[{"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": "Wannamaker, Philip; Hill, Graham", "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:\u003cbr/\u003eThis 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.\u003cbr/\u003e\u003cbr/\u003eTechnical Description:\u003cbr/\u003eThe 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": "2224611 Schofield, Oscar; 2026045 Schofield, Oscar", "bounds_geometry": "POLYGON((-79.65 -63.738,-77.9728 -63.738,-76.29560000000001 -63.738,-74.61840000000001 -63.738,-72.94120000000001 -63.738,-71.26400000000001 -63.738,-69.58680000000001 -63.738,-67.9096 -63.738,-66.2324 -63.738,-64.5552 -63.738,-62.878 -63.738,-62.878 -64.3683,-62.878 -64.9986,-62.878 -65.6289,-62.878 -66.25919999999999,-62.878 -66.8895,-62.878 -67.5198,-62.878 -68.1501,-62.878 -68.7804,-62.878 -69.41069999999999,-62.878 -70.041,-64.5552 -70.041,-66.2324 -70.041,-67.9096 -70.041,-69.5868 -70.041,-71.26400000000001 -70.041,-72.94120000000001 -70.041,-74.61840000000001 -70.041,-76.29560000000001 -70.041,-77.9728 -70.041,-79.65 -70.041,-79.65 -69.41069999999999,-79.65 -68.7804,-79.65 -68.1501,-79.65 -67.5198,-79.65 -66.8895,-79.65 -66.25919999999999,-79.65 -65.6289,-79.65 -64.9986,-79.65 -64.3683,-79.65 -63.738))", "dataset_titles": "Expedition Data of LMG2301; Expedition Data of NBP2113; Palmer LTER data in the Environmental Data Initiative Repository", "datasets": [{"dataset_uid": "200371", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG2301", "url": "https://www.rvdata.us/search/cruise/LMG2301"}, {"dataset_uid": "200370", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2113", "url": "https://www.rvdata.us/search/cruise/NBP2113"}, {"dataset_uid": "200367", "doi": "", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "Palmer LTER data in the Environmental Data Initiative Repository", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=PAL"}], "date_created": "Wed, 26 Jul 2023 00:00:00 GMT", "description": "The goal of all LTER sites is to conduct policy-relevant ecosystem research for questions that require tens of years of data and cover large geographical areas. The Palmer Antarctica Long Term Ecological Research (PAL-LTER) site has been in operation since 1990 and has been studying how the marine ecosystem west of the Antarctica Peninsula (WAP) is responding to a climate that is changing as rapidly as any place on the Earth. The study is evaluating how warming conditions and decreased ice cover leading to extended periods of open water are affecting many aspects of ecosystem function. The team is using combined cutting-edge approaches including yearly ship-based research cruises, small-boat weekly sampling, autonomous vehicles, animal biologging, oceanographic floats and seafloor moorings, manipulative lab-based process studies and modeling to evaluate both seasonal and annual ecosystem responses. These combined approaches are allowing for the study the ecosystem changes at scales needed to assess both short-term and long-term drivers. The study region also includes submarine canyons that are special regions of enhanced biological activity within the WAP. This research program is paired with a comprehensive education and outreach program promoting the global significance of Antarctic science and research. In addition to training for graduate and undergraduate students, they are using newly-developed Polar Literacy Principles as a foundation in a virtual schoolyard program that shares polar instructional materials and provides learning opportunities for K-12 educators. The PAL-LTER team is also leveraging the development of Out of School Time materials for afterschool and summer camp programs, sharing Palmer LTER-specific teaching materials with University, Museum, and 4-H Special Interest Club partners.\r\n\r\nPolar ecosystems are among the most rapidly changing on Earth. The Palmer LTER (PAL-LTER) program builds on three decades of coordinated research along the western side of the Antarctic Peninsula (WAP) to gain new mechanistic and predictive understanding of ecosystem changes in response to disturbances spanning long-term decadal (press) drivers and changes due to higher-frequency (pulse) drivers, such as large storms and extreme seasonal anomaly in sea ice cover. The influence of major natural climate modes that modulate variations in sea ice, weather, and oceanographic conditions to drive changes in ecosystem structure and function (e.g., El Nio Southern Oscillation and Southern Annular Mode) are being studied at multiple time scales from diel, seasonal, interannual, to decadal intervals, and space scalesfrom hemispheric to global scale investigated by remote sensing, the regional scales. Specifically, the team is evaluating how variability of physical properties (such as vertical and alongshore connectivity processes) interact to modulate biogeochemical cycling and community ecology in the WAP region. The study is providing an evaluation of ecosystem resilience and ecological responses to long-term press-pulse drivers and a decadal-level reversal in sea ice coverage. This program is providing fundamental understanding of population and biogeochemical responses for a marine ecosystem experiencing profound change.", "east": -62.878, "geometry": "POINT(-71.26400000000001 -66.8895)", "instruments": null, "is_usap_dc": true, "keywords": "SEA ICE; PLANKTON; PELAGIC; West Antarctic Shelf; R/V NBP; OCEAN MIXED LAYER; COMMUNITY DYNAMICS; PENGUINS; R/V LMG", "locations": "West Antarctic Shelf", "north": -63.738, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Schofield, Oscar; Steinberg, Deborah", "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": "EDI; R2R", "science_programs": "LTER", "south": -70.041, "title": "LTER: Ecological Response and Resilience to \u201cPress-Pulse\u201d Disturbances and a Recent Decadal Reversal in Sea Ice Trends Along the West Antarctic Peninsula", "uid": "p0010426", "west": -79.65}, {"awards": "1841879 Aydin, Murat; 1841858 Souney, Joseph; 1841844 Steig, Eric", "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. \u003cbr/\u003e\u003cbr/\u003eHercules 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.\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": -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": "2218402 Fegyveresi, John", "bounds_geometry": "POLYGON((-115 -85.5,-113.5 -85.5,-112 -85.5,-110.5 -85.5,-109 -85.5,-107.5 -85.5,-106 -85.5,-104.5 -85.5,-103 -85.5,-101.5 -85.5,-100 -85.5,-100 -85.65,-100 -85.8,-100 -85.95,-100 -86.1,-100 -86.25,-100 -86.4,-100 -86.55,-100 -86.7,-100 -86.85,-100 -87,-101.5 -87,-103 -87,-104.5 -87,-106 -87,-107.5 -87,-109 -87,-110.5 -87,-112 -87,-113.5 -87,-115 -87,-115 -86.85,-115 -86.7,-115 -86.55,-115 -86.4,-115 -86.25,-115 -86.1,-115 -85.95,-115 -85.8,-115 -85.65,-115 -85.5))", "dataset_titles": "Multi-Site Brittle Ice Data and Measurements", "datasets": [{"dataset_uid": "601786", "doi": "10.15784/601786", "keywords": "Antarctica; Brittle Ice; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Glaciology; Ice Core; Ice Core Records; Ice Core Records; Physical Properties; Simple Dome; Siple Dome; South Pole; SPICEcore; Subgrain Boundaries; WAIS Divide", "people": "Barnett, Samantha; Fegyveresi, John", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Multi-Site Brittle Ice Data and Measurements", "url": "https://www.usap-dc.org/view/dataset/601786"}], "date_created": "Mon, 19 Sep 2022 00:00:00 GMT", "description": "Brittle ice has been a long-standing and consistent challenge for ice-coring projects, complicating sampling, and introducing the possibility of contamination. Several procedures have been tested to reduce brittle damage to recovered cores, but many come with high monetary and time costs. Our background research suggests that bubble size and c-axis fabric are primary drivers for brittleness and are predictable from site characteristics, enabling prediction of brittleness before coring. We propose to improve understanding of the mechanisms involved in brittle ice onset and behavior, through targeted investigations of various ice physical properties, in carefully selected samples across multiple ice-core sites, in order to guide the upcoming Hercules Dome ice-core drilling and science communities. This project will involve collaboration between Northern Arizona University, the National Science Foundation Ice Core Facility, and Pennsylvania State University, and will utilize new and existing ice-core physical properties data from several previously drilled sites. This is a high-risk, low-cost project that could yield important results, and thus is well-suited for EAGER funding. This proposal utilizes existing ice cores and does not require Antarctic fieldwork. ", "east": -100.0, "geometry": "POINT(-107.5 -86.25)", "instruments": null, "is_usap_dc": true, "keywords": "Hercules Dome Ice Core; West Antarctica; Grain Statistics; LABORATORY; Ice Core; ICE SHEETS; Physical Properties; Brittle Ice; C-Axis Fabric; Bubble; ICE CORE RECORDS", "locations": "West Antarctica", "north": -85.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fegyveresi, John", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Hercules Dome Ice Core", "south": -87.0, "title": "EAGER: Constraining the Expected Brittle-ice Behavior for the Hercules Dome Ice-core Site.", "uid": "p0010378", "west": -115.0}, {"awards": "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": "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": "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"}], "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. \u003cbr/\u003e\u003cbr/\u003eUnderstanding 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.\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": -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": "USAP-DC", "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": "2149518 Fudge, Tyler", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations", "datasets": [{"dataset_uid": "601854", "doi": "10.15784/601854", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Fudge, T. J.; Kirkpatrick, Liam; Carter, Austin; Marks Peterson, Julia; Shackleton, Sarah", "repository": "USAP-DC", "science_program": "COLDEX", "title": "ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations", "url": "https://www.usap-dc.org/view/dataset/601854"}], "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "Interpreting highly compressed portions of ice cores is increasingly important as projects target climate records in basal ice, and in ice recovered from blue-ice areas. This project will integrate precisely co-registered electrical conductivity measurements (ECM), hyperspectral imaging, laser ablation ICPMS measurements of impurities, and ice physical properties to investigate sub-cm chemical and physical variations in polar ice. This work will establish to what extent annual layer interpretations of polar ice with sub-cm layering is possible. Critical to resolving thin ice layers is understanding the across-core variations which may obscure or distort the vertical layering. Analyses will be focused on samples from WAIS Divide, SPICEcore, and GISP2, which have well established seasonal cycles that yielded benchmark timescales, as well a large diameter ice core from a blue ice area.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE CORE RECORDS; Ice Core", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Fegyveresi, John M", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Testing Next Generation Measurement Techniques for Reconstruction of Paleoclimate Archives from Thin or Disturbed Ice Cores Sections", "uid": "p0010365", "west": -180.0}, {"awards": "1443637 Zakon, Harold", "bounds_geometry": null, "dataset_titles": "Evolutionary analysis of transient receptor potential (TRP) channels in notothenioid fishes; Functional characterization of temperature activated ion channels from Antarctic fishes; TagSeq tissue specific expression data for Antarctic Harpagifer antarcticus and tropical African cichlid Astatotilapia (Haplochromis) burtoni", "datasets": [{"dataset_uid": "200292", "doi": "10.18738/T8/NXGNEI", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "Evolutionary analysis of transient receptor potential (TRP) channels in notothenioid fishes", "url": "https://doi.org/10.18738/T8/NXGNEI"}, {"dataset_uid": "200293", "doi": "", "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "TagSeq tissue specific expression data for Antarctic Harpagifer antarcticus and tropical African cichlid Astatotilapia (Haplochromis) burtoni", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA758918"}, {"dataset_uid": "601695", "doi": "10.15784/601695", "keywords": "Antarctica; Notothenioid; Southern Ocean", "people": "York, Julia", "repository": "USAP-DC", "science_program": null, "title": "Functional characterization of temperature activated ion channels from Antarctic fishes", "url": "https://www.usap-dc.org/view/dataset/601695"}], "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "We studied the molecular evolution and physiology of two types of ion channels: voltage gated potassium channels and transient receptor potential (TRP) channels. We also studied the molecular evolution and expression of water-passing channels, the aquaporins, to determine if these show signs of evolutionary change in notothenioids. \r\n\r\nWe noted apparent amino acid substitutions at a number of sites in a muscle-expressing\r\npotassium channel (Kv1.3). We were surprised to find that although the AAs at these sites\r\nappeared highly conserved in teleosts and even in tetrapods, reverting them singly, in pairs,\r\nor all together back to the ancestral condition had no effect on the biophysical properties of\r\nthe channels that we measured (voltage-sensitivity; rate of activation) at room temperature\r\nas well as over a range of temperatures down to 4oC.\r\n\r\nThe results for the TRP channels and aquaporins can be accessed in their publications. York and Zakon (2022) in Genome Biology and Evolution, and two forthcoming papers.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; USAP-DC; USA/NSF; FIELD INVESTIGATION; AMD; FISHERIES", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Zakon, Harold", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "Texas Data Repository", "repositories": "GenBank; Texas Data Repository; USAP-DC", "science_programs": null, "south": null, "title": "Analysis of Voltage-gated Ion Channels in Antarctic Fish", "uid": "p0010331", "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 I-188 Field Season Report 2022-2023; Allan Hills ice water stable isotope record for dD, d18O; COLDEX Raw MARFA Ice Penetrating Radar data; NSF COLDEX 2022-23 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets; NSF COLDEX 2023-24 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets; 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", "datasets": [{"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": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Kurbatov, Andrei V.; Mayewski, Paul A.; Introne, Douglas; Severinghaus, Jeffrey P.; Higgins, John; Brook, Edward", "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": "601854", "doi": "10.15784/601854", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Fudge, T. J.; Kirkpatrick, Liam; Carter, Austin; Marks Peterson, Julia; Shackleton, Sarah", "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": "601878", "doi": "10.15784/601878", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Cryosphere; Methane", "people": "Severinghaus, Jeffrey P.; Marks Peterson, Julia; Brook, Edward; Kalk, Michael; Hishamunda, Valens; Shackleton, Sarah", "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": "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": "601826", "doi": "10.15784/601826", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Horlings, Annika; Epifanio, Jenna; Conway, Howard; Shaya, Margot; Manos, John-Morgan", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills I-188 Field Season Report 2022-2023", "url": "https://www.usap-dc.org/view/dataset/601826"}, {"dataset_uid": "601824", "doi": "10.15784/601824", "keywords": "Allan Hills; Antarctica; Coldex; Cryosphere", "people": "Higgins, John; Marks Peterson, Julia; Epifanio, Jenna; Mayo, Emalia; Goverman, Ashley; Jayred, Michael; Morton, Elizabeth; Banerjee, Asmita; Hudak, Abigail; Manos, John-Morgan; Carter, Austin; Shackleton, Sarah; Brook, Edward J.", "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": "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": "601819", "doi": "10.15784/601819", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Shackleton, Sarah; Carter, Austin; Nesbitt, Ian; Zajicek, Anna; Morton, Elizabeth; Kuhl, Tanner; Epifanio, Jenna; Morgan, Jacob; Higgins, John", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2019-2020 Allan Hills Field Report", "url": "https://www.usap-dc.org/view/dataset/601819"}, {"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": "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": "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": "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": "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": "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": "601768", "doi": null, "keywords": "Antarctica; East Antarctic Plateau", "people": "Kerr, Megan; Ng, Gregory; Greenbaum, Jamin; Buhl, Dillon; Chan, Kristian; Kempf, Scott D.; Young, Duncan A.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "COLDEX Raw MARFA Ice Penetrating Radar data", "url": "https://www.usap-dc.org/view/dataset/601768"}, {"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Kurbatov, Andrei V.; Higgins, John; Severinghaus, Jeffrey P.; Brook, Edward; Introne, Douglas; Mayewski, Paul A.", "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"}], "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.\r\n\r\nKnowledge 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.", "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": "OPR", "repositories": "OPR; Texas Data Repository; University Digital Conservancy; USAP-DC", "science_programs": "COLDEX", "south": -90.0, "title": "Center for Oldest Ice Exploration", "uid": "p0010321", "west": -180.0}, {"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\u003cbr/\u003eThe 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.\u003cbr/\u003e\u003cbr/\u003ePart II: Technical summary\u003cbr/\u003eIn 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.\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": -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": "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": "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. We 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, we 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. \r\n\r\nTo test our hypothesis, we will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) We will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. We will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) We 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) We 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. We will integrate these data 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.\r\n", "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": "1744946 Gettelman, Andrew; 1744965 Diao, Minghui", "bounds_geometry": "POINT(166.7 -77.8)", "dataset_titles": "AWARE_Campaign_Data; Diao, M. (2020). VCSEL 1 Hz Water Vapor Data Version 1.0 for NSF SOCRATES Campaign; Diao, M. (2020). VCSEL 25 Hz Water Vapor Data Version 1.0 for NSF SOCRATES Campaign", "datasets": [{"dataset_uid": "200225", "doi": "10.26023/V925-2H41-SD0F", "keywords": null, "people": null, "repository": "UCAR", "science_program": null, "title": "Diao, M. (2020). VCSEL 25 Hz Water Vapor Data Version 1.0 for NSF SOCRATES Campaign", "url": "https://data.eol.ucar.edu/dataset/290779"}, {"dataset_uid": "200224", "doi": "10.26023/KFSD-Y8DQ-YC0D", "keywords": null, "people": null, "repository": "UCAR", "science_program": null, "title": "Diao, M. (2020). VCSEL 1 Hz Water Vapor Data Version 1.0 for NSF SOCRATES Campaign", "url": "https://data.eol.ucar.edu/dataset/552.051"}, {"dataset_uid": "200223", "doi": "10.17632/x6n4r3yxb2.1", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "AWARE_Campaign_Data", "url": "http://dx.doi.org/10.17632/x6n4r3yxb2.1"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "Ice supersaturation plays a key role in cloud formation and evolution, and it determines the partitioning among ice, liquid and vapor phases. Over the Southern Ocean and Antarctica, the transition between mixed-phase and ice clouds significantly impacts the radiative effects of clouds. Remote regions such as the Antarctica and Southern Ocean historically have been under-sampled by in-situ observations, especially by airborne observations. Even though more attention has been given to the cloud microphysical properties over these regions, the distribution and characteristics of ice supersaturation and its role in the current and future climate have not been fully investigated at the higher latitudes in the Southern Hemisphere. One of the main objectives of this study is to analyze observations from three recent major field campaigns sponsored by NSF and DOE, which provide intensive in-situ, airborne measurements over the Southern Ocean and ground-based observations at McMurdo station in Antarctica.\r\n\r\nThis project will analyze aircraft-based and ground-based observations over the Southern Ocean and Antarctica, and compare the observations with the Community Earth System Model Version 2 (CESM2) simulations. The focus will be on the observations of ice supersaturation and the relative humidity distribution in mixed-phase and ice clouds, as well as their relationship with cloud micro- and macrophysical properties. Observations will be compared to CESM2 simulations to elucidate model biases. Surface radiation and the precipitation budget at the McMurdo station will be quantified and compared against the CESM2 simulations to improve the fidelity of the representation of Antarctic climate (and climate prediction over Antarctica). Results from our research will be released to the community for improving the understanding of cloud radiative effects and the mass transport of water in the high southern latitudes. Comparisons between the simulations and observations will provide valuable information for improving the next generation CESM model. Two education/outreach projects will be carried out by PI Diao at San Jose State University (SJSU), including a unique undergraduate student research project with hands-on laboratory work on an airborne instrument, and an outreach program that uses social media to broadcast news on polar research to the public.", "east": 166.7, "geometry": "POINT(166.7 -77.8)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; CLIMATE MODELS; USA/NSF; SNOW; Amd/Us; USAP-DC; Chile; ATMOSPHERIC WATER VAPOR; ATMOSPHERIC TEMPERATURE; Antarctica; Southern Ocean; AMD", "locations": "Antarctica; Southern Ocean; Chile", "north": -77.8, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Diao, Minghui; Gettelman, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e MODELS \u003e CLIMATE MODELS", "repo": "UCAR", "repositories": "Publication; UCAR", "science_programs": null, "south": -77.8, "title": "Collaborative Research: Ice Supersaturation over the Southern Ocean and Antarctica, and its Role in Climate", "uid": "p0010209", "west": 166.7}, {"awards": "1914698 Hansen, Samantha; 1914767 Winberry, Paul; 1914668 Aschwanden, Andy; 1914743 Becker, Thorsten", "bounds_geometry": "POLYGON((90 -65,99 -65,108 -65,117 -65,126 -65,135 -65,144 -65,153 -65,162 -65,171 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,171 -90,162 -90,153 -90,144 -90,135 -90,126 -90,117 -90,108 -90,99 -90,90 -90,90 -87.5,90 -85,90 -82.5,90 -80,90 -77.5,90 -75,90 -72.5,90 -70,90 -67.5,90 -65))", "dataset_titles": "East Antarctic Seismicity from different Automated Event Detection Algorithms; Full Waveform Ambient Noise Tomography for East Antarctica", "datasets": [{"dataset_uid": "601763", "doi": "10.15784/601763", "keywords": "Ambient Noise; Antarctica; East Antarctica; Geoscientificinformation; Seismic Tomography; Seismology", "people": "Hansen, Samantha; Emry, Erica", "repository": "USAP-DC", "science_program": null, "title": "Full Waveform Ambient Noise Tomography for East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601763"}, {"dataset_uid": "601762", "doi": "10.15784/601762", "keywords": "Antarctica; Geoscientificinformation; Machine Learning; Seismic Event Detection; Seismology; Seismometer", "people": "Walter, Jacob; Ho, Long; Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "East Antarctic Seismicity from different Automated Event Detection Algorithms", "url": "https://www.usap-dc.org/view/dataset/601762"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "Part I: Nontechnical \u003cbr/\u003eEarths warming climate has the potential to drive widespread collapse of glaciers and ice sheets across the planet, driving global sea-level rise. Understanding both the rate and magnitude of such changes is essential for predicting future sea-level and how it will impact infrastructure and property. Collapse of the ice sheets of Antarctica has the potential to raise global sea-level by up to 60 meters. However, not all regions of Antarctica are equally suspectable to collapse. One area with potential for collapse is the Wilkes Subglacial Basin in East Antarctica, a region twice the size of California\u0027s Central Valley. Geologic evidence indicates that the ice-sheet in this region has retreated significantly in response to past global warming events. While the geologic record clearly indicates ice-sheets in this area are vulnerable, the rate and magnitude of any future retreat will be influenced significantly by geology of the region. Constraining the geologic controls on the stability of the ice-sheets of the Wilkes Subglacial Basin remains challenging since the ice-sheet hides the geology beneath kilometers of ice. As a step in understanding the potential for future ice loss in the Wilkes Subglacial Basin this project will conduct geophysical analysis of existing data to better constrain the geology of the region. These results will constrain new models designed to understand the tectonics that control the behavior of the ice-sheets in the region. These new models will highlight the geological properties that exert the most significant control on the future of the ice-sheets of the Wilkes Subglacial Basin. Such insights are critical to guide future efforts aimed at collecting in-situ observations needed to more fully constrain Antarctica\u0027s potential for future sea-level. \u003cbr/\u003e\u003cbr/\u003e Part II: Technical Description \u003cbr/\u003eIn polar environments, inward-sloping marine basins are susceptible to an effect known as the marine ice-sheet instability (MISI): run-away ice stream drainage caused by warm ocean water eroding the ice shelf from below. The magnitude and time-scale of the ice-sheet response strongly depend on the physical conditions along the ice-bed interface, which are, to a first order, controlled by the tectonic evolution of the basin. Topography, sedimentology, geothermal heat flux, and mantle viscosity all play critical roles in ice-sheet stability. However, in most cases, these solid-Earth parameters for regions susceptible to the MISI are largely unknown. One region with potential susceptibility to MISI is the Wilkes Subglacial Basin of East Antarctica. The project will provide an integrated investigation of the Wilkes Subglacial Basin, combining geophysical analyses with both mantle flow and ice-sheet modeling to understand the stability of the ice sheet in this region, and the associated potential sea level rise. The work will be focused on four primary objectives: (1) to develop an improved tectonic model for the region based on existing seismic observations as well as existing geophysical and geological data; (2) to use the new tectonic model and seismic data to estimate the thermal, density, and viscosity structure of the upper mantle and to develop a heat flow map for the WSB; (3) to simulate mantle flow and to assess paleotopography based on our density and viscosity constraints; and (4) to assess ice-sheet behavior by modeling (a) past ice-sheet stability using our paleotopography estimates and (b) future ice-sheet stability using our heat flow and mantle viscosity estimates. Ultimately, the project will generate improved images of the geophysical structure beneath the WSB that will allow us to assess the geodynamic origin for this region and to assess the influence of geologic parameters on past, current, and future ice-sheet behavior. These efforts will then highlight areas and geophysical properties that should be the focus of future geophysical deployments.", "east": 180.0, "geometry": "POINT(135 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "TECTONICS; AMD; Wilkes Subglacial Basin; ICE SHEETS; USA/NSF; Amd/Us; SEISMOLOGICAL STATIONS; SEISMIC SURFACE WAVES; East Antarctica; USAP-DC", "locations": "East Antarctica; Wilkes Subglacial Basin", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Becker, Thorsten; Binder, April; Hansen, Samantha; Aschwanden, Andy; Winberry, Paul", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes\r\nSubglacial Basin (RESISSt)", "uid": "p0010204", "west": 90.0}, {"awards": "1844793 Aksoy, Mustafa", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic Firn Brightness Temperatures Measured by AMSR2 and SSMIS (Concordia, Vostok, and the Entire Ice Sheet)); In-Situ Density, Temperature, Grain Size, and Layer Thickness data for the Antarctic Ice Sheet", "datasets": [{"dataset_uid": "601550", "doi": "10.15784/601550", "keywords": "Antarctica; Antarctic Ice Sheet; Satellite; Vostok", "people": "Kaurejo, Dua; Aksoy, Mustafa; Kar, Rahul", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Firn Brightness Temperatures Measured by AMSR2 and SSMIS (Concordia, Vostok, and the Entire Ice Sheet))", "url": "https://www.usap-dc.org/view/dataset/601550"}, {"dataset_uid": "601551", "doi": "10.15784/601551", "keywords": "Antarctica; Antarctic Ice Sheet", "people": "Aksoy, Mustafa; Kaurejo, Dua; Kar, Rahul", "repository": "USAP-DC", "science_program": null, "title": "In-Situ Density, Temperature, Grain Size, and Layer Thickness data for the Antarctic Ice Sheet", "url": "https://www.usap-dc.org/view/dataset/601551"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "This project will test the hypothesis that physical and thermal properties of Antarctic firn--partially compacted granular snow in an intermediate stage between snow and glacier ice--can be remotely measured from space. Although these properties, such as internal temperature, density, grain size, and layer thickness, are highly relevant to studies of Antarctic climate, ice-sheet dynamics, and mass balance, their measurement currently relies on sparse in-situ surveys under challenging weather conditions. Sensors on polar-orbiting satellites can observe the entire Antarctic every few days during their years-long lifetime. Consequently, the approaches developed in this study, when coupled with the advancing technologies of small and low-cost CubeSats, aim to contribute to Antarctic science and lead to cost-effective, convenient, and accurate long-term analyses of the Antarctic system while reducing the human footprint on the continent. Moreover, the project will be solely based on publicly-available datasets; thus, while contributing to interdisciplinary undergraduate and graduate research and education at the grantee\u0027s institution, the project will also encourage engagement of citizen scientists through its website.\r\n\r\nThe overarching goal of this project is to characterize Antarctic firn layers in terms of their thickness, physical temperature, density, and grain size through multi-frequency microwave radiometer measurements from space. Electromagnetic penetration depth changes with frequency in ice; thus, multi-frequency radiometers are able to profile firn layer properties versus depth. To achieve its objective, the project will utilize the Global Precipitation Measurement (GPM) satellite constellation as a single multi-frequency microwave radiometer system with 11 frequency channels observing the Antarctic Ice Sheet. Archived in-situ measurements of Antarctic firn density, grain size, temperature, and layer thickness will be collected and separated into training and test datasets. Microwave emissions simulated using the training data will be compared to GPM constellation measurements to evaluate and improve state-of-the-art forward microwave emission models. Based on these models, the project will develop numerical retrieval algorithms for the thermal and physical properties of Antarctic firn. Results of retrievals will be validated using the test dataset, and uncertainty and error analyses will be conducted. Lastly, changes in the thermal and physical characteristics of Antarctic firn will be examined through long-term retrieval studies exploiting GPM constellation measurements.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; FIRN; Amd/Us; USA/NSF; ICE SHEETS; SNOW DENSITY; Multi-Frequency Passive Remote Sensing; University At Albany; USAP-DC; SNOW/ICE TEMPERATURE; SATELLITES; SNOW/ICE", "locations": "University At Albany", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aksoy, Mustafa", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Characterization of Antarctic Firn by Multi-Frequency Passive Remote Sensing from Space", "uid": "p0010206", "west": -180.0}, {"awards": "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.\r\n\r\nPhysical 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": "1246416 Stephen, Ralph; 1246151 Bromirski, Peter", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.4,-175 -77.8,-175 -78.2,-175 -78.6,-175 -79,-175 -79.4,-175 -79.8,-175 -80.2,-175 -80.6,-175 -81,-175.5 -81,-176 -81,-176.5 -81,-177 -81,-177.5 -81,-178 -81,-178.5 -81,-179 -81,-179.5 -81,180 -81,179 -81,178 -81,177 -81,176 -81,175 -81,174 -81,173 -81,172 -81,171 -81,170 -81,170 -80.6,170 -80.2,170 -79.8,170 -79.4,170 -79,170 -78.6,170 -78.2,170 -77.8,170 -77.4,170 -77,171 -77,172 -77,173 -77,174 -77,175 -77,176 -77,177 -77,178 -77,179 -77,-180 -77))", "dataset_titles": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ; Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "datasets": [{"dataset_uid": "200207", "doi": "10.7914/SN/XH_2014", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ", "url": "http://www.fdsn.org/networks/detail/XH_2014/"}, {"dataset_uid": "200209", "doi": "10.7283/58E3-GA46", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "url": "https://doi.org/10.7283/58E3-GA46"}], "date_created": "Thu, 15 Apr 2021 00:00:00 GMT", "description": "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.\n\r\nUnderstanding and being able to anticipate changes in the glaciological regime of the Ross Ice Shelf (RIS) and West Antarctic Ice Sheet (WAIS) are key to improving sea level rise projections due to ongoing ice mass loss in West Antarctica. The fate of the WAIS is a first-order climate change and global societal issue for this century and beyond that affects coastal communities and coastal infrastructure globally. \r\n\r\nIce shelf--ocean interactions include impacts from tsunami, ocean swell (10-30s period), and very long period ocean waves that impact ice shelves and produce vibrations that induce a variety of seismic signals detected by seismometers buried in the ice shelf surface layer, called firn. To study the wave-induced vibrations in the RIS, an extensive seismic array was deployed from Nov. 2014 to Nov. 2016. This unique seismometer array deployment on an ice shelf made continuous observations of the response of the RIS to ocean wave impacts from ocean swell and very long period waves. An extensive description of the project motivation and background (including photos and videos of the deployment operations), and list of published studies of analyses of the seismic data collected by this project, are available at the project website https://iceshelfvibes.ucsd.edu. \r\n\r\nTwo types of seismic signals detected by the seismic array are most prevalent: flexural gravity waves (plate waves) and icequakes (signals analogous to those from earthquakes but from fracturing of the ice). \r\nLong period ocean waves flex the ice shelf at the same period as the ocean waves, with wave energy at periods greater than ocean swell more efficient at coupling energy into flexing the ice shelf. Termed flexural gravity waves or plate waves (Chen et al., 2018), their wave-induced vibrations can reach 100\u2019s of km from the ice edge where they are excited, with long period wave energy propagating in the water layer below the shelf coupled with the ice shelf flexure. Flexural gravity waves at very long periods (\u003e 300 s period), such as from tsunami impacts (Bromirski et al., 2017), can readily reach grounding zones and may play a role in long-term grounding zone evolution. \r\nSwell-induced icequake activity was found to be most prevalent at the shelf front during the austral summer (January \u2013 March) when seasonal sea ice is absent and the associated damping of swell by sea ice is minimal (Chen et al., 2019). \r\n\r\nIn addition to the seismic array, a 14 station GPS (global positioning system) array was installed during seismic data retrieval and station servicing operations in October-November 2015. The GPS stations, co-located with seismic stations, extended from the shelf front southward to about 415 km at interior station RS18. Due to logistical constraints associated with battery weight during installation, only one station (at DR10) operated year-round. The GPS data collected give a detailed record of changes in iceflow velocity that are in close agreement with the increasing velocity estimates approaching the shelf front from satellite observations. Importantly, the year-round data at DR10 show an unprecedented seasonal cycle of changes in iceflow velocity, with a speed-up in northward (seaward) ice flow during Jan.-May and then a velocity decrease from June-Sep. (returning to the long-term mean flow velocity). This annual ice flow velocity change cycle has been attributed in part to seasonal changes in ice shelf mass (thinning, reducing buttressing) due to melting at the RIS basal (bottom) surface from intrusion of warmer ocean water (Klein et al., 2020). ", "east": 170.0, "geometry": "POINT(177.5 -79)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; GLACIER MOTION/ICE SHEET MOTION; USAP-DC; Amd/Us; AMD; USA/NSF; Iris; Ross Ice Shelf", "locations": "Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Bromirski, Peter; Gerstoft, Peter; Stephen, Ralph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "IRIS", "repositories": "IRIS; UNAVCO", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations", "uid": "p0010169", "west": -175.0}, {"awards": "0639286 Halzen, Francis; 0937462 Halzen, Francis; 2042807 Halzen, Francis; 1600823 Halzen, Francis", "bounds_geometry": "POINT(-180 -90)", "dataset_titles": "Amanda 7 Year Data Set; IceCube data releases", "datasets": [{"dataset_uid": "601438", "doi": "10.15784/601438", "keywords": "Amanda-ii; Antarctica; Neutrino; Neutrino Candidate Events; Neutrino Telescope; South Pole", "people": "Riedel, Benedikt; Halzen, Francis", "repository": "USAP-DC", "science_program": "IceCube", "title": "Amanda 7 Year Data Set", "url": "https://www.usap-dc.org/view/dataset/601438"}, {"dataset_uid": "200374", "doi": "", "keywords": null, "people": null, "repository": "IceCube", "science_program": null, "title": "IceCube data releases", "url": "https://icecube.wisc.edu/science/data-releases/"}], "date_created": "Wed, 07 Apr 2021 00:00:00 GMT", "description": "This award funds the continued management and operations (M\u0026O) of the IceCube Neutrino Observatory (ICNO) located at the South Pole Station. The core team of researchers and engineers maintain the existing ICNO infrastructure at the South Pole and home institution, guaranteeing an uninterrupted stream of scientifically unique, high-quality data. The M\u0026O activities are built upon eight highly successful years of managing the overall ICNO operations after the start of science operations in 2008. Construction of ICNO was supported by NSF\u0027s Major Research Equipment and Facilities Construction (MREFC) account and was completed on schedule and within budget in 2010. Effective coordination of efforts by the core M\u0026O personnel and efforts by personnel within the IceCube Collaboration has yielded significant increases in the performance of this cubic-kilometer detector over time. The scientific output from the IceCube Collaboration during the past five years has been outstanding. \u003cbr/\u003e\u003cbr/\u003eThe broader impacts of the ICNO/M\u0026O activities are strong, involving postdoctoral, graduate, and (in some cases) undergraduate students in the day-today operation \u0026 calibration of the neutrino detector. The extraordinary physics results recently produced by ICNO and its extraordinary location at South Pole have a high potential to excite the imagination of high school children and the public in general at a national and international level.\u003cbr/\u003e\u003cbr/\u003eThe current ICNO/M\u0026O effort produces better energy and angular resolution information about detected neutrino events, has more efficient data filters and more accurate detector simulations, and enables continuous software development for systems that are needed to acquire and analyze data. This has produced data acquisition and data management systems with high robustness, traceability, and maintainability. The current ICNO/M\u0026O effort includes: (1) resources for both distributed and centrally managed activities, and (2) additional accountability mechanisms for \"in-kind\" and institutional contributions. Both are necessary to ensure that the detector maintains its capability to produce quality scientific data at the level required to achieve the detector\u0027s scientific discovery objectives. Recent ICNO discoveries of cosmic high-energy neutrinos (some reaching energies close to and over 2.5 PeV) and oscillating atmospheric neutrinos in a previously unexplored energy range from 10 to 60 GeV became possible because of the \"state-of-the-art\" detector configuration, excellently supported infrastructure, and cutting-edge science analyses. The ICNO has set limits on Dark Matter annihilations, made precision measurements of the angular distribution of cosmic ray muons, and characterized in detail physical properties of the Antarctic 2.5-km thick ice sheet at South Pole. The discovery of high-energy cosmic neutrinos by IceCube with a flux at the level anticipated for those associated with high-energy gamma- and cosmic-ray accelerators brightens the prospect for identifying the sources of the highest energy particles.", "east": -180.0, "geometry": "POINT(-180 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e ICECUBE", "is_usap_dc": true, "keywords": "USA/NSF; South Pole; OBSERVATORIES; Amd/Us; AMD; GLACIERS/ICE SHEETS; Icecube; Neutrino; USAP-DC", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "Halzen, Francis; Karle, Albrecht", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e OBSERVATORIES", "repo": "USAP-DC", "repositories": "IceCube; USAP-DC", "science_programs": "IceCube", "south": -90.0, "title": "Management and Operations of the IceCube Neutrino Observatory 2021-2026", "uid": "p0010168", "west": -180.0}, {"awards": "1643301 Gerbi, Christopher; 1643353 Christianson, Knut", "bounds_geometry": null, "dataset_titles": "ImpDAR: an impulse radar processor; SeidarT; South Pole Lake ApRES Radar; South Pole Lake GNSS; South Pole Lake: ground-based ice-penetrating radar", "datasets": [{"dataset_uid": "200244", "doi": " https://zenodo.org/badge/latestdoi/382590632", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "SeidarT", "url": "https://github.com/UMainedynamics/SeidarT"}, {"dataset_uid": "601502", "doi": "10.15784/601502", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GNSS; GPS; GPS Data; South Pole; Subglacial Lakes", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake GNSS", "url": "https://www.usap-dc.org/view/dataset/601502"}, {"dataset_uid": "200202", "doi": "http://doi.org/10.5281/zenodo.3833057", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "ImpDAR: an impulse radar processor", "url": "https://www.github.com/dlilien/ImpDAR"}, {"dataset_uid": "200203", "doi": "", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "South Pole Lake: ground-based ice-penetrating radar", "url": "http://hdl.handle.net/1773/45293"}, {"dataset_uid": "601503", "doi": "10.15784/601503", "keywords": "Antarctica; Apres; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; South Pole; Subglacial Lakes; Vertical Velocity", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake ApRES Radar", "url": "https://www.usap-dc.org/view/dataset/601503"}], "date_created": "Wed, 17 Feb 2021 00:00:00 GMT", "description": "This award supports a project to develop software that will allow researchers considering seismic or radar field surveys to test, ahead of time, whether the data they plan to collect will have sufficient resolution to measure the natural variations in the mechanical properties of ice, which determine the response of flowing ice to changing climatic conditions. The mechanical properties of ice depend largely on the temperature and the orientation of the crystals that make up the ice. The most accurate method for measuring ice crystal orientation and temperature is through drilling and direct analysis of an ice core. However, this method is very costly, time-consuming, and limited in spatial coverage. Geophysical techniques, such as seismic and radar, can cover much more area, but we have little knowledge about the practical limitations of these techniques as they relate to calculating mechanical properties. This project addresses that knowledge gap through construction of a computational toolbox that will allow accurate assessment of the ability of geophysical surveys to image crystal orientation and ice temperature. Researchers can then use these tools to adjust the field survey plans to maximize the return on investment. By working to improve the efficiency and effectiveness of future geophysical work related to glacial flow, this proposal will improve scientists? ability to quantify sea-level variations within the larger context of climate change. The project includes building new user-friendly, publicly accessible software and instructional modules. The work will provide training for graduate and undergraduate students, who will play a role in research and develop instructional materials. \r\n\r\nIce viscosity, the resistance of ice to flow, exerts significant control over ice velocity. Therefore, mapping ice viscosity is important for understanding the current and future behavior of glaciers and ice sheets. To do so, scientists must determine the temperature and crystal orientation fabric throughout the ice. Seismic and radar techniques can survey large areas quickly, and thus are promising, yet not fully tested, methods to efficiently measure the thermal and mechanical structure of flowing ice. As part of this project, scientists will develop and use a computational framework to quantify the degree to which seismic and radar techniques can resolve the crystal orientation fabric and temperature of streaming ice, and then test how sensitive ice flow is to the attendant uncertainty. To meet these goals, a numerical toolbox will be built which will allow the glacier/ice stream geometry and physical properties (temperature, crystal orientation fabric, density and acidity) to be varied. The toolbox will be capable of both creating synthetic radar and seismic profiles through forward modeling and inverting synthetic profiles to allow evaluation of how well geophysical techniques can image the original thermal and mechanical structure. These simulated radar and seismic data will allow scientists to better quantify the influence of the variability in mechanical properties of the ice on flow velocities and patterns. The results of this work will guide planning for future field campaigns, making them more effective and efficient. This project does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; GLACIERS/ICE SHEETS; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; South Pole; USA/NSF; AMD; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; FIELD SURVEYS; Amd/Us", "locations": "South Pole; United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Gerbi, Christopher; Campbell, Seth; Vel, Senthil", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "GitHub", "repositories": "GitHub; Uni. Washington ResearchWorks Archive; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Computational Methods Supporting Joint Seismic and Radar Inversion for Ice Fabric and Temperature in Streaming Flow", "uid": "p0010160", "west": null}, {"awards": "1141411 Baker, Ian", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Laboratory Experiments with H2SO4-Doped Ice; The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "datasets": [{"dataset_uid": "600380", "doi": "10.15784/600380", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Physical Properties; Snow", "people": "Baker, Ian", "repository": "USAP-DC", "science_program": null, "title": "The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "url": "https://www.usap-dc.org/view/dataset/600380"}, {"dataset_uid": "601081", "doi": "10.15784/601081", "keywords": null, "people": "Hammonds, Kevin", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Experiments with H2SO4-Doped Ice", "url": "https://www.usap-dc.org/view/dataset/601081"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "This award supports a project to undertake a systematic examination of the effects of soluble impurities, particularly sulfuric acid, on the creep of polycrystalline ice as function of temperature, strain rate and impurity concentration. The working hypothesis is that soluble impurities will increase the flow rate of polycrystalline ice compared to high-purity ice, that this effect will be temperature dependent and that the impurities by affecting the re-crystallization and grain growth will change the fabric of the ice. Both H2SO4-doped and high-purity poly-crystalline ice will be produced by freezing sheets of ice, breaking them up, sieving the ice particles and then sintering them in a mold into fine-grained cylindrical specimens with at least ten grains across their diameter. The resulting microstructures (dislocation structure, grain size and shape, grain boundary character and micro-structural location of the acid) will be characterized using a variety of techniques including: optical microscopy, scanning electron microscopy, including secondary electron imaging, electron backscattered patterns, energy dispersive X-ray spectroscopy, electron channeling contrast imaging, and X-ray topography. The creep of both the H2SO4-doped and the high-purity polycrystalline ice will be undertaken at a range of temperatures and stresses. The ice?s response to the creep deformation (grain boundary sliding, dislocation motion, re-crystallization, grain boundary migration, impurity redistribution) will be studied using a combination of methods. The creep behavior will be modeled and related to the microstructure. Of particular interest is how impurities affect the activation energy for creep. The intellectual merit of the work is that it will lead to a better understanding of glacier ice and will enable glaciologists to model the influence of impurities on the flow and fabric development in polycrystalline ice. The broader impacts of the project include the knowledge that will be gained of the effects of impurities on the flow of ice which will allow paleoclimatologists to better interpret ice core data and will allow scientists developing predictive models to better address the flow of ice sheets under various climate change scenarios. The project will also lead to the education and training of a Ph.D. student, several undergraduates and some high school students. Results from the research will be published in refereed journals. Several undergraduates, typically two per year, will also perform the work. Dartmouth aggressively courts minority students at all degree levels, and we will seek women or minority group undergraduates for this project. The undergraduates will be supported by Dartmouth?s nationally-honored Women In Science Project or by REU funding. The undergraduates? research will integrate closely with the Ph.D. student?s studies. Hanover High School students will also be involved in the project and develop an educational kit to introduce students to the properties of ice. Results from the research will be published in refereed journals and presented at conferences.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; USAP-DC; SNOW/ICE; Amd/Us; LABORATORY; Antarctica; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "uid": "p0010133", "west": -180.0}, {"awards": "1543396 Christner, Brent; 1543441 Fricker, Helen; 1543453 Lyons, W. Berry; 1543405 Leventer, Amy; 1543347 Rosenheim, Brad; 1543537 Priscu, John", "bounds_geometry": "POLYGON((-163.611 -84.33543,-162.200034 -84.33543,-160.789068 -84.33543,-159.378102 -84.33543,-157.967136 -84.33543,-156.55617 -84.33543,-155.145204 -84.33543,-153.734238 -84.33543,-152.323272 -84.33543,-150.912306 -84.33543,-149.50134 -84.33543,-149.50134 -84.3659157,-149.50134 -84.3964014,-149.50134 -84.4268871,-149.50134 -84.4573728,-149.50134 -84.4878585,-149.50134 -84.5183442,-149.50134 -84.5488299,-149.50134 -84.5793156,-149.50134 -84.6098013,-149.50134 -84.640287,-150.912306 -84.640287,-152.323272 -84.640287,-153.734238 -84.640287,-155.145204 -84.640287,-156.55617 -84.640287,-157.967136 -84.640287,-159.378102 -84.640287,-160.789068 -84.640287,-162.200034 -84.640287,-163.611 -84.640287,-163.611 -84.6098013,-163.611 -84.5793156,-163.611 -84.5488299,-163.611 -84.5183442,-163.611 -84.4878585,-163.611 -84.4573728,-163.611 -84.4268871,-163.611 -84.3964014,-163.611 -84.3659157,-163.611 -84.33543))", "dataset_titles": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset; Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland; CTD data from Mercer Subglacial Lake and access borehole; Discrete bulk sediment properties data from Mercer Subglacial Lake; Isotopic data from Whillans Ice Stream grounding zone, West Antarctica; Mercer Subglacial Lake radiocarbon and stable isotope data ; Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995); Mercer Subglacial Lake (SLM) noble gas and isotopic data; Mercer Subglacial Lake water column viral metagenomic sequencing; Salsa sediment cores; Sediment porewater properties data from Mercer Subglacial Lake; Water column biogeochemical data from Mercer Subglacial Lake", "datasets": [{"dataset_uid": "601672", "doi": "10.15784/601672", "keywords": "Antarctica; Isotope; Mercer Subglacial Lake; Radiocarbon; Subglacial Lake", "people": "Venturelli, Ryan; Rosenheim, Brad", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake radiocarbon and stable isotope data ", "url": "https://www.usap-dc.org/view/dataset/601672"}, {"dataset_uid": "200212", "doi": "10.7283/PT0Q-JB95", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/PT0Q-JB95"}, {"dataset_uid": "200213", "doi": "10.7283/F7BB-JH05", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F7BB-JH05"}, {"dataset_uid": "200214", "doi": "10.7283/YW8Z-TK03", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/YW8Z-TK03"}, {"dataset_uid": "200215", "doi": "10.7283/C503-KS23", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/C503-KS23"}, {"dataset_uid": "200216", "doi": "10.7283/F8NH-CV04", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F8NH-CV04"}, {"dataset_uid": "200217", "doi": "10.7283/3JMY-Y504", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/3JMY-Y504"}, {"dataset_uid": "200282", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995)", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA790995"}, {"dataset_uid": "601472", "doi": "10.15784/601472", "keywords": "Antarctica; Bistatic Radar; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS Data; Greenland; Lake Whillans; Radar; Store Glacier; Whillans Ice Stream; WISSARD", "people": "Siegfried, Matthew; Bienert, Nicole; Schroeder, Dustin; Christoffersen, Poul; Dawson, Eliza; MacKie, Emma; Peters, Sean", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland", "url": "https://www.usap-dc.org/view/dataset/601472"}, {"dataset_uid": "200246", "doi": "", "keywords": null, "people": null, "repository": "OSU-MGR", "science_program": null, "title": "Salsa sediment cores", "url": "https://osu-mgr.org"}, {"dataset_uid": "200342", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Mercer Subglacial Lake water column viral metagenomic sequencing", "url": "https://www.ncbi.nlm.nih.gov/biosample/32811410"}, {"dataset_uid": "601664", "doi": "10.15784/601664", "keywords": "Antarctica; Gas; Geochemistry; Glacier; Glaciology; Mercer Subglacial Lake; Methane; SALSA; Sediment Core; West Antarctic Ice Sheet", "people": "Steigmeyer, August; Science Team, SALSA; Tranter, Martyn; Skidmore, Mark; Michaud, Alexander; Dore, John", "repository": "USAP-DC", "science_program": null, "title": "Sediment porewater properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601664"}, {"dataset_uid": "601663", "doi": "10.15784/601663", "keywords": "Antarctica; Carbon; Cell Counts; Geochemistry; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mercer Subglacial Lake; Microbes; Nutrients; SALSA; Stable Isotopes; Trace Elements; West Antarctic Ice Sheet", "people": "Skidmore, Mark; Science Team, SALSA; Li, Wei; Barker, Joel; Tranter, Martyn; Priscu, John; Steigmeyer, August; Hawkings, Jon; Dore, John", "repository": "USAP-DC", "science_program": null, "title": "Water column biogeochemical data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601663"}, {"dataset_uid": "601661", "doi": "10.15784/601661", "keywords": "Antarctica; Carbon; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Iron; Mercer Subglacial Lake; Mineralogy; Particle Size; Physical Properties; SALSA; Sediment Core; Sulfur; West Antarctic Ice Sheet", "people": "Dore, John; Hawkings, Jon; Science Team, SALSA; Venturelli, Ryan A; Skidmore, Mark; Tranter, Martyn; Michaud, Alexander; Campbell, Timothy", "repository": "USAP-DC", "science_program": null, "title": "Discrete bulk sediment properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601661"}, {"dataset_uid": "601498", "doi": "10.15784/601498", "keywords": "Antarctica; Mercer Subglacial Lake; Noble Gas", "people": "Lyons, W. Berry; Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake (SLM) noble gas and isotopic data", "url": "https://www.usap-dc.org/view/dataset/601498"}, {"dataset_uid": "601657", "doi": "10.15784/601657", "keywords": "Antarctica; Conductivity; CTD; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hot Water Drill; Mercer Subglacial Lake; Physical Properties; SALSA; Subglacial Lake; Temperature", "people": "Dore, John; Leventer, Amy; Rosenheim, Brad; Priscu, John", "repository": "USAP-DC", "science_program": null, "title": "CTD data from Mercer Subglacial Lake and access borehole", "url": "https://www.usap-dc.org/view/dataset/601657"}, {"dataset_uid": "601360", "doi": "10.15784/601360", "keywords": "Antarctica; Radiocarbon; Sediment; Whillans Ice Stream", "people": "Venturelli, Ryan A", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Isotopic data from Whillans Ice Stream grounding zone, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601360"}], "date_created": "Thu, 16 Jul 2020 00:00:00 GMT", "description": "The Antarctic subglacial environment remains one of the least explored regions on Earth. This project will examine the physical and biological characteristics of Subglacial Lake Mercer, a lake that lies 1200m beneath the West Antarctic Ice Sheet. This study will address key questions relating to the stability of the ice sheet, the subglacial hydrological system, and the deep-cold subglacial biosphere. The education and outreach component aims to widely disseminate results to the scientific community and to the general public through short films, a blog, and a website.\u003cbr/\u003e\u003cbr/\u003eSubglacial Lake Mercer is one of the larger hydrologically active lakes in the southern basin of the Whillans Ice Plain, West Antarctica. It receives about 25 percent of its water from East Antarctica with the remainder originating from West Antarctica, is influenced by drain/fill cycles in a lake immediately upstream (Subglacial Lake Conway), and lies about 100 km upstream of the present grounding line of the Ross Ice Shelf. This site will yield information on the history of the Whillans and Mercer Ice Streams, and on grounding line migration. The integrated study will include direct sampling of basal ice, water, and sediment from the lake in concert with surface geophysical surveys over a three-year period to define the hydrological connectivity among lakes on the Whillans Ice Plain and their flow paths to the sea. The geophysical surveys will furnish information on subglacial hydrology, aid the site selection for hot-water drilling, and provide spatial context for interpreting findings. The hot-water-drilled boreholes will be used to collect basal ice samples, provide access for direct measurement of subglacial physical, chemical, and biological conditions in the water column and sediments, and to explore the subglacial water cavities using a remotely operated vehicle equipped with sensors, cameras, and sampling equipment. Data collected from this study will address the overarching hypothesis \\\"Contemporary biodiversity and carbon cycling in hydrologically-active subglacial environments associated with the Mercer and Whillans ice streams are regulated by the mineralization and cycling of relict marine organic matter and through interactions among ice, rock, water, and sediments\\\". The project will be undertaken by a collaborative team of scientists, with expertise in microbiology, biogeochemistry, hydrology, geophysics, glaciology, marine geology, paleoceanography, and science communication.", "east": -149.50134, "geometry": "POINT(-156.55617 -84.4878585)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; Antarctica; ISOTOPES; Subglacial Lake; USAP-DC; VIRUSES; PALEOCLIMATE RECONSTRUCTIONS; BACTERIA/ARCHAEA; LABORATORY; Radiocarbon; Whillans Ice Stream; AMD; SALSA; ECOSYSTEM FUNCTIONS; RADIOCARBON; FIELD INVESTIGATION; ICE MOTION; Mercer Ice Stream; Amd/Us; USA/NSF; GLACIERS/ICE SHEETS", "locations": "Antarctica; Mercer Ice Stream; Whillans Ice Stream", "north": -84.33543, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Instrumentation and Support; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Rosenheim, Brad; Fricker, Helen; Priscu, John; Leventer, Amy; Dore, John; Lyons, W. Berry; Christner, Brent", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "GenBank; NCBI GenBank; OSU-MGR; UNAVCO; USAP-DC", "science_programs": null, "south": -84.640287, "title": "Collaborative Research: Subglacial Antarctic Lakes Scientific Access (SALSA): Integrated Study of Carbon Cycling in Hydrologically-active Subglacial Environments", "uid": "p0010119", "west": -163.611}, {"awards": "1643864 Talghader, Joseph", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": " Automated c-axis stage images of WDC-06A 420 vertical thin section from WAIS Divide, Antarctica", "datasets": [{"dataset_uid": "601254", "doi": "10.15784/601254", "keywords": "Antarctica; C-axis; Ice; Microscopy; Thin Sections", "people": "Talghader, Joseph; Mah, Merlin", "repository": "USAP-DC", "science_program": null, "title": " Automated c-axis stage images of WDC-06A 420 vertical thin section from WAIS Divide, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601254"}], "date_created": "Sat, 08 Feb 2020 00:00:00 GMT", "description": "This dataset comprises new photographs and measurements of a WAIS Divide vertical thin section, WDC-06A 420 VTS, previously prepared and measured by J. Fitzpatrick, D. E. Voigt, and R. Alley (dataset DOI: 10.7265/N5W093VM; http://www.usap-dc.org/view/dataset/609605) as part of a larger study of the WAIS Divide ice core (Fitzpatrick, J. et al, 2014, Physical properties of the WAIS Divide ice core, Journal of Glaciology, 60, 224, 1181-1198. (doi:10.3189/2014JoG14J100). These images were taken as a design test of our new automated lightweight c-axis analyzer, dubbed ALPACA, which implements the ice fabric analysis functionality of the Wilen system used by Fitzpatrick et al. in an easily-portable, field-deployable form factor.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": null, "is_usap_dc": true, "keywords": "WAIS Divide; USAP-DC; Amd/Us; GLACIERS/ICE SHEETS; USA/NSF; FIELD INVESTIGATION; Ice Core; AMD", "locations": "WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Talghader, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Borehole Logging to Classify Volcanic Signatures in Antarctic Ice", "uid": "p0010080", "west": -112.085}, {"awards": "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; NBP1902 Expedition data; Physical and geochemical data from sediment cores collected offshore Thwaites Glacier", "datasets": [{"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"}, {"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": "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": "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"}], "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.\u003cbr/\u003e\u003cbr/\u003eUncertainty 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.\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": -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": "USAP-DC", "repositories": "R2R; UK PDC; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: THwaites Offshore Research (THOR)", "uid": "p0010062", "west": -120.0}, {"awards": "1443566 Bay, Ryan", "bounds_geometry": "POINT(90 -90)", "dataset_titles": "Laser Dust Logging of the South Pole Ice Core (SPICE)", "datasets": [{"dataset_uid": "601222", "doi": "10.15784/601222", "keywords": "Antarctica; Dust; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; SPICEcore", "people": "Bay, Ryan", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Laser Dust Logging of the South Pole Ice Core (SPICE)", "url": "https://www.usap-dc.org/view/dataset/601222"}], "date_created": "Thu, 31 Oct 2019 00:00:00 GMT", "description": "This award supports the deployment and analysis of data from an oriented laser dust logger in the South Pole ice core borehole to complement study of the ice core record. Before the core is even processed, data from the borehole probe will immediately determine the depth-age relationship, augment 3D mapping of South Pole stratigraphy, aid in searches for the oldest ice in Antarctica, and reveal layers of volcanic or extraterrestrial fallout. Regarding the intellectual merit, the oriented borehole log will be essential for investigating features in the ice sheet that may have implications for ice core chronology, ice flow, ice sheet physical properties and stability in response to climate change. The tools and techniques developed in this program have applications in glaciology, biogeoscience and exploration of other planetary bodies. The program aims for a deeper understanding of the consequences and causes of abrupt climate change. The broader impacts of the project are that it will include outreach and education, providing a broad training ground for students and post-docs. Data and metadata will be made available through data centers and repositories such as the National Snow and Ice Data Center web portal. \u003cbr/\u003e\u003cbr/\u003eThe laser dust logger detects reproducible paleoclimate features at sub-centimeter depth scale. Dust logger data are being used for synchronizing records and dating any site on the continent, revealing accumulation anomalies and episodes of rapid ice sheet thinning, and discovering particulate horizons of special interest. In this project we will deploy a laser dust logger equipped with a magnetic compass to find direct evidence of preferentially oriented dust. Using optical scattering measurements from IceCube calibration studies at South Pole and borehole logs at WAIS Divide, we have detected a persistent anisotropy correlated with flow and crystal fabric which suggests that the majority of insoluble particulates must be located within ice grains. With typical concentrations of parts-per-billion, little is known about the location of impurities within the polycrystalline structure of polar ice. While soluble impurities are generally thought to concentrate at inter-grain boundaries and determine electrical conductivity, the fate of insoluble particulates is much less clear, and microscopic examinations are extremely challenging. These in situ borehole measurements will help to unravel intimate relationships between impurities, flow, and crystal fabric. Data from this project will further develop a unique record of South Pole surface roughness as a proxy for paleowind and provide new insights for understanding glacial radar propagation. This project has field work in Antarctica.", "east": 90.0, "geometry": "POINT(90 -90)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; Antarctica; ICE CORE RECORDS; USAP-DC", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bay, Ryan", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Laser Dust Logging of a South Pole Ice Core", "uid": "p0010061", "west": 90.0}, {"awards": "1341479 Marchetti, Adrian", "bounds_geometry": "POLYGON((-72.8 -48,-67.12 -48,-61.44 -48,-55.76 -48,-50.08 -48,-44.4 -48,-38.72 -48,-33.04 -48,-27.36 -48,-21.68 -48,-16 -48,-16 -50.02,-16 -52.04,-16 -54.06,-16 -56.08,-16 -58.1,-16 -60.12,-16 -62.14,-16 -64.16,-16 -66.18,-16 -68.2,-21.68 -68.2,-27.36 -68.2,-33.04 -68.2,-38.72 -68.2,-44.4 -68.2,-50.08 -68.2,-55.76 -68.2,-61.44 -68.2,-67.12 -68.2,-72.8 -68.2,-72.8 -66.18,-72.8 -64.16,-72.8 -62.14,-72.8 -60.12,-72.8 -58.1,-72.8 -56.08,-72.8 -54.06,-72.8 -52.04,-72.8 -50.02,-72.8 -48))", "dataset_titles": "16S and 18S Sequence data; Fragilariopsis kerguelensis iron and light transcriptomes; Physiology and transcriptomes of polar isolates; Polar isolate transcriptomes; Sequence data from Ocean Station Papa seawater ; Sequence data RNA-Seq of marine phytoplankton: FeB12", "datasets": [{"dataset_uid": "200017", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Sequence data RNA-Seq of marine phytoplankton: FeB12", "url": "https://www.ncbi.nlm.nih.gov/sra/SRP074366"}, {"dataset_uid": "200020", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Physiology and transcriptomes of polar isolates", "url": "https://www.bco-dmo.org/project/653229"}, {"dataset_uid": "200021", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "16S and 18S Sequence data", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA299401"}, {"dataset_uid": "200016", "doi": "", "keywords": null, "people": null, "repository": "iMicrobe", "science_program": null, "title": "Fragilariopsis kerguelensis iron and light transcriptomes", "url": "https://www.imicrobe.us/#/projects/104"}, {"dataset_uid": "200019", "doi": "", "keywords": null, "people": null, "repository": "Cyverse Data Commons", "science_program": null, "title": "Polar isolate transcriptomes", "url": "http://datacommons.cyverse.org/search/?search_term=unc_phyto_isolates"}, {"dataset_uid": "200018", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Sequence data from Ocean Station Papa seawater ", "url": "https://www.ncbi.nlm.nih.gov/sra/SRP006906"}], "date_created": "Mon, 11 Mar 2019 00:00:00 GMT", "description": "The Southern Ocean surrounding Antarctica is changing rapidly in response to Earth\u0027s warming climate. These changes will undoubtedly influence communities of primary producers (the organisms at the base of the food chain, particularly plant-like organisms using sunlight for energy) by altering conditions that influence their growth and composition. Because primary producers such as phytoplankton play an important role in global biogeochemical cycling, it is essential to understand how they will respond to changes in their environment. The growth of phytoplankton in certain regions of the Southern Ocean is constrained by steep gradients in chemical and physical properties that vary in both space and time. Light and iron have been identified as key variables influencing phytoplankton abundance and distribution within Antarctic waters. Microscopic algae known as diatoms are dominant members of the phytoplankton and sea ice communities, accounting for significant proportions of primary production. The overall objective of this project is to identify the molecular bases for the physiological responses of polar diatoms to varying light and iron conditions. The project should provide a means of evaluating the extent these factors regulate diatom growth and influence net community productivity in Antarctic waters. Although numerous studies have investigated how polar diatoms are affected by varying light and iron, the cellular mechanisms leading to their distinct physiological responses remain unknown. We observed several growth responses, but a majority of polar diatom growth rates and photophysiology did not appear to be co-limited by iron and light limitation. Using comparative transcriptomics, we have examined the expression patterns of key genes and metabolic pathways in several ecologically important polar diatoms isolated from Antarctic waters and grown under varying iron and irradiance conditions. In addition, molecular indicators for iron and light limitation will be developed within these polar diatoms through the identification of iron- and light-responsive genes -- the expression patterns of which can be used to determine their physiological status. Upon verification in laboratory cultures, these indicators will be utilized by way of metatranscriptomic sequencing to examine iron and light limitation in natural diatom assemblages collected along environmental gradients in Western Antarctic Peninsula waters. In order to fully understand the role phytoplankton play in Southern Ocean biogeochemical cycles, dependable methods that provide a means of elucidating the physiological status of phytoplankton at any given time and location are essential.", "east": -16.0, "geometry": "POINT(-44.4 -58.1)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; AQUATIC SCIENCES; PHYTOPLANKTON; USAP-DC; Southern Ocean; Sea Surface; DIATOMS", "locations": "Sea Surface; Southern Ocean", "north": -48.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Marchetti, Adrian", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "BCO-DMO; Cyverse Data Commons; iMicrobe; NCBI GenBank", "science_programs": null, "south": -68.2, "title": "Iron and Light Limitation in Ecologically Important Polar Diatoms: Comparative Transcriptomics and Development of Molecular Indicators", "uid": "p0010018", "west": -72.8}, {"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": "Waddington, Edwin D.; Fudge, T. J.", "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. \u003cbr/\u003e \u003cbr/\u003eThe 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": "1141939 Lubin, Dan", "bounds_geometry": "POLYGON((-167.0365 -77.5203,-166.96385 -77.5203,-166.8912 -77.5203,-166.81855 -77.5203,-166.7459 -77.5203,-166.67325 -77.5203,-166.6006 -77.5203,-166.52795 -77.5203,-166.4553 -77.5203,-166.38265 -77.5203,-166.31 -77.5203,-166.31 -77.52527,-166.31 -77.53024,-166.31 -77.53521,-166.31 -77.54018,-166.31 -77.54515,-166.31 -77.55012,-166.31 -77.55509,-166.31 -77.56006,-166.31 -77.56503,-166.31 -77.57,-166.38265 -77.57,-166.4553 -77.57,-166.52795 -77.57,-166.6006 -77.57,-166.67325 -77.57,-166.7459 -77.57,-166.81855 -77.57,-166.8912 -77.57,-166.96385 -77.57,-167.0365 -77.57,-167.0365 -77.56503,-167.0365 -77.56006,-167.0365 -77.55509,-167.0365 -77.55012,-167.0365 -77.54515,-167.0365 -77.54018,-167.0365 -77.53521,-167.0365 -77.53024,-167.0365 -77.52527,-167.0365 -77.5203))", "dataset_titles": "Shortwave Spectroradiometer Data from Ross Island, Antarctica", "datasets": [{"dataset_uid": "601074", "doi": "10.15784/601074", "keywords": "Antarctica; Atmosphere; Meteorology; Radiosounding; Ross Island", "people": "Lubin, Dan", "repository": "USAP-DC", "science_program": null, "title": "Shortwave Spectroradiometer Data from Ross Island, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601074"}], "date_created": "Wed, 20 Dec 2017 00:00:00 GMT", "description": "Antarctic clouds constitute an important parameter of the surface radiation budget and thus play a significant role in Antarctic climate and climate change. The variability in, and long term trends of, cloud optical and microphysical properties are therefore fundamental in parameterizing the mixed phase (water-snow-ice) coastal Antarctic stratiform clouds experienced around the continent.\u003cbr/\u003e\u003cbr/\u003eUsing a spectoradiometer that covers the wavelength range of 350 to 2200nm, the downwelled spectral irradiance at the earth surface (Ross Island) will be used to retrieve the optical depth, thermodynamic phase, liquid water droplet effective radius, and ice-cloud effective particle size of overhead clouds, at hourly intervals and for an austral summer season (Oct-March). Based on the very limited data sets that exist for the maritime Antarctic, expectations are that Ross Island (Lat 78 S) should exhibit clouds with:\u003cbr/\u003ea) An abundance of supercooled liquid water, and related mixed-phase cloud processes\u003cbr/\u003eb) Cloud nucleation from year round biogenic and oceanic sources, in an otherwise pristine environment\u003cbr/\u003ec) Simple cloud geometries of predominantly stratiform cloud decks\u003cbr/\u003e\u003cbr/\u003eIncreased understanding of the cloud properties in the region of the main USAP base, McMurdo station is also relevant to operational weather forecasting relevant to aviation. A range of educational and outreach activities are associate with the project, including provision of workshops for high school teachers will be carried out.", "east": -166.31, "geometry": "POINT(-166.67325 -77.54515)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided; USAP-DC", "locations": null, "north": -77.5203, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Lubin, Dan", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.57, "title": "Antarctic Cloud Physics: Fundamental Observations from Ross Island", "uid": "p0000327", "west": -167.0365}, {"awards": "1542778 Alley, Richard", "bounds_geometry": null, "dataset_titles": "c-Axis Fabric of the South Pole Ice Core, SPC14; South Pole Ice Core (SPC14) Bubble Number-Density Data; South Pole Ice Core (SPIcecore) Visual Observations", "datasets": [{"dataset_uid": "601088", "doi": "10.15784/601088", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; South Pole; Visual Observations", "people": "Alley, Richard; Fegyveresi, John", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPIcecore) Visual Observations", "url": "https://www.usap-dc.org/view/dataset/601088"}, {"dataset_uid": "601057", "doi": "10.15784/601057", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; South Pole; SPICEcore", "people": "Voigt, Donald E.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "c-Axis Fabric of the South Pole Ice Core, SPC14", "url": "https://www.usap-dc.org/view/dataset/601057"}, {"dataset_uid": "601880", "doi": "10.15784/601880", "keywords": "Antarctic; Antarctica; Bubble Number Density; Cryosphere; Glaciers; Glaciology; Ice; Ice Core Data; Ice Core Records; NSF-ICF Microtome and Photography Stage; Paleoclimate; Physical Properties; Snow; South Pole", "people": "Fegyveresi, John", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPC14) Bubble Number-Density Data", "url": "https://www.usap-dc.org/view/dataset/601880"}], "date_created": "Fri, 29 Sep 2017 00:00:00 GMT", "description": "This award supports a three-year effort to study physical properties of the South Pole ice core to help provide a high-time-resolution history of trace gases and other paleoclimatic indicators from an especially cold site with high preservation potential for important signals. The physical-properties studies include visual inspection to identify any flow disturbances and for identifying annual layers and other features, and combined bubble, grain and ice crystal orientation studies to better understand the processes occurring in the ice that affect the climate record and the ice-sheet behavior. Success of these efforts will provide necessary support for dating and quality control to others studying the ice core, as well as determining the climate history of the site, flow state, and key physical processes in ice.\u003cbr/\u003e\u003cbr/\u003eThe intellectual merits of the project include better understanding of physical processes, paleoclimatic reconstruction, dating of the ice, and quality assurance. Visual inspection of the core will help identify evidence of flow disturbances that would disrupt the integrity of the climate record and will reveal volcanic horizons and other features of interest. Annual layer counting will be conducted to help estimate accumulation rate over time as recorded in the ice core. Measurements of C-axis fabric, grain size and shapes, and bubble characteristics will provide information about processes occurring in the ice sheet as well as the history of ice flow, current flow state and how the ice is flowing and how easily it will flow in the future. Analysis of this data in conjunction with microCT data will help to reveal grain-scale processes. The broader impacts of the project include support for an early-career, post-doctoral researcher, and improved paleoclimatic data of societal relevance. The results will be incorporated into the active program of education and outreach which have educated many students, members of the public and policy makers through the sharing of information and educational materials about all aspects of ice core science and paleoclimate.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard; Fegyveresi, John; Voigt, Donald E.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": null, "title": "Climate History and Flow Processes from Physical Analyses of the SPICECORE South Pole Ice Core", "uid": "p0000141", "west": null}, {"awards": "1142085 Alley, Richard", "bounds_geometry": null, "dataset_titles": "Firn-temperature time series in Dronning Maud Land, East Antarctica", "datasets": [{"dataset_uid": "601050", "doi": "10.15784/601050", "keywords": "Antarctica; Borehole Logging; Dronning Maud Land; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Physical Properties; Snow; Temperature", "people": "Muto, Atsu", "repository": "USAP-DC", "science_program": null, "title": "Firn-temperature time series in Dronning Maud Land, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601050"}], "date_created": "Mon, 11 Sep 2017 00:00:00 GMT", "description": "Alley/1142085\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to continue the collection and analyses of firn temperature data from three automated firn thermal profiling units deployed in Dronning Maud Land sector of East Antarctica as part of the Norway-US IPY Traverse project between 2007 and 2009. The intellectual merits of this project are as follows: 1) to constrain and improve the parameterization of firn thermal properties (thermal conductivity and specific heat capacity) that are required for the borehole paleothermometry, 2) to study the change in firn temperature since the deployment of thermal profiling units ~5 years ago and derive the surface temperature trend for that time period, and 3) to compare and contrast the surface temperatures and their trends derived from the measured firn temperatures and satellite thermal infrared data for the past three decades. The project also involves acquiring and deploying an automated system to record transient temperatures at multiple depths in the top 16 meters of the shallow borehole at Dome Fuji, to provide useful data and to prepare for the possibility of conducting temperature-logging in the existing deep (3035 m) and shallow (112 m) boreholes at Dome Fuji in the near future. The preparation of the shallow borehole and the installation of the automated system will be carried out by collaborators from the Japanese Antarctic Research Expedition (JARE) in 2012-13 Antarctic field season. The data collected by this automated system will be used to constrain the thermal properties of upper firn layer at Dome Fuji, as well as comparing with data from other sites, increasing the geographic extent of these studies. The broader impacts of the project include presentation of results at scientific conferences and publication of results in peer-reviewed journals. Public outreach will include targeted work with science teachers and middle school students.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Revealing Late Holocence Climate Variability in Antarctica from Borehole Paleothermometry", "uid": "p0000440", "west": null}, {"awards": "0944197 Waddington, Edwin; 0944191 Taylor, Kendrick", "bounds_geometry": "POLYGON((-180 -79,-173.3 -79,-166.6 -79,-159.9 -79,-153.2 -79,-146.5 -79,-139.8 -79,-133.1 -79,-126.4 -79,-119.7 -79,-113 -79,-113 -79.1,-113 -79.2,-113 -79.3,-113 -79.4,-113 -79.5,-113 -79.6,-113 -79.7,-113 -79.8,-113 -79.9,-113 -80,-119.7 -80,-126.4 -80,-133.1 -80,-139.8 -80,-146.5 -80,-153.2 -80,-159.9 -80,-166.6 -80,-173.3 -80,180 -80,150.9 -80,121.8 -80,92.7 -80,63.6 -80,34.5 -80,5.4 -80,-23.7 -80,-52.8 -80,-81.9 -80,-111 -80,-111 -79.9,-111 -79.8,-111 -79.7,-111 -79.6,-111 -79.5,-111 -79.4,-111 -79.3,-111 -79.2,-111 -79.1,-111 -79,-81.9 -79,-52.8 -79,-23.7 -79,5.4 -79,34.5 -79,63.6 -79,92.7 -79,121.8 -79,150.9 -79,-180 -79))", "dataset_titles": "Accumulation Rates from the WAIS Divide Ice Core; WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica; WAIS Divide Multi Track Electrical Measurements; WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "datasets": [{"dataset_uid": "601172", "doi": "10.15784/601172", "keywords": "Antarctic; Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; Wais Project; West Antarctic Ice Sheet", "people": "Fudge, T. J.; Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": null, "title": "WAIS Divide Multi Track Electrical Measurements", "url": "https://www.usap-dc.org/view/dataset/601172"}, {"dataset_uid": "609591", "doi": "10.7265/N5B56GPJ", "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Taylor, Kendrick C.; Fudge, T. J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609591"}, {"dataset_uid": "601004", "doi": "10.15784/601004", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Snow Accumulation; WAIS Divide Ice Core", "people": "Buizert, Christo; Fudge, T. J.; Waddington, Edwin D.; Conway, Howard", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Accumulation Rates from the WAIS Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/601004"}, {"dataset_uid": "601015", "doi": "10.15784/601015", "keywords": "Antarctica; Depth-Age-Model; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "url": "https://www.usap-dc.org/view/dataset/601015"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "This award supports a project to help to establish the depth-age chronology and the histories of accumulation and ice dynamics for the WAIS Divide ice core. The depth-age relationship and the histories of accumulation and ice dynamics are coupled. An accurate age scale is needed to infer histories of accumulation rate and ice-thickness change using ice-flow models. In turn, the accumulation-rate history is needed to calculate the age difference of ice to determine the age of the trapped gases. The accumulation history is also needed to calculate atmospheric concentrations of impurities trapped in the ice and is an important characteristic of climate. The history of ice-thickness change is also fundamental to understanding the stability of the WAIS. The primary goals of the WAIS Divide ice core project are to investigate climate forcing by greenhouse gases, the initiation of climate changes, and the stability of the West Antarctic Ice Sheet (WAIS). An accurate age scale is fundamental for achieving these goals. The first objective of this project is to establish an annually resolved depth-age relationship for the past 40,000 years. This will be done by measuring variations in electrical conductivity along the ice core, which are caused by seasonal variations in chemistry. We expect to be able to resolve annual layers back to 40,000 years before present (3,000 m depth) using this method. The second objective is to search for stratigraphic disturbances in the core that would compromise the paleoclimate record. Irregular layering will be identified by measuring the electrical conductivity of the ice in a vertical plan through the core. The third objective is to derive a preliminary chronology for the entire core. For the deeper ice we will use an ice-flow model to interpolate between known age markers, such as dated volcanic horizons and tie points from the methane gas chronology. The fourth objective is to derive a refined chronology simultaneously with histories of accumulation and ice-sheet thickness. An ice-flow model and all available data will be used to formulate an inverse problem, in which we infer the most appropriate histories of accumulation and ice-thickness, together with estimates of uncertainties. The flow model associated with those preferred histories then produces the best estimate of the chronology. The research contributes directly to the primary goals of the West Antarctic Ice Sheet Initiative. The project will help develop the next generation of scientists through the education and training of one Ph.D. student and several undergraduate students. This project will result in instrumentation for measuring the electrical conductivity of ice cores being available at the National Ice Core Lab for other researchers to use on other projects. All collaborators are committed to fostering diversity and currently participate in scientific outreach and most participate in undergraduate education. Outreach will be accomplished through regularly scheduled community and K-12 outreach events at UW, talks and popular writing by the PIs, as well as through our respective press offices.", "east": -111.0, "geometry": "POINT(-112 -79.5)", "instruments": null, "is_usap_dc": true, "keywords": "Ice Core Depth; National Ice Core Lab; Electrical Conductivity; FIELD INVESTIGATION; Not provided", "locations": null, "north": -79.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Conway, Howard; Fudge, T. J.; Taylor, Kendrick C.; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -80.0, "title": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core", "uid": "p0000026", "west": -113.0}, {"awards": "0538427 McConnell, Joseph", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "Gas measurement from Higgins et al., 2015 - PNAS; WAIS Divide Ice-Core Aerosol Records from 1.5 to 577 m; WAIS Divide Ice-Core Aerosol Records from Intermediate Core WDC05A; WAIS Divide Ice-Core Aerosol Records from Intermediate Core WDC05Q; WAIS Divide Ice-Core Chronology from Intermediate Core WDC05A; WAIS Divide Ice-Core Chronology from Intermediate Core WDC05Q", "datasets": [{"dataset_uid": "601010", "doi": "10.15784/601010", "keywords": "Aerosol; Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Aerosol Records from Intermediate Core WDC05A", "url": "https://www.usap-dc.org/view/dataset/601010"}, {"dataset_uid": "601013", "doi": "10.15784/601013", "keywords": "Antarctica; Depth-Age-Model; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Chronology from Intermediate Core WDC05Q", "url": "https://www.usap-dc.org/view/dataset/601013"}, {"dataset_uid": "601012", "doi": "10.15784/601012", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Snow Accumulation; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Chronology from Intermediate Core WDC05A", "url": "https://www.usap-dc.org/view/dataset/601012"}, {"dataset_uid": "601014", "doi": "10.15784/601014", "keywords": "Allan Hills; Antarctica; Argon; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope", "people": "Higgins, John", "repository": "USAP-DC", "science_program": null, "title": "Gas measurement from Higgins et al., 2015 - PNAS", "url": "https://www.usap-dc.org/view/dataset/601014"}, {"dataset_uid": "601009", "doi": "10.15784/601009", "keywords": "Aerosol; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Aerosol Records from 1.5 to 577 m", "url": "https://www.usap-dc.org/view/dataset/601009"}, {"dataset_uid": "601011", "doi": "10.15784/601011", "keywords": "Aerosol; Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Aerosol Records from Intermediate Core WDC05Q", "url": "https://www.usap-dc.org/view/dataset/601011"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "0538427\u003cbr/\u003eMcConnell \u003cbr/\u003eThis award supports a project to use unique, high-depth-resolution records of a range of elements, chemical species, and ice properties measured in two WAIS Divide shallow ice cores and one shallow British ice core from West Antarctic to address critical paleoclimate, environmental, and ice-sheet mass-balance questions. Recent development of the CFA-TE method for ice-core analysis presents the opportunity to develop high-resolution, broad-spectrum glaciochemical records at WAIS Divide at relatively modest cost. Together with CFA-TE measurements from Greenland and other Antarctic sites spanning recent decades to centuries, these rich data will open new avenues for using glaciochemical data to investigate environmental and global changes issues ranging from anthropogenic and volcanic-trace-element fallout to changes in hemispheric-scale circulation, biogeochemistry, rapid-climate-change events, long-term climate change, and ice-sheet mass balance. As part of the proposed research, collaborations with U.S., Argentine, and British researchers will be initiated and expanded to directly address three major IPY themes (i.e., present environmental status, past and present environmental and human change, and polar-global interactions). Included in the contributions from these international collaborators will be ice-core samples, ice-core and meteorological model data, and extensive expertise in Antarctic glaciology, climatology, meteorology, and biogeochemistry. The broader impacts of the work include the training of students. The project will partially support one Ph.D. student and hourly undergraduate involvement. Every effort will be made to attract students from underrepresented groups to these positions. To address the challenge of introducing results of scientific research to the public policy debate, we will continue efforts to publish findings in high visibility journals, provide research results to policy makers, and work with the NSF media office to reach the public through mass-media programs. K-12 teacher and classroom involvement will be realized through outreach to local schools and NSF\u0027s Teachers Experiencing the Antarctic and Arctic (or similar) program in collaboration with WAIS Divide and other polar researchers.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bender, Michael; McConnell, Joseph", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Trace and Ultra-Trace Chemistry Measurements of the WAIS Divide Ice Core", "uid": "p0000148", "west": -112.1115}, {"awards": "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": "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": "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.; Alley, Richard; Fitzpatrick, Joan; Spencer, Matthew; 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": "609550", "doi": "10.7265/N5V69GJW", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Clow, Gary D.; Cuffey, Kurt M.", "repository": "USAP-DC", "science_program": null, "title": "Temperature Profile of the West Antarctic Ice Sheet Divide Deep Borehole", "url": "https://www.usap-dc.org/view/dataset/609550"}, {"dataset_uid": "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": "Fitzpatrick, Joan; Cravens, Eric D.", "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": "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": "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": "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"}], "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": "0944794 Winberry, J. Paul; 0944671 Wiens, Douglas", "bounds_geometry": "POLYGON((-163 -83.7,-161.9 -83.7,-160.8 -83.7,-159.7 -83.7,-158.6 -83.7,-157.5 -83.7,-156.4 -83.7,-155.3 -83.7,-154.2 -83.7,-153.1 -83.7,-152 -83.7,-152 -83.8,-152 -83.9,-152 -84,-152 -84.1,-152 -84.2,-152 -84.3,-152 -84.4,-152 -84.5,-152 -84.6,-152 -84.7,-153.1 -84.7,-154.2 -84.7,-155.3 -84.7,-156.4 -84.7,-157.5 -84.7,-158.6 -84.7,-159.7 -84.7,-160.8 -84.7,-161.9 -84.7,-163 -84.7,-163 -84.6,-163 -84.5,-163 -84.4,-163 -84.3,-163 -84.2,-163 -84.1,-163 -84,-163 -83.9,-163 -83.8,-163 -83.7))", "dataset_titles": "Geophysical Study of Ice Stream Stick Slip; Whillans Ice Stream Stick-slip", "datasets": [{"dataset_uid": "000169", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Geophysical Study of Ice Stream Stick Slip", "url": "http://ds.iris.edu/mda/2C/?timewindow=2010-2011"}, {"dataset_uid": "609632", "doi": "10.7265/N5PC309V", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Whillans Ice Stream", "people": "Alley, Richard; Wiens, Douglas; Anandakrishnan, Sridhar; Winberry, Paul", "repository": "USAP-DC", "science_program": null, "title": "Whillans Ice Stream Stick-slip", "url": "https://www.usap-dc.org/view/dataset/609632"}], "date_created": "Wed, 16 Nov 2016 00:00:00 GMT", "description": "This award supports a three-year study of the ongoing deceleration and stick-slip motion of Whillans Ice Stream (WIS), West Antarctica. Understanding the dynamic behavior of ice streams is essential for predicting the future of the West Antarctic Ice Sheet (WAIS). Despite being one of the best-studied ice streams in Antarctica, the surprising flow characteristics of WIS continue to demand interdisciplinary research. Recent estimates indicate that the WIS may stagnate within 50 years, resulting in a significant change to the mass balance of the Siple Coast sector of West Antarctica. The reasons for the ongoing stagnation are not well known, and are possibly linked (causally or coincidentally) to the stick-slip behavior. Our recent work on WIS stick-slip motion suggest that all slip events nucleate from a common location on the ice stream, suggesting that a relatively small (approximately 10 km in diameter) region of the exerts fundamental control over the flow of this large ice stream (100s of km long and 100 kilometers wide). We hypothesize that this is a region of increased bed strength and our measurements will address that hypothesis. We will deploy a series of GPS receivers and seismometers on the ice stream to accurately locate the nucleation region so that a comprehensive ground based geophysical survey can be conducted to determine the physical properties of bed at the nucleation point. The ground geophysical program will consist of reflection seismic and ice-penetrating radar studies that will better constrain the properties of both the hypothesized higher-friction nucleation zone and the surrounding regions. Slip events also generate seismic energy that can be recorded 100s of km away from the ice stream, thus, the GPS and seismometer deployment will also aid us in relating seismic waveforms directly with the rapid motion that occurs during slip events. The increased ability to relate rupture processes with seismic emissions will allow us to use archived seismic records to explore changes in the behavior of WIS during the later half of the 20th century. Broader impacts of this study include improved knowledge ice sheet dynamics, which remain a poorly constrained component of the climate system, thus, limiting our ability to predict the Earth\u0027s response to climate change. The scientific work includes the education of two graduate students and continued training of one post-doctoral scholar, thus helping to train the next generation of polar scientists. We will expose the broader public to polar science through interactions with the media and by take advantaging of programs to include K-12 educators in our field work.", "east": -152.0, "geometry": "POINT(-157.5 -84.2)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "West Antarctic Ice Sheet; Geodesy; GROUND-BASED OBSERVATIONS; Not provided; Seismic; Geodetic Gps Data", "locations": "West Antarctic Ice Sheet", "north": -83.7, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Winberry, Paul; Anandakrishnan, Sridhar; Alley, Richard; Wiens, Douglas", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided", "repo": "IRIS", "repositories": "IRIS; USAP-DC", "science_programs": null, "south": -84.7, "title": "Collaborative Research: Geophysical Study of Ice Stream Stick-slip Dynamics", "uid": "p0000053", "west": -163.0}, {"awards": "1039982 Anandakrishnan, Sridhar", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Seismological Data at IRIS (full data link not provided)", "datasets": [{"dataset_uid": "000170", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismological Data at IRIS (full data link not provided)", "url": "http://ds.iris.edu/"}], "date_created": "Mon, 23 Nov 2015 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eKnowledge of englacial and subglacial conditions are critical for ice sheet models and predictions of sea-level change. Some of the critical variables that are poorly known but essential for improving flow models and predictions of sea-level change are: basal roughness, subglacial sedimentary and hydrologic conditions, and the temporal and spatial variability of the ice sheet flow field. Seismic reflection and refraction imaging and dense arrays of continuously operating GPS receivers can determine these parameters. The PIs propose to develop a network of wirelessly interconnected geophysical sensors (geoPebble) that will allow glaciologists to carry out these experiments simultaneously. This sensor web will provide a new way of imaging the ice sheet that is not possible with current instruments. With this sensor web, the PIs will extend the range of existing instruments from 2D to 3D, from low resolution to high resolution, but more importantly, all the geophysical measurements will be conducted synchronously. By the end of the proposal period the PIs will produce a network of 150-200 geoPebbles that will be available for NSF-sponsored glaciology research projects. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eImproved knowledge of the flow law of ice, the sliding of glaciers and ice streams, and paleoclimate history will contribute to assessments of the potential for abrupt ice-sheet mass change, with consequent sea-level effects and significant societal impacts. This improved modeling ability will be a direct consequence of better knowledge of the physical properties of ice sheets, which this project will facilitate. The development effort will be integrated with the undergraduate education program via the capstone design classes in EE and the senior thesis requirement in Geoscience. The PIs will also form a cohort of first-year and sophomore students who will work in their labs from the beginning of the project to develop specifications through the commissioning of the network.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anandakrishnan, Sridhar; Bilen, Sven; Urbina, Julio", "platforms": "Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -90.0, "title": "MRI: Development of a Wirelessly-Connected Network of Seismometers and GPS Instruments for Polar and Geophysical Research", "uid": "p0000405", "west": -180.0}, {"awards": "0632136 Nyblade, Andrew; 0632322 Wilson, Terry", "bounds_geometry": "POLYGON((-20 -70,-1 -70,18 -70,37 -70,56 -70,75 -70,94 -70,113 -70,132 -70,151 -70,170 -70,170 -72,170 -74,170 -76,170 -78,170 -80,170 -82,170 -84,170 -86,170 -88,170 -90,151 -90,132 -90,113 -90,94 -90,75 -90,56 -90,37 -90,18 -90,-1 -90,-20 -90,-20 -88,-20 -86,-20 -84,-20 -82,-20 -80,-20 -78,-20 -76,-20 -74,-20 -72,-20 -70))", "dataset_titles": "Incorporated Research Institutions for Seismology (IRIS); University NAVSTAR Consortium (UNAVCO)", "datasets": [{"dataset_uid": "000131", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "University NAVSTAR Consortium (UNAVCO)", "url": "http://www.unavco.org/data/gps-gnss/data-access-methods/dai2/app/dai2.html#groupingMod=contains;grouping=POLENET%20-%20ANET;scope=Station;sampleRate=normal"}, {"dataset_uid": "000132", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Incorporated Research Institutions for Seismology (IRIS)", "url": "http://www.iris.edu/mda/YT?timewindow=2007-2018"}], "date_created": "Thu, 22 Jan 2015 00:00:00 GMT", "description": "This project constructs POLENET a network of GPS and seismic stations in West Antarctica to understand how the mass of the West Antarctic ice sheet (WAIS) changes with time. The information is ultimately used to predict sea level rise accompanying global warming and interpret climate change records. The GPS (global positioning system) stations measure vertical and horizontal movements of bedrock, while the seismic stations characterize physical properties of the ice/rock interface, lithosphere, and mantle. Combined with satellite data, this project offers a more complete picture of the ice sheet\u0027s current state, its likely change in the near future, and its overall size during the last glacial maximum. This data will also be used to infer sub-ice sheet geology and the terrestrial heat flux, critical inputs to models of glacier movement. As well, this project improves tomographic models of the earth\u0027s deep interior and core through its location in the Earth\u0027s poorly instrumented southern hemisphere. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eBroader impacts of this project are varied. The work is relevant to society for improving our understanding of the impacts of global warming on sea level rise. It also supports education at the postdoctoral, graduate, and undergraduate levels, and outreach to groups underrepresented in the sciences. As an International Polar Year contribution, this project establishes a legacy of infrastructure for polar measurements. It also involves an international collaboration of twenty four countries. For more information see IPY Project #185 at IPY.org. NSF is supporting a complementary Arctic POLENET array being constructed in Greenland under NSF Award #0632320.", "east": 170.0, "geometry": "POINT(75 -80)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "Antarctica; Bedrock; Ice/Rock Interface; Climate Change; Seismic; West Antarctic Ice Sheet; FIELD SURVEYS; LABORATORY; Not provided; FIELD INVESTIGATION; Mass Balance; COMPUTERS; Sub-Ice Sheet Geology; Sea Level; Terrestrial Heat Flux", "locations": "Antarctica; West Antarctic Ice Sheet", "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wilson, Terry; Bevis, Michael; Anandakrishnan, Sridhar; Wiens, Douglas; Aster, Richard; Smalley, Robert; Nyblade, Andrew; Winberry, Paul; Hothem, Larry; Dalziel, Ian W.; Huerta, Audrey D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "UNAVCO", "repositories": "IRIS; UNAVCO", "science_programs": null, "south": -90.0, "title": "Collaborative Research: IPY: POLENET-Antarctica: Investigating Links Between Geodynamics and Ice Sheets", "uid": "p0000315", "west": -20.0}, {"awards": "0944199 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": "WAIS Divide Sonic Log Data", "datasets": [{"dataset_uid": "609592", "doi": "10.7265/N5T72FD2", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; Sonic Log; WAIS Divide; WAIS Divide Ice Core", "people": "McCarthy, Michael; Matsuoka, Kenichi; Anandakrishnan, Sridhar; Kluskiewicz, Dan; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Sonic Log Data", "url": "https://www.usap-dc.org/view/dataset/609592"}], "date_created": "Wed, 03 Sep 2014 00:00:00 GMT", "description": "0944199/Matsuoka\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to test the hypothesis that abrupt changes in fabric exist and are associated with both climate transitions and volcanic eruptions. It requires depth-continuous measurements of the fabric. By lowering a new logging tool into the WAIS Divide borehole after the completion of the core drilling, this project will measure acoustic-wave speeds as a function of depth and interpret it in terms of ice fabrics. This interpretation will be guided by ice-core-measured fabrics at sparse depths. This project will apply established analytical techniques for the ice-sheet logging and estimate depth profiles of both compressional- and shear-wave speeds at short intervals (~ 1 m). Previous logging projects measured only compressional-wave speeds averaged over typically 5-7 m intervals. Thus the new logger will enable more precise fabric interpretations. Fabric measurements using thin sections have revealed distinct fabric patterns separated by less than several meters; fabric measurements over a shorter period are crucial. At the WAIS Divide borehole, six two-way logging runs will be made with different observational parameters so that multiple wave-propagation modes will be identified, yielding estimates of both compressional- and shear-wave speeds. Each run takes approximately 24 hours to complete; we propose to occupy the boreholes in total eight days. The logging at WAIS Divide is temporarily planned in December 2011, but the timing is not critical. This project?s scope is limited to the completion of the logging and fabric interpretations. Results will be immediately shared with other WAIS Divide researchers. Direct benefits of this data sharing include guiding further thin-section analysis of the fabric, deriving a precise thinning function that retrieves more accurate accumulation history and depth-age scales. The PIs of this project have conducted radar and seismic surveys in this area and this project will provide a ground truth for these regional remote-sensing assessments of the ice interior. In turn, these remote sensing means can extend the results from the borehole to larger parts of the central West Antarctica. This project supports education for two graduate students for geophysics, glaciology, paleoclimate, and polar logistics. The instrument that will be acquired in this project can be used at other boreholes for ice-fabric characterizations and for englacial hydrology (wetness of temperate ice).", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e PROBES", "is_usap_dc": true, "keywords": "WAIS Divide; GROUND STATIONS; Western Divide Core; Antarctic Ice Sheet", "locations": "Antarctic Ice Sheet; WAIS Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Matsuoka, Kenichi; Kluskiewicz, Dan; Anandakrishnan, Sridhar; McCarthy, Michael; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Collaborative research: acoustic logging of the WAIS Divide borehole", "uid": "p0000051", "west": null}, {"awards": "0944078 Albert, Mary", "bounds_geometry": "POINT(112.05 79.28)", "dataset_titles": "Firn Permeability and Density at WAIS Divide", "datasets": [{"dataset_uid": "609602", "doi": "10.7265/N57942NT", "keywords": "Antarctica; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Albert, Mary R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Firn Permeability and Density at WAIS Divide", "url": "https://www.usap-dc.org/view/dataset/609602"}], "date_created": "Fri, 15 Aug 2014 00:00:00 GMT", "description": "This award supports a project to investigate the transformations from snow to firn to ice and the underlying physics controlling firn\u0027s ability to store atmospheric samples from the past. Senior researchers, a graduate student, and several undergraduates will make high-resolution measurements of both the diffusivity and permeability profiles of firn cores from several sites in Antarctica and correlate the results with their microstructures quantified using advanced materials characterization techniques (scanning electron microscopy and x-ray computed tomography). The use of cores from different sites will enable us to examine the influence of different local climate conditions on the firn structure. We will use the results to help interpret existing measurements of firn air chemical composition at several sites where firn air measurements exist. There are three closely-linked goals of this project: to quantify the dependence of interstitial transport properties on firn microstructure from the surface down to the pore close-off depth, to determine at what depths bubbles form and entrap air, and investigate the extent to which these features exhibit site-to-site differences, and to use the measurements of firn air composition and firn structure to better quantify the differences between atmospheric composition (present and past), and the air trapped in both the firn and in air bubbles within ice by comparing the results of the proposed work with firn air measurements that have been made at the WAIS Divide and Megadunes sites. The broader impacts of this project are that the study will this study will enable us to elucidate the fundamental controls on the metamorphism of firn microstructure and its impact on processes of gas entrapment that are important to understanding ice core evidence of past atmospheric composition and climate change. The project will form the basis for the graduate research of a PhD student at Dartmouth, with numerous opportunities for undergraduate involvement in cold room measurements and outreach. The investigators have a track record of successfully mentoring women students, and will build on this experience. In conjunction with local earth science teachers, and graduate and undergraduate students will design a teacher-training module on the role of the Polar Regions in climate change. Once developed and tested, this module will be made available to the broader polar research community for their use with teachers in their communities.", "east": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e MICROTOMOGRAPHY; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": true, "keywords": "Firn Air; FIELD SURVEYS; Physics; GROUND-BASED OBSERVATIONS; Antarctica; Megadunes; Tomography; Wais Divide-project; Firn Core; FIELD INVESTIGATION; Not provided; Firn Permeability; LABORATORY; Visual Observations; Ice; Firn; WAIS Divide; Microstructure; Density", "locations": "Antarctica; WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Albert, Mary R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.28, "title": "Firn Metamorphism: Microstructure and Physical Properties", "uid": "p0000049", "west": -112.05}, {"awards": "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": "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": "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": "601034", "doi": "10.15784/601034", "keywords": "Antarctica; Atmosphere; Black Carbon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph; Arienzo, Monica", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Holocene Black Carbon in Antarctica", "url": "https://www.usap-dc.org/view/dataset/601034"}, {"dataset_uid": "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": "1019838 Wendt, Dean", "bounds_geometry": null, "dataset_titles": "Real-Time Characterization of Adelie Penguin Foraging Environment Using an Autonomous Underwater Vehicle", "datasets": [{"dataset_uid": "600120", "doi": "10.15784/600120", "keywords": "Biota; Oceans; Southern Ocean", "people": "Wendt, Dean; Moline, Mark", "repository": "USAP-DC", "science_program": null, "title": "Real-Time Characterization of Adelie Penguin Foraging Environment Using an Autonomous Underwater Vehicle", "url": "https://www.usap-dc.org/view/dataset/600120"}], "date_created": "Mon, 30 Dec 2013 00:00:00 GMT", "description": "Abstract \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). \u003cbr/\u003e\u003cbr/\u003eThe Antarctic Peninsula is among the most rapidly warming regions on earth. Increased heat from the Antarctic Circumpolar Current has elevated the temperature of the 300 m of shelf water below the permanent pycnocline by 0.7 degrees C. This trend has displaced the once dominant cold, dry continental Antarctic climate, and is causing multi-level responses in the marine ecosystem. One striking example of the ecosystem response to warming has been the local declines in ice-dependent Ad\u00c3\u00a9lie penguins. The changes in these apex predators are thought to be driven by alterations in phytoplankton and zooplankton community composition, and the foraging limitations and diet differences between these species. One of the most elusive questions facing researchers interested in the foraging ecology of the Ad\u00c3\u00a9lie penguin, namely, what are the biophysical properties that characterize the three dimensional foraging space of this top predator? The research will combine the real-time site and diving information from the Ad\u00c3\u00a9lie penguin satellite tags with the full characterization of the oceanography and the penguins prey field using an autonomous underwater vehicle (AUV). While some of these changes have been documented over large spatial scales of the WAP, it is now thought that the causal mechanisms that favor of one life history strategy over another may actually operate over much smaller scales than previously thought, specifically on the scale of local breeding sites and over-wintering areas. Characterization of prey fields on these local scales has yet to be done and one that the AUV is ideally suited. The results will have a direct tie to the climate induced changes that are occurring in the West Antarctic Peninsula. This study will also highlight a new approach to linking an autonomous platform to bird behavior that could be expanded to include the other two species of penguins and examine the seasonal differences in their foraging behavior and prey selection. From a vehicle perspective, this effort will inform the AUV user community of new sensor suites and/or data processing approaches that are required to better evaluate foraging habitat. The project also will help transition AUV platforms into routine investigative tools for this region, which is chronically under sampled and will remain difficult to access", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; Amd/Us; USAP-DC; AMD; FIELD INVESTIGATION", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Wendt, Dean; Moline, Mark", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Real-Time Characterization of Adelie Penguin Foraging Environment Using an Autonomous Underwater Vehicle", "uid": "p0000662", "west": null}, {"awards": "0944042 Warren, Joseph", "bounds_geometry": "POLYGON((-70 -59,-68 -59,-66 -59,-64 -59,-62 -59,-60 -59,-58 -59,-56 -59,-54 -59,-52 -59,-50 -59,-50 -59.7,-50 -60.4,-50 -61.1,-50 -61.8,-50 -62.5,-50 -63.2,-50 -63.9,-50 -64.6,-50 -65.3,-50 -66,-52 -66,-54 -66,-56 -66,-58 -66,-60 -66,-62 -66,-64 -66,-66 -66,-68 -66,-70 -66,-70 -65.3,-70 -64.6,-70 -63.9,-70 -63.2,-70 -62.5,-70 -61.8,-70 -61.1,-70 -60.4,-70 -59.7,-70 -59))", "dataset_titles": "Data from expdition LMG1010; Expedition Data; Expedition data of LMG1010; Expedition data of LMG1110", "datasets": [{"dataset_uid": "002671", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1110", "url": "https://www.rvdata.us/search/cruise/LMG1110"}, {"dataset_uid": "000153", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Data from expdition LMG1010", "url": "https://www.rvdata.us/search/cruise/LMG1010"}, {"dataset_uid": "001445", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1110"}, {"dataset_uid": "002723", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1010", "url": "https://www.rvdata.us/search/cruise/LMG1010"}], "date_created": "Tue, 03 Dec 2013 00:00:00 GMT", "description": "The importance of gelatinous zooplankton in marine systems worldwide is increasing. In Southern Ocean, increasing salp densities could have a detrimental effect on higher predators, including penguins, fur seals, and baleen whales. The proposed research is a methods-develoment project that will improve the capability to indirectly assess abundances and distributions of salps in the Southern Ocean through acoustic surveys. Hydrographic, net tow, and acoustic backscatter data will be collected in the waters surrounding the South Shetland Islands and the Antarctic peninsula, where both krill and salps are found and compete for food. Shipboard experimental manipulations and measurements will lead to improved techniques for assessment of salp biomass acoustically. Experiments will focus on material properties (density and sound speed), size and shape of salps, as well as how these physical properties will vary with the salp\u0027s environment, feeding rate, and reproductive status. In the field, volume backscattering data from an acoustic echosounder will be collected at the same locations as the net tows to enable comparison of net and acoustic estimates of salp abundance. A physics-based scattering model for salps will be developed and validated, to determine if multiple acoustic frequencies can be used to discriminate between scattering associated with krill swarms and that from salp blooms. During the same period as the Antarctic field work, a parallel outreach and education study will be undertaken in Long Island, New York examining local gelatinous zooplankton. This study will enable project participants to learn and practice research procedures and methods before traveling to Antarctica; provide a comparison time-series that will be used for educational purposes; and include many more students and teachers in the research project than would be able to participate in the Antarctic field component.", "east": -50.0, "geometry": "POINT(-60 -62.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e XBT; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; 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": "R/V LMG; Not provided", "locations": null, "north": -59.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Warren, Joseph", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -66.0, "title": "Acoustic Assessment of Southern Ocean Salps and Their Ecosystem Impact", "uid": "p0000481", "west": -70.0}, {"awards": "0838850 Gooseff, Michael", "bounds_geometry": "POLYGON((162.32 -77.62,162.418 -77.62,162.516 -77.62,162.614 -77.62,162.712 -77.62,162.81 -77.62,162.90800000000002 -77.62,163.006 -77.62,163.104 -77.62,163.202 -77.62,163.3 -77.62,163.3 -77.631,163.3 -77.64200000000001,163.3 -77.653,163.3 -77.664,163.3 -77.67500000000001,163.3 -77.686,163.3 -77.697,163.3 -77.708,163.3 -77.71900000000001,163.3 -77.73,163.202 -77.73,163.104 -77.73,163.006 -77.73,162.90800000000002 -77.73,162.81 -77.73,162.712 -77.73,162.614 -77.73,162.516 -77.73,162.418 -77.73,162.32 -77.73,162.32 -77.71900000000001,162.32 -77.708,162.32 -77.697,162.32 -77.686,162.32 -77.67500000000001,162.32 -77.664,162.32 -77.653,162.32 -77.64200000000001,162.32 -77.631,162.32 -77.62))", "dataset_titles": "The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys", "datasets": [{"dataset_uid": "600100", "doi": "10.15784/600100", "keywords": "Antarctica; Critical Zone; Mps-1 Water Potential Sensor; Physical Properties; Soil Moisture; Soil Temperature", "people": "Gooseff, Michael N.", "repository": "USAP-DC", "science_program": null, "title": "The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys", "url": "https://www.usap-dc.org/view/dataset/600100"}], "date_created": "Tue, 26 Nov 2013 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/\u003eTwo models have been proposed to describe controls over microbial biogeography. One model proposes that microbes are ubiquitously distributed across the global environment, and that environmental conditions select for taxa physiologically adapted to local physical conditions. An alternative model predicts that dispersal is the important limitation to the distribution of microorganisms and that spatial heterogeneity of microbial communities is a result of both dispersal and local environmental limitations. According to both models, spatial heterogeneity of microbial communities may be especially pronounced in extreme ecosystems where the environmental selection for organisms with suitable physiology is most strongly manifest. We propose that Antarctic terrestrial environments are ideal places to examine microbial biogeography for 3 reasons: 1) the pristine nature and remoteness of Antarctica minimizes the prevalence of exotic species dispersed through human vectors; 2) the extreme conditions of Antarctic environments provide a strong environmental filter which limits the establishment of non-indigenous taxa; and 3) extreme heterogeneity in the terrestrial environment provides natural gradients of soil conditions (temperature, water and nutrient availability). In the proposed research we will investigate the influence of snow on the composition and spatial distribution of soil microbial communities and linked biogeochemical cycling in the McMurdo Dry Valleys. We will conduct fieldwork at the landscape scale (repeated remote sensing to characterize snow distribution), at the valley and patch scales (quantify snow patch ablation, microbial communities and biogeochemical cycling in subnivian soils). We hypothesize that snow patches play an important role in structuring the spatial distribution of soil microbial communities and their associated ecosystem functioning because of the physical and hydrological influences that snow patches have on the soil environment. The research will contribute to greater public awareness of the importance of polar research to fundamental questions of biology, ecology and hydrology through direct linkages with International Antarctic Institute public outreach activities, including dissemination of web-based learning units on environmental science and microbiology, targeted as resources for secondary and post-secondary educators. Three graduate students, one postdoctoral scholar and multiple undergraduates will participate in the research activities.", "east": 163.3, "geometry": "POINT(162.81 -77.675)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.62, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Gooseff, Michael N.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.73, "title": "Collaborative Research: The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys", "uid": "p0000489", "west": 162.32}, {"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": "0636767 Dunbar, Nelia; 0636740 Kreutz, Karl", "bounds_geometry": "POINT(112.11666 -79.46666)", "dataset_titles": "Microparticle, Conductivity, and Density Measurements from the WAIS Divide Deep Ice Core, Antarctica; Snowpit Chemistry - Methods Comparison, WAIS Divide, Antarctica; Snowpit evidence of the 2011 Puyehue-Cordon Caulle (Chile) eruption in West Antarctica; WAIS Divide Microparticle Concentration and Size Distribution, 0-2400 ka; WAIS Divide Snowpit Chemical and Isotope Measurements, Antarctica; WAIS Divide WDC06A Discrete ICP-MS Chemistry", "datasets": [{"dataset_uid": "601023", "doi": "10.15784/601023", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; ICP-MS; Isotope; WAIS Divide; WAIS Divide Ice Core", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide WDC06A Discrete ICP-MS Chemistry", "url": "https://www.usap-dc.org/view/dataset/601023"}, {"dataset_uid": "609506", "doi": "10.7265/N5SJ1HHN", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Isotope; Microparticle Concentration; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core", "people": "Kreutz, Karl; Koffman, Bess", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Snowpit Chemical and Isotope Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609506"}, {"dataset_uid": "609616", "doi": "10.7265/N5KK98QZ", "keywords": "Antarctica; Dust; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Particle Size; WAIS Divide; WAIS Divide Ice Core", "people": "Koffman, Bess; Kreutz, Karl", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Microparticle Concentration and Size Distribution, 0-2400 ka", "url": "https://www.usap-dc.org/view/dataset/609616"}, {"dataset_uid": "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": "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": "Kreutz, Karl; Koffman, Bess", "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"}], "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": "1043313 Spencer, Matthew; 1043528 Alley, Richard", "bounds_geometry": "POINT(112.1166 -79.4666)", "dataset_titles": "Average Annual Layer Thickness of the WAIS Divide Ice Core from Visual Stratigraphy; C-axis Fabric from Physical Properties Samples of the WAIS Divide Ice Core; Updated (2017) bubble number-density, size, shape, and modeled paleoclimate data; WAIS Divide 580m Bubble and Grain Hybrid Data; WAIS Divide Surface and Snow-pit Data, 2009-2013", "datasets": [{"dataset_uid": "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": "Fitzpatrick, Joan; Voigt, Donald E.; Alley, Richard", "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": "Alley, Richard; Fegyveresi, John", "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": "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.; Alley, Richard; Fitzpatrick, Joan; Spencer, Matthew; 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": "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\u003cbr/\u003e\u003cbr/\u003eThis 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 Glaciology; Antarctic Earth Sciences", "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": "0940650 Pettit, Erin; 0636996 Waddington, Edwin", "bounds_geometry": "POLYGON((-165 -75,-159 -75,-153 -75,-147 -75,-141 -75,-135 -75,-129 -75,-123 -75,-117 -75,-111 -75,-105 -75,-105 -76,-105 -77,-105 -78,-105 -79,-105 -80,-105 -81,-105 -82,-105 -83,-105 -84,-105 -85,-111 -85,-117 -85,-123 -85,-129 -85,-135 -85,-141 -85,-147 -85,-153 -85,-159 -85,-165 -85,-165 -84,-165 -83,-165 -82,-165 -81,-165 -80,-165 -79,-165 -78,-165 -77,-165 -76,-165 -75))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 16 Mar 2012 00:00:00 GMT", "description": "Pettit/0636795\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to constrain the accumulation rate, thickness, and temperature history for Siple Dome using a vertical velocity profile that includes the effects of an evolving fabric on deformation through time, to invert the depth-profile of fabric determined from sonic velocity measurements and grain size observed in thin sections in Siple Dome for the surface temperature and accumulation rate changes in the past, focusing on the apparent abrupt climate change events at 22ka and 15ka. The intellectual merit of the work is that it will extract past climate information from a number of physical properties of the deep ice using a coupled fabric evolution and ice-sheet flow model. The focus will be on the deep ice-age ice at Siple Dome, where the ice-core record shows puzzling signals and where modeling results imply intriguing deformation patterns. The method will also be applied to the records from Byrd Station and Taylor Dome to ultimately form a basis for future analysis of the West Antarctic Divide core. The broader impacts of the project are that it will ultimately contribute to our understanding of the effects of anisotropy on ice flow dynamics in West Antarctica. It will contribute to our understanding of the connection between ice flow and the paleoclimate record in ice cores, particularly with respect to the relationship between the chemical record and ice deformation. And it will contribute a new ice-flow model that includes the effects of anisotropy and fabric evolution. The project will also contribute to advancing the career of a new, young, female investigator and will support a couple of graduate students. Finally, the work will encouraging diversity in the physical sciences by directly helping to support the Girls on Ice a program that encourages young women to explore science and the natural world.", "east": -105.0, "geometry": "POINT(-135 -80)", "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY; FIELD SURVEYS; FIELD INVESTIGATION; Vertical Velocity; COMPUTERS; Ice Core; Firn; Accumulation Rate; Siple Dome; Ice Thickness; Abrupt Climate Change; Ice Temperature; Metamorphism; Anisotropy; Antarctica", "locations": "Siple Dome; Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Waddington, Edwin D.", "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", "repositories": null, "science_programs": null, "south": -85.0, "title": "Collaborative Research: Anisotropy, Abrupt Climate Change, and the Deep Ice in West Antarctica", "uid": "p0000741", "west": -165.0}, {"awards": "0636929 Bales, Roger", "bounds_geometry": null, "dataset_titles": "Measurements of Air and Snow Photochemical Species at WAIS Divide, Antarctica", "datasets": [{"dataset_uid": "609585", "doi": "10.7265/N5GX48HW", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Bales, Roger", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Measurements of Air and Snow Photochemical Species at WAIS Divide, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609585"}], "date_created": "Thu, 14 Jul 2011 00:00:00 GMT", "description": "This award supports a project to understand how recent changes in atmospheric chemistry, and historical changes as recorded in snow, firn and ice, have affected atmospheric photochemistry over Antarctica. Atmospheric, snow and firn core measurements of selected gas, meteorological and snow physical properties will be made and modeling of snow-atmosphere exchange will be carried out. The intellectual merit of the project is that it will lead to a better an understanding of the atmospheric chemistry in West Antarctica, its bi-directional linkages with the snowpack, and how it responds to regional influences. There are at least four broader impacts of this work. First is education of university students at both the graduate and undergraduate levels. One postdoctoral researcher and one graduate student will carry out much of the work, and a number of undergraduates will be involved. Second, involvement with the WAIS-Divide coring program will be used to help recruit under-represented groups as UC Merced students. As part of UC Merced\u0027s outreach efforts in the San Joaquin Valley, whose students are under-represented in the UC system, the PI and co-PI give short research talks to groups of prospective students, community college and high school educators and other groups. They will develop one such talk highlighting this project. Including high-profile research in these recruiting talks has proven to be an effective way to promote dialog, and interest students in UC Merced. Third, talks such as this also contribute to the scientific literacy of the general public. The PI and grad student will all seek opportunities to share project information with K-14 and community audiences. Fourth, results of the research will be disseminated broadly to the scientific community, and the researchers will seek additional applications for the transfer functions as tools to improve interpretation of ice-cores. This research is highly collaborative, and leverages the expertise and data from a number of other groups.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e CHEMILUMINESCENCE", "is_usap_dc": true, "keywords": "Snow; Atmospheric Chemistry; Not provided; LABORATORY; Antarctica; FIELD SURVEYS; Snow Physical Properties; Meteorology; Wais Divide-project; Firn; Atmosphere Exchange; WAIS Divide; FIELD INVESTIGATION", "locations": "Antarctica; WAIS Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bales, Roger", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Atmospheric, Snow and Firn Chemistry Studies for Interpretation of WAIS-Divide Cores", "uid": "p0000041", "west": null}, {"awards": "0836112 Smith, Walker; 0836144 Yager, Patricia; 0836061 Dennett, Mark", "bounds_geometry": "POLYGON((100 -69,107 -69,114 -69,121 -69,128 -69,135 -69,142 -69,149 -69,156 -69,163 -69,170 -69,170 -70,170 -71,170 -72,170 -73,170 -74,170 -75,170 -76,170 -77,170 -78,170 -79,163 -79,156 -79,149 -79,142 -79,135 -79,128 -79,121 -79,114 -79,107 -79,100 -79,100 -78,100 -77,100 -76,100 -75,100 -74,100 -73,100 -72,100 -71,100 -70,100 -69))", "dataset_titles": "Amundsen Sea Polynya International Research Expedition (ASPIRE) data; Controls on Climate-Active Gases by Amundsen Sea Ice Biota", "datasets": [{"dataset_uid": "000146", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Amundsen Sea Polynya International Research Expedition (ASPIRE) data", "url": "https://www.bco-dmo.org/project/2132"}, {"dataset_uid": "600092", "doi": "10.15784/600092", "keywords": "Amundsen Sea; Antarctica; Chemistry:fluid; Chemistry:Fluid; CTD Data; Oceans; Oden; Oden2008; Sea Ice; Sea Surface; Southern Ocean", "people": "Smith, Walker", "repository": "USAP-DC", "science_program": null, "title": "Controls on Climate-Active Gases by Amundsen Sea Ice Biota", "url": "https://www.usap-dc.org/view/dataset/600092"}, {"dataset_uid": "600091", "doi": "10.15784/600091", "keywords": "Amundsen Sea; Antarctica; Biota; Oceans; Oden; Oden2008; Plankton; Sea Ice; Southern Ocean", "people": "Dennett, Mark", "repository": "USAP-DC", "science_program": null, "title": "Controls on Climate-Active Gases by Amundsen Sea Ice Biota", "url": "https://www.usap-dc.org/view/dataset/600091"}], "date_created": "Sun, 24 Apr 2011 00:00:00 GMT", "description": "Convincing evidence now confirms that polar regions are changing rapidly in response to human activities. Changes in sea ice extent and thickness will have profound implications for productivity, food webs and carbon fluxes at high latitudes, since sea ice biota are a significant source of biogenic matter for the ecosystem. While sea ice is often thought to be a barrier to gas exchange between the ocean and the atmosphere, it more likely functions as a source or sink for climate-active gases such as carbon dioxide and ozone-depleting organohalogens, due in part to activities of microbes embedded in the sea ice matrix. This project brings together experienced US and Swedish investigators to examine the controls by sea-ice biota on the production and degradation of key climate-active gases in the Pacific sector of the Southern Ocean. We hypothesize that 1) the physical properties of the sea-ice environment will determine the community structure and activities of the sea ice biota; 2) the productivity, biomass, physiological state and species composition of ice algae will determine the production of specific classes of organic carbon, including organohalogens; 3) heterotrophic co-metabolism within the ice will break down these compounds to some extent, depending on the microbial community structure and productivity, and 4) the sea ice to atmosphere fluxes of CO2 and organohalogens will be inversely related. This project will build close scientific collaborations between US and Swedish researchers and also train young scientists, including members of underrepresented groups. Dissemination of results will include the scientific literature, and public outreach venues including interactions with a PolarTrec teacher.", "east": 170.0, "geometry": "POINT(135 -74)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -69.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Walker; Yager, Patricia; Dennett, Mark", "platforms": "Not provided", "repo": "BCO-DMO", "repositories": "BCO-DMO; USAP-DC", "science_programs": null, "south": -79.0, "title": "Collaborative Research: Controls on climate-active gases by Amundsen Sea ice biota", "uid": "p0000137", "west": 100.0}, {"awards": "0838842 Passchier, Sandra", "bounds_geometry": "POLYGON((-180 -68,-177 -68,-174 -68,-171 -68,-168 -68,-165 -68,-162 -68,-159 -68,-156 -68,-153 -68,-150 -68,-150 -69,-150 -70,-150 -71,-150 -72,-150 -73,-150 -74,-150 -75,-150 -76,-150 -77,-150 -78,-153 -78,-156 -78,-159 -78,-162 -78,-165 -78,-168 -78,-171 -78,-174 -78,-177 -78,180 -78,178 -78,176 -78,174 -78,172 -78,170 -78,168 -78,166 -78,164 -78,162 -78,160 -78,160 -77,160 -76,160 -75,160 -74,160 -73,160 -72,160 -71,160 -70,160 -69,160 -68,162 -68,164 -68,166 -68,168 -68,170 -68,172 -68,174 -68,176 -68,178 -68,-180 -68))", "dataset_titles": "Particle-size measurements for diamictites AND-2A sediment core, McMurdo Sound", "datasets": [{"dataset_uid": "601452", "doi": "10.15784/601452", "keywords": "Antarctica; McMurdo Sound; Miocene; Particle Size; Pleistocene; Pliocene", "people": "Passchier, Sandra; Hansen, Melissa A.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Particle-size measurements for diamictites AND-2A sediment core, McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601452"}], "date_created": "Fri, 27 Aug 2010 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The project aims on studying sediment cores collected from Prydz Bay and the Ross Sea to unravel the Neogene paleoclimatic history of the East Antarctic ice sheet. In the light of current measurements and predictions of a substantial rise in global temperature, investigations into the sensitivity of the East Antarctic ice sheet to climate change and its role in the climate system are essential. Geological records of former periods of climate change provide an opportunity to ground truth model predictions. The scientific objective of this project is to identify a previously proposed middle Miocene transition from a more dynamic wet-based East Antarctic ice sheet to the present semi-permanent ice sheet that is partially frozen to its bed. The timing and significance of this transition is controversial due to a lack of quantitative studies on well-dated ice-proximal sedimentary sequences. This project partially fills that gap using the composition and physical properties of diamictites and sandstones to establish shifts in ice-sheet drainage pathways, paleoenvironments and basal ice conditions. The results from the two key areas around the Antarctic continental margin will provide insight into the behavior of the East Antarctic ice sheet across the middle Miocene transition and through known times of warming in the late Miocene and Pliocene.", "east": -150.0, "geometry": "POINT(-175 -73)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples", "uid": "p0000147", "west": 160.0}, {"awards": "0538494 Meese, Debra", "bounds_geometry": null, "dataset_titles": "Microstructural Location and Composition of Impurities in Polar Ice Cores", "datasets": [{"dataset_uid": "609436", "doi": "10.7265/N5DF6P5P", "keywords": "Antarctica; Arctic; Byrd Glacier; Byrd Ice Core; Chemistry:ice; Chemistry:Ice; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Lake Vostok; Paleoclimate; Vostok Ice Core", "people": "Obbard, Rachel; Baker, Ian", "repository": "USAP-DC", "science_program": null, "title": "Microstructural Location and Composition of Impurities in Polar Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609436"}], "date_created": "Thu, 03 Jun 2010 00:00:00 GMT", "description": "0538494\u003cbr/\u003eMeese\u003cbr/\u003eThis award supports a project for physical properties research on snow pits and firn/ice cores with specific objectives that include stratigraphic analysis including determination of accumulation rates, annual layers, depth hoar, ice and wind crusts and rates of grain growth with depth. Studies of firn densification rates and how these parameters relate to the meteorology and climatology over the last 200 years of snow accumulation in Antarctica will also be investigated. The project will also determine the seasonality of accumulation by co-registration of stratigraphy and chemistry and determination of chemical species at the grain boundaries, how these may change with depth/densification (and therefore temperature), precipitation, and may affect grain growth. Fabric analyses will be made, including variation with depth, location on undulations and if any variation exists with climate/chemistry. The large spatial coverage of the US ITASE program offers the opportunity to determine how these parameters are affected by a large range of temperature, precipitation and topographic effects. The intellectual merit of the project includes the fact that ITASE is the terrestrial equivalent of a polar research vessel that provides a unique, logistically efficient, multi-dimensional (x, y, z and time) view of the atmosphere, ice sheet and their histories. Physical properties measurements/ analyses are an integral part of understanding the dynamic processes to which the accumulated snow is subjected. Recent advancements in the field along with multiple core sites provide an excellent opportunity to gain a much broader understanding of the spatial, temporal and physical variables that impact firnification and the possible resultant impact on climatic interpretation. In terms of broader impacts, the data collected by US ITASE and its international ITASE partners is available to a broad scientific community. US ITASE has an extensive program of public outreach and provides significant opportunities for many students to experience multidisciplinary Antarctic research. A graduate student, a post-doctoral fellow and at least one undergraduate would be funded by this work. Dr. Meese is also a member of the New England Science Collaborative, an organization that educates the public on climate change based on recent scientific advancements.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": false, "keywords": "LABORATORY; Grain Growth; FIELD SURVEYS; Accumulation Rate; Firn Core; FIELD INVESTIGATION; Chemistry; Snow Pit; Depth Hoar; Firn Density; Ice Core; Not provided; Stratigraphic Analysis; Firn; US ITASE; Annual Layers", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Meese, Deb; MEESE, DEBRA", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "The Physical Properties of the US ITASE Firn and Ice Cores from South Pole to Taylor Dome", "uid": "p0000289", "west": null}, {"awards": "9117721 Jeffries, Martin", "bounds_geometry": "POLYGON((-110.149 -52.353,-104.86076 -52.353,-99.57252 -52.353,-94.28428 -52.353,-88.99604 -52.353,-83.7078 -52.353,-78.41956 -52.353,-73.13132 -52.353,-67.84308 -52.353,-62.55484 -52.353,-57.2666 -52.353,-57.2666 -54.17539,-57.2666 -55.99778,-57.2666 -57.82017,-57.2666 -59.64256,-57.2666 -61.46495,-57.2666 -63.28734,-57.2666 -65.10973,-57.2666 -66.93212,-57.2666 -68.75451,-57.2666 -70.5769,-62.55484 -70.5769,-67.84308 -70.5769,-73.13132 -70.5769,-78.41956 -70.5769,-83.7078 -70.5769,-88.99604 -70.5769,-94.28428 -70.5769,-99.57252 -70.5769,-104.86076 -70.5769,-110.149 -70.5769,-110.149 -68.75451,-110.149 -66.93212,-110.149 -65.10973,-110.149 -63.28734,-110.149 -61.46495,-110.149 -59.64256,-110.149 -57.82017,-110.149 -55.99778,-110.149 -54.17539,-110.149 -52.353))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002253", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9405"}, {"dataset_uid": "002283", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9305"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is an examination of the physical and structural properties of the antarctic ice pack in the Amundsen, Bellingshausen, and Ross Seas, with the goal of defining the geographical variability of various ice types, the deformation processes that are active in the antarctic ice pack, and the large-scale thermodynamics and heat exchange processes of the ice- covered Southern Ocean. An additional goal is to relate specific characteristics of antarctic sea ice to its synthetic aperture radar (SAR) signature as observed from satellites. Physical properties include the salinity, temperature, and brine volumes, while structural properties include the fraction of frazil, platelet, and congelation ice of the seasonal antarctic pack ice. Differences in ice types are the result of differences in the environment in which the ice forms: frazil ice is formed in supercooled sea water, normally through wind or wave-induced turbulence, while platelet and congelation ice is formed under quiescent conditions. The fraction of frazil ice (which has been observed to be generally in excess of 50% in Weddell Sea ice floes) is an important variable in the energy budget of the upper ocean, and contributes significantly to the stabilization of the surface layers. The integration of sea ice field observations and synthetic aperture radar data analysis and modeling studies will contribute to a better understanding of sea ice parameters and their geophysical controls, and will be useful in defining the kind of air-ice-ocean interactions that can be studied using SAR data, as well as having broader relevance and application to atmospheric, biological, and oceanographic investigations of the Southern Ocean.", "east": -57.2666, "geometry": "POINT(-83.7078 -61.46495)", "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.353, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jeffries, Martin", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -70.5769, "title": "Sea Ice Physical-Structrual Characteristics: Development and SAR Signature in the Pacific Sector of the Southern Ocean", "uid": "p0000647", "west": -110.149}, {"awards": "0538195 Marone, Chris", "bounds_geometry": "POLYGON((-147.75896 -61.77943,-147.758362 -61.77943,-147.757764 -61.77943,-147.757166 -61.77943,-147.756568 -61.77943,-147.75597 -61.77943,-147.755372 -61.77943,-147.754774 -61.77943,-147.754176 -61.77943,-147.753578 -61.77943,-147.75298 -61.77943,-147.75298 -61.779665,-147.75298 -61.7799,-147.75298 -61.780135,-147.75298 -61.78037,-147.75298 -61.780605,-147.75298 -61.78084,-147.75298 -61.781075,-147.75298 -61.78131,-147.75298 -61.781545,-147.75298 -61.78178,-147.753578 -61.78178,-147.754176 -61.78178,-147.754774 -61.78178,-147.755372 -61.78178,-147.75597 -61.78178,-147.756568 -61.78178,-147.757166 -61.78178,-147.757764 -61.78178,-147.758362 -61.78178,-147.75896 -61.78178,-147.75896 -61.781545,-147.75896 -61.78131,-147.75896 -61.781075,-147.75896 -61.78084,-147.75896 -61.780605,-147.75896 -61.78037,-147.75896 -61.780135,-147.75896 -61.7799,-147.75896 -61.779665,-147.75896 -61.77943))", "dataset_titles": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "datasets": [{"dataset_uid": "609460", "doi": "10.7265/N5WH2MX7", "keywords": "Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Shear Stress; Solid Earth; Strain", "people": "Anandakrishnan, Sridhar; Marone, Chris", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "url": "https://www.usap-dc.org/view/dataset/609460"}, {"dataset_uid": "600054", "doi": "10.15784/600054", "keywords": "Antarctica; Glacial Till; Glaciers/ice Sheet; Glaciers/Ice Sheet; Lab Experiment; Marine Sediments; Physical Properties; Solid Earth", "people": "Marone, Chris; Anandakrishnan, Sridhar", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "url": "https://www.usap-dc.org/view/dataset/600054"}], "date_created": "Thu, 18 Jun 2009 00:00:00 GMT", "description": "0538195\u003cbr/\u003eMarone\u003cbr/\u003eThis award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.", "east": -147.75298, "geometry": "POINT(-147.75597 -61.780605)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE TRANSDUCERS", "is_usap_dc": true, "keywords": "Subglacial Observations; Laboratory Investigation; LABORATORY; Subglacial", "locations": null, "north": -61.77943, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Marone, Chris; Anandakrishnan, Sridhar", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -61.78178, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "uid": "p0000554", "west": -147.75896}, {"awards": "0228052 Kreutz, Karl", "bounds_geometry": "POLYGON((161.0434 -77.3002,161.241645 -77.3002,161.43989 -77.3002,161.638135 -77.3002,161.83638 -77.3002,162.034625 -77.3002,162.23287 -77.3002,162.431115 -77.3002,162.62936 -77.3002,162.827605 -77.3002,163.02585 -77.3002,163.02585 -77.3784846,163.02585 -77.4567692,163.02585 -77.5350538,163.02585 -77.6133384,163.02585 -77.691623,163.02585 -77.7699076,163.02585 -77.8481922,163.02585 -77.9264768,163.02585 -78.0047614,163.02585 -78.083046,162.827605 -78.083046,162.62936 -78.083046,162.431115 -78.083046,162.23287 -78.083046,162.034625 -78.083046,161.83638 -78.083046,161.638135 -78.083046,161.43989 -78.083046,161.241645 -78.083046,161.0434 -78.083046,161.0434 -78.0047614,161.0434 -77.9264768,161.0434 -77.8481922,161.0434 -77.7699076,161.0434 -77.691623,161.0434 -77.6133384,161.0434 -77.5350538,161.0434 -77.4567692,161.0434 -77.3784846,161.0434 -77.3002))", "dataset_titles": "Late Holocene Climate Variability, Dry Valleys, Antarctica", "datasets": [{"dataset_uid": "609399", "doi": "10.7265/N5FF3Q92", "keywords": "Antarctica; Borehole Temperature; Chemistry:ice; Chemistry:Ice; Dry Valleys; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Mass Balance; Paleoclimate; Physical Properties", "people": "Mayewski, Paul A.; Kreutz, Karl", "repository": "USAP-DC", "science_program": null, "title": "Late Holocene Climate Variability, Dry Valleys, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609399"}], "date_created": "Tue, 21 Oct 2008 00:00:00 GMT", "description": "This award supports a project to collect and develop high-resolution ice core records from the Dry Valleys region of Antarctica, and provide interpretations of interannual to decadal-scale climate variability during the last 2000 years (late Holocene). The project will test hypotheses related to ocean/atmosphere teleconnections (e.g., El Nino Southern Oscillation, Antarctic Oscillation) that may be responsible for major late Holocene climate events such as the Little Ice Age in the Southern Hemisphere. Conceptual and quantitative models of these processes in the Dry Valleys during the late Holocene are critical for understanding recent climate changes, and represent the main scientific merit of the project. We plan to collect intermediate-length ice cores (100-200m) at four sites along transects in Taylor Valley and Wright Valley, and analyze each core at high resolution for stable isotopes (d18O, dD), major ions (Na+, Mg2+, Ca2+, K+, NH4+, Cl-, NO3-, SO42-, MSA), and trace elements (Al, Fe, S, Sr, B). A suite of statistical techniques will be applied to the multivariate glaciochemical dataset to identify chemical associations and to calibrate the time-series records with available instrumental data. Broader impacts of the project include: 1) contributions to several ongoing interdisciplinary Antarctic research programs; 2) graduate and undergraduate student involvement in field, laboratory, and data interpretation activities; 3) use of project data and ideas in several UMaine courses and outreach activities; and 4) data dissemination through peer-reviewed publications, UMaine and other paleoclimate data archive websites, and presentations at national and international meetings.", "east": 163.02585, "geometry": "POINT(162.034625 -77.691623)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MC-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e HUMIDITY SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e TEMPERATURE SENSORS", "is_usap_dc": true, "keywords": "Holocene; Climate Research; AWS Climate Data; Paleoclimate; Climate Variation; Dry Valleys; Wright Valley; Little Ice Age; Stable Isotopes; Glaciochemical; Ice Core; FIELD INVESTIGATION; Enso; Antarctic Oscillation; Climate; GPS; El Nino-Southern Oscillation; LABORATORY; Not provided; Climate Change; Ice Core Records; Antarctica; Taylor Valley; FIELD SURVEYS; Variability", "locations": "Antarctica; Dry Valleys; Taylor Valley; Wright Valley", "north": -77.3002, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Kreutz, Karl; Arcone, Steven; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.083046, "title": "Dry Valleys Late Holocene Climate Variability", "uid": "p0000155", "west": 161.0434}, {"awards": "0917509 Spencer, Matthew; 0440447 Spencer, Matthew", "bounds_geometry": "POINT(-148.81 -81.65)", "dataset_titles": "Firn depth and bubble density for Siple Ice Core and other sites", "datasets": [{"dataset_uid": "601746", "doi": "10.15784/601746", "keywords": "Antarctica; Density; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Data; Ice Core Records; Siple Dome; Snow/ice; Snow/Ice", "people": "Spencer, Matthew", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Firn depth and bubble density for Siple Ice Core and other sites", "url": "https://www.usap-dc.org/view/dataset/601746"}], "date_created": "Mon, 19 May 2008 00:00:00 GMT", "description": "This award supports a two-year collaborative effort to more fully understand the climatic history and physical properties of the Siple Dome, Antarctica deep ice core, to develop a new paleoclimatic technique based on bubble number-density, and to improve the U.S. capability to analyze ice-core physical properties rapidly and accurately. The Siple Dome ice core from West Antarctica is yielding important paleoclimatic insights, but has proven more difficult than some cores to interpret owing to the large iceflow effects on the paleoclimatic record. Paleoclimatic indicators that do not rely on iceflow corrections thus would be of value. The bubble number-density offers one such indicator, because it preserves information on mean temperature and accumulation rate during the transformation of firn to ice. We will focus on thin-section characteristics that are important to ice flow and the interpretation of the ice-core history, such as c-axis fabrics, and will use indicators that we have been developing, such as the correlation between grain elongation and the c-axis orientation, to gain additional information. To achieve this quickly and accurately, and to prepare for future projects, we propose to upgrade the automatic caxis- fabric analyzer that Wilen has built and housed at the National Ice Core Laboratory. The intellectual merit of the proposed activity includes improved estimates of paleoclimatic conditions in an important region, improved understanding of a new paleoclimatic research tool, greater understanding of ice flow and of linkages to physical properties, and a better instrument for further U.S. research in ice-core physical properties at the National Ice Core Laboratory. The broader impacts resulting from the proposed activity include providing better understanding of abrupt climate change and of ice flow, which eventually should help policy-makers, as well as an improved U.S. capability to analyze ice cores. The proposed research will assist the studies of two promising young scientists. Results of the research will be incorporated into courses and public outreach reaching at least hundreds or thousands of people per year.", "east": -148.81, "geometry": "POINT(-148.81 -81.65)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided; Ice Core; Ice Flow; Bubble Number Density; LABORATORY; Thin Sections; Paleoclimate; FIELD INVESTIGATION; Fabric; Siple Dome; Climate; Antarctica; Antarctic; FIELD SURVEYS", "locations": "Siple Dome; Antarctica; Antarctic", "north": -81.65, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Spencer, Matthew; Wilen, Larry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.65, "title": "Collaborative Research: Combined Physical Property Measurements at Siple Dome", "uid": "p0000658", "west": -148.81}, {"awards": "0230288 Anastasio, Cort", "bounds_geometry": "POLYGON((123.30014 -75.093445,123.307404 -75.093445,123.314668 -75.093445,123.321932 -75.093445,123.329196 -75.093445,123.33646 -75.093445,123.343724 -75.093445,123.350988 -75.093445,123.358252 -75.093445,123.365516 -75.093445,123.37278 -75.093445,123.37278 -75.0952669,123.37278 -75.0970888,123.37278 -75.0989107,123.37278 -75.1007326,123.37278 -75.1025545,123.37278 -75.1043764,123.37278 -75.1061983,123.37278 -75.1080202,123.37278 -75.1098421,123.37278 -75.111664,123.365516 -75.111664,123.358252 -75.111664,123.350988 -75.111664,123.343724 -75.111664,123.33646 -75.111664,123.329196 -75.111664,123.321932 -75.111664,123.314668 -75.111664,123.307404 -75.111664,123.30014 -75.111664,123.30014 -75.1098421,123.30014 -75.1080202,123.30014 -75.1061983,123.30014 -75.1043764,123.30014 -75.1025545,123.30014 -75.1007326,123.30014 -75.0989107,123.30014 -75.0970888,123.30014 -75.0952669,123.30014 -75.093445))", "dataset_titles": "Light Absorption Coefficients for Soluble Species in Snow, Dome C, Antarctica", "datasets": [{"dataset_uid": "609519", "doi": "10.7265/N5MS3QP0", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Dome C Ice Core; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice", "people": "Anastasio, Cort; Robles, Tony", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Light Absorption Coefficients for Soluble Species in Snow, Dome C, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609519"}], "date_created": "Wed, 07 Mar 2007 00:00:00 GMT", "description": "Photochemical reactions in snow can have important effects on the chemistry and composition of the snowpack as well as the overlying atmosphere. For example, recent measurements in the Antarctic and Arctic have revealed that sunlit snow releases a number of important pollutants to the atmosphere. Our ability to understand and model this chemistry is currently limited, in part because we lack fundamental photochemical information for a number of important chemical species in snow. This award supports research that will help fill this gap by characterizing the low-temperature photochemistry of three of these key species: nitrite (NO2-), nitrous acid (HNO2), and hydrogen peroxide (HOOH). We will measure quantum yields for these reactions on ice using a sensitive technique that we recently developed during a study of nitrate (NO3-) photochemistry. In addition to this basic research, we will also measure the rates of formation of hydroxyl radical (OH), nitrogen oxides (NOx), and HOOH in illuminated Antarctic snow samples. These measurements will be important inputs for future models, and will allow us to test whether known species (e.g., NO3-, NO2- and HNO2) are responsible for most of snowpack reactivity (e.g., OH formation). Overall, results from this award will significantly improve our ability to understand snowpack chemistry, and the resulting effects on the atmosphere, both in the Antarctic as well as in the many other regions with permanent or seasonal snow. These results will also strengthen efforts to use ice core records to monitor global change. In addition to these impacts, this award will help train students and a postdoctoral fellow, and results from this work will be integrated into two classes in order to expose students to some of the important issues facing polar regions.", "east": 123.37278, "geometry": "POINT(123.33646 -75.1025545)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e HPLC; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Snow Chemistry; Antarctica; Snowpack Chemistry; Snow Samples; Hydrogen Peroxide; Snow Properties; Pollutants; Chemistry; Light Absorption; Antarctic; Chemical Species; Snow; East Antarctica; Organic Compounds; Photochemistry; LABORATORY", "locations": "Antarctica; East Antarctica; Antarctic", "north": -75.093445, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anastasio, Cort; Robles, Tony", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Dome C Ice Core", "south": -75.111664, "title": "Laboratory Studies of Photochemistry in Antarctic Snow and Ice", "uid": "p0000175", "west": 123.30014}, {"awards": "0125276 Albert, Mary; 0125570 Scambos, Ted", "bounds_geometry": null, "dataset_titles": "Access AGDC data online by navigating to Data Sets. Data sets are arranged by Principal Investigators. Access data that are combined into multiple data sets, or compiled products.; AWS Data: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation; GPR and GPS Data: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation; Snow and Firn Permeability: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation; The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "datasets": [{"dataset_uid": "609282", "doi": "10.7265/N5Q23X5F", "keywords": "Antarctica; East Antarctic Plateau; Glaciology; GPR; GPS; Navigation; Paleoclimate; Snow/ice; Snow/Ice", "people": "Bauer, Rob; Scambos, Ted", "repository": "USAP-DC", "science_program": null, "title": "GPR and GPS Data: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation", "url": "https://www.usap-dc.org/view/dataset/609282"}, {"dataset_uid": "609299", "doi": "10.7265/N5639MPD", "keywords": "Antarctica; East Antarctic Plateau; Glaciology; Physical Properties; Snow/ice; Snow/Ice", "people": "Courville, Zoe; Cathles, Mac; Albert, Mary R.", "repository": "USAP-DC", "science_program": null, "title": "Snow and Firn Permeability: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation", "url": "https://www.usap-dc.org/view/dataset/609299"}, {"dataset_uid": "001343", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "url": "https://nsidc.org/data/agdc/"}, {"dataset_uid": "001669", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Access AGDC data online by navigating to Data Sets. Data sets are arranged by Principal Investigators. Access data that are combined into multiple data sets, or compiled products.", "url": "http://nsidc.org/data/agdc_investigators.html"}, {"dataset_uid": "609283", "doi": "10.7265/N5K935F3", "keywords": "Antarctica; Atmosphere; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meteorology; Snow/ice; Snow/Ice", "people": "Bauer, Rob; Haran, Terry; Scambos, Ted; Fahnestock, Mark", "repository": "USAP-DC", "science_program": null, "title": "AWS Data: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation", "url": "https://www.usap-dc.org/view/dataset/609283"}], "date_created": "Wed, 04 Jan 2006 00:00:00 GMT", "description": "This award supports a program of field surveys of an area within the large, well-developed megadune field southeast of Vostok station. The objectives are to determine the physical characteristics of the firn across the dunes, including typical climate indicators such as stable isotopes and major chemical species, and to install instruments to measure the time variation of near-surface wind and temperature with depth, to test and refine hypotheses for megadune formation. Field study will consist of surface snowpit and shallow core sampling, ground penetrating radar (GPR) profiling, GPS topographic and ice motion surveys, AWS installation, accumulation/ ablation measurements, subsurface temperature, and firn permeability studies. Field work in two successive seasons is proposed. Continent-wide remote sensing studies of the dunes will be continued, using the new group of instruments that are now, or will shortly be available (e.g., MODIS, MISR, GLAS, AMSR). The earlier study of topographic, passive microwave, and SAR characteristics will be extended, with the intent of determining the relationships of dune amplitude and wavelength to climate parameters, and further development of models of dune formation. Diffusion, ventilation, and vapor transport processes within the dune firn will be modeled as well. A robust program of outreach is planned and reporting to inform both the public and scientists of the fundamental in-situ and remote sensing characteristics of these uniquely Antarctic features will be an important part of the work. Because of their extreme nature, their broad extent, and their potential impact on the climate record, it is important to improve our current understanding of these. Megadunes are a manifestation of an extreme terrestrial climate and may provide insight on past terrestrial climate, or to processes active on other planets. Megadunes are likely to represent an end-member in firn diagenesis, and as such, may have much to teach us about the processes involved.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ICE AUGERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e SNOWPACK TEMPERATURE PROBE; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e PERMEAMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e CURRENT/WIND METERS \u003e ANEMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e AIR PERMEAMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CURRENT/WIND METERS \u003e ANEMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e RADIO \u003e ARGOS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e WIND PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e DENSIOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e BALANCE", "is_usap_dc": true, "keywords": "Internal Layering; ICESAT; Vapor-Redeposition; Antarctic; Wind Speed; FIELD INVESTIGATION; Surface Morphology; Antarctica; GROUND-BASED OBSERVATIONS; ARWS; Polar Firn Air; Microstructure; Gas Diffusivity; WEATHER STATIONS; Surface Temperatures; RADARSAT-2; Ice Core; Wind Direction; AWS; Ice Sheet; Snow Pit; Dunefields; Climate Record; Megadunes; GROUND STATIONS; METEOROLOGICAL STATIONS; Antarctic Ice Sheet; Density; Atmospheric Pressure; Firn Permeability; FIELD SURVEYS; Radar; Permeability; Field Survey; Firn Temperature Measurements; Snow Megadunes; Thermal Conductivity; LANDSAT; Firn; Ice Core Interpretation; East Antarctic Plateau; Not provided; Surface Winds; Sublimation; Snow Density; Ice Climate Record; Glaciology; Snow Permeability; Air Temperature; Paleoenvironment; Automated Weather Station", "locations": "Antarctica; Antarctic Ice Sheet; Antarctic; East Antarctic Plateau", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Courville, Zoe; Cathles, Mac; Scambos, Ted; Bauer, Rob; Fahnestock, Mark; Haran, Terry; Shuman, Christopher A.; Albert, Mary R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e ARWS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e METEOROLOGICAL STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e WEATHER STATIONS; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e ICE, CLOUD AND LAND ELEVATION SATELLITE (ICESAT) \u003e ICESAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e RADARSAT \u003e RADARSAT-2", "repo": "USAP-DC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation", "uid": "p0000587", "west": null}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "Vostok Ice Core Chemistry, Timescale, Isotope, and Temperature Data", "datasets": [{"dataset_uid": "609242", "doi": "", "repository": "USAP-DC", "science_program": null, "title": "Vostok Ice Core Chemistry, Timescale, Isotope, and Temperature Data", "url": "http://www.usap-dc.org/view/dataset/609242"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Lake Vostok; Paleoclimate; Physical Properties; Temperature; Vostok Ice Core", "locations": "Lake Vostok; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fishcer, Hubertus; Blunier, Thomas; Ruddiman, William; Raymo, Maureen; Lorius, Claude; Brook, Edward J.; Bender, Michael; Chappellaz, Jerome; Sowers, Todd A.; Jouzel, Jean; Petit, Jean Robert; Barnola, J. M.; Lal, Devendra", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "8411018 Frisic, David", "bounds_geometry": null, "dataset_titles": "Dominion Range Ice Core Beta Profiles, Chemistry, and Density Data; Newall Glacier Ice Core and Snow Pit Beta Profiles, Chemistry, and Stratigraphy; Newall Glacier Snow Pit and Ice Core, 1987 to 1989", "datasets": [{"dataset_uid": "609249", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Newall Glacier; Paleoclimate; Physical Properties; Snow/ice; Snow/Ice; Statigraphy", "people": "Mayewski, Paul A.; Welch, Kathy A.", "repository": "USAP-DC", "science_program": null, "title": "Newall Glacier Ice Core and Snow Pit Beta Profiles, Chemistry, and Stratigraphy", "url": "https://www.usap-dc.org/view/dataset/609249"}, {"dataset_uid": "609248", "doi": "", "keywords": "Antarctica; Beta Profiles; Chemistry:ice; Chemistry:Ice; Density; Dominion Range; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Physical Properties", "people": "Saltzman, Eric; Mayewski, Paul A.; Meese, Deb; Gow, Tony; Grootes, Pieter; Watson, M. Scott; 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"}], "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": "XXXXXXX Palais, Julie", "bounds_geometry": null, "dataset_titles": "European Project for Ice Coring in Antarctica (EPICA) Dome C Ice Core Data", "datasets": [{"dataset_uid": "609244", "doi": "", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "European Project for Ice Coring in Antarctica (EPICA) Dome C Ice Core Data", "url": "http://www.usap-dc.org/view/dataset/609244"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Dome C Ice Core; Epica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Physical Properties", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fluckiger, Jacqueline; Monnin, Eric; Wolff, Eric W.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Dome C Ice Core", "south": null, "title": null, "uid": null, "west": null}, {"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": "9615347 Conway, Howard", "bounds_geometry": null, "dataset_titles": "Roosevelt Island Bedrock and Surface Elevations; Roosevelt Island Ice Core Density and Beta Count Data", "datasets": [{"dataset_uid": "609140", "doi": "10.7265/N51J97NB", "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Roosevelt Island; Solid Earth", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Bedrock and Surface Elevations", "url": "https://www.usap-dc.org/view/dataset/609140"}, {"dataset_uid": "609139", "doi": "10.7265/N55718ZW", "keywords": "Antarctica; Beta Count; Density; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Roosevelt Island", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Ice Core Density and Beta Count Data", "url": "https://www.usap-dc.org/view/dataset/609139"}], "date_created": "Fri, 23 May 2003 00:00:00 GMT", "description": "This award is for two years of support to perform radar investigations across former shear margins at Roosevelt Island and Ice Stream C in order to measure changes in the configuration and continuity of internal layers and the bed. The broad goal of these investigations is to gain an understanding of ice stream flow and the timing and mechanisms of ice stream shutdown. A high-resolution short-pulse radar system will be used for detailed examination of the uppermost hundred meters of the firn and ice, and a monopulse sounding-radar system will be used to image the rest of the ice column (including internal layers) and the bed. Changes in the shape and continuity of layers will be used to interpret mechanisms and modes of ice stream flow including the possible migration of stagnation fronts and rates of shut-down. Variations in bed reflectivity will be used to deduce basal hydrology conditions across lineations. Accumulation rates deduced from snow pits and shallow cores will be used to estimate near-surface depth-age profiles. Improved understanding of ice stream history opens the possibility of linking changes in the West Antarctic ice sheet with the geologic evidence from Northern Victoria Land and the ocean record of the retreat of the grounding line in the Ross Sea.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RA; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Radioactive Decay; Radar Echo Sounder; Antarctica; Radar Altimetry; Densification; Bedrock Elevation; Ice Sheet Elevation; Satellite Radar Data; GROUND-BASED OBSERVATIONS; Radar; Ice Core; Snow Stratigraphy; Terrain Elevation; Antarctic Ice Sheet; Stable Isotopes; Ice Surface Elevation; Surface Elevation; Glaciology; Snow Densification; Ice Core Data; GROUND STATIONS; Not provided; Altimetry; Antarctic; Ice Core Stratigraphy; Ice Stratigraphy", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Radar Investigations of Former Shear Margins: Roosevelt Island and Ice Stream C", "uid": "p0000164", "west": null}, {"awards": "9527262 Gow, Anthony", "bounds_geometry": null, "dataset_titles": "Physical and Structural Properties of the Siple Dome Ice Cores", "datasets": [{"dataset_uid": "609128", "doi": "10.7265/N5668B34", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Photo/video; Photo/Video; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Gow, Tony; Meese, Deb", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Physical and Structural Properties of the Siple Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609128"}], "date_created": "Wed, 14 May 2003 00:00:00 GMT", "description": "This award is for support for a program to investigate the visual stratigraphy, index physical properties, relaxation characteristics and crystalline structure of ice cores from Siple Dome, West Antarctica. This investigation will include measurements of a time-priority nature that must be initiated at the drill site on freshly-drilled cores. This will be especially true of cores from the brittle ice zone, which is expected to comprise a significant fraction of the ice core. The brittle zone includes ice in which relaxation , resulting from the release of confining pressure is maximized and leads to significant changes in the mechanical condition of the core that must be considered in relation to the processing and analysis of ice samples for entrapped gas and chemical studies. This relaxation will be monitored via precision density measurements made initially at the drill site and repeated at intervals back in the U.S. Other studies will include measurement of the annual layering in the core to as great a depth as visual stratigraphy can be deciphered, crystal size measurements as a function of depth and age, c-axis fabric studies, and analysis of the physical properties of any debris-bearing basal ice and its relationship to the underlying bedrock. Only through careful documentation and analysis of these key properties can we hope to accurately assess the dynamic state of the ice and the age-depth relationships essential to deciphering the paleoclimate record at this location.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Siple Dome; Antarctica; Stratigraphy; Ice Sheet; GROUND-BASED OBSERVATIONS; Density; Siple; Chemical Composition; Volcanic Deposits; Siple Coast; WAISCORES; Not provided; GROUND STATIONS; Pico; Ice Core; Tephra; Fabric; Glaciology; Snow", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Gow, Tony; Meese, Deb", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Physical and Structural Properties of the Siple Dome Core", "uid": "p0000064", "west": null}, {"awards": "9526420 Taylor, Kendrick", "bounds_geometry": null, "dataset_titles": "Siple Dome Cores Electrical Measurement Data", "datasets": [{"dataset_uid": "609133", "doi": "10.7265/N5DR2SDN", "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Cores Electrical Measurement Data", "url": "https://www.usap-dc.org/view/dataset/609133"}], "date_created": "Thu, 08 May 2003 00:00:00 GMT", "description": "This award is for support for the measurement of electrical and optical properties of the Siple Dome ice core. The electrical methods can be used to determine the concentration of the hydrogen ions and the concentration of a weighted sum of all ions. The electrical measurements can resolve features as small as 1 cm. The albedo of the core is also measured with a laser system that can resolve features as small as 0.5 cm. The high spatial resolution of these methods makes them ideal for resolving narrow features in the core, which can be missed in larger composite samples. The measurements will be particularly useful for assisting to date the core and to identify short duration features in the record, such as volcanic eruptions. These measurements will also provide useful information for assessing the temporal variability of Holocene accumulation rate and atmospheric circulation.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Densification; Siple Dome; Glaciology; Snow; Thermometry; WAISCORES; Electrical; Isotope; GROUND STATIONS; GROUND-BASED OBSERVATIONS; Not provided; Ice Sheet; Siple Coast; Ice Core; Siple; Antarctica", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Taylor, Kendrick C.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Electrical and Optical Measurements on the Siple Dome Ice Core", "uid": "p0000163", "west": null}, {"awards": "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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General Description:<br/>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.<br/><br/>Technical Description:<br/>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.
The goal of all LTER sites is to conduct policy-relevant ecosystem research for questions that require tens of years of data and cover large geographical areas. The Palmer Antarctica Long Term Ecological Research (PAL-LTER) site has been in operation since 1990 and has been studying how the marine ecosystem west of the Antarctica Peninsula (WAP) is responding to a climate that is changing as rapidly as any place on the Earth. The study is evaluating how warming conditions and decreased ice cover leading to extended periods of open water are affecting many aspects of ecosystem function. The team is using combined cutting-edge approaches including yearly ship-based research cruises, small-boat weekly sampling, autonomous vehicles, animal biologging, oceanographic floats and seafloor moorings, manipulative lab-based process studies and modeling to evaluate both seasonal and annual ecosystem responses. These combined approaches are allowing for the study the ecosystem changes at scales needed to assess both short-term and long-term drivers. The study region also includes submarine canyons that are special regions of enhanced biological activity within the WAP. This research program is paired with a comprehensive education and outreach program promoting the global significance of Antarctic science and research. In addition to training for graduate and undergraduate students, they are using newly-developed Polar Literacy Principles as a foundation in a virtual schoolyard program that shares polar instructional materials and provides learning opportunities for K-12 educators. The PAL-LTER team is also leveraging the development of Out of School Time materials for afterschool and summer camp programs, sharing Palmer LTER-specific teaching materials with University, Museum, and 4-H Special Interest Club partners.
Polar ecosystems are among the most rapidly changing on Earth. The Palmer LTER (PAL-LTER) program builds on three decades of coordinated research along the western side of the Antarctic Peninsula (WAP) to gain new mechanistic and predictive understanding of ecosystem changes in response to disturbances spanning long-term decadal (press) drivers and changes due to higher-frequency (pulse) drivers, such as large storms and extreme seasonal anomaly in sea ice cover. The influence of major natural climate modes that modulate variations in sea ice, weather, and oceanographic conditions to drive changes in ecosystem structure and function (e.g., El Nio Southern Oscillation and Southern Annular Mode) are being studied at multiple time scales from diel, seasonal, interannual, to decadal intervals, and space scalesfrom hemispheric to global scale investigated by remote sensing, the regional scales. Specifically, the team is evaluating how variability of physical properties (such as vertical and alongshore connectivity processes) interact to modulate biogeochemical cycling and community ecology in the WAP region. The study is providing an evaluation of ecosystem resilience and ecological responses to long-term press-pulse drivers and a decadal-level reversal in sea ice coverage. This program is providing fundamental understanding of population and biogeochemical responses for a marine ecosystem experiencing profound change.
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. <br/><br/>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.<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.
Brittle ice has been a long-standing and consistent challenge for ice-coring projects, complicating sampling, and introducing the possibility of contamination. Several procedures have been tested to reduce brittle damage to recovered cores, but many come with high monetary and time costs. Our background research suggests that bubble size and c-axis fabric are primary drivers for brittleness and are predictable from site characteristics, enabling prediction of brittleness before coring. We propose to improve understanding of the mechanisms involved in brittle ice onset and behavior, through targeted investigations of various ice physical properties, in carefully selected samples across multiple ice-core sites, in order to guide the upcoming Hercules Dome ice-core drilling and science communities. This project will involve collaboration between Northern Arizona University, the National Science Foundation Ice Core Facility, and Pennsylvania State University, and will utilize new and existing ice-core physical properties data from several previously drilled sites. This is a high-risk, low-cost project that could yield important results, and thus is well-suited for EAGER funding. This proposal utilizes existing ice cores and does not require Antarctic fieldwork.
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. <br/><br/>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.<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.
Interpreting highly compressed portions of ice cores is increasingly important as projects target climate records in basal ice, and in ice recovered from blue-ice areas. This project will integrate precisely co-registered electrical conductivity measurements (ECM), hyperspectral imaging, laser ablation ICPMS measurements of impurities, and ice physical properties to investigate sub-cm chemical and physical variations in polar ice. This work will establish to what extent annual layer interpretations of polar ice with sub-cm layering is possible. Critical to resolving thin ice layers is understanding the across-core variations which may obscure or distort the vertical layering. Analyses will be focused on samples from WAIS Divide, SPICEcore, and GISP2, which have well established seasonal cycles that yielded benchmark timescales, as well a large diameter ice core from a blue ice area.
We studied the molecular evolution and physiology of two types of ion channels: voltage gated potassium channels and transient receptor potential (TRP) channels. We also studied the molecular evolution and expression of water-passing channels, the aquaporins, to determine if these show signs of evolutionary change in notothenioids.
We noted apparent amino acid substitutions at a number of sites in a muscle-expressing
potassium channel (Kv1.3). We were surprised to find that although the AAs at these sites
appeared highly conserved in teleosts and even in tetrapods, reverting them singly, in pairs,
or all together back to the ancestral condition had no effect on the biophysical properties of
the channels that we measured (voltage-sensitivity; rate of activation) at room temperature
as well as over a range of temperatures down to 4oC.
The results for the TRP channels and aquaporins can be accessed in their publications. York and Zakon (2022) in Genome Biology and Evolution, and two forthcoming papers.
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.
Part I: Non-technical summary<br/>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.<br/><br/>Part II: Technical summary<br/>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.<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.
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. We 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, we 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 our hypothesis, we will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) We will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. We will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) We 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) We 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. We will integrate these data 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.
Ice supersaturation plays a key role in cloud formation and evolution, and it determines the partitioning among ice, liquid and vapor phases. Over the Southern Ocean and Antarctica, the transition between mixed-phase and ice clouds significantly impacts the radiative effects of clouds. Remote regions such as the Antarctica and Southern Ocean historically have been under-sampled by in-situ observations, especially by airborne observations. Even though more attention has been given to the cloud microphysical properties over these regions, the distribution and characteristics of ice supersaturation and its role in the current and future climate have not been fully investigated at the higher latitudes in the Southern Hemisphere. One of the main objectives of this study is to analyze observations from three recent major field campaigns sponsored by NSF and DOE, which provide intensive in-situ, airborne measurements over the Southern Ocean and ground-based observations at McMurdo station in Antarctica.
This project will analyze aircraft-based and ground-based observations over the Southern Ocean and Antarctica, and compare the observations with the Community Earth System Model Version 2 (CESM2) simulations. The focus will be on the observations of ice supersaturation and the relative humidity distribution in mixed-phase and ice clouds, as well as their relationship with cloud micro- and macrophysical properties. Observations will be compared to CESM2 simulations to elucidate model biases. Surface radiation and the precipitation budget at the McMurdo station will be quantified and compared against the CESM2 simulations to improve the fidelity of the representation of Antarctic climate (and climate prediction over Antarctica). Results from our research will be released to the community for improving the understanding of cloud radiative effects and the mass transport of water in the high southern latitudes. Comparisons between the simulations and observations will provide valuable information for improving the next generation CESM model. Two education/outreach projects will be carried out by PI Diao at San Jose State University (SJSU), including a unique undergraduate student research project with hands-on laboratory work on an airborne instrument, and an outreach program that uses social media to broadcast news on polar research to the public.
Part I: Nontechnical <br/>Earths warming climate has the potential to drive widespread collapse of glaciers and ice sheets across the planet, driving global sea-level rise. Understanding both the rate and magnitude of such changes is essential for predicting future sea-level and how it will impact infrastructure and property. Collapse of the ice sheets of Antarctica has the potential to raise global sea-level by up to 60 meters. However, not all regions of Antarctica are equally suspectable to collapse. One area with potential for collapse is the Wilkes Subglacial Basin in East Antarctica, a region twice the size of California's Central Valley. Geologic evidence indicates that the ice-sheet in this region has retreated significantly in response to past global warming events. While the geologic record clearly indicates ice-sheets in this area are vulnerable, the rate and magnitude of any future retreat will be influenced significantly by geology of the region. Constraining the geologic controls on the stability of the ice-sheets of the Wilkes Subglacial Basin remains challenging since the ice-sheet hides the geology beneath kilometers of ice. As a step in understanding the potential for future ice loss in the Wilkes Subglacial Basin this project will conduct geophysical analysis of existing data to better constrain the geology of the region. These results will constrain new models designed to understand the tectonics that control the behavior of the ice-sheets in the region. These new models will highlight the geological properties that exert the most significant control on the future of the ice-sheets of the Wilkes Subglacial Basin. Such insights are critical to guide future efforts aimed at collecting in-situ observations needed to more fully constrain Antarctica's potential for future sea-level. <br/><br/> Part II: Technical Description <br/>In polar environments, inward-sloping marine basins are susceptible to an effect known as the marine ice-sheet instability (MISI): run-away ice stream drainage caused by warm ocean water eroding the ice shelf from below. The magnitude and time-scale of the ice-sheet response strongly depend on the physical conditions along the ice-bed interface, which are, to a first order, controlled by the tectonic evolution of the basin. Topography, sedimentology, geothermal heat flux, and mantle viscosity all play critical roles in ice-sheet stability. However, in most cases, these solid-Earth parameters for regions susceptible to the MISI are largely unknown. One region with potential susceptibility to MISI is the Wilkes Subglacial Basin of East Antarctica. The project will provide an integrated investigation of the Wilkes Subglacial Basin, combining geophysical analyses with both mantle flow and ice-sheet modeling to understand the stability of the ice sheet in this region, and the associated potential sea level rise. The work will be focused on four primary objectives: (1) to develop an improved tectonic model for the region based on existing seismic observations as well as existing geophysical and geological data; (2) to use the new tectonic model and seismic data to estimate the thermal, density, and viscosity structure of the upper mantle and to develop a heat flow map for the WSB; (3) to simulate mantle flow and to assess paleotopography based on our density and viscosity constraints; and (4) to assess ice-sheet behavior by modeling (a) past ice-sheet stability using our paleotopography estimates and (b) future ice-sheet stability using our heat flow and mantle viscosity estimates. Ultimately, the project will generate improved images of the geophysical structure beneath the WSB that will allow us to assess the geodynamic origin for this region and to assess the influence of geologic parameters on past, current, and future ice-sheet behavior. These efforts will then highlight areas and geophysical properties that should be the focus of future geophysical deployments.
This project will test the hypothesis that physical and thermal properties of Antarctic firn--partially compacted granular snow in an intermediate stage between snow and glacier ice--can be remotely measured from space. Although these properties, such as internal temperature, density, grain size, and layer thickness, are highly relevant to studies of Antarctic climate, ice-sheet dynamics, and mass balance, their measurement currently relies on sparse in-situ surveys under challenging weather conditions. Sensors on polar-orbiting satellites can observe the entire Antarctic every few days during their years-long lifetime. Consequently, the approaches developed in this study, when coupled with the advancing technologies of small and low-cost CubeSats, aim to contribute to Antarctic science and lead to cost-effective, convenient, and accurate long-term analyses of the Antarctic system while reducing the human footprint on the continent. Moreover, the project will be solely based on publicly-available datasets; thus, while contributing to interdisciplinary undergraduate and graduate research and education at the grantee's institution, the project will also encourage engagement of citizen scientists through its website.
The overarching goal of this project is to characterize Antarctic firn layers in terms of their thickness, physical temperature, density, and grain size through multi-frequency microwave radiometer measurements from space. Electromagnetic penetration depth changes with frequency in ice; thus, multi-frequency radiometers are able to profile firn layer properties versus depth. To achieve its objective, the project will utilize the Global Precipitation Measurement (GPM) satellite constellation as a single multi-frequency microwave radiometer system with 11 frequency channels observing the Antarctic Ice Sheet. Archived in-situ measurements of Antarctic firn density, grain size, temperature, and layer thickness will be collected and separated into training and test datasets. Microwave emissions simulated using the training data will be compared to GPM constellation measurements to evaluate and improve state-of-the-art forward microwave emission models. Based on these models, the project will develop numerical retrieval algorithms for the thermal and physical properties of Antarctic firn. Results of retrievals will be validated using the test dataset, and uncertainty and error analyses will be conducted. Lastly, changes in the thermal and physical characteristics of Antarctic firn will be examined through long-term retrieval studies exploiting GPM constellation measurements.
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.
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.
Understanding and being able to anticipate changes in the glaciological regime of the Ross Ice Shelf (RIS) and West Antarctic Ice Sheet (WAIS) are key to improving sea level rise projections due to ongoing ice mass loss in West Antarctica. The fate of the WAIS is a first-order climate change and global societal issue for this century and beyond that affects coastal communities and coastal infrastructure globally.
Ice shelf--ocean interactions include impacts from tsunami, ocean swell (10-30s period), and very long period ocean waves that impact ice shelves and produce vibrations that induce a variety of seismic signals detected by seismometers buried in the ice shelf surface layer, called firn. To study the wave-induced vibrations in the RIS, an extensive seismic array was deployed from Nov. 2014 to Nov. 2016. This unique seismometer array deployment on an ice shelf made continuous observations of the response of the RIS to ocean wave impacts from ocean swell and very long period waves. An extensive description of the project motivation and background (including photos and videos of the deployment operations), and list of published studies of analyses of the seismic data collected by this project, are available at the project website https://iceshelfvibes.ucsd.edu.
Two types of seismic signals detected by the seismic array are most prevalent: flexural gravity waves (plate waves) and icequakes (signals analogous to those from earthquakes but from fracturing of the ice).
Long period ocean waves flex the ice shelf at the same period as the ocean waves, with wave energy at periods greater than ocean swell more efficient at coupling energy into flexing the ice shelf. Termed flexural gravity waves or plate waves (Chen et al., 2018), their wave-induced vibrations can reach 100’s of km from the ice edge where they are excited, with long period wave energy propagating in the water layer below the shelf coupled with the ice shelf flexure. Flexural gravity waves at very long periods (> 300 s period), such as from tsunami impacts (Bromirski et al., 2017), can readily reach grounding zones and may play a role in long-term grounding zone evolution.
Swell-induced icequake activity was found to be most prevalent at the shelf front during the austral summer (January – March) when seasonal sea ice is absent and the associated damping of swell by sea ice is minimal (Chen et al., 2019).
In addition to the seismic array, a 14 station GPS (global positioning system) array was installed during seismic data retrieval and station servicing operations in October-November 2015. The GPS stations, co-located with seismic stations, extended from the shelf front southward to about 415 km at interior station RS18. Due to logistical constraints associated with battery weight during installation, only one station (at DR10) operated year-round. The GPS data collected give a detailed record of changes in iceflow velocity that are in close agreement with the increasing velocity estimates approaching the shelf front from satellite observations. Importantly, the year-round data at DR10 show an unprecedented seasonal cycle of changes in iceflow velocity, with a speed-up in northward (seaward) ice flow during Jan.-May and then a velocity decrease from June-Sep. (returning to the long-term mean flow velocity). This annual ice flow velocity change cycle has been attributed in part to seasonal changes in ice shelf mass (thinning, reducing buttressing) due to melting at the RIS basal (bottom) surface from intrusion of warmer ocean water (Klein et al., 2020).
This award funds the continued management and operations (M&O) of the IceCube Neutrino Observatory (ICNO) located at the South Pole Station. The core team of researchers and engineers maintain the existing ICNO infrastructure at the South Pole and home institution, guaranteeing an uninterrupted stream of scientifically unique, high-quality data. The M&O activities are built upon eight highly successful years of managing the overall ICNO operations after the start of science operations in 2008. Construction of ICNO was supported by NSF's Major Research Equipment and Facilities Construction (MREFC) account and was completed on schedule and within budget in 2010. Effective coordination of efforts by the core M&O personnel and efforts by personnel within the IceCube Collaboration has yielded significant increases in the performance of this cubic-kilometer detector over time. The scientific output from the IceCube Collaboration during the past five years has been outstanding. <br/><br/>The broader impacts of the ICNO/M&O activities are strong, involving postdoctoral, graduate, and (in some cases) undergraduate students in the day-today operation & calibration of the neutrino detector. The extraordinary physics results recently produced by ICNO and its extraordinary location at South Pole have a high potential to excite the imagination of high school children and the public in general at a national and international level.<br/><br/>The current ICNO/M&O effort produces better energy and angular resolution information about detected neutrino events, has more efficient data filters and more accurate detector simulations, and enables continuous software development for systems that are needed to acquire and analyze data. This has produced data acquisition and data management systems with high robustness, traceability, and maintainability. The current ICNO/M&O effort includes: (1) resources for both distributed and centrally managed activities, and (2) additional accountability mechanisms for "in-kind" and institutional contributions. Both are necessary to ensure that the detector maintains its capability to produce quality scientific data at the level required to achieve the detector's scientific discovery objectives. Recent ICNO discoveries of cosmic high-energy neutrinos (some reaching energies close to and over 2.5 PeV) and oscillating atmospheric neutrinos in a previously unexplored energy range from 10 to 60 GeV became possible because of the "state-of-the-art" detector configuration, excellently supported infrastructure, and cutting-edge science analyses. The ICNO has set limits on Dark Matter annihilations, made precision measurements of the angular distribution of cosmic ray muons, and characterized in detail physical properties of the Antarctic 2.5-km thick ice sheet at South Pole. The discovery of high-energy cosmic neutrinos by IceCube with a flux at the level anticipated for those associated with high-energy gamma- and cosmic-ray accelerators brightens the prospect for identifying the sources of the highest energy particles.
This award supports a project to develop software that will allow researchers considering seismic or radar field surveys to test, ahead of time, whether the data they plan to collect will have sufficient resolution to measure the natural variations in the mechanical properties of ice, which determine the response of flowing ice to changing climatic conditions. The mechanical properties of ice depend largely on the temperature and the orientation of the crystals that make up the ice. The most accurate method for measuring ice crystal orientation and temperature is through drilling and direct analysis of an ice core. However, this method is very costly, time-consuming, and limited in spatial coverage. Geophysical techniques, such as seismic and radar, can cover much more area, but we have little knowledge about the practical limitations of these techniques as they relate to calculating mechanical properties. This project addresses that knowledge gap through construction of a computational toolbox that will allow accurate assessment of the ability of geophysical surveys to image crystal orientation and ice temperature. Researchers can then use these tools to adjust the field survey plans to maximize the return on investment. By working to improve the efficiency and effectiveness of future geophysical work related to glacial flow, this proposal will improve scientists? ability to quantify sea-level variations within the larger context of climate change. The project includes building new user-friendly, publicly accessible software and instructional modules. The work will provide training for graduate and undergraduate students, who will play a role in research and develop instructional materials.
Ice viscosity, the resistance of ice to flow, exerts significant control over ice velocity. Therefore, mapping ice viscosity is important for understanding the current and future behavior of glaciers and ice sheets. To do so, scientists must determine the temperature and crystal orientation fabric throughout the ice. Seismic and radar techniques can survey large areas quickly, and thus are promising, yet not fully tested, methods to efficiently measure the thermal and mechanical structure of flowing ice. As part of this project, scientists will develop and use a computational framework to quantify the degree to which seismic and radar techniques can resolve the crystal orientation fabric and temperature of streaming ice, and then test how sensitive ice flow is to the attendant uncertainty. To meet these goals, a numerical toolbox will be built which will allow the glacier/ice stream geometry and physical properties (temperature, crystal orientation fabric, density and acidity) to be varied. The toolbox will be capable of both creating synthetic radar and seismic profiles through forward modeling and inverting synthetic profiles to allow evaluation of how well geophysical techniques can image the original thermal and mechanical structure. These simulated radar and seismic data will allow scientists to better quantify the influence of the variability in mechanical properties of the ice on flow velocities and patterns. The results of this work will guide planning for future field campaigns, making them more effective and efficient. This project does not require fieldwork in the Antarctic.
This award supports a project to undertake a systematic examination of the effects of soluble impurities, particularly sulfuric acid, on the creep of polycrystalline ice as function of temperature, strain rate and impurity concentration. The working hypothesis is that soluble impurities will increase the flow rate of polycrystalline ice compared to high-purity ice, that this effect will be temperature dependent and that the impurities by affecting the re-crystallization and grain growth will change the fabric of the ice. Both H2SO4-doped and high-purity poly-crystalline ice will be produced by freezing sheets of ice, breaking them up, sieving the ice particles and then sintering them in a mold into fine-grained cylindrical specimens with at least ten grains across their diameter. The resulting microstructures (dislocation structure, grain size and shape, grain boundary character and micro-structural location of the acid) will be characterized using a variety of techniques including: optical microscopy, scanning electron microscopy, including secondary electron imaging, electron backscattered patterns, energy dispersive X-ray spectroscopy, electron channeling contrast imaging, and X-ray topography. The creep of both the H2SO4-doped and the high-purity polycrystalline ice will be undertaken at a range of temperatures and stresses. The ice?s response to the creep deformation (grain boundary sliding, dislocation motion, re-crystallization, grain boundary migration, impurity redistribution) will be studied using a combination of methods. The creep behavior will be modeled and related to the microstructure. Of particular interest is how impurities affect the activation energy for creep. The intellectual merit of the work is that it will lead to a better understanding of glacier ice and will enable glaciologists to model the influence of impurities on the flow and fabric development in polycrystalline ice. The broader impacts of the project include the knowledge that will be gained of the effects of impurities on the flow of ice which will allow paleoclimatologists to better interpret ice core data and will allow scientists developing predictive models to better address the flow of ice sheets under various climate change scenarios. The project will also lead to the education and training of a Ph.D. student, several undergraduates and some high school students. Results from the research will be published in refereed journals. Several undergraduates, typically two per year, will also perform the work. Dartmouth aggressively courts minority students at all degree levels, and we will seek women or minority group undergraduates for this project. The undergraduates will be supported by Dartmouth?s nationally-honored Women In Science Project or by REU funding. The undergraduates? research will integrate closely with the Ph.D. student?s studies. Hanover High School students will also be involved in the project and develop an educational kit to introduce students to the properties of ice. Results from the research will be published in refereed journals and presented at conferences.
The Antarctic subglacial environment remains one of the least explored regions on Earth. This project will examine the physical and biological characteristics of Subglacial Lake Mercer, a lake that lies 1200m beneath the West Antarctic Ice Sheet. This study will address key questions relating to the stability of the ice sheet, the subglacial hydrological system, and the deep-cold subglacial biosphere. The education and outreach component aims to widely disseminate results to the scientific community and to the general public through short films, a blog, and a website.<br/><br/>Subglacial Lake Mercer is one of the larger hydrologically active lakes in the southern basin of the Whillans Ice Plain, West Antarctica. It receives about 25 percent of its water from East Antarctica with the remainder originating from West Antarctica, is influenced by drain/fill cycles in a lake immediately upstream (Subglacial Lake Conway), and lies about 100 km upstream of the present grounding line of the Ross Ice Shelf. This site will yield information on the history of the Whillans and Mercer Ice Streams, and on grounding line migration. The integrated study will include direct sampling of basal ice, water, and sediment from the lake in concert with surface geophysical surveys over a three-year period to define the hydrological connectivity among lakes on the Whillans Ice Plain and their flow paths to the sea. The geophysical surveys will furnish information on subglacial hydrology, aid the site selection for hot-water drilling, and provide spatial context for interpreting findings. The hot-water-drilled boreholes will be used to collect basal ice samples, provide access for direct measurement of subglacial physical, chemical, and biological conditions in the water column and sediments, and to explore the subglacial water cavities using a remotely operated vehicle equipped with sensors, cameras, and sampling equipment. Data collected from this study will address the overarching hypothesis \"Contemporary biodiversity and carbon cycling in hydrologically-active subglacial environments associated with the Mercer and Whillans ice streams are regulated by the mineralization and cycling of relict marine organic matter and through interactions among ice, rock, water, and sediments\". The project will be undertaken by a collaborative team of scientists, with expertise in microbiology, biogeochemistry, hydrology, geophysics, glaciology, marine geology, paleoceanography, and science communication.
This dataset comprises new photographs and measurements of a WAIS Divide vertical thin section, WDC-06A 420 VTS, previously prepared and measured by J. Fitzpatrick, D. E. Voigt, and R. Alley (dataset DOI: 10.7265/N5W093VM; http://www.usap-dc.org/view/dataset/609605) as part of a larger study of the WAIS Divide ice core (Fitzpatrick, J. et al, 2014, Physical properties of the WAIS Divide ice core, Journal of Glaciology, 60, 224, 1181-1198. (doi:10.3189/2014JoG14J100). These images were taken as a design test of our new automated lightweight c-axis analyzer, dubbed ALPACA, which implements the ice fabric analysis functionality of the Wilen system used by Fitzpatrick et al. in an easily-portable, field-deployable form factor.
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.<br/><br/>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.<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.
This award supports the deployment and analysis of data from an oriented laser dust logger in the South Pole ice core borehole to complement study of the ice core record. Before the core is even processed, data from the borehole probe will immediately determine the depth-age relationship, augment 3D mapping of South Pole stratigraphy, aid in searches for the oldest ice in Antarctica, and reveal layers of volcanic or extraterrestrial fallout. Regarding the intellectual merit, the oriented borehole log will be essential for investigating features in the ice sheet that may have implications for ice core chronology, ice flow, ice sheet physical properties and stability in response to climate change. The tools and techniques developed in this program have applications in glaciology, biogeoscience and exploration of other planetary bodies. The program aims for a deeper understanding of the consequences and causes of abrupt climate change. The broader impacts of the project are that it will include outreach and education, providing a broad training ground for students and post-docs. Data and metadata will be made available through data centers and repositories such as the National Snow and Ice Data Center web portal. <br/><br/>The laser dust logger detects reproducible paleoclimate features at sub-centimeter depth scale. Dust logger data are being used for synchronizing records and dating any site on the continent, revealing accumulation anomalies and episodes of rapid ice sheet thinning, and discovering particulate horizons of special interest. In this project we will deploy a laser dust logger equipped with a magnetic compass to find direct evidence of preferentially oriented dust. Using optical scattering measurements from IceCube calibration studies at South Pole and borehole logs at WAIS Divide, we have detected a persistent anisotropy correlated with flow and crystal fabric which suggests that the majority of insoluble particulates must be located within ice grains. With typical concentrations of parts-per-billion, little is known about the location of impurities within the polycrystalline structure of polar ice. While soluble impurities are generally thought to concentrate at inter-grain boundaries and determine electrical conductivity, the fate of insoluble particulates is much less clear, and microscopic examinations are extremely challenging. These in situ borehole measurements will help to unravel intimate relationships between impurities, flow, and crystal fabric. Data from this project will further develop a unique record of South Pole surface roughness as a proxy for paleowind and provide new insights for understanding glacial radar propagation. This project has field work in Antarctica.
The Southern Ocean surrounding Antarctica is changing rapidly in response to Earth's warming climate. These changes will undoubtedly influence communities of primary producers (the organisms at the base of the food chain, particularly plant-like organisms using sunlight for energy) by altering conditions that influence their growth and composition. Because primary producers such as phytoplankton play an important role in global biogeochemical cycling, it is essential to understand how they will respond to changes in their environment. The growth of phytoplankton in certain regions of the Southern Ocean is constrained by steep gradients in chemical and physical properties that vary in both space and time. Light and iron have been identified as key variables influencing phytoplankton abundance and distribution within Antarctic waters. Microscopic algae known as diatoms are dominant members of the phytoplankton and sea ice communities, accounting for significant proportions of primary production. The overall objective of this project is to identify the molecular bases for the physiological responses of polar diatoms to varying light and iron conditions. The project should provide a means of evaluating the extent these factors regulate diatom growth and influence net community productivity in Antarctic waters. Although numerous studies have investigated how polar diatoms are affected by varying light and iron, the cellular mechanisms leading to their distinct physiological responses remain unknown. We observed several growth responses, but a majority of polar diatom growth rates and photophysiology did not appear to be co-limited by iron and light limitation. Using comparative transcriptomics, we have examined the expression patterns of key genes and metabolic pathways in several ecologically important polar diatoms isolated from Antarctic waters and grown under varying iron and irradiance conditions. In addition, molecular indicators for iron and light limitation will be developed within these polar diatoms through the identification of iron- and light-responsive genes -- the expression patterns of which can be used to determine their physiological status. Upon verification in laboratory cultures, these indicators will be utilized by way of metatranscriptomic sequencing to examine iron and light limitation in natural diatom assemblages collected along environmental gradients in Western Antarctic Peninsula waters. In order to fully understand the role phytoplankton play in Southern Ocean biogeochemical cycles, dependable methods that provide a means of elucidating the physiological status of phytoplankton at any given time and location are essential.
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. <br/> <br/>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.
Antarctic clouds constitute an important parameter of the surface radiation budget and thus play a significant role in Antarctic climate and climate change. The variability in, and long term trends of, cloud optical and microphysical properties are therefore fundamental in parameterizing the mixed phase (water-snow-ice) coastal Antarctic stratiform clouds experienced around the continent.<br/><br/>Using a spectoradiometer that covers the wavelength range of 350 to 2200nm, the downwelled spectral irradiance at the earth surface (Ross Island) will be used to retrieve the optical depth, thermodynamic phase, liquid water droplet effective radius, and ice-cloud effective particle size of overhead clouds, at hourly intervals and for an austral summer season (Oct-March). Based on the very limited data sets that exist for the maritime Antarctic, expectations are that Ross Island (Lat 78 S) should exhibit clouds with:<br/>a) An abundance of supercooled liquid water, and related mixed-phase cloud processes<br/>b) Cloud nucleation from year round biogenic and oceanic sources, in an otherwise pristine environment<br/>c) Simple cloud geometries of predominantly stratiform cloud decks<br/><br/>Increased understanding of the cloud properties in the region of the main USAP base, McMurdo station is also relevant to operational weather forecasting relevant to aviation. A range of educational and outreach activities are associate with the project, including provision of workshops for high school teachers will be carried out.
This award supports a three-year effort to study physical properties of the South Pole ice core to help provide a high-time-resolution history of trace gases and other paleoclimatic indicators from an especially cold site with high preservation potential for important signals. The physical-properties studies include visual inspection to identify any flow disturbances and for identifying annual layers and other features, and combined bubble, grain and ice crystal orientation studies to better understand the processes occurring in the ice that affect the climate record and the ice-sheet behavior. Success of these efforts will provide necessary support for dating and quality control to others studying the ice core, as well as determining the climate history of the site, flow state, and key physical processes in ice.<br/><br/>The intellectual merits of the project include better understanding of physical processes, paleoclimatic reconstruction, dating of the ice, and quality assurance. Visual inspection of the core will help identify evidence of flow disturbances that would disrupt the integrity of the climate record and will reveal volcanic horizons and other features of interest. Annual layer counting will be conducted to help estimate accumulation rate over time as recorded in the ice core. Measurements of C-axis fabric, grain size and shapes, and bubble characteristics will provide information about processes occurring in the ice sheet as well as the history of ice flow, current flow state and how the ice is flowing and how easily it will flow in the future. Analysis of this data in conjunction with microCT data will help to reveal grain-scale processes. The broader impacts of the project include support for an early-career, post-doctoral researcher, and improved paleoclimatic data of societal relevance. The results will be incorporated into the active program of education and outreach which have educated many students, members of the public and policy makers through the sharing of information and educational materials about all aspects of ice core science and paleoclimate.
Alley/1142085<br/><br/>This award supports a project to continue the collection and analyses of firn temperature data from three automated firn thermal profiling units deployed in Dronning Maud Land sector of East Antarctica as part of the Norway-US IPY Traverse project between 2007 and 2009. The intellectual merits of this project are as follows: 1) to constrain and improve the parameterization of firn thermal properties (thermal conductivity and specific heat capacity) that are required for the borehole paleothermometry, 2) to study the change in firn temperature since the deployment of thermal profiling units ~5 years ago and derive the surface temperature trend for that time period, and 3) to compare and contrast the surface temperatures and their trends derived from the measured firn temperatures and satellite thermal infrared data for the past three decades. The project also involves acquiring and deploying an automated system to record transient temperatures at multiple depths in the top 16 meters of the shallow borehole at Dome Fuji, to provide useful data and to prepare for the possibility of conducting temperature-logging in the existing deep (3035 m) and shallow (112 m) boreholes at Dome Fuji in the near future. The preparation of the shallow borehole and the installation of the automated system will be carried out by collaborators from the Japanese Antarctic Research Expedition (JARE) in 2012-13 Antarctic field season. The data collected by this automated system will be used to constrain the thermal properties of upper firn layer at Dome Fuji, as well as comparing with data from other sites, increasing the geographic extent of these studies. The broader impacts of the project include presentation of results at scientific conferences and publication of results in peer-reviewed journals. Public outreach will include targeted work with science teachers and middle school students.
This award supports a project to help to establish the depth-age chronology and the histories of accumulation and ice dynamics for the WAIS Divide ice core. The depth-age relationship and the histories of accumulation and ice dynamics are coupled. An accurate age scale is needed to infer histories of accumulation rate and ice-thickness change using ice-flow models. In turn, the accumulation-rate history is needed to calculate the age difference of ice to determine the age of the trapped gases. The accumulation history is also needed to calculate atmospheric concentrations of impurities trapped in the ice and is an important characteristic of climate. The history of ice-thickness change is also fundamental to understanding the stability of the WAIS. The primary goals of the WAIS Divide ice core project are to investigate climate forcing by greenhouse gases, the initiation of climate changes, and the stability of the West Antarctic Ice Sheet (WAIS). An accurate age scale is fundamental for achieving these goals. The first objective of this project is to establish an annually resolved depth-age relationship for the past 40,000 years. This will be done by measuring variations in electrical conductivity along the ice core, which are caused by seasonal variations in chemistry. We expect to be able to resolve annual layers back to 40,000 years before present (3,000 m depth) using this method. The second objective is to search for stratigraphic disturbances in the core that would compromise the paleoclimate record. Irregular layering will be identified by measuring the electrical conductivity of the ice in a vertical plan through the core. The third objective is to derive a preliminary chronology for the entire core. For the deeper ice we will use an ice-flow model to interpolate between known age markers, such as dated volcanic horizons and tie points from the methane gas chronology. The fourth objective is to derive a refined chronology simultaneously with histories of accumulation and ice-sheet thickness. An ice-flow model and all available data will be used to formulate an inverse problem, in which we infer the most appropriate histories of accumulation and ice-thickness, together with estimates of uncertainties. The flow model associated with those preferred histories then produces the best estimate of the chronology. The research contributes directly to the primary goals of the West Antarctic Ice Sheet Initiative. The project will help develop the next generation of scientists through the education and training of one Ph.D. student and several undergraduate students. This project will result in instrumentation for measuring the electrical conductivity of ice cores being available at the National Ice Core Lab for other researchers to use on other projects. All collaborators are committed to fostering diversity and currently participate in scientific outreach and most participate in undergraduate education. Outreach will be accomplished through regularly scheduled community and K-12 outreach events at UW, talks and popular writing by the PIs, as well as through our respective press offices.
0538427<br/>McConnell <br/>This award supports a project to use unique, high-depth-resolution records of a range of elements, chemical species, and ice properties measured in two WAIS Divide shallow ice cores and one shallow British ice core from West Antarctic to address critical paleoclimate, environmental, and ice-sheet mass-balance questions. Recent development of the CFA-TE method for ice-core analysis presents the opportunity to develop high-resolution, broad-spectrum glaciochemical records at WAIS Divide at relatively modest cost. Together with CFA-TE measurements from Greenland and other Antarctic sites spanning recent decades to centuries, these rich data will open new avenues for using glaciochemical data to investigate environmental and global changes issues ranging from anthropogenic and volcanic-trace-element fallout to changes in hemispheric-scale circulation, biogeochemistry, rapid-climate-change events, long-term climate change, and ice-sheet mass balance. As part of the proposed research, collaborations with U.S., Argentine, and British researchers will be initiated and expanded to directly address three major IPY themes (i.e., present environmental status, past and present environmental and human change, and polar-global interactions). Included in the contributions from these international collaborators will be ice-core samples, ice-core and meteorological model data, and extensive expertise in Antarctic glaciology, climatology, meteorology, and biogeochemistry. The broader impacts of the work include the training of students. The project will partially support one Ph.D. student and hourly undergraduate involvement. Every effort will be made to attract students from underrepresented groups to these positions. To address the challenge of introducing results of scientific research to the public policy debate, we will continue efforts to publish findings in high visibility journals, provide research results to policy makers, and work with the NSF media office to reach the public through mass-media programs. K-12 teacher and classroom involvement will be realized through outreach to local schools and NSF's Teachers Experiencing the Antarctic and Arctic (or similar) program in collaboration with WAIS Divide and other polar researchers.
0539578<br/>Alley <br/>This award supports a five-year collaborative project to study the physical-properties of the planned deep ice core and the temperature of the ice in the divide region of the West Antarctic Ice Sheet. The intellectual merit of the proposed research is to provide fundamental information on the state of the ice sheet, to validate the integrity of the climate record, to help reconstruct the climate record, and to understand the flow state and history of the ice sheet. This information will initially be supplied to other investigators and then to the public and to appropriate databases, and will be published in the refereed scientific literature. The objectives of the proposed research are to aid in dating of the core through counting of annual layers, to identify any exceptionally warm intervals in the past through counting of melt layers, to learn as much as possible about the flow state and history of the ice through measurement of size, shape and arrangements of bubbles, clathrate inclusions, grains and their c-axes, to identify any flow disturbances through these indicators, and to learn the history of snow accumulation and temperature from analyses of bubbles and borehole temperatures combined with flow modeling and use of data from other collaborators. These results will then be synthesized and communicated. Failure to examine cores can lead to erroneous identification of flow features as climate changes, so careful examination is required. Independent reconstruction of accumulation rate provides important data on climate change, and improves confidence in interpretation of other climate indicators. Borehole temperatures are useful recorders of temperature history. Flow state and history are important in understanding climate history and potential contribution of ice to sea-level change. By contributing to all of these and additional issues, the proposed research will be of considerable value. The broader impacts of the research include making available to the public improved knowledge on societally central questions involving abrupt climate change and sea-level rise. The project will also contribute to the education of advanced students, will utilize results in education of introductory students, and will make vigorous efforts in outreach, informal science education, and supplying information to policy-makers as requested, thus contributing to a more-informed society.
This award supports a three-year study of the ongoing deceleration and stick-slip motion of Whillans Ice Stream (WIS), West Antarctica. Understanding the dynamic behavior of ice streams is essential for predicting the future of the West Antarctic Ice Sheet (WAIS). Despite being one of the best-studied ice streams in Antarctica, the surprising flow characteristics of WIS continue to demand interdisciplinary research. Recent estimates indicate that the WIS may stagnate within 50 years, resulting in a significant change to the mass balance of the Siple Coast sector of West Antarctica. The reasons for the ongoing stagnation are not well known, and are possibly linked (causally or coincidentally) to the stick-slip behavior. Our recent work on WIS stick-slip motion suggest that all slip events nucleate from a common location on the ice stream, suggesting that a relatively small (approximately 10 km in diameter) region of the exerts fundamental control over the flow of this large ice stream (100s of km long and 100 kilometers wide). We hypothesize that this is a region of increased bed strength and our measurements will address that hypothesis. We will deploy a series of GPS receivers and seismometers on the ice stream to accurately locate the nucleation region so that a comprehensive ground based geophysical survey can be conducted to determine the physical properties of bed at the nucleation point. The ground geophysical program will consist of reflection seismic and ice-penetrating radar studies that will better constrain the properties of both the hypothesized higher-friction nucleation zone and the surrounding regions. Slip events also generate seismic energy that can be recorded 100s of km away from the ice stream, thus, the GPS and seismometer deployment will also aid us in relating seismic waveforms directly with the rapid motion that occurs during slip events. The increased ability to relate rupture processes with seismic emissions will allow us to use archived seismic records to explore changes in the behavior of WIS during the later half of the 20th century. Broader impacts of this study include improved knowledge ice sheet dynamics, which remain a poorly constrained component of the climate system, thus, limiting our ability to predict the Earth's response to climate change. The scientific work includes the education of two graduate students and continued training of one post-doctoral scholar, thus helping to train the next generation of polar scientists. We will expose the broader public to polar science through interactions with the media and by take advantaging of programs to include K-12 educators in our field work.
Intellectual Merit: <br/>Knowledge of englacial and subglacial conditions are critical for ice sheet models and predictions of sea-level change. Some of the critical variables that are poorly known but essential for improving flow models and predictions of sea-level change are: basal roughness, subglacial sedimentary and hydrologic conditions, and the temporal and spatial variability of the ice sheet flow field. Seismic reflection and refraction imaging and dense arrays of continuously operating GPS receivers can determine these parameters. The PIs propose to develop a network of wirelessly interconnected geophysical sensors (geoPebble) that will allow glaciologists to carry out these experiments simultaneously. This sensor web will provide a new way of imaging the ice sheet that is not possible with current instruments. With this sensor web, the PIs will extend the range of existing instruments from 2D to 3D, from low resolution to high resolution, but more importantly, all the geophysical measurements will be conducted synchronously. By the end of the proposal period the PIs will produce a network of 150-200 geoPebbles that will be available for NSF-sponsored glaciology research projects. <br/><br/>Broader impacts: <br/>Improved knowledge of the flow law of ice, the sliding of glaciers and ice streams, and paleoclimate history will contribute to assessments of the potential for abrupt ice-sheet mass change, with consequent sea-level effects and significant societal impacts. This improved modeling ability will be a direct consequence of better knowledge of the physical properties of ice sheets, which this project will facilitate. The development effort will be integrated with the undergraduate education program via the capstone design classes in EE and the senior thesis requirement in Geoscience. The PIs will also form a cohort of first-year and sophomore students who will work in their labs from the beginning of the project to develop specifications through the commissioning of the network.
This project constructs POLENET a network of GPS and seismic stations in West Antarctica to understand how the mass of the West Antarctic ice sheet (WAIS) changes with time. The information is ultimately used to predict sea level rise accompanying global warming and interpret climate change records. The GPS (global positioning system) stations measure vertical and horizontal movements of bedrock, while the seismic stations characterize physical properties of the ice/rock interface, lithosphere, and mantle. Combined with satellite data, this project offers a more complete picture of the ice sheet's current state, its likely change in the near future, and its overall size during the last glacial maximum. This data will also be used to infer sub-ice sheet geology and the terrestrial heat flux, critical inputs to models of glacier movement. As well, this project improves tomographic models of the earth's deep interior and core through its location in the Earth's poorly instrumented southern hemisphere. <br/><br/><br/><br/>Broader impacts of this project are varied. The work is relevant to society for improving our understanding of the impacts of global warming on sea level rise. It also supports education at the postdoctoral, graduate, and undergraduate levels, and outreach to groups underrepresented in the sciences. As an International Polar Year contribution, this project establishes a legacy of infrastructure for polar measurements. It also involves an international collaboration of twenty four countries. For more information see IPY Project #185 at IPY.org. NSF is supporting a complementary Arctic POLENET array being constructed in Greenland under NSF Award #0632320.
0944199/Matsuoka<br/><br/>This award supports a project to test the hypothesis that abrupt changes in fabric exist and are associated with both climate transitions and volcanic eruptions. It requires depth-continuous measurements of the fabric. By lowering a new logging tool into the WAIS Divide borehole after the completion of the core drilling, this project will measure acoustic-wave speeds as a function of depth and interpret it in terms of ice fabrics. This interpretation will be guided by ice-core-measured fabrics at sparse depths. This project will apply established analytical techniques for the ice-sheet logging and estimate depth profiles of both compressional- and shear-wave speeds at short intervals (~ 1 m). Previous logging projects measured only compressional-wave speeds averaged over typically 5-7 m intervals. Thus the new logger will enable more precise fabric interpretations. Fabric measurements using thin sections have revealed distinct fabric patterns separated by less than several meters; fabric measurements over a shorter period are crucial. At the WAIS Divide borehole, six two-way logging runs will be made with different observational parameters so that multiple wave-propagation modes will be identified, yielding estimates of both compressional- and shear-wave speeds. Each run takes approximately 24 hours to complete; we propose to occupy the boreholes in total eight days. The logging at WAIS Divide is temporarily planned in December 2011, but the timing is not critical. This project?s scope is limited to the completion of the logging and fabric interpretations. Results will be immediately shared with other WAIS Divide researchers. Direct benefits of this data sharing include guiding further thin-section analysis of the fabric, deriving a precise thinning function that retrieves more accurate accumulation history and depth-age scales. The PIs of this project have conducted radar and seismic surveys in this area and this project will provide a ground truth for these regional remote-sensing assessments of the ice interior. In turn, these remote sensing means can extend the results from the borehole to larger parts of the central West Antarctica. This project supports education for two graduate students for geophysics, glaciology, paleoclimate, and polar logistics. The instrument that will be acquired in this project can be used at other boreholes for ice-fabric characterizations and for englacial hydrology (wetness of temperate ice).
This award supports a project to investigate the transformations from snow to firn to ice and the underlying physics controlling firn's ability to store atmospheric samples from the past. Senior researchers, a graduate student, and several undergraduates will make high-resolution measurements of both the diffusivity and permeability profiles of firn cores from several sites in Antarctica and correlate the results with their microstructures quantified using advanced materials characterization techniques (scanning electron microscopy and x-ray computed tomography). The use of cores from different sites will enable us to examine the influence of different local climate conditions on the firn structure. We will use the results to help interpret existing measurements of firn air chemical composition at several sites where firn air measurements exist. There are three closely-linked goals of this project: to quantify the dependence of interstitial transport properties on firn microstructure from the surface down to the pore close-off depth, to determine at what depths bubbles form and entrap air, and investigate the extent to which these features exhibit site-to-site differences, and to use the measurements of firn air composition and firn structure to better quantify the differences between atmospheric composition (present and past), and the air trapped in both the firn and in air bubbles within ice by comparing the results of the proposed work with firn air measurements that have been made at the WAIS Divide and Megadunes sites. The broader impacts of this project are that the study will this study will enable us to elucidate the fundamental controls on the metamorphism of firn microstructure and its impact on processes of gas entrapment that are important to understanding ice core evidence of past atmospheric composition and climate change. The project will form the basis for the graduate research of a PhD student at Dartmouth, with numerous opportunities for undergraduate involvement in cold room measurements and outreach. The investigators have a track record of successfully mentoring women students, and will build on this experience. In conjunction with local earth science teachers, and graduate and undergraduate students will design a teacher-training module on the role of the Polar Regions in climate change. Once developed and tested, this module will be made available to the broader polar research community for their use with teachers in their communities.
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.
The importance of gelatinous zooplankton in marine systems worldwide is increasing. In Southern Ocean, increasing salp densities could have a detrimental effect on higher predators, including penguins, fur seals, and baleen whales. The proposed research is a methods-develoment project that will improve the capability to indirectly assess abundances and distributions of salps in the Southern Ocean through acoustic surveys. Hydrographic, net tow, and acoustic backscatter data will be collected in the waters surrounding the South Shetland Islands and the Antarctic peninsula, where both krill and salps are found and compete for food. Shipboard experimental manipulations and measurements will lead to improved techniques for assessment of salp biomass acoustically. Experiments will focus on material properties (density and sound speed), size and shape of salps, as well as how these physical properties will vary with the salp's environment, feeding rate, and reproductive status. In the field, volume backscattering data from an acoustic echosounder will be collected at the same locations as the net tows to enable comparison of net and acoustic estimates of salp abundance. A physics-based scattering model for salps will be developed and validated, to determine if multiple acoustic frequencies can be used to discriminate between scattering associated with krill swarms and that from salp blooms. During the same period as the Antarctic field work, a parallel outreach and education study will be undertaken in Long Island, New York examining local gelatinous zooplankton. This study will enable project participants to learn and practice research procedures and methods before traveling to Antarctica; provide a comparison time-series that will be used for educational purposes; and include many more students and teachers in the research project than would be able to participate in the Antarctic field component.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>Two models have been proposed to describe controls over microbial biogeography. One model proposes that microbes are ubiquitously distributed across the global environment, and that environmental conditions select for taxa physiologically adapted to local physical conditions. An alternative model predicts that dispersal is the important limitation to the distribution of microorganisms and that spatial heterogeneity of microbial communities is a result of both dispersal and local environmental limitations. According to both models, spatial heterogeneity of microbial communities may be especially pronounced in extreme ecosystems where the environmental selection for organisms with suitable physiology is most strongly manifest. We propose that Antarctic terrestrial environments are ideal places to examine microbial biogeography for 3 reasons: 1) the pristine nature and remoteness of Antarctica minimizes the prevalence of exotic species dispersed through human vectors; 2) the extreme conditions of Antarctic environments provide a strong environmental filter which limits the establishment of non-indigenous taxa; and 3) extreme heterogeneity in the terrestrial environment provides natural gradients of soil conditions (temperature, water and nutrient availability). In the proposed research we will investigate the influence of snow on the composition and spatial distribution of soil microbial communities and linked biogeochemical cycling in the McMurdo Dry Valleys. We will conduct fieldwork at the landscape scale (repeated remote sensing to characterize snow distribution), at the valley and patch scales (quantify snow patch ablation, microbial communities and biogeochemical cycling in subnivian soils). We hypothesize that snow patches play an important role in structuring the spatial distribution of soil microbial communities and their associated ecosystem functioning because of the physical and hydrological influences that snow patches have on the soil environment. The research will contribute to greater public awareness of the importance of polar research to fundamental questions of biology, ecology and hydrology through direct linkages with International Antarctic Institute public outreach activities, including dissemination of web-based learning units on environmental science and microbiology, targeted as resources for secondary and post-secondary educators. Three graduate students, one postdoctoral scholar and multiple undergraduates will participate in the research activities.
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.
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.
1043528/Alley<br/><br/>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.
Pettit/0636795<br/><br/>This award supports a project to constrain the accumulation rate, thickness, and temperature history for Siple Dome using a vertical velocity profile that includes the effects of an evolving fabric on deformation through time, to invert the depth-profile of fabric determined from sonic velocity measurements and grain size observed in thin sections in Siple Dome for the surface temperature and accumulation rate changes in the past, focusing on the apparent abrupt climate change events at 22ka and 15ka. The intellectual merit of the work is that it will extract past climate information from a number of physical properties of the deep ice using a coupled fabric evolution and ice-sheet flow model. The focus will be on the deep ice-age ice at Siple Dome, where the ice-core record shows puzzling signals and where modeling results imply intriguing deformation patterns. The method will also be applied to the records from Byrd Station and Taylor Dome to ultimately form a basis for future analysis of the West Antarctic Divide core. The broader impacts of the project are that it will ultimately contribute to our understanding of the effects of anisotropy on ice flow dynamics in West Antarctica. It will contribute to our understanding of the connection between ice flow and the paleoclimate record in ice cores, particularly with respect to the relationship between the chemical record and ice deformation. And it will contribute a new ice-flow model that includes the effects of anisotropy and fabric evolution. The project will also contribute to advancing the career of a new, young, female investigator and will support a couple of graduate students. Finally, the work will encouraging diversity in the physical sciences by directly helping to support the Girls on Ice a program that encourages young women to explore science and the natural world.
This award supports a project to understand how recent changes in atmospheric chemistry, and historical changes as recorded in snow, firn and ice, have affected atmospheric photochemistry over Antarctica. Atmospheric, snow and firn core measurements of selected gas, meteorological and snow physical properties will be made and modeling of snow-atmosphere exchange will be carried out. The intellectual merit of the project is that it will lead to a better an understanding of the atmospheric chemistry in West Antarctica, its bi-directional linkages with the snowpack, and how it responds to regional influences. There are at least four broader impacts of this work. First is education of university students at both the graduate and undergraduate levels. One postdoctoral researcher and one graduate student will carry out much of the work, and a number of undergraduates will be involved. Second, involvement with the WAIS-Divide coring program will be used to help recruit under-represented groups as UC Merced students. As part of UC Merced's outreach efforts in the San Joaquin Valley, whose students are under-represented in the UC system, the PI and co-PI give short research talks to groups of prospective students, community college and high school educators and other groups. They will develop one such talk highlighting this project. Including high-profile research in these recruiting talks has proven to be an effective way to promote dialog, and interest students in UC Merced. Third, talks such as this also contribute to the scientific literacy of the general public. The PI and grad student will all seek opportunities to share project information with K-14 and community audiences. Fourth, results of the research will be disseminated broadly to the scientific community, and the researchers will seek additional applications for the transfer functions as tools to improve interpretation of ice-cores. This research is highly collaborative, and leverages the expertise and data from a number of other groups.
Convincing evidence now confirms that polar regions are changing rapidly in response to human activities. Changes in sea ice extent and thickness will have profound implications for productivity, food webs and carbon fluxes at high latitudes, since sea ice biota are a significant source of biogenic matter for the ecosystem. While sea ice is often thought to be a barrier to gas exchange between the ocean and the atmosphere, it more likely functions as a source or sink for climate-active gases such as carbon dioxide and ozone-depleting organohalogens, due in part to activities of microbes embedded in the sea ice matrix. This project brings together experienced US and Swedish investigators to examine the controls by sea-ice biota on the production and degradation of key climate-active gases in the Pacific sector of the Southern Ocean. We hypothesize that 1) the physical properties of the sea-ice environment will determine the community structure and activities of the sea ice biota; 2) the productivity, biomass, physiological state and species composition of ice algae will determine the production of specific classes of organic carbon, including organohalogens; 3) heterotrophic co-metabolism within the ice will break down these compounds to some extent, depending on the microbial community structure and productivity, and 4) the sea ice to atmosphere fluxes of CO2 and organohalogens will be inversely related. This project will build close scientific collaborations between US and Swedish researchers and also train young scientists, including members of underrepresented groups. Dissemination of results will include the scientific literature, and public outreach venues including interactions with a PolarTrec teacher.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The project aims on studying sediment cores collected from Prydz Bay and the Ross Sea to unravel the Neogene paleoclimatic history of the East Antarctic ice sheet. In the light of current measurements and predictions of a substantial rise in global temperature, investigations into the sensitivity of the East Antarctic ice sheet to climate change and its role in the climate system are essential. Geological records of former periods of climate change provide an opportunity to ground truth model predictions. The scientific objective of this project is to identify a previously proposed middle Miocene transition from a more dynamic wet-based East Antarctic ice sheet to the present semi-permanent ice sheet that is partially frozen to its bed. The timing and significance of this transition is controversial due to a lack of quantitative studies on well-dated ice-proximal sedimentary sequences. This project partially fills that gap using the composition and physical properties of diamictites and sandstones to establish shifts in ice-sheet drainage pathways, paleoenvironments and basal ice conditions. The results from the two key areas around the Antarctic continental margin will provide insight into the behavior of the East Antarctic ice sheet across the middle Miocene transition and through known times of warming in the late Miocene and Pliocene.
0538494<br/>Meese<br/>This award supports a project for physical properties research on snow pits and firn/ice cores with specific objectives that include stratigraphic analysis including determination of accumulation rates, annual layers, depth hoar, ice and wind crusts and rates of grain growth with depth. Studies of firn densification rates and how these parameters relate to the meteorology and climatology over the last 200 years of snow accumulation in Antarctica will also be investigated. The project will also determine the seasonality of accumulation by co-registration of stratigraphy and chemistry and determination of chemical species at the grain boundaries, how these may change with depth/densification (and therefore temperature), precipitation, and may affect grain growth. Fabric analyses will be made, including variation with depth, location on undulations and if any variation exists with climate/chemistry. The large spatial coverage of the US ITASE program offers the opportunity to determine how these parameters are affected by a large range of temperature, precipitation and topographic effects. The intellectual merit of the project includes the fact that ITASE is the terrestrial equivalent of a polar research vessel that provides a unique, logistically efficient, multi-dimensional (x, y, z and time) view of the atmosphere, ice sheet and their histories. Physical properties measurements/ analyses are an integral part of understanding the dynamic processes to which the accumulated snow is subjected. Recent advancements in the field along with multiple core sites provide an excellent opportunity to gain a much broader understanding of the spatial, temporal and physical variables that impact firnification and the possible resultant impact on climatic interpretation. In terms of broader impacts, the data collected by US ITASE and its international ITASE partners is available to a broad scientific community. US ITASE has an extensive program of public outreach and provides significant opportunities for many students to experience multidisciplinary Antarctic research. A graduate student, a post-doctoral fellow and at least one undergraduate would be funded by this work. Dr. Meese is also a member of the New England Science Collaborative, an organization that educates the public on climate change based on recent scientific advancements.
This project is an examination of the physical and structural properties of the antarctic ice pack in the Amundsen, Bellingshausen, and Ross Seas, with the goal of defining the geographical variability of various ice types, the deformation processes that are active in the antarctic ice pack, and the large-scale thermodynamics and heat exchange processes of the ice- covered Southern Ocean. An additional goal is to relate specific characteristics of antarctic sea ice to its synthetic aperture radar (SAR) signature as observed from satellites. Physical properties include the salinity, temperature, and brine volumes, while structural properties include the fraction of frazil, platelet, and congelation ice of the seasonal antarctic pack ice. Differences in ice types are the result of differences in the environment in which the ice forms: frazil ice is formed in supercooled sea water, normally through wind or wave-induced turbulence, while platelet and congelation ice is formed under quiescent conditions. The fraction of frazil ice (which has been observed to be generally in excess of 50% in Weddell Sea ice floes) is an important variable in the energy budget of the upper ocean, and contributes significantly to the stabilization of the surface layers. The integration of sea ice field observations and synthetic aperture radar data analysis and modeling studies will contribute to a better understanding of sea ice parameters and their geophysical controls, and will be useful in defining the kind of air-ice-ocean interactions that can be studied using SAR data, as well as having broader relevance and application to atmospheric, biological, and oceanographic investigations of the Southern Ocean.
0538195<br/>Marone<br/>This award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.
This award supports a project to collect and develop high-resolution ice core records from the Dry Valleys region of Antarctica, and provide interpretations of interannual to decadal-scale climate variability during the last 2000 years (late Holocene). The project will test hypotheses related to ocean/atmosphere teleconnections (e.g., El Nino Southern Oscillation, Antarctic Oscillation) that may be responsible for major late Holocene climate events such as the Little Ice Age in the Southern Hemisphere. Conceptual and quantitative models of these processes in the Dry Valleys during the late Holocene are critical for understanding recent climate changes, and represent the main scientific merit of the project. We plan to collect intermediate-length ice cores (100-200m) at four sites along transects in Taylor Valley and Wright Valley, and analyze each core at high resolution for stable isotopes (d18O, dD), major ions (Na+, Mg2+, Ca2+, K+, NH4+, Cl-, NO3-, SO42-, MSA), and trace elements (Al, Fe, S, Sr, B). A suite of statistical techniques will be applied to the multivariate glaciochemical dataset to identify chemical associations and to calibrate the time-series records with available instrumental data. Broader impacts of the project include: 1) contributions to several ongoing interdisciplinary Antarctic research programs; 2) graduate and undergraduate student involvement in field, laboratory, and data interpretation activities; 3) use of project data and ideas in several UMaine courses and outreach activities; and 4) data dissemination through peer-reviewed publications, UMaine and other paleoclimate data archive websites, and presentations at national and international meetings.
This award supports a two-year collaborative effort to more fully understand the climatic history and physical properties of the Siple Dome, Antarctica deep ice core, to develop a new paleoclimatic technique based on bubble number-density, and to improve the U.S. capability to analyze ice-core physical properties rapidly and accurately. The Siple Dome ice core from West Antarctica is yielding important paleoclimatic insights, but has proven more difficult than some cores to interpret owing to the large iceflow effects on the paleoclimatic record. Paleoclimatic indicators that do not rely on iceflow corrections thus would be of value. The bubble number-density offers one such indicator, because it preserves information on mean temperature and accumulation rate during the transformation of firn to ice. We will focus on thin-section characteristics that are important to ice flow and the interpretation of the ice-core history, such as c-axis fabrics, and will use indicators that we have been developing, such as the correlation between grain elongation and the c-axis orientation, to gain additional information. To achieve this quickly and accurately, and to prepare for future projects, we propose to upgrade the automatic caxis- fabric analyzer that Wilen has built and housed at the National Ice Core Laboratory. The intellectual merit of the proposed activity includes improved estimates of paleoclimatic conditions in an important region, improved understanding of a new paleoclimatic research tool, greater understanding of ice flow and of linkages to physical properties, and a better instrument for further U.S. research in ice-core physical properties at the National Ice Core Laboratory. The broader impacts resulting from the proposed activity include providing better understanding of abrupt climate change and of ice flow, which eventually should help policy-makers, as well as an improved U.S. capability to analyze ice cores. The proposed research will assist the studies of two promising young scientists. Results of the research will be incorporated into courses and public outreach reaching at least hundreds or thousands of people per year.
Photochemical reactions in snow can have important effects on the chemistry and composition of the snowpack as well as the overlying atmosphere. For example, recent measurements in the Antarctic and Arctic have revealed that sunlit snow releases a number of important pollutants to the atmosphere. Our ability to understand and model this chemistry is currently limited, in part because we lack fundamental photochemical information for a number of important chemical species in snow. This award supports research that will help fill this gap by characterizing the low-temperature photochemistry of three of these key species: nitrite (NO2-), nitrous acid (HNO2), and hydrogen peroxide (HOOH). We will measure quantum yields for these reactions on ice using a sensitive technique that we recently developed during a study of nitrate (NO3-) photochemistry. In addition to this basic research, we will also measure the rates of formation of hydroxyl radical (OH), nitrogen oxides (NOx), and HOOH in illuminated Antarctic snow samples. These measurements will be important inputs for future models, and will allow us to test whether known species (e.g., NO3-, NO2- and HNO2) are responsible for most of snowpack reactivity (e.g., OH formation). Overall, results from this award will significantly improve our ability to understand snowpack chemistry, and the resulting effects on the atmosphere, both in the Antarctic as well as in the many other regions with permanent or seasonal snow. These results will also strengthen efforts to use ice core records to monitor global change. In addition to these impacts, this award will help train students and a postdoctoral fellow, and results from this work will be integrated into two classes in order to expose students to some of the important issues facing polar regions.
This award supports a program of field surveys of an area within the large, well-developed megadune field southeast of Vostok station. The objectives are to determine the physical characteristics of the firn across the dunes, including typical climate indicators such as stable isotopes and major chemical species, and to install instruments to measure the time variation of near-surface wind and temperature with depth, to test and refine hypotheses for megadune formation. Field study will consist of surface snowpit and shallow core sampling, ground penetrating radar (GPR) profiling, GPS topographic and ice motion surveys, AWS installation, accumulation/ ablation measurements, subsurface temperature, and firn permeability studies. Field work in two successive seasons is proposed. Continent-wide remote sensing studies of the dunes will be continued, using the new group of instruments that are now, or will shortly be available (e.g., MODIS, MISR, GLAS, AMSR). The earlier study of topographic, passive microwave, and SAR characteristics will be extended, with the intent of determining the relationships of dune amplitude and wavelength to climate parameters, and further development of models of dune formation. Diffusion, ventilation, and vapor transport processes within the dune firn will be modeled as well. A robust program of outreach is planned and reporting to inform both the public and scientists of the fundamental in-situ and remote sensing characteristics of these uniquely Antarctic features will be an important part of the work. Because of their extreme nature, their broad extent, and their potential impact on the climate record, it is important to improve our current understanding of these. Megadunes are a manifestation of an extreme terrestrial climate and may provide insight on past terrestrial climate, or to processes active on other planets. Megadunes are likely to represent an end-member in firn diagenesis, and as such, may have much to teach us about the processes involved.
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2004-08-26
Fishcer, Hubertus; Blunier, Thomas; Ruddiman, William; Raymo, Maureen; Lorius, Claude; Brook, Edward J.; Bender, Michael; Chappellaz, Jerome; Sowers, Todd A.; Jouzel, Jean; Petit, Jean Robert; Barnola, J. M.; Lal, Devendra
This award provides one year of support to use newly developed technology in which an ice-core melter is coupled with both an Inductively Coupled Plasma - Mass Spectrometer (ICP-MS) and a traditional Continuous Flow Analysis (CFA) system, to measure a continuous time series of chemical and trace element deposition on the Siple Dome ice core from West Antarctica. A coupled ice-core melter, ICP-MS, and CFA system will be used to measure concentrations of a number of elements, isotopes and chemical species at very high depth resolution (~2-cm) in the top 54 m of the Siple Dome A-core. Pilot data from analyses of ~6 m from the nearby but much lower accumulation J-core site at Siple Dome, together with more extensive results from Summit, Greenland, indicate that it will be possible to obtain exactly co-registered, high-quality records of at least 12 seasonally varying elements (sodium, magnesium, aluminum, potassium, calcium, iron, manganese, rubidium, strontium, zirconium, barium, lead) and three other chemical species and ions (ammonium, nitrate, calcium ion) with this system. Under this proposed research, we will also add continuous measurements of sulfate to our system. Because more than sufficient core from Siple Dome for these depths is archived at the National Ice Core Laboratory, the proposed research will require no fieldwork. The continuous, very high-resolution, ~350-y record of these elemental tracers will enhance the value of previous chemical and isotopic measurements that have been made on the Siple Dome core and will be particularly valuable for comparisons between ice-core proxies and modern instrumental data related to El Nino-Southern Oscillation (ENSO) as well as for validation of model simulations of atmospheric circulation. These data, and the expertise gained through this research, will be invaluable when this novel chemical analysis technology is eventually applied to deep ice-core records for the study of rapid climate-change events.
This award is for two years of support to perform radar investigations across former shear margins at Roosevelt Island and Ice Stream C in order to measure changes in the configuration and continuity of internal layers and the bed. The broad goal of these investigations is to gain an understanding of ice stream flow and the timing and mechanisms of ice stream shutdown. A high-resolution short-pulse radar system will be used for detailed examination of the uppermost hundred meters of the firn and ice, and a monopulse sounding-radar system will be used to image the rest of the ice column (including internal layers) and the bed. Changes in the shape and continuity of layers will be used to interpret mechanisms and modes of ice stream flow including the possible migration of stagnation fronts and rates of shut-down. Variations in bed reflectivity will be used to deduce basal hydrology conditions across lineations. Accumulation rates deduced from snow pits and shallow cores will be used to estimate near-surface depth-age profiles. Improved understanding of ice stream history opens the possibility of linking changes in the West Antarctic ice sheet with the geologic evidence from Northern Victoria Land and the ocean record of the retreat of the grounding line in the Ross Sea.
This award is for support for a program to investigate the visual stratigraphy, index physical properties, relaxation characteristics and crystalline structure of ice cores from Siple Dome, West Antarctica. This investigation will include measurements of a time-priority nature that must be initiated at the drill site on freshly-drilled cores. This will be especially true of cores from the brittle ice zone, which is expected to comprise a significant fraction of the ice core. The brittle zone includes ice in which relaxation , resulting from the release of confining pressure is maximized and leads to significant changes in the mechanical condition of the core that must be considered in relation to the processing and analysis of ice samples for entrapped gas and chemical studies. This relaxation will be monitored via precision density measurements made initially at the drill site and repeated at intervals back in the U.S. Other studies will include measurement of the annual layering in the core to as great a depth as visual stratigraphy can be deciphered, crystal size measurements as a function of depth and age, c-axis fabric studies, and analysis of the physical properties of any debris-bearing basal ice and its relationship to the underlying bedrock. Only through careful documentation and analysis of these key properties can we hope to accurately assess the dynamic state of the ice and the age-depth relationships essential to deciphering the paleoclimate record at this location.
This award is for support for the measurement of electrical and optical properties of the Siple Dome ice core. The electrical methods can be used to determine the concentration of the hydrogen ions and the concentration of a weighted sum of all ions. The electrical measurements can resolve features as small as 1 cm. The albedo of the core is also measured with a laser system that can resolve features as small as 0.5 cm. The high spatial resolution of these methods makes them ideal for resolving narrow features in the core, which can be missed in larger composite samples. The measurements will be particularly useful for assisting to date the core and to identify short duration features in the record, such as volcanic eruptions. These measurements will also provide useful information for assessing the temporal variability of Holocene accumulation rate and atmospheric circulation.
This award 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.
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.