{"dp_type": "Dataset", "free_text": "Electrical Conductivity"}
[{"awards": "2149518 Fudge, Tyler; 2019719 Brook, Edward", "bounds_geometry": ["POINT(159.36 -76.73)"], "date_created": "Fri, 06 Dec 2024 00:00:00 GMT", "description": "This dataset includes three-dimensional multitrack electrical conductivity measurements (3D ECM) results from measurements in the upper sections of the ALHIC2201 and ALHIC2302 large (241mm) diameter ice cores drilled in the Allan Hills blue ice area (76.73\u00b0S,159.36\u00b0E) in Victoria Land, East Antarctica. The data extends from the surface to 23.0 m depth in ALHIC2201 and from 8.5 m to 46.3 m depth in ALHIC2302. We include the raw 3D ECM data (AC and DC multitrack ECM measurements on perpendicular faces of a quarter-core cut) in CSV format and basic plots of this data. We also provide dip and dip direction estimates of the layering observed in each core section in a CSV table.", "east": 159.36, "geometry": ["POINT(159.36 -76.73)"], "keywords": "Allan Hills; Antarctica; Cryosphere", "locations": "Allan Hills; Antarctica", "north": -76.73, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "persons": "Kirkpatrick, Liam; Carter, Austin; Marks Peterson, Julia; Shackleton, Sarah; Fudge, T. J.", "project_titles": "Center for Oldest Ice Exploration; Collaborative Research: Testing Next Generation Measurement Techniques for Reconstruction of Paleoclimate Archives from Thin or Disturbed Ice Cores Sections", "projects": [{"proj_uid": "p0010321", "repository": "USAP-DC", "title": "Center for Oldest Ice Exploration"}, {"proj_uid": "p0010365", "repository": "USAP-DC", "title": "Collaborative Research: Testing Next Generation Measurement Techniques for Reconstruction of Paleoclimate Archives from Thin or Disturbed Ice Cores Sections"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "COLDEX", "south": -76.73, "title": "ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations", "uid": "601854", "west": 159.36}, {"awards": "1443232 Waddington, Edwin", "bounds_geometry": ["POINT(-180 -90)"], "date_created": "Mon, 08 Jul 2019 00:00:00 GMT", "description": "These are AC-ECM data used to identify volcanic events in SPICEcore. The data have been normalized to get a consistent baseline for data collected from three different processing seasons.", "east": -180.0, "geometry": ["POINT(-180 -90)"], "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; South Pole; SPICEcore; Volcanic", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Waddington, Edwin D.; Fudge, T. J.", "project_titles": "Using Electrical Conductance Measurements to Develop the South Pole Ice Core Chronology", "projects": [{"proj_uid": "p0000378", "repository": "USAP-DC", "title": "Using Electrical Conductance Measurements to Develop the South Pole Ice Core Chronology"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "AC-ECM for SPICEcore", "uid": "601189", "west": -180.0}, {"awards": "0944191 Taylor, Kendrick; 0944197 Waddington, Edwin", "bounds_geometry": ["POLYGON((-115 -80,-114.5 -80,-114 -80,-113.5 -80,-113 -80,-112.5 -80,-112 -80,-111.5 -80,-111 -80,-110.5 -80,-110 -80,-110 -79.9,-110 -79.8,-110 -79.7,-110 -79.6,-110 -79.5,-110 -79.4,-110 -79.3,-110 -79.2,-110 -79.1,-110 -79,-110.5 -79,-111 -79,-111.5 -79,-112 -79,-112.5 -79,-113 -79,-113.5 -79,-114 -79,-114.5 -79,-115 -79,-115 -79.1,-115 -79.2,-115 -79.3,-115 -79.4,-115 -79.5,-115 -79.6,-115 -79.7,-115 -79.8,-115 -79.9,-115 -80))"], "date_created": "Fri, 12 Apr 2019 00:00:00 GMT", "description": "Images of the multi-track electrical data for depths below 1956 m are given in mt_compiled_1958_3406.pdf. Images are approximately to scale. Data for individual sections can be obtained by contacting T.J. Fudge at tjfudge@uw.edu.\r\n\r\nWarm colors are high electrical conductivity. Cool colors are low electrical conductivity. Each track is normalized by subtracting the mean and dividing by the standard deviation. Plotted values are a 3-measurement (3mm) running average. Measurements affected by breaks in the core have been masked out.\r\n\r\nX-axis is approximate horizontal position on the ice core, as measured from left from looking from bottom to top of the core. Y-axis is depth in meters. Title is the tube number. \r\n", "east": -110.0, "geometry": ["POINT(-112.5 -79.5)"], "keywords": "Antarctic; Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; Wais Project; West Antarctic Ice Sheet", "locations": "WAIS Divide; Antarctica; West Antarctic Ice Sheet; Antarctic", "north": -79.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "persons": "Fudge, T. J.; Taylor, Kendrick C.", "project_titles": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core", "projects": [{"proj_uid": "p0000026", "repository": "USAP-DC", "title": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "WAIS Divide Multi Track Electrical Measurements", "uid": "601172", "west": -115.0}, {"awards": "0944197 Waddington, Edwin", "bounds_geometry": ["POINT(-112.1115 -79.481)"], "date_created": "Tue, 28 Mar 2017 00:00:00 GMT", "description": "The West Antarctic Ice Sheet Divide (WAIS Divide, WD) ice core is a newly drilled, high-accumulation deep ice core that provides Antarctic climate records of the past ~68 ka at unprecedented temporal resolution. The upper 2850 m (back to 31.2 ka BP) have been dated using annual-layer counting. Here we present a chronology for the deep part of the core (67.8-31.2 ka BP), which is based on stratigraphic matching to annual-layer-counted Greenland ice cores using globally well-mixed atmospheric methane. We calculate the WD gas age-ice age difference (Delta age) using a combination of firn densification modeling, ice-flow modeling, and a data set of d15N-N2, a proxy for past firn column thickness. The largest Delta age at WD occurs during the Last Glacial Maximum, and is 525 +/- 120 years. Internally consistent solutions can be found only when assuming little to no influence of impurity content on densification rates, contrary to a recently proposed hypothesis. We synchronize the WD chronology to a linearly scaled version of the layer-counted Greenland Ice Core Chronology (GICC05), which brings the age of Dansgaard-Oeschger (DO) events into agreement with the U/Th absolutely dated Hulu Cave speleothem record. The small Delta age at WD provides valuable opportunities to investigate the timing of atmospheric greenhouse gas variations relative to Antarctic climate, as well as the interhemispheric phasing of the \\\"bipolar seesaw\\\".\n\nWe present the WD2014 chronology for the upper part (0-2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core. The chronology is based on counting of annual layers observed in the chemical, dust and electrical conductivity records. These layers are caused by seasonal changes in the source, transport, and deposition of aerosols. The measurements were interpreted manually and with the aid of two automated methods. We validated the chronology by comparing to two high-accuracy, absolutely dated chronologies. For the Holocene, the cosmogenic isotope records of 10Be from WAIS Divide and 14C for IntCal13 demonstrated that WD2014 was consistently accurate to better than 0.5% of the age. For the glacial period, comparisons to the Hulu Cave chronology demonstrated that WD2014 had an accuracy of better than 1% of the age at three abrupt climate change events between 27 and 31ka. WD2014 has consistently younger ages than Greenland ice core chronologies during most of the Holocene. For the Younger Dryas-Preboreal transition (11.595 ka; 24 years younger) and the Bolling-Allerod Warming (14.621 ka; 7 years younger), WD2014 ages are within the combined uncertainties of the timescales. Given its high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere, with synchronization to other chronologies feasible using high-quality proxies of volcanism, solar activity, atmospheric mineral dust, and atmospheric methane concentrations.", "east": -112.1115, "geometry": ["POINT(-112.1115 -79.481)"], "keywords": "Antarctica; Depth-Age-Model; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "locations": "Antarctica; WAIS Divide", "north": -79.481, "nsf_funding_programs": null, "persons": "Fudge, T. J.", "project_titles": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core", "projects": [{"proj_uid": "p0000026", "repository": "USAP-DC", "title": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "uid": "601015", "west": -112.1115}, {"awards": "0440819 Taylor, Kendrick; 0230396 Taylor, Kendrick; 0944348 Taylor, Kendrick; 0944191 Taylor, Kendrick; 0440817 Taylor, Kendrick", "bounds_geometry": ["POINT(-112.1115 -79.481)"], "date_created": "Mon, 18 Aug 2014 00:00:00 GMT", "description": "This data set contains electrical measurements that were used to develop the WDC06A-7 timescale.", "east": -112.1115, "geometry": ["POINT(-112.1115 -79.481)"], "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Fudge, T. J.; Taylor, Kendrick C.", "project_titles": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core", "projects": [{"proj_uid": "p0000026", "repository": "USAP-DC", "title": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica", "uid": "609591", "west": -112.1115}, {"awards": "0636740 Kreutz, Karl", "bounds_geometry": ["POINT(112.088333 -79.482778)", "POINT(-112.088333 -79.482778)"], "date_created": "Sat, 01 Oct 2011 00:00:00 GMT", "description": "This data set includes microparticle concentration, electrical conductivity, and density measurements from the West Antarctic Ice Sheet (WAIS) Divide deep ice core, WDC06A. Microparticle concentration data are reported as total particles per ml of meltwater. Concentration was measured using a laser detector and the University of Maine WAIS Melt Monitor system. Conductivity is measured in micro-Siemens per cm (uS/cm). Density data were collected on 3 by 3 by 100 cm sticks from the WDC06A core, using the Maine Automated Density Gauge Experiment (MADGE). Density data span 0 to 160 m in depth, while the particle and conductivity measurements span the upper 577 m of the core. \n\nData are available via FTP in ASCII text format (.txt).", "east": 112.088333, "geometry": ["POINT(112.088333 -79.482778)", "POINT(-112.088333 -79.482778)"], "keywords": "Antarctica; Density; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Microparticle Concentration; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.482778, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Kreutz, Karl; Hamilton, Gordon S.; Breton, Daniel; Koffman, Bess", "project_titles": "Collaborative Research: Microparticle/tephra analysis of the WAIS Divide ice core", "projects": [{"proj_uid": "p0000040", "repository": "USAP-DC", "title": "Collaborative Research: Microparticle/tephra analysis of the WAIS Divide ice core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.482778, "title": "Microparticle, Conductivity, and Density Measurements from the WAIS Divide Deep Ice Core, Antarctica", "uid": "609499", "west": -112.088333}, {"awards": "0538674 Winebrenner, Dale", "bounds_geometry": ["POINT(73.17 -78.47)"], "date_created": "Mon, 15 Aug 2011 00:00:00 GMT", "description": "This data set provides a modeled radar attenuation rate profile, showing the predicted contributions from pure ice and impurities to radar attenuation at the Vostok 5G ice core site in Antarctica, as well as the total attenuation rate and its formal uncertainty. The model data are based on borehole temperature logs, concentrations of major soluble ions measured from melted ice core samples, and information about the electrical conductivity of ice. Attenuation rates and their spatial variability are important constraints for radar studies of ice sheets. Parameters include depth, total attenuation rate, and attenuation rate contribution from pure ice, acidity, and salinity.\n\nData are available via FTP as a text file (.txt) with columns in comma separated value format.", "east": 73.17, "geometry": ["POINT(73.17 -78.47)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Radar Attenuation Rate; Vostok Ice Core", "locations": "Lake Vostok; Antarctica", "north": -78.47, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Macgregor, Joseph A.; Matsuoka, Kenichi; Studinger, Michael S.", "project_titles": "Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data", "projects": [{"proj_uid": "p0000090", "repository": "USAP-DC", "title": "Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.47, "title": "Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica", "uid": "609501", "west": 73.17}, {"awards": "0440759 Sowers, Todd", "bounds_geometry": ["POINT(112.09 -79.47)"], "date_created": "Tue, 01 Dec 2009 00:00:00 GMT", "description": "This data set includes methane (CH4) isotope data from the West Antarctic Ice Sheet (WAIS) Divide ice core, WDC05A, in Antarctica. The data include depth, gas age, and the isotopic composition of methane (\u0026#8706;13C and \u0026#8706;D of CH4). The ice core was collected during the 2005-2006 Antarctic field season. The CH4 isotope data was generated in 2008 using wet extraction methodology. Samples span the last 1,000 years, at a resolution of about 15 years. Data for samples above 69 meters were from firn air, and data below 69 meters from ice. The dating of the ice was based on continuous chemical analyses above 69 meters and Electrical Conductivity/Dielectric Property (ECM/DEP) measurements from ice. Dating uncertainty is estimated to be better than five years.\n\nData are available via FTP in Microsoft Excel (.xls) tab delimited format", "east": 112.09, "geometry": ["POINT(112.09 -79.47)"], "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "locations": "Antarctica; WAIS Divide", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Sowers, Todd A.", "project_titles": "Collaborative Research: Gases in Firn Air and Shallow Ice at the Proposed WAIS Divide Drilling Site", "projects": [{"proj_uid": "p0000368", "repository": "USAP-DC", "title": "Collaborative Research: Gases in Firn Air and Shallow Ice at the Proposed WAIS Divide Drilling Site"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Methane Isotopes from the WAIS Divide Ice Core", "uid": "609435", "west": 112.09}, {"awards": "XXXXXXX Palais, Julie", "bounds_geometry": ["POINT(123.332196 -75.09978)"], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": "This data set is a collection of analyses done on the the European Project for Ice Coring in Antarctica (EPICA)Dome C ice cores. The data include deuterium and other chemistry, insoluble dust, ice grain radius, dielectric profiling, electrical conductivity, and timescales.\n\nEPICA has completed one core in the Dome Concordia region (Core EDC96, started in 1996, 788 m length). Drilling is ongoing on a second core EDC99 (started in 1999, reached a depth of 3200 m during the 2002/2003 field season. The ice at this depth is estimated to be about 700,000 years old.)", "east": 123.332196, "geometry": ["POINT(123.332196 -75.09978)"], "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Dome C Ice Core; Epica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Physical Properties", "locations": "Antarctica", "north": -75.09978, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Wolff, Eric W.; Monnin, Eric; Fluckiger, Jacqueline", "project_titles": null, "projects": null, "repositories": null, "science_programs": "Dome C Ice Core", "south": -75.09978, "title": "European Project for Ice Coring in Antarctica (EPICA) Dome C Ice Core Data", "uid": "609244", "west": 123.332196}, {"awards": "9526420 Taylor, Kendrick", "bounds_geometry": ["POINT(-149 -81)"], "date_created": "Thu, 08 May 2003 00:00:00 GMT", "description": "This data set is part of the WAISCORES project, an NSF-funded project to understand the influence of the West Antarctic ice sheet on climate and sea level change. WAISCORES researchers acquired and analyzed ice cores from the Siple Dome, in the Siple Coast region, West Antarctica.\n\nTaylor measured the electrical conductivity (ECM) and Complex Conductivity (CC), a measure of the total ions in the ice, in the main Siple Dome ice core. Measurements were taken along the core from a depth of 0 m to 800 m. The project also analyzed shallower cores for ECM and dielectric properties (DEP). (DEP is also a measure of the total ions in the ice, but with lower spatial resolution than the CC.) Albedo measurements where made on the shallow cores and the main core to a depth of 391 m. The data set includes images showing the electrical conductivity of a vertical section of the core.", "east": -149.0, "geometry": ["POINT(-149 -81)"], "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Siple Dome; Siple Dome Ice Core; WAISCORES", "locations": "Antarctica; Siple Dome", "north": -81.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Taylor, Kendrick C.", "project_titles": "Electrical and Optical Measurements on the Siple Dome Ice Core", "projects": [{"proj_uid": "p0000163", "repository": "USAP-DC", "title": "Electrical and Optical Measurements on the Siple Dome Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.0, "title": "Siple Dome Cores Electrical Measurement Data", "uid": "609133", "west": -149.0}]
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations
|
2149518 2019719 |
2024-12-06 | Kirkpatrick, Liam; Carter, Austin; Marks Peterson, Julia; Shackleton, Sarah; Fudge, T. J. |
Center for Oldest Ice Exploration Collaborative Research: Testing Next Generation Measurement Techniques for Reconstruction of Paleoclimate Archives from Thin or Disturbed Ice Cores Sections |
This dataset includes three-dimensional multitrack electrical conductivity measurements (3D ECM) results from measurements in the upper sections of the ALHIC2201 and ALHIC2302 large (241mm) diameter ice cores drilled in the Allan Hills blue ice area (76.73°S,159.36°E) in Victoria Land, East Antarctica. The data extends from the surface to 23.0 m depth in ALHIC2201 and from 8.5 m to 46.3 m depth in ALHIC2302. We include the raw 3D ECM data (AC and DC multitrack ECM measurements on perpendicular faces of a quarter-core cut) in CSV format and basic plots of this data. We also provide dip and dip direction estimates of the layering observed in each core section in a CSV table. | ["POINT(159.36 -76.73)"] | ["POINT(159.36 -76.73)"] | false | false |
AC-ECM for SPICEcore
|
1443232 |
2019-07-08 | Waddington, Edwin D.; Fudge, T. J. |
Using Electrical Conductance Measurements to Develop the South Pole Ice Core Chronology |
These are AC-ECM data used to identify volcanic events in SPICEcore. The data have been normalized to get a consistent baseline for data collected from three different processing seasons. | ["POINT(-180 -90)"] | ["POINT(-180 -90)"] | false | false |
WAIS Divide Multi Track Electrical Measurements
|
0944191 0944197 |
2019-04-12 | Fudge, T. J.; Taylor, Kendrick C. |
Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core |
Images of the multi-track electrical data for depths below 1956 m are given in mt_compiled_1958_3406.pdf. Images are approximately to scale. Data for individual sections can be obtained by contacting T.J. Fudge at tjfudge@uw.edu. Warm colors are high electrical conductivity. Cool colors are low electrical conductivity. Each track is normalized by subtracting the mean and dividing by the standard deviation. Plotted values are a 3-measurement (3mm) running average. Measurements affected by breaks in the core have been masked out. X-axis is approximate horizontal position on the ice core, as measured from left from looking from bottom to top of the core. Y-axis is depth in meters. Title is the tube number. | ["POLYGON((-115 -80,-114.5 -80,-114 -80,-113.5 -80,-113 -80,-112.5 -80,-112 -80,-111.5 -80,-111 -80,-110.5 -80,-110 -80,-110 -79.9,-110 -79.8,-110 -79.7,-110 -79.6,-110 -79.5,-110 -79.4,-110 -79.3,-110 -79.2,-110 -79.1,-110 -79,-110.5 -79,-111 -79,-111.5 -79,-112 -79,-112.5 -79,-113 -79,-113.5 -79,-114 -79,-114.5 -79,-115 -79,-115 -79.1,-115 -79.2,-115 -79.3,-115 -79.4,-115 -79.5,-115 -79.6,-115 -79.7,-115 -79.8,-115 -79.9,-115 -80))"] | ["POINT(-112.5 -79.5)"] | false | false |
WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)
|
0944197 |
2017-03-28 | Fudge, T. J. |
Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core |
The West Antarctic Ice Sheet Divide (WAIS Divide, WD) ice core is a newly drilled, high-accumulation deep ice core that provides Antarctic climate records of the past ~68 ka at unprecedented temporal resolution. The upper 2850 m (back to 31.2 ka BP) have been dated using annual-layer counting. Here we present a chronology for the deep part of the core (67.8-31.2 ka BP), which is based on stratigraphic matching to annual-layer-counted Greenland ice cores using globally well-mixed atmospheric methane. We calculate the WD gas age-ice age difference (Delta age) using a combination of firn densification modeling, ice-flow modeling, and a data set of d15N-N2, a proxy for past firn column thickness. The largest Delta age at WD occurs during the Last Glacial Maximum, and is 525 +/- 120 years. Internally consistent solutions can be found only when assuming little to no influence of impurity content on densification rates, contrary to a recently proposed hypothesis. We synchronize the WD chronology to a linearly scaled version of the layer-counted Greenland Ice Core Chronology (GICC05), which brings the age of Dansgaard-Oeschger (DO) events into agreement with the U/Th absolutely dated Hulu Cave speleothem record. The small Delta age at WD provides valuable opportunities to investigate the timing of atmospheric greenhouse gas variations relative to Antarctic climate, as well as the interhemispheric phasing of the \"bipolar seesaw\". We present the WD2014 chronology for the upper part (0-2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core. The chronology is based on counting of annual layers observed in the chemical, dust and electrical conductivity records. These layers are caused by seasonal changes in the source, transport, and deposition of aerosols. The measurements were interpreted manually and with the aid of two automated methods. We validated the chronology by comparing to two high-accuracy, absolutely dated chronologies. For the Holocene, the cosmogenic isotope records of 10Be from WAIS Divide and 14C for IntCal13 demonstrated that WD2014 was consistently accurate to better than 0.5% of the age. For the glacial period, comparisons to the Hulu Cave chronology demonstrated that WD2014 had an accuracy of better than 1% of the age at three abrupt climate change events between 27 and 31ka. WD2014 has consistently younger ages than Greenland ice core chronologies during most of the Holocene. For the Younger Dryas-Preboreal transition (11.595 ka; 24 years younger) and the Bolling-Allerod Warming (14.621 ka; 7 years younger), WD2014 ages are within the combined uncertainties of the timescales. Given its high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere, with synchronization to other chronologies feasible using high-quality proxies of volcanism, solar activity, atmospheric mineral dust, and atmospheric methane concentrations. | ["POINT(-112.1115 -79.481)"] | ["POINT(-112.1115 -79.481)"] | false | false |
WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica
|
0440819 0230396 0944348 0944191 0440817 |
2014-08-18 | Fudge, T. J.; Taylor, Kendrick C. |
Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core |
This data set contains electrical measurements that were used to develop the WDC06A-7 timescale. | ["POINT(-112.1115 -79.481)"] | ["POINT(-112.1115 -79.481)"] | false | false |
Microparticle, Conductivity, and Density Measurements from the WAIS Divide Deep Ice Core, Antarctica
|
0636740 |
2011-10-01 | Kreutz, Karl; Hamilton, Gordon S.; Breton, Daniel; Koffman, Bess |
Collaborative Research: Microparticle/tephra analysis of the WAIS Divide ice core |
This data set includes microparticle concentration, electrical conductivity, and density measurements from the West Antarctic Ice Sheet (WAIS) Divide deep ice core, WDC06A. Microparticle concentration data are reported as total particles per ml of meltwater. Concentration was measured using a laser detector and the University of Maine WAIS Melt Monitor system. Conductivity is measured in micro-Siemens per cm (uS/cm). Density data were collected on 3 by 3 by 100 cm sticks from the WDC06A core, using the Maine Automated Density Gauge Experiment (MADGE). Density data span 0 to 160 m in depth, while the particle and conductivity measurements span the upper 577 m of the core. Data are available via FTP in ASCII text format (.txt). | ["POINT(112.088333 -79.482778)", "POINT(-112.088333 -79.482778)"] | ["POINT(112.088333 -79.482778)", "POINT(-112.088333 -79.482778)"] | false | false |
Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica
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0538674 |
2011-08-15 | Macgregor, Joseph A.; Matsuoka, Kenichi; Studinger, Michael S. |
Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data |
This data set provides a modeled radar attenuation rate profile, showing the predicted contributions from pure ice and impurities to radar attenuation at the Vostok 5G ice core site in Antarctica, as well as the total attenuation rate and its formal uncertainty. The model data are based on borehole temperature logs, concentrations of major soluble ions measured from melted ice core samples, and information about the electrical conductivity of ice. Attenuation rates and their spatial variability are important constraints for radar studies of ice sheets. Parameters include depth, total attenuation rate, and attenuation rate contribution from pure ice, acidity, and salinity. Data are available via FTP as a text file (.txt) with columns in comma separated value format. | ["POINT(73.17 -78.47)"] | ["POINT(73.17 -78.47)"] | false | false |
Methane Isotopes from the WAIS Divide Ice Core
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0440759 |
2009-12-01 | Sowers, Todd A. |
Collaborative Research: Gases in Firn Air and Shallow Ice at the Proposed WAIS Divide Drilling Site |
This data set includes methane (CH4) isotope data from the West Antarctic Ice Sheet (WAIS) Divide ice core, WDC05A, in Antarctica. The data include depth, gas age, and the isotopic composition of methane (∂13C and ∂D of CH4). The ice core was collected during the 2005-2006 Antarctic field season. The CH4 isotope data was generated in 2008 using wet extraction methodology. Samples span the last 1,000 years, at a resolution of about 15 years. Data for samples above 69 meters were from firn air, and data below 69 meters from ice. The dating of the ice was based on continuous chemical analyses above 69 meters and Electrical Conductivity/Dielectric Property (ECM/DEP) measurements from ice. Dating uncertainty is estimated to be better than five years. Data are available via FTP in Microsoft Excel (.xls) tab delimited format | ["POINT(112.09 -79.47)"] | ["POINT(112.09 -79.47)"] | false | false |
European Project for Ice Coring in Antarctica (EPICA) Dome C Ice Core Data
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None | 2004-08-26 | Wolff, Eric W.; Monnin, Eric; Fluckiger, Jacqueline | No project link provided | This data set is a collection of analyses done on the the European Project for Ice Coring in Antarctica (EPICA)Dome C ice cores. The data include deuterium and other chemistry, insoluble dust, ice grain radius, dielectric profiling, electrical conductivity, and timescales. EPICA has completed one core in the Dome Concordia region (Core EDC96, started in 1996, 788 m length). Drilling is ongoing on a second core EDC99 (started in 1999, reached a depth of 3200 m during the 2002/2003 field season. The ice at this depth is estimated to be about 700,000 years old.) | ["POINT(123.332196 -75.09978)"] | ["POINT(123.332196 -75.09978)"] | false | false |
Siple Dome Cores Electrical Measurement Data
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9526420 |
2003-05-08 | Taylor, Kendrick C. |
Electrical and Optical Measurements on the Siple Dome Ice Core |
This data set is part of the WAISCORES project, an NSF-funded project to understand the influence of the West Antarctic ice sheet on climate and sea level change. WAISCORES researchers acquired and analyzed ice cores from the Siple Dome, in the Siple Coast region, West Antarctica. Taylor measured the electrical conductivity (ECM) and Complex Conductivity (CC), a measure of the total ions in the ice, in the main Siple Dome ice core. Measurements were taken along the core from a depth of 0 m to 800 m. The project also analyzed shallower cores for ECM and dielectric properties (DEP). (DEP is also a measure of the total ions in the ice, but with lower spatial resolution than the CC.) Albedo measurements where made on the shallow cores and the main core to a depth of 391 m. The data set includes images showing the electrical conductivity of a vertical section of the core. | ["POINT(-149 -81)"] | ["POINT(-149 -81)"] | false | false |