{"dp_type": "Dataset", "free_text": "Grounding Line"}
[{"awards": "1929991 Pettit, Erin C", "bounds_geometry": ["POLYGON((-106.5 -74.5,-106.3 -74.5,-106.1 -74.5,-105.9 -74.5,-105.7 -74.5,-105.5 -74.5,-105.3 -74.5,-105.1 -74.5,-104.9 -74.5,-104.7 -74.5,-104.5 -74.5,-104.5 -74.6,-104.5 -74.7,-104.5 -74.8,-104.5 -74.9,-104.5 -75,-104.5 -75.1,-104.5 -75.2,-104.5 -75.3,-104.5 -75.4,-104.5 -75.5,-104.7 -75.5,-104.9 -75.5,-105.1 -75.5,-105.3 -75.5,-105.5 -75.5,-105.7 -75.5,-105.9 -75.5,-106.1 -75.5,-106.3 -75.5,-106.5 -75.5,-106.5 -75.4,-106.5 -75.3,-106.5 -75.2,-106.5 -75.1,-106.5 -75,-106.5 -74.9,-106.5 -74.8,-106.5 -74.7,-106.5 -74.6,-106.5 -74.5))"], "date_created": "Fri, 21 Feb 2025 00:00:00 GMT", "description": "This dataset comprises GeoTiff files that capture the yearly averages of ice-flow velocity (including x- and y-components, and flow speed) and strain rates (longitudinal, transverse, and shear) for the Thwaites Eastern Ice Shelf (TEIS) from 2013 to 2022. The velocity grids were generated using ITS_LIVE image-pair velocities available throughout the year, ensuring a consistent extent and spatial resolution for each annual composite. These composites were created by stacking all available image pairs and taking the median value for each grid cell. Small data gaps near the grounding line were filled using bilinear interpolation. Each pixel in the grid represents the median value of all available pixels during the specified period. The data are gridded at a spatial resolution of 120m in a polar stereographic projection (EPSG:3031). Speed is given in metres per day (m/yr), and strain rates are given in units/day. Additional funding was received from NE/S006419/1.", "east": -104.5, "geometry": ["POINT(-105.5 -75)"], "keywords": "Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Glaciology; Ice Shelf; Remote Sensing; Satellite Imagery; Thwaites; Thwaites Glacier; Velocity", "locations": "Thwaites Glacier; Antarctica; Thwaites; Antarctica", "north": -74.5, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Banerjee, Debangshu; Lilien, David; Truffer, Martin; Luckman, Adrian; Wild, Christian; Pettit, Erin; Scambos, Ted; Muto, Atsuhiro; Alley, Karen", "project_titles": "NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment", "projects": [{"proj_uid": "p0010162", "repository": "USAP-DC", "title": "NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -75.5, "title": "Yearly velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2013-2022", "uid": "601904", "west": -106.5}, {"awards": "1738989 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-104.9429 -75.1543,-104.92228999999999 -75.1543,-104.90168 -75.1543,-104.88107 -75.1543,-104.86046 -75.1543,-104.83985 -75.1543,-104.81924 -75.1543,-104.79863 -75.1543,-104.77802 -75.1543,-104.75741000000001 -75.1543,-104.7368 -75.1543,-104.7368 -75.16263000000001,-104.7368 -75.17096000000001,-104.7368 -75.17929000000001,-104.7368 -75.18762000000001,-104.7368 -75.19595000000001,-104.7368 -75.20428,-104.7368 -75.21261,-104.7368 -75.22094,-104.7368 -75.22927,-104.7368 -75.2376,-104.75741000000001 -75.2376,-104.77802 -75.2376,-104.79863 -75.2376,-104.81924 -75.2376,-104.83985 -75.2376,-104.86046 -75.2376,-104.88107 -75.2376,-104.90168 -75.2376,-104.92228999999999 -75.2376,-104.9429 -75.2376,-104.9429 -75.22927,-104.9429 -75.22094,-104.9429 -75.21261,-104.9429 -75.20428,-104.9429 -75.19595000000001,-104.9429 -75.18762000000001,-104.9429 -75.17929000000001,-104.9429 -75.17096000000001,-104.9429 -75.16263000000001,-104.9429 -75.1543))"], "date_created": "Mon, 25 Nov 2024 00:00:00 GMT", "description": "Contains ice-penetrating radar data (10 and 400 MHz) from the Thwaites Glacier grounding zone. The main purpose of collecting these data was for safety assessment at a camp put-in; deep (10 MHz) radar data were also collected opportunistically.", "east": -104.7368, "geometry": ["POINT(-104.83985 -75.19595000000001)"], "keywords": "Antarctica; Cryosphere; Grounding Zone; Ice Penetrating Radar; Thwaites Glacier", "locations": "Antarctica; Thwaites Glacier", "north": -75.1543, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Balco, Greg; Campbell, Seth; Goehring, Brent", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -75.2376, "title": "Ice-penetrating radar data from the Thwaites Glacier grounding zone", "uid": "601860", "west": -104.9429}, {"awards": "1738989 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-110.9665 -75.1967,-110.92041 -75.1967,-110.87432 -75.1967,-110.82822999999999 -75.1967,-110.78214 -75.1967,-110.73605 -75.1967,-110.68996 -75.1967,-110.64386999999999 -75.1967,-110.59778 -75.1967,-110.55169000000001 -75.1967,-110.5056 -75.1967,-110.5056 -75.20331,-110.5056 -75.20992000000001,-110.5056 -75.21653,-110.5056 -75.22314,-110.5056 -75.22975,-110.5056 -75.23636,-110.5056 -75.24297,-110.5056 -75.24958,-110.5056 -75.25619,-110.5056 -75.2628,-110.55169000000001 -75.2628,-110.59778 -75.2628,-110.64386999999999 -75.2628,-110.68996 -75.2628,-110.73605 -75.2628,-110.78214 -75.2628,-110.82822999999999 -75.2628,-110.87432 -75.2628,-110.92041 -75.2628,-110.9665 -75.2628,-110.9665 -75.25619,-110.9665 -75.24958,-110.9665 -75.24297,-110.9665 -75.23636,-110.9665 -75.22975,-110.9665 -75.22314,-110.9665 -75.21653,-110.9665 -75.20992000000001,-110.9665 -75.20331,-110.9665 -75.1967))"], "date_created": "Wed, 13 Nov 2024 00:00:00 GMT", "description": "Contains ice-penetrating radar data (10, 100, and 400 MHz) from the north side of the Mt. Murphy massif. Most of these data are closely spaced lines used for reconnaissance and site selection for a subglacial bedrock recovery drilling project very close to the ice margin at the north ridge of Kay Peak, a sub-peak of the massif. In addition, there are several longer exploratory lines that cross the embayment between the massif and the Crosson Ice Shelf, some of which may cross grounding lines. ", "east": -110.5056, "geometry": ["POINT(-110.73605 -75.22975)"], "keywords": "Antarctica; Cryosphere; Mount Murphy", "locations": "Antarctica; Mount Murphy", "north": -75.1967, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Balco, Greg; Campbell, Seth; Goehring, Brent", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -75.2628, "title": "Ice-penetrating radar data from the northern embayment of the Mt. Murphy massif", "uid": "601834", "west": -110.9665}, {"awards": "2317097 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-99.793 -74.857,-99.7882 -74.857,-99.7834 -74.857,-99.77860000000001 -74.857,-99.77380000000001 -74.857,-99.769 -74.857,-99.7642 -74.857,-99.7594 -74.857,-99.75460000000001 -74.857,-99.74980000000001 -74.857,-99.745 -74.857,-99.745 -74.8583,-99.745 -74.8596,-99.745 -74.8609,-99.745 -74.8622,-99.745 -74.8635,-99.745 -74.8648,-99.745 -74.8661,-99.745 -74.8674,-99.745 -74.8687,-99.745 -74.87,-99.74980000000001 -74.87,-99.75460000000001 -74.87,-99.7594 -74.87,-99.7642 -74.87,-99.769 -74.87,-99.77380000000001 -74.87,-99.77860000000001 -74.87,-99.7834 -74.87,-99.7882 -74.87,-99.793 -74.87,-99.793 -74.8687,-99.793 -74.8674,-99.793 -74.8661,-99.793 -74.8648,-99.793 -74.8635,-99.793 -74.8622,-99.793 -74.8609,-99.793 -74.8596,-99.793 -74.8583,-99.793 -74.857))"], "date_created": "Wed, 02 Oct 2024 00:00:00 GMT", "description": "This data set contains an ice and firn density profile from Winkie Nunatak, West Antarctica. These data were collected when drilling a sub-ice access hole with an Eclipse drill in preparation for Winkie drill collection of subglacial bedrock. ", "east": -99.745, "geometry": ["POINT(-99.769 -74.8635)"], "keywords": "Antarctica; Cryosphere; Density; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Density; Ice Core Records; Snow/ice; Snow/Ice", "locations": "Antarctica", "north": -74.857, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Venturelli, Ryan", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -74.87, "title": "Firn and Ice Density at Winkie Nunatak", "uid": "601838", "west": -99.793}, {"awards": "1745043 Simkins, Lauren", "bounds_geometry": ["POINT(-100 -75)"], "date_created": "Thu, 11 Apr 2024 00:00:00 GMT", "description": "This dataset contains the elevation raster for Pine Island Bay and the raw elevation profiles used for each site. The transects are organized based on their orientation in relation to paleo-ice flow. They are spaced 500 meters apart, with elevation measurements extracted every 50 meters along each transect.", "east": -100.0, "geometry": ["POINT(-100 -75)"], "keywords": "Antarctica; Bed Roughness; Cryosphere; Geomorphology; Pine Island Bay", "locations": "Pine Island Bay; Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Munevar Garcia, Santiago", "project_titles": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations", "projects": [{"proj_uid": "p0010269", "repository": "USAP-DC", "title": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0, "title": "Elevation transects from Pine Island Bay", "uid": "601774", "west": -100.0}, {"awards": "1443677 Padman, Laurence; 9896041 Padman, Laurence", "bounds_geometry": ["POLYGON((-180 -40.231,-144 -40.231,-108 -40.231,-72 -40.231,-36 -40.231,0 -40.231,36 -40.231,72 -40.231,108 -40.231,144 -40.231,180 -40.231,180 -45.2079,180 -50.1848,180 -55.161699999999996,180 -60.1386,180 -65.1155,180 -70.0924,180 -75.0693,180 -80.0462,180 -85.0231,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.0231,-180 -80.0462,-180 -75.0693,-180 -70.0924,-180 -65.1155,-180 -60.138600000000004,-180 -55.1617,-180 -50.1848,-180 -45.2079,-180 -40.231))"], "date_created": "Wed, 27 Mar 2024 00:00:00 GMT", "description": "CATS2008_v2023 is an update of the original CATS2008 tide model (Howard et al., 2019 [https://doi.org/10.15784/601235]; Padman et al., 2002 [https://doi.org/10.3189/172756402781817752]). It introduces a new model file format, increased resolution, more accurate coastlines, and a simple scaling for ice shelf flexure near grounding lines. The changes included in the new CATS2008_v2023 model are: (1) The CATS2008 model has been interpolated to a finer grid (2 km for CATS2008_v2023 vs 4 km for CATS2008) to provide a better representation of coastlines and ice shelf grounding lines. (2) Coastlines have been adjusted to match BedMachine Antarctica v3 (Morlighem et al., 2020 [https://doi.org/10.1038/s41561-019-0510-8]; Morlighem, 2022 [https://doi.org/10.5067/FPSU0V1MWUB6]). Areas that were previously grounded and had no tidal constituent data in CATS2008 have been filled using MATLAB\u0027s \u2018regionfill\u2019 function, applied to the real and imaginary components of tidal constituents individually. An ocean mask matching BedMachine Antarctica v3 is provided in the model file to mask out grounded areas. (3) Water depth (water column thickness under ice shelves) has been adjusted to match BedMachine Antarctica v3. (4) An ice shelf flexure model has been included for estimating tidal deflections in grounding zones. Flexure is approximated by a forward 1D linear elastic model applied to BedMachine Antarctica v3 ice geometry, with elastic modulus E=4.8 GPa and Poisson\u0027s ratio nu=0.4. The ice flexure can be included as an option when using TMD3.0 (Greene et al., 2024 [https://doi.org/10.21105/joss.06018]) and pyTMD (Sutterley, 2024 [https://doi.org/10.5281/zenodo.10501349]) software packages. (5) The model is provided as a consolidated NetCDF file that can be used with TMD3.0 and pyTMD, but not with earlier TMD versions. ", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Cryosphere; Inverse Modeling; Model Data; Ocean Currents; Oceans; Sea Surface; Southern Ocean; Tide Model; Tides", "locations": "Antarctica; Sea Surface; Southern Ocean", "north": -40.231, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "persons": "Howard, Susan L.; Greene, Chad A.; Padman, Laurence; Erofeeva, Svetlana; Sutterley, Tyler", "project_titles": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE); Ocean Tides around Antarctica and in the Southern Ocean", "projects": [{"proj_uid": "p0010116", "repository": "USAP-DC", "title": "Ocean Tides around Antarctica and in the Southern Ocean"}, {"proj_uid": "p0010035", "repository": "USAP-DC", "title": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023", "uid": "601772", "west": -180.0}, {"awards": null, "bounds_geometry": ["POLYGON((-156 -82.5,-155.9 -82.5,-155.8 -82.5,-155.7 -82.5,-155.6 -82.5,-155.5 -82.5,-155.4 -82.5,-155.3 -82.5,-155.2 -82.5,-155.1 -82.5,-155 -82.5,-155 -82.53,-155 -82.56,-155 -82.59,-155 -82.62,-155 -82.65,-155 -82.67999999999999,-155 -82.71,-155 -82.74,-155 -82.77,-155 -82.8,-155.1 -82.8,-155.2 -82.8,-155.3 -82.8,-155.4 -82.8,-155.5 -82.8,-155.6 -82.8,-155.7 -82.8,-155.8 -82.8,-155.9 -82.8,-156 -82.8,-156 -82.77,-156 -82.74,-156 -82.71,-156 -82.67999999999999,-156 -82.65,-156 -82.62,-156 -82.59,-156 -82.56,-156 -82.53,-156 -82.5))"], "date_created": "Tue, 12 Sep 2023 00:00:00 GMT", "description": "Contained in this folder are the raw and processed data files for data collected with the underwater robot Icefin in the ocean cavity beneath Ross Ice Shelf, near the grounding line of Kamb Ice Stream. Most of these data are located within a basal crevasse. They were collected in December 2019 as part of the Aotearoa New Zealand Antarctic Science Platform and Victoria University of Wellington Hot Water Drilling initiative, and the NASA RISEUP grant (NNX16AL07G, PI B. E. Schmidt). The code that converted raw data files to processed can be found at https://zenodo.org/record/8338529. Direct questions to Peter Washam at pwasham@cornell.edu.", "east": -155.0, "geometry": ["POINT(-155.5 -82.65)"], "keywords": "Antarctica; Basal Crevassing; Basal Freezing; Basal Melting; Ice Shelf; Kamb Ice Stream; Oceanography", "locations": "Kamb Ice Stream; Antarctica", "north": -82.5, "nsf_funding_programs": null, "persons": "Washam, Peter", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -82.8, "title": "Direct observations of melting, freezing, and ocean circulation in an ice shelf basal crevasse", "uid": "601733", "west": -156.0}, {"awards": "1738989 Venturelli, Ryan", "bounds_geometry": ["POINT(-110.96038 -75.21526)"], "date_created": "Mon, 10 Jul 2023 00:00:00 GMT", "description": "Included in this dataset are in situ carbon-14 concentrations for a series of bedrock cores recovered from the subglacial extension of Kay Peak, a grounding-line-proximal ridge of the volcanic edifice Mount Murphy (near Thwaites and Pope glaciers). Concentrations measured in these bedrock samples have been used in the associated publication to demonstrate that the Thwaites-Pope glacier system was thinner in the Holocene than it is today. ", "east": -110.96038, "geometry": ["POINT(-110.96038 -75.21526)"], "keywords": "Antarctica; Cosmogenic Radionuclides; Mount Murphy; Subglacial Bedrock", "locations": "Mount Murphy; Antarctica", "north": -75.21526, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Venturelli, Ryan; Goehring, Brent; Balco, Gregory", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -75.21526, "title": "In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers", "uid": "601705", "west": -110.96038}, {"awards": "2317097 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-99.793 -74.857,-99.7882 -74.857,-99.7834 -74.857,-99.77860000000001 -74.857,-99.77380000000001 -74.857,-99.769 -74.857,-99.7642 -74.857,-99.7594 -74.857,-99.75460000000001 -74.857,-99.74980000000001 -74.857,-99.745 -74.857,-99.745 -74.8583,-99.745 -74.8596,-99.745 -74.8609,-99.745 -74.8622,-99.745 -74.8635,-99.745 -74.8648,-99.745 -74.8661,-99.745 -74.8674,-99.745 -74.8687,-99.745 -74.87,-99.74980000000001 -74.87,-99.75460000000001 -74.87,-99.7594 -74.87,-99.7642 -74.87,-99.769 -74.87,-99.77380000000001 -74.87,-99.77860000000001 -74.87,-99.7834 -74.87,-99.7882 -74.87,-99.793 -74.87,-99.793 -74.8687,-99.793 -74.8674,-99.793 -74.8661,-99.793 -74.8648,-99.793 -74.8635,-99.793 -74.8622,-99.793 -74.8609,-99.793 -74.8596,-99.793 -74.8583,-99.793 -74.857))"], "date_created": "Fri, 24 Mar 2023 00:00:00 GMT", "description": "This data set contains unprocessed radar profiles collected with a GSSI 200 MHz Hyperstacking antenna near Winkie Nunatak, West Antarctica. This data was collected to estimate depth-to-bedrock along a subglacial ridge line at depths between 20 - 120 meters. ", "east": -99.745, "geometry": ["POINT(-99.769 -74.8635)"], "keywords": "Antarctica; Ice Penetrating Radar; Pine Island Glacier; Subglacial Bedrock", "locations": "Pine Island Glacier; Antarctica", "north": -74.857, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Braddock, Scott", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -74.87, "title": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica", "uid": "601677", "west": -99.793}, {"awards": "NNX16AL07G TBD", "bounds_geometry": ["POLYGON((-155.3 -82.75,-155.27 -82.75,-155.24 -82.75,-155.21 -82.75,-155.18 -82.75,-155.15 -82.75,-155.12 -82.75,-155.09 -82.75,-155.06 -82.75,-155.03 -82.75,-155 -82.75,-155 -82.76,-155 -82.77,-155 -82.78,-155 -82.78999999999999,-155 -82.8,-155 -82.81,-155 -82.82,-155 -82.83,-155 -82.83999999999999,-155 -82.85,-155.03 -82.85,-155.06 -82.85,-155.09 -82.85,-155.12 -82.85,-155.15 -82.85,-155.18 -82.85,-155.21 -82.85,-155.24 -82.85,-155.27 -82.85,-155.3 -82.85,-155.3 -82.83999999999999,-155.3 -82.83,-155.3 -82.82,-155.3 -82.81,-155.3 -82.8,-155.3 -82.78999999999999,-155.3 -82.78,-155.3 -82.77,-155.3 -82.76,-155.3 -82.75))"], "date_created": "Wed, 14 Dec 2022 00:00:00 GMT", "description": "This work was primarily funded by the NASA-funded RISE-UP: Ross Ice Shelf \u0026 Europa Underwater Probe (PI Britney E. Schmidt) project. Field work at the KIS-1 site during the 2019-2020 season was completed through international collaboration between NASA, NSF/USAP, and Antarctica New Zealand, funded by the Aotearoa New Zealand Antarctic Science Platform (ANTA1801) Antarctic Ice Dynamics Project (ASP02101), and the NZARI-funded Aotearoa New Zealand Ross Ice Shelf Programme, \u201cVulnerability of the Ross Ice Shelf in a Warming World\u201d (grant no. 2014-11).\r\n\r\nThe data contained in this directory are merged and calibrated data files from three missions conducted with ROV Icefin through a borehole drilled through Ross Ice Shelf at KIS1 (-82.78410, -155.26267), near the Kamb Ice Stream grounding zone. Missions were conducted in 2019 on December 16th, 18th, and 21st (UTC). For questions or assistance working with the data please contact Britney Schmidt (britneys@cornell.edu) and Justin Lawrence (jdl287@cornell.edu).", "east": -155.0, "geometry": ["POINT(-155.15 -82.8)"], "keywords": "Antarctica; Grounding Line; Grounding Zone; Ice Shelf; Kamb Ice Stream; Ross Ice Shelf", "locations": "Kamb Ice Stream; Antarctica; Kamb Ice Stream; Ross Ice Shelf; Antarctica", "north": -82.75, "nsf_funding_programs": null, "persons": "Lawrence, Justin; Schmidt, Britney", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -82.85, "title": "KIS-1 ROV Icefin Missions", "uid": "601625", "west": -155.3}, {"awards": "1933764 Enderlin, Ellyn", "bounds_geometry": ["POLYGON((-63.1 -65.2,-62.99 -65.2,-62.88 -65.2,-62.77 -65.2,-62.660000000000004 -65.2,-62.55 -65.2,-62.44 -65.2,-62.33 -65.2,-62.22 -65.2,-62.11 -65.2,-62 -65.2,-62 -65.24000000000001,-62 -65.28,-62 -65.32,-62 -65.36,-62 -65.4,-62 -65.44,-62 -65.47999999999999,-62 -65.52,-62 -65.56,-62 -65.6,-62.11 -65.6,-62.22 -65.6,-62.33 -65.6,-62.44 -65.6,-62.55 -65.6,-62.660000000000004 -65.6,-62.77 -65.6,-62.88 -65.6,-62.99 -65.6,-63.1 -65.6,-63.1 -65.56,-63.1 -65.52,-63.1 -65.47999999999999,-63.1 -65.44,-63.1 -65.4,-63.1 -65.36,-63.1 -65.32,-63.1 -65.28,-63.1 -65.24000000000001,-63.1 -65.2))"], "date_created": "Mon, 24 Oct 2022 00:00:00 GMT", "description": "This dataset contains observed and modeled conditions along the Crane Glacier centerline for ~1994\u20142100. Observations include centerline (cl) coordinates, downscaled RACMO climate variables (runoff, snowfall, snowmelt, and surface mass balance), bed elevations (b), surface elevations (h), glacier width (W), calving front positions (xcf), and surface speeds (U) when available for the 1994\u20142019 period. Modeling results include glacier centerline geometry, speed, glacier mass discharge (Q_gl), and calving front and grounding line positions (x_cf and x_gl) under different future climate scenarios with varying surface mass balance (SMB), ocean thermal forcing (FT), SMB with potential feedbacks associated with enhanced surface melt water discharge and plume strengthening (SMB_enh), and concurrent SMB_enh and FT perturbations (SMB_enh_FT). Data are in \u201c.mat\u201d format, which can be read using MATLAB\u2019s \u201cload\u201d function or using Python with the Scipy \u201cscipy.io.loadmat\u201d function. ", "east": -62.0, "geometry": ["POINT(-62.55 -65.4)"], "keywords": "Antarctica; Antarctic Peninsula; Crane Glacier; Glacier Dynamics; Glacier Mass Discharge; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Modeling; Model Output", "locations": "Crane Glacier; Antarctica; Antarctic Peninsula", "north": -65.2, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Aberle, Rainey; Enderlin, Ellyn; Marshall, Hans-Peter; Kopera, Michal; Meehan, Tate", "project_titles": "Antarctic Submarine Melt Variability from Remote Sensing of Icebergs", "projects": [{"proj_uid": "p0010210", "repository": "USAP-DC", "title": "Antarctic Submarine Melt Variability from Remote Sensing of Icebergs"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.6, "title": "Crane Glacier centerline observations and modeling results ", "uid": "601617", "west": -63.1}, {"awards": "1738989 Venturelli, Ryan", "bounds_geometry": ["POLYGON((-105 -73,-104.5 -73,-104 -73,-103.5 -73,-103 -73,-102.5 -73,-102 -73,-101.5 -73,-101 -73,-100.5 -73,-100 -73,-100 -73.1,-100 -73.2,-100 -73.3,-100 -73.4,-100 -73.5,-100 -73.6,-100 -73.7,-100 -73.8,-100 -73.9,-100 -74,-100.5 -74,-101 -74,-101.5 -74,-102 -74,-102.5 -74,-103 -74,-103.5 -74,-104 -74,-104.5 -74,-105 -74,-105 -73.9,-105 -73.8,-105 -73.7,-105 -73.6,-105 -73.5,-105 -73.4,-105 -73.3,-105 -73.2,-105 -73.1,-105 -73))"], "date_created": "Mon, 11 Apr 2022 00:00:00 GMT", "description": "This dataset includes radiocarbon dates and elevations of organic samples in raised beaches in the Edwards, Lindsey, and Schaefer Islands. It also includes a limited number of cosmogenic exposure-age data of bedrock from these islands.", "east": -100.0, "geometry": ["POINT(-102.5 -73.5)"], "keywords": "Antarctica; Pine Island Bay; Radiocarbon; Raised Beaches", "locations": "Antarctica; Pine Island Bay; Pine Island Bay", "north": -73.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Braddock, Scott; Hall, Brenda", "project_titles": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "projects": [{"proj_uid": "p0010165", "repository": "USAP-DC", "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -74.0, "title": "Pine Island Bay Relative Sea-Level Data", "uid": "601554", "west": -105.0}, {"awards": "1929991 Pettit, Erin C", "bounds_geometry": ["POLYGON((-108 -74.5,-107.6 -74.5,-107.2 -74.5,-106.8 -74.5,-106.4 -74.5,-106 -74.5,-105.6 -74.5,-105.2 -74.5,-104.8 -74.5,-104.4 -74.5,-104 -74.5,-104 -74.6,-104 -74.7,-104 -74.8,-104 -74.9,-104 -75,-104 -75.1,-104 -75.2,-104 -75.3,-104 -75.4,-104 -75.5,-104.4 -75.5,-104.8 -75.5,-105.2 -75.5,-105.6 -75.5,-106 -75.5,-106.4 -75.5,-106.8 -75.5,-107.2 -75.5,-107.6 -75.5,-108 -75.5,-108 -75.4,-108 -75.3,-108 -75.2,-108 -75.1,-108 -75,-108 -74.9,-108 -74.8,-108 -74.7,-108 -74.6,-108 -74.5))"], "date_created": "Thu, 23 Dec 2021 00:00:00 GMT", "description": "This data set includes two grounding-line products of Thwaites Glacier and a series of offshore pinning points for 2014 and 2019/20. The grounding lines where delineated manually from height above flotation calculations using the bathymetry model from Jordan et al. (2020), the REMA digital surface elevation model (Howat et al., 2019) for the 2014 product and ICESat-2 surface altimetry data (Smith et al., 2019) for the 2019/20 product. More details about the processing, corrections and uncertainties can be found in our publication. We would appreciate if users who think the grounding-line products are useful for your own research would cite our manuscript.", "east": -104.0, "geometry": ["POINT(-106 -75)"], "keywords": "Amundsen Sea; Antarctica; Glaciology; Grounding Line; Ice Shelf; Thwaites Glacier", "locations": "Thwaites Glacier; Amundsen Sea; Antarctica; Antarctica; Thwaites Glacier", "north": -74.5, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "persons": "Wild, Christian; Alley, Karen; Muto, Atsu; Truffer, Martin; Scambos, Ted; Pettit, Erin", "project_titles": "NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment", "projects": [{"proj_uid": "p0010162", "repository": "USAP-DC", "title": "NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -75.5, "title": "Thwaites Glacier grounding lines for 2014 and 2019/20 from height above flotation", "uid": "601499", "west": -108.0}, {"awards": "1246353 Anderson, John; 1745055 Stearns, Leigh; 1745043 Simkins, Lauren", "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": "Wed, 10 Nov 2021 00:00:00 GMT", "description": "The dataset here allows exploration of the causes and significance of Antarctic grounding-line sinuosity by coupling observations of contemporary Antarctic grounding lines and paleo-grounding lines expressed as ice-marginal landforms on the Ross Sea continental shelf. Modern grounding lines are derived from the MEaSUREs Version 2 Differential Satellite Radar Interferometry dataset with spatial resolutions of 25-120 m spanning February 1992 to December 2014 (Rignot et al., 2016; Mouginot et al., 2017). The boundaries of individual grounding lines representative of individual glacial catchments (n=664) were delineated by the inflection points of the shear strain rate, \u03b5xy (c.f Van der Veen et al., 2011). Sinuosity was calculated as the ratio of the true length, orthogonal to ice-flow direction, of the grounding lines and the straight line length between end-points and in units of km/km. Raster data were extracted at 1-km points along each grounding line; the mean was calculated for each grounding line and merged in a table with sinuosity data. A dataset of 6,275 paleo-grounding lines expressed as ice-marginal landforms on the deglaciated western Ross Sea continental shelf are used in this study, originally published by Simkins et al., 2018. The ice-marginal landforms were mapped from multibeam echo sounder data that 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 30-60% swath overlap (Cruise DOI: 10.7284/901477). The resulting bathymetry data was gridded at 20-40 m with decimeter vertical elevation resolution depending on water depth and sea-state. Sinuosity is calculated as a ratio of true (mapped) landform length, measured in the across paleo-ice flow direction at the crest of the landform, to the straight line distance between the mapped landform endpoints and in units of km/km. \r\n\r\nTo compare modern and paleo-grounding lines, we use a consistent length scale by segmenting the grounding lines into 2-km sections for the two datasets (modern, n=12,966; paleo, n=5,832), even though this eliminates grounding lines that are less than 2-km long and thus results in 1 modern and 3,873 paleo-grounding lines removed. The full-length and 2-km segmented groundings lines are provided as shapefiles \"InSAR_groundinglines_full\" and \"InSAR_groundinglines_2km\", the paleo-grounding lines are provided as shapefiles \"RossSea_icemarginal_full\" and \"RossSea_icemarginal_2km\", and points marking modern grounding lines retreat from repeat InSAR surveys are provided as shapefile \"InSAR_retreat_points\", all stored together in a geodatabase named \"Antarctic_groundinglines.gbd\". Additional grounding line metrics, including length, sinuosity, bed roughness, and bed slope for modern and paleo-grounding lines, and height-above-buoyancy gradient, ice-flow velocity, presence of pinning points and ice shelves are provided for modern grounding lines. \r\n\r\nThe published dataset was compiled and analyzed in the article \"Controls on circum-Antarctic grounding-line sinuosity \" by Simkins, L.M., Stearns, L.A., and Riverman, K.L, which will be submitted to a peer-review journal in November 2021.\r\n\r\nReferences\r\nMouginot, J., B. Scheuchl, and E. Rignot. 2017. MEaSUREs Antarctic Boundaries for IPY 2007-2009 from Satellite Radar, Version 2. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. \r\n\r\nRignot, E., J. Mouginot, and B. Scheuchl. 2016. MEaSUREs Antarctic Grounding Line from Differential Satellite Radar Interferometry, Version 2. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. \r\n\r\nSimkins, L. M., Greenwood, S. L., \u0026 Anderson, J. B. (2018). Diagnosing ice sheet grounding line stability from landform morphology. The Cryosphere, 12(8), 2707-2726.\r\n\r\nVan der Veen, C. J., J. C. Plummer, \u0026 L. A. Stearns. (2011). Controls on the recent speed up of Jakobshavn Isbr\u00e6, West Greenland. Journal of Glaciology, 57(204), 770-782", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Bed Roughness; Bed Slope; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pinning Points", "locations": "Antarctica; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Simkins, Lauren; Stearns, Leigh; Riverman, Kiya", "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": "p0000395", "repository": "USAP-DC", "title": "Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum."}, {"proj_uid": "p0010269", "repository": "USAP-DC", "title": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Circum-Antarctic grounding-line sinuosity", "uid": "601484", "west": -180.0}, {"awards": "1246353 Anderson, John; 1745055 Stearns, Leigh; 1745043 Simkins, Lauren", "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": "Ross Sea; Pennell Trough; Antarctica", "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": "0440670 Hulbe, Christina", "bounds_geometry": ["POLYGON((-180 -77,-177 -77,-174 -77,-171 -77,-168 -77,-165 -77,-162 -77,-159 -77,-156 -77,-153 -77,-150 -77,-150 -77.9,-150 -78.8,-150 -79.7,-150 -80.6,-150 -81.5,-150 -82.4,-150 -83.3,-150 -84.2,-150 -85.1,-150 -86,-153 -86,-156 -86,-159 -86,-162 -86,-165 -86,-168 -86,-171 -86,-174 -86,-177 -86,180 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77))"], "date_created": "Fri, 19 Feb 2021 00:00:00 GMT", "description": "The surface of the Ross Ice Shelf (RIS) is textured by flow stripes, crevasses and other fea- tures related to ice flow and deformation. Here, moderate resolution optical satellite images are used to map and classify regions of the RIS characterized by different surface textures. Because the textures arise from ice deformation, the map is used to identify structural provinces with common deformation history. We classify four province types: regions associated with large outlet glaciers, shear zones, exten- sion downstream of obstacles and suture zones between provinces with different upstream sources. Adjacent provinces with contrasting histories are in some locations deforming at different rates, suggest- ing that our province map is also an ice fabric map. Structural provinces have more complicated shapes in the part of the ice shelf fed by West Antarctic ice streams than in the part fed by outlet glaciers from the Transantarctic Mountains. The map may be used to infer past variations in stress conditions and flow events that cannot be inferred from flow traces alone.", "east": 155.0, "geometry": ["POINT(-177.5 -81.5)"], "keywords": "Antarctica", "locations": "Antarctica", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hulbe, Christina; Ledoux, Christine; Forbes, Martin", "project_titles": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "projects": [{"proj_uid": "p0000096", "repository": "USAP-DC", "title": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.0, "title": "MOA-derived Structural Feature Map of the Ross Ice Shelf", "uid": "601432", "west": -150.0}, {"awards": "1543452 Blankenship, Donald; 0733025 Blankenship, Donald; 1443690 Young, Duncan; 0636724 Blankenship, Donald", "bounds_geometry": ["POLYGON((80 -65,89 -65,98 -65,107 -65,116 -65,125 -65,134 -65,143 -65,152 -65,161 -65,170 -65,170 -66.5,170 -68,170 -69.5,170 -71,170 -72.5,170 -74,170 -75.5,170 -77,170 -78.5,170 -80,161 -80,152 -80,143 -80,134 -80,125 -80,116 -80,107 -80,98 -80,89 -80,80 -80,80 -78.5,80 -77,80 -75.5,80 -74,80 -72.5,80 -71,80 -69.5,80 -68,80 -66.5,80 -65))"], "date_created": "Mon, 24 Aug 2020 00:00:00 GMT", "description": "The International Collaborative Exploration of the Cryosphere though Airborne Profiling (ICECAP) collected five seasons of aerogeophysical data data through the NSFs International Polar Year and NASAs Operation Ice Bridge programs in East Antarctica, using the coherent HiCARS 60 MHz radar system. By comparing echo strengths for different focusing apertures, and accounting for the ranges and angles involved, we can derive the \"specularity content\" of the bed echo, a proxy for small scale bed roughness and a good indicator for subglacial water pressure in regions of distributed subglacial water (Schroeder et al., 2014, IEEE GRSL, 10.1109/LGRS.2014.2337878; IEEE; Dow et al., 2019, EPSL https://doi.org/10.1016/j.epsl.2019.115961). Specularity data are inherently noisy, so these products have been smoothed with a 1 km filter.", "east": 170.0, "geometry": ["POINT(125 -72.5)"], "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "locations": "East Antarctica; Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Young, Duncan A.; Blankenship, Donald D.; Roberts, Jason; Siegert, Martin; van Ommen, Tas; Greenbaum, Jamin; Schroeder, Dustin", "project_titles": "Collaborative Research: Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP); Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System; East Antarctic Grounding Line Experiment (EAGLE); IPY Research: Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP)", "projects": [{"proj_uid": "p0010115", "repository": "USAP-DC", "title": "Collaborative Research: Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP)"}, {"proj_uid": "p0000254", "repository": "USAP-DC", "title": "East Antarctic Grounding Line Experiment (EAGLE)"}, {"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": "p0000719", "repository": "USAP-DC", "title": "IPY Research: Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "uid": "601371", "west": 80.0}, {"awards": "9896041 Padman, Laurence; 1443677 Padman, Laurence", "bounds_geometry": ["POLYGON((-180 -40.231,-144 -40.231,-108 -40.231,-72 -40.231,-36 -40.231,0 -40.231,36 -40.231,72 -40.231,108 -40.231,144 -40.231,180 -40.231,180 -45.2079,180 -50.1848,180 -55.1617,180 -60.1386,180 -65.1155,180 -70.0924,180 -75.0693,180 -80.0462,180 -85.0231,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.0231,-180 -80.0462,-180 -75.0693,-180 -70.0924,-180 -65.1155,-180 -60.1386,-180 -55.1617,-180 -50.1848,-180 -45.2079,-180 -40.231))"], "date_created": "Thu, 19 Dec 2019 00:00:00 GMT", "description": "CATS2008 is a regional inverse barotropic tide model for the circum-Antarctic ocean on a 4 km grid. The model domain includes ocean cavities under the floating ice shelves. The coastline is based on the MODIS MOA [Scambos et al., 2007; Remote Sensing of Environment] feature identification files, adjusted to match ICESat-derived grounding lines for the Ross and Filchner-Ronne ice shelves and Interferometric Synthetic Aperture Radar (InSAR) grounding lines. The water depth map for open water is based on the 2007 release update to Smith and Sandwell [1997; Science]. Adjustments to this map have been made in various regions, including the open continental shelf in front of the Larsen-C Ice Shelf which has been blended with GEBCO bathymetry.\r\n\nModel type: Tides only; Inverse (data assimilation); barotropic (no vertical variation of currents). \nGrid: 4-km uniform polar stereographic (centered at 71 degrees S, 70 degrees W) \nConstituents: M2, S2, N2, K2, K1, O1, P1, Q1, Mf, Mm. \nUnits: z (sea surface height; meters); u,v (currents; cm/s); U,V (transports; m2/s). \nCoordinates: Currents (u, v) and depth-integrated transports (U, V) are given as East (u, U) and North (v, V) components. \nCitation: \"\u2026 an update to the inverse model described by Padman et al. [2002].\" \n\nSee CATS2008_README.pdf for further details.\r", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "locations": "Antarctica; Sea Surface", "north": -40.231, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "persons": "Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana", "project_titles": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE); Ocean Tides around Antarctica and in the Southern Ocean", "projects": [{"proj_uid": "p0010116", "repository": "USAP-DC", "title": "Ocean Tides around Antarctica and in the Southern Ocean"}, {"proj_uid": "p0010035", "repository": "USAP-DC", "title": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "CATS2008: Circum-Antarctic Tidal Simulation version 2008", "uid": "601235", "west": -180.0}, {"awards": "1443356 Conway, Howard; 1443552 Paul Winberry, J.", "bounds_geometry": ["POLYGON((-174.95 -82.65,-174.35 -82.65,-173.75 -82.65,-173.15 -82.65,-172.55 -82.65,-171.95 -82.65,-171.35 -82.65,-170.75 -82.65,-170.15 -82.65,-169.55 -82.65,-168.95 -82.65,-168.95 -82.729,-168.95 -82.808,-168.95 -82.887,-168.95 -82.966,-168.95 -83.045,-168.95 -83.124,-168.95 -83.203,-168.95 -83.282,-168.95 -83.361,-168.95 -83.44,-169.55 -83.44,-170.15 -83.44,-170.75 -83.44,-171.35 -83.44,-171.95 -83.44,-172.55 -83.44,-173.15 -83.44,-173.75 -83.44,-174.35 -83.44,-174.95 -83.44,-174.95 -83.361,-174.95 -83.282,-174.95 -83.203,-174.95 -83.124,-174.95 -83.045,-174.95 -82.966,-174.95 -82.887,-174.95 -82.808,-174.95 -82.729,-174.95 -82.65))"], "date_created": "Mon, 20 May 2019 00:00:00 GMT", "description": "This data set contains radar-detected measurements of surface topography, internal stratigraphy, ice thickness and derived bed topography across Crary Ice Rise in the Ross Sea Embayment.", "east": -168.95, "geometry": ["POINT(-171.95 -83.045)"], "keywords": "Antarctica; Bed Elevation; Crary Ice Rise; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Ice Sheet Elevation; Ice Shelf; Ice Thickness; Internal Stratigraphy; Radar; Ross Ice Shelf; Snow/ice; Snow/Ice; Surface Elevation", "locations": "Ross Ice Shelf; Antarctica; Crary Ice Rise", "north": -82.65, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "persons": "Conway, Howard; Koutnik, Michelle; Winberry, Paul; Paden, John", "project_titles": "Collaborative Research: Grounding Line Dynamics: Crary Ice Rise Revisited", "projects": [{"proj_uid": "p0010026", "repository": "USAP-DC", "title": "Collaborative Research: Grounding Line Dynamics: Crary Ice Rise Revisited"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -83.44, "title": "Geophysical data from Crary Ice Rise, Ross Sea Embayment", "uid": "601181", "west": -174.95}, {"awards": "0838947 Tulaczyk, Slawek", "bounds_geometry": ["POLYGON((-165.28 -84.24,-165.086 -84.24,-164.892 -84.24,-164.698 -84.24,-164.504 -84.24,-164.31 -84.24,-164.116 -84.24,-163.922 -84.24,-163.728 -84.24,-163.534 -84.24,-163.34 -84.24,-163.34 -84.252,-163.34 -84.264,-163.34 -84.276,-163.34 -84.288,-163.34 -84.3,-163.34 -84.312,-163.34 -84.324,-163.34 -84.336,-163.34 -84.348,-163.34 -84.36,-163.534 -84.36,-163.728 -84.36,-163.922 -84.36,-164.116 -84.36,-164.31 -84.36,-164.504 -84.36,-164.698 -84.36,-164.892 -84.36,-165.086 -84.36,-165.28 -84.36,-165.28 -84.348,-165.28 -84.336,-165.28 -84.324,-165.28 -84.312,-165.28 -84.3,-165.28 -84.288,-165.28 -84.276,-165.28 -84.264,-165.28 -84.252,-165.28 -84.24))"], "date_created": "Sun, 09 Sep 2018 00:00:00 GMT", "description": "This dataset contains ice-shelf basal melt rates and vertical strain rates for 11 sites near the Whillans Ice Stream grounding line. These rates were determined using Autonomous Phase-Sensitive Radar. Data processing is described in Begeman et al. 2018, JGR Oceans. These sites are concentrated within an embayment of the Ross Ice Shelf. These melt rates and strain rates were determined over periods ranging from 10 to 38 days in December 2014 to January 2015. ", "east": -163.34, "geometry": ["POINT(-164.31 -84.3)"], "keywords": "Antarctica; Flexure Zone; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Ice-Shelf Basal Melting; Ice-Shelf Strain Rate", "locations": "Antarctica", "north": -84.24, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Begeman, Carolyn", "project_titles": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)", "projects": [{"proj_uid": "p0000105", "repository": "USAP-DC", "title": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WISSARD", "south": -84.36, "title": "Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line", "uid": "601122", "west": -165.28}, {"awards": "1043580 Reusch, David", "bounds_geometry": ["POLYGON((-180 -47,-144 -47,-108 -47,-72 -47,-36 -47,0 -47,36 -47,72 -47,108 -47,144 -47,180 -47,180 -51.3,180 -55.6,180 -59.9,180 -64.2,180 -68.5,180 -72.8,180 -77.1,180 -81.4,180 -85.7,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.7,-180 -81.4,-180 -77.1,-180 -72.8,-180 -68.5,-180 -64.2,-180 -59.9,-180 -55.6,-180 -51.3,-180 -47))"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "The presence of ice ponds from surface melting of glacial ice can be a significant threshold in assessing the stability of ice sheets, and their overall response to a warming climate. Snow melt has a much reduced albedo, leading to additional seasonal melting from warming insolation. Water run-off not only contributes to the mass loss of ice sheets directly, but meltwater reaching the glacial ice bed may lubricate faster flow of ice sheets towards the ocean. Surficial meltwater may also reach the grounding lines of glacial ice through the wedging open of existing crevasses. The occurrence and amount of meltwater refreeze has even been suggested as a paleo proxy of near-surface atmospheric temperature regimes.\nUsing contemporary remote sensing (microwave) satellite assessment of surface melt occurrence and extent, the predictive skill of regional meteorological models and reanalyses (e.g. WRF, ERA-Interim) to describe the synoptic conditions favourable to surficial melt is to be investigated. Statistical approaches and pattern recognition techniques are argued to provide a context for projecting future ice sheet change.\nThe previous Intergovernmental Panel on Climate Change (IPCC AR4) commented on our lack of understanding of ice-sheet mass balance processes in polar regions and the potential for sea-level change. The IPPC suggested that the forthcoming AR5 efforts highlight regional cryosphere modeling efforts, such as is proposed here.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Atmosphere; Climate Model; Meteorology; Surface Melt", "locations": "Antarctica", "north": -47.0, "nsf_funding_programs": null, "persons": "Reusch, David", "project_titles": "Collaborative Research: Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "projects": [{"proj_uid": "p0000447", "repository": "USAP-DC", "title": "Collaborative Research: Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "uid": "600166", "west": -180.0}, {"awards": "0839107 Powell, Ross", "bounds_geometry": ["POLYGON((-163.7 -84,-163.68 -84,-163.66 -84,-163.64 -84,-163.62 -84,-163.6 -84,-163.58 -84,-163.56 -84,-163.54 -84,-163.52 -84,-163.5 -84,-163.5 -84.05,-163.5 -84.1,-163.5 -84.15,-163.5 -84.2,-163.5 -84.25,-163.5 -84.3,-163.5 -84.35,-163.5 -84.4,-163.5 -84.45,-163.5 -84.5,-163.52 -84.5,-163.54 -84.5,-163.56 -84.5,-163.58 -84.5,-163.6 -84.5,-163.62 -84.5,-163.64 -84.5,-163.66 -84.5,-163.68 -84.5,-163.7 -84.5,-163.7 -84.45,-163.7 -84.4,-163.7 -84.35,-163.7 -84.3,-163.7 -84.25,-163.7 -84.2,-163.7 -84.15,-163.7 -84.1,-163.7 -84.05,-163.7 -84))"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "The RAGES project (Robotic Access to Grounding zones for Exploration and Science) is one of three research components of the WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) integrative initiative that is being funded by the Antarctic Integrated System Science Program of NSF\u0027s Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The RAGES component of WISSARD concentrates on the stability of ice stream grounding zones (GZ), the area where the ice, ocean waters and glacial and sea floor sediment interact. Based on our present limited data and modeling efforts, GZs can be perturbed by (i) internal ice stream dynamics, (ii) filling/draining cycles of subglacial lakes, (iii) increased melting by warming ocean waters, and/or (iv) rates of subglacial sediment (till) supply to the GZ. GZs are seen as high priority targets to investigate due to their unknown contributions to ice sheet stability under future global warming scenarios. The three main science goals for RAGES are to assess: (a) West Antarctic Ice Sheet (WAIS) stability relative to the magnitudes of the four main variables listed above; (b) the degree to which grounding-zone sedimentary systems house important records of past WAIS dynamics; and (c) the importance of microbial activity and subglacial geochemical weathering in supplying nutrients to the WAIS grounding zone, the Ross Ice Shelf (RIS) cavity, and the highly productive Southern Ocean that may ultimately influence global biogeochemical cycles. The RAGES field sampling plan integrates surface geophysical surveys with borehole and subglacial sampling and measurements. The boreholes provide: (1) samples of subglacial water, sediments, and basal ice for biological, geochemical, glaciological, sedimentological, and micropaleontological analyses; (2) measures of subglacial and sub-ice-shelf cavity physical and chemical conditions and their spatial variability; and (3) data on sediment types, state and change of the subglacial water discharge, oceanography, and basal ice at the grounding line and within the nearby sub-ice-shelf cavity. Unique tools to be deployed include a multisensor Sub-Ice ROVer (Remotely Operated Vehicle) and long-term, sub-ice oceanographic moorings.\nThe latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations.\nSocietal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. The RAGES project represents a significant advance in polar technology by incorporating the use of complex new instrumentation like the Sub-Ice ROVer and subglacial ocean/lake mooring systems. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars.", "east": -163.5, "geometry": ["POINT(-163.6 -84.25)"], "keywords": "Antarctica; Glaciology; Oceans; Southern Ocean; WISSARD", "locations": "Antarctica; Southern Ocean", "north": -84.0, "nsf_funding_programs": null, "persons": "Powell, Ross", "project_titles": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)", "projects": [{"proj_uid": "p0000105", "repository": "USAP-DC", "title": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.5, "title": "Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES)", "uid": "600155", "west": -163.7}, {"awards": "1043485 Curtice, Josh", "bounds_geometry": ["POLYGON((163.4 -77.47989,163.9848 -77.47989,164.5696 -77.47989,165.1544 -77.47989,165.7392 -77.47989,166.324 -77.47989,166.9088 -77.47989,167.4936 -77.47989,168.0784 -77.47989,168.6632 -77.47989,169.248 -77.47989,169.248 -77.565701,169.248 -77.651512,169.248 -77.737323,169.248 -77.823134,169.248 -77.908945,169.248 -77.994756,169.248 -78.080567,169.248 -78.166378,169.248 -78.252189,169.248 -78.338,168.6632 -78.338,168.0784 -78.338,167.4936 -78.338,166.9088 -78.338,166.324 -78.338,165.7392 -78.338,165.1544 -78.338,164.5696 -78.338,163.9848 -78.338,163.4 -78.338,163.4 -78.252189,163.4 -78.166378,163.4 -78.080567,163.4 -77.994756,163.4 -77.908945,163.4 -77.823134,163.4 -77.737323,163.4 -77.651512,163.4 -77.565701,163.4 -77.47989))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "This award supports a project to develop a better understanding of the response of the WAIS to climate change. The timing of the last deglaciation of the western Ross Sea will be improved using in situ terrestrial cosmogenic nuclides (3He, 10Be, 14C, 26Al, 36Cl) to date glacial erratics at key areas and elevations along the western Ross Sea coast. A state-of-the art ice sheet-shelf model will be used to identify mechanisms of deglaciation of the Ross Sea sector of WAIS. The model results and forcing will be compared with observations including the new cosmogenic data proposed here, with the aim of better determining and understanding the history and causes of WAIS deglaciation in the Ross Sea. There is considerable uncertainty, however, in the history of grounding line retreat from its last glacial maximum position, and virtually nothing is known about the timing of ice- surface lowering prior to ~10,000 years ago. Given these uncertainties, we are currently unable to assess one of the most important questions regarding the last deglaciation of the global ice sheets, namely as to whether the Ross Sea sector of WAIS contributed significantly to meltwater pulse 1A (MWP-1A), an extraordinarily rapid (~500-year duration) episode of ~20 m sea-level rise that occurred ~14,500 years ago. The intellectual merit of this project is that recent observations of startling changes at the margins of the Greenland and Antarctic ice sheets indicate that dynamic responses to warming may play a much greater role in the future mass balance of ice sheets than considered in current numerical projections of sea level rise. The broader impacts of this work are that it has direct societal relevance to developing an improved understanding of the response of the West Antarctic ice sheet to current and possible future environmental changes including the sea-level response to glacier and ice sheet melting due to global warming. The PI will communicate results from this project to a variety of audiences through the publication of peer-reviewed papers and by giving talks to public audiences. Finally the project will support a graduate student and undergraduate students in all phases of field-work, laboratory work and data interpretation.\n", "east": 169.248, "geometry": ["POINT(166.324 -77.908945)"], "keywords": "Antarctica; Cosmogenic Dating; Ross Sea; Sample/collection Description; Sample/Collection Description; Southern Ocean; WAIS", "locations": "WAIS; Ross Sea; Southern Ocean; Antarctica", "north": -77.47989, "nsf_funding_programs": null, "persons": "Kurz, Mark D.; Curtice, Josh", "project_titles": "Collaborative Research: A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea", "projects": [{"proj_uid": "p0000194", "repository": "USAP-DC", "title": "Collaborative Research: A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.338, "title": "A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea", "uid": "600123", "west": 163.4}, {"awards": "0440670 Hulbe, Christina; 0125754 Hulbe, Christina", "bounds_geometry": ["POLYGON((-86.557 -74.355,-80.5124 -74.355,-74.4678 -74.355,-68.4232 -74.355,-62.3786 -74.355,-56.334 -74.355,-50.2894 -74.355,-44.2448 -74.355,-38.2002 -74.355,-32.1556 -74.355,-26.111 -74.355,-26.111 -75.3874,-26.111 -76.4198,-26.111 -77.4522,-26.111 -78.4846,-26.111 -79.517,-26.111 -80.5494,-26.111 -81.5818,-26.111 -82.6142,-26.111 -83.6466,-26.111 -84.679,-32.1556 -84.679,-38.2002 -84.679,-44.2448 -84.679,-50.2894 -84.679,-56.334 -84.679,-62.3786 -84.679,-68.4232 -84.679,-74.4678 -84.679,-80.5124 -84.679,-86.557 -84.679,-86.557 -83.6466,-86.557 -82.6142,-86.557 -81.5818,-86.557 -80.5494,-86.557 -79.517,-86.557 -78.4846,-86.557 -77.4522,-86.557 -76.4198,-86.557 -75.3874,-86.557 -74.355))"], "date_created": "Fri, 15 Jul 2011 00:00:00 GMT", "description": "This data set provides a structural feature map of the Ronne Ice Shelf in Antarctica (also known as the Filchner-Ronne Ice Shelf). The map was developed as part of a project to study fracture propagation in the Ronne Ice Shelf, with special focus on the Evans Ice Stream. Features were digitized from the MODIS Mosaic of Antartica (MOA), a composite of individual Moderate Resolution Imaging Spectradiometer (MODIS) images taken between 20 November 2003 and 29 February 2004, with an effective resolution of 125 m. The data set includes estimates of the shelf boundary, including ice stream grounding zones, outlets of glaciers feeding the shelf, extents of islands and ice rises, and the location of the shelf front, and features observed within the shelf, including suture zones between ice streams, streaklines, fractures (crevasses and rifts), and fold-like features. Individual features can be extracted as a group of points and grouping is used to facilitate identification and plotting. \n\nData files are available via FTP in ASCII text (.txt) format. One image file, in Portable Document Format (.pdf), shows the data included in the dataset, plotted using MATLAB. The data set also provides a MATLAB script which can be used to plot the data.", "east": -26.111, "geometry": ["POINT(-56.334 -79.517)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MOA; MODIS; Ronne Ice Shelf", "locations": "Antarctica; Ronne Ice Shelf", "north": -74.355, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hulbe, Christina; Ledoux, Christine", "project_titles": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "projects": [{"proj_uid": "p0000096", "repository": "USAP-DC", "title": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.679, "title": "MOA-derived Structural Feature Map of the Ronne Ice Shelf", "uid": "609497", "west": -86.557}, {"awards": "0538015 Hulbe, Christina", "bounds_geometry": ["POLYGON((154.71 -82.78,154.79 -82.78,154.87 -82.78,154.95 -82.78,155.03 -82.78,155.11 -82.78,155.19 -82.78,155.27 -82.78,155.35 -82.78,155.43 -82.78,155.51 -82.78,155.51 -82.788,155.51 -82.796,155.51 -82.804,155.51 -82.812,155.51 -82.82,155.51 -82.828,155.51 -82.836,155.51 -82.844,155.51 -82.852,155.51 -82.86,155.43 -82.86,155.35 -82.86,155.27 -82.86,155.19 -82.86,155.11 -82.86,155.03 -82.86,154.95 -82.86,154.87 -82.86,154.79 -82.86,154.71 -82.86,154.71 -82.852,154.71 -82.844,154.71 -82.836,154.71 -82.828,154.71 -82.82,154.71 -82.812,154.71 -82.804,154.71 -82.796,154.71 -82.788,154.71 -82.78))"], "date_created": "Fri, 01 Jul 2011 00:00:00 GMT", "description": "This data set provides the results from a strain grid survey deployed across the Kamb Ice Stream grounding line on the West Antarctic Ice Sheet. The grid was deployed in 2006 and resurveyed in 2007 using a Global Positioning System (GPS). Parameters measured include latitude, longitude, and height of each survey mark in the strain grid, as well as northing, easting, elevations, and displacement of each point during the year between surveys.\n\nData are available via FTP in Microsoft Excel (.xls) format.", "east": 155.51, "geometry": ["POINT(155.11 -82.82)"], "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Grounding Line; Kamb Ice Stream; Strain", "locations": "Antarctica; Kamb Ice Stream", "north": -82.78, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hulbe, Christina", "project_titles": "Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region", "projects": [{"proj_uid": "p0000019", "repository": "USAP-DC", "title": "Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -82.86, "title": "Grounding Line Strain Grid Surveys, Kamb Ice Stream, Antarctica", "uid": "609494", "west": 154.71}, {"awards": "XXXXXXX Palais, Julie", "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 -62,180 -64,180 -66,180 -68,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,144 -80,108 -80,72 -80,36 -80,0 -80,-36 -80,-72 -80,-108 -80,-144 -80,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70,-180 -68,-180 -66,-180 -64,-180 -62,-180 -60))"], "date_created": "Sun, 20 Feb 2011 00:00:00 GMT", "description": "This data set provides grounding line and hydrostatic line locations for the Antarctic coastline and islands around Antarctica. The data are derived using customized software to combine data from Landsat-7 imagery and Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry, which were primarily collected between 1999 to 2003. The data set also includes elevations along each line, selected from six candidate digital elevation models. The data were developed as part of the Antarctic Surface Accumulation and Ice Discharge (ASAID) project. \r\n\r\nFunding trough NASA grant 509496.02.08.01.81\r\nData are provided in both ASCII text (.txt) and shapefile (.shp, .dbf, .shx) formats.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; ASAID; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Grounding Line Hydrostatic Line; Oceans", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Bindschadler, Robert; Choi, Hyeungu", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -80.0, "title": "High-resolution Image-derived Grounding and Hydrostatic Lines for the Antarctic Ice Sheet", "uid": "609489", "west": -180.0}, {"awards": "0538120 Catania, Ginny", "bounds_geometry": ["POLYGON((-160 -81,-158.5 -81,-157 -81,-155.5 -81,-154 -81,-152.5 -81,-151 -81,-149.5 -81,-148 -81,-146.5 -81,-145 -81,-145 -81.2,-145 -81.4,-145 -81.6,-145 -81.8,-145 -82,-145 -82.2,-145 -82.4,-145 -82.6,-145 -82.8,-145 -83,-146.5 -83,-148 -83,-149.5 -83,-151 -83,-152.5 -83,-154 -83,-155.5 -83,-157 -83,-158.5 -83,-160 -83,-160 -82.8,-160 -82.6,-160 -82.4,-160 -82.2,-160 -82,-160 -81.8,-160 -81.6,-160 -81.4,-160 -81.2,-160 -81))"], "date_created": "Fri, 01 Jan 2010 00:00:00 GMT", "description": "These data consist of ice-penetrating radar data collected on the ground across the grounding line near Siple Dome during the 2006 and 2007 Antarctic summer field seasons. Primarily, the data consist of low-frequency radar data (2 MHz, approximately 50 meter resolution) in order to observe deep internal layers and the ice-bed interface. The data set also contains one file with high-frequency (100 MHz, approximately 1 meter resolution) radar data, for a sub-region of one of the low-frequency radar profiles. Coincident kinematic GPS data were also collected to correct the radar data for topography along each profile. Radar profiles are typically approximately 20 km in length with the grounding line crossed centrally where possible. \n\nData are available via FTP in Matlab (.mat) format.", "east": -145.0, "geometry": ["POINT(-152.5 -82)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; GPR; Grounding Line; Radar; Siple Coast", "locations": "Siple Coast; Antarctica", "north": -81.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hulbe, Christina; Catania, Ginny", "project_titles": "Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region", "projects": [{"proj_uid": "p0000019", "repository": "USAP-DC", "title": "Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -83.0, "title": "Ice-Penetrating Radar Data Across Siple Coast Grounding Lines", "uid": "609474", "west": -160.0}, {"awards": "0440636 Fahnestock, Mark", "bounds_geometry": null, "date_created": "Thu, 25 Sep 2008 00:00:00 GMT", "description": null, "east": null, "geometry": null, "keywords": null, "locations": null, "north": null, "nsf_funding_programs": null, "persons": "Fahnestock, Mark", "project_titles": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "projects": [{"proj_uid": "p0000096", "repository": "USAP-DC", "title": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "uid": "600024", "west": null}, {"awards": "XXXXXXX Palais, Julie", "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": "Wed, 02 Nov 2005 00:00:00 GMT", "description": "The MODIS Mosaic of Antarctica 2003-2004 (MOA2004) Image Map consists of two cloud-free digital image maps that show mean surface morphology and a quantitative measure of optical snow grain size on the Antarctic continent and surrounding islands. The 260 orbit swaths used to create the 2003/2004 MOA Surface Morphology Image Map and the 2003/2004 MOA Grain Size Image Map were acquired 20 November 2003 through 29 February 2004 by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on board the NASA EOS Aqua and Terra satellites. The 122 orbit swaths used to create the 2003 MOA Grain Size Image Map were acquired 1 November 2003 through 17 December 2003. Vector data sets with the corresponding coastlines, ice sheet grounding lines, and islands are also provided.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MODIS; Sample/collection Description; Sample/Collection Description; Solid Earth", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Haran, Terry; Bohlander, Jennifer; Scambos, Ted; Painter, Thomas; Fahnestock, Mark", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "MODIS Mosaic of Antarctica 2003-2004 (MOA2004) Image Map", "uid": "609280", "west": -180.0}]
X
X
Help on the Results MapX
This window can be dragged by its header, and can be resized from the bottom right corner.
Clicking the Layers button - the blue square in the top left of the Results Map - will display a list of map layers you can add or remove
from the currently displayed map view.
The Results Map and the Results Table
- The Results Map displays the centroids of the geographic bounds of all the results returned by the search.
- Results that are displayed in the current map view will be highlighted in blue and brought to the top of the Results Table.
- As the map is panned or zoomed, the highlighted rows in the table will update.
- If you click on a centroid on the map, it will turn yellow and display a popup with details for that project/dataset - including a link to the landing page. The bounds for the project(s)/dataset(s) selected will be displayed in red. The selected result(s) will be highlighted in red and brought to the top of the table.
- The default table sorting order is: Selected, Visible, Date (descending), but this can be changed by clicking on column headers in the table.
- Selecting Show on Map for an individual row will both display the geographic bounds for that result on a mini map, and also display the bounds and highlight the centroid on the Results Map.
- Clicking the 'Show boundaries' checkbox at the top of the Results Map will display all the bounds for the filtered results.
Defining a search area on the Results Map
- If you click on the Rectangle or Polygon icons in the top right of the Results Map, you can define a search area which will be added to any other search criteria already selected.
- After you have drawn a polygon, you can edit it using the Edit Geometry dropdown in the search form at the top.
- Clicking Clear in the map will clear any drawn polygon.
- Clicking Search in the map, or Search on the form will have the same effect.
- The returned results will be any projects/datasets with bounds that intersect the polygon.
- Use the Exclude project/datasets checkbox to exclude any projects/datasets that cover the whole Antarctic region.
Viewing map layers on the Results Map
To sort the table of search results, click the header of the column you wish to search by. To sort by multiple columns, hold down the shift key whilst selecting the sort columns in order.
Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
Yearly velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2013-2022
|
1929991 |
2025-02-21 | Banerjee, Debangshu; Lilien, David; Truffer, Martin; Luckman, Adrian; Wild, Christian; Pettit, Erin; Scambos, Ted; Muto, Atsuhiro; Alley, Karen |
NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment |
This dataset comprises GeoTiff files that capture the yearly averages of ice-flow velocity (including x- and y-components, and flow speed) and strain rates (longitudinal, transverse, and shear) for the Thwaites Eastern Ice Shelf (TEIS) from 2013 to 2022. The velocity grids were generated using ITS_LIVE image-pair velocities available throughout the year, ensuring a consistent extent and spatial resolution for each annual composite. These composites were created by stacking all available image pairs and taking the median value for each grid cell. Small data gaps near the grounding line were filled using bilinear interpolation. Each pixel in the grid represents the median value of all available pixels during the specified period. The data are gridded at a spatial resolution of 120m in a polar stereographic projection (EPSG:3031). Speed is given in metres per day (m/yr), and strain rates are given in units/day. Additional funding was received from NE/S006419/1. | ["POLYGON((-106.5 -74.5,-106.3 -74.5,-106.1 -74.5,-105.9 -74.5,-105.7 -74.5,-105.5 -74.5,-105.3 -74.5,-105.1 -74.5,-104.9 -74.5,-104.7 -74.5,-104.5 -74.5,-104.5 -74.6,-104.5 -74.7,-104.5 -74.8,-104.5 -74.9,-104.5 -75,-104.5 -75.1,-104.5 -75.2,-104.5 -75.3,-104.5 -75.4,-104.5 -75.5,-104.7 -75.5,-104.9 -75.5,-105.1 -75.5,-105.3 -75.5,-105.5 -75.5,-105.7 -75.5,-105.9 -75.5,-106.1 -75.5,-106.3 -75.5,-106.5 -75.5,-106.5 -75.4,-106.5 -75.3,-106.5 -75.2,-106.5 -75.1,-106.5 -75,-106.5 -74.9,-106.5 -74.8,-106.5 -74.7,-106.5 -74.6,-106.5 -74.5))"] | ["POINT(-105.5 -75)"] | false | false |
Ice-penetrating radar data from the Thwaites Glacier grounding zone
|
1738989 |
2024-11-25 | Balco, Greg; Campbell, Seth; Goehring, Brent |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
Contains ice-penetrating radar data (10 and 400 MHz) from the Thwaites Glacier grounding zone. The main purpose of collecting these data was for safety assessment at a camp put-in; deep (10 MHz) radar data were also collected opportunistically. | ["POLYGON((-104.9429 -75.1543,-104.92228999999999 -75.1543,-104.90168 -75.1543,-104.88107 -75.1543,-104.86046 -75.1543,-104.83985 -75.1543,-104.81924 -75.1543,-104.79863 -75.1543,-104.77802 -75.1543,-104.75741000000001 -75.1543,-104.7368 -75.1543,-104.7368 -75.16263000000001,-104.7368 -75.17096000000001,-104.7368 -75.17929000000001,-104.7368 -75.18762000000001,-104.7368 -75.19595000000001,-104.7368 -75.20428,-104.7368 -75.21261,-104.7368 -75.22094,-104.7368 -75.22927,-104.7368 -75.2376,-104.75741000000001 -75.2376,-104.77802 -75.2376,-104.79863 -75.2376,-104.81924 -75.2376,-104.83985 -75.2376,-104.86046 -75.2376,-104.88107 -75.2376,-104.90168 -75.2376,-104.92228999999999 -75.2376,-104.9429 -75.2376,-104.9429 -75.22927,-104.9429 -75.22094,-104.9429 -75.21261,-104.9429 -75.20428,-104.9429 -75.19595000000001,-104.9429 -75.18762000000001,-104.9429 -75.17929000000001,-104.9429 -75.17096000000001,-104.9429 -75.16263000000001,-104.9429 -75.1543))"] | ["POINT(-104.83985 -75.19595000000001)"] | false | false |
Ice-penetrating radar data from the northern embayment of the Mt. Murphy massif
|
1738989 |
2024-11-13 | Balco, Greg; Campbell, Seth; Goehring, Brent |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
Contains ice-penetrating radar data (10, 100, and 400 MHz) from the north side of the Mt. Murphy massif. Most of these data are closely spaced lines used for reconnaissance and site selection for a subglacial bedrock recovery drilling project very close to the ice margin at the north ridge of Kay Peak, a sub-peak of the massif. In addition, there are several longer exploratory lines that cross the embayment between the massif and the Crosson Ice Shelf, some of which may cross grounding lines. | ["POLYGON((-110.9665 -75.1967,-110.92041 -75.1967,-110.87432 -75.1967,-110.82822999999999 -75.1967,-110.78214 -75.1967,-110.73605 -75.1967,-110.68996 -75.1967,-110.64386999999999 -75.1967,-110.59778 -75.1967,-110.55169000000001 -75.1967,-110.5056 -75.1967,-110.5056 -75.20331,-110.5056 -75.20992000000001,-110.5056 -75.21653,-110.5056 -75.22314,-110.5056 -75.22975,-110.5056 -75.23636,-110.5056 -75.24297,-110.5056 -75.24958,-110.5056 -75.25619,-110.5056 -75.2628,-110.55169000000001 -75.2628,-110.59778 -75.2628,-110.64386999999999 -75.2628,-110.68996 -75.2628,-110.73605 -75.2628,-110.78214 -75.2628,-110.82822999999999 -75.2628,-110.87432 -75.2628,-110.92041 -75.2628,-110.9665 -75.2628,-110.9665 -75.25619,-110.9665 -75.24958,-110.9665 -75.24297,-110.9665 -75.23636,-110.9665 -75.22975,-110.9665 -75.22314,-110.9665 -75.21653,-110.9665 -75.20992000000001,-110.9665 -75.20331,-110.9665 -75.1967))"] | ["POINT(-110.73605 -75.22975)"] | false | false |
Firn and Ice Density at Winkie Nunatak
|
2317097 |
2024-10-02 | Venturelli, Ryan |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
This data set contains an ice and firn density profile from Winkie Nunatak, West Antarctica. These data were collected when drilling a sub-ice access hole with an Eclipse drill in preparation for Winkie drill collection of subglacial bedrock. | ["POLYGON((-99.793 -74.857,-99.7882 -74.857,-99.7834 -74.857,-99.77860000000001 -74.857,-99.77380000000001 -74.857,-99.769 -74.857,-99.7642 -74.857,-99.7594 -74.857,-99.75460000000001 -74.857,-99.74980000000001 -74.857,-99.745 -74.857,-99.745 -74.8583,-99.745 -74.8596,-99.745 -74.8609,-99.745 -74.8622,-99.745 -74.8635,-99.745 -74.8648,-99.745 -74.8661,-99.745 -74.8674,-99.745 -74.8687,-99.745 -74.87,-99.74980000000001 -74.87,-99.75460000000001 -74.87,-99.7594 -74.87,-99.7642 -74.87,-99.769 -74.87,-99.77380000000001 -74.87,-99.77860000000001 -74.87,-99.7834 -74.87,-99.7882 -74.87,-99.793 -74.87,-99.793 -74.8687,-99.793 -74.8674,-99.793 -74.8661,-99.793 -74.8648,-99.793 -74.8635,-99.793 -74.8622,-99.793 -74.8609,-99.793 -74.8596,-99.793 -74.8583,-99.793 -74.857))"] | ["POINT(-99.769 -74.8635)"] | false | false |
Elevation transects from Pine Island Bay
|
1745043 |
2024-04-11 | Munevar Garcia, Santiago |
Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations |
This dataset contains the elevation raster for Pine Island Bay and the raw elevation profiles used for each site. The transects are organized based on their orientation in relation to paleo-ice flow. They are spaced 500 meters apart, with elevation measurements extracted every 50 meters along each transect. | ["POINT(-100 -75)"] | ["POINT(-100 -75)"] | false | false |
CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023
|
1443677 9896041 |
2024-03-27 | Howard, Susan L.; Greene, Chad A.; Padman, Laurence; Erofeeva, Svetlana; Sutterley, Tyler |
Ocean Tides around Antarctica and in the Southern Ocean Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE) |
CATS2008_v2023 is an update of the original CATS2008 tide model (Howard et al., 2019 [https://doi.org/10.15784/601235]; Padman et al., 2002 [https://doi.org/10.3189/172756402781817752]). It introduces a new model file format, increased resolution, more accurate coastlines, and a simple scaling for ice shelf flexure near grounding lines. The changes included in the new CATS2008_v2023 model are: (1) The CATS2008 model has been interpolated to a finer grid (2 km for CATS2008_v2023 vs 4 km for CATS2008) to provide a better representation of coastlines and ice shelf grounding lines. (2) Coastlines have been adjusted to match BedMachine Antarctica v3 (Morlighem et al., 2020 [https://doi.org/10.1038/s41561-019-0510-8]; Morlighem, 2022 [https://doi.org/10.5067/FPSU0V1MWUB6]). Areas that were previously grounded and had no tidal constituent data in CATS2008 have been filled using MATLAB's ‘regionfill’ function, applied to the real and imaginary components of tidal constituents individually. An ocean mask matching BedMachine Antarctica v3 is provided in the model file to mask out grounded areas. (3) Water depth (water column thickness under ice shelves) has been adjusted to match BedMachine Antarctica v3. (4) An ice shelf flexure model has been included for estimating tidal deflections in grounding zones. Flexure is approximated by a forward 1D linear elastic model applied to BedMachine Antarctica v3 ice geometry, with elastic modulus E=4.8 GPa and Poisson's ratio nu=0.4. The ice flexure can be included as an option when using TMD3.0 (Greene et al., 2024 [https://doi.org/10.21105/joss.06018]) and pyTMD (Sutterley, 2024 [https://doi.org/10.5281/zenodo.10501349]) software packages. (5) The model is provided as a consolidated NetCDF file that can be used with TMD3.0 and pyTMD, but not with earlier TMD versions. | ["POLYGON((-180 -40.231,-144 -40.231,-108 -40.231,-72 -40.231,-36 -40.231,0 -40.231,36 -40.231,72 -40.231,108 -40.231,144 -40.231,180 -40.231,180 -45.2079,180 -50.1848,180 -55.161699999999996,180 -60.1386,180 -65.1155,180 -70.0924,180 -75.0693,180 -80.0462,180 -85.0231,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.0231,-180 -80.0462,-180 -75.0693,-180 -70.0924,-180 -65.1155,-180 -60.138600000000004,-180 -55.1617,-180 -50.1848,-180 -45.2079,-180 -40.231))"] | ["POINT(0 -89.999)"] | false | false |
Direct observations of melting, freezing, and ocean circulation in an ice shelf basal crevasse
|
None | 2023-09-12 | Washam, Peter | No project link provided | Contained in this folder are the raw and processed data files for data collected with the underwater robot Icefin in the ocean cavity beneath Ross Ice Shelf, near the grounding line of Kamb Ice Stream. Most of these data are located within a basal crevasse. They were collected in December 2019 as part of the Aotearoa New Zealand Antarctic Science Platform and Victoria University of Wellington Hot Water Drilling initiative, and the NASA RISEUP grant (NNX16AL07G, PI B. E. Schmidt). The code that converted raw data files to processed can be found at https://zenodo.org/record/8338529. Direct questions to Peter Washam at pwasham@cornell.edu. | ["POLYGON((-156 -82.5,-155.9 -82.5,-155.8 -82.5,-155.7 -82.5,-155.6 -82.5,-155.5 -82.5,-155.4 -82.5,-155.3 -82.5,-155.2 -82.5,-155.1 -82.5,-155 -82.5,-155 -82.53,-155 -82.56,-155 -82.59,-155 -82.62,-155 -82.65,-155 -82.67999999999999,-155 -82.71,-155 -82.74,-155 -82.77,-155 -82.8,-155.1 -82.8,-155.2 -82.8,-155.3 -82.8,-155.4 -82.8,-155.5 -82.8,-155.6 -82.8,-155.7 -82.8,-155.8 -82.8,-155.9 -82.8,-156 -82.8,-156 -82.77,-156 -82.74,-156 -82.71,-156 -82.67999999999999,-156 -82.65,-156 -82.62,-156 -82.59,-156 -82.56,-156 -82.53,-156 -82.5))"] | ["POINT(-155.5 -82.65)"] | false | false |
In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers
|
1738989 |
2023-07-10 | Venturelli, Ryan; Goehring, Brent; Balco, Gregory |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
Included in this dataset are in situ carbon-14 concentrations for a series of bedrock cores recovered from the subglacial extension of Kay Peak, a grounding-line-proximal ridge of the volcanic edifice Mount Murphy (near Thwaites and Pope glaciers). Concentrations measured in these bedrock samples have been used in the associated publication to demonstrate that the Thwaites-Pope glacier system was thinner in the Holocene than it is today. | ["POINT(-110.96038 -75.21526)"] | ["POINT(-110.96038 -75.21526)"] | false | false |
200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica
|
2317097 |
2023-03-24 | Braddock, Scott |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
This data set contains unprocessed radar profiles collected with a GSSI 200 MHz Hyperstacking antenna near Winkie Nunatak, West Antarctica. This data was collected to estimate depth-to-bedrock along a subglacial ridge line at depths between 20 - 120 meters. | ["POLYGON((-99.793 -74.857,-99.7882 -74.857,-99.7834 -74.857,-99.77860000000001 -74.857,-99.77380000000001 -74.857,-99.769 -74.857,-99.7642 -74.857,-99.7594 -74.857,-99.75460000000001 -74.857,-99.74980000000001 -74.857,-99.745 -74.857,-99.745 -74.8583,-99.745 -74.8596,-99.745 -74.8609,-99.745 -74.8622,-99.745 -74.8635,-99.745 -74.8648,-99.745 -74.8661,-99.745 -74.8674,-99.745 -74.8687,-99.745 -74.87,-99.74980000000001 -74.87,-99.75460000000001 -74.87,-99.7594 -74.87,-99.7642 -74.87,-99.769 -74.87,-99.77380000000001 -74.87,-99.77860000000001 -74.87,-99.7834 -74.87,-99.7882 -74.87,-99.793 -74.87,-99.793 -74.8687,-99.793 -74.8674,-99.793 -74.8661,-99.793 -74.8648,-99.793 -74.8635,-99.793 -74.8622,-99.793 -74.8609,-99.793 -74.8596,-99.793 -74.8583,-99.793 -74.857))"] | ["POINT(-99.769 -74.8635)"] | false | false |
KIS-1 ROV Icefin Missions
|
NNX16AL07G |
2022-12-14 | Lawrence, Justin; Schmidt, Britney | No project link provided | This work was primarily funded by the NASA-funded RISE-UP: Ross Ice Shelf & Europa Underwater Probe (PI Britney E. Schmidt) project. Field work at the KIS-1 site during the 2019-2020 season was completed through international collaboration between NASA, NSF/USAP, and Antarctica New Zealand, funded by the Aotearoa New Zealand Antarctic Science Platform (ANTA1801) Antarctic Ice Dynamics Project (ASP02101), and the NZARI-funded Aotearoa New Zealand Ross Ice Shelf Programme, “Vulnerability of the Ross Ice Shelf in a Warming World” (grant no. 2014-11). The data contained in this directory are merged and calibrated data files from three missions conducted with ROV Icefin through a borehole drilled through Ross Ice Shelf at KIS1 (-82.78410, -155.26267), near the Kamb Ice Stream grounding zone. Missions were conducted in 2019 on December 16th, 18th, and 21st (UTC). For questions or assistance working with the data please contact Britney Schmidt (britneys@cornell.edu) and Justin Lawrence (jdl287@cornell.edu). | ["POLYGON((-155.3 -82.75,-155.27 -82.75,-155.24 -82.75,-155.21 -82.75,-155.18 -82.75,-155.15 -82.75,-155.12 -82.75,-155.09 -82.75,-155.06 -82.75,-155.03 -82.75,-155 -82.75,-155 -82.76,-155 -82.77,-155 -82.78,-155 -82.78999999999999,-155 -82.8,-155 -82.81,-155 -82.82,-155 -82.83,-155 -82.83999999999999,-155 -82.85,-155.03 -82.85,-155.06 -82.85,-155.09 -82.85,-155.12 -82.85,-155.15 -82.85,-155.18 -82.85,-155.21 -82.85,-155.24 -82.85,-155.27 -82.85,-155.3 -82.85,-155.3 -82.83999999999999,-155.3 -82.83,-155.3 -82.82,-155.3 -82.81,-155.3 -82.8,-155.3 -82.78999999999999,-155.3 -82.78,-155.3 -82.77,-155.3 -82.76,-155.3 -82.75))"] | ["POINT(-155.15 -82.8)"] | false | false |
Crane Glacier centerline observations and modeling results
|
1933764 |
2022-10-24 | Aberle, Rainey; Enderlin, Ellyn; Marshall, Hans-Peter; Kopera, Michal; Meehan, Tate |
Antarctic Submarine Melt Variability from Remote Sensing of Icebergs |
This dataset contains observed and modeled conditions along the Crane Glacier centerline for ~1994—2100. Observations include centerline (cl) coordinates, downscaled RACMO climate variables (runoff, snowfall, snowmelt, and surface mass balance), bed elevations (b), surface elevations (h), glacier width (W), calving front positions (xcf), and surface speeds (U) when available for the 1994—2019 period. Modeling results include glacier centerline geometry, speed, glacier mass discharge (Q_gl), and calving front and grounding line positions (x_cf and x_gl) under different future climate scenarios with varying surface mass balance (SMB), ocean thermal forcing (FT), SMB with potential feedbacks associated with enhanced surface melt water discharge and plume strengthening (SMB_enh), and concurrent SMB_enh and FT perturbations (SMB_enh_FT). Data are in “.mat” format, which can be read using MATLAB’s “load” function or using Python with the Scipy “scipy.io.loadmat” function. | ["POLYGON((-63.1 -65.2,-62.99 -65.2,-62.88 -65.2,-62.77 -65.2,-62.660000000000004 -65.2,-62.55 -65.2,-62.44 -65.2,-62.33 -65.2,-62.22 -65.2,-62.11 -65.2,-62 -65.2,-62 -65.24000000000001,-62 -65.28,-62 -65.32,-62 -65.36,-62 -65.4,-62 -65.44,-62 -65.47999999999999,-62 -65.52,-62 -65.56,-62 -65.6,-62.11 -65.6,-62.22 -65.6,-62.33 -65.6,-62.44 -65.6,-62.55 -65.6,-62.660000000000004 -65.6,-62.77 -65.6,-62.88 -65.6,-62.99 -65.6,-63.1 -65.6,-63.1 -65.56,-63.1 -65.52,-63.1 -65.47999999999999,-63.1 -65.44,-63.1 -65.4,-63.1 -65.36,-63.1 -65.32,-63.1 -65.28,-63.1 -65.24000000000001,-63.1 -65.2))"] | ["POINT(-62.55 -65.4)"] | false | false |
Pine Island Bay Relative Sea-Level Data
|
1738989 |
2022-04-11 | Braddock, Scott; Hall, Brenda |
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System |
This dataset includes radiocarbon dates and elevations of organic samples in raised beaches in the Edwards, Lindsey, and Schaefer Islands. It also includes a limited number of cosmogenic exposure-age data of bedrock from these islands. | ["POLYGON((-105 -73,-104.5 -73,-104 -73,-103.5 -73,-103 -73,-102.5 -73,-102 -73,-101.5 -73,-101 -73,-100.5 -73,-100 -73,-100 -73.1,-100 -73.2,-100 -73.3,-100 -73.4,-100 -73.5,-100 -73.6,-100 -73.7,-100 -73.8,-100 -73.9,-100 -74,-100.5 -74,-101 -74,-101.5 -74,-102 -74,-102.5 -74,-103 -74,-103.5 -74,-104 -74,-104.5 -74,-105 -74,-105 -73.9,-105 -73.8,-105 -73.7,-105 -73.6,-105 -73.5,-105 -73.4,-105 -73.3,-105 -73.2,-105 -73.1,-105 -73))"] | ["POINT(-102.5 -73.5)"] | false | false |
Thwaites Glacier grounding lines for 2014 and 2019/20 from height above flotation
|
1929991 |
2021-12-23 | Wild, Christian; Alley, Karen; Muto, Atsu; Truffer, Martin; Scambos, Ted; Pettit, Erin |
NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment |
This data set includes two grounding-line products of Thwaites Glacier and a series of offshore pinning points for 2014 and 2019/20. The grounding lines where delineated manually from height above flotation calculations using the bathymetry model from Jordan et al. (2020), the REMA digital surface elevation model (Howat et al., 2019) for the 2014 product and ICESat-2 surface altimetry data (Smith et al., 2019) for the 2019/20 product. More details about the processing, corrections and uncertainties can be found in our publication. We would appreciate if users who think the grounding-line products are useful for your own research would cite our manuscript. | ["POLYGON((-108 -74.5,-107.6 -74.5,-107.2 -74.5,-106.8 -74.5,-106.4 -74.5,-106 -74.5,-105.6 -74.5,-105.2 -74.5,-104.8 -74.5,-104.4 -74.5,-104 -74.5,-104 -74.6,-104 -74.7,-104 -74.8,-104 -74.9,-104 -75,-104 -75.1,-104 -75.2,-104 -75.3,-104 -75.4,-104 -75.5,-104.4 -75.5,-104.8 -75.5,-105.2 -75.5,-105.6 -75.5,-106 -75.5,-106.4 -75.5,-106.8 -75.5,-107.2 -75.5,-107.6 -75.5,-108 -75.5,-108 -75.4,-108 -75.3,-108 -75.2,-108 -75.1,-108 -75,-108 -74.9,-108 -74.8,-108 -74.7,-108 -74.6,-108 -74.5))"] | ["POINT(-106 -75)"] | false | false |
Circum-Antarctic grounding-line sinuosity
|
1246353 1745055 1745043 |
2021-11-10 | Simkins, Lauren; Stearns, Leigh; Riverman, Kiya |
Evidence for Paleo Ice Stream Collapse in the Western Ross Sea since the Last Glacial Maximum. Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations |
The dataset here allows exploration of the causes and significance of Antarctic grounding-line sinuosity by coupling observations of contemporary Antarctic grounding lines and paleo-grounding lines expressed as ice-marginal landforms on the Ross Sea continental shelf. Modern grounding lines are derived from the MEaSUREs Version 2 Differential Satellite Radar Interferometry dataset with spatial resolutions of 25-120 m spanning February 1992 to December 2014 (Rignot et al., 2016; Mouginot et al., 2017). The boundaries of individual grounding lines representative of individual glacial catchments (n=664) were delineated by the inflection points of the shear strain rate, εxy (c.f Van der Veen et al., 2011). Sinuosity was calculated as the ratio of the true length, orthogonal to ice-flow direction, of the grounding lines and the straight line length between end-points and in units of km/km. Raster data were extracted at 1-km points along each grounding line; the mean was calculated for each grounding line and merged in a table with sinuosity data. A dataset of 6,275 paleo-grounding lines expressed as ice-marginal landforms on the deglaciated western Ross Sea continental shelf are used in this study, originally published by Simkins et al., 2018. The ice-marginal landforms were mapped from multibeam echo sounder data that 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 30-60% swath overlap (Cruise DOI: 10.7284/901477). The resulting bathymetry data was gridded at 20-40 m with decimeter vertical elevation resolution depending on water depth and sea-state. Sinuosity is calculated as a ratio of true (mapped) landform length, measured in the across paleo-ice flow direction at the crest of the landform, to the straight line distance between the mapped landform endpoints and in units of km/km. To compare modern and paleo-grounding lines, we use a consistent length scale by segmenting the grounding lines into 2-km sections for the two datasets (modern, n=12,966; paleo, n=5,832), even though this eliminates grounding lines that are less than 2-km long and thus results in 1 modern and 3,873 paleo-grounding lines removed. The full-length and 2-km segmented groundings lines are provided as shapefiles "InSAR_groundinglines_full" and "InSAR_groundinglines_2km", the paleo-grounding lines are provided as shapefiles "RossSea_icemarginal_full" and "RossSea_icemarginal_2km", and points marking modern grounding lines retreat from repeat InSAR surveys are provided as shapefile "InSAR_retreat_points", all stored together in a geodatabase named "Antarctic_groundinglines.gbd". Additional grounding line metrics, including length, sinuosity, bed roughness, and bed slope for modern and paleo-grounding lines, and height-above-buoyancy gradient, ice-flow velocity, presence of pinning points and ice shelves are provided for modern grounding lines. The published dataset was compiled and analyzed in the article "Controls on circum-Antarctic grounding-line sinuosity " by Simkins, L.M., Stearns, L.A., and Riverman, K.L, which will be submitted to a peer-review journal in November 2021. References Mouginot, J., B. Scheuchl, and E. Rignot. 2017. MEaSUREs Antarctic Boundaries for IPY 2007-2009 from Satellite Radar, Version 2. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. Rignot, E., J. Mouginot, and B. Scheuchl. 2016. MEaSUREs Antarctic Grounding Line from Differential Satellite Radar Interferometry, Version 2. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. Simkins, L. M., Greenwood, S. L., & Anderson, J. B. (2018). Diagnosing ice sheet grounding line stability from landform morphology. The Cryosphere, 12(8), 2707-2726. Van der Veen, C. J., J. C. Plummer, & L. A. Stearns. (2011). Controls on the recent speed up of Jakobshavn Isbræ, West Greenland. Journal of Glaciology, 57(204), 770-782 | ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"] | ["POINT(0 -89.999)"] | false | false |
Pennell Trough, Ross Sea bathymetry and glacial landforms
|
1246353 1745055 1745043 |
2021-10-04 | Greenwood, Sarah; Munevar Garcia, Santiago; Eareckson, Elizabeth; Anderson, John; Prothro, Lindsay; Simkins, Lauren |
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. |
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°×1° beam width, swath angular coverage set to 62°×62°, 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). | ["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))"] | ["POINT(176 -76)"] | false | false |
MOA-derived Structural Feature Map of the Ross Ice Shelf
|
0440670 |
2021-02-19 | Hulbe, Christina; Ledoux, Christine; Forbes, Martin |
Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams |
The surface of the Ross Ice Shelf (RIS) is textured by flow stripes, crevasses and other fea- tures related to ice flow and deformation. Here, moderate resolution optical satellite images are used to map and classify regions of the RIS characterized by different surface textures. Because the textures arise from ice deformation, the map is used to identify structural provinces with common deformation history. We classify four province types: regions associated with large outlet glaciers, shear zones, exten- sion downstream of obstacles and suture zones between provinces with different upstream sources. Adjacent provinces with contrasting histories are in some locations deforming at different rates, suggest- ing that our province map is also an ice fabric map. Structural provinces have more complicated shapes in the part of the ice shelf fed by West Antarctic ice streams than in the part fed by outlet glaciers from the Transantarctic Mountains. The map may be used to infer past variations in stress conditions and flow events that cannot be inferred from flow traces alone. | ["POLYGON((-180 -77,-177 -77,-174 -77,-171 -77,-168 -77,-165 -77,-162 -77,-159 -77,-156 -77,-153 -77,-150 -77,-150 -77.9,-150 -78.8,-150 -79.7,-150 -80.6,-150 -81.5,-150 -82.4,-150 -83.3,-150 -84.2,-150 -85.1,-150 -86,-153 -86,-156 -86,-159 -86,-162 -86,-165 -86,-168 -86,-171 -86,-174 -86,-177 -86,180 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77))"] | ["POINT(-177.5 -81.5)"] | false | false |
ICECAP Basal Interface Specularity Content Profiles: IPY and OIB
|
1543452 0733025 1443690 0636724 |
2020-08-24 | Young, Duncan A.; Blankenship, Donald D.; Roberts, Jason; Siegert, Martin; van Ommen, Tas; Greenbaum, Jamin; Schroeder, Dustin |
Collaborative Research: Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP) East Antarctic Grounding Line Experiment (EAGLE) Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System IPY Research: Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP) |
The International Collaborative Exploration of the Cryosphere though Airborne Profiling (ICECAP) collected five seasons of aerogeophysical data data through the NSFs International Polar Year and NASAs Operation Ice Bridge programs in East Antarctica, using the coherent HiCARS 60 MHz radar system. By comparing echo strengths for different focusing apertures, and accounting for the ranges and angles involved, we can derive the "specularity content" of the bed echo, a proxy for small scale bed roughness and a good indicator for subglacial water pressure in regions of distributed subglacial water (Schroeder et al., 2014, IEEE GRSL, 10.1109/LGRS.2014.2337878; IEEE; Dow et al., 2019, EPSL https://doi.org/10.1016/j.epsl.2019.115961). Specularity data are inherently noisy, so these products have been smoothed with a 1 km filter. | ["POLYGON((80 -65,89 -65,98 -65,107 -65,116 -65,125 -65,134 -65,143 -65,152 -65,161 -65,170 -65,170 -66.5,170 -68,170 -69.5,170 -71,170 -72.5,170 -74,170 -75.5,170 -77,170 -78.5,170 -80,161 -80,152 -80,143 -80,134 -80,125 -80,116 -80,107 -80,98 -80,89 -80,80 -80,80 -78.5,80 -77,80 -75.5,80 -74,80 -72.5,80 -71,80 -69.5,80 -68,80 -66.5,80 -65))"] | ["POINT(125 -72.5)"] | false | false |
CATS2008: Circum-Antarctic Tidal Simulation version 2008
|
9896041 1443677 |
2019-12-19 | Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana |
Ocean Tides around Antarctica and in the Southern Ocean Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE) |
CATS2008 is a regional inverse barotropic tide model for the circum-Antarctic ocean on a 4 km grid. The model domain includes ocean cavities under the floating ice shelves. The coastline is based on the MODIS MOA [Scambos et al., 2007; Remote Sensing of Environment] feature identification files, adjusted to match ICESat-derived grounding lines for the Ross and Filchner-Ronne ice shelves and Interferometric Synthetic Aperture Radar (InSAR) grounding lines. The water depth map for open water is based on the 2007 release update to Smith and Sandwell [1997; Science]. Adjustments to this map have been made in various regions, including the open continental shelf in front of the Larsen-C Ice Shelf which has been blended with GEBCO bathymetry. Model type: Tides only; Inverse (data assimilation); barotropic (no vertical variation of currents). Grid: 4-km uniform polar stereographic (centered at 71 degrees S, 70 degrees W) Constituents: M2, S2, N2, K2, K1, O1, P1, Q1, Mf, Mm. Units: z (sea surface height; meters); u,v (currents; cm/s); U,V (transports; m2/s). Coordinates: Currents (u, v) and depth-integrated transports (U, V) are given as East (u, U) and North (v, V) components. Citation: "… an update to the inverse model described by Padman et al. [2002]." See CATS2008_README.pdf for further details. | ["POLYGON((-180 -40.231,-144 -40.231,-108 -40.231,-72 -40.231,-36 -40.231,0 -40.231,36 -40.231,72 -40.231,108 -40.231,144 -40.231,180 -40.231,180 -45.2079,180 -50.1848,180 -55.1617,180 -60.1386,180 -65.1155,180 -70.0924,180 -75.0693,180 -80.0462,180 -85.0231,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.0231,-180 -80.0462,-180 -75.0693,-180 -70.0924,-180 -65.1155,-180 -60.1386,-180 -55.1617,-180 -50.1848,-180 -45.2079,-180 -40.231))"] | ["POINT(0 -89.999)"] | false | false |
Geophysical data from Crary Ice Rise, Ross Sea Embayment
|
1443356 1443552 |
2019-05-20 | Conway, Howard; Koutnik, Michelle; Winberry, Paul; Paden, John |
Collaborative Research: Grounding Line Dynamics: Crary Ice Rise Revisited |
This data set contains radar-detected measurements of surface topography, internal stratigraphy, ice thickness and derived bed topography across Crary Ice Rise in the Ross Sea Embayment. | ["POLYGON((-174.95 -82.65,-174.35 -82.65,-173.75 -82.65,-173.15 -82.65,-172.55 -82.65,-171.95 -82.65,-171.35 -82.65,-170.75 -82.65,-170.15 -82.65,-169.55 -82.65,-168.95 -82.65,-168.95 -82.729,-168.95 -82.808,-168.95 -82.887,-168.95 -82.966,-168.95 -83.045,-168.95 -83.124,-168.95 -83.203,-168.95 -83.282,-168.95 -83.361,-168.95 -83.44,-169.55 -83.44,-170.15 -83.44,-170.75 -83.44,-171.35 -83.44,-171.95 -83.44,-172.55 -83.44,-173.15 -83.44,-173.75 -83.44,-174.35 -83.44,-174.95 -83.44,-174.95 -83.361,-174.95 -83.282,-174.95 -83.203,-174.95 -83.124,-174.95 -83.045,-174.95 -82.966,-174.95 -82.887,-174.95 -82.808,-174.95 -82.729,-174.95 -82.65))"] | ["POINT(-171.95 -83.045)"] | false | false |
Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line
|
0838947 |
2018-09-09 | Begeman, Carolyn |
Collaborative Research: Integrative Study of Marine Ice Sheet Stability & Subglacial Life Habitats in W Antarctica - Lake & Ice Stream Subglacial Access Research Drilling (LISSARD) |
This dataset contains ice-shelf basal melt rates and vertical strain rates for 11 sites near the Whillans Ice Stream grounding line. These rates were determined using Autonomous Phase-Sensitive Radar. Data processing is described in Begeman et al. 2018, JGR Oceans. These sites are concentrated within an embayment of the Ross Ice Shelf. These melt rates and strain rates were determined over periods ranging from 10 to 38 days in December 2014 to January 2015. | ["POLYGON((-165.28 -84.24,-165.086 -84.24,-164.892 -84.24,-164.698 -84.24,-164.504 -84.24,-164.31 -84.24,-164.116 -84.24,-163.922 -84.24,-163.728 -84.24,-163.534 -84.24,-163.34 -84.24,-163.34 -84.252,-163.34 -84.264,-163.34 -84.276,-163.34 -84.288,-163.34 -84.3,-163.34 -84.312,-163.34 -84.324,-163.34 -84.336,-163.34 -84.348,-163.34 -84.36,-163.534 -84.36,-163.728 -84.36,-163.922 -84.36,-164.116 -84.36,-164.31 -84.36,-164.504 -84.36,-164.698 -84.36,-164.892 -84.36,-165.086 -84.36,-165.28 -84.36,-165.28 -84.348,-165.28 -84.336,-165.28 -84.324,-165.28 -84.312,-165.28 -84.3,-165.28 -84.288,-165.28 -84.276,-165.28 -84.264,-165.28 -84.252,-165.28 -84.24))"] | ["POINT(-164.31 -84.3)"] | false | false |
Decoding & Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs
|
1043580 |
2016-01-01 | Reusch, David |
Collaborative Research: Decoding & Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs |
The presence of ice ponds from surface melting of glacial ice can be a significant threshold in assessing the stability of ice sheets, and their overall response to a warming climate. Snow melt has a much reduced albedo, leading to additional seasonal melting from warming insolation. Water run-off not only contributes to the mass loss of ice sheets directly, but meltwater reaching the glacial ice bed may lubricate faster flow of ice sheets towards the ocean. Surficial meltwater may also reach the grounding lines of glacial ice through the wedging open of existing crevasses. The occurrence and amount of meltwater refreeze has even been suggested as a paleo proxy of near-surface atmospheric temperature regimes. Using contemporary remote sensing (microwave) satellite assessment of surface melt occurrence and extent, the predictive skill of regional meteorological models and reanalyses (e.g. WRF, ERA-Interim) to describe the synoptic conditions favourable to surficial melt is to be investigated. Statistical approaches and pattern recognition techniques are argued to provide a context for projecting future ice sheet change. The previous Intergovernmental Panel on Climate Change (IPCC AR4) commented on our lack of understanding of ice-sheet mass balance processes in polar regions and the potential for sea-level change. The IPPC suggested that the forthcoming AR5 efforts highlight regional cryosphere modeling efforts, such as is proposed here. | ["POLYGON((-180 -47,-144 -47,-108 -47,-72 -47,-36 -47,0 -47,36 -47,72 -47,108 -47,144 -47,180 -47,180 -51.3,180 -55.6,180 -59.9,180 -64.2,180 -68.5,180 -72.8,180 -77.1,180 -81.4,180 -85.7,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.7,-180 -81.4,-180 -77.1,-180 -72.8,-180 -68.5,-180 -64.2,-180 -59.9,-180 -55.6,-180 -51.3,-180 -47))"] | ["POINT(0 -89.999)"] | false | false |
Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES)
|
0839107 |
2016-01-01 | Powell, Ross |
Collaborative Research: Integrative Study of Marine Ice Sheet Stability & Subglacial Life Habitats in W Antarctica - Lake & Ice Stream Subglacial Access Research Drilling (LISSARD) |
The RAGES project (Robotic Access to Grounding zones for Exploration and Science) is one of three research components of the WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) integrative initiative that is being funded by the Antarctic Integrated System Science Program of NSF's Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The RAGES component of WISSARD concentrates on the stability of ice stream grounding zones (GZ), the area where the ice, ocean waters and glacial and sea floor sediment interact. Based on our present limited data and modeling efforts, GZs can be perturbed by (i) internal ice stream dynamics, (ii) filling/draining cycles of subglacial lakes, (iii) increased melting by warming ocean waters, and/or (iv) rates of subglacial sediment (till) supply to the GZ. GZs are seen as high priority targets to investigate due to their unknown contributions to ice sheet stability under future global warming scenarios. The three main science goals for RAGES are to assess: (a) West Antarctic Ice Sheet (WAIS) stability relative to the magnitudes of the four main variables listed above; (b) the degree to which grounding-zone sedimentary systems house important records of past WAIS dynamics; and (c) the importance of microbial activity and subglacial geochemical weathering in supplying nutrients to the WAIS grounding zone, the Ross Ice Shelf (RIS) cavity, and the highly productive Southern Ocean that may ultimately influence global biogeochemical cycles. The RAGES field sampling plan integrates surface geophysical surveys with borehole and subglacial sampling and measurements. The boreholes provide: (1) samples of subglacial water, sediments, and basal ice for biological, geochemical, glaciological, sedimentological, and micropaleontological analyses; (2) measures of subglacial and sub-ice-shelf cavity physical and chemical conditions and their spatial variability; and (3) data on sediment types, state and change of the subglacial water discharge, oceanography, and basal ice at the grounding line and within the nearby sub-ice-shelf cavity. Unique tools to be deployed include a multisensor Sub-Ice ROVer (Remotely Operated Vehicle) and long-term, sub-ice oceanographic moorings. The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. The RAGES project represents a significant advance in polar technology by incorporating the use of complex new instrumentation like the Sub-Ice ROVer and subglacial ocean/lake mooring systems. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars. | ["POLYGON((-163.7 -84,-163.68 -84,-163.66 -84,-163.64 -84,-163.62 -84,-163.6 -84,-163.58 -84,-163.56 -84,-163.54 -84,-163.52 -84,-163.5 -84,-163.5 -84.05,-163.5 -84.1,-163.5 -84.15,-163.5 -84.2,-163.5 -84.25,-163.5 -84.3,-163.5 -84.35,-163.5 -84.4,-163.5 -84.45,-163.5 -84.5,-163.52 -84.5,-163.54 -84.5,-163.56 -84.5,-163.58 -84.5,-163.6 -84.5,-163.62 -84.5,-163.64 -84.5,-163.66 -84.5,-163.68 -84.5,-163.7 -84.5,-163.7 -84.45,-163.7 -84.4,-163.7 -84.35,-163.7 -84.3,-163.7 -84.25,-163.7 -84.2,-163.7 -84.15,-163.7 -84.1,-163.7 -84.05,-163.7 -84))"] | ["POINT(-163.6 -84.25)"] | false | false |
A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea
|
1043485 |
2015-01-01 | Kurz, Mark D.; Curtice, Josh |
Collaborative Research: A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea |
This award supports a project to develop a better understanding of the response of the WAIS to climate change. The timing of the last deglaciation of the western Ross Sea will be improved using in situ terrestrial cosmogenic nuclides (3He, 10Be, 14C, 26Al, 36Cl) to date glacial erratics at key areas and elevations along the western Ross Sea coast. A state-of-the art ice sheet-shelf model will be used to identify mechanisms of deglaciation of the Ross Sea sector of WAIS. The model results and forcing will be compared with observations including the new cosmogenic data proposed here, with the aim of better determining and understanding the history and causes of WAIS deglaciation in the Ross Sea. There is considerable uncertainty, however, in the history of grounding line retreat from its last glacial maximum position, and virtually nothing is known about the timing of ice- surface lowering prior to ~10,000 years ago. Given these uncertainties, we are currently unable to assess one of the most important questions regarding the last deglaciation of the global ice sheets, namely as to whether the Ross Sea sector of WAIS contributed significantly to meltwater pulse 1A (MWP-1A), an extraordinarily rapid (~500-year duration) episode of ~20 m sea-level rise that occurred ~14,500 years ago. The intellectual merit of this project is that recent observations of startling changes at the margins of the Greenland and Antarctic ice sheets indicate that dynamic responses to warming may play a much greater role in the future mass balance of ice sheets than considered in current numerical projections of sea level rise. The broader impacts of this work are that it has direct societal relevance to developing an improved understanding of the response of the West Antarctic ice sheet to current and possible future environmental changes including the sea-level response to glacier and ice sheet melting due to global warming. The PI will communicate results from this project to a variety of audiences through the publication of peer-reviewed papers and by giving talks to public audiences. Finally the project will support a graduate student and undergraduate students in all phases of field-work, laboratory work and data interpretation. | ["POLYGON((163.4 -77.47989,163.9848 -77.47989,164.5696 -77.47989,165.1544 -77.47989,165.7392 -77.47989,166.324 -77.47989,166.9088 -77.47989,167.4936 -77.47989,168.0784 -77.47989,168.6632 -77.47989,169.248 -77.47989,169.248 -77.565701,169.248 -77.651512,169.248 -77.737323,169.248 -77.823134,169.248 -77.908945,169.248 -77.994756,169.248 -78.080567,169.248 -78.166378,169.248 -78.252189,169.248 -78.338,168.6632 -78.338,168.0784 -78.338,167.4936 -78.338,166.9088 -78.338,166.324 -78.338,165.7392 -78.338,165.1544 -78.338,164.5696 -78.338,163.9848 -78.338,163.4 -78.338,163.4 -78.252189,163.4 -78.166378,163.4 -78.080567,163.4 -77.994756,163.4 -77.908945,163.4 -77.823134,163.4 -77.737323,163.4 -77.651512,163.4 -77.565701,163.4 -77.47989))"] | ["POINT(166.324 -77.908945)"] | false | false |
MOA-derived Structural Feature Map of the Ronne Ice Shelf
|
0440670 0125754 |
2011-07-15 | Hulbe, Christina; Ledoux, Christine |
Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams |
This data set provides a structural feature map of the Ronne Ice Shelf in Antarctica (also known as the Filchner-Ronne Ice Shelf). The map was developed as part of a project to study fracture propagation in the Ronne Ice Shelf, with special focus on the Evans Ice Stream. Features were digitized from the MODIS Mosaic of Antartica (MOA), a composite of individual Moderate Resolution Imaging Spectradiometer (MODIS) images taken between 20 November 2003 and 29 February 2004, with an effective resolution of 125 m. The data set includes estimates of the shelf boundary, including ice stream grounding zones, outlets of glaciers feeding the shelf, extents of islands and ice rises, and the location of the shelf front, and features observed within the shelf, including suture zones between ice streams, streaklines, fractures (crevasses and rifts), and fold-like features. Individual features can be extracted as a group of points and grouping is used to facilitate identification and plotting. Data files are available via FTP in ASCII text (.txt) format. One image file, in Portable Document Format (.pdf), shows the data included in the dataset, plotted using MATLAB. The data set also provides a MATLAB script which can be used to plot the data. | ["POLYGON((-86.557 -74.355,-80.5124 -74.355,-74.4678 -74.355,-68.4232 -74.355,-62.3786 -74.355,-56.334 -74.355,-50.2894 -74.355,-44.2448 -74.355,-38.2002 -74.355,-32.1556 -74.355,-26.111 -74.355,-26.111 -75.3874,-26.111 -76.4198,-26.111 -77.4522,-26.111 -78.4846,-26.111 -79.517,-26.111 -80.5494,-26.111 -81.5818,-26.111 -82.6142,-26.111 -83.6466,-26.111 -84.679,-32.1556 -84.679,-38.2002 -84.679,-44.2448 -84.679,-50.2894 -84.679,-56.334 -84.679,-62.3786 -84.679,-68.4232 -84.679,-74.4678 -84.679,-80.5124 -84.679,-86.557 -84.679,-86.557 -83.6466,-86.557 -82.6142,-86.557 -81.5818,-86.557 -80.5494,-86.557 -79.517,-86.557 -78.4846,-86.557 -77.4522,-86.557 -76.4198,-86.557 -75.3874,-86.557 -74.355))"] | ["POINT(-56.334 -79.517)"] | false | false |
Grounding Line Strain Grid Surveys, Kamb Ice Stream, Antarctica
|
0538015 |
2011-07-01 | Hulbe, Christina |
Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region |
This data set provides the results from a strain grid survey deployed across the Kamb Ice Stream grounding line on the West Antarctic Ice Sheet. The grid was deployed in 2006 and resurveyed in 2007 using a Global Positioning System (GPS). Parameters measured include latitude, longitude, and height of each survey mark in the strain grid, as well as northing, easting, elevations, and displacement of each point during the year between surveys. Data are available via FTP in Microsoft Excel (.xls) format. | ["POLYGON((154.71 -82.78,154.79 -82.78,154.87 -82.78,154.95 -82.78,155.03 -82.78,155.11 -82.78,155.19 -82.78,155.27 -82.78,155.35 -82.78,155.43 -82.78,155.51 -82.78,155.51 -82.788,155.51 -82.796,155.51 -82.804,155.51 -82.812,155.51 -82.82,155.51 -82.828,155.51 -82.836,155.51 -82.844,155.51 -82.852,155.51 -82.86,155.43 -82.86,155.35 -82.86,155.27 -82.86,155.19 -82.86,155.11 -82.86,155.03 -82.86,154.95 -82.86,154.87 -82.86,154.79 -82.86,154.71 -82.86,154.71 -82.852,154.71 -82.844,154.71 -82.836,154.71 -82.828,154.71 -82.82,154.71 -82.812,154.71 -82.804,154.71 -82.796,154.71 -82.788,154.71 -82.78))"] | ["POINT(155.11 -82.82)"] | false | false |
High-resolution Image-derived Grounding and Hydrostatic Lines for the Antarctic Ice Sheet
|
None | 2011-02-20 | Bindschadler, Robert; Choi, Hyeungu | No project link provided | This data set provides grounding line and hydrostatic line locations for the Antarctic coastline and islands around Antarctica. The data are derived using customized software to combine data from Landsat-7 imagery and Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry, which were primarily collected between 1999 to 2003. The data set also includes elevations along each line, selected from six candidate digital elevation models. The data were developed as part of the Antarctic Surface Accumulation and Ice Discharge (ASAID) project. Funding trough NASA grant 509496.02.08.01.81 Data are provided in both ASCII text (.txt) and shapefile (.shp, .dbf, .shx) formats. | ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -62,180 -64,180 -66,180 -68,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,144 -80,108 -80,72 -80,36 -80,0 -80,-36 -80,-72 -80,-108 -80,-144 -80,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70,-180 -68,-180 -66,-180 -64,-180 -62,-180 -60))"] | ["POINT(0 -89.999)"] | false | false |
Ice-Penetrating Radar Data Across Siple Coast Grounding Lines
|
0538120 |
2010-01-01 | Hulbe, Christina; Catania, Ginny |
Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region |
These data consist of ice-penetrating radar data collected on the ground across the grounding line near Siple Dome during the 2006 and 2007 Antarctic summer field seasons. Primarily, the data consist of low-frequency radar data (2 MHz, approximately 50 meter resolution) in order to observe deep internal layers and the ice-bed interface. The data set also contains one file with high-frequency (100 MHz, approximately 1 meter resolution) radar data, for a sub-region of one of the low-frequency radar profiles. Coincident kinematic GPS data were also collected to correct the radar data for topography along each profile. Radar profiles are typically approximately 20 km in length with the grounding line crossed centrally where possible. Data are available via FTP in Matlab (.mat) format. | ["POLYGON((-160 -81,-158.5 -81,-157 -81,-155.5 -81,-154 -81,-152.5 -81,-151 -81,-149.5 -81,-148 -81,-146.5 -81,-145 -81,-145 -81.2,-145 -81.4,-145 -81.6,-145 -81.8,-145 -82,-145 -82.2,-145 -82.4,-145 -82.6,-145 -82.8,-145 -83,-146.5 -83,-148 -83,-149.5 -83,-151 -83,-152.5 -83,-154 -83,-155.5 -83,-157 -83,-158.5 -83,-160 -83,-160 -82.8,-160 -82.6,-160 -82.4,-160 -82.2,-160 -82,-160 -81.8,-160 -81.6,-160 -81.4,-160 -81.2,-160 -81))"] | ["POINT(-152.5 -82)"] | false | false |
Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams
|
0440636 |
2008-09-25 | Fahnestock, Mark |
Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams |
None | [] | [] | false | false |
MODIS Mosaic of Antarctica 2003-2004 (MOA2004) Image Map
|
None | 2005-11-02 | Haran, Terry; Bohlander, Jennifer; Scambos, Ted; Painter, Thomas; Fahnestock, Mark | No project link provided | The MODIS Mosaic of Antarctica 2003-2004 (MOA2004) Image Map consists of two cloud-free digital image maps that show mean surface morphology and a quantitative measure of optical snow grain size on the Antarctic continent and surrounding islands. The 260 orbit swaths used to create the 2003/2004 MOA Surface Morphology Image Map and the 2003/2004 MOA Grain Size Image Map were acquired 20 November 2003 through 29 February 2004 by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on board the NASA EOS Aqua and Terra satellites. The 122 orbit swaths used to create the 2003 MOA Grain Size Image Map were acquired 1 November 2003 through 17 December 2003. Vector data sets with the corresponding coastlines, ice sheet grounding lines, and islands are also provided. | ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"] | ["POINT(0 -89.999)"] | false | false |