{"dp_type": "Dataset", "free_text": "Layers"}
[{"awards": "0087144 Conway, Howard", "bounds_geometry": ["POLYGON((-150 -83.5,-148 -83.5,-146 -83.5,-144 -83.5,-142 -83.5,-140 -83.5,-138 -83.5,-136 -83.5,-134 -83.5,-132 -83.5,-130 -83.5,-130 -83.65,-130 -83.8,-130 -83.95,-130 -84.1,-130 -84.25,-130 -84.4,-130 -84.55,-130 -84.7,-130 -84.85,-130 -85,-132 -85,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-150 -84.85,-150 -84.7,-150 -84.55,-150 -84.4,-150 -84.25,-150 -84.1,-150 -83.95,-150 -83.8,-150 -83.65,-150 -83.5))"], "date_created": "Mon, 22 Jul 2024 00:00:00 GMT", "description": "Marine ice sheets are low-pass filters of climate variability that take centuries to adjust to interior and near-terminus changes in mass balance. Constraining these century-scale changes from satellite observations that span only the last 40 years is challenging. Here, we take a different approach of carefully synthesizing different data sets to infer changes in the configurations of van der Veen and Mercer Ice Streams on the Siple Coast over the past 3000 years from englacial features encoded in ice-penetrating radar data. Englacial radar data from Conway Ridge reveal smooth, surface conformal layers overlying disrupted stratigraphy that suggest the van der Veen Ice Stream was 40 km wider over 3000 years ago. Englacial layer dating indicates that the ice stream narrowed to its present configuration between $\\sim3000$ and $\\sim1000$ years ago. Similarly disrupted stratigraphy and buried crevasses suggest that ice flowing from Mercer to Whillans Ice Stream across the northwestern tip of the ridge slowed shortly after. Using an ice-flow model capable of simulating shear margin migration, we evaluate whether small changes in ice thickness can lead to large changes in shear margin location. Our results suggest that the tip of Conway Ridge is sensitive to thinning and thickening, and that when the basal strength at the tip of the ridge increases with the height above flotation, the ice sheet shear margins can change quickly.", "east": -130.0, "geometry": ["POINT(-140 -84.25)"], "keywords": "Antarctica; Cryosphere; Siple Coast", "locations": "Siple Coast; Antarctica", "north": -83.5, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hoffman, Andrew; Conway, Howard; Christianson, Knut", "project_titles": "Glacial History of Ridge AB, West Antarctica", "projects": [{"proj_uid": "p0010470", "repository": "USAP-DC", "title": "Glacial History of Ridge AB, West Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Impulse HF radar data from Conway Ridge", "uid": "601810", "west": -150.0}, {"awards": "1043761 Young, Duncan; 0230197 Holt, John; 0636724 Blankenship, Donald; 2127606 Young, Duncan A.", "bounds_geometry": ["POLYGON((-136 -74,-131.9 -74,-127.8 -74,-123.7 -74,-119.6 -74,-115.5 -74,-111.4 -74,-107.30000000000001 -74,-103.2 -74,-99.1 -74,-95 -74,-95 -74.7,-95 -75.4,-95 -76.1,-95 -76.8,-95 -77.5,-95 -78.2,-95 -78.9,-95 -79.6,-95 -80.3,-95 -81,-99.1 -81,-103.2 -81,-107.3 -81,-111.4 -81,-115.5 -81,-119.6 -81,-123.69999999999999 -81,-127.8 -81,-131.9 -81,-136 -81,-136 -80.3,-136 -79.6,-136 -78.9,-136 -78.2,-136 -77.5,-136 -76.8,-136 -76.1,-136 -75.4,-136 -74.7,-136 -74))"], "date_created": "Wed, 15 Mar 2023 00:00:00 GMT", "description": "This file contains internal radar horizon 1 (lm-MERGE-lay9-grg) for West Antarctica, collected during the SOAR/CASERTZ (1991-1996), SOAR/DVD (1999), ATRS (2001), AGASEA (2004-05) and GIMBLE (2013-2014) expeditions. Only data collected in AGASEA is contained in this specific product.\r\nThis data set is linked to PH.D thesis Muldoon, G. 2018 \"West Antarctic Ice Sheet Retreat during the Last Interglacial\"Spatial and temporal distributions of accumulation rates on the catchment of Thwaites Glacier, West Antarctica\", University of Texas at Austin\r\n https://doi.org/10.15781/T23B5WS0D\r\nThe internal radar horizon (IRH) was traced semi-automatically by Gail R. Muldoon using Haliburtons\u0027s Landmark software and picker, in a combination of 2D focused and unfocused data.\r\nDepths were calculated using a 2 way velocity in ice of 84.5 m/microsecond, and no firn correction. \r\n\r\nIsochron age is 4711 (+/- 246 ) years. \r\n\r\nFunding for this dataset as provided by NSF grants and The G. Unger Vetlesen Foundation.", "east": -95.0, "geometry": ["POINT(-115.5 -77.5)"], "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "locations": "Thwaites Glacier; Antarctica", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences", "persons": "Muldoon, Gail R.; Young, Duncan A.; Jackson, Charles; Blankenship, Donald D.", "project_titles": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA); Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System; Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE)", "projects": [{"proj_uid": "p0000174", "repository": "USAP-DC", "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System"}, {"proj_uid": "p0000435", "repository": "USAP-DC", "title": "Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE)"}, {"proj_uid": "p0000243", "repository": "USAP-DC", "title": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.0, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "uid": "601673", "west": -136.0}, {"awards": "1744993 Higgins, John", "bounds_geometry": ["POLYGON((159.16667 -76.66667,159.19167000000002 -76.66667,159.21667000000002 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667000000002 -76.66667,159.34167000000002 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.67333599999999,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.69999999999999,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.71999799999999,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167000000002 -76.73333,159.31667000000002 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667000000002 -76.73333,159.19167000000002 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.71999799999999,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.69999999999999,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.67333599999999,159.16667 -76.66667))"], "date_created": "Fri, 03 Mar 2023 00:00:00 GMT", "description": "This document details the ground-penetrating radar (GPR) collection activities carried out by I. Nesbitt in the Allan Hills during the 2019-2020 field season. This document is intended as an informal catalogue of the fild work and post-processing activities performed at the Allan Hills and later at McMurdo and elsewhere. It contains preliminary post-processing and analysis only. Any interpretation made and presented in this report based on the data herein is subject to change pending further examination. GPR was used to examine sub-ice bedrock topography and the stratigraphic relationship between two shallow ice core drill sites (CMC1 and CMC2), as well as to explore potential future drill sites. In accordance with. the project\u0027s objective to drill and analyze ancient ice at relatively shallow depths, the two main features of interest in this study are 1) bedrock topographic features in which ancient ice could be trapped, and 2) englacial stratigraphic layers, especially those which may represent large age discontinuities.", "east": 159.41667, "geometry": ["POINT(159.29167 -76.69999999999999)"], "keywords": "Allan Hills; Antarctica; GPR; Ice Core; Report", "locations": "Allan Hills; Antarctica", "north": -76.66667, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Nesbitt, Ian; Brook, Edward J.", "project_titles": "Collaborative research: Snapshots of Early and Mid-Pleistocene Climate and Atmospheric Composition from the Allan Hills Blue Ice Area ", "projects": [{"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": -76.73333, "title": "I-165-M GPR Field Report 2019-2020", "uid": "601669", "west": 159.16667}, {"awards": "1543361 Kurbatov, Andrei; 1543454 Dunbar, Nelia", "bounds_geometry": ["POLYGON((-180 -50,-163 -50,-146 -50,-129 -50,-112 -50,-95 -50,-78 -50,-61 -50,-44 -50,-27 -50,-10 -50,-10 -54,-10 -58,-10 -62,-10 -66,-10 -70,-10 -74,-10 -78,-10 -82,-10 -86,-10 -90,-27 -90,-44 -90,-61 -90,-78 -90,-95 -90,-112 -90,-129 -90,-146 -90,-163 -90,180 -90,175 -90,170 -90,165 -90,160 -90,155 -90,150 -90,145 -90,140 -90,135 -90,130 -90,130 -86,130 -82,130 -78,130 -74,130 -70,130 -66,130 -62,130 -58,130 -54,130 -50,135 -50,140 -50,145 -50,150 -50,155 -50,160 -50,165 -50,170 -50,175 -50,-180 -50))"], "date_created": "Thu, 16 Feb 2023 00:00:00 GMT", "description": "This dataset contains the geochemical composition of three tephra layers that were used in the development of the SPICEcore timescale (Winski et al., 2019). All tephra have been correlated to WDC06A ice core. ", "east": 130.0, "geometry": ["POINT(-120 -70)"], "keywords": "Antarctica; Electron Microprobe; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; South Pole; Tephra", "locations": "South Pole; Antarctica", "north": -50.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Iverson, Nels", "project_titles": "Collaborative Research: Tephrochronology of a South Pole Ice Core", "projects": [{"proj_uid": "p0010311", "repository": "USAP-DC", "title": "Collaborative Research: Tephrochronology of a South Pole Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "SPICEcore visable tephra", "uid": "601667", "west": -10.0}, {"awards": "1744584 Klein, Andrew", "bounds_geometry": ["POLYGON((-78 -60,-74.6 -60,-71.2 -60,-67.8 -60,-64.4 -60,-61 -60,-57.6 -60,-54.2 -60,-50.8 -60,-47.400000000000006 -60,-44 -60,-44 -61.3,-44 -62.6,-44 -63.9,-44 -65.2,-44 -66.5,-44 -67.8,-44 -69.1,-44 -70.4,-44 -71.7,-44 -73,-47.4 -73,-50.8 -73,-54.2 -73,-57.6 -73,-61 -73,-64.4 -73,-67.8 -73,-71.2 -73,-74.6 -73,-78 -73,-78 -71.7,-78 -70.4,-78 -69.1,-78 -67.8,-78 -66.5,-78 -65.2,-78 -63.9,-78 -62.6,-78 -61.3,-78 -60))"], "date_created": "Thu, 29 Dec 2022 00:00:00 GMT", "description": "This dataset contains gridded sea ice concentrations developed from vector GIS National Ice Center (NIC) Charts for a portion of the western Antarctic Peninsula. This dataset was developed in support of projects ANT-1744550, -1744570, -1744584, and -1744602. It contains geotif files containing the minimum, maximum, and midpoint (average) sea ice concentrations in tenths calculated from NIC vector GIS layers for the 2008-2019 time period.", "east": -44.0, "geometry": ["POINT(-61 -66.5)"], "keywords": "Antarctica; Antarctic Peninsula; LMG1904; National Ice Center Charts; R/v Laurence M. Gould; Sea Ice Concentration", "locations": "Antarctic Peninsula; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Klein, Andrew", "project_titles": "Collaborative Research: Sea ice as a driver of Antarctic benthic macroalgal community composition and nearshore trophic connectivity", "projects": [{"proj_uid": "p0010104", "repository": "USAP-DC", "title": "Collaborative Research: Sea ice as a driver of Antarctic benthic macroalgal community composition and nearshore trophic connectivity"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -73.0, "title": "Gridded sea ice concentrations from National Ice Center (NIC) Charts 2014-2019 for Western Antarctic Peninsula ", "uid": "601643", "west": -78.0}, {"awards": "1643248 Hall, Brenda; 0944150 Hall, Brenda", "bounds_geometry": ["POLYGON((164 -78,164.04 -78,164.08 -78,164.12 -78,164.16 -78,164.2 -78,164.24 -78,164.28 -78,164.32 -78,164.36 -78,164.4 -78,164.4 -78.01,164.4 -78.02,164.4 -78.03,164.4 -78.04,164.4 -78.05,164.4 -78.06,164.4 -78.07,164.4 -78.08,164.4 -78.09,164.4 -78.1,164.36 -78.1,164.32 -78.1,164.28 -78.1,164.24 -78.1,164.2 -78.1,164.16 -78.1,164.12 -78.1,164.08 -78.1,164.04 -78.1,164 -78.1,164 -78.09,164 -78.08,164 -78.07,164 -78.06,164 -78.05,164 -78.04,164 -78.03,164 -78.02,164 -78.01,164 -78))"], "date_created": "Tue, 01 Mar 2022 00:00:00 GMT", "description": "This dataset contains raw and calibrated radiocarbon data for lacustrine algal layers from glacial lacustrine deposits associated with Ross Sea drift in Marshall Valley.", "east": 164.4, "geometry": ["POINT(164.2 -78.05)"], "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marshall Valley; Radiocarbon; Ross Sea Drift; Royal Society Range", "locations": "Marshall Valley; Royal Society Range; Ross Sea Drift; Antarctica", "north": -78.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "persons": "Hall, Brenda", "project_titles": "Response of the Antarctic Ice Sheet to the last great global warming; Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles", "projects": [{"proj_uid": "p0010302", "repository": "USAP-DC", "title": "Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles"}, {"proj_uid": "p0010301", "repository": "USAP-DC", "title": "Response of the Antarctic Ice Sheet to the last great global warming"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.1, "title": "Marshall Valley Radiocarbon Data", "uid": "601529", "west": 164.0}, {"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": "1542778 Alley, Richard", "bounds_geometry": ["POLYGON((-180 -89.9,-144 -89.9,-108 -89.9,-72 -89.9,-36 -89.9,0 -89.9,36 -89.9,72 -89.9,108 -89.9,144 -89.9,180 -89.9,180 -89.91,180 -89.92,180 -89.93,180 -89.94,180 -89.95,180 -89.96,180 -89.97,180 -89.98,180 -89.99,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -89.99,-180 -89.98,-180 -89.97,-180 -89.96,-180 -89.95,-180 -89.94,-180 -89.93,-180 -89.92,-180 -89.91,-180 -89.9))"], "date_created": "Mon, 05 Mar 2018 00:00:00 GMT", "description": "This dataset includes all visible observations made of the South Pole Ice core within a dark booth during core processing at the National Ice Core Laboratory. This dataset includes observations starting at 735 meters depth, down to the bottom of the drilled core at 1751 meters. All visible and cloudy layers are noted, as well as any other observed feature or cracks. In addition, all Volcanic layers measured on the ECM were noted.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; South Pole; Visual Observations", "locations": "South Pole; Antarctica", "north": -89.9, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Fegyveresi, John; Alley, Richard", "project_titles": "Climate History and Flow Processes from Physical Analyses of the SPICECORE South Pole Ice Core", "projects": [{"proj_uid": "p0000141", "repository": "USAP-DC", "title": "Climate History and Flow Processes from Physical Analyses of the SPICECORE South Pole Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "South Pole Ice Core (SPIcecore) Visual Observations", "uid": "601088", "west": -180.0}, {"awards": "1246203 Gooseff, Michael", "bounds_geometry": ["POLYGON((163.1778 -77.6233,163.17792 -77.6233,163.17804 -77.6233,163.17816 -77.6233,163.17828 -77.6233,163.1784 -77.6233,163.17852 -77.6233,163.17864 -77.6233,163.17876 -77.6233,163.17888 -77.6233,163.179 -77.6233,163.179 -77.63331,163.179 -77.64332,163.179 -77.65333,163.179 -77.66334,163.179 -77.67335,163.179 -77.68336,163.179 -77.69337,163.179 -77.70338,163.179 -77.71339,163.179 -77.7234,163.17888 -77.7234,163.17876 -77.7234,163.17864 -77.7234,163.17852 -77.7234,163.1784 -77.7234,163.17828 -77.7234,163.17816 -77.7234,163.17804 -77.7234,163.17792 -77.7234,163.1778 -77.7234,163.1778 -77.71339,163.1778 -77.70338,163.1778 -77.69337,163.1778 -77.68336,163.1778 -77.67335,163.1778 -77.66334,163.1778 -77.65333,163.1778 -77.64332,163.1778 -77.63331,163.1778 -77.6233))"], "date_created": "Mon, 18 Dec 2017 00:00:00 GMT", "description": "As a part of the project titled \"Collaborative Research: The McMurdo Dry Valleys: A landscape on the threshold of change\", we measured ground temperatures from 0-20cm at three stream bank positions (base, mid-slope, and top) at 4 locations along Crescent Stream in Taylor Valley - 2 on the east bank, 2 on the west bank. The goal was to evaluate differences in thermal conduction and temperature dynamics of the active layers of these locations, in particular, in a stream that has undergone extensive bank erosion since 2012 due to permafrost degradation. One of the datalogging stations had significant technical problems and has very little data compared to the almost 2 years of temperature date from the other 3 stations (2015-2017). ", "east": 163.179, "geometry": ["POINT(163.1784 -77.67335)"], "keywords": "Antarctica; Dry Valleys; Glaciology; Paleoclimate; Permafrost; Soil Temperature; Taylor Valley", "locations": "Dry Valleys; Taylor Valley; Antarctica", "north": -77.6233, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Gooseff, Michael N.", "project_titles": "Collaborative Research: THE MCMURDO DRY VALLEYS: A landscape on the Threshold of Change", "projects": [{"proj_uid": "p0000076", "repository": "USAP-DC", "title": "Collaborative Research: THE MCMURDO DRY VALLEYS: A landscape on the Threshold of Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.7234, "title": "Active Layer Temperatures from Crescent Stream banks, Taylor Valley Antarctica", "uid": "601075", "west": 163.1778}, {"awards": "1142069 Dunbar, Nelia; 1142007 Kurbatov, Andrei", "bounds_geometry": ["POLYGON((0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,216 -60,252 -60,288 -60,324 -60,360 -60,360 -63,360 -66,360 -69,360 -72,360 -75,360 -78,360 -81,360 -84,360 -87,360 -90,324 -90,288 -90,252 -90,216 -90,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,0 -87,0 -84,0 -81,0 -78,0 -75,0 -72,0 -69,0 -66,0 -63,0 -60))"], "date_created": "Wed, 13 Sep 2017 00:00:00 GMT", "description": "This collaborative interdisciplinary research project aims to consolidate, into a single user-friendly database, information about volcanic products detected in Antarctica. By consolidating information about volcanic sources, and physical and geochemical characteristics of volcanic products, this systematic data collection approach will improve the ability of researchers to identify volcanic ash, or tephra, from specific volcanic eruptions that may be spread over large areas in a geologically instantaneous amount of time. AntT database is designed to assist in the identification and cross-correlation of time intervals in various paleoclimate archives that contain volcanic layers from often unknown sources.", "east": 360.0, "geometry": ["POINT(180 -75)"], "keywords": "Antarctica; Geochemistry; Geochronology; Glaciology; Intracontinental Magmatism; IntraContinental Magmatism; Sample/collection Description; Sample/Collection Description; Tephra", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Kurbatov, Andrei V.; Dunbar, Nelia", "project_titles": "Collaborative Research: Developing an Antarctic Tephra Database for Interdisciplinary Paleoclimate Research (AntT)", "projects": [{"proj_uid": "p0000328", "repository": "USAP-DC", "title": "Collaborative Research: Developing an Antarctic Tephra Database for Interdisciplinary Paleoclimate Research (AntT)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Antarctic Tephra Data Base AntT static web site ", "uid": "601052", "west": 0.0}, {"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": "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": "0944653 Forster, Richard", "bounds_geometry": ["POLYGON((-119.4 -78.1,-118.46 -78.1,-117.52 -78.1,-116.58 -78.1,-115.64 -78.1,-114.7 -78.1,-113.76 -78.1,-112.82 -78.1,-111.88 -78.1,-110.94 -78.1,-110 -78.1,-110 -78.29,-110 -78.48,-110 -78.67,-110 -78.86,-110 -79.05,-110 -79.24,-110 -79.43,-110 -79.62,-110 -79.81,-110 -80,-110.94 -80,-111.88 -80,-112.82 -80,-113.76 -80,-114.7 -80,-115.64 -80,-116.58 -80,-117.52 -80,-118.46 -80,-119.4 -80,-119.4 -79.81,-119.4 -79.62,-119.4 -79.43,-119.4 -79.24,-119.4 -79.05,-119.4 -78.86,-119.4 -78.67,-119.4 -78.48,-119.4 -78.29,-119.4 -78.1))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "This award supports a project to broaden the knowledge of annual accumulation patterns over the West Antarctic Ice Sheet by processing existing near-surface radar data taken on the US ITASE traverse in 2000 and by gathering and validating new ultra/super-high-frequency (UHF) radar images of near surface layers (to depths of ~15 m), expanding abilities to monitor recent annual accumulation patterns from point source ice cores to radar lines. Shallow (15 m) ice cores will be collected in conjunction with UHF radar images to confirm that radar echoed returns correspond with annual layers, and/or sub-annual density changes in the near-surface snow, as determined from ice core stable isotopes. This project will additionally improve accumulation monitoring from space-borne instruments by comparing the spatial-radar-derived-annual accumulation time series to the passive microwave time series dating back over 3 decades and covering most of Antarctica. The intellectual merit of this project is that mapping the spatial and temporal variations in accumulation rates over the Antarctic ice sheet is essential for understanding ice sheet responses to climate forcing. Antarctic precipitation rate is projected to increase up to 20% in the coming century from the predicted warming. Accumulation is a key component for determining ice sheet mass balance and, hence, sea level rise, yet our ability to measure annual accumulation variability over the past 5 decades (satellite era) is mostly limited to point-source ice cores. Developing a radar and ice core derived annual accumulation dataset will provide validation data for space-born remote sensing algorithms, climate models and, additionally, establish accumulation trends. The broader impacts of the project are that it will advance discovery and understanding within the climatology, glaciology and remote sensing communities by verifying the use of UHF radars to monitor annual layers as determined by visual, chemical and isotopic analysis from corresponding shallow ice cores and will provide a dataset of annual to near-annual accumulation measurements over the past ~5 decades across WAIS divide from existing radar data and proposed radar data. By determining if temporal changes in the passive microwave signal are correlated with temporal changes in accumulation will help assess the utility of passive microwave remote sensing to monitor accumulation rates over ice sheets for future decades. The project will promote teaching, training and learning, and increase representation of underrepresented groups by becoming involved in the NASA History of Winter project and Thermochron Mission and by providing K-12 teachers with training to monitor snow accumulation and temperature here in the US, linking polar research to the student\u0027s backyard. The project will train both undergraduate and graduate students in polar research and will encouraging young investigators to become involved in careers in science. In particular, two REU students will participate in original research projects as part of this larger project, from development of a hypothesis to presentation and publication of the results. The support of a new, young woman scientist will help to increase gender diversity in polar research.\n", "east": -110.0, "geometry": ["POINT(-114.7 -79.05)"], "keywords": "Airborne Radar; Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -78.1, "nsf_funding_programs": null, "persons": "Forster, Richard", "project_titles": "Collaborative Research: Annual satellite era accumulation patterns over WAIS Divide: A study using shallow ice cores, near-surface radars and satellites", "projects": [{"proj_uid": "p0000079", "repository": "USAP-DC", "title": "Collaborative Research: Annual satellite era accumulation patterns over WAIS Divide: A study using shallow ice cores, near-surface radars and satellites"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -80.0, "title": "Annual Satellite Era Accumulation Patterns Over WAIS Divide: A Study Using Shallow Ice Cores, Near-Surface Radars and Satellites", "uid": "600146", "west": -119.4}, {"awards": "1041022 McClintock, James", "bounds_geometry": ["POLYGON((-79 -60,-76.4 -60,-73.8 -60,-71.2 -60,-68.6 -60,-66 -60,-63.4 -60,-60.8 -60,-58.2 -60,-55.6 -60,-53 -60,-53 -61,-53 -62,-53 -63,-53 -64,-53 -65,-53 -66,-53 -67,-53 -68,-53 -69,-53 -70,-55.6 -70,-58.2 -70,-60.8 -70,-63.4 -70,-66 -70,-68.6 -70,-71.2 -70,-73.8 -70,-76.4 -70,-79 -70,-79 -69,-79 -68,-79 -67,-79 -66,-79 -65,-79 -64,-79 -63,-79 -62,-79 -61,-79 -60))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "The research will investigate the individual and combined effects of rising ocean acidification and sea surface temperatures on shallow-water calcified benthic organisms in western Antarctic Peninsular (WAP) marine communities. The Southern Ocean is predicted to become undersaturated in terms of both aragonite and calcite within 50 and 100 years, respectively, challenging calcification processes. Adding to the problem, antarctic calcified benthic marine organisms are more vulnerable to ocean acidification than temperate and tropical species because they are generally weakly calcified. Many antarctic organisms are essentially stenothermal, and those in the West Antarctic Peninsula are being subjected to rising seawater temperatures. The project employs both single-species and multi-species level approaches to evaluating the impacts of rising ocean acidification and seawater temperature on representative calcified and non-calcified macroalgae, on calcified and non-calcified mesograzers, and on a calcified macro-grazer, all of which are important ecological players in the rich benthic communities. Multi-species analysis will focus on the diverse assemblage of amphipods and mesogastropods that are associated with dominant macroalgae that collectively play a key role in community dynamics along the WAP. The project will support undergraduate research, both through NSF programs, as well as home university-based programs, some designed to enhance the representation of minorities in the sciences. The principal investigators also will support and foster graduate education through mentoring of graduate students. Through their highly successful UAB IN ANTARCTICA interactive web program, they will continue to involve large numbers of teachers, K-12 students, and other members of the community at large in their scientific endeavors in Antarctica.", "east": -53.0, "geometry": ["POINT(-66 -65)"], "keywords": "Antarctic Peninsula; Biota; Oceans; Southern Ocean", "locations": "Antarctic Peninsula; Southern Ocean", "north": -60.0, "nsf_funding_programs": null, "persons": "McClintock, James; Amsler, Charles; Angus, Robert", "project_titles": "The effects of ocean acidification and rising sea surface temperatures on shallow-water benthic organisms in Antarctica", "projects": [{"proj_uid": "p0000426", "repository": "USAP-DC", "title": "The effects of ocean acidification and rising sea surface temperatures on shallow-water benthic organisms in Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "The effects of ocean acidification and rising sea surface temperatures on shallow-water benthic organisms in Antarctica", "uid": "600122", "west": -79.0}, {"awards": "0944489 Williams, Trevor", "bounds_geometry": ["POLYGON((-55 -58,-33.2 -58,-11.4 -58,10.4 -58,32.2 -58,54 -58,75.8 -58,97.6 -58,119.4 -58,141.2 -58,163 -58,163 -60,163 -62,163 -64,163 -66,163 -68,163 -70,163 -72,163 -74,163 -76,163 -78,141.2 -78,119.4 -78,97.6 -78,75.8 -78,54 -78,32.2 -78,10.4 -78,-11.4 -78,-33.2 -78,-55 -78,-55 -76,-55 -74,-55 -72,-55 -70,-55 -68,-55 -66,-55 -64,-55 -62,-55 -60,-55 -58))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to study the stability and dynamics of the East Antarctic ice sheet during the Pliocene in the area of the Wilkes and Aurora subglacial basins. Models indicate the ice sheet is most sensitive to warming in these low-lying areas. This study is important as there is very little direct evidence about which parts of the East Antarctic ice sheet became unstable under warm conditions. In a pilot study the PIs have shown that the isotopic geochemical signature of downcore ice-rafted debris (IRD) can be linked to continental source areas indicating which parts of the ice sheet reached the coast and calved IRD-bearing icebergs. Their initial results suggest rapid iceberg discharge from the Wilkes Land and Adelie Land coastal areas at times in the late Miocene and early Pliocene. In this study the PIs will analyze IRD from IODP sediment cores collected on the continental rise off East Antarctica. By analyzing 40Ar/39Ar ages of hornblende IRD grains, U-Pb ages of zircons, and Sm-Nd isotopes of the fine fraction of several IRD-rich layers for each core, they will be able to fingerprint continental source areas that indicate ice extent and dynamics on East Antarctica. The PIs will also carry out detailed studies across a few of these layers to characterize the anatomy of the ice-rafting event and better understand the mechanism of ice destabilization. Broader impacts: The data collected will be important for scientists in a broad variety of fields. The project will involve one undergraduate student and one summer intern at LDEO, and a graduate student at Imperial College London. The project will expose to cutting edge methodologies as well as an international research team. Data from the project will be deposited in the online databases (SedDB) and all results and methods will be made available to the scientific community through publications in peer-reviewed journals and attendance at international conferences\n", "east": 163.0, "geometry": ["POINT(54 -68)"], "keywords": "Geochronology; George V Land; IODP U1356; IODP U1361; Marine Sediments; ODP1165; Prydz Bay; Solid Earth; Southern Ocean; Wilkes Land", "locations": "George V Land; Prydz Bay; Wilkes Land; Southern Ocean", "north": -58.0, "nsf_funding_programs": null, "persons": "Williams, Trevor; Hemming, Sidney R.", "project_titles": "History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris", "projects": [{"proj_uid": "p0000353", "repository": "USAP-DC", "title": "History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris", "uid": "600116", "west": -55.0}, {"awards": "1039365 Rimmer, Susan", "bounds_geometry": null, "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. The broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming.\n", "east": null, "geometry": null, "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Solid Earth; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica", "north": null, "nsf_funding_programs": null, "persons": "Rimmer, Susan", "project_titles": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter", "projects": [{"proj_uid": "p0000507", "repository": "USAP-DC", "title": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter", "uid": "600121", "west": null}, {"awards": "0087521 Waddington, Edwin", "bounds_geometry": ["POINT(-148.82 -81.66)"], "date_created": "Sun, 15 Apr 2012 00:00:00 GMT", "description": "Researchers gathered data on annual snow layers at Siple Dome, Antarctica, using borehole optical stratigraphy. This data set contains annual layer depths and firn optical brightness. The brightness log is a record of reflectivity of the firn, and peaks in brightness are interpreted to be fine-grained high-density winter snow, as part of the wind slab depth-hoar couplet. \n\nData are available via FTP in ASCII text (.txt) format", "east": -148.82, "geometry": ["POINT(-148.82 -81.66)"], "keywords": "Antarctica; Borehole Optical Stratigraphy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Siple Dome; Siple Dome Ice Core; Snow/ice; Snow/Ice", "locations": "Siple Dome; Antarctica", "north": -81.66, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hawley, Robert L.; Waddington, Edwin D.; Alley, Richard; Taylor, Kendrick C.", "project_titles": "Borehole Fingerprinting: Vertical Strain, Firn Compaction, and Firn Depth-Age Scales", "projects": [{"proj_uid": "p0000173", "repository": "USAP-DC", "title": "Borehole Fingerprinting: Vertical Strain, Firn Compaction, and Firn Depth-Age Scales"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.66, "title": "Annual Layers at Siple Dome, Antarctica, from Borehole Optical Stratigraphy", "uid": "609515", "west": -148.82}, {"awards": "0538674 Winebrenner, Dale", "bounds_geometry": ["POLYGON((68.4 -75.7,69.61 -75.7,70.82 -75.7,72.03 -75.7,73.24 -75.7,74.45 -75.7,75.66 -75.7,76.87 -75.7,78.08 -75.7,79.29 -75.7,80.5 -75.7,80.5 -76.04,80.5 -76.38,80.5 -76.72,80.5 -77.06,80.5 -77.4,80.5 -77.74,80.5 -78.08,80.5 -78.42,80.5 -78.76,80.5 -79.1,79.29 -79.1,78.08 -79.1,76.87 -79.1,75.66 -79.1,74.45 -79.1,73.24 -79.1,72.03 -79.1,70.82 -79.1,69.61 -79.1,68.4 -79.1,68.4 -78.76,68.4 -78.42,68.4 -78.08,68.4 -77.74,68.4 -77.4,68.4 -77.06,68.4 -76.72,68.4 -76.38,68.4 -76.04,68.4 -75.7))"], "date_created": "Mon, 01 Aug 2011 00:00:00 GMT", "description": "This data set consists of inferred accumulation rates from three radar layers (26, 35 and 41 thousand years old) in the Vostok Subglacial Lake region. Accumulation rates were inferred using Local-Layer Approximation (LLA), which assumes that the strain-rate history of a particle traveling through the ice sheet can be approximated by the vertical strain-rate profile at the current position of the particle, which the researchers assume to be uniform. Parameters include location, in latitude and longitude, polar stereographic coordinates, and local grid X and Y coordinates, along with layer age, in thousands of years (ka), and inferred accumulation rate (cm/a). The data cover a 150 by 350 km area.\n\nData are available via FTP, as a text file (.txt) with columns in comma separated value format.", "east": 80.5, "geometry": ["POINT(74.45 -77.4)"], "keywords": "Accumulation Rate; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok", "locations": "Lake Vostok; Antarctica", "north": -75.7, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Macgregor, Joseph A.; Matsuoka, Kenichi; Studinger, Michael S.; Waddington, Edwin D.; Winebrenner, Dale", "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": -79.1, "title": "Millennially Averaged Accumulation Rates for Lake Vostok", "uid": "609500", "west": 68.4}, {"awards": "0440666 Waddington, Edwin", "bounds_geometry": ["POINT(158.716667 -77.783333)", "POINT(-111.816667 -79.416667)"], "date_created": "Sun, 20 Jun 2010 00:00:00 GMT", "description": "This data set contains radar internal layer and ice sheet topography data for two sites in Antarctica, along with associated model results from two studies. This project used geophysical inverse theory and a 2.5 D flowband ice-flow forward model to extract robust transient accumulation patterns from multiple deeper layers. Histories of divide migration, or the movement of the ice sheet and ice-surface evolution are also provided. The data used to solve the inverse problem, and the model solutions are provided. Internal layers, modern ice-surface velocities, and modern ice-sheet geometry at Taylor Mouth are available, as well as the pattern of accumulation inferred by Waddington et al. (2007).\n\nData are available via FTP in Matlab (.mat) format. Supporting information is available as text files (.rtf and .txt).", "east": 158.716667, "geometry": ["POINT(158.716667 -77.783333)", "POINT(-111.816667 -79.416667)"], "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -77.783333, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Waddington, Edwin D.; Koutnik, Michelle", "project_titles": "Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach", "projects": [{"proj_uid": "p0000018", "repository": "USAP-DC", "title": "Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.416667, "title": "Histories of Accumulation, Thickness, and WAIS Divide Location, Antarctica", "uid": "609473", "west": -111.816667}, {"awards": "0338151 Raymond, Charles", "bounds_geometry": ["POINT(-112.09 -79.47)"], "date_created": "Tue, 15 Jun 2010 00:00:00 GMT", "description": "This data set contains the results of a model study of spatial variations of ice temperature and subglacial conditions using available ice-penetrating radar data around a future deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet. The model data are based on radar data collected by the Support Office of Aerogeophysical Research (SOAR) at the University of Texas, and the University of Washington, in 2000. The data include values for attenuation estimates for individual radar profiles.\n\nData are available via FTP in MATLAB (.mat) and Portable Document (.pdf) formats.", "east": -112.09, "geometry": ["POINT(-112.09 -79.47)"], "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar; WAIS Divide", "locations": "WAIS Divide; Antarctica", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Raymond, Charles; Matsuoka, Kenichi", "project_titles": "Glaciological Characteristics of the Ross/Amundsen Sea Ice-flow Divide Deduced by a New Analysis of Ice-penetrating Radar Data", "projects": [{"proj_uid": "p0000017", "repository": "USAP-DC", "title": "Glaciological Characteristics of the Ross/Amundsen Sea Ice-flow Divide Deduced by a New Analysis of Ice-penetrating Radar Data"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Englacial Layers and Attenuation Rates across the Ross and Amundsen Sea Ice-Flow Divide (WAIS Divide), West Antarctica", "uid": "609470", "west": -112.09}, {"awards": "0739372 Conway, Howard", "bounds_geometry": ["POLYGON((-123 -76,-120.65 -76,-118.3 -76,-115.95 -76,-113.6 -76,-111.25 -76,-108.9 -76,-106.55 -76,-104.2 -76,-101.85 -76,-99.5 -76,-99.5 -76.37,-99.5 -76.74,-99.5 -77.11,-99.5 -77.48,-99.5 -77.85,-99.5 -78.22,-99.5 -78.59,-99.5 -78.96,-99.5 -79.33,-99.5 -79.7,-101.85 -79.7,-104.2 -79.7,-106.55 -79.7,-108.9 -79.7,-111.25 -79.7,-113.6 -79.7,-115.95 -79.7,-118.3 -79.7,-120.65 -79.7,-123 -79.7,-123 -79.33,-123 -78.96,-123 -78.59,-123 -78.22,-123 -77.85,-123 -77.48,-123 -77.11,-123 -76.74,-123 -76.37,-123 -76))"], "date_created": "Sat, 01 May 2010 00:00:00 GMT", "description": "This data set contains past flow lines of Thwaites Glacier. The flow lines were identified using layer patterns tracked between parallel radar layers, from a radar profile of the Thwaites Glacier catchment. The radar data was run and processed by the University of Texas Institute for Geophysics. The flow lines were identified from distinct layer patterns tracked between parallel radar layers. \n\nData are available via FTP in ASCII text (.txt) format.", "east": -99.5, "geometry": ["POINT(-111.25 -77.85)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Flow Lines; Thwaites Glacier", "locations": "Thwaites Glacier; Antarctica", "north": -76.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Conway, Howard; Fudge, T. J.; Catania, Ginny", "project_titles": "Collaborative Research: Ice-flow history of the Thwaites Glacier, West Antarctica", "projects": [{"proj_uid": "p0000143", "repository": "USAP-DC", "title": "Collaborative Research: Ice-flow history of the Thwaites Glacier, West Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.7, "title": "Ice Flow History of the Thwaites Glacier, West Antarctica", "uid": "609463", "west": -123.0}, {"awards": "0538120 Catania, Ginny", "bounds_geometry": ["POLYGON((-160 -81,-158.5 -81,-157 -81,-155.5 -81,-154 -81,-152.5 -81,-151 -81,-149.5 -81,-148 -81,-146.5 -81,-145 -81,-145 -81.2,-145 -81.4,-145 -81.6,-145 -81.8,-145 -82,-145 -82.2,-145 -82.4,-145 -82.6,-145 -82.8,-145 -83,-146.5 -83,-148 -83,-149.5 -83,-151 -83,-152.5 -83,-154 -83,-155.5 -83,-157 -83,-158.5 -83,-160 -83,-160 -82.8,-160 -82.6,-160 -82.4,-160 -82.2,-160 -82,-160 -81.8,-160 -81.6,-160 -81.4,-160 -81.2,-160 -81))"], "date_created": "Fri, 01 Jan 2010 00:00:00 GMT", "description": "These data consist of ice-penetrating radar data collected on the ground across the grounding line near Siple Dome during the 2006 and 2007 Antarctic summer field seasons. Primarily, the data consist of low-frequency radar data (2 MHz, approximately 50 meter resolution) in order to observe deep internal layers and the ice-bed interface. The data set also contains one file with high-frequency (100 MHz, approximately 1 meter resolution) radar data, for a sub-region of one of the low-frequency radar profiles. Coincident kinematic GPS data were also collected to correct the radar data for topography along each profile. Radar profiles are typically approximately 20 km in length with the grounding line crossed centrally where possible. \n\nData are available via FTP in Matlab (.mat) format.", "east": -145.0, "geometry": ["POINT(-152.5 -82)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; GPR; Grounding Line; Radar; Siple Coast", "locations": "Siple Coast; Antarctica", "north": -81.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hulbe, Christina; Catania, Ginny", "project_titles": "Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region", "projects": [{"proj_uid": "p0000019", "repository": "USAP-DC", "title": "Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -83.0, "title": "Ice-Penetrating Radar Data Across Siple Coast Grounding Lines", "uid": "609474", "west": -160.0}, {"awards": "0338097 DiTullio, Giacomo", "bounds_geometry": ["POLYGON((-169.94 -52.24,-169.449 -52.24,-168.958 -52.24,-168.467 -52.24,-167.976 -52.24,-167.485 -52.24,-166.994 -52.24,-166.503 -52.24,-166.012 -52.24,-165.521 -52.24,-165.03 -52.24,-165.03 -54.879,-165.03 -57.518,-165.03 -60.157,-165.03 -62.796,-165.03 -65.435,-165.03 -68.074,-165.03 -70.713,-165.03 -73.352,-165.03 -75.991,-165.03 -78.63,-165.521 -78.63,-166.012 -78.63,-166.503 -78.63,-166.994 -78.63,-167.485 -78.63,-167.976 -78.63,-168.467 -78.63,-168.958 -78.63,-169.449 -78.63,-169.94 -78.63,-169.94 -75.991,-169.94 -73.352,-169.94 -70.713,-169.94 -68.074,-169.94 -65.435,-169.94 -62.796,-169.94 -60.157,-169.94 -57.518,-169.94 -54.879,-169.94 -52.24))"], "date_created": "Fri, 01 Jan 2010 00:00:00 GMT", "description": "The objectives of this proposal are to investigate the controls on the large-scale distribution and production of the two major bloom-forming phytoplankton taxa in the Southern Ocean, diatoms and Phaeocystis Antarctica. These two groups, through their involvement in the biogeochemical cycles of carbon, sulfur and nutrient elements, may have played important roles in the climate variations of the late Quaternary, and they also may be key players in future environmental change. A current paradigm is that irradiance and iron availability drive phytoplankton dynamics in the Southern Ocean. Recent work, however, suggests that carbon dioxide (CO2) concentrations may also be important in structuring algal assemblages, due to species-specific differences in the physiology. This proposal examines the interactive effects of iron, light and CO2 on the physiology, ecology and relative dominance of Phaeocystis and diatoms in the Southern Ocean. The Ross Sea is an ideal system in which to investigate the environmental factors that regulate the distribution and production of these two algal groups, since it is characterized by seasonal blooms of both P. Antarctica and diatoms that are typically separated in both space and time. This study will take the form of an interdisciplinary investigation that includes a field survey and statistical analysis of algal assemblage composition, iron, mixed layer depth, and CO2 levels in the southern Ross Sea, coupled with shipboard experiments to examine the response of diatom and P. Antarctica assemblages to high and low levels of iron, light and CO2 during spring and summer. This project will provide information on some of the major factors controlling the production and distribution of the two major bloom forming phytoplankton in the Southern Ocean and the related biogeochemical cycling of carbon, sulfur and nutrient elements. The results may ultimately advance the ability to predict how the Southern Ocean will be affected by and possibly modulate future climate change. This project will also make significant educational contributions at several levels, including the planned research involvement of graduate and undergraduate students, postdoctoral associates, a student teacher, and community outreach and educational activities. A number of activities are planned to interface the project with K-12 education. Presentations will be made at local schools to discuss the research and events of the research cruise. During the cruise there will be daily interactive email contact with elementary classrooms. Established websites will be used to allow students to learn about the ongoing research, and to allow researchers to communicate with students through text and downloaded images.", "east": -165.03, "geometry": ["POINT(-167.485 -65.435)"], "keywords": "Biota; Chemistry:fluid; Chemistry:Fluid; Diatom; Oceans; Phytoplankton; Ross Sea; Southern Ocean", "locations": "Ross Sea; Southern Ocean", "north": -52.24, "nsf_funding_programs": null, "persons": "DiTullio, Giacomo", "project_titles": "Collaborative Research: Interactive Effects of Iron, Light and Carbon Dioxide on Phytoplankton Community Dynamics in the Ross Sea", "projects": [{"proj_uid": "p0000540", "repository": "USAP-DC", "title": "Collaborative Research: Interactive Effects of Iron, Light and Carbon Dioxide on Phytoplankton Community Dynamics in the Ross Sea"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.63, "title": "Interactive Effects of Iron, Light and Carbon Dioxide on Phytoplankton Community Dynamics in the Ross Sea", "uid": "600036", "west": -169.94}, {"awards": "9725882 Raymond, Charles", "bounds_geometry": ["POLYGON((-141.6722 -80.1678,-141.34195 -80.1678,-141.0117 -80.1678,-140.68145 -80.1678,-140.3512 -80.1678,-140.02095 -80.1678,-139.6907 -80.1678,-139.36045 -80.1678,-139.0302 -80.1678,-138.69995 -80.1678,-138.3697 -80.1678,-138.3697 -80.4863,-138.3697 -80.8048,-138.3697 -81.1233,-138.3697 -81.4418,-138.3697 -81.7603,-138.3697 -82.0788,-138.3697 -82.3973,-138.3697 -82.7158,-138.3697 -83.0343,-138.3697 -83.3528,-138.69995 -83.3528,-139.0302 -83.3528,-139.36045 -83.3528,-139.6907 -83.3528,-140.02095 -83.3528,-140.3512 -83.3528,-140.68145 -83.3528,-141.0117 -83.3528,-141.34195 -83.3528,-141.6722 -83.3528,-141.6722 -83.0343,-141.6722 -82.7158,-141.6722 -82.3973,-141.6722 -82.0788,-141.6722 -81.7603,-141.6722 -81.4418,-141.6722 -81.1233,-141.6722 -80.8048,-141.6722 -80.4863,-141.6722 -80.1678))"], "date_created": "Fri, 06 Jul 2007 00:00:00 GMT", "description": "This data set consists of surface-based radar measurements, including geometry of the bed, surface, and internal layers, and bed reflectivity measurements at two sites along ice stream margins at Siple Dome, Antarctica. The research is a radar examination of bed reflection characteristics and internal layer geometry in two inter-ice-stream ridges, the Shabtaie Ridge (Ridge D/E) and the Engelhardt Ridge (Ridge B/C), and across margins with the adjacent ice streams, the MacAyeal Ice Stream (Ice Stream E) and the Whillans Ice Stream (Ice Stream B). Investigators collected these radar data from 14 November through 13 December 1998. \n\nData are in Microsoft Word, PDF, ASCII text, MATLAB, binary, and various image formats. Investigators have also provided code for MATLAB routines that they used to view the radar data. Data are available via FTP.", "east": -138.3697, "geometry": ["POINT(-140.02095 -81.7603)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Siple Dome", "locations": "Siple Dome; Antarctica", "north": -80.1678, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Nereson, Nadine A.; Raymond, Charles", "project_titles": "Internal Stratigraphy and Basal Conditions at the Margins ofActive Ice Streams of the Siple Coast, Antarctica", "projects": [{"proj_uid": "p0000626", "repository": "USAP-DC", "title": "Internal Stratigraphy and Basal Conditions at the Margins ofActive Ice Streams of the Siple Coast, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -83.3528, "title": "Radar Investigations of Antarctic Ice Stream Margins, Siple Dome, 1998", "uid": "609303", "west": -141.6722}, {"awards": "0088035 Arcone, Steven; 0196441 Hamilton, Gordon; 0096299 Mayewski, Paul; 0229573 Mayewski, Paul", "bounds_geometry": ["POLYGON((-123.993 -77.6832,-123.6019 -77.6832,-123.2108 -77.6832,-122.8197 -77.6832,-122.4286 -77.6832,-122.0375 -77.6832,-121.6464 -77.6832,-121.2553 -77.6832,-120.8642 -77.6832,-120.4731 -77.6832,-120.082 -77.6832,-120.082 -77.7232,-120.082 -77.7632,-120.082 -77.8032,-120.082 -77.8432,-120.082 -77.8832,-120.082 -77.9232,-120.082 -77.9632,-120.082 -78.0032,-120.082 -78.0432,-120.082 -78.0832,-120.4731 -78.0832,-120.8642 -78.0832,-121.2553 -78.0832,-121.6464 -78.0832,-122.0375 -78.0832,-122.4286 -78.0832,-122.8197 -78.0832,-123.2108 -78.0832,-123.6019 -78.0832,-123.993 -78.0832,-123.993 -78.0432,-123.993 -78.0032,-123.993 -77.9632,-123.993 -77.9232,-123.993 -77.8832,-123.993 -77.8432,-123.993 -77.8032,-123.993 -77.7632,-123.993 -77.7232,-123.993 -77.6832))"], "date_created": "Wed, 06 Apr 2005 00:00:00 GMT", "description": "Snow accumulation rates typically show high variability over short distances. This data set contains accumulation rates derived from ground-penetrating radar (GPR) used to detect isochronal layers in the firn in West Antarctica. These layers were then dated using results from ice core analyses. These data show that accumulation rates along this profile have decreased in recent decades. The radar profile extends between two ice core sites taken along one of the US-ITASE traverse routes.", "east": -120.082, "geometry": ["POINT(-122.0375 -77.8832)"], "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; ITASE; WAIS", "locations": "WAIS; Antarctica", "north": -77.6832, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Spikes, Vandy Blue; Hamilton, Gordon S.; Mayewski, Paul A.; Arcone, Steven; Kaspari, Susan", "project_titles": "High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet", "projects": [{"proj_uid": "p0000146", "repository": "USAP-DC", "title": "High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -78.0832, "title": "US International Trans-Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping", "uid": "609269", "west": -123.993}, {"awards": "9527373 Dunbar, Nelia", "bounds_geometry": ["POLYGON((158.55 -75.86,158.562 -75.86,158.574 -75.86,158.586 -75.86,158.598 -75.86,158.61 -75.86,158.622 -75.86,158.634 -75.86,158.646 -75.86,158.658 -75.86,158.67 -75.86,158.67 -75.864,158.67 -75.868,158.67 -75.872,158.67 -75.876,158.67 -75.88,158.67 -75.884,158.67 -75.888,158.67 -75.892,158.67 -75.896,158.67 -75.9,158.658 -75.9,158.646 -75.9,158.634 -75.9,158.622 -75.9,158.61 -75.9,158.598 -75.9,158.586 -75.9,158.574 -75.9,158.562 -75.9,158.55 -75.9,158.55 -75.896,158.55 -75.892,158.55 -75.888,158.55 -75.884,158.55 -75.88,158.55 -75.876,158.55 -75.872,158.55 -75.868,158.55 -75.864,158.55 -75.86))"], "date_created": "Tue, 18 Feb 2003 00:00:00 GMT", "description": "This data set is the result of a study of volcanic ash and rock fragment (tephra) layers in exposed blue ice areas on Brimstone Peak (75.888S 158.55E) in East Antarctica. Tephra samples were collected between 15 November 1996 and 15 January 1997.\n\nThe Antarctic ice sheets preserve a record of the volcanic ash layers and chemical aerosol signatures of local and distant volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas will allow a better understanding of the geometry of ice flow in these areas. Tephra layers in deep ice cores can also provide unique time-stratigraphic markers in cores that are difficult to date.\n\nData include the following information for each sample site: a general description, electron microprobe analysis, GPS location, neutron activation analysis, and a visual description of the petrography.Data are provided as Excel 97 data files, JPG map files, and GIF-formatted BSE images. Data are available via ftp.", "east": 158.67, "geometry": ["POINT(158.61 -75.88)"], "keywords": "Antarctica; Blue Ice; Brimstone Peak; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Petrography; Tephra", "locations": "Brimstone Peak; Antarctica", "north": -75.86, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Dunbar, Nelia", "project_titles": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region", "projects": [{"proj_uid": "p0000065", "repository": "USAP-DC", "title": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.9, "title": "Blue Ice Tephra II - Brimstone Peak", "uid": "609114", "west": 158.55}, {"awards": "9527373 Dunbar, Nelia", "bounds_geometry": ["POINT(-159.51 -77.12)"], "date_created": "Sat, 01 Feb 2003 00:00:00 GMT", "description": "This data set is the result of a study of volcanic ash and rock fragment (tephra) layers in exposed blue ice areas on Mt. DeWitt, Antarctica (77.12 deg S, 159.51 deg E). Tephra samples were collected between 15 November 1996 and 15 January 1997.\n\nData include the following information for each sample site: a general description, electron microprobe analysis, GPS location, neutron activation analysis, and a visual description of the petrography. Data are provided as an Excel 97 data file, (this file is also divided into various text files) and TIF images. Data are available via ftp.\n\nAntarctic ice sheets preserve a record of the volcanic ash layers and chemical aerosol signatures of local and distant volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas will allow a better understanding of the geometry of ice flow in these areas. Tephra layers in deep ice cores can also provide unique time-stratigraphic markers in cores that are difficult to date.", "east": -159.51, "geometry": ["POINT(-159.51 -77.12)"], "keywords": "Antarctica; Blue Ice; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mount Dewitt; Petrography; Tephra", "locations": "Mount Dewitt; Antarctica", "north": -77.12, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Dunbar, Nelia", "project_titles": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region", "projects": [{"proj_uid": "p0000065", "repository": "USAP-DC", "title": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.12, "title": "Blue Ice Tephra II - Mt. DeWitt", "uid": "609115", "west": -159.51}, {"awards": "9526374 Alley, Richard", "bounds_geometry": ["POINT(-149 -81)"], "date_created": "Wed, 01 Jan 1997 00:00:00 GMT", "description": "This data set is part of the West Antarctic Ice Sheet cores (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\nThis data set includes melt layers and annual layer data for Siple Dome cores A through J, and upstream core C (UpC). Cores were examined on a light table after the core had been sectioned longitudinally and samples removed for isotopic, chemical, and other analyses, and after the surface had been smoothed using a planer. Major stratigraphic features were noted, such as coarse-grained and fine-grained firn at shallow depths, and coarse-bubbled and fine-bubbled ice at greater depth. Melt layers were identified as bubble-free or nearly-bubble-free zones. Core lengths ranged from 30 to 133 meters.\n\nData in this collection were obtained in the summer of 1997. The data set is available via FTP as ACSII data (.dat), metadata (.meta) and text (.txt) files.", "east": -149.0, "geometry": ["POINT(-149 -81)"], "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Sample/collection Description; Sample/Collection Description; Siple Dome; Siple Dome Ice Core; WAISCORES", "locations": "Siple Dome; Antarctica", "north": -81.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Alley, Richard", "project_titles": "Physical Properties of the Siple Dome Deep Ice Core", "projects": [{"proj_uid": "p0000059", "repository": "USAP-DC", "title": "Physical Properties of the Siple Dome Deep Ice Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.0, "title": "Visible Stratigraphic Dating, Siple Dome and Upstream C Cores", "uid": "609121", "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 |
---|---|---|---|---|---|---|---|---|---|
Impulse HF radar data from Conway Ridge
|
0087144 |
2024-07-22 | Hoffman, Andrew; Conway, Howard; Christianson, Knut |
Glacial History of Ridge AB, West Antarctica |
Marine ice sheets are low-pass filters of climate variability that take centuries to adjust to interior and near-terminus changes in mass balance. Constraining these century-scale changes from satellite observations that span only the last 40 years is challenging. Here, we take a different approach of carefully synthesizing different data sets to infer changes in the configurations of van der Veen and Mercer Ice Streams on the Siple Coast over the past 3000 years from englacial features encoded in ice-penetrating radar data. Englacial radar data from Conway Ridge reveal smooth, surface conformal layers overlying disrupted stratigraphy that suggest the van der Veen Ice Stream was 40 km wider over 3000 years ago. Englacial layer dating indicates that the ice stream narrowed to its present configuration between $\sim3000$ and $\sim1000$ years ago. Similarly disrupted stratigraphy and buried crevasses suggest that ice flowing from Mercer to Whillans Ice Stream across the northwestern tip of the ridge slowed shortly after. Using an ice-flow model capable of simulating shear margin migration, we evaluate whether small changes in ice thickness can lead to large changes in shear margin location. Our results suggest that the tip of Conway Ridge is sensitive to thinning and thickening, and that when the basal strength at the tip of the ridge increases with the height above flotation, the ice sheet shear margins can change quickly. | ["POLYGON((-150 -83.5,-148 -83.5,-146 -83.5,-144 -83.5,-142 -83.5,-140 -83.5,-138 -83.5,-136 -83.5,-134 -83.5,-132 -83.5,-130 -83.5,-130 -83.65,-130 -83.8,-130 -83.95,-130 -84.1,-130 -84.25,-130 -84.4,-130 -84.55,-130 -84.7,-130 -84.85,-130 -85,-132 -85,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-150 -84.85,-150 -84.7,-150 -84.55,-150 -84.4,-150 -84.25,-150 -84.1,-150 -83.95,-150 -83.8,-150 -83.65,-150 -83.5))"] | ["POINT(-140 -84.25)"] | false | false |
AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment
|
1043761 0230197 0636724 2127606 |
2023-03-15 | Muldoon, Gail R.; Young, Duncan A.; Jackson, Charles; Blankenship, Donald D. |
Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE) Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA) |
This file contains internal radar horizon 1 (lm-MERGE-lay9-grg) for West Antarctica, collected during the SOAR/CASERTZ (1991-1996), SOAR/DVD (1999), ATRS (2001), AGASEA (2004-05) and GIMBLE (2013-2014) expeditions. Only data collected in AGASEA is contained in this specific product. This data set is linked to PH.D thesis Muldoon, G. 2018 "West Antarctic Ice Sheet Retreat during the Last Interglacial"Spatial and temporal distributions of accumulation rates on the catchment of Thwaites Glacier, West Antarctica", University of Texas at Austin https://doi.org/10.15781/T23B5WS0D The internal radar horizon (IRH) was traced semi-automatically by Gail R. Muldoon using Haliburtons's Landmark software and picker, in a combination of 2D focused and unfocused data. Depths were calculated using a 2 way velocity in ice of 84.5 m/microsecond, and no firn correction. Isochron age is 4711 (+/- 246 ) years. Funding for this dataset as provided by NSF grants and The G. Unger Vetlesen Foundation. | ["POLYGON((-136 -74,-131.9 -74,-127.8 -74,-123.7 -74,-119.6 -74,-115.5 -74,-111.4 -74,-107.30000000000001 -74,-103.2 -74,-99.1 -74,-95 -74,-95 -74.7,-95 -75.4,-95 -76.1,-95 -76.8,-95 -77.5,-95 -78.2,-95 -78.9,-95 -79.6,-95 -80.3,-95 -81,-99.1 -81,-103.2 -81,-107.3 -81,-111.4 -81,-115.5 -81,-119.6 -81,-123.69999999999999 -81,-127.8 -81,-131.9 -81,-136 -81,-136 -80.3,-136 -79.6,-136 -78.9,-136 -78.2,-136 -77.5,-136 -76.8,-136 -76.1,-136 -75.4,-136 -74.7,-136 -74))"] | ["POINT(-115.5 -77.5)"] | false | false |
I-165-M GPR Field Report 2019-2020
|
1744993 |
2023-03-03 | Nesbitt, Ian; Brook, Edward J. |
Collaborative research: Snapshots of Early and Mid-Pleistocene Climate and Atmospheric Composition from the Allan Hills Blue Ice Area |
This document details the ground-penetrating radar (GPR) collection activities carried out by I. Nesbitt in the Allan Hills during the 2019-2020 field season. This document is intended as an informal catalogue of the fild work and post-processing activities performed at the Allan Hills and later at McMurdo and elsewhere. It contains preliminary post-processing and analysis only. Any interpretation made and presented in this report based on the data herein is subject to change pending further examination. GPR was used to examine sub-ice bedrock topography and the stratigraphic relationship between two shallow ice core drill sites (CMC1 and CMC2), as well as to explore potential future drill sites. In accordance with. the project's objective to drill and analyze ancient ice at relatively shallow depths, the two main features of interest in this study are 1) bedrock topographic features in which ancient ice could be trapped, and 2) englacial stratigraphic layers, especially those which may represent large age discontinuities. | ["POLYGON((159.16667 -76.66667,159.19167000000002 -76.66667,159.21667000000002 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667000000002 -76.66667,159.34167000000002 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.67333599999999,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.69999999999999,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.71999799999999,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167000000002 -76.73333,159.31667000000002 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667000000002 -76.73333,159.19167000000002 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.71999799999999,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.69999999999999,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.67333599999999,159.16667 -76.66667))"] | ["POINT(159.29167 -76.69999999999999)"] | false | false |
SPICEcore visable tephra
|
1543361 1543454 |
2023-02-16 | Iverson, Nels |
Collaborative Research: Tephrochronology of a South Pole Ice Core |
This dataset contains the geochemical composition of three tephra layers that were used in the development of the SPICEcore timescale (Winski et al., 2019). All tephra have been correlated to WDC06A ice core. | ["POLYGON((-180 -50,-163 -50,-146 -50,-129 -50,-112 -50,-95 -50,-78 -50,-61 -50,-44 -50,-27 -50,-10 -50,-10 -54,-10 -58,-10 -62,-10 -66,-10 -70,-10 -74,-10 -78,-10 -82,-10 -86,-10 -90,-27 -90,-44 -90,-61 -90,-78 -90,-95 -90,-112 -90,-129 -90,-146 -90,-163 -90,180 -90,175 -90,170 -90,165 -90,160 -90,155 -90,150 -90,145 -90,140 -90,135 -90,130 -90,130 -86,130 -82,130 -78,130 -74,130 -70,130 -66,130 -62,130 -58,130 -54,130 -50,135 -50,140 -50,145 -50,150 -50,155 -50,160 -50,165 -50,170 -50,175 -50,-180 -50))"] | ["POINT(-120 -70)"] | false | false |
Gridded sea ice concentrations from National Ice Center (NIC) Charts 2014-2019 for Western Antarctic Peninsula
|
1744584 |
2022-12-29 | Klein, Andrew |
Collaborative Research: Sea ice as a driver of Antarctic benthic macroalgal community composition and nearshore trophic connectivity |
This dataset contains gridded sea ice concentrations developed from vector GIS National Ice Center (NIC) Charts for a portion of the western Antarctic Peninsula. This dataset was developed in support of projects ANT-1744550, -1744570, -1744584, and -1744602. It contains geotif files containing the minimum, maximum, and midpoint (average) sea ice concentrations in tenths calculated from NIC vector GIS layers for the 2008-2019 time period. | ["POLYGON((-78 -60,-74.6 -60,-71.2 -60,-67.8 -60,-64.4 -60,-61 -60,-57.6 -60,-54.2 -60,-50.8 -60,-47.400000000000006 -60,-44 -60,-44 -61.3,-44 -62.6,-44 -63.9,-44 -65.2,-44 -66.5,-44 -67.8,-44 -69.1,-44 -70.4,-44 -71.7,-44 -73,-47.4 -73,-50.8 -73,-54.2 -73,-57.6 -73,-61 -73,-64.4 -73,-67.8 -73,-71.2 -73,-74.6 -73,-78 -73,-78 -71.7,-78 -70.4,-78 -69.1,-78 -67.8,-78 -66.5,-78 -65.2,-78 -63.9,-78 -62.6,-78 -61.3,-78 -60))"] | ["POINT(-61 -66.5)"] | false | false |
Marshall Valley Radiocarbon Data
|
1643248 0944150 |
2022-03-01 | Hall, Brenda |
Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles Response of the Antarctic Ice Sheet to the last great global warming |
This dataset contains raw and calibrated radiocarbon data for lacustrine algal layers from glacial lacustrine deposits associated with Ross Sea drift in Marshall Valley. | ["POLYGON((164 -78,164.04 -78,164.08 -78,164.12 -78,164.16 -78,164.2 -78,164.24 -78,164.28 -78,164.32 -78,164.36 -78,164.4 -78,164.4 -78.01,164.4 -78.02,164.4 -78.03,164.4 -78.04,164.4 -78.05,164.4 -78.06,164.4 -78.07,164.4 -78.08,164.4 -78.09,164.4 -78.1,164.36 -78.1,164.32 -78.1,164.28 -78.1,164.24 -78.1,164.2 -78.1,164.16 -78.1,164.12 -78.1,164.08 -78.1,164.04 -78.1,164 -78.1,164 -78.09,164 -78.08,164 -78.07,164 -78.06,164 -78.05,164 -78.04,164 -78.03,164 -78.02,164 -78.01,164 -78))"] | ["POINT(164.2 -78.05)"] | false | false |
The South Pole Ice Core (SPICEcore) chronology and supporting data
|
1443336 |
2019-08-29 | 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 |
Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements |
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 δ15N 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 δ15N of N2 and photolyzed chemical compounds. | ["POINT(-180 -90)"] | ["POINT(-180 -90)"] | false | false |
South Pole Ice Core (SPIcecore) Visual Observations
|
1542778 |
2018-03-05 | Fegyveresi, John; Alley, Richard |
Climate History and Flow Processes from Physical Analyses of the SPICECORE South Pole Ice Core |
This dataset includes all visible observations made of the South Pole Ice core within a dark booth during core processing at the National Ice Core Laboratory. This dataset includes observations starting at 735 meters depth, down to the bottom of the drilled core at 1751 meters. All visible and cloudy layers are noted, as well as any other observed feature or cracks. In addition, all Volcanic layers measured on the ECM were noted. | ["POLYGON((-180 -89.9,-144 -89.9,-108 -89.9,-72 -89.9,-36 -89.9,0 -89.9,36 -89.9,72 -89.9,108 -89.9,144 -89.9,180 -89.9,180 -89.91,180 -89.92,180 -89.93,180 -89.94,180 -89.95,180 -89.96,180 -89.97,180 -89.98,180 -89.99,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -89.99,-180 -89.98,-180 -89.97,-180 -89.96,-180 -89.95,-180 -89.94,-180 -89.93,-180 -89.92,-180 -89.91,-180 -89.9))"] | ["POINT(0 -89.999)"] | false | false |
Active Layer Temperatures from Crescent Stream banks, Taylor Valley Antarctica
|
1246203 |
2017-12-18 | Gooseff, Michael N. |
Collaborative Research: THE MCMURDO DRY VALLEYS: A landscape on the Threshold of Change |
As a part of the project titled "Collaborative Research: The McMurdo Dry Valleys: A landscape on the threshold of change", we measured ground temperatures from 0-20cm at three stream bank positions (base, mid-slope, and top) at 4 locations along Crescent Stream in Taylor Valley - 2 on the east bank, 2 on the west bank. The goal was to evaluate differences in thermal conduction and temperature dynamics of the active layers of these locations, in particular, in a stream that has undergone extensive bank erosion since 2012 due to permafrost degradation. One of the datalogging stations had significant technical problems and has very little data compared to the almost 2 years of temperature date from the other 3 stations (2015-2017). | ["POLYGON((163.1778 -77.6233,163.17792 -77.6233,163.17804 -77.6233,163.17816 -77.6233,163.17828 -77.6233,163.1784 -77.6233,163.17852 -77.6233,163.17864 -77.6233,163.17876 -77.6233,163.17888 -77.6233,163.179 -77.6233,163.179 -77.63331,163.179 -77.64332,163.179 -77.65333,163.179 -77.66334,163.179 -77.67335,163.179 -77.68336,163.179 -77.69337,163.179 -77.70338,163.179 -77.71339,163.179 -77.7234,163.17888 -77.7234,163.17876 -77.7234,163.17864 -77.7234,163.17852 -77.7234,163.1784 -77.7234,163.17828 -77.7234,163.17816 -77.7234,163.17804 -77.7234,163.17792 -77.7234,163.1778 -77.7234,163.1778 -77.71339,163.1778 -77.70338,163.1778 -77.69337,163.1778 -77.68336,163.1778 -77.67335,163.1778 -77.66334,163.1778 -77.65333,163.1778 -77.64332,163.1778 -77.63331,163.1778 -77.6233))"] | ["POINT(163.1784 -77.67335)"] | false | false |
Antarctic Tephra Data Base AntT static web site
|
1142069 1142007 |
2017-09-13 | Kurbatov, Andrei V.; Dunbar, Nelia |
Collaborative Research: Developing an Antarctic Tephra Database for Interdisciplinary Paleoclimate Research (AntT) |
This collaborative interdisciplinary research project aims to consolidate, into a single user-friendly database, information about volcanic products detected in Antarctica. By consolidating information about volcanic sources, and physical and geochemical characteristics of volcanic products, this systematic data collection approach will improve the ability of researchers to identify volcanic ash, or tephra, from specific volcanic eruptions that may be spread over large areas in a geologically instantaneous amount of time. AntT database is designed to assist in the identification and cross-correlation of time intervals in various paleoclimate archives that contain volcanic layers from often unknown sources. | ["POLYGON((0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,216 -60,252 -60,288 -60,324 -60,360 -60,360 -63,360 -66,360 -69,360 -72,360 -75,360 -78,360 -81,360 -84,360 -87,360 -90,324 -90,288 -90,252 -90,216 -90,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,0 -87,0 -84,0 -81,0 -78,0 -75,0 -72,0 -69,0 -66,0 -63,0 -60))"] | ["POINT(180 -75)"] | 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 |
Annual Satellite Era Accumulation Patterns Over WAIS Divide: A Study Using Shallow Ice Cores, Near-Surface Radars and Satellites
|
0944653 |
2015-01-01 | Forster, Richard |
Collaborative Research: Annual satellite era accumulation patterns over WAIS Divide: A study using shallow ice cores, near-surface radars and satellites |
This award supports a project to broaden the knowledge of annual accumulation patterns over the West Antarctic Ice Sheet by processing existing near-surface radar data taken on the US ITASE traverse in 2000 and by gathering and validating new ultra/super-high-frequency (UHF) radar images of near surface layers (to depths of ~15 m), expanding abilities to monitor recent annual accumulation patterns from point source ice cores to radar lines. Shallow (15 m) ice cores will be collected in conjunction with UHF radar images to confirm that radar echoed returns correspond with annual layers, and/or sub-annual density changes in the near-surface snow, as determined from ice core stable isotopes. This project will additionally improve accumulation monitoring from space-borne instruments by comparing the spatial-radar-derived-annual accumulation time series to the passive microwave time series dating back over 3 decades and covering most of Antarctica. The intellectual merit of this project is that mapping the spatial and temporal variations in accumulation rates over the Antarctic ice sheet is essential for understanding ice sheet responses to climate forcing. Antarctic precipitation rate is projected to increase up to 20% in the coming century from the predicted warming. Accumulation is a key component for determining ice sheet mass balance and, hence, sea level rise, yet our ability to measure annual accumulation variability over the past 5 decades (satellite era) is mostly limited to point-source ice cores. Developing a radar and ice core derived annual accumulation dataset will provide validation data for space-born remote sensing algorithms, climate models and, additionally, establish accumulation trends. The broader impacts of the project are that it will advance discovery and understanding within the climatology, glaciology and remote sensing communities by verifying the use of UHF radars to monitor annual layers as determined by visual, chemical and isotopic analysis from corresponding shallow ice cores and will provide a dataset of annual to near-annual accumulation measurements over the past ~5 decades across WAIS divide from existing radar data and proposed radar data. By determining if temporal changes in the passive microwave signal are correlated with temporal changes in accumulation will help assess the utility of passive microwave remote sensing to monitor accumulation rates over ice sheets for future decades. The project will promote teaching, training and learning, and increase representation of underrepresented groups by becoming involved in the NASA History of Winter project and Thermochron Mission and by providing K-12 teachers with training to monitor snow accumulation and temperature here in the US, linking polar research to the student's backyard. The project will train both undergraduate and graduate students in polar research and will encouraging young investigators to become involved in careers in science. In particular, two REU students will participate in original research projects as part of this larger project, from development of a hypothesis to presentation and publication of the results. The support of a new, young woman scientist will help to increase gender diversity in polar research. | ["POLYGON((-119.4 -78.1,-118.46 -78.1,-117.52 -78.1,-116.58 -78.1,-115.64 -78.1,-114.7 -78.1,-113.76 -78.1,-112.82 -78.1,-111.88 -78.1,-110.94 -78.1,-110 -78.1,-110 -78.29,-110 -78.48,-110 -78.67,-110 -78.86,-110 -79.05,-110 -79.24,-110 -79.43,-110 -79.62,-110 -79.81,-110 -80,-110.94 -80,-111.88 -80,-112.82 -80,-113.76 -80,-114.7 -80,-115.64 -80,-116.58 -80,-117.52 -80,-118.46 -80,-119.4 -80,-119.4 -79.81,-119.4 -79.62,-119.4 -79.43,-119.4 -79.24,-119.4 -79.05,-119.4 -78.86,-119.4 -78.67,-119.4 -78.48,-119.4 -78.29,-119.4 -78.1))"] | ["POINT(-114.7 -79.05)"] | false | false |
The effects of ocean acidification and rising sea surface temperatures on shallow-water benthic organisms in Antarctica
|
1041022 |
2015-01-01 | McClintock, James; Amsler, Charles; Angus, Robert |
The effects of ocean acidification and rising sea surface temperatures on shallow-water benthic organisms in Antarctica |
The research will investigate the individual and combined effects of rising ocean acidification and sea surface temperatures on shallow-water calcified benthic organisms in western Antarctic Peninsular (WAP) marine communities. The Southern Ocean is predicted to become undersaturated in terms of both aragonite and calcite within 50 and 100 years, respectively, challenging calcification processes. Adding to the problem, antarctic calcified benthic marine organisms are more vulnerable to ocean acidification than temperate and tropical species because they are generally weakly calcified. Many antarctic organisms are essentially stenothermal, and those in the West Antarctic Peninsula are being subjected to rising seawater temperatures. The project employs both single-species and multi-species level approaches to evaluating the impacts of rising ocean acidification and seawater temperature on representative calcified and non-calcified macroalgae, on calcified and non-calcified mesograzers, and on a calcified macro-grazer, all of which are important ecological players in the rich benthic communities. Multi-species analysis will focus on the diverse assemblage of amphipods and mesogastropods that are associated with dominant macroalgae that collectively play a key role in community dynamics along the WAP. The project will support undergraduate research, both through NSF programs, as well as home university-based programs, some designed to enhance the representation of minorities in the sciences. The principal investigators also will support and foster graduate education through mentoring of graduate students. Through their highly successful UAB IN ANTARCTICA interactive web program, they will continue to involve large numbers of teachers, K-12 students, and other members of the community at large in their scientific endeavors in Antarctica. | ["POLYGON((-79 -60,-76.4 -60,-73.8 -60,-71.2 -60,-68.6 -60,-66 -60,-63.4 -60,-60.8 -60,-58.2 -60,-55.6 -60,-53 -60,-53 -61,-53 -62,-53 -63,-53 -64,-53 -65,-53 -66,-53 -67,-53 -68,-53 -69,-53 -70,-55.6 -70,-58.2 -70,-60.8 -70,-63.4 -70,-66 -70,-68.6 -70,-71.2 -70,-73.8 -70,-76.4 -70,-79 -70,-79 -69,-79 -68,-79 -67,-79 -66,-79 -65,-79 -64,-79 -63,-79 -62,-79 -61,-79 -60))"] | ["POINT(-66 -65)"] | false | false |
History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris
|
0944489 |
2014-01-01 | Williams, Trevor; Hemming, Sidney R. |
History of the East Antarctic Ice Sheet since the mid-Miocene: New Evidence from Provenance of Ice-rafted Debris |
Intellectual Merit: The PIs propose to study the stability and dynamics of the East Antarctic ice sheet during the Pliocene in the area of the Wilkes and Aurora subglacial basins. Models indicate the ice sheet is most sensitive to warming in these low-lying areas. This study is important as there is very little direct evidence about which parts of the East Antarctic ice sheet became unstable under warm conditions. In a pilot study the PIs have shown that the isotopic geochemical signature of downcore ice-rafted debris (IRD) can be linked to continental source areas indicating which parts of the ice sheet reached the coast and calved IRD-bearing icebergs. Their initial results suggest rapid iceberg discharge from the Wilkes Land and Adelie Land coastal areas at times in the late Miocene and early Pliocene. In this study the PIs will analyze IRD from IODP sediment cores collected on the continental rise off East Antarctica. By analyzing 40Ar/39Ar ages of hornblende IRD grains, U-Pb ages of zircons, and Sm-Nd isotopes of the fine fraction of several IRD-rich layers for each core, they will be able to fingerprint continental source areas that indicate ice extent and dynamics on East Antarctica. The PIs will also carry out detailed studies across a few of these layers to characterize the anatomy of the ice-rafting event and better understand the mechanism of ice destabilization. Broader impacts: The data collected will be important for scientists in a broad variety of fields. The project will involve one undergraduate student and one summer intern at LDEO, and a graduate student at Imperial College London. The project will expose to cutting edge methodologies as well as an international research team. Data from the project will be deposited in the online databases (SedDB) and all results and methods will be made available to the scientific community through publications in peer-reviewed journals and attendance at international conferences | ["POLYGON((-55 -58,-33.2 -58,-11.4 -58,10.4 -58,32.2 -58,54 -58,75.8 -58,97.6 -58,119.4 -58,141.2 -58,163 -58,163 -60,163 -62,163 -64,163 -66,163 -68,163 -70,163 -72,163 -74,163 -76,163 -78,141.2 -78,119.4 -78,97.6 -78,75.8 -78,54 -78,32.2 -78,10.4 -78,-11.4 -78,-33.2 -78,-55 -78,-55 -76,-55 -74,-55 -72,-55 -70,-55 -68,-55 -66,-55 -64,-55 -62,-55 -60,-55 -58))"] | ["POINT(54 -68)"] | false | false |
The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter
|
1039365 |
2013-01-01 | Rimmer, Susan |
Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter |
This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. The broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming. | [] | [] | false | false |
Annual Layers at Siple Dome, Antarctica, from Borehole Optical Stratigraphy
|
0087521 |
2012-04-15 | Hawley, Robert L.; Waddington, Edwin D.; Alley, Richard; Taylor, Kendrick C. |
Borehole Fingerprinting: Vertical Strain, Firn Compaction, and Firn Depth-Age Scales |
Researchers gathered data on annual snow layers at Siple Dome, Antarctica, using borehole optical stratigraphy. This data set contains annual layer depths and firn optical brightness. The brightness log is a record of reflectivity of the firn, and peaks in brightness are interpreted to be fine-grained high-density winter snow, as part of the wind slab depth-hoar couplet. Data are available via FTP in ASCII text (.txt) format | ["POINT(-148.82 -81.66)"] | ["POINT(-148.82 -81.66)"] | false | false |
Millennially Averaged Accumulation Rates for Lake Vostok
|
0538674 |
2011-08-01 | Macgregor, Joseph A.; Matsuoka, Kenichi; Studinger, Michael S.; Waddington, Edwin D.; Winebrenner, Dale |
Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data |
This data set consists of inferred accumulation rates from three radar layers (26, 35 and 41 thousand years old) in the Vostok Subglacial Lake region. Accumulation rates were inferred using Local-Layer Approximation (LLA), which assumes that the strain-rate history of a particle traveling through the ice sheet can be approximated by the vertical strain-rate profile at the current position of the particle, which the researchers assume to be uniform. Parameters include location, in latitude and longitude, polar stereographic coordinates, and local grid X and Y coordinates, along with layer age, in thousands of years (ka), and inferred accumulation rate (cm/a). The data cover a 150 by 350 km area. Data are available via FTP, as a text file (.txt) with columns in comma separated value format. | ["POLYGON((68.4 -75.7,69.61 -75.7,70.82 -75.7,72.03 -75.7,73.24 -75.7,74.45 -75.7,75.66 -75.7,76.87 -75.7,78.08 -75.7,79.29 -75.7,80.5 -75.7,80.5 -76.04,80.5 -76.38,80.5 -76.72,80.5 -77.06,80.5 -77.4,80.5 -77.74,80.5 -78.08,80.5 -78.42,80.5 -78.76,80.5 -79.1,79.29 -79.1,78.08 -79.1,76.87 -79.1,75.66 -79.1,74.45 -79.1,73.24 -79.1,72.03 -79.1,70.82 -79.1,69.61 -79.1,68.4 -79.1,68.4 -78.76,68.4 -78.42,68.4 -78.08,68.4 -77.74,68.4 -77.4,68.4 -77.06,68.4 -76.72,68.4 -76.38,68.4 -76.04,68.4 -75.7))"] | ["POINT(74.45 -77.4)"] | false | false |
Histories of Accumulation, Thickness, and WAIS Divide Location, Antarctica
|
0440666 |
2010-06-20 | Waddington, Edwin D.; Koutnik, Michelle |
Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach |
This data set contains radar internal layer and ice sheet topography data for two sites in Antarctica, along with associated model results from two studies. This project used geophysical inverse theory and a 2.5 D flowband ice-flow forward model to extract robust transient accumulation patterns from multiple deeper layers. Histories of divide migration, or the movement of the ice sheet and ice-surface evolution are also provided. The data used to solve the inverse problem, and the model solutions are provided. Internal layers, modern ice-surface velocities, and modern ice-sheet geometry at Taylor Mouth are available, as well as the pattern of accumulation inferred by Waddington et al. (2007). Data are available via FTP in Matlab (.mat) format. Supporting information is available as text files (.rtf and .txt). | ["POINT(158.716667 -77.783333)", "POINT(-111.816667 -79.416667)"] | ["POINT(158.716667 -77.783333)", "POINT(-111.816667 -79.416667)"] | false | false |
Englacial Layers and Attenuation Rates across the Ross and Amundsen Sea Ice-Flow Divide (WAIS Divide), West Antarctica
|
0338151 |
2010-06-15 | Raymond, Charles; Matsuoka, Kenichi |
Glaciological Characteristics of the Ross/Amundsen Sea Ice-flow Divide Deduced by a New Analysis of Ice-penetrating Radar Data |
This data set contains the results of a model study of spatial variations of ice temperature and subglacial conditions using available ice-penetrating radar data around a future deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet. The model data are based on radar data collected by the Support Office of Aerogeophysical Research (SOAR) at the University of Texas, and the University of Washington, in 2000. The data include values for attenuation estimates for individual radar profiles. Data are available via FTP in MATLAB (.mat) and Portable Document (.pdf) formats. | ["POINT(-112.09 -79.47)"] | ["POINT(-112.09 -79.47)"] | false | false |
Ice Flow History of the Thwaites Glacier, West Antarctica
|
0739372 |
2010-05-01 | Conway, Howard; Fudge, T. J.; Catania, Ginny |
Collaborative Research: Ice-flow history of the Thwaites Glacier, West Antarctica |
This data set contains past flow lines of Thwaites Glacier. The flow lines were identified using layer patterns tracked between parallel radar layers, from a radar profile of the Thwaites Glacier catchment. The radar data was run and processed by the University of Texas Institute for Geophysics. The flow lines were identified from distinct layer patterns tracked between parallel radar layers. Data are available via FTP in ASCII text (.txt) format. | ["POLYGON((-123 -76,-120.65 -76,-118.3 -76,-115.95 -76,-113.6 -76,-111.25 -76,-108.9 -76,-106.55 -76,-104.2 -76,-101.85 -76,-99.5 -76,-99.5 -76.37,-99.5 -76.74,-99.5 -77.11,-99.5 -77.48,-99.5 -77.85,-99.5 -78.22,-99.5 -78.59,-99.5 -78.96,-99.5 -79.33,-99.5 -79.7,-101.85 -79.7,-104.2 -79.7,-106.55 -79.7,-108.9 -79.7,-111.25 -79.7,-113.6 -79.7,-115.95 -79.7,-118.3 -79.7,-120.65 -79.7,-123 -79.7,-123 -79.33,-123 -78.96,-123 -78.59,-123 -78.22,-123 -77.85,-123 -77.48,-123 -77.11,-123 -76.74,-123 -76.37,-123 -76))"] | ["POINT(-111.25 -77.85)"] | false | false |
Ice-Penetrating Radar Data Across Siple Coast Grounding Lines
|
0538120 |
2010-01-01 | Hulbe, Christina; Catania, Ginny |
Collaborative Research: Grounding Line Forensics: The History of Grounding Line Retreat in the Kamb Ice Stream Outlet Region |
These data consist of ice-penetrating radar data collected on the ground across the grounding line near Siple Dome during the 2006 and 2007 Antarctic summer field seasons. Primarily, the data consist of low-frequency radar data (2 MHz, approximately 50 meter resolution) in order to observe deep internal layers and the ice-bed interface. The data set also contains one file with high-frequency (100 MHz, approximately 1 meter resolution) radar data, for a sub-region of one of the low-frequency radar profiles. Coincident kinematic GPS data were also collected to correct the radar data for topography along each profile. Radar profiles are typically approximately 20 km in length with the grounding line crossed centrally where possible. Data are available via FTP in Matlab (.mat) format. | ["POLYGON((-160 -81,-158.5 -81,-157 -81,-155.5 -81,-154 -81,-152.5 -81,-151 -81,-149.5 -81,-148 -81,-146.5 -81,-145 -81,-145 -81.2,-145 -81.4,-145 -81.6,-145 -81.8,-145 -82,-145 -82.2,-145 -82.4,-145 -82.6,-145 -82.8,-145 -83,-146.5 -83,-148 -83,-149.5 -83,-151 -83,-152.5 -83,-154 -83,-155.5 -83,-157 -83,-158.5 -83,-160 -83,-160 -82.8,-160 -82.6,-160 -82.4,-160 -82.2,-160 -82,-160 -81.8,-160 -81.6,-160 -81.4,-160 -81.2,-160 -81))"] | ["POINT(-152.5 -82)"] | false | false |
Interactive Effects of Iron, Light and Carbon Dioxide on Phytoplankton Community Dynamics in the Ross Sea
|
0338097 |
2010-01-01 | DiTullio, Giacomo |
Collaborative Research: Interactive Effects of Iron, Light and Carbon Dioxide on Phytoplankton Community Dynamics in the Ross Sea |
The objectives of this proposal are to investigate the controls on the large-scale distribution and production of the two major bloom-forming phytoplankton taxa in the Southern Ocean, diatoms and Phaeocystis Antarctica. These two groups, through their involvement in the biogeochemical cycles of carbon, sulfur and nutrient elements, may have played important roles in the climate variations of the late Quaternary, and they also may be key players in future environmental change. A current paradigm is that irradiance and iron availability drive phytoplankton dynamics in the Southern Ocean. Recent work, however, suggests that carbon dioxide (CO2) concentrations may also be important in structuring algal assemblages, due to species-specific differences in the physiology. This proposal examines the interactive effects of iron, light and CO2 on the physiology, ecology and relative dominance of Phaeocystis and diatoms in the Southern Ocean. The Ross Sea is an ideal system in which to investigate the environmental factors that regulate the distribution and production of these two algal groups, since it is characterized by seasonal blooms of both P. Antarctica and diatoms that are typically separated in both space and time. This study will take the form of an interdisciplinary investigation that includes a field survey and statistical analysis of algal assemblage composition, iron, mixed layer depth, and CO2 levels in the southern Ross Sea, coupled with shipboard experiments to examine the response of diatom and P. Antarctica assemblages to high and low levels of iron, light and CO2 during spring and summer. This project will provide information on some of the major factors controlling the production and distribution of the two major bloom forming phytoplankton in the Southern Ocean and the related biogeochemical cycling of carbon, sulfur and nutrient elements. The results may ultimately advance the ability to predict how the Southern Ocean will be affected by and possibly modulate future climate change. This project will also make significant educational contributions at several levels, including the planned research involvement of graduate and undergraduate students, postdoctoral associates, a student teacher, and community outreach and educational activities. A number of activities are planned to interface the project with K-12 education. Presentations will be made at local schools to discuss the research and events of the research cruise. During the cruise there will be daily interactive email contact with elementary classrooms. Established websites will be used to allow students to learn about the ongoing research, and to allow researchers to communicate with students through text and downloaded images. | ["POLYGON((-169.94 -52.24,-169.449 -52.24,-168.958 -52.24,-168.467 -52.24,-167.976 -52.24,-167.485 -52.24,-166.994 -52.24,-166.503 -52.24,-166.012 -52.24,-165.521 -52.24,-165.03 -52.24,-165.03 -54.879,-165.03 -57.518,-165.03 -60.157,-165.03 -62.796,-165.03 -65.435,-165.03 -68.074,-165.03 -70.713,-165.03 -73.352,-165.03 -75.991,-165.03 -78.63,-165.521 -78.63,-166.012 -78.63,-166.503 -78.63,-166.994 -78.63,-167.485 -78.63,-167.976 -78.63,-168.467 -78.63,-168.958 -78.63,-169.449 -78.63,-169.94 -78.63,-169.94 -75.991,-169.94 -73.352,-169.94 -70.713,-169.94 -68.074,-169.94 -65.435,-169.94 -62.796,-169.94 -60.157,-169.94 -57.518,-169.94 -54.879,-169.94 -52.24))"] | ["POINT(-167.485 -65.435)"] | false | false |
Radar Investigations of Antarctic Ice Stream Margins, Siple Dome, 1998
|
9725882 |
2007-07-06 | Nereson, Nadine A.; Raymond, Charles |
Internal Stratigraphy and Basal Conditions at the Margins ofActive Ice Streams of the Siple Coast, Antarctica |
This data set consists of surface-based radar measurements, including geometry of the bed, surface, and internal layers, and bed reflectivity measurements at two sites along ice stream margins at Siple Dome, Antarctica. The research is a radar examination of bed reflection characteristics and internal layer geometry in two inter-ice-stream ridges, the Shabtaie Ridge (Ridge D/E) and the Engelhardt Ridge (Ridge B/C), and across margins with the adjacent ice streams, the MacAyeal Ice Stream (Ice Stream E) and the Whillans Ice Stream (Ice Stream B). Investigators collected these radar data from 14 November through 13 December 1998. Data are in Microsoft Word, PDF, ASCII text, MATLAB, binary, and various image formats. Investigators have also provided code for MATLAB routines that they used to view the radar data. Data are available via FTP. | ["POLYGON((-141.6722 -80.1678,-141.34195 -80.1678,-141.0117 -80.1678,-140.68145 -80.1678,-140.3512 -80.1678,-140.02095 -80.1678,-139.6907 -80.1678,-139.36045 -80.1678,-139.0302 -80.1678,-138.69995 -80.1678,-138.3697 -80.1678,-138.3697 -80.4863,-138.3697 -80.8048,-138.3697 -81.1233,-138.3697 -81.4418,-138.3697 -81.7603,-138.3697 -82.0788,-138.3697 -82.3973,-138.3697 -82.7158,-138.3697 -83.0343,-138.3697 -83.3528,-138.69995 -83.3528,-139.0302 -83.3528,-139.36045 -83.3528,-139.6907 -83.3528,-140.02095 -83.3528,-140.3512 -83.3528,-140.68145 -83.3528,-141.0117 -83.3528,-141.34195 -83.3528,-141.6722 -83.3528,-141.6722 -83.0343,-141.6722 -82.7158,-141.6722 -82.3973,-141.6722 -82.0788,-141.6722 -81.7603,-141.6722 -81.4418,-141.6722 -81.1233,-141.6722 -80.8048,-141.6722 -80.4863,-141.6722 -80.1678))"] | ["POINT(-140.02095 -81.7603)"] | false | false |
US International Trans-Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping
|
0088035 0196441 0096299 0229573 |
2005-04-06 | Spikes, Vandy Blue; Hamilton, Gordon S.; Mayewski, Paul A.; Arcone, Steven; Kaspari, Susan |
High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet |
Snow accumulation rates typically show high variability over short distances. This data set contains accumulation rates derived from ground-penetrating radar (GPR) used to detect isochronal layers in the firn in West Antarctica. These layers were then dated using results from ice core analyses. These data show that accumulation rates along this profile have decreased in recent decades. The radar profile extends between two ice core sites taken along one of the US-ITASE traverse routes. | ["POLYGON((-123.993 -77.6832,-123.6019 -77.6832,-123.2108 -77.6832,-122.8197 -77.6832,-122.4286 -77.6832,-122.0375 -77.6832,-121.6464 -77.6832,-121.2553 -77.6832,-120.8642 -77.6832,-120.4731 -77.6832,-120.082 -77.6832,-120.082 -77.7232,-120.082 -77.7632,-120.082 -77.8032,-120.082 -77.8432,-120.082 -77.8832,-120.082 -77.9232,-120.082 -77.9632,-120.082 -78.0032,-120.082 -78.0432,-120.082 -78.0832,-120.4731 -78.0832,-120.8642 -78.0832,-121.2553 -78.0832,-121.6464 -78.0832,-122.0375 -78.0832,-122.4286 -78.0832,-122.8197 -78.0832,-123.2108 -78.0832,-123.6019 -78.0832,-123.993 -78.0832,-123.993 -78.0432,-123.993 -78.0032,-123.993 -77.9632,-123.993 -77.9232,-123.993 -77.8832,-123.993 -77.8432,-123.993 -77.8032,-123.993 -77.7632,-123.993 -77.7232,-123.993 -77.6832))"] | ["POINT(-122.0375 -77.8832)"] | false | false |
Blue Ice Tephra II - Brimstone Peak
|
9527373 |
2003-02-18 | Dunbar, Nelia |
Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region |
This data set is the result of a study of volcanic ash and rock fragment (tephra) layers in exposed blue ice areas on Brimstone Peak (75.888S 158.55E) in East Antarctica. Tephra samples were collected between 15 November 1996 and 15 January 1997. The Antarctic ice sheets preserve a record of the volcanic ash layers and chemical aerosol signatures of local and distant volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas will allow a better understanding of the geometry of ice flow in these areas. Tephra layers in deep ice cores can also provide unique time-stratigraphic markers in cores that are difficult to date. Data include the following information for each sample site: a general description, electron microprobe analysis, GPS location, neutron activation analysis, and a visual description of the petrography.Data are provided as Excel 97 data files, JPG map files, and GIF-formatted BSE images. Data are available via ftp. | ["POLYGON((158.55 -75.86,158.562 -75.86,158.574 -75.86,158.586 -75.86,158.598 -75.86,158.61 -75.86,158.622 -75.86,158.634 -75.86,158.646 -75.86,158.658 -75.86,158.67 -75.86,158.67 -75.864,158.67 -75.868,158.67 -75.872,158.67 -75.876,158.67 -75.88,158.67 -75.884,158.67 -75.888,158.67 -75.892,158.67 -75.896,158.67 -75.9,158.658 -75.9,158.646 -75.9,158.634 -75.9,158.622 -75.9,158.61 -75.9,158.598 -75.9,158.586 -75.9,158.574 -75.9,158.562 -75.9,158.55 -75.9,158.55 -75.896,158.55 -75.892,158.55 -75.888,158.55 -75.884,158.55 -75.88,158.55 -75.876,158.55 -75.872,158.55 -75.868,158.55 -75.864,158.55 -75.86))"] | ["POINT(158.61 -75.88)"] | false | false |
Blue Ice Tephra II - Mt. DeWitt
|
9527373 |
2003-02-01 | Dunbar, Nelia |
Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region |
This data set is the result of a study of volcanic ash and rock fragment (tephra) layers in exposed blue ice areas on Mt. DeWitt, Antarctica (77.12 deg S, 159.51 deg E). Tephra samples were collected between 15 November 1996 and 15 January 1997. Data include the following information for each sample site: a general description, electron microprobe analysis, GPS location, neutron activation analysis, and a visual description of the petrography. Data are provided as an Excel 97 data file, (this file is also divided into various text files) and TIF images. Data are available via ftp. Antarctic ice sheets preserve a record of the volcanic ash layers and chemical aerosol signatures of local and distant volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas will allow a better understanding of the geometry of ice flow in these areas. Tephra layers in deep ice cores can also provide unique time-stratigraphic markers in cores that are difficult to date. | ["POINT(-159.51 -77.12)"] | ["POINT(-159.51 -77.12)"] | false | false |
Visible Stratigraphic Dating, Siple Dome and Upstream C Cores
|
9526374 |
1997-01-01 | Alley, Richard |
Physical Properties of the Siple Dome Deep Ice Core |
This data set is part of the West Antarctic Ice Sheet cores (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. This data set includes melt layers and annual layer data for Siple Dome cores A through J, and upstream core C (UpC). Cores were examined on a light table after the core had been sectioned longitudinally and samples removed for isotopic, chemical, and other analyses, and after the surface had been smoothed using a planer. Major stratigraphic features were noted, such as coarse-grained and fine-grained firn at shallow depths, and coarse-bubbled and fine-bubbled ice at greater depth. Melt layers were identified as bubble-free or nearly-bubble-free zones. Core lengths ranged from 30 to 133 meters. Data in this collection were obtained in the summer of 1997. The data set is available via FTP as ACSII data (.dat), metadata (.meta) and text (.txt) files. | ["POINT(-149 -81)"] | ["POINT(-149 -81)"] | false | false |