USAP-DC

{"dp_type": "Dataset", "free_text": "Ice Core Chronology"}

[{"awards": "1443105 Steig, Eric; 1141839 Steig, Eric; 1443336 Osterberg, Erich; 1443397 Kreutz, Karl; 1443663 Cole-Dai, Jihong", "bounds_geometry": ["POINT(-99 -90)"], "date_created": "Wed, 20 Nov 2024 00:00:00 GMT", "description": "This dataset includes all major ion chemistry data from the South Pole Ice Core as well as sea salt sodium data resampled at annual resolution. The development of this dataset is discussed in Winski et al. 2021. The chloride, nitrate, sulfate, magnesium and calcium data have not yet been published, nor has any data prior to the Holocene. Please contact the dataset authors if you have questions.", "east": -99.0, "geometry": ["POINT(-99 -90)"], "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "locations": "South Pole; Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "persons": "Winski, Dominic A.", "project_titles": "Collaborative Research: A 1500m Ice Core from South Pole; Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole; Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "projects": [{"proj_uid": "p0010060", "repository": "USAP-DC", "title": "Collaborative Research: A 1500m Ice Core from South Pole"}, {"proj_uid": "p0010065", "repository": "USAP-DC", "title": "Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole"}, {"proj_uid": "p0010051", "repository": "USAP-DC", "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "South Pole Ice Core Sea Salt and Major Ions", "uid": "601851", "west": -99.0}, {"awards": "1443336 Osterberg, Erich; 1443397 Kreutz, Karl; 1443663 Cole-Dai, Jihong; 1443105 Steig, Eric; 1141839 Steig, Eric", "bounds_geometry": ["POINT(-89.16 -89.99)"], "date_created": "Mon, 18 Nov 2024 00:00:00 GMT", "description": "This dataset includes major ion and seasonal sea salt chemistry data from the South Pole Ice Core. Included are the raw major ion data, annually resolved mean, maximum and minimum sea salt sodium concentrations and centennially resolved principal components (discussed in Winski et al. (2021).", "east": -89.16, "geometry": ["POINT(-89.16 -89.99)"], "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "locations": "Antarctica; South Pole", "north": -89.99, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "persons": "Winski, Dominic A.", "project_titles": "Collaborative Research: A 1500m Ice Core from South Pole; Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole; Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "projects": [{"proj_uid": "p0010065", "repository": "USAP-DC", "title": "Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole"}, {"proj_uid": "p0010051", "repository": "USAP-DC", "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements"}, {"proj_uid": "p0010060", "repository": "USAP-DC", "title": "Collaborative Research: A 1500m Ice Core from South Pole"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -89.99, "title": "South Pole Ice Core Holocene Major Ion Dataset", "uid": "601850", "west": -89.16}, {"awards": "1443397 Kreutz, Karl", "bounds_geometry": ["POINT(-180 -90)"], "date_created": "Thu, 16 Mar 2023 00:00:00 GMT", "description": "This dataset contains biologically relevant trace metal concentrations metrics for the\r\nSPICEcore intermediate core (SPC14), from the surface to 1751 m (~54 ka). The data set\r\nincludes cleaned Fe and Mn biologically relevant concentrations (operationally defined pH 5)\r\ntrace mental concentration measurements and dissolved concentrations (operationally defined as concentration \u0026lt;0.45\u00b5m and acidified to \u0026lt;pH 1).", "east": -180.0, "geometry": ["POINT(-180 -90)"], "keywords": "Antarctica; South Pole; SPICEcore", "locations": "South Pole; Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Kreutz, Karl", "project_titles": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "projects": [{"proj_uid": "p0010051", "repository": "USAP-DC", "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.", "uid": "601675", "west": -180.0}, {"awards": "1744832 Severinghaus, Jeffrey", "bounds_geometry": ["POINT(159.3562 -76.73243)"], "date_created": "Tue, 22 Nov 2022 00:00:00 GMT", "description": "These data cover the penultimate glacial period (MIS 6) and parts of MIS5, in Allan Hills ice. The d18Oatm data are useful for dating the core, and the 15N is useful for inferring firn thickness. Importantly, the data have only been corrected for gas loss using published methods (i.e. Baggenstos et al. 2017), but not for recently recognized (and unpublished) effects of declining contemporary atmospheric O2/N2 due to fossil fuel burning. These changes unfortunately affect the La Jolla Air standard gas O2/N2 ratio that is used in our lab to make the measurements. Users of this data are encouraged to contact Jeff Severinghaus for help in making these novel corrections to the standard gas.", "east": 159.3562, "geometry": ["POINT(159.3562 -76.73243)"], "keywords": "18O; Allan Hills; Allan Hills Blue Ice; Antarctica; Blue Ice; Delta 15N; Delta 18O; Dole Effect; Firn Thickness; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chronology; Ice Core Records", "locations": "Allan Hills; Antarctica", "north": -76.73243, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Severinghaus, Jeffrey P.", "project_titles": "Center for Oldest Ice Exploration; Collaborative research: Snapshots of Early and Mid-Pleistocene Climate and Atmospheric Composition from the Allan Hills Blue Ice Area ", "projects": [{"proj_uid": "p0010321", "repository": "USAP-DC", "title": "Center for Oldest Ice Exploration"}, {"proj_uid": "p0010253", "repository": "USAP-DC", "title": "Collaborative research: Snapshots of Early and Mid-Pleistocene Climate and Atmospheric Composition from the Allan Hills Blue Ice Area "}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.73243, "title": "Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022", "uid": "601620", "west": 159.3562}, {"awards": "1443397 Kreutz, Karl", "bounds_geometry": ["POINT(0 -90)"], "date_created": "Fri, 01 Apr 2022 00:00:00 GMT", "description": "This dataset contains particle metrics for the South Pole Ice Core (SPICEcore) intermediate core (SPC14), from the surface to 1751 m depth (~54,000 years before present [BP]). Data were collected via Klotz Abakus laser particle counter via continuous-flow-analysis (CFA), Beckman Coulter Multisizer 3 using Coulter Counter (CC) principles, and dynamic particle imaging using a FlowCAM instrument. CFA measurements were made at Dartmouth College, CC measurements were made at Colby College, and FlowCAM measurements were made at the University of Maine.", "east": 0.0, "geometry": ["POINT(0 -90)"], "keywords": "Antarctica; Dust; Ice Core; South Pole", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Kreutz, Karl", "project_titles": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "projects": [{"proj_uid": "p0010051", "repository": "USAP-DC", "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements", "uid": "601553", "west": 0.0}, {"awards": "1443663 Cole-Dai, Jihong", "bounds_geometry": ["POLYGON((-180 -89.99,-152.184 -89.99,-124.368 -89.99,-96.552 -89.99,-68.736 -89.99,-40.92 -89.99,-13.104 -89.99,14.712 -89.99,42.528 -89.99,70.344 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,70.344 -89.99,42.528 -89.99,14.712 -89.99,-13.104 -89.99,-40.92 -89.99,-68.736 -89.99,-96.552 -89.99,-124.368 -89.99,-152.184 -89.99,180 -89.99,152.184 -89.99,124.368 -89.99,96.552 -89.99,68.736 -89.99,40.92 -89.99,13.104 -89.99,-14.712 -89.99,-42.528 -89.99,-70.344 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-70.344 -89.99,-42.528 -89.99,-14.712 -89.99,13.104 -89.99,40.92 -89.99,68.736 -89.99,96.552 -89.99,124.368 -89.99,152.184 -89.99,-180 -89.99))"], "date_created": "Sat, 30 Jan 2021 00:00:00 GMT", "description": "Major ion concentrations in SPICEcore samples from the section of 400-480 m were measured with ion chromatography. The ions are chloride, nitrate, sulfate, sodium, potassium, magnesium, and calcium.\r\nThis section was analyzed to replicate the measurement of the same section at Dartmouth College.", "east": -98.16, "geometry": ["POINT(-180 -89.99)"], "keywords": "Antarctica; Ions; South Pole; SPICEcore", "locations": "South Pole; Antarctica", "north": -89.99, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Cole-Dai, Jihong; Larrick, Carleigh", "project_titles": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "projects": [{"proj_uid": "p0010051", "repository": "USAP-DC", "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -89.99, "title": "SPICEcore 400-480 m Major Ions SDSU", "uid": "601430", "west": 98.16}, {"awards": "1804154 Sowers, Todd; 1443472 Brook, Edward J.; 1643394 Buizert, Christo; 1443336 Osterberg, Erich; 1141839 Steig, Eric; 1443710 Severinghaus, Jeffrey; 1443397 Kreutz, Karl; 1443464 Sowers, Todd; 1142517 Aydin, Murat; 1443470 Aydin, Murat", "bounds_geometry": ["POINT(-99.16 -89.99)"], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "We present the methane (CH4) concentration data for the South Pole ice core (SPC14). CH4 concentrations were measured jointly at Oregon State University and Pennsylvania State University. All depths are in meters below the surface. Methane data have been corrected for blank offsets, solubility, and gravitational fractionation. All ages are in years before 1950 C.E. on the SP19 gas chronology. ", "east": -99.16, "geometry": ["POINT(-99.16 -89.99)"], "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "locations": "Antarctica; South Pole; Antarctica", "north": -89.99, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences", "persons": "Severinghaus, Jeffrey P.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.; Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Winski, Dominic A.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.", "project_titles": "Carbonyl Sulfide, Methyl Chloride, and Methyl Bromide Measurements in the New Intermediate-depth South Pole Ice Core; Collaborative Research: A 1500m Ice Core from South Pole; Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core; Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "projects": [{"proj_uid": "p0010089", "repository": "USAP-DC", "title": "Carbonyl Sulfide, Methyl Chloride, and Methyl Bromide Measurements in the New Intermediate-depth South Pole Ice Core"}, {"proj_uid": "p0010051", "repository": "USAP-DC", "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements"}, {"proj_uid": "p0010060", "repository": "USAP-DC", "title": "Collaborative Research: A 1500m Ice Core from South Pole"}, {"proj_uid": "p0010005", "repository": "USAP-DC", "title": "Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -89.99, "title": "South Pole ice core (SPC14) discrete methane data", "uid": "601381", "west": -99.16}, {"awards": "1443232 Waddington, Edwin", "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": "Tue, 28 Jul 2020 00:00:00 GMT", "description": "These data were collected with DC and AC ECM at the NSF Ice Core Facility.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "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": "ECM (DC and AC) multi-track data and images from 2016 processing season", "uid": "601366", "west": -180.0}, {"awards": "1443336 Osterberg, Erich", "bounds_geometry": ["POINT(-180 -90)"], "date_created": "Thu, 29 Aug 2019 00:00:00 GMT", "description": "The South Pole Ice Core (SPICEcore) was drilled in 2014-2016 to provide a detailed multi-proxy archive of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. Interpretation of these records requires an accurate depth-age relationship. Here, we present the SP19 timescale for the age of the ice of SPICEcore. SP19 is synchronized to the WD2014 chronology from the West Antarctic Ice Sheet Divide (WAIS Divide) ice core using stratigraphic matching of 251 volcanic events. These events indicate an age of 54,302 +/- 519 years BP (before the year 1950) at the bottom of SPICEcore. Annual layers identified in sodium and magnesium ions to 11,341 BP were used to interpolate between stratigraphic volcanic tie points, yielding an annually-resolved chronology through the Holocene. Estimated timescale uncertainty during the Holocene is less than 18 years relative to WD2014, with the exception of the interval between 1800 to 3100 BP when uncertainty estimates reach +/- 25 years due to widely spaced volcanic tie points. Prior to the Holocene, uncertainties remain within 124 years relative to WD2014. Results show an average Holocene accumulation rate of 7.4 cm/yr (water equivalent). The time variability of accumulation rate is consistent with expectations for steady-state ice flow through the modern spatial pattern of accumulation rate. Time variations in nitrate concentration, nitrate seasonal amplitude, and \u03b415N of N2 in turn are as expected for the accumulation-rate variations. The highly variable yet well-constrained Holocene accumulation history at the site can help improve scientific understanding of deposition-sensitive climate proxies such as \u03b415N of N2 and photolyzed chemical compounds.", "east": -180.0, "geometry": ["POINT(-180 -90)"], "keywords": "Antarctica; Calcium (ca); Chemistry:ice; Chemistry:Ice; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciochemistry; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Ice Core Records; Ice Core Stratigraphy; Nitrate; Nitrogen Isotopes; Paleoclimate; Snow/ice; Snow/Ice; South Pole; SPICEcore", "locations": "South Pole; Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Winski, Dominic A.; Fudge, T. J.; Dunbar, Nelia; Buizert, Christo; Bay, Ryan; Souney, Joseph Jr.; Sigl, Michael; McConnell, Joseph; Fegyveresi, John; Cole-Dai, Jihong; Thundercloud, Zayta; Cox, Thomas S.; Kreutz, Karl; Epifanio, Jenna; Ortman, Nikolas; Brook, Edward J.; Beaudette, Ross; Sowers, Todd A.; Steig, Eric J.; Morris, Valerie; Kahle, Emma; Ferris, David G.; Aydin, Murat; Nicewonger, Melinda R.; Casey, Kimberly A.; Alley, Richard; Waddington, Edwin D.; Osterberg, Erich; Severinghaus, Jeffrey P.; Jones, Tyler R.; Iverson, Nels", "project_titles": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "projects": [{"proj_uid": "p0010051", "repository": "USAP-DC", "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "The South Pole Ice Core (SPICEcore) chronology and supporting data", "uid": "601206", "west": -180.0}, {"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": "1043518 Brook, Edward J.", "bounds_geometry": ["POLYGON((-113 -79,-112.8 -79,-112.6 -79,-112.4 -79,-112.2 -79,-112 -79,-111.8 -79,-111.6 -79,-111.4 -79,-111.2 -79,-111 -79,-111 -79.1,-111 -79.2,-111 -79.3,-111 -79.4,-111 -79.5,-111 -79.6,-111 -79.7,-111 -79.8,-111 -79.9,-111 -80,-111.2 -80,-111.4 -80,-111.6 -80,-111.8 -80,-112 -80,-112.2 -80,-112.4 -80,-112.6 -80,-112.8 -80,-113 -80,-113 -79.9,-113 -79.8,-113 -79.7,-113 -79.6,-113 -79.5,-113 -79.4,-113 -79.3,-113 -79.2,-113 -79.1,-113 -79))"], "date_created": "Mon, 11 Sep 2017 00:00:00 GMT", "description": "Below we present the early Holocene discrete CH4 dataset from Siple Dome (SDMA), Antarctica, measured at Oregon State University (OSU) and Seoul National University (SNU) by discrete wet extraction technique. Analytical method is described in Grachev et al. (2009) and Mitchell et al. (2011) for OSU data, and Yang et al. (2017) for SNU data. SDMA CH4 composite record was constructed by combining OSU data for 7.6 - 9.0 ka and SNU data for 9.0 - 11.6 ka to maximize temporal resolution. SDMA gas chronology was synchronized to Greenland Ice Core Chronology 2005 (GICC05) scale. For detailed description on synchronization and age uncertainty please refer to Yang et al. (2017).", "east": -111.0, "geometry": ["POINT(-112 -79.5)"], "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome; Siple Dome Ice Core", "locations": "Siple Dome; Antarctica", "north": -79.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Yang, Ji-Woong; Ahn, Jinho", "project_titles": "Collaborative Research: Completing an ultra-high resolution methane record from the WAIS Divide ice core", "projects": [{"proj_uid": "p0000185", "repository": "USAP-DC", "title": "Collaborative Research: Completing an ultra-high resolution methane record from the WAIS Divide ice core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core; Siple Dome Ice Core", "south": -80.0, "title": "Early Holocene methane records from Siple Dome, Antarctica", "uid": "601055", "west": -113.0}, {"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": "0126343 Nishiizumi, Kunihiko", "bounds_geometry": ["POINT(-148.812 -81.6588)"], "date_created": "Thu, 31 May 2007 00:00:00 GMT", "description": "This data set includes a record of cosmogenic radionuclide concentrations in the Siple Dome A ice core collected as part of the West Antarctic ice core program. The investigators measured profiles of both \u003csup\u003e10\u003c/sup\u003eBe (half-life = 1.5x10\u003csup\u003e6\u003c/sup\u003e years) and \u003csup\u003e36\u003c/sup\u003eCl (half-life = 3.0x10\u003csup\u003e5\u003c/sup\u003e years) in the entire ice core, which spans the time period from the present to about 100,000 years before present. These data are being used for perfecting the ice core chronology, deducing the history of solar activity, deducing the history of variations in the geomagnetic field, and studying the possible role of solar variations on climate. \n\nData are distributed as a PDF file and are available via FTP.", "east": -148.812, "geometry": ["POINT(-148.812 -81.6588)"], "keywords": "Antarctica; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "locations": "Siple Dome; Antarctica", "north": -81.6588, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Finkel, R. C.; Nishiizumi, Kunihiko", "project_titles": "Cosmogenic Radionuclides in the Siple Dome Ice Core", "projects": [{"proj_uid": "p0000358", "repository": "USAP-DC", "title": "Cosmogenic Radionuclides in the Siple Dome Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.6588, "title": "Cosmogenic Radionuclides in the Siple Dome A Ice Core", "uid": "609307", "west": -148.812}]

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