USAP-DC

{"dp_type": "Dataset", "free_text": "AGASEA"}

[{"awards": "0636724 Blankenship, Donald; 1043761 Young, Duncan; 0230197 Holt, John; 2127606 Young, Duncan A.", "bounds_geometry": ["POLYGON((-136 -74,-131.9 -74,-127.8 -74,-123.7 -74,-119.6 -74,-115.5 -74,-111.4 -74,-107.30000000000001 -74,-103.2 -74,-99.1 -74,-95 -74,-95 -74.7,-95 -75.4,-95 -76.1,-95 -76.8,-95 -77.5,-95 -78.2,-95 -78.9,-95 -79.6,-95 -80.3,-95 -81,-99.1 -81,-103.2 -81,-107.3 -81,-111.4 -81,-115.5 -81,-119.6 -81,-123.69999999999999 -81,-127.8 -81,-131.9 -81,-136 -81,-136 -80.3,-136 -79.6,-136 -78.9,-136 -78.2,-136 -77.5,-136 -76.8,-136 -76.1,-136 -75.4,-136 -74.7,-136 -74))"], "date_created": "Wed, 15 Mar 2023 00:00:00 GMT", "description": "This file contains internal radar horizon 1 (lm-MERGE-lay9-grg) for West Antarctica, collected during the SOAR/CASERTZ (1991-1996), SOAR/DVD (1999), ATRS (2001), AGASEA (2004-05) and GIMBLE (2013-2014) expeditions. Only data collected in AGASEA is contained in this specific product.\r\nThis data set is linked to PH.D thesis Muldoon, G. 2018 \"West Antarctic Ice Sheet Retreat during the Last Interglacial\"Spatial and temporal distributions of accumulation rates on the catchment of Thwaites Glacier, West Antarctica\", University of Texas at Austin\r\n https://doi.org/10.15781/T23B5WS0D\r\nThe internal radar horizon (IRH) was traced semi-automatically by Gail R. Muldoon using Haliburtons\u0027s Landmark software and picker, in a combination of 2D focused and unfocused data.\r\nDepths were calculated using a 2 way velocity in ice of 84.5 m/microsecond, and no firn correction. \r\n\r\nIsochron age is 4711 (+/- 246 ) years. \r\n\r\nFunding for this dataset as provided by NSF grants and The G. Unger Vetlesen Foundation.", "east": -95.0, "geometry": ["POINT(-115.5 -77.5)"], "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "locations": "Antarctica; Thwaites Glacier", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Muldoon, Gail R.; Young, Duncan A.; Jackson, Charles; Blankenship, Donald D.", "project_titles": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA); Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System; Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE)", "projects": [{"proj_uid": "p0000174", "repository": "USAP-DC", "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System"}, {"proj_uid": "p0000435", "repository": "USAP-DC", "title": "Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE)"}, {"proj_uid": "p0000243", "repository": "USAP-DC", "title": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.0, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "uid": "601673", "west": -136.0}, {"awards": "1745137 Schroeder, Dustin", "bounds_geometry": ["POLYGON((-130 -72.9,-125.27 -72.9,-120.54 -72.9,-115.81 -72.9,-111.08 -72.9,-106.35 -72.9,-101.62 -72.9,-96.89 -72.9,-92.16 -72.9,-87.43 -72.9,-82.7 -72.9,-82.7 -73.76,-82.7 -74.62,-82.7 -75.48,-82.7 -76.34,-82.7 -77.2,-82.7 -78.06,-82.7 -78.92,-82.7 -79.78,-82.7 -80.64,-82.7 -81.5,-87.43 -81.5,-92.16 -81.5,-96.89 -81.5,-101.62 -81.5,-106.35 -81.5,-111.08 -81.5,-115.81 -81.5,-120.54 -81.5,-125.27 -81.5,-130 -81.5,-130 -80.64,-130 -79.78,-130 -78.92,-130 -78.06,-130 -77.2,-130 -76.34,-130 -75.48,-130 -74.62,-130 -73.76,-130 -72.9))"], "date_created": "Fri, 05 Mar 2021 00:00:00 GMT", "description": "The dataset contains radargrams from the 2004-2005 airborne radar sounding surveys on Pine Island Glacier and Thwaites Glacier as part of the BBAS and AGASEA projects. It also includes basal reflectivity and one-way attenuation rates derived from these radargrams. Radar data from the Pine Island Ice Shelf inland to the Bentley Sublglacial Trench were collected by the British Antarctica Survey (BAS) with the Polarimetric-radar Airborne Science INstrument (PASIN) radar sounder, operating at a center frequency of 150 MHz and 15 MHz bandwidth. Data over Thwaites Glacier were collected by the University of Texas Institute for Geophysics (UTIG) High Capability Airborne Radar Sounder (HiCARS) operating at a center frequency of 60 MHz with 15 MHz of bandwidth. Data are provided as 50km segments in NetCDF files, along with kml location files, and pdf files for browsing radargrams images by flight transect. Details of the processing methods are included in the associated README file. The processed data sets (reflectivity and attenuation) are provided as a single NetCDF file for each flight transect. Details of the calibration and processing procedures are provided in Chu, et al (in review).", "east": -82.7, "geometry": ["POINT(-106.35 -77.2)"], "keywords": "Amundsen Sea; Antarctica; Bed Reflectivity; Ice Penetrating Radar; Radar Echo Sounder", "locations": "Antarctica; Amundsen Sea", "north": -72.9, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Chu, Winnie; Hilger, Andrew M.; Culberg, Riley; Schroeder, Dustin; Jordan, Thomas M.; Seroussi, Helene; Young, Duncan A.; Vaughan, David G.", "project_titles": "CAREER: Cross-Instrument Synthesis of Antarctic Radar Sounding Observations", "projects": [{"proj_uid": "p0010058", "repository": "USAP-DC", "title": "CAREER: Cross-Instrument Synthesis of Antarctic Radar Sounding Observations"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.5, "title": "Radar Sounding Observations of the Amundsen Sea Embayment, 2004-2005", "uid": "601436", "west": -130.0}, {"awards": "0636724 Blankenship, Donald", "bounds_geometry": ["POLYGON((-120 -75,-117 -75,-114 -75,-111 -75,-108 -75,-105 -75,-102 -75,-99 -75,-96 -75,-93 -75,-90 -75,-90 -75.5,-90 -76,-90 -76.5,-90 -77,-90 -77.5,-90 -78,-90 -78.5,-90 -79,-90 -79.5,-90 -80,-93 -80,-96 -80,-99 -80,-102 -80,-105 -80,-108 -80,-111 -80,-114 -80,-117 -80,-120 -80,-120 -79.5,-120 -79,-120 -78.5,-120 -78,-120 -77.5,-120 -77,-120 -76.5,-120 -76,-120 -75.5,-120 -75))"], "date_created": "Mon, 21 May 2012 00:00:00 GMT", "description": "This data set contains subglacial water flow paths beneath Thwaites Glacier, West Antarctica, interpreted from ice thickness and bed elevation measurements collected between 7 December 2004 and 31 January 2005 by the Airborne Geophysical Survey of the Amundsen Embayment (AGASEA) expedition. Data consist of an ASCII text file with geographical coordinates, hydraulic head, and bed and surface elevations, and a corresponding .pdf map.\n\nData are available via FTP.", "east": -90.0, "geometry": ["POINT(-105 -77.5)"], "keywords": "AGASEA; Airborne Radar; Antarctica; Elevation; Flow Paths; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "locations": "Thwaites Glacier; Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Carter, Sasha P.; Young, Duncan A.; Blankenship, Donald D.", "project_titles": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "projects": [{"proj_uid": "p0000174", "repository": "USAP-DC", "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Subglacial water flow paths under Thwaites Glacier, West Antarctica", "uid": "609518", "west": -120.0}, {"awards": "0636724 Blankenship, Donald", "bounds_geometry": ["POLYGON((-125 -73,-121.5 -73,-118 -73,-114.5 -73,-111 -73,-107.5 -73,-104 -73,-100.5 -73,-97 -73,-93.5 -73,-90 -73,-90 -74,-90 -75,-90 -76,-90 -77,-90 -78,-90 -79,-90 -80,-90 -81,-90 -82,-90 -83,-93.5 -83,-97 -83,-100.5 -83,-104 -83,-107.5 -83,-111 -83,-114.5 -83,-118 -83,-121.5 -83,-125 -83,-125 -82,-125 -81,-125 -80,-125 -79,-125 -78,-125 -77,-125 -76,-125 -75,-125 -74,-125 -73))"], "date_created": "Thu, 03 May 2012 00:00:00 GMT", "description": "This data set contains line-based radar-derived ice thickness and bed elevation data, collected as part of the Airborne Geophysical Survey of the Amundsen Embayment (AGASEA) expedition, which took place over Thwaites Glacier in West Antarctica from 2004 to 2005. The data set includes ice thickness, ice sheet bed elevation, and ice sheet surface elevation, derived from ice-penetrating radar and aircraft GPS positions. The data are spaced on a 15 km by 15 km grid over the entire catchment of the glacier, and sampled at approximately 15 meters along track. Most of the radar data used for this dataset has been processed using a 1-D focusing algorithm, to reduce the along track resolution to tens of meters, to improve boundary conditions for ice sheet models. \n\nData are available via FTP in space-delimited ASCII format.", "east": -90.0, "geometry": ["POINT(-107.5 -78)"], "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness", "locations": "Antarctica; Amundsen Sea", "north": -73.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Blankenship, Donald D.; Young, Duncan A.; Holt, John W.; Kempf, Scott D.", "project_titles": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "projects": [{"proj_uid": "p0000174", "repository": "USAP-DC", "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -83.0, "title": "AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica", "uid": "609517", "west": -125.0}, {"awards": "0636724 Blankenship, Donald; 0230197 Holt, John", "bounds_geometry": ["POLYGON((-130 -75,-126.5 -75,-123 -75,-119.5 -75,-116 -75,-112.5 -75,-109 -75,-105.5 -75,-102 -75,-98.5 -75,-95 -75,-95 -75.5,-95 -76,-95 -76.5,-95 -77,-95 -77.5,-95 -78,-95 -78.5,-95 -79,-95 -79.5,-95 -80,-98.5 -80,-102 -80,-105.5 -80,-109 -80,-112.5 -80,-116 -80,-119.5 -80,-123 -80,-126.5 -80,-130 -80,-130 -79.5,-130 -79,-130 -78.5,-130 -78,-130 -77.5,-130 -77,-130 -76.5,-130 -76,-130 -75.5,-130 -75))"], "date_created": "Tue, 01 Jan 2008 00:00:00 GMT", "description": "This data set includes airborne altimetry collected over the catchment and main trunk of Thwaites Glacier, one of Antarctica\u0027s most active ice streams. The airborne altimetry comprises 35,000 line-kilometers sampled at 20 meters along track. The full dataset has an internal error of \u00b120 cm; a primary subset has an error of \u00b18 cm. We find a +20 cm bias with Geoscience Laser Altimeter System data over a flat interior region. These data will serve as an additional temporal reference for the evolution of Thwaites Glacier surface, as well as aid the construction of future high resolution Digital Elevation Models (DEM). Line data are available in space-delimited ASCII format and are available via FTP.", "east": -95.0, "geometry": ["POINT(-112.5 -77.5)"], "keywords": "AGASEA; Airborne Altimetry; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "locations": "Thwaites Glacier; Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Young, Duncan A.; Kempf, Scott D.; Blankenship, Donald D.; Holt, John W.; Morse, David L.", "project_titles": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "projects": [{"proj_uid": "p0000174", "repository": "USAP-DC", "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica", "uid": "609334", "west": -130.0}, {"awards": "0230197 Holt, John", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Mon, 01 Jan 2007 00:00:00 GMT", "description": "This data set includes a nested model, that starts at low resolution for the whole Antarctic Ice Sheet, and then embeds higher resolution data at limited domains. There are at least three levels of nesting: whole, regional, and specific ice streams. Investigators focused on the Thwaites Glacier and the Pine Island Glacier. The model was produced using data from (Holt et al. 2006) and (Vaughan et al. 2006). Data are in Network Common Data Form (NetCDF) format and are available via FTP.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "locations": "Amundsen Sea; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Fastook, James L.", "project_titles": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)", "projects": [{"proj_uid": "p0000243", "repository": "USAP-DC", "title": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Amundsen Sea Sector Data Set", "uid": "609312", "west": -180.0}, {"awards": "0230197 Holt, John", "bounds_geometry": ["POLYGON((-134.9 -71.7,-129.86 -71.7,-124.82 -71.7,-119.78 -71.7,-114.74 -71.7,-109.7 -71.7,-104.66 -71.7,-99.62 -71.7,-94.58 -71.7,-89.54 -71.7,-84.5 -71.7,-84.5 -72.7,-84.5 -73.7,-84.5 -74.7,-84.5 -75.7,-84.5 -76.7,-84.5 -77.7,-84.5 -78.7,-84.5 -79.7,-84.5 -80.7,-84.5 -81.7,-89.54 -81.7,-94.58 -81.7,-99.62 -81.7,-104.66 -81.7,-109.7 -81.7,-114.74 -81.7,-119.78 -81.7,-124.82 -81.7,-129.86 -81.7,-134.9 -81.7,-134.9 -80.7,-134.9 -79.7,-134.9 -78.7,-134.9 -77.7,-134.9 -76.7,-134.9 -75.7,-134.9 -74.7,-134.9 -73.7,-134.9 -72.7,-134.9 -71.7))"], "date_created": "Wed, 25 Oct 2006 00:00:00 GMT", "description": "This data set includes 5 km gridded data from the Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA) conducted during the 2004-2005 austral summer. Investigators derived maps of the ice sheet surface and subglacial topography, which covers the entire catchments of both the Thwaites Glacier and the Pine Islands Glacier, from airborne survey systems mounted on a Twin Otter aircraft. The surveys had sufficient density to identify critical ice dynamic transitions within the Amundsen Sea Embayment (ASE). \n\nThe ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Modeling of the Western Antarctic Ice Sheet (WAIS) deglaciation pinpointed the Pine Island Glacier and the Thwaites Glacier, which comprise a major portion of the ASE, as the most vulnerable features of the WAIS. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change, and it is not yet determined whether these changes are evidence of ongoing deglaciation or simply a fluctuation that does not threaten the equilibrium of the ice sheet. This research will support the efforts of a community of United States and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE. \n\nThese data are available via FTP.", "east": -84.5, "geometry": ["POINT(-109.7 -76.7)"], "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Solid Earth", "locations": "Antarctica; Amundsen Sea", "north": -71.7, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Holt, John W.; Blankenship, Donald D.; Morse, David L.; Vaughan, David G.; Corr, Hugh F. J.; Young, Duncan A.", "project_titles": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)", "projects": [{"proj_uid": "p0000243", "repository": "USAP-DC", "title": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.7, "title": "Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "uid": "609292", "west": -134.9}]

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