on three main objectives: the first objective is to characterize the gene complement and stage-specific gene expression patterns in Antarctic copepods within an evolutionary context. The second objective is to measure and compare the physiological and molecular responses of juvenile copepods to variable feeding conditions. The third objective is to characterize metabolic variation within natural copepod populations. The metabolically diverse Antarctic copepods also provide an excellent opportunity to compare mechanisms regulating energy storage and utilization and to test hypotheses regarding the roles of specific genes. The field studies will aim to utilize information from an ongoing long term research program (the Palmer Long-Term Ecological Research), which complements the ongoing program and provides extensive context for this project. To make the data more useful to the research community, a database will be developed facilitating comparison of transcriptomes between copepod species. This project will provide hands-on training opportunities to graduate and undergraduate students. Efforts will be made to recruit students who are members of underrepresented minorities. Results and scientific concepts will be broadly disseminated through an expedition blog, a series of interactive animations, and public presentations. 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": -55.0, "geometry": "POINT(-67.5 -65)", "instruments": null, "is_usap_dc": true, "keywords": "ARTHROPODS; AMD; PELAGIC; USA/NSF; USAP-DC; PLANKTON; West Antarctic Shelf; Amd/Us; SHIPS", "locations": "West Antarctic Shelf", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Tarrant, Ann", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "NCBI", "repositories": "NCBI; R2R", "science_programs": null, "south": -70.0, "title": "Physiological Ecology of \"Herbivorous\" Antarctic Copepods", "uid": "p0010239", "west": -80.0}, {"awards": "1744878 Lazzara, Matthew; 1745097 Cassano, John", "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": "2032473 Kurbatov, Andrei; 2032463 Talghader, Joseph", "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": "Mah, Merlin; Kurbatov, Andrei V.; Talghader, Joseph", "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": "1937748 Sumner, Dawn", "bounds_geometry": "POINT(163.183333 -77.616667)", "dataset_titles": "Lake Fryxell 2022-2023 benthic microbial mat thickness and number of laminae", "datasets": [{"dataset_uid": "601839", "doi": "10.15784/601839", "keywords": "Antarctica; Cryosphere; Dry Valleys; Lake Fryxell; Laminae; Microbial Mat; Thickness", "people": "Mackey, Tyler; Juarez Rivera, Marisol; Sumner, Dawn; Paul, Ann; Hawes, Ian", "repository": "USAP-DC", "science_program": null, "title": "Lake Fryxell 2022-2023 benthic microbial mat thickness and number of laminae", "url": "https://www.usap-dc.org/view/dataset/601839"}], "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "Part I: Non-technical summary: This project focuses on understanding annual changes in microbial life that grows on the bottom of Lake Fryxell, Antarctica. Because of its polar latitude, photosynthesis can only occur during the summer months. During summer, photosynthetic bacteria supply communities with energy and oxygen. However, it is unknown how the microbes behave in the dark winter, when observations are not possible. This project will install environmental monitors and light-blocking shades over parts of these communities. The shades will extend winter conditions into the spring to allow researchers to characterize the winter behavior of the microbial communities. Researchers will measure changes in the water chemistry due to microbial activities when the shades are removed and the mats first receive light. Results are expected to provide insights into how organisms interact with and change their environments. The project includes training of graduate students and early career scientists in fieldwork, including scientific ice diving techniques. In addition, the members of the project team will develop a web-based \u201cGuide to Thrive\u201d, which will compile field tips ranging from basic gear use to advanced environmental protection techniques. This will be a valuable resource for group leaders ranging from undergraduate teaching assistants to Antarctic expedition leaders to lead well-planned and tailored field expeditions. Part II: Technical summary: The research team will measure seasonal metabolic and biogeochemical changes in benthic mats using differential gene expression and geochemical gradients. They will identify seasonal phenotypic differences in microbial communities and ecosystem effects induced by spring oxygen production. To do so, researchers will install environmental sensors and opaque shades over mats at three depths in the lake. The following spring, shaded and unshaded mats will be sampled. The shades will then be removed, and changes in pore water O2, H2S, pH, and redox will be measured using microelectrodes. Mats will also be sampled for transcriptomic gene expression analyses at intervals guided by geochemical changes. Pore water will be sampled for nutrient analyses. Field research will be supplemented with laboratory experiments to refine field techniques, gene expression data analysis, and integration of results into a seasonal model of productivity and nitrogen cycling in Lake Fryxell. Results will provide insights into several key priorities for NSF, including how biotic, abiotic and environmental components of the benthic mats interact to affect Antarctic lakes. 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": 163.183333, "geometry": "POINT(163.183333 -77.616667)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Amd/Us; AMD; USA/NSF; FIELD SURVEYS; ECOSYSTEM FUNCTIONS; Lake Fryxell; USAP-DC; LAKE/POND", "locations": "Antarctica; Lake Fryxell", "north": -77.616667, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sumner, Dawn; Mackey, Tyler", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.616667, "title": "Seasonal Primary Productivity and Nitrogen Cycling in Photosynthetic Mats, Lake Fryxell, McMurdo Dry Valleys", "uid": "p0010219", "west": 163.183333}, {"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": "601759", "doi": "10.15784/601759", "keywords": "Antarctica", "people": "Severi, Mirko; Fudge, T. J.", "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"}, {"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"}], "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 Science and Technology; Antarctic Glaciology; 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": "1933764 Enderlin, Ellyn; 1643455 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": "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": "Enderlin, Ellyn; Aberle, Rainey; Marshall, Hans-Peter; 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"}, {"dataset_uid": "601679", "doi": "10.15784/601679", "keywords": "Antarctica; Elevation; Glaciology; Iceberg; Meltwater; Submarine Melt", "people": "Enderlin, Ellyn; Aberle, Rainey; Oliver, Caitlin; Dryak, Mariama; Miller, Emily; Dickson, Adam", "repository": "USAP-DC", "science_program": null, "title": "Remotely-sensed iceberg geometries and meltwater fluxes", "url": "https://www.usap-dc.org/view/dataset/601679"}], "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": "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": "Giulivi, Claudia F.; Jacobs, Stanley", "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 Instrumentation and Support; Antarctic Glaciology; 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": "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": "Iverson, Neal; Fowler, Jacob", "repository": "USAP-DC", "science_program": null, "title": "Ice permeameter experimental parameters and results", "url": "https://www.usap-dc.org/view/dataset/601515"}, {"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"}], "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": "1643494 Saal, Alberto", "bounds_geometry": "POLYGON((-68.074 -57.345,-66.6033 -57.345,-65.1326 -57.345,-63.6619 -57.345,-62.1912 -57.345,-60.7205 -57.345,-59.2498 -57.345,-57.7791 -57.345,-56.3084 -57.345,-54.8377 -57.345,-53.367 -57.345,-53.367 -58.12517,-53.367 -58.90534,-53.367 -59.68551,-53.367 -60.46568,-53.367 -61.24585,-53.367 -62.02602,-53.367 -62.80619,-53.367 -63.58636,-53.367 -64.36653,-53.367 -65.1467,-54.8377 -65.1467,-56.3084 -65.1467,-57.7791 -65.1467,-59.2498 -65.1467,-60.7205 -65.1467,-62.1912 -65.1467,-63.6619 -65.1467,-65.1326 -65.1467,-66.6033 -65.1467,-68.074 -65.1467,-68.074 -64.36653,-68.074 -63.58636,-68.074 -62.80619,-68.074 -62.02602,-68.074 -61.24585,-68.074 -60.46568,-68.074 -59.68551,-68.074 -58.90534,-68.074 -58.12517,-68.074 -57.345))", "dataset_titles": "Major, trace elements contents and radiogenic isotopes of erupted lavas Antarctic Peninsula and Phoenix Ridge", "datasets": [{"dataset_uid": "601519", "doi": "10.15784/601519", "keywords": "Antarctica; Antarctic Peninsula; Chemical Composition; Chemistry:rock; Chemistry:Rock; Geochemistry; Isotope Data; Trace Elements", "people": "Saal, Alberto", "repository": "USAP-DC", "science_program": null, "title": "Major, trace elements contents and radiogenic isotopes of erupted lavas Antarctic Peninsula and Phoenix Ridge", "url": "https://www.usap-dc.org/view/dataset/601519"}], "date_created": "Tue, 22 Jun 2021 00:00:00 GMT", "description": "The Earth\u0027s mantle influences the movement of tectonic plates and volcanism on the surface. One way to understand the composition and nature of the Earth\u0027s mantle is by studying the chemistry of basalts, which originate by volcanic eruptions of partially melting mantle rocks. This study will establish the budget and distribution of volatile elements (hydrogen, carbon, fluorine, chlorine, sulfur) in volcanic basalts to better understand the composition of the Earth\u0027s interior. Volatiles influence mantle melting, magma crystallization, magma migration and volcanic eruptions. Their abundances and spatial distribution provide important constraints on models of mantle flow and temperature. Moreover, volatiles are key constituents of the Earth\u0027s atmosphere and oceans. Establishing the cycles of volatiles between the Earth\u0027s interior and surface is of fundamental importance to understand the long-term evolution of our planet. This project supports a graduate student and research scientist at Brown University. It promotes the collaboration with geochemists from eleven institutions representing six different countries: USA, Germany, United Kingdom, Argentina, South Korea and Japan, and utilizes several NSF-funded USA analytical facilities. Communication of results will occur through: 1) peer-reviewed journals, presentations at conferences and invited university lectures, 2) hands-on science learning activities for local elementary and high school classes, and 3) outreach to the general audience through public lectures. Over the last 60 years of funded research, the Antarctic Peninsula and nearby ocean ridges have been extensively investigated providing information on the origin of the magmatism, and the composition, structure, temperature and evolution of the lithospheric and asthenospheric mantle. Diverse hypotheses have been proposed for the origin of the magmatism in the Antarctic Peninsula, from flux melting of the mantle wedge during devolatilization of the subducted Phoenix plate, to adiabatic decompression melting of a carbonated and hydrous asthenosphere, to melting of a volatile-rich metasomatized subcontinental lithospheric mantle. All proposed hypotheses invoke the role of volatiles. Surprisingly, data on the volatile contents of basalts and mantle from this region are non-existent. This is a significant omission from the geochemical data set, given the important role volatile elements play in the generation and composition of magmas and their sources. The focus of our research is to examine the regional variations in volatile contents (C, H, F, S, Cl) in geochemically well-characterized Pliocene-recent basalts from the Antarctic Peninsula and Phoenix ridge. Our goal is to establish the budget and distribution of volatiles in the mantle to understand 1) the processes responsible for the generation of chemically diverse basalts in close spatial and temporal proximity and 2) the nature (lithology, composition and temperature) of the heterogeneous mantle source beneath the Antarctic Peninsula and Phoenix ridge.", "east": -53.367, "geometry": "POINT(-60.7205 -61.24585)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; USA/NSF; USAP-DC; TRACE ELEMENTS; MAJOR ELEMENTS; Amd/Us; LABORATORY; ROCKS/MINERALS/CRYSTALS; Magmatic Volatiles; AMD", "locations": "Antarctic Peninsula", "north": -57.345, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Saal, Alberto", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.1467, "title": "Magmatic Volatiles, Unraveling the Reservoirs and Processes of the Volcanism in the Antarctic Peninsula", "uid": "p0010196", "west": -68.074}, {"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": "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": "601806", "doi": "10.15784/601806", "keywords": "Antarctica; Cryosphere; Erosion; Isotope Data; Major Elements; Soil; Taylor Glacier; Taylor Valley", "people": "Tulaczyk, Slawek; Edwards, Graham; Piccione, Gavin; Blackburn, Terrence", "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": "601594", "doi": "10.15784/601594", "keywords": "Antarctica; East Antarctica", "people": "Blackburn, Terrence; Piccione, Gavin", "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": "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": "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"}], "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": "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": "1543286 Walter, Jacob; 1543399 Peng, Zhigang; 1745135 Walter, Jacob", "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": "1543344 Soreghan, Gerilyn", "bounds_geometry": null, "dataset_titles": "Data and metadata for \"Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems\"", "datasets": [{"dataset_uid": "601599", "doi": "10.15784/601599", "keywords": "Antarctica; Anza Borrego; Iceland; McMurdo Dry Valleys; Norway; Peru; Puerto Rico; Taylor Valley; Washington; Wright Valley", "people": "Demirel-Floyd, Cansu", "repository": "USAP-DC", "science_program": null, "title": "Data and metadata for \"Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems\"", "url": "https://www.usap-dc.org/view/dataset/601599"}], "date_created": "Tue, 18 May 2021 00:00:00 GMT", "description": "As glaciers creep across the landscape, they can act as earthmovers, plucking up rocks and grinding them into fine sediments. Glaciers have moved across the Antarctic landscape over thousands to millions of years, leaving these ground-up sediments in their wake. This study builds on pilot discoveries by the investigators that revealed remarkably large and variable measurements of surface area in glacially-derived fine-grained sediments found in the McMurdo Dry Valleys (MDV), one of the few landscapes on the Antarctic continent not currently covered by ice. Surface area is key to chemical weathering, the process by which rock is converted to soils as ions are carried away in streams and groundwater. These chemical weathering processes are also one of the primary means by which the Earth system naturally removes carbon dioxide from the atmosphere. Hence, high surface areas observed in sediments implies high \"weatherability\" which in turn translates to more potential carbon dioxide removed from the atmosphere. Therefore, chemical weathering in high surface area glacial sediments may have significant impacts on Earth\u0027s carbon cycle. The researchers will measure the chemical and physical properties of sediments previously collected from the Dry Valleys to understand what factors lead to production of sediment with high-surface area and potential \"weather ability\" and investigate how sediment produced in these glacial systems could ultimately impact Earth\u0027s carbon budget. Results from this research will help scientists (including modelers) refine predictions of the effects of melting glaciers- and attendant exposure of glacial sediment? on atmospheric carbon levels. These results may also contribute to applied research efforts on development of carbon-dioxide removal technologies utilizing principles of rock weathering. In addition to the scientific benefits, this research will involve several students at the undergraduate, graduate, and post-doctoral levels, including science education undergraduates, thus contributing to training of the next-generation STEM workforce. Physical weathering produces fresh surfaces, greatly enhancing specific surface area (SSA) and reactive surface area (RSA) of primary minerals. Quantifying SSA and RSA of sediments is key to determining dissolution and leaching rates during natural weathering, but few data exist on distribution of sediment SA, particularly in glacial and fluvial systems. Pilot data from glacial stream systems in Taylor Valley and Wright Valley (located in the MDV) exhibit remarkably high and variable values in both SSA and RSA, values that in some cases greatly exceed values from muds in temperate glacial systems. This discovery motivates the current research, which aims to investigate the hypothesis that high and variable SAs of muds within Wright and Taylor Valleys reflect textural and/or compositional inheritance from the differing depositional settings within the MDV, biologic controls, dust additions, and/or pedogenic processes. These hypotheses will be tested by sedimentologically, mineralogically, and geochemically characterizing muds from glacially derived sediment deposited in various environments (cold vs. wet based glaciation; fluvial, lacustrine, dust, and drift deposits) and of varying age (Miocene to Modern) from the MDV and quantifying variation of SA and reactivity. Comparisons with analyzed muds from temperate glacial systems will enable polar-temperate comparisons. Analyses will focus on muds of previously collected sediment from the MDVs. Grain size and SSA will be measured by Laser Analysis and N2 adsorption BET, respectively. After carbonate removal, samples will be re-analyzed for SSA, and muds characterized geochemically. Mineralogy and bulk chemistry will also be assessed on co-occurring sand fractions, and textural attributes documented. SSA-normalized dissolution experiments will be used to compare solutes released from sediments to determine RSAs. Results will be integrated with the various sedimentologic and geochemical analyses to test the posed hypotheses. Ultimately, this research should shed light on how weathering in Antarctic systems contributes to global carbon cycling.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; AMD; FIELD INVESTIGATION; USA/NSF; Dry Valleys; SEDIMENT CHEMISTRY; Amd/Us; Antarctica; Weathering", "locations": "Antarctica; Dry Valleys", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Soreghan, Gerilyn; Elwood Madden, Megan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems", "uid": "p0010181", "west": null}, {"awards": "1935870 Ballard, Grant; 1935901 Dugger, Katie", "bounds_geometry": "POLYGON((-180 -60,-177 -60,-174 -60,-171 -60,-168 -60,-165 -60,-162 -60,-159 -60,-156 -60,-153 -60,-150 -60,-150 -61.8,-150 -63.6,-150 -65.4,-150 -67.2,-150 -69,-150 -70.8,-150 -72.6,-150 -74.4,-150 -76.2,-150 -78,-153 -78,-156 -78,-159 -78,-162 -78,-165 -78,-168 -78,-171 -78,-174 -78,-177 -78,180 -78,178.5 -78,177 -78,175.5 -78,174 -78,172.5 -78,171 -78,169.5 -78,168 -78,166.5 -78,165 -78,165 -76.2,165 -74.4,165 -72.6,165 -70.8,165 -69,165 -67.2,165 -65.4,165 -63.6,165 -61.8,165 -60,166.5 -60,168 -60,169.5 -60,171 -60,172.5 -60,174 -60,175.5 -60,177 -60,178.5 -60,-180 -60))", "dataset_titles": "Adelie penguin resighting data 1997-2021 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science; P2P 2022-2023 Adelie Penguin Biologging Data", "datasets": [{"dataset_uid": "601444", "doi": "10.15784/601444", "keywords": "Adelie Penguin; Antarctica; Biota; Demography; Mark-Recapture; Monitoring; Penguin; Ross Island", "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin resighting data 1997-2021 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "url": "https://www.usap-dc.org/view/dataset/601444"}, {"dataset_uid": "601928", "doi": null, "keywords": "Adelie Penguin; Antarctica; Biologging; Cape Crozier; Cryosphere; Ross Sea", "people": "Ainley, David; Ballard, Grant; Schmidt, Annie", "repository": "USAP-DC", "science_program": null, "title": "P2P 2022-2023 Adelie Penguin Biologging Data", "url": "https://www.usap-dc.org/view/dataset/601928"}], "date_created": "Wed, 12 May 2021 00:00:00 GMT", "description": "Part 1: Non-technical description Polar regions are experiencing some of the most dramatic effects of climate change resulting in large-scale changes in sea ice cover. Despite this, there are relatively few long-term studies on polar species that evaluate the full scope of these effects. Over the last two decades, this team has conducted globally unique demographic studies of Ad\u00e9lie penguins in the Ross Sea, Antarctica, to explore several potential mechanisms for population change. This five-year project will use penguin-borne sensors to evaluate foraging conditions and behavior and environmental conditions on early life stages of Ad\u00e9lie penguins. Results will help to better understand population dynamics and how populations might respond to future environmental change. To promote STEM literacy, education and public outreach efforts will include multiple activities. The PenguinCam and PenguinScience.com website (impacts of \u003e1 million hits per month and use by \u003e300 classrooms/~10,000 students) will be continued. Each field season will also have \u2018Live From the Penguins\u2019 Skype calls to classes (~120/season). Classroom-ready activities that are aligned with Next Generation Science Standards will be developed with media products and science journal papers translated to grade 5-8 literacy level. The project will also train early career scientists, postdoctoral scholars, graduate students and post-graduate interns. Finally, in partnership with an Environmental Leadership Program, the team will host 2-year Roger Arliner Young Conservation Fellow, which is a program designed to increase opportunities for recent college graduates of color to learn about, engage with, and enter the environmental conservation sector. Part II: Technical description: Leveraging 25 years of data on marked individuals from two Ad\u00e9lie penguin colonies in the Ross Sea, combined with new biologging tags that track detailed penguin foraging efforts and environmental conditions, researchers will accomplish three major goals: 1) assess the quality of natal conditions by determining how environmental conditions, relative prey availability, and diet composition influence parental foraging behavior, chick provisioning, and fledging mass; 2) determine the spatial distribution and foraging behavior of juvenile Ad\u00e9lie penguins and the relative influence of natal versus post-fledging environmental conditions on their survival; and 3) determine the role of natal and post-fledging conditions in shaping individual life history traits and colony growth. Data from several types of penguin-borne biologging devices will be used to provide multiple lines of evidence for how early-life conditions and penguin behavior relate to penguin energetics and population size. This study is the first to integrate salinity, temperature, light level, depth, accelerometry, video loggers, and GPS data with longitudinal demographic information, providing an unprecedented ability to understand how penguins use the environment and enabling new insights from previously collected data. Changes in salinity due to increased glacial melt have important implications for sea ice formation, ocean circulation and productivity of the Southern Ocean, and potentially global temperature change. The penguin-borne sensors deployed in this study will support the NSF Office of Polar Programs priority: How does society more efficiently observe and measure the polar regions? It represents only the second study to track juvenile Ad\u00e9lie penguins at sea, the first in the Ross Sea region, the first with substantial sample sizes, and the first to assess juvenile survival rates directly, integrating early life factors and environmental conditions to better understand colony growth trajectories. 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(-172.5 -69)", "instruments": null, "is_usap_dc": true, "keywords": "Ross Island; AMD; MARINE ECOSYSTEMS; Amd/Us; Adelie Penguin; USAP-DC; USA/NSF; FIELD SURVEYS", "locations": "Ross Island", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ballard, Grant; Schmidt, Annie; Varsani, Arvind; Dugger, Katie; Orben, Rachael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Population Growth at the Southern Extreme: Effects of Early Life Conditions on Adelie penguin Individuals and Colonies", "uid": "p0010179", "west": 165.0}, {"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": "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"}, {"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"}], "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": "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": "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"}, {"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/"}], "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": "UNAVCO", "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": "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": "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": "601478", "doi": "10.15784/601478", "keywords": "Antarctica; Glaciology; Ice Shelf; Ice Velocity; Strain Rate; Thwaites Glacier", "people": "Klinger, Marin; Wild, Christian; Scambos, Ted; Wallin, Bruce; Truffer, Martin; Alley, Karen; Pettit, Erin; 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": "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; Alley, Karen; Wild, Christian; Scambos, Ted; Truffer, Martin", "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": "601499", "doi": "10.15784/601499", "keywords": "Amundsen Sea; Antarctica; Glaciology; Grounding Line; Ice Shelf; Thwaites Glacier", "people": "Truffer, Martin; Pettit, Erin; Scambos, Ted; Muto, Atsu; Alley, Karen; Wild, Christian", "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": "601914", "doi": null, "keywords": "Antarctica; Cryosphere; Glaciology; Ice Shelf; Thwaites Glacier; Velocity", "people": "Wild, Christian; Alley, Karen; Muto, Atsuhiro; Scambos, Ted; Pettit, Erin; Truffer, Martin; Luckman, Adrian; Lilien, David; Banerjee, Debangshu", "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"}, {"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": "Pettit, Erin; Alley, Karen; Wild, Christian; Banerjee, Debangshu; Lilien, David; Truffer, Martin; Muto, Atsuhiro; Luckman, Adrian; Scambos, Ted", "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": "Lilien, David; Alley, Karen; Truffer, Martin; Luckman, Adrian; Wild, Christian; Banerjee, Debangshu; Pettit, Erin; Scambos, Ted; Muto, Atsuhiro", "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": "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": "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": "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": "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": "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": "601578", "doi": "10.15784/601578", "keywords": "Antarctica; Dotson Ice Shelf; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Segabinazzi-Dotto, Tiago; Wild, Christian", "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": "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": "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": "601827", "doi": "10.15784/601827", "keywords": "Antarctica; Cryosphere; Dotson Ice Shelf; Thwaites Glacier", "people": "Pettit, Erin; Wild, Christian; Alley, Karen; Scambos, Ted; Muto, Atsuhiro; Truffer, Martin; Pomraning, Dale; Wallin, Bruce; Roccaro, Alexander", "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"}], "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 Glaciology; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "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": "USAP-DC", "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": "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": "1643551 Hansen, Samantha", "bounds_geometry": null, "dataset_titles": "Investigating Ultra-low Velocity Zones (ULVZs) using an Antarctic Dataset", "datasets": [{"dataset_uid": "601265", "doi": "10.15784/601265", "keywords": "Antarctica; Core-Mantle Boundary; ScP; Southern Hemisphere; Ultra-Low Velocity Zones", "people": "Rost, Sebastian; Hansen, Samantha; Carson, Sarah; Garnero, Edward; Yu, Shule", "repository": "USAP-DC", "science_program": null, "title": "Investigating Ultra-low Velocity Zones (ULVZs) using an Antarctic Dataset", "url": "https://www.usap-dc.org/view/dataset/601265"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "Non-Technical Project Description This research will study Ultralow Velocity Zones (ULVZs), located in Earth\u0027s interior on top of the boundary between the Earth\u0027s solid mantle and its fluid outer core. The ULVZs are so named because seismic waves passing through the Earth slow down dramatically when they encounter these zones. While ULVZs are thought to be related to melting processes, there is growing controversy regarding their origin and the role they play in the thermal and chemical evolution of our planet. The ULVZs may include the largest magma chambers in Earth\u0027s interior. Currently, researchers have only searched 40% of Earth\u0027s core-mantle boundary for the ULVZs and this project would use existing seismic data to map an unexplored area under Antarctica and interpret the nature of the ULVZs. This project will support two graduate students and create opportunities for undergraduate involvement. Project results will be published in scientific journals, presented at science fairs, and communicated through the researchers\u0027 websites. The research team will also take part in the NSF-sponsored PolarTREC (Teachers and Researchers Exploring and Collaborating) program to communicate the science to students and the broader community. Technical Project Description The National Research Council has highlighted high-resolution imaging of core-mantle boundary (CMB) structure as a high-priority, emerging research opportunity in the Earth Sciences since anomalies along the CMB likely play a critical role in the thermal and chemical evolution of our planet. Of particular interest are ultralow velocity zones (ULVZs), thin laterally-varying boundary layers associated with dramatic seismic velocity decreases and increases in density that are seen just above the CMB. Many questions exist regarding the origin of ULVZs, but incomplete seismic sampling of the lowermost mantle has limited our ability to map global ULVZ structure in detail. Using recently collected data from the Transantarctic Mountains Northern Network (TAMNNET) in Antarctica, this project will use core-reflected seismic phases (ScP, PcP, and ScS) to investigate ULVZ presence/absence along previously unexplored sections of the CMB. The data sampling includes the southern boundary of the Pacific Large Low Shear Velocity Province (LLSVP), a dominant feature in global shear wave tomography models, and will allow the researchers to examine a possible connection between ULVZs and LLSVPs. The main objectives of the project are to: 1) use TAMNNET data to document ULVZ presence/absence in previously unexplored regions of the lowermost mantle with array-based approaches; 2) model the data with 1- and 2.5-D wave propagation tools to obtain ULVZ properties and to assess trade-offs among the models; 3) use high quality events to augment the densely-spaced TAMNNET data with that from the more geographically-distributed, open-access Antarctic stations to increase CMB coverage with single-station analyses; and 4) explore the implications of ULVZ solution models for origin, present-day dynamics, and evolution, including their connection to other deep mantle structures, like LLSVPs. The project aims to provide new constraints on ULVZs, including their potential connection to LLSVPs, and thus relates to other seismic and geodynamic investigations focused on processes within the Earth?s interior. This project will promote a new research collaboration between The University of Alabama (UA) and Arizona State University (ASU), each of which brings specific strengths to the initiative.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; SEISMIC PROFILE; NOT APPLICABLE", "locations": "Antarctica", "north": null, "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": null, "title": "Collaborative Research: Antarctic Seismic Investigations of ULVZ Structure", "uid": "p0010136", "west": null}, {"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": "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"}, {"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"}], "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": "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": "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": "Wallin, Bruce; Miller, Olivia; Mi\u00e8ge, Cl\u00e9ment; Solomon, Kip; Miller, Julie; Scambos, Ted; Forster, Richard; Koenig, Lora; Montgomery, Lynn", "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"}, {"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": "Miege, Clement; Wallin, Bruce; Montgomery, Lynn; Miller, Julie; Scambos, Ted", "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"}], "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": "1935945 Tremblay, Marissa; 1935755 Lamp, Jennifer; 1935907 Balco, Gregory", "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 Facilities; Antarctic Instrumentation and Support", "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": "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": "601235", "doi": "10.15784/601235", "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "people": "Erofeeva, Svetlana; Padman, Laurence; Howard, Susan L.", "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": "601358", "doi": "10.15784/601358", "keywords": "Antarctica; Oceans; Sea Surface Height; Tide Gauges; Tides", "people": "King, Matt; Padman, Laurence; Howard, Susan L.", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Tide Gauge Database, version 1", "url": "https://www.usap-dc.org/view/dataset/601358"}, {"dataset_uid": "200158", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "pyTMD", "url": "https://github.com/tsutterley/pyTMD"}, {"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": "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": "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"}], "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": "USAP-DC", "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": "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": "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/"}, {"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/"}], "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": "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"}, {"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"}], "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": "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": "601582", "doi": "10.15784/601582", "keywords": "Antarctica; Glaciation; IODP 650; IODP 696; Paleoceanography; Provenance; Sediment Core Data; Weathering; Weddell Sea", "people": "Passchier, Sandra; Lepp, Allison; States, Abbey; Li, Xiaona; Hojnacki, Victoria", "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"}, {"dataset_uid": "601581", "doi": "10.15784/601581", "keywords": "Antarctica; Glaciation; IODP 696; Marine Geoscience; Marine Sediments; Paleoceanography; Sediment Core Data; Weddell Sea", "people": "Horowitz Castaldo, Josie; Passchier, Sandra; Lepp, Allison; Light, Jennifer", "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"}], "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": "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": "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": "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": "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": "Studinger, Michael S.; Bell, Robin", "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": "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": "Bell, Robin; Studinger, Michael S.", "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": "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": "Bell, Robin; Studinger, Michael S.", "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": "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": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey surface elevation data", "url": "https://www.usap-dc.org/view/dataset/601298"}], "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": "1643733 Trusel, Luke; 1643715 Moussavi, Mahsa Sadat", "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; Pope, Allen; Moussavi, Mahsa; 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": "1341494 Gao, Yuan", "bounds_geometry": "POINT(-64.05 -64.77)", "dataset_titles": "Concentrations and Particle Size Distributions of Aerosol Trace Elements; Particle sizes of aerosol iron", "datasets": [{"dataset_uid": "601370", "doi": "10.15784/601370", "keywords": "Antarctica; Antarctic Peninsula; Palmer Station; Trace Elements", "people": "Gao, Yuan", "repository": "USAP-DC", "science_program": null, "title": "Concentrations and Particle Size Distributions of Aerosol Trace Elements", "url": "https://www.usap-dc.org/view/dataset/601370"}, {"dataset_uid": "601257", "doi": "10.15784/601257", "keywords": "Aerosol Concentration; Antarctica; Chemistry:gas; Chemistry:Gas; Iron; Palmer Station; Particle Size", "people": "Gao, Yuan", "repository": "USAP-DC", "science_program": null, "title": "Particle sizes of aerosol iron", "url": "https://www.usap-dc.org/view/dataset/601257"}], "date_created": "Thu, 20 Feb 2020 00:00:00 GMT", "description": "The research seeks to further quantify the input of atmospheric Fe into the sparsely sampled Southern Ocean (SO), specifically in the vicinity of the West Antarctic Peninsula (WAP) and adjacent continental shelf waters in the Drake Passage. This is typically a high nutrient low chlorophyll region where surface trace metal and primary productivity data are suggestive of Fe limitation. The WAP is characterized by high productivity in the austral summer, and at this time may be in the path of northern dust (aeolian Fe) input or subject to melt influx of elevated Fe accumulated from glacial and present-day sea ice sources. Primary scientific questions are: (1) to what extent does atmospheric Fe contribute to nutrient cycles and ecosystem dynamics in the SO? (2) How is warming climate occurring in the WAP affecting the aerosol composition of the maritime atmosphere. The primary productivity of the Southern Ocean is key to understanding oceanic uptake of anthropogenic greenhouse gases such as carbon dioxide.", "east": -64.05, "geometry": "POINT(-64.05 -64.77)", "instruments": null, "is_usap_dc": true, "keywords": "Aerosol Concentration; TRACE GASES/TRACE SPECIES; Particle Size; Palmer Station; FIELD INVESTIGATION; Trace Elements; Iron; AEROSOL OPTICAL DEPTH/THICKNESS; USAP-DC", "locations": "Palmer Station", "north": -64.77, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Gao, Yuan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.77, "title": "Quantifying Atmospheric Iron Properties over West Antarctic Peninsula", "uid": "p0010082", "west": -64.05}, {"awards": "1644020 Sims, Kenneth W.; 1644027 Wallace, Paul; 1644013 Gaetani, Glenn", "bounds_geometry": "POLYGON((164.1 -77.1,164.65 -77.1,165.2 -77.1,165.75 -77.1,166.3 -77.1,166.85 -77.1,167.4 -77.1,167.95 -77.1,168.5 -77.1,169.05 -77.1,169.6 -77.1,169.6 -77.235,169.6 -77.37,169.6 -77.505,169.6 -77.64,169.6 -77.775,169.6 -77.91,169.6 -78.045,169.6 -78.18,169.6 -78.315,169.6 -78.45,169.05 -78.45,168.5 -78.45,167.95 -78.45,167.4 -78.45,166.85 -78.45,166.3 -78.45,165.75 -78.45,165.2 -78.45,164.65 -78.45,164.1 -78.45,164.1 -78.315,164.1 -78.18,164.1 -78.045,164.1 -77.91,164.1 -77.775,164.1 -77.64,164.1 -77.505,164.1 -77.37,164.1 -77.235,164.1 -77.1))", "dataset_titles": "G170 Electron Microprobe Analyses of Melt Inclusions and Host Olivines; G170 Raman Spectroscopy \u0026 Tomography Volumes of Melt Inclusions and Vapor Bubbles; G170 Sample Locations Ross Island \u0026 Discovery Province; G170 Secondary Ion Mass Spectrometry Analses of Melt Inclusion Volatiles; G170 Secondary Ion Mass Spectrometry Analyses of Melt Inclusion Hydrogen Isotopes; Location and Description of Tephra Samples from the Erebus and Discovery Sub-provinces", "datasets": [{"dataset_uid": "601505", "doi": "10.15784/601505", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Electron Microprobe Analyses; Olivine; Petrography; Ross Island", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Electron Microprobe Analyses of Melt Inclusions and Host Olivines", "url": "https://www.usap-dc.org/view/dataset/601505"}, {"dataset_uid": "601507", "doi": "10.15784/601507", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Hydrogen; Ion Mass Spectrometry; Ross Island", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Secondary Ion Mass Spectrometry Analyses of Melt Inclusion Hydrogen Isotopes", "url": "https://www.usap-dc.org/view/dataset/601507"}, {"dataset_uid": "601506", "doi": "10.15784/601506", "keywords": "Antarctica; Ion Mass Spectrometry; Ross Island; Volatiles", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Secondary Ion Mass Spectrometry Analses of Melt Inclusion Volatiles", "url": "https://www.usap-dc.org/view/dataset/601506"}, {"dataset_uid": "601250", "doi": "10.15784/601250", "keywords": "Antarctica; Hut Point Peninsula; Mt. Bird; Mt. Morning; Mt. Terror; Ross Island; Turks Head; Turtle Rock", "people": "Gaetani, Glenn; Pamukcu, Ayla", "repository": "USAP-DC", "science_program": null, "title": "Location and Description of Tephra Samples from the Erebus and Discovery Sub-provinces", "url": "https://www.usap-dc.org/view/dataset/601250"}, {"dataset_uid": "601504", "doi": "10.15784/601504", "keywords": "Antarctica; Ross Island; Sample/collection Description; Sample/Collection Description; Sample Location", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Sample Locations Ross Island \u0026 Discovery Province", "url": "https://www.usap-dc.org/view/dataset/601504"}, {"dataset_uid": "601508", "doi": "10.15784/601508", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Melt Inclusions; Raman Spectroscopy; Ross Island; Vapor Bubbles; Volcanic", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Raman Spectroscopy \u0026 Tomography Volumes of Melt Inclusions and Vapor Bubbles", "url": "https://www.usap-dc.org/view/dataset/601508"}], "date_created": "Sat, 08 Feb 2020 00:00:00 GMT", "description": "Nontechnical project description Globally, 500 million people live near and are threatened by active volcanoes. An important step in mitigating volcanic hazards is understanding the variables that influence the explosivity of eruptions. The rate at which a magma ascends from the reservoir within the Earth to the surface is one such variable. However, magma ascent rates are particularly difficult to determine because of the lack of reliable methods for investigating the process. This research applies a new approach to study magma storage depths and ascent rates at the Erebus volcanic province of Antarctica, one of Earth\u0027s largest alkaline volcanic centers. Small pockets of magma that become trapped within growing olivine crystals are called melt inclusions. The concentrations of water and carbon dioxide in these melt inclusions preserve information on the depth of magma reservoirs. Changes to the concentration and isotopic composition of water in the inclusions provide information on how long it took for the host magma to rise to the surface. In combination, these data from samples of olivine-rich volcanic deposits in the Erebus volcanic province will be used to determine the depths at which magmas are stored and their ascent rates. The project results will provide a framework for understanding volcanic hazards associated with alkaline volcanism worldwide. In addition, this project facilitates collaboration among three institutions, and provides an important educational opportunity for a postdoctoral researcher. Technical project description The depths at which magmas are stored, their pre-eruptive volatile contents, and the rates at which they ascend to the Earth\u0027s surface are important controls on the dynamics of volcanic eruptions. Basaltic magmas are likely to be vapor undersaturated as they begin their ascent from the mantle through the crust, but volatile solubility drops with decreasing pressure. Once vapor saturation is achieved and the magma begins to degas, its pre-eruptive volatile content is determined largely by the depth at which it resides within the crust. Magma stored in deeper reservoirs tend to experience less pre-eruptive degassing and to be richer in volatiles than magma shallower reservoirs. Eruptive style is influenced by the rate at which a magma ascends from the reservoir to the surface through its effect on the efficiency of vapor bubble nucleation, growth, and coalescence. The proposed work will advance our understanding of pre-eruptive storage conditions and syn-eruptive ascent rates through a combined field and analytical research program. Volatile measurements from olivine-hosted melt inclusions will be used to systematically investigate magma storage depths and ascent rates associated with alkaline volcanism in the Erebus volcanic province. A central goal of the project is to provide a spatial and temporal framework for interpreting results from studies of present-day volcanic processes at Mt Erebus volcano. The Erebus volcanic province of Antarctica is especially well suited to this type of investigation because: (1) there are many exposed mafic scoria cones, fissure vents, and hyaloclastites (exposed in sea cliffs) that produced rapidly quenched, olivine-rich tephra; (2) existing volatile data for Ross Island MIs show that magma storage was relatively deep compared to many mafic volcanic systems; (3) some of the eruptive centers ejected mantle xenoliths, allowing for comparison of ascent rates for xenolith-bearing and xenolith-free eruptions, and comparison of ascent rates for those bearing xenoliths with times estimated from settling velocities; and (4) the cold, dry conditions in Antarctica result in excellent tephra preservation compared to tropical and even many temperate localities. The project provides new tools for assessing volcanic hazards, facilitates collaboration involving researchers from three different institutions (WHOI, U Wyoming, and U Oregon), supports the researchers\u0027 involvement in teaching, advising, and outreach, and provides an educational opportunity for a promising young postdoctoral researcher. Understanding the interrelationships among magma volatile contents, reservoir depths, and ascent rates is vital for assessing volcanic hazards associated with alkaline volcanism across the globe.", "east": 169.6, "geometry": "POINT(166.85 -77.775)", "instruments": null, "is_usap_dc": true, "keywords": "Tephra; Turtle Rock; USA/NSF; Amd/Us; LABORATORY; AMD; Ross Island; Turks Head; Hut Point Peninsula; LAVA SPEED/FLOW; USAP-DC; Mt. Morning; Mt. Terror; ROCKS/MINERALS/CRYSTALS; Mt. Bird; FIELD INVESTIGATION", "locations": "Ross Island; Mt. Morning; Mt. Bird; Mt. Terror; Hut Point Peninsula; Turtle Rock; Turks Head", "north": -77.1, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Gaetani, Glenn; Le Roux, Veronique; Sims, Kenneth; Wallace, Paul", "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": -78.45, "title": "Collaborative Research: Determining Magma Storage Depths and Ascent Rates for the Erebus Volcanic Province, Antarctica Using Diffusive Water Loss from Olivine-hosted Melt Inclusion", "uid": "p0010081", "west": 164.1}, {"awards": "1443296 Cottle, John", "bounds_geometry": "POLYGON((-180 -76.85314,-179.4383642 -76.85314,-178.8767284 -76.85314,-178.3150926 -76.85314,-177.7534568 -76.85314,-177.191821 -76.85314,-176.6301852 -76.85314,-176.0685494 -76.85314,-175.5069136 -76.85314,-174.9452778 -76.85314,-174.383642 -76.85314,-174.383642 -77.658865,-174.383642 -78.46459,-174.383642 -79.270315,-174.383642 -80.07604,-174.383642 -80.881765,-174.383642 -81.68749,-174.383642 -82.493215,-174.383642 -83.29894,-174.383642 -84.104665,-174.383642 -84.91039,-174.9452778 -84.91039,-175.5069136 -84.91039,-176.0685494 -84.91039,-176.6301852 -84.91039,-177.191821 -84.91039,-177.7534568 -84.91039,-178.3150926 -84.91039,-178.8767284 -84.91039,-179.4383642 -84.91039,180 -84.91039,177.4459565 -84.91039,174.891913 -84.91039,172.3378695 -84.91039,169.783826 -84.91039,167.2297825 -84.91039,164.675739 -84.91039,162.1216955 -84.91039,159.567652 -84.91039,157.0136085 -84.91039,154.459565 -84.91039,154.459565 -84.104665,154.459565 -83.29894,154.459565 -82.493215,154.459565 -81.68749,154.459565 -80.881765,154.459565 -80.07604,154.459565 -79.270315,154.459565 -78.46459,154.459565 -77.658865,154.459565 -76.85314,157.0136085 -76.85314,159.567652 -76.85314,162.1216955 -76.85314,164.675739 -76.85314,167.2297825 -76.85314,169.783826 -76.85314,172.3378695 -76.85314,174.891913 -76.85314,177.4459565 -76.85314,-180 -76.85314))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 02 Dec 2019 00:00:00 GMT", "description": "Subduction takes place at convergent plate boundaries and involves sinking of one tectonic plate underneath another. Although this process is a key aspect of plate tectonics that shapes the planet over geologic time, and is a primary cause of earthquakes, it is not known what causes subduction to cease, and what effect it has on the deepest portions of the crust and the upper part of the mantle. By studying the age and composition of igneous rocks emplaced at the very end of the subduction cycle, this project seeks to understand what causes subduction to cease, and how this changes the composition and structure of the crust and upper mantle. Because this process occurs deep within the earth, the project will focus on rocks in the root of an ancient subduction zone, now exposed in the Transantarctic Mountains of Antarctica. In addition, Antarctica remains relatively poorly understood, and this project will contribute directly to increasing our understanding of the geologic history of this region. The project will focus on training graduate and undergraduate students - incorporating hands-on experience with an array of state-of-the-art analytical instrumentation. Students will also gain a range of more general skills including Geographic Information Systems (GIS), written and oral communication, and data management - strengths that are highly relevant to careers both in the academic and Geosciences industry. Each summer, high school students will be incorporated into aspects of the laboratory-based research through the UCSB research mentorship program. The PI and graduate students will engage the general public through a purpose-built iPhone App and multimedia website. Activities will include live phone and video conversations from the field between elementary school students and members of the team in Antarctica. The mechanisms by which the deep crustal delaminates or \"founders\" and is returned to the mantle remains a fundamental problem in earth science. Specifically, little is known about the temporal and spatial scales over which this process occurs or the mechanisms that trigger such catastrophic events. Igneous rocks highly enriched in potassium, called lamprophyres, are often emplaced during, and immediately after, termination of subduction and therefore potentially provide direct insight into foundering. These enigmatic rocks are important because they represent near-primary mantle melt compositions and therefore their age, geochemistry and petrologic evolution reveal key information on both the composition of the upper mantle and its thermal state. Of equal importance, they reveal how these key parameters vary through both space and time. By evaluating lamprophyres along a subduction zone margin it is possible to extract: 1) local-scale information, such as the timing and duration of melting and the role of igneous crystallization processes in generation of isotopic heterogeneities; 2) along-strike variations in mantle source composition, temperature, and depth of melting 3) the plate-scale forces that control foundering and termination of subduction. This project will study a suite of lamprophyres along the axis of the Transantarctic Mountains, emplaced during the latest stages of the Neoproterozoic - Ordovician Ross orogeny, Antarctica (roughly 505 to 470 million years before present). High-precision geochronology (age determinations) will be combined with geochemical measurements on the rocks and minerals to understand the mechanisms and timing of deep crustal foundering/delamination.", "east": -174.383642, "geometry": "POINT(170.0379615 -80.881765)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "AGE DETERMINATIONS; ISOTOPES; PLATE TECTONICS; Antarctica; USAP-DC; NOT APPLICABLE", "locations": "Antarctica", "north": -76.85314, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Cottle, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -84.91039, "title": "Petrologic Constraints on Subduction Termination From Lamprophyres, Ross Orogen, Antarctica", "uid": "p0010071", "west": 154.459565}, {"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": "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": "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": "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": "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": "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 Earth Sciences; Antarctic Glaciology", "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": "UK PDC", "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": "1443578 Schmidt, Steven", "bounds_geometry": "POLYGON((161.5 -77.5,161.7 -77.5,161.9 -77.5,162.1 -77.5,162.3 -77.5,162.5 -77.5,162.7 -77.5,162.9 -77.5,163.1 -77.5,163.3 -77.5,163.5 -77.5,163.5 -77.53,163.5 -77.56,163.5 -77.59,163.5 -77.62,163.5 -77.65,163.5 -77.68,163.5 -77.71,163.5 -77.74,163.5 -77.77,163.5 -77.8,163.3 -77.8,163.1 -77.8,162.9 -77.8,162.7 -77.8,162.5 -77.8,162.3 -77.8,162.1 -77.8,161.9 -77.8,161.7 -77.8,161.5 -77.8,161.5 -77.77,161.5 -77.74,161.5 -77.71,161.5 -77.68,161.5 -77.65,161.5 -77.62,161.5 -77.59,161.5 -77.56,161.5 -77.53,161.5 -77.5))", "dataset_titles": "16S and 18S amplicon sequencing of Antarctic cryoconite holes; Genomes of Antarctic ssDNA viruses (GenBank accession numbers MN311489-MN311492 and MN328267-MN328291); Metadata from samples (in the process of submitting to EDI; will update with DOI once completed); Microbial species-area relationships in Antarctic cryoconite holes; Soil microbial communities of a mountain landscape, McMurdo Dry Valleys, Antarctica", "datasets": [{"dataset_uid": "200279", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Metadata from samples (in the process of submitting to EDI; will update with DOI once completed)", "url": "https://github.com/pacificasommers/Cryoconite-metadata"}, {"dataset_uid": "200081", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "16S and 18S amplicon sequencing of Antarctic cryoconite holes", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA480849/"}, {"dataset_uid": "200280", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Soil microbial communities of a mountain landscape, McMurdo Dry Valleys, Antarctica", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA721735/"}, {"dataset_uid": "200281", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Microbial species-area relationships in Antarctic cryoconite holes", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA668398/"}, {"dataset_uid": "200084", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Genomes of Antarctic ssDNA viruses (GenBank accession numbers MN311489-MN311492 and MN328267-MN328291)", "url": ""}], "date_created": "Fri, 01 Nov 2019 00:00:00 GMT", "description": "Cryoconite holes are pockets of life completely encased in otherwise barren glacial ice. These pockets of life form when dust blown onto the ice melts a small, largely isolated hole that can function as its own tiny ecosystem. This dust can contain microorganisms such as bacteria, algae, or microscopic animals. The microorganisms within the hole interact and carry out functions typical of a larger ecosystem, such as a forest. Cryoconite holes are especially important in extreme cold environments such as the Antarctic Dry Valleys, where they function as repositories of life. Because cryoconite holes are mostly enclosed and persist for years, they can be tracked over time to test fundamental scientific questions about how communities of interacting organisms develop to become fully functioning ecosystems. This project will sample existing and experimentally created cryoconite holes to understand how these ecosystems develop and to what degree random processes (such as which organisms get there first) affect the final community composition and functioning. The results will not only improve our understanding of how microbial communities assemble and affect the functioning of microecosystems such as cryoconite holes, but also how the processes of community assembly affect functioning of larger ecosystems, such as forests. A better understanding of community establishment, development, and response to abiotic factors are essential to forecasting ecological responses to environmental change. It is essential to unravel the links between community assembly, biodiversity, and nutrient cycling across numerous ecosystems because these are critical factors determining ecological responses to environmental change. The unique, largely isolated nature of cryoconite holes provides an experimental system that will advance fundamental understanding of the processes (e.g., stochastic dynamics such as dispersal limitation, assembly order, and ecological drift) driving community assembly. This project will use a field sampling campaign and a number of manipulative experiments to test a hypothesis that unites theory in community and ecosystem ecology: the degree to which stochastic processes guide microbial community assembly and affects regional patterns in biodiversity and ecosystem processes. Cryoconite holes will be sampled to compare community composition, environmental factors, and ecosystem functioning between hydrologically connected and isolated holes. New cryoconite holes will also be constructed and monitored over the course of two growing seasons to specifically alter assembly order and community size, thereby pairing a unique manipulative experiment with field surveys to address questions with relevance to the Antarctic and beyond. Amplicon sequencing, metagenomics, microscopy, sensitive environmental chemistry methods, and photosynthesis and respiration measurements will be used to test a series of sub-hypotheses that relate stochasticity to patterns in regional biodiversity, heterogeneity in environmental factors, and ecosystem processes.", "east": 163.5, "geometry": "POINT(162.5 -77.65)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "GLACIERS; Antarctica; USAP-DC; FIELD INVESTIGATION", "locations": "Antarctica", "north": -77.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Schmidt, Steven; Cawley, Kaelin; Fountain, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "GitHub", "repositories": "GitHub; NCBI GenBank", "science_programs": null, "south": -77.8, "title": "Collaborative Research: Stochasticity and Cryoconite Community Assembly and Function", "uid": "p0010063", "west": 161.5}, {"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": "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/"}, {"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": "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": "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": "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/"}], "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": "1443585 Polito, Michael; 1443424 McMahon, Kelton; 1826712 McMahon, Kelton; 1443386 Emslie, Steven", "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": "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": "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": "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; Kristan, Allyson; McMahon, Kelton; Maiti, Kanchan", "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": "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": "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": "601760", "doi": "10.15784/601760", "keywords": "Adelie Penguin; Amino Acids; Antarctica; Antarctic Peninsula; Ross Sea; Stable Isotope Analysis; Trophic Position", "people": "Emslie, Steven D.; Wonder, Michael; McCarthy, Matthew; Patterson, William; McMahon, Kelton; Michelson, Chantel; Polito, Michael", "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": "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": "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": "Ciriani, Yanina; Emslie, Steven D.", "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": "601263", "doi": "10.15784/601263", "keywords": "Abandoned Colonies; Antarctica; Holocene; Penguin; Ross Sea; Stable Isotope Analysis", "people": "Emslie, Steven D.; Patterson, William; 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": "Clucas, Gemma; Kalvakaalva, Rohit; Polito, Michael; Herman, Rachael", "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": "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": "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"}, {"dataset_uid": "601913", "doi": "10.15784/601913", "keywords": "Adelie Penguin; Antarctica; Cryosphere; Foraging; Polynya; Pygoscelis Adeliae; Ross Sea; Stable Isotopes", "people": "Reaves, Megan; Emslie, Steven D.; Powers, Shannon", "repository": "USAP-DC", "science_program": null, "title": "Stable isotopes of Adelie Penguin chick bone collagen", "url": "https://www.usap-dc.org/view/dataset/601913"}], "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": "1643735 Li, Yun; 1643901 Zhang, Weifeng; 2021245 Li, Yun", "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": "Dynamic fine-scale sea-icescape shapes adult emperor penguin foraging habitat in East Antarctica; Monthly Stratification Climatology (1978-2021) in Antarctic Coastal Polynyas", "datasets": [{"dataset_uid": "601209", "doi": "10.15784/601209", "keywords": "Animal Behavior Observation; Antarctica; Biota; East Antarctica; GPS; Oceans; Penguin; Southern Ocean", "people": "Pinaud, David; Wienecke, Barbara; Kirkwood, Roger; Ropert-Coudert, Yan; Resinger, Ryan; Jonsen, Ian; Porter-Smith, Rick; Barbraud, Christophe; Ji, Rubao; Jenouvrier, Stephanie; Sumner, Michael; Bost, Charles-Andr\u00e9; Labrousse, Sara; Fraser, Alexander; Tamura, Takeshi", "repository": "USAP-DC", "science_program": null, "title": "Dynamic fine-scale sea-icescape shapes adult emperor penguin foraging habitat in East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601209"}, {"dataset_uid": "601628", "doi": "10.15784/601628", "keywords": "Antarctic; Antarctica; Antarctic Coastal Polynyas; Polynya", "people": "Zhang, Weifeng; Shunk, Nathan; Li, Yun", "repository": "USAP-DC", "science_program": null, "title": "Monthly Stratification Climatology (1978-2021) in Antarctic Coastal Polynyas", "url": "https://www.usap-dc.org/view/dataset/601628"}], "date_created": "Wed, 07 Aug 2019 00:00:00 GMT", "description": "During winter, sea-ice coverage along the Antarctic coast is punctuated by numerous polynyas--isolated openings of tens to hundreds of kilometer wide. These coastal polynyas are hotspots of sea ice production and the primary source regions of the bottom water in the global ocean. They also host high levels of biological activities and are the feeding grounds of Emperor penguins and marine mammals. The polynyas are a key component of the Antarctic coastal system and crucial for the survival of penguins and many other species. These features also differ dramatically from each other in timing of formation, duration, phytoplankton growth season, and overall biological productivity. Yet, the underlying reasons for differences among them are largely unknown. This project studies the fundamental biophysical processes at a variety of polynyas, examines the connection between the physical environment and the phytoplankton and penguin ecology, and investigates the mechanisms behind polynya variability. The results of this interdisciplinary study will provide a context for interpretation of field measurements in Antarctic coastal polynyas, set a baseline for future polynya studies, and examine how polynya ecosystems may respond to local and large-scale environmental changes. The project will include educational and outreach activities that convey scientific messages to a broad audience. It aims to increase public awareness of the interconnection between large-scale environmental change and Antarctic coastal systems. The main objectives of this study are to form a comprehensive understanding of the temporal and spatial variability of Antarctic coastal polynyas and the physical controls of polynya ecosystems. The project takes an interdisciplinary approach and seeks to establish a modeling system centered on the Regional Ocean Modeling System. This system links the ice and ocean conditions to the plankton ecology and penguin population. Applications of the modeling system in representative polynyas, in conjunction with analysis of existing observations, will determine the biophysical influences of individual forcing factors. In particular, this study will test a set of hypothesized effects of winds, offshore water intrusion, ice-shelf melting, sea-ice formation, glacier tongues, and ocean stratification on the timing of polynya phytoplankton bloom and the overall polynya biological productivity. The project will also examine how changing polynya state affects penguin breeding success, adult survival, and population growth. The team will conduct idealized sensitivity analysis to explore implications of forcing variability, including local and large-scale environmental change, on Antarctic coastal ecosystems.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; Animal Behavior; Penguin; FIELD INVESTIGATION; USAP-DC; COASTAL; PENGUINS; SEA ICE; Antarctica; OCEAN MIXED LAYER", "locations": "Southern Ocean; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Zhang, Weifeng; Ji, Rubao; Jenouvrier, Stephanie; Maksym, Edward; Li, Yun", "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: Polynyas in Coastal Antarctica (PICA): Linking Physical Dynamics to Biological Variability", "uid": "p0010044", "west": -180.0}, {"awards": "1744645 Young, Jodi", "bounds_geometry": "POLYGON((-64.4 -64.2,-64.38 -64.2,-64.36 -64.2,-64.34 -64.2,-64.32 -64.2,-64.3 -64.2,-64.28 -64.2,-64.26 -64.2,-64.24 -64.2,-64.22 -64.2,-64.2 -64.2,-64.2 -64.26,-64.2 -64.32,-64.2 -64.38,-64.2 -64.44,-64.2 -64.5,-64.2 -64.56,-64.2 -64.62,-64.2 -64.68,-64.2 -64.74,-64.2 -64.8,-64.22 -64.8,-64.24 -64.8,-64.26 -64.8,-64.28 -64.8,-64.3 -64.8,-64.32 -64.8,-64.34 -64.8,-64.36 -64.8,-64.38 -64.8,-64.4 -64.8,-64.4 -64.74,-64.4 -64.68,-64.4 -64.62,-64.4 -64.56,-64.4 -64.5,-64.4 -64.44,-64.4 -64.38,-64.4 -64.32,-64.4 -64.26,-64.4 -64.2))", "dataset_titles": "Dataset: Particulate Organic Carbon and Particulate Nitrogen; Dataset: Photosynthetic Pigments; Dataset: Physical Profiles of Temperature, Salinity, and Brine Volume; Sea-ice diatom compatible solute shifts", "datasets": [{"dataset_uid": "200322", "doi": "10.21228/M84386", "keywords": null, "people": null, "repository": "Metabolomics workbench", "science_program": null, "title": "Sea-ice diatom compatible solute shifts", "url": "https://www.metabolomicsworkbench.org/data/DRCCMetadata.php?Mode=Study\u0026StudyID=ST001393"}, {"dataset_uid": "200378", "doi": "10.26008/1912/bco-dmo.913655.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Physical Profiles of Temperature, Salinity, and Brine Volume", "url": "https://www.bco-dmo.org/dataset/913655"}, {"dataset_uid": "200377", "doi": "10.26008/1912/bco-dmo.913222.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Photosynthetic Pigments", "url": "https://www.bco-dmo.org/dataset/913222"}, {"dataset_uid": "200376", "doi": "10.26008/1912/bco-dmo.913566.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Particulate Organic Carbon and Particulate Nitrogen", "url": "https://www.bco-dmo.org/dataset/913566"}], "date_created": "Tue, 23 Jul 2019 00:00:00 GMT", "description": "Rapid changes in the extent and thickness of sea ice during the austral spring subject microorganisms within or attached to the ice to large fluctuations in temperature, salinity, light and nutrients. This project aims to identify cellular responses in sea-ice algae to increasing temperature and decreasing salinity during the spring melt along the western Antarctic Peninsula and to determine how associated changes at the cellular level can potentially affect dynamic, biologically driven processes. Understanding how sea-ice algae cope with, and are adapted to, their environment will not only help predict how polar ecosystems may change as the extent and thickness of sea ice change, but will also provide a better understanding of the widespread success of photosynthetic life on Earth. The scientific context and resulting advances from the research will be communicated to the general public through outreach activities that includes work with Science Communication Fellows and the popular Polar Science Weekend at the Pacific Science Center in Seattle, Washington. The project will provide student training to college students as well as provide for educational experiences for K-12 school children. There is currently a poor understanding of feedback relationships that exist between the rapidly changing environment in the western Antarctic Peninsula region and sea-ice algal production. The large shifts in temperature and salinity that algae experience during the spring melt affect critical cellular processes, including rates of enzyme-catalyzed reactions involved in photosynthesis and respiration, and the production of stress-protective compounds. These changes in cellular processes are poorly constrained but can be large and may have impacts on local ecosystem productivity and biogeochemical cycles. In particular, this study will focus on the thermal sensitivity of enzymes and the cycling of compatible solutes and exopolymers used for halo- and cryo-protection, and how they influence primary production and the biogeochemical cycling of carbon and nitrogen. Approaches will include field sampling during spring melt, incubation experiments of natural sea-ice communities under variable temperature and salinity conditions, and controlled manipulation of sea-ice algal species in laboratory culture. Employment of a range of techniques, from fast repetition rate fluorometry and gross and net photosynthetic measurements to metabolomics and enzyme kinetics, will tease apart the mechanistic effects of temperature and salinity on cell metabolism and primary production with the goal of quantifying how these changes will impact biogeochemical processes along the western Antarctic Peninsula. 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": -64.2, "geometry": "POINT(-64.3 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; SHIPS; DIATOMS; Antarctic Peninsula", "locations": "Antarctic Peninsula", "north": -64.2, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Young, Jodi; Deming, Jody", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "Metabolomics workbench", "repositories": "BCO-DMO; Metabolomics workbench", "science_programs": null, "south": -64.8, "title": "Spring Blooms of Sea Ice Algae Along the Western Antarctic Peninsula: Effects of Warming and Freshening on Cell Physiology and Biogeochemical Cycles.", "uid": "p0010039", "west": -64.4}, {"awards": "1543229 Severinghaus, Jeffrey; 1543267 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": "Multi-site ice core Krypton stable isotope ratios; Noble Gas Data from recent ice in Antarctica for 86Kr problem", "datasets": [{"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.; Baggenstos, Daniel; Mosley-Thompson, Ellen; Etheridge, David; Buizert, Christo; Bereiter, Bernhard; Bertler, Nancy; Pyne, Rebecca L.; Brook, Edward J.; Shackleton, Sarah; Mulvaney, Robert", "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"}, {"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; Mulvaney, Robert; Brook, Edward J.; Baggenstos, Daniel; Pyne, Rebecca L.; Buizert, Christo; Bereiter, Bernhard; Bertler, Nancy; Severinghaus, Jeffrey P.; Mosley-Thompson, Ellen; Shackleton, Sarah", "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": "601195", "doi": "10.15784/601195", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Krypton; Noble Gas; Xenon", "people": "Shackleton, Sarah; Severinghaus, Jeffrey P.", "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": "Bereiter, Bernhard; Mosley-Thompson, Ellen; Mulvaney, Robert; Pyne, Rebecca L.; Bertler, Nancy; Etheridge, David; Baggenstos, Daniel; Brook, Edward J.; Severinghaus, Jeffrey P.; Shackleton, Sarah; Buizert, Christo", "repository": "USAP-DC", "science_program": "SPICEcore", "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": "1745053 Salvatore, Mark; 1744849 Sokol, Eric; 1744785 Barrett, John", "bounds_geometry": "POLYGON((162.92 -77.56,162.971 -77.56,163.022 -77.56,163.073 -77.56,163.124 -77.56,163.175 -77.56,163.226 -77.56,163.277 -77.56,163.328 -77.56,163.379 -77.56,163.43 -77.56,163.43 -77.571,163.43 -77.582,163.43 -77.593,163.43 -77.604,163.43 -77.615,163.43 -77.626,163.43 -77.637,163.43 -77.648,163.43 -77.659,163.43 -77.67,163.379 -77.67,163.328 -77.67,163.277 -77.67,163.226 -77.67,163.175 -77.67,163.124 -77.67,163.073 -77.67,163.022 -77.67,162.971 -77.67,162.92 -77.67,162.92 -77.659,162.92 -77.648,162.92 -77.637,162.92 -77.626,162.92 -77.615,162.92 -77.604,162.92 -77.593,162.92 -77.582,162.92 -77.571,162.92 -77.56))", "dataset_titles": "McMurdo Dry Valleys LTER: Microbial mat biomass and Normalized Difference Vegetation Index (NDVI) values from Lake Fryxell Basin, Antarctica, January 2018", "datasets": [{"dataset_uid": "200344", "doi": "10.6073/pasta/9acbbde9abc1e013f8c9fd9c383327f4", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "McMurdo Dry Valleys LTER: Microbial mat biomass and Normalized Difference Vegetation Index (NDVI) values from Lake Fryxell Basin, Antarctica, January 2018", "url": "https://portal.edirepository.org/nis/mapbrowse?packageid=knb-lter-mcm.263.1"}], "date_created": "Wed, 03 Jul 2019 00:00:00 GMT", "description": "Microbial mats are found throughout the McMurdo Dry Valleys where summer snowmelt provides liquid water that allows these mats to flourish. Researchers have long studied the environmental conditions microbial mats need to grow. Despite these efforts, it has been difficult to develop a broad picture of these unique ecosystems. Recent advances in satellite technology now provide researchers an exciting new tool to study these special Antarctic ecosystems from space using the unique spectral signatures associated with microbial mats. This new technology not only offers the promise that microbial mats can be mapped and studied from space, this research will also help protect these delicate environments from potentially harmful human impacts that can occur when studying them from the ground. This project will use satellite imagery and spectroscopic techniques to identify and map microbial mat communities and relate their properties and distributions to both field and lab-based measurements. This research provides an exciting new tool to help document and understand the distribution of a major component of the Antarctic ecosystem in the McMurdo Dry Valleys. The goal of this project is to establish quantitative relationships between spectral signatures derived from orbit and the physiological status and biogeochemical properties of microbial mat communities in Taylor Valley, Antarctica, as measured by field and laboratory analyses on collected samples. The goal wioll be met by (1) refining atmospheric correction techniques using in situ radiometric rectification to derive accurate surface spectra; (2) collecting multispectral orbital images concurrent with in situ sampling and spectral measurements in the field to ensure temporal comparability; (3) measuring sediment, water, and microbial mat samples for organic and inorganic carbon content, essential biogeochemical nutrients, and chlorophyll-a to determine relevant mat characteristics; and (4) quantitatively associating these laboratory-derived characteristics with field-derived and orbital spectral signatures and parameters. The result of this work will be a more robust quantitative link between the distribution of microbial mat communities and their biogeochemical properties to landscape-scale spectral signatures. 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": 163.43, "geometry": "POINT(163.175 -77.615)", "instruments": null, "is_usap_dc": true, "keywords": "RIVERS/STREAM; CYANOBACTERIA (BLUE-GREEN ALGAE); USAP-DC; Taylor Valley; INFRARED IMAGERY; WORLDVIEW-2; WORLDVIEW-3; Antarctica; FIELD INVESTIGATION; Amd/Us; ACTIVE LAYER", "locations": "Antarctica; Taylor Valley", "north": -77.56, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Salvatore, Mark; Barrett, John; Sokol, Eric", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e WORLDVIEW \u003e WORLDVIEW-2; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e WORLDVIEW \u003e WORLDVIEW-3", "repo": "EDI", "repositories": "EDI", "science_programs": null, "south": -77.67, "title": "COLLABORATIVE RESEARCH: Remote Characterization of Microbial Mats in Taylor Valley, Antarctica, through In Situ Sampling and Spectral Validation", "uid": "p0010036", "west": 162.92}, {"awards": "1443677 Padman, Laurence; 1443534 Bell, Robin; 1443497 Siddoway, Christine; 1443498 Fricker, Helen", "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": "601235", "doi": "10.15784/601235", "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "people": "Erofeeva, Svetlana; Padman, Laurence; Howard, Susan L.", "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": "601788", "doi": null, "keywords": "Antarctica; Cryosphere; Ross Ice Shelf", "people": "Dhakal, Tejendra; Bertinato, Christopher; Boghosian, Alexandra; Locke, Caitlin; 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": "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"}, {"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": "601794", "doi": null, "keywords": "Antarctica; Cryosphere; Remote Sensing; Ross Ice Shelf", "people": "Dong, LingLing; Packard, Sarah; Spergel, Julian; Cordero, Isabel; Frearson, Nicholas; Dhakal, Tejendra; Bertinato, Christopher; Chu, Winnie; Wearing, Martin; Keeshin, Skye; Bell, Robin; Das, Indrani", "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": "Frearson, Nicholas; Dhakal, Tejendra; Bertinato, Christopher; Millstein, Joanna; Wilner, Joel; Dong, LingLing; Das, Indrani; Spergel, Julian; Chu, Winnie; Bell, Robin; Cordero, Isabel", "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": "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": "Cordero, Isabel; Tinto, Kirsty; Siegfried, Matthew; Frearson, Nicholas; Mosbeux, Cyrille; Siddoway, Christine; Hulbe, Christina; Fricker, Helen; Bell, Robin; Padman, Laurence; Das, Indrani; Dhakal, Tejendra", "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"}], "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 Integrated System Science; Antarctic Glaciology; 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": "1341717 Ackley, Stephen; 1341513 Maksym, Edward; 1341606 Stammerjohn, Sharon; 1543483 Sedwick, Peter; 1341725 Guest, Peter", "bounds_geometry": "POLYGON((-180 -55,-177 -55,-174 -55,-171 -55,-168 -55,-165 -55,-162 -55,-159 -55,-156 -55,-153 -55,-150 -55,-150 -57.3,-150 -59.6,-150 -61.9,-150 -64.2,-150 -66.5,-150 -68.8,-150 -71.1,-150 -73.4,-150 -75.7,-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 -75.7,160 -73.4,160 -71.1,160 -68.8,160 -66.5,160 -64.2,160 -61.9,160 -59.6,160 -57.3,160 -55,162 -55,164 -55,166 -55,168 -55,170 -55,172 -55,174 -55,176 -55,178 -55,-180 -55))", "dataset_titles": "ASPeCt Visual Ice Observations on PIPERS Cruise NBP1704 April-June 2017; Expedition data of NBP1704; Impact of Convective Processes and Sea Ice Formation on the Distribution of Iron in the Ross Sea: Closing the Seasonal Cycle; NBP1704 CTD sensor data; NBP1704 Expedition Data; PIPERS Airborne LiDAR Data; PIPERS Meteorology Rawinsonde Data; PIPERS Meteorology Time Series; PIPERS Noble Gases; Sea Ice Layer Cakes, PIPERS 2017; SUMO unmanned aerial system (UAS) atmospheric data", "datasets": [{"dataset_uid": "601191", "doi": "10.15784/601191", "keywords": "Air Temperature; Antarctica; Atmosphere; Meteorology; NBP1704; PIPERS; R/v Nathaniel B. Palmer; Southern Ocean; Temperature Profiles; UAV; Unmanned Aircraft", "people": "Cassano, John", "repository": "USAP-DC", "science_program": null, "title": "SUMO unmanned aerial system (UAS) atmospheric data", "url": "https://www.usap-dc.org/view/dataset/601191"}, {"dataset_uid": "601188", "doi": "10.15784/601188", "keywords": "Aerogeophysics; Airborne Laser Altimetry; Antarctica; LIDAR; PIPERS; Ross Sea; Sea Ice", "people": "Dhakal, Tejendra; Bertinato, Christopher; Xie, Hongjie; Bell, Robin; Locke, Caitlin", "repository": "USAP-DC", "science_program": null, "title": "PIPERS Airborne LiDAR Data", "url": "https://www.usap-dc.org/view/dataset/601188"}, {"dataset_uid": "601185", "doi": "10.15784/601185 ", "keywords": "Air Temperature; Antarctica; Atmosphere; Atmospheric Surface Winds; Meteorology; NBP1704; PIPERS; Pressure; Radiosonde; Rawinsonde; Relative Humidity; Ross Sea; R/v Nathaniel B. Palmer; Wind Direction; Wind Speed", "people": "Guest, Peter", "repository": "USAP-DC", "science_program": null, "title": "PIPERS Meteorology Rawinsonde Data", "url": "https://www.usap-dc.org/view/dataset/601185"}, {"dataset_uid": "200150", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Impact of Convective Processes and Sea Ice Formation on the Distribution of Iron in the Ross Sea: Closing the Seasonal Cycle", "url": "https://www.bco-dmo.org/project/815403"}, {"dataset_uid": "601183", "doi": "10.15784/601183", "keywords": "Antarctica; Glaciology; Ice Concentration; Ice Thickness; Ice Type; NBP1704; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Sea Ice; Snow Depth; Snow/ice; Snow/Ice; Visual Observations", "people": "Ackley, Stephen", "repository": "USAP-DC", "science_program": null, "title": "ASPeCt Visual Ice Observations on PIPERS Cruise NBP1704 April-June 2017", "url": "https://www.usap-dc.org/view/dataset/601183"}, {"dataset_uid": "601207", "doi": "10.15784/601207", "keywords": "Antarctica; Digital Elevation Model; Glaciology; Ice; Ice Thickness; Ice Thickness Distribution; LIDAR; NBP1704; PIPERS; Ross Sea; R/v Nathaniel B. Palmer; Sea Ice; Snow; Snow Depth; Surface Elevation", "people": "Mei, M. Jeffrey; Maksym, Edward; Jeffrey Mei, M.", "repository": "USAP-DC", "science_program": null, "title": "Sea Ice Layer Cakes, PIPERS 2017", "url": "https://www.usap-dc.org/view/dataset/601207"}, {"dataset_uid": "002663", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1704", "url": "https://www.rvdata.us/search/cruise/NBP1704"}, {"dataset_uid": "601609", "doi": "10.15784/601609", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Mass Spectrometer; NBP1704; Noble Gas; Oceans; Ross Sea; R/v Nathaniel B. Palmer", "people": "Loose, Brice", "repository": "USAP-DC", "science_program": null, "title": "PIPERS Noble Gases", "url": "https://www.usap-dc.org/view/dataset/601609"}, {"dataset_uid": "001363", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1704 Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1704"}, {"dataset_uid": "601422", "doi": "10.15784/601422", "keywords": "Antarctica; CTD; CTD Data; NBP1704; Ocean Profile Data; Ross Sea; R/v Nathaniel B. Palmer; Salinity; Temperature", "people": "Stammerjohn, Sharon", "repository": "USAP-DC", "science_program": null, "title": "NBP1704 CTD sensor data", "url": "https://www.usap-dc.org/view/dataset/601422"}, {"dataset_uid": "601184", "doi": "10.15784/601184 ", "keywords": "Air Temperature; Antarctica; Atmosphere; Meteorology; Near-Surface Air Temperatures; PIPERS; Radiation; Sea Ice Temperatures; Temperature; Weather Station Data; Wind Direction; Wind Speed", "people": "Guest, Peter", "repository": "USAP-DC", "science_program": null, "title": "PIPERS Meteorology Time Series", "url": "https://www.usap-dc.org/view/dataset/601184"}], "date_created": "Mon, 10 Jun 2019 00:00:00 GMT", "description": "Proposal Title: Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica (working title changed from submitted title) Institutions: UT-San Antonio; Columbia University; Naval Postgraduate School; Woods Hole Oceanographic Institute; UC@Boulder The one place on Earth consistently showing increases in sea ice area, duration, and concentration is the Ross Sea in Antarctica. Satellite imagery shows about half of the Ross Sea increases are associated with changes in the austral fall, when the new sea ice is forming. The most pronounced changes are also located near polynyas, which are areas of open ocean surrounded by sea ice. To understand the processes driving the sea ice increase, and to determine if the increase in sea ice area is also accompanied by a change in ice thickness, this project will conduct an oceanographic cruise to the polynyas of the Ross Sea in April and May, 2017, which is the austral fall. The team will deploy state of the art research tools including unmanned airborne systems (UASs, commonly called drones), autonomous underwater vehicles (AUVs), and remotely operated underwater vehicles (ROVs). Using these tools and others, the team will study atmospheric, oceanic, and sea ice properties and processes concurrently. A change in sea ice production will necessarily change the ocean water below, which may have significant consequences for global ocean circulation patterns, a topic of international importance. All the involved institutions will be training students, and all share the goal of expanding climate literacy in the US, emphasizing the role high latitudes play in the Earth\u0027s dynamic climate. The main goal of the project is to improve estimates of sea ice production and water mass transformation in the Ross Sea. The team will fully capture the spatial and temporal changes in air-ice-ocean interactions when they are initiated in the austral fall, and then track the changes into the winter and spring using ice buoys, and airborne mapping with the newly commissioned IcePod instrument system, which is deployed on the US Antarctic Program\u0027s LC-130 fleet. The oceanographic cruise will include stations in and outside of both the Terra Nova Bay and Ross Ice Shelf polynyas. Measurements to be made include air-sea boundary layer fluxes of heat, freshwater, and trace gases, radiation, and meteorology in the air; ice formation processes, ice thickness, snow depth, mass balance, and ice drift within the sea ice zone; and temperature, salinity, and momentum in the ocean below. Following collection of the field data, the team will improve both model parameterizations of air-sea-ice interactions and remote sensing algorithms. Model parameterizations are needed to determine if sea-ice production has increased in crucial areas, and if so, why (e.g., stronger winds or fresher oceans). The remote sensing validation will facilitate change detection over wider areas and verify model predictions over time. Accordingly this project will contribute to the international Southern Ocean Observing System (SOOS) goal of measuring essential climate variables continuously to monitor the state of the ocean and ice cover into the future.", "east": -150.0, "geometry": "POINT(-175 -66.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LIDAR; 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; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e XBT; 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": "OCEAN MIXED LAYER; TRACE ELEMENTS; CARBON DIOXIDE; ATMOSPHERIC RADIATION; ICE GROWTH/MELT; AMD; BOUNDARY LAYER TEMPERATURE; SULFUR COMPOUNDS; NBP1704; HEAT FLUX; ICE DEPTH/THICKNESS; R/V NBP; USA/NSF; BOUNDARY LAYER WINDS; SNOW DEPTH; VERTICAL PROFILES; METHANE; POLYNYAS; CONDUCTIVITY; SEA ICE; Ross Sea; WATER MASSES; TURBULENCE; USAP-DC; Amd/Us", "locations": "Ross Sea", "north": -55.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Ackley, Stephen; Bell, Robin; Weissling, Blake; Nuss, Wendell; Maksym, Edward; Stammerjohn, Sharon; Cassano, John; Guest, Peter; Sedwick, Peter; Xie, Hongjie", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "BCO-DMO; R2R; USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica", "uid": "p0010032", "west": 160.0}, {"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": "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": "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"}], "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": "R2R", "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": "1637708 Gooseff, Michael", "bounds_geometry": "POLYGON((160 -77.25,160.5 -77.25,161 -77.25,161.5 -77.25,162 -77.25,162.5 -77.25,163 -77.25,163.5 -77.25,164 -77.25,164.5 -77.25,165 -77.25,165 -77.375,165 -77.5,165 -77.625,165 -77.75,165 -77.875,165 -78,165 -78.125,165 -78.25,165 -78.375,165 -78.5,164.5 -78.5,164 -78.5,163.5 -78.5,163 -78.5,162.5 -78.5,162 -78.5,161.5 -78.5,161 -78.5,160.5 -78.5,160 -78.5,160 -78.375,160 -78.25,160 -78.125,160 -78,160 -77.875,160 -77.75,160 -77.625,160 -77.5,160 -77.375,160 -77.25))", "dataset_titles": "EDI Data Portal: McMurdo Dry Valleys LTER; McMurdo Dry Valleys LTER Data Repository", "datasets": [{"dataset_uid": "200036", "doi": "", "keywords": null, "people": null, "repository": "LTER", "science_program": null, "title": "McMurdo Dry Valleys LTER Data Repository", "url": "http://mcm.lternet.edu/power-search/data-set"}, {"dataset_uid": "200037", "doi": "", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "EDI Data Portal: McMurdo Dry Valleys LTER", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=MCM"}], "date_created": "Fri, 31 May 2019 00:00:00 GMT", "description": "The McMurdo Dry Valleys, Antarctica, are a mosaic of terrestrial and aquatic ecosystems in a cold desert. The McMurdo Long Term Ecological Research (LTER) project has been observing these ecosystems since 1993 and this award will support key long-term measurements, manipulation experiments, synthesis, and modeling to test current theories on ecosystem structure and function. Data collection is focused on meteorology and physical and biological dimensions of soils, streams, lakes, glaciers, and permafrost. The long-term measurements show that biological communities have adapted to the seasonally cold, dark, and arid conditions that prevail for all but a short period in the austral summer. Physical (climate and geological) drivers impart a dynamic connectivity among portions of the Dry Valley landscape over seasonal to millennial time scales. For instance, lakes and soils have been connected through cycles of lake-level rise and fall over the past 20,000 years while streams connect glaciers to lakes over seasonal time scales. Overlaid upon this physical system are biotic communities that are structured by the environment and by the movement of individual organisms within and between the glaciers, streams, lakes, and soils. The new work to be conducted at the McMurdo LTER site will explore how the layers of connectivity in the McMurdo Dry Valleys influence ecosystem structure and function. This project will test the hypothesis that increased ecological connectivity following enhanced melt conditions within the McMurdo Dry Valleys ecosystem will amplify exchange of biota, energy, and matter, homogenizing ecosystem structure and functioning. This hypothesis will be tested with new and continuing experiments that examine: 1) how climate variation alters connectivity among landscape units, and 2) how biota are connected across a heterogeneous landscape using state-of-the-science tools and methods including automated sensor networks, analysis of seasonal satellite imagery, biogeochemical analyses, and next-generation sequencing. McMurdo LTER education programs and outreach activities will be continued, and expanded with new programs associated with the 200th anniversary of the first recorded sightings of Antarctica. These activities will advance societal understanding of how polar ecosystems respond to change. McMurdo 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 lead the development of international environmental stewardship protocols for human activities in the region.", "east": 165.0, "geometry": "POINT(162.5 -77.875)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; NOT APPLICABLE; Antarctica; RIVERS/STREAM; USAP-DC; TERRESTRIAL ECOSYSTEMS; LAKE/POND; Polar", "locations": "Antarctica; Polar", "north": -77.25, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Gooseff, Michael N.; Takacs-Vesbach, Cristina; Howkins, Adrian; McKnight, Diane; Doran, Peter; Adams, Byron; Barrett, John; Morgan-Kiss, Rachael; Priscu, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "LTER", "repositories": "EDI; LTER", "science_programs": "LTER", "south": -78.5, "title": "LTER: Ecosystem Response to Amplified Landscape Connectivity in the McMurdo Dry Valleys, Antarctica", "uid": "p0010031", "west": 160.0}, {"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": "Schoof, Christian; DeConto, Robert; Das, Indrani; Bell, Robin; Banwell, Alison; Lenaerts, Jan; Trusel, Luke; Kingslake, Jonathan; Tedesco, Marco", "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": "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": "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"}, {"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": "001885", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "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": "1443733 Winsor, Peter; 1443680 Smith, Craig; 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": "601193", "doi": "10.15784/601193", "keywords": "Antarctica; Geochronology; Grain Size; LMG1510; NBP1603; Sediment; Sediment Core Data", "people": "Nittrouer, Charles; Eidam, Emily; Smith, Craig; Homolka, Khadijah", "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": "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"}, {"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": "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": "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": "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": "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": "601158", "doi": "10.15784/601158", "keywords": "Antarctica; Antarctic Peninsula; Biota; Ecology; Fjord; Phytoplankton", "people": "Manck, Lauren; Vernet, Maria; Pan, B. Jack; Forsch, Kiefer", "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": "001366", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "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"}], "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": "USAP-DC", "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": "1443394 Pollard, David; 1443347 Condron, Alan", "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": "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"}, {"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"}], "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": "1341612 Bowser, Samuel", "bounds_geometry": null, "dataset_titles": "Aerial survey of Explorers Cove shoreline, late January 2005; Astrammina rara genome sequencing and assembly; Astrammina triangularis genome sequencing and assembly; Crithionina delacai mitochondrial genome sequence and assembly; Scanning electron micrographs: Influence of heavy metal (Pb, Cd) exposure on shell morphogenesis in Astrammina rara, a giant agglutinated Antarctic foraminiferan protist", "datasets": [{"dataset_uid": "601229", "doi": "10.15784/601229", "keywords": "Aerial Imagery; Antarctica; Camera; Delta; Freshwater; Helicopter; Moat; Shoreline Survey; Small Ponds; Snow Melt; Tide Pools", "people": "Bowser, Samuel; Alexander, Steve", "repository": "USAP-DC", "science_program": null, "title": "Aerial survey of Explorers Cove shoreline, late January 2005", "url": "https://www.usap-dc.org/view/dataset/601229"}, {"dataset_uid": "200089", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Astrammina triangularis genome sequencing and assembly", "url": "https://dataview.ncbi.nlm.nih.gov/object/PRJNA521279?reviewer=g418tpq02sif2g6do94dpmmjdv"}, {"dataset_uid": "601138", "doi": "10.15784/601138", "keywords": "Antarctica; Biota; Foraminifera; Heavy Metal Toxicity; Scanning Electron Microscop; Scanning Electron Microscope (SEM) Images; Scanning Electron Microscopy; Transantarctic Mountains", "people": "Bowser, Samuel; Andreas, Amanda", "repository": "USAP-DC", "science_program": null, "title": "Scanning electron micrographs: Influence of heavy metal (Pb, Cd) exposure on shell morphogenesis in Astrammina rara, a giant agglutinated Antarctic foraminiferan protist", "url": "https://www.usap-dc.org/view/dataset/601138"}, {"dataset_uid": "200090", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Astrammina rara genome sequencing and assembly", "url": "https://dataview.ncbi.nlm.nih.gov/object/PRJNA521081?reviewer=25e190ih1svottjkrrpfa7huoe"}, {"dataset_uid": "200091", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Crithionina delacai mitochondrial genome sequence and assembly", "url": "https://dataview.ncbi.nlm.nih.gov/object/PRJNA592714?reviewer=ivse8455h3gfaiilg4nqle0vm1"}], "date_created": "Thu, 29 Nov 2018 00:00:00 GMT", "description": "Agglutinated foraminifera (forams for short) are early-evolving, single-celled organisms. These \"living fossils\" construct protective shells using sediment grains held together by adhesive substances that they secrete. During shell construction, agglutinated forams display amazing properties of selection - for example, some species build their shells of clear quartz grains, while other species use only grains of a specific size. Understanding how these single cells assemble complex structures may contribute to nanotechnology by enabling people to use forams as \"cellular machines\" to aid in the construction of nano-devices. This project will analyze the genomes of at least six key foram species, and then \"mine\" these genomes for technologically useful products and processes. The project will focus initially on the adhesive materials forams secrete, which may have wide application in biomedicine and biotechnology. Furthermore, the work will further develop a molecular toolkit which could open up new avenues of research on the physiology, ecology, and population dynamics of this important group of Antarctic organisms. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. Educational experiences related to the \"thrill of scientific exploration and discovery\" for students and the general public will be provided through freely-available short films and a traveling art/science exhibition. The project will also provide hands-on research opportunities for undergraduate students. Explorers Cove, situated on the western shore of McMurdo Sound, harbors a unique population of foraminiferan taxa at depths accessible by scuba diving that otherwise are primarily found in the deep sea. The project will use next-generation DNA sequencing and microdissection methods to obtain and analyze nuclear and mitochondrial genomes from crown members of two species each from three distinct, early-evolving foraminiferal groups. It will also use next generation sequencing methods to characterize the in-situ prokaryotic assemblages (microbiomes) of one of these groups and compare them to reference sediment microbiomes. The phyogenomic studies of the targeted Antarctic genera will help fill significant gaps in our current understanding of early foram evolution. Furthermore, comparative genomic analyses of these six species are expected to yield a better understanding of the physiology of single-chambered agglutinated forams, especially the bioadhesive proteins and regulatory factors involved in shell composition and morphogenesis. Additionally, the molecular basis of cold adaptation in forams will be examined, particularly with respect to key proteins.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; NOT APPLICABLE", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Bowser, Samuel", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "NCBI GenBank; USAP-DC", "science_programs": null, "south": null, "title": "Assembling and Mining the Genomes of Giant Antarctic Foraminifera", "uid": "p0000004", "west": null}, {"awards": "1144177 Pettit, Erin; 1144176 Lyons, W. Berry; 1144192 Tulaczyk, Slawek; 1727387 Mikucki, Jill", "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": "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": "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": "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": "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": "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": "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": "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/"}, {"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": "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": "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"}], "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": "1443306 Mayewski, Paul; 1443263 Higgins, John", "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": "Higgins, John; Yan, Yuzhen; Bender, Michael; Brook, Edward J.", "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": "601425", "doi": "10.15784/601425", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Ice Core; Methane", "people": "Yan, Yuzhen; Brook, Edward J.", "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": "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": "Ng, Jessica; Severinghaus, Jeffrey P.; Yan, Yuzhen; Bender, Michael; Higgins, John", "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": "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.; Yan, Yuzhen; Introne, Douglas; Mayewski, Paul A.", "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": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Mayewski, Paul A.; Introne, Douglas; Severinghaus, Jeffrey P.; Kurbatov, Andrei V.; Higgins, John; Brook, Edward", "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": "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; Mayewski, Paul A.; Kurbatov, Andrei V.; 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": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Higgins, John; Introne, Douglas; Brook, Edward; Mayewski, Paul A.; Severinghaus, Jeffrey P.; 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": "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": "Introne, Douglas; Kurbatov, Andrei V.; Yan, Yuzhen; Mayewski, Paul A.", "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": "601483", "doi": "10.15784/601483", "keywords": "Allan Hills; Antarctica; Argon; Ice; Ice Core Data; Ice Core Gas Records; Isotope; Mass Spectrometry; Nitrogen; Oxygen", "people": "Yan, Yuzhen; Bender, Michael; Higgins, John", "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": "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": "Yan, Yuzhen; Bender, Michael; Brook, Edward J.; 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"}, {"dataset_uid": "601512", "doi": "10.15784/601512", "keywords": "Allan Hills; Antarctica; Blue Ice; Ice Core; Ice Core Gas Records; Isotope; Nitrogen; Oxygen", "people": "Bender, Michael; Yan, Yuzhen; Higgins, John", "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"}], "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": "0839142 Tulaczyk, Slawek; 0839059 Powell, Ross; 0838764 Anandakrishnan, Sridhar; 0838947 Tulaczyk, Slawek; 0838855 Jacobel, Robert; 0838763 Anandakrishnan, Sridhar; 0839107 Powell, Ross", "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": "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": "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": "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; Coenen, Jason; Askin, Rosemary; Casta\u00f1eda, Isla", "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": "601245", "doi": "10.15784/601245", "keywords": "Antarctica; Pollen; West Antarctica; WISSARD", "people": "Baudoin, Patrick; Coenen, Jason; Warny, Sophie; Askin, Rosemary; Scherer, Reed Paul; Casta\u00f1eda, Isla", "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": "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": "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": "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"}, {"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": "000148", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IRIS ID#s 201035, 201162, 201205", "url": "http://ds.iris.edu/"}], "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": "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": "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"}, {"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": "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": "Banwell, Alison; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "McMurdo Ice Shelf AWS data", "url": "https://www.usap-dc.org/view/dataset/601106"}, {"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"}], "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": "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": "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": "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"}, {"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"}], "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": "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": "Riverman, Kiya; Stearns, Leigh; 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": "Simkins, Lauren; Prothro, Lindsay; Anderson, John; Greenwood, Sarah; Eareckson, Elizabeth; Munevar Garcia, Santiago", "repository": "USAP-DC", "science_program": null, "title": "Pennell Trough, Ross Sea bathymetry and glacial landforms", "url": "https://www.usap-dc.org/view/dataset/601474"}, {"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"}], "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": "0732711 Smith, Craig; 0732625 Leventer, Amy; 0732655 Mosley-Thompson, Ellen; 0732602 Truffer, Martin; 0732651 Gordon, Arnold; 0732983 Vernet, Maria", "bounds_geometry": "POLYGON((-68 -57.8,-66.78 -57.8,-65.56 -57.8,-64.34 -57.8,-63.12 -57.8,-61.9 -57.8,-60.68 -57.8,-59.46 -57.8,-58.24 -57.8,-57.02 -57.8,-55.8 -57.8,-55.8 -58.8,-55.8 -59.8,-55.8 -60.8,-55.8 -61.8,-55.8 -62.8,-55.8 -63.8,-55.8 -64.8,-55.8 -65.8,-55.8 -66.8,-55.8 -67.8,-57.02 -67.8,-58.24 -67.8,-59.46 -67.8,-60.68 -67.8,-61.9 -67.8,-63.12 -67.8,-64.34 -67.8,-65.56 -67.8,-66.78 -67.8,-68 -67.8,-68 -66.8,-68 -65.8,-68 -64.8,-68 -63.8,-68 -62.8,-68 -61.8,-68 -60.8,-68 -59.8,-68 -58.8,-68 -57.8))", "dataset_titles": "Abrupt Environmental Change in the Larsen Ice Shelf System (LARISSA) - Marine Ecosystems; Biology Species Abundance from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expeditions NBP1001 and NBP1203; Bruce Plateau Accumulation O18 2009-1900; Easten Antarctic Peninsula Surface Sediment Diatom Data; LMG13-11 JKC-1 Paleoceanographic data; Macrofauna Species Abundance Raw Data from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expedition NBP1001; Megafauna Species Abundance Raw Data from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expedition NBP1001; NBP1001 cruise data; NBP1203 cruise data; Processed CTD Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001; Processed CTD Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203; Processed ship-based LADCP Sonar 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 near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203; Radioisotope data (C-14 and Pb-210) from bulk sediments, Larsen A Ice Shelf; Sediment samples (full data link not provided)", "datasets": [{"dataset_uid": "601306", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Biota; Box Corer; LARISSA; Larsen Ice Shelf; Macrofauna; NBP1001; Oceans; R/v Nathaniel B. Palmer; Seafloor Sampling; Species Abundance", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Macrofauna Species Abundance Raw Data from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601306"}, {"dataset_uid": "601348", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; CTD; CTD Data; LARISSA; Larsen Ice Shelf; NBP1203; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Temperature", "people": "Huber, Bruce; Gordon, Arnold", "repository": "USAP-DC", "science_program": null, "title": "Processed CTD Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601348"}, {"dataset_uid": "000226", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Biology Species Abundance from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expeditions NBP1001 and NBP1203", "url": "https://doi.org/10.1594/ieda/320821"}, {"dataset_uid": "600073", "doi": "10.15784/600073", "keywords": "Antarctica; Antarctic Peninsula; Araon1304; Biota; LARISSA; Larsen B Ice Shelf; NBP1001; NBP1203; Oceans; Physical Oceanography; Southern Ocean; Weddell Sea", "people": "Vernet, Maria", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Abrupt Environmental Change in the Larsen Ice Shelf System (LARISSA) - Marine Ecosystems", "url": "https://www.usap-dc.org/view/dataset/600073"}, {"dataset_uid": "600167", "doi": "10.15784/600167", "keywords": "Antarctica; Antarctic Peninsula; Bruce Plateau; Glaciology; Ice Core Records; Isotope; LARISSA; Paleoclimate; Sample/collection Description; Sample/Collection Description; Snow Accumulation", "people": "Thompson, Lonnie G.; Mosley-Thompson, Ellen", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Bruce Plateau Accumulation O18 2009-1900", "url": "https://www.usap-dc.org/view/dataset/600167"}, {"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": "601336", "doi": "10.15784/601336", "keywords": "Antarctica; Carbon-14; Larsen Ice Shelf; Lead-210; Marine Sediments; Radioisotope Analysis", "people": "Taylor, Richard; DeMaster, David", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Radioisotope data (C-14 and Pb-210) from bulk sediments, Larsen A Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601336"}, {"dataset_uid": "601211", "doi": "10.15784/601211", "keywords": "Antarctica; Antarctic Peninsula; Benthos; Biota; Diatom; Geology/Geophysics - Other; LMG0502; Marine Geoscience; Marine Sediments; Microscope; NBP0003; NBP0107; NBP0603; NBP1203; R/v Nathaniel B. Palmer; Surface Sediment", "people": "Leventer, Amy", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Easten Antarctic Peninsula Surface Sediment Diatom Data", "url": "https://www.usap-dc.org/view/dataset/601211"}, {"dataset_uid": "000145", "doi": "", "keywords": null, "people": null, "repository": "AMGRF", "science_program": null, "title": "Sediment samples (full data link not provided)", "url": "http://arf.fsu.edu/"}, {"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": "601485", "doi": "10.15784/601485", "keywords": "Antarctica; Antarctic Peninsula; Delta 13C; Delta 18O; Paleoceanography; Temperature", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": "LARISSA", "title": "LMG13-11 JKC-1 Paleoceanographic data", "url": "https://www.usap-dc.org/view/dataset/601485"}, {"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": "601347", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Current Measurements; LADCP; LARISSA; Larsen Ice Shelf; NBP1203; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601347"}, {"dataset_uid": "601305", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Biota; Box Corer; LARISSA; Larsen Ice Shelf; Macrofauna; Megafauna; NBP1001; Oceans; R/v Nathaniel B. Palmer; Seafloor Sampling; Species Abundance", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Megafauna Species Abundance Raw Data from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601305"}, {"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": "Huber, Bruce; Gordon, Arnold", "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"}], "date_created": "Thu, 01 Feb 2018 00:00:00 GMT", "description": "Like no other region on Earth, the northern Antarctic Peninsula represents a spectacular natural laboratory of climate change and provides the opportunity to study the record of past climate and ecological shifts alongside the present-day changes in one of the most rapidly warming regions on Earth. This award supports the cryospheric and oceano-graphic components of an integrated multi-disciplinary program to address these rapid and fundamental changes now taking place in Antarctic Peninsula (AP). By making use of a marine research platform (the RV NB Palmer and on-board helicopters) and additional logistical support from the Argentine Antarctic program, the project will bring glaciologists, oceanographers, marine geologists and biologists together, working collaboratively to address fundamentally interdisciplinary questions regarding climate change. The project will include gathering a new, high-resolution paleoclimate record from the Bruce Plateau of Graham Land, and using it to compare Holocene- and possibly glacial-epoch climate to the modern period; investigating the stability of the remaining Larsen Ice Shelf and rapid post-breakup glacier response ? in particular, the roles of surface melt and ice-ocean interactions in the speed-up and retreat; observing the contribution of, and response of, oceanographic systems to ice shelf disintegration and ice-glacier interactions. Helicopter support on board will allow access to a wide range of glacial and geological areas of interest adjacent to the Larsen embayment. At these locations, long-term in situ glacial monitoring, isostatic uplift, and ice flow GPS sites will be established, and high-resolution ice core records will be obtained using previously tested lightweight drilling equipment. Long-term monitoring of deep water outflow will, for the first time, be integrated into changes in ice shelf extent and thickness, bottom water formation, and multi-level circulation by linking near-source observations to distal sites of concentrated outflow. The broader impacts of this international, multidisciplinary effort are that it will significantly advance our understanding of linkages amongst the earth\u0027s systems in the Polar Regions, and are proposed with international participation (UK, Spain, Belgium, Germany and Argentina) and interdisciplinary engagement in the true spirit of the International Polar Year (IPY). It will also provide a means of engaging and educating the public in virtually all aspects of polar science and the effects of ongoing climate change. The research team has a long record of involving undergraduates in research, educating high-performing graduate students, and providing innovative and engaging outreach products to the K-12 education and public media forums. Moreover, forging the new links both in science and international Antarctic programs will provide a continuing legacy, beyond IPY, of improved understanding and cooperation in Antarctica.", "east": -55.8, "geometry": "POINT(-61.9 -62.8)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e BOX CORE; 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", "is_usap_dc": true, "keywords": "Paleoclimate; Megafauna; USAP-DC; AMD; Amd/Us; Antarctica; Climate Change; LABORATORY; Climate Variability; Multi-Disciplinary; Cryosphere; NBP1001; FIELD SURVEYS; Not provided; Antarctic Peninsula; R/V NBP; FIELD INVESTIGATION; USA/NSF; Ice Core; Holocene", "locations": "Antarctica; Antarctic Peninsula", "north": -57.8, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Truffer, Martin; Gordon, Arnold; Huber, Bruce; Mosley-Thompson, Ellen; Leventer, Amy; Vernet, Maria; Smith, Craig; Thompson, Lonnie G.", "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; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "AMGRF; MGDS; R2R; USAP-DC", "science_programs": "LARISSA", "south": -67.8, "title": "Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach -- Cryosphere and Oceans", "uid": "p0000101", "west": -68.0}, {"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": "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"}, {"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"}], "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": "1143834 Huber, Bruce; 1430550 Domack, Eugene; 1143836 Leventer, Amy; 1143833 Orsi, Alejandro", "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": "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": "Domack, Eugene Walter; Smith, Catherine; Shevenell, Amelia", "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": "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": "Leventer, Amy; Domack, Eugene Walter; Orsi, Alejandro; Post, Alexandra; Shevenell, Amelia; Blankenship, Donald D.; Huber, Bruce; Gulick, Sean", "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": "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": "Gulick, Sean; Domack, Eugene Walter; Shevenell, Amelia; Orsi, Alejandro; Huber, Bruce; Leventer, Amy; Post, Alexandra", "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": "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": "601046", "doi": "10.15784/601046", "keywords": "Antarctica; Biota; Marine Sediments; NBP1402; Oceans; Paleoclimate; Pollen; Sabrina Coast; Sediment Core; Southern Ocean; Totten Glacier", "people": "Smith, Catherine; Domack, Eugene Walter; Shevenell, Amelia", "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"}, {"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": "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": "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": "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": "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": "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": "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"}], "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": "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": "000402", "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": "001366", "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": "1246342 Fountain, Andrew; 1245749 Levy, Joseph; 1246203 Gooseff, Michael", "bounds_geometry": "POLYGON((160.105465 -77.2119,160.7907435 -77.2119,161.476022 -77.2119,162.1613005 -77.2119,162.846579 -77.2119,163.5318575 -77.2119,164.217136 -77.2119,164.9024145 -77.2119,165.587693 -77.2119,166.2729715 -77.2119,166.95825 -77.2119,166.95825 -77.3189628,166.95825 -77.4260256,166.95825 -77.5330884,166.95825 -77.6401512,166.95825 -77.747214,166.95825 -77.8542768,166.95825 -77.9613396,166.95825 -78.0684024,166.95825 -78.1754652,166.95825 -78.282528,166.2729715 -78.282528,165.587693 -78.282528,164.9024145 -78.282528,164.217136 -78.282528,163.5318575 -78.282528,162.846579 -78.282528,162.1613005 -78.282528,161.476022 -78.282528,160.7907435 -78.282528,160.105465 -78.282528,160.105465 -78.1754652,160.105465 -78.0684024,160.105465 -77.9613396,160.105465 -77.8542768,160.105465 -77.747214,160.105465 -77.6401512,160.105465 -77.5330884,160.105465 -77.4260256,160.105465 -77.3189628,160.105465 -77.2119))", "dataset_titles": "2014-2015 lidar survey of the McMurdo Dry Valleys, Antarctica; Active Layer Temperatures from Crescent Stream banks, Taylor Valley Antarctica", "datasets": [{"dataset_uid": "000209", "doi": "", "keywords": null, "people": null, "repository": "OpenTopo", "science_program": null, "title": "2014-2015 lidar survey of the McMurdo Dry Valleys, Antarctica", "url": "http://opentopo.sdsc.edu/datasetMetadata?otCollectionID=OT.112016.3294.1"}, {"dataset_uid": "601075", "doi": "10.15784/601075", "keywords": "Antarctica; Dry Valleys; Glaciology; Paleoclimate; Permafrost; Soil Temperature; Taylor Valley", "people": "Gooseff, Michael N.", "repository": "USAP-DC", "science_program": null, "title": "Active Layer Temperatures from Crescent Stream banks, Taylor Valley Antarctica", "url": "https://www.usap-dc.org/view/dataset/601075"}], "date_created": "Wed, 20 Dec 2017 00:00:00 GMT", "description": "Collaborative Research: THE MCMURDO DRY VALLEYS: A Landscape on the Threshold of Change is supported by the Antarctic Integrated System Science (AISS) program in the Antarctic Sciences Section of the Division of Polar Programs within the Geosciences Directorate of the National Sciences Foundation (NSF). The funds will support the collection of state-of-the-art high resolution LIDAR (combining the terms light and radar) imagery of the Dry Valleys of Antarctica in the 2014/2015 Antarctic field season, with LIDAR data collection and processing being provided by the NSF-supported NCALM (National Center for Airborne Laser Mapping) facility. LIDAR images collected in 2014/2015 will be compared to images from 2001 in order to detect decadal change. Additional fieldwork will look at the distribution of buried massive ice, and the impacts that major changes like slumping are having on the biota. All field data will be used to improve models on energy balance, and hydrology. Intellectual Merit: There have been dramatic changes over the past decade in the McMurdo Dry Valleys: glaciers are deflating by tens of meters, rivers are incising by more than three meters, and thermokarst slumps are appearing near several streams and lakes. These observations have all been made by researchers in the field, but none of the changes have been mapped on a valley-wide scale. This award will provide a new baseline map for the entire Dry Valley system, with high-resolution imagery provided for the valley floors, and lower resolution imagery available for the higher elevation areas that are undergoing less change. The project will test the idea that sediment-covered ice is associated with the most dramatic changes, due to differential impacts of the increased solar radiation on sediment-covered compared to clean ice, and despite the current trend of slightly cooling air temperatures within the Dry Valleys. Information collected on the topography, coupled with the GPR determined buried ice distributions, will also be incorporated into improved energy and hydrological models. In addition to providing the new high-resolution digital elevation model (DEM), the project will ultimately result in identification of areas that are susceptible to sediment-enhanced melt-driven change, providing a powerful prediction tool for the impacts of climate change. Broader Impacts: The new DEM will be immediately useful to a wide range of disciplines, and will provide a comprehensive new baseline against which future changes will be compared. The project will provide a tool for the whole community to use, and the investigators will work with the community to make them aware of the new assets via public presentations, and perhaps via a workshop. The map will have international interest, and will also serve as a tool for environmental managers to draw on as they consider conservation plans. Several undergraduate and graduate students will participate in the project, and one of the co-PIs is a new investigator. The imagery collected is expected to be of interest to the general public in addition to scientific researchers, and venues for outreach such as museum exhibits and the internet will be explored. The proposed work is synergistic with 1) the co-located McMurdo LTER program, and 2) the NCALM facility that is also funded by the Geosciences Directorate.", "east": 166.95825, "geometry": "POINT(163.5318575 -77.747214)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e AIRBORNE LASER SCANNER", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; Not provided; LANDFORMS; NOT APPLICABLE", "locations": "Antarctica", "north": -77.2119, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Levy, Joseph; Gooseff, Michael N.; Fountain, Andrew", "platforms": "Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "OpenTopo", "repositories": "OpenTopo; USAP-DC", "science_programs": null, "south": -78.282528, "title": "Collaborative Research: THE MCMURDO DRY VALLEYS: A landscape on the Threshold of Change", "uid": "p0000076", "west": 160.105465}, {"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": "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/"}, {"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"}], "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": "ICE-D", "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": "1341284 Swanger, Kate", "bounds_geometry": "POLYGON((161 -77.5,161.2 -77.5,161.4 -77.5,161.6 -77.5,161.8 -77.5,162 -77.5,162.2 -77.5,162.4 -77.5,162.6 -77.5,162.8 -77.5,163 -77.5,163 -77.525,163 -77.55,163 -77.575,163 -77.6,163 -77.625,163 -77.65,163 -77.675,163 -77.7,163 -77.725,163 -77.75,162.8 -77.75,162.6 -77.75,162.4 -77.75,162.2 -77.75,162 -77.75,161.8 -77.75,161.6 -77.75,161.4 -77.75,161.2 -77.75,161 -77.75,161 -77.725,161 -77.7,161 -77.675,161 -77.65,161 -77.625,161 -77.6,161 -77.575,161 -77.55,161 -77.525,161 -77.5))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 09 Oct 2017 00:00:00 GMT", "description": "Paragraph for Laypersons: This research focuses on the history of rock glaciers and buried glacial ice in the McMurdo Dry Valleys region of Antarctica. Rock glaciers are flowing mixtures of ice and sediments common throughout alpine and high-latitude regions on Earth and Mars. Despite similar appearances, rock glaciers can form under highly variable environmental and hydrological conditions. The main research questions addressed here are: 1) what environmental and climatological conditions foster long-term preservation of rock glaciers in Antarctica, 2) what role do rock glaciers play in Antarctic landscape evolution and the local water cycle, and 3) what can rock glaciers reveal about the extent and timing of previous glacial advances? The project will involve two Antarctic field seasons to image the interior of Antarctic rock glaciers using ground-penetrating radar, to gather ice cores for chemical analyses, and to gather surface sediments for dating. The Dry Valleys host the world?s southernmost terrestrial ecosystem (soil, stream and lake micro-organisms and mosses); rock glaciers and ground-ice are an important and poorly-studied source of meltwater and nutrients for these ecosystems. This research will shed light on the glacial and hydrological history of the Dry Valleys region and the general environmental conditions the foster rock glaciers, features that generally occur in warmer and/or wetter locations. The research will provide support for five graduate/undergraduate students, who will actively gather data in the field, followed by interpretation, dissemination and presentation of the data. Additionally, the researchers will participate in a range of educational activities including outreach with local K-12 in the Lowell, MA region, such as summer workshops and classroom visits with hands-on activities. A series of time-lapse images of hydrological processes, and videos of researchers in the field, will serve as a dramatic centerpiece in community and school presentations. Paragraph for Scientific Community: Rock glaciers are common in the McMurdo Dry Valleys, but are concentrated in a few isolated regions: western Taylor Valley, western Wright Valley, Pearse Valley and Bull Pass. The investigators hypothesize that the origin and age of these features varies by region: that rock glaciers in Pearse and Taylor valley originated as buried glacier ice, whereas rock glaciers in Wright Valley formed through permafrost processes, such as mobilization of ice-rich talus. To address these hypotheses, the project will: 1) develop relative and absolute chronologies for the rock glaciers through field mapping and optically stimulated luminescence dating of overlying sediments, 2) assess the origin of clean-ice cores through stable isotopic analyses, and 3) determine if present-day soil-moisture and temperature conditions are conducive to rock glacier formation/preservation. The proposed research will provide insight into the spatial and temporal distribution of buried glacier ice and melt-water-derived ground ice in the McMurdo Dry Valleys, with implications for glacial history, as well as the potential role of rock glaciers in the regional hydrologic cycle (and the role of ground-ice as a source for moisture and nutrient for local ecosystems). The project will provide general constraints on the climatic and hydrologic conditions that foster permafrost rock glaciers, features that generally occur under warmer and wetter conditions than those found in the present-day McMurdo Dry Valleys. The application of OSL and cosmogenic exposure dating is novel to rock glaciers, geomorphic features that have proven difficult to date, despite their ubiquity in Antarctica and their potential scientific importance. The research will provide support for five graduate/undergraduate students, who will participate in the field work, followed by interpretation, dissemination and presentation of the data. The researchers will participate in a range of educational activities including outreach with local K-12 in the Lowell, MA region, such as summer workshops and classroom visits with hands-on activities.", "east": 163.0, "geometry": "POINT(162 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Swanger, Kate", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -77.75, "title": "Origin and Climatic Significance of Rock Glaciers in the McMurdo Dry Valleys: Assessing Spatial and Temporal Variability", "uid": "p0000297", "west": 161.0}, {"awards": "1341390 Frank, Tracy", "bounds_geometry": null, "dataset_titles": "Stable carbon and oxygen isotope data from drill cores from McMurdo Sound, Antarctica", "datasets": [{"dataset_uid": "000195", "doi": "", "keywords": null, "people": null, "repository": "EarthChem", "science_program": null, "title": "Stable carbon and oxygen isotope data from drill cores from McMurdo Sound, Antarctica", "url": "http://dx.doi.org/10.1594/IEDA/100718"}], "date_created": "Fri, 06 Oct 2017 00:00:00 GMT", "description": "Intellectual Merit: This project will use sediment cores from the Victoria Land Basin (VLB), Antarctica, to study secondary (diagenetic) carbonate minerals, as indicators of the basin?s fluid-flow history, within the well-constrained tectonic, depositional, and climatic context provided by sediment cores. This study will provide insights into subsurface processes in Victoria Land Basin, Antarctica and their relationships with the region?s climatic, cryospheric, and tectonic history. The work will utilize cores previously recovered by US-sponsored stratigraphic drilling projects (CIROS, CRP, and ANDRILL projects). This work is motivated by the unexpected discovery of dense brine in the subsurface of Southern McMurdo Sound during drilling by the ANDRILL Southern McMurdo Sound project. The presence of the brine is intriguing because it contradicts previous models for the origin of subsurface fluids that called upon large contributions from glacial melt water. Project objectives involve documenting the distribution of the brine (and potentially other fluids) via characterization of diagenetic precipitates. The approach will involve integration of petrographic and geochemical data (including conventional carbon, oxygen, and ?clumped? isotopes) to fully characterize diagenetic phases and allow development of a robust paragenetic history. This work will provide novel insights into the Cenozoic evolution of the VLB and, more broadly, the role of glacial processes in generating subsurface fluids. Broader impacts: Results from this project will help understand the origins of brines, groundwater and hydrocarbon reservoirs in analogous modern and ancient deposits elsewhere, which is of broad interest. This project will support the training of one graduate and one undergraduate student at the University of Nebraska-Lincoln (UNL) providing learning opportunities in sedimentary geology and diagenesis, fields with wide applicability. This proposal emphasizes rapid dissemination of results to the scientific community via conference presentations and contributions to peer-reviewed publications. The results will be integrated into education activities designed to develop skills in petrography and diagenesis, which are highly sought after in the energy sector. The project will generate a well-constrained dataset that allows direct linkage of diagenetic phases to environmental and tectonic change across a large sedimentary basin which will provide the basis for a comprehensive case study in an upper-level course (Sedimentary Petrography and Diagenesis) at UNL. In addition, online exercises will be developed and submitted to an open-access site (SEPM Stratigraphy Web) dedicated to sedimentary geology.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Frank, Tracy; Fielding, Christopher", "platforms": "Not provided", "repo": "EarthChem", "repositories": "EarthChem", "science_programs": null, "south": null, "title": "Insights into the Burial, Tectonic, and Hydrologic History of the Cenozoic Succession in McMurdo Sound, Antarctica through Analysis of Diagenetic Phases", "uid": "p0000256", "west": null}, {"awards": "1141993 Rich, Jeremy", "bounds_geometry": "POLYGON((-60 -70,-59.3 -70,-58.6 -70,-57.9 -70,-57.2 -70,-56.5 -70,-55.8 -70,-55.1 -70,-54.4 -70,-53.7 -70,-53 -70,-53 -70.9,-53 -71.8,-53 -72.7,-53 -73.6,-53 -74.5,-53 -75.4,-53 -76.3,-53 -77.2,-53 -78.1,-53 -79,-53.7 -79,-54.4 -79,-55.1 -79,-55.8 -79,-56.5 -79,-57.2 -79,-57.9 -79,-58.6 -79,-59.3 -79,-60 -79,-60 -78.1,-60 -77.2,-60 -76.3,-60 -75.4,-60 -74.5,-60 -73.6,-60 -72.7,-60 -71.8,-60 -70.9,-60 -70))", "dataset_titles": "Seasonal Succession of Bacterial Communities in Coastal Waters of the Western Antarctic Peninsula", "datasets": [{"dataset_uid": "601032", "doi": "10.15784/601032", "keywords": "Antarctica; Antarctic Peninsula; Bacteria; Biota; Genetic; Geochemistry; Palmer Station; Sample/collection Description; Sample/Collection Description; Sea Water; Southern Ocean", "people": "Rich, Jeremy", "repository": "USAP-DC", "science_program": null, "title": "Seasonal Succession of Bacterial Communities in Coastal Waters of the Western Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601032"}], "date_created": "Thu, 15 Jun 2017 00:00:00 GMT", "description": "The Western Antarctic Peninsula (WAP) has experienced unprecedented warming and shifts in sea ice cover over the past fifty years. How these changes impact marine microbial communities, and subsequently how these shifts in the biota may affect the carbon cycle in surface waters is unknown. This work will examine how these ecosystem-level changes affect microbial community structure and function. This research will use modern metagenomic and transcriptomic approaches to test the hypothesis that the introduction of organic matter from spring phytoplankton blooms drives turnover in microbial communities. This research will characterize patterns in bacterial and archaeal succession during the transition from the austral winter at two long-term monitoring sites: Palmer Station in the north and Rothera Station in the south. This project will also include microcosm incubations to directly assess the effects of additions of organic carbon and melted sea ice on microbial community structure and function. The results of this work will provide a broader understanding of the roles of both rare and abundant microorganisms in carbon cycling within the WAP region, and how these communities may shift in structure and function in response to climate change. Results will be widely disseminated through publications as well as through presentations at national and international meetings. The research will provide training opportunities for both graduate and undergraduate students and will enhance international collaborations with the British Antarctic Survey.", "east": -53.0, "geometry": "POINT(-56.5 -74.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Rich, Jeremy", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "Collaborative Research: Microbial Community Assembly in Coastal Waters of the Western Antarctic Peninsula", "uid": "p0000409", "west": -60.0}, {"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": "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": "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"}, {"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": "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"}], "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": "1553824 Heine, John", "bounds_geometry": "POINT(166.667 -77.85)", "dataset_titles": "Rebreather Testing for the United States Antarctic Scientific Diving Program", "datasets": [{"dataset_uid": "601024", "doi": "10.15784/601024", "keywords": "Antarctica; Diving; Global; Physical Oceanography", "people": "Heine, John", "repository": "USAP-DC", "science_program": null, "title": "Rebreather Testing for the United States Antarctic Scientific Diving Program", "url": "https://www.usap-dc.org/view/dataset/601024"}], "date_created": "Fri, 26 May 2017 00:00:00 GMT", "description": "There are a number of areas of Antarctic research by scientists from the United States where rebreather technology (which unlike normal SCUBA diving releases few if any air bubbles) would be valuable tools. These include but are not limited to behavioral studies (because noise from bubbles released by standard SCUBA alters the behavior of many marine organisms), studies of communities on the underside of sea ice (because the bubbles disrupt the communities while or before they are sampled), and studies of highly stratified lake communities (because the bubbles cause mixing and because lighter line could be used to tether a diver to the surface which would probably also cause less water column disruption). The latter scientific advantage of less mixing in highly stratified (not naturally mixed) lakes is also a significant environmental advantage of rebreathers. However, for safety reasons, no US science projects will be approved for the use of rebreathers until they are tested by the US Antarctic Program (USAP). This award provides funds for the USAP Scientific Diving Officer to conduct such tests in conjunction with other diving professionals experienced in polar diving in general and specifically with rebreather technology in non-polar environments. A team of six scientific diving professionals will evaluate seven or more commercial rebreather models that are being most commonly used in non-polar scientific diving. This will be done through holes drilled or melted in sea ice at McMurdo Station, Antarctica. A limited number of test dives of the best performing models will subsequently be made in stratified lakes in the McMurdo Dry Valleys.", "east": 166.667, "geometry": "POINT(166.667 -77.85)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.85, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Heine, John", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.85, "title": "Rebreather Testing for the United States Antarctic Scientific Diving Program", "uid": "p0000377", "west": 166.667}, {"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": "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": "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": "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": "Fegyveresi, John; Alley, Richard", "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": "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": "Cuffey, Kurt M.; Clow, Gary D.", "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": "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": "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.; Fitzpatrick, Joan; Spencer, Matthew; Alley, Richard; Fegyveresi, John", "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": "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; 1043517 Clark, Peter; 1043485 Curtice, Josh", "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": "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"}, {"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"}], "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": "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": "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"}, {"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"}], "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": "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": "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"}, {"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.; Beers, Thomas M.; Kurbatov, Andrei V.", "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"}], "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": "1142156 Marschall, Horst", "bounds_geometry": "POLYGON((-6.44 -71.93,-5.378 -71.93,-4.316 -71.93,-3.254 -71.93,-2.192 -71.93,-1.13 -71.93,-0.068 -71.93,0.994 -71.93,2.056 -71.93,3.118 -71.93,4.18 -71.93,4.18 -71.998,4.18 -72.066,4.18 -72.134,4.18 -72.202,4.18 -72.27,4.18 -72.338,4.18 -72.406,4.18 -72.474,4.18 -72.542,4.18 -72.61,3.118 -72.61,2.056 -72.61,0.994 -72.61,-0.068 -72.61,-1.13 -72.61,-2.192 -72.61,-3.254 -72.61,-4.316 -72.61,-5.378 -72.61,-6.44 -72.61,-6.44 -72.542,-6.44 -72.474,-6.44 -72.406,-6.44 -72.338,-6.44 -72.27,-6.44 -72.202,-6.44 -72.134,-6.44 -72.066,-6.44 -71.998,-6.44 -71.93))", "dataset_titles": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica", "datasets": [{"dataset_uid": "600135", "doi": "10.15784/600135", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Dronning Maud Land; Geochemistry; Geochronology; Solid Earth", "people": "Marschall, Horst", "repository": "USAP-DC", "science_program": null, "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/600135"}], "date_created": "Fri, 23 Oct 2015 00:00:00 GMT", "description": "Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth?s crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica. Dronning Maud Land (DML) occupied a central location during the formation of supercontinents ? large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth?s history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007?2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML.", "east": 4.18, "geometry": "POINT(-1.13 -72.27)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -71.93, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Marschall, Horst", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.61, "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica", "uid": "p0000448", "west": -6.44}, {"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": "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": "601809", "doi": "10.15784/601809", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Mooring; Ocean Currents; Pressure; Salinity; Temperature", "people": "Jacobs, Stanley; Giulivi, Claudia F.", "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": "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": "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": "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": "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": "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": "R2R", "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": "0944254 Smith, Walker; 0944165 McGillicuddy, Dennis", "bounds_geometry": "POLYGON((168 -65,168.2 -65,168.4 -65,168.6 -65,168.8 -65,169 -65,169.2 -65,169.4 -65,169.6 -65,169.8 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,169.8 -65,169.6 -65,169.4 -65,169.2 -65,169 -65,168.8 -65,168.6 -65,168.4 -65,168.2 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65))", "dataset_titles": "Data from expdition NBP1201; Expedition Data; Project data: Processes Regulating Iron Supply at the Mesoscale - Ross Sea", "datasets": [{"dataset_uid": "001442", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1201"}, {"dataset_uid": "000155", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Project data: Processes Regulating Iron Supply at the Mesoscale - Ross Sea", "url": "http://www.bco-dmo.org/project/2155"}, {"dataset_uid": "000156", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Data from expdition NBP1201", "url": "http://www.bco-dmo.org/deployment/506350"}], "date_created": "Wed, 08 Jul 2015 00:00:00 GMT", "description": "The Ross Sea continental shelf is one of the most productive areas in the Southern Ocean, and may comprise a significant, but unaccounted for, oceanic CO2 sink, largely driven by phytoplankton production. The processes that control the magnitude of primary production in this region are not well understood, but data suggest that iron limitation is a factor. Field observations and model simulations indicate four potential sources of dissolved iron to surface waters of the Ross Sea: (1) circumpolar deep water intruding from the shelf edge; (2) sediments on shallow banks and nearshore areas; (3) melting sea ice around the perimeter of the polynya; and (4) glacial meltwater from the Ross Ice Shelf. The principal investigators hypothesize that hydrodynamic transport via mesoscale currents, fronts, and eddies facilitate the supply of dissolved iron from these four sources to the surface waters of the Ross Sea polynya. These hypotheses will be tested through a combination of in situ observations and numerical modeling, complemented by satellite remote sensing. In situ observations will be obtained during a month-long cruise in the austral summer. The field data will be incorporated into model simulations, which allow quantification of the relative contributions of the various hypothesized iron supply mechanisms, and assessment of their impact on primary production. The research will provide new insights and a mechanistic understanding of the complex oceanographic phenomena that regulate iron supply, primary production, and biogeochemical cycling. The research will thus form the basis for predictions about how this system may change in a warming climate. The broader impacts include training of graduate and undergraduate students, international collaboration, and partnership with several ongoing outreach programs that address scientific research in the Southern Ocean. The research also will contribute to the goals of the international research programs ICED (Integrated Climate and Ecosystem Dynamics) and GEOTRACES (Biogeochemical cycling and trace elements in the marine environment).", "east": 170.0, "geometry": "POINT(169 -65)", "instruments": "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 PROFILERS/SOUNDERS \u003e PROFILERS; 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 PROFILERS/SOUNDERS \u003e XBT; 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": -65.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Walker; McGillicuddy, Dennis", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "BCO-DMO; R2R", "science_programs": null, "south": -65.0, "title": "Collaborative Research: Impact of Mesoscale Processes on Iron Supply and Phytoplankton Dynamics in the Ross Sea", "uid": "p0000330", "west": 168.0}, {"awards": "1332492 Lohmann, Rainer", "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": "Origin of Persistent Organic Pollutants in the Antarctic Atmosphere, Snow and Marine Food Web", "datasets": [{"dataset_uid": "600138", "doi": "10.15784/600138", "keywords": "Animal Tracking; Antarctica; Antarctic Peninsula; Atmosphere; Biota; Chemistry:fluid; Chemistry:Fluid; Human Dimensions; McMurdo Sound; Oceans; Palmer Station; Pollution; Ross Sea; Sample/collection Description; Sample/Collection Description; Seals; Southern Ocean; Weddell Sea", "people": "Lohmann, Rainer", "repository": "USAP-DC", "science_program": null, "title": "Origin of Persistent Organic Pollutants in the Antarctic Atmosphere, Snow and Marine Food Web", "url": "https://www.usap-dc.org/view/dataset/600138"}], "date_created": "Tue, 09 Jun 2015 00:00:00 GMT", "description": "Many persistent organic pollutants (POPs), though banned in the U.S. since the 1970s, remain in the environment and continue to reach hitherto pristine regions such as the Arctic and Antarctic. The overall goals of this RAPID project are to better understand the remobilization of POPs from melting glaciers in the Antarctic, and their transfer into the food-web. Legacy POPs have characteristic chemical signatures that will be used ascertain the origin of POPs in the Antarctic atmosphere and marine food-web. Samples that were collected in 2010 will be analyzed for a wide range of legacy POPs, and their behavior will be contrasted with results for emerging contaminants. The intellectual merit of the proposed research combines (a) the use of chemical signatures to assess whether melting glaciers are releasing legacy POPs back into the Antarctic marine ecosystem, and (b) a better understanding of the food-web dynamics of legacy POPs versus emerging organic pollutants. The broader impacts of the proposed research project will include the training of the next generation of scientists through support for a graduate student and a postdoctoral scholar. As well, this work will result in a better understanding of the relationship between pollutants, trophic food web ecology and global climate change in the pristine Antarctic ecosystem.", "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 Organisms and Ecosystems", "paleo_time": null, "persons": "Lohmann, Rainer", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "RAPID: Origin of Persistent Organic Pollutants in the Antarctic Atmosphere, Snow and Marine Food WEB", "uid": "p0000344", "west": -180.0}, {"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": "Zagorodnov, Victor; Holland, David; 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": "0944645 Goodge, John", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 11 Feb 2015 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eBecause of extensive ice cover and sparse remote-sensing data, the geology of the Precambrian East Antarctic Shield (EAS) remains largely unexplored with information limited to coastal outcrops from the African, Indian and Australian sectors. The East Antarctic lithosphere is globally important: as one of the largest coherent Precambrian shields, including rocks as old as ~3.8 Ga, it played an important role in global crustal growth; it is a key piece in assembly of the Rodinia and Gondwana supercontinents; it is the substrate to Earth?s major ice cap, including numerous sub-glacial lakes, and influences its thermal state and mechanical stability; and its geotectonic association with formerly adjacent continental blocks in South Africa, India and Australia suggest that it might harbor important mineral resources. This project will increase understanding of the age and composition of the western EAS lithosphere underlying and adjacent to the Transantarctic Mountains (TAM) using U-Pb ages, and Hf- and O-isotope analysis of zircon in early Paleozoic granitoids and Pleistocene glacial tills. TAM granites of the early Paleozoic Ross Orogen represent an areally extensive continental-margin arc suite that can provide direct information about the EAS crust from which it melted and/or through which it passed. Large rock clasts of igneous and metamorphic lithologies entrained in glacial tills at the head of major outlet glaciers traversing the TAM provide eroded samples of the proximal EAS basement. Zircons in these materials will provide data about age and inheritance (U-Pb), crustal vs. mantle origin (O isotopes), and crustal sources and evolution (Hf isotopes). Integrated along a significant part of the TAM, these data will help define broader crustal provinces that can be correlated with geophysical data and used to test models of crustal assembly. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis project will provide a research opportunity for undergraduate and graduate students. Undergraduates will be involved as Research Assistants in sample preparation, imaging, and analytical procedures, and conducting their own independent research. The two main elements of this project will form the basis of MS thesis projects for two graduate students at UMD. Through this project they will gain a good understanding of petrology, isotope geochemistry, and analytical methods. The broader scientific impacts of this work are that it will help develop a better understanding of the origin and evolution of East Antarctic lithosphere underlying and adjacent to the TAM, which will be of value to the broader earth science and glaciological community. Furthermore, knowledge of East Antarctic geology is of continuing interest to the general public because of strong curiosity about past supercontinents, what?s under the ice, and the impact of global warming on ice-sheet stability.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Transantarctic Mountains; Not provided", "locations": "Transantarctic Mountains", "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": "Age and Composition of the East Antarctic Shield by Isotopic Analysis of Granite and Glacial Till", "uid": "p0000258", "west": null}, {"awards": "0732869 Holland, David; 0732730 Truffer, Martin; 0732906 Nowicki, Sophie; 0732804 McPhee, Miles", "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": "609627", "doi": "10.7265/N5T151MV", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Pine Island Glacier; Temperature", "people": "Stanton, Timothy; Truffer, Martin", "repository": "USAP-DC", "science_program": null, "title": "Borehole Temperatures at Pine Island Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609627"}, {"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": "Holland, David; Mojica Moncada, Jhon F.", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Automatic Weather Station Pine Island Glacier", "url": "https://www.usap-dc.org/view/dataset/601216"}], "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": "1441432 Scambos, Ted", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 30 Dec 2014 00:00:00 GMT", "description": "The investigators propose to build and test a multi-sensor, automated measurement station for monitoring Arctic and Antarctic ice-ocean environments. The system, based on a previously successful design, will incorporate weather and climate sensors, camera, snow and firn sensors, instruments to measure ice motion, ice and ocean thermal profilers, hydrophone, and salinity sensors. This new system will have two-way communications for real-time data delivery and is designed for rapid deployment by a small field group. AMIGOS-II will be capable of providing real time information on geophysical processes such as weather, snowmelt, ice motion and strain, fractures and melt ponds, firn thermal profiling, and ocean conditions from multiple levels every few hours for 2-4 years. Project personnel will conduct a field test of the new system at a location with a deep ice-covered lake. Development of AMIGOS-II is motivated by recent calls by the U.S. Antarctic Program Blue-Ribbon Panel to increase Antarctic logistical effectiveness, which cites a need for greater efficiency in logistical operations. Installation of autonomous stations with reduced logistical requirements advances this goal.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e CURRENT/WIND METERS \u003e CURRENT METERS; 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 PROFILERS/SOUNDERS \u003e TEMPERATURE PROFILERS", "is_usap_dc": false, "keywords": "Ice Ocean Interface; FIELD SURVEYS; Climate; Firn Temperature Measurements; Snowmelt; Strain; Ice Movement; Melt Ponds; LABORATORY; Not provided; Multi-Sensor; FIELD INVESTIGATION", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Scambos, Ted", "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": null, "title": "A Low-power, Quick-install Polar Observation System (\u0027AMIGOS-II\u0027) for Monitoring Climate-ice-ocean Interactions", "uid": "p0000443", "west": null}, {"awards": "0944615 Brown, Michael; 0944600 Siddoway, Christine", "bounds_geometry": "POLYGON((-146.5 -76,-145.95 -76,-145.4 -76,-144.85 -76,-144.3 -76,-143.75 -76,-143.2 -76,-142.65 -76,-142.1 -76,-141.55 -76,-141 -76,-141 -76.15,-141 -76.3,-141 -76.45,-141 -76.6,-141 -76.75,-141 -76.9,-141 -77.05,-141 -77.2,-141 -77.35,-141 -77.5,-141.55 -77.5,-142.1 -77.5,-142.65 -77.5,-143.2 -77.5,-143.75 -77.5,-144.3 -77.5,-144.85 -77.5,-145.4 -77.5,-145.95 -77.5,-146.5 -77.5,-146.5 -77.35,-146.5 -77.2,-146.5 -77.05,-146.5 -76.9,-146.5 -76.75,-146.5 -76.6,-146.5 -76.45,-146.5 -76.3,-146.5 -76.15,-146.5 -76))", "dataset_titles": "Rock Samples collected from bedrock exposures, Ford Ranges, MBL", "datasets": [{"dataset_uid": "200415", "doi": "", "keywords": null, "people": null, "repository": "Polar Rock Repository", "science_program": null, "title": "Rock Samples collected from bedrock exposures, Ford Ranges, MBL", "url": "http://bprc.osu.edu/rr/"}], "date_created": "Thu, 09 Oct 2014 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThe northern Ford ranges in Marie Byrd Land, Antarctica, record events and processes that transformed a voluminous succession of Lower Paleozoic turbidites intruded by calc-alkaline plutonic rocks into differentiated continental crust along the margin of Gondwana. In this study the Fosdick migmatite?granite complex will be used to investigate crustal evolution through an integrated program of fieldwork, structural geology, petrology, mineral equilibria modeling, geochronology and geochemistry. The PIs propose detailed traverses at four sites within the complex to investigate Paleozoic and Mesozoic orogenic cycles. They will use petrological associations, structural geometry, and microstructures of host gneisses and leucogranites to distinguish the migration and coalescence patterns for remnant melt flow networks, and carry out detailed sampling for geochronology, geochemistry and isotope research. Mafic plutonic phases will be sampled to acquire information about mantle contributions at the source. Mineral equilibria modeling of source rocks and granite products, combined with in situ mineral dating, will be employed to resolve the P?T?t trajectories arising from thickening/thinning of crust during orogenic cycles and to investigate melting and melt loss history. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis work involves research and educational initiatives for an early career female scientist, as well as Ph.D. and undergraduate students. Educational programs for high school audiences and undergraduate courses on interdisciplinary Antarctic science will be developed.", "east": -141.0, "geometry": "POINT(-143.75 -76.75)", "instruments": null, "is_usap_dc": true, "keywords": "Tectonic; TECTONICS; Transcurrent Faults; MAJOR ELEMENTS; Migmatite; Structural Geology; Gneiss Dome; Geochronology; AGE DETERMINATIONS; Detachment Faults; Marie Byrd Land", "locations": "Marie Byrd Land", "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Siddoway, Christine; Brown, Mike", "platforms": null, "repo": "Polar Rock Repository", "repositories": "Polar Rock Repository", "science_programs": null, "south": -77.5, "title": "Collaborative research: Polyphase Orogenesis and Crustal Differentiation in West Antarctica", "uid": "p0000259", "west": -146.5}, {"awards": "0944193 MacAyeal, Douglas", "bounds_geometry": null, "dataset_titles": "Iceberg Capsize Kinematics and Energetics", "datasets": [{"dataset_uid": "609590", "doi": "10.7265/N56H4FCJ", "keywords": "Antarctica; Glaciology; Iceberg; Kinetics", "people": "MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Capsize Kinematics and Energetics", "url": "https://www.usap-dc.org/view/dataset/609590"}], "date_created": "Mon, 25 Aug 2014 00:00:00 GMT", "description": "This award supports a project to examine and test a 3-step process model for explosive ice-shelf disintegration that emerged in the wake of the recent 2008 and 2009 events of the Wilkins Ice Shelf. The model is conditioned on Summer melt-driven increase in free-surface water coupled with surface and basal crevasse density growth necessary to satisfy an \"enabling condition\". Once met, the collapse proceeds through three steps: (Step 1), calving of a \"leading phalanx\" of tabular icebergs from the seaward ice front of the ice shelf which creates in its wake a region, called a \"mosh pit\" (located between the phalanx and the edge of the intact ice shelf), where ocean surface-gravity waves are trapped by reflection (a fast mechanically enabled process), (Step 2), and a rapid, runaway conversion of gravitational potential energy into ocean-wave energy by iceberg capsize and fragmentation within the \"mosh pit\" which leads to further wave-induced calving, capsize and fragmentation (Step 3). The project will be conducted by a multidisciplinary team and will focus on theoretical model development, numerical method development and application and new observations. The project will participate in both the Research Experience for Undergraduates program in the Physics Department and the Summer Research Early Identification Program (SR-EIP) that fosters participation in research by underrepresented minorities. The PIs, postdoctoral scholar, graduate students and unfunded participants will develop a graduate-level seminar/tutorial to introduce advanced computational methods to glaciology. A postdoctoral scholar and graduate student will be trained in new research techniques during the project.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e VIDEO CAMERA", "is_usap_dc": true, "keywords": "LABORATORY; Iceberg Kinetic Energy; Iceberg Velocity", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Explosive Ice-Shelf Disintegration", "uid": "p0000005", "west": null}, {"awards": "1045215 Gooseff, Michael", "bounds_geometry": "POLYGON((160 -77.25,160.5 -77.25,161 -77.25,161.5 -77.25,162 -77.25,162.5 -77.25,163 -77.25,163.5 -77.25,164 -77.25,164.5 -77.25,165 -77.25,165 -77.375,165 -77.5,165 -77.625,165 -77.75,165 -77.875,165 -78,165 -78.125,165 -78.25,165 -78.375,165 -78.5,164.5 -78.5,164 -78.5,163.5 -78.5,163 -78.5,162.5 -78.5,162 -78.5,161.5 -78.5,161 -78.5,160.5 -78.5,160 -78.5,160 -78.375,160 -78.25,160 -78.125,160 -78,160 -77.875,160 -77.75,160 -77.625,160 -77.5,160 -77.375,160 -77.25))", "dataset_titles": "Are the Dry Valleys Getting Wetter? A Preliminary Assessment of Wetness Across the McMurdo Dry Valleys Landscape", "datasets": [{"dataset_uid": "600131", "doi": "10.15784/600131", "keywords": "Antarctica; Climate; Critical Zone; Dry Valleys; Radar; Soil Moisture", "people": "Gooseff, Michael N.", "repository": "USAP-DC", "science_program": null, "title": "Are the Dry Valleys Getting Wetter? A Preliminary Assessment of Wetness Across the McMurdo Dry Valleys Landscape", "url": "https://www.usap-dc.org/view/dataset/600131"}], "date_created": "Tue, 01 Jul 2014 00:00:00 GMT", "description": "Intellectual Merit: Until recently, wetted soils in the Dry Valleys were generally only found adjacent to streams and lakes. Since the warm austral summer of 2002, numerous ?wet spots? have been observed far from shorelines on relatively flat valley floor locations and as downslope fingers of flow on valley walls. The source of the water to wet these soils is unclear, as is the spatial and temporal pattern of occurrence from year to year. Their significance is potentially great as enhanced soil moisture may change the thermodynamics, hydrology, and erosion rate of surface soils, and facilitate transport of materials that had previously been stable. These changes to the soil active layer could significantly modify permafrost and ground ice stability within the Dry Valleys. The PIs seek to investigate these changes to address two competing hypotheses: that the source of water to these ?wet spots? is ground ice melt and that the source of this water is snowmelt. The PIs will document the spatiotemporal dynamics of these wet areas using high frequency remote sensing data from Quickbird and Wordview satellites to document the occurrence, dimensions, and growth of wet spots during the 2010-\u00ad11 and 2011-\u00ad12 austral summers. They will test their hypotheses by determining whether wet spots recur in the same locations in each season, and they will compare present to past distribution using archived imagery. They will also determine whether spatial snow accumulation patterns and temporal ablation patterns are coincident with wet spot formation. Broader impacts: One graduate student will be trained on this project. Findings will be reported at scientific meetings and published in peer reviewed journals. They will also develop a teaching module on remote sensing applications to hydrology for the Modular Curriculum for Hydrologic Advancement and an innovative prototype project designed to leverage public participation in mapping wet spots and snow patches across the Dry Valleys through the use of social media and mobile computing applications.", "east": 165.0, "geometry": "POINT(162.5 -77.875)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; USAP-DC; ANALYTICAL LAB; Amd/Us", "locations": null, "north": -77.25, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Gooseff, Michael N.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.5, "title": "EAGER: Are the Dry Valleys Getting Wetter? A Preliminary Assessment of Wetness Across the McMurdo Dry Valleys Landscape", "uid": "p0000471", "west": 160.0}, {"awards": "1321588 Mukasa, Samuel", "bounds_geometry": "POLYGON((129.26361 -71.3575,132.914609 -71.3575,136.565608 -71.3575,140.216607 -71.3575,143.867606 -71.3575,147.518605 -71.3575,151.169604 -71.3575,154.820603 -71.3575,158.471602 -71.3575,162.122601 -71.3575,165.7736 -71.3575,165.7736 -72.145583,165.7736 -72.933666,165.7736 -73.721749,165.7736 -74.509832,165.7736 -75.297915,165.7736 -76.085998,165.7736 -76.874081,165.7736 -77.662164,165.7736 -78.450247,165.7736 -79.23833,162.122601 -79.23833,158.471602 -79.23833,154.820603 -79.23833,151.169604 -79.23833,147.518605 -79.23833,143.867606 -79.23833,140.216607 -79.23833,136.565608 -79.23833,132.914609 -79.23833,129.26361 -79.23833,129.26361 -78.450247,129.26361 -77.662164,129.26361 -76.874081,129.26361 -76.085998,129.26361 -75.297915,129.26361 -74.509832,129.26361 -73.721749,129.26361 -72.933666,129.26361 -72.145583,129.26361 -71.3575))", "dataset_titles": "Geochemistry and Geochronology of Intraplate Lavas Recovered from the Arctic Ocean", "datasets": [{"dataset_uid": "000222", "doi": "", "keywords": null, "people": null, "repository": "EarthChem", "science_program": null, "title": "Geochemistry and Geochronology of Intraplate Lavas Recovered from the Arctic Ocean", "url": "http://dx.doi.org/10.1594/IEDA/100555"}], "date_created": "Fri, 27 Jun 2014 00:00:00 GMT", "description": "This project is a geochemical study of volcanic rocks from the West Antarctic Rift system. Its goal is to understand the link between mantle composition and the diverse, regional geodynamic processes, which include uplift, rifting, and volcanism. This project uses argon dating to time the processes, and isotope geochemistry and melt inclusion studies to determine whether the area is underlain by hot or wet mantle. The main broader impacts are support for a woman graduate student, undergraduate research, and research infrastructure.", "east": 165.7736, "geometry": "POINT(147.518605 -75.297915)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -71.3575, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Mukasa, Samuel", "platforms": "Not provided", "repo": "EarthChem", "repositories": "EarthChem", "science_programs": null, "south": -79.23833, "title": "Submarine and On-Land Volcanism in the West Antarctic Rift System: A Petrologic and Geochemical Study to Assess Melting Processes and Eruption History", "uid": "p0000494", "west": 129.26361}, {"awards": "0839122 Saltzman, Eric; 0839093 McConnell, Joseph; 0839075 Priscu, John", "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": "Priscu, John; D\u0027Andrilli, Juliana", "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": "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": "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": "Arienzo, Monica; McConnell, Joseph", "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": "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": "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": "0739648 Cary, Stephen", "bounds_geometry": "POINT(163 -77.5)", "dataset_titles": "Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams", "datasets": [{"dataset_uid": "600079", "doi": "10.15784/600079", "keywords": "Antarctica; Biota; Cell Counts; Dry Valleys; Microbiology", "people": "Cary, S. Craig", "repository": "USAP-DC", "science_program": null, "title": "Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams", "url": "https://www.usap-dc.org/view/dataset/600079"}], "date_created": "Tue, 10 Dec 2013 00:00:00 GMT", "description": "The glacial streams of the McMurdo Dry Valleys have extensive cyanobacterial mats that are a probable source of fixed C and N to the Valleys. The research will examine the interplay between the microbial mats in the ephemeral glacial streams and the microbiota of the hyporheic soils (wetted soil zone) underlying and adjacent to those mats. It is hypothesized that the mats are important sources of organic carbon and fixed nitrogen for the soil communities of the hyporheic zone, and release dissolved organic carbon (DOC) and nitrogen (DON) that serves the entire Dry Valley ecosystem. Field efforts will entail both observational and experimental components. Direct comparisons will be made between the mats and microbial populations underlying naturally rehydrated and desiccated mat areas, and between mat areas in the melt streams of the Adams and Miers Glaciers in Miers Valley. Both physiological and phylogenetic indices of the soil microbiota will be examined. Observations will include estimates of rates of mat carbon and nitrogen fixation, soil respiration and leucine and thymidine uptake (as measures of protein \u0026 DNA synthesis, respectively) by soil bacteria, bacterial densities and their molecular ecology. Experimental manipulations will include experimental re-wetting of soils and observations of the time course of response of the microbial community. The research will integrate modern molecular genetic approaches (ARISA-DNA fingerprinting and ultra deep 16S rDNA microbial phylogenetic analysis) with geochemistry to study the diversity, ecology, and function of microbial communities that thrive in these extreme environments. The broader impacts of the project include research and educational opportunities for graduate students and a postdoctoral associate. The P.I.s will involve undergraduates as work-study students and in REU programs, and will participate in educational and outreach programs.", "east": 163.0, "geometry": "POINT(163 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cary, Stephen", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.5, "title": "Collaborative Research: Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams", "uid": "p0000476", "west": 163.0}, {"awards": "1142083 Kyle, Philip", "bounds_geometry": "POINT(167.15334 -77.529724)", "dataset_titles": "Database of Erebus cave field seasons; Icequakes at Erebus volcano, Antarctica; Mount Erebus Observatory GPS data; Mount Erebus Seismic Data; Mount Erebus Thermodynamic model code; Mount Erebus Volcano Observatory: Operations, Science and Outreach (MEVO-OSO); Seismic data used for high-resolution active-source seismic tomography", "datasets": [{"dataset_uid": "200032", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Mount Erebus Seismic Data", "url": "http://ds.iris.edu/mda/ER/"}, {"dataset_uid": "200030", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Database of Erebus cave field seasons", "url": "https://github.com/foobarbecue/troggle"}, {"dataset_uid": "200034", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismic data used for high-resolution active-source seismic tomography", "url": "http://ds.iris.edu/mda/ZW/?timewindow=2007-2009http://ds.iris.edu/mda/Y4?timewindow=2008-2009http://ds.iris.edu/ds/nodes/dmc/forms/assembled-data/?dataset_report_number=09-015"}, {"dataset_uid": "200031", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Mount Erebus Thermodynamic model code", "url": "https://github.com/kaylai/Iacovino2015_thermodynamic_model"}, {"dataset_uid": "600381", "doi": "10.15784/600381", "keywords": "Antarctica; Cable Observatory; Geology/Geophysics - Other; Infrared Imagery; Intracontinental Magmatism; IntraContinental Magmatism; MEVO; Mount Erebus; Photo/video; Photo/Video; Ross Island; Solid Earth; Thermal Camera; Volcano", "people": "Oppenheimer, Clive; Kyle, Philip", "repository": "USAP-DC", "science_program": "MEVO", "title": "Mount Erebus Volcano Observatory: Operations, Science and Outreach (MEVO-OSO)", "url": "https://www.usap-dc.org/view/dataset/600381"}, {"dataset_uid": "200027", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Mount Erebus Observatory GPS data", "url": "https://www.unavco.org/data/gps-gnss/data-access-methods/dai1/monument.php?mid=22083\u0026parent_link=Permanent\u0026pview=original"}, {"dataset_uid": "200033", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Icequakes at Erebus volcano, Antarctica", "url": "http://ds.iris.edu/mda/ZW/?timewindow=2007-2009http://ds.iris.edu/mda/Y4?timewindow=2008-2009http://ds.iris.edu/mda/ZO?timewindow=2011-2012"}], "date_created": "Tue, 03 Sep 2013 00:00:00 GMT", "description": "Intellectual Merit: Mt. Erebus is one of only a handful of volcanoes worldwide that have lava lakes with readily observable and nearly continuous Strombolian explosive activity. Erebus is also unique in having a permanent convecting lava lake of anorthoclase phonolite magma. Over the years significant infrastructure has been established at the summit of Mt. Erebus as part of the Mount Erebus Volcano Observatory (MEVO), which serves as a natural laboratory to study a wide range of volcanic processes, especially magma degassing associated with an open convecting magma conduit. The PI proposes to continue operating MEVO for a further five years. The fundamental fundamental research objectives are: to understand diffuse flank degassing by using distributed temperature sensing and gas measurements in ice caves, to understand conduit processes, and to examine the environmental impact of volcanic emissions from Erebus on atmospheric and cryospheric environments. To examine conduit processes the PI will make simultaneous observations with video records, thermal imaging, measurements of gas emission rates and gas compositions, seismic, and infrasound data. Broader impacts: An important aspect of Erebus research is the education and training of students. Both graduate and undergraduate students will have the opportunity to work on MEVO data and deploy to the field site. In addition, this proposal will support a middle or high school science teacher for two field seasons. The PI will also continue working with various media organizations and filmmakers.", "east": 167.15334, "geometry": "POINT(167.15334 -77.529724)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e TIRS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e SPECTROMETERS \u003e FTIR SPECTROMETER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e SPECTROMETERS \u003e DOAS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e LASER RANGING \u003e MOBLAS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e PETROGRAPHIC MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e HRDI; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e TIRS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e INFRASONIC MICROPHONES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e XRF; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-ES; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e LASER RANGING \u003e MOBLAS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e IRGA; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE CHAMBERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e SPECTROMETERS \u003e FTIR SPECTROMETER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e MICROTOMOGRAPHY; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e SIMS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Earthquakes; Vesuvius; Cosmogenic Radionuclides; Infrasonic Signals; Icequakes; Magma Shells; Phase Equilibria; Passcal; Correlation; Backscattering; Eruptive History; Degassing; Volatiles; Magma Convection; Thermodynamics; Tremors; Optech; Uv Doas; Energy Partitioning; Erebus; Cronus; Holocene; Lava Lake; Phonolite; Vagrant; Thermal Infrared Camera; Flir; USA/NSF; Mount Erebus; Active Source Seismic; GROUND-BASED OBSERVATIONS; Interferometry; Volatile Solubility; Redox State; Viscosity; Hydrogen Emission; Seismicity; Eruptions; Explosion Energy; FIELD SURVEYS; Radar Spectra; OBSERVATION BASED; Seismic Events; Strombolian Eruptions; Anorthoclase; Ice Caves; Iris; VOLCANO OBSERVATORY; Melt Inclusions; Ftir; Alkaline Volcanism; Tomography; TLS; Volcanic Gases; ANALYTICAL LAB", "locations": "Vesuvius; Cronus; Vagrant; Mount Erebus; Passcal", "north": -77.529724, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Kyle, Philip; Oppenheimer, Clive; Chaput, Julien; Jones, Laura; Fischer, Tobias", "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 VOLCANO OBSERVATORY; OTHER \u003e MODELS \u003e OBSERVATION BASED; OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB", "repo": "IRIS", "repositories": "GitHub; IRIS; UNAVCO; USAP-DC", "science_programs": "MEVO", "south": -77.529724, "title": "Mount Erebus Volcano Observatory: Operations, Science and Outreach (MEVO-OSO)", "uid": "p0000383", "west": 167.15334}, {"awards": "0739779 Warren, Stephen; 1142963 Warren, Stephen", "bounds_geometry": "POLYGON((157 -76,158.1 -76,159.2 -76,160.3 -76,161.4 -76,162.5 -76,163.6 -76,164.7 -76,165.8 -76,166.9 -76,168 -76,168 -76.2,168 -76.4,168 -76.6,168 -76.8,168 -77,168 -77.2,168 -77.4,168 -77.6,168 -77.8,168 -78,166.9 -78,165.8 -78,164.7 -78,163.6 -78,162.5 -78,161.4 -78,160.3 -78,159.2 -78,158.1 -78,157 -78,157 -77.8,157 -77.6,157 -77.4,157 -77.2,157 -77,157 -76.8,157 -76.6,157 -76.4,157 -76.2,157 -76))", "dataset_titles": "Ice on the Oceans of Snowball Earth Project Data", "datasets": [{"dataset_uid": "000183", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Ice on the Oceans of Snowball Earth Project Data", "url": "https://digital.lib.washington.edu/researchworks/handle/1773/37320"}], "date_created": "Wed, 10 Jul 2013 00:00:00 GMT", "description": "The climatic changes of late Precambrian time, 600-800 million years ago, included episodes of extreme glaciation, during which ice may have covered nearly the entire ocean for several million years, according to the Snowball Earth hypothesis. These episodes would hold an important place in Earth?s evolutionary history; they could have encouraged biodiversity by trapping life forms in small isolated ice-free areas, or they could have caused massive extinctions that cleared the path for new life forms to fill empty niches. What caused the Earth to become iced over, and what later caused the ice to melt? Scientific investigation of these questions will result in greater understanding of the climatic changes that the Earth can experience, and will enable better predictions of future climate. This project involves Antarctic field observations as well as laboratory studies and computer modeling. The aim of this project is not to prove or disprove the Snowball Earth hypothesis but rather to quantify processes that are important for simulating snowball events in climate models. The principal goal is to identify the types of ice that would have been present on the frozen ocean, and to determine how much sunlight they would reflect back to space. Reflection of sunlight by bright surfaces of snow and ice is what would maintain the cold climate at low latitudes. The melting of the ocean required buildup of greenhouse gases, but it was probably aided by deposition of desert dust and volcanic ash darkening the snow and ice. With so much ice on the Earth?s surface, even small differences in the amount of light that the ice absorbed or reflected could cause significant changes in climate. The properties of the ice would also determine where, and in what circumstances, photosynthetic life could have survived. Some kinds of ice that are rare on the modern Earth may have been pivotal in allowing the tropical ocean to freeze. The ocean surfaces would have included some ice types that now exist only in Antarctica: bare cold sea ice with precipitated salts, and \"blue ice\" areas of the Transantarctic Mountains that were exposed by sublimation and have not experienced melting. Field expeditions were mounted to examine these ice types, and the data analysis is underway. A third ice type, sea ice with a salt crust, is being studied in a freezer laboratory. Modeling will show how sunlight would interact with ice containing light-absorbing dust and volcanic ash. Aside from its reflection of sunlight, ice on the Snowball ocean would have been thick enough to flow under its own weight, invading all parts of the ocean. Yet evidence for the survival of photosynthetic life indicates that some regions of liquid water were maintained at the ocean surface. One possible refuge for photosynthetic organisms is a bay at the far end of a nearly enclosed tropical sea, formed by continental rifting and surrounded by desert, such as the modern Red Sea. A model of glacier flow is being developed to determine the dimensions of the channel, connecting the sea to the ocean, necessary to prevent invasion by the flowing ice yet maintain a water supply to replenish evaporation.", "east": 168.0, "geometry": "POINT(162.5 -77)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Warren, Stephen; Light, Bonnie; Campbell, Adam; Carns, Regina; Dadic, Ruzica; Mullen, Peter; Brandt, Richard; Waddington, Edwin D.", "platforms": "Not provided", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -78.0, "title": "Ocean Surfaces on Snowball Earth", "uid": "p0000402", "west": 157.0}, {"awards": "0839053 Ackley, Stephen", "bounds_geometry": "POLYGON((-180 -67.05,-170.9866 -67.05,-161.9732 -67.05,-152.9598 -67.05,-143.9464 -67.05,-134.933 -67.05,-125.9196 -67.05,-116.9062 -67.05,-107.8928 -67.05,-98.8794 -67.05,-89.866 -67.05,-89.866 -68.1033,-89.866 -69.1566,-89.866 -70.2099,-89.866 -71.2632,-89.866 -72.3165,-89.866 -73.3698,-89.866 -74.4231,-89.866 -75.4764,-89.866 -76.5297,-89.866 -77.583,-98.8794 -77.583,-107.8928 -77.583,-116.9062 -77.583,-125.9196 -77.583,-134.933 -77.583,-143.9464 -77.583,-152.9598 -77.583,-161.9732 -77.583,-170.9866 -77.583,180 -77.583,178.57 -77.583,177.14 -77.583,175.71 -77.583,174.28 -77.583,172.85 -77.583,171.42 -77.583,169.99 -77.583,168.56 -77.583,167.13 -77.583,165.7 -77.583,165.7 -76.5297,165.7 -75.4764,165.7 -74.4231,165.7 -73.3698,165.7 -72.3165,165.7 -71.2632,165.7 -70.2099,165.7 -69.1566,165.7 -68.1033,165.7 -67.05,167.13 -67.05,168.56 -67.05,169.99 -67.05,171.42 -67.05,172.85 -67.05,174.28 -67.05,175.71 -67.05,177.14 -67.05,178.57 -67.05,-180 -67.05))", "dataset_titles": "The Sea Ice System in Antarctic Summer, Oden Southern Ocean Expedition (OSO 2010-11)", "datasets": [{"dataset_uid": "600106", "doi": "10.15784/600106", "keywords": "Ice Core Records; Oceans; Oden; OSO1011; Sea Ice; Sea Ice Salinity; Sea Ice Thickness; Southern Ocean", "people": "Ackley, Stephen", "repository": "USAP-DC", "science_program": null, "title": "The Sea Ice System in Antarctic Summer, Oden Southern Ocean Expedition (OSO 2010-11)", "url": "https://www.usap-dc.org/view/dataset/600106"}], "date_created": "Fri, 03 May 2013 00:00:00 GMT", "description": "Several aspect of the seasonal melting and reformation cycle of Antarctic sea ice appear to be divergent from those occurring in the Arctic. This is most clearly demonstrated by the dramatic diminishing extent and thinning of the Arctic sea ice, to be contrasted to the changes in Antarctic sea-ice extent, which recently (decadaly) shows small increases. Current climate models do not resolve this discrepancy which likely results from both a lack of relevant observational sea-ice data in the Antarctic, along with inadequacies in the physical parameterization of sea-ice properties in climate models.\u003cbr/\u003e\u003cbr/\u003eResearchers will take advantage of the cruise track of the I/B Oden during transit through the Antarctic sea-ice zones in the region of the Bellingshausen, Amundsen and Ross (BAR) seas on a cruise to McMurdo Station. Because of its remoteness and inaccessibility, the BAR region is of considerable scientific interest as being one of the last under described and perhaps unexploited marine ecosystems left on the planet .\u003cbr/\u003e\u003cbr/\u003eA series of on station and underway observations of sea ice properties will be undertaken, thematically linked to broader questions of summer ice survival and baseline physical properties (e.g. estimates of heat and salt fluxes). In situ spatiotemporal variability of sea-ice cover extent, thickness and snow cover depths will be observed.", "east": 165.7, "geometry": "POINT(-142.083 -72.3165)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -67.05, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Ackley, Stephen", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.583, "title": "The Sea Ice System in Antarctic Summer, Oden Southern Ocean Expedition (OSO 2010-11)", "uid": "p0000676", "west": -89.866}, {"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": "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": "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"}, {"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"}], "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": "0838973 Nyblade, Andrew; 0838934 Wiens, Douglas", "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": "Seismological Record ID# ZM 2007-12; Seismological Record Network Code# ZM (full data link not provided)", "datasets": [{"dataset_uid": "000152", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismological Record Network Code# ZM (full data link not provided)", "url": "http://www.iris.edu/"}, {"dataset_uid": "000149", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismological Record ID# ZM 2007-12", "url": "http://www.iris.edu/"}], "date_created": "Mon, 21 Jan 2013 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The high elevations of East Antarctica are critical in localizing the initial Cenozoic glaciation and stabilizing it with respect to melting during warm interglacials. However, the geological history for this region and the geophysical mechanism for maintaining the highlands are poorly understood. In 2007-2009, an array of 24 broadband seismographs (named GAMSEIS) was installed across the Gamburtsev Mountains area of the East Antarctic Plateau as part of the Antarctica?s Gamburtsev Province (AGAP) International Polar Year project. The IPY AGAP/GAMSEIS program included plans by other international partners to install seismographs at locations along the flanks of the Gamburtsev Mountains and in other East Antarctic regions. The proposed project will continue operating six of the deployed AGAP/GAMSEIS stations for two more years together with two new broadband seismic stations added to broaden the geographic scope of the array. Most stations will be located at the existing U.S. Autonomous Geophysical Observatories and the USAP fuel cache locations in order to minimize logistical support. This array, combined with seismographs deployed by China and Japan (and possibly Australia, France, and Italy in near future) will provide a sparse but large-scale network of seismometers for the longer-term studies of the crustal and upper mantle structures underneath the East Antarctic Plateau. Continued reliance on students provides a broader impact to this proposed research and firmly grounds this effort in its educational mission.", "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; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wiens, Douglas; Nyblade, Andrew", "platforms": "Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -84.0, "title": "Collaborative Research: Polenet East: An International Seismological Network for East Antarctica", "uid": "p0000504", "west": 40.0}, {"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": "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; McGrath, Daniel; Steffen, Konrad", "repository": "USAP-DC", "science_program": null, "title": "Larsen C automatic weather station data 2008\u20132011", "url": "https://www.usap-dc.org/view/dataset/601445"}, {"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": "Kuipers Munneke, Peter; Steffen, Konrad; McGrath, Daniel", "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"}], "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": "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": "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; Studinger, Michael S.; Macgregor, Joseph A.", "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"}, {"dataset_uid": "609500", "doi": "10.7265/N5F769HV", "keywords": "Accumulation Rate; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok", "people": "Studinger, Michael S.; Winebrenner, Dale; Waddington, Edwin D.; Macgregor, Joseph A.; Matsuoka, Kenichi", "repository": "USAP-DC", "science_program": null, "title": "Millennially Averaged Accumulation Rates for Lake Vostok", "url": "https://www.usap-dc.org/view/dataset/609500"}], "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": "1043528 Alley, Richard; 1043313 Spencer, Matthew", "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.; Fitzpatrick, Joan; Spencer, Matthew; Alley, Richard; Fegyveresi, John", "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": "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": "Fegyveresi, John; Alley, Richard", "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": "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": "Alley, Richard; Voigt, Donald E.; 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": "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": "0636740 Kreutz, Karl; 0636767 Dunbar, Nelia", "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": "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": "Koffman, Bess; Breton, Daniel; Hamilton, Gordon S.; Kreutz, Karl", "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"}, {"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": "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": "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": "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": "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"}], "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": "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": "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": "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": "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"}, {"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": "Huber, Bruce; Gordon, Arnold", "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": "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": "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/"}], "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": "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": "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": "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"}, {"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": "Jacobs, Stanley; Mele, Phil; Mortlock, R. A.; Smethie, William M", "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": "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"}], "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": "9615053 Domack, Eugene", "bounds_geometry": null, "dataset_titles": "Expedition data of LMG9802", "datasets": [{"dataset_uid": "002718", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9802", "url": "https://www.rvdata.us/search/cruise/LMG9802"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Domack: OPP 9615053 Manley: OPP 9615670 Banerjee: OPP 9615695 Dunbar: OPP 9615668 Ishman: OPP 9615669 Leventer: OPP 9714371 Abstract This award supports a multi-disciplinary, multi-institutional effort to elucidate the detailed climate history of the Antarctic Peninsula during the Holocene epoch (the last 10,000 years). The Holocene is an important, but often overlooked, portion of the Antarctic paleoclimatic record because natural variability in Holocene climate on time scales of decades to millennia can be evaluated as a model for our present \"interglacial\" world. This project builds on over ten years of prior investigation into the depositional processes, productivity patterns and climate regime of the Antarctic Peninsula. This previous work identified key locations that contain ultra-high resolution records of past climatic variation. These data indicate that solar cycles operating on multi-century and millennial time scales are important regulators of meltwater production and paleoproductivity. These marine records can be correlated with ice core records in Greenland and Antarctica. This project will focus on sediment dispersal patterns across the Palmer Deep region. The objective is to understand the present links between the modern climatic and oceanographic systems and sediment distribution. In particular, additional information is needed regarding the influence of sea ice on the distribution of both biogenic and terrigenous sediment distribution. Sediment samples will be collected with a variety of grab sampling and coring devices. Analytical work will include carbon-14 dating of surface sediments using accellerator mass spectrometry and standard sedimentologic, micropaleontologic and magnetic granulometric analyses. This multiparameter approach is the most effective way to extract the paleoclimatic signals contained in the marine sediment cores. Two additional objectives are the deployment of sediment traps in front of the Muller Ice Shelf in Lallemand Fjord and seismic reflection work in conjunction with site augmentation funded through the Joint Oceanographic Institute. The goal of sediment trap work is to address whether sand transport and deposition adjacent to the ice shelf calving line results from meltwater or aeolian processes. In addition, the relationship between sea ice conditions and primary productivity will be investigated. The collection of a short series of seismic lines across the Palmer Deep basins will fully resolve the question of depth to acoustic basement. The combination of investigators on this project, all with many years of experience working in high latitude settings, provides an effective team to complete the project in a timely fashion. A combination of undergraduate, graduate and post-graduate students will be involved in all stages of the project so that educational objectives will be met in-tandem with research goals of the project.", "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": "Domack, Eugene Walter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Holocene Paleoenvironmental Change Along the Antarctic Peninsula: A Test of the Solar/Bi-Polar Signal", "uid": "p0000869", "west": null}, {"awards": "9317598 Asper, Vernon", "bounds_geometry": "POLYGON((-180 -43.56582,-144.00001 -43.56582,-108.00002 -43.56582,-72.00003 -43.56582,-36.00004 -43.56582,-0.000049999999987 -43.56582,35.99994 -43.56582,71.99993 -43.56582,107.99992 -43.56582,143.99991 -43.56582,179.9999 -43.56582,179.9999 -46.943299,179.9999 -50.320778,179.9999 -53.698257,179.9999 -57.075736,179.9999 -60.453215,179.9999 -63.830694,179.9999 -67.208173,179.9999 -70.585652,179.9999 -73.963131,179.9999 -77.34061,143.99991 -77.34061,107.99992 -77.34061,71.99993 -77.34061,35.99994 -77.34061,-0.000050000000016 -77.34061,-36.00004 -77.34061,-72.00003 -77.34061,-108.00002 -77.34061,-144.00001 -77.34061,-180 -77.34061,-180 -73.963131,-180 -70.585652,-180 -67.208173,-180 -63.830694,-180 -60.453215,-180 -57.075736,-180 -53.698257,-180 -50.320778,-180 -46.943299,-180 -43.56582))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002252", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9406"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "9317598 Asper The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. This component will focus on the collection of vertical flux samples which will be analyzed for carbon, nitrogen and total mass flux and also provided to the other investigators for their specific analyses. Profiles of the abundance of large aggregates in the water column using a non- contact photographic method will be made. These data will be used to complement other particle determinations, to investigate the role of these aggregates in particle flux and to determine the mechanisms of particle export as a function of season and phytoplankton species. The end result will be a better understanding of the bloom processes and significant contributions to the data base on aggregates and export mechanisms in this environment.", "east": 179.9999, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -43.56582, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Asper, Vernon; Smith, Walker", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -77.34061, "title": "Collaborative Research on Bloom Dynamics and Food Web Structure in the Ross Sea: Vertical Flux of Carbon and Nitrogen", "uid": "p0000646", "west": -180.0}, {"awards": "0337159 McPhee, Miles", "bounds_geometry": "POLYGON((-64.71659 -53.00174,-57.631677 -53.00174,-50.546764 -53.00174,-43.461851 -53.00174,-36.376938 -53.00174,-29.292025 -53.00174,-22.207112 -53.00174,-15.122199 -53.00174,-8.037286 -53.00174,-0.952373 -53.00174,6.13254 -53.00174,6.13254 -54.292069,6.13254 -55.582398,6.13254 -56.872727,6.13254 -58.163056,6.13254 -59.453385,6.13254 -60.743714,6.13254 -62.034043,6.13254 -63.324372,6.13254 -64.614701,6.13254 -65.90503,-0.952373 -65.90503,-8.037286 -65.90503,-15.122199 -65.90503,-22.207112 -65.90503,-29.292025 -65.90503,-36.376938 -65.90503,-43.461851 -65.90503,-50.546764 -65.90503,-57.631677 -65.90503,-64.71659 -65.90503,-64.71659 -64.614701,-64.71659 -63.324372,-64.71659 -62.034043,-64.71659 -60.743714,-64.71659 -59.453385,-64.71659 -58.163056,-64.71659 -56.872727,-64.71659 -55.582398,-64.71659 -54.292069,-64.71659 -53.00174))", "dataset_titles": "Expedition Data; Processed ADCP Sonar and CTD Data from the Maud Rise acquired during the Nathaniel B. Palmer expedition NBP0506", "datasets": [{"dataset_uid": "601342", "doi": null, "keywords": "ADCP Acoustic Doppler Current Profiler; Antarctica; CTD; Maud Rise; NBP0506; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature; Turbulance; Weddell Sea", "people": "McPhee, Miles G.", "repository": "USAP-DC", "science_program": null, "title": "Processed ADCP Sonar and CTD Data from the Maud Rise acquired during the Nathaniel B. Palmer expedition NBP0506", "url": "https://www.usap-dc.org/view/dataset/601342"}, {"dataset_uid": "001590", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0506"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is an investigation into one mechanism by which deep ocean convection can evolve from stable initial conditions, to the extent that it becomes well enough established to bring warm water to the surface and melt an existing ice cover in late, or possibly even mid-winter. The specific study will investigate how the non-linear dependence of seawater density on temperature and salinity (the equation of state) can enhance vertical convection under typical antarctic conditions. When layers of seawater with similar densities but strong contrasts in temperature and salinity interact, there are a number of possible non-linear instabilities that can convert existing potential energy to turbulent energy. In the Weddell Sea, a cold surface mixed layer is often separated from the underlying warm, more saline water by a thin, weak pycnocline, making the water column particularly susceptible to an instability associated with thermobaricity (the pressure dependence of the thermal expansion coefficient). The project is a collaboration between New York University, Earth and Space Research, the University of Washington, the Naval Postgraduate School, and McPhee Research Company.\u003cbr/\u003eThe work has strong practical applications in contributing to the explanation for the existence of the Weddell Polynya, a 300,000 square kilometer area of open water within the seasonal sea ice of the Weddell Sea, from approximately 1975 to 1979. It has not recurred since, although indications of much smaller and less persistent areas of open water do occur in the vicinity of the Maud Rise seamount. \u003cbr/\u003e The experimental component will be carried out on board the RVIB Nathaniel B. Palmer between July and September, 2005.", "east": 6.13254, "geometry": "POINT(-29.292025 -59.453385)", "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": "R/V NBP", "locations": null, "north": -53.00174, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "McPhee, Miles G.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -65.90503, "title": "Collaborative Research: The Maud Rise Nonlinear Equation of State Study (MaudNESS)", "uid": "p0000579", "west": -64.71659}, {"awards": "9726180 Dorman, LeRoy", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP9905", "datasets": [{"dataset_uid": "002581", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP9905", "url": "https://www.rvdata.us/search/cruise/NBP9905"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Office of Polar Programs of the National Science Foundation, supports research to investigate the seismicity and tectonics of the South Shetland Arc and the Bransfield Strait. This region presents an intriguing and unique tectonic setting, with slowing of subduction, cessation of island arc volcanism, as well as the apparent onset of backarc rifting occurring within the last four million years. This project will carry out a 5-month deployment of 14 ocean bottom seismographs (OBSs) to complement and extend a deployment of 6 broadband land seismic stations that were successfully installed during early 1997. The OBSs include 2 instruments with broadband sensors, and all have flowmeters for measuring and sampling hydrothermal fluids. The OBSs will be used to examine many of the characteristics of the Shetland- Bransfield tectonic system, including: --- The existence and depth of penetration of a Shetland Slab: The existence of a downgoing Shetland slab will be determined from earthquake locations and from seismic tomography. The maximum depth of earthquake activity and the depth of the slab velocity anomaly will constrain the current configuration of the slab, and may help clarify the relationship between the subducting slab and the cessation of arc volcanism. -- Shallow Shetland trench seismicity?: No teleseismic shallow thrust faulting seismicity has been observed along the South Shetland Trench from available seismic information. Using the OBS data, the level of small earthquake activity along the shallow thrust zone will be determined and compared to other regions undergoing slow subduction of young oceanic lithosphere, such as Cascadia, which also generally shows very low levels of thrust zone seismicity. -- Mode of deformation along the Bransfield Rift: The Bransfield backarc has an active rift in the center, but there is considerable evidence for off-rift faulting. There is a long-standing controversy about whet her back-arc extension occurs along discrete rift zones, or is more diffuse geographically. This project will accurately locate small earthquakes to better determine whether Bransfield extension is discrete or diffuse. -- Identification of volcanism and hydrothermal activity: Seismic records will be used to identify the locations of active seafloor volcanism along the Bransfield rift. Flowmeters attached to the OBSs will record and sample the fluid flux out of the sediments. -- Upper mantle structure of the Bransfield - evidence for partial melting?: Other backarc basins show very slow upper mantle seismic velocities and high seismic attenuation, characteristics due to the presence of partially molten material. This project will use seismic tomography to resolve the upper mantle structure of the Bransfield backarc, allowing comparison with other backarc regions and placing constraints on the existence of partially molten material and the importance of partial melting as a mantle process in this region. Collaborative awards: OPP 9725679 and OPP 9726180", "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 Earth Sciences", "paleo_time": null, "persons": "Wiens, Douglas", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Study of the Structure and Tectonics of the South Shetland Trench and Bransfield Backarc Using Ocean Bottom Seismographs", "uid": "p0000801", "west": null}, {"awards": "0338371 Hallet, Bernard; 0338137 Anderson, John", "bounds_geometry": "POLYGON((-74.59492 -45.98986,-74.072309 -45.98986,-73.549698 -45.98986,-73.027087 -45.98986,-72.504476 -45.98986,-71.981865 -45.98986,-71.459254 -45.98986,-70.936643 -45.98986,-70.414032 -45.98986,-69.891421 -45.98986,-69.36881 -45.98986,-69.36881 -46.835236,-69.36881 -47.680612,-69.36881 -48.525988,-69.36881 -49.371364,-69.36881 -50.21674,-69.36881 -51.062116,-69.36881 -51.907492,-69.36881 -52.752868,-69.36881 -53.598244,-69.36881 -54.44362,-69.891421 -54.44362,-70.414032 -54.44362,-70.936643 -54.44362,-71.459254 -54.44362,-71.981865 -54.44362,-72.504476 -54.44362,-73.027087 -54.44362,-73.549698 -54.44362,-74.072309 -54.44362,-74.59492 -54.44362,-74.59492 -53.598244,-74.59492 -52.752868,-74.59492 -51.907492,-74.59492 -51.062116,-74.59492 -50.21674,-74.59492 -49.371364,-74.59492 -48.525988,-74.59492 -47.680612,-74.59492 -46.835236,-74.59492 -45.98986))", "dataset_titles": "Expedition data of NBP0505; Expedition data of NBP0703; NBP0505 CTD data; NBP0505 sediment core locations", "datasets": [{"dataset_uid": "601363", "doi": "10.15784/601363", "keywords": "Chile; CTD; CTD Data; Depth; Fjord; NBP0505; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Temperature", "people": "Wellner, Julia; Anderson, John", "repository": "USAP-DC", "science_program": null, "title": "NBP0505 CTD data", "url": "https://www.usap-dc.org/view/dataset/601363"}, {"dataset_uid": "002642", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0703", "url": "https://www.rvdata.us/search/cruise/NBP0703"}, {"dataset_uid": "002609", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0505", "url": "https://www.rvdata.us/search/cruise/NBP0505"}, {"dataset_uid": "601362", "doi": "10.15784/601362", "keywords": "Chile; Fjord; Marine Geoscience; NBP0505; R/v Nathaniel B. Palmer; Sample/collection Description; Sample/Collection Description; Sediment Core; Sediment Corer; Station List", "people": "Anderson, John; Wellner, Julia", "repository": "USAP-DC", "science_program": null, "title": "NBP0505 sediment core locations", "url": "https://www.usap-dc.org/view/dataset/601362"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project examines the role of glacier dynamics in glacial sediment yields. The results will shed light on how glacial erosion influences both orogenic processes and produces sediments that accumulate in basins, rich archives of climate variability. Our hypothesis is that erosion rates are a function of sliding speed, and should diminish sharply as the glacier\u0027s basal temperatures drop below the melting point. To test this hypothesis, we will determine sediment accumulation rates from seismic studies of fjord sediments for six tidewater glaciers that range from fast-moving temperate glaciers in Patagonia to slow-moving polar glaciers on the Antarctic Peninsula. Two key themes are addressed for each glacier system: 1) sediment yields and erosion rates by determining accumulation rates within the fjords using seismic profiles and core data, and 2) dynamic properties and basin characteristics of each glacier in order to seek an empirical relationship between glacial erosion rates and ice dynamics. The work is based in Patagonia and the Antarctic Peninsula, ideal natural laboratories for these purposes because the large latitudinal range provides a large range of precipitation and thermal regimes over relatively homogeneous lithologies and tectonic settings. Prior studies of these regions noted significant decreases in glaciomarine sediment accumulations in the fjords to the south. As well, the fjords constitute accessible and nearly perfect natural sediment traps.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this study include inter-disciplinary collaboration with Chilean glaciologists and marine geologists, support for one postdoctoral and three doctoral students, inclusion of undergraduates in research, and outreach to under-represented groups in Earth sciences and K-12 educators. The results of the project will also contribute to a better understanding of the linkages between climate and evolution of all high mountain ranges.", "east": -69.36881, "geometry": "POINT(-71.981865 -50.21674)", "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 SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e WATER BOTTLES; 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; Penguin Glacier", "locations": null, "north": -45.98986, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John; Hallet, Bernard; Wellner, Julia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -54.44362, "title": "Collaborative Research: Controls on Sediment Yields from Tidewater Glaciers from Patagonia to Antarctica", "uid": "p0000821", "west": -74.59492}, {"awards": "0538516 Ackley, Stephen", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP0709", "datasets": [{"dataset_uid": "002648", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0709", "url": "https://www.rvdata.us/search/cruise/NBP0709"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is a study of the evolution of the sea ice cover, and the mass balance of ice in the Amundsen Sea and the Bellingshausen Sea in the internationally collaborative context of the International Polar Year (2007-2008). In its simplest terms, the mass balance is the net freezing and melting that occurs over an annual cycle at a given location. If the ice were stationary and were completely to melt every year, the mass balance would be zero. While non-zero balances have significance in questions of climate and environmental change, the process itself has global consequences since the seasonal freeze-melt cycle has the effect of distilling the surface water. Oceanic salt is concentrated into brine and rejected from the ice into deeper layers in the freezing process, while during melt, the newly released and relatively fresh water stabilizes the surface layers. The observation program will be carried out during a drift program of the Nathaniel B. Palmer, and through a buoy network established on the sea ice that will make year-long measurements of ice thickness, and temperature profile, large-scale deformation, and other characteristics. The project is a component of the Antarctic Sea Ice Program, endorsed internationally by the Joint Committee for IPY. Additionally, the buoys to be deployed have been endorsed as an IPY contribution to the World Climate Research Program/Scientific Committee on Antarctic Research (WCRP/SCAR) International Programme on Antarctic Buoys (IPAB). While prior survey information has been obtained in this region, seasonal and time-series measurements on sea ice mass balance are crucial data in interpreting the mechanisms of air-ice-ocean interaction. \u003cbr/\u003e The network will consist of an array of twelve buoys capable of GPS positioning. Three buoys will be equipped with thermister strings and ice and snow thickness measurement gauges, as well as a barometer. Two buoys will be equipped with meteorological sensors including wind speed and direction, atmospheric pressure, and incoming radiation. Seven additional buoys will have GPS positioning only, and will be deployed approximately 100 km from the central site. These outer buoys will be critical in capturing high frequency motion complementary to satellite-derived ice motion products. Additional buoys have been committed internationally through IPAB and will be deployed in the region as part of this program.\u003cbr/\u003e This project will complement similar projects to be carried out in the Weddell Sea by the German Antarctic Program, and around East Antarctica by the Australian Antarctic Program. The combined buoy and satellite deformation measurements, together with the mass balance measurements, will provide a comprehensive annual data set on sea ice thermodynamics and dynamics for comparison with both coupled and high-resolution sea ice models.", "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 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": "Ackley, Stephen", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Sea Ice Mass Balance in the Antarctic-SIMBA Drift Station", "uid": "p0000839", "west": null}, {"awards": "0125818 Gargett, Ann", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0508", "datasets": [{"dataset_uid": "001584", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0508"}, {"dataset_uid": "002610", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0508", "url": "https://www.rvdata.us/search/cruise/NBP0508"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Ultraviolet radiation influences the dynamics of plankton processes in the near-surface waters of most aquatic ecosystems. In particular, the Southern Ocean is affected in the austral spring period when biologically damaging ultraviolet radiation is enhanced by ozone depletion. While progress has been made in estimating the quantitative impact of ultraviolet radiation on bacteria and phytoplankton in the Southern Ocean, some important issues remain to be resolved. Little is known about responses in systems dominated by the colonial haptophyte Phaeocystis antarctica, which dominates spring blooms in a polyna that develops in the southern Ross Sea. The Ross Sea is also of interest because of the occurrence of open water at a far southerly location in the spring, well within the ozone hole, and continuous daylight, with implications for the regulation of DNA repair. A number of studies suggest that vertical mixing can significant modify the impact of ultraviolet radiation in the Southern Ocean and elsewhere. However, there are limited measurements of turbulence intensity in the surface layer and measurements have not been integrated with parallel studies of ultraviolet radiation effects on phytoplankton and bacterioplankton. To address these issues, this collaborative study will focus on vertical mixing and the impact of ultraviolet radiation in the Ross Sea. The spectral and temporal responses of phytoplankton and bacterioplankton to ultraviolet radiation will be characterized in both laboratory and solar incubations. These will lead to the definition of biological weighting functions and response models capable of predicting the depth and time distribution of ultraviolet radiation impacts on photosynthesis, bacterial incorporation and DNA damage in the surface layer. Diel sampling will measure depth-dependent profiles of DNA damage, bacterial incorporation, photosynthesis and fluorescence parameters over a 24 h cycle. Sampling will include stations with contrasting wind-driven mixing and stratification as the polyna develops. The program of vertical mixing measurements is optimized for the typical springtime Ross Sea situation in which turbulence of intermediate intensity is insufficient to mix the upper layer thoroughly in the presence of stabilizing influences like solar heating and/or surface freshwater input from melting ice. Fine-scale vertical density profiles will be measured with a free-fall CTD unit and the profiles will be used to directly estimate large-eddy scales by determining Thorpe scales. Eddy scales and estimated turbulent diffusivities will be directly related to surface layer effects, and used to generate lagrangian depth-time trajectories in models of ultraviolet radiation responses in the surface mixed layer. The proposed research will be the first in-depth study of ultraviolet radiation effects in the Ross Sea and provide a valuable comparison with previous work in the Weddell-Scotia Confluence and Palmer Station regions. It will also enhance the understanding of vertical mixing processes, trophic interactions and biogeochemical cycling in the Ross Sea.", "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; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V NBP; B-15J", "locations": "B-15J", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Neale, Patrick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Interactive effects of UV and vertical mixing on phytoplankton and bacterioplankton in the Ross Sea", "uid": "p0000822", "west": null}, {"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": "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"}, {"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": "Jacobs, Stanley; Giulivi, Claudia F.", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Continental Shelf Mooring Data (2006-2007)", "url": "https://www.usap-dc.org/view/dataset/601809"}], "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": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "The Amundsen Continental Shelf and the Antarctic Ice Sheet", "uid": "p0000836", "west": null}, {"awards": "9317538 Nelson, David", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP9406", "datasets": [{"dataset_uid": "002591", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP9406", "url": "https://www.rvdata.us/search/cruise/NBP9406"}, {"dataset_uid": "002252", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9406"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "9317538 Nelson The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. This component will test the closely related hypotheses that: (1) phytoplankton growth is controlled primarily by the relationship between solar irradiance and mixed-layer depth throughout the spring (2) diatom growth rates are much higher in spring than at any other time of year, in response to the more favorable irradiance/mixing relationships, and (3) persistence of diatom blooms in summer results from the diatoms\u0027 ability to outcompete other groups under the light-limited conditions that develop in turbid, high-biomass waters. These hypotheses will be tested by (1) obtaining the first reliable estimates of the Sverdrup \"critical depth\" in the Antarctic so that the changing relationship between the critical depth and the mixed- layer depth in spring can be defined, and (2) estimating diatom growth rates and the gross and net production attributable to diatoms throughout the spring. The results will provide information critical to an understanding of phytoplankton bloom dynamics in the Ross Sea.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Smith, Walker", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Bloom Dynamics and Food-Web Structure in the Ross Sea: The Irradiance/Mixing Regime and Diatom Growith in Spring", "uid": "p0000810", "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": "9316035 Gowing, Marcia", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP9406", "datasets": [{"dataset_uid": "002592", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP9406", "url": "https://www.rvdata.us/search/cruise/NBP9406"}, {"dataset_uid": "002252", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9406"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. The focus of this proposal is the role of microzooplankton in controlling the production and fate of carbon during the two types of blooms. Objectives are: 1) to determine biomass, abundance, size and selected species composition of primary producer assemblages, 2) to determine similar features of nano- and microplanktonic heterotrophic assemblages, 3) to measure total community grazing on heterotrophic bacteria and phytoplankton, 4) to examine which grazers are the major herbivores and bacterivores, and 5) to measure the contribution of microzooplankton and mesozooplankton egesta, sinking of algal cells and colonies, and sinking of protozoan assemblages associated with detritus to the total carbon flux from the euphotic zone through 250 m depth. Water samples for abundance and biomass determinations will be taken and samples will be examined with epifluorescence microscopy. Grazing rates will be measured using the dilution grazing technique and the dual-isotope radiolabeling single cell method. Carbon fluxes will be determined on sinking material collected with particle interceptor traps at the base of the euphotic zone and two deeper depths, using microscopical analysis . An understanding of these processes and other fundamental processes studied by collaborating investigators will contribute to the understanding of the role of the Southern Ocean in present, past and predicted future sequestration of carbon, as well as in other global elemental cycles.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Walker", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Bloom Dynamics and Food Web Structure in the Ross Sea: Role of Microzooplankton in Controlling Production", "uid": "p0000811", "west": null}, {"awards": "9317587 Smith, Walker", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP9406", "datasets": [{"dataset_uid": "002252", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9406"}, {"dataset_uid": "002582", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP9406", "url": "https://www.rvdata.us/search/cruise/NBP9406"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. This component will conduct a set of process-oriented experiments designed to elucidate the controls of phytoplankton productivity, growth and accumulation as well as the mechanisms which control bacterial abundance and productivity in Antarctic waters. Specifically, the relative photosynthetic and nutrient (nitrate, ammonium) characteristics of diatom- vs. Phaeocystis- dominated assemblages will be examined to test if Phaeocystis simply grows faster under spring conditions in the Ross Sea. Phytoplankton and bacterial biomass, productivity and their interactions will be measured to elucidate the complex physical-chemical-biological interactions which occur. Substantial understanding of the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions will result from this research. Finally, because the Antarctic is the ocean\u0027s largest high-nutrient, low biomass system, and hence has the greatest potential for sequestering carbon dioxide, knowledge of the dynamics of the Ross Sea phytoplankton will also increase our understanding of the carbo n cycle of the Southern Ocean.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Walker", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Bloom Dynamics and Food Web Structure in the Ross Sea: Primary Productivity, New Production and Bacterial Growth", "uid": "p0000802", "west": null}, {"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": "Hawley, Robert L.; Fudge, T. J.; Waddington, Edwin D.; 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": "0741510 Yuan, Xiaojun", "bounds_geometry": "POLYGON((-180 -69,-172 -69,-164 -69,-156 -69,-148 -69,-140 -69,-132 -69,-124 -69,-116 -69,-108 -69,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-100 -77,-100 -78,-100 -79,-108 -79,-116 -79,-124 -79,-132 -79,-140 -79,-148 -79,-156 -79,-164 -79,-172 -79,180 -79,178.5 -79,177 -79,175.5 -79,174 -79,172.5 -79,171 -79,169.5 -79,168 -79,166.5 -79,165 -79,165 -78,165 -77,165 -76,165 -75,165 -74,165 -73,165 -72,165 -71,165 -70,165 -69,166.5 -69,168 -69,169.5 -69,171 -69,172.5 -69,174 -69,175.5 -69,177 -69,178.5 -69,-180 -69))", "dataset_titles": "Temperature and salinity measurements collected using XBT, XCTD from the Oden and other platforms in the Southern Oceans from 2003-2008 (NODC Accession 0053045)", "datasets": [{"dataset_uid": "000214", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Temperature and salinity measurements collected using XBT, XCTD from the Oden and other platforms in the Southern Oceans from 2003-2008 (NODC Accession 0053045)", "url": "https://data.nodc.noaa.gov/cgi-bin/iso?id=gov.noaa.nodc:0053045"}], "date_created": "Sat, 20 Feb 2010 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003eThe project goal is to investigate the ocean-atmosphere-ice (OAI) interactions in the Amundsen and Ross Seas during the austral summer of 2007-08 using hydrographic measurements (CTD and XBT) in conjunction with (1) ship-based observations and satellite-derived estimates of sea ice concentration, and (2) ship-based observations and re-analyses of meteorological variables. The major scientific objectives are as follows: (1) to examine upper ocean characteristics along three transects in the Amundsen Sea and two transects in the Ross Sea within the context of ice-atmosphere variability over the preceding winter-spring season and as compared to other years where data are available; (2) to determine if there is additional evidence of increased upwelling of warm Circumpolar Deep Water onto the shelf in the Amundsen Sea and/or increased freshening in the Ross Sea as has been inferred by previous, but limited, ocean surveys in these regions; and (3) to examine the spatial variability in ocean thermal structure along the ship\u0027s track (outside the transects) to provide greater regional context and to compare with ocean XBT data collected during Oden 2006-07. A repeated temperature survey between the Amundsen and Ross Sea is particularly invaluable, given that this sector is the regional center of the high latitude OAI response to ENSO, thus providing opportunity for examining and linking regional oceanic temporal variability to global climate variability. The research will improve our understanding of the high latitude OAI response to climate change, and provide the physical context for the observed biology and geochemistry (investigated by our colleagues. Our results will be made widely available through research publications and internet-available databases, and through the strong public outreach efforts of Lamont-Doherty Earth Observatory. The outreach efforts will help increase awareness and understanding of anthropogenic climate change, melting ice, and ecosystem alteration in the highly sensitive Antarctic.", "east": -100.0, "geometry": "POINT(-147.5 -74)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -69.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Yuan, Xiaojun; Stammerjohn, Sharon", "platforms": "Not provided", "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -79.0, "title": "SGER: Science-of-Opportunity Aboard Icebreaker Oden: Ocean-Atmosphere-Ice Interactions and Changes", "uid": "p0000562", "west": 165.0}, {"awards": "0338008 Wemple, Beverley", "bounds_geometry": null, "dataset_titles": "Laboratory Studies of Isotopic Exchange in Snow; Snow Accumulation and Snow Melt in a Mixed Northern Hardwood-Conifer Forest", "datasets": [{"dataset_uid": "609445", "doi": "10.7265/N51834DX", "keywords": "Atmosphere; Chemistry:ice; Chemistry:Ice; Snow/ice; Snow/Ice; Snow Sublimation Rate", "people": "Neumann, Thomas A.", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Studies of Isotopic Exchange in Snow", "url": "https://www.usap-dc.org/view/dataset/609445"}, {"dataset_uid": "609441", "doi": "10.7265/N54X55R2", "keywords": "Snow/ice; Snow/Ice", "people": "Wemple, Beverley C.", "repository": "USAP-DC", "science_program": null, "title": "Snow Accumulation and Snow Melt in a Mixed Northern Hardwood-Conifer Forest", "url": "https://www.usap-dc.org/view/dataset/609441"}], "date_created": "Fri, 01 Jan 2010 00:00:00 GMT", "description": "This award supports a project to develop a quantitative understanding of the processes active in isotopic exchange between snow/firn and water vapor, which is of paramount importance to ice core interpretation. Carefully controlled laboratory studies will be conducted at a variety of temperatures to empirically measure the mass transfer coefficient (the rate at which water moves from the solid to the vapor phase) for sublimating snow and to determine the time scale for isotopic equilibration between water vapor and ice. In addition the isotopic fractionation coefficient for vapor derived from sublimating ice will be determined and the results will be used to update existing models of mass transfer and isotopic evolution in firn. It is well known that water vapor moves through firn due to diffusion, free convection and forced convection. Although vapor movement through variably-saturated firn due to these processes has been modeled, because of a lack of laboratory data the mass transfer coefficient had to be estimated. Field studies have documented the magnitudes of post-depositional changes, but field studies do not permit rigorous analysis of the relative importance of the many processes which are likely to act in natural snow packs. The results of these laboratory investigations will be broadly applicable to a number of studies and will allow for improvement of existing physically-based models of post-depositional isotopic change, isotopic diffusion in firn, and vapor motion in firn. A major component of this project will be the design and fabrication of the necessary, novel experimental apparatus, which will be facilitated by existing technical expertise, cold room facilities, and laboratory equipment at CRREL. This project is a necessary step toward a quantitative understanding of the isotopic effects of water vapor movement in firn. The proposed work has broader impacts in several different areas. The modeling results will be applicable to a wide range of studies of water in the polar environment, including studies of wind-blown or drifting snow. The proposed collaborative study will partially support a Dartmouth graduate student for three years. This project will also provide support for a young first-time NSF investigator at the University of Vermont. Undergraduate students from Dartmouth will be involved in the research through the Women in Science Project and undergraduate students at the University of Vermont will be supported through the Research Experiences for Undergraduates program. The principal investigators and graduate student will continue their tradition of k-12 school outreach by giving science lessons and talks in local schools each year. Research results will be disseminated through scientific conferences, journal publications, and institutional seminars.", "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 PROBES \u003e SNOW TUBE; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e HYGROMETERS \u003e HYGROMETERS", "is_usap_dc": true, "keywords": "Snow Accumulation; Snow Chemistry; Snow Melt; Snowfall; Snow Water Equivalent; LABORATORY; Seasonal Snow Cover; Not provided; Snow; Sublimation Rate; FIELD SURVEYS; FIELD INVESTIGATION", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Neumann, Thomas A.; Wemple, Beverley 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": null, "south": null, "title": "Collaborative Research: Laboratory Studies of Isotopic Exchange in Snow and Firn", "uid": "p0000132", "west": null}, {"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": "0440919 Isbell, John; 0440954 Miller, Molly; 0551163 Sidor, Christian", "bounds_geometry": "POLYGON((159.3 -76.59,159.542 -76.59,159.784 -76.59,160.026 -76.59,160.268 -76.59,160.51 -76.59,160.752 -76.59,160.994 -76.59,161.236 -76.59,161.478 -76.59,161.72 -76.59,161.72 -76.811,161.72 -77.032,161.72 -77.253,161.72 -77.474,161.72 -77.695,161.72 -77.916,161.72 -78.137,161.72 -78.358,161.72 -78.579,161.72 -78.8,161.478 -78.8,161.236 -78.8,160.994 -78.8,160.752 -78.8,160.51 -78.8,160.268 -78.8,160.026 -78.8,159.784 -78.8,159.542 -78.8,159.3 -78.8,159.3 -78.579,159.3 -78.358,159.3 -78.137,159.3 -77.916,159.3 -77.695,159.3 -77.474,159.3 -77.253,159.3 -77.032,159.3 -76.811,159.3 -76.59))", "dataset_titles": "Burke Museum of Natural History and Culture, University of Washington ID#s UWBM 88593-88601, UWBM 88617; Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica", "datasets": [{"dataset_uid": "600045", "doi": "10.15784/600045", "keywords": "Allan Hills; Antarctica; Paleontology; Sample/collection Description; Sample/Collection Description; Solid Earth", "people": "Miller, Molly", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600045"}, {"dataset_uid": "000124", "doi": "", "keywords": null, "people": null, "repository": "Burke Museum", "science_program": null, "title": "Burke Museum of Natural History and Culture, University of Washington ID#s UWBM 88593-88601, UWBM 88617", "url": "http://www.washington.edu/burkemuseum/collections/"}], "date_created": "Mon, 12 Oct 2009 00:00:00 GMT", "description": "This project studies fossils from two to three hundred million year old rocks in the Allan Hills area of Antarctica. Similar deposits from lower latitudes have been used to develop a model of Permo-Triassic climate, wherein melting of continental glaciers in the early Permian leads to the establishment of forests in a cold, wet climate. Conditions became warmer and dryer by the early Triassic, inhibiting plant growth until a moistening climate in the late Triassic allowed plant to flourish once again. This project will test and refine this model and investigate the general effects of climate change on landscapes and ecosystems using the unique exposures and well-preserved fossil and sediment records in the Allan Hills area. The area will be searched for fossil forests, vertebrate tracks and burrows, arthropod trackways, and subaqueously produced biogenic structures, which have been found in other areas of Antarctica. Finds will be integrated with previous paleobiologic studies to reconstruct and interpret ecosystems and their changes. Structures and rock types documenting the end phases of continental glaciation and other major episodic sedimentations will also be described and interpreted. This project contributes to understanding the: (1) evolution of terrestrial and freshwater ecosystems and how they were affected by the end-Permian extinction, (2) abundance and diversity of terrestrial and aquatic arthropods at high latitudes, (3) paleogeographic distribution and evolution of vertebrates and invertebrates as recorded by trace and body fossils; and (3) response of landscapes to changes in climate.\u003cbr/\u003e\u003cbr/\u003eIn terms of broader impacts, this project will provide an outstanding introduction to field research for graduate and undergraduate students, and generate related opportunities for several undergraduates. It will also stimulate exchange of ideas among research and primarily undergraduate institutions. Novel outreach activities are also planned to convey Earth history to the general public, including a short film on the research process and products, and paintings by a professional scientific illustrator of Permo-Traissic landscapes and ecosystems.", "east": 161.72, "geometry": "POINT(160.51 -77.695)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.59, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e PALEOZOIC \u003e CARBONIFEROUS \u003e PENNSYLVANIAN; PHANEROZOIC \u003e PALEOZOIC \u003e PERMIAN; PHANEROZOIC \u003e MESOZOIC \u003e TRIASSIC", "persons": "Miller, Molly; Sidor, Christian; Isbell, John", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "Burke Museum; USAP-DC", "science_programs": "Allan Hills", "south": -78.8, "title": "Collaborative Research: Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica", "uid": "p0000207", "west": 159.3}, {"awards": "0739583 Bowser, Samuel; 0739512 Walker, Sally; 0739496 Miller, Molly", "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": "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": "601764", "doi": "10.15784/601764", "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Gillikin, David; Puhalski, Emma; Camarra, Steve; Cronin, Kelly; Verheyden, Anouk; Walker, Sally", "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": "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": "0538630 Severinghaus, Jeffrey", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 01 Apr 2009 00:00:00 GMT", "description": "0538630\u003cbr/\u003eSeveringhaus\u003cbr/\u003eThis award supports a project to produce the first record of Kr/N2 in the paleo-atmosphere as measured in air bubbles trapped in ice cores. These measurements may be indicative of past variations in mean ocean temperature. Knowing the mean ocean temperature in the past will give insight into past variations in deep ocean temperature, which remain poorly understood. Deep ocean temperature variations are important for understanding the mechanisms of climate change. Krypton is highly soluble in water, and its solubility varies with temperature, with higher solubilities at colder water temperatures. A colder ocean during the last glacial period would therefore hold more krypton than today\u0027s ocean. Because the total amount of krypton in the ocean-atmosphere system is constant, the increase in the krypton inventory in the glacial ocean should cause a resultant decrease in the atmospheric inventory of krypton. The primary goal of this work is to develop the use of Kr/N2 as an indicator of paleo-oceanic mean temperature. This will involve improving the analytical technique for the Kr/N2 measurement itself, and measuring the Kr/N2 in air bubbles in ice from the last glacial maximum (LGM) and the late Holocene in the Vostok and GISP2 ice cores. This provides an estimate of LGM mean ocean temperature change, and allows for a comparison between previous estimates of deep ocean temperature during the LGM. The Vostok ice core is ideal for this purpose because of the absence of melt layers, which compromise the krypton and xenon signal. Another goal is to improve precision on the Xe/N2 measurement, which could serve as a second, independent proxy of ocean temperature change. A mean ocean temperature time series during this transition may help to explain these observations. Additionally, the proposed work will measure the Kr/N2 from marine isotope stage (MIS) 3 in the GISP2 ice core. Knowing the past ocean temperature during MIS 3 will help to constrain sea level estimates during this time period. The broader impacts of the proposed work: are that it will provide the first estimate of the extent and timing of mean ocean temperature change in the past. This will help to constrain previously proposed mechanisms of climate change involving large changes in deep ocean temperature. This project will also support the education of a graduate student. The PI gives interviews and talks to the media and public about climate change, and the work will enhance these outreach activities. Finally, the work will occur during the International Polar Year (IPY), and will underscore the unique importance of the polar regions for understanding the global atmosphere and ocean system.", "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": "Severinghaus, Jeffrey P.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Paleoatmospheric Krypton and Xenon Abundances from Trapped Air in Polar Ice as Indicators of Past Mean Ocean Temperature", "uid": "p0000553", "west": null}, {"awards": "0228842 Grew, Edward", "bounds_geometry": "POLYGON((76 -69.3,76.05 -69.3,76.1 -69.3,76.15 -69.3,76.2 -69.3,76.25 -69.3,76.3 -69.3,76.35 -69.3,76.4 -69.3,76.45 -69.3,76.5 -69.3,76.5 -69.32,76.5 -69.34,76.5 -69.36,76.5 -69.38,76.5 -69.4,76.5 -69.42,76.5 -69.44,76.5 -69.46,76.5 -69.48,76.5 -69.5,76.45 -69.5,76.4 -69.5,76.35 -69.5,76.3 -69.5,76.25 -69.5,76.2 -69.5,76.15 -69.5,76.1 -69.5,76.05 -69.5,76 -69.5,76 -69.48,76 -69.46,76 -69.44,76 -69.42,76 -69.4,76 -69.38,76 -69.36,76 -69.34,76 -69.32,76 -69.3))", "dataset_titles": "Boron in Antarctic granulite-facies rocks: under what conditions is boron retained in the middle crust?", "datasets": [{"dataset_uid": "600030", "doi": "10.15784/600030", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Geochronology; Solid Earth", "people": "Grew, Edward", "repository": "USAP-DC", "science_program": null, "title": "Boron in Antarctic granulite-facies rocks: under what conditions is boron retained in the middle crust?", "url": "https://www.usap-dc.org/view/dataset/600030"}], "date_created": "Tue, 10 Mar 2009 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 role and fate of Boron in high-grade metamorphic rocks of the Larsemann Hills region of Antarctica. Trace elements provide valuable information on the changes sedimentary rocks undergo as temperature and pressure increase during burial. One such element, boron, is particularly sensitive to increasing temperature because of its affinity for aqueous fluids, which are lost as rocks are buried. Boron contents of unmetamorphosed pelitic sediments range from 20 to over 200 parts per million, but rarely exceed 5 parts per million in rocks subjected to conditions of the middle and lower crust, that is, temperatures of 700 degrees C or more in the granulite-facies, which is characterized by very low water activities at pressures of 5 to 10 kbar (18-35 km burial). Devolatization reactions with loss of aqueous fluid and partial melting with removal of melt have been cited as primary causes for boron depletion under granulite-facies conditions. Despite the pervasiveness of both these processes, rocks rich in boron are locally found in the granulite-facies, that is, there are mechanisms for retaining boron during the metamorphic process. The Larsemann Hills, Prydz Bay, Antarctica, are a prime example. More than 20 lenses and layered bodies containing four borosilicate mineral species crop out over a 50 square kilometer area, which thus would be well suited for research on boron-rich granulite-facies metamorphic rocks. \u003cbr/\u003e\u003cbr/\u003eWhile most investigators have focused on the causes for loss of boron, this work will investigate how boron is retained during high-grade metamorphism. Field observations and mapping in the Larsemann Hills, chemical analyses of minerals and their host rocks, and microprobe age dating will be used to identify possible precursors and deduce how the precursor materials recrystallized into borosilicate rocks under granulite-facies conditions. The working hypothesis is that high initial boron content facilitates retention of boron during metamorphism because above a certain threshold boron content, a mechanism \"kicks in\" that facilitates retention of boron in metamorphosed rocks. For example, in a rock with large amounts of the borosilicate tourmaline, such as stratabound tourmalinite, the breakdown of tourmaline to melt could result in the formation of prismatine and grandidierite, two borosilicates found in the Larsemann Hills. This situation is rarely observed in rocks with modest boron content, in which breakdown of tourmaline releases boron into partial melts, which in turn remove boron when they leave the system. Stratabound tourmalinite is associated with manganese-rich quartzite, phosphorus-rich rocks and sulfide concentrations that could be diagnostic for recognizing a tourmalinite protolith in a highly metamorphosed complex where sedimentary features have been destroyed by deformation. Because partial melting plays an important role in the fate of boron during metamorphism, our field and laboratory research will focus on the relationship between the borosilicate units, granite pegmatites and other granitic intrusives. The results of our study will provide information on cycling of boron at deeper levels in the Earth\u0027s crust and on possible sources of boron for granites originating from deep-seated rocks.\u003cbr/\u003e\u003cbr/\u003eAn undergraduate student will participate in the electron microprobe age-dating of monazite and xenotime as part of a senior project, thereby integrating the proposed research into the educational mission of the University of Maine. In response to a proposal for fieldwork, the Australian Antarctic Division, which maintains Davis station near the Larsemann Hills, has indicated that they will support the Antarctic fieldwork.", "east": 76.5, "geometry": "POINT(76.25 -69.4)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION", "locations": null, "north": -69.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Grew, Edward", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.5, "title": "Boron in Antarctic granulite-facies rocks: under what conditions is boron retained in the middle crust?", "uid": "p0000431", "west": 76.0}, {"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": "Thom, Jonathan; MacAyeal, Douglas; Sergienko, Olga", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Firn Temperatures, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609352"}, {"dataset_uid": "609353", "doi": "10.7265/N5GF0RFF", "keywords": "Glaciology; Iceberg; Oceans; Ross Ice Shelf; Sea Ice; Southern Ocean; Tiltmeter", "people": "Kim, Young-Jin; Bliss, Andrew; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Tiltmeter Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609353"}, {"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": "609350", "doi": "10.7265/N5VM496K", "keywords": "AWS; Glaciology; GPS; Iceberg; Meteorology; Oceans; Ross Sea; Sea Ice; Southern Ocean; Weatherstation", "people": "Okal, Emile; MacAyeal, Douglas; Aster, Richard; Bassis, Jeremy", "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": "609349", "doi": "10.7265/N5445JD6", "keywords": "Geology/Geophysics - Other; Glaciology; Iceberg; Oceans; Ross Sea; Sea Ice; Seismometer; Southern Ocean", "people": "MacAyeal, Douglas; Okal, Emile; Aster, Richard; Bassis, Jeremy", "repository": "USAP-DC", "science_program": null, "title": "Iceberg Harmonic Tremor, Seismometer Data, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609349"}, {"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": "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"}, {"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": "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": "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": "609354", "doi": "10.7265/N5BP00Q3", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ross Ice Shelf; Snow/ice; Snow/Ice; Temperature", "people": "Muto, Atsu; Sergienko, Olga; MacAyeal, Douglas; Scambos, Ted", "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/"}], "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": "0338279 Siddoway, Christine", "bounds_geometry": "POLYGON((-157 -75,-155.3 -75,-153.6 -75,-151.9 -75,-150.2 -75,-148.5 -75,-146.8 -75,-145.1 -75,-143.4 -75,-141.7 -75,-140 -75,-140 -75.3,-140 -75.6,-140 -75.9,-140 -76.2,-140 -76.5,-140 -76.8,-140 -77.1,-140 -77.4,-140 -77.7,-140 -78,-141.7 -78,-143.4 -78,-145.1 -78,-146.8 -78,-148.5 -78,-150.2 -78,-151.9 -78,-153.6 -78,-155.3 -78,-157 -78,-157 -77.7,-157 -77.4,-157 -77.1,-157 -76.8,-157 -76.5,-157 -76.2,-157 -75.9,-157 -75.6,-157 -75.3,-157 -75))", "dataset_titles": "Bedrock sample data, Ford Ranges region (Marie Byrd Land)", "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"}], "date_created": "Wed, 09 Jul 2008 00:00:00 GMT", "description": "This project will study migmatite domes found in the Fosdick Mountains of the Ford Ranges, western Marie Byrd Land, Antarctica. This area offers unique, three-dimensional exposures that may offer new insight into dome formation, which is a fundamental process of mountain building. These domes are derived from sedimentary and plutonic protoliths that are complexly interfolded at decimeter to kilometer scales. Preliminary findings from geobarometry and U-Pb monazite dating of anatexite suggest that peak metamorphism was underway at 105 Ma at crustal depths of ~25 km, followed by decompression as the Fosdick dome was emplaced to 16-17 km, or possibly as low as 8.5 km, in the crust by 99 Ma. Near-isothermal conditions were maintained during ascent, favorable for producing substantial volumes of melt through biotite-dehydration melting. This dome has been interpreted as a product of extensional exhumation. This is a viable interpretation from the regional standpoint, because the dome was emplaced in mid-Cretaceous time during the rapid onset of divergent tectonics along the proto- Pacific margin of Gondwana. However, the complex internal structures of the Fosdick Mountains have yet to be considered and may be more consistent with alternative intepretations such as upward extrusion within a contractional setting or lateral flow within a transcurrent attachment zone. This proposal is for detailed structural analysis, paired with geothermobarometry and geochronology, to determine the flow behavior and structural style that produced the internal architecture of the Fosdick dome. The results will improve our general understanding of the role of gneiss domes in transferring material and heat during mountain-building, and will characterize the behavior of the middle crust during a time of rapid transition from divergent to convergent tectonics along the active margin of Gondwana. In terms of broader impacts, this work will train undergraduate and graduate students, and involve them as collaborators in the development of curricular materials. It will also foster mentoring relationships between graduate and undergraduate students.", "east": -140.0, "geometry": "POINT(-148.5 -76.5)", "instruments": null, "is_usap_dc": false, "keywords": "Transcurrent Faults; Geochronology; Tectonic; Detachment Faults; Structural Geology; Not provided; Gneiss Dome; Migmatite", "locations": null, "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Siddoway, Christine; Teyssier, Christian", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Gneiss Dome architecture: Investigation of Form and Process in the Fosdick Mountains, W. Antarctica", "uid": "p0000744", "west": -157.0}, {"awards": "0233823 Fountain, Andrew; 0230338 Hallet, Bernard", "bounds_geometry": "POLYGON((162.132 -77.73,162.1495 -77.73,162.167 -77.73,162.1845 -77.73,162.202 -77.73,162.2195 -77.73,162.237 -77.73,162.2545 -77.73,162.272 -77.73,162.2895 -77.73,162.307 -77.73,162.307 -77.7303,162.307 -77.7306,162.307 -77.7309,162.307 -77.7312,162.307 -77.7315,162.307 -77.7318,162.307 -77.7321,162.307 -77.7324,162.307 -77.7327,162.307 -77.733,162.2895 -77.733,162.272 -77.733,162.2545 -77.733,162.237 -77.733,162.2195 -77.733,162.202 -77.733,162.1845 -77.733,162.167 -77.733,162.1495 -77.733,162.132 -77.733,162.132 -77.7327,162.132 -77.7324,162.132 -77.7321,162.132 -77.7318,162.132 -77.7315,162.132 -77.7312,162.132 -77.7309,162.132 -77.7306,162.132 -77.7303,162.132 -77.73))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 02 Jul 2008 00:00:00 GMT", "description": "This award supports a comprehensive study of land-based polar ice cliffs. Through field measurements, modeling, and remote sensing, the physics underlying the formation of ice cliffs at the margin of Taylor Glacier in the McMurdo Dry Valleys will be investigated. At three sites, measurements of ice deformation and temperature fields near the cliff face will be combined with existing energy balance data to quantify ice-cliff evolution over one full seasonal cycle. In addition, a small seismic network will monitor local \"ice quakes\" associated with calving events. Numerical modeling, validated by the field data, will enable determination of the sensitivity of ice cliff evolution to environmental variables. There are both local and global motivations for studying the ice cliffs of Taylor Glacier. On a global scale, this work will provide insight into the fundamental processes of calving and glacier terminus A better grasp of ice cliff processes will also improve boundary conditions required for predicting glaciers\u0027 response to climate change. Locally, the Taylor Glacier is an important component of the McMurdo Dry Valleys landscape and the results of this study will aid in defining ecologically-important sources of glacial meltwater and will lead to a better understanding of moraine formation at polar ice cliffs. This study will help launch the career of a female scientist, will support one graduate student, and provide experiential learning experiences for two undergraduates. The post-doctoral researcher will also use this research in the curriculum of a wilderness science experiential education program for high school girls.", "east": 162.307, "geometry": "POINT(162.2195 -77.7315)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOCOUPLES \u003e THERMOCOUPLES; 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 SEISMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e SURVEYING TOOLS", "is_usap_dc": false, "keywords": "SEISMOLOGICAL STATIONS; Ice Quakes; Ice Cliffs; Not provided; Taylor Glacier; FIELD SURVEYS; Remote Sensing; GROUND-BASED OBSERVATIONS; Modeling; Ice Deformation; Glacial Meltwater; FIELD INVESTIGATION; McMurdo Dry Valleys", "locations": "McMurdo Dry Valleys; Taylor Glacier", "north": -77.73, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Hallet, Bernard; Fountain, Andrew", "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; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS; Not provided", "repositories": null, "science_programs": null, "south": -77.733, "title": "Collaborative Research: Mechanics of Dry-Land Calving of Ice Cliffs", "uid": "p0000721", "west": 162.132}, {"awards": "0127022 Jeffrey, Wade", "bounds_geometry": "POLYGON((-177.639 -43.5676,-143.1091 -43.5676,-108.5792 -43.5676,-74.0493 -43.5676,-39.5194 -43.5676,-4.9895 -43.5676,29.5404 -43.5676,64.0703 -43.5676,98.6002 -43.5676,133.1301 -43.5676,167.66 -43.5676,167.66 -46.99877,167.66 -50.42994,167.66 -53.86111,167.66 -57.29228,167.66 -60.72345,167.66 -64.15462,167.66 -67.58579,167.66 -71.01696,167.66 -74.44813,167.66 -77.8793,133.1301 -77.8793,98.6002 -77.8793,64.0703 -77.8793,29.5404 -77.8793,-4.9895 -77.8793,-39.5194 -77.8793,-74.0493 -77.8793,-108.5792 -77.8793,-143.1091 -77.8793,-177.639 -77.8793,-177.639 -74.44813,-177.639 -71.01696,-177.639 -67.58579,-177.639 -64.15462,-177.639 -60.72345,-177.639 -57.29228,-177.639 -53.86111,-177.639 -50.42994,-177.639 -46.99877,-177.639 -43.5676))", "dataset_titles": "Expedition Data; Ross Sea microbial biomass and production", "datasets": [{"dataset_uid": "600029", "doi": "10.15784/600029", "keywords": "Biota; Chemistry:fluid; Chemistry:Fluid; CTD Data; Microbiology; Oceans; Phytoplankton; Ross Sea; Southern Ocean", "people": "Jeffrey, Wade H.", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea microbial biomass and production", "url": "https://www.usap-dc.org/view/dataset/600029"}, {"dataset_uid": "001584", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0508"}, {"dataset_uid": "001690", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0304B"}], "date_created": "Thu, 12 Jun 2008 00:00:00 GMT", "description": "Ultraviolet radiation influences the dynamics of plankton processes in the near-surface waters of most aquatic ecosystems. In particular, the Southern Ocean is affected in the austral spring period when biologically damaging ultraviolet radiation is enhanced by ozone depletion. While progress has been made in estimating the quantitative impact of ultraviolet radiation on bacteria and phytoplankton in the Southern Ocean, some important issues remain to be resolved. Little is known about responses in systems dominated by the colonial haptophyte Phaeocystis antarctica, which dominates spring blooms in a polyna that develops in the southern Ross Sea. The Ross Sea is also of interest because of the occurrence of open water at a far southerly location in the spring, well within the ozone hole, and continuous daylight, with implications for the regulation of DNA repair. A number of studies suggest that vertical mixing can significant modify the impact of ultraviolet radiation in the Southern Ocean and elsewhere. However, there are limited measurements of turbulence intensity in the surface layer and measurements have not been integrated with parallel studies of ultraviolet radiation effects on phytoplankton and bacterioplankton. To address these issues, this collaborative study will focus on vertical mixing and the impact of ultraviolet radiation in the Ross Sea. The spectral and temporal responses of phytoplankton and bacterioplankton to ultraviolet radiation will be characterized in both laboratory and solar incubations. These will lead to the definition of biological weighting functions and response models capable of predicting the depth and time distribution of ultraviolet radiation impacts on photosynthesis, bacterial incorporation and DNA damage in the surface layer. Diel sampling will measure depth-dependent profiles of DNA damage, bacterial incorporation, photosynthesis and fluorescence parameters over a 24 h cycle. Sampling will include stations with contrasting wind-driven mixing and stratification as the polyna develops. The program of vertical mixing measurements is optimized for the typical springtime Ross Sea situation in which turbulence of intermediate intensity is insufficient to mix the upper layer thoroughly in the presence of stabilizing influences like solar heating and/or surface freshwater input from melting ice. Fine-scale vertical density profiles will be measured with a free-fall CTD unit and the profiles will be used to directly estimate large-eddy scales by determining Thorpe scales. Eddy scales and estimated turbulent diffusivities will be directly related to surface layer effects, and used to generate lagrangian depth-time trajectories in models of ultraviolet radiation responses in the surface mixed layer. The proposed research will be the first in-depth study of ultraviolet radiation effects in the Ross Sea and provide a valuable comparison with previous work in the Weddell-Scotia Confluence and Palmer Station regions. It will also enhance the understanding of vertical mixing processes, trophic interactions and biogeochemical cycling in the Ross Sea.", "east": 167.66, "geometry": "POINT(-4.9895 -60.72345)", "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; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e WATER BOTTLES; 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 CHEMICAL METERS/ANALYZERS \u003e FLUORESCENCE MICROSCOPY; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e GO-FLO BOTTLES", "is_usap_dc": true, "keywords": "R/V NBP; B-15J", "locations": "B-15J", "north": -43.5676, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Jeffrey, Wade H.; Neale, Patrick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -77.8793, "title": "Collaborative Proposal: Interactive Effects of UV Radiation and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross See Phaeocystis Blooms", "uid": "p0000578", "west": -177.639}, {"awards": "0337656 Lee, Richard", "bounds_geometry": "POLYGON((-64.1 -64.75,-64.085 -64.75,-64.07 -64.75,-64.055 -64.75,-64.04 -64.75,-64.025 -64.75,-64.01 -64.75,-63.995 -64.75,-63.98 -64.75,-63.965 -64.75,-63.95 -64.75,-63.95 -64.757,-63.95 -64.764,-63.95 -64.771,-63.95 -64.778,-63.95 -64.785,-63.95 -64.792,-63.95 -64.799,-63.95 -64.806,-63.95 -64.813,-63.95 -64.82,-63.965 -64.82,-63.98 -64.82,-63.995 -64.82,-64.01 -64.82,-64.025 -64.82,-64.04 -64.82,-64.055 -64.82,-64.07 -64.82,-64.085 -64.82,-64.1 -64.82,-64.1 -64.813,-64.1 -64.806,-64.1 -64.799,-64.1 -64.792,-64.1 -64.785,-64.1 -64.778,-64.1 -64.771,-64.1 -64.764,-64.1 -64.757,-64.1 -64.75))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 06 Jun 2008 00:00:00 GMT", "description": "Polar terrestrial environments are often described as deserts, where water availability is recognized as one of the most important limits on the distribution of terrestrial organisms. In addition, prolonged low winter temperatures threaten survival, and summer temperatures challenge organisms with extensive diel variations and rapid transitions from freezing to desiccating conditions. Global warming has further impacted the extreme thermal and hydric conditions experienced by Antarctic terrestrial plant and arthropod communities, especially as a result of glacial retreat along the Antarctic Peninsula. This research will focus on thermal and hydric adaptations in the terrestrial midge, Belgica antarctica, the largest and most southerly holometabolous insect living in this challenging and changing environment. \u003cbr/\u003eOverwintering midge larvae encased in the frozen substrate must endure desert-like conditions for more than 300 days since free water is biologically unavailable as ice. During the summer, larvae may be immersed in melt water or outwash from penguin colonies and seal wallows, in addition to saltwater splash. Alternatively, the larvae may be subjected to extended periods of desiccation as their microhabitats dry out. Due to their small size, relative immobility and the patchiness of suitable microhabitats, larvae may thus be subjected to stresses that include desiccation, hypo- or hyperosmotic conditions, high salinity exposure, and anoxia for extended periods. Research efforts will focus in three areas relevant to the stress tolerance mechanisms operating in these midges:(1) obtaining a detailed characterization of microclimatic conditions experienced by B. antarctica, especially those related to thermal and hydric diversity, both seasonally and among microhabitat types in the vicinity of Palmer Station, Antarctica; (2) examining the effects of extreme fluctuations in water availability and effects on physiological and molecular responses - to determine if midge larvae utilize the mechanism of cryoprotective dehydration for winter survival, and if genes encoding heat shock proteins and other genes are upregulated in larval responses to dehydration and rehydration; (3) investigating the dietary transmission of cryoprotectants from plant to insect host, which will test the hypothesis that midge larvae acquire increased resistance to desiccation and temperature stress by acquiring cryoprotectants from their host plants. \u003cbr/\u003eThis project will provide outreach to both elementary and secondary educators and their students. The team will include a teacher who will benefit professionally by full participation in the research, and will also assist in providing outreach to other teachers and their students. From Palmer Station, the field team will communicate daily research progress by e-mail supplemented with digital pictures with teachers and their elementary students to stimulate interest in an Antarctic biology and scientific research. These efforts will be supplemented with presentations at local schools and national teacher meetings, and by publishing hands-on, inquiry-based articles related to cryobiology and polar biology in education journals. Furthermore, the principal investigators will maintain major commitments to training graduate students and postdoctoral scholars, as well as undergraduate students by providing extended research experience that includes publication of scientific papers and presentations at national meetings.", "east": -63.95, "geometry": "POINT(-64.025 -64.785)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -64.75, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Denlinger, David; Lee, Richard", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -64.82, "title": "Physiological and Molecular Mechanisms of Stress Tolerance in a Polar Insect", "uid": "p0000742", "west": -64.1}, {"awards": "0701232 Martinson, Douglas", "bounds_geometry": "POLYGON((-72 -64,-71.2 -64,-70.4 -64,-69.6 -64,-68.8 -64,-68 -64,-67.2 -64,-66.4 -64,-65.6 -64,-64.8 -64,-64 -64,-64 -64.4,-64 -64.8,-64 -65.2,-64 -65.6,-64 -66,-64 -66.4,-64 -66.8,-64 -67.2,-64 -67.6,-64 -68,-64.8 -68,-65.6 -68,-66.4 -68,-67.2 -68,-68 -68,-68.8 -68,-69.6 -68,-70.4 -68,-71.2 -68,-72 -68,-72 -67.6,-72 -67.2,-72 -66.8,-72 -66.4,-72 -66,-72 -65.6,-72 -65.2,-72 -64.8,-72 -64.4,-72 -64))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 03 Jun 2008 00:00:00 GMT", "description": "The Antarctic Peninsula (AP) is characterized by (1) the most rapid recent regional (winter) warming (5.35 times global mean), (2) a loss of nearly all its perennial sea ice cover on its western margin, and (3) 87% of the glaciers in retreat, contributing to global sea level rise. An ability to understand this change depends upon researchers\u0027 ability to better understand the underlying sources of this change and their driving mechanisms. Despite intensive efforts, the western AP (WAP) is chronically under-sampled. Therefore developing a capability to maintain a sustained in situ presence is a high scientific priority. The current proposal addresses this critical need through 2 objectives: (1) establish the feasibility of a Slocum Webb ocean glider to enable real-time high resolution data-adaptive polar oceanographic research; (2) address a critical question involving the regional climate change by measuring the ocean heat budget within a grid containing 14 years of ship-based ocean snapshots. This will involve the launch of the glider during the PAL-LTER austral summer research cruise, where it will fly the full along-shore distance of the LTER sample grid to be recovered at the southern extreme when the ship arrives there later in the summer. The glider will provide nearly continuous ocean property (temperature, salinity and pressure) coverage over this distance.\u003cbr/\u003e\u003cbr/\u003eIntellectual merit. The proposed activity will involve state of the art sampling methodology that will revolutionize the ability to address climate change and other scientific issues requiring sampling densities that could not be achieved by research vessels. Specifically, the adaptive sampling capability of the glider will be used to alter its course allowing identification of routes by which the source waters of the ocean heat (and nutrients) enter the continental shelf region, while the near-continuous sampling will provide a diagnosis of how well standard shipborne stations close the heat budget. Resources are adequate for this study due to heavy leveraging by the availability of the Rutgers SLOCUM Web glider, glider control center and participation of the team of experts that flew the first such glider.\u003cbr/\u003e\u003cbr/\u003eBroader Impacts. The proposed activity will advance discovery and understanding of the WAP responses to climate variability, to study the intricate feedback mechanisms associated with this variability and to better understand the chemical and physical processes associated with climate change. The data will be made available across the World Wide Web as it is collected, almost in real time, a potential bonanza for scientists during the upcoming International Polar Year, for classroom instruction and general outreach. Society will ultimately benefit from the improved knowledge of how climate change elsewhere in the world is impacting the unique ecosystem of the Antarctic, and driving glacial melt (sea level rise), among its other influences.", "east": -64.0, "geometry": "POINT(-68 -66)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e TEMPERATURE PROFILERS", "is_usap_dc": false, "keywords": "Pressure; Oceanography; AUVS; SLOCUM Web Glider; Salinity; Climate; Sampling", "locations": null, "north": -64.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Martinson, Douglas; Kerfoot, John", "platforms": "WATER-BASED PLATFORMS \u003e UNCREWED VEHICLES \u003e SUBSURFACE \u003e AUVS", "repositories": null, "science_programs": null, "south": -68.0, "title": "Collaborative Research: Sloccum Glider in Western Antarctic Peninsula Continental Shelf Waters Pilot Study", "uid": "p0000734", "west": -72.0}, {"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": "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; Bohlander, Jennifer; Scambos, Ted; Yermolin, Yevgeny; 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"}, {"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"}], "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": "0603729 Mukasa, Samuel", "bounds_geometry": "POLYGON((161.2 -77.5029,161.26 -77.5029,161.32 -77.5029,161.38 -77.5029,161.44 -77.5029,161.5 -77.5029,161.56 -77.5029,161.62 -77.5029,161.68 -77.5029,161.74 -77.5029,161.8 -77.5029,161.8 -77.52511,161.8 -77.54732,161.8 -77.56953,161.8 -77.59174,161.8 -77.61395,161.8 -77.63616,161.8 -77.65837,161.8 -77.68058,161.8 -77.70279,161.8 -77.725,161.74 -77.725,161.68 -77.725,161.62 -77.725,161.56 -77.725,161.5 -77.725,161.44 -77.725,161.38 -77.725,161.32 -77.725,161.26 -77.725,161.2 -77.725,161.2 -77.70279,161.2 -77.68058,161.2 -77.65837,161.2 -77.63616,161.2 -77.61395,161.2 -77.59174,161.2 -77.56953,161.2 -77.54732,161.2 -77.52511,161.2 -77.5029))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 02 Aug 2007 00:00:00 GMT", "description": "This Small Grant for Exploratory Research supports measurement of PGE abundances and Hf, Nd, Sr and Pb isotopic ratios of the Basement Sill and Dais Intrusion lobe of the Ferrar Magmatic Province, Antarctica. This province played a key role in the breakup of Gondwanaland. Models to be tested are magma production by plume activity versus decompression melting in a fossil subduction zone. The PGE data will also be used to evaluate the behavior of volatiles during magma crystallization, which other evidence indicates may have reached saturation. The samples to be studied were collected during the NSF-sponsored, Magmatic Field Laboratory Workshop held in Antarctica in 2005. This study\u0027s results will be compliled with complementary data from other attendees to develop a new multidisciplinary model of Ferrar magmatism.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts fo this work include international collaboration and informal science education through public outreach to K12 students.", "east": 161.8, "geometry": "POINT(161.5 -77.61395)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS", "is_usap_dc": false, "keywords": "Magma Crystallization; Ferrar Magmatic Province; Dais Intrusion Lobe; Basement Sill; Antarctic; HELICOPTER; Ferrar Magmatism; Antarctica", "locations": "Basement Sill; Ferrar Magmatic Province; Antarctica; Antarctic", "north": -77.5029, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Mukasa, Samuel", "platforms": "AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER \u003e HELICOPTER", "repositories": null, "science_programs": null, "south": -77.725, "title": "SGER: Basement Sill, Antarctica: Constraints from its PGE Abundance Patterns and Isotopic Compositions on Magma Source Characteristics and Crystallization Processes", "uid": "p0000278", "west": 161.2}, {"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": "Raymond, Charles; Nereson, Nadine A.", "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": "0230149 McGwire, Kenneth", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 04 Jun 2007 00:00:00 GMT", "description": "This award supports the development of novel methods for digital image analysis of glacial ice cores that are stored at the National Ice Core Laboratory (NICL) in Denver, Colorado. Ice cores are a critical source of information on how Earth has changed over time, since indicators of local climate (snow accumulation, temperature), regional characteristics (wind-blown materials such as sea salt, dust and pollen), global processes (e.g., CO2, methane), and even extraterrestrial influences (cosmogenic isotopes) are stored in the ice on a common time scale. This project will develop a high-resolution optical scanning system for laboratory curation of ice core images, internet-based search and retrieval capabilities, a digital image analysis system specifically for ice core studies, and methods to integrate ice core image analysis with other dating methods. These tools will be developed and tested in conjunction with scientific investigations of NICL holdings. Optical scanning and analysis tools will improve understanding of the historical development of the ice collected from a particular location and will help to resolve challenges such as ice that has lost stratigraphic order through flow processes. \u003cbr/\u003eBy providing permanent online digital archives of ice core images, this project will greatly improve the documentation and availability of ice core data while reducing time and costs for subsequent scientific investigations. Using the internet, ice core scientists will be able to determine the appropriateness of specific NICL holdings for various scientific studies. By optically scanning ice cores as they are processed at NICL, any researcher will be able to examine an ice core in similar detail to the few investigators who were fortunate enough to observe it before modifications from sampling and storage. Re-examination of cores could be done decades later by anyone at any location, which is not possible now because only the interpretation of the original observer is recorded. Integration of digital image data into ice core analysis will speed discovery, allow collaborative interpretation, and enhance consistency of analysis to improve ice core dating, identification of melt layers, location of flow disturbances, and more. The equipment will be housed at NICL and will be available to the broad community, improving scientific infrastructure.\u003cbr/\u003eThis work will also have numerous broader impacts. Ice core science addresses fundamental questions of human interest related to global warming, abrupt climate change, biogeochemical cycling, and more. The principal investigators broadly disseminate their scientific findings through numerous outlets, ranging from meeting with government officials, chairing and serving on NRC panels, writing popular books and articles, publishing in scientific literature, teaching classes, talking to civic groups, and appearing on radio and television. The results from ice core analyses have directly informed policymakers and will continue to do so. Thus, by improving ice core science, this projectl will benefit society.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e VISUAL OBSERVATIONS", "is_usap_dc": false, "keywords": "Image; Ice Core; Not provided; Scanner; Stratigraphy", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McGwire, Kenneth C.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Digital Optical Imaging of Ice Cores for Curation and Scientific Applications", "uid": "p0000735", "west": null}, {"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": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Blankenship, Donald D.; Muldoon, Gail R.; Young, Duncan A.; Jackson, Charles", "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": "609292", "doi": "10.7265/N59W0CDC", "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Solid Earth", "people": "Holt, John W.; Young, Duncan A.; Corr, Hugh F. J.; Blankenship, Donald D.; Morse, David L.; Vaughan, David G.", "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"}], "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": "0126149 Liu, Hongxing", "bounds_geometry": null, "dataset_titles": "Access to Antarctic coastline coverage and reference documents; Access to Antarctic snow zone coverage and reference documents; Access to boundary file and reference documents; Access to ice velocity data and reference documents; Access to snow melt extent image files and reference documents", "datasets": [{"dataset_uid": "001779", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to ice velocity data and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001640", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to snow melt extent image files and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001350", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to boundary file and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001351", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to Antarctic coastline coverage and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001352", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to Antarctic snow zone coverage and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}], "date_created": "Tue, 15 Aug 2006 00:00:00 GMT", "description": "This award supports a project to characterize the morphology, ice motion velocity and mass balance of Lambert Glacier, Antarctica using state-of-the-art remote sensing and GIS techniques. Lambert Glacier is the largest ice stream in the world. Because of its size, it plays a fundamental role in the study of glacial dynamics and mass budget in response to present and future climate changes. Along with the bedrock topography and ice thickness data derived from airborne radio echo soundings and snow accumulation data compiled from ground-based measurements, the dynamic behavior and mass balance of the Lambert glacial basin in a Geographic Information Systems (GIS) environment will be examined. Specific objectives are to: (1) Extract two-dimensional ice velocity field over the entire Lambert glacial basin using speckle matching and differential interferometric SAR (InSAR) techniques, and produce a full coverage of radar coherence map over the drainage basin. With the ice velocity data, calculate the strain rate field from the initiation areas of the ice stream onto the Amery Ice Shelf; (2) Derive high-resolution digital elevation model (DEM) over the Lambert glacial drainage basin using SAR stereo, differential interferometric SAR, and GLAS laser altimetry techniques. Based on the DEM, extract ice divides and ice flow directions, delineate the snow catchment basin, and calculate the balance deformation velocity and the basal shear stress; (3) Interpolate traverse ice thickness data collected by Australian and Russian airborne radio echo sounding surveys into a regular grid, and derive a regular grid of bedrock topography in combination with the DEM; (4) Integrate newly derived ice velocity and ice thickness data as well as snow accumulation rate data compiled from previous ground-based measurements into a geographic information system (GIS), and calculate the mass flux through the ice stream at the grounding lines and net mass balance throughout the drainage basin. With these new measurements and calculations derived from advanced remote sensing techniques, we will be able to improve our understanding of dynamic behavior and current mass balance status of the Lambert glacial basin, gain an insight on the relationship between ice mass change and the variation in regional and global climate at decadal scale, and provide an evaluation on the issue of whether the Lambert glacier basin is subject to surging in the context of future climate change.", "east": null, "geometry": null, "instruments": "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; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IFSAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR", "is_usap_dc": false, "keywords": "DEM; Not provided; RADARSAT-1", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Liu, Hongxing; Jezek, Kenneth", "platforms": "Not provided; OTHER \u003e MODELS \u003e DEM; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e RADARSAT \u003e RADARSAT-1", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": null, "title": "High-Resolution Modeling of Surface Topography, Ice Motion, and Mass Balance in the Lambert Glacial Basin using Radar Remote Sensing and GIS Techniques", "uid": "p0000204", "west": null}, {"awards": "0088047 Bell, Robin", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 03 Jan 2006 00:00:00 GMT", "description": "0088047\u003cbr/\u003eBell\u003cbr/\u003e\u003cbr/\u003eThis award supports a two year project to address fundamental questions about the mass and energy flux through Lake Vostok, a subglacial lake in East Antarctica, sealed beneath almost 4 kilometers of ice. The project will involve developing lake circulation models, complemented by the analysis of new ice penetrating radar data over the lake and surrounding regions. This project will help to accurately define the regions of melting and freezing within the lake and help to provide an improved estimate of the form of the lake. The combined data analysis and modeling effort will provide a critical framework for developing international plans to sample the waters of Lake Vostok for biota and to recover sediments from Lake Vostok for paleoclimate studies.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Paleoclimate; Circulation Models; Lake Vostok; Data Analysis; Subglacial; Modeling; Not provided", "locations": "Lake Vostok", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bell, Robin; Tremblay, Bruno; Hohmann, Roland; Clarke, Garry; Studinger, Michael S.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Mass and Energy Fluxes Through Lake Vostok: Observations and Models", "uid": "p0000093", "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": "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": "Meese, Deb; Gow, Tony; Saltzman, Eric; Watson, M. Scott; Grootes, Pieter; Mayewski, Paul A.; Sowers, Todd A.", "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"}, {"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"}], "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": "0087235 Grew, Edward", "bounds_geometry": "POLYGON((42 -64,43.2 -64,44.4 -64,45.6 -64,46.8 -64,48 -64,49.2 -64,50.4 -64,51.6 -64,52.8 -64,54 -64,54 -64.4,54 -64.8,54 -65.2,54 -65.6,54 -66,54 -66.4,54 -66.8,54 -67.2,54 -67.6,54 -68,52.8 -68,51.6 -68,50.4 -68,49.2 -68,48 -68,46.8 -68,45.6 -68,44.4 -68,43.2 -68,42 -68,42 -67.6,42 -67.2,42 -66.8,42 -66.4,42 -66,42 -65.6,42 -65.2,42 -64.8,42 -64.4,42 -64))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 09 Aug 2004 00:00:00 GMT", "description": "0087235\u003cbr/\u003eGrew\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the role of beryllium in lower crustal partial melting events. The formation of granitic liquids by partial melting deep in the Earth\u0027s crust is one of the major topics of research in igneous and metamorphic petrology today. One aspect of this sphere of research is the beginning of the process, specifically, the geochemical interaction between melts and source rocks before the melt has left the source area. One example of anatexis in metamorphic rocks affected by conditions found deep in the Earth\u0027s crust is pegmatite in the Archean ultrahigh temperature granulite-facies Napier Complex of Enderby Land, East Antarctica. Peak conditions for this granulite-facies metamorphism are estimated to have reached nearly 1100 Degrees Celsius and 11 kilobar, that is, conditions in the Earth\u0027s lower crust in Archean time. The proposed research is a study of the Napier Complex pegmatites with an emphasis on the minerals and geochemistry of beryllium. This element, which is estimated to constitute 3 ppm of the Earth\u0027s upper crust, is very rarely found in any significant concentrations in metamorphic rocks subjected to conditions of the Earth\u0027s lower crust. Structural, geochronological, and mineralogical studies will be carried out to test the hypothesis that the beryllium pegmatites resulted from anatexis of their metapelitic host rocks during the ultrahigh-temperature metamorphic event in the late Archean. Host rocks will be analyzed for major and trace elements. Minerals will be analyzed by the electron microprobe for major constituents including fluorine and by the ion microprobe for lithium, beryllium and boron. The analytical data will be used to determine how beryllium and other trace constituents were extracted from host rocks under ultrahigh-temperature conditions and subsequently concentrated in the granitic melt, eventually to crystallize out in a pegmatite as beryllian sapphirine and khmaralite, minerals not found in pegmatites elsewhere. Mineral compositions and assemblages will be used to determine the evolution and conditions of crystallization and recrystallization of the pegmatites and their host rocks during metamorphic episodes following the ultrahigh-temperature event. Monazite will be analyzed for lead, thorium and uranium to date the ages of these events. Because fluorine is instrumental in mobilizing beryllium, an undergraduate student will study the magnesium fluorphosphate wagnerite in the pegmatites in order to estimate fluorine activity in the melt as part of a senior project. The results of the present project will provide important insights on the melting process in general and on the geochemical behavior of beryllium in particular under the high temperatures and low water activities characteristic of the Earth\u0027s lower crust.", "east": 54.0, "geometry": "POINT(48 -66)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ION MICROPROBES", "is_usap_dc": false, "keywords": "Metamorphism; Li; Be; Pegmatitic Leucosomes; Partial Melting; Lithium; Granulites; Napier Complex; Boron; Beryllium; Mineralogy; Not provided; Continental Crust", "locations": "Napier Complex", "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Grew, Edward", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -68.0, "title": "Beryllium in Antarctic Ultrahigh-Temperature Granulite-Facies Rocks and its Role in Partial Melting of the Lower Continental Crust", "uid": "p0000370", "west": 42.0}, {"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": "9316715 Taylor, Susan", "bounds_geometry": null, "dataset_titles": "Micrometeorites from the South Pole Water Well", "datasets": [{"dataset_uid": "609113", "doi": "10.7265/N5R49NQK", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Cosmos; Geochemistry; Meteorite; Scanning Electron Microscope (SEM) Images; South Pole", "people": "Taylor, Susan", "repository": "USAP-DC", "science_program": null, "title": "Micrometeorites from the South Pole Water Well", "url": "https://www.usap-dc.org/view/dataset/609113"}], "date_created": "Tue, 01 Jan 2002 00:00:00 GMT", "description": "9316715 Taylor This award is for support to collect micrometeorites from the bottom of the new water well at South Pole Station, Antarctica. The large volume of firn and ice being melted provides the concentrating mechanism needed to collect large numbers of micrometeorites that occur in low concentrations in the ice. The first task of the project is to design a collection system to retrieve the micrometeorites from the bottom of the water well. The collector must be reliable, easy to operate, must collect all particles larger than 10 mm and should not contaminate the well\u0027s water quality. Following successful design and deployment of the collector, recovered particles will be catalogued and distributed to interested researchers. ***", "east": null, "geometry": null, "instruments": "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 SAMPLERS \u003e GRABBERS/TRAPS/COLLECTORS \u003e SEDIMENT TRAPS", "is_usap_dc": true, "keywords": "USAP-DC; Micrometeorites; SEM/EMAX; GROUND-BASED OBSERVATIONS; South Pole Water Well; Glass Spherules", "locations": "South Pole Water Well", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Taylor, Susan", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Retrieval and Analysis of Extraterrestrial Particles from the Water Well at the South Pole Station, Antarctica", "uid": "p0000057", "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": "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}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||||||||||
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RAPID: International Collaborative Airborne Sensor Deployments near Antarctic Ice Shelves
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2114454 |
2025-02-10 | Greenbaum, Jamin |
|
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. | 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)) | POINT(-106.5 -75) | false | false | |||||||||||
Erosional landscapes of the Transantarctic Mountains produced by East Antarctic subglacial water?
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2422677 |
2024-10-29 | Hall, Brenda; Denton, George | No dataset link provided | 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. | None | None | false | false | |||||||||||
Fe Behavior and Bioavailability in Sub-aerial Runoff into the Ross Sea
|
1841228 |
2024-10-16 | Lyons, W. Berry; Gardner, Christopher B. | Phytoplankton, or microscopic marine algae, are an important part of the carbon cycle and can lower the rates of atmospheric carbon dioxide by transferring the atmospheric carbon into the oceans. The concentration of phytoplankton in the Southern Ocean is regularly limited by the availability of marine iron. This in turn influences the rate of carbon transfer from the atmosphere to the ocean. The primary source of iron in the Southern Ocean is eroded continental rock. Understanding the current and future sources of iron to the Southern Ocean as a result of increased melting of terrestrial glaciers is necessary for predicting future concentrations of Southern Ocean phytoplankton and the subsequent influence on the carbon cycle. A poorly understood source of iron to the Southern Ocean is stream input from ice-free regions such as the McMurdo Dry Valleys in Antarctica. This source of iron is likely to become larger if glaciers retreat. This study investigates the sources and amount of iron transported by McMurdo Dry Valley streams directly into the Southern Ocean. Because not all forms of iron can be used by phytoplankton, experiments will be performed to determine how available iron is to phytoplankton and how iron mixes with seawater. Immersive 360-degree video, infographics, and educational videos of findings from this project will be shared on social media, at schools and science events, and in an urban science center. In the Southern Ocean (SO) there is an excess of macronutrients but regional primary production is limited or co-limited due to iron. An addition of iron to the ocean will affect biochemical cycles, increase primary production, and affect the structure and composition of phytoplankton communities in the SO. Iron flux to the SO is globally significant, as increased Fe fertilization leads to increased carbon sequestration which acts as a negative feedback to increased atmospheric pCO2. One source of potentially bioavailable iron to the coastal regions of the SO is from direct sub-aerial stream discharge in ice-free areas of Antarctica, a source that may become more important if terrestrial glaciers retreat. It is imperative to understand the source, nature, potential fate, and flux of iron to the SO if better predictive models for the carbon cycle and atmospheric chemistry are to be developed. This project will investigate in-stream processes and characteristics controlling dissolved iron draining into the Ross Sea including photoreduction, temperature, and complexation with organic matter. The novel study will quantify bioavailability of particulate iron and bioavailability of dissolved iron in Antarctic in streams draining into the SO. On-site speciation measurements will be performed on dissolved iron species, particulate iron speciation will be determined using high-resolution spectroscopy, mixing experiments will be performed with coastal marine water, and the bioavailability of Fe will be determined through marine bioassays. This project will provide two students with valuable Antarctic field experience and reach thousands of individuals through existing partnerships with K-12 schools, public STEM events, an urban science center, and a strong social media presence. 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. | POLYGON((163.37428 -77.558627,163.3922735 -77.558627,163.410267 -77.558627,163.4282605 -77.558627,163.446254 -77.558627,163.4642475 -77.558627,163.482241 -77.558627,163.5002345 -77.558627,163.518228 -77.558627,163.5362215 -77.558627,163.554215 -77.558627,163.554215 -77.56397510000001,163.554215 -77.5693232,163.554215 -77.5746713,163.554215 -77.5800194,163.554215 -77.5853675,163.554215 -77.59071560000001,163.554215 -77.5960637,163.554215 -77.60141180000001,163.554215 -77.6067599,163.554215 -77.612108,163.5362215 -77.612108,163.518228 -77.612108,163.5002345 -77.612108,163.482241 -77.612108,163.4642475 -77.612108,163.446254 -77.612108,163.4282605 -77.612108,163.410267 -77.612108,163.3922735 -77.612108,163.37428 -77.612108,163.37428 -77.6067599,163.37428 -77.60141180000001,163.37428 -77.5960637,163.37428 -77.59071560000001,163.37428 -77.5853675,163.37428 -77.5800194,163.37428 -77.5746713,163.37428 -77.5693232,163.37428 -77.56397510000001,163.37428 -77.558627)) | POINT(163.4642475 -77.5853675) | false | false | ||||||||||||
Modeling the Coupled Dynamics of Groundwater, Subglacial Hydrology and Ice Sheets
|
2336328 |
2024-10-08 | Larochelle, Stacy; Kingslake, Jonathan | No dataset link provided | 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. | None | None | false | false | |||||||||||
RAPID: Is Biomass Mobilization at Ice-covered Lake Fryxell, Antarctica reaching a Critical Threshold?
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2336354 |
2024-07-05 | Juarez Rivera, Marisol |
|
Perennially ice-covered lakes in the McMurdo Dry Valleys of Antarctica contain abundant microbial mats, and the export of this mat material can fertilize the surrounding polar desert ecosystems. These desert soils are one of the most organic-poor on earth yet host a community of microorganisms. Microbial mat material is exported from the shallow, gas-supersaturated regions of the lakes when gas bubbles form in the mats, lifting them to the ice cover; the perennial ice cover maintains gas supersaturation. These mats freeze in and are exported to the surrounding soils through ice ablation. The largest seasonal decrease and thinnest ice cover in the history of Lake Fryxell was recorded during the 2022-2023 Austral summer. In this thin ice year, the water column dissolved oxygen increased over prior observations, and the lake bottom surface area with bubble-disrupted mat was more than double that observed in 1980-1981 and 2006-2007. This work will constrain mat mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning to understand how future changing regional climate and predicted seasonal loss of lake ice cover will affect nutrient transport in the McMurdo Dry Valleys. Exceptional years of mat export are hypothesized to have the most significant impact on nutrient export to soil communities; variability in mat liftoff may thus play a role in the McMurdo Dry Valleys ecosystem response to changing climate. The perennial ice cover of lakes in the McMurdo Dry Valleys of Antarctica modulates the transfer of gasses, organic and inorganic material, between the lakes and surrounding soils. The export of biomass in these lakes is driven by the supersaturation of atmospheric gasses in the shallow regions under perennial ice cover. Gas bubbles nucleate in the mats, producing buoyancy that lifts them to the bottom of the ice, where they freeze in and are exported to the surrounding soils through ice ablation. These mats represent a significant source of biomass and nutrients to the McMurdo Dry Valleys soils, which are among the most organic-poor on earth. Nevertheless, this biomass remains unaccounted for in organic carbon cycling models for the McMurdo Dry Valleys. Ice cover data from the McMurdo Dry Valleys Long Term Ecological Research Project shows that the ice thickness has undergone cyclical variation over the last 40 years, reaching the largest seasonal decrease and thinnest ice-cover in the recorded history of Lake Fryxell during the 2022-2023 austral summer. Preliminary work shows that the surface area with mat liftoff at Lake Fryxell is more than double that observed in 1980-1981 and 2006-2007, coinciding with this unprecedented thinning of the ice-cover and an increase in the water column dissolved O2. This research will constrain biomass mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning. The researchers hypothesize that a thinner ice cover promotes more biomass mobilization by 1) stimulating additional production of gas bubbles from the existing gas-supersaturated waters during summertime photosynthesis to create microbial mat liftoff and 2) promoting mat liftoff in deeper, thicker microbial mats, and 3) that this biomass can be traced into the soils by characterizing its chemistry and modeling the most likely depositional settings. This work will use microbial mat samples, lake dissolved oxygen and photosynthetically active radiation data and underwater drone footage documenting the depth distribution of liftoff mats in January 2023, and long-term ice cover thickness, photosynthetically active radiation, and lake level change data collected by the McMurdo Dry Valleys Long Term Ecological Research Project to test hypotheses 1-3. The dispersal of the liftoff mat exposed at Lake Fryxell surface will be modeled using a Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Exceptional liftoff years like the present are hypothesized to have the most significant impact on the soil communities as the rates of soil respiration increase with the addition of carbon. However, continued warming in the next 10 - 40 years may result in seasonal loss of the ice cover and cessation of liftoff mat export. 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. | 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)) | POINT(162.25 -77.5) | false | false | |||||||||||
Benthic Iron Fluxes and Cycling in the Amundsen Sea
|
None | 2024-06-13 | None | No dataset link provided | The Amundsen Sea, near the fastest melting Antarctic glaciers, hosts one of the most productive polar ecosystems in the world. Phytoplankton serve as the base of the food chain, and their growth also removes carbon dioxide from the atmosphere. Phytoplankton growth is fertilized in this area by nutrient iron, which is only present at low concentrations in seawater. Prior studies have shown the seabed sediments may provide iron to the Amundsen Sea ecosystem. However, sediment sources of iron have never been studied here directly. This project fills this gap by analyzing sediments from the Amundsen Sea and investigating whether sediment iron fertilizes plankton growth. The results will help scientists understand the basic ecosystem drivers and predict the effects of climate change on this vibrant, vulnerable region. This project also emphasizes inclusivity and openness to the public. The researchers will establish a mentoring network for diverse polar scientists through the Polar Impact Network and communicate their results to the public through the website CryoConnect.org. <br/><br/>This project leverages samples already collected from the Amundsen Sea (NBP22-02) to investigate sediment iron (Fe) cycling and fluxes. The broad questions driving this research are 1) does benthic Fe fertilize Antarctic coastal primary productivity, and 2) what are the feedbacks between benthic Fe release and carbon cycling in the coastal Antarctic? To answer these questions, the researchers will analyze pore water Fe content and speciation and calculate fluxes of Fe across the sediment-water interface. These results will be compared to sediment characteristics (e.g., organic carbon content, reactive Fe content, proximity to glacial sources) to identify controls on benthic Fe release. This research dovetails with and expands on the science goals of the ?Accelerating Thwaites Ecosystem Impacts for the Southern Ocean? (ARTEMIS) project through which the field samples were collected. In turn, the findings of ARTEMIS regarding modeled and observed trace metal dynamics, surface water productivity, and carbon cycling will inform the conclusions of this project, allowing insight into the impact of benthic Fe in the whole system. This project represents a unique opportunity for combined study of the water column and sediment biogeochemistry which will be of great value to the marine biogeochemistry community and will inform future sediment-ocean studies in polar oceanography and beyond.<br/><br/>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. | None | None | false | false | |||||||||||
EAGER: Pedogenic Carbonates Record Insolation Driven Surface Melting in Antarctica
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2423761 |
2024-05-14 | Blackburn, Terrence |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
NSFGEO-NERC: Understanding the Response to Ocean Melting for Two of East Antarctica's Most Vulnerable Glaciers: Totten and Denman
|
2231230 |
2024-02-29 | Joughin, Ian; Shapero, Daniel; Smith, Benjamin E | No dataset link provided | 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. | 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)) | POINT(107.5 -66) | false | false | |||||||||||
NSFGEO-NERC: Ice-shelf Instability Caused by Active Surface Meltwater Production, Movement, Ponding and Hydrofracture
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1841607 1841467 |
2024-02-15 | Banwell, Alison; Macayeal, Douglas |
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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. | 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)) | POINT(-67.89 -71.35) | false | false | |||||||||||
Magma Sources, Residence and Pathways of Mount Erebus Phonolitic Volcano, Antarctica, from Magnetotelluric Resistivity Structure
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1443522 |
2024-02-05 | Wannamaker, Philip |
|
General Description: This project is intended to reveal the magma source regions, staging areas, and eruptive pathways within the active volcano Mount Erebus. This volcano is an end-member type known as phonolitic, which refers to the lava composition, and is almost purely carbon-dioxide-bearing and occurs in continental rift settings. It is in contrast to the better known water-bearing volcanoes which occur at plate boundary settings (such as Mount St Helens or Mount Fuji). Phonolitic volcanic eruptions elsewhere such as Tamboro or Vesuvius have caused more than 50,000 eruption related fatalities. Phonolites are also associated with rare earth element deposits, giving them economic interest. To illuminate the inner workings of Mount Erebus, we will cover the volcano with a dense network of geophysical probes based on magnetotelluric (MT) measurements. MT makes use of naturally occurring electromagnetic (EM) waves generated mainly by the sun as sources to provide images of the electrical conductivity structure of the Earth's interior. Conductivity is sensitive to the presence of fluids and melts in the Earth and so is well suited to understanding volcanic processes. The project is a cooperative effort between scientists from the United States, New Zealand, Japan and Canada. It implements new technology developed by the lead investigator and associates that allows such measurements to be taken on snow-covered terrains. This has applicability for frozen environments generally, such as resource exploration in the Arctic. The project supports a new post-doctoral researcher, and leverages imaging and measurement methods developed through support by other agencies and interfaced with commercial platforms. Technical Description: The investigators propose to test magmatic evolution models for Mount Erebus volcano, Antarctica, using the magnetotelluric (MT) method. The phonolite lava flow compositions on Mount Erebus are uncommon, but provide a window into the range of upper mantle source compositions and melt differentiation paths. Explosive phonolite eruptions have been known worldwide for devastating eruptions such as Tambora and Vesuvius, and commonly host rare earth element deposits. In the MT method, temporal variations in the Earth's natural electromagnetic (EM) field are used as source fields to probe the electrical resistivity structure in the depth range of 1 to 100 kilometers. This effort will consist of approximately 100 MT sites, with some concentration in the summit area. Field acquisition will take place over two field seasons. The main goals are to 1) confirm the existence and the geometry of the uppermost magma chamber thought to reside at 5-10 kilometer depths; 2) attempt to identify, in the deeper resistivity structure, the magma staging area near the crust-mantle boundary; 3) image the steep, crustal-scale, near-vertical conduit carrying magma from the mantle; 4) infer the physical and chemical state from geophysical properties of a CO2-dominated mafic shield volcano; and 5) constrain the relationships between structural and magmatic/ hydrothermal activity related to the Terror Rift. Tomographic imaging of the interior resistivity will be performed using a new inversion platform developed at Utah, based on the deformable edge finite element method, that is the best available for accommodating the steep topography of the study area. The project is an international cooperation between University of Utah, GNS Science Wellington New Zealand (G. Hill, Co-I), and Tokyo Institute of Technology Japan (Y. Ogawa, Co-I), plus participation by University of Alberta (M. Unsworth) and Missouri State University (K. Mickus). Instrument deployments will be made exclusively by helicopter. The project implements new technology that allows MT measurements to be taken on snow-covered terrains. The project supports a new post-doctoral researcher, and leverages imaging and measurement methods developed through support by other agencies and interfaced with commercial platforms. | POLYGON((166 -77.15,166.34 -77.15,166.68 -77.15,167.02 -77.15,167.36 -77.15,167.7 -77.15,168.04 -77.15,168.38 -77.15,168.72 -77.15,169.06 -77.15,169.4 -77.15,169.4 -77.22500000000001,169.4 -77.30000000000001,169.4 -77.375,169.4 -77.45,169.4 -77.525,169.4 -77.60000000000001,169.4 -77.67500000000001,169.4 -77.75,169.4 -77.825,169.4 -77.9,169.06 -77.9,168.72 -77.9,168.38 -77.9,168.04 -77.9,167.7 -77.9,167.36 -77.9,167.02 -77.9,166.68 -77.9,166.34 -77.9,166 -77.9,166 -77.825,166 -77.75,166 -77.67500000000001,166 -77.60000000000001,166 -77.525,166 -77.45,166 -77.375,166 -77.30000000000001,166 -77.22500000000001,166 -77.15)) | POINT(167.7 -77.525) | false | false | |||||||||||
Investigating Effects of Transient and Non-Newtonian Mantle Viscosity on Glacial Isostatic Adjustment Process and their Implications for GPS Observations in Antarctica
|
2333940 |
2024-01-08 | Zhong, Shijie | No dataset link provided | 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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
LTER: MCM6 - The Roles of Legacy and Ecological Connectivity in a Polar Desert Ecosystem
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2224760 |
2023-11-14 | 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. |
|
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. | POINT(162.87 -77) | POINT(162.87 -77) | false | false | |||||||||||
NSFGEO-NERC: Investigating the Direct Influence of Meltwater on Antarctic Ice Sheet Dynamics
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2053169 |
2023-09-15 | Kingslake, Jonathan; Sole, Andrew; Livingstone, Stephen; Winter, Kate; Ely, Jeremy | No dataset link provided | 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. | None | None | false | false | |||||||||||
Collaborative Research: Freeze-on of Subglacial Sediments in Experiments and Theory
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2012958 |
2023-09-13 | Meyer, Colin; Rempel, Alan; Zoet, Lucas |
|
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. | None | None | false | false | |||||||||||
None
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None | 2023-09-12 | Washam, Peter |
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None | None | None | false | false | |||||||||||
ANT LIA: The Role of Sex Determination in the Radiation of Antarctic Notothenioid Fish
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2232891 |
2023-08-14 | Postlethwait, John; Desvignes, Thomas | No dataset link provided | 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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
CAREER: Experimentally Testing the Role of Sympagic Algae in Sea-ice Environments using a Laboratory Scale Ice-tank.
|
2142491 |
2023-07-26 | Young, Jodi | No dataset link provided | Sea ice in Antarctic coastal waters shape ecosystems, both in the surface waters and at the bottom of the ocean, environments that depend on algae living in sea ice for their productivity. With high variability in sea ice formation and melt between years and as a response to climate change, it is of importance to obtain better understanding of the interaction of sea ice with algae, as well as provide better data for global climate models. This project will accomplish those goals by measuring phytoplankton growth and cellular properties in sea ice with experiments performed using an ice tank. Laboratory experiments will be based on previous observations in the Antarctic Peninsula coastal waters, providing realistic conditions to emulate. The scientific importance of the proposed work aligns with the National Science Foundation goals to understand the biological and chemical properties of sea ice bio-geo-chemistry and its feedbacks with seasonal sea ice dynamics and climate. The finding from this project will be of interest to a broad scientific community, including oceanographers, biologists, chemists, and ecosystem and ocean modelers. To address the scarcity of data on sea ice microbes that limits our ability to predict future Antarctic climate with accuracy, the principal investigator will develop an Antarctic Science Minor in order to train future scientists with an environmental perspective and prepare the future US workforce with a strong scientific background on Earth and Biological Sciences. There is a paucity of data to understand the processes underlying observed patters in sea ice quality and their interaction with the sea-ice microbial community. This project will provide a mechanistic understanding of primary production and physiology of sympagic algae over the seasonal cycle of formation and melt of Antarctic sea ice. Although sea ice is central to the Antarctic coastal ecosystems, little is known of how they affect, and are in turn affected, by sea-ice algae. This project concentrates on first-year sea ice, forming and melting each year, creating unique and very dynamic habitats. The study will be structured by 4 main objectives: 1) how different algal species adapt to the seasonal changes in sea ice conditions, 2) how different methods to measure primary production (carbon dioxide drawdown, oxygen production and variable fluorescence) relate in sea ice and differ from sea water measurements, 3) how sympagic algae influence the physical structure of sea ice, 4) how sympagic algae contribute to organic matter cycling during ice melt. Due to expected changes in sea ice due to climate change, this study is uniquely positioned to provide needed data on short-term and seasonal processes. Results from this study will be useful to refine models of algal production in Antarctic and Arctic ecosystems, data not available to date as sea ice and its biogeochemistry are often poorly represented in earth system models. This project will also provide education for graduate and undergraduate students as well as material to develop class curriculum for middle-school students. 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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation
|
2302832 |
2023-07-12 | Reilly, Brendan | 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. | 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)) | POINT(-55 -60.5) | false | false | ||||||||||||
Collaborative Research: Water on the Antarctic Ice Sheet: Quantifying Surface Melt and Mapping Supraglacial Lakes
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2021699 |
2023-06-02 | Trusel, Luke; Moussavi, Mahsa | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
EAGER: ANT LIA: Persist or Perish: Records of Microbial Survival and Long-term Persistence from the West Antarctic Ice Sheet
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2228257 |
2023-05-31 | Michaud, Alexander; Winski, Dominic A. | No dataset link provided | 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. | POINT(-112.05 -79.28) | POINT(-112.05 -79.28) | false | false | |||||||||||
Collaborative Research: Role of Nutrient Limitation and Viral Interactions on Antarctic Microbial Community Assembly: A Cryoconite Microcosm Study
|
2137378 2137377 2137376 2137375 |
2023-05-10 | Varsani, Arvind; Porazinska, Dorota; Schmidt, Steven; Bergstrom, Anna | No dataset link provided | Cryoconite holes are sediment-filled melt holes in the surface of glaciers that can be important sites of active microbial life in an otherwise mostly frozen and barren landscape. Previous studies in the McMurdo Dry Valleys, Antarctica suggest that viral infections of microbes, and a general lack of fertilizers (i.e., nutrients), may be important factors shaping the development and functioning of microbial communities in cryoconite holes. The researchers propose an experimental approach to understand how nutrient limitation affects diversity (number of species) and overall abundance of microbes, and how the diversity and abundance of microbes in turn affects the diversity, abundance, and infection type of viruses that parasitize the microbes in cryoconite sediments. The researchers will use sediments previously collected from Antarctic glaciers that have varying concentrations of viruses and nutrients, to set up a nutrient-addition experiment to determine how nutrients affect microbial and viral population dynamics. The results will deepen our understanding of how microbial communities in general are shaped by nutrients and viruses and give new insights into the functioning of viruses in extremely cold environments. The researchers will publish their findings in scientific journals and will share their discoveries with K-12 students from rural schools in collaboration with the Pinhead Institute and will connect undergraduate students from under-represented minorities to polar research through participation in the university’s Science, Technology, Engineering & Mathematics Routes Uplift Research Program. Outreach will be achieved through videos produced and distributed by a professional science communicator. The research advances a National Science Foundation goal of expanding fundamental knowledge of Antarctic systems, biota, and processes by utilizing the unique characteristics of the Antarctic region as a science observing platform. The Principal Investigators propose an experimental approach to understand how nutrient limitation affects microbial diversity and abundances and their cascading effects on virus diversity, abundance, and mode of infection (lysis vs. lysogeny) in Antarctic cryoconite holes. Cryoconite holes are ideal natural microcosms for manipulative studies, not available in other cryospheric ecosystems. The PIs will use previously collected cryoconite from across a gradient of both viral diversity and nutrient levels to address questions about key limiting nutrients and microbial-viral community dynamics in cryoconite sediments. Nutrient manipulation experiments will be conducted in a growth chamber that closely approximates the light and temperature regime of in situ cryoconite holes to test three core hypotheses: (1) phosphorus availability limits microbial productivity and abundance in cryoconite holes; (2) relaxing nutrient limitation in cryoconite from low-diversity glaciers will increase species diversity, leading microbial communities to resemble those found on more nutrient-rich glaciers; (3) relaxing nutrient limitation will increase the diversity and abundance of viruses by increasing the availability of suitable hosts, and decrease the prevalence of lysogenic infections. By manipulating nutrient limitation within a realistic range, this project will help verify hypothesized phosphorus limitation of Antarctic cryoconite holes and will extend understanding of the connections between nutrients, diversity, and viral infection dynamics in the cryosphere more generally. A better understanding of these dynamics in cryoconite sediments improves the ability of scientists to forecast future impacts of environmental changes in the cryosphere. 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. | None | None | false | false | |||||||||||
None
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1739003 |
2023-03-28 | Paden, John |
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None | None | None | false | false | |||||||||||
Collaborative Research: Circum-Antarctic Processes from Archived Marine Sediment Cores (ANTS)
|
2224679 2224681 2224680 |
2023-02-24 | 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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: Present and Projected Future Forcings on Antarctic Peninsula Glaciers and Ice Shelves using the Weather Forecasting and Research (WRF) Model
|
1543445 |
2023-02-24 | Zhang, Jing; Hock, Regine; Fahnestock, Mark |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: An Ice Core from Hercules Dome, East Antarctica
|
1841858 1841844 1841879 |
2023-02-06 | Steig, Eric J.; Fudge, T. J. | No dataset link provided | 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. | POINT(-105 -86) | POINT(-105 -86) | false | false | |||||||||||
A Test of Global and Antarctic Models for Cosmogenic-nuclide Production Rates using High-precision Dating of 40Ar/39Ar Lava Flows from Mount Erebus
|
1644234 |
2022-12-12 | Phillips, Fred; Kyle, Philip; Heizler, Matthew T | No dataset link provided | Nontechnical Description: The age of rocks and soils at the surface of the Earth can help answer multiple questions that are important for human welfare, including: when did volcanoes erupt and are they likely to erupt again? when did glaciers advance and what do they tell us about climate? what is the frequency of hazards such as landslides, floods, and debris flows? how long does it take soils to form and is erosion of soils going to make farming unsustainable? One method that is used thousands of times every year to address these questions is called 'cosmogenic surface-exposure dating'. This method takes advantage of cosmic rays, which are powerful protons and neutrons produced by supernova that constantly bombard the Earth's atmosphere. Some cosmic rays reach Earth's surface and produce nuclear reactions that result in rare isotopes. Measuring the quantity of the rare isotopes enables the length of time that the rock or soil has been exposed to the atmosphere to be calculated. The distribution of cosmic rays around the globe depends on Earth's magnetic field, and this distribution must be accurately known if useful exposure ages are to be obtained. Currently there are two remaining theories, narrowed down from many, of how to calculate this distribution. Measurements from a site that is at both high altitude and high latitude (close to the poles) are needed to test the two theories. This study involves both field and lab research and includes a Ph.D. student and an undergraduate student. The research team will collect rocks from lava flows on an active volcano in Antarctica named Mount Erebus and measure the amounts of two rare isotopes: 36Cl and 3He. The age of eruption of the samples will be determined using a highly accurate method that does not depend on cosmic rays, called 40Ar/39Ar dating. The two cosmic-ray theories will be used to calculate the ages of the samples using the 36Cl and 3He concentrations and will then be compared to the ages calculated from the 40Ar/39Ar dating. The accurate cosmic-ray theory will be the one that gives the same ages as the 40Ar/39Ar dating. Identification of the accurate theory will enable use of the cosmogenic surface dating methods anywhere on earth. Technical Description: Nuclides produced by cosmic rays in rocks at the surface of the earth are widely used for Quaternary geochronology and geomorphic studies and their use is increasing every year. The recently completed CRONUS-Earth Project (Cosmic-Ray Produced Nuclides on Earth) has systematically evaluated the production rates and theoretical underpinnings of cosmogenic nuclides. However, the CRONUS-Earth Project was not able to discriminate between the two leading theoretical approaches: the original Lal model (St) and the new Lifton-Sato-Dunai model (LSD). Mathematical models used to scale the production of the nuclides as a function of location on the earth, elevation, and magnetic field configuration are an essential component of this dating method. The inability to distinguish between the two models was because the predicted production rates did not differ sufficiently at the location of the calibration sites. The cosmogenic-nuclide production rates that are predicted by the two models differ significantly from each other at Erebus volcano, Antarctica. Mount Erebus is therefore an excellent site for testing which production model best describes actual cosmogenic-nuclide production variations over the globe. The research team recently measured 3He and 36Cl in mineral separates extracted from Erebus lava flows. The exposure ages for each nuclide were reproducible within each flow (~2% standard deviation) and in very good agreement between the 3He and the 36Cl ages. However, the ages calculated by the St and LSD scaling methods differ by ~15-25% due to the sensitivity of the production rate to the scaling at this latitude and elevation. These results lend confidence that Erebus qualifies as a suitable high- latitude/high-elevation calibration site. The remaining component that is still lacking is accurate and reliable independent (i.e., non-cosmogenic) ages, however, published 40Ar/39Ar ages are too imprecise and typically biased to older ages due to excess argon contained in melt inclusions. The research team's new 40Ar/39Ar data show that previous problems with Erebus anorthoclase geochronology are now overcome with modern mass spectrometry and better sample preparation. This indicates a high likelihood of success for this proposal in defining an accurate global scaling model. Although encouraging, much remains to be accomplished. This project will sample lava flows over 3 km in elevation and determine their 40Ar/39Ar and exposure ages. These combined data will discriminate between the two scaling methods, resulting in a preferred scaling model for global cosmogenic geochronology. The LSD method contains two sub-methods, the 'plain' LSD scales all nuclides the same, whereas LSDn scales each nuclide individually. The project can discriminate between these models using 3He and 36Cl data from lava flows at different elevations, because the first model predicts that the production ratio for these two nuclides will be invariant with elevation and the second that there should be ~10% difference over the range of elevations to be sampled. Finally, the project will provide a local, finite-age calibration site for cosmogenic-nuclide investigations in Antarctica. | POLYGON((166.17 -77.3,166.32799999999997 -77.3,166.486 -77.3,166.644 -77.3,166.802 -77.3,166.95999999999998 -77.3,167.118 -77.3,167.276 -77.3,167.434 -77.3,167.59199999999998 -77.3,167.75 -77.3,167.75 -77.34,167.75 -77.38,167.75 -77.42,167.75 -77.46,167.75 -77.5,167.75 -77.54,167.75 -77.58,167.75 -77.62,167.75 -77.66,167.75 -77.7,167.59199999999998 -77.7,167.434 -77.7,167.276 -77.7,167.118 -77.7,166.95999999999998 -77.7,166.802 -77.7,166.644 -77.7,166.486 -77.7,166.32799999999997 -77.7,166.17 -77.7,166.17 -77.66,166.17 -77.62,166.17 -77.58,166.17 -77.54,166.17 -77.5,166.17 -77.46,166.17 -77.42,166.17 -77.38,166.17 -77.34,166.17 -77.3)) | POINT(166.95999999999998 -77.5) | false | false | |||||||||||
Estimation of Antarctic Ice Melt using Stable Isotopic Analyses of Seawater
|
1644118 |
2022-09-21 | Dunbar, Robert |
|
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. | 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)) | POINT(-104.5 -74.5) | false | false | |||||||||||
Measuring Dissolved Gases to Reveal the Processes that Drive the Solubility Pump and Determine Gas Concentration in Antarctic Bottom Water
|
1744562 |
2022-09-14 | Loose, Brice |
|
Near the Antarctic coast, polynyas are open-water regions where extreme heat loss in winter causes seawater to become cold, salty, and dense enough to sink into the deep sea. The formation of this dense water has regional and global importance because it influences the ocean current system. Polynya processes are also tied to the amount of sea ice formed, ocean heat lost to atmosphere, and atmospheric CO2 absorbed by the Southern Ocean. Unfortunately, the ocean-atmosphere interactions that influence the deep ocean water properties are difficult to observe directly during the Antarctic winter. This project will combine field measurements and laboratory experiments to investigate whether differences in the concentration of noble gasses (helium, neon, argon, xenon, and krypton) dissolved in ocean waters can be linked to environmental conditions at the time of their formation. If so, noble gas concentrations could provide insight into the mechanisms controlling shelf and bottom-water properties, and be used to reconstruct past climate conditions. Project results will contribute to the Southern Ocean Observing System (SOOS) theme of The Future and Consequences of Carbon Uptake in the Southern Ocean. The project will also train undergraduate and graduate students in environmental monitoring, and earth and ocean sciences methods. Understanding the causal links between Antarctic coastal processes and changes in the deep ocean system requires study of winter polynya processes. The winter period of intense ocean heat loss and sea ice production impacts two important Antarctic water masses: High-Salinity Shelf Water (HSSW), and Antarctic Bottom Water (AABW), which then influence the strength of the ocean solubility pump and meridional overturning circulation. To better characterize how sea ice cover, ocean-atmosphere exchange, brine rejection, and glacial melt influence the physical properties of AABW and HSSW, this project will analyze samples and data collected from two Ross Sea polynyas during the 2017 PIPERS winter cruise. Gas concentrations will be measured in seawater samples collected by a CTD rosette, from an underwater mass-spectrometer, and from a benchtop Membrane Inlet Mass Spectrometer. Noble gas concentrations will reveal the ocean-atmosphere (dis)equilibrium that exists at the time that surface water is transformed into HSSW and AABW, and provide a fingerprint of past conditions. In addition, nitrogen (N2), oxygen (O2), argon, and CO2 concentration will be used to determine the net metabolic balance, and to evaluate the efficacy of N2 as an alternative to O2 as glacial meltwater tracer. Laboratory experiments will determine the gas partitioning ratios during sea ice formation. Findings will be synthesized with PIPERS and related projects, and so provide an integrated view of the role of the wintertime Antarctic coastal system on deep water composition. 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. | POLYGON((-180 -71,-179.9 -71,-179.8 -71,-179.7 -71,-179.6 -71,-179.5 -71,-179.4 -71,-179.3 -71,-179.2 -71,-179.1 -71,-179 -71,-179 -71.7,-179 -72.4,-179 -73.1,-179 -73.8,-179 -74.5,-179 -75.2,-179 -75.9,-179 -76.6,-179 -77.3,-179 -78,-179.1 -78,-179.2 -78,-179.3 -78,-179.4 -78,-179.5 -78,-179.6 -78,-179.7 -78,-179.8 -78,-179.9 -78,180 -78,177.5 -78,175 -78,172.5 -78,170 -78,167.5 -78,165 -78,162.5 -78,160 -78,157.5 -78,155 -78,155 -77.3,155 -76.6,155 -75.9,155 -75.2,155 -74.5,155 -73.8,155 -73.1,155 -72.4,155 -71.7,155 -71,157.5 -71,160 -71,162.5 -71,165 -71,167.5 -71,170 -71,172.5 -71,175 -71,177.5 -71,-180 -71)) | POINT(168 -74.5) | false | false | |||||||||||
Collaborative Research: US GEOTRACES GP17-ANT: Dissolved concentrations, isotopes, and colloids of the bioactive trace metals
|
2123491 2123333 2123354 |
2022-09-08 | Conway, Timothy; Fitzsimmons, Jessica; John, Seth | No dataset link provided | The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes (TEIs) in the oceans. Many trace metals such as iron are essential for life and thus considered nutrients for phytoplankton growth, with trace metal cycling being especially important for influencing carbon cycling in the iron-limited Southern Ocean, where episodic supply of iron from a range of different external sources is important. The primary goal of this project is to measure the dissolved concentrations, size partitioning, and dissolved isotope signature of Fe on a transect of water-column stations throughout the Amundsen Sea and surrounding region of the Antarctic Margin, as part of the GP17-ANT Expedition. The secondary goal of this project is to analyze the concentrations and size partitioning of the trace metals manganese, zinc, copper, cadmium, nickel, and lead in all water-column samples, measure the isotope ratios of zinc, cadmium, nickel, and copper in a subset of water column samples, and measure the Fe isotopic signature of aerosols, porewaters, and particles. Observations from this project will be incorporated into regional and global biogeochemistry models to assess TEI cycling within the Amundsen Sea and implications for the wider Southern Ocean. This project spans three institutions, four graduate students, undergraduate students, and will provide ultrafiltered samples and data to other PIs as service. The US GEOTRACES GP17 ANT expedition, planned for austral summer 2023/2024 aims to determine the distribution and cycling of trace elements and their isotopes in the Amundsen Sea Sector (100-135°W) of the Antarctic Margin. The cruise will follow the Amundsen Sea ‘conveyor belt’ by sampling waters coming from the Antarctic Circumpolar Current onto the continental shelf, including near the Dotson and Pine Island ice shelves, the productive Amundsen Sea Polynya (ASP), and outflowing waters. Episodic addition of dissolved Fe and other TEIs from dust, ice-shelves, melting ice, and sediments drive seasonal primary productivity and carbon export over the Antarctic shelf and offshore into Southern Ocean. Seasonal coastal polynyas such as the highly productive ASP thus act as key levers on global carbon cycling. However, field observations of TEIs in such regions remain scarce, and biogeochemical cycling processes are poorly captured in models of ocean biogeochemistry. The investigators will use their combined analytical toolbox, in collaboration with the diagnostic chemical tracers and regional models of other funded groups to address four main objectives: 1) What is the relative importance of different sources in supplying Fe and other TEIs to the ASP? 2) What is the physiochemical speciation of this Fe, and its potential for transport? 3) How do biological uptake, scavenging and regeneration in the ASP influence TEI distributions, stoichiometry, and nutrient limitation? 4) What is the flux and signature of TEIs transported offshore to the ACC and Southern Ocean? 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. | POLYGON((-135 -66,-131.5 -66,-128 -66,-124.5 -66,-121 -66,-117.5 -66,-114 -66,-110.5 -66,-107 -66,-103.5 -66,-100 -66,-100 -67,-100 -68,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-103.5 -76,-107 -76,-110.5 -76,-114 -76,-117.5 -76,-121 -76,-124.5 -76,-128 -76,-131.5 -76,-135 -76,-135 -75,-135 -74,-135 -73,-135 -72,-135 -71,-135 -70,-135 -69,-135 -68,-135 -67,-135 -66)) | POINT(-117.5 -71) | false | false | |||||||||||
Collaborative Research: Investigating the Role of Coastal Polynya Variability in Modulating Antarctic Marine-Terminating Glacier Drawdown
|
2205008 |
2022-08-07 | 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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
OPP-PRF: Benthic Iron Fluxes and Cycling in the Amundsen Sea
|
2212904 2407093 |
2022-08-07 | Herbert, Lisa | No dataset link provided | The Amundsen Sea, near the fastest melting Antarctic glaciers, hosts one of the most productive polar ecosystems in the world. Phytoplankton serve as the base of the food chain, and their growth also removes carbon dioxide from the atmosphere. Phytoplankton growth is fertilized in this area by nutrient iron, which is only present at low concentrations in seawater. Prior studies have shown the seabed sediments may provide iron to the Amundsen Sea ecosystem. However, sediment sources of iron have never been studied here directly. This project fills this gap by analyzing sediments from the Amundsen Sea and investigating whether sediment iron fertilizes plankton growth. The results will help scientists understand the basic ecosystem drivers and predict the effects of climate change on this vibrant, vulnerable region. This project also emphasizes inclusivity and openness to the public. The researchers will establish a mentoring network for diverse polar scientists through the Polar Impact Network and communicate their results to the public through the website CryoConnect.org. This project leverages samples already collected from the Amundsen Sea (NBP22-02) to investigate sediment iron (Fe) cycling and fluxes. The broad questions driving this research are 1) does benthic Fe fertilize Antarctic coastal primary productivity, and 2) what are the feedbacks between benthic Fe release and carbon cycling in the coastal Antarctic? To answer these questions, the researchers will analyze pore water Fe content and speciation and calculate fluxes of Fe across the sediment-water interface. These results will be compared to sediment characteristics (e.g., organic carbon content, reactive Fe content, proximity to glacial sources) to identify controls on benthic Fe release. This research dovetails with and expands on the science goals of the “Accelerating Thwaites Ecosystem Impacts for the Southern Ocean” (ARTEMIS) project through which the field samples were collected. In turn, the findings of ARTEMIS regarding modeled and observed trace metal dynamics, surface water productivity, and carbon cycling will inform the conclusions of this project, allowing insight into the impact of benthic Fe in the whole system. This project represents a unique opportunity for combined study of the water column and sediment biogeochemistry which will be of great value to the marine biogeochemistry community and will inform future sediment-ocean studies in polar oceanography 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. | 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)) | POINT(-110 -73) | false | false | |||||||||||
Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity
|
2201129 |
2022-06-14 | Fischer, Karen; Dalton, Colleen |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Proposal: Miocene Climate Extremes: A Ross Sea Perspective from IODP Expedition 374 and DSDP Leg 28 Marine Sediments
|
1947646 1947657 1947558 |
2022-06-08 | Shevenell, Amelia | No dataset link provided | 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. | 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)) | POINT(-176 -75.75) | false | false | |||||||||||
CAREER: The Transformation, Cross-shore Export, and along-shore Transport of Freshwater on Antarctic Shelves
|
1945127 |
2022-06-03 | Moffat, Carlos | No dataset link provided | Freshwater discharges from melting high-latitude continental ice glacial reserves strongly control salt budgets, circulation and associated ocean water mass formation arising from polar ice shelves. These are different in nature than freshwater inputs associated with riverine coastal inputs. The PI proposes an observational deployment to measure a specific, previously-identified example of a coastal freshwater-driven current, the Antarctic Peninsula Coastal Current (APCC). The research component of this CAREER project aims to improve understanding of the dynamics of freshwater discharge around the Antarctic continent. Associated research questions pertain to the i) controls on the cross- and along-shelf spreading of fresh, buoyant coastal currents, ii) the role of distributed coastal freshwater sources (as opposed to 'point' source river outflow sources typical of lower latitudes), and iii) the contribution of these coastal currents to water mass transformation and heat transfer on the continental shelf. An educational CAREER program component leverages a series of field experiences and research outputs including data, model outputs, and theory, to bring polar science to the classroom and the general public, as well as training a new polar scientist. This combined strategy will allow the investigator to lay the foundation for a successful academic career as a researcher and teacher at the University of Delaware. The project will also provide the opportunity to train a PhD student. Informal outreach efforts will include giving public lectures at University of Deleware's sponsored events, including Coast Day, a summer event that attracts 8000-10000 people, and remote lectures from the field using an existing outreach network. This proposal requires 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. | None | None | false | false | |||||||||||
Center for Oldest Ice Exploration
|
2019719 |
2022-05-21 | Brook, Edward J.; Neff, Peter | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
Collaborative Research: Do Ocean Wave Impacts Pose a Hazard to the Stability of West Antarctic Ice Shelves?
|
1744856 1744958 1744759 1246151 |
2022-05-16 | Dunham, Eric; Bromirski, Peter; Wei, Yong | 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. | None | None | false | false | ||||||||||||
Collaborative Research: Modeling ice-ocean interaction for the rapidly evolving ice shelf cavities of Pine Island and Thwaites glaciers, Antarctica
|
1643285 1643174 |
2022-05-13 | Joughin, Ian; Dutrieux, Pierre; Padman, Laurence; Springer, Scott |
|
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. | 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)) | POINT(-95 -77) | false | false | |||||||||||
Revising Models of the Glacier-Ocean Boundary Layer with Novel Laboratory Experiments
|
2146791 |
2022-05-06 | Lai, Chung; Robel, Alexander | No dataset link provided | 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. | None | None | false | false | |||||||||||
Collaborative Research: Moving Beyond the Margins: Modeling Water Availability and Habitable Terrestrial Ecosystems in the Polar Desert of the McMurdo Dry Valleys
|
2046260 2045880 |
2022-04-21 | Salvatore, Mark; Gooseff, Michael N.; Sokol, Eric; Barrett, John | No dataset link provided | Part I: Non-technical description: Water is life and nowhere is it more notable than in deserts. Within the drylands on Earth, the Antarctic deserts, represented in this study by the McMurdo Dry Valleys, exemplify life in extreme environments with scarce water, low temperatures and long periods of darkness during the polar winter. There is a scarcity of methods to determine water availability, data necessary to predict which species are successful in the drylands, unless measurements are done manually or with field instruments. This project aims to develop a new method of determining soil moisture and use the new data to identify locations suitable for life. Combining these habitats with known species distributions in the McMurdo Dry Valleys, results from this project will predict which species should be present, and also what is the expected species distribution in a changing environment. In this way the project takes advantage of a combination of methods, from recent remote sensing products, ecological models and 30 years of field collections to bring a prediction of how life might change in the McMurdo Dry Valleys in a warmer, and possibly, moister future climate. This project benefits the National Science Foundation goals of expanding fundamental knowledge of Antarctic biota and the processes that sustain life in extreme environments. The knowledge acquired in this project will be disseminated to other drylands through training of high-school curricular programming in Native American communities of the SouthWest. Part II: Technical description: Terrestrial environments in Antarctica are characterized by low liquid water supply, sub-zero temperatures and the polar night in winter months. During summer, melting of snow patches, seasonal steams from glacial melt and vicinity to lakes provide a variety of environments that maintain life, not yet studied at landscape-scale level for habitat suitability and the processes that drive them. This project proposes to integrate remote sensing, hydrological models and ecological models to establish habitat suitability for species in the McMurdo Dry Valleys based on water availability. The approach is at a landscape level in order to establish present-day and future scenarios of species distribution. There are four main objectives: remote sensing development of moisture levels in soils, combining biological and soil data, building and calibrating models of habitat suitability by combining species distribution and environmental variability and applying statistical species distribution model. The field data to develop habitat suitability and calibration of models will leverage a the 30-year dataset collected by the McMurdo Long-Term Ecological Research program. Mechanistic models developed will be essential to predict species distribution in future climate scenarios. Training of post-doctoral researchers and a graduate student will prepare for the next generation of Antarctic scientists. Results from this project will train high-school students from native American communities in the SouthWest where similar desert conditions exist. 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. | POLYGON((161.88 -77.47,162.075 -77.47,162.27 -77.47,162.465 -77.47,162.66 -77.47,162.855 -77.47,163.05 -77.47,163.245 -77.47,163.44 -77.47,163.635 -77.47,163.83 -77.47,163.83 -77.501,163.83 -77.532,163.83 -77.563,163.83 -77.594,163.83 -77.625,163.83 -77.656,163.83 -77.687,163.83 -77.718,163.83 -77.749,163.83 -77.78,163.635 -77.78,163.44 -77.78,163.245 -77.78,163.05 -77.78,162.855 -77.78,162.66 -77.78,162.465 -77.78,162.27 -77.78,162.075 -77.78,161.88 -77.78,161.88 -77.749,161.88 -77.718,161.88 -77.687,161.88 -77.656,161.88 -77.625,161.88 -77.594,161.88 -77.563,161.88 -77.532,161.88 -77.501,161.88 -77.47)) | POINT(162.855 -77.625) | false | false | |||||||||||
Collaborative Research: Exploring the Functional Role of Antarctic Plants during Terrestrial Succession
|
1932876 |
2022-04-14 | Ball, Becky | No dataset link provided | Part I: Non-technical summary The Antarctic Peninsula warmed very rapidly in the late part of the 20th century, much faster than the global average, and this warming is predicted to resume and continue over the rest of the 21st century. One consequence of this rapid warming is the melting and subsequent retreat of glaciers, leading to an increase in newly-exposed land on the Peninsula that was previously covered with ice. Once new terrain is exposed, the process of ecological succession begins, with the arrival of early-colonizing plants, such as moss and lichens, and soil organisms - a process commonly referred to as the “greening” of Antarctica. Early stages of succession will be an increasingly common feature on the Antarctic Peninsula, but the mechanisms by which they occur on the Antarctic continent is not well understood. Once the plants have established on the newly-exposed soil, they can change many important properties, such as water dynamics, nutrient recycling, soil development, and habitat for microscopic organisms, which will ultimately determine the structure and functioning of the future ecosystem as it develops. These relationships between vegetation, soil, and the associated microorganisms, referred to as “plant-soil” interactions, are something we know virtually nothing about. This project will be the first to make a comprehensive study of how the type of colonizing plant, and the expansion of those plants from climate change, will influence terrestrial ecosystems in Antarctica. Understanding these processes is critical to understanding how the greening Antarctica is occurring and how soil communities and processes are influenced by these expanding plant communities. Through this work the research team, will also be intensively training undergraduate and graduate students, including training of students from underrepresented groups and collaborative training of students from Chile and the US. Additionally, the research groups will continue their focus on scientific outreach with K-12 schools and the general public to expand awareness of the effects of climate change in Antarctica. Part II: Technical summary In this study, the researchers will use surveys across succession sites along the Antarctic Peninsula and Scotia Arc as well as a manipulative field experiment at glacier succession sites to test how species-specific plant functional traits impact soil properties and associated microbial and invertebrate communities in a greening Antarctica. In doing so, they will pursue three integrated aims to understand how Antarctic plant functional traits alter their soil environment and soil communities during succession after glacial retreat. AIM 1) Characterize six fundamental plant functional traits (thermal conductivity, water holding capacity, albedo, decomposability, tissue nutrient content, and secondary chemistry) among diverse Antarctica flora; AIM 2) Measure the relative effects of fundamental plant functional traits on soil physical properties and soil biogeochemistry across glacial succession gradients in Antarctica; and AIM 3) Measure the relative effects of fundamental plant functional traits on soil microbial and invertebrate communities across glacial succession gradients in Antarctica. They will explore how early-colonizing plants, especially mosses and lichens, alter soil physical, biogeochemical, and biological components, potentially impacting later patterns of succession. The researhcers will use intensive surveys of plant-soil interactions across succession sites and a manipulative transplant experiment in the South Shetland Islands, Antarctica to address their aims. The investigators will collect data on plant functional traits and their effects on soil physical properties, biogeochemistry, biotic abundance, and microbial metagenomics. The data collected will be the first comprehensive measures of the relative importance of plant functional types during glacial retreat and vegetative expansion from climate change in Antarctica, aiding our understanding of how plant functional group diversity and abundance are changing in a greening 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. | POLYGON((-59.666116 -62.15,-59.5128377 -62.15,-59.3595594 -62.15,-59.2062811 -62.15,-59.0530028 -62.15,-58.8997245 -62.15,-58.7464462 -62.15,-58.5931679 -62.15,-58.4398896 -62.15,-58.2866113 -62.15,-58.133333 -62.15,-58.133333 -62.1731502,-58.133333 -62.1963004,-58.133333 -62.2194506,-58.133333 -62.2426008,-58.133333 -62.265751,-58.133333 -62.2889012,-58.133333 -62.3120514,-58.133333 -62.3352016,-58.133333 -62.3583518,-58.133333 -62.381502,-58.2866113 -62.381502,-58.4398896 -62.381502,-58.5931679 -62.381502,-58.7464462 -62.381502,-58.8997245 -62.381502,-59.0530028 -62.381502,-59.2062811 -62.381502,-59.3595594 -62.381502,-59.5128377 -62.381502,-59.666116 -62.381502,-59.666116 -62.3583518,-59.666116 -62.3352016,-59.666116 -62.3120514,-59.666116 -62.2889012,-59.666116 -62.265751,-59.666116 -62.2426008,-59.666116 -62.2194506,-59.666116 -62.1963004,-59.666116 -62.1731502,-59.666116 -62.15)) | POINT(-58.8997245 -62.265751) | false | false | |||||||||||
Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change
|
0342484 |
2022-02-04 | Harwood, David; Levy, Richard |
|
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. | POINT(167.083333 -77.888889) | POINT(167.083333 -77.888889) | false | false | |||||||||||
Surface Energy Balance on West Antarctica and the Ross Ice Shelf
|
1744954 |
2022-02-02 | Lubin, Dan |
|
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. | POINT(-148.81 -81.65) | POINT(-148.81 -81.65) | false | false | |||||||||||
Collaborative Research: Cloud Radiative Impact on the Surface Energy Budget of the Antarctic Peninsula
|
2127633 2127632 |
2022-02-01 | Zou, Xun | No dataset link provided | This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The Western Antarctic Peninsula (WAP; AP) has been warming faster than the global average since the mid-1960s. Concurrent mobilization of ice shelves has been associated with glacial discharge into the ocean, with important implications for global sea level rise. This work will enhance our understanding of the contributions of clouds, water vapor and surface radiation to warming over the WAP. Processes governing phase partitioning and amounts of supercooled liquid water are crucial for understanding surface melt, and will be explored. In addition, the role of clouds and moisture during foehn and atmospheric river (AR) events, will be characterized. Clouds and atmospheric water vapor have strong radiative signals that vary seasonally and with cloud properties. This work will lead to a better understanding of how clouds are impacting surface melt on the AP in the changing climate. In addition, the proposed work will include several undergraduate research projects. Finally, broader impacts include public outreach through participation in GeoWeek at Ohio State University and Polar Science Weekend at the Pacific Science Center in Seattle, WA. It is crucial to human welfare to understand mechanisms responsible for the rapid pace of Antarctic ice loss. This work will lead to a better understanding of how clouds are impacting surface melt on the WAP in the changing climate. The project will use surface- and satellite-based measurements to characterize clouds and humidity. The project maximizes value by using a variety of previous, ongoing, and planned measurements made by an international group of collaborators, along with measurements and model (AMPS, Polar-WRF) results. These will be used to quantify clouds, water vapor, and radiation and their effects on the surface energy balance at three strategically-located stations: Rothera (upwind of the WAP), Marambio (downwind of the WAP) and Escudero (north of the WAP), in order to provide a detailed characterization of cloud radiative and precipitation-formation properties and their role in surface warming and melt events. These mechanisms lead to the following hypotheses: 1) Through their effect on the surface energy balance, clouds play an important role in surface warming on the AP; this role is seasonally varying and sensitive to cloud thermodynamic phase, 2) Radiative heating during foehn events is an important contributor to warming at the northern AP, and 3) The radiative effects of clouds and water vapor have strong influences on heating before and during AR events, with significant differences on the two sides of the WAP. 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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Modeling Giant Icebergs and Their Decay
|
1744835 1744800 |
2022-01-18 | Wagner, Till; Eisenman, Ian |
|
Icebergs are a component of the Antarctic climate system, yet a comprehensive representation of their dynamics in climate models has remained elusive. Representing the role of icebergs in global climate models (GCMs) poses a formidable challenge to the scientific community. The most striking shortcoming of current iceberg models is arguably that they do not represent giant tabular icebergs, even though giant icebergs carry most of the freshwater stored in icebergs in the Southern Ocean. This lack of large icebergs in models is mostly due to the difficulties associated with adequately modeling iceberg decay. In particular, fracturing and breakup are not typically considered in iceberg models, despite being dominant iceberg decay processes. Investigators are to address these issues using a hierarchy of iceberg models, ranging from an idealized analytical model to a comprehensive GCM, in concert with recent observational data. The main objective of this study is to develop a new iceberg model that: (i) accounts for iceberg breakup and fracturing processes that have been neglected to date, (ii) improves on the representation of iceberg decay processes that were considered in previous models, (iii) explicitly represents large tabular icebergs. The primary broader impact of the proposed work will be through a K-12 teacher workshop series showcasing this project as an example of how scientists develop physical models. Ongoing changes in the California K-12 science standards will enable the teachers to creatively use this material in their classrooms. 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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Linking Antarctic Cold Desert Groundwater to Thermokarst & Chemical Weathering in Partnership with the Geoscience UAV Academy
|
1847067 |
2021-12-24 | Levy, Joseph |
|
Antarctic groundwater drives the regional carbon cycle and can accelerate permafrost thaw shaping Antarctic surface features. However, groundwater extent, flow, and processes on a continent virtually locked in ice are poorly understood. The proposed work investigates the interplay between groundwater, sediment, and ice in Antarctica's cold desert landscape to determine when, where, and why Antarctic groundwater is flowing, and how it may evolve Antarctic frozen deserts from dry and stable to wet and dynamic. Mapping the changing extent of Antarctic near-surface groundwater requires the ability to measure soil moisture rapidly and repeatedly over large areas. The research will capture changes in near-surface groundwater distribution through an unmanned aerial vehicle (UAV) mapping approach. The project integrates a diverse range of sensors with new UAV technologies to provide a higher-resolution and more frequent assessment of Antarctic groundwater extent and composition than can be accomplished using satellite observations alone. To complement the research objectives, the PI will develop a new UAV summer field school, the Geosciences UAV Academy, focused on training undergraduate-level UAV pilots in conducting novel earth sciences research using cutting edge imaging tools. The integration of research and technology will prepare students for careers in UAV-related industries and research. The project will deliver new UAV tools and workflows for soil moisture mapping relevant to arid regions including Antarctica as well as temperate desert and dryland systems and will train student research pilots to tackle next generation airborne challenges. Water tracks are the basic hydrological unit that currently feeds the rapidly-changing permafrost and wetlands in the Antarctic McMurdo Dry Valleys (MDV). Despite the importance of water tracks in the MDV hydrologic cycle and their influence on biogeochemistry, little is known about how these water tracks control the unique brine processes operating in Antarctic ice-free areas. Both groundwater availability and geochemistry shape Antarctic microbial communities, connecting soil geology and hydrology to carbon cycling and ecosystem functioning. The objectives of this CAREER proposal are to 1) map water tracks to determine the spatial distribution and seasonal magnitude of groundwater impacts on the MDV near-surface environment to determine how near-surface groundwater drives permafrost thaw and enhances chemical weathering and biogeochemical cycling; 2) establish a UAV academy training earth sciences students to answer geoscience questions using drone-based platforms and remote sensing techniques; and 3) provide a formative step in the development of the PI as a teacher-scholar. UAV-borne hyperspectral imaging complemented with field soil sampling will determine the aerial extent and timing of inundation, water level, and water budget of representative water tracks in the MDV. Soil moisture will be measured via near-infrared reflectance spectroscopy while bulk chemistry of soils and groundwater will be analyzed via ion chromatography and soil x-ray fluorescence. Sedimentological and hydrological properties will be determined via analysis of intact core samples. These data will be used to test competing hypotheses regarding the origin of water track solutions and water movement through seasonal wetlands. The work will provide a regional understanding of groundwater sources, shallow groundwater flux, and the influence of regional hydrogeology on solute export to the Southern Ocean and on soil/atmosphere linkages in earth's carbon budget. The UAV school will 1) provide comprehensive instruction at the undergraduate level in both how and why UAVs can advance geoscience research and learning; and 2) provide educational infrastructure for an eventual self-sustaining summer program for undergraduate UAV education. 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. | POLYGON((161 -76,161.35 -76,161.7 -76,162.05 -76,162.4 -76,162.75 -76,163.1 -76,163.45 -76,163.8 -76,164.15 -76,164.5 -76,164.5 -76.2,164.5 -76.4,164.5 -76.6,164.5 -76.8,164.5 -77,164.5 -77.2,164.5 -77.4,164.5 -77.6,164.5 -77.8,164.5 -78,164.15 -78,163.8 -78,163.45 -78,163.1 -78,162.75 -78,162.4 -78,162.05 -78,161.7 -78,161.35 -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)) | POINT(162.75 -77) | false | false | |||||||||||
Collaborative Research: Holocene and Late Pleistocene Stream Deposition in the McMurdo Dry Valleys, Antarctica as a Proxy for Glacial Meltwater and Paleoclimate
|
2039419 |
2021-12-16 | Swanger, Kate | No dataset link provided | The McMurdo Dry Valleys are the largest ice-free region in Antarctica and home to a seasonally active hydrologic system, with streams and saline lakes. Streams are fed by summer meltwater from local glaciers and snowbanks. Therefore, streamflow is tied to summer climate conditions such as air temperatures, ground temperatures, winds, and incoming solar radiation. Based on 50 years of monitoring, summer stream activity has been observed to change, and it likely varied during the geologic past in response to regional climate change and fluctuating glaciers. Thus, deposits from these streams can address questions about past climate, meltwater, and lake level changes in this region. How did meltwater streamflow respond to past climate change? How did streamflow vary during periods of glacial advance and retreat? At what times did large lakes fill many of the valleys and what was their extent? The researchers plan to acquire a record of stream activity for the Dry Valleys that will span the three largest valleys and a time period of about 100,000 years. This record will come from a series of active and ancient alluvial fans that were deposited by streams as they flowed from valley sidewalls onto valley floors. The study will provide a long-term context with which to assess recent observed changes to stream activity and lake levels. The research will be led by two female mid-career investigators and contribute significantly to student research opportunities and education. The research will contribute to graduate and undergraduate education by including students in both field and laboratory research, as well as incorporating data and results into the classroom. The research will be disseminated to K-12 and non-scientific communities through outreach that includes professional development training for K-12 teachers in eastern Massachusetts, development of hands-on activities, visits to K-12 classrooms, and STEM education and literacy activities in North Carolina. The PIs propose to constrain rates of fluvial deposition and periods of increased fluvial activity in the McMurdo Dry Valleys during the Holocene and late Pleistocene. During 50 years of hydrologic monitoring in the Dry Valleys, scientists have observed that streams exhibit significant response to summer conditions. Previous studies of glacial and lacustrine deposits indicate regional glacier advance in the Dry Valleys during recent interglacial periods and high lake levels during and after the Last Glacial Maximum (LGM), with potentially significant low and high stands during the Holocene. However, the geologic record of meltwater activity is poorly constrained. The PIs seek to develop the first spatially-extensive record of stream deposition in the Dry Valleys by analyzing and dating alluvial fans. Given that alluvial fans are deposited by summer meltwater streams in a relatively stable tectonic setting, this record will serve as a proxy of regional summer climate conditions. Meltwater streams are an important component of the regional hydrologic system, connecting glaciers to lakes and affecting ecosystems and soils. A record of fluvial deposition is key to understanding the relationship between past climate change and regional hydrology. The proposed research will include remote- and field-based mapping of alluvial fans, stream channels, and meltwater sources as well as modeling potential incoming solar radiation to the fans and moisture sources during the austral summer. In the field, the PIs will document stratigraphy, collect near-surface sediments from 25 fans across four valleys (Taylor, Pearse, Wright, and Victoria), and collect 2- to 3-m vertical cores of ice-cemented sediments from three alluvial fan complexes. The PIs will then conduct depositional dating of fluvial sands via optically stimulated luminescence, and analyze mineralogy and bulk major element chemistry with X-ray powder diffraction and X-ray fluorescence. From these analyses, the PIs propose to (1) determine the timing of local- to regional-scale periods of high fluvial deposition, (2) calculate depositional rates, and (3) constrain depositional environments and sediment provenance. Given that many of the alluvial fans occur below the hypothesized maximum extents of glacially-dammed lakes in Wright and Victoria valleys, detailed stratigraphy, sediment provenance, and OSL dating of these fans could shed light on ongoing debates regarding the timing and extent of LGM and post-LGM lakes. The work will support a postdoctoral researcher, a PhD student, and many undergraduate and master’s students in cross-disciplinary research that spans stratigraphy, geochemistry, paleoclimatology and physics. 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. | POLYGON((161 -77.3,161.2 -77.3,161.4 -77.3,161.6 -77.3,161.8 -77.3,162 -77.3,162.2 -77.3,162.4 -77.3,162.6 -77.3,162.8 -77.3,163 -77.3,163 -77.35,163 -77.4,163 -77.45,163 -77.5,163 -77.55,163 -77.6,163 -77.65,163 -77.7,163 -77.75,163 -77.8,162.8 -77.8,162.6 -77.8,162.4 -77.8,162.2 -77.8,162 -77.8,161.8 -77.8,161.6 -77.8,161.4 -77.8,161.2 -77.8,161 -77.8,161 -77.75,161 -77.7,161 -77.65,161 -77.6,161 -77.55,161 -77.5,161 -77.45,161 -77.4,161 -77.35,161 -77.3)) | POINT(162 -77.55) | false | false | |||||||||||
Collaborative Research: Remote characterization of microbial mats in Taylor Valley, Antarctica through in situ sampling and spectral validation
|
1744785 |
2021-11-30 | Barrett, John; Salvatore, Mark |
|
Microbial mats are found throughout the McMurdo Dry Valleys where summer snowmelt provides liquid water that allows these mats to flourish. Researchers have long studied the environmental conditions microbial mats need to grow. Despite these efforts, it has been difficult to develop a broad picture of these unique ecosystems. Recent advances in satellite technology now provide researchers an exciting new tool to study these special Antarctic ecosystems from space using the unique spectral signatures associated with microbial mats. This new technology not only offers the promise that microbial mats can be mapped and studied from space, this research will also help protect these delicate environments from potentially harmful human impacts that can occur when studying them from the ground. This project will use satellite imagery and spectroscopic techniques to identify and map microbial mat communities and relate their properties and distributions to both field and lab-based measurements. This research provides an exciting new tool to help document and understand the distribution of a major component of the Antarctic ecosystem in the McMurdo Dry Valleys. The goal of this project is to establish quantitative relationships between spectral signatures derived from orbit and the physiological status and biogeochemical properties of microbial mat communities in Taylor Valley, Antarctica, as measured by field and laboratory analyses on collected samples. The goal wioll be met by (1) refining atmospheric correction techniques using in situ radiometric rectification to derive accurate surface spectra; (2) collecting multispectral orbital images concurrent with in situ sampling and spectral measurements in the field to ensure temporal comparability; (3) measuring sediment, water, and microbial mat samples for organic and inorganic carbon content, essential biogeochemical nutrients, and chlorophyll-a to determine relevant mat characteristics; and (4) quantitatively associating these laboratory-derived characteristics with field-derived and orbital spectral signatures and parameters. The result of this work will be a more robust quantitative link between the distribution of microbial mat communities and their biogeochemical properties to landscape-scale spectral signatures. 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. | POLYGON((-180 -77.62,-145.683 -77.62,-111.366 -77.62,-77.049 -77.62,-42.732 -77.62,-8.415 -77.62,25.902 -77.62,60.219 -77.62,94.536 -77.62,128.853 -77.62,163.17 -77.62,163.17 -77.618,163.17 -77.616,163.17 -77.614,163.17 -77.612,163.17 -77.61,163.17 -77.608,163.17 -77.606,163.17 -77.604,163.17 -77.602,163.17 -77.6,128.853 -77.6,94.536 -77.6,60.219 -77.6,25.902 -77.6,-8.415 -77.6,-42.732 -77.6,-77.049 -77.6,-111.366 -77.6,-145.683 -77.6,180 -77.6,178.319 -77.6,176.638 -77.6,174.957 -77.6,173.276 -77.6,171.595 -77.6,169.914 -77.6,168.233 -77.6,166.552 -77.6,164.871 -77.6,163.19 -77.6,163.19 -77.602,163.19 -77.604,163.19 -77.606,163.19 -77.608,163.19 -77.61,163.19 -77.612,163.19 -77.614,163.19 -77.616,163.19 -77.618,163.19 -77.62,164.871 -77.62,166.552 -77.62,168.233 -77.62,169.914 -77.62,171.595 -77.62,173.276 -77.62,174.957 -77.62,176.638 -77.62,178.319 -77.62,-180 -77.62)) | POINT(-16.82 -77.61) | false | false | |||||||||||
Collaborative Research: EAGER: Generation of high resolution surface melting maps over Antarctica using regional climate models, remote sensing and machine learning
|
2136938 2136940 2136939 |
2021-11-08 | Tedesco, Marco | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
Investigating the influence of ocean temperature on Antarctic Ice Sheet evolution during the early to middle Pleistocene
|
2139051 |
2021-11-05 | Michelle, Guitard | No dataset link provided | 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. | 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)) | POINT(-41.5 -59.5) | false | false | |||||||||||
OPP-PRF Calving, Icebergs, and Climate
|
2139002 |
2021-11-05 | Huth, Alex |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
EAGER: L-Band Radar Ice Sounder for Measuring Ice Basal Conditions and Ice-Shelf Melt Rate
|
1921418 |
2021-10-11 | Gogineni, Prasad; O'Neill, Charles; Yan, Stephen; Taylor, Drew |
|
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. | None | None | false | false | |||||||||||
Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations
|
1745043 1745055 |
2021-09-28 | Simkins, Lauren; Stearns, Leigh; Anderson, John; van der Veen, Cornelis |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: Investigating Four Decades of Ross Ice Shelf Subsurface Change with Historical and Modern Radar Sounding Data
|
2049332 |
2021-09-15 | Chu, Winnie; Schroeder, Dustin; Siegfried, Matthew |
|
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. | 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)) | POINT(-167.5 -80.5) | false | false | |||||||||||
CAREER: Coastal Antarctic Snow Algae and Light Absorbing Particles: Snowmelt, Climate and Ecosystem Impacts
|
2046240 |
2021-09-10 | Khan, Alia | No dataset link provided | ________________________________________________________________________________________________ Part I: Non-technical Summary The Antarctic Peninsula is one of the most rapidly warming regions on the planet. This 5-yr time-series program will build on an ongoing international collaboration with scientists from the Chilean Antarctic Program to evaluate the role of temperature, light absorbing particles, snow-algae growth, and their radiative forcing effects on snow and ice melt in the Western Antarctic Peninsula. There is strong evidence that these effects may be intensifying due to a warming climate. Rising temperatures can increase the growth rate of coastal snow algae as well as enhance the input of particles from sources such as the long-range transport of black carbon to the Antarctic continent from intensifying Southern Hemisphere wildfire seasons. Particle and algae feedbacks can have immediate local impacts on snow melt and long-term regional impacts on climate because reduced snow cover alters how the Antarctic continent interacts with the rest of the global climate. A variety of ground-based and remote sensing data collected across multiple spatial scales will be used. Ground measurements will be compared to satellite imagery to develop novel computer algorithms to map ice algal bloom effects under changing climates. The project is expected to fundamentally advance knowledge of the spatial and temporal snow algae growing season, which is needed to quantify impacts on regional snow and ice melt. The program also has a strong partnership with the International Association of Antarctic Tour Operators to involve cruise passengers as citizen scientists for sample collection. Antarctic research results will be integrated into undergraduate curricula and research opportunities through studies to LAPs and snow algae in the Pacific Northwest. The PI will recruit and train a diverse pool of students in cryosphere climate related research methods on Mt. Baker in Western Washington. Trained undergraduate will then serve as instructors for a local Snow School that takes middle school students to Mt. Baker to learn about snow science. Resulting datasets from Antarctica and Mt. Baker will be used in University classes to explore regional effects of climate change. Along with enhancing cryosphere-oriented place-based undergraduate field courses in the Pacific Northwest, the PI will recruit and train a diverse pool of undergraduate students to serve as instructors for the Mt. Baker Snow School program. This award will advance our understanding of cryosphere-climate feedbacks, which are likely changing and will continue to evolve in a warming world, while also increasing under-represented student engagement in the polar geosciences. Part 2: Technical Summary Rapid and persistent climate warming in the Western Antarctic Peninsula is likely resulting in intensified snow-algae growth and an extended bloom season in coastal areas. Similarly, deposition of light absorbing particles (LAPs) onto Antarctica cryosphere surfaces, such as black carbon from intensifying Southern Hemisphere wildfire seasons, and dust from the expansion of ice-free regions in the Antarctic Peninsula, may be increasing. The presence of snow algae blooms and LAPs enhance the absorption of solar radiation by snow and ice surfaces. This positive feedback creates a measurable radiative forcing, which can have immediate local and long-term regional impacts on albedo, snow melt and downstream ecosystems. This project will investigate the spatial and temporal distribution of snow algae, black carbon and dust across the Western Antarctica Peninsula region, their response to climate warming, and their role in regional snow and ice melt. Data will be collected across multiple spatial scales from in situ field measurements and sample collection to imagery from ground-based photos and high resolution multi-spectral satellite sensors. Ground measurements will inform development and application of novel algorithms to map algal bloom extent through time using 0.5-3m spatial resolution multi-spectral satellite imagery. Results will be used to improve snow algae parameterization in a new version of the Snow Ice Aerosol Radiation model (SNICARv3) that includes bio-albedo feedbacks, eventually informing models of ice-free area expansion through incorporation of SNICARv3 in the Community Earth System Model. Citizen scientists will be mentored and engaged in the research through an active partnership with the International Association of Antarctic Tour Operators that frequently visits the region. The cruise ship association will facilitate sampling to develop a unique snow algae observing network to validate remote sensing algorithms that map snow algae with high-resolution multi-spectral satellite imagery from space. These time-series will inform instantaneous and interannual radiative forcing calculations to assess impacts of snow algae and LAPs on regional snow melt. Quantifying the spatio-temporal growing season of snow algae and impacts from black carbon and dust will increase our ability to model their impact on snow melt, regional climate warming and ice-free expansion in the Antarctic Peninsula region. 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. | POLYGON((-75 -62,-73.5 -62,-72 -62,-70.5 -62,-69 -62,-67.5 -62,-66 -62,-64.5 -62,-63 -62,-61.5 -62,-60 -62,-60 -62.85,-60 -63.7,-60 -64.55,-60 -65.4,-60 -66.25,-60 -67.1,-60 -67.95,-60 -68.8,-60 -69.65,-60 -70.5,-61.5 -70.5,-63 -70.5,-64.5 -70.5,-66 -70.5,-67.5 -70.5,-69 -70.5,-70.5 -70.5,-72 -70.5,-73.5 -70.5,-75 -70.5,-75 -69.65,-75 -68.8,-75 -67.95,-75 -67.1,-75 -66.25,-75 -65.4,-75 -64.55,-75 -63.7,-75 -62.85,-75 -62)) | POINT(-67.5 -66.25) | false | false | |||||||||||
Investigating Antarctic Ice Sheet-Ocean-Carbon Cycle Interactions During the Last Deglaciation
|
2103032 |
2021-09-09 | 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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation
|
2114786 |
2021-09-09 | Warnock, Jonathan | No dataset link provided | 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. | None | None | false | false | |||||||||||
COLLABORATIVE RESEARCH: Resolving Ambiguous Exposure-Age Chronologies of Antarctic Deglaciation with Measurements of In-Situ-Produced Cosmogenic Carbon-14
|
1542976 1542936 |
2021-09-03 | Goehring, Brent; Balco, Gregory |
|
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. | 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)) | POINT(12.86 -74.268) | false | false | |||||||||||
West Antarctic Ice-sheet Change and Paleoceanography in the Amundsen Sea Across the Pliocene Climatic Optimum
|
2114839 |
2021-08-25 | Passchier, Sandra | 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. | None | None | false | false | ||||||||||||
NSFGEO-NERC: Collaborative Research: Accelerating Thwaites Ecosystem Impacts for the Southern Ocean (ARTEMIS)
|
1941304 1941308 1941483 1941327 1941292 |
2021-08-20 | Yager, Patricia; Medeiros, Patricia; Sherrell, Robert; St-Laurent, Pierre; Fitzsimmons, Jessica; Stammerjohn, Sharon | 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. | 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)) | POINT(-110 -73) | false | false | ||||||||||||
Collaborative research: The Antarctic Scallop as Key to Paleoenvironments and Sea Ice Conditions: Understanding the Modern to Predict the Past
|
1745064 1745057 1745080 |
2021-08-06 | Walker, Sally; Gillikin, David; Perez-Huerta, Alberto; Andrus, Fred | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
Physiological Ecology of "Herbivorous" Antarctic Copepods
|
1746087 |
2021-08-06 | Tarrant, Ann | Animals in the polar oceans have adapted to dramatic seasonal changes in day length, food availability, and ice cover, as well as to consistently cold waters. This project focuses on the adaptations of copepods - small animals that live in the water column and are an important food source to many different predators. The field studies will take place in the western Antarctic Peninsula, an environment and ecosystem that is rapidly changing. Antarctic copepods have developed particular feeding and behavioral strategies to survive in their very seasonal environment, however it is not known how each of these species will respond to environmental change. The overall goal of this project is to examine and compare these adaptations across species and to understand how each species responds to short-term changes in food availability. The project contains three main objectives: the first objective is to compare the sets of genes across species, especially looking at genes related to storage of energy from food. The second objective is to measure and compare the responses of copepods to changes in food availability. The third objective is to determine how variation across the western Antarctic Pensinsula habitat affects the feeding condition of the copepods. To make the data more useful to the broader research community, a database will be developed enabling easy comparison of genetic information between copepod species. This project will provide hands-on training opportunities to graduate and undergraduate student and will seek to recruit students from underrepresented groups. Results and scientific concepts will be shared through outreach activities, including an expedition blog, a series of interactive animations, and public presentations. Polar marine organisms have adapted to dramatic seasonal changes in photoperiod, light intensity, and ice cover, as well as to cold but stable thermal environments. The western Antarctic Peninsula, the focal region for the field studies, has experienced rapid warming and ice melt. While it is difficult to predict exactly how physical conditions in this region will change, effects on species distributions have already been documented. Large Antarctic copepods in the families Calanidae and Rhincalanidae are dominant components of the mesozooplankton that use different metabolic and behavioral strategies to optimize their use of a highly seasonal food supply. The overall goal of this project is to leverage molecular approaches to examine the physiological and metabolic adaptations at the individual and species level. The project focuses on three main objectives: the first objective is to characterize the gene complement and stage-specific gene expression patterns in Antarctic copepods within an evolutionary context. The second objective is to measure and compare the physiological and molecular responses of juvenile copepods to variable feeding conditions. The third objective is to characterize metabolic variation within natural copepod populations. The metabolically diverse Antarctic copepods also provide an excellent opportunity to compare mechanisms regulating energy storage and utilization and to test hypotheses regarding the roles of specific genes. The field studies will aim to utilize information from an ongoing long term research program (the Palmer Long-Term Ecological Research), which complements the ongoing program and provides extensive context for this project. To make the data more useful to the research community, a database will be developed facilitating comparison of transcriptomes between copepod species. This project will provide hands-on training opportunities to graduate and undergraduate students. Efforts will be made to recruit students who are members of underrepresented minorities. Results and scientific concepts will be broadly disseminated through an expedition blog, a series of interactive animations, and public presentations. 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. | POLYGON((-80 -60,-77.5 -60,-75 -60,-72.5 -60,-70 -60,-67.5 -60,-65 -60,-62.5 -60,-60 -60,-57.5 -60,-55 -60,-55 -61,-55 -62,-55 -63,-55 -64,-55 -65,-55 -66,-55 -67,-55 -68,-55 -69,-55 -70,-57.5 -70,-60 -70,-62.5 -70,-65 -70,-67.5 -70,-70 -70,-72.5 -70,-75 -70,-77.5 -70,-80 -70,-80 -69,-80 -68,-80 -67,-80 -66,-80 -65,-80 -64,-80 -63,-80 -62,-80 -61,-80 -60)) | POINT(-67.5 -65) | false | false | ||||||||||||
Collaborative Research: Observing the Atmospheric Boundary over the West Antarctic Ice Sheet
|
1744878 1745097 |
2021-07-06 | Cassano, John; Lazzara, Matthew | No dataset link provided | 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. | 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)) | POINT(-112 -79.5) | false | false | |||||||||||
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
|
2000992 |
2021-07-06 | Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie |
|
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. | POINT(-172.873074 -74.274008) | POINT(-172.873074 -74.274008) | false | false | |||||||||||
The Antarctic Ice Sheet Large Ensemble (AISLENS) Project: Assessing the Role of Climate Variability in Past and Future Ice Sheet Mass Loss
|
1947882 |
2021-07-01 | Robel, Alexander | No dataset link provided | 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. | None | None | false | false | |||||||||||
Collaborative Research: Laser Cutting Technology for Borehole Sampling
|
2032473 2032463 |
2021-06-30 | Talghader, Joseph; Kurbatov, Andrei V. |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Seasonal Primary Productivity and Nitrogen Cycling in Photosynthetic Mats, Lake Fryxell, McMurdo Dry Valleys
|
1937748 |
2021-06-30 | Sumner, Dawn; Mackey, Tyler |
|
Part I: Non-technical summary: This project focuses on understanding annual changes in microbial life that grows on the bottom of Lake Fryxell, Antarctica. Because of its polar latitude, photosynthesis can only occur during the summer months. During summer, photosynthetic bacteria supply communities with energy and oxygen. However, it is unknown how the microbes behave in the dark winter, when observations are not possible. This project will install environmental monitors and light-blocking shades over parts of these communities. The shades will extend winter conditions into the spring to allow researchers to characterize the winter behavior of the microbial communities. Researchers will measure changes in the water chemistry due to microbial activities when the shades are removed and the mats first receive light. Results are expected to provide insights into how organisms interact with and change their environments. The project includes training of graduate students and early career scientists in fieldwork, including scientific ice diving techniques. In addition, the members of the project team will develop a web-based “Guide to Thrive”, which will compile field tips ranging from basic gear use to advanced environmental protection techniques. This will be a valuable resource for group leaders ranging from undergraduate teaching assistants to Antarctic expedition leaders to lead well-planned and tailored field expeditions. Part II: Technical summary: The research team will measure seasonal metabolic and biogeochemical changes in benthic mats using differential gene expression and geochemical gradients. They will identify seasonal phenotypic differences in microbial communities and ecosystem effects induced by spring oxygen production. To do so, researchers will install environmental sensors and opaque shades over mats at three depths in the lake. The following spring, shaded and unshaded mats will be sampled. The shades will then be removed, and changes in pore water O2, H2S, pH, and redox will be measured using microelectrodes. Mats will also be sampled for transcriptomic gene expression analyses at intervals guided by geochemical changes. Pore water will be sampled for nutrient analyses. Field research will be supplemented with laboratory experiments to refine field techniques, gene expression data analysis, and integration of results into a seasonal model of productivity and nitrogen cycling in Lake Fryxell. Results will provide insights into several key priorities for NSF, including how biotic, abiotic and environmental components of the benthic mats interact to affect Antarctic lakes. 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. | POINT(163.183333 -77.616667) | POINT(163.183333 -77.616667) | false | false | |||||||||||
Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation
|
1851022 1851094 |
2021-06-28 | Baker, Ian; Fudge, T. J. | 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. | None | None | false | false | ||||||||||||
Antarctic Submarine Melt Variability from Remote Sensing of Icebergs
|
1933764 1643455 |
2021-06-28 | Enderlin, Ellyn |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
West Antarctic Ice Shelf- Ocean Interactions
|
1644159 |
2021-06-25 | Jacobs, Stanley |
|
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. | 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)) | POINT(-174 -75.75) | false | false | |||||||||||
NSF-NERC: Thwaites Interdisciplinary Margin Evolution (TIME): The Role of Shear Margin Dynamics in the Future Evolution of the Thwaites Drainage Basin
|
1739027 |
2021-06-24 | Tulaczyk, Slawek | No dataset link provided | 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. | 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)) | POINT(-110.5 -76.5) | false | false | |||||||||||
NSFGEO-NERC: Collaborative Research: Two-Phase Dynamics of Temperate Ice
|
1643120 |
2021-06-23 | Iverson, Neal; Zoet, Lucas | 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. | None | None | false | false | ||||||||||||
Magmatic Volatiles, Unraveling the Reservoirs and Processes of the Volcanism in the Antarctic Peninsula
|
1643494 |
2021-06-22 | Saal, Alberto |
|
The Earth's mantle influences the movement of tectonic plates and volcanism on the surface. One way to understand the composition and nature of the Earth's mantle is by studying the chemistry of basalts, which originate by volcanic eruptions of partially melting mantle rocks. This study will establish the budget and distribution of volatile elements (hydrogen, carbon, fluorine, chlorine, sulfur) in volcanic basalts to better understand the composition of the Earth's interior. Volatiles influence mantle melting, magma crystallization, magma migration and volcanic eruptions. Their abundances and spatial distribution provide important constraints on models of mantle flow and temperature. Moreover, volatiles are key constituents of the Earth's atmosphere and oceans. Establishing the cycles of volatiles between the Earth's interior and surface is of fundamental importance to understand the long-term evolution of our planet. This project supports a graduate student and research scientist at Brown University. It promotes the collaboration with geochemists from eleven institutions representing six different countries: USA, Germany, United Kingdom, Argentina, South Korea and Japan, and utilizes several NSF-funded USA analytical facilities. Communication of results will occur through: 1) peer-reviewed journals, presentations at conferences and invited university lectures, 2) hands-on science learning activities for local elementary and high school classes, and 3) outreach to the general audience through public lectures. Over the last 60 years of funded research, the Antarctic Peninsula and nearby ocean ridges have been extensively investigated providing information on the origin of the magmatism, and the composition, structure, temperature and evolution of the lithospheric and asthenospheric mantle. Diverse hypotheses have been proposed for the origin of the magmatism in the Antarctic Peninsula, from flux melting of the mantle wedge during devolatilization of the subducted Phoenix plate, to adiabatic decompression melting of a carbonated and hydrous asthenosphere, to melting of a volatile-rich metasomatized subcontinental lithospheric mantle. All proposed hypotheses invoke the role of volatiles. Surprisingly, data on the volatile contents of basalts and mantle from this region are non-existent. This is a significant omission from the geochemical data set, given the important role volatile elements play in the generation and composition of magmas and their sources. The focus of our research is to examine the regional variations in volatile contents (C, H, F, S, Cl) in geochemically well-characterized Pliocene-recent basalts from the Antarctic Peninsula and Phoenix ridge. Our goal is to establish the budget and distribution of volatiles in the mantle to understand 1) the processes responsible for the generation of chemically diverse basalts in close spatial and temporal proximity and 2) the nature (lithology, composition and temperature) of the heterogeneous mantle source beneath the Antarctic Peninsula and Phoenix ridge. | POLYGON((-68.074 -57.345,-66.6033 -57.345,-65.1326 -57.345,-63.6619 -57.345,-62.1912 -57.345,-60.7205 -57.345,-59.2498 -57.345,-57.7791 -57.345,-56.3084 -57.345,-54.8377 -57.345,-53.367 -57.345,-53.367 -58.12517,-53.367 -58.90534,-53.367 -59.68551,-53.367 -60.46568,-53.367 -61.24585,-53.367 -62.02602,-53.367 -62.80619,-53.367 -63.58636,-53.367 -64.36653,-53.367 -65.1467,-54.8377 -65.1467,-56.3084 -65.1467,-57.7791 -65.1467,-59.2498 -65.1467,-60.7205 -65.1467,-62.1912 -65.1467,-63.6619 -65.1467,-65.1326 -65.1467,-66.6033 -65.1467,-68.074 -65.1467,-68.074 -64.36653,-68.074 -63.58636,-68.074 -62.80619,-68.074 -62.02602,-68.074 -61.24585,-68.074 -60.46568,-68.074 -59.68551,-68.074 -58.90534,-68.074 -58.12517,-68.074 -57.345)) | POINT(-60.7205 -61.24585) | false | false | |||||||||||
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
|
1744970 |
2021-06-22 | Shevenell, Amelia | No dataset link provided | 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. | 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)) | POINT(120.5 -66.5) | false | false | |||||||||||
Collaborative Research: Reconstructing East Antarctica’s Past Response to Climate using Subglacial Precipitates
|
2045611 2042495 |
2021-06-18 | Blackburn, Terrence; Tulaczyk, Slawek; Hain, Mathis; Rasbury, Troy | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
Satellite observations and modelling of surface meltwater flow and its impact on ice shelves
|
1743310 |
2021-06-02 | Kingslake, Jonathan |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: Triggering of Antarctic Icequakes, Slip Events, and other Tectonic Phenomena by Distant Earthquakes
|
1543286 1543399 1745135 |
2021-05-19 | Walter, Jacob; Peng, Zhigang | No dataset link provided | 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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems
|
1543344 |
2021-05-18 | Soreghan, Gerilyn; Elwood Madden, Megan |
|
As glaciers creep across the landscape, they can act as earthmovers, plucking up rocks and grinding them into fine sediments. Glaciers have moved across the Antarctic landscape over thousands to millions of years, leaving these ground-up sediments in their wake. This study builds on pilot discoveries by the investigators that revealed remarkably large and variable measurements of surface area in glacially-derived fine-grained sediments found in the McMurdo Dry Valleys (MDV), one of the few landscapes on the Antarctic continent not currently covered by ice. Surface area is key to chemical weathering, the process by which rock is converted to soils as ions are carried away in streams and groundwater. These chemical weathering processes are also one of the primary means by which the Earth system naturally removes carbon dioxide from the atmosphere. Hence, high surface areas observed in sediments implies high "weatherability" which in turn translates to more potential carbon dioxide removed from the atmosphere. Therefore, chemical weathering in high surface area glacial sediments may have significant impacts on Earth's carbon cycle. The researchers will measure the chemical and physical properties of sediments previously collected from the Dry Valleys to understand what factors lead to production of sediment with high-surface area and potential "weather ability" and investigate how sediment produced in these glacial systems could ultimately impact Earth's carbon budget. Results from this research will help scientists (including modelers) refine predictions of the effects of melting glaciers- and attendant exposure of glacial sediment? on atmospheric carbon levels. These results may also contribute to applied research efforts on development of carbon-dioxide removal technologies utilizing principles of rock weathering. In addition to the scientific benefits, this research will involve several students at the undergraduate, graduate, and post-doctoral levels, including science education undergraduates, thus contributing to training of the next-generation STEM workforce. Physical weathering produces fresh surfaces, greatly enhancing specific surface area (SSA) and reactive surface area (RSA) of primary minerals. Quantifying SSA and RSA of sediments is key to determining dissolution and leaching rates during natural weathering, but few data exist on distribution of sediment SA, particularly in glacial and fluvial systems. Pilot data from glacial stream systems in Taylor Valley and Wright Valley (located in the MDV) exhibit remarkably high and variable values in both SSA and RSA, values that in some cases greatly exceed values from muds in temperate glacial systems. This discovery motivates the current research, which aims to investigate the hypothesis that high and variable SAs of muds within Wright and Taylor Valleys reflect textural and/or compositional inheritance from the differing depositional settings within the MDV, biologic controls, dust additions, and/or pedogenic processes. These hypotheses will be tested by sedimentologically, mineralogically, and geochemically characterizing muds from glacially derived sediment deposited in various environments (cold vs. wet based glaciation; fluvial, lacustrine, dust, and drift deposits) and of varying age (Miocene to Modern) from the MDV and quantifying variation of SA and reactivity. Comparisons with analyzed muds from temperate glacial systems will enable polar-temperate comparisons. Analyses will focus on muds of previously collected sediment from the MDVs. Grain size and SSA will be measured by Laser Analysis and N2 adsorption BET, respectively. After carbonate removal, samples will be re-analyzed for SSA, and muds characterized geochemically. Mineralogy and bulk chemistry will also be assessed on co-occurring sand fractions, and textural attributes documented. SSA-normalized dissolution experiments will be used to compare solutes released from sediments to determine RSAs. Results will be integrated with the various sedimentologic and geochemical analyses to test the posed hypotheses. Ultimately, this research should shed light on how weathering in Antarctic systems contributes to global carbon cycling. | None | None | false | false | |||||||||||
Population Growth at the Southern Extreme: Effects of Early Life Conditions on Adelie penguin Individuals and Colonies
|
1935870 1935901 |
2021-05-12 | Ballard, Grant; Schmidt, Annie; Varsani, Arvind; Dugger, Katie; Orben, Rachael |
|
Part 1: Non-technical description Polar regions are experiencing some of the most dramatic effects of climate change resulting in large-scale changes in sea ice cover. Despite this, there are relatively few long-term studies on polar species that evaluate the full scope of these effects. Over the last two decades, this team has conducted globally unique demographic studies of Adélie penguins in the Ross Sea, Antarctica, to explore several potential mechanisms for population change. This five-year project will use penguin-borne sensors to evaluate foraging conditions and behavior and environmental conditions on early life stages of Adélie penguins. Results will help to better understand population dynamics and how populations might respond to future environmental change. To promote STEM literacy, education and public outreach efforts will include multiple activities. The PenguinCam and PenguinScience.com website (impacts of >1 million hits per month and use by >300 classrooms/~10,000 students) will be continued. Each field season will also have ‘Live From the Penguins’ Skype calls to classes (~120/season). Classroom-ready activities that are aligned with Next Generation Science Standards will be developed with media products and science journal papers translated to grade 5-8 literacy level. The project will also train early career scientists, postdoctoral scholars, graduate students and post-graduate interns. Finally, in partnership with an Environmental Leadership Program, the team will host 2-year Roger Arliner Young Conservation Fellow, which is a program designed to increase opportunities for recent college graduates of color to learn about, engage with, and enter the environmental conservation sector. Part II: Technical description: Leveraging 25 years of data on marked individuals from two Adélie penguin colonies in the Ross Sea, combined with new biologging tags that track detailed penguin foraging efforts and environmental conditions, researchers will accomplish three major goals: 1) assess the quality of natal conditions by determining how environmental conditions, relative prey availability, and diet composition influence parental foraging behavior, chick provisioning, and fledging mass; 2) determine the spatial distribution and foraging behavior of juvenile Adélie penguins and the relative influence of natal versus post-fledging environmental conditions on their survival; and 3) determine the role of natal and post-fledging conditions in shaping individual life history traits and colony growth. Data from several types of penguin-borne biologging devices will be used to provide multiple lines of evidence for how early-life conditions and penguin behavior relate to penguin energetics and population size. This study is the first to integrate salinity, temperature, light level, depth, accelerometry, video loggers, and GPS data with longitudinal demographic information, providing an unprecedented ability to understand how penguins use the environment and enabling new insights from previously collected data. Changes in salinity due to increased glacial melt have important implications for sea ice formation, ocean circulation and productivity of the Southern Ocean, and potentially global temperature change. The penguin-borne sensors deployed in this study will support the NSF Office of Polar Programs priority: How does society more efficiently observe and measure the polar regions? It represents only the second study to track juvenile Adélie penguins at sea, the first in the Ross Sea region, the first with substantial sample sizes, and the first to assess juvenile survival rates directly, integrating early life factors and environmental conditions to better understand colony growth trajectories. 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. | POLYGON((-180 -60,-177 -60,-174 -60,-171 -60,-168 -60,-165 -60,-162 -60,-159 -60,-156 -60,-153 -60,-150 -60,-150 -61.8,-150 -63.6,-150 -65.4,-150 -67.2,-150 -69,-150 -70.8,-150 -72.6,-150 -74.4,-150 -76.2,-150 -78,-153 -78,-156 -78,-159 -78,-162 -78,-165 -78,-168 -78,-171 -78,-174 -78,-177 -78,180 -78,178.5 -78,177 -78,175.5 -78,174 -78,172.5 -78,171 -78,169.5 -78,168 -78,166.5 -78,165 -78,165 -76.2,165 -74.4,165 -72.6,165 -70.8,165 -69,165 -67.2,165 -65.4,165 -63.6,165 -61.8,165 -60,166.5 -60,168 -60,169.5 -60,171 -60,172.5 -60,174 -60,175.5 -60,177 -60,178.5 -60,-180 -60)) | POINT(-172.5 -69) | false | false | |||||||||||
Collaborative Research: Elucidating Environmental Controls of Productivity in Polynas and the Western Antarctic Peninsula
|
1643652 1643618 |
2021-04-29 | van Dijken, Gert; Arrigo, Kevin; Dinniman, Michael; Hofmann, Eileen |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations
|
1246151 1246416 |
2021-04-15 | Bromirski, Peter; Gerstoft, Peter; Stephen, Ralph | 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. | 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)) | POINT(177.5 -79) | false | false | ||||||||||||
NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment
|
1738992 1929991 |
2021-02-22 | Truffer, Martin; Scambos, Ted; Muto, Atsu; Heywood, Karen; Boehme, Lars; Hall, Robert; Wahlin, Anna; Lenaerts, Jan; Pettit, Erin | 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. | 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)) | POINT(-109 -75) | false | false | ||||||||||||
High Resolution Heterogeneity at the Base of Whillans Ice Stream and its Control on Ice Dynamics
|
1443525 |
2021-02-12 | Tulaczyk, Slawek; Schwartz, Susan |
|
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. | 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)) | POINT(-155 -84.4) | false | false | |||||||||||
Collaborative Research: Monitoring Antarctic Ice Sheet Changes with Ambient Seismic Noise Methods
|
1643795 |
2021-01-15 | Mordret, Aurelien; Mikesell, Dylan |
|
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. | 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)) | POINT(-116.25 -79.25) | false | false | |||||||||||
Collaborative Research: Antarctic Seismic Investigations of ULVZ Structure
|
1643551 |
2020-10-09 | Hansen, Samantha |
|
Non-Technical Project Description This research will study Ultralow Velocity Zones (ULVZs), located in Earth's interior on top of the boundary between the Earth's solid mantle and its fluid outer core. The ULVZs are so named because seismic waves passing through the Earth slow down dramatically when they encounter these zones. While ULVZs are thought to be related to melting processes, there is growing controversy regarding their origin and the role they play in the thermal and chemical evolution of our planet. The ULVZs may include the largest magma chambers in Earth's interior. Currently, researchers have only searched 40% of Earth's core-mantle boundary for the ULVZs and this project would use existing seismic data to map an unexplored area under Antarctica and interpret the nature of the ULVZs. This project will support two graduate students and create opportunities for undergraduate involvement. Project results will be published in scientific journals, presented at science fairs, and communicated through the researchers' websites. The research team will also take part in the NSF-sponsored PolarTREC (Teachers and Researchers Exploring and Collaborating) program to communicate the science to students and the broader community. Technical Project Description The National Research Council has highlighted high-resolution imaging of core-mantle boundary (CMB) structure as a high-priority, emerging research opportunity in the Earth Sciences since anomalies along the CMB likely play a critical role in the thermal and chemical evolution of our planet. Of particular interest are ultralow velocity zones (ULVZs), thin laterally-varying boundary layers associated with dramatic seismic velocity decreases and increases in density that are seen just above the CMB. Many questions exist regarding the origin of ULVZs, but incomplete seismic sampling of the lowermost mantle has limited our ability to map global ULVZ structure in detail. Using recently collected data from the Transantarctic Mountains Northern Network (TAMNNET) in Antarctica, this project will use core-reflected seismic phases (ScP, PcP, and ScS) to investigate ULVZ presence/absence along previously unexplored sections of the CMB. The data sampling includes the southern boundary of the Pacific Large Low Shear Velocity Province (LLSVP), a dominant feature in global shear wave tomography models, and will allow the researchers to examine a possible connection between ULVZs and LLSVPs. The main objectives of the project are to: 1) use TAMNNET data to document ULVZ presence/absence in previously unexplored regions of the lowermost mantle with array-based approaches; 2) model the data with 1- and 2.5-D wave propagation tools to obtain ULVZ properties and to assess trade-offs among the models; 3) use high quality events to augment the densely-spaced TAMNNET data with that from the more geographically-distributed, open-access Antarctic stations to increase CMB coverage with single-station analyses; and 4) explore the implications of ULVZ solution models for origin, present-day dynamics, and evolution, including their connection to other deep mantle structures, like LLSVPs. The project aims to provide new constraints on ULVZs, including their potential connection to LLSVPs, and thus relates to other seismic and geodynamic investigations focused on processes within the Earth?s interior. This project will promote a new research collaboration between The University of Alabama (UA) and Arizona State University (ASU), each of which brings specific strengths to the initiative. | None | None | false | false | |||||||||||
Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance
|
1724670 |
2020-09-10 | Williams, Trevor; Hemming, Sidney R. | 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. | 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)) | POINT(-45 -72.5) | false | false | ||||||||||||
Antarctic Firn Aquifers: Extent, Characteristics, and Comparison with Greenland Occurrences
|
1745116 |
2020-09-08 | Scambos, Ted | 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. | 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)) | POINT(-70 -71.5) | false | false | ||||||||||||
Collaborative
Research: Reconstructing Temperatures during the Mid-Pliocene Warm
Period in the McMurdo Dry Valleys with Cosmogenic Noble Gases
|
1935945 1935755 1935907 |
2020-08-25 | Tremblay, Marissa; Granger, Darryl; Balco, Gregory; Lamp, Jennifer | No dataset link provided | . ______________________________________________________________________________________________________________ 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. | 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)) | POINT(162 -77.625) | false | false | |||||||||||
Collaborative Research: Toward Dense Observation of Geothermal Fluxes in Antarctica Via Logistically Light Instrument Deployment
|
1745049 |
2020-08-03 | Tyler, Scott W. |
|
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. | None | None | false | false | |||||||||||
Ocean Tides around Antarctica and in the Southern Ocean
|
0125252 0125602 |
2020-07-07 | Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana; King, Matt | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
Investigating Early Miocene Sub-ice Volcanoes in Antarctica for Improved Modeling and understanding of a Large Magmatic Province
|
1443576 |
2020-06-05 | Panter, Kurt |
|
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. | 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)) | POINT(-153.75 -87) | false | false | |||||||||||
Comprehensive Seismic and Thermal Models for Antarctica and the Southern Oceans: A Synthesis of 15-years of Seismic Exploration
|
1744883 |
2020-06-02 | Wiens, Douglas; Shen, Weisen | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
A High Resolution Atmospheric Methane Record from the South Pole Ice Core
|
1643722 |
2020-06-02 | Brook, Edward J. |
|
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. | POINT(0 -90) | POINT(0 -90) | false | false | |||||||||||
Timing and Spatial Distribution of Antarctic Ice Sheet Growth and Sea-ice Formation across the Eocene-Oligocene Transition
|
1743643 |
2020-05-26 | Passchier, Sandra | 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. | None | None | false | false | ||||||||||||
Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Work
|
9978236 |
2020-04-24 | Bell, Robin; Studinger, Michael S. | 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. | 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)) | POINT(105.5 -77.25) | false | false | ||||||||||||
Collaborative Research: Water on the Antarctic Ice Sheet: Quantifying Surface Melt and Mapping Supraglacial Lakes
|
1643733 1643715 |
2020-03-16 | Moussavi, Mahsa; Pope, Allen; Trusel, Luke |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Quantifying Atmospheric Iron Properties over West Antarctic Peninsula
|
1341494 |
2020-02-20 | Gao, Yuan |
|
The research seeks to further quantify the input of atmospheric Fe into the sparsely sampled Southern Ocean (SO), specifically in the vicinity of the West Antarctic Peninsula (WAP) and adjacent continental shelf waters in the Drake Passage. This is typically a high nutrient low chlorophyll region where surface trace metal and primary productivity data are suggestive of Fe limitation. The WAP is characterized by high productivity in the austral summer, and at this time may be in the path of northern dust (aeolian Fe) input or subject to melt influx of elevated Fe accumulated from glacial and present-day sea ice sources. Primary scientific questions are: (1) to what extent does atmospheric Fe contribute to nutrient cycles and ecosystem dynamics in the SO? (2) How is warming climate occurring in the WAP affecting the aerosol composition of the maritime atmosphere. The primary productivity of the Southern Ocean is key to understanding oceanic uptake of anthropogenic greenhouse gases such as carbon dioxide. | POINT(-64.05 -64.77) | POINT(-64.05 -64.77) | false | false | |||||||||||
Collaborative Research: Determining Magma Storage Depths and Ascent Rates for the Erebus Volcanic Province, Antarctica Using Diffusive Water Loss from Olivine-hosted Melt Inclusion
|
1644020 1644027 1644013 |
2020-02-08 | Gaetani, Glenn; Le Roux, Veronique; Sims, Kenneth; Wallace, Paul | Nontechnical project description Globally, 500 million people live near and are threatened by active volcanoes. An important step in mitigating volcanic hazards is understanding the variables that influence the explosivity of eruptions. The rate at which a magma ascends from the reservoir within the Earth to the surface is one such variable. However, magma ascent rates are particularly difficult to determine because of the lack of reliable methods for investigating the process. This research applies a new approach to study magma storage depths and ascent rates at the Erebus volcanic province of Antarctica, one of Earth's largest alkaline volcanic centers. Small pockets of magma that become trapped within growing olivine crystals are called melt inclusions. The concentrations of water and carbon dioxide in these melt inclusions preserve information on the depth of magma reservoirs. Changes to the concentration and isotopic composition of water in the inclusions provide information on how long it took for the host magma to rise to the surface. In combination, these data from samples of olivine-rich volcanic deposits in the Erebus volcanic province will be used to determine the depths at which magmas are stored and their ascent rates. The project results will provide a framework for understanding volcanic hazards associated with alkaline volcanism worldwide. In addition, this project facilitates collaboration among three institutions, and provides an important educational opportunity for a postdoctoral researcher. Technical project description The depths at which magmas are stored, their pre-eruptive volatile contents, and the rates at which they ascend to the Earth's surface are important controls on the dynamics of volcanic eruptions. Basaltic magmas are likely to be vapor undersaturated as they begin their ascent from the mantle through the crust, but volatile solubility drops with decreasing pressure. Once vapor saturation is achieved and the magma begins to degas, its pre-eruptive volatile content is determined largely by the depth at which it resides within the crust. Magma stored in deeper reservoirs tend to experience less pre-eruptive degassing and to be richer in volatiles than magma shallower reservoirs. Eruptive style is influenced by the rate at which a magma ascends from the reservoir to the surface through its effect on the efficiency of vapor bubble nucleation, growth, and coalescence. The proposed work will advance our understanding of pre-eruptive storage conditions and syn-eruptive ascent rates through a combined field and analytical research program. Volatile measurements from olivine-hosted melt inclusions will be used to systematically investigate magma storage depths and ascent rates associated with alkaline volcanism in the Erebus volcanic province. A central goal of the project is to provide a spatial and temporal framework for interpreting results from studies of present-day volcanic processes at Mt Erebus volcano. The Erebus volcanic province of Antarctica is especially well suited to this type of investigation because: (1) there are many exposed mafic scoria cones, fissure vents, and hyaloclastites (exposed in sea cliffs) that produced rapidly quenched, olivine-rich tephra; (2) existing volatile data for Ross Island MIs show that magma storage was relatively deep compared to many mafic volcanic systems; (3) some of the eruptive centers ejected mantle xenoliths, allowing for comparison of ascent rates for xenolith-bearing and xenolith-free eruptions, and comparison of ascent rates for those bearing xenoliths with times estimated from settling velocities; and (4) the cold, dry conditions in Antarctica result in excellent tephra preservation compared to tropical and even many temperate localities. The project provides new tools for assessing volcanic hazards, facilitates collaboration involving researchers from three different institutions (WHOI, U Wyoming, and U Oregon), supports the researchers' involvement in teaching, advising, and outreach, and provides an educational opportunity for a promising young postdoctoral researcher. Understanding the interrelationships among magma volatile contents, reservoir depths, and ascent rates is vital for assessing volcanic hazards associated with alkaline volcanism across the globe. | POLYGON((164.1 -77.1,164.65 -77.1,165.2 -77.1,165.75 -77.1,166.3 -77.1,166.85 -77.1,167.4 -77.1,167.95 -77.1,168.5 -77.1,169.05 -77.1,169.6 -77.1,169.6 -77.235,169.6 -77.37,169.6 -77.505,169.6 -77.64,169.6 -77.775,169.6 -77.91,169.6 -78.045,169.6 -78.18,169.6 -78.315,169.6 -78.45,169.05 -78.45,168.5 -78.45,167.95 -78.45,167.4 -78.45,166.85 -78.45,166.3 -78.45,165.75 -78.45,165.2 -78.45,164.65 -78.45,164.1 -78.45,164.1 -78.315,164.1 -78.18,164.1 -78.045,164.1 -77.91,164.1 -77.775,164.1 -77.64,164.1 -77.505,164.1 -77.37,164.1 -77.235,164.1 -77.1)) | POINT(166.85 -77.775) | false | false | ||||||||||||
Petrologic Constraints on Subduction Termination From Lamprophyres, Ross Orogen, Antarctica
|
1443296 |
2019-12-02 | Cottle, John | No dataset link provided | Subduction takes place at convergent plate boundaries and involves sinking of one tectonic plate underneath another. Although this process is a key aspect of plate tectonics that shapes the planet over geologic time, and is a primary cause of earthquakes, it is not known what causes subduction to cease, and what effect it has on the deepest portions of the crust and the upper part of the mantle. By studying the age and composition of igneous rocks emplaced at the very end of the subduction cycle, this project seeks to understand what causes subduction to cease, and how this changes the composition and structure of the crust and upper mantle. Because this process occurs deep within the earth, the project will focus on rocks in the root of an ancient subduction zone, now exposed in the Transantarctic Mountains of Antarctica. In addition, Antarctica remains relatively poorly understood, and this project will contribute directly to increasing our understanding of the geologic history of this region. The project will focus on training graduate and undergraduate students - incorporating hands-on experience with an array of state-of-the-art analytical instrumentation. Students will also gain a range of more general skills including Geographic Information Systems (GIS), written and oral communication, and data management - strengths that are highly relevant to careers both in the academic and Geosciences industry. Each summer, high school students will be incorporated into aspects of the laboratory-based research through the UCSB research mentorship program. The PI and graduate students will engage the general public through a purpose-built iPhone App and multimedia website. Activities will include live phone and video conversations from the field between elementary school students and members of the team in Antarctica. The mechanisms by which the deep crustal delaminates or "founders" and is returned to the mantle remains a fundamental problem in earth science. Specifically, little is known about the temporal and spatial scales over which this process occurs or the mechanisms that trigger such catastrophic events. Igneous rocks highly enriched in potassium, called lamprophyres, are often emplaced during, and immediately after, termination of subduction and therefore potentially provide direct insight into foundering. These enigmatic rocks are important because they represent near-primary mantle melt compositions and therefore their age, geochemistry and petrologic evolution reveal key information on both the composition of the upper mantle and its thermal state. Of equal importance, they reveal how these key parameters vary through both space and time. By evaluating lamprophyres along a subduction zone margin it is possible to extract: 1) local-scale information, such as the timing and duration of melting and the role of igneous crystallization processes in generation of isotopic heterogeneities; 2) along-strike variations in mantle source composition, temperature, and depth of melting 3) the plate-scale forces that control foundering and termination of subduction. This project will study a suite of lamprophyres along the axis of the Transantarctic Mountains, emplaced during the latest stages of the Neoproterozoic - Ordovician Ross orogeny, Antarctica (roughly 505 to 470 million years before present). High-precision geochronology (age determinations) will be combined with geochemical measurements on the rocks and minerals to understand the mechanisms and timing of deep crustal foundering/delamination. | POLYGON((-180 -76.85314,-179.4383642 -76.85314,-178.8767284 -76.85314,-178.3150926 -76.85314,-177.7534568 -76.85314,-177.191821 -76.85314,-176.6301852 -76.85314,-176.0685494 -76.85314,-175.5069136 -76.85314,-174.9452778 -76.85314,-174.383642 -76.85314,-174.383642 -77.658865,-174.383642 -78.46459,-174.383642 -79.270315,-174.383642 -80.07604,-174.383642 -80.881765,-174.383642 -81.68749,-174.383642 -82.493215,-174.383642 -83.29894,-174.383642 -84.104665,-174.383642 -84.91039,-174.9452778 -84.91039,-175.5069136 -84.91039,-176.0685494 -84.91039,-176.6301852 -84.91039,-177.191821 -84.91039,-177.7534568 -84.91039,-178.3150926 -84.91039,-178.8767284 -84.91039,-179.4383642 -84.91039,180 -84.91039,177.4459565 -84.91039,174.891913 -84.91039,172.3378695 -84.91039,169.783826 -84.91039,167.2297825 -84.91039,164.675739 -84.91039,162.1216955 -84.91039,159.567652 -84.91039,157.0136085 -84.91039,154.459565 -84.91039,154.459565 -84.104665,154.459565 -83.29894,154.459565 -82.493215,154.459565 -81.68749,154.459565 -80.881765,154.459565 -80.07604,154.459565 -79.270315,154.459565 -78.46459,154.459565 -77.658865,154.459565 -76.85314,157.0136085 -76.85314,159.567652 -76.85314,162.1216955 -76.85314,164.675739 -76.85314,167.2297825 -76.85314,169.783826 -76.85314,172.3378695 -76.85314,174.891913 -76.85314,177.4459565 -76.85314,-180 -76.85314)) | POINT(170.0379615 -80.881765) | false | false | |||||||||||
NSF-NERC: THwaites Offshore Research (THOR)
|
1738942 |
2019-11-01 | Wellner, Julia; Larter, Robert; Minzoni, Rebecca; Hogan, Kelly; Anderson, John; Graham, Alastair; Hillenbrand, Claus-Dieter; Nitsche, Frank O.; Simkins, Lauren; Smith, James A. | 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. | 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)) | POINT(-110 -73.5) | false | false | ||||||||||||
Collaborative Research: Stochasticity and Cryoconite Community Assembly and Function
|
1443578 |
2019-11-01 | Schmidt, Steven; Cawley, Kaelin; Fountain, Andrew |
|
Cryoconite holes are pockets of life completely encased in otherwise barren glacial ice. These pockets of life form when dust blown onto the ice melts a small, largely isolated hole that can function as its own tiny ecosystem. This dust can contain microorganisms such as bacteria, algae, or microscopic animals. The microorganisms within the hole interact and carry out functions typical of a larger ecosystem, such as a forest. Cryoconite holes are especially important in extreme cold environments such as the Antarctic Dry Valleys, where they function as repositories of life. Because cryoconite holes are mostly enclosed and persist for years, they can be tracked over time to test fundamental scientific questions about how communities of interacting organisms develop to become fully functioning ecosystems. This project will sample existing and experimentally created cryoconite holes to understand how these ecosystems develop and to what degree random processes (such as which organisms get there first) affect the final community composition and functioning. The results will not only improve our understanding of how microbial communities assemble and affect the functioning of microecosystems such as cryoconite holes, but also how the processes of community assembly affect functioning of larger ecosystems, such as forests. A better understanding of community establishment, development, and response to abiotic factors are essential to forecasting ecological responses to environmental change. It is essential to unravel the links between community assembly, biodiversity, and nutrient cycling across numerous ecosystems because these are critical factors determining ecological responses to environmental change. The unique, largely isolated nature of cryoconite holes provides an experimental system that will advance fundamental understanding of the processes (e.g., stochastic dynamics such as dispersal limitation, assembly order, and ecological drift) driving community assembly. This project will use a field sampling campaign and a number of manipulative experiments to test a hypothesis that unites theory in community and ecosystem ecology: the degree to which stochastic processes guide microbial community assembly and affects regional patterns in biodiversity and ecosystem processes. Cryoconite holes will be sampled to compare community composition, environmental factors, and ecosystem functioning between hydrologically connected and isolated holes. New cryoconite holes will also be constructed and monitored over the course of two growing seasons to specifically alter assembly order and community size, thereby pairing a unique manipulative experiment with field surveys to address questions with relevance to the Antarctic and beyond. Amplicon sequencing, metagenomics, microscopy, sensitive environmental chemistry methods, and photosynthesis and respiration measurements will be used to test a series of sub-hypotheses that relate stochasticity to patterns in regional biodiversity, heterogeneity in environmental factors, and ecosystem processes. | POLYGON((161.5 -77.5,161.7 -77.5,161.9 -77.5,162.1 -77.5,162.3 -77.5,162.5 -77.5,162.7 -77.5,162.9 -77.5,163.1 -77.5,163.3 -77.5,163.5 -77.5,163.5 -77.53,163.5 -77.56,163.5 -77.59,163.5 -77.62,163.5 -77.65,163.5 -77.68,163.5 -77.71,163.5 -77.74,163.5 -77.77,163.5 -77.8,163.3 -77.8,163.1 -77.8,162.9 -77.8,162.7 -77.8,162.5 -77.8,162.3 -77.8,162.1 -77.8,161.9 -77.8,161.7 -77.8,161.5 -77.8,161.5 -77.77,161.5 -77.74,161.5 -77.71,161.5 -77.68,161.5 -77.65,161.5 -77.62,161.5 -77.59,161.5 -77.56,161.5 -77.53,161.5 -77.5)) | POINT(162.5 -77.65) | false | false | |||||||||||
EXPROBE-WAIS: Exposed Rock Beneath the West Antarctic Ice Sheet, A Test for Interglacial Ice Sheet Collapse
|
1341728 |
2019-10-08 | Stone, John | 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. | 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)) | POINT(-85.65 -81.15) | false | false | ||||||||||||
Collaborative Research: Evaluating Retreat in the Amundsen Sea Embayment: Assessing Controlling Processes, Uncertainties, and Projections
|
1443190 |
2019-09-16 | Pollard, David; Parizek, Byron R. | No dataset link provided | 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. | 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)) | POINT(-107.5 -77.5) | false | false | |||||||||||
Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators
|
1443585 1443424 1826712 1443386 |
2019-08-08 | Polito, Michael; Kelton, McMahon; Patterson, William; McCarthy, Matthew | 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. | 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)) | POINT(-120 -69) | false | false | ||||||||||||
Collaborative Research: Polynyas in Coastal Antarctica (PICA): Linking Physical Dynamics to Biological Variability
|
1643735 1643901 2021245 |
2019-08-07 | Zhang, Weifeng; Ji, Rubao; Jenouvrier, Stephanie; Maksym, Edward; Li, Yun |
|
During winter, sea-ice coverage along the Antarctic coast is punctuated by numerous polynyas--isolated openings of tens to hundreds of kilometer wide. These coastal polynyas are hotspots of sea ice production and the primary source regions of the bottom water in the global ocean. They also host high levels of biological activities and are the feeding grounds of Emperor penguins and marine mammals. The polynyas are a key component of the Antarctic coastal system and crucial for the survival of penguins and many other species. These features also differ dramatically from each other in timing of formation, duration, phytoplankton growth season, and overall biological productivity. Yet, the underlying reasons for differences among them are largely unknown. This project studies the fundamental biophysical processes at a variety of polynyas, examines the connection between the physical environment and the phytoplankton and penguin ecology, and investigates the mechanisms behind polynya variability. The results of this interdisciplinary study will provide a context for interpretation of field measurements in Antarctic coastal polynyas, set a baseline for future polynya studies, and examine how polynya ecosystems may respond to local and large-scale environmental changes. The project will include educational and outreach activities that convey scientific messages to a broad audience. It aims to increase public awareness of the interconnection between large-scale environmental change and Antarctic coastal systems. The main objectives of this study are to form a comprehensive understanding of the temporal and spatial variability of Antarctic coastal polynyas and the physical controls of polynya ecosystems. The project takes an interdisciplinary approach and seeks to establish a modeling system centered on the Regional Ocean Modeling System. This system links the ice and ocean conditions to the plankton ecology and penguin population. Applications of the modeling system in representative polynyas, in conjunction with analysis of existing observations, will determine the biophysical influences of individual forcing factors. In particular, this study will test a set of hypothesized effects of winds, offshore water intrusion, ice-shelf melting, sea-ice formation, glacier tongues, and ocean stratification on the timing of polynya phytoplankton bloom and the overall polynya biological productivity. The project will also examine how changing polynya state affects penguin breeding success, adult survival, and population growth. The team will conduct idealized sensitivity analysis to explore implications of forcing variability, including local and large-scale environmental change, on Antarctic coastal ecosystems. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Spring Blooms of Sea Ice Algae Along the Western Antarctic Peninsula: Effects of Warming and Freshening on Cell Physiology and Biogeochemical Cycles.
|
1744645 |
2019-07-23 | Young, Jodi; Deming, Jody |
|
Rapid changes in the extent and thickness of sea ice during the austral spring subject microorganisms within or attached to the ice to large fluctuations in temperature, salinity, light and nutrients. This project aims to identify cellular responses in sea-ice algae to increasing temperature and decreasing salinity during the spring melt along the western Antarctic Peninsula and to determine how associated changes at the cellular level can potentially affect dynamic, biologically driven processes. Understanding how sea-ice algae cope with, and are adapted to, their environment will not only help predict how polar ecosystems may change as the extent and thickness of sea ice change, but will also provide a better understanding of the widespread success of photosynthetic life on Earth. The scientific context and resulting advances from the research will be communicated to the general public through outreach activities that includes work with Science Communication Fellows and the popular Polar Science Weekend at the Pacific Science Center in Seattle, Washington. The project will provide student training to college students as well as provide for educational experiences for K-12 school children. There is currently a poor understanding of feedback relationships that exist between the rapidly changing environment in the western Antarctic Peninsula region and sea-ice algal production. The large shifts in temperature and salinity that algae experience during the spring melt affect critical cellular processes, including rates of enzyme-catalyzed reactions involved in photosynthesis and respiration, and the production of stress-protective compounds. These changes in cellular processes are poorly constrained but can be large and may have impacts on local ecosystem productivity and biogeochemical cycles. In particular, this study will focus on the thermal sensitivity of enzymes and the cycling of compatible solutes and exopolymers used for halo- and cryo-protection, and how they influence primary production and the biogeochemical cycling of carbon and nitrogen. Approaches will include field sampling during spring melt, incubation experiments of natural sea-ice communities under variable temperature and salinity conditions, and controlled manipulation of sea-ice algal species in laboratory culture. Employment of a range of techniques, from fast repetition rate fluorometry and gross and net photosynthetic measurements to metabolomics and enzyme kinetics, will tease apart the mechanistic effects of temperature and salinity on cell metabolism and primary production with the goal of quantifying how these changes will impact biogeochemical processes along the western Antarctic Peninsula. 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. | POLYGON((-64.4 -64.2,-64.38 -64.2,-64.36 -64.2,-64.34 -64.2,-64.32 -64.2,-64.3 -64.2,-64.28 -64.2,-64.26 -64.2,-64.24 -64.2,-64.22 -64.2,-64.2 -64.2,-64.2 -64.26,-64.2 -64.32,-64.2 -64.38,-64.2 -64.44,-64.2 -64.5,-64.2 -64.56,-64.2 -64.62,-64.2 -64.68,-64.2 -64.74,-64.2 -64.8,-64.22 -64.8,-64.24 -64.8,-64.26 -64.8,-64.28 -64.8,-64.3 -64.8,-64.32 -64.8,-64.34 -64.8,-64.36 -64.8,-64.38 -64.8,-64.4 -64.8,-64.4 -64.74,-64.4 -64.68,-64.4 -64.62,-64.4 -64.56,-64.4 -64.5,-64.4 -64.44,-64.4 -64.38,-64.4 -64.32,-64.4 -64.26,-64.4 -64.2)) | POINT(-64.3 -64.5) | false | false | |||||||||||
Collaborative research: Kr-86 as a proxy for barometric pressure variability and movement of the SH westerlies during the last
deglaciation
|
1543229 1543267 |
2019-07-10 | Severinghaus, Jeffrey P.; Brook, Edward J. | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
COLLABORATIVE RESEARCH: Remote Characterization of Microbial Mats in Taylor Valley, Antarctica, through In Situ Sampling and Spectral Validation
|
1745053 1744849 1744785 |
2019-07-03 | Salvatore, Mark; Barrett, John; Sokol, Eric |
|
Microbial mats are found throughout the McMurdo Dry Valleys where summer snowmelt provides liquid water that allows these mats to flourish. Researchers have long studied the environmental conditions microbial mats need to grow. Despite these efforts, it has been difficult to develop a broad picture of these unique ecosystems. Recent advances in satellite technology now provide researchers an exciting new tool to study these special Antarctic ecosystems from space using the unique spectral signatures associated with microbial mats. This new technology not only offers the promise that microbial mats can be mapped and studied from space, this research will also help protect these delicate environments from potentially harmful human impacts that can occur when studying them from the ground. This project will use satellite imagery and spectroscopic techniques to identify and map microbial mat communities and relate their properties and distributions to both field and lab-based measurements. This research provides an exciting new tool to help document and understand the distribution of a major component of the Antarctic ecosystem in the McMurdo Dry Valleys. The goal of this project is to establish quantitative relationships between spectral signatures derived from orbit and the physiological status and biogeochemical properties of microbial mat communities in Taylor Valley, Antarctica, as measured by field and laboratory analyses on collected samples. The goal wioll be met by (1) refining atmospheric correction techniques using in situ radiometric rectification to derive accurate surface spectra; (2) collecting multispectral orbital images concurrent with in situ sampling and spectral measurements in the field to ensure temporal comparability; (3) measuring sediment, water, and microbial mat samples for organic and inorganic carbon content, essential biogeochemical nutrients, and chlorophyll-a to determine relevant mat characteristics; and (4) quantitatively associating these laboratory-derived characteristics with field-derived and orbital spectral signatures and parameters. The result of this work will be a more robust quantitative link between the distribution of microbial mat communities and their biogeochemical properties to landscape-scale spectral signatures. 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. | POLYGON((162.92 -77.56,162.971 -77.56,163.022 -77.56,163.073 -77.56,163.124 -77.56,163.175 -77.56,163.226 -77.56,163.277 -77.56,163.328 -77.56,163.379 -77.56,163.43 -77.56,163.43 -77.571,163.43 -77.582,163.43 -77.593,163.43 -77.604,163.43 -77.615,163.43 -77.626,163.43 -77.637,163.43 -77.648,163.43 -77.659,163.43 -77.67,163.379 -77.67,163.328 -77.67,163.277 -77.67,163.226 -77.67,163.175 -77.67,163.124 -77.67,163.073 -77.67,163.022 -77.67,162.971 -77.67,162.92 -77.67,162.92 -77.659,162.92 -77.648,162.92 -77.637,162.92 -77.626,162.92 -77.615,162.92 -77.604,162.92 -77.593,162.92 -77.582,162.92 -77.571,162.92 -77.56)) | POINT(163.175 -77.615) | false | false | |||||||||||
Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE)
|
1443677 1443534 1443497 1443498 |
2019-07-03 | Bell, Robin; Frearson, Nicholas; Das, Indrani; Fricker, Helen; Padman, Laurence; Springer, Scott; Siddoway, Christine; Tinto, Kirsty | 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. | 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)) | POINT(-174.5 -81.5) | false | false | ||||||||||||
Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica
|
1341717 1341513 1341606 1543483 1341725 |
2019-06-10 | Ackley, Stephen; Bell, Robin; Weissling, Blake; Nuss, Wendell; Maksym, Edward; Stammerjohn, Sharon; Cassano, John; Guest, Peter; Sedwick, Peter; Xie, Hongjie | Proposal Title: Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica (working title changed from submitted title) Institutions: UT-San Antonio; Columbia University; Naval Postgraduate School; Woods Hole Oceanographic Institute; UC@Boulder The one place on Earth consistently showing increases in sea ice area, duration, and concentration is the Ross Sea in Antarctica. Satellite imagery shows about half of the Ross Sea increases are associated with changes in the austral fall, when the new sea ice is forming. The most pronounced changes are also located near polynyas, which are areas of open ocean surrounded by sea ice. To understand the processes driving the sea ice increase, and to determine if the increase in sea ice area is also accompanied by a change in ice thickness, this project will conduct an oceanographic cruise to the polynyas of the Ross Sea in April and May, 2017, which is the austral fall. The team will deploy state of the art research tools including unmanned airborne systems (UASs, commonly called drones), autonomous underwater vehicles (AUVs), and remotely operated underwater vehicles (ROVs). Using these tools and others, the team will study atmospheric, oceanic, and sea ice properties and processes concurrently. A change in sea ice production will necessarily change the ocean water below, which may have significant consequences for global ocean circulation patterns, a topic of international importance. All the involved institutions will be training students, and all share the goal of expanding climate literacy in the US, emphasizing the role high latitudes play in the Earth's dynamic climate. The main goal of the project is to improve estimates of sea ice production and water mass transformation in the Ross Sea. The team will fully capture the spatial and temporal changes in air-ice-ocean interactions when they are initiated in the austral fall, and then track the changes into the winter and spring using ice buoys, and airborne mapping with the newly commissioned IcePod instrument system, which is deployed on the US Antarctic Program's LC-130 fleet. The oceanographic cruise will include stations in and outside of both the Terra Nova Bay and Ross Ice Shelf polynyas. Measurements to be made include air-sea boundary layer fluxes of heat, freshwater, and trace gases, radiation, and meteorology in the air; ice formation processes, ice thickness, snow depth, mass balance, and ice drift within the sea ice zone; and temperature, salinity, and momentum in the ocean below. Following collection of the field data, the team will improve both model parameterizations of air-sea-ice interactions and remote sensing algorithms. Model parameterizations are needed to determine if sea-ice production has increased in crucial areas, and if so, why (e.g., stronger winds or fresher oceans). The remote sensing validation will facilitate change detection over wider areas and verify model predictions over time. Accordingly this project will contribute to the international Southern Ocean Observing System (SOOS) goal of measuring essential climate variables continuously to monitor the state of the ocean and ice cover into the future. | POLYGON((-180 -55,-177 -55,-174 -55,-171 -55,-168 -55,-165 -55,-162 -55,-159 -55,-156 -55,-153 -55,-150 -55,-150 -57.3,-150 -59.6,-150 -61.9,-150 -64.2,-150 -66.5,-150 -68.8,-150 -71.1,-150 -73.4,-150 -75.7,-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 -75.7,160 -73.4,160 -71.1,160 -68.8,160 -66.5,160 -64.2,160 -61.9,160 -59.6,160 -57.3,160 -55,162 -55,164 -55,166 -55,168 -55,170 -55,172 -55,174 -55,176 -55,178 -55,-180 -55)) | POINT(-175 -66.5) | false | false | ||||||||||||
Timing and Duration of the LGM and Post-LGM Grounding Events in Whales Deep Paleo Ice Stream, Eastern Ross Sea Middle Continental Shelf
|
1246357 |
2019-06-03 | Bart, Philip; Steinberg, Deborah |
|
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. | None | None | false | false | |||||||||||
LTER: Ecosystem Response to Amplified Landscape Connectivity in the McMurdo Dry Valleys, Antarctica
|
1637708 |
2019-05-31 | Gooseff, Michael N.; Takacs-Vesbach, Cristina; Howkins, Adrian; McKnight, Diane; Doran, Peter; Adams, Byron; Barrett, John; Morgan-Kiss, Rachael; Priscu, John |
|
The McMurdo Dry Valleys, Antarctica, are a mosaic of terrestrial and aquatic ecosystems in a cold desert. The McMurdo Long Term Ecological Research (LTER) project has been observing these ecosystems since 1993 and this award will support key long-term measurements, manipulation experiments, synthesis, and modeling to test current theories on ecosystem structure and function. Data collection is focused on meteorology and physical and biological dimensions of soils, streams, lakes, glaciers, and permafrost. The long-term measurements show that biological communities have adapted to the seasonally cold, dark, and arid conditions that prevail for all but a short period in the austral summer. Physical (climate and geological) drivers impart a dynamic connectivity among portions of the Dry Valley landscape over seasonal to millennial time scales. For instance, lakes and soils have been connected through cycles of lake-level rise and fall over the past 20,000 years while streams connect glaciers to lakes over seasonal time scales. Overlaid upon this physical system are biotic communities that are structured by the environment and by the movement of individual organisms within and between the glaciers, streams, lakes, and soils. The new work to be conducted at the McMurdo LTER site will explore how the layers of connectivity in the McMurdo Dry Valleys influence ecosystem structure and function. This project will test the hypothesis that increased ecological connectivity following enhanced melt conditions within the McMurdo Dry Valleys ecosystem will amplify exchange of biota, energy, and matter, homogenizing ecosystem structure and functioning. This hypothesis will be tested with new and continuing experiments that examine: 1) how climate variation alters connectivity among landscape units, and 2) how biota are connected across a heterogeneous landscape using state-of-the-science tools and methods including automated sensor networks, analysis of seasonal satellite imagery, biogeochemical analyses, and next-generation sequencing. McMurdo LTER education programs and outreach activities will be continued, and expanded with new programs associated with the 200th anniversary of the first recorded sightings of Antarctica. These activities will advance societal understanding of how polar ecosystems respond to change. McMurdo 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 lead the development of international environmental stewardship protocols for human activities in the region. | POLYGON((160 -77.25,160.5 -77.25,161 -77.25,161.5 -77.25,162 -77.25,162.5 -77.25,163 -77.25,163.5 -77.25,164 -77.25,164.5 -77.25,165 -77.25,165 -77.375,165 -77.5,165 -77.625,165 -77.75,165 -77.875,165 -78,165 -78.125,165 -78.25,165 -78.375,165 -78.5,164.5 -78.5,164 -78.5,163.5 -78.5,163 -78.5,162.5 -78.5,162 -78.5,161.5 -78.5,161 -78.5,160.5 -78.5,160 -78.5,160 -78.375,160 -78.25,160 -78.125,160 -78,160 -77.875,160 -77.75,160 -77.625,160 -77.5,160 -77.375,160 -77.25)) | POINT(162.5 -77.875) | false | false | |||||||||||
Workshop on Antarctic Surface Hydrology and Future Ice-shelf Stability
|
1743326 |
2019-03-26 | Kingslake, Jonathan; Tedesco, Marco; Trusel, Luke |
|
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. | None | None | false | false | |||||||||||
Circumpolar Deep Water and the West Antarctic Ice Sheet
|
9725024 |
2019-03-11 | Jacobs, Stanley; Visbeck, Martin |
|
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. | 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)) | POINT(145 -66.5) | false | false | |||||||||||
Collaborative Research: Fjord Ecosystem Structure and Function on the West Antarctic Peninsula - Hotspots of Productivity and Biodiversity? (FjordEco)
|
1443733 1443680 1443705 |
2019-02-13 | Winsor, Peter; Truffer, Martin; Smith, Craig; Powell, Brian; Merrifield, Mark; Vernet, Maria; Kohut, Josh | 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. | 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)) | POINT(-64 -64.5) | false | false | ||||||||||||
Collaborative Research: Assessing the Global Climate Response to Melting of the Antarctic Ice Sheet
|
1443394 1443347 |
2019-02-04 | Pollard, David; Condron, Alan; DeConto, Robert | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
Assembling and Mining the Genomes of Giant Antarctic Foraminifera
|
1341612 |
2018-11-29 | Bowser, Samuel | Agglutinated foraminifera (forams for short) are early-evolving, single-celled organisms. These "living fossils" construct protective shells using sediment grains held together by adhesive substances that they secrete. During shell construction, agglutinated forams display amazing properties of selection - for example, some species build their shells of clear quartz grains, while other species use only grains of a specific size. Understanding how these single cells assemble complex structures may contribute to nanotechnology by enabling people to use forams as "cellular machines" to aid in the construction of nano-devices. This project will analyze the genomes of at least six key foram species, and then "mine" these genomes for technologically useful products and processes. The project will focus initially on the adhesive materials forams secrete, which may have wide application in biomedicine and biotechnology. Furthermore, the work will further develop a molecular toolkit which could open up new avenues of research on the physiology, ecology, and population dynamics of this important group of Antarctic organisms. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. Educational experiences related to the "thrill of scientific exploration and discovery" for students and the general public will be provided through freely-available short films and a traveling art/science exhibition. The project will also provide hands-on research opportunities for undergraduate students. Explorers Cove, situated on the western shore of McMurdo Sound, harbors a unique population of foraminiferan taxa at depths accessible by scuba diving that otherwise are primarily found in the deep sea. The project will use next-generation DNA sequencing and microdissection methods to obtain and analyze nuclear and mitochondrial genomes from crown members of two species each from three distinct, early-evolving foraminiferal groups. It will also use next generation sequencing methods to characterize the in-situ prokaryotic assemblages (microbiomes) of one of these groups and compare them to reference sediment microbiomes. The phyogenomic studies of the targeted Antarctic genera will help fill significant gaps in our current understanding of early foram evolution. Furthermore, comparative genomic analyses of these six species are expected to yield a better understanding of the physiology of single-chambered agglutinated forams, especially the bioadhesive proteins and regulatory factors involved in shell composition and morphogenesis. Additionally, the molecular basis of cold adaptation in forams will be examined, particularly with respect to key proteins. | None | None | false | false | ||||||||||||
Collaborative Research: MIDGE: Minimally Invasive Direct Glacial Exploration of Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys
|
1144177 1144176 1144192 1727387 |
2018-11-28 | Tulaczyk, Slawek; Pettit, Erin; Lyons, W. Berry; Mikucki, Jill | 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. | 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)) | POINT(162.2 -77.735) | false | false | ||||||||||||
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
|
1443306 1443263 |
2018-10-18 | Mayewski, Paul A.; Kurbatov, Andrei V.; Higgins, John; Bender, Michael | 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. | None | None | false | false | ||||||||||||
Collaborative Research: Integrative Study of Marine Ice Sheet Stability & Subglacial Life Habitats in W Antarctica - Lake & Ice Stream Subglacial Access Research Drilling (LISSARD)
|
0839142 0839059 0838764 0838947 0838855 0838763 0839107 |
2018-09-10 | Tulaczyk, Slawek; Fisher, Andrew; Powell, Ross; Anandakrishnan, Sridhar; Jacobel, Robert; Scherer, Reed Paul | 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. | None | None | false | false | ||||||||||||
Impact of Supraglacial Lakes on Ice-Shelf Stability
|
1443126 |
2018-07-24 | MacAyeal, Douglas | 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. | 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)) | POINT(166.3344 -77.91835) | false | false | ||||||||||||
Collaborative Research: Bipolar Coupling of late Quaternary Ice Sheet Variability
|
1341311 |
2018-06-26 | Timmermann, Axel |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Using Electrical Conductance Measurements to Develop the South Pole Ice Core Chronology
|
1443232 |
2018-05-08 | Fudge, T. J.; Waddington, Edwin D. |
|
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. | 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)) | POINT(145 -89.5) | false | false | |||||||||||
Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum.
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1246353 |
2018-02-06 | Anderson, John |
|
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. | 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)) | POINT(175.495 -75.5) | false | false | |||||||||||
Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach -- Cryosphere and Oceans
|
0732711 0732625 0732655 0732602 0732651 0732983 |
2018-02-01 | Truffer, Martin; Gordon, Arnold; Huber, Bruce; Mosley-Thompson, Ellen; Leventer, Amy; Vernet, Maria; Smith, Craig; Thompson, Lonnie G. | Like no other region on Earth, the northern Antarctic Peninsula represents a spectacular natural laboratory of climate change and provides the opportunity to study the record of past climate and ecological shifts alongside the present-day changes in one of the most rapidly warming regions on Earth. This award supports the cryospheric and oceano-graphic components of an integrated multi-disciplinary program to address these rapid and fundamental changes now taking place in Antarctic Peninsula (AP). By making use of a marine research platform (the RV NB Palmer and on-board helicopters) and additional logistical support from the Argentine Antarctic program, the project will bring glaciologists, oceanographers, marine geologists and biologists together, working collaboratively to address fundamentally interdisciplinary questions regarding climate change. The project will include gathering a new, high-resolution paleoclimate record from the Bruce Plateau of Graham Land, and using it to compare Holocene- and possibly glacial-epoch climate to the modern period; investigating the stability of the remaining Larsen Ice Shelf and rapid post-breakup glacier response ? in particular, the roles of surface melt and ice-ocean interactions in the speed-up and retreat; observing the contribution of, and response of, oceanographic systems to ice shelf disintegration and ice-glacier interactions. Helicopter support on board will allow access to a wide range of glacial and geological areas of interest adjacent to the Larsen embayment. At these locations, long-term in situ glacial monitoring, isostatic uplift, and ice flow GPS sites will be established, and high-resolution ice core records will be obtained using previously tested lightweight drilling equipment. Long-term monitoring of deep water outflow will, for the first time, be integrated into changes in ice shelf extent and thickness, bottom water formation, and multi-level circulation by linking near-source observations to distal sites of concentrated outflow. The broader impacts of this international, multidisciplinary effort are that it will significantly advance our understanding of linkages amongst the earth's systems in the Polar Regions, and are proposed with international participation (UK, Spain, Belgium, Germany and Argentina) and interdisciplinary engagement in the true spirit of the International Polar Year (IPY). It will also provide a means of engaging and educating the public in virtually all aspects of polar science and the effects of ongoing climate change. The research team has a long record of involving undergraduates in research, educating high-performing graduate students, and providing innovative and engaging outreach products to the K-12 education and public media forums. Moreover, forging the new links both in science and international Antarctic programs will provide a continuing legacy, beyond IPY, of improved understanding and cooperation in Antarctica. | POLYGON((-68 -57.8,-66.78 -57.8,-65.56 -57.8,-64.34 -57.8,-63.12 -57.8,-61.9 -57.8,-60.68 -57.8,-59.46 -57.8,-58.24 -57.8,-57.02 -57.8,-55.8 -57.8,-55.8 -58.8,-55.8 -59.8,-55.8 -60.8,-55.8 -61.8,-55.8 -62.8,-55.8 -63.8,-55.8 -64.8,-55.8 -65.8,-55.8 -66.8,-55.8 -67.8,-57.02 -67.8,-58.24 -67.8,-59.46 -67.8,-60.68 -67.8,-61.9 -67.8,-63.12 -67.8,-64.34 -67.8,-65.56 -67.8,-66.78 -67.8,-68 -67.8,-68 -66.8,-68 -65.8,-68 -64.8,-68 -63.8,-68 -62.8,-68 -61.8,-68 -60.8,-68 -59.8,-68 -58.8,-68 -57.8)) | POINT(-61.9 -62.8) | false | false | ||||||||||||
Ice sheet Dynamics and Processes along the West Antarctic Continental Shelf
|
0838735 |
2018-01-26 | Nitsche, Frank O. |
|
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. | 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)) | POINT(-120 -71.75) | false | false | |||||||||||
Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics
|
1143834 1430550 1143836 1143833 |
2018-01-26 | Orsi, Alejandro; Huber, Bruce; Leventer, Amy; Domack, Eugene Walter | 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. | 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)) | POINT(118.5 -66.1) | false | false | ||||||||||||
Continuation of the LARISSA Continuous GPS Network in View of Observed Dynamic Response to Antarctic Peninsula Ice Mass Balance and Required Geologic Constraints
|
1143981 |
2017-12-29 | Kohut, Josh; Domack, Eugene Walter |
|
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. | 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)) | POINT(-65.34175 -60.54515) | false | false | |||||||||||
Collaborative Research: THE MCMURDO DRY VALLEYS: A landscape on the Threshold of Change
|
1246342 1245749 1246203 |
2017-12-20 | Levy, Joseph; Gooseff, Michael N.; Fountain, Andrew |
|
Collaborative Research: THE MCMURDO DRY VALLEYS: A Landscape on the Threshold of Change is supported by the Antarctic Integrated System Science (AISS) program in the Antarctic Sciences Section of the Division of Polar Programs within the Geosciences Directorate of the National Sciences Foundation (NSF). The funds will support the collection of state-of-the-art high resolution LIDAR (combining the terms light and radar) imagery of the Dry Valleys of Antarctica in the 2014/2015 Antarctic field season, with LIDAR data collection and processing being provided by the NSF-supported NCALM (National Center for Airborne Laser Mapping) facility. LIDAR images collected in 2014/2015 will be compared to images from 2001 in order to detect decadal change. Additional fieldwork will look at the distribution of buried massive ice, and the impacts that major changes like slumping are having on the biota. All field data will be used to improve models on energy balance, and hydrology. Intellectual Merit: There have been dramatic changes over the past decade in the McMurdo Dry Valleys: glaciers are deflating by tens of meters, rivers are incising by more than three meters, and thermokarst slumps are appearing near several streams and lakes. These observations have all been made by researchers in the field, but none of the changes have been mapped on a valley-wide scale. This award will provide a new baseline map for the entire Dry Valley system, with high-resolution imagery provided for the valley floors, and lower resolution imagery available for the higher elevation areas that are undergoing less change. The project will test the idea that sediment-covered ice is associated with the most dramatic changes, due to differential impacts of the increased solar radiation on sediment-covered compared to clean ice, and despite the current trend of slightly cooling air temperatures within the Dry Valleys. Information collected on the topography, coupled with the GPR determined buried ice distributions, will also be incorporated into improved energy and hydrological models. In addition to providing the new high-resolution digital elevation model (DEM), the project will ultimately result in identification of areas that are susceptible to sediment-enhanced melt-driven change, providing a powerful prediction tool for the impacts of climate change. Broader Impacts: The new DEM will be immediately useful to a wide range of disciplines, and will provide a comprehensive new baseline against which future changes will be compared. The project will provide a tool for the whole community to use, and the investigators will work with the community to make them aware of the new assets via public presentations, and perhaps via a workshop. The map will have international interest, and will also serve as a tool for environmental managers to draw on as they consider conservation plans. Several undergraduate and graduate students will participate in the project, and one of the co-PIs is a new investigator. The imagery collected is expected to be of interest to the general public in addition to scientific researchers, and venues for outreach such as museum exhibits and the internet will be explored. The proposed work is synergistic with 1) the co-located McMurdo LTER program, and 2) the NCALM facility that is also funded by the Geosciences Directorate. | POLYGON((160.105465 -77.2119,160.7907435 -77.2119,161.476022 -77.2119,162.1613005 -77.2119,162.846579 -77.2119,163.5318575 -77.2119,164.217136 -77.2119,164.9024145 -77.2119,165.587693 -77.2119,166.2729715 -77.2119,166.95825 -77.2119,166.95825 -77.3189628,166.95825 -77.4260256,166.95825 -77.5330884,166.95825 -77.6401512,166.95825 -77.747214,166.95825 -77.8542768,166.95825 -77.9613396,166.95825 -78.0684024,166.95825 -78.1754652,166.95825 -78.282528,166.2729715 -78.282528,165.587693 -78.282528,164.9024145 -78.282528,164.217136 -78.282528,163.5318575 -78.282528,162.846579 -78.282528,162.1613005 -78.282528,161.476022 -78.282528,160.7907435 -78.282528,160.105465 -78.282528,160.105465 -78.1754652,160.105465 -78.0684024,160.105465 -77.9613396,160.105465 -77.8542768,160.105465 -77.747214,160.105465 -77.6401512,160.105465 -77.5330884,160.105465 -77.4260256,160.105465 -77.3189628,160.105465 -77.2119)) | POINT(163.5318575 -77.747214) | false | false | |||||||||||
Collaborative Research: Assessing the Antarctic Contribution to Sea-level Changes during the Last Deglaciation: Constraints from Darwin Glacier
|
1246170 1246110 |
2017-10-23 | Hall, Brenda; Stone, John; Conway, Howard |
|
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. | 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)) | POINT(157.5 -80) | false | false | |||||||||||
Origin and Climatic Significance of Rock Glaciers in the McMurdo Dry Valleys: Assessing Spatial and Temporal Variability
|
1341284 |
2017-10-09 | Swanger, Kate | No dataset link provided | Paragraph for Laypersons: This research focuses on the history of rock glaciers and buried glacial ice in the McMurdo Dry Valleys region of Antarctica. Rock glaciers are flowing mixtures of ice and sediments common throughout alpine and high-latitude regions on Earth and Mars. Despite similar appearances, rock glaciers can form under highly variable environmental and hydrological conditions. The main research questions addressed here are: 1) what environmental and climatological conditions foster long-term preservation of rock glaciers in Antarctica, 2) what role do rock glaciers play in Antarctic landscape evolution and the local water cycle, and 3) what can rock glaciers reveal about the extent and timing of previous glacial advances? The project will involve two Antarctic field seasons to image the interior of Antarctic rock glaciers using ground-penetrating radar, to gather ice cores for chemical analyses, and to gather surface sediments for dating. The Dry Valleys host the world?s southernmost terrestrial ecosystem (soil, stream and lake micro-organisms and mosses); rock glaciers and ground-ice are an important and poorly-studied source of meltwater and nutrients for these ecosystems. This research will shed light on the glacial and hydrological history of the Dry Valleys region and the general environmental conditions the foster rock glaciers, features that generally occur in warmer and/or wetter locations. The research will provide support for five graduate/undergraduate students, who will actively gather data in the field, followed by interpretation, dissemination and presentation of the data. Additionally, the researchers will participate in a range of educational activities including outreach with local K-12 in the Lowell, MA region, such as summer workshops and classroom visits with hands-on activities. A series of time-lapse images of hydrological processes, and videos of researchers in the field, will serve as a dramatic centerpiece in community and school presentations. Paragraph for Scientific Community: Rock glaciers are common in the McMurdo Dry Valleys, but are concentrated in a few isolated regions: western Taylor Valley, western Wright Valley, Pearse Valley and Bull Pass. The investigators hypothesize that the origin and age of these features varies by region: that rock glaciers in Pearse and Taylor valley originated as buried glacier ice, whereas rock glaciers in Wright Valley formed through permafrost processes, such as mobilization of ice-rich talus. To address these hypotheses, the project will: 1) develop relative and absolute chronologies for the rock glaciers through field mapping and optically stimulated luminescence dating of overlying sediments, 2) assess the origin of clean-ice cores through stable isotopic analyses, and 3) determine if present-day soil-moisture and temperature conditions are conducive to rock glacier formation/preservation. The proposed research will provide insight into the spatial and temporal distribution of buried glacier ice and melt-water-derived ground ice in the McMurdo Dry Valleys, with implications for glacial history, as well as the potential role of rock glaciers in the regional hydrologic cycle (and the role of ground-ice as a source for moisture and nutrient for local ecosystems). The project will provide general constraints on the climatic and hydrologic conditions that foster permafrost rock glaciers, features that generally occur under warmer and wetter conditions than those found in the present-day McMurdo Dry Valleys. The application of OSL and cosmogenic exposure dating is novel to rock glaciers, geomorphic features that have proven difficult to date, despite their ubiquity in Antarctica and their potential scientific importance. The research will provide support for five graduate/undergraduate students, who will participate in the field work, followed by interpretation, dissemination and presentation of the data. The researchers will participate in a range of educational activities including outreach with local K-12 in the Lowell, MA region, such as summer workshops and classroom visits with hands-on activities. | POLYGON((161 -77.5,161.2 -77.5,161.4 -77.5,161.6 -77.5,161.8 -77.5,162 -77.5,162.2 -77.5,162.4 -77.5,162.6 -77.5,162.8 -77.5,163 -77.5,163 -77.525,163 -77.55,163 -77.575,163 -77.6,163 -77.625,163 -77.65,163 -77.675,163 -77.7,163 -77.725,163 -77.75,162.8 -77.75,162.6 -77.75,162.4 -77.75,162.2 -77.75,162 -77.75,161.8 -77.75,161.6 -77.75,161.4 -77.75,161.2 -77.75,161 -77.75,161 -77.725,161 -77.7,161 -77.675,161 -77.65,161 -77.625,161 -77.6,161 -77.575,161 -77.55,161 -77.525,161 -77.5)) | POINT(162 -77.625) | false | false | |||||||||||
Insights into the Burial, Tectonic, and Hydrologic History of the Cenozoic Succession in McMurdo Sound, Antarctica through Analysis of Diagenetic Phases
|
1341390 |
2017-10-06 | Frank, Tracy; Fielding, Christopher |
|
Intellectual Merit: This project will use sediment cores from the Victoria Land Basin (VLB), Antarctica, to study secondary (diagenetic) carbonate minerals, as indicators of the basin?s fluid-flow history, within the well-constrained tectonic, depositional, and climatic context provided by sediment cores. This study will provide insights into subsurface processes in Victoria Land Basin, Antarctica and their relationships with the region?s climatic, cryospheric, and tectonic history. The work will utilize cores previously recovered by US-sponsored stratigraphic drilling projects (CIROS, CRP, and ANDRILL projects). This work is motivated by the unexpected discovery of dense brine in the subsurface of Southern McMurdo Sound during drilling by the ANDRILL Southern McMurdo Sound project. The presence of the brine is intriguing because it contradicts previous models for the origin of subsurface fluids that called upon large contributions from glacial melt water. Project objectives involve documenting the distribution of the brine (and potentially other fluids) via characterization of diagenetic precipitates. The approach will involve integration of petrographic and geochemical data (including conventional carbon, oxygen, and ?clumped? isotopes) to fully characterize diagenetic phases and allow development of a robust paragenetic history. This work will provide novel insights into the Cenozoic evolution of the VLB and, more broadly, the role of glacial processes in generating subsurface fluids. Broader impacts: Results from this project will help understand the origins of brines, groundwater and hydrocarbon reservoirs in analogous modern and ancient deposits elsewhere, which is of broad interest. This project will support the training of one graduate and one undergraduate student at the University of Nebraska-Lincoln (UNL) providing learning opportunities in sedimentary geology and diagenesis, fields with wide applicability. This proposal emphasizes rapid dissemination of results to the scientific community via conference presentations and contributions to peer-reviewed publications. The results will be integrated into education activities designed to develop skills in petrography and diagenesis, which are highly sought after in the energy sector. The project will generate a well-constrained dataset that allows direct linkage of diagenetic phases to environmental and tectonic change across a large sedimentary basin which will provide the basis for a comprehensive case study in an upper-level course (Sedimentary Petrography and Diagenesis) at UNL. In addition, online exercises will be developed and submitted to an open-access site (SEPM Stratigraphy Web) dedicated to sedimentary geology. | None | None | false | false | |||||||||||
Collaborative Research: Microbial Community Assembly in Coastal Waters of the Western Antarctic Peninsula
|
1141993 |
2017-06-15 | Rich, Jeremy |
|
The Western Antarctic Peninsula (WAP) has experienced unprecedented warming and shifts in sea ice cover over the past fifty years. How these changes impact marine microbial communities, and subsequently how these shifts in the biota may affect the carbon cycle in surface waters is unknown. This work will examine how these ecosystem-level changes affect microbial community structure and function. This research will use modern metagenomic and transcriptomic approaches to test the hypothesis that the introduction of organic matter from spring phytoplankton blooms drives turnover in microbial communities. This research will characterize patterns in bacterial and archaeal succession during the transition from the austral winter at two long-term monitoring sites: Palmer Station in the north and Rothera Station in the south. This project will also include microcosm incubations to directly assess the effects of additions of organic carbon and melted sea ice on microbial community structure and function. The results of this work will provide a broader understanding of the roles of both rare and abundant microorganisms in carbon cycling within the WAP region, and how these communities may shift in structure and function in response to climate change. Results will be widely disseminated through publications as well as through presentations at national and international meetings. The research will provide training opportunities for both graduate and undergraduate students and will enhance international collaborations with the British Antarctic Survey. | POLYGON((-60 -70,-59.3 -70,-58.6 -70,-57.9 -70,-57.2 -70,-56.5 -70,-55.8 -70,-55.1 -70,-54.4 -70,-53.7 -70,-53 -70,-53 -70.9,-53 -71.8,-53 -72.7,-53 -73.6,-53 -74.5,-53 -75.4,-53 -76.3,-53 -77.2,-53 -78.1,-53 -79,-53.7 -79,-54.4 -79,-55.1 -79,-55.8 -79,-56.5 -79,-57.2 -79,-57.9 -79,-58.6 -79,-59.3 -79,-60 -79,-60 -78.1,-60 -77.2,-60 -76.3,-60 -75.4,-60 -74.5,-60 -73.6,-60 -72.7,-60 -71.8,-60 -70.9,-60 -70)) | POINT(-56.5 -74.5) | false | false | |||||||||||
CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin
|
1148982 |
2017-06-04 | Hansen, Samantha | 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. | 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)) | POINT(159.223506 -74.6349495) | false | false | ||||||||||||
Rebreather Testing for the United States Antarctic Scientific Diving Program
|
1553824 |
2017-05-26 | Heine, John |
|
There are a number of areas of Antarctic research by scientists from the United States where rebreather technology (which unlike normal SCUBA diving releases few if any air bubbles) would be valuable tools. These include but are not limited to behavioral studies (because noise from bubbles released by standard SCUBA alters the behavior of many marine organisms), studies of communities on the underside of sea ice (because the bubbles disrupt the communities while or before they are sampled), and studies of highly stratified lake communities (because the bubbles cause mixing and because lighter line could be used to tether a diver to the surface which would probably also cause less water column disruption). The latter scientific advantage of less mixing in highly stratified (not naturally mixed) lakes is also a significant environmental advantage of rebreathers. However, for safety reasons, no US science projects will be approved for the use of rebreathers until they are tested by the US Antarctic Program (USAP). This award provides funds for the USAP Scientific Diving Officer to conduct such tests in conjunction with other diving professionals experienced in polar diving in general and specifically with rebreather technology in non-polar environments. A team of six scientific diving professionals will evaluate seven or more commercial rebreather models that are being most commonly used in non-polar scientific diving. This will be done through holes drilled or melted in sea ice at McMurdo Station, Antarctica. A limited number of test dives of the best performing models will subsequently be made in stratified lakes in the McMurdo Dry Valleys. | POINT(166.667 -77.85) | POINT(166.667 -77.85) | false | false | |||||||||||
Collaborative Research: Physical Properties of the WAIS Divide Deep Core
|
0539578 0539232 |
2017-01-12 | Fitzpatrick, Joan; Alley, Richard; Fegyveresi, John; Clow, Gary D.; Cuffey, Kurt M.; Cravens, Eric D. | 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. | POINT(112.083 -79.467) | POINT(112.083 -79.467) | false | false | ||||||||||||
Collaborative Research: Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins
|
1043554 |
2016-11-09 | Willenbring, Jane |
|
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. | POINT(161.5 -77.5) | POINT(161.5 -77.5) | false | false | |||||||||||
Collaborative Research: A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea
|
1043018 1043517 1043485 |
2016-10-15 | Pollard, David; Curtice, Josh; Clark, Peter; Kurz, Mark D. |
|
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. | 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)) | POINT(164.425 -77.945) | false | false | |||||||||||
Collaborative Research: Decoding & Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs
|
1043580 |
2016-07-28 | Reusch, David; Lampkin, Derrick | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
Enhanced Spatial Resolution Surface Melting over the Antarctic Peninsula (1958 - to date) from a Regional Climate Model Validated through Remote Sensing Observations
|
1141973 |
2016-06-10 | Tedesco, Marco |
|
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. | 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)) | POINT(-67.23435 -68.2063) | false | false | |||||||||||
Roosevelt Island Climate Evolution Project (RICE): US Deep Ice Core Glaciochemistry Contribution (2011- 2014)
|
1042883 |
2015-10-27 | Haines, Skylar; Kurbatov, Andrei V.; Mayewski, Paul A.; Beers, Thomas M. |
|
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. | None | None | false | false | |||||||||||
Geomorphic investigations of Northern Victoria Land, Antarctica
|
1144224 |
2015-10-23 | Marchant, David | No dataset link provided | 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). | 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)) | POINT(165 -74.75) | false | false | |||||||||||
Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica
|
1142156 |
2015-10-23 | Marschall, Horst |
|
Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth?s crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica. Dronning Maud Land (DML) occupied a central location during the formation of supercontinents ? large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth?s history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007?2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML. | POLYGON((-6.44 -71.93,-5.378 -71.93,-4.316 -71.93,-3.254 -71.93,-2.192 -71.93,-1.13 -71.93,-0.068 -71.93,0.994 -71.93,2.056 -71.93,3.118 -71.93,4.18 -71.93,4.18 -71.998,4.18 -72.066,4.18 -72.134,4.18 -72.202,4.18 -72.27,4.18 -72.338,4.18 -72.406,4.18 -72.474,4.18 -72.542,4.18 -72.61,3.118 -72.61,2.056 -72.61,0.994 -72.61,-0.068 -72.61,-1.13 -72.61,-2.192 -72.61,-3.254 -72.61,-4.316 -72.61,-5.378 -72.61,-6.44 -72.61,-6.44 -72.542,-6.44 -72.474,-6.44 -72.406,-6.44 -72.338,-6.44 -72.27,-6.44 -72.202,-6.44 -72.134,-6.44 -72.066,-6.44 -71.998,-6.44 -71.93)) | POINT(-1.13 -72.27) | false | false | |||||||||||
Collaborative International Research: Amundsen Sea Influence on West Antarctic Ice Sheet Stability and Sea Level Rise - IPY/ASEP
|
0632282 |
2015-09-25 | Jacobs, Stanley; Hellmer, Hartmut; Jenkins, Adrian | 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. | 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)) | POINT(-103.8 -64.65) | false | false | ||||||||||||
Collaborative Research: Impact of Mesoscale Processes on Iron Supply and Phytoplankton Dynamics in the Ross Sea
|
0944254 0944165 |
2015-07-08 | Smith, Walker; McGillicuddy, Dennis |
|
The Ross Sea continental shelf is one of the most productive areas in the Southern Ocean, and may comprise a significant, but unaccounted for, oceanic CO2 sink, largely driven by phytoplankton production. The processes that control the magnitude of primary production in this region are not well understood, but data suggest that iron limitation is a factor. Field observations and model simulations indicate four potential sources of dissolved iron to surface waters of the Ross Sea: (1) circumpolar deep water intruding from the shelf edge; (2) sediments on shallow banks and nearshore areas; (3) melting sea ice around the perimeter of the polynya; and (4) glacial meltwater from the Ross Ice Shelf. The principal investigators hypothesize that hydrodynamic transport via mesoscale currents, fronts, and eddies facilitate the supply of dissolved iron from these four sources to the surface waters of the Ross Sea polynya. These hypotheses will be tested through a combination of in situ observations and numerical modeling, complemented by satellite remote sensing. In situ observations will be obtained during a month-long cruise in the austral summer. The field data will be incorporated into model simulations, which allow quantification of the relative contributions of the various hypothesized iron supply mechanisms, and assessment of their impact on primary production. The research will provide new insights and a mechanistic understanding of the complex oceanographic phenomena that regulate iron supply, primary production, and biogeochemical cycling. The research will thus form the basis for predictions about how this system may change in a warming climate. The broader impacts include training of graduate and undergraduate students, international collaboration, and partnership with several ongoing outreach programs that address scientific research in the Southern Ocean. The research also will contribute to the goals of the international research programs ICED (Integrated Climate and Ecosystem Dynamics) and GEOTRACES (Biogeochemical cycling and trace elements in the marine environment). | POLYGON((168 -65,168.2 -65,168.4 -65,168.6 -65,168.8 -65,169 -65,169.2 -65,169.4 -65,169.6 -65,169.8 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,169.8 -65,169.6 -65,169.4 -65,169.2 -65,169 -65,168.8 -65,168.6 -65,168.4 -65,168.2 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65)) | POINT(169 -65) | false | false | |||||||||||
RAPID: Origin of Persistent Organic Pollutants in the Antarctic Atmosphere, Snow and Marine Food WEB
|
1332492 |
2015-06-09 | Lohmann, Rainer |
|
Many persistent organic pollutants (POPs), though banned in the U.S. since the 1970s, remain in the environment and continue to reach hitherto pristine regions such as the Arctic and Antarctic. The overall goals of this RAPID project are to better understand the remobilization of POPs from melting glaciers in the Antarctic, and their transfer into the food-web. Legacy POPs have characteristic chemical signatures that will be used ascertain the origin of POPs in the Antarctic atmosphere and marine food-web. Samples that were collected in 2010 will be analyzed for a wide range of legacy POPs, and their behavior will be contrasted with results for emerging contaminants. The intellectual merit of the proposed research combines (a) the use of chemical signatures to assess whether melting glaciers are releasing legacy POPs back into the Antarctic marine ecosystem, and (b) a better understanding of the food-web dynamics of legacy POPs versus emerging organic pollutants. The broader impacts of the proposed research project will include the training of the next generation of scientists through support for a graduate student and a postdoctoral scholar. As well, this work will result in a better understanding of the relationship between pollutants, trophic food web ecology and global climate change in the pristine Antarctic ecosystem. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: Application of Distributed Temperature Sensors (DTS) for Antarctic Ice Shelves and Cavities
|
1043217 |
2015-05-05 | Zagorodnov, Victor; Holland, David; Tyler, Scott W. |
|
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. | None | None | false | false | |||||||||||
Age and Composition of the East Antarctic Shield by Isotopic Analysis of Granite and Glacial Till
|
0944645 |
2015-02-11 | Goodge, John | No dataset link provided | Intellectual Merit: <br/>Because of extensive ice cover and sparse remote-sensing data, the geology of the Precambrian East Antarctic Shield (EAS) remains largely unexplored with information limited to coastal outcrops from the African, Indian and Australian sectors. The East Antarctic lithosphere is globally important: as one of the largest coherent Precambrian shields, including rocks as old as ~3.8 Ga, it played an important role in global crustal growth; it is a key piece in assembly of the Rodinia and Gondwana supercontinents; it is the substrate to Earth?s major ice cap, including numerous sub-glacial lakes, and influences its thermal state and mechanical stability; and its geotectonic association with formerly adjacent continental blocks in South Africa, India and Australia suggest that it might harbor important mineral resources. This project will increase understanding of the age and composition of the western EAS lithosphere underlying and adjacent to the Transantarctic Mountains (TAM) using U-Pb ages, and Hf- and O-isotope analysis of zircon in early Paleozoic granitoids and Pleistocene glacial tills. TAM granites of the early Paleozoic Ross Orogen represent an areally extensive continental-margin arc suite that can provide direct information about the EAS crust from which it melted and/or through which it passed. Large rock clasts of igneous and metamorphic lithologies entrained in glacial tills at the head of major outlet glaciers traversing the TAM provide eroded samples of the proximal EAS basement. Zircons in these materials will provide data about age and inheritance (U-Pb), crustal vs. mantle origin (O isotopes), and crustal sources and evolution (Hf isotopes). Integrated along a significant part of the TAM, these data will help define broader crustal provinces that can be correlated with geophysical data and used to test models of crustal assembly. <br/><br/>Broader impacts: <br/>This project will provide a research opportunity for undergraduate and graduate students. Undergraduates will be involved as Research Assistants in sample preparation, imaging, and analytical procedures, and conducting their own independent research. The two main elements of this project will form the basis of MS thesis projects for two graduate students at UMD. Through this project they will gain a good understanding of petrology, isotope geochemistry, and analytical methods. The broader scientific impacts of this work are that it will help develop a better understanding of the origin and evolution of East Antarctic lithosphere underlying and adjacent to the TAM, which will be of value to the broader earth science and glaciological community. Furthermore, knowledge of East Antarctic geology is of continuing interest to the general public because of strong curiosity about past supercontinents, what?s under the ice, and the impact of global warming on ice-sheet stability. | None | None | false | false | |||||||||||
Collaborative Research; IPY: Ocean-Ice Interaction in the Amundsen Sea sector of West Antarctica
|
0732869 0732730 0732906 0732804 |
2014-12-30 | Truffer, Martin; Stanton, Timothy; Bindschadler, Robert; Behar, Alberto; Nowicki, Sophie; Anandakrishnan, Sridhar; Holland, David; McPhee, Miles G. |
|
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. | POINT(-100.728 -75.0427) | POINT(-100.728 -75.0427) | false | false | |||||||||||
A Low-power, Quick-install Polar Observation System ('AMIGOS-II') for Monitoring Climate-ice-ocean Interactions
|
1441432 |
2014-12-30 | Scambos, Ted | No dataset link provided | The investigators propose to build and test a multi-sensor, automated measurement station for monitoring Arctic and Antarctic ice-ocean environments. The system, based on a previously successful design, will incorporate weather and climate sensors, camera, snow and firn sensors, instruments to measure ice motion, ice and ocean thermal profilers, hydrophone, and salinity sensors. This new system will have two-way communications for real-time data delivery and is designed for rapid deployment by a small field group. AMIGOS-II will be capable of providing real time information on geophysical processes such as weather, snowmelt, ice motion and strain, fractures and melt ponds, firn thermal profiling, and ocean conditions from multiple levels every few hours for 2-4 years. Project personnel will conduct a field test of the new system at a location with a deep ice-covered lake. Development of AMIGOS-II is motivated by recent calls by the U.S. Antarctic Program Blue-Ribbon Panel to increase Antarctic logistical effectiveness, which cites a need for greater efficiency in logistical operations. Installation of autonomous stations with reduced logistical requirements advances this goal. | None | None | false | false | |||||||||||
Collaborative research: Polyphase Orogenesis and Crustal Differentiation in West Antarctica
|
0944615 0944600 |
2014-10-09 | Siddoway, Christine; Brown, Mike |
|
Intellectual Merit: <br/>The northern Ford ranges in Marie Byrd Land, Antarctica, record events and processes that transformed a voluminous succession of Lower Paleozoic turbidites intruded by calc-alkaline plutonic rocks into differentiated continental crust along the margin of Gondwana. In this study the Fosdick migmatite?granite complex will be used to investigate crustal evolution through an integrated program of fieldwork, structural geology, petrology, mineral equilibria modeling, geochronology and geochemistry. The PIs propose detailed traverses at four sites within the complex to investigate Paleozoic and Mesozoic orogenic cycles. They will use petrological associations, structural geometry, and microstructures of host gneisses and leucogranites to distinguish the migration and coalescence patterns for remnant melt flow networks, and carry out detailed sampling for geochronology, geochemistry and isotope research. Mafic plutonic phases will be sampled to acquire information about mantle contributions at the source. Mineral equilibria modeling of source rocks and granite products, combined with in situ mineral dating, will be employed to resolve the P?T?t trajectories arising from thickening/thinning of crust during orogenic cycles and to investigate melting and melt loss history. <br/><br/>Broader impacts: <br/>This work involves research and educational initiatives for an early career female scientist, as well as Ph.D. and undergraduate students. Educational programs for high school audiences and undergraduate courses on interdisciplinary Antarctic science will be developed. | POLYGON((-146.5 -76,-145.95 -76,-145.4 -76,-144.85 -76,-144.3 -76,-143.75 -76,-143.2 -76,-142.65 -76,-142.1 -76,-141.55 -76,-141 -76,-141 -76.15,-141 -76.3,-141 -76.45,-141 -76.6,-141 -76.75,-141 -76.9,-141 -77.05,-141 -77.2,-141 -77.35,-141 -77.5,-141.55 -77.5,-142.1 -77.5,-142.65 -77.5,-143.2 -77.5,-143.75 -77.5,-144.3 -77.5,-144.85 -77.5,-145.4 -77.5,-145.95 -77.5,-146.5 -77.5,-146.5 -77.35,-146.5 -77.2,-146.5 -77.05,-146.5 -76.9,-146.5 -76.75,-146.5 -76.6,-146.5 -76.45,-146.5 -76.3,-146.5 -76.15,-146.5 -76)) | POINT(-143.75 -76.75) | false | false | |||||||||||
Collaborative Research: Explosive Ice-Shelf Disintegration
|
0944193 |
2014-08-25 | MacAyeal, Douglas |
|
This award supports a project to examine and test a 3-step process model for explosive ice-shelf disintegration that emerged in the wake of the recent 2008 and 2009 events of the Wilkins Ice Shelf. The model is conditioned on Summer melt-driven increase in free-surface water coupled with surface and basal crevasse density growth necessary to satisfy an "enabling condition". Once met, the collapse proceeds through three steps: (Step 1), calving of a "leading phalanx" of tabular icebergs from the seaward ice front of the ice shelf which creates in its wake a region, called a "mosh pit" (located between the phalanx and the edge of the intact ice shelf), where ocean surface-gravity waves are trapped by reflection (a fast mechanically enabled process), (Step 2), and a rapid, runaway conversion of gravitational potential energy into ocean-wave energy by iceberg capsize and fragmentation within the "mosh pit" which leads to further wave-induced calving, capsize and fragmentation (Step 3). The project will be conducted by a multidisciplinary team and will focus on theoretical model development, numerical method development and application and new observations. The project will participate in both the Research Experience for Undergraduates program in the Physics Department and the Summer Research Early Identification Program (SR-EIP) that fosters participation in research by underrepresented minorities. The PIs, postdoctoral scholar, graduate students and unfunded participants will develop a graduate-level seminar/tutorial to introduce advanced computational methods to glaciology. A postdoctoral scholar and graduate student will be trained in new research techniques during the project. | None | None | false | false | |||||||||||
EAGER: Are the Dry Valleys Getting Wetter? A Preliminary Assessment of Wetness Across the McMurdo Dry Valleys Landscape
|
1045215 |
2014-07-01 | Gooseff, Michael N. |
|
Intellectual Merit: Until recently, wetted soils in the Dry Valleys were generally only found adjacent to streams and lakes. Since the warm austral summer of 2002, numerous ?wet spots? have been observed far from shorelines on relatively flat valley floor locations and as downslope fingers of flow on valley walls. The source of the water to wet these soils is unclear, as is the spatial and temporal pattern of occurrence from year to year. Their significance is potentially great as enhanced soil moisture may change the thermodynamics, hydrology, and erosion rate of surface soils, and facilitate transport of materials that had previously been stable. These changes to the soil active layer could significantly modify permafrost and ground ice stability within the Dry Valleys. The PIs seek to investigate these changes to address two competing hypotheses: that the source of water to these ?wet spots? is ground ice melt and that the source of this water is snowmelt. The PIs will document the spatiotemporal dynamics of these wet areas using high frequency remote sensing data from Quickbird and Wordview satellites to document the occurrence, dimensions, and growth of wet spots during the 2010-11 and 2011-12 austral summers. They will test their hypotheses by determining whether wet spots recur in the same locations in each season, and they will compare present to past distribution using archived imagery. They will also determine whether spatial snow accumulation patterns and temporal ablation patterns are coincident with wet spot formation. Broader impacts: One graduate student will be trained on this project. Findings will be reported at scientific meetings and published in peer reviewed journals. They will also develop a teaching module on remote sensing applications to hydrology for the Modular Curriculum for Hydrologic Advancement and an innovative prototype project designed to leverage public participation in mapping wet spots and snow patches across the Dry Valleys through the use of social media and mobile computing applications. | POLYGON((160 -77.25,160.5 -77.25,161 -77.25,161.5 -77.25,162 -77.25,162.5 -77.25,163 -77.25,163.5 -77.25,164 -77.25,164.5 -77.25,165 -77.25,165 -77.375,165 -77.5,165 -77.625,165 -77.75,165 -77.875,165 -78,165 -78.125,165 -78.25,165 -78.375,165 -78.5,164.5 -78.5,164 -78.5,163.5 -78.5,163 -78.5,162.5 -78.5,162 -78.5,161.5 -78.5,161 -78.5,160.5 -78.5,160 -78.5,160 -78.375,160 -78.25,160 -78.125,160 -78,160 -77.875,160 -77.75,160 -77.625,160 -77.5,160 -77.375,160 -77.25)) | POINT(162.5 -77.875) | false | false | |||||||||||
Submarine and On-Land Volcanism in the West Antarctic Rift System: A Petrologic and Geochemical Study to Assess Melting Processes and Eruption History
|
1321588 |
2014-06-27 | Mukasa, Samuel |
|
This project is a geochemical study of volcanic rocks from the West Antarctic Rift system. Its goal is to understand the link between mantle composition and the diverse, regional geodynamic processes, which include uplift, rifting, and volcanism. This project uses argon dating to time the processes, and isotope geochemistry and melt inclusion studies to determine whether the area is underlain by hot or wet mantle. The main broader impacts are support for a woman graduate student, undergraduate research, and research infrastructure. | POLYGON((129.26361 -71.3575,132.914609 -71.3575,136.565608 -71.3575,140.216607 -71.3575,143.867606 -71.3575,147.518605 -71.3575,151.169604 -71.3575,154.820603 -71.3575,158.471602 -71.3575,162.122601 -71.3575,165.7736 -71.3575,165.7736 -72.145583,165.7736 -72.933666,165.7736 -73.721749,165.7736 -74.509832,165.7736 -75.297915,165.7736 -76.085998,165.7736 -76.874081,165.7736 -77.662164,165.7736 -78.450247,165.7736 -79.23833,162.122601 -79.23833,158.471602 -79.23833,154.820603 -79.23833,151.169604 -79.23833,147.518605 -79.23833,143.867606 -79.23833,140.216607 -79.23833,136.565608 -79.23833,132.914609 -79.23833,129.26361 -79.23833,129.26361 -78.450247,129.26361 -77.662164,129.26361 -76.874081,129.26361 -76.085998,129.26361 -75.297915,129.26361 -74.509832,129.26361 -73.721749,129.26361 -72.933666,129.26361 -72.145583,129.26361 -71.3575)) | POINT(147.518605 -75.297915) | false | false | |||||||||||
Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core
|
0839122 0839093 0839075 |
2014-05-30 | Foreman, Christine; Skidmore, Mark; Saltzman, Eric; McConnell, Joseph; Priscu, John | 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. | POINT(112.05 -79.28) | POINT(112.05 -79.28) | false | false | ||||||||||||
Model Studies of Surface Water Behavior on Ice Shelves
|
0944248 |
2013-12-21 | MacAyeal, Douglas |
|
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. | 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)) | POINT(-59.585 -65.518) | false | false | |||||||||||
Collaborative Research: Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams
|
0739648 |
2013-12-10 | Cary, Stephen |
|
The glacial streams of the McMurdo Dry Valleys have extensive cyanobacterial mats that are a probable source of fixed C and N to the Valleys. The research will examine the interplay between the microbial mats in the ephemeral glacial streams and the microbiota of the hyporheic soils (wetted soil zone) underlying and adjacent to those mats. It is hypothesized that the mats are important sources of organic carbon and fixed nitrogen for the soil communities of the hyporheic zone, and release dissolved organic carbon (DOC) and nitrogen (DON) that serves the entire Dry Valley ecosystem. Field efforts will entail both observational and experimental components. Direct comparisons will be made between the mats and microbial populations underlying naturally rehydrated and desiccated mat areas, and between mat areas in the melt streams of the Adams and Miers Glaciers in Miers Valley. Both physiological and phylogenetic indices of the soil microbiota will be examined. Observations will include estimates of rates of mat carbon and nitrogen fixation, soil respiration and leucine and thymidine uptake (as measures of protein & DNA synthesis, respectively) by soil bacteria, bacterial densities and their molecular ecology. Experimental manipulations will include experimental re-wetting of soils and observations of the time course of response of the microbial community. The research will integrate modern molecular genetic approaches (ARISA-DNA fingerprinting and ultra deep 16S rDNA microbial phylogenetic analysis) with geochemistry to study the diversity, ecology, and function of microbial communities that thrive in these extreme environments. The broader impacts of the project include research and educational opportunities for graduate students and a postdoctoral associate. The P.I.s will involve undergraduates as work-study students and in REU programs, and will participate in educational and outreach programs. | POINT(163 -77.5) | POINT(163 -77.5) | false | false | |||||||||||
Mount Erebus Volcano Observatory: Operations, Science and Outreach (MEVO-OSO)
|
1142083 |
2013-09-03 | Kyle, Philip; Oppenheimer, Clive; Chaput, Julien; Jones, Laura; Fischer, Tobias | Intellectual Merit: Mt. Erebus is one of only a handful of volcanoes worldwide that have lava lakes with readily observable and nearly continuous Strombolian explosive activity. Erebus is also unique in having a permanent convecting lava lake of anorthoclase phonolite magma. Over the years significant infrastructure has been established at the summit of Mt. Erebus as part of the Mount Erebus Volcano Observatory (MEVO), which serves as a natural laboratory to study a wide range of volcanic processes, especially magma degassing associated with an open convecting magma conduit. The PI proposes to continue operating MEVO for a further five years. The fundamental fundamental research objectives are: to understand diffuse flank degassing by using distributed temperature sensing and gas measurements in ice caves, to understand conduit processes, and to examine the environmental impact of volcanic emissions from Erebus on atmospheric and cryospheric environments. To examine conduit processes the PI will make simultaneous observations with video records, thermal imaging, measurements of gas emission rates and gas compositions, seismic, and infrasound data. Broader impacts: An important aspect of Erebus research is the education and training of students. Both graduate and undergraduate students will have the opportunity to work on MEVO data and deploy to the field site. In addition, this proposal will support a middle or high school science teacher for two field seasons. The PI will also continue working with various media organizations and filmmakers. | POINT(167.15334 -77.529724) | POINT(167.15334 -77.529724) | false | false | ||||||||||||
Ocean Surfaces on Snowball Earth
|
0739779 1142963 |
2013-07-10 | Warren, Stephen; Light, Bonnie; Campbell, Adam; Carns, Regina; Dadic, Ruzica; Mullen, Peter; Brandt, Richard; Waddington, Edwin D. |
|
The climatic changes of late Precambrian time, 600-800 million years ago, included episodes of extreme glaciation, during which ice may have covered nearly the entire ocean for several million years, according to the Snowball Earth hypothesis. These episodes would hold an important place in Earth?s evolutionary history; they could have encouraged biodiversity by trapping life forms in small isolated ice-free areas, or they could have caused massive extinctions that cleared the path for new life forms to fill empty niches. What caused the Earth to become iced over, and what later caused the ice to melt? Scientific investigation of these questions will result in greater understanding of the climatic changes that the Earth can experience, and will enable better predictions of future climate. This project involves Antarctic field observations as well as laboratory studies and computer modeling. The aim of this project is not to prove or disprove the Snowball Earth hypothesis but rather to quantify processes that are important for simulating snowball events in climate models. The principal goal is to identify the types of ice that would have been present on the frozen ocean, and to determine how much sunlight they would reflect back to space. Reflection of sunlight by bright surfaces of snow and ice is what would maintain the cold climate at low latitudes. The melting of the ocean required buildup of greenhouse gases, but it was probably aided by deposition of desert dust and volcanic ash darkening the snow and ice. With so much ice on the Earth?s surface, even small differences in the amount of light that the ice absorbed or reflected could cause significant changes in climate. The properties of the ice would also determine where, and in what circumstances, photosynthetic life could have survived. Some kinds of ice that are rare on the modern Earth may have been pivotal in allowing the tropical ocean to freeze. The ocean surfaces would have included some ice types that now exist only in Antarctica: bare cold sea ice with precipitated salts, and "blue ice" areas of the Transantarctic Mountains that were exposed by sublimation and have not experienced melting. Field expeditions were mounted to examine these ice types, and the data analysis is underway. A third ice type, sea ice with a salt crust, is being studied in a freezer laboratory. Modeling will show how sunlight would interact with ice containing light-absorbing dust and volcanic ash. Aside from its reflection of sunlight, ice on the Snowball ocean would have been thick enough to flow under its own weight, invading all parts of the ocean. Yet evidence for the survival of photosynthetic life indicates that some regions of liquid water were maintained at the ocean surface. One possible refuge for photosynthetic organisms is a bay at the far end of a nearly enclosed tropical sea, formed by continental rifting and surrounded by desert, such as the modern Red Sea. A model of glacier flow is being developed to determine the dimensions of the channel, connecting the sea to the ocean, necessary to prevent invasion by the flowing ice yet maintain a water supply to replenish evaporation. | POLYGON((157 -76,158.1 -76,159.2 -76,160.3 -76,161.4 -76,162.5 -76,163.6 -76,164.7 -76,165.8 -76,166.9 -76,168 -76,168 -76.2,168 -76.4,168 -76.6,168 -76.8,168 -77,168 -77.2,168 -77.4,168 -77.6,168 -77.8,168 -78,166.9 -78,165.8 -78,164.7 -78,163.6 -78,162.5 -78,161.4 -78,160.3 -78,159.2 -78,158.1 -78,157 -78,157 -77.8,157 -77.6,157 -77.4,157 -77.2,157 -77,157 -76.8,157 -76.6,157 -76.4,157 -76.2,157 -76)) | POINT(162.5 -77) | false | false | |||||||||||
The Sea Ice System in Antarctic Summer, Oden Southern Ocean Expedition (OSO 2010-11)
|
0839053 |
2013-05-03 | Ackley, Stephen |
|
Several aspect of the seasonal melting and reformation cycle of Antarctic sea ice appear to be divergent from those occurring in the Arctic. This is most clearly demonstrated by the dramatic diminishing extent and thinning of the Arctic sea ice, to be contrasted to the changes in Antarctic sea-ice extent, which recently (decadaly) shows small increases. Current climate models do not resolve this discrepancy which likely results from both a lack of relevant observational sea-ice data in the Antarctic, along with inadequacies in the physical parameterization of sea-ice properties in climate models.<br/><br/>Researchers will take advantage of the cruise track of the I/B Oden during transit through the Antarctic sea-ice zones in the region of the Bellingshausen, Amundsen and Ross (BAR) seas on a cruise to McMurdo Station. Because of its remoteness and inaccessibility, the BAR region is of considerable scientific interest as being one of the last under described and perhaps unexploited marine ecosystems left on the planet .<br/><br/>A series of on station and underway observations of sea ice properties will be undertaken, thematically linked to broader questions of summer ice survival and baseline physical properties (e.g. estimates of heat and salt fluxes). In situ spatiotemporal variability of sea-ice cover extent, thickness and snow cover depths will be observed. | POLYGON((-180 -67.05,-170.9866 -67.05,-161.9732 -67.05,-152.9598 -67.05,-143.9464 -67.05,-134.933 -67.05,-125.9196 -67.05,-116.9062 -67.05,-107.8928 -67.05,-98.8794 -67.05,-89.866 -67.05,-89.866 -68.1033,-89.866 -69.1566,-89.866 -70.2099,-89.866 -71.2632,-89.866 -72.3165,-89.866 -73.3698,-89.866 -74.4231,-89.866 -75.4764,-89.866 -76.5297,-89.866 -77.583,-98.8794 -77.583,-107.8928 -77.583,-116.9062 -77.583,-125.9196 -77.583,-134.933 -77.583,-143.9464 -77.583,-152.9598 -77.583,-161.9732 -77.583,-170.9866 -77.583,180 -77.583,178.57 -77.583,177.14 -77.583,175.71 -77.583,174.28 -77.583,172.85 -77.583,171.42 -77.583,169.99 -77.583,168.56 -77.583,167.13 -77.583,165.7 -77.583,165.7 -76.5297,165.7 -75.4764,165.7 -74.4231,165.7 -73.3698,165.7 -72.3165,165.7 -71.2632,165.7 -70.2099,165.7 -69.1566,165.7 -68.1033,165.7 -67.05,167.13 -67.05,168.56 -67.05,169.99 -67.05,171.42 -67.05,172.85 -67.05,174.28 -67.05,175.71 -67.05,177.14 -67.05,178.57 -67.05,-180 -67.05)) | POINT(-142.083 -72.3165) | false | false | |||||||||||
Subglacial Lakes and the Onset of Ice Streaming: Recovery Lakes
|
0636883 |
2013-04-02 | Bell, Robin; Studinger, Michael S. |
|
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. | 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)) | POINT(35 -82.5) | false | false | |||||||||||
Basal Conditions of Ice Stream D and Related Borehole Studies of Antarctic Ice Stream Mechanics
|
9615420 |
2013-02-14 | Kamb, Barclay; Engelhardt, Hermann |
|
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. | POINT(-136.404633 -82.39955) | POINT(-136.404633 -82.39955) | false | false | |||||||||||
Collaborative Research: Polenet East: An International Seismological Network for East Antarctica
|
0838973 0838934 |
2013-01-21 | Wiens, Douglas; Nyblade, Andrew |
|
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The high elevations of East Antarctica are critical in localizing the initial Cenozoic glaciation and stabilizing it with respect to melting during warm interglacials. However, the geological history for this region and the geophysical mechanism for maintaining the highlands are poorly understood. In 2007-2009, an array of 24 broadband seismographs (named GAMSEIS) was installed across the Gamburtsev Mountains area of the East Antarctic Plateau as part of the Antarctica?s Gamburtsev Province (AGAP) International Polar Year project. The IPY AGAP/GAMSEIS program included plans by other international partners to install seismographs at locations along the flanks of the Gamburtsev Mountains and in other East Antarctic regions. The proposed project will continue operating six of the deployed AGAP/GAMSEIS stations for two more years together with two new broadband seismic stations added to broaden the geographic scope of the array. Most stations will be located at the existing U.S. Autonomous Geophysical Observatories and the USAP fuel cache locations in order to minimize logistical support. This array, combined with seismographs deployed by China and Japan (and possibly Australia, France, and Italy in near future) will provide a sparse but large-scale network of seismometers for the longer-term studies of the crustal and upper mantle structures underneath the East Antarctic Plateau. Continued reliance on students provides a broader impact to this proposed research and firmly grounds this effort in its educational mission. | 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)) | POINT(90 -80) | false | false | |||||||||||
IPY: Stability of Larsen C Ice Shelf in a Warming Climate
|
0732946 |
2012-10-03 | Steffen, Konrad |
|
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. | None | None | false | false | |||||||||||
Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data
|
0537752 0538674 |
2012-08-09 | Matsuoka, Kenichi; Winebrenner, Dale; Creyts, Timothy; Macgregor, Joseph A.; Studinger, Michael S.; Waddington, Edwin D. |
|
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. | None | None | false | false | |||||||||||
Estimating the Salinity of Subglacial Lakes From Existing Aerogeophysical Data
|
0636584 |
2012-08-07 | Creyts, Timothy; Studinger, Michael S. | No dataset link provided | 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. | None | None | false | false | |||||||||||
Collaborative Research: Continued Study of Physical Properties of the WAIS Divide Deep Core
|
1043528 1043313 |
2012-06-19 | Spencer, Matthew; Alley, Richard; Fitzpatrick, Joan; Voigt, Donald E. | 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. | POINT(112.1166 -79.4666) | POINT(112.1166 -79.4666) | false | false | ||||||||||||
Collaborative Research: Microparticle/tephra analysis of the WAIS Divide ice core
|
0636740 0636767 |
2012-06-19 | Koffman, Bess; Kreutz, Karl; Breton, Daniel; Dunbar, Nelia; Hamilton, Gordon S. | 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. | POINT(112.11666 -79.46666) | POINT(112.11666 -79.46666) | false | false | ||||||||||||
Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach - Marine and Quaternary Geosciences
|
0732467 |
2011-03-03 | Domack, Eugene Walter; Blanchette, Robert | 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". | None | None | false | false | ||||||||||||
Major Ion Chemistry of WAIS Divide Ice Core
|
0538553 |
2010-08-25 | Cole-Dai, Jihong |
|
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. | POINT(-112.085 -79.467) | POINT(-112.085 -79.467) | false | false | |||||||||||
Circumpolar Deep Water and the West Antarctic Ice Sheet
|
9725024 |
2010-05-04 | Jacobs, Stanley |
|
*** 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. *** | None | None | false | false | |||||||||||
Holocene Paleoenvironmental Change Along the Antarctic Peninsula: A Test of the Solar/Bi-Polar Signal
|
9615053 |
2010-05-04 | Domack, Eugene Walter |
|
Domack: OPP 9615053 Manley: OPP 9615670 Banerjee: OPP 9615695 Dunbar: OPP 9615668 Ishman: OPP 9615669 Leventer: OPP 9714371 Abstract This award supports a multi-disciplinary, multi-institutional effort to elucidate the detailed climate history of the Antarctic Peninsula during the Holocene epoch (the last 10,000 years). The Holocene is an important, but often overlooked, portion of the Antarctic paleoclimatic record because natural variability in Holocene climate on time scales of decades to millennia can be evaluated as a model for our present "interglacial" world. This project builds on over ten years of prior investigation into the depositional processes, productivity patterns and climate regime of the Antarctic Peninsula. This previous work identified key locations that contain ultra-high resolution records of past climatic variation. These data indicate that solar cycles operating on multi-century and millennial time scales are important regulators of meltwater production and paleoproductivity. These marine records can be correlated with ice core records in Greenland and Antarctica. This project will focus on sediment dispersal patterns across the Palmer Deep region. The objective is to understand the present links between the modern climatic and oceanographic systems and sediment distribution. In particular, additional information is needed regarding the influence of sea ice on the distribution of both biogenic and terrigenous sediment distribution. Sediment samples will be collected with a variety of grab sampling and coring devices. Analytical work will include carbon-14 dating of surface sediments using accellerator mass spectrometry and standard sedimentologic, micropaleontologic and magnetic granulometric analyses. This multiparameter approach is the most effective way to extract the paleoclimatic signals contained in the marine sediment cores. Two additional objectives are the deployment of sediment traps in front of the Muller Ice Shelf in Lallemand Fjord and seismic reflection work in conjunction with site augmentation funded through the Joint Oceanographic Institute. The goal of sediment trap work is to address whether sand transport and deposition adjacent to the ice shelf calving line results from meltwater or aeolian processes. In addition, the relationship between sea ice conditions and primary productivity will be investigated. The collection of a short series of seismic lines across the Palmer Deep basins will fully resolve the question of depth to acoustic basement. The combination of investigators on this project, all with many years of experience working in high latitude settings, provides an effective team to complete the project in a timely fashion. A combination of undergraduate, graduate and post-graduate students will be involved in all stages of the project so that educational objectives will be met in-tandem with research goals of the project. | None | None | false | false | |||||||||||
Collaborative Research on Bloom Dynamics and Food Web Structure in the Ross Sea: Vertical Flux of Carbon and Nitrogen
|
9317598 |
2010-05-04 | Asper, Vernon; Smith, Walker |
|
9317598 Asper The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. This component will focus on the collection of vertical flux samples which will be analyzed for carbon, nitrogen and total mass flux and also provided to the other investigators for their specific analyses. Profiles of the abundance of large aggregates in the water column using a non- contact photographic method will be made. These data will be used to complement other particle determinations, to investigate the role of these aggregates in particle flux and to determine the mechanisms of particle export as a function of season and phytoplankton species. The end result will be a better understanding of the bloom processes and significant contributions to the data base on aggregates and export mechanisms in this environment. | POLYGON((-180 -43.56582,-144.00001 -43.56582,-108.00002 -43.56582,-72.00003 -43.56582,-36.00004 -43.56582,-0.000049999999987 -43.56582,35.99994 -43.56582,71.99993 -43.56582,107.99992 -43.56582,143.99991 -43.56582,179.9999 -43.56582,179.9999 -46.943299,179.9999 -50.320778,179.9999 -53.698257,179.9999 -57.075736,179.9999 -60.453215,179.9999 -63.830694,179.9999 -67.208173,179.9999 -70.585652,179.9999 -73.963131,179.9999 -77.34061,143.99991 -77.34061,107.99992 -77.34061,71.99993 -77.34061,35.99994 -77.34061,-0.000050000000016 -77.34061,-36.00004 -77.34061,-72.00003 -77.34061,-108.00002 -77.34061,-144.00001 -77.34061,-180 -77.34061,-180 -73.963131,-180 -70.585652,-180 -67.208173,-180 -63.830694,-180 -60.453215,-180 -57.075736,-180 -53.698257,-180 -50.320778,-180 -46.943299,-180 -43.56582)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: The Maud Rise Nonlinear Equation of State Study (MaudNESS)
|
0337159 |
2010-05-04 | McPhee, Miles G. |
|
This project is an investigation into one mechanism by which deep ocean convection can evolve from stable initial conditions, to the extent that it becomes well enough established to bring warm water to the surface and melt an existing ice cover in late, or possibly even mid-winter. The specific study will investigate how the non-linear dependence of seawater density on temperature and salinity (the equation of state) can enhance vertical convection under typical antarctic conditions. When layers of seawater with similar densities but strong contrasts in temperature and salinity interact, there are a number of possible non-linear instabilities that can convert existing potential energy to turbulent energy. In the Weddell Sea, a cold surface mixed layer is often separated from the underlying warm, more saline water by a thin, weak pycnocline, making the water column particularly susceptible to an instability associated with thermobaricity (the pressure dependence of the thermal expansion coefficient). The project is a collaboration between New York University, Earth and Space Research, the University of Washington, the Naval Postgraduate School, and McPhee Research Company.<br/>The work has strong practical applications in contributing to the explanation for the existence of the Weddell Polynya, a 300,000 square kilometer area of open water within the seasonal sea ice of the Weddell Sea, from approximately 1975 to 1979. It has not recurred since, although indications of much smaller and less persistent areas of open water do occur in the vicinity of the Maud Rise seamount. <br/> The experimental component will be carried out on board the RVIB Nathaniel B. Palmer between July and September, 2005. | POLYGON((-64.71659 -53.00174,-57.631677 -53.00174,-50.546764 -53.00174,-43.461851 -53.00174,-36.376938 -53.00174,-29.292025 -53.00174,-22.207112 -53.00174,-15.122199 -53.00174,-8.037286 -53.00174,-0.952373 -53.00174,6.13254 -53.00174,6.13254 -54.292069,6.13254 -55.582398,6.13254 -56.872727,6.13254 -58.163056,6.13254 -59.453385,6.13254 -60.743714,6.13254 -62.034043,6.13254 -63.324372,6.13254 -64.614701,6.13254 -65.90503,-0.952373 -65.90503,-8.037286 -65.90503,-15.122199 -65.90503,-22.207112 -65.90503,-29.292025 -65.90503,-36.376938 -65.90503,-43.461851 -65.90503,-50.546764 -65.90503,-57.631677 -65.90503,-64.71659 -65.90503,-64.71659 -64.614701,-64.71659 -63.324372,-64.71659 -62.034043,-64.71659 -60.743714,-64.71659 -59.453385,-64.71659 -58.163056,-64.71659 -56.872727,-64.71659 -55.582398,-64.71659 -54.292069,-64.71659 -53.00174)) | POINT(-29.292025 -59.453385) | false | false | |||||||||||
Study of the Structure and Tectonics of the South Shetland Trench and Bransfield Backarc Using Ocean Bottom Seismographs
|
9726180 |
2010-05-04 | Wiens, Douglas |
|
This award, provided by the Office of Polar Programs of the National Science Foundation, supports research to investigate the seismicity and tectonics of the South Shetland Arc and the Bransfield Strait. This region presents an intriguing and unique tectonic setting, with slowing of subduction, cessation of island arc volcanism, as well as the apparent onset of backarc rifting occurring within the last four million years. This project will carry out a 5-month deployment of 14 ocean bottom seismographs (OBSs) to complement and extend a deployment of 6 broadband land seismic stations that were successfully installed during early 1997. The OBSs include 2 instruments with broadband sensors, and all have flowmeters for measuring and sampling hydrothermal fluids. The OBSs will be used to examine many of the characteristics of the Shetland- Bransfield tectonic system, including: --- The existence and depth of penetration of a Shetland Slab: The existence of a downgoing Shetland slab will be determined from earthquake locations and from seismic tomography. The maximum depth of earthquake activity and the depth of the slab velocity anomaly will constrain the current configuration of the slab, and may help clarify the relationship between the subducting slab and the cessation of arc volcanism. -- Shallow Shetland trench seismicity?: No teleseismic shallow thrust faulting seismicity has been observed along the South Shetland Trench from available seismic information. Using the OBS data, the level of small earthquake activity along the shallow thrust zone will be determined and compared to other regions undergoing slow subduction of young oceanic lithosphere, such as Cascadia, which also generally shows very low levels of thrust zone seismicity. -- Mode of deformation along the Bransfield Rift: The Bransfield backarc has an active rift in the center, but there is considerable evidence for off-rift faulting. There is a long-standing controversy about whet her back-arc extension occurs along discrete rift zones, or is more diffuse geographically. This project will accurately locate small earthquakes to better determine whether Bransfield extension is discrete or diffuse. -- Identification of volcanism and hydrothermal activity: Seismic records will be used to identify the locations of active seafloor volcanism along the Bransfield rift. Flowmeters attached to the OBSs will record and sample the fluid flux out of the sediments. -- Upper mantle structure of the Bransfield - evidence for partial melting?: Other backarc basins show very slow upper mantle seismic velocities and high seismic attenuation, characteristics due to the presence of partially molten material. This project will use seismic tomography to resolve the upper mantle structure of the Bransfield backarc, allowing comparison with other backarc regions and placing constraints on the existence of partially molten material and the importance of partial melting as a mantle process in this region. Collaborative awards: OPP 9725679 and OPP 9726180 | None | None | false | false | |||||||||||
Collaborative Research: Controls on Sediment Yields from Tidewater Glaciers from Patagonia to Antarctica
|
0338371 0338137 |
2010-05-04 | Anderson, John; Hallet, Bernard; Wellner, Julia |
|
This project examines the role of glacier dynamics in glacial sediment yields. The results will shed light on how glacial erosion influences both orogenic processes and produces sediments that accumulate in basins, rich archives of climate variability. Our hypothesis is that erosion rates are a function of sliding speed, and should diminish sharply as the glacier's basal temperatures drop below the melting point. To test this hypothesis, we will determine sediment accumulation rates from seismic studies of fjord sediments for six tidewater glaciers that range from fast-moving temperate glaciers in Patagonia to slow-moving polar glaciers on the Antarctic Peninsula. Two key themes are addressed for each glacier system: 1) sediment yields and erosion rates by determining accumulation rates within the fjords using seismic profiles and core data, and 2) dynamic properties and basin characteristics of each glacier in order to seek an empirical relationship between glacial erosion rates and ice dynamics. The work is based in Patagonia and the Antarctic Peninsula, ideal natural laboratories for these purposes because the large latitudinal range provides a large range of precipitation and thermal regimes over relatively homogeneous lithologies and tectonic settings. Prior studies of these regions noted significant decreases in glaciomarine sediment accumulations in the fjords to the south. As well, the fjords constitute accessible and nearly perfect natural sediment traps.<br/><br/>The broader impacts of this study include inter-disciplinary collaboration with Chilean glaciologists and marine geologists, support for one postdoctoral and three doctoral students, inclusion of undergraduates in research, and outreach to under-represented groups in Earth sciences and K-12 educators. The results of the project will also contribute to a better understanding of the linkages between climate and evolution of all high mountain ranges. | POLYGON((-74.59492 -45.98986,-74.072309 -45.98986,-73.549698 -45.98986,-73.027087 -45.98986,-72.504476 -45.98986,-71.981865 -45.98986,-71.459254 -45.98986,-70.936643 -45.98986,-70.414032 -45.98986,-69.891421 -45.98986,-69.36881 -45.98986,-69.36881 -46.835236,-69.36881 -47.680612,-69.36881 -48.525988,-69.36881 -49.371364,-69.36881 -50.21674,-69.36881 -51.062116,-69.36881 -51.907492,-69.36881 -52.752868,-69.36881 -53.598244,-69.36881 -54.44362,-69.891421 -54.44362,-70.414032 -54.44362,-70.936643 -54.44362,-71.459254 -54.44362,-71.981865 -54.44362,-72.504476 -54.44362,-73.027087 -54.44362,-73.549698 -54.44362,-74.072309 -54.44362,-74.59492 -54.44362,-74.59492 -53.598244,-74.59492 -52.752868,-74.59492 -51.907492,-74.59492 -51.062116,-74.59492 -50.21674,-74.59492 -49.371364,-74.59492 -48.525988,-74.59492 -47.680612,-74.59492 -46.835236,-74.59492 -45.98986)) | POINT(-71.981865 -50.21674) | false | false | |||||||||||
Sea Ice Mass Balance in the Antarctic-SIMBA Drift Station
|
0538516 |
2010-05-04 | Ackley, Stephen |
|
This project is a study of the evolution of the sea ice cover, and the mass balance of ice in the Amundsen Sea and the Bellingshausen Sea in the internationally collaborative context of the International Polar Year (2007-2008). In its simplest terms, the mass balance is the net freezing and melting that occurs over an annual cycle at a given location. If the ice were stationary and were completely to melt every year, the mass balance would be zero. While non-zero balances have significance in questions of climate and environmental change, the process itself has global consequences since the seasonal freeze-melt cycle has the effect of distilling the surface water. Oceanic salt is concentrated into brine and rejected from the ice into deeper layers in the freezing process, while during melt, the newly released and relatively fresh water stabilizes the surface layers. The observation program will be carried out during a drift program of the Nathaniel B. Palmer, and through a buoy network established on the sea ice that will make year-long measurements of ice thickness, and temperature profile, large-scale deformation, and other characteristics. The project is a component of the Antarctic Sea Ice Program, endorsed internationally by the Joint Committee for IPY. Additionally, the buoys to be deployed have been endorsed as an IPY contribution to the World Climate Research Program/Scientific Committee on Antarctic Research (WCRP/SCAR) International Programme on Antarctic Buoys (IPAB). While prior survey information has been obtained in this region, seasonal and time-series measurements on sea ice mass balance are crucial data in interpreting the mechanisms of air-ice-ocean interaction. <br/> The network will consist of an array of twelve buoys capable of GPS positioning. Three buoys will be equipped with thermister strings and ice and snow thickness measurement gauges, as well as a barometer. Two buoys will be equipped with meteorological sensors including wind speed and direction, atmospheric pressure, and incoming radiation. Seven additional buoys will have GPS positioning only, and will be deployed approximately 100 km from the central site. These outer buoys will be critical in capturing high frequency motion complementary to satellite-derived ice motion products. Additional buoys have been committed internationally through IPAB and will be deployed in the region as part of this program.<br/> This project will complement similar projects to be carried out in the Weddell Sea by the German Antarctic Program, and around East Antarctica by the Australian Antarctic Program. The combined buoy and satellite deformation measurements, together with the mass balance measurements, will provide a comprehensive annual data set on sea ice thermodynamics and dynamics for comparison with both coupled and high-resolution sea ice models. | None | None | false | false | |||||||||||
Collaborative Research: Interactive effects of UV and vertical mixing on phytoplankton and bacterioplankton in the Ross Sea
|
0125818 |
2010-05-04 | Neale, Patrick |
|
Ultraviolet radiation influences the dynamics of plankton processes in the near-surface waters of most aquatic ecosystems. In particular, the Southern Ocean is affected in the austral spring period when biologically damaging ultraviolet radiation is enhanced by ozone depletion. While progress has been made in estimating the quantitative impact of ultraviolet radiation on bacteria and phytoplankton in the Southern Ocean, some important issues remain to be resolved. Little is known about responses in systems dominated by the colonial haptophyte Phaeocystis antarctica, which dominates spring blooms in a polyna that develops in the southern Ross Sea. The Ross Sea is also of interest because of the occurrence of open water at a far southerly location in the spring, well within the ozone hole, and continuous daylight, with implications for the regulation of DNA repair. A number of studies suggest that vertical mixing can significant modify the impact of ultraviolet radiation in the Southern Ocean and elsewhere. However, there are limited measurements of turbulence intensity in the surface layer and measurements have not been integrated with parallel studies of ultraviolet radiation effects on phytoplankton and bacterioplankton. To address these issues, this collaborative study will focus on vertical mixing and the impact of ultraviolet radiation in the Ross Sea. The spectral and temporal responses of phytoplankton and bacterioplankton to ultraviolet radiation will be characterized in both laboratory and solar incubations. These will lead to the definition of biological weighting functions and response models capable of predicting the depth and time distribution of ultraviolet radiation impacts on photosynthesis, bacterial incorporation and DNA damage in the surface layer. Diel sampling will measure depth-dependent profiles of DNA damage, bacterial incorporation, photosynthesis and fluorescence parameters over a 24 h cycle. Sampling will include stations with contrasting wind-driven mixing and stratification as the polyna develops. The program of vertical mixing measurements is optimized for the typical springtime Ross Sea situation in which turbulence of intermediate intensity is insufficient to mix the upper layer thoroughly in the presence of stabilizing influences like solar heating and/or surface freshwater input from melting ice. Fine-scale vertical density profiles will be measured with a free-fall CTD unit and the profiles will be used to directly estimate large-eddy scales by determining Thorpe scales. Eddy scales and estimated turbulent diffusivities will be directly related to surface layer effects, and used to generate lagrangian depth-time trajectories in models of ultraviolet radiation responses in the surface mixed layer. The proposed research will be the first in-depth study of ultraviolet radiation effects in the Ross Sea and provide a valuable comparison with previous work in the Weddell-Scotia Confluence and Palmer Station regions. It will also enhance the understanding of vertical mixing processes, trophic interactions and biogeochemical cycling in the Ross Sea. | None | None | false | false | |||||||||||
The Amundsen Continental Shelf and the Antarctic Ice Sheet
|
0440775 |
2010-05-04 | Jacobs, Stanley |
|
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. | None | None | false | false | |||||||||||
Collaborative Research: Bloom Dynamics and Food-Web Structure in the Ross Sea: The Irradiance/Mixing Regime and Diatom Growith in Spring
|
9317538 |
2010-05-04 | Smith, Walker |
|
9317538 Nelson The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. This component will test the closely related hypotheses that: (1) phytoplankton growth is controlled primarily by the relationship between solar irradiance and mixed-layer depth throughout the spring (2) diatom growth rates are much higher in spring than at any other time of year, in response to the more favorable irradiance/mixing relationships, and (3) persistence of diatom blooms in summer results from the diatoms' ability to outcompete other groups under the light-limited conditions that develop in turbid, high-biomass waters. These hypotheses will be tested by (1) obtaining the first reliable estimates of the Sverdrup "critical depth" in the Antarctic so that the changing relationship between the critical depth and the mixed- layer depth in spring can be defined, and (2) estimating diatom growth rates and the gross and net production attributable to diatoms throughout the spring. The results will provide information critical to an understanding of phytoplankton bloom dynamics in the Ross Sea. | None | None | false | false | |||||||||||
Mechanism and Timing of West Antarctic Ice Sheet Retreat at the End of the Last Glacial Maximum
|
9527876 |
2010-05-04 | Anderson, John |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Collaborative Research: Bloom Dynamics and Food Web Structure in the Ross Sea: Role of Microzooplankton in Controlling Production
|
9316035 |
2010-05-04 | Smith, Walker |
|
The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. The focus of this proposal is the role of microzooplankton in controlling the production and fate of carbon during the two types of blooms. Objectives are: 1) to determine biomass, abundance, size and selected species composition of primary producer assemblages, 2) to determine similar features of nano- and microplanktonic heterotrophic assemblages, 3) to measure total community grazing on heterotrophic bacteria and phytoplankton, 4) to examine which grazers are the major herbivores and bacterivores, and 5) to measure the contribution of microzooplankton and mesozooplankton egesta, sinking of algal cells and colonies, and sinking of protozoan assemblages associated with detritus to the total carbon flux from the euphotic zone through 250 m depth. Water samples for abundance and biomass determinations will be taken and samples will be examined with epifluorescence microscopy. Grazing rates will be measured using the dilution grazing technique and the dual-isotope radiolabeling single cell method. Carbon fluxes will be determined on sinking material collected with particle interceptor traps at the base of the euphotic zone and two deeper depths, using microscopical analysis . An understanding of these processes and other fundamental processes studied by collaborating investigators will contribute to the understanding of the role of the Southern Ocean in present, past and predicted future sequestration of carbon, as well as in other global elemental cycles. | None | None | false | false | |||||||||||
Collaborative Research: Bloom Dynamics and Food Web Structure in the Ross Sea: Primary Productivity, New Production and Bacterial Growth
|
9317587 |
2010-05-04 | Smith, Walker |
|
The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. This component will conduct a set of process-oriented experiments designed to elucidate the controls of phytoplankton productivity, growth and accumulation as well as the mechanisms which control bacterial abundance and productivity in Antarctic waters. Specifically, the relative photosynthetic and nutrient (nitrate, ammonium) characteristics of diatom- vs. Phaeocystis- dominated assemblages will be examined to test if Phaeocystis simply grows faster under spring conditions in the Ross Sea. Phytoplankton and bacterial biomass, productivity and their interactions will be measured to elucidate the complex physical-chemical-biological interactions which occur. Substantial understanding of the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions will result from this research. Finally, because the Antarctic is the ocean's largest high-nutrient, low biomass system, and hence has the greatest potential for sequestering carbon dioxide, knowledge of the dynamics of the Ross Sea phytoplankton will also increase our understanding of the carbo n cycle of the Southern Ocean. | None | None | false | false | |||||||||||
Borehole Optical Stratigraphy: Ice Microphysics, Climate Change, and the Optical Properties of Firn
|
0335330 |
2010-04-01 | Smith, Ben; Waddington, Edwin D.; Hawley, Robert L.; Fudge, T. J. |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
SGER: Science-of-Opportunity Aboard Icebreaker Oden: Ocean-Atmosphere-Ice Interactions and Changes
|
0741510 |
2010-02-20 | Yuan, Xiaojun; Stammerjohn, Sharon |
|
Abstract<br/><br/>The project goal is to investigate the ocean-atmosphere-ice (OAI) interactions in the Amundsen and Ross Seas during the austral summer of 2007-08 using hydrographic measurements (CTD and XBT) in conjunction with (1) ship-based observations and satellite-derived estimates of sea ice concentration, and (2) ship-based observations and re-analyses of meteorological variables. The major scientific objectives are as follows: (1) to examine upper ocean characteristics along three transects in the Amundsen Sea and two transects in the Ross Sea within the context of ice-atmosphere variability over the preceding winter-spring season and as compared to other years where data are available; (2) to determine if there is additional evidence of increased upwelling of warm Circumpolar Deep Water onto the shelf in the Amundsen Sea and/or increased freshening in the Ross Sea as has been inferred by previous, but limited, ocean surveys in these regions; and (3) to examine the spatial variability in ocean thermal structure along the ship's track (outside the transects) to provide greater regional context and to compare with ocean XBT data collected during Oden 2006-07. A repeated temperature survey between the Amundsen and Ross Sea is particularly invaluable, given that this sector is the regional center of the high latitude OAI response to ENSO, thus providing opportunity for examining and linking regional oceanic temporal variability to global climate variability. The research will improve our understanding of the high latitude OAI response to climate change, and provide the physical context for the observed biology and geochemistry (investigated by our colleagues. Our results will be made widely available through research publications and internet-available databases, and through the strong public outreach efforts of Lamont-Doherty Earth Observatory. The outreach efforts will help increase awareness and understanding of anthropogenic climate change, melting ice, and ecosystem alteration in the highly sensitive Antarctic. | POLYGON((-180 -69,-172 -69,-164 -69,-156 -69,-148 -69,-140 -69,-132 -69,-124 -69,-116 -69,-108 -69,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-100 -77,-100 -78,-100 -79,-108 -79,-116 -79,-124 -79,-132 -79,-140 -79,-148 -79,-156 -79,-164 -79,-172 -79,180 -79,178.5 -79,177 -79,175.5 -79,174 -79,172.5 -79,171 -79,169.5 -79,168 -79,166.5 -79,165 -79,165 -78,165 -77,165 -76,165 -75,165 -74,165 -73,165 -72,165 -71,165 -70,165 -69,166.5 -69,168 -69,169.5 -69,171 -69,172.5 -69,174 -69,175.5 -69,177 -69,178.5 -69,-180 -69)) | POINT(-147.5 -74) | false | false | |||||||||||
Collaborative Research: Laboratory Studies of Isotopic Exchange in Snow and Firn
|
0338008 |
2010-01-01 | Neumann, Thomas A.; Wemple, Beverley C. |
|
This award supports a project to develop a quantitative understanding of the processes active in isotopic exchange between snow/firn and water vapor, which is of paramount importance to ice core interpretation. Carefully controlled laboratory studies will be conducted at a variety of temperatures to empirically measure the mass transfer coefficient (the rate at which water moves from the solid to the vapor phase) for sublimating snow and to determine the time scale for isotopic equilibration between water vapor and ice. In addition the isotopic fractionation coefficient for vapor derived from sublimating ice will be determined and the results will be used to update existing models of mass transfer and isotopic evolution in firn. It is well known that water vapor moves through firn due to diffusion, free convection and forced convection. Although vapor movement through variably-saturated firn due to these processes has been modeled, because of a lack of laboratory data the mass transfer coefficient had to be estimated. Field studies have documented the magnitudes of post-depositional changes, but field studies do not permit rigorous analysis of the relative importance of the many processes which are likely to act in natural snow packs. The results of these laboratory investigations will be broadly applicable to a number of studies and will allow for improvement of existing physically-based models of post-depositional isotopic change, isotopic diffusion in firn, and vapor motion in firn. A major component of this project will be the design and fabrication of the necessary, novel experimental apparatus, which will be facilitated by existing technical expertise, cold room facilities, and laboratory equipment at CRREL. This project is a necessary step toward a quantitative understanding of the isotopic effects of water vapor movement in firn. The proposed work has broader impacts in several different areas. The modeling results will be applicable to a wide range of studies of water in the polar environment, including studies of wind-blown or drifting snow. The proposed collaborative study will partially support a Dartmouth graduate student for three years. This project will also provide support for a young first-time NSF investigator at the University of Vermont. Undergraduate students from Dartmouth will be involved in the research through the Women in Science Project and undergraduate students at the University of Vermont will be supported through the Research Experiences for Undergraduates program. The principal investigators and graduate student will continue their tradition of k-12 school outreach by giving science lessons and talks in local schools each year. Research results will be disseminated through scientific conferences, journal publications, and institutional seminars. | None | None | false | false | |||||||||||
Collaborative Research: New insights into the Holocene methane budget from dual isotope systematics and a high resolution record of the interpolar gradient
|
0520523 |
2009-12-09 | Brook, Edward J. |
|
Not Available | None | None | false | false | |||||||||||
Collaborative Research: Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica
|
0440919 0440954 0551163 |
2009-10-12 | Miller, Molly; Sidor, Christian; Isbell, John | This project studies fossils from two to three hundred million year old rocks in the Allan Hills area of Antarctica. Similar deposits from lower latitudes have been used to develop a model of Permo-Triassic climate, wherein melting of continental glaciers in the early Permian leads to the establishment of forests in a cold, wet climate. Conditions became warmer and dryer by the early Triassic, inhibiting plant growth until a moistening climate in the late Triassic allowed plant to flourish once again. This project will test and refine this model and investigate the general effects of climate change on landscapes and ecosystems using the unique exposures and well-preserved fossil and sediment records in the Allan Hills area. The area will be searched for fossil forests, vertebrate tracks and burrows, arthropod trackways, and subaqueously produced biogenic structures, which have been found in other areas of Antarctica. Finds will be integrated with previous paleobiologic studies to reconstruct and interpret ecosystems and their changes. Structures and rock types documenting the end phases of continental glaciation and other major episodic sedimentations will also be described and interpreted. This project contributes to understanding the: (1) evolution of terrestrial and freshwater ecosystems and how they were affected by the end-Permian extinction, (2) abundance and diversity of terrestrial and aquatic arthropods at high latitudes, (3) paleogeographic distribution and evolution of vertebrates and invertebrates as recorded by trace and body fossils; and (3) response of landscapes to changes in climate.<br/><br/>In terms of broader impacts, this project will provide an outstanding introduction to field research for graduate and undergraduate students, and generate related opportunities for several undergraduates. It will also stimulate exchange of ideas among research and primarily undergraduate institutions. Novel outreach activities are also planned to convey Earth history to the general public, including a short film on the research process and products, and paintings by a professional scientific illustrator of Permo-Traissic landscapes and ecosystems. | POLYGON((159.3 -76.59,159.542 -76.59,159.784 -76.59,160.026 -76.59,160.268 -76.59,160.51 -76.59,160.752 -76.59,160.994 -76.59,161.236 -76.59,161.478 -76.59,161.72 -76.59,161.72 -76.811,161.72 -77.032,161.72 -77.253,161.72 -77.474,161.72 -77.695,161.72 -77.916,161.72 -78.137,161.72 -78.358,161.72 -78.579,161.72 -78.8,161.478 -78.8,161.236 -78.8,160.994 -78.8,160.752 -78.8,160.51 -78.8,160.268 -78.8,160.026 -78.8,159.784 -78.8,159.542 -78.8,159.3 -78.8,159.3 -78.579,159.3 -78.358,159.3 -78.137,159.3 -77.916,159.3 -77.695,159.3 -77.474,159.3 -77.253,159.3 -77.032,159.3 -76.811,159.3 -76.59)) | POINT(160.51 -77.695) | false | false | ||||||||||||
Collaborative Research: Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores
|
0739583 0739512 0739496 |
2009-07-15 | Walker, Sally; Bowser, Samuel; Miller, Molly; Furbish, David | 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. | 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)) | POINT(163.66667 -77.516665) | false | false | ||||||||||||
Paleoatmospheric Krypton and Xenon Abundances from Trapped Air in Polar Ice as Indicators of Past Mean Ocean Temperature
|
0538630 |
2009-04-01 | Severinghaus, Jeffrey P. | No dataset link provided | 0538630<br/>Severinghaus<br/>This award supports a project to produce the first record of Kr/N2 in the paleo-atmosphere as measured in air bubbles trapped in ice cores. These measurements may be indicative of past variations in mean ocean temperature. Knowing the mean ocean temperature in the past will give insight into past variations in deep ocean temperature, which remain poorly understood. Deep ocean temperature variations are important for understanding the mechanisms of climate change. Krypton is highly soluble in water, and its solubility varies with temperature, with higher solubilities at colder water temperatures. A colder ocean during the last glacial period would therefore hold more krypton than today's ocean. Because the total amount of krypton in the ocean-atmosphere system is constant, the increase in the krypton inventory in the glacial ocean should cause a resultant decrease in the atmospheric inventory of krypton. The primary goal of this work is to develop the use of Kr/N2 as an indicator of paleo-oceanic mean temperature. This will involve improving the analytical technique for the Kr/N2 measurement itself, and measuring the Kr/N2 in air bubbles in ice from the last glacial maximum (LGM) and the late Holocene in the Vostok and GISP2 ice cores. This provides an estimate of LGM mean ocean temperature change, and allows for a comparison between previous estimates of deep ocean temperature during the LGM. The Vostok ice core is ideal for this purpose because of the absence of melt layers, which compromise the krypton and xenon signal. Another goal is to improve precision on the Xe/N2 measurement, which could serve as a second, independent proxy of ocean temperature change. A mean ocean temperature time series during this transition may help to explain these observations. Additionally, the proposed work will measure the Kr/N2 from marine isotope stage (MIS) 3 in the GISP2 ice core. Knowing the past ocean temperature during MIS 3 will help to constrain sea level estimates during this time period. The broader impacts of the proposed work: are that it will provide the first estimate of the extent and timing of mean ocean temperature change in the past. This will help to constrain previously proposed mechanisms of climate change involving large changes in deep ocean temperature. This project will also support the education of a graduate student. The PI gives interviews and talks to the media and public about climate change, and the work will enhance these outreach activities. Finally, the work will occur during the International Polar Year (IPY), and will underscore the unique importance of the polar regions for understanding the global atmosphere and ocean system. | None | None | false | false | |||||||||||
Boron in Antarctic granulite-facies rocks: under what conditions is boron retained in the middle crust?
|
0228842 |
2009-03-10 | Grew, Edward |
|
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the role and fate of Boron in high-grade metamorphic rocks of the Larsemann Hills region of Antarctica. Trace elements provide valuable information on the changes sedimentary rocks undergo as temperature and pressure increase during burial. One such element, boron, is particularly sensitive to increasing temperature because of its affinity for aqueous fluids, which are lost as rocks are buried. Boron contents of unmetamorphosed pelitic sediments range from 20 to over 200 parts per million, but rarely exceed 5 parts per million in rocks subjected to conditions of the middle and lower crust, that is, temperatures of 700 degrees C or more in the granulite-facies, which is characterized by very low water activities at pressures of 5 to 10 kbar (18-35 km burial). Devolatization reactions with loss of aqueous fluid and partial melting with removal of melt have been cited as primary causes for boron depletion under granulite-facies conditions. Despite the pervasiveness of both these processes, rocks rich in boron are locally found in the granulite-facies, that is, there are mechanisms for retaining boron during the metamorphic process. The Larsemann Hills, Prydz Bay, Antarctica, are a prime example. More than 20 lenses and layered bodies containing four borosilicate mineral species crop out over a 50 square kilometer area, which thus would be well suited for research on boron-rich granulite-facies metamorphic rocks. <br/><br/>While most investigators have focused on the causes for loss of boron, this work will investigate how boron is retained during high-grade metamorphism. Field observations and mapping in the Larsemann Hills, chemical analyses of minerals and their host rocks, and microprobe age dating will be used to identify possible precursors and deduce how the precursor materials recrystallized into borosilicate rocks under granulite-facies conditions. The working hypothesis is that high initial boron content facilitates retention of boron during metamorphism because above a certain threshold boron content, a mechanism "kicks in" that facilitates retention of boron in metamorphosed rocks. For example, in a rock with large amounts of the borosilicate tourmaline, such as stratabound tourmalinite, the breakdown of tourmaline to melt could result in the formation of prismatine and grandidierite, two borosilicates found in the Larsemann Hills. This situation is rarely observed in rocks with modest boron content, in which breakdown of tourmaline releases boron into partial melts, which in turn remove boron when they leave the system. Stratabound tourmalinite is associated with manganese-rich quartzite, phosphorus-rich rocks and sulfide concentrations that could be diagnostic for recognizing a tourmalinite protolith in a highly metamorphosed complex where sedimentary features have been destroyed by deformation. Because partial melting plays an important role in the fate of boron during metamorphism, our field and laboratory research will focus on the relationship between the borosilicate units, granite pegmatites and other granitic intrusives. The results of our study will provide information on cycling of boron at deeper levels in the Earth's crust and on possible sources of boron for granites originating from deep-seated rocks.<br/><br/>An undergraduate student will participate in the electron microprobe age-dating of monazite and xenotime as part of a senior project, thereby integrating the proposed research into the educational mission of the University of Maine. In response to a proposal for fieldwork, the Australian Antarctic Division, which maintains Davis station near the Larsemann Hills, has indicated that they will support the Antarctic fieldwork. | POLYGON((76 -69.3,76.05 -69.3,76.1 -69.3,76.15 -69.3,76.2 -69.3,76.25 -69.3,76.3 -69.3,76.35 -69.3,76.4 -69.3,76.45 -69.3,76.5 -69.3,76.5 -69.32,76.5 -69.34,76.5 -69.36,76.5 -69.38,76.5 -69.4,76.5 -69.42,76.5 -69.44,76.5 -69.46,76.5 -69.48,76.5 -69.5,76.45 -69.5,76.4 -69.5,76.35 -69.5,76.3 -69.5,76.25 -69.5,76.2 -69.5,76.15 -69.5,76.1 -69.5,76.05 -69.5,76 -69.5,76 -69.48,76 -69.46,76 -69.44,76 -69.42,76 -69.4,76 -69.38,76 -69.36,76 -69.34,76 -69.32,76 -69.3)) | POINT(76.25 -69.4) | false | false | |||||||||||
Collaborative Research of Earth's Largest Icebergs
|
0229546 |
2008-09-19 | 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 | 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. | POINT(-178 -78) | POINT(-178 -78) | false | false | ||||||||||||
Gneiss Dome architecture: Investigation of Form and Process in the Fosdick Mountains, W. Antarctica
|
0338279 |
2008-07-09 | Siddoway, Christine; Teyssier, Christian |
|
This project will study migmatite domes found in the Fosdick Mountains of the Ford Ranges, western Marie Byrd Land, Antarctica. This area offers unique, three-dimensional exposures that may offer new insight into dome formation, which is a fundamental process of mountain building. These domes are derived from sedimentary and plutonic protoliths that are complexly interfolded at decimeter to kilometer scales. Preliminary findings from geobarometry and U-Pb monazite dating of anatexite suggest that peak metamorphism was underway at 105 Ma at crustal depths of ~25 km, followed by decompression as the Fosdick dome was emplaced to 16-17 km, or possibly as low as 8.5 km, in the crust by 99 Ma. Near-isothermal conditions were maintained during ascent, favorable for producing substantial volumes of melt through biotite-dehydration melting. This dome has been interpreted as a product of extensional exhumation. This is a viable interpretation from the regional standpoint, because the dome was emplaced in mid-Cretaceous time during the rapid onset of divergent tectonics along the proto- Pacific margin of Gondwana. However, the complex internal structures of the Fosdick Mountains have yet to be considered and may be more consistent with alternative intepretations such as upward extrusion within a contractional setting or lateral flow within a transcurrent attachment zone. This proposal is for detailed structural analysis, paired with geothermobarometry and geochronology, to determine the flow behavior and structural style that produced the internal architecture of the Fosdick dome. The results will improve our general understanding of the role of gneiss domes in transferring material and heat during mountain-building, and will characterize the behavior of the middle crust during a time of rapid transition from divergent to convergent tectonics along the active margin of Gondwana. In terms of broader impacts, this work will train undergraduate and graduate students, and involve them as collaborators in the development of curricular materials. It will also foster mentoring relationships between graduate and undergraduate students. | POLYGON((-157 -75,-155.3 -75,-153.6 -75,-151.9 -75,-150.2 -75,-148.5 -75,-146.8 -75,-145.1 -75,-143.4 -75,-141.7 -75,-140 -75,-140 -75.3,-140 -75.6,-140 -75.9,-140 -76.2,-140 -76.5,-140 -76.8,-140 -77.1,-140 -77.4,-140 -77.7,-140 -78,-141.7 -78,-143.4 -78,-145.1 -78,-146.8 -78,-148.5 -78,-150.2 -78,-151.9 -78,-153.6 -78,-155.3 -78,-157 -78,-157 -77.7,-157 -77.4,-157 -77.1,-157 -76.8,-157 -76.5,-157 -76.2,-157 -75.9,-157 -75.6,-157 -75.3,-157 -75)) | POINT(-148.5 -76.5) | false | false | |||||||||||
Collaborative Research: Mechanics of Dry-Land Calving of Ice Cliffs
|
0233823 0230338 |
2008-07-02 | Pettit, Erin; Hallet, Bernard; Fountain, Andrew | No dataset link provided | This award supports a comprehensive study of land-based polar ice cliffs. Through field measurements, modeling, and remote sensing, the physics underlying the formation of ice cliffs at the margin of Taylor Glacier in the McMurdo Dry Valleys will be investigated. At three sites, measurements of ice deformation and temperature fields near the cliff face will be combined with existing energy balance data to quantify ice-cliff evolution over one full seasonal cycle. In addition, a small seismic network will monitor local "ice quakes" associated with calving events. Numerical modeling, validated by the field data, will enable determination of the sensitivity of ice cliff evolution to environmental variables. There are both local and global motivations for studying the ice cliffs of Taylor Glacier. On a global scale, this work will provide insight into the fundamental processes of calving and glacier terminus A better grasp of ice cliff processes will also improve boundary conditions required for predicting glaciers' response to climate change. Locally, the Taylor Glacier is an important component of the McMurdo Dry Valleys landscape and the results of this study will aid in defining ecologically-important sources of glacial meltwater and will lead to a better understanding of moraine formation at polar ice cliffs. This study will help launch the career of a female scientist, will support one graduate student, and provide experiential learning experiences for two undergraduates. The post-doctoral researcher will also use this research in the curriculum of a wilderness science experiential education program for high school girls. | POLYGON((162.132 -77.73,162.1495 -77.73,162.167 -77.73,162.1845 -77.73,162.202 -77.73,162.2195 -77.73,162.237 -77.73,162.2545 -77.73,162.272 -77.73,162.2895 -77.73,162.307 -77.73,162.307 -77.7303,162.307 -77.7306,162.307 -77.7309,162.307 -77.7312,162.307 -77.7315,162.307 -77.7318,162.307 -77.7321,162.307 -77.7324,162.307 -77.7327,162.307 -77.733,162.2895 -77.733,162.272 -77.733,162.2545 -77.733,162.237 -77.733,162.2195 -77.733,162.202 -77.733,162.1845 -77.733,162.167 -77.733,162.1495 -77.733,162.132 -77.733,162.132 -77.7327,162.132 -77.7324,162.132 -77.7321,162.132 -77.7318,162.132 -77.7315,162.132 -77.7312,162.132 -77.7309,162.132 -77.7306,162.132 -77.7303,162.132 -77.73)) | POINT(162.2195 -77.7315) | false | false | |||||||||||
Collaborative Proposal: Interactive Effects of UV Radiation and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross See Phaeocystis Blooms
|
0127022 |
2008-06-12 | Jeffrey, Wade H.; Neale, Patrick |
|
Ultraviolet radiation influences the dynamics of plankton processes in the near-surface waters of most aquatic ecosystems. In particular, the Southern Ocean is affected in the austral spring period when biologically damaging ultraviolet radiation is enhanced by ozone depletion. While progress has been made in estimating the quantitative impact of ultraviolet radiation on bacteria and phytoplankton in the Southern Ocean, some important issues remain to be resolved. Little is known about responses in systems dominated by the colonial haptophyte Phaeocystis antarctica, which dominates spring blooms in a polyna that develops in the southern Ross Sea. The Ross Sea is also of interest because of the occurrence of open water at a far southerly location in the spring, well within the ozone hole, and continuous daylight, with implications for the regulation of DNA repair. A number of studies suggest that vertical mixing can significant modify the impact of ultraviolet radiation in the Southern Ocean and elsewhere. However, there are limited measurements of turbulence intensity in the surface layer and measurements have not been integrated with parallel studies of ultraviolet radiation effects on phytoplankton and bacterioplankton. To address these issues, this collaborative study will focus on vertical mixing and the impact of ultraviolet radiation in the Ross Sea. The spectral and temporal responses of phytoplankton and bacterioplankton to ultraviolet radiation will be characterized in both laboratory and solar incubations. These will lead to the definition of biological weighting functions and response models capable of predicting the depth and time distribution of ultraviolet radiation impacts on photosynthesis, bacterial incorporation and DNA damage in the surface layer. Diel sampling will measure depth-dependent profiles of DNA damage, bacterial incorporation, photosynthesis and fluorescence parameters over a 24 h cycle. Sampling will include stations with contrasting wind-driven mixing and stratification as the polyna develops. The program of vertical mixing measurements is optimized for the typical springtime Ross Sea situation in which turbulence of intermediate intensity is insufficient to mix the upper layer thoroughly in the presence of stabilizing influences like solar heating and/or surface freshwater input from melting ice. Fine-scale vertical density profiles will be measured with a free-fall CTD unit and the profiles will be used to directly estimate large-eddy scales by determining Thorpe scales. Eddy scales and estimated turbulent diffusivities will be directly related to surface layer effects, and used to generate lagrangian depth-time trajectories in models of ultraviolet radiation responses in the surface mixed layer. The proposed research will be the first in-depth study of ultraviolet radiation effects in the Ross Sea and provide a valuable comparison with previous work in the Weddell-Scotia Confluence and Palmer Station regions. It will also enhance the understanding of vertical mixing processes, trophic interactions and biogeochemical cycling in the Ross Sea. | POLYGON((-177.639 -43.5676,-143.1091 -43.5676,-108.5792 -43.5676,-74.0493 -43.5676,-39.5194 -43.5676,-4.9895 -43.5676,29.5404 -43.5676,64.0703 -43.5676,98.6002 -43.5676,133.1301 -43.5676,167.66 -43.5676,167.66 -46.99877,167.66 -50.42994,167.66 -53.86111,167.66 -57.29228,167.66 -60.72345,167.66 -64.15462,167.66 -67.58579,167.66 -71.01696,167.66 -74.44813,167.66 -77.8793,133.1301 -77.8793,98.6002 -77.8793,64.0703 -77.8793,29.5404 -77.8793,-4.9895 -77.8793,-39.5194 -77.8793,-74.0493 -77.8793,-108.5792 -77.8793,-143.1091 -77.8793,-177.639 -77.8793,-177.639 -74.44813,-177.639 -71.01696,-177.639 -67.58579,-177.639 -64.15462,-177.639 -60.72345,-177.639 -57.29228,-177.639 -53.86111,-177.639 -50.42994,-177.639 -46.99877,-177.639 -43.5676)) | POINT(-4.9895 -60.72345) | false | false | |||||||||||
Physiological and Molecular Mechanisms of Stress Tolerance in a Polar Insect
|
0337656 |
2008-06-06 | Denlinger, David; Lee, Richard | No dataset link provided | Polar terrestrial environments are often described as deserts, where water availability is recognized as one of the most important limits on the distribution of terrestrial organisms. In addition, prolonged low winter temperatures threaten survival, and summer temperatures challenge organisms with extensive diel variations and rapid transitions from freezing to desiccating conditions. Global warming has further impacted the extreme thermal and hydric conditions experienced by Antarctic terrestrial plant and arthropod communities, especially as a result of glacial retreat along the Antarctic Peninsula. This research will focus on thermal and hydric adaptations in the terrestrial midge, Belgica antarctica, the largest and most southerly holometabolous insect living in this challenging and changing environment. <br/>Overwintering midge larvae encased in the frozen substrate must endure desert-like conditions for more than 300 days since free water is biologically unavailable as ice. During the summer, larvae may be immersed in melt water or outwash from penguin colonies and seal wallows, in addition to saltwater splash. Alternatively, the larvae may be subjected to extended periods of desiccation as their microhabitats dry out. Due to their small size, relative immobility and the patchiness of suitable microhabitats, larvae may thus be subjected to stresses that include desiccation, hypo- or hyperosmotic conditions, high salinity exposure, and anoxia for extended periods. Research efforts will focus in three areas relevant to the stress tolerance mechanisms operating in these midges:(1) obtaining a detailed characterization of microclimatic conditions experienced by B. antarctica, especially those related to thermal and hydric diversity, both seasonally and among microhabitat types in the vicinity of Palmer Station, Antarctica; (2) examining the effects of extreme fluctuations in water availability and effects on physiological and molecular responses - to determine if midge larvae utilize the mechanism of cryoprotective dehydration for winter survival, and if genes encoding heat shock proteins and other genes are upregulated in larval responses to dehydration and rehydration; (3) investigating the dietary transmission of cryoprotectants from plant to insect host, which will test the hypothesis that midge larvae acquire increased resistance to desiccation and temperature stress by acquiring cryoprotectants from their host plants. <br/>This project will provide outreach to both elementary and secondary educators and their students. The team will include a teacher who will benefit professionally by full participation in the research, and will also assist in providing outreach to other teachers and their students. From Palmer Station, the field team will communicate daily research progress by e-mail supplemented with digital pictures with teachers and their elementary students to stimulate interest in an Antarctic biology and scientific research. These efforts will be supplemented with presentations at local schools and national teacher meetings, and by publishing hands-on, inquiry-based articles related to cryobiology and polar biology in education journals. Furthermore, the principal investigators will maintain major commitments to training graduate students and postdoctoral scholars, as well as undergraduate students by providing extended research experience that includes publication of scientific papers and presentations at national meetings. | POLYGON((-64.1 -64.75,-64.085 -64.75,-64.07 -64.75,-64.055 -64.75,-64.04 -64.75,-64.025 -64.75,-64.01 -64.75,-63.995 -64.75,-63.98 -64.75,-63.965 -64.75,-63.95 -64.75,-63.95 -64.757,-63.95 -64.764,-63.95 -64.771,-63.95 -64.778,-63.95 -64.785,-63.95 -64.792,-63.95 -64.799,-63.95 -64.806,-63.95 -64.813,-63.95 -64.82,-63.965 -64.82,-63.98 -64.82,-63.995 -64.82,-64.01 -64.82,-64.025 -64.82,-64.04 -64.82,-64.055 -64.82,-64.07 -64.82,-64.085 -64.82,-64.1 -64.82,-64.1 -64.813,-64.1 -64.806,-64.1 -64.799,-64.1 -64.792,-64.1 -64.785,-64.1 -64.778,-64.1 -64.771,-64.1 -64.764,-64.1 -64.757,-64.1 -64.75)) | POINT(-64.025 -64.785) | false | false | |||||||||||
Collaborative Research: Sloccum Glider in Western Antarctic Peninsula Continental Shelf Waters Pilot Study
|
0701232 |
2008-06-03 | Martinson, Douglas; Kerfoot, John | No dataset link provided | The Antarctic Peninsula (AP) is characterized by (1) the most rapid recent regional (winter) warming (5.35 times global mean), (2) a loss of nearly all its perennial sea ice cover on its western margin, and (3) 87% of the glaciers in retreat, contributing to global sea level rise. An ability to understand this change depends upon researchers' ability to better understand the underlying sources of this change and their driving mechanisms. Despite intensive efforts, the western AP (WAP) is chronically under-sampled. Therefore developing a capability to maintain a sustained in situ presence is a high scientific priority. The current proposal addresses this critical need through 2 objectives: (1) establish the feasibility of a Slocum Webb ocean glider to enable real-time high resolution data-adaptive polar oceanographic research; (2) address a critical question involving the regional climate change by measuring the ocean heat budget within a grid containing 14 years of ship-based ocean snapshots. This will involve the launch of the glider during the PAL-LTER austral summer research cruise, where it will fly the full along-shore distance of the LTER sample grid to be recovered at the southern extreme when the ship arrives there later in the summer. The glider will provide nearly continuous ocean property (temperature, salinity and pressure) coverage over this distance.<br/><br/>Intellectual merit. The proposed activity will involve state of the art sampling methodology that will revolutionize the ability to address climate change and other scientific issues requiring sampling densities that could not be achieved by research vessels. Specifically, the adaptive sampling capability of the glider will be used to alter its course allowing identification of routes by which the source waters of the ocean heat (and nutrients) enter the continental shelf region, while the near-continuous sampling will provide a diagnosis of how well standard shipborne stations close the heat budget. Resources are adequate for this study due to heavy leveraging by the availability of the Rutgers SLOCUM Web glider, glider control center and participation of the team of experts that flew the first such glider.<br/><br/>Broader Impacts. The proposed activity will advance discovery and understanding of the WAP responses to climate variability, to study the intricate feedback mechanisms associated with this variability and to better understand the chemical and physical processes associated with climate change. The data will be made available across the World Wide Web as it is collected, almost in real time, a potential bonanza for scientists during the upcoming International Polar Year, for classroom instruction and general outreach. Society will ultimately benefit from the improved knowledge of how climate change elsewhere in the world is impacting the unique ecosystem of the Antarctic, and driving glacial melt (sea level rise), among its other influences. | POLYGON((-72 -64,-71.2 -64,-70.4 -64,-69.6 -64,-68.8 -64,-68 -64,-67.2 -64,-66.4 -64,-65.6 -64,-64.8 -64,-64 -64,-64 -64.4,-64 -64.8,-64 -65.2,-64 -65.6,-64 -66,-64 -66.4,-64 -66.8,-64 -67.2,-64 -67.6,-64 -68,-64.8 -68,-65.6 -68,-66.4 -68,-67.2 -68,-68 -68,-68.8 -68,-69.6 -68,-70.4 -68,-71.2 -68,-72 -68,-72 -67.6,-72 -67.2,-72 -66.8,-72 -66.4,-72 -66,-72 -65.6,-72 -65.2,-72 -64.8,-72 -64.4,-72 -64)) | POINT(-68 -66) | false | false | |||||||||||
Investigating Iceberg Evolution During Drift and Break-Up: A Proxy for Climate-Related Changes in Antarctic Ice Shelves
|
0540915 |
2007-08-16 | Scambos, Ted; Bohlander, Jennifer; Bauer, Rob; Yermolin, Yevgeny; Thom, Jonathan | 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. | 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)) | POINT(-47.83505 -56.8641) | false | false | ||||||||||||
A 45-Y Hindcast of Antarctic Surface Mass Balance Using Polar MM5
|
0337948 |
2007-08-02 | Bromwich, David; Monaghan, Andrew |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
SGER: Basement Sill, Antarctica: Constraints from its PGE Abundance Patterns and Isotopic Compositions on Magma Source Characteristics and Crystallization Processes
|
0603729 |
2007-08-02 | Mukasa, Samuel | No dataset link provided | This Small Grant for Exploratory Research supports measurement of PGE abundances and Hf, Nd, Sr and Pb isotopic ratios of the Basement Sill and Dais Intrusion lobe of the Ferrar Magmatic Province, Antarctica. This province played a key role in the breakup of Gondwanaland. Models to be tested are magma production by plume activity versus decompression melting in a fossil subduction zone. The PGE data will also be used to evaluate the behavior of volatiles during magma crystallization, which other evidence indicates may have reached saturation. The samples to be studied were collected during the NSF-sponsored, Magmatic Field Laboratory Workshop held in Antarctica in 2005. This study's results will be compliled with complementary data from other attendees to develop a new multidisciplinary model of Ferrar magmatism.<br/><br/>The broader impacts fo this work include international collaboration and informal science education through public outreach to K12 students. | POLYGON((161.2 -77.5029,161.26 -77.5029,161.32 -77.5029,161.38 -77.5029,161.44 -77.5029,161.5 -77.5029,161.56 -77.5029,161.62 -77.5029,161.68 -77.5029,161.74 -77.5029,161.8 -77.5029,161.8 -77.52511,161.8 -77.54732,161.8 -77.56953,161.8 -77.59174,161.8 -77.61395,161.8 -77.63616,161.8 -77.65837,161.8 -77.68058,161.8 -77.70279,161.8 -77.725,161.74 -77.725,161.68 -77.725,161.62 -77.725,161.56 -77.725,161.5 -77.725,161.44 -77.725,161.38 -77.725,161.32 -77.725,161.26 -77.725,161.2 -77.725,161.2 -77.70279,161.2 -77.68058,161.2 -77.65837,161.2 -77.63616,161.2 -77.61395,161.2 -77.59174,161.2 -77.56953,161.2 -77.54732,161.2 -77.52511,161.2 -77.5029)) | POINT(161.5 -77.61395) | false | false | |||||||||||
Melting and Calving of Antarctic Ice Shelves
|
0233303 |
2007-07-09 | Jacobs, Stanley | No dataset link provided | 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. | None | None | false | false | |||||||||||
Internal Stratigraphy and Basal Conditions at the Margins ofActive Ice Streams of the Siple Coast, Antarctica
|
9725882 |
2007-07-06 | Raymond, Charles; Nereson, Nadine A. |
|
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. | 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)) | POINT(-140.02095 -81.7603) | false | false | |||||||||||
Collaborative Research: Digital Optical Imaging of Ice Cores for Curation and Scientific Applications
|
0230149 |
2007-06-04 | McGwire, Kenneth C. | No dataset link provided | This award supports the development of novel methods for digital image analysis of glacial ice cores that are stored at the National Ice Core Laboratory (NICL) in Denver, Colorado. Ice cores are a critical source of information on how Earth has changed over time, since indicators of local climate (snow accumulation, temperature), regional characteristics (wind-blown materials such as sea salt, dust and pollen), global processes (e.g., CO2, methane), and even extraterrestrial influences (cosmogenic isotopes) are stored in the ice on a common time scale. This project will develop a high-resolution optical scanning system for laboratory curation of ice core images, internet-based search and retrieval capabilities, a digital image analysis system specifically for ice core studies, and methods to integrate ice core image analysis with other dating methods. These tools will be developed and tested in conjunction with scientific investigations of NICL holdings. Optical scanning and analysis tools will improve understanding of the historical development of the ice collected from a particular location and will help to resolve challenges such as ice that has lost stratigraphic order through flow processes. <br/>By providing permanent online digital archives of ice core images, this project will greatly improve the documentation and availability of ice core data while reducing time and costs for subsequent scientific investigations. Using the internet, ice core scientists will be able to determine the appropriateness of specific NICL holdings for various scientific studies. By optically scanning ice cores as they are processed at NICL, any researcher will be able to examine an ice core in similar detail to the few investigators who were fortunate enough to observe it before modifications from sampling and storage. Re-examination of cores could be done decades later by anyone at any location, which is not possible now because only the interpretation of the original observer is recorded. Integration of digital image data into ice core analysis will speed discovery, allow collaborative interpretation, and enhance consistency of analysis to improve ice core dating, identification of melt layers, location of flow disturbances, and more. The equipment will be housed at NICL and will be available to the broad community, improving scientific infrastructure.<br/>This work will also have numerous broader impacts. Ice core science addresses fundamental questions of human interest related to global warming, abrupt climate change, biogeochemical cycling, and more. The principal investigators broadly disseminate their scientific findings through numerous outlets, ranging from meeting with government officials, chairing and serving on NRC panels, writing popular books and articles, publishing in scientific literature, teaching classes, talking to civic groups, and appearing on radio and television. The results from ice core analyses have directly informed policymakers and will continue to do so. Thus, by improving ice core science, this projectl will benefit society. | None | None | false | false | |||||||||||
Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)
|
0230197 |
2007-01-01 | Blankenship, Donald D.; Fastook, James L.; Corr, Hugh F. J.; Holt, John W.; Morse, David L.; Vaughan, David G.; Young, Duncan A. | 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. | 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)) | POINT(0 -89.999) | false | false | ||||||||||||
High-Resolution Modeling of Surface Topography, Ice Motion, and Mass Balance in the Lambert Glacial Basin using Radar Remote Sensing and GIS Techniques
|
0126149 |
2006-08-15 | Liu, Hongxing; Jezek, Kenneth | This award supports a project to characterize the morphology, ice motion velocity and mass balance of Lambert Glacier, Antarctica using state-of-the-art remote sensing and GIS techniques. Lambert Glacier is the largest ice stream in the world. Because of its size, it plays a fundamental role in the study of glacial dynamics and mass budget in response to present and future climate changes. Along with the bedrock topography and ice thickness data derived from airborne radio echo soundings and snow accumulation data compiled from ground-based measurements, the dynamic behavior and mass balance of the Lambert glacial basin in a Geographic Information Systems (GIS) environment will be examined. Specific objectives are to: (1) Extract two-dimensional ice velocity field over the entire Lambert glacial basin using speckle matching and differential interferometric SAR (InSAR) techniques, and produce a full coverage of radar coherence map over the drainage basin. With the ice velocity data, calculate the strain rate field from the initiation areas of the ice stream onto the Amery Ice Shelf; (2) Derive high-resolution digital elevation model (DEM) over the Lambert glacial drainage basin using SAR stereo, differential interferometric SAR, and GLAS laser altimetry techniques. Based on the DEM, extract ice divides and ice flow directions, delineate the snow catchment basin, and calculate the balance deformation velocity and the basal shear stress; (3) Interpolate traverse ice thickness data collected by Australian and Russian airborne radio echo sounding surveys into a regular grid, and derive a regular grid of bedrock topography in combination with the DEM; (4) Integrate newly derived ice velocity and ice thickness data as well as snow accumulation rate data compiled from previous ground-based measurements into a geographic information system (GIS), and calculate the mass flux through the ice stream at the grounding lines and net mass balance throughout the drainage basin. With these new measurements and calculations derived from advanced remote sensing techniques, we will be able to improve our understanding of dynamic behavior and current mass balance status of the Lambert glacial basin, gain an insight on the relationship between ice mass change and the variation in regional and global climate at decadal scale, and provide an evaluation on the issue of whether the Lambert glacier basin is subject to surging in the context of future climate change. | None | None | false | false | ||||||||||||
Mass and Energy Fluxes Through Lake Vostok: Observations and Models
|
0088047 |
2006-01-03 | Bell, Robin; Tremblay, Bruno; Hohmann, Roland; Clarke, Garry; Studinger, Michael S. | No dataset link provided | 0088047<br/>Bell<br/><br/>This award supports a two year project to address fundamental questions about the mass and energy flux through Lake Vostok, a subglacial lake in East Antarctica, sealed beneath almost 4 kilometers of ice. The project will involve developing lake circulation models, complemented by the analysis of new ice penetrating radar data over the lake and surrounding regions. This project will help to accurately define the regions of melting and freezing within the lake and help to provide an improved estimate of the form of the lake. The combined data analysis and modeling effort will provide a critical framework for developing international plans to sample the waters of Lake Vostok for biota and to recover sediments from Lake Vostok for paleoclimate studies. | None | None | false | false | |||||||||||
Characterization of Climatic Events for the Last 2 x 103y through the Retrieval of Ice Cores from the Transantarctic Mountains, Antarctica
|
8411018 |
2004-08-26 | Frisic, David; Meese, Deb; Gow, Tony; Saltzman, Eric; Mayewski, Paul A.; Sowers, Todd A.; Welch, Kathy A.; Grootes, Pieter; Watson, M. Scott; Grootes, Peiter | Not available | None | None | false | false | ||||||||||||
Beryllium in Antarctic Ultrahigh-Temperature Granulite-Facies Rocks and its Role in Partial Melting of the Lower Continental Crust
|
0087235 |
2004-08-09 | Grew, Edward | No dataset link provided | 0087235<br/>Grew<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the role of beryllium in lower crustal partial melting events. The formation of granitic liquids by partial melting deep in the Earth's crust is one of the major topics of research in igneous and metamorphic petrology today. One aspect of this sphere of research is the beginning of the process, specifically, the geochemical interaction between melts and source rocks before the melt has left the source area. One example of anatexis in metamorphic rocks affected by conditions found deep in the Earth's crust is pegmatite in the Archean ultrahigh temperature granulite-facies Napier Complex of Enderby Land, East Antarctica. Peak conditions for this granulite-facies metamorphism are estimated to have reached nearly 1100 Degrees Celsius and 11 kilobar, that is, conditions in the Earth's lower crust in Archean time. The proposed research is a study of the Napier Complex pegmatites with an emphasis on the minerals and geochemistry of beryllium. This element, which is estimated to constitute 3 ppm of the Earth's upper crust, is very rarely found in any significant concentrations in metamorphic rocks subjected to conditions of the Earth's lower crust. Structural, geochronological, and mineralogical studies will be carried out to test the hypothesis that the beryllium pegmatites resulted from anatexis of their metapelitic host rocks during the ultrahigh-temperature metamorphic event in the late Archean. Host rocks will be analyzed for major and trace elements. Minerals will be analyzed by the electron microprobe for major constituents including fluorine and by the ion microprobe for lithium, beryllium and boron. The analytical data will be used to determine how beryllium and other trace constituents were extracted from host rocks under ultrahigh-temperature conditions and subsequently concentrated in the granitic melt, eventually to crystallize out in a pegmatite as beryllian sapphirine and khmaralite, minerals not found in pegmatites elsewhere. Mineral compositions and assemblages will be used to determine the evolution and conditions of crystallization and recrystallization of the pegmatites and their host rocks during metamorphic episodes following the ultrahigh-temperature event. Monazite will be analyzed for lead, thorium and uranium to date the ages of these events. Because fluorine is instrumental in mobilizing beryllium, an undergraduate student will study the magnesium fluorphosphate wagnerite in the pegmatites in order to estimate fluorine activity in the melt as part of a senior project. The results of the present project will provide important insights on the melting process in general and on the geochemical behavior of beryllium in particular under the high temperatures and low water activities characteristic of the Earth's lower crust. | POLYGON((42 -64,43.2 -64,44.4 -64,45.6 -64,46.8 -64,48 -64,49.2 -64,50.4 -64,51.6 -64,52.8 -64,54 -64,54 -64.4,54 -64.8,54 -65.2,54 -65.6,54 -66,54 -66.4,54 -66.8,54 -67.2,54 -67.6,54 -68,52.8 -68,51.6 -68,50.4 -68,49.2 -68,48 -68,46.8 -68,45.6 -68,44.4 -68,43.2 -68,42 -68,42 -67.6,42 -67.2,42 -66.8,42 -66.4,42 -66,42 -65.6,42 -65.2,42 -64.8,42 -64.4,42 -64)) | POINT(48 -66) | false | false | |||||||||||
Continuous High Resolution Ice-Core Chemistry using ICP-MS at Siple Dome
|
0126286 |
2004-04-19 | Lamorey, Gregg W.; McConnell, Joseph |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||||
Retrieval and Analysis of Extraterrestrial Particles from the Water Well at the South Pole Station, Antarctica
|
9316715 |
2002-01-01 | Taylor, Susan |
|
9316715 Taylor This award is for support to collect micrometeorites from the bottom of the new water well at South Pole Station, Antarctica. The large volume of firn and ice being melted provides the concentrating mechanism needed to collect large numbers of micrometeorites that occur in low concentrations in the ice. The first task of the project is to design a collection system to retrieve the micrometeorites from the bottom of the water well. The collector must be reliable, easy to operate, must collect all particles larger than 10 mm and should not contaminate the well's water quality. Following successful design and deployment of the collector, recovered particles will be catalogued and distributed to interested researchers. *** | None | None | false | false | |||||||||||
Collaborative Research: Seismic Traverse of the Byrd Subglacial Basin-Field Test
|
9222121 |
2002-01-01 | Bender, Michael; Dalziel, Ian W. |
|
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. | None | None | false | false | |||||||||||
Physical Properties of the Siple Dome Deep Ice Core
|
9526374 |
1997-01-01 | Alley, Richard |
|
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. | None | None | false | false |