[{"awards": "8020002 Kyle, Philip", "bounds_geometry": "POLYGON((163.6 -73,163.76 -73,163.92 -73,164.07999999999998 -73,164.23999999999998 -73,164.39999999999998 -73,164.56 -73,164.72 -73,164.88 -73,165.04 -73,165.2 -73,165.2 -73.05,165.2 -73.1,165.2 -73.15,165.2 -73.2,165.2 -73.25,165.2 -73.3,165.2 -73.35,165.2 -73.4,165.2 -73.45,165.2 -73.5,165.04 -73.5,164.88 -73.5,164.72 -73.5,164.56 -73.5,164.39999999999998 -73.5,164.23999999999998 -73.5,164.07999999999998 -73.5,163.92 -73.5,163.76 -73.5,163.6 -73.5,163.6 -73.45,163.6 -73.4,163.6 -73.35,163.6 -73.3,163.6 -73.25,163.6 -73.2,163.6 -73.15,163.6 -73.1,163.6 -73.05,163.6 -73))", "dataset_titles": "Mount Overlord, northern Victoria Land. Age, mineralogical and geochemical data", "datasets": [{"dataset_uid": "601799", "doi": "10.15784/601799", "keywords": "Antarctica; Cryosphere; Geochemistry; Mount Overlord", "people": "Kyle, Philip", "repository": "USAP-DC", "science_program": null, "title": "Mount Overlord, northern Victoria Land. Age, mineralogical and geochemical data", "url": "https://www.usap-dc.org/view/dataset/601799"}], "date_created": "Tue, 29 Oct 2024 00:00:00 GMT", "description": "Not Available", "east": 165.2, "geometry": "POINT(164.39999999999998 -73.25)", "instruments": null, "is_usap_dc": true, "keywords": "Victoria Land; LAVA COMPOSITION/TEXTURE; FIELD INVESTIGATION; FIELD SURVEYS; GEOCHEMISTRY", "locations": "Victoria Land", "north": -73.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kyle, Philip", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -73.5, "title": "Petrogenesis of the McMurdo Volcanic Group and the Nature of the Subcontinental Mantle in Victoria Land, Antarctica", "uid": "p0010487", "west": 163.6}, {"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": "Marks Peterson, Julia; Kirkpatrick, Liam; Fudge, T. J.; Carter, Austin; 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": "Ice cores provide valuable records of past climate such as atmospheric concentrations of greenhouse gasses and unmatched evidence of past abrupt climate change. Key to understanding past climate changes are the measurements of annual layers that are used to determine the age of the ice, and the timing and pace of major climate events. The current measurement limit for annual layers in ice cores is at the centimeter scale. This project aims to improve the depth resolution of measurements of the chemical impurities in ice using measurements such as electrical conductivity, hyperspectral imaging, major elements measured with laser ablation, and ice grain properties. This will advance understanding of the preservation and layering in ice cores and improve the accuracy and length of annual timescales for existing ice cores. Most of the past time preserved in an ice core is near the bed where the layers have been thinned to only a fraction of their original thickness. Interpreting highly compressed portions of ice cores is increasingly important as projects target climate records in basal ice, and old ice recovered from blue-ice areas. This project will integrate precisely co-registered electrical conductivity measurements, hyperspectral imaging, laser ablation mass spectrometer measurements of impurities, and ice physical properties to investigate sub-centimeter chemical and physical variations in polar ice. Critical to resolving thin ice layers is understanding the across-core variations that may obscure or distort the vertical layering. Analyses will be focused on samples from the WDC-06A (WAIS Divide), SPC-14 (South Pole), and GISP2 (Greenland Ice Sheet Project 2) ice cores that have well-established seasonal cycles that yielded benchmark timescales, as well a large-diameter ice core from the Allan Hills blue ice area. This work will develop state-of-the-art instrumentation and FAIR (findable, accessible, interoperable, and reusable) data handling workflow at the National Science Foundation Ice Core Facility available to the community both to enhance understanding of existing ice cores, and for use in future projects. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE CORE RECORDS; Ice Core", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Fegyveresi, John M", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Testing Next Generation Measurement Techniques for Reconstruction of Paleoclimate Archives from Thin or Disturbed Ice Cores Sections", "uid": "p0010365", "west": -180.0}, {"awards": "2019719 Brook, Edward", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "2019-2020 Allan Hills Field Report; 2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report; 2023-2024 Allan Hills End-of-Season Science Report; Airborne Radar Data: 2022-23 (CXA1) flight based HDF5/matlab format data; Airborne Radar Data: 2022-23 (CXA1) transect based (science organized) unfocused data; Airborne Radar Data: 2023-24 (CXA2) flight based data HDF5/matlab format; Airborne Radar Data: 2023-24 (CXA2) transect based (science organized) unfocused data; ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations; Allan Hills 2022-23 Shallow Ice Core Field Report; Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022; Allan Hills I-188 Field Season Report 2022-2023; Allan Hills ice water stable isotope record for dD, d18O; Basal Ice Unit Thickness Mapped by the NSF COLDEX MARFA Ice Penetrating Radar; CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903; COLDEX VHF MARFA Open Polar Radar radargrams; Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area; Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903; I-165-M GPR Field Report 2019-2020; MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903; NSF COLDEX 2022-2023 Airborne Season (CXA1): Level 1B Serial Instrument Measurements; NSF COLDEX 2022-2023 Airborne Season (CXA1): Level 1 gravimeter instrument measurements; NSF COLDEX 2022-23 GNSS/IMU Level 1 instrument measurements from Dome A, East Antarctica; NSF COLDEX 2022-23 Level 2 Basal Specularity Content Profiles; NSF COLDEX 2022-23 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets; NSF COLDEX 2023-24 Level 2 Basal Specularity Content Profiles; NSF COLDEX 2023-24 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets; NSF COLDEX Ice Penetrating Radar Derived Grids of the Southern Flank of Dome C; NSF COLDEX/Open Polar Radar Example Delay Doppler Classification of Englacial Reflectors; NSF COLDEX Raw MARFA Ice Penetrating Radar data; Oxygen and hydrogen isotope compositions and associated d-excess of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area; Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area; Replicate O-17-excess by continuous flow laser spectroscopy for an ice core section at Summit, Greenland; Rising Seas: Representations of Antarctica, Climate Change, and Sea Level Rise in U.S. Newspaper Coverage; Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old; Social network analysis to understand participant engagement in transdisciplinary team science: a large U.S. science and technology center case study; Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "datasets": [{"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Introne, Douglas; Brook, Edward; Mayewski, Paul A.; Kurbatov, Andrei V.; Severinghaus, Jeffrey P.; Higgins, John", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Severinghaus, Jeffrey P.; Brook, Edward; Kurbatov, Andrei V.; Mayewski, Paul A.; Higgins, John; Introne, Douglas", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "200461", "doi": "10.18738/T8/6T5JS6", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2022-23 Level 2 Basal Specularity Content Profiles", "url": "https://doi.org/10.18738/T8/6T5JS6"}, {"dataset_uid": "200462", "doi": "10.18738/T8/KHUT1U", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2023-24 Level 2 Basal Specularity Content Profiles", "url": "https://doi.org/10.18738/T8/KHUT1U"}, {"dataset_uid": "200463", "doi": "10.18738/T8/M77ANK", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX Ice Penetrating Radar Derived Grids of the Southern Flank of Dome C", "url": "https://doi.org/10.18738/T8/M77ANK"}, {"dataset_uid": "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": "601854", "doi": "10.15784/601854", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Marks Peterson, Julia; Kirkpatrick, Liam; Fudge, T. J.; Carter, Austin; 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": "601768", "doi": "10.15784/601768", "keywords": "Antarctica; Coldex; East Antarctic Plateau; Glaciology; Radar Echo Sounder", "people": "Blankenship, Donald D.; Young, Duncan A.; Ng, Gregory; Buhl, Dillon; Kerr, Megan; Greenbaum, Jamin; Chan, Kristian; Kempf, Scott D.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "NSF COLDEX Raw MARFA Ice Penetrating Radar data", "url": "https://www.usap-dc.org/view/dataset/601768"}, {"dataset_uid": "601897", "doi": "10.15784/601897", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciology; Ice Core Data; MOT; Ocean Temperature; Paleoclimate; Xe/Kr", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601897"}, {"dataset_uid": "601878", "doi": "10.15784/601878", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Cryosphere; Methane", "people": "Severinghaus, Jeffrey P.; Shackleton, Sarah; Hishamunda, Valens; Kalk, Michael; Brook, Edward; Marks Peterson, Julia", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old", "url": "https://www.usap-dc.org/view/dataset/601878"}, {"dataset_uid": "601669", "doi": "10.15784/601669", "keywords": "Allan Hills; Antarctica; GPR; Ice Core; Report", "people": "Brook, Edward J.; Nesbitt, Ian", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "I-165-M GPR Field Report 2019-2020", "url": "https://www.usap-dc.org/view/dataset/601669"}, {"dataset_uid": "601620", "doi": "10.15784/601620", "keywords": "18O; Allan Hills; Allan Hills Blue Ice; Antarctica; Blue Ice; Delta 15N; Delta 18O; Dole Effect; Firn Thickness; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chronology; Ice Core Records", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022", "url": "https://www.usap-dc.org/view/dataset/601620"}, {"dataset_uid": "601912", "doi": "10.15784/601912", "keywords": "Antarctica; Coldex; Cryosphere; East Antarctica; East Antarctic Plateau; Glaciology; Radar Echo Sounder", "people": "Kerr, Megan; Yan, Shuai; Young, Duncan A.; Vega Gonzalez, Alejandra; Singh, Shivangini; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Basal Ice Unit Thickness Mapped by the NSF COLDEX MARFA Ice Penetrating Radar", "url": "https://www.usap-dc.org/view/dataset/601912"}, {"dataset_uid": "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": "200467", "doi": "doi:10.15784/601825", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601825"}, {"dataset_uid": "200468", "doi": "https://doi.org/10.15784/601820", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601820"}, {"dataset_uid": "601933", "doi": null, "keywords": "Aerogeophysics; Antarctica; Cryosphere; South Pole", "people": "Young, Duncan; Young, Duncan A.; Kerr, Megan; Greenbaum, Jamin Stevens; Buhl, Dillon; Chan, Kristian; Echeverry, Gonzalo; Singh, Shivangini; Ng, Gregory; Kempf, Scott D.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "NSF COLDEX 2022-23 GNSS/IMU Level 1 instrument measurements from Dome A, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601933"}, {"dataset_uid": "200469", "doi": "https://doi.org/10.15784/601821", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601821"}, {"dataset_uid": "200470", "doi": "doi:10.15784/601822", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "Oxygen and hydrogen isotope compositions and associated d-excess of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601822"}, {"dataset_uid": "200432", "doi": "10.18738/T8/XPMLCC", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "Airborne Radar Data: 2022-23 (CXA1) transect based (science organized) unfocused data", "url": "https://dataverse.tdl.org/dataset.xhtml?persistentId=doi:10.18738/T8/XPMLCC"}, {"dataset_uid": "200433", "doi": "10.18738/T8/FV6VNT", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "Airborne Radar Data: 2023-24 (CXA2) transect based (science organized) unfocused data", "url": "https://dataverse.tdl.org/dataset.xhtml?persistentId=doi:10.18738/T8/FV6VNT"}, {"dataset_uid": "200434", "doi": "10.18738/T8/99IEOG", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2022-23 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets", "url": "https://doi.org/10.18738/T8/99IEOG"}, {"dataset_uid": "601826", "doi": "10.15784/601826", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Manos, John-Morgan; Conway, Howard; Epifanio, Jenna; Horlings, Annika; Shaya, Margot", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills I-188 Field Season Report 2022-2023", "url": "https://www.usap-dc.org/view/dataset/601826"}, {"dataset_uid": "601824", "doi": "10.15784/601824", "keywords": "Allan Hills; Antarctica; Coldex; Cryosphere", "people": "Epifanio, Jenna; Goverman, Ashley; Jayred, Michael; Morton, Elizabeth; Banerjee, Asmita; Hudak, Abigail; Manos, John-Morgan; Carter, Austin; Shackleton, Sarah; Brook, Edward J.; Higgins, John; Marks Peterson, Julia; Mayo, Emalia", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2023-2024 Allan Hills End-of-Season Science Report", "url": "https://www.usap-dc.org/view/dataset/601824"}, {"dataset_uid": "601819", "doi": "10.15784/601819", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Shackleton, Sarah; Higgins, John; Carter, Austin; Nesbitt, Ian; Zajicek, Anna; Morton, Elizabeth; Kuhl, Tanner; Epifanio, Jenna; Morgan, Jacob", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2019-2020 Allan Hills Field Report", "url": "https://www.usap-dc.org/view/dataset/601819"}, {"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": "Brook, Edward J.; Conway, Howard", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report", "url": "https://www.usap-dc.org/view/dataset/601697"}, {"dataset_uid": "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": "200452", "doi": "https://hdl.handle.net/11299/270020", "keywords": null, "people": null, "repository": "UMN University Digital Conservancy", "science_program": null, "title": "Social network analysis to understand participant engagement in transdisciplinary team science: a large U.S. science and technology center case study", "url": "https://hdl.handle.net/11299/270020"}, {"dataset_uid": "601895", "doi": "10.15784/601895", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Noble Gas", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601895"}, {"dataset_uid": "601896", "doi": "10.15784/601896", "keywords": "Allan Hills; Antarctica; Ch4; CO2; Cryosphere; Glaciology; Glaciology; Ice Core Data; Ice Core Records", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601896"}, {"dataset_uid": "200498", "doi": "10.18738/T8/ANTMMV", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2022-2023 Airborne Season (CXA1): Level 1B Serial Instrument Measurements", "url": "https://doi.org/10.18738/T8/ANTMMV"}, {"dataset_uid": "200497", "doi": "10.18738/T8/ANTMMV", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2022-2023 Airborne Season (CXA1): Level 1 gravimeter instrument measurements", "url": "https://doi.org/10.18738/T8/ANTMMV"}, {"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": "200464", "doi": "10.18738/T8/DM10IG", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX/Open Polar Radar Example Delay Doppler Classification of Englacial Reflectors", "url": "https://doi.org/10.18738/T8/DM10IG"}, {"dataset_uid": "200465", "doi": "10.18738/T8/DM10IG", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "COLDEX VHF MARFA Open Polar Radar radargrams", "url": "https://doi.org/10.18738/T8/DM10IG"}], "date_created": "Sat, 21 May 2022 00:00:00 GMT", "description": "Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth\u2019s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth\u2019s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community. Knowledge of Earth\u2019s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth\u2019s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; Antarctica; Amd/Us; Coldex; USAP-DC; FIELD SURVEYS; ICE DEPTH/THICKNESS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Polar Special Initiatives", "paleo_time": null, "persons": "Neff, Peter; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "OPR; Texas Data Repository; UMN University Digital Conservancy; University Digital Conservancy; USAP-DC", "science_programs": "COLDEX", "south": -90.0, "title": "Center for Oldest Ice Exploration", "uid": "p0010321", "west": -180.0}, {"awards": "1644171 Blackburn, Terrence", "bounds_geometry": "POLYGON((162 -77.5,162.2 -77.5,162.4 -77.5,162.6 -77.5,162.8 -77.5,163 -77.5,163.2 -77.5,163.4 -77.5,163.6 -77.5,163.8 -77.5,164 -77.5,164 -77.525,164 -77.55,164 -77.575,164 -77.6,164 -77.625,164 -77.65,164 -77.675,164 -77.7,164 -77.725,164 -77.75,163.8 -77.75,163.6 -77.75,163.4 -77.75,163.2 -77.75,163 -77.75,162.8 -77.75,162.6 -77.75,162.4 -77.75,162.2 -77.75,162 -77.75,162 -77.725,162 -77.7,162 -77.675,162 -77.65,162 -77.625,162 -77.6,162 -77.575,162 -77.55,162 -77.525,162 -77.5))", "dataset_titles": "Isotopic ratios for subglacial precipitates from East Antarctica; U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "datasets": [{"dataset_uid": "200240", "doi": "10.26022/IEDA/111548 ", "keywords": null, "people": null, "repository": "EarthChem", "science_program": null, "title": "Isotopic ratios for subglacial precipitates from East Antarctica", "url": "https://doi.org/10.26022/IEDA/111548"}, {"dataset_uid": "601806", "doi": "10.15784/601806", "keywords": "Antarctica; Cryosphere; Erosion; Isotope Data; Major Elements; Soil; Taylor Glacier; Taylor Valley", "people": "Piccione, Gavin; Edwards, Graham; Blackburn, Terrence; Tulaczyk, Slawek", "repository": "USAP-DC", "science_program": null, "title": "U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601806"}], "date_created": "Fri, 13 Aug 2021 00:00:00 GMT", "description": "A\u00a0nontechnical\u00a0description of the project The primary scientific goal of the project is to test whether Taylor Valley, Antarctica has been eroded significantly by glaciers in the last ~2 million years (Ma). Taylor Valley is one of the Dry Valleys of the Transantarctic Mountains, which are characterized by low mean annual temperatures, low precipitation, and limited erosion. These conditions have allowed fragile glacial landforms to be preserved for up to 15 Ma. Sediment eroded and deposited by glaciers is found on the valley walls and floors, with progressively younger deposits preserved at lower elevations. Scientists can date glacial deposits to understand the process and timing of past glacial erosion. Previous work in the Dry Valleys region suggested that extremely cold glaciers like Taylor Glacier, a major outlet glacier entering the valleys, were not erosive during the last several million years. This research will test a new hypothesis that glacial erosion and sediment production beneath Taylor Glacier have been active in the last few million years. This hypothesis will be tested using a new isotopic dating method called \"comminution dating\u0027 which determines when fine-grained sediment particles called silt were formed. If the sediment age is young, then the results will suggest that glacial processes have been more dynamic than previously thought. Overall, this study will increase our understanding of the nature and extent of past glaciations in Antarctica. Because the silt produced by erosion sediment is a nutrient for local ecosystems, the results will also shed light on delivery of nutrients to soils, streams, and coastal zones in high polar regions. This project will be led by an early career scientist and includes training of a Ph.D. student. A\u00a0technical description of the project There is a long-standing scientific controversy about the stability of the East Antarctic Ice Sheet with much evidence centered in the Dry Valleys region of South Victoria Land. A prevailing view of geomorphologists is that the landscape has been very stable and that the effects of glaciation have been minimal for the past ~15 Ma. This project will distinguish between two end-member scenarios of glacial erosion and deposition by Taylor Glacier, an outlet glacier of the East Antarctic Ice Sheet that terminates in Taylor Valley in the Dry Valleys region of Antarctica. In the first scenario, all valley relief is generated prior to 15 Ma when non-polar climates enabled warm-based glaciers to incise and widen ancient river channels. In this case, younger glacial deposits record advances of cold-based glaciers of decreasing ice volume and limited glacial erosion, and sediment generation resulted in glacial deposits composed primarily of older recycled sediments. In the second scenario, selective erosion of the valley floor has continued to deepen Taylor Valley but has not affected the adjacent peaks over the last 2 Ma. In this scenario, the \"bathtub rings\" of Quaternary glacial deposits situated at progressively lower elevations through time could be due to the lowering of the valley floor by subglacial erosion and with it, production of new sediment which is now incorporated into these deposits. While either scenario would result in the present-day topography, they differ in the implied evolution of regional glacial ice volume over time and the timing of both valley relief production and generation of fine-grained particles. The two scenarios will be tested by placing time constraints on fine particle production using U-series comminution dating. This new geochronologic tool exploits the loss of 234U due to alpha-recoil. The deficiency in 234U only becomes detectable in fine-grained particles with a sufficiently high surface-area-to-volume ratio which can incur appreciable 234U loss. The timing of comminution and particle size controls the magnitude of 234U loss. While this geochronologic tool is in its infancy, the scientific goal of this proposal can be achieved by resolving between ancient and recently comminuted fine particles, a binary question that the preliminary modeling and measured data show is readily resolved.", "east": 164.0, "geometry": "POINT(163 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Taylor Valley", "locations": "Taylor Valley", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blackburn, Terrence; Tulaczyk, Slawek", "platforms": null, "repo": "EarthChem", "repositories": "EarthChem; USAP-DC", "science_programs": null, "south": -77.75, "title": "U-Series Comminution Age Constraints on Taylor Valley Erosion", "uid": "p0010243", "west": 162.0}, {"awards": "1341500 Ryberg, Patricia", "bounds_geometry": null, "dataset_titles": "Images of Fossil Plants of Antarctica", "datasets": [{"dataset_uid": "601066", "doi": "10.15784/601066", "keywords": "Antarctica; Biota; Fossil; Sample/collection Description; Sample/Collection Description; Transantarctic Mountains", "people": "Ryberg, Patricia", "repository": "USAP-DC", "science_program": null, "title": "Images of Fossil Plants of Antarctica", "url": "https://www.usap-dc.org/view/dataset/601066"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "This project will involve examination of Glossopteridales, fossil plants from Upper Permian deposits, in samples from the central Transantarctic Mountains and Southern Victoria Land, Antarctica. The glossopterids are an important fossil group because they are possible ancestors to the flowering plants. Permian sedimentary rocks (295-270 Ma before present) are important because they record a time of rapid biotic change, as the Late Paleozoic Age ended and the Mesozoic greenhouse environment began. The proposed research will rely entirely on specimens collected during recent field excursions to the central Transantarctic Mountains (CTM; 2010?2011) and southern Victoria Land (SVL; 2012?2013). Only a few of the specimens have been studied, but already have yielded anatomically well-preserved glossopterids with a complete pollen cone, which has never been found before. Additionally, several seed-bearing structures, which have never before been observed in Antarctica, have been found in both CTM and SVL. The project will allow comparison of whole-plant fossil glossopterids from the CTM with other paleo-latitudes, and will document the floral diversity within and between two depositional basins (CTM \u0026 SVL) during a time of global change, with the overall goal of linking environmental changes with fossil morphology. Broader impacts: The Broader Impacts of this project will include mentoring undergraduates in research projects, at an institution with a substantial minority enrollment. Public outreach will focus on involving middle/high school students through the ?Expanding Your Horizons? programs in Kansas and Missouri, as well as interactive presentations at schools in the Kansas City Area. The lead PI is an early-career scientist at an institution that serves minorities.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; AMD; PLANTS; Victoria Land Basin; Transantarctic Mountains; Amd/Us; USA/NSF; Fossils; SEDIMENTS; FIELD INVESTIGATION; USAP-DC", "locations": "Antarctica; Transantarctic Mountains; Victoria Land Basin", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Ryberg, Patricia", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "RUI: Antarctic Paleobotany: Permian Floral Characteristics in a Sedimentary Setting", "uid": "p0010134", "west": null}, {"awards": "9615832 Blankenship, Donald; 9615704 Bell, Robin", "bounds_geometry": "POLYGON((-180 -74,-176 -74,-172 -74,-168 -74,-164 -74,-160 -74,-156 -74,-152 -74,-148 -74,-144 -74,-140 -74,-140 -75.6,-140 -77.2,-140 -78.8,-140 -80.4,-140 -82,-140 -83.6,-140 -85.2,-140 -86.8,-140 -88.4,-140 -90,-144 -90,-148 -90,-152 -90,-156 -90,-160 -90,-164 -90,-168 -90,-172 -90,-176 -90,180 -90,174 -90,168 -90,162 -90,156 -90,150 -90,144 -90,138 -90,132 -90,126 -90,120 -90,120 -88.4,120 -86.8,120 -85.2,120 -83.6,120 -82,120 -80.4,120 -78.8,120 -77.2,120 -75.6,120 -74,126 -74,132 -74,138 -74,144 -74,150 -74,156 -74,162 -74,168 -74,174 -74,-180 -74))", "dataset_titles": "SOAR-PPT Airborne gravity data; SOAR-WLK Airborne gravity data", "datasets": [{"dataset_uid": "601293", "doi": "10.15784/601293", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Potential Field; Solid Earth; Transantarctic Mountains", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WLK Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601293"}, {"dataset_uid": "601292", "doi": "10.15784/601292", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Potential Field; Solid Earth; Transantarctic Mountains", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-PPT Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601292"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "Bell and Buck: OPP 9615704 Blankenship: OPP 9615832 Abstract Continental extension produces a great variety of structures from the linear narrow rifts of the East African Rift to the diffuse extension of the Basin and Range Province of the Western U.S. Rift shoulder uplift varies dramatically between rift flanks. The cause of variable rift width and crustal thinning is fairly well explained by variable initial heat flow and crustal thickness. Mechanical stretching of the lithosphere has been linked to rift shoulder uplift but the cause of variable rift flank uplift remains poorly understood. The Transantarctic Mountains (TAM) are an extreme example of rift flank uplift, extending over 3500 km across Antarctica and reaching elevations up to 4500 m and thus constitute a unique feature of EarthOs crust. The range was formed in the extensional environment associated with the Mesozoic and Cenozoic breakup of Gondwanaland. Geological and geophysical work has shown that the TAM developed along the long-lived lithospheric boundary between East and West Antarctica reactivated by a complex history of extensional and translational microplate motions. The TAM are not uniform along strike. Along the OWilkes FrontO, the northern segment of the rift extends from North Victoria Land to Byrd Glacier. The Wilkes Front architecture consists of (1) thin, extended crust forming the Victoria Land Basin in the Ross Sea, (2) the TAM rift shoulder, and (3) a long-wavelength down- ward forming the Wilkes Basin. Contrasting structures are mapped along the OPensacola/PoleO Front, the southern segment of the rift extending from the Nimrod Glacier to the Pensacola Mountains. Along this southern section no rift basin has been mapped to date and the down-ward along the East Antarctic, or ObacksideO, edge of the mountains is less pronounced. A flexural model linking the extension in the Ross Sea to the formation of both the mountains and the Wilkes Basin has been considered as a me chanism for uplift of the entire mountain range. The variability in fundamental architecture along the TAM indicates that neither a single event nor a sequence of identical events produced the rift flank uplift. The observation of variable architecture suggests complex mechanisms and possibly a fundamental limitation in maximum sustainable rift flank elevation. The motivation for studying the TAM is to try to understand the geodynamics of this extreme elevation rift flank. Are the geodynamics of the area unique, or does the history of glaciation and related erosion contribute to the extreme uplift? With the existing data sets it is difficult to confidently constrain the geological architecture across representative sections of the TAM. Any effort to refine geodynamic mechanisms requires this basic understanding of the TAM architecture. The goal of this project is to (1) constrain the architecture of the rift system as well as the distribution and structure of sedimentary basins, glacial erosion and mafic igneous rocks surrounding the rift flank by acquiring three long wavelength geophysical transects with integrated gravity, magnetics, ice- penetrating radar, and ice surface measurements, (2) quantify the contribution of various geodynamic mechanisms to understand the geological conditions which can lead to extreme rift flank uplift, and (3) use the improved understanding of architecture and geophysical data to test geodynamic models in order to improve our understanding both of the TAM geodynamics and the general problem of the geodynamics of rift flank uplift worldwide. This project will allow development of a generalized framework for understanding the development of rift flank uplift as well as address the question of the specific geodynamic evolution of the TAM.", "east": -140.0, "geometry": "POINT(170 -82)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": true, "keywords": "USAP-DC; Transantarctic Mountains; GRAVITY FIELD; TECTONICS", "locations": "Transantarctic Mountains", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Buck, W. Roger; Blankenship, Donald D.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Contrasting Architecture and Dynamics of the Transantarctic Mountains", "uid": "p0010095", "west": 120.0}, {"awards": "1142108 Koch, Paul", "bounds_geometry": "POLYGON((-180 -55.1,-168.1 -55.1,-156.2 -55.1,-144.3 -55.1,-132.4 -55.1,-120.5 -55.1,-108.6 -55.1,-96.7 -55.1,-84.8 -55.1,-72.9 -55.1,-61 -55.1,-61 -57.4,-61 -59.7,-61 -62,-61 -64.3,-61 -66.6,-61 -68.9,-61 -71.2,-61 -73.5,-61 -75.8,-61 -78.1,-72.9 -78.1,-84.8 -78.1,-96.7 -78.1,-108.6 -78.1,-120.5 -78.1,-132.4 -78.1,-144.3 -78.1,-156.2 -78.1,-168.1 -78.1,180 -78.1,178.47 -78.1,176.94 -78.1,175.41 -78.1,173.88 -78.1,172.35 -78.1,170.82 -78.1,169.29 -78.1,167.76 -78.1,166.23 -78.1,164.7 -78.1,164.7 -75.8,164.7 -73.5,164.7 -71.2,164.7 -68.9,164.7 -66.6,164.7 -64.3,164.7 -62,164.7 -59.7,164.7 -57.4,164.7 -55.1,166.23 -55.1,167.76 -55.1,169.29 -55.1,170.82 -55.1,172.35 -55.1,173.88 -55.1,175.41 -55.1,176.94 -55.1,178.47 -55.1,-180 -55.1))", "dataset_titles": "Southern Ocean Pinnipeds", "datasets": [{"dataset_uid": "000242", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Southern Ocean Pinnipeds", "url": "https://www.bco-dmo.org/project/726874"}], "date_created": "Wed, 28 Feb 2018 00:00:00 GMT", "description": "Building on previously funded NSF research, the use of paleobiological and paleogenetic data from mummified elephant seal carcasses found along the Dry Valleys and Victoria Land Coast in areas that today are too cold to support seal colonies (Mirougina leonina; southern elephant seals; SES) supports the former existence of these seals in this region. The occurrence and then subsequent disappearance of these SES colonies is consistent with major shifts in the Holocene climate to much colder conditions at the last ~1000 years BCE). \u003cbr/\u003e\u003cbr/\u003eFurther analysis of the preserved remains of three other abundant pinnipeds ? crabeater (Lobodon carciophagus), Weddell (Leptonychotes weddelli) and leopard (Hydrurga leptonyx) will be studied to track changes in their population size (revealed by DNA analysis) and their diet (studied via stable isotope analysis). Combined with known differences in life history, preferred ice habitat and ecosystem sensitivity among these species, this paleoclimate proxy data will be used to assess their exposure and sensitivity to climate change in the Ross Sea region during the past ~1-2,000 years", "east": -61.0, "geometry": "POINT(-128.15 -66.6)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; NOT APPLICABLE", "locations": null, "north": -55.1, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Koch, Paul; Costa, Daniel; Hoelzel, A. Rus", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -78.1, "title": "Collaborative Research: Exploring the Vulnerability of Southern Ocean Pinnipeds to Climate Change - An Integrated Approach", "uid": "p0000410", "west": 164.7}, {"awards": "1056396 Morgan-Kiss, Rachael", "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": "Genetic sequence identifier: Accession Numbers: GU132860-GU132939; JN091926-JN091960; JQ9243533-JQ924384; KJ848331-KJ848439; KU196097-KU196166; PRJNA396917", "datasets": [{"dataset_uid": "000241", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Genetic sequence identifier: Accession Numbers: GU132860-GU132939; JN091926-JN091960; JQ9243533-JQ924384; KJ848331-KJ848439; KU196097-KU196166; PRJNA396917", "url": "https://www.ncbi.nlm.nih.gov/genbank/"}], "date_created": "Mon, 26 Feb 2018 00:00:00 GMT", "description": "This CAREER proposal will support an early career female PI to establish an integrated research and education program in the fields of polar biology and environmental microbiology, focusing on single-celled eukaryotes (protists) in high latitude ice-covered Antarctic lakes systems. Protists play important roles in energy flow and material cycling, and act as both primary producers (fixing inorganic carbon by photosynthesis) and consumers (preying on bacteria by phagotrophic digestion). The McMurdo Dry Valleys (MDV) located in Victoria Land, Antarctica, harbor microbial communities which are isolated in the unique aquatic ecosystem of perennially ice-capped lakes. The lakes support exclusively microbial consortia in chemically stratified water columns that are not influenced by seasonal mixing, allochthonous inputs, or direct human impact. This project will exploit permanently stratified biogeochemistry that is unique across the water columns of several MDV lakes to address gaps in our understanding of protist trophic function in aquatic food webs. The proposed research will examine (1) the impact of permanent biogeochemical gradients on protist trophic strategy, (2) the effect of major abiotic drivers (light and nutrients) on the distribution of two key mixotrophic and photoautotrophic protist species, and (3) the effect of episodic nutrient pulses on mixotroph communities in high latitude (ultraoligotrophic) MDV lakes versus low latitude (eutrophic) watersheds. The project will impact the fields of microbial ecology and environmental microbiology by combining results from field, laboratory and in situ incubation studies to synthesize new models for the protist trophic roles in the aquatic food web. The research component of this proposed project will be tightly integrated with the development of two new education activities designed to exploit the inherent excitement associated with polar biological research. The educational objectives are: 1) to establish a teaching module in polar biology in a core undergraduate course for microbiology majors; 2) to develop an instructional module to engage middle school girls in STEM disciplines. Undergraduates and middle school girls will also work with a doctoral student on his experiments in local Ohio watersheds.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Morgan-Kiss, Rachael", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -90.0, "title": "CAREER:Protist Nutritional Strategies in Permanently Stratified Antarctic Lakes", "uid": "p0000310", "west": -180.0}, {"awards": "1341364 Todd, Claire; 1460449 Goehring, Brent; 1341420 Balco, Gregory", "bounds_geometry": "POLYGON((164.08 -74.6,164.0842 -74.6,164.0884 -74.6,164.0926 -74.6,164.0968 -74.6,164.101 -74.6,164.1052 -74.6,164.1094 -74.6,164.1136 -74.6,164.1178 -74.6,164.122 -74.6,164.122 -74.6023,164.122 -74.6046,164.122 -74.6069,164.122 -74.6092,164.122 -74.6115,164.122 -74.6138,164.122 -74.6161,164.122 -74.6184,164.122 -74.6207,164.122 -74.623,164.1178 -74.623,164.1136 -74.623,164.1094 -74.623,164.1052 -74.623,164.101 -74.623,164.0968 -74.623,164.0926 -74.623,164.0884 -74.623,164.0842 -74.623,164.08 -74.623,164.08 -74.6207,164.08 -74.6184,164.08 -74.6161,164.08 -74.6138,164.08 -74.6115,164.08 -74.6092,164.08 -74.6069,164.08 -74.6046,164.08 -74.6023,164.08 -74.6))", "dataset_titles": "Interface to observational data associated with exposure-age measurements and resulting calculated ages. Dynamic content, updated.", "datasets": [{"dataset_uid": "200196", "doi": null, "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Interface to observational data associated with exposure-age measurements and resulting calculated ages. Dynamic content, updated.", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Wed, 18 Oct 2017 00:00:00 GMT", "description": "The investigators will map glacial deposits and date variations in glacier variability at several ice-free regions in northern Victoria Land, Antarctica. These data will constrain the nature and timing of past ice thickness changes for major glaciers that drain into the northwestern Ross Sea. This is important because during the Last Glacial Maximum (15,000 - 18,000 years ago) these glaciers were most likely flowing together with grounded ice from both the East and West Antarctic Ice Sheets that expanded across the Ross Sea continental shelf to near the present shelf edge. Thus, the thickness of these glaciers was most likely controlled in part by the extent and thickness of the Ross Sea ice sheet and ice shelf. The data the PIs propose to collect can provide constraints on the position of the grounding line in the western Ross Sea during the Last Glacial Maximum, the time that position was reached, and ice thickness changes that occurred after that time. The primary intellectual merit of this project will be to improve understanding of a period of Antarctic ice sheet history that is relatively unconstrained at present and also potentially important in understanding past ice sheet-sea level interactions. This proposal will support an early career researcher\u0027s ongoing program of undergraduate education and research that is building a socio-economically diverse student body with students from backgrounds underrepresented in the geosciences. This proposal will also bring an early career researcher into Antarctic research.", "east": 164.122, "geometry": "POINT(164.101 -74.6115)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; Cosmogenic Dating; Exposure Age; LABORATORY; NOT APPLICABLE; Amd/Us; Ross Sea", "locations": "Ross Sea", "north": -74.6, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Goehring, Brent; Balco, Gregory; Todd, Claire", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -74.623, "title": "Collaborative Research: Terrestrial Exposure-Age Constraints on the last Glacial Maximum Extent of the Antarctic Ice Sheet in the Western Ross Sea", "uid": "p0000306", "west": 164.08}, {"awards": "1341390 Frank, Tracy", "bounds_geometry": null, "dataset_titles": "Stable carbon and oxygen isotope data from drill cores from McMurdo Sound, Antarctica", "datasets": [{"dataset_uid": "000195", "doi": "", "keywords": null, "people": null, "repository": "EarthChem", "science_program": null, "title": "Stable carbon and oxygen isotope data from drill cores from McMurdo Sound, Antarctica", "url": "http://dx.doi.org/10.1594/IEDA/100718"}], "date_created": "Fri, 06 Oct 2017 00:00:00 GMT", "description": "Intellectual Merit: This project will use sediment cores from the Victoria Land Basin (VLB), Antarctica, to study secondary (diagenetic) carbonate minerals, as indicators of the basin?s fluid-flow history, within the well-constrained tectonic, depositional, and climatic context provided by sediment cores. This study will provide insights into subsurface processes in Victoria Land Basin, Antarctica and their relationships with the region?s climatic, cryospheric, and tectonic history. The work will utilize cores previously recovered by US-sponsored stratigraphic drilling projects (CIROS, CRP, and ANDRILL projects). This work is motivated by the unexpected discovery of dense brine in the subsurface of Southern McMurdo Sound during drilling by the ANDRILL Southern McMurdo Sound project. The presence of the brine is intriguing because it contradicts previous models for the origin of subsurface fluids that called upon large contributions from glacial melt water. Project objectives involve documenting the distribution of the brine (and potentially other fluids) via characterization of diagenetic precipitates. The approach will involve integration of petrographic and geochemical data (including conventional carbon, oxygen, and ?clumped? isotopes) to fully characterize diagenetic phases and allow development of a robust paragenetic history. This work will provide novel insights into the Cenozoic evolution of the VLB and, more broadly, the role of glacial processes in generating subsurface fluids. Broader impacts: Results from this project will help understand the origins of brines, groundwater and hydrocarbon reservoirs in analogous modern and ancient deposits elsewhere, which is of broad interest. This project will support the training of one graduate and one undergraduate student at the University of Nebraska-Lincoln (UNL) providing learning opportunities in sedimentary geology and diagenesis, fields with wide applicability. This proposal emphasizes rapid dissemination of results to the scientific community via conference presentations and contributions to peer-reviewed publications. The results will be integrated into education activities designed to develop skills in petrography and diagenesis, which are highly sought after in the energy sector. The project will generate a well-constrained dataset that allows direct linkage of diagenetic phases to environmental and tectonic change across a large sedimentary basin which will provide the basis for a comprehensive case study in an upper-level course (Sedimentary Petrography and Diagenesis) at UNL. In addition, online exercises will be developed and submitted to an open-access site (SEPM Stratigraphy Web) dedicated to sedimentary geology.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Frank, Tracy; Fielding, Christopher", "platforms": "Not provided", "repo": "EarthChem", "repositories": "EarthChem", "science_programs": null, "south": null, "title": "Insights into the Burial, Tectonic, and Hydrologic History of the Cenozoic Succession in McMurdo Sound, Antarctica through Analysis of Diagenetic Phases", "uid": "p0000256", "west": null}, {"awards": "1148982 Hansen, Samantha", "bounds_geometry": "POLYGON((153.327 -73.032547,154.5063012 -73.032547,155.6856024 -73.032547,156.8649036 -73.032547,158.0442048 -73.032547,159.223506 -73.032547,160.4028072 -73.032547,161.5821084 -73.032547,162.7614096 -73.032547,163.9407108 -73.032547,165.120012 -73.032547,165.120012 -73.3530275,165.120012 -73.673508,165.120012 -73.9939885,165.120012 -74.314469,165.120012 -74.6349495,165.120012 -74.95543,165.120012 -75.2759105,165.120012 -75.596391,165.120012 -75.9168715,165.120012 -76.237352,163.9407108 -76.237352,162.7614096 -76.237352,161.5821084 -76.237352,160.4028072 -76.237352,159.223506 -76.237352,158.0442048 -76.237352,156.8649036 -76.237352,155.6856024 -76.237352,154.5063012 -76.237352,153.327 -76.237352,153.327 -75.9168715,153.327 -75.596391,153.327 -75.2759105,153.327 -74.95543,153.327 -74.6349495,153.327 -74.314469,153.327 -73.9939885,153.327 -73.673508,153.327 -73.3530275,153.327 -73.032547))", "dataset_titles": "Crustal Structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for Tectonic Origins; Shear Wave Splitting Analysis and Seismic Anisotropy beneath the Northern Transantarctic Mountains; Upper Mantle Seismic Structure beneath the Northern Transantarctic Mountains from Regional P- and S-wave Tomography; Upper Mantle Shear Wave Velocity Structure beneath the Northern Transantarctic Mountains", "datasets": [{"dataset_uid": "601194", "doi": "10.15784/601194", "keywords": "Antarctica; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Crustal Structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for Tectonic Origins", "url": "https://www.usap-dc.org/view/dataset/601194"}, {"dataset_uid": "601019", "doi": "10.15784/601019", "keywords": "Antarctica; Geology/Geophysics - Other; GPS; Sample/collection Description; Sample/Collection Description; Seismology; Shearwave Spitting; Solid Earth; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Shear Wave Splitting Analysis and Seismic Anisotropy beneath the Northern Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601019"}, {"dataset_uid": "601018", "doi": "10.15784/601018", "keywords": "Antarctica; Geology/Geophysics - Other; Model; Seismology; Solid Earth; Tomography; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Upper Mantle Shear Wave Velocity Structure beneath the Northern Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601018"}, {"dataset_uid": "601017", "doi": "10.15784/601017", "keywords": "Antarctica; Geology/Geophysics - Other; Model; Seismology; Solid Earth; Tomography; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Upper Mantle Seismic Structure beneath the Northern Transantarctic Mountains from Regional P- and S-wave Tomography", "url": "https://www.usap-dc.org/view/dataset/601017"}], "date_created": "Sun, 04 Jun 2017 00:00:00 GMT", "description": "Intellectual Merit: To understand Antarctica\u0027s geodynamic development, origin of the Transantarctic Mountains (TAMs) and the Wilkes Subglacial Basin (WSB) must be determined. Current constraints on the crustal thickness and seismic velocity structure beneath the TAMs and the WSB are limited, leading to uncertainties over competing geologic models that have been suggested to explain their formation. The PI proposes to broaden the investigation of this region with a new seismic deployment, the Transantarctic Mountains Northern Network (TAMNNET), a 15-station array across the northern TAMs and the WSB that will fill a major gap in seismic coverage. Data from TAMNNET will be combined with that from other previous and ongoing seismic initiatives and will be analyzed using proven modeling techniques to generate a detailed image of the seismic structure beneath the TAMs and the WSB. These data will be used to test three fundamental hypotheses: the TAMs are underlain by thickened crust, the WSB is characterized by thin crust and thick sedimentary layers, and slow seismic velocities are prevalent along strike beneath the TAMs. Results from the proposed study will provide new information about the nature and formation of the Antarctic continent and will help to advance our understanding of important global processes, such as mountain building and basin formation. The proposed research also has important implications for other fields of Antarctic science. Constraints on the origin of the TAMs uplift are critical for climate and ice sheet models, and new information acquired about variations in the thermal and lithospheric structure beneath the TAMs and the WSB will be used to estimate critical ice sheet boundary conditions. Broader impacts: This project incorporates three educational strategies to promote the integration of teaching and research. Graduate students will be trained in Antarctic tectonics and seismic processing through hands-on fieldwork and data analysis techniques. Through NSF\u0027s PolarTREC program, the PI will work with K-12 educators. The PI will develop a three-week summer field program for recent high school graduates and early-career undergraduate students from Minority-Serving Institutions in Alabama. Teaching materials and participant experiences will be shared with individuals outside the program via a course website. Following the summer program, participants who were particularly engaged will be offered internship opportunities to analyze TAMNNET data. In successive years, the students could assist with fieldwork and could be recruited into the graduate program under the PI\u0027s supervision. Ultimately, this program would not only serve to educate undergraduates but would also generate a pipeline of underrepresented students into the geosciences.", "east": 165.120012, "geometry": "POINT(159.223506 -74.6349495)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -73.032547, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Hansen, Samantha", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.237352, "title": "CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin", "uid": "p0000300", "west": 153.327}, {"awards": "1043750 Chen, Jianli", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "datasets": [{"dataset_uid": "600159", "doi": "10.15784/600159", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; GRACE; Potential Field; Satellite Data", "people": "Chen, Jianli", "repository": "USAP-DC", "science_program": null, "title": "Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "url": "https://www.usap-dc.org/view/dataset/600159"}], "date_created": "Fri, 13 May 2016 00:00:00 GMT", "description": "1043750/Chen This award supports a project to improve the estimate of long-term and inter-annual variability of Antarctic ice sheet mass balance at continental, regional, and catchment scales, using satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and other geodetic measurements. The work will improve the quantification of long-term mass change rates over Antarctica using GRACE gravity data with a longer record and newer generation(s) of products and will develop advanced numerical forward modeling techniques that can accurately correct leakage effects associated with GRACE data processing, and significantly improve spatial resolution of GRACE mass rate estimates over Antarctica. The work will also contribute to a better understanding of crustal uplift rates due to postglacial rebound (PGR) and present day ice load change over Antarctica via PGR models, GPS measurements, and combined analysis of GRACE and ICESat elevation changes. Inter-annual variations of ice mass over Antarctica will be investigated at continental and catchment scales and connections to regional climate change will be studied. The major deliverables from this study will be improved assessments of ice mass balance for the entire Antarctic ice sheet and potential contribution to global mean sea level rise. The work will also provide estimates of regional ice mass change rates over Antarctica, with a focus along the coast in the Amundsen Sea Embayment, the Peninsula in West Antarctica, and in Wilkes Land and Victoria Land in East Antarctica. Estimates of inter-annual ice mass change over Antarctica at various spatial scales, and assessments of uncertainty of GRACE ice rate estimates and PGR models errors over Antarctica will also be made. The intellectual merits of the proposed investigation include 1) providing improved assessments of Antarctic ice mass balance at different temporal and spatial scales with unprecedented accuracy, an important contribution to broad areas of polar science research; 2) combining high accuracy GPS vertical uplift measurements and PGR models to better quantify long-term crust uplift effects that are not distinguishable from ice mass changes by GRACE; and 3) unifying the work of several investigations at the forefront of quantifying ice sheet and glacier mass balance and crustal uplift based on a variety of modern space geodetic observations. The broader impacts include the fact that the project will actively involve student participation and training, through the support of two graduate students. In addition the project will contribute to general education and public outreach (E/PO) activities and the results from this investigation will help inspire future geoscientists and promote public awareness of significant manifestations of climate change.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e LASER RANGING \u003e GRACE LRR", "is_usap_dc": true, "keywords": "SATELLITES; GRACE; Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Chen, Jianli; Wilson, Clark; Blankenship, Donald D.; Tapley, Byron", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e NASA EARTH SYSTEM SCIENCE PATHFINDER \u003e GRACE; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "uid": "p0000415", "west": -180.0}, {"awards": "1144224 Marchant, David", "bounds_geometry": "POLYGON((160 -71.5,161 -71.5,162 -71.5,163 -71.5,164 -71.5,165 -71.5,166 -71.5,167 -71.5,168 -71.5,169 -71.5,170 -71.5,170 -72.15,170 -72.8,170 -73.45,170 -74.1,170 -74.75,170 -75.4,170 -76.05,170 -76.7,170 -77.35,170 -78,169 -78,168 -78,167 -78,166 -78,165 -78,164 -78,163 -78,162 -78,161 -78,160 -78,160 -77.35,160 -76.7,160 -76.05,160 -75.4,160 -74.75,160 -74.1,160 -73.45,160 -72.8,160 -72.15,160 -71.5))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 23 Oct 2015 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose a two-year project to map the distribution of climate-sensitive landforms throughout Northern Victoria Land between the Convoy Range and Cape Adare. This work will produce geospatial products to aid their geomorphic work on ice sheet stability and landscape evolution. Specifically, the PI will investigate the potential for extensive surface melting and ice-sheet retreat with modest warming in areas north of the Convoy Range in Northern Victoria Land. The hypothesis is that if key landform elements of the Dry Valleys assemblage are lacking in NVL it suggests a major variation in current climate conditions, and perhaps changes in climate evolution. The proposed work will also benefit the broader research community, as it will demonstrate the potential for using geospatial imagery in geomorphic research and produce geospatial products that can be used by other researchers. Broader impacts: This work will help the research community better leverage the investment being made in the Polar Geospatial Center (PGC) and will help further demonstrate the significance of satellite imagery for doing ?virtual? field work in the Polar regions. More effective use of satellite imagery by field scientists in Antarctica will help reduce the logistical footprint on the Continent. The proposed research will support one graduate student at Boston University who will be trained in image analysis, map production, Antarctic geomorphology, and geospatial technologies. The proposed work will help to forge stronger links between PGC and Boston University?s Digital Image Analyses Lab (DIAL).", "east": 170.0, "geometry": "POINT(165 -74.75)", "instruments": null, "is_usap_dc": false, "keywords": "Bu/es Data Repository; Not provided", "locations": null, "north": -71.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Marchant, David", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -78.0, "title": "Geomorphic investigations of Northern Victoria Land, Antarctica", "uid": "p0000231", "west": 160.0}, {"awards": "1043657 Cassano, John", "bounds_geometry": "POLYGON((163 -74.5,163.9 -74.5,164.8 -74.5,165.7 -74.5,166.6 -74.5,167.5 -74.5,168.4 -74.5,169.3 -74.5,170.2 -74.5,171.1 -74.5,172 -74.5,172 -74.9,172 -75.3,172 -75.7,172 -76.1,172 -76.5,172 -76.9,172 -77.3,172 -77.7,172 -78.1,172 -78.5,171.1 -78.5,170.2 -78.5,169.3 -78.5,168.4 -78.5,167.5 -78.5,166.6 -78.5,165.7 -78.5,164.8 -78.5,163.9 -78.5,163 -78.5,163 -78.1,163 -77.7,163 -77.3,163 -76.9,163 -76.5,163 -76.1,163 -75.7,163 -75.3,163 -74.9,163 -74.5))", "dataset_titles": "Ocean-Ice-Atmosphere Interactions in the Terra Nova Bay Polynya, Antarctica", "datasets": [{"dataset_uid": "600125", "doi": "10.15784/600125", "keywords": "Antarctica; Atmosphere; Meteorology; Navigation; Oceans; Southern Ocean; Unmanned Aircraft", "people": "Palo, Scott; Cassano, John", "repository": "USAP-DC", "science_program": null, "title": "Ocean-Ice-Atmosphere Interactions in the Terra Nova Bay Polynya, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600125"}], "date_created": "Thu, 22 Oct 2015 00:00:00 GMT", "description": "Antarctic coastal polynas are, at the same time, sea-ice free sites and \u0027sea-ice factories\u0027. They are open water surface locations where water mass transformation and densification occurs, and where atmospheric exchanges with the deep ocean circulation are established. Various models of the formation and persistence of these productive and diverse ocean ecosystems are hampered by the relative lack of in situ meteorological and physical oceanographic observations, especially during the inhospitable conditions of their formation and activity during the polar night. Characterization of the lower atmosphere properties, air-sea surface heat fluxes and corresponding ocean hydrographic profiles of Antarctic polynyas, especially during strong wind events, is sought for a more detailed understanding of the role of polynyas in the production of latent-heat type sea ice and the formation, through sea ice brine rejection, of dense ocean bottom waters A key technological innovation in this work continues to be the use of instrumented unmanned aircraft systems (UAS), to enable the persistent and safe observation of the interaction of light and strong katabatic wind fields, and mesocale cyclones in the Terra Nova Bay (Victoria Land, Antarctica) polynya waters during late winter and early summer time frames.", "east": 172.0, "geometry": "POINT(167.5 -76.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -74.5, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Cassano, John; Palo, Scott", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.5, "title": "Collaborative Research: Ocean-Ice-Atmosphere Interactions in the Terra Nova Bay Polynya, Antarctica", "uid": "p0000417", "west": 163.0}, {"awards": "1043700 Harry, Dennis", "bounds_geometry": "POLYGON((-180 -70,-176.5 -70,-173 -70,-169.5 -70,-166 -70,-162.5 -70,-159 -70,-155.5 -70,-152 -70,-148.5 -70,-145 -70,-145 -71,-145 -72,-145 -73,-145 -74,-145 -75,-145 -76,-145 -77,-145 -78,-145 -79,-145 -80,-148.5 -80,-152 -80,-155.5 -80,-159 -80,-162.5 -80,-166 -80,-169.5 -80,-173 -80,-176.5 -80,180 -80,177.5 -80,175 -80,172.5 -80,170 -80,167.5 -80,165 -80,162.5 -80,160 -80,157.5 -80,155 -80,155 -79,155 -78,155 -77,155 -76,155 -75,155 -74,155 -73,155 -72,155 -71,155 -70,157.5 -70,160 -70,162.5 -70,165 -70,167.5 -70,170 -70,172.5 -70,175 -70,177.5 -70,-180 -70))", "dataset_titles": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History; Ross Sea post-middle Miocene seismic interpretation", "datasets": [{"dataset_uid": "601227", "doi": "10.15784/601227", "keywords": "Andrill; Antarctica; Marine Geoscience; Ross Sea; Seismic Interpretation; Seismic Reflection; Stratigraphy; Subsidence; Victoria Land Basin", "people": "Harry, Dennis L.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Ross Sea post-middle Miocene seismic interpretation", "url": "https://www.usap-dc.org/view/dataset/601227"}, {"dataset_uid": "600128", "doi": "10.15784/600128", "keywords": "Andrill; Antarctica; Continental Rift; Geology/Geophysics - Other; Lithosphere; Model; Ross Sea; Solid Earth; Tectonic; Transantarctic Mountains", "people": "Harry, Dennis L.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "url": "https://www.usap-dc.org/view/dataset/600128"}], "date_created": "Sun, 31 Aug 2014 00:00:00 GMT", "description": "Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.", "east": -145.0, "geometry": "POINT(-175 -75)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; MARINE GEOPHYSICS; Antarctica; NOT APPLICABLE", "locations": "Antarctica", "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harry, Dennis L.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -80.0, "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "uid": "p0000467", "west": 155.0}, {"awards": "0739464 Cassano, John", "bounds_geometry": "POLYGON((160 -74.5,161.5 -74.5,163 -74.5,164.5 -74.5,166 -74.5,167.5 -74.5,169 -74.5,170.5 -74.5,172 -74.5,173.5 -74.5,175 -74.5,175 -74.9,175 -75.3,175 -75.7,175 -76.1,175 -76.5,175 -76.9,175 -77.3,175 -77.7,175 -78.1,175 -78.5,173.5 -78.5,172 -78.5,170.5 -78.5,169 -78.5,167.5 -78.5,166 -78.5,164.5 -78.5,163 -78.5,161.5 -78.5,160 -78.5,160 -78.1,160 -77.7,160 -77.3,160 -76.9,160 -76.5,160 -76.1,160 -75.7,160 -75.3,160 -74.9,160 -74.5))", "dataset_titles": "Atmosphere-Ocean-Ice Interaction in a Coastal Polynya", "datasets": [{"dataset_uid": "600075", "doi": "10.15784/600075", "keywords": "Antarctica; Atmosphere; Meteorology; Navigation; Oceans; Ross Sea; Sea Ice; Southern Ocean; Terra Nova Bay; UAV", "people": "Cassano, John; Maslanik, Jim", "repository": "USAP-DC", "science_program": null, "title": "Atmosphere-Ocean-Ice Interaction in a Coastal Polynya", "url": "https://www.usap-dc.org/view/dataset/600075"}], "date_created": "Thu, 13 Sep 2012 00:00:00 GMT", "description": "Antarctic polynyas are the ice free zones often persisting in continental sea ice. Characterization of the lower atmosphere properties, air-sea surface heat fluxes and corresponding ocean depth profiles of Antarctic polynyas, especially during strong wind events, is needed for a more detailed understanding of the role of polynya in the production of latent-heat type sea ice and the formation, through brine rejection, of dense ocean bottom waters. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: A key technological innovation, the use of instrumented uninhabited aircraft systems (UAS), will be employed to enable the persistent and safe observation of the interaction of light and strong katabatic wind fields with the Terra Nova Bay (Victoria Land, Antarctica) polynya waters during late winter and early summer time frames. The use of UAS observational platforms on the continent to date has to date been modest, but demonstration of their versatility and effectiveness in surveying and observing mode is a welcome development. The projects use of UAS platforms by University of Colorado and LDEO (Columbia) researchers is both high risk, and potentially transformative for the systematic data measurement tasks that many Antarctic science applications increasingly require.", "east": 175.0, "geometry": "POINT(167.5 -76.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -74.5, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Cassano, John; Maslanik, Jim", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.5, "title": "Collaborative Research: Atmosphere-Ocean-Ice Interaction in a Coastal Polynya", "uid": "p0000678", "west": 160.0}, {"awards": "9527571 Whillans, Ian", "bounds_geometry": "POLYGON((158.25 -76.66667,158.325 -76.66667,158.4 -76.66667,158.475 -76.66667,158.55 -76.66667,158.625 -76.66667,158.7 -76.66667,158.775 -76.66667,158.85 -76.66667,158.925 -76.66667,159 -76.66667,159 -76.683336,159 -76.700002,159 -76.716668,159 -76.733334,159 -76.75,159 -76.766666,159 -76.783332,159 -76.799998,159 -76.816664,159 -76.83333,158.925 -76.83333,158.85 -76.83333,158.775 -76.83333,158.7 -76.83333,158.625 -76.83333,158.55 -76.83333,158.475 -76.83333,158.4 -76.83333,158.325 -76.83333,158.25 -76.83333,158.25 -76.816664,158.25 -76.799998,158.25 -76.783332,158.25 -76.766666,158.25 -76.75,158.25 -76.733334,158.25 -76.716668,158.25 -76.700002,158.25 -76.683336,158.25 -76.66667))", "dataset_titles": "GPS Ice Flow Measurements, Allan Hills, Antarctica", "datasets": [{"dataset_uid": "609507", "doi": "10.7265/N5NS0RSX", "keywords": "Allan Hills; Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity", "people": "Spikes, Vandy Blue; Kurbatov, Andrei V.; Spaulding, Nicole; Hamilton, Gordon S.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "GPS Ice Flow Measurements, Allan Hills, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609507"}], "date_created": "Tue, 20 Dec 2011 00:00:00 GMT", "description": "Whillans, Wilson, Goad OPP 9527571 Abstract This award supports a project to initiate Global Positioning System (GPS) measurements for rock motions in South Victoria Land and vicinity. The results will be used to test some of the leading models for ice-sheet change and tectonism, in particular, whether the continent is rebounding due to reduced ice load from East or West Antarctica and whether there is tectonic motion due to Terror Rift or uplift of the Transantarctic Mountains. A modest program to measure ice motion will be conducted as well. The motive is to test models for ice flow in the Allan Hills meteorite concentration region and to determine whether small glaciers in the Dry Valleys are thickening or thinning. Monuments will be set into rock and ice and GPS receivers used to determine their locations. Repeats in later years will determine motion. Field activities will involve close cooperation with the USGS.", "east": 159.0, "geometry": "POINT(158.625 -76.75)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; LABORATORY; Not provided; Ice Movement; GPS Data; Vertical Motions; GPS; FIELD INVESTIGATION", "locations": null, "north": -76.66667, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Whillans, Ian; Spaulding, Nicole; Hamilton, Gordon S.; Spikes, Vandy Blue; Kurbatov, Andrei V.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.83333, "title": "GPS Measurements of Rock and Ice Motions in South Victoria Land", "uid": "p0000523", "west": 158.25}, {"awards": "0439906 Koch, Paul", "bounds_geometry": "POLYGON((162 -72,162.6 -72,163.2 -72,163.8 -72,164.4 -72,165 -72,165.6 -72,166.2 -72,166.8 -72,167.4 -72,168 -72,168 -72.6,168 -73.2,168 -73.8,168 -74.4,168 -75,168 -75.6,168 -76.2,168 -76.8,168 -77.4,168 -78,167.4 -78,166.8 -78,166.2 -78,165.6 -78,165 -78,164.4 -78,163.8 -78,163.2 -78,162.6 -78,162 -78,162 -77.4,162 -76.8,162 -76.2,162 -75.6,162 -75,162 -74.4,162 -73.8,162 -73.2,162 -72.6,162 -72))", "dataset_titles": "Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic, Isotopic, and Geologic Approaches toward Understanding Holocene Environmental Change", "datasets": [{"dataset_uid": "600041", "doi": "10.15784/600041", "keywords": "Biota; Isotope; Penguin; Ross Sea; Seals; Southern Ocean", "people": "Koch, Paul", "repository": "USAP-DC", "science_program": null, "title": "Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic, Isotopic, and Geologic Approaches toward Understanding Holocene Environmental Change", "url": "https://www.usap-dc.org/view/dataset/600041"}], "date_created": "Sat, 30 Oct 2010 00:00:00 GMT", "description": "During previous NSF-sponsored research, the PI\u0027s discovered that southern elephant seal colonies once existed along the Victoria Land coast (VLC) of Antarctica, a region where they are no longer observed. Molted seal skin and hair occur along 300 km of coastline, more than 1000 km from any extant colony. The last record of a seal at a former colony site is at ~A.D. 1600. Because abandonment occurred prior to subantarctic sealing, disappearance of the VLC colony probably was due to environmental factors, possibly cooling and encroachment of land-fast, perennial sea ice that made access to haul-out sites difficult. The record of seal inhabitation along the VLC, therefore, has potential as a proxy for climate change. Elephant seals are a predominantly subantarctic species with circumpolar distribution. Genetic studies have revealed significant differentiation among populations, particularly with regard to that at Macquarie I., which is the extant population nearest to the abandoned VLC colony. Not only is the Macquarie population unique genetically, but it is has undergone unexplained decline of 2%/yr over the last 50 years3. In a pilot study, genetic analyses showed a close relationship between the VLC seals and those at Macquarie I. An understanding of the relationship between the two populations, as well as of the environmental pressures that led to the demise of the VLC colonies, will provide a better understanding of present-day population genetic structure, the effect of environmental change on seal populations, and possibly the reasons underlying the modern decline at Macquarie Island.\u003cbr/\u003eThis project addresses several key research problems: (1) Why did elephant seals colonize and then abandon the VLC? (2) What does the elephant seal record reveal about Holocene climate change and sea-ice conditions? (3) What were the foraging strategies of the seals and did these strategies change over time as climate varied? (4) How does the genetic structure of the VLC seals relate to extant populations? (5) How did genetic diversity change over time and with colony decline? (6) Using ancient samples to estimate mtDNA mutation rates, what can be learned about VLC population dynamics over time? (7) What was the ecological relationship between elephant seals and Adelie penguins that occupied the same sites, but apparently at different times? The proposed work includes the professional training of young researchers and incorporation of data into graduate and undergraduate courses.", "east": 168.0, "geometry": "POINT(165 -75)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS", "locations": null, "north": -72.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Earth Sciences", "paleo_time": null, "persons": "Koch, Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research: Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic, Isotopic, and Geologic Approaches toward Understanding Holocene Environmental Change", "uid": "p0000533", "west": 162.0}, {"awards": "0088143 Luyendyk, Bruce; 0087392 Bartek, Louis", "bounds_geometry": "POLYGON((-179.99786 -75.91667,-143.99852 -75.91667,-107.99918 -75.91667,-71.99984 -75.91667,-36.0005 -75.91667,-0.00115999999997 -75.91667,35.99818 -75.91667,71.99752 -75.91667,107.99686 -75.91667,143.9962 -75.91667,179.99554 -75.91667,179.99554 -76.183531,179.99554 -76.450392,179.99554 -76.717253,179.99554 -76.984114,179.99554 -77.250975,179.99554 -77.517836,179.99554 -77.784697,179.99554 -78.051558,179.99554 -78.318419,179.99554 -78.58528,143.9962 -78.58528,107.99686 -78.58528,71.99752 -78.58528,35.99818 -78.58528,-0.00116000000003 -78.58528,-36.0005 -78.58528,-71.99984 -78.58528,-107.99918 -78.58528,-143.99852 -78.58528,-179.99786 -78.58528,-179.99786 -78.318419,-179.99786 -78.051558,-179.99786 -77.784697,-179.99786 -77.517836,-179.99786 -77.250975,-179.99786 -76.984114,-179.99786 -76.717253,-179.99786 -76.450392,-179.99786 -76.183531,-179.99786 -75.91667))", "dataset_titles": "Expedition Data; NBP0301 data; NBP0306 data", "datasets": [{"dataset_uid": "000105", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0306 data", "url": "https://www.rvdata.us/search/cruise/NBP0306"}, {"dataset_uid": "001724", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0301"}, {"dataset_uid": "000104", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0301 data", "url": "https://www.rvdata.us/search/cruise/NBP0301"}, {"dataset_uid": "001668", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0306"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Luyendyk et.al.: OPP 0088143\u003cbr/\u003eBartek: OPP 0087392\u003cbr/\u003eDiebold: OPP 0087983\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program in marine geology and geophysics in the southern central and eastern Ross Sea. The project will conduct sites surveys for drilling from the Ross Ice Shelf into the seafloor beneath it. Many of the outstanding problems concerning the evolution of the East and West Antarctic Ice Sheets, Antarctic climate, global sea level, and the tectonic history of the West Antarctic Rift System can be addressed by drilling into the seafloor of the Ross Sea. Climate data for Cretaceous and Early Cenozoic time are lacking for this sector of Antarctica. Climate questions include: Was there any ice in Late Cretaceous time? What was the Antarctic climate during the Paleocene-Eocene global warming? When was the Cenozoic onset of Antarctic glaciation, when did glaciers reach the coast and when did they advance out onto the margin? Was the Ross Sea shelf non-marine in Late Cretaceous time; when did it become marine? Tectonic questions include: What was the timing of the Cretaceous extension in the Ross Sea rift; where was it located? What is the basement composition and structure? Where are the time and space limits of the effects of Adare Trough spreading? Another drilling objective is to sample and date the sedimentary section bounding the mapped RSU6 unconformity in the Eastern Basin and Central Trough to resolve questions about its age and regional extent. Deep Sea Drilling Project (DSDP) Leg 28 completed sampling at four drill sites in the early 1970\u0027s but had low recovery and did not sample the Early Cenozoic. Other drilling has been restricted to the McMurdo Sound area of the western Ross Sea and results can be correlated into the Victoria Land Basin but not eastward across basement highs. Further, Early Cenozoic and Cretaceous rocks have not been sampled. A new opportunity is developing to drill from the Ross Ice Shelf. This is a successor program to the Cape Roberts Drilling Project. One overriding difficulty is the need for site surveys at drilling locations under the ice shelf. This project will overcome this impediment by conducting marine geophysical drill site surveys at the front of the Ross Ice Shelf in the Central Trough and Eastern Basin. The surveys will be conducted a kilometer or two north of the ice shelf front where recent calving events have resulted in a southerly position of the ice shelf edge. In several years the northward advance of the ice shelf will override the surveyed locations and drilling could be accomplished. Systems to be used include swath bathymetry, gravity, magnetics, chirp sonar, high resolution seismic profiling, and 48 fold seismics. Cores will be collected to obtain samples for geotechnical properties, to study sub-ice shelf modern sedimentary processes, and at locations where deeper section is exposed.\u003cbr/\u003e\u003cbr/\u003eThis survey will include long profiles and detailed grids over potential drill sites. Survey lines will be tied to existing geophysical profiles and DSDP 270. A recent event that makes this plan timely is the calving of giant iceberg B-15 (in March, 2000) and others from the ice front in the eastern Ross Sea. This new calving event and one in 1987 have exposed 16,000 square kilometers of seafloor that had been covered by ice shelf for decades and is not explored. Newly exposed territory can now be mapped by modern geophysical methods. This project will map geological structure and stratigraphy below unconformity RSU6 farther south and east, study the place of Roosevelt Island in the Ross Sea rifting history, and determine subsidence history during Late Cenozoic time (post RSU6) in the far south and east. Finally the project will observe present day sedimentary processes beneath the ice shelf in the newly exposed areas.", "east": 179.99554, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "R/V NBP", "locations": null, "north": -75.91667, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bartek, Louis; Luyendyk, Bruce P.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -78.58528, "title": "Collaborative Research: Antarctic Cretaceous-Cenozoic Climate, Glaciation, and Tectonics: Site surveys for drilling from the edge of the Ross Ice Shelf", "uid": "p0000425", "west": -179.99786}, {"awards": "0230285 Wilson, Terry", "bounds_geometry": "POLYGON((152.833 -75.317,154.4897 -75.317,156.1464 -75.317,157.8031 -75.317,159.4598 -75.317,161.1165 -75.317,162.7732 -75.317,164.4299 -75.317,166.0866 -75.317,167.7433 -75.317,169.4 -75.317,169.4 -75.9186,169.4 -76.5202,169.4 -77.1218,169.4 -77.7234,169.4 -78.325,169.4 -78.9266,169.4 -79.5282,169.4 -80.1298,169.4 -80.7314,169.4 -81.333,167.7433 -81.333,166.0866 -81.333,164.4299 -81.333,162.7732 -81.333,161.1165 -81.333,159.4598 -81.333,157.8031 -81.333,156.1464 -81.333,154.4897 -81.333,152.833 -81.333,152.833 -80.7314,152.833 -80.1298,152.833 -79.5282,152.833 -78.9266,152.833 -78.325,152.833 -77.7234,152.833 -77.1218,152.833 -76.5202,152.833 -75.9186,152.833 -75.317))", "dataset_titles": null, "datasets": null, "date_created": "Sat, 12 Dec 2009 00:00:00 GMT", "description": "OPP-0230285/OPP-0230356\u003cbr/\u003ePIs: Wilson, Terry J./Hothem, Larry D.\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to conduct GPS measurements of bedrock crustal motions in an extended Transantarctic Mountains Deformation network (TAMDEF) to document neotectonic displacements due to tectonic deformation within the West Antarctic rift and/or to mass change of the Antarctic ice sheets. Horizontal displacements related to active neotectonic rifting, strike-slip translations, and volcanism will be tightly constrained by monitoring the combined TAMDEF and Italian VLNDEF networks of bedrock GPS stations along the Transantarctic Mountains and on offshore islands in the Ross Sea. Glacio-isostatic adjustments due to deglaciation since the Last Glacial Maximum and to modern mass change of the ice sheets will be modeled from GPS-derived crustal motions together with new information from other programs on the configurations, thicknesses, deglaciation history and modern mass balance of the ice sheets. Tectonic and rheological information from ongoing structural and seismic investigations in the Victoria Land region will also be integrated in the modeling. The integrative and iterative modeling will yield a holistic interpretation of neotectonics and ice sheet history that will help us to discriminate tectonic crustal displacements from viscoelastic/elastic glacio-isostatic motions. These results will provide key information to interpret broad, continental-scale crustal motion patterns detected by sparse, regionally distributed GPS continuous trackers and by spaceborne instruments. This study will contribute to international programs focused on Antarctic neotectonic and global change issues.\u003cbr/\u003e\u003cbr/\u003eStrategies to meet these science objectives include repeat surveys of key sites in the existing TAMDEF network, extension of the array of TAMDEF sites southward about 250 km along the Transantarctic Mountains, linked measurements with the VLNDEF network, and integration of quasi-continuous trackers within the campaign network. By extending the array of bedrock sites southward, these measurements will cross gradients in predicted vertical motion due to viscoelastic rebound. The southward extension will also allow determination of the southern limit of the active Terror Rift and will provide a better baseline for constraints on any ongoing tectonic displacements across the West Antarctic rift system as a whole that might be possible using GPS data collected by the West Antarctic GPS Network. This project will also investigate unique aspects of GPS geodesy in Antarctica to determine how the error spectrum compares to mid-latitude regions and to identify the optimum measurement and data processing schemes for Antarctic conditions. The geodetic research will improve position accuracies within our network and will also yield general recommendations for deformation monitoring networks in polar regions.\u003cbr/\u003e\u003cbr/\u003eAn education and outreach program is planned and will be targeted at non-science-major undergraduate students taking Earth System Science at Ohio State University. The objective will be to illuminate the research process for nonscientists. This effort will educate students on the process of science and inform them about Antarctica and how it relates to global science issues.", "east": 169.4, "geometry": "POINT(161.1165 -78.325)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "GPS", "locations": null, "north": -75.317, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wilson, Terry", "platforms": "SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repositories": null, "science_programs": null, "south": -81.333, "title": "Collaborative Research: Transantarctic Mountains Deformation Network: GPS Measurements of Neotectonic Motion in the Antarctic Interior", "uid": "p0000574", "west": 152.833}, {"awards": "0440954 Miller, Molly; 0551163 Sidor, Christian; 0440919 Isbell, John", "bounds_geometry": "POLYGON((159.3 -76.59,159.542 -76.59,159.784 -76.59,160.026 -76.59,160.268 -76.59,160.51 -76.59,160.752 -76.59,160.994 -76.59,161.236 -76.59,161.478 -76.59,161.72 -76.59,161.72 -76.811,161.72 -77.032,161.72 -77.253,161.72 -77.474,161.72 -77.695,161.72 -77.916,161.72 -78.137,161.72 -78.358,161.72 -78.579,161.72 -78.8,161.478 -78.8,161.236 -78.8,160.994 -78.8,160.752 -78.8,160.51 -78.8,160.268 -78.8,160.026 -78.8,159.784 -78.8,159.542 -78.8,159.3 -78.8,159.3 -78.579,159.3 -78.358,159.3 -78.137,159.3 -77.916,159.3 -77.695,159.3 -77.474,159.3 -77.253,159.3 -77.032,159.3 -76.811,159.3 -76.59))", "dataset_titles": "Burke Museum of Natural History and Culture, University of Washington ID#s UWBM 88593-88601, UWBM 88617; Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica", "datasets": [{"dataset_uid": "000124", "doi": "", "keywords": null, "people": null, "repository": "Burke Museum", "science_program": null, "title": "Burke Museum of Natural History and Culture, University of Washington ID#s UWBM 88593-88601, UWBM 88617", "url": "http://www.washington.edu/burkemuseum/collections/"}, {"dataset_uid": "600045", "doi": "10.15784/600045", "keywords": "Allan Hills; Antarctica; Paleontology; Sample/collection Description; Sample/Collection Description; Solid Earth", "people": "Miller, Molly", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600045"}], "date_created": "Mon, 12 Oct 2009 00:00:00 GMT", "description": "This project studies fossils from two to three hundred million year old rocks in the Allan Hills area of Antarctica. Similar deposits from lower latitudes have been used to develop a model of Permo-Triassic climate, wherein melting of continental glaciers in the early Permian leads to the establishment of forests in a cold, wet climate. Conditions became warmer and dryer by the early Triassic, inhibiting plant growth until a moistening climate in the late Triassic allowed plant to flourish once again. This project will test and refine this model and investigate the general effects of climate change on landscapes and ecosystems using the unique exposures and well-preserved fossil and sediment records in the Allan Hills area. The area will be searched for fossil forests, vertebrate tracks and burrows, arthropod trackways, and subaqueously produced biogenic structures, which have been found in other areas of Antarctica. Finds will be integrated with previous paleobiologic studies to reconstruct and interpret ecosystems and their changes. Structures and rock types documenting the end phases of continental glaciation and other major episodic sedimentations will also be described and interpreted. This project contributes to understanding the: (1) evolution of terrestrial and freshwater ecosystems and how they were affected by the end-Permian extinction, (2) abundance and diversity of terrestrial and aquatic arthropods at high latitudes, (3) paleogeographic distribution and evolution of vertebrates and invertebrates as recorded by trace and body fossils; and (3) response of landscapes to changes in climate.\u003cbr/\u003e\u003cbr/\u003eIn terms of broader impacts, this project will provide an outstanding introduction to field research for graduate and undergraduate students, and generate related opportunities for several undergraduates. It will also stimulate exchange of ideas among research and primarily undergraduate institutions. Novel outreach activities are also planned to convey Earth history to the general public, including a short film on the research process and products, and paintings by a professional scientific illustrator of Permo-Traissic landscapes and ecosystems.", "east": 161.72, "geometry": "POINT(160.51 -77.695)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.59, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e PALEOZOIC \u003e CARBONIFEROUS \u003e PENNSYLVANIAN; PHANEROZOIC \u003e PALEOZOIC \u003e PERMIAN; PHANEROZOIC \u003e MESOZOIC \u003e TRIASSIC", "persons": "Miller, Molly; Sidor, Christian; Isbell, John", "platforms": "Not provided", "repo": "Burke Museum", "repositories": "Burke Museum; USAP-DC", "science_programs": "Allan Hills", "south": -78.8, "title": "Collaborative Research: Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica", "uid": "p0000207", "west": 159.3}, {"awards": "0440414 Steig, Eric", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Stable Isotope Studies at East Antarctic US ITASE Sites", "datasets": [{"dataset_uid": "600042", "doi": "10.15784/600042", "keywords": "Antarctica; Atmosphere; Climate; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; ITASE; Meteorology; Paleoclimate; Satellite Remote Sensing; Weather Station Data", "people": "Steig, Eric J.", "repository": "USAP-DC", "science_program": "ITASE", "title": "Stable Isotope Studies at East Antarctic US ITASE Sites", "url": "https://www.usap-dc.org/view/dataset/600042"}], "date_created": "Mon, 14 Sep 2009 00:00:00 GMT", "description": "This award supports a project to obtain stable isotope profiles from shallow (\u003c100 m) ice cores from East Antarctica, to add to the growing database of environmental proxy data collected under the auspices of the \"ITASE\" (International TransAntarctic Scientific Expedition) program. In Antarctica, the instrumental record of climate is particularly short (~40 years except in a few isolated locations on the coast), and ice core proxy data are the only means available for extending this record into the past. The use of stable isotopes of water (18-O/16-O and D/H ratios) from ice cores as proxies for temperature is well established for both very short (i.e. seasonal) and long timescales (centuries, millennia). Using multivariate regression methods and shallow ice cores from West Antarctica, a reconstruction of Antarctic climate over the last ~150 years has been developed which suggests the continent has been warming, on average, at a rate of ~0.2 K/century. Further improving these reconstructions is the chief motivation for further extending the US ITASE project. Ten to fifteen shallow (~ 100 m) from Victoria Land, East Antarctica will be obtained and analyzed. The core will be collected along a traverse route beginning at Taylor Dome and ending at the South Pole. Age-depth relationships for the cores will be determined through a combination of stable isotopes, visual stratigraphy and seasonal chemical signatures and marker horizons. Reconstructions of Antarctic climate obtained from these cores will be incorporated into the global network of paleoclimate information, which has been important in science, policy and educational contexts. The project will include graduate student and postdoctoral training and field experience.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -90.0, "title": "Stable Isotope Studies at East Antarctic US ITASE Sites", "uid": "p0000202", "west": -180.0}, {"awards": "0125098 Emslie, Steven", "bounds_geometry": "POLYGON((-50 -60,-29 -60,-8 -60,13 -60,34 -60,55 -60,76 -60,97 -60,118 -60,139 -60,160 -60,160 -63,160 -66,160 -69,160 -72,160 -75,160 -78,160 -81,160 -84,160 -87,160 -90,139 -90,118 -90,97 -90,76 -90,55 -90,34 -90,13 -90,-8 -90,-29 -90,-50 -90,-50 -87,-50 -84,-50 -81,-50 -78,-50 -75,-50 -72,-50 -69,-50 -66,-50 -63,-50 -60))", "dataset_titles": "Occupation History and Diet of Adelie Penguins in the Ross Sea Region", "datasets": [{"dataset_uid": "600028", "doi": "10.15784/600028", "keywords": "Antarctica; Biota; Geochronology; Oceans; Paleoclimate; Penguin; Radiocarbon; Ross Sea; Southern Ocean", "people": "Emslie, Steven D.", "repository": "USAP-DC", "science_program": null, "title": "Occupation History and Diet of Adelie Penguins in the Ross Sea Region", "url": "https://www.usap-dc.org/view/dataset/600028"}], "date_created": "Sun, 01 Feb 2009 00:00:00 GMT", "description": "#0125098\u003cbr/\u003eSteve Emslie\u003cbr/\u003e\u003cbr/\u003eOccupation History and Diet of Adelie Penguins in the Ross Sea Region\u003cbr/\u003e\u003cbr/\u003eThis project will build on previous studies to investigate the occupation history and diet of Adelie penguins (Pygoscelis adeliae) in the Ross Sea region, Antarctica, with excavations of abandoned and active penguin colonies. Numerous active and abandoned colonies exist on the Victoria Land coast, from Cape Adare to Marble Point will be sampled. Some of these sites have been radiocarbon-dated and indicate a long occupation history for Adelie penguins extending to 13,000 years before present (B. P.). The material recovered from excavations, as demonstrated from previous investigations, will include penguin bones, tissue, and eggshell fragments as well as abundant remains of prey (fish bones, otoliths, squid beaks) preserved in ornithogenic (formed from bird guano) soils. These organic remains will be quantified and subjected to radiocarbon analyses to obtain a colonization history of penguins in this region. Identification of prey remains in the sediments will allow assessment of penguin diet. Other data (ancient DNA) from these sites will be analyzed through collaboration with New Zealand scientists. Past climatic conditions will be interpreted from published ice-core and marine-sediment records. These data will be used to test the hypothesis that Adelie penguins respond to climate change, past and present, in a predictable manner. In addition, the hypothesis that Adelie penguins alter their diet in accordance with climate, sea-ice conditions, and other marine environmental variables along a latitudinal gradient will be tested. Graduate and undergraduate students will be involved in this project and a project Web site will be developed to report results and maintain educational interaction between the PI and students at local middle and high schools in Wilmington, NC.", "east": 160.0, "geometry": "POINT(55 -75)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": null, "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Occupation History and Diet of Adelie Penguins in the Ross Sea Region", "uid": "p0000220", "west": -50.0}, {"awards": "0229573 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Antarctic Mean Annual Temperature Map", "datasets": [{"dataset_uid": "609318", "doi": "10.7265/N51C1TTV", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Temperature", "people": "Dixon, Daniel A.", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Mean Annual Temperature Map", "url": "https://www.usap-dc.org/view/dataset/609318"}], "date_created": "Wed, 04 Apr 2007 00:00:00 GMT", "description": "This award supports a science management office for a pilot ice-core drilling and analysis program to test the feasibility of obtaining well-dated, high-resolution isotope and chemistry records from East Antarctica. Shallow ice cores will be obtained from two locations: 1) ~100 km from South Pole towards the Pole of Inaccessibility, as an extension of the Byrd Station-to-South Pole ITASE traverse [International Trans Antarctic Scientific Expedition]; 2) at Taylor Dome, near the original deep coring site, and (3) possibly at AGO 3 and AGO 4 as part of a logistics traverse to these sites. All of the cores collected will be sampled at very high resolution (~1/2 cm) and analyzed for major ions. Results from this calibration work, along with those from another project that is analyzing stable isotopes will be used to help plan a program of larger scope, with the objective of mapping the spatial expression of climate variability in East Antarctica. Funds are also provided to organize a community workshop for coordination of the second phase of US ITASE and for one workshop per year for two years dedicated to writing and preparation of scientific papers from phase one of US ITASE. In addition, route selection activities for the follow-on traverse activities in East Antarctica will be conducted using satellite image mapping. A summary document will be produced and made available to the community to help with planning of related field programs (e.g. deep ice radar, firn radar profiling, atmospheric chemistry, ice coring, snow surface properties for satellite observations, ice surface elevation and mass balance).", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOCOUPLES \u003e THERMOCOUPLES; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; West Antarctica; FIELD INVESTIGATION; West Antarctic Ice Sheet; Antarctic; Temperature; East Antarctic Plateau; FIELD SURVEYS; Antarctica; Not provided", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; West Antarctica; West Antarctic Ice Sheet; East Antarctic Plateau", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Dixon, Daniel A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "A Science Management Office for the U. S. Component of the International Trans Antarctic Expedition (US ITASE SMO)A Collaborative Pgrm of Research from S. Pole to N. Victoria Land", "uid": "p0000199", "west": null}, {"awards": "0125579 Cuffey, Kurt; 0126202 Blankenship, Donald", "bounds_geometry": "POLYGON((160 -77.6,160.25 -77.6,160.5 -77.6,160.75 -77.6,161 -77.6,161.25 -77.6,161.5 -77.6,161.75 -77.6,162 -77.6,162.25 -77.6,162.5 -77.6,162.5 -77.63,162.5 -77.66,162.5 -77.69,162.5 -77.72,162.5 -77.75,162.5 -77.78,162.5 -77.81,162.5 -77.84,162.5 -77.87,162.5 -77.9,162.25 -77.9,162 -77.9,161.75 -77.9,161.5 -77.9,161.25 -77.9,161 -77.9,160.75 -77.9,160.5 -77.9,160.25 -77.9,160 -77.9,160 -77.87,160 -77.84,160 -77.81,160 -77.78,160 -77.75,160 -77.72,160 -77.69,160 -77.66,160 -77.63,160 -77.6))", "dataset_titles": "Ablation Rates of Taylor Glacier, Antarctica; Stable Isotopes of Ice on the Surface of Taylor Glacier, Antarctica; Surface Velocities of Taylor Glacier, Antarctica", "datasets": [{"dataset_uid": "609326", "doi": "10.7265/N5N29TW8", "keywords": "Ablation Poles; Ablation Rates; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Taylor Glacier", "people": "Kavanaugh, Jeffrey; Cuffey, Kurt M.; Bliss, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Ablation Rates of Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609326"}, {"dataset_uid": "609323", "doi": "10.7265/N5WM1BBZ", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Isotope; Taylor Glacier", "people": "Aciego, Sarah; Cuffey, Kurt M.; Bliss, Andrew; Kavanaugh, Jeffrey", "repository": "USAP-DC", "science_program": null, "title": "Stable Isotopes of Ice on the Surface of Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609323"}, {"dataset_uid": "609324", "doi": "10.7265/N5RV0KM7", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Velocity; Taylor Glacier", "people": "Kavanaugh, Jeffrey; Cuffey, Kurt M.; Bliss, Andrew; Aciego, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Surface Velocities of Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609324"}], "date_created": "Tue, 13 Feb 2007 00:00:00 GMT", "description": "This award supports a project to significantly improve our understanding of how Taylor Glacier flows and responds to climate changes. Taylor Glacier drains the Taylor Dome region of the East Antarctic Ice Sheet and terminates in Taylor Valley, one of the Dry Valleys of Victoria Land. It provides a crucial and unique link between two intensively studied Antarctic environments: the Taylor Dome, from which a 130 kyr ice core paleoclimate record has recently been extracted, and the Dry Valleys, a pivotal Long-Term Ecological Research (LTER) site and a focus of research on geomorphology and glacial geology. The proposed work will thus make an important contribution to ongoing efforts to exploit the Taylor Dome - Dry Valleys system to build a uniquely comprehensive view of regional long-term environmental changes. The proposed work has two complementary components: field research and numerical modelling. Two field seasons will be used to measure velocity, surface strain rate, mass balance, ice thickness, glacier bed reflectance, and subglacial topography, along a nearly complete longitudinal transect of the Taylor Glacier, and along select cross-valley transects. This information will be used to constrain numerical models of ice and heat flow for the Taylor Dome - Taylor Glacier system. These calibrated models will be used to analyze the time-dependent response of the Taylor Glacier to climate changes. The synthesis of results will be aimed to improve understanding of the glacial geomorphology of Taylor Valley, and to illuminate impacts on the Taylor Valley lakes ecosystem. The project will have a major role in furthering the careers of a doctoral-level graduate student and a post-doctoral researcher.", "east": 162.5, "geometry": "POINT(161.25 -77.75)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Glacier; Glacier Surface; Glacier Surface Ablation; Ice Velocity; Velocity Measurements; Taylor Glacier; Isotope; GPS; Ice Sheet Elevation; Not provided; FIELD INVESTIGATION; Ice Surface Elevation; Ablation; Oxygen Isotope; Elevation; Deuterium; GROUND-BASED OBSERVATIONS; Glacier Surface Ablation Rate; Surface Elevation", "locations": "Taylor Glacier", "north": -77.6, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Bliss, Andrew; Kavanaugh, Jeffrey; Aciego, Sarah; Cuffey, Kurt M.; Morse, David L.; Blankenship, Donald D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.9, "title": "Collaborative Research: Dynamics and Climatic Response of the Taylor Glacier System", "uid": "p0000084", "west": 160.0}, {"awards": "0229917 Becker, Luann", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 24 Jan 2007 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an interdisciplinary study of fluvial sediments in Antarctica for evidence of what caused the greatest of all mass extinctions in the history of life at the Permian-Triassic boundary. This boundary was, until recently, difficult to locate and thought to be unequivocally disconformable in Antarctica. New studies, particularly of carbon isotopic chemostratigraphy and of paleosols and root traces as paleoecosystem indicators, together with improved fossil plant, reptile and pollen biostratigraphy, now suggest that the precise location of the boundary might be identified and have led to local discovery of iridium anomalies, shocked quartz, and fullerenes with extraterrestrial noble gases. These anomalies are associated with a distinctive claystone breccia bed, similar to strata known in South Africa and Australia, and taken as evidence of deforestation. There is already much evidence from Antarctica and elsewhere that the mass extinction on land was abrupt and synchronous with extinction in the ocean. The problem now is what led to such death and destruction. Carbon isotopic values are so low in these and other Permian-Triassic boundary sections that there was likely to have been some role for catastrophic destabilization of methane clathrates. Getting the modeled amount of methane out of likely reservoirs would require such catastrophic events as bolide impact, flood-basalt eruption or continental-shelf collapse, which have all independently been implicated in the mass extinction and for which there is independent evidence. Teasing apart these various hypotheses requires careful re-examination of beds that appear to represent the Permian-Triassic boundary, and search for more informative sequences, as was the case for the Cretaceous-Tertiary boundary. This collaborative research on geochemistry and petrography of boundary beds and paleosols (by Retallack), on carbon isotopic variation through the boundary interval (by Jahren), and on fullerenes, iridium and helium (by Becker) is designed to test these ideas about the Permian-Triassic boundary in Antarctica and to shed light on processes which contributed to this largest of mass extinctions on Earth. Fieldwork for this research will be conducted in the central Transantarctic Mountains and in Southern Victoria Land with an initial objective of examining the stratigraphic sequences for continuity across the boundary. Stratigraphic continuity is a critical element that must exist for the work to be successful. If fieldwork indicates sufficiently continuous sections, the full analytical program will follow fieldwork.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e PROBES; SOLAR/SPACE OBSERVING INSTRUMENTS \u003e PARTICLE DETECTORS \u003e SEM", "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Becker, Luann", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Permian-Triassic Mass Extinction in Antarctica", "uid": "p0000718", "west": null}, {"awards": "9615347 Conway, Howard", "bounds_geometry": null, "dataset_titles": "Roosevelt Island Bedrock and Surface Elevations; Roosevelt Island Ice Core Density and Beta Count Data", "datasets": [{"dataset_uid": "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}]
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Ice cores provide valuable records of past climate such as atmospheric concentrations of greenhouse gasses and unmatched evidence of past abrupt climate change. Key to understanding past climate changes are the measurements of annual layers that are used to determine the age of the ice, and the timing and pace of major climate events. The current measurement limit for annual layers in ice cores is at the centimeter scale. This project aims to improve the depth resolution of measurements of the chemical impurities in ice using measurements such as electrical conductivity, hyperspectral imaging, major elements measured with laser ablation, and ice grain properties. This will advance understanding of the preservation and layering in ice cores and improve the accuracy and length of annual timescales for existing ice cores. Most of the past time preserved in an ice core is near the bed where the layers have been thinned to only a fraction of their original thickness. Interpreting highly compressed portions of ice cores is increasingly important as projects target climate records in basal ice, and old ice recovered from blue-ice areas. This project will integrate precisely co-registered electrical conductivity measurements, hyperspectral imaging, laser ablation mass spectrometer measurements of impurities, and ice physical properties to investigate sub-centimeter chemical and physical variations in polar ice. Critical to resolving thin ice layers is understanding the across-core variations that may obscure or distort the vertical layering. Analyses will be focused on samples from the WDC-06A (WAIS Divide), SPC-14 (South Pole), and GISP2 (Greenland Ice Sheet Project 2) ice cores that have well-established seasonal cycles that yielded benchmark timescales, as well a large-diameter ice core from the Allan Hills blue ice area. This work will develop state-of-the-art instrumentation and FAIR (findable, accessible, interoperable, and reusable) data handling workflow at the National Science Foundation Ice Core Facility available to the community both to enhance understanding of existing ice cores, and for use in future projects. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth’s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth’s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community. Knowledge of Earth’s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth’s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
A nontechnical description of the project The primary scientific goal of the project is to test whether Taylor Valley, Antarctica has been eroded significantly by glaciers in the last ~2 million years (Ma). Taylor Valley is one of the Dry Valleys of the Transantarctic Mountains, which are characterized by low mean annual temperatures, low precipitation, and limited erosion. These conditions have allowed fragile glacial landforms to be preserved for up to 15 Ma. Sediment eroded and deposited by glaciers is found on the valley walls and floors, with progressively younger deposits preserved at lower elevations. Scientists can date glacial deposits to understand the process and timing of past glacial erosion. Previous work in the Dry Valleys region suggested that extremely cold glaciers like Taylor Glacier, a major outlet glacier entering the valleys, were not erosive during the last several million years. This research will test a new hypothesis that glacial erosion and sediment production beneath Taylor Glacier have been active in the last few million years. This hypothesis will be tested using a new isotopic dating method called "comminution dating' which determines when fine-grained sediment particles called silt were formed. If the sediment age is young, then the results will suggest that glacial processes have been more dynamic than previously thought. Overall, this study will increase our understanding of the nature and extent of past glaciations in Antarctica. Because the silt produced by erosion sediment is a nutrient for local ecosystems, the results will also shed light on delivery of nutrients to soils, streams, and coastal zones in high polar regions. This project will be led by an early career scientist and includes training of a Ph.D. student. A technical description of the project There is a long-standing scientific controversy about the stability of the East Antarctic Ice Sheet with much evidence centered in the Dry Valleys region of South Victoria Land. A prevailing view of geomorphologists is that the landscape has been very stable and that the effects of glaciation have been minimal for the past ~15 Ma. This project will distinguish between two end-member scenarios of glacial erosion and deposition by Taylor Glacier, an outlet glacier of the East Antarctic Ice Sheet that terminates in Taylor Valley in the Dry Valleys region of Antarctica. In the first scenario, all valley relief is generated prior to 15 Ma when non-polar climates enabled warm-based glaciers to incise and widen ancient river channels. In this case, younger glacial deposits record advances of cold-based glaciers of decreasing ice volume and limited glacial erosion, and sediment generation resulted in glacial deposits composed primarily of older recycled sediments. In the second scenario, selective erosion of the valley floor has continued to deepen Taylor Valley but has not affected the adjacent peaks over the last 2 Ma. In this scenario, the "bathtub rings" of Quaternary glacial deposits situated at progressively lower elevations through time could be due to the lowering of the valley floor by subglacial erosion and with it, production of new sediment which is now incorporated into these deposits. While either scenario would result in the present-day topography, they differ in the implied evolution of regional glacial ice volume over time and the timing of both valley relief production and generation of fine-grained particles. The two scenarios will be tested by placing time constraints on fine particle production using U-series comminution dating. This new geochronologic tool exploits the loss of 234U due to alpha-recoil. The deficiency in 234U only becomes detectable in fine-grained particles with a sufficiently high surface-area-to-volume ratio which can incur appreciable 234U loss. The timing of comminution and particle size controls the magnitude of 234U loss. While this geochronologic tool is in its infancy, the scientific goal of this proposal can be achieved by resolving between ancient and recently comminuted fine particles, a binary question that the preliminary modeling and measured data show is readily resolved.
This project will involve examination of Glossopteridales, fossil plants from Upper Permian deposits, in samples from the central Transantarctic Mountains and Southern Victoria Land, Antarctica. The glossopterids are an important fossil group because they are possible ancestors to the flowering plants. Permian sedimentary rocks (295-270 Ma before present) are important because they record a time of rapid biotic change, as the Late Paleozoic Age ended and the Mesozoic greenhouse environment began. The proposed research will rely entirely on specimens collected during recent field excursions to the central Transantarctic Mountains (CTM; 2010?2011) and southern Victoria Land (SVL; 2012?2013). Only a few of the specimens have been studied, but already have yielded anatomically well-preserved glossopterids with a complete pollen cone, which has never been found before. Additionally, several seed-bearing structures, which have never before been observed in Antarctica, have been found in both CTM and SVL. The project will allow comparison of whole-plant fossil glossopterids from the CTM with other paleo-latitudes, and will document the floral diversity within and between two depositional basins (CTM & SVL) during a time of global change, with the overall goal of linking environmental changes with fossil morphology. Broader impacts: The Broader Impacts of this project will include mentoring undergraduates in research projects, at an institution with a substantial minority enrollment. Public outreach will focus on involving middle/high school students through the ?Expanding Your Horizons? programs in Kansas and Missouri, as well as interactive presentations at schools in the Kansas City Area. The lead PI is an early-career scientist at an institution that serves minorities.
Bell and Buck: OPP 9615704 Blankenship: OPP 9615832 Abstract Continental extension produces a great variety of structures from the linear narrow rifts of the East African Rift to the diffuse extension of the Basin and Range Province of the Western U.S. Rift shoulder uplift varies dramatically between rift flanks. The cause of variable rift width and crustal thinning is fairly well explained by variable initial heat flow and crustal thickness. Mechanical stretching of the lithosphere has been linked to rift shoulder uplift but the cause of variable rift flank uplift remains poorly understood. The Transantarctic Mountains (TAM) are an extreme example of rift flank uplift, extending over 3500 km across Antarctica and reaching elevations up to 4500 m and thus constitute a unique feature of EarthOs crust. The range was formed in the extensional environment associated with the Mesozoic and Cenozoic breakup of Gondwanaland. Geological and geophysical work has shown that the TAM developed along the long-lived lithospheric boundary between East and West Antarctica reactivated by a complex history of extensional and translational microplate motions. The TAM are not uniform along strike. Along the OWilkes FrontO, the northern segment of the rift extends from North Victoria Land to Byrd Glacier. The Wilkes Front architecture consists of (1) thin, extended crust forming the Victoria Land Basin in the Ross Sea, (2) the TAM rift shoulder, and (3) a long-wavelength down- ward forming the Wilkes Basin. Contrasting structures are mapped along the OPensacola/PoleO Front, the southern segment of the rift extending from the Nimrod Glacier to the Pensacola Mountains. Along this southern section no rift basin has been mapped to date and the down-ward along the East Antarctic, or ObacksideO, edge of the mountains is less pronounced. A flexural model linking the extension in the Ross Sea to the formation of both the mountains and the Wilkes Basin has been considered as a me chanism for uplift of the entire mountain range. The variability in fundamental architecture along the TAM indicates that neither a single event nor a sequence of identical events produced the rift flank uplift. The observation of variable architecture suggests complex mechanisms and possibly a fundamental limitation in maximum sustainable rift flank elevation. The motivation for studying the TAM is to try to understand the geodynamics of this extreme elevation rift flank. Are the geodynamics of the area unique, or does the history of glaciation and related erosion contribute to the extreme uplift? With the existing data sets it is difficult to confidently constrain the geological architecture across representative sections of the TAM. Any effort to refine geodynamic mechanisms requires this basic understanding of the TAM architecture. The goal of this project is to (1) constrain the architecture of the rift system as well as the distribution and structure of sedimentary basins, glacial erosion and mafic igneous rocks surrounding the rift flank by acquiring three long wavelength geophysical transects with integrated gravity, magnetics, ice- penetrating radar, and ice surface measurements, (2) quantify the contribution of various geodynamic mechanisms to understand the geological conditions which can lead to extreme rift flank uplift, and (3) use the improved understanding of architecture and geophysical data to test geodynamic models in order to improve our understanding both of the TAM geodynamics and the general problem of the geodynamics of rift flank uplift worldwide. This project will allow development of a generalized framework for understanding the development of rift flank uplift as well as address the question of the specific geodynamic evolution of the TAM.
Building on previously funded NSF research, the use of paleobiological and paleogenetic data from mummified elephant seal carcasses found along the Dry Valleys and Victoria Land Coast in areas that today are too cold to support seal colonies (Mirougina leonina; southern elephant seals; SES) supports the former existence of these seals in this region. The occurrence and then subsequent disappearance of these SES colonies is consistent with major shifts in the Holocene climate to much colder conditions at the last ~1000 years BCE). <br/><br/>Further analysis of the preserved remains of three other abundant pinnipeds ? crabeater (Lobodon carciophagus), Weddell (Leptonychotes weddelli) and leopard (Hydrurga leptonyx) will be studied to track changes in their population size (revealed by DNA analysis) and their diet (studied via stable isotope analysis). Combined with known differences in life history, preferred ice habitat and ecosystem sensitivity among these species, this paleoclimate proxy data will be used to assess their exposure and sensitivity to climate change in the Ross Sea region during the past ~1-2,000 years
This CAREER proposal will support an early career female PI to establish an integrated research and education program in the fields of polar biology and environmental microbiology, focusing on single-celled eukaryotes (protists) in high latitude ice-covered Antarctic lakes systems. Protists play important roles in energy flow and material cycling, and act as both primary producers (fixing inorganic carbon by photosynthesis) and consumers (preying on bacteria by phagotrophic digestion). The McMurdo Dry Valleys (MDV) located in Victoria Land, Antarctica, harbor microbial communities which are isolated in the unique aquatic ecosystem of perennially ice-capped lakes. The lakes support exclusively microbial consortia in chemically stratified water columns that are not influenced by seasonal mixing, allochthonous inputs, or direct human impact. This project will exploit permanently stratified biogeochemistry that is unique across the water columns of several MDV lakes to address gaps in our understanding of protist trophic function in aquatic food webs. The proposed research will examine (1) the impact of permanent biogeochemical gradients on protist trophic strategy, (2) the effect of major abiotic drivers (light and nutrients) on the distribution of two key mixotrophic and photoautotrophic protist species, and (3) the effect of episodic nutrient pulses on mixotroph communities in high latitude (ultraoligotrophic) MDV lakes versus low latitude (eutrophic) watersheds. The project will impact the fields of microbial ecology and environmental microbiology by combining results from field, laboratory and in situ incubation studies to synthesize new models for the protist trophic roles in the aquatic food web. The research component of this proposed project will be tightly integrated with the development of two new education activities designed to exploit the inherent excitement associated with polar biological research. The educational objectives are: 1) to establish a teaching module in polar biology in a core undergraduate course for microbiology majors; 2) to develop an instructional module to engage middle school girls in STEM disciplines. Undergraduates and middle school girls will also work with a doctoral student on his experiments in local Ohio watersheds.
The investigators will map glacial deposits and date variations in glacier variability at several ice-free regions in northern Victoria Land, Antarctica. These data will constrain the nature and timing of past ice thickness changes for major glaciers that drain into the northwestern Ross Sea. This is important because during the Last Glacial Maximum (15,000 - 18,000 years ago) these glaciers were most likely flowing together with grounded ice from both the East and West Antarctic Ice Sheets that expanded across the Ross Sea continental shelf to near the present shelf edge. Thus, the thickness of these glaciers was most likely controlled in part by the extent and thickness of the Ross Sea ice sheet and ice shelf. The data the PIs propose to collect can provide constraints on the position of the grounding line in the western Ross Sea during the Last Glacial Maximum, the time that position was reached, and ice thickness changes that occurred after that time. The primary intellectual merit of this project will be to improve understanding of a period of Antarctic ice sheet history that is relatively unconstrained at present and also potentially important in understanding past ice sheet-sea level interactions. This proposal will support an early career researcher's ongoing program of undergraduate education and research that is building a socio-economically diverse student body with students from backgrounds underrepresented in the geosciences. This proposal will also bring an early career researcher into Antarctic research.
Intellectual Merit: This project will use sediment cores from the Victoria Land Basin (VLB), Antarctica, to study secondary (diagenetic) carbonate minerals, as indicators of the basin?s fluid-flow history, within the well-constrained tectonic, depositional, and climatic context provided by sediment cores. This study will provide insights into subsurface processes in Victoria Land Basin, Antarctica and their relationships with the region?s climatic, cryospheric, and tectonic history. The work will utilize cores previously recovered by US-sponsored stratigraphic drilling projects (CIROS, CRP, and ANDRILL projects). This work is motivated by the unexpected discovery of dense brine in the subsurface of Southern McMurdo Sound during drilling by the ANDRILL Southern McMurdo Sound project. The presence of the brine is intriguing because it contradicts previous models for the origin of subsurface fluids that called upon large contributions from glacial melt water. Project objectives involve documenting the distribution of the brine (and potentially other fluids) via characterization of diagenetic precipitates. The approach will involve integration of petrographic and geochemical data (including conventional carbon, oxygen, and ?clumped? isotopes) to fully characterize diagenetic phases and allow development of a robust paragenetic history. This work will provide novel insights into the Cenozoic evolution of the VLB and, more broadly, the role of glacial processes in generating subsurface fluids. Broader impacts: Results from this project will help understand the origins of brines, groundwater and hydrocarbon reservoirs in analogous modern and ancient deposits elsewhere, which is of broad interest. This project will support the training of one graduate and one undergraduate student at the University of Nebraska-Lincoln (UNL) providing learning opportunities in sedimentary geology and diagenesis, fields with wide applicability. This proposal emphasizes rapid dissemination of results to the scientific community via conference presentations and contributions to peer-reviewed publications. The results will be integrated into education activities designed to develop skills in petrography and diagenesis, which are highly sought after in the energy sector. The project will generate a well-constrained dataset that allows direct linkage of diagenetic phases to environmental and tectonic change across a large sedimentary basin which will provide the basis for a comprehensive case study in an upper-level course (Sedimentary Petrography and Diagenesis) at UNL. In addition, online exercises will be developed and submitted to an open-access site (SEPM Stratigraphy Web) dedicated to sedimentary geology.
Intellectual Merit: To understand Antarctica's geodynamic development, origin of the Transantarctic Mountains (TAMs) and the Wilkes Subglacial Basin (WSB) must be determined. Current constraints on the crustal thickness and seismic velocity structure beneath the TAMs and the WSB are limited, leading to uncertainties over competing geologic models that have been suggested to explain their formation. The PI proposes to broaden the investigation of this region with a new seismic deployment, the Transantarctic Mountains Northern Network (TAMNNET), a 15-station array across the northern TAMs and the WSB that will fill a major gap in seismic coverage. Data from TAMNNET will be combined with that from other previous and ongoing seismic initiatives and will be analyzed using proven modeling techniques to generate a detailed image of the seismic structure beneath the TAMs and the WSB. These data will be used to test three fundamental hypotheses: the TAMs are underlain by thickened crust, the WSB is characterized by thin crust and thick sedimentary layers, and slow seismic velocities are prevalent along strike beneath the TAMs. Results from the proposed study will provide new information about the nature and formation of the Antarctic continent and will help to advance our understanding of important global processes, such as mountain building and basin formation. The proposed research also has important implications for other fields of Antarctic science. Constraints on the origin of the TAMs uplift are critical for climate and ice sheet models, and new information acquired about variations in the thermal and lithospheric structure beneath the TAMs and the WSB will be used to estimate critical ice sheet boundary conditions. Broader impacts: This project incorporates three educational strategies to promote the integration of teaching and research. Graduate students will be trained in Antarctic tectonics and seismic processing through hands-on fieldwork and data analysis techniques. Through NSF's PolarTREC program, the PI will work with K-12 educators. The PI will develop a three-week summer field program for recent high school graduates and early-career undergraduate students from Minority-Serving Institutions in Alabama. Teaching materials and participant experiences will be shared with individuals outside the program via a course website. Following the summer program, participants who were particularly engaged will be offered internship opportunities to analyze TAMNNET data. In successive years, the students could assist with fieldwork and could be recruited into the graduate program under the PI's supervision. Ultimately, this program would not only serve to educate undergraduates but would also generate a pipeline of underrepresented students into the geosciences.
1043750/Chen This award supports a project to improve the estimate of long-term and inter-annual variability of Antarctic ice sheet mass balance at continental, regional, and catchment scales, using satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and other geodetic measurements. The work will improve the quantification of long-term mass change rates over Antarctica using GRACE gravity data with a longer record and newer generation(s) of products and will develop advanced numerical forward modeling techniques that can accurately correct leakage effects associated with GRACE data processing, and significantly improve spatial resolution of GRACE mass rate estimates over Antarctica. The work will also contribute to a better understanding of crustal uplift rates due to postglacial rebound (PGR) and present day ice load change over Antarctica via PGR models, GPS measurements, and combined analysis of GRACE and ICESat elevation changes. Inter-annual variations of ice mass over Antarctica will be investigated at continental and catchment scales and connections to regional climate change will be studied. The major deliverables from this study will be improved assessments of ice mass balance for the entire Antarctic ice sheet and potential contribution to global mean sea level rise. The work will also provide estimates of regional ice mass change rates over Antarctica, with a focus along the coast in the Amundsen Sea Embayment, the Peninsula in West Antarctica, and in Wilkes Land and Victoria Land in East Antarctica. Estimates of inter-annual ice mass change over Antarctica at various spatial scales, and assessments of uncertainty of GRACE ice rate estimates and PGR models errors over Antarctica will also be made. The intellectual merits of the proposed investigation include 1) providing improved assessments of Antarctic ice mass balance at different temporal and spatial scales with unprecedented accuracy, an important contribution to broad areas of polar science research; 2) combining high accuracy GPS vertical uplift measurements and PGR models to better quantify long-term crust uplift effects that are not distinguishable from ice mass changes by GRACE; and 3) unifying the work of several investigations at the forefront of quantifying ice sheet and glacier mass balance and crustal uplift based on a variety of modern space geodetic observations. The broader impacts include the fact that the project will actively involve student participation and training, through the support of two graduate students. In addition the project will contribute to general education and public outreach (E/PO) activities and the results from this investigation will help inspire future geoscientists and promote public awareness of significant manifestations of climate change.
Intellectual Merit: The PIs propose a two-year project to map the distribution of climate-sensitive landforms throughout Northern Victoria Land between the Convoy Range and Cape Adare. This work will produce geospatial products to aid their geomorphic work on ice sheet stability and landscape evolution. Specifically, the PI will investigate the potential for extensive surface melting and ice-sheet retreat with modest warming in areas north of the Convoy Range in Northern Victoria Land. The hypothesis is that if key landform elements of the Dry Valleys assemblage are lacking in NVL it suggests a major variation in current climate conditions, and perhaps changes in climate evolution. The proposed work will also benefit the broader research community, as it will demonstrate the potential for using geospatial imagery in geomorphic research and produce geospatial products that can be used by other researchers. Broader impacts: This work will help the research community better leverage the investment being made in the Polar Geospatial Center (PGC) and will help further demonstrate the significance of satellite imagery for doing ?virtual? field work in the Polar regions. More effective use of satellite imagery by field scientists in Antarctica will help reduce the logistical footprint on the Continent. The proposed research will support one graduate student at Boston University who will be trained in image analysis, map production, Antarctic geomorphology, and geospatial technologies. The proposed work will help to forge stronger links between PGC and Boston University?s Digital Image Analyses Lab (DIAL).
Antarctic coastal polynas are, at the same time, sea-ice free sites and 'sea-ice factories'. They are open water surface locations where water mass transformation and densification occurs, and where atmospheric exchanges with the deep ocean circulation are established. Various models of the formation and persistence of these productive and diverse ocean ecosystems are hampered by the relative lack of in situ meteorological and physical oceanographic observations, especially during the inhospitable conditions of their formation and activity during the polar night. Characterization of the lower atmosphere properties, air-sea surface heat fluxes and corresponding ocean hydrographic profiles of Antarctic polynyas, especially during strong wind events, is sought for a more detailed understanding of the role of polynyas in the production of latent-heat type sea ice and the formation, through sea ice brine rejection, of dense ocean bottom waters A key technological innovation in this work continues to be the use of instrumented unmanned aircraft systems (UAS), to enable the persistent and safe observation of the interaction of light and strong katabatic wind fields, and mesocale cyclones in the Terra Nova Bay (Victoria Land, Antarctica) polynya waters during late winter and early summer time frames.
Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.
Antarctic polynyas are the ice free zones often persisting in continental sea ice. Characterization of the lower atmosphere properties, air-sea surface heat fluxes and corresponding ocean depth profiles of Antarctic polynyas, especially during strong wind events, is needed for a more detailed understanding of the role of polynya in the production of latent-heat type sea ice and the formation, through brine rejection, of dense ocean bottom waters. <br/><br/>Broader impacts: A key technological innovation, the use of instrumented uninhabited aircraft systems (UAS), will be employed to enable the persistent and safe observation of the interaction of light and strong katabatic wind fields with the Terra Nova Bay (Victoria Land, Antarctica) polynya waters during late winter and early summer time frames. The use of UAS observational platforms on the continent to date has to date been modest, but demonstration of their versatility and effectiveness in surveying and observing mode is a welcome development. The projects use of UAS platforms by University of Colorado and LDEO (Columbia) researchers is both high risk, and potentially transformative for the systematic data measurement tasks that many Antarctic science applications increasingly require.
Whillans, Wilson, Goad OPP 9527571 Abstract This award supports a project to initiate Global Positioning System (GPS) measurements for rock motions in South Victoria Land and vicinity. The results will be used to test some of the leading models for ice-sheet change and tectonism, in particular, whether the continent is rebounding due to reduced ice load from East or West Antarctica and whether there is tectonic motion due to Terror Rift or uplift of the Transantarctic Mountains. A modest program to measure ice motion will be conducted as well. The motive is to test models for ice flow in the Allan Hills meteorite concentration region and to determine whether small glaciers in the Dry Valleys are thickening or thinning. Monuments will be set into rock and ice and GPS receivers used to determine their locations. Repeats in later years will determine motion. Field activities will involve close cooperation with the USGS.
During previous NSF-sponsored research, the PI's discovered that southern elephant seal colonies once existed along the Victoria Land coast (VLC) of Antarctica, a region where they are no longer observed. Molted seal skin and hair occur along 300 km of coastline, more than 1000 km from any extant colony. The last record of a seal at a former colony site is at ~A.D. 1600. Because abandonment occurred prior to subantarctic sealing, disappearance of the VLC colony probably was due to environmental factors, possibly cooling and encroachment of land-fast, perennial sea ice that made access to haul-out sites difficult. The record of seal inhabitation along the VLC, therefore, has potential as a proxy for climate change. Elephant seals are a predominantly subantarctic species with circumpolar distribution. Genetic studies have revealed significant differentiation among populations, particularly with regard to that at Macquarie I., which is the extant population nearest to the abandoned VLC colony. Not only is the Macquarie population unique genetically, but it is has undergone unexplained decline of 2%/yr over the last 50 years3. In a pilot study, genetic analyses showed a close relationship between the VLC seals and those at Macquarie I. An understanding of the relationship between the two populations, as well as of the environmental pressures that led to the demise of the VLC colonies, will provide a better understanding of present-day population genetic structure, the effect of environmental change on seal populations, and possibly the reasons underlying the modern decline at Macquarie Island.<br/>This project addresses several key research problems: (1) Why did elephant seals colonize and then abandon the VLC? (2) What does the elephant seal record reveal about Holocene climate change and sea-ice conditions? (3) What were the foraging strategies of the seals and did these strategies change over time as climate varied? (4) How does the genetic structure of the VLC seals relate to extant populations? (5) How did genetic diversity change over time and with colony decline? (6) Using ancient samples to estimate mtDNA mutation rates, what can be learned about VLC population dynamics over time? (7) What was the ecological relationship between elephant seals and Adelie penguins that occupied the same sites, but apparently at different times? The proposed work includes the professional training of young researchers and incorporation of data into graduate and undergraduate courses.
Luyendyk et.al.: OPP 0088143<br/>Bartek: OPP 0087392<br/>Diebold: OPP 0087983<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program in marine geology and geophysics in the southern central and eastern Ross Sea. The project will conduct sites surveys for drilling from the Ross Ice Shelf into the seafloor beneath it. Many of the outstanding problems concerning the evolution of the East and West Antarctic Ice Sheets, Antarctic climate, global sea level, and the tectonic history of the West Antarctic Rift System can be addressed by drilling into the seafloor of the Ross Sea. Climate data for Cretaceous and Early Cenozoic time are lacking for this sector of Antarctica. Climate questions include: Was there any ice in Late Cretaceous time? What was the Antarctic climate during the Paleocene-Eocene global warming? When was the Cenozoic onset of Antarctic glaciation, when did glaciers reach the coast and when did they advance out onto the margin? Was the Ross Sea shelf non-marine in Late Cretaceous time; when did it become marine? Tectonic questions include: What was the timing of the Cretaceous extension in the Ross Sea rift; where was it located? What is the basement composition and structure? Where are the time and space limits of the effects of Adare Trough spreading? Another drilling objective is to sample and date the sedimentary section bounding the mapped RSU6 unconformity in the Eastern Basin and Central Trough to resolve questions about its age and regional extent. Deep Sea Drilling Project (DSDP) Leg 28 completed sampling at four drill sites in the early 1970's but had low recovery and did not sample the Early Cenozoic. Other drilling has been restricted to the McMurdo Sound area of the western Ross Sea and results can be correlated into the Victoria Land Basin but not eastward across basement highs. Further, Early Cenozoic and Cretaceous rocks have not been sampled. A new opportunity is developing to drill from the Ross Ice Shelf. This is a successor program to the Cape Roberts Drilling Project. One overriding difficulty is the need for site surveys at drilling locations under the ice shelf. This project will overcome this impediment by conducting marine geophysical drill site surveys at the front of the Ross Ice Shelf in the Central Trough and Eastern Basin. The surveys will be conducted a kilometer or two north of the ice shelf front where recent calving events have resulted in a southerly position of the ice shelf edge. In several years the northward advance of the ice shelf will override the surveyed locations and drilling could be accomplished. Systems to be used include swath bathymetry, gravity, magnetics, chirp sonar, high resolution seismic profiling, and 48 fold seismics. Cores will be collected to obtain samples for geotechnical properties, to study sub-ice shelf modern sedimentary processes, and at locations where deeper section is exposed.<br/><br/>This survey will include long profiles and detailed grids over potential drill sites. Survey lines will be tied to existing geophysical profiles and DSDP 270. A recent event that makes this plan timely is the calving of giant iceberg B-15 (in March, 2000) and others from the ice front in the eastern Ross Sea. This new calving event and one in 1987 have exposed 16,000 square kilometers of seafloor that had been covered by ice shelf for decades and is not explored. Newly exposed territory can now be mapped by modern geophysical methods. This project will map geological structure and stratigraphy below unconformity RSU6 farther south and east, study the place of Roosevelt Island in the Ross Sea rifting history, and determine subsidence history during Late Cenozoic time (post RSU6) in the far south and east. Finally the project will observe present day sedimentary processes beneath the ice shelf in the newly exposed areas.
OPP-0230285/OPP-0230356<br/>PIs: Wilson, Terry J./Hothem, Larry D.<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to conduct GPS measurements of bedrock crustal motions in an extended Transantarctic Mountains Deformation network (TAMDEF) to document neotectonic displacements due to tectonic deformation within the West Antarctic rift and/or to mass change of the Antarctic ice sheets. Horizontal displacements related to active neotectonic rifting, strike-slip translations, and volcanism will be tightly constrained by monitoring the combined TAMDEF and Italian VLNDEF networks of bedrock GPS stations along the Transantarctic Mountains and on offshore islands in the Ross Sea. Glacio-isostatic adjustments due to deglaciation since the Last Glacial Maximum and to modern mass change of the ice sheets will be modeled from GPS-derived crustal motions together with new information from other programs on the configurations, thicknesses, deglaciation history and modern mass balance of the ice sheets. Tectonic and rheological information from ongoing structural and seismic investigations in the Victoria Land region will also be integrated in the modeling. The integrative and iterative modeling will yield a holistic interpretation of neotectonics and ice sheet history that will help us to discriminate tectonic crustal displacements from viscoelastic/elastic glacio-isostatic motions. These results will provide key information to interpret broad, continental-scale crustal motion patterns detected by sparse, regionally distributed GPS continuous trackers and by spaceborne instruments. This study will contribute to international programs focused on Antarctic neotectonic and global change issues.<br/><br/>Strategies to meet these science objectives include repeat surveys of key sites in the existing TAMDEF network, extension of the array of TAMDEF sites southward about 250 km along the Transantarctic Mountains, linked measurements with the VLNDEF network, and integration of quasi-continuous trackers within the campaign network. By extending the array of bedrock sites southward, these measurements will cross gradients in predicted vertical motion due to viscoelastic rebound. The southward extension will also allow determination of the southern limit of the active Terror Rift and will provide a better baseline for constraints on any ongoing tectonic displacements across the West Antarctic rift system as a whole that might be possible using GPS data collected by the West Antarctic GPS Network. This project will also investigate unique aspects of GPS geodesy in Antarctica to determine how the error spectrum compares to mid-latitude regions and to identify the optimum measurement and data processing schemes for Antarctic conditions. The geodetic research will improve position accuracies within our network and will also yield general recommendations for deformation monitoring networks in polar regions.<br/><br/>An education and outreach program is planned and will be targeted at non-science-major undergraduate students taking Earth System Science at Ohio State University. The objective will be to illuminate the research process for nonscientists. This effort will educate students on the process of science and inform them about Antarctica and how it relates to global science issues.
This project studies fossils from two to three hundred million year old rocks in the Allan Hills area of Antarctica. Similar deposits from lower latitudes have been used to develop a model of Permo-Triassic climate, wherein melting of continental glaciers in the early Permian leads to the establishment of forests in a cold, wet climate. Conditions became warmer and dryer by the early Triassic, inhibiting plant growth until a moistening climate in the late Triassic allowed plant to flourish once again. This project will test and refine this model and investigate the general effects of climate change on landscapes and ecosystems using the unique exposures and well-preserved fossil and sediment records in the Allan Hills area. The area will be searched for fossil forests, vertebrate tracks and burrows, arthropod trackways, and subaqueously produced biogenic structures, which have been found in other areas of Antarctica. Finds will be integrated with previous paleobiologic studies to reconstruct and interpret ecosystems and their changes. Structures and rock types documenting the end phases of continental glaciation and other major episodic sedimentations will also be described and interpreted. This project contributes to understanding the: (1) evolution of terrestrial and freshwater ecosystems and how they were affected by the end-Permian extinction, (2) abundance and diversity of terrestrial and aquatic arthropods at high latitudes, (3) paleogeographic distribution and evolution of vertebrates and invertebrates as recorded by trace and body fossils; and (3) response of landscapes to changes in climate.<br/><br/>In terms of broader impacts, this project will provide an outstanding introduction to field research for graduate and undergraduate students, and generate related opportunities for several undergraduates. It will also stimulate exchange of ideas among research and primarily undergraduate institutions. Novel outreach activities are also planned to convey Earth history to the general public, including a short film on the research process and products, and paintings by a professional scientific illustrator of Permo-Traissic landscapes and ecosystems.
This award supports a project to obtain stable isotope profiles from shallow (<100 m) ice cores from East Antarctica, to add to the growing database of environmental proxy data collected under the auspices of the "ITASE" (International TransAntarctic Scientific Expedition) program. In Antarctica, the instrumental record of climate is particularly short (~40 years except in a few isolated locations on the coast), and ice core proxy data are the only means available for extending this record into the past. The use of stable isotopes of water (18-O/16-O and D/H ratios) from ice cores as proxies for temperature is well established for both very short (i.e. seasonal) and long timescales (centuries, millennia). Using multivariate regression methods and shallow ice cores from West Antarctica, a reconstruction of Antarctic climate over the last ~150 years has been developed which suggests the continent has been warming, on average, at a rate of ~0.2 K/century. Further improving these reconstructions is the chief motivation for further extending the US ITASE project. Ten to fifteen shallow (~ 100 m) from Victoria Land, East Antarctica will be obtained and analyzed. The core will be collected along a traverse route beginning at Taylor Dome and ending at the South Pole. Age-depth relationships for the cores will be determined through a combination of stable isotopes, visual stratigraphy and seasonal chemical signatures and marker horizons. Reconstructions of Antarctic climate obtained from these cores will be incorporated into the global network of paleoclimate information, which has been important in science, policy and educational contexts. The project will include graduate student and postdoctoral training and field experience.
#0125098<br/>Steve Emslie<br/><br/>Occupation History and Diet of Adelie Penguins in the Ross Sea Region<br/><br/>This project will build on previous studies to investigate the occupation history and diet of Adelie penguins (Pygoscelis adeliae) in the Ross Sea region, Antarctica, with excavations of abandoned and active penguin colonies. Numerous active and abandoned colonies exist on the Victoria Land coast, from Cape Adare to Marble Point will be sampled. Some of these sites have been radiocarbon-dated and indicate a long occupation history for Adelie penguins extending to 13,000 years before present (B. P.). The material recovered from excavations, as demonstrated from previous investigations, will include penguin bones, tissue, and eggshell fragments as well as abundant remains of prey (fish bones, otoliths, squid beaks) preserved in ornithogenic (formed from bird guano) soils. These organic remains will be quantified and subjected to radiocarbon analyses to obtain a colonization history of penguins in this region. Identification of prey remains in the sediments will allow assessment of penguin diet. Other data (ancient DNA) from these sites will be analyzed through collaboration with New Zealand scientists. Past climatic conditions will be interpreted from published ice-core and marine-sediment records. These data will be used to test the hypothesis that Adelie penguins respond to climate change, past and present, in a predictable manner. In addition, the hypothesis that Adelie penguins alter their diet in accordance with climate, sea-ice conditions, and other marine environmental variables along a latitudinal gradient will be tested. Graduate and undergraduate students will be involved in this project and a project Web site will be developed to report results and maintain educational interaction between the PI and students at local middle and high schools in Wilmington, NC.
This award supports a science management office for a pilot ice-core drilling and analysis program to test the feasibility of obtaining well-dated, high-resolution isotope and chemistry records from East Antarctica. Shallow ice cores will be obtained from two locations: 1) ~100 km from South Pole towards the Pole of Inaccessibility, as an extension of the Byrd Station-to-South Pole ITASE traverse [International Trans Antarctic Scientific Expedition]; 2) at Taylor Dome, near the original deep coring site, and (3) possibly at AGO 3 and AGO 4 as part of a logistics traverse to these sites. All of the cores collected will be sampled at very high resolution (~1/2 cm) and analyzed for major ions. Results from this calibration work, along with those from another project that is analyzing stable isotopes will be used to help plan a program of larger scope, with the objective of mapping the spatial expression of climate variability in East Antarctica. Funds are also provided to organize a community workshop for coordination of the second phase of US ITASE and for one workshop per year for two years dedicated to writing and preparation of scientific papers from phase one of US ITASE. In addition, route selection activities for the follow-on traverse activities in East Antarctica will be conducted using satellite image mapping. A summary document will be produced and made available to the community to help with planning of related field programs (e.g. deep ice radar, firn radar profiling, atmospheric chemistry, ice coring, snow surface properties for satellite observations, ice surface elevation and mass balance).
This award supports a project to significantly improve our understanding of how Taylor Glacier flows and responds to climate changes. Taylor Glacier drains the Taylor Dome region of the East Antarctic Ice Sheet and terminates in Taylor Valley, one of the Dry Valleys of Victoria Land. It provides a crucial and unique link between two intensively studied Antarctic environments: the Taylor Dome, from which a 130 kyr ice core paleoclimate record has recently been extracted, and the Dry Valleys, a pivotal Long-Term Ecological Research (LTER) site and a focus of research on geomorphology and glacial geology. The proposed work will thus make an important contribution to ongoing efforts to exploit the Taylor Dome - Dry Valleys system to build a uniquely comprehensive view of regional long-term environmental changes. The proposed work has two complementary components: field research and numerical modelling. Two field seasons will be used to measure velocity, surface strain rate, mass balance, ice thickness, glacier bed reflectance, and subglacial topography, along a nearly complete longitudinal transect of the Taylor Glacier, and along select cross-valley transects. This information will be used to constrain numerical models of ice and heat flow for the Taylor Dome - Taylor Glacier system. These calibrated models will be used to analyze the time-dependent response of the Taylor Glacier to climate changes. The synthesis of results will be aimed to improve understanding of the glacial geomorphology of Taylor Valley, and to illuminate impacts on the Taylor Valley lakes ecosystem. The project will have a major role in furthering the careers of a doctoral-level graduate student and a post-doctoral researcher.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an interdisciplinary study of fluvial sediments in Antarctica for evidence of what caused the greatest of all mass extinctions in the history of life at the Permian-Triassic boundary. This boundary was, until recently, difficult to locate and thought to be unequivocally disconformable in Antarctica. New studies, particularly of carbon isotopic chemostratigraphy and of paleosols and root traces as paleoecosystem indicators, together with improved fossil plant, reptile and pollen biostratigraphy, now suggest that the precise location of the boundary might be identified and have led to local discovery of iridium anomalies, shocked quartz, and fullerenes with extraterrestrial noble gases. These anomalies are associated with a distinctive claystone breccia bed, similar to strata known in South Africa and Australia, and taken as evidence of deforestation. There is already much evidence from Antarctica and elsewhere that the mass extinction on land was abrupt and synchronous with extinction in the ocean. The problem now is what led to such death and destruction. Carbon isotopic values are so low in these and other Permian-Triassic boundary sections that there was likely to have been some role for catastrophic destabilization of methane clathrates. Getting the modeled amount of methane out of likely reservoirs would require such catastrophic events as bolide impact, flood-basalt eruption or continental-shelf collapse, which have all independently been implicated in the mass extinction and for which there is independent evidence. Teasing apart these various hypotheses requires careful re-examination of beds that appear to represent the Permian-Triassic boundary, and search for more informative sequences, as was the case for the Cretaceous-Tertiary boundary. This collaborative research on geochemistry and petrography of boundary beds and paleosols (by Retallack), on carbon isotopic variation through the boundary interval (by Jahren), and on fullerenes, iridium and helium (by Becker) is designed to test these ideas about the Permian-Triassic boundary in Antarctica and to shed light on processes which contributed to this largest of mass extinctions on Earth. Fieldwork for this research will be conducted in the central Transantarctic Mountains and in Southern Victoria Land with an initial objective of examining the stratigraphic sequences for continuity across the boundary. Stratigraphic continuity is a critical element that must exist for the work to be successful. If fieldwork indicates sufficiently continuous sections, the full analytical program will follow fieldwork.
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.