USAP-DC

{"dp_type": "Dataset", "free_text": "Glacial History"}

[{"awards": "0087144 Conway, Howard", "bounds_geometry": ["POLYGON((-150 -83.5,-148 -83.5,-146 -83.5,-144 -83.5,-142 -83.5,-140 -83.5,-138 -83.5,-136 -83.5,-134 -83.5,-132 -83.5,-130 -83.5,-130 -83.65,-130 -83.8,-130 -83.95,-130 -84.1,-130 -84.25,-130 -84.4,-130 -84.55,-130 -84.7,-130 -84.85,-130 -85,-132 -85,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-150 -84.85,-150 -84.7,-150 -84.55,-150 -84.4,-150 -84.25,-150 -84.1,-150 -83.95,-150 -83.8,-150 -83.65,-150 -83.5))"], "date_created": "Mon, 22 Jul 2024 00:00:00 GMT", "description": "Marine ice sheets are low-pass filters of climate variability that take centuries to adjust to interior and near-terminus changes in mass balance. Constraining these century-scale changes from satellite observations that span only the last 40 years is challenging. Here, we take a different approach of carefully synthesizing different data sets to infer changes in the configurations of van der Veen and Mercer Ice Streams on the Siple Coast over the past 3000 years from englacial features encoded in ice-penetrating radar data. Englacial radar data from Conway Ridge reveal smooth, surface conformal layers overlying disrupted stratigraphy that suggest the van der Veen Ice Stream was 40 km wider over 3000 years ago. Englacial layer dating indicates that the ice stream narrowed to its present configuration between $\\sim3000$ and $\\sim1000$ years ago. Similarly disrupted stratigraphy and buried crevasses suggest that ice flowing from Mercer to Whillans Ice Stream across the northwestern tip of the ridge slowed shortly after. Using an ice-flow model capable of simulating shear margin migration, we evaluate whether small changes in ice thickness can lead to large changes in shear margin location. Our results suggest that the tip of Conway Ridge is sensitive to thinning and thickening, and that when the basal strength at the tip of the ridge increases with the height above flotation, the ice sheet shear margins can change quickly.", "east": -130.0, "geometry": ["POINT(-140 -84.25)"], "keywords": "Antarctica; Cryosphere; Siple Coast", "locations": "Siple Coast; Antarctica", "north": -83.5, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hoffman, Andrew; Conway, Howard; Christianson, Knut", "project_titles": "Glacial History of Ridge AB, West Antarctica", "projects": [{"proj_uid": "p0010470", "repository": "USAP-DC", "title": "Glacial History of Ridge AB, West Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Impulse HF radar data from Conway Ridge", "uid": "601810", "west": -150.0}, {"awards": "1643248 Hall, Brenda", "bounds_geometry": ["POLYGON((163 -78.2,163.05 -78.2,163.1 -78.2,163.15 -78.2,163.2 -78.2,163.25 -78.2,163.3 -78.2,163.35 -78.2,163.4 -78.2,163.45 -78.2,163.5 -78.2,163.5 -78.21000000000001,163.5 -78.22,163.5 -78.23,163.5 -78.24,163.5 -78.25,163.5 -78.26,163.5 -78.27,163.5 -78.28,163.5 -78.28999999999999,163.5 -78.3,163.45 -78.3,163.4 -78.3,163.35 -78.3,163.3 -78.3,163.25 -78.3,163.2 -78.3,163.15 -78.3,163.1 -78.3,163.05 -78.3,163 -78.3,163 -78.28999999999999,163 -78.28,163 -78.27,163 -78.26,163 -78.25,163 -78.24,163 -78.23,163 -78.22,163 -78.21000000000001,163 -78.2))"], "date_created": "Fri, 21 Oct 2022 00:00:00 GMT", "description": "This dataset includes beryllium-10 surface exposure data collected in conjunction with a glacial history project in the Walcott Bay region of southern McMurdo Sound. The data are presented in the conventional CRONUS input format.", "east": 163.5, "geometry": ["POINT(163.25 -78.25)"], "keywords": "Antarctica; Beryllium-10; Exposure Age; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; McMurdo Sound; Royal Society Range; Walcott Glacier", "locations": "Royal Society Range; Antarctica; Royal Society Range; Walcott Glacier; McMurdo Sound", "north": -78.2, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Hall, Brenda", "project_titles": "Response of the Antarctic Ice Sheet to the last great global warming", "projects": [{"proj_uid": "p0010301", "repository": "USAP-DC", "title": "Response of the Antarctic Ice Sheet to the last great global warming"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.3, "title": "Walcott Glacier Exposure Data", "uid": "601616", "west": 163.0}, {"awards": "1745043 Simkins, Lauren; 1246353 Anderson, John; 1745055 Stearns, Leigh", "bounds_geometry": ["POLYGON((174 -75,174.4 -75,174.8 -75,175.2 -75,175.6 -75,176 -75,176.4 -75,176.8 -75,177.2 -75,177.6 -75,178 -75,178 -75.2,178 -75.4,178 -75.6,178 -75.8,178 -76,178 -76.2,178 -76.4,178 -76.6,178 -76.8,178 -77,177.6 -77,177.2 -77,176.8 -77,176.4 -77,176 -77,175.6 -77,175.2 -77,174.8 -77,174.4 -77,174 -77,174 -76.8,174 -76.6,174 -76.4,174 -76.2,174 -76,174 -75.8,174 -75.6,174 -75.4,174 -75.2,174 -75))"], "date_created": "Mon, 04 Oct 2021 00:00:00 GMT", "description": "Bathymetry from multibeam echo sounding data in Pennell Trough, Ross Sea, Antarctica was collected onboard the RVIB Nathaniel B. Palmer (NBP) 15-02 cruise using a Kongsberg EM122 operating in dual swath mode at 12 kHz frequency with a 1\u00b0\u00d71\u00b0 beam width, swath angular coverage set to 62\u00b0\u00d762\u00b0, and 30-60% overlap between survey lines. All raw, ping-edited geophysical data collected on NBP15-02 can be accessed using the Marine Geoscience Data System (Cruise DOI: 10.7284/901477). The bathymetry dataset here is gridded at 20-m resolution with a water depth-dependent vertical resolution on the order of decimeters. Two shapefiles are provided for ice-marginal landforms and meltwater landforms observable in the bathymetry data. The purpose of collecting the bathymetry data on cruise NBP15-02 was to better understand the glacial history of the Ross Sea, and the dataset, inclusive of bathymetry data and shapefiles of glacial landforms, from Pennell Trough are used to understand impacts on subglacial channel morphology and organization during the deglaciation of the region following the Last Glacial Maximum. The published dataset was used and analyzed in the article \"Topographic controls on channelized meltwater in the subglacial environment\" by Simkins, L.M., Greenwood, S.L., Munevar Garcia, S., Eareckson, E.A., Anderson, J.B., and Prothro, L.O, which was published in Geophysical Research Letters in 2021 (DOI: 10.1029/2021GL094678).", "east": 178.0, "geometry": ["POINT(176 -76)"], "keywords": "Antarctica; Bathymetry; Elevation; Geomorphology; Glacial History; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; NBP1502; Pennell Trough; Ross Sea; R/v Nathaniel B. Palmer", "locations": "Antarctica; Pennell Trough; Ross Sea", "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Greenwood, Sarah; Munevar Garcia, Santiago; Eareckson, Elizabeth; Anderson, John; Prothro, Lindsay; Simkins, Lauren", "project_titles": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations; Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum.", "projects": [{"proj_uid": "p0010269", "repository": "USAP-DC", "title": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations"}, {"proj_uid": "p0000395", "repository": "USAP-DC", "title": "Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Pennell Trough, Ross Sea bathymetry and glacial landforms", "uid": "601474", "west": 174.0}, {"awards": "1341631 Lyons, W. Berry; 1341736 Adams, Byron", "bounds_geometry": ["POLYGON((-177.4099 -84.4661,-177.08229 -84.4661,-176.75468 -84.4661,-176.42707 -84.4661,-176.09946 -84.4661,-175.77185 -84.4661,-175.44424 -84.4661,-175.11663 -84.4661,-174.78902 -84.4661,-174.46141 -84.4661,-174.1338 -84.4661,-174.1338 -84.56828,-174.1338 -84.67046,-174.1338 -84.77264,-174.1338 -84.87482,-174.1338 -84.977,-174.1338 -85.07918,-174.1338 -85.18136,-174.1338 -85.28354,-174.1338 -85.38572,-174.1338 -85.4879,-174.46141 -85.4879,-174.78902 -85.4879,-175.11663 -85.4879,-175.44424 -85.4879,-175.77185 -85.4879,-176.09946 -85.4879,-176.42707 -85.4879,-176.75468 -85.4879,-177.08229 -85.4879,-177.4099 -85.4879,-177.4099 -85.38572,-177.4099 -85.28354,-177.4099 -85.18136,-177.4099 -85.07918,-177.4099 -84.977,-177.4099 -84.87482,-177.4099 -84.77264,-177.4099 -84.67046,-177.4099 -84.56828,-177.4099 -84.4661))"], "date_created": "Sun, 03 Jan 2021 00:00:00 GMT", "description": "We collected soil surface samples (n = 21) and depth profiles (n = 25) every 5 cm to refusal (up to 30 cm) from eleven ice-free areas along the Shackleton Glacier, a major outlet glacier of the East Antarctic Ice Sheet (EAIS). We measured meteoric 10Be concentrations, which were later used to estimate relative surface exposure ages of the soils from seven locations. ", "east": -174.1338, "geometry": ["POINT(-175.77185 -84.977)"], "keywords": "Antarctica; Be-10; Beryllium-10; Cosmogenic Radionuclides; Geochemistry; Geomorphology; Shackleton Glacier; Surface Exposure Dates", "locations": "Shackleton Glacier; Antarctica", "north": -84.4661, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Diaz, Melisa A.", "project_titles": "Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains", "projects": [{"proj_uid": "p0010140", "repository": "USAP-DC", "title": "Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.4879, "title": "Meteoric 10Be data of soils from the Shackleton Glacier region", "uid": "601421", "west": -177.4099}, {"awards": "1341736 Adams, Byron; 1341631 Lyons, W. Berry", "bounds_geometry": ["POLYGON((-177.3907 -84.46466667,-177.06501 -84.46466667,-176.73932 -84.46466667,-176.41363 -84.46466667,-176.08794 -84.46466667,-175.76225 -84.46466667,-175.43656 -84.46466667,-175.11087 -84.46466667,-174.78518 -84.46466667,-174.45949 -84.46466667,-174.1338 -84.46466667,-174.1338 -84.566988336,-174.1338 -84.669310002,-174.1338 -84.771631668,-174.1338 -84.873953334,-174.1338 -84.976275,-174.1338 -85.078596666,-174.1338 -85.180918332,-174.1338 -85.283239998,-174.1338 -85.385561664,-174.1338 -85.48788333,-174.45949 -85.48788333,-174.78518 -85.48788333,-175.11087 -85.48788333,-175.43656 -85.48788333,-175.76225 -85.48788333,-176.08794 -85.48788333,-176.41363 -85.48788333,-176.73932 -85.48788333,-177.06501 -85.48788333,-177.3907 -85.48788333,-177.3907 -85.385561664,-177.3907 -85.283239998,-177.3907 -85.180918332,-177.3907 -85.078596666,-177.3907 -84.976275,-177.3907 -84.873953334,-177.3907 -84.771631668,-177.3907 -84.669310002,-177.3907 -84.566988336,-177.3907 -84.46466667))"], "date_created": "Sat, 02 Jan 2021 00:00:00 GMT", "description": "Soil samples were collected from the Shackleton Glacier region, located in the Queen Maud Mountains during the 2017-2018 austral summer. A subset of 27 samples were analyzed for stable isotopes of S, N, C, and O in nitrate, sulfate, and (bi)carbonate. ). \u03b415N-NO3 values ranged from -47.8 to 20.4\u2030 and, while all \u039417O-NO3 values are positive, they ranged from 15.7 to 45.9\u2030. \u03b434S-SO4 and \u03b418O-SO4 values ranged from 12.5 and 17.9\u2030 and -14.5 to -7.1\u2030, respectively. Total inorganic carbon isotopes ((bi)carbonate) in bulk soil samples ranged from 0.2 to 8.5\u2030 for \u03b413C and -38.8 to -9.6\u2030 for \u03b418O.", "east": -174.1338, "geometry": ["POINT(-175.76225 -84.976275)"], "keywords": "Antarctica; Geochemistry; Nitrate; Shackleton Glacier; Stable Isotopes; Sulfate; Transantarctic Mountains", "locations": "Shackleton Glacier; Antarctica; Transantarctic Mountains", "north": -84.46466667, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Diaz, Melisa A.; Lyons, W. Berry; Gardner, Christopher B.", "project_titles": "Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains", "projects": [{"proj_uid": "p0010140", "repository": "USAP-DC", "title": "Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.48788333, "title": "Shackleton Glacier region water-soluble salt isotopes", "uid": "601419", "west": -177.3907}, {"awards": "1341736 Adams, Byron; 1341631 Lyons, W. Berry", "bounds_geometry": ["POLYGON((-177.4213 -84.4647,-177.08802 -84.4647,-176.75474 -84.4647,-176.42146 -84.4647,-176.08818 -84.4647,-175.7549 -84.4647,-175.42162 -84.4647,-175.08834 -84.4647,-174.75506 -84.4647,-174.42178 -84.4647,-174.0885 -84.4647,-174.0885 -84.56732,-174.0885 -84.66994,-174.0885 -84.77256,-174.0885 -84.87518,-174.0885 -84.9778,-174.0885 -85.08042,-174.0885 -85.18304,-174.0885 -85.28566,-174.0885 -85.38828,-174.0885 -85.4909,-174.42178 -85.4909,-174.75506 -85.4909,-175.08834 -85.4909,-175.42162 -85.4909,-175.7549 -85.4909,-176.08818 -85.4909,-176.42146 -85.4909,-176.75474 -85.4909,-177.08802 -85.4909,-177.4213 -85.4909,-177.4213 -85.38828,-177.4213 -85.28566,-177.4213 -85.18304,-177.4213 -85.08042,-177.4213 -84.9778,-177.4213 -84.87518,-177.4213 -84.77256,-177.4213 -84.66994,-177.4213 -84.56732,-177.4213 -84.4647))"], "date_created": "Sat, 02 Jan 2021 00:00:00 GMT", "description": "During the 2017-2018 austral summer, 220 surface soil samples (~top 5 cm) were collected from 11 distinct ice-free areas (Roberts Massif, Schroeder Hill, Mt. Augustana, Bennett Platform, Mt. Heekin, Thanksgiving Valley, Taylor Nunatak, Mt. Franke, Mt. Wasko, Nilsen Peak, and Mt. Speed) along the Shackleton Glacier. Dried soils were leached at a 1:5 soil to DI water ratio, and the leachate was filtered through 0.4 \u00b5m Nucleopore membrane filters. The leachate was analyzed for anions (F-, Cl-, Br-, and SO42-) which were measured on a Dionex ICS-2100 ion chromatograph, cations (K+, Na+, Ca2+, Mg2+, and Sr2+) which were measured on a PerkinElmer Optima 8300 Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES), and nutrients (NO3- + NO2-, PO43-, H4SiO4, and NH3) which were measured on a Skalar San++ Automated Wet Chemistry Analyzer at The Ohio State University. Perchlorate (ClO4-) and chlorate (ClO3-) were measured using an ion chromatograph-tandem mass spectrometry technique (IC-MS/MS) at Texas Tech University. Accuracy was typically better than 5% for all major anions, cations, and nutrients, as determined by the NIST 1643e external reference standard and the 2015 USGS interlaboratory calibration standard (M-216), and better than 10% for perchlorate and chlorate, as determined by spike recoveries.", "east": -174.0885, "geometry": ["POINT(-175.7549 -84.9778)"], "keywords": "Antarctica; Geochemistry; Shackleton Glacier", "locations": "Shackleton Glacier; Antarctica", "north": -84.4647, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "persons": "Diaz, Melisa A.; Lyons, W. Berry; Gardner, Christopher B.", "project_titles": "Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains", "projects": [{"proj_uid": "p0010140", "repository": "USAP-DC", "title": "Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.4909, "title": "Shackleton Glacier region soil water-soluble geochemical data", "uid": "601418", "west": -177.4213}, {"awards": "9909367 Leventer, Amy", "bounds_geometry": ["POINT(62.99 -67.13)"], "date_created": "Fri, 01 May 2020 00:00:00 GMT", "description": "This data set was acquired with a Jumbo Piston Core Sediment Sampler during R/V Nathaniel B. Palmer expedition NBP0101 conducted in 2001. This data file is of Microsoft Excel format and includes Quantitative Diatom Assemblage data; counts completed on randomly settled slides (Scherer, R.P., 1994. A new method for the determination of absolute abundance of diatoms and other silt-sized sedimentary particles. Journal of Paleolimnology, 12 (1), 171-178, doi:10.1007/BF00678093). These counts were completed at closely spaced intervals in NBP0101 JPC41, a jumbo piston core from Iceberg Alley, Mac.Robertson Shelf, East Antarctica", "east": 62.99, "geometry": ["POINT(62.99 -67.13)"], "keywords": "Antarctica; Biota; Diatom; East Antarctica; Mac. Robertson Shelf; Marine Geoscience; Microscope; NBP0101; Paleoclimate; Piston Corer; R/v Nathaniel B. Palmer; Sediment Core; Species Abundance", "locations": "Mac. Robertson Shelf; East Antarctica; Antarctica; Mac. Robertson Shelf", "north": -67.13, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Leventer, Amy", "project_titles": "Quaternary Glacial History and Paleoenvironments of the East Antarctic Margin", "projects": [{"proj_uid": "p0000609", "repository": "USAP-DC", "title": "Quaternary Glacial History and Paleoenvironments of the East Antarctic Margin"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.13, "title": "Quantitative Diatom Assemblage Data from Iceberg Alley, Mac. Robertson Shelf, East Antarctica acquired during expedition NBP0101", "uid": "601307", "west": 62.99}, {"awards": "1143836 Leventer, Amy", "bounds_geometry": ["POLYGON((117 -66,119.9 -66,122.8 -66,125.7 -66,128.6 -66,131.5 -66,134.4 -66,137.3 -66,140.2 -66,143.1 -66,146 -66,146 -66.1,146 -66.2,146 -66.3,146 -66.4,146 -66.5,146 -66.6,146 -66.7,146 -66.8,146 -66.9,146 -67,143.1 -67,140.2 -67,137.3 -67,134.4 -67,131.5 -67,128.6 -67,125.7 -67,122.8 -67,119.9 -67,117 -67,117 -66.9,117 -66.8,117 -66.7,117 -66.6,117 -66.5,117 -66.4,117 -66.3,117 -66.2,117 -66.1,117 -66))"], "date_created": "Thu, 27 Feb 2020 00:00:00 GMT", "description": "Totten Glacier is the termination of the largest marine-based portion of the East Antarctic Ice Sheet, the Aurora Subglacial Basin. Yet little is known about the glacial evolution of the catchment and the factors influencing its present and past behavior. Due its remote location and heavy sea ice, the continental shelf in front of the Totten Glacier had not been comprehensively surveyed prior to this study. Satellite observations indicate that the Totten ice drainage system is thinning, and it has been hypothesized that this thinning is in response to undermelting by warm ocean waters over the continental shelf. While this process is observed elsewhere in Antarctica (e.g. the rapidly retreating Pine Island Glacier in West Antarctica), the Totten Glacier system is potentially Antarcticas most important glacial drainage system due to its large size; it is three times larger than any system in West Antarctica. \u003c/br\u003eThe main goals of this proposal were: \u003c/br\u003eTo generate multibeam bathymetric maps of the continental shelf proximal to the Totten Glacier system to understand the recent regional glacial history and to document the pathways, if any, for circumpolar deep water to move onto the shelf. \u003c/br\u003eTo conduct a physical oceanographic survey of the region proximal to the Totten Glacier system, to determine the presence, if any, of warm ocean waters over the continental shelf.\u003c/br\u003eTo conduct a seismic survey of the continental shelf to assess the long-term evolution of the glacial system in the Aurora Subglacial Basin.\u003c/br\u003eTo collect marine sediment cores to determine the regional deglacial to Holocene climate history and the influence of warm circumpolar deep water.", "east": 146.0, "geometry": ["POINT(131.5 -66.5)"], "keywords": "Antarctica; Diatom; NBP1402; Totten Glacier", "locations": "Totten Glacier; Antarctica", "north": -66.0, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "NBP1402 science party; Leventer, Amy", "project_titles": "Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics", "projects": [{"proj_uid": "p0000008", "repository": "USAP-DC", "title": "Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.0, "title": "NBP1402 diatom data", "uid": "601258", "west": 117.0}, {"awards": "9909367 Leventer, Amy", "bounds_geometry": ["POLYGON((57 -66,57.3 -66,57.6 -66,57.9 -66,58.2 -66,58.5 -66,58.8 -66,59.1 -66,59.4 -66,59.7 -66,60 -66,60 -66.1,60 -66.2,60 -66.3,60 -66.4,60 -66.5,60 -66.6,60 -66.7,60 -66.8,60 -66.9,60 -67,59.7 -67,59.4 -67,59.1 -67,58.8 -67,58.5 -67,58.2 -67,57.9 -67,57.6 -67,57.3 -67,57 -67,57 -66.9,57 -66.8,57 -66.7,57 -66.6,57 -66.5,57 -66.4,57 -66.3,57 -66.2,57 -66.1,57 -66))"], "date_created": "Thu, 25 Apr 2019 00:00:00 GMT", "description": "This data set describes diatom assemblages and abundances from two sediment cores retrieved from Edward VIII Gulf. The assemblages are used to reconstruct paleoceanographic conditions throughout the Holocene.", "east": 60.0, "geometry": ["POINT(58.5 -66.5)"], "keywords": "Antarctica; Biota; Diatom; East Antarctica; Microscopy; NBP0101; Oceans; Paleoceanography; Paleoclimate; R/v Nathaniel B. Palmer; Sediment Corer", "locations": "East Antarctica; Antarctica", "north": -66.0, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Leventer, Amy", "project_titles": "Quaternary Glacial History and Paleoenvironments of the East Antarctic Margin", "projects": [{"proj_uid": "p0000609", "repository": "USAP-DC", "title": "Quaternary Glacial History and Paleoenvironments of the East Antarctic Margin"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.0, "title": "Diatom assemblages from Edward VIII Gulf, Kemp Coast, East Antarctica", "uid": "601177", "west": 57.0}, {"awards": "1142162 Stone, John", "bounds_geometry": ["POLYGON((-104.14 -81.07,-102.24 -81.07,-100.34 -81.07,-98.44 -81.07,-96.54 -81.07,-94.64 -81.07,-92.74 -81.07,-90.84 -81.07,-88.94 -81.07,-87.04 -81.07,-85.14 -81.07,-85.14 -81.207,-85.14 -81.344,-85.14 -81.481,-85.14 -81.618,-85.14 -81.755,-85.14 -81.892,-85.14 -82.029,-85.14 -82.166,-85.14 -82.303,-85.14 -82.44,-87.04 -82.44,-88.94 -82.44,-90.84 -82.44,-92.74 -82.44,-94.64 -82.44,-96.54 -82.44,-98.44 -82.44,-100.34 -82.44,-102.24 -82.44,-104.14 -82.44,-104.14 -82.303,-104.14 -82.166,-104.14 -82.029,-104.14 -81.892,-104.14 -81.755,-104.14 -81.618,-104.14 -81.481,-104.14 -81.344,-104.14 -81.207,-104.14 -81.07))"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "This award supports a reconnaissance geological and radar-sounding study of promising sites in West Antarctica for a future project to measure cosmogenic nuclides in subglacial bedrock. Field work will take place in the Whitmore Mountains, close to the WAIS divide, and on the Nash and Pirrit Hills, downflow from the divide in the Weddell Sea drainage. At each site geological indicators of higher (and lower) ice levels in the past will be mapped and evidence of subglacial erosion or its absence will be documented. Elevation transects of both glacial erratics and adjacent bedrock samples will be collected to establish the timing of recent deglaciation at the sites and provide a complement to similar measurements on material from depth transects obtained by future subglacial drilling. At each site, bedrock ridges will be traced into the subsurface with closely-spaced ice-penetrating radar surveys, using a combination of instruments and frequencies to obtain the highest possible surface detail. Collectively the results will define prospective sites for subglacial sampling, and maximize the potential information to be obtained from such samples in future studies. The intellectual merit of this project is that measurements of cosmogenic nuclides in subglacial bedrock hold promise for resolving the questions of whether the West Antarctic ice sheet collapsed completely in the past, whether it is prone to repeated large deglaciations, and if so, what is their magnitude and frequency. Such studies will require careful choice of targets, to locate sites where bedrock geology is favorable, cosmogenic nuclide records are likely to have been protected from subglacial erosion, and the local ice-surface response is indicative of large-scale ice sheet behavior. The broader impacts of this work include helping to determine whether subglacial surfaces in West Antarctica were ever exposed to cosmic rays, which will provide unambiguous evidence for or against a smaller ice sheet in the past. This is an important step towards establishing whether the WAIS is vulnerable to collapse in future, and will ultimately help to address uncertainty in forecasting sea level change. The results will also provide ground truth for models of ice-sheet dynamics and long-term ice sheet evolution, and will help researchers use these models to identify paleoclimate conditions responsible for WAIS deglaciation. The education and training of students (both undergraduate and graduate students) will play an important role in the project, which will involve Antarctic fieldwork, technically challenging labwork, data collection and interpretation, and communication of the outcome to scientists and the general public.", "east": -85.14, "geometry": ["POINT(-94.64 -81.755)"], "keywords": "Antarctica; Be-10; Chemistry:rock; Chemistry:Rock; Cosmogenic Dating; Glaciology; Nunataks; Sample/collection Description; Sample/Collection Description; Solid Earth; Whitmore Mountains", "locations": "Antarctica; Whitmore Mountains", "north": -81.07, "nsf_funding_programs": null, "persons": "Stone, John", "project_titles": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "projects": [{"proj_uid": "p0000335", "repository": "USAP-DC", "title": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -82.44, "title": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "uid": "600162", "west": -104.14}, {"awards": "1043619 Hemming, Sidney", "bounds_geometry": ["POLYGON((-180 -63.997,-179.7982 -63.997,-179.5964 -63.997,-179.3946 -63.997,-179.1928 -63.997,-178.991 -63.997,-178.7892 -63.997,-178.5874 -63.997,-178.3856 -63.997,-178.1838 -63.997,-177.982 -63.997,-177.982 -66.3324,-177.982 -68.6678,-177.982 -71.0032,-177.982 -73.3386,-177.982 -75.674,-177.982 -78.0094,-177.982 -80.3448,-177.982 -82.6802,-177.982 -85.0156,-177.982 -87.351,-178.1838 -87.351,-178.3856 -87.351,-178.5874 -87.351,-178.7892 -87.351,-178.991 -87.351,-179.1928 -87.351,-179.3946 -87.351,-179.5964 -87.351,-179.7982 -87.351,180 -87.351,172.54273 -87.351,165.08546 -87.351,157.62819 -87.351,150.17092 -87.351,142.71365 -87.351,135.25638 -87.351,127.79911 -87.351,120.34184 -87.351,112.88457 -87.351,105.4273 -87.351,105.4273 -85.0156,105.4273 -82.6802,105.4273 -80.3448,105.4273 -78.0094,105.4273 -75.674,105.4273 -73.3386,105.4273 -71.0032,105.4273 -68.6678,105.4273 -66.3324,105.4273 -63.997,112.88457 -63.997,120.34184 -63.997,127.79911 -63.997,135.25638 -63.997,142.71365 -63.997,150.17092 -63.997,157.62819 -63.997,165.08546 -63.997,172.54273 -63.997,-180 -63.997))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: The PIs proposed a provenance study of glacial deposits in the Ross Embayment that will provide a broad scale geochronologic survey of detrital minerals in till to help characterize bedrock beneath the East Antarctic ice sheet and constrain Antarctica?s glacial history. This project capitalizes on previous investments in field sampling. Analytical tools applied to single mineral grains extracted from existing collections of glacial till will generate ?fingerprints? of East Antarctic outlet glaciers and West Antarctic till to refine paleo-ice flow models for the Ross Embayment during the last glacial maximum, older records from ANDRILL cores, and to assess IRD sources in the Southern Ocean. New provenance tracers will include a suite of geochronological methods that together provide greater insights into the orogenic and erosional history the region. This project will include U/Pb of detrital zircons, (U-Th)/He on a subset of the U/Pb dated zircons, as well as Ar-Ar of detrital hornblende, mica and feldspars.\nBroader Impacts: This research will train one M.S. student at IUPUI, a Ph.D. student at Columbia, and several undergraduates at both institutions. Graduate students involved in the project will be involved in mentoring undergraduate researchers. Incorporation of research discoveries will be brought into the classroom by providing concrete examples and exercises at the appropriate level. Licht and Columbia graduate student E. Pierce are developing outreach projects with local secondary school teachers to investigate the provenance of glacial materials in their local areas. The research will have broad applicability to many fields.", "east": 105.4273, "geometry": ["POINT(143.72265 -75.674)"], "keywords": "Antarctica; East Antarctica; Geochemistry; Ross Sea; Sample/collection Description; Sample/Collection Description; Solid Earth; Southern Ocean; West Antarctica", "locations": "Southern Ocean; Antarctica; Ross Sea; East Antarctica; West Antarctica", "north": -63.997, "nsf_funding_programs": null, "persons": "Hemming, Sidney R.", "project_titles": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "projects": [{"proj_uid": "p0000333", "repository": "USAP-DC", "title": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.351, "title": "East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "uid": "600124", "west": -177.982}, {"awards": "0636629 Kurz, Mark", "bounds_geometry": ["POLYGON((160.7 -77.8,161.06 -77.8,161.42 -77.8,161.78 -77.8,162.14 -77.8,162.5 -77.8,162.86 -77.8,163.22 -77.8,163.58 -77.8,163.94 -77.8,164.3 -77.8,164.3 -77.86,164.3 -77.92,164.3 -77.98,164.3 -78.04,164.3 -78.1,164.3 -78.16,164.3 -78.22,164.3 -78.28,164.3 -78.34,164.3 -78.4,163.94 -78.4,163.58 -78.4,163.22 -78.4,162.86 -78.4,162.5 -78.4,162.14 -78.4,161.78 -78.4,161.42 -78.4,161.06 -78.4,160.7 -78.4,160.7 -78.34,160.7 -78.28,160.7 -78.22,160.7 -78.16,160.7 -78.1,160.7 -78.04,160.7 -77.98,160.7 -77.92,160.7 -77.86,160.7 -77.8))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This project uses cosmogenic nuclide dating and LIDAR studies of surface roughness to understand weathering and landscape evolution in the Dry Valleys of Antarctica. The work focuses on two processes: cryoturbation of frozen soils and the development of patterned, frozen ground on ancient lava flows. The approach includes innovative uses of He3 profiling. Results will also be applied to understanding the glacial history of the Dry Valleys. There are potential applications to understanding the history of the East Antarctic Ice Sheet and the formation of Martian landscapes. The broader impacts include graduate student education. As well, the work may contribute to our understanding of the history of the Antarctic ice sheets, which is important to modeling their behavior during global climate change.", "east": 164.3, "geometry": ["POINT(162.5 -78.1)"], "keywords": "Antarctica; Cosmogenic Radionuclides; Dry Valleys; Geology/Geophysics - Other; Glaciology; LIDAR; Navigation; Sample/collection Description; Sample/Collection Description", "locations": "Antarctica; Dry Valleys", "north": -77.8, "nsf_funding_programs": null, "persons": "Soule, S. Adam; Kurz, Mark D.", "project_titles": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "projects": [{"proj_uid": "p0000559", "repository": "USAP-DC", "title": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.4, "title": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "uid": "600066", "west": 160.7}]

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