[{"awards": "1851022 Fudge, Tyler", "bounds_geometry": ["POINT(123.33 -75.09)"], "date_created": "Fri, 22 Dec 2023 00:00:00 GMT", "description": "Volcanic deposition of sulfuric acid in ice cores is important both for understanding past volcanic activity and for synchronizing ice core timescales. Sulfuric acid has a low eutectic point, so it can potentially exist in liquid at grain boundaries and veins, accelerating chemical diffusion. A high effective diffusivity would allow post-depositional diffusion to obscure the climate history and the peak matching among older portions of ice cores. Here, we use records of sulfate from the EPICA Dome C (EDC) ice core to estimate the effective diffusivity of sulfuric acid in ice. We focus on EDC because multiple glacial-interglacial cycles are preserved, allowing analysis for long timescales and deposition in similar climates. We calculate the mean concentration gradient and the width of prominent volcanic events, and analyze the evolution of each with depth/age. We find the effective diffusivities for interglacials and glacial maximums to be 5 \u00b1 3 \u00d7 10-9 m2 a-1, an order of magnitude lower than a previous estimate derived from the Holocene portion of EDC (Barnes et al., 2003). The effective diffusivity may be even smaller if the bias from artificial smoothing from the sampling is accounted for. Effective diffusivity is not obviously affected by the ice temperature until about -10\u00b0C, 3000m depth, which is also where anomalous sulfate peaks begin to be observed (Traversi et al., 2009). Low effective diffusivity suggests that sulfuric acid is not readily diffusing in liquid-like veins in the upper portions of the Antarctic ice sheet and that records may be preserved in deep, old ice if the ice temperature remains well below the pressure melting point.", "east": 123.33, "geometry": ["POINT(123.33 -75.09)"], "keywords": "Antarctica", "locations": "Antarctica", "north": -75.09, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Fudge, T. J.; Severi, Mirko", "project_titles": "Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation", "projects": [{"proj_uid": "p0010211", "repository": "USAP-DC", "title": "Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "COLDEX", "south": -75.09, "title": "EPICA Dome C Sulfate Data 7-3190m", "uid": "601759", "west": 123.33}, {"awards": null, "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, 20 May 2020 00:00:00 GMT", "description": "Temperature mesaurements from 10-meter depth in drill holes, dating back prior to 1956 and the International Geophysical Year, including measurements from several major recent surveys. Data cover the entire continental ice sheet and several ice shelves, but coverage density is generally low. For more information, please see the notes available for each 10-meter data set, and the list of related publications. The deeper drill-hole temperature data collection also covers a large portion of the ice sheet. The time frame covered by this collection is 1949-1979.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Firn Temperature Measurements", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": null, "persons": "Scambos, Ted", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Compilation of ice temperature measurements at 10 m depth from international traverses 1957-1996.", "uid": "601325", "west": -180.0}, {"awards": "1341725 Guest, Peter", "bounds_geometry": ["POLYGON((-180 -62,-179.5 -62,-179 -62,-178.5 -62,-178 -62,-177.5 -62,-177 -62,-176.5 -62,-176 -62,-175.5 -62,-175 -62,-175 -63.6,-175 -65.2,-175 -66.8,-175 -68.4,-175 -70,-175 -71.6,-175 -73.2,-175 -74.8,-175 -76.4,-175 -78,-175.5 -78,-176 -78,-176.5 -78,-177 -78,-177.5 -78,-178 -78,-178.5 -78,-179 -78,-179.5 -78,180 -78,178.8 -78,177.6 -78,176.4 -78,175.2 -78,174 -78,172.8 -78,171.6 -78,170.4 -78,169.2 -78,168 -78,168 -76.4,168 -74.8,168 -73.2,168 -71.6,168 -70,168 -68.4,168 -66.8,168 -65.2,168 -63.6,168 -62,169.2 -62,170.4 -62,171.6 -62,172.8 -62,174 -62,175.2 -62,176.4 -62,177.6 -62,178.8 -62,-180 -62))"], "date_created": "Wed, 12 Jun 2019 00:00:00 GMT", "description": "This file contains times series data from the 2017 PIPERS cruise for the period 15 April 0000 \u2013 8 June 1200 (UT). The time series data represent one minute means and include data collected by the Naval Postgraduate School from the starboard side boom (including occasionally on ice surface temp sampling), radiation system on the helo deck and sometimes in situ surface temp. Also included are meteorological, navigation and surface oceanography (from intake) data from the standard ship systems. ", "east": -175.0, "geometry": ["POINT(176.5 -70)"], "keywords": "Air Temperature; Antarctica; Atmosphere; Meteorology; Near-Surface Air Temperatures; PIPERS; Radiation; Sea Ice Temperatures; Temperature; Weather Station Data; Wind Direction; Wind Speed", "locations": "Antarctica", "north": -62.0, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Guest, Peter", "project_titles": "Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica", "projects": [{"proj_uid": "p0010032", "repository": "USAP-DC", "title": "Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "PIPERS Meteorology Time Series", "uid": "601184", "west": 168.0}, {"awards": "1144192 Tulaczyk, Slawek", "bounds_geometry": ["POINT(162.2673 -77.722528)"], "date_created": "Wed, 28 Nov 2018 00:00:00 GMT", "description": "", "east": 162.2673, "geometry": ["POINT(162.2673 -77.722528)"], "keywords": "Antarctica; Borehole; Borehole Logging; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Temperature; Snow/ice; Snow/Ice; Temperature; Temperature Profiles", "locations": "Antarctica", "north": -77.722528, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Tulaczyk, Slawek", "project_titles": "Collaborative Research: MIDGE: Minimally Invasive Direct Glacial Exploration of Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys", "projects": [{"proj_uid": "p0000002", "repository": "USAP-DC", "title": "Collaborative Research: MIDGE: Minimally Invasive Direct Glacial Exploration of Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.722528, "title": "Ice Temperature in Shallow Boreholes Near Blood Falls at the Terminus of Taylor Glacier, McMurdo Dry Valleys, Antarctica", "uid": "601139", "west": 162.2673}, {"awards": "0338151 Raymond, Charles", "bounds_geometry": ["POINT(-112.09 -79.47)"], "date_created": "Tue, 15 Jun 2010 00:00:00 GMT", "description": "This data set contains the results of a model study of spatial variations of ice temperature and subglacial conditions using available ice-penetrating radar data around a future deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet. The model data are based on radar data collected by the Support Office of Aerogeophysical Research (SOAR) at the University of Texas, and the University of Washington, in 2000. The data include values for attenuation estimates for individual radar profiles.\n\nData are available via FTP in MATLAB (.mat) and Portable Document (.pdf) formats.", "east": -112.09, "geometry": ["POINT(-112.09 -79.47)"], "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar; WAIS Divide", "locations": "WAIS Divide; Antarctica", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Raymond, Charles; Matsuoka, Kenichi", "project_titles": "Glaciological Characteristics of the Ross/Amundsen Sea Ice-flow Divide Deduced by a New Analysis of Ice-penetrating Radar Data", "projects": [{"proj_uid": "p0000017", "repository": "USAP-DC", "title": "Glaciological Characteristics of the Ross/Amundsen Sea Ice-flow Divide Deduced by a New Analysis of Ice-penetrating Radar Data"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Englacial Layers and Attenuation Rates across the Ross and Amundsen Sea Ice-Flow Divide (WAIS Divide), West Antarctica", "uid": "609470", "west": -112.09}]

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Dataset Title/Abstract/Map	NSF Award(s)	Date Created	PIs / Scientists	Project Links	Abstract	Bounds Geometry	Geometry	Selected	Visible
EPICA Dome C Sulfate Data 7-3190m	1851022	2023-12-22	Fudge, T. J.; Severi, Mirko	Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation	Volcanic deposition of sulfuric acid in ice cores is important both for understanding past volcanic activity and for synchronizing ice core timescales. Sulfuric acid has a low eutectic point, so it can potentially exist in liquid at grain boundaries and veins, accelerating chemical diffusion. A high effective diffusivity would allow post-depositional diffusion to obscure the climate history and the peak matching among older portions of ice cores. Here, we use records of sulfate from the EPICA Dome C (EDC) ice core to estimate the effective diffusivity of sulfuric acid in ice. We focus on EDC because multiple glacial-interglacial cycles are preserved, allowing analysis for long timescales and deposition in similar climates. We calculate the mean concentration gradient and the width of prominent volcanic events, and analyze the evolution of each with depth/age. We find the effective diffusivities for interglacials and glacial maximums to be 5 ± 3 × 10-9 m2 a-1, an order of magnitude lower than a previous estimate derived from the Holocene portion of EDC (Barnes et al., 2003). The effective diffusivity may be even smaller if the bias from artificial smoothing from the sampling is accounted for. Effective diffusivity is not obviously affected by the ice temperature until about -10°C, 3000m depth, which is also where anomalous sulfate peaks begin to be observed (Traversi et al., 2009). Low effective diffusivity suggests that sulfuric acid is not readily diffusing in liquid-like veins in the upper portions of the Antarctic ice sheet and that records may be preserved in deep, old ice if the ice temperature remains well below the pressure melting point.	["POINT(123.33 -75.09)"]	["POINT(123.33 -75.09)"]	false	false
Compilation of ice temperature measurements at 10 m depth from international traverses 1957-1996.	None	2020-05-20	Scambos, Ted	No project link provided	Temperature mesaurements from 10-meter depth in drill holes, dating back prior to 1956 and the International Geophysical Year, including measurements from several major recent surveys. Data cover the entire continental ice sheet and several ice shelves, but coverage density is generally low. For more information, please see the notes available for each 10-meter data set, and the list of related publications. The deeper drill-hole temperature data collection also covers a large portion of the ice sheet. The time frame covered by this collection is 1949-1979.	["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
PIPERS Meteorology Time Series	1341725	2019-06-12	Guest, Peter	Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica	This file contains times series data from the 2017 PIPERS cruise for the period 15 April 0000 – 8 June 1200 (UT). The time series data represent one minute means and include data collected by the Naval Postgraduate School from the starboard side boom (including occasionally on ice surface temp sampling), radiation system on the helo deck and sometimes in situ surface temp. Also included are meteorological, navigation and surface oceanography (from intake) data from the standard ship systems.	["POLYGON((-180 -62,-179.5 -62,-179 -62,-178.5 -62,-178 -62,-177.5 -62,-177 -62,-176.5 -62,-176 -62,-175.5 -62,-175 -62,-175 -63.6,-175 -65.2,-175 -66.8,-175 -68.4,-175 -70,-175 -71.6,-175 -73.2,-175 -74.8,-175 -76.4,-175 -78,-175.5 -78,-176 -78,-176.5 -78,-177 -78,-177.5 -78,-178 -78,-178.5 -78,-179 -78,-179.5 -78,180 -78,178.8 -78,177.6 -78,176.4 -78,175.2 -78,174 -78,172.8 -78,171.6 -78,170.4 -78,169.2 -78,168 -78,168 -76.4,168 -74.8,168 -73.2,168 -71.6,168 -70,168 -68.4,168 -66.8,168 -65.2,168 -63.6,168 -62,169.2 -62,170.4 -62,171.6 -62,172.8 -62,174 -62,175.2 -62,176.4 -62,177.6 -62,178.8 -62,-180 -62))"]	["POINT(176.5 -70)"]	false	false
Ice Temperature in Shallow Boreholes Near Blood Falls at the Terminus of Taylor Glacier, McMurdo Dry Valleys, Antarctica	1144192	2018-11-28	Tulaczyk, Slawek	Collaborative Research: MIDGE: Minimally Invasive Direct Glacial Exploration of Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys		["POINT(162.2673 -77.722528)"]	["POINT(162.2673 -77.722528)"]	false	false
Englacial Layers and Attenuation Rates across the Ross and Amundsen Sea Ice-Flow Divide (WAIS Divide), West Antarctica	0338151	2010-06-15	Raymond, Charles; Matsuoka, Kenichi	Glaciological Characteristics of the Ross/Amundsen Sea Ice-flow Divide Deduced by a New Analysis of Ice-penetrating Radar Data	This data set contains the results of a model study of spatial variations of ice temperature and subglacial conditions using available ice-penetrating radar data around a future deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet. The model data are based on radar data collected by the Support Office of Aerogeophysical Research (SOAR) at the University of Texas, and the University of Washington, in 2000. The data include values for attenuation estimates for individual radar profiles. Data are available via FTP in MATLAB (.mat) and Portable Document (.pdf) formats.	["POINT(-112.09 -79.47)"]	["POINT(-112.09 -79.47)"]	false	false

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U.S. ANTARCTIC PROGRAM DATA CENTER

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