{"dp_type": "Dataset", "free_text": "Air Bubbles"}
[{"awards": "1643664 Severinghaus, Jeffrey", "bounds_geometry": null, "date_created": "Tue, 16 Aug 2022 00:00:00 GMT", "description": "This data set comprises measurements of noble and inert gases in the firn at the DE08-OH site sampled in 2018-2019 near the summit of Law Dome, Antarctica. The data show the expected gravitational enrichment of heavy isotopes with depth, somewhat attenuated by the high accumulation rate and a near-surface well-mixed zone (convective zone), and the \"lock-in\" horizon at 68 m depth. As seen at many other sites, the heavy isotope of oxygen 18O is depleted progressively with depth within the lock-in zone due to faster gas permeation of 16O16O relative to 18O16O from compressed air bubbles.", "east": null, "geometry": null, "keywords": "Antarctica; Firn; Firn Density; Gravitational Settling; Inert Gases; Law Dome", "locations": "Law Dome; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Severinghaus, Jeffrey P.", "project_titles": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability", "projects": [{"proj_uid": "p0010341", "repository": "USAP-DC", "title": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2", "uid": "601598", "west": null}, {"awards": "1245659 Petrenko, Vasilii; 1246148 Severinghaus, Jeffrey; 1245821 Brook, Edward", "bounds_geometry": ["POINT(162.167 -77.733)"], "date_created": "Mon, 12 Aug 2019 00:00:00 GMT", "description": "New ice cores retrieved from the Taylor Glacier (Antarctica) blue ice area contain ice and air spanning the Marine Isotope Stage (MIS) 5-4 transition, a period of global cooling and ice sheet expansion. We determine chronologies for the ice and air bubbles in the new ice cores by visually matching variations in gas- and ice- phase tracers to preexisting ice core records. The chronologies reveal an ice age-gas age difference (\u0394age) approaching 10 ka during MIS 4, implying very low snow accumulation in the Taylor Glacier accumulation zone. A revised chronology for the analagous section of the Taylor Dome ice core (84 to 55 ka), located to the south of the Taylor Glacier accumulation zone, shows that \u0394age did not exceed 3 ka. The difference in \u0394age between the two records during MIS 4 is similar in magnitude but opposite in direction to what is observed at the Last Glacial Maximum. This relationship implies that a spatial gradient in snow accumulation existed across the Taylor Dome region during MIS 4 that was oriented in the opposite direction of the accumulation gradient during the Last Glacial Maximum.", "east": 162.167, "geometry": ["POINT(162.167 -77.733)"], "keywords": "Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; CO2; Dust; Gas; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Mass Spectrometer; Methane; Nitrogen Isotopes; Oxygen Isotope; Paleoclimate; Snow/ice; Snow/Ice; Taylor Dome; Taylor Dome Ice Core", "locations": "Taylor Dome; Antarctica", "north": -77.733, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "persons": "Menking, James; Brook, Edward J.; Marcott, Shaun; Barker, Stephen; Shackleton, Sarah; Dyonisius, Michael; Petrenko, Vasilii; McConnell, Joseph; Rhodes, Rachel; Bauska, Thomas; Baggenstos, Daniel; Severinghaus, Jeffrey P.", "project_titles": "Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "projects": [{"proj_uid": "p0000283", "repository": "USAP-DC", "title": "Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.733, "title": "Gas and Dust Measurements for Taylor Glacier and Taylor Dome Ice Cores", "uid": "601198", "west": 162.167}, {"awards": "0539578 Alley, Richard", "bounds_geometry": ["POINT(-112.085 -79.467)"], "date_created": "Thu, 01 Mar 2018 00:00:00 GMT", "description": "This dataset contains detailed grain and bubble properties data for a new hybrid analysis study relating bubble elongation to crystal orientations. All data are from a depth of 580 meters in a sample from the WAIS Divide ice core.", "east": -112.085, "geometry": ["POINT(-112.085 -79.467)"], "keywords": "Air Bubbles; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Strain; Physical Ice Properties; Snow/ice; Snow/Ice; Strain", "locations": "Antarctica", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Fegyveresi, John; Alley, Richard", "project_titles": "Collaborative Research: Continued Study of Physical Properties of the WAIS Divide Deep Core", "projects": [{"proj_uid": "p0000027", "repository": "USAP-DC", "title": "Collaborative Research: Continued Study of Physical Properties of the WAIS Divide Deep Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "WAIS Divide 580m Bubble and Grain Hybrid Data", "uid": "601087", "west": -112.085}, {"awards": "0539578 Alley, Richard", "bounds_geometry": ["POINT(-112.3 -79.433333)"], "date_created": "Thu, 14 Aug 2014 00:00:00 GMT", "description": "This data set includes bubble number-density measured at depths from 120 meters to 560 meters at 20-meter intervals in both horizontal and vertical samples. The data set also includes modeled temperature reconstructions based on the model developed by Spencer and others (2006).", "east": -112.3, "geometry": ["POINT(-112.3 -79.433333)"], "keywords": "Air Bubbles; Antarctica; Camera; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records", "locations": "Antarctica", "north": -79.433333, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Alley, Richard; Fegyveresi, John", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -79.433333, "title": "Bubble Number-density Data and Modeled Paleoclimates", "uid": "609538", "west": -112.3}, {"awards": "0838849 Bender, Michael", "bounds_geometry": ["POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "This award supports a project to generate an absolute timescale for the Allan Hills Blue Ice Area (BIA), and then to reconstruct details of past climate changes and greenhouse gas concentrations for certain time periods back to 2.5 Ma. Ice ages will be determined by applying emerging methods for absolute and relative dating of trapped air bubbles (based on Argon-40/Argon-38, delta-18O of O2, and the O2/N2 ratio). To demonstrate the potential of the Allan Hills BIAs as a paleoclimate archive trenches and ice cores will be collected for age intervals corresponding to 110-140 ka, 1 Ma, and 2.5 Ma. During the proposed two field seasons a total of 6x100 m and additional 15 m cores will be combined with trenching. The intellectual merit of the proposed activity is that the results of this work will extend the landmark work of EPICA and other deep ice coring efforts, which give records dating back to 0.8 Ma, and will complement work planned by IPICS to drill a continuous Antarctic ice core extending to 1.5 Ma. The results will help to advance understanding of major climate regimes and transitions that took place between 0-2.5 Ma, including the 40 kyr world and the mid-Pleistocene climate transition. A major long-term scientific goal is to provide a transformative approach to the collection of paleoclimate records by establishing an \u0027International Climate Park\u0027 in the Allan Hills BIA that would enable sampling of large quantities of known age ice as old as 2.5 Ma, by any interested American or foreign investigator. The broader impacts resulting from the proposed activity include training students who are well versed in advanced field, laboratory and numerical modeling methods combining geochemistry, glaciology, and paleoclimatology. We will include material relevant to our proposed research in our ongoing efforts in local education and in our outreach efforts for media. The University of Maine already has cyberinfrastructure, using state of the art web-based technology, which can provide a wide community of scientists with fast access to the results of our research. The work will contribute to the broad array of climate change studies that is informing worldwide understanding of natural and anthropogenic forced climate change, and the options for responding. This award has field work in Antarctica.\n", "east": 159.41667, "geometry": ["POINT(159.29167 -76.7)"], "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Ice Core Records; Paleoclimate; Solid Earth", "locations": "Allan Hills; Antarctica", "north": -76.66667, "nsf_funding_programs": null, "persons": "Bender, Michael", "project_titles": "Collaborative Research: Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)", "projects": [{"proj_uid": "p0000046", "repository": "USAP-DC", "title": "Collaborative Research: Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.73333, "title": "Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)", "uid": "600099", "west": 159.16667}, {"awards": "0230260 Bender, Michael", "bounds_geometry": ["POINT(106.8 -72.4667)"], "date_created": "Tue, 10 Jul 2007 00:00:00 GMT", "description": "This data set includes a time scale for the Vostok ice core, retrieved from Vostok Station on the East Antarctic Plateau. This chronology is derived by orbitally tuning to molecular oxygen to nitrogen (O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e) ratios in occluded air for depths deeper than 1550 m (greater than 112,000 years old), and by gas correlation to the Greenland Ice Sheet Project 2 (GISP2) chronology for the ice core section that is shallower than 1422 m (less than 102,000 years old). Because of poor gas preservation in air bubbles in shallower depths, investigators could only constrain the Vostok chronology for the section deeper than 1550 m by O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e. Thus for the shallower section of the core, they synchronized the Vostok delta oxygen-18 (\u0026delta;\u003csup\u003e18\u003c/sup\u003eO) and methane (CH\u003csub\u003e4\u003c/sub\u003e) measurements to those of the GISP2 to obtain the chronology (see Bender, et al. 2006). Note, CH\u003csub\u003e4\u003c/sub\u003e data are not included in this data set.\n\nInvestigators analyzed the O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e and the\u003cem\u003e\u003cstrong\u003e \u003c/strong\u003e\u003c/em\u003e\u0026delta;\u003csup\u003e18\u003c/sup\u003eO record ratios for approximately the past 115,000 to 400,000 years in the Vostok ice core. They combined new measurements for O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e and \u0026delta;\u003csup\u003e18\u003c/sup\u003eO with data from Bender (2002) and Petit, et al. (1999), respectively.\n\nData are in Microsoft Excel format and are available via FTP.", "east": 106.8, "geometry": ["POINT(106.8 -72.4667)"], "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Lake Vostok; Paleoclimate; Vostok; Vostok Ice Core", "locations": "Lake Vostok; Vostok; Antarctica", "north": -72.4667, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Bender, Michael; Suwa, Makoto", "project_titles": "Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core", "projects": [{"proj_uid": "p0000257", "repository": "USAP-DC", "title": "Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.4667, "title": "Trapped Gas Composition and Chronology of the Vostok Ice Core", "uid": "609311", "west": 106.8}, {"awards": "9725305 Severinghaus, Jeffrey; 0230260 Bender, Michael; 0230452 Severinghaus, Jeffrey", "bounds_geometry": ["POINT(0 -90)", "POINT(-148.767 -80.667)"], "date_created": "Thu, 17 Aug 2006 00:00:00 GMT", "description": "This data set includes gas ratios in polar firn air: O\u003csub\u003e2\u003c/sub\u003e/N\u003csub\u003e2\u003c/sub\u003e, \u003csup\u003e15\u003c/sup\u003eN/\u003csup\u003e14\u003c/sup\u003eN, \u003csup\u003e40\u003c/sup\u003eAr/N\u003csub\u003e2\u003c/sub\u003e, \u003csup\u003e40\u003c/sup\u003eAr/\u003csup\u003e36\u003c/sup\u003eAr, \u003csup\u003e40\u003c/sup\u003eAr/\u003csup\u003e38\u003c/sup\u003eAr, \u003csup\u003e84\u003c/sup\u003eKr/\u003csup\u003e36\u003c/sup\u003eAr, \u003csup\u003e132\u003c/sup\u003eXe/\u003csup\u003e36\u003c/sup\u003eAr, and \u003csup\u003e22\u003c/sup\u003eNe/\u003csup\u003e36\u003c/sup\u003eAr. Investigators sampled air from the permeable snowpack (firn) layer at two sites: Siple Dome, Antarctica in 1996 and at the South Pole in 2001. They observed and modeled the processes of gravitational settling, thermal fractionation, and preferential exclusion of small gas molecules from closed air bubbles. The purpose of this study was to understand these physical processes, which affect the composition of bubbles trapped in ice. By measuring these gas ratios in the ancient air preserved in bubbles trapped in ice, researchers can determine past atmospheric composition and local temperature changes along with the relative timing and magnitude of such events.\n\nThe data file is available in Microsoft Excel format. The research paper is available in PDF. Data and the research paper are available via FTP.", "east": 0.0, "geometry": ["POINT(0 -90)", "POINT(-148.767 -80.667)"], "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciology; Paleoclimate; Siple Dome; Snow/ice; Snow/Ice; South Pole", "locations": "Siple Dome; South Pole; Antarctica", "north": -80.667, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Severinghaus, Jeffrey P.; Battle, Mark; Bender, Michael", "project_titles": "Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core", "projects": [{"proj_uid": "p0000257", "repository": "USAP-DC", "title": "Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -90.0, "title": "Firn Air Inert Gas and Oxygen Observations from Siple Dome, 1996, and the South Pole, 2001", "uid": "609290", "west": -148.767}]
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2
|
1643664 |
2022-08-16 | Severinghaus, Jeffrey P. |
Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability |
This data set comprises measurements of noble and inert gases in the firn at the DE08-OH site sampled in 2018-2019 near the summit of Law Dome, Antarctica. The data show the expected gravitational enrichment of heavy isotopes with depth, somewhat attenuated by the high accumulation rate and a near-surface well-mixed zone (convective zone), and the "lock-in" horizon at 68 m depth. As seen at many other sites, the heavy isotope of oxygen 18O is depleted progressively with depth within the lock-in zone due to faster gas permeation of 16O16O relative to 18O16O from compressed air bubbles. | [] | [] | false | false |
Gas and Dust Measurements for Taylor Glacier and Taylor Dome Ice Cores
|
1245659 1246148 1245821 |
2019-08-12 | Menking, James; Brook, Edward J.; Marcott, Shaun; Barker, Stephen; Shackleton, Sarah; Dyonisius, Michael; Petrenko, Vasilii; McConnell, Joseph; Rhodes, Rachel; Bauska, Thomas; Baggenstos, Daniel; Severinghaus, Jeffrey P. |
Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive |
New ice cores retrieved from the Taylor Glacier (Antarctica) blue ice area contain ice and air spanning the Marine Isotope Stage (MIS) 5-4 transition, a period of global cooling and ice sheet expansion. We determine chronologies for the ice and air bubbles in the new ice cores by visually matching variations in gas- and ice- phase tracers to preexisting ice core records. The chronologies reveal an ice age-gas age difference (Δage) approaching 10 ka during MIS 4, implying very low snow accumulation in the Taylor Glacier accumulation zone. A revised chronology for the analagous section of the Taylor Dome ice core (84 to 55 ka), located to the south of the Taylor Glacier accumulation zone, shows that Δage did not exceed 3 ka. The difference in Δage between the two records during MIS 4 is similar in magnitude but opposite in direction to what is observed at the Last Glacial Maximum. This relationship implies that a spatial gradient in snow accumulation existed across the Taylor Dome region during MIS 4 that was oriented in the opposite direction of the accumulation gradient during the Last Glacial Maximum. | ["POINT(162.167 -77.733)"] | ["POINT(162.167 -77.733)"] | false | false |
WAIS Divide 580m Bubble and Grain Hybrid Data
|
0539578 |
2018-03-01 | Fegyveresi, John; Alley, Richard |
Collaborative Research: Continued Study of Physical Properties of the WAIS Divide Deep Core |
This dataset contains detailed grain and bubble properties data for a new hybrid analysis study relating bubble elongation to crystal orientations. All data are from a depth of 580 meters in a sample from the WAIS Divide ice core. | ["POINT(-112.085 -79.467)"] | ["POINT(-112.085 -79.467)"] | false | false |
Bubble Number-density Data and Modeled Paleoclimates
|
0539578 |
2014-08-14 | Alley, Richard; Fegyveresi, John | No project link provided | This data set includes bubble number-density measured at depths from 120 meters to 560 meters at 20-meter intervals in both horizontal and vertical samples. The data set also includes modeled temperature reconstructions based on the model developed by Spencer and others (2006). | ["POINT(-112.3 -79.433333)"] | ["POINT(-112.3 -79.433333)"] | false | false |
Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)
|
0838849 |
2014-01-01 | Bender, Michael |
Collaborative Research: Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA) |
This award supports a project to generate an absolute timescale for the Allan Hills Blue Ice Area (BIA), and then to reconstruct details of past climate changes and greenhouse gas concentrations for certain time periods back to 2.5 Ma. Ice ages will be determined by applying emerging methods for absolute and relative dating of trapped air bubbles (based on Argon-40/Argon-38, delta-18O of O2, and the O2/N2 ratio). To demonstrate the potential of the Allan Hills BIAs as a paleoclimate archive trenches and ice cores will be collected for age intervals corresponding to 110-140 ka, 1 Ma, and 2.5 Ma. During the proposed two field seasons a total of 6x100 m and additional 15 m cores will be combined with trenching. The intellectual merit of the proposed activity is that the results of this work will extend the landmark work of EPICA and other deep ice coring efforts, which give records dating back to 0.8 Ma, and will complement work planned by IPICS to drill a continuous Antarctic ice core extending to 1.5 Ma. The results will help to advance understanding of major climate regimes and transitions that took place between 0-2.5 Ma, including the 40 kyr world and the mid-Pleistocene climate transition. A major long-term scientific goal is to provide a transformative approach to the collection of paleoclimate records by establishing an 'International Climate Park' in the Allan Hills BIA that would enable sampling of large quantities of known age ice as old as 2.5 Ma, by any interested American or foreign investigator. The broader impacts resulting from the proposed activity include training students who are well versed in advanced field, laboratory and numerical modeling methods combining geochemistry, glaciology, and paleoclimatology. We will include material relevant to our proposed research in our ongoing efforts in local education and in our outreach efforts for media. The University of Maine already has cyberinfrastructure, using state of the art web-based technology, which can provide a wide community of scientists with fast access to the results of our research. The work will contribute to the broad array of climate change studies that is informing worldwide understanding of natural and anthropogenic forced climate change, and the options for responding. This award has field work in Antarctica. | ["POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667))"] | ["POINT(159.29167 -76.7)"] | false | false |
Trapped Gas Composition and Chronology of the Vostok Ice Core
|
0230260 |
2007-07-10 | Bender, Michael; Suwa, Makoto |
Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core |
This data set includes a time scale for the Vostok ice core, retrieved from Vostok Station on the East Antarctic Plateau. This chronology is derived by orbitally tuning to molecular oxygen to nitrogen (O<sub>2</sub>/N<sub>2</sub>) ratios in occluded air for depths deeper than 1550 m (greater than 112,000 years old), and by gas correlation to the Greenland Ice Sheet Project 2 (GISP2) chronology for the ice core section that is shallower than 1422 m (less than 102,000 years old). Because of poor gas preservation in air bubbles in shallower depths, investigators could only constrain the Vostok chronology for the section deeper than 1550 m by O<sub>2</sub>/N<sub>2</sub>. Thus for the shallower section of the core, they synchronized the Vostok delta oxygen-18 (δ<sup>18</sup>O) and methane (CH<sub>4</sub>) measurements to those of the GISP2 to obtain the chronology (see Bender, et al. 2006). Note, CH<sub>4</sub> data are not included in this data set. Investigators analyzed the O<sub>2</sub>/N<sub>2</sub> and the<em><strong> </strong></em>δ<sup>18</sup>O record ratios for approximately the past 115,000 to 400,000 years in the Vostok ice core. They combined new measurements for O<sub>2</sub>/N<sub>2</sub> and δ<sup>18</sup>O with data from Bender (2002) and Petit, et al. (1999), respectively. Data are in Microsoft Excel format and are available via FTP. | ["POINT(106.8 -72.4667)"] | ["POINT(106.8 -72.4667)"] | false | false |
Firn Air Inert Gas and Oxygen Observations from Siple Dome, 1996, and the South Pole, 2001
|
9725305 0230260 0230452 |
2006-08-17 | Severinghaus, Jeffrey P.; Battle, Mark; Bender, Michael |
Collaborative Research: Trapped Gas Composition and the Chronology of the Vostok Ice Core |
This data set includes gas ratios in polar firn air: O<sub>2</sub>/N<sub>2</sub>, <sup>15</sup>N/<sup>14</sup>N, <sup>40</sup>Ar/N<sub>2</sub>, <sup>40</sup>Ar/<sup>36</sup>Ar, <sup>40</sup>Ar/<sup>38</sup>Ar, <sup>84</sup>Kr/<sup>36</sup>Ar, <sup>132</sup>Xe/<sup>36</sup>Ar, and <sup>22</sup>Ne/<sup>36</sup>Ar. Investigators sampled air from the permeable snowpack (firn) layer at two sites: Siple Dome, Antarctica in 1996 and at the South Pole in 2001. They observed and modeled the processes of gravitational settling, thermal fractionation, and preferential exclusion of small gas molecules from closed air bubbles. The purpose of this study was to understand these physical processes, which affect the composition of bubbles trapped in ice. By measuring these gas ratios in the ancient air preserved in bubbles trapped in ice, researchers can determine past atmospheric composition and local temperature changes along with the relative timing and magnitude of such events. The data file is available in Microsoft Excel format. The research paper is available in PDF. Data and the research paper are available via FTP. | ["POINT(0 -90)", "POINT(-148.767 -80.667)"] | ["POINT(0 -90)", "POINT(-148.767 -80.667)"] | false | false |