USAP-DC

{"dp_type": "Dataset", "free_text": "Isotope record"}

[{"awards": "1443263 Higgins, John; 1443306 Mayewski, Paul", "bounds_geometry": ["POINT(159.3562 -76.73243)"], "date_created": "Tue, 16 Oct 2018 00:00:00 GMT", "description": "Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills\r Blue ice area have been generated under a collaborative effort by the\r University of Maine Climate Change Institute (NSF Award#1443263) and\r Princeton University (NSF Award# 1443263). This data set contains stable isotope data (dD, d18O) of meltwater samples collected from the\r ice core AH-1503 (76.73243 S,\u00a0159.3562 E). Ice core site AH-1503 used the same borehole as AH- BIT58 drilled down to 124 m during the 2011-12 field season. All drilling was conducted with a 3\" Eclipse drill (Ice Drilling Design and Operations (IDDO)).\r\n", "east": 159.3562, "geometry": ["POINT(159.3562 -76.73243)"], "keywords": "Allan Hills; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Record; Mass Spectrometry; Stable Water Isotopes", "locations": "Allan Hills; Antarctica", "north": -76.73243, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "persons": "Kurbatov, Andrei V.; Mayewski, Paul A.; Introne, Douglas; Yan, Yuzhen", "project_titles": "Collaborative Research: Window into the World with 40,000-year Glacial Cycles from Climate Records in Million Year-old Ice from the Allan Hills Blue Ice Area", "projects": [{"proj_uid": "p0000760", "repository": "USAP-DC", "title": "Collaborative Research: Window into the World with 40,000-year Glacial Cycles from Climate Records in Million Year-old Ice from the Allan Hills Blue Ice Area"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.73243, "title": "Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area", "uid": "601128", "west": 159.3562}, {"awards": "1246223 Hastings, Meredith", "bounds_geometry": ["POINT(-112.1115 -79.481)"], "date_created": "Wed, 26 Apr 2017 00:00:00 GMT", "description": "This dataset contains nitrate concentration and isotopic composition (d15N, d18O, D17O) measurements on the WAIS Divide WDC06A ice core.", "east": -112.1115, "geometry": ["POINT(-112.1115 -79.481)"], "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrate; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.481, "nsf_funding_programs": null, "persons": "Buffen, Aron; Hastings, Meredith", "project_titles": "Investigating Source, Chemistry and Climate changes using the Isotopic Composition of Nitrate in Antarctic Snow and Ice", "projects": [{"proj_uid": "p0000399", "repository": "USAP-DC", "title": "Investigating Source, Chemistry and Climate changes using the Isotopic Composition of Nitrate in Antarctic Snow and Ice"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "WAIS Divide WDC06A Nitrate Isotope Record", "uid": "601022", "west": -112.1115}, {"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": "WAIS Divide; Antarctica", "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": "1043167 White, James", "bounds_geometry": ["POINT(-112.08 -79.47)"], "date_created": "Fri, 01 Jan 2016 00:00:00 GMT", "description": "This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.", "east": -112.08, "geometry": ["POINT(-112.08 -79.47)"], "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; Snow Accumulation; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.47, "nsf_funding_programs": null, "persons": "White, James; Morris, Valerie; Vaughn, Bruce; Jones, Tyler R.", "project_titles": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "projects": [{"proj_uid": "p0000078", "repository": "USAP-DC", "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "uid": "600169", "west": -112.08}, {"awards": "1043092 Steig, Eric", "bounds_geometry": ["POINT(-112.05 -79.28)"], "date_created": "Tue, 28 Apr 2015 00:00:00 GMT", "description": "This data set contains complete low resolution (0.25 to 100 cm) oxygen isotope data from the WAIS Divide Ice Core WDC06A, 0 to 3404.7 m depth. Also included is the WDC2014 timescale.", "east": -112.05, "geometry": ["POINT(-112.05 -79.28)"], "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Steig, Eric J.", "project_titles": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "projects": [{"proj_uid": "p0000010", "repository": "USAP-DC", "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.28, "title": "WAIS Divide WDC06A Oxygen Isotope Record", "uid": "609629", "west": -112.05}, {"awards": "0636731 Bender, Michael", "bounds_geometry": ["POLYGON((-180 -72.6,-176.887 -72.6,-173.774 -72.6,-170.661 -72.6,-167.548 -72.6,-164.435 -72.6,-161.322 -72.6,-158.209 -72.6,-155.096 -72.6,-151.983 -72.6,-148.87 -72.6,-148.87 -73.533,-148.87 -74.466,-148.87 -75.399,-148.87 -76.332,-148.87 -77.265,-148.87 -78.198,-148.87 -79.131,-148.87 -80.064,-148.87 -80.997,-148.87 -81.93,-151.983 -81.93,-155.096 -81.93,-158.209 -81.93,-161.322 -81.93,-164.435 -81.93,-167.548 -81.93,-170.661 -81.93,-173.774 -81.93,-176.887 -81.93,180 -81.93,174.335 -81.93,168.67 -81.93,163.005 -81.93,157.34 -81.93,151.675 -81.93,146.01 -81.93,140.345 -81.93,134.68 -81.93,129.015 -81.93,123.35 -81.93,123.35 -80.997,123.35 -80.064,123.35 -79.131,123.35 -78.198,123.35 -77.265,123.35 -76.332,123.35 -75.399,123.35 -74.466,123.35 -73.533,123.35 -72.6,129.015 -72.6,134.68 -72.6,140.345 -72.6,146.01 -72.6,151.675 -72.6,157.34 -72.6,163.005 -72.6,168.67 -72.6,174.335 -72.6,-180 -72.6))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "This project studies ancient ice buried in the Dry Valleys of Antarctica. The ice, which may approach ten million years in age, will be dated using argon and uranium radioisotope techniques. High-risk work, if successful it will offer the first and perhaps only samples of the Earth\u0027s atmosphere from millions of years in the past. These samples could offer critically important tests of paleoclimate records and proxies, as well as a glimpse into the characteristics of a past world much like the predicted future, warmer Earth. The broader impacts are graduate student education, and potentially contributing to society\u0027s understanding of global climate change and sea level rise.\n", "east": 123.35, "geometry": ["POINT(167.24 -77.265)"], "keywords": "Antarctica; Dry Valleys; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Record; Lake Vostok; Paleoclimate", "locations": "Lake Vostok; Dry Valleys; Antarctica", "north": -72.6, "nsf_funding_programs": null, "persons": "Bender, Michael", "project_titles": "Collaborative Research: Dating and Paleoenvironmental Studies on Ancient Ice in the Dry Valleys, Antarctica", "projects": [{"proj_uid": "p0000039", "repository": "USAP-DC", "title": "Collaborative Research: Dating and Paleoenvironmental Studies on Ancient Ice in the Dry Valleys, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.93, "title": "Dating and Paleoenvironmental Studies on Ancient Ice in the Dry Valleys, Antarctica", "uid": "600069", "west": -148.87}, {"awards": "0739452 Mukhopadhyay, Sujoy", "bounds_geometry": ["POLYGON((161 -76,161.2 -76,161.4 -76,161.6 -76,161.8 -76,162 -76,162.2 -76,162.4 -76,162.6 -76,162.8 -76,163 -76,163 -76.2,163 -76.4,163 -76.6,163 -76.8,163 -77,163 -77.2,163 -77.4,163 -77.6,163 -77.8,163 -78,162.8 -78,162.6 -78,162.4 -78,162.2 -78,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,161 -77.8,161 -77.6,161 -77.4,161 -77.2,161 -77,161 -76.8,161 -76.6,161 -76.4,161 -76.2,161 -76))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "This project seeks to answer a simple question: how old are potholes and related geomorphic features found in the uplands of the McMurdo Dry Valleys, Antarctica? Some research suggests that they are over ten million years old and date the growth of the East Antarctic Ice Sheet, the world\u0027s largest. However, some evidence suggests that these are young, erosional features that continuing to evolve to this day. This project uses cosmogenic nuclide dating to determine the age of the pothole floors. The results are important for determining the ice sheet?s history and interpreting the O-isotope record from the marine sediment cores, key records of global climate. Broader impacts include K12 outreach and incorporation of outcomes into university courses.", "east": 163.0, "geometry": ["POINT(162 -77)"], "keywords": "Antarctica; Cosmogenic Dating; Dry Valleys; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Paleoclimate; Sample/collection Description; Sample/Collection Description; Solid Earth", "locations": "Dry Valleys; Antarctica", "north": -76.0, "nsf_funding_programs": null, "persons": "Mukhopadhyay, Sujoy", "project_titles": "Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica", "projects": [{"proj_uid": "p0000461", "repository": "USAP-DC", "title": "Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica", "uid": "600074", "west": 161.0}]

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