USAP-DC

{"dp_type": "Project", "free_text": "interglacial"}

[{"awards": "1939139 Scherer, Reed", "bounds_geometry": "POLYGON((-120 -66,-117.5 -66,-115 -66,-112.5 -66,-110 -66,-107.5 -66,-105 -66,-102.5 -66,-100 -66,-97.5 -66,-95 -66,-95 -67.1,-95 -68.2,-95 -69.3,-95 -70.4,-95 -71.5,-95 -72.6,-95 -73.7,-95 -74.8,-95 -75.9,-95 -77,-97.5 -77,-100 -77,-102.5 -77,-105 -77,-107.5 -77,-110 -77,-112.5 -77,-115 -77,-117.5 -77,-120 -77,-120 -75.9,-120 -74.8,-120 -73.7,-120 -72.6,-120 -71.5,-120 -70.4,-120 -69.3,-120 -68.2,-120 -67.1,-120 -66))", "dataset_titles": "Last Interglacial Southern Ocean paleothermometry from diatom morphometrics: Analysis and application of the F. kerguelensis Valve Rectangularity Sea Surface Temperature proxy.; Pliocene diatom abundance, IODP 397-U1532", "datasets": [{"dataset_uid": "601769", "doi": null, "keywords": "Antarctica; Biogenic Silica; Diatom", "people": "Scherer, Reed Paul", "repository": "USAP-DC", "science_program": null, "title": "Pliocene diatom abundance, IODP 397-U1532", "url": "https://www.usap-dc.org/view/dataset/601769"}, {"dataset_uid": "601767", "doi": null, "keywords": "Amundsen Sea; Antarctica; Sabrina Coast; Southern Ocean", "people": "Ruggiero, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Last Interglacial Southern Ocean paleothermometry from diatom morphometrics: Analysis and application of the F. kerguelensis Valve Rectangularity Sea Surface Temperature proxy.", "url": "https://www.usap-dc.org/view/dataset/601767"}], "date_created": "Tue, 20 Feb 2024 00:00:00 GMT", "description": "Part I, Non-technical Abstract \u003cbr/\u003eConcerns that the West Antarctic Ice Sheet (WAIS) might be susceptible to releasing its ice as giant icebergs into the Southern Ocean due to a warming climate, raising global sea level, were first expressed more than 40 years ago. To best-assess this threat, scientists need to know whether such events occurred in the geologically recent past, during warm intervals of past glacial-interglacial cycles. Ocean drilling near the most vulnerable sector of the WAIS, in 2019, yielded seafloor geologic records demonstrating times when icebergs dropped large volumes of sands and pebbles, called ice-rafted detritus (IRD) in deep water of the Amundsen Sea. Occurring together with IRD that was eroded from bedrock beneath the ice sheets, there are abundant microfossils of diatoms (algal plankton), which indicate high biological productivity in the open ocean. The new sediment cores provide a complete, uninterrupted record of a time of dramatic fluctuations of ice sheet extent that occurred over the last 3 million years. Therefore, they provide the means to obtain clear answers to the question whether ice sheet collapse occurred in the past and offering clues to its potential future. This project will investigate sediment intervals where IRD coincides with evidence of high diatom production, to test whether these two criteria indicate rapid ice sheet collapse. Geochemical analysis of IRD pebbles will help trace the source of the icebergs to likely on-land sites. By analyzing conditions of high diatom and IRD accumulation in deep ocean sediment, where local coastal influences can be avoided, we will assess oceanographic and climatic conditions associated with past ice sheet collapse events. Diatoms provide powerful evidence of temperature and ocean productivity changes in the past, that, when linked to time, can translate into rates of ice sheet drawdown. These results will provide critical data for designing, constraining and testing the next suite computer models that can determine the likelihood and timing of future ice sheet collapse in a warming world. The project will include training of undergraduate and graduate students from diverse backgrounds, and the public will be introduced to Antarctic science and engaged through several different outreach efforts.\u003cbr/\u003e\u003cbr/\u003ePart 2, Technical Abstract\u003cbr/\u003e\u003cbr/\u003eNew drillcores from the Amundsen Sea, Antarctica (IODP Expedition 379) contain a continuous record of oceanographic changes and iceberg rafted debris (IRD) spanning the last 5 million years. This study aims to identify the signature of retreat/collapse of the West Antarctic Ice Sheet (WAIS) in these continental margin, deep-sea sediments by quantitatively analyzing, in detail, diatom and IRD records across glacial-interglacial lithostratigraphic transitions to establish the timing and frequency of Late Pliocene and Pleistocene WAIS collapse events. The investigators will secure age constraints and diagnostic observations of marine paleoenvironmental conditions for selected interglacial intervals of cores from sites U1532 and U1533, using high resolution micropaleontology of diatom assemblages coupled with microstratigraphic analysis of IRD depositional events, while petrography, geochronology and thermochronology of iceberg rafted clasts will provide evidence of iceberg sources and pathways. Depositional paleotemperatures will be assessed via a new paleotemperature proxy based on quantitative assessment of morphologic changes in the dominant Southern Ocean diatom Fragilariopsis kerguelensis. Their results will contribute to parameterization of new ice sheet models that seek to reconstruct and forecast West Antarctic Ice Sheet behavior. This project will directly contribute to undergraduate education at an undergraduate-only college and at a public university that serves a demographic typified by first generation university students and underrepresented groups. Spanning geology, geochemistry, sedimentology, paleontology and paleoceanography, the proposed work will allow undergraduate students to develop diverse skills through hands-on research within a collaborative team that is dedicated to societally relevant research. The two graduate students will conduct original research and work alongside/mentor undergraduates, making for a well-rounded research experience that prepares them for success in future academic or employment sectors. The discoveries that come from this deep-sea record from West Antarctica will be communicated by students and investigators at national and international conferences and an array of public science outreach events.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -71.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICEBERGS; SEA SURFACE TEMPERATURE; Amundsen Sea; MICROFOSSILS", "locations": "Amundsen Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE", "persons": "Scherer, Reed Paul", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Collaborative Research: Testing the Linchpin of WAIS Collapse with Diatoms and IRD in Pleistocene and Late Pliocene Strata of the Resolution Drift, Amundsen Sea, Antarctica", "uid": "p0010451", "west": -120.0}, {"awards": "1745078 Brook, Edward", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Atmospheric methane across the Last Glacial Maximum and deglaciation from the GISP2, NEEM and WAIS Divide ice cores ; Atmospheric methane interpolar difference and four-box troposphere model output across the Last Glacial Maximum and Deglaciation; Carbon-13 isotopic composition of atmospheric methane across Heinrich Stadials 1 and 5, and Dansgaard Oesgher Event 12, WAIS Divide Ice Core, Antarctica", "datasets": [{"dataset_uid": "601736", "doi": "10.15784/601736", "keywords": "Antarctica; Greenland; Methane; Paleoclimate; West Antarctic Ice Sheet", "people": "Fischer, Hubertus; Blunier, Thomas; Schmitt, Jochen; M\u00fchl, Michaela; Edwards, Jon S.; Lee, James; Martin, Kaden; Buizert, Christo; Rosen, Julia; Brook, Edward; Riddell-Young, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "Atmospheric methane interpolar difference and four-box troposphere model output across the Last Glacial Maximum and Deglaciation", "url": "https://www.usap-dc.org/view/dataset/601736"}, {"dataset_uid": "601683", "doi": "10.15784/601683", "keywords": "Antarctica; Methane; West Antarctic Ice Sheet", "people": "Riddell-Young, Benjamin", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Carbon-13 isotopic composition of atmospheric methane across Heinrich Stadials 1 and 5, and Dansgaard Oesgher Event 12, WAIS Divide Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601683"}, {"dataset_uid": "601737", "doi": "10.15784/601737", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Greenland; Ice Core Records; Methane; West Antarctic Ice Sheet", "people": "Lee, James; Edwards, Jon S.; Brook, Edward; Martin, Kaden; Rosen, Julia; Riddell-Young, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "Atmospheric methane across the Last Glacial Maximum and deglaciation from the GISP2, NEEM and WAIS Divide ice cores ", "url": "https://www.usap-dc.org/view/dataset/601737"}], "date_created": "Mon, 01 May 2023 00:00:00 GMT", "description": "This project will develop methods to measure the ratios of carbon-13 to carbon-12, and heavy to light hydrogen in methane in air trapped in ice cores. The ratios of the different forms of carbon and hydrogen are \"fingerprints\" of different sources of this gas in the past--for example wetlands in the tropics versus methane frozen in the sea floor. Once the analysis method is developed, the measurements will be used to examine why methane changed abruptly in the past, both during the last ice age, and during previous warm periods. The data will be used to understand how methane sources like wildfires, methane hydrates, and wetlands respond to climate change. This information is needed to understand future risks of large changes in methane in the atmosphere as Earth warms. \u003cbr/\u003e\u003cbr/\u003eThe project involves two tasks. First, the investigators will build and test a gas extraction system for methane isotopic measurements using continuous flow methods, with the goal of equaling or bettering the precision attained by the few other laboratories that make these measurements. The system will be interfaced with existing mass spectrometers at Oregon State University. The system consists of a vacuum chamber and sequence of traps, purification columns, and furnaces that separate methane from other gases and convert it to carbon dioxide or hydrogen for mass spectrometry. Second, the team will measure the isotopic composition of methane across large changes in concentration associated with two past interglacial periods and during abrupt methane changes of the last ice age. These measurements will be used to understand if the main reason for these concentration changes is climate-driven changes in emissions from wetlands, or whether other sources are involved, for example methane hydrates or wildfires.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; TRACE GASES/TRACE SPECIES; METHANE", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Tracing Past Methane Variations with Stable Isotopes in Antarctic Ice Cores", "uid": "p0010416", "west": -180.0}, {"awards": "1542723 Alexander, Becky", "bounds_geometry": "POINT(-112.05 -79.28)", "dataset_titles": "WAIS Divide ice core nitrate isotopes", "datasets": [{"dataset_uid": "601456", "doi": "10.15784/601456", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chemistry; Ice Core Records; Nitrate; Nitrate Isotopes; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Alexander, Becky", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide ice core nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601456"}], "date_created": "Mon, 13 Feb 2023 00:00:00 GMT", "description": "The Earth\u0027s atmosphere is a highly oxidizing medium. The abundance of oxidants such as ozone in the atmosphere strongly influences the concentrations of pollutants and greenhouse gases, with implications for human health and welfare. Because oxidants are not preserved in geological archives, knowledge of how oxidants have varied in the past under changing climate conditions is extremely limited. This award will measure a proxy for oxidant concentrations in a West Antarctic ice core over several major climate transitions over the past 50,000 years. These measurements will complement similar measurements from a Greenland ice core, which showed significant changes in atmospheric oxidants over major climate transitions covering this same time period. The addition of measurements from Antarctica will allow researchers to examine if the oxidant changes suggested by the Greenland ice core record are regional or global in scale. Knowledge of how oxidants vary naturally with climate will better inform predictions of the composition of the future atmosphere under a warming climate.\u003cbr/\u003e\u003cbr/\u003eThis award will support measurements of the isotopic composition of nitrate in a West Antarctic ice core as a proxy for oxidant concentrations in the past atmosphere. The nitrogen isotopes of nitrate provide information on the degree of preservation of nitrate in the ice core record, and thus aid in the interpretation of the observed variability in the observed nitrate concentrations and oxygen isotopes in ice core records. By providing information about the spatial scale of oxidant changes over abrupt climate change events during the last glacial period, this project may also improve our understanding of mechanisms driving these abrupt events. Insight from this project will prove valuable for forecasting the response of stratospheric circulation to climate change, which has large implications for climate feedbacks and tropospheric composition. In addition, the information gleaned from this project on the mechanisms and feedbacks during abrupt climate change events will help determine the likelihood of such rapid events occurring in the future, which would have dramatic impacts on humankind. This award will provide training for one graduate and one undergraduate student, and will support the development of a hands-on activity related to rapid climate change to be used at the annual Polar Science Weekend at the Pacific Science Center in Seattle, WA.", "east": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": null, "is_usap_dc": true, "keywords": "Nitrate Isotopes; ICE CORE RECORDS; WAIS Divide; LABORATORY", "locations": "WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.28, "title": "Measuring an Ice-core Proxy for Relative Oxidant Abundances over Glacial-interglacial and Rapid Climate changes in a West Antarctic Ice Core", "uid": "p0010403", "west": -112.05}, {"awards": "1841844 Steig, Eric; 1841858 Souney, Joseph; 1841879 Aydin, Murat", "bounds_geometry": "POINT(-105 -86)", "dataset_titles": null, "datasets": null, "date_created": "Mon, 06 Feb 2023 00:00:00 GMT", "description": "The goal of this project is to drill and recover an ice core from Hercules Dome, Antarctica. The geographic setting of Hercules Dome makes it well-situated to investigate changes in the size of the West Antarctic ice sheet over long time periods. The base of the West Antarctic ice sheet lies below sea level, which makes this part of Antarctica vulnerable to melting from the relatively warm deep water of the Southern Ocean. An important research question is whether the West Antarctic Ice Sheet collapsed during Earth\u0027s last prolonged warm period, about 125,000 years ago, when the ocean was warmer and sea level was several meters higher than today. Evidence for or against such a collapse will be recorded in the chemistry and physical properties of the ice. The Hercules Dome ice core will be obtained over three to four field seasons in Antarctica using efficient drilling technology. This grant includes support for project management, pre-drilling science community engagement, ice-core recovery, and education and outreach activities. \u003cbr/\u003e\u003cbr/\u003eHercules Dome is located at the edge of the East Antarctic ice sheet, south of the Transantarctic Mountains at 86 degrees South, 105 degrees West. Glaciological conditions at Hercules Dome are simple, with well-defined layering to the bed, optimal for the recovery of a deep ice core reaching to the last interglacial period at depths between 1600 and 2800 meters. An ice core from Hercules Dome will provide a research opportunity for ice-core analysts and others to make progress on a number of science priorities, including the environmental conditions of the last interglacial period, the history of gases and aerosols, and the magnitude and timing of changes in temperature and snow accumulation over the last 150,000 years. Together with the network of ice cores obtained by U.S. and international researchers over the last few decades, results from Hercules Dome will yield improved estimates of the boundary conditions necessary for the implementation and validation of ice-sheet models critical to the projection of future Antarctic ice-sheet change and sea level.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -105.0, "geometry": "POINT(-105 -86)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Hercules Dome; FIELD SURVEYS; AIR TEMPERATURE; SNOW/ICE CHEMISTRY; GLACIER ELEVATION/ICE SHEET ELEVATION; PALEOCLIMATE RECONSTRUCTIONS", "locations": "Hercules Dome", "north": -86.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.; Fudge, T. J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": "Hercules Dome Ice Core", "south": -86.0, "title": "Collaborative Research: An Ice Core from Hercules Dome, East Antarctica", "uid": "p0010401", "west": -105.0}, {"awards": "2002422 TBD", "bounds_geometry": null, "dataset_titles": "Clumped-isotope composition of molecular oxygen trapped in the Allan Hills S27 ice core", "datasets": [{"dataset_uid": "601593", "doi": "10.15784/601593", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Clumped-isotope composition of molecular oxygen trapped in the Allan Hills S27 ice core", "url": "http://www.usap-dc.org/view/dataset/601593"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Allan Hills; Antarctica; Last Interglacial; Oxygen", "locations": "Allan Hills; Antarctica", "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": "Banerjee, Asmita; Yan, Yuzhen; Yeung, Laurence", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": null, "title": null, "uid": null, "west": null}, {"awards": "1744649 Christianson, Knut", "bounds_geometry": "POLYGON((-120 -85.5,-117.5 -85.5,-115 -85.5,-112.5 -85.5,-110 -85.5,-107.5 -85.5,-105 -85.5,-102.5 -85.5,-100 -85.5,-97.5 -85.5,-95 -85.5,-95 -85.62,-95 -85.74,-95 -85.86,-95 -85.98,-95 -86.1,-95 -86.22,-95 -86.34,-95 -86.46000000000001,-95 -86.58,-95 -86.7,-97.5 -86.7,-100 -86.7,-102.5 -86.7,-105 -86.7,-107.5 -86.7,-110 -86.7,-112.5 -86.7,-115 -86.7,-117.5 -86.7,-120 -86.7,-120 -86.58,-120 -86.46000000000001,-120 -86.34,-120 -86.22,-120 -86.1,-120 -85.98,-120 -85.86,-120 -85.74,-120 -85.62,-120 -85.5))", "dataset_titles": "Hercules Dome ApRES Data; Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data; Hercules Dome Ice-Penetrating Radar Swath Topographies; Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets; ITASE Impulse Radar Hercules Dome to South Pole", "datasets": [{"dataset_uid": "601710", "doi": "10.15784/601710", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Holschuh, Nicholas; Horlings, Annika; Christian, John; O\u0027Connor, Gemma; Christianson, Knut; Hoffman, Andrew; Hills, Benjamin", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data", "url": "https://www.usap-dc.org/view/dataset/601710"}, {"dataset_uid": "601606", "doi": "10.15784/601606", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Christianson, Knut", "repository": "USAP-DC", "science_program": null, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "url": "https://www.usap-dc.org/view/dataset/601606"}, {"dataset_uid": "601739", "doi": "10.15784/601739", "keywords": "Antarctica; Apres; Crystal Orientation Fabric; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hercules Dome; Ice Dynamic; Ice Penetrating Radar; Radar Interferometry; Radar Polarimetry", "people": "Horlings, Annika; Erwin, Emma; Steig, Eric J.; Christianson, Knut; Fudge, Tyler J; Hoffman, Andrew; Holschuh, Nicholas; Hills, Benjamin", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome ApRES Data", "url": "https://www.usap-dc.org/view/dataset/601739"}, {"dataset_uid": "601712", "doi": "10.15784/601712", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Welch, Brian; Christianson, Knut; Hoffman, Andrew; Jacobel, Robert", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "ITASE Impulse Radar Hercules Dome to South Pole", "url": "https://www.usap-dc.org/view/dataset/601712"}, {"dataset_uid": "601711", "doi": "10.15784/601711", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Holschuh, Nicholas; Christianson, Knut; Paden, John; Hoffman, Andrew", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome Ice-Penetrating Radar Swath Topographies", "url": "https://www.usap-dc.org/view/dataset/601711"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington\u0027s annual Polar Science Weekend in Seattle, and art-science collaboration.\u003cbr/\u003e\u003cbr/\u003eThis project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a \"Raymond Bump\") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -86.1)", "instruments": null, "is_usap_dc": true, "keywords": "West Antarctica; ICE DEPTH/THICKNESS; East Antarctica", "locations": "West Antarctica; East Antarctica", "north": -85.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Hoffman, Andrew; Holschuh, Nicholas", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.7, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "uid": "p0010359", "west": -120.0}, {"awards": "0944150 Hall, Brenda", "bounds_geometry": "POLYGON((163.6 -77.5,163.7 -77.5,163.8 -77.5,163.9 -77.5,164 -77.5,164.1 -77.5,164.2 -77.5,164.3 -77.5,164.4 -77.5,164.5 -77.5,164.6 -77.5,164.6 -77.57,164.6 -77.64,164.6 -77.71,164.6 -77.78,164.6 -77.85,164.6 -77.92,164.6 -77.99,164.6 -78.06,164.6 -78.13,164.6 -78.2,164.5 -78.2,164.4 -78.2,164.3 -78.2,164.2 -78.2,164.1 -78.2,164 -78.2,163.9 -78.2,163.8 -78.2,163.7 -78.2,163.6 -78.2,163.6 -78.13,163.6 -78.06,163.6 -77.99,163.6 -77.92,163.6 -77.85,163.6 -77.78,163.6 -77.71,163.6 -77.64,163.6 -77.57,163.6 -77.5))", "dataset_titles": "Marshall Valley Radiocarbon Data; Marshall Valley U-Series Data; Royal Society Range Headland Moraine Belt Radiocarbon Data; Salmon Valley Radiocarbon Data", "datasets": [{"dataset_uid": "601556", "doi": "10.15784/601556", "keywords": "Antarctica; Last Glacial Maximum; Mcmurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Salmon Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601556"}, {"dataset_uid": "601555", "doi": "10.15784/601555", "keywords": "Antarctica; Last Glacial Maximum; Mcmurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Royal Society Range Headland Moraine Belt Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601555"}, {"dataset_uid": "601528", "doi": "10.15784/601528", "keywords": "234U/230Th Dating; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Last Glacial Maximum; Marshall Drift; Marshall Valley; MIS 6; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley U-Series Data", "url": "https://www.usap-dc.org/view/dataset/601528"}, {"dataset_uid": "601529", "doi": "10.15784/601529", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marshall Valley; Radiocarbon; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601529"}], "date_created": "Thu, 03 Mar 2022 00:00:00 GMT", "description": "This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth\u0027s climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area. ", "east": 164.6, "geometry": "POINT(164.1 -77.85)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; Amd/Us; AMD; USA/NSF; GLACIAL LANDFORMS; USAP-DC; Royal Society Range; GLACIER ELEVATION/ICE SHEET ELEVATION", "locations": "Royal Society Range", "north": -77.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Denton, George", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.2, "title": "Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles", "uid": "p0010302", "west": 163.6}, {"awards": "0342484 Harwood, David", "bounds_geometry": "POINT(167.083333 -77.888889)", "dataset_titles": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "datasets": [{"dataset_uid": "601451", "doi": "10.15784/601451", "keywords": "Andrill; Antarctica; Continental Shelf; Diamict; Mcmurdo Sound; Miocene; Paleoclimate; Particle Size", "people": "Passchier, Sandra; Candice, Falk", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601451"}], "date_created": "Fri, 04 Feb 2022 00:00:00 GMT", "description": "ANDRILL is a scientific drilling program to investigate Antarctica\u0027s role in global climate change over the last sixty million years. The approach integrates geophysical surveys, new drilling technology, multidisciplinary core analysis, and ice sheet modeling to address four scientific themes: (1) the history of Antarctica\u0027s climate and ice sheets; (2) the evolution of polar biota and ecosystems; (3) the timing and nature of major tectonic and volcanic episodes; and (4) the role of Antarctica in the Earth\u0027s ocean-climate system. \u003cbr/\u003e\u003cbr/\u003eThis award initiates what may become a long-term program with drilling of two previously inaccessible sediment records beneath the McMurdo Ice Shelf and in South McMurdo Sound. These stratigraphic records cover critical time periods in the development of Antarctica\u0027s major ice sheets. The McMurdo Ice Shelf site focuses on the Ross Ice Shelf, whose size is a sensitive indicator of global climate change. It has recently undergone major calving events, and there is evidence of a thousand-kilometer contraction since the last glacial maximum. As a generator of cold bottom water, the shelf may also play a key role in ocean circulation. The core obtained from this site will also offer insight into sub-ice shelf sedimentary, biologic, and oceanographic processes; the history of Ross Island volcanism; and the flexural response of the lithosphere to volcanic loading, which is important for geophysical and tectonic studies of the region.\u003cbr/\u003e\u003cbr/\u003eThe South McMurdo Sound site is located adjacent to the Dry Valleys, and focuses on the major ice sheet overlying East Antarctica. A debate persists regarding the stability of this ice sheet. Evidence from the Dry Valleys supports contradictory conclusions; a stable ice sheet for at least the last fifteen million years or an active ice sheet that cycled through expansions and contractions as recently as a few millions of years ago. Constraining this history is critical to deep-time models of global climate change. The sediment cores will be used to construct an overall glacial and interglacial history for the region; including documentation of sea-ice coverage, sea level, terrestrial vegetation, and melt-water discharge events. The core will also provide a general chronostratigraphic framework for regional seismic studies and help unravel the area\u0027s complex tectonic history.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society\u0027s understanding of global climate change. Education is supported at the postdoctoral, graduate, undergraduate, and K-12 levels. Teachers and curriculum specialists are integrated into the research program, and a range of video resources will be produced, including a science documentary for television release. New research infrastructure includes equipment for core analysis and ice sheet modeling, as well as development of a unique drilling system to penetrate ice shelves. Drill development and the overall project are co-supported by international collaboration with scientists and the National Antarctic programs of New Zealand, Germany, and Italy. The program also forges new collaborations between research and primarily undergraduate institutions within the United States. \u003cbr/\u003e\u003cbr/\u003eAs key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica\u0027s ice sheets are important to society\u0027s understanding of global climate change. ANDRILL offers new data on marine and terrestrial temperatures, and changes our understanding of extreme climate events like the formation of polar ice caps. Such data are critical to developing accurate models of the Earth\u0027s climatic future.", "east": 167.083333, "geometry": "POINT(167.083333 -77.888889)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; FIELD SURVEYS; ICE SHEETS; USA/NSF; Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; Ross Ice Shelf; SEDIMENTS", "locations": "Ross Ice Shelf", "north": -77.888889, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harwood, David; Levy, Richard", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.888889, "title": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change", "uid": "p0010297", "west": 167.083333}, {"awards": "2039419 Swanger, Kate", "bounds_geometry": "POLYGON((161 -77.3,161.2 -77.3,161.4 -77.3,161.6 -77.3,161.8 -77.3,162 -77.3,162.2 -77.3,162.4 -77.3,162.6 -77.3,162.8 -77.3,163 -77.3,163 -77.35,163 -77.4,163 -77.45,163 -77.5,163 -77.55,163 -77.6,163 -77.65,163 -77.7,163 -77.75,163 -77.8,162.8 -77.8,162.6 -77.8,162.4 -77.8,162.2 -77.8,162 -77.8,161.8 -77.8,161.6 -77.8,161.4 -77.8,161.2 -77.8,161 -77.8,161 -77.75,161 -77.7,161 -77.65,161 -77.6,161 -77.55,161 -77.5,161 -77.45,161 -77.4,161 -77.35,161 -77.3))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 16 Dec 2021 00:00:00 GMT", "description": "The McMurdo Dry Valleys are the largest ice-free region in Antarctica and home to a seasonally active hydrologic system, with streams and saline lakes. Streams are fed by summer meltwater from local glaciers and snowbanks. Therefore, streamflow is tied to summer climate conditions such as air temperatures, ground temperatures, winds, and incoming solar radiation. Based on 50 years of monitoring, summer stream activity has been observed to change, and it likely varied during the geologic past in response to regional climate change and fluctuating glaciers. Thus, deposits from these streams can address questions about past climate, meltwater, and lake level changes in this region. How did meltwater streamflow respond to past climate change? How did streamflow vary during periods of glacial advance and retreat? At what times did large lakes fill many of the valleys and what was their extent? The researchers plan to acquire a record of stream activity for the Dry Valleys that will span the three largest valleys and a time period of about 100,000 years. This record will come from a series of active and ancient alluvial fans that were deposited by streams as they flowed from valley sidewalls onto valley floors. The study will provide a long-term context with which to assess recent observed changes to stream activity and lake levels. The research will be led by two female mid-career investigators and contribute significantly to student research opportunities and education. The research will contribute to graduate and undergraduate education by including students in both field and laboratory research, as well as incorporating data and results into the classroom. The research will be disseminated to K-12 and non-scientific communities through outreach that includes professional development training for K-12 teachers in eastern Massachusetts, development of hands-on activities, visits to K-12 classrooms, and STEM education and literacy activities in North Carolina.\r\n\r\nThe PIs propose to constrain rates of fluvial deposition and periods of increased fluvial activity in the McMurdo Dry Valleys during the Holocene and late Pleistocene. During 50 years of hydrologic monitoring in the Dry Valleys, scientists have observed that streams exhibit significant response to summer conditions. Previous studies of glacial and lacustrine deposits indicate regional glacier advance in the Dry Valleys during recent interglacial periods and high lake levels during and after the Last Glacial Maximum (LGM), with potentially significant low and high stands during the Holocene. However, the geologic record of meltwater activity is poorly constrained. The PIs seek to develop the first spatially-extensive record of stream deposition in the Dry Valleys by analyzing and dating alluvial fans. Given that alluvial fans are deposited by summer meltwater streams in a relatively stable tectonic setting, this record will serve as a proxy of regional summer climate conditions. Meltwater streams are an important component of the regional hydrologic system, connecting glaciers to lakes and affecting ecosystems and soils. A record of fluvial deposition is key to understanding the relationship between past climate change and regional hydrology. The proposed research will include remote- and field-based mapping of alluvial fans, stream channels, and meltwater sources as well as modeling potential incoming solar radiation to the fans and moisture sources during the austral summer. In the field, the PIs will document stratigraphy, collect near-surface sediments from 25 fans across four valleys (Taylor, Pearse, Wright, and Victoria), and collect 2- to 3-m vertical cores of ice-cemented sediments from three alluvial fan complexes. The PIs will then conduct depositional dating of fluvial sands via optically stimulated luminescence, and analyze mineralogy and bulk major element chemistry with X-ray powder diffraction and X-ray fluorescence. From these analyses, the PIs propose to (1) determine the timing of local- to regional-scale periods of high fluvial deposition, (2) calculate depositional rates, and (3) constrain depositional environments and sediment provenance. Given that many of the alluvial fans occur below the hypothesized maximum extents of glacially-dammed lakes in Wright and Victoria valleys, detailed stratigraphy, sediment provenance, and OSL dating of these fans could shed light on ongoing debates regarding the timing and extent of LGM and post-LGM lakes. The work will support a postdoctoral researcher, a PhD student, and many undergraduate and master\u2019s students in cross-disciplinary research that spans stratigraphy, geochemistry, paleoclimatology and physics.", "east": 163.0, "geometry": "POINT(162 -77.55)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Amd/Us; SEDIMENTS; USA/NSF; AMD; Dry Valleys; USAP-DC", "locations": "Dry Valleys", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Swanger, Kate", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -77.8, "title": "Collaborative Research: Holocene and Late Pleistocene Stream Deposition in the McMurdo Dry Valleys, Antarctica as a Proxy for Glacial Meltwater and Paleoclimate", "uid": "p0010285", "west": 161.0}, {"awards": "2139051 Guitard, Michelle", "bounds_geometry": "POLYGON((-45 -57,-44.3 -57,-43.6 -57,-42.9 -57,-42.2 -57,-41.5 -57,-40.8 -57,-40.1 -57,-39.4 -57,-38.7 -57,-38 -57,-38 -57.5,-38 -58,-38 -58.5,-38 -59,-38 -59.5,-38 -60,-38 -60.5,-38 -61,-38 -61.5,-38 -62,-38.7 -62,-39.4 -62,-40.1 -62,-40.8 -62,-41.5 -62,-42.2 -62,-42.9 -62,-43.6 -62,-44.3 -62,-45 -62,-45 -61.5,-45 -61,-45 -60.5,-45 -60,-45 -59.5,-45 -59,-45 -58.5,-45 -58,-45 -57.5,-45 -57))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "The Mid-Pleistocene Transition (MPT; ~1.25\u20130.7 Ma) marks the shift from glacial-interglacial cycles paced by obliquity (~41 kyr cycles) to those paced by eccentricity (~100-kyr cycles). This transition occurred despite little variation in Earth\u2019s orbital parameters, suggesting a role for internal climate feedbacks. The MPT was accompanied by decreasing atmospheric pCO2, increasing deep ocean carbon storage, and changes in deep water formation and distribution, all of which are linked to Antarctic margin atmosphere-ice-ocean interactions. However, Pleistocene records that document such interactions are rarely preserved on the shelf due to repeated Antarctic Ice Sheet (AIS) advance; instead, they are preserved in deep Southern Ocean basins. This project takes advantage of the excellent preservation and recovery of continuous Pleistocene sediment sequences collected from the Scotia Sea during International Ocean Discovery Program Expedition 382 to test the following hypotheses: 1) Southern Ocean upper ocean temperatures vary on orbital timescales during the early to middle Pleistocene (2.6\u20130.7 Ma), and 2) Southern Ocean temperatures co-vary with AIS advance/retreat cycles. Paleotemperatures will be reconstructed using the TetraEther indeX of tetraethers containing 86 carbons (TEX86), a proxy that utilizes marine archaeal biomarkers. The Scotia Sea TEX86-based paleotemperature record will be compared to records of AIS variability, including ice rafted debris. Expedition 382 records will be compared to orbitally paced climatic time series and the benthic oxygen isotope record of global ice volume and bottom water temperature to determine if a correlation exists between upper ocean temperature, AIS retreat/advance, and orbital climate forcing. ", "east": -38.0, "geometry": "POINT(-41.5 -59.5)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; SEA SURFACE TEMPERATURE; USAP-DC; USA/NSF; LABORATORY; AMD; Scotia Sea", "locations": "Scotia Sea", "north": -57.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Michelle, Guitard", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -62.0, "title": "Investigating the influence of ocean temperature on Antarctic Ice Sheet evolution during the early to middle Pleistocene ", "uid": "p0010275", "west": -45.0}, {"awards": "1744927 Mitrovica, Jerry; 1745015 Zimmerer, Matthew; 1744949 Campbell, Seth", "bounds_geometry": "POLYGON((-145 -74,-141.6 -74,-138.2 -74,-134.8 -74,-131.4 -74,-128 -74,-124.6 -74,-121.2 -74,-117.8 -74,-114.4 -74,-111 -74,-111 -74.6,-111 -75.2,-111 -75.8,-111 -76.4,-111 -77,-111 -77.6,-111 -78.2,-111 -78.8,-111 -79.4,-111 -80,-114.4 -80,-117.8 -80,-121.2 -80,-124.6 -80,-128 -80,-131.4 -80,-134.8 -80,-138.2 -80,-141.6 -80,-145 -80,-145 -79.4,-145 -78.8,-145 -78.2,-145 -77.6,-145 -77,-145 -76.4,-145 -75.8,-145 -75.2,-145 -74.6,-145 -74))", "dataset_titles": "Mt. Waesche ground-penetrating radar data 2018-2019", "datasets": [{"dataset_uid": "601490", "doi": "10.15784/601490", "keywords": "Antarctica; GPR; Mt. Waesche", "people": "Braddock, Scott", "repository": "USAP-DC", "science_program": null, "title": "Mt. Waesche ground-penetrating radar data 2018-2019", "url": "https://www.usap-dc.org/view/dataset/601490"}], "date_created": "Fri, 22 Oct 2021 00:00:00 GMT", "description": "Projecting future changes in West Antarctic Ice Sheet (WAIS) volume and global sea level rise in response to anthropogenic climate warming requires dynamic ice sheet models, which are enhanced by testing and calibrating with geologic evidence. Successfully modeling WAIS behavior during past collapse events \r\nprovides a basis for predictions of future sea level change. Exposure ages of erratics and bedrock throughout west Antarctica constrain higher-than-present WAIS geometry during the LGM and the last deglaciation. Quantifying the past surface elevation from the interior of the ice sheet is especially useful as it directly constrains ice thickness and volume where most of the mass is located. Data that determines WAIS geometry during the last interglacial, the last time that climate was warmer than present and when global sea level was 3-6 m higher, is critical for empirically constraining changes in WAIS volume and its contribution to sea level, as well as, to calibrate ice sheet models. These datasets are essentially non-\r\nexistent, as such evidence is now covered by the WAIS. Initial results from ground-penetrating radar surveys indicate ice depths around 1200 m. ", "east": -111.0, "geometry": "POINT(-128 -77)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Mt. Waesche; USA/NSF; SNOW/ICE; GLACIER THICKNESS/ICE SHEET THICKNESS; PALEOCLIMATE RECONSTRUCTIONS; LABORATORY; LAVA COMPOSITION/TEXTURE; Amd/Us; AMD; USAP-DC", "locations": "Mt. Waesche", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Braddock, Scott; Campbell, Seth; Ackert, Robert; Zimmerer, Matthew; Mitrovica, Jerry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Collaborative Research: Constraining West Antarctic Ice Sheet elevation during the last interglacial", "uid": "p0010272", "west": -145.0}, {"awards": "2035637 Tabor, Clay; 2035580 Aarons, Sarah", "bounds_geometry": null, "dataset_titles": "Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.; Oxygen and hydrogen isotope compositions of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area.; Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.; Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "datasets": [{"dataset_uid": "601751", "doi": "10.15784/601751", "keywords": "ALHIC1903; Allan Hills; Antarctica; Deuterium; Glaciology; Hydrogen; Ice; Ice Core Data; Ice Core Records; Isotope; Oxygen; Snow/ice; Snow/Ice; Water", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Oxygen and hydrogen isotope compositions of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601751"}, {"dataset_uid": "601750", "doi": "10.15784/601750", "keywords": "ALHIC1903; Allan Hills; Antarctica; Blue Ice; Dust; Glaciology; Ice Core Records; Leach; Rare Earth Element; Snow/ice; Snow/Ice", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601750"}, {"dataset_uid": "601749", "doi": "10.15784/601749", "keywords": "ALHIC1903; Allan Hills; Antarctica; Dust; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Isotope; Nd; Neodymium; Snow/ice; Snow/Ice; Sr; Strontium", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": null, "title": "Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601749"}, {"dataset_uid": "601748", "doi": "10.15784/601748", "keywords": "ALHIC1903; Allan Hills; Antarctica; Blue Ice; Concentration; Dust; Flux; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Snow/ice; Snow/Ice", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": null, "title": "Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601748"}], "date_created": "Wed, 06 Oct 2021 00:00:00 GMT", "description": "The spatial extent of the West Antarctic Ice Sheet during the last interglacial period (129,000 to 116,000 years ago) is currently unknown, yet this information is fundamental to projections of the future stability of the ice sheet in a warming climate. Paleoclimate records and proxy evidence such as dust can inform on past environmental conditions and ice-sheet coverage. This project will combine new, high-sensitivity geochemical measurements of dust from Antarctic ice collected at Allan Hills with existing water isotope records to document climate and environmental changes through the last interglacial period. These changes will then be compared with Earth-system model simulations of dust and water isotopes to determine past conditions and constrain the sensitivity of the West Antarctic Ice Sheet to warming. The project will test the hypothesis that the uncharacteristically volcanic dust composition observed at another peripheral ice core site at Taylor Glacier during the last interglacial period is related to changes in the spatial extent of the West Antarctic Ice Sheet.\r\n\r\nThis project aims to characterize mineral dust transport during the penultimate glacial-interglacial transition. The team will apply high-precision geochemical techniques to the high-volume, high-resolution ice core drilled at the Allan Hills site in combination with Earth system model simulations to: (1) determine if the volcanic dust signature found in interglacial ice from Taylor Glacier is also found at Allan Hills, (2) determine the likely dust source(s) to this site during the last interglacial, and (3) probe the atmospheric and environmental changes during the last interglacial with a diminished West Antarctic Ice Sheet. The team will develop a suite of measurements on previously drilled ice from Allan Hills, including isotopic compositions of Strontium and Neodymium, trace element concentrations, dust-size distribution, and imaging of ice-core dust to confirm the original signal observed and provide a broader spatial reconstruction of dust transport. In tandem, the team will conduct Earth system modeling with prognostic dust and water-isotope capability to test the sensitivity of dust transport under several plausible ice-sheet and freshwater-flux configurations. By comparing dust reconstruction and model simulations, the team aims to elucidate the driving mechanisms behind dust transport during the last interglacial period.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "MICROPARTICLE CONCENTRATION; FIELD SURVEYS; GEOCHEMISTRY; ICE EXTENT; Amd/Us; USA/NSF; PALEOCLIMATE RECONSTRUCTIONS; AMD; Allan Hills; ICE CORE RECORDS; USAP-DC", "locations": "Allan Hills", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Aarons, Sarah; Tabor, Clay", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Peripheral East Antarctic ice as a unique recorder of climate variability during the Last Interglacial", "uid": "p0010270", "west": null}, {"awards": "2114839 Passchier, Sandra", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 25 Aug 2021 00:00:00 GMT", "description": "The project targets the long-term variability of the West Antarctic Ice Sheet over several glacial-interglacial cycles in the early Pliocene sedimentary record drilled by the International Ocean Discovery Program (IODP) Expedition 379 in the Amundsen Sea. Data collection includes 1) the sand provenance of ice-rafted debris and shelf diamictites and its sources within the Amundsen Sea and Antarctic Peninsula region; 2) sedimentary structures and sortable silt calculations from particle size records and reconstructions of current intensities and interactions; and 3) the bulk provenance of continental rise sediments compared to existing data from the Amundsen Sea shelf with investigations into downslope currents as pathways for Antarctic Bottom Water formation. The results are analyzed within a cyclostratigraphic framework of reflectance spectroscopy and colorimetry (RSC) and X-ray fluorescence scanner (XRF) data to gain insight into orbital forcing of the high-latitude processes. The early Pliocene Climatic Optimum (PCO) ~4.5-4.1 Ma spans a major warm period recognized in deep-sea stable isotope and sea-surface temperature records. This period also coincides with a global mean sea level highstand of \u003e 20 m requiring contributions in ice mass loss from Antarctica. The following hypotheses will be tested: 1) that the West Antarctic Ice Sheet retreated from the continental shelf break through an increase in sub iceshelf melt and iceberg calving at the onset of the PCO ~4.5 Ma, and 2) that dense shelf water cascaded down through slope channels after ~4.5 Ma as the continental shelf became exposed during glacial terminations. The project will reveal for the first time how the West Antarctic Ice Sheet operated in a warmer climate state prior to the onset of the current \u201cicehouse\u201d period ~3.3 Ma.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; TERRIGENOUS SEDIMENTS; Amd/Us; SEDIMENTS; FIELD SURVEYS; Amundsen Sea; USAP-DC; AMD", "locations": "Amundsen Sea", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": null, "title": "West Antarctic Ice-sheet Change and Paleoceanography in the Amundsen Sea Across the Pliocene Climatic Optimum", "uid": "p0010252", "west": null}, {"awards": "2122248 Waters, Laura", "bounds_geometry": "POLYGON((-127.143608 -77.1380528,-127.1012394 -77.1380528,-127.0588708 -77.1380528,-127.0165022 -77.1380528,-126.9741336 -77.1380528,-126.931765 -77.1380528,-126.8893964 -77.1380528,-126.8470278 -77.1380528,-126.8046592 -77.1380528,-126.7622906 -77.1380528,-126.719922 -77.1380528,-126.719922 -77.14809141,-126.719922 -77.15813002,-126.719922 -77.16816863,-126.719922 -77.17820724,-126.719922 -77.18824585,-126.719922 -77.19828446,-126.719922 -77.20832307,-126.719922 -77.21836168,-126.719922 -77.22840029,-126.719922 -77.2384389,-126.7622906 -77.2384389,-126.8046592 -77.2384389,-126.8470278 -77.2384389,-126.8893964 -77.2384389,-126.931765 -77.2384389,-126.9741336 -77.2384389,-127.0165022 -77.2384389,-127.0588708 -77.2384389,-127.1012394 -77.2384389,-127.143608 -77.2384389,-127.143608 -77.22840029,-127.143608 -77.21836168,-127.143608 -77.20832307,-127.143608 -77.19828446,-127.143608 -77.18824585,-127.143608 -77.17820724,-127.143608 -77.16816863,-127.143608 -77.15813002,-127.143608 -77.14809141,-127.143608 -77.1380528))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 19 Aug 2021 00:00:00 GMT", "description": "Isotopic and sedimentary datasets reveal that volcanic activity typically increases during interglacial periods. However, the physical mechanisms through which changes in the surface loading affect volcanic magmatic plumbing systems remain unconstrained. Recently generated 40Ar/39Ar eruption ages indicate that 86% of the dated samples from Mt. Waesche, a late Quaternary volcano in Marie Byrd land, correlate with interglacial periods, suggesting this volcano uniquely responds to changes in the West Antarctic Ice Sheet. We propose to combine the petrology of Mount Waesche\u2019s volcanic record, constraints on changing ice loads through time, and geodynamic modelling to: (1) Determine how pre-eruptive storage conditions change during glacial and interglacial periods using whole rock and mineral compositions of volcanic rocks; (2) Conduct geodynamic modeling to elucidate the relationship between lithospheric structure, temporal variations in ice sheet thickness, and subsequent changes in crustal stresses and magmatic transport and, therefore, the mechanism(s) by which deglaciation impacts magmatic plumbing systems; (3) Use the outcomes of objectives (1) and (2) to provide new constraints on the changes in ice sheet thickness through time that could plausibly trigger future volcanic and magmatic activity in West Antarctica. This collaborative approach will provide a novel methodology to determine prior magnitudes and rates of ice load changes within the Marie Byrd Land region of Antarctica. Lastly, estimates of WAIS elevation changes from this study will be compared to ongoing studies at Mount Waesche focused on constraining last interglacial ice sheet draw down using cosmogenic exposure ages obtained from shallow drilling. The scope of work also includes a partnership with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online.", "east": -126.719922, "geometry": "POINT(-126.931765 -77.18824585)", "instruments": null, "is_usap_dc": true, "keywords": "Mt. Waesche; GEOCHEMISTRY; LITHOSPHERIC PLATE MOTION; STRESS; Amd/Us; West Antarctica; Executive Committee Range; NOT APPLICABLE; USAP-DC; AMD; MAJOR ELEMENTS; USA/NSF; ROCKS/MINERALS/CRYSTALS", "locations": "West Antarctica; Mt. Waesche; Executive Committee Range", "north": -77.1380528, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Waters, Laura; Naliboff, John; Zimmerer, Matthew", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -77.2384389, "title": "Integrating petrologic records and geodynamics: Quantifying the effects of glaciation on crustal stress and eruptive patterns at Mt. Waesche, Executive Committee Range, Antarctica", "uid": "p0010248", "west": -127.143608}, {"awards": "2000992 Romans, Brian", "bounds_geometry": "POINT(-172.873074 -74.274008)", "dataset_titles": null, "datasets": null, "date_created": "Tue, 06 Jul 2021 00:00:00 GMT", "description": "Geological records from the Antarctic Ice Sheet (AIS) margin demonstrate that the ice sheet oscillated in response to orbital variations in insolation (i.e., ~400, 100, 41, and 20 kyr), and it appears to be more sensitive to specific frequencies that regulate mean annual insolation (i.e., 41-kyr obliquity), particularly when the ice sheet extends into marine environments and is impacted by ocean circulation. However, the relationship between orbital forcing and the production of Antarctic Bottom Water (AABW) is unconstrained. Thus, a knowledge gap exists in understanding how changing insolation impacts ice marginal and Southern Ocean conditions that directly influence ventilation of the global ocean. We hypothesize that insolation-driven changes directly affected the production and export of AABW to the Southern Ocean from the Pliocene through the Pleistocene. For example, obliquity amplification during the warmer Pliocene may have led to enhanced production and export of dense waters from the shelf due to reduced AIS extent, which, in turn, led to greater AABW outflow. To determine the relationship of AABW production to orbital regime, we plan to reconstruct both from a single, continuous record from the levee of Hillary Canyon, a major conduit of AABW outflow, on the Ross Sea continental rise. \r\n\r\nTo test our hypothesis, we will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) We will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. We will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) We will use grain-size data, physical properties, XRF core scanning, CT imaging, and hyperspectral imaging to guide lithofacies analysis to infer processes occurring during glacial, deglacial, and interglacial periods. Statistical techniques and optimization methods will be applied to test for astronomical forcing of sedimentary packages in order to provide a cyclostratigraphic framework and interpret the orbital-forcing regime. (3) We will use bulk sedimentary carbon and nitrogen abundance and isotope data to determine how relative contributions of terrigenous and marine organic matter change in response to orbital forcing. We will integrate these data with sedimentological records to deconvolve organic matter production from its deposition or remobilization due to AABW outflow as a function of the oscillating extent of the AIS. These data sets will be integrated into a unified chronostratigraphy to determine the relationship between AABW outflow and orbital-forcing scenarios under the varying climate regimes of the Plio-Pleistocene.\r\n", "east": -172.873074, "geometry": "POINT(-172.873074 -74.274008)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; LABORATORY; AMD; USA/NSF; SEDIMENTS; Amd/Us; Ross Sea", "locations": "Ross Sea", "north": -74.274008, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Romans, Brian; Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -74.274008, "title": "COLLABORATIVE RESEARCH: Orbital-scale Variability of the West Antarctic Ice Sheet and the Formation of Bottom Water in the Ross Sea during the Pliocene-Pleistocene", "uid": "p0010227", "west": -172.873074}, {"awards": "1341658 Mukhopadhyay, Sujoy", "bounds_geometry": "POLYGON((-116.45 -84.786,-116.443 -84.786,-116.436 -84.786,-116.429 -84.786,-116.422 -84.786,-116.415 -84.786,-116.408 -84.786,-116.401 -84.786,-116.394 -84.786,-116.387 -84.786,-116.38 -84.786,-116.38 -84.7864,-116.38 -84.7868,-116.38 -84.7872,-116.38 -84.7876,-116.38 -84.788,-116.38 -84.7884,-116.38 -84.7888,-116.38 -84.7892,-116.38 -84.7896,-116.38 -84.79,-116.387 -84.79,-116.394 -84.79,-116.401 -84.79,-116.408 -84.79,-116.415 -84.79,-116.422 -84.79,-116.429 -84.79,-116.436 -84.79,-116.443 -84.79,-116.45 -84.79,-116.45 -84.7896,-116.45 -84.7892,-116.45 -84.7888,-116.45 -84.7884,-116.45 -84.788,-116.45 -84.7876,-116.45 -84.7872,-116.45 -84.7868,-116.45 -84.7864,-116.45 -84.786))", "dataset_titles": "Ohio Range Subglacial rock core cosmogenic nuclide data", "datasets": [{"dataset_uid": "601351", "doi": "10.15784/601351", "keywords": "Aluminum-26; Antarctica; Beryllium-10; Cosmogenic Dating; Cosmogenic Radionuclides; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Fluctuations; Ohio Range; Rocks", "people": "Mukhopadhyay, Sujoy", "repository": "USAP-DC", "science_program": null, "title": "Ohio Range Subglacial rock core cosmogenic nuclide data", "url": "https://www.usap-dc.org/view/dataset/601351"}], "date_created": "Sun, 28 Jun 2020 00:00:00 GMT", "description": "Modeling fluctuations in the extent of the West Antarctic Ice Sheet (WAIS) over time is a principal goal of the glaciological community. These models will provide a critical basis for predictions of future sea level change, and therefore this work great societal relevance. The mid-Pliocene time interval is of particular interest, as it is the most recent period in which global temperatures were warmer and atmospheric CO2 concentrations may have been higher than current levels. However, observational constraints on fluctuations in the WAIS older than the last glacial maximum are rare.\r\nTo test model predictions,sub-glacial rock cores were obtained from the Ohio Range along the Transantarctic Mountains near the present-day WAIS divide using a Winkie drill. Rock cores were recovered from 10 to ~30 m under the present-day ice levels. At the Ohio Range, the glacial to interglacial variations in ice sheet levels is ~120 meters. So 30 meters represent a significant fraction of the variation over the course of an ice age.\r\nHigh concentrations of the cosmic ray produced isotopes were detected in the rock cores, indicating extensive periods of ice-free exposure to cosmic irradiation during the last 2 million years. Modeling of the data suggest that bedrock surfaces at the Ohio Range that are currently covered by 30 meters of ice experienced more exposure than ice cover, especially in the Pleistocene. An ice sheet model prediction for the Ohio Range subglacial sample sites however, significantly underestimates exposure in the last 2 million years, and over-predicts ice cover in the Pleistocene. To adjust for the higher amounts of exposure we observe in our samples, the ice sheet model simulations require more frequent and/or longer-lasting WAIS ice drawdowns. This has important implications for future sea-level change as the model maybe under-predicting the magnitude of sea-level contributions from WAIS during the ice-age cycles. Improving the accuracy of the ice sheet models through model-data comparison should remain a prime objective in the face of a warming planet as understanding WAIS behavior is going to be key for predicting and planning for the effects of sea-level change. The project helped support and train a graduate student in climate research related to Antarctica, cosmogenic nuclide analyses and led to a Master\u2019s Thesis. The project also provide partial support to a postdoctoral scholar obtaining cosmogenic neon measurements and for training and mentoring the graduate student\u0027s cosmogenic neon measurements and interpretation. The project results were communicated to the scientific community at conferences and through seminars. The broader community was engaged through the University of California Davis\u0027s Picnic Day celebration, an annual open house that attracts over 70,000 people to the campus, and through classroom visit at a local elementary school.", "east": -116.38, "geometry": "POINT(-116.415 -84.788)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Sheet Fluctuations; ALUMINUM-26 ANALYSIS; BERYLLIUM-10 ANALYSIS; Cosmogenic Radionuclides; USAP-DC; FIELD INVESTIGATION; AMD; Ohio Range; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; LABORATORY", "locations": "Ohio Range", "north": -84.786, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Mukhopadhyay, Sujoy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.79, "title": "Constraining Plio-Pleistocene West Antarctic Ice Sheet Behavior from the Ohio Range and Scott Glacier", "uid": "p0010113", "west": -116.45}, {"awards": "9978236 Bell, Robin", "bounds_geometry": "POLYGON((101 -75.5,101.9 -75.5,102.8 -75.5,103.7 -75.5,104.6 -75.5,105.5 -75.5,106.4 -75.5,107.3 -75.5,108.2 -75.5,109.1 -75.5,110 -75.5,110 -75.85,110 -76.2,110 -76.55,110 -76.9,110 -77.25,110 -77.6,110 -77.95,110 -78.3,110 -78.65,110 -79,109.1 -79,108.2 -79,107.3 -79,106.4 -79,105.5 -79,104.6 -79,103.7 -79,102.8 -79,101.9 -79,101 -79,101 -78.65,101 -78.3,101 -77.95,101 -77.6,101 -77.25,101 -76.9,101 -76.55,101 -76.2,101 -75.85,101 -75.5))", "dataset_titles": "SOAR-Lake Vostok Survey airborne radar data; SOAR-Lake Vostok Survey bed elevation data; SOAR-Lake Vostok Survey Gravity data; SOAR-Lake Vostok Survey ice thickness data; SOAR-Lake Vostok survey magnetic anomaly data; SOAR-Lake Vostok Survey surface elevation data", "datasets": [{"dataset_uid": "601300", "doi": "10.1594/IEDA/306568", "keywords": "Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Navigation; Radar; SOAR; Subglacial Lakes", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey airborne radar data", "url": "https://www.usap-dc.org/view/dataset/601300"}, {"dataset_uid": "601295", "doi": "10.1594/IEDA/306563", "keywords": "Airborne Gravity; Airplane; Antarctica; East Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Lake Vostok; Potential Field; Solid Earth", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey Gravity data", "url": "https://www.usap-dc.org/view/dataset/601295"}, {"dataset_uid": "601296", "doi": " 10.1594/IEDA/306564", "keywords": "Airborne Magnetic; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Lake Vostok; Magnetic; Magnetic Anomaly; Magnetometer; Potential Field; SOAR; Solid Earth", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok survey magnetic anomaly data", "url": "https://www.usap-dc.org/view/dataset/601296"}, {"dataset_uid": "601299", "doi": "10.1594/IEDA/306565", "keywords": "Airborne Laser Altimeters; Airborne Laser Altimetry; Airborne Radar; Airplane; Antarctica; Bed Elevation; Bedrock Elevation; Digital Elevation Model; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Lake Vostok; Radar; Radar Echo Sounder; SOAR", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey bed elevation data", "url": "https://www.usap-dc.org/view/dataset/601299"}, {"dataset_uid": "601297", "doi": "10.1594/IEDA/306567", "keywords": "Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Sheet; Ice Stratigraphy; Ice Thickness; Ice Thickness Distribution; Lake Vostok; Radar; Radar Altimetry; Radar Echo Sounder; SOAR; Subglacial Lake", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey ice thickness data", "url": "https://www.usap-dc.org/view/dataset/601297"}, {"dataset_uid": "601298", "doi": "10.1594/IEDA/306566", "keywords": "Airborne Altimetry; Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Sheet Elevation; Ice Surface; Lake Vostok; Radar Echo Sounder; SOAR; Surface Elevation", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey surface elevation data", "url": "https://www.usap-dc.org/view/dataset/601298"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "This award, provided by the Office of Polar Programs under the Life in Extreme Environments (LExEn) Program, supports a geophysical study of Lake Vostok, a large lake beneath the East Antarctic Ice Sheet. \u003cbr/\u003e\u003cbr/\u003eSubglacial ecosystems, in particular subglacial lake ecosystems are extreme oligotrophic environments. These environments, and the ecosystems which may exist within them, should provide key insights into a range of fundamental questions about the development of Earth and other bodies in the Solar System including: 1) the processes associated with rapid evolutionary radiation after the extensive Neoproterozoic glaciations; 2) the overall carbon cycle through glacial and interglacial periods; and 3) the possible adaptations organisms may require to thrive in environments such as on Europa, the ice covered moon of Jupiter. Over 70 subglacial lakes have been identified beneath the 3-4 kilometer thick ice of Antarctica. One lake, Lake Vostok, is sufficiently large to be clearly identified from space with satellite altimetry. Lake Vostok is similar to Lake Ontario in area but with a much larger volume including measured water depths of 600 meters. The overlying ice sheet is acting as a conveyer belt continually delivering new water, nutrients, gas hydrates, sediments and microbes as the ice sheet flows across the lake. \u003cbr/\u003e\u003cbr/\u003eThe goal of this program is to determine the fundamental boundary conditions for this subglacial lake as an essential first step toward understanding the physical processes within the lake. An aerogeophysical survey over the lake and into the surrounding regions will be acquired to meet this goal. This data set includes gravity, magnetic, laser altimetry and ice penetrating radar data and will be used to compile a basic set of ice surface elevation, subglacial topography, gravity and magnetic anomaly maps. \u003cbr/\u003e\u003cbr/\u003ePotential field methods widely used in the oil industry will be modified to estimate the subglacial topography from gravity data where the ice penetrating radar will be unable to recover the depth of the lake. A similar method can be modified to estimate the thickness of the sediments beneath the lake from magnetic data. These methods will be tested and applied to subglacial lakes near South Pole prior to the Lake Vostok field campaign and will provide valuable comparisons to the planned survey. Once the methods have been adjusted for the Lake Vostok application, maps of the water cavity and sediment thickness beneath the lake will be produced.\u003cbr/\u003e\u003cbr/\u003eThese maps will become tools to explore the geologic origin of the lake. The two endmember models are, first, that the lake is an active tectonic rift such as Lake Baikal and, second, the lake is the result of glacial scouring. The distinct characteristics of an extensional rift can be easily identified with our aerogeophysical survey. The geological interpretation of the airborne geophysical survey will provide the first geological constraints of the interior of the East Antarctic continent based on modern data. In addition, the underlying geology will influence the ecosystem within the lake. \u003cbr/\u003e\u003cbr/\u003eOne of the critical issues for the ecosystem within the lake will be the flux of nutrients. A preliminary estimation of the regions of freezing and melting based on the distance between distinctive internal layers observed on the radar data will be made. These basic boundary conditions will provide guidance for a potential international effort aimed at in situ exploration of the lake and improve the understanding of East Antarctic geologic structures.", "east": 110.0, "geometry": "POINT(105.5 -77.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e MAGNETOMETERS \u003e MGF; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e AIRGRAV", "is_usap_dc": true, "keywords": "Gravity; GLACIERS/ICE SHEETS; East Antarctica; USAP-DC; Lake Vostok; Airborne Radar; Subglacial Lake; MAGNETIC FIELD; GRAVITY", "locations": "East Antarctica; Lake Vostok", "north": -75.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Studinger, Michael S.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Work\r\n", "uid": "p0010097", "west": 101.0}, {"awards": "1341464 Robinson, Rebecca; 1341432 Brzezinski, Mark", "bounds_geometry": "POLYGON((-175 -54,-174 -54,-173 -54,-172 -54,-171 -54,-170 -54,-169 -54,-168 -54,-167 -54,-166 -54,-165 -54,-165 -55.3,-165 -56.6,-165 -57.9,-165 -59.2,-165 -60.5,-165 -61.8,-165 -63.1,-165 -64.4,-165 -65.7,-165 -67,-166 -67,-167 -67,-168 -67,-169 -67,-170 -67,-171 -67,-172 -67,-173 -67,-174 -67,-175 -67,-175 -65.7,-175 -64.4,-175 -63.1,-175 -61.8,-175 -60.5,-175 -59.2,-175 -57.9,-175 -56.6,-175 -55.3,-175 -54))", "dataset_titles": "Diatom assemblage counts from NBP17-02 shipboard carboy experiments; Dissolved nutrient profiles from along 170\u00b0W between 67 and 54\u00b0S; Expedition Data of NBP1702; Particle composition measurements from along 170\u00b0W between 67-54\u00b0S; Particulate silicon and nitrogen concentrations and isotopic composition measurements in McLane pump profiles from 67\u00b0S to 55\u00b0S latitude in the Pacific Sector of the Southern Ocean; Silicon concentration and isotopic composition measurements in pore waters and sediments from 67\u00b0S to 55\u00b0S latitude in the Pacific Sector of the Southern Ocean; Surface Southern Ocean community growouts to evaluate the diatom bound N isotope proxy", "datasets": [{"dataset_uid": "601523", "doi": "10.15784/601523", "keywords": "Antarctica; Biota; Carboy Growouts; Diatom; Diatom Assemblage Data; NBP1702; Oceans; R/v Nathaniel B. Palmer; Southern Ocean; Southern Ocean Summer", "people": "Robinson, Rebecca; Riesselman, Christina; Robinson, Rebecca ; Jones, Colin", "repository": "USAP-DC", "science_program": null, "title": "Diatom assemblage counts from NBP17-02 shipboard carboy experiments", "url": "https://www.usap-dc.org/view/dataset/601523"}, {"dataset_uid": "601269", "doi": "10.15784/601269", "keywords": "Antarctica; Chlorophyll; Southern Ocean", "people": "Robinson, Rebecca; Brzezinski, Mark", "repository": "USAP-DC", "science_program": null, "title": "Dissolved nutrient profiles from along 170\u00b0W between 67 and 54\u00b0S", "url": "https://www.usap-dc.org/view/dataset/601269"}, {"dataset_uid": "601276", "doi": "10.15784/601276", "keywords": "Antarctica; Biogenic Silica; Nitrogen Isotopes; Southern Ocean", "people": "Robinson, Rebecca; Brzezinski, Mark", "repository": "USAP-DC", "science_program": null, "title": "Particle composition measurements from along 170\u00b0W between 67-54\u00b0S", "url": "https://www.usap-dc.org/view/dataset/601276"}, {"dataset_uid": "601562", "doi": "10.15784/601562", "keywords": "Antarctica; Biogenic Silica; Chemistry:sediment; Chemistry:Sediment; Lithogenic Silica; Marine Geoscience; NBP1702; Pore Water Biogeochemistry; Sediment; Silicon Cycle; Silicon Stable Isotope; Southern Ocean", "people": "Jones, Janice L.; Brzezinski, Mark; Closset, Ivia", "repository": "USAP-DC", "science_program": null, "title": "Silicon concentration and isotopic composition measurements in pore waters and sediments from 67\u00b0S to 55\u00b0S latitude in the Pacific Sector of the Southern Ocean", "url": "https://www.usap-dc.org/view/dataset/601562"}, {"dataset_uid": "200126", "doi": "10.7284/907211", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP1702", "url": "https://www.rvdata.us/search/cruise/NBP1702"}, {"dataset_uid": "601576", "doi": "10.15784/601576", "keywords": "Antarctica; Biogenic Silica; Chemistry:sediment; Chemistry:Sediment; Diatom; Diatom Bound; Lithogenic Silica; Marine Geoscience; NBP1702; Nitrogen Isotopes; Silicon Cycle; Silicon Stable Isotope; Southern Ocean", "people": "Jones, Janice L.; Brzezinski, Mark; Closset, Ivia; Robinson, Rebecca", "repository": "USAP-DC", "science_program": null, "title": " Particulate silicon and nitrogen concentrations and isotopic composition measurements in McLane pump profiles from 67\u00b0S to 55\u00b0S latitude in the Pacific Sector of the Southern Ocean", "url": "https://www.usap-dc.org/view/dataset/601576"}, {"dataset_uid": "601522", "doi": "10.15784/601522", "keywords": "Antarctica; Nitrogen Isotopes; Oceans; Paleoproxies; Southern Ocean", "people": "Robinson, Rebecca ; Robinson, Rebecca; Riesselman, Christina; Jones, Colin; Closset, Ivia; Kelly, Roger; Brzezinski, Mark", "repository": "USAP-DC", "science_program": null, "title": "Surface Southern Ocean community growouts to evaluate the diatom bound N isotope proxy", "url": "https://www.usap-dc.org/view/dataset/601522"}], "date_created": "Wed, 26 Feb 2020 00:00:00 GMT", "description": "The rise in atmospheric carbon dioxide concentrations and associated climate changes make understanding the role of the ocean in large scale carbon cycle a priority. Geologic samples allow exploration of potential mechanisms for carbon dioxide drawdown during glacial periods through the use of geochemical proxies. Nitrogen and silicon isotope signatures from fossil diatoms (microscopic plants) are used to investigate changes in the physical supply and biological demand for nutrients (like nitrogen and silicon and carbon) in the Southern Ocean. The project will evaluate the use the nitrogen and silicon isotope proxies through a series of laboratory experiments and Southern Ocean field sampling. The results will provide quantification of real relationships between nitrogen and silicon isotopes and nutrient usage in the Southern Ocean and allow exploration of the role of other factors, including biological diversity, ice cover, and mixing, in altering the chemical signatures recorded by diatoms. Seafloor sediment samples will be used to evaluate how well the signal created in the water column is recorded by fossil diatoms buried in the seafloor. Improving the nutrient isotope proxies will allow for a more quantitative understanding of the role of polar biology in regulating natural variation in atmospheric carbon dioxide. The project will also result in the training of a graduate student and development of outreach materials targeting a broad popular audience.\r\n\r\nThis project seeks to test the fidelity of the diatom nitrogen and silicon isotope proxies, two commonly used paleoceanographic tools for investigating the role of the Southern Ocean biological pump in regulating atmospheric CO2 concentrations on glacial-interglacial timescales. Existing ground-truthing data, including culture experiments, surface sediment data and downcore reconstructions, all suggest that nutrient utilization is the primary driver of isotopic variation in the Southern Ocean. However, strong contribution of interspecific variation is implied by recent culture results. Moreover, field and laboratory studies present some contradictory results in terms of the relative importance of interspecific variation and of inferred post-depositional alteration of the nutrient isotope signals. Here, a first order test of the N and Si diatom nutrient isotope paleo-proxies, involving water column dissolved and particulate sampling and laboratory culturing of field-isolates, is proposed. Southern Ocean water, biomass, live diatoms and fossil diatom sampling will be conducted to investigate species and assemblage related variability in diatom nitrogen and silicon isotopes and their relationship to surface nutrient fields and early diagenesis. Access to fresh materials produced in an analogous environmental context to the sediments of primary interest is critical for making robust paleoceanographic reconstructions. Field sampling will occur along 175\u00b0W, transecting the Antarctic Circumpolar Current from the subtropics to the marginal ice edge. Collection of water, sinking/suspended particles and multi-core samples from 13 stations and 3 shipboard incubation experiments will be used to test four proposed hypotheses that together evaluate the significance of existing culture results and seek to allow the best use of diatom nutrient isotope proxies in evaluating the biological pump.", "east": -165.0, "geometry": "POINT(-170 -60.5)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; AMD; NITROGEN ISOTOPES; R/V NBP; NSF/USA; NUTRIENTS; USAP-DC; Amd/Us", "locations": "Southern Ocean", "north": -54.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Robinson, Rebecca; Brzezinski, Mark", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -67.0, "title": "Collaborative Proposal: A Field and Laboratory Examination of the Diatom N and Si Isotope Proxies: Implications for Assessing the Southern Ocean Biological Pump", "uid": "p0010083", "west": -175.0}, {"awards": "1443437 Carlson, Anders; 1443268 Beard, Brian", "bounds_geometry": "POLYGON((-80 -65,-79 -65,-78 -65,-77 -65,-76 -65,-75 -65,-74 -65,-73 -65,-72 -65,-71 -65,-70 -65,-70 -65.5,-70 -66,-70 -66.5,-70 -67,-70 -67.5,-70 -68,-70 -68.5,-70 -69,-70 -69.5,-70 -70,-71 -70,-72 -70,-73 -70,-74 -70,-75 -70,-76 -70,-77 -70,-78 -70,-79 -70,-80 -70,-80 -69.5,-80 -69,-80 -68.5,-80 -68,-80 -67.5,-80 -67,-80 -66.5,-80 -66,-80 -65.5,-80 -65))", "dataset_titles": "Radiogenic isotopes of ODP Site 178-1096; Sand content of ODP Site 178-1096", "datasets": [{"dataset_uid": "200108", "doi": " doi:10.1594/PANGAEA.909407 ", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Radiogenic isotopes of ODP Site 178-1096", "url": "https://doi.pangaea.de/10.1594/PANGAEA.909407"}, {"dataset_uid": "200109", "doi": " doi:10.1594/PANGAEA.909411", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Sand content of ODP Site 178-1096", "url": "https://doi.pangaea.de/10.1594/PANGAEA.909411 "}], "date_created": "Fri, 31 Jan 2020 00:00:00 GMT", "description": "This project developed sediment provenance proxies to trace the sources of sediment discharged by the WAIS to the continental rise. The WAIS erodes sediments from various West Antarctic geologic terranes that are deposited in adjacent drift sites. The geochemistry and magnetic properties of drift sediments reflect the tectono-metamorphic history of their source terranes. Deglaciation of a terrane during WAIS collapse should be detectable by the loss of the terrane\u2019s geochemical and magnetic signature in continental-rise detrital sediments. Continental shelf late-Holocene sediments from near the current WAIS groundling line were analyzed for silt- and claysize Sr-Nd-Pb isotopes and major-trace elements. The suite of cores spans from the eastern Ross Sea to the northern tip of the Antarctic Peninsula and established the provenance signatures of the Ross and Amundsen Provinces of Marie Byrd Land, Pine Island Bay, Thurston Island/Eight Coast Block, Ellsworth-Whitmore Crustal Block, and Antarctic Peninsula terranes. Many of these terranes have similar tectono-metamorphic histories but Sr-Nd isotope data from detrital sediments suggest at least 3 distinct provenance signatures. This comprehensive grain-size-specific provenance data adds to on-going collection of glacial till mineral and bulk provenance data. An initial down core study of Ocean Drilling Program Site 1096 in the Bellingshausen Sea was used to assess the utility of these new grain-size-specific provenance proxies in documenting WAIS collapse. We found the presence of both the WAIS and APIS over the last 115,000 years, but absence of the WAIS before 115,000 years ago. This means that the WAIS was gone during the last interglacial period, an interval when sea level was at least 6 meters above present. ", "east": -70.0, "geometry": "POINT(-75 -67.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "West Antarctic Ice Sheet; GLACIERS/ICE SHEETS; West Antarctica; PALEOCLIMATE RECONSTRUCTIONS; NOT APPLICABLE; USAP-DC; ISOTOPES; GEOCHEMISTRY; Bellingshausen Sea", "locations": "West Antarctic Ice Sheet; West Antarctica; Bellingshausen Sea", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Anders, Carlson; Beard, Brian; Stoner, Joseph", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "PANGAEA", "repositories": "PANGAEA", "science_programs": null, "south": -70.0, "title": "Collaborative Research: Development of a Suite of Proxies to Detect Past Collapse of the West Antarctic Ice Sheet", "uid": "p0010079", "west": -80.0}, {"awards": "1341728 Stone, John", "bounds_geometry": "POLYGON((-86.3 -81,-86.17 -81,-86.04 -81,-85.91 -81,-85.78 -81,-85.65 -81,-85.52 -81,-85.39 -81,-85.26 -81,-85.13 -81,-85 -81,-85 -81.03,-85 -81.06,-85 -81.09,-85 -81.12,-85 -81.15,-85 -81.18,-85 -81.21,-85 -81.24,-85 -81.27,-85 -81.3,-85.13 -81.3,-85.26 -81.3,-85.39 -81.3,-85.52 -81.3,-85.65 -81.3,-85.78 -81.3,-85.91 -81.3,-86.04 -81.3,-86.17 -81.3,-86.3 -81.3,-86.3 -81.27,-86.3 -81.24,-86.3 -81.21,-86.3 -81.18,-86.3 -81.15,-86.3 -81.12,-86.3 -81.09,-86.3 -81.06,-86.3 -81.03,-86.3 -81))", "dataset_titles": "Cosmogenic nuclide data, Harter Nunatak; Cosmogenic nuclide data, John Nunatak; Cosmogenic nuclide data, Mt Axtell; Cosmogenic nuclide data, Mt Goodwin; Cosmogenic nuclide data, Mt Tidd; Cosmogenic nuclide data, Mt Turcotte; Pirrit Hills subglacial bedrock core RB-2, cosmogenic Be-10, Al-26 data", "datasets": [{"dataset_uid": "200075", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Mt Axtell", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "601214", "doi": "10.15784/601214", "keywords": "Aluminum-26; Antarctica; Be-10; Bedrock Core; Beryllium-10; Chemistry:rock; Chemistry:Rock; Cosmogenic; Cosmogenic Dating; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Data; Pirrit Hills; Rocks; Solid Earth; Subglacial Bedrock", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Pirrit Hills subglacial bedrock core RB-2, cosmogenic Be-10, Al-26 data", "url": "https://www.usap-dc.org/view/dataset/601214"}, {"dataset_uid": "200080", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, John Nunatak", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200079", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Harter Nunatak", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200078", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Mt Goodwin", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200077", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Mt Turcotte", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200076", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data, Mt Tidd", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Tue, 08 Oct 2019 00:00:00 GMT", "description": "This award supports a project to determine if the West Antarctic Ice Sheet (WAIS) has thinned and collapsed in the past few million years, and if so, when and how frequently this occurred. The principal aim is to identify climatic conditions or thresholds in the climate system that led to ice-sheet collapse in the past, and assess the threat of climate change to vulnerable ice sheets in the future. We recovered a subglacial bedrock core from beneath 150 m of ice cover in the Pirrit Hills, in West Antarctica, and measured cosmogenic nuclide profiles to determine the bedrock exposure history. Cosmic-ray-produced Be-10 and Al-26 in the core indicate: (i) Continuous Pleistocene ice cover averaging ~200 m; and (ii) One or more pre-Pleistocene deglaciations that exposed the core site for ~200-800 years in the Pliocene, or \u003e 800 years, in the Miocene. Optically stimulated luminescence (OSL) dating of the core top precludes exposure to sunlight since ~450 ka, consistent with the Be-10 and Al-26 data. Trapped atmospheric argon in ice recovered from 80 cm above the bedrock surface indicates an age for the enclosing ice \u003e 2 Ma (delta 40Ar/36Ar = -0.15 per-mil). Together, these results rule out any Pleistocene thinning of ice in the Pirrit Hills by more than 150 m.", "east": -85.0, "geometry": "POINT(-85.65 -81.15)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "DEPTH AT SPECIFIC AGES; USAP-DC; Antarctica; NOT APPLICABLE", "locations": "Antarctica", "north": -81.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "ICE-D", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -81.3, "title": "EXPROBE-WAIS: Exposed Rock Beneath the West Antarctic Ice Sheet, A Test for Interglacial Ice Sheet Collapse", "uid": "p0010057", "west": -86.3}, {"awards": "1443497 Siddoway, Christine; 1443534 Bell, Robin; 1443677 Padman, Laurence; 1443498 Fricker, Helen", "bounds_geometry": "POLYGON((-180 -77,-177 -77,-174 -77,-171 -77,-168 -77,-165 -77,-162 -77,-159 -77,-156 -77,-153 -77,-150 -77,-150 -77.9,-150 -78.8,-150 -79.7,-150 -80.6,-150 -81.5,-150 -82.4,-150 -83.3,-150 -84.2,-150 -85.1,-150 -86,-153 -86,-156 -86,-159 -86,-162 -86,-165 -86,-168 -86,-171 -86,-174 -86,-177 -86,180 -86,178.1 -86,176.2 -86,174.3 -86,172.4 -86,170.5 -86,168.6 -86,166.7 -86,164.8 -86,162.9 -86,161 -86,161 -85.1,161 -84.2,161 -83.3,161 -82.4,161 -81.5,161 -80.6,161 -79.7,161 -78.8,161 -77.9,161 -77,162.9 -77,164.8 -77,166.7 -77,168.6 -77,170.5 -77,172.4 -77,174.3 -77,176.2 -77,178.1 -77,-180 -77))", "dataset_titles": "Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data; CATS2008: Circum-Antarctic Tidal Simulation version 2008; CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023; ROSETTA-Ice data page; Ross Sea ocean model simulation used to support ROSETTA-Ice ", "datasets": [{"dataset_uid": "601235", "doi": "10.15784/601235", "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "people": "Padman, Laurence; Erofeeva, Svetlana; Howard, Susan L.", "repository": "USAP-DC", "science_program": null, "title": "CATS2008: Circum-Antarctic Tidal Simulation version 2008", "url": "https://www.usap-dc.org/view/dataset/601235"}, {"dataset_uid": "601772", "doi": "10.15784/601772", "keywords": "Antarctica; Cryosphere; Inverse Modeling; Model Data; Ocean Currents; Oceans; Sea Surface; Southern Ocean; Tide Model; Tides", "people": "Greene, Chad A.; Sutterley, Tyler; Erofeeva, Svetlana; Padman, Laurence; Howard, Susan L.", "repository": "USAP-DC", "science_program": null, "title": "CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023", "url": "https://www.usap-dc.org/view/dataset/601772"}, {"dataset_uid": "601255", "doi": "10.15784/601255", "keywords": "Antarctica; Basal Melt; Ice Shelf; Model Output; Ocean Circulation Model; Ross Ice Shelf; Ross Sea", "people": "Springer, Scott; Howard, Susan L.; Padman, Laurence", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea ocean model simulation used to support ROSETTA-Ice ", "url": "https://www.usap-dc.org/view/dataset/601255"}, {"dataset_uid": "601242", "doi": "10.15784/601242", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Penetrating Radar; Ice-Shelf Basal Melting; Radar Echo Sounder; Radar Echo Sounding; Snow/ice; Snow/Ice", "people": "Tinto, Kirsty; Cordero, Isabel; Das, Indrani; Padman, Laurence; Bell, Robin; Fricker, Helen; Hulbe, Christina; Siddoway, Christine; Dhakal, Tejendra; Frearson, Nicholas; Mosbeux, Cyrille; Siegfried, Matt", "repository": "USAP-DC", "science_program": null, "title": "Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data", "url": "https://www.usap-dc.org/view/dataset/601242"}, {"dataset_uid": "200100", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "ROSETTA-Ice data page", "url": "http://wonder.ldeo.columbia.edu/data/ROSETTA-Ice/"}], "date_created": "Wed, 03 Jul 2019 00:00:00 GMT", "description": "The Ross Ice Shelf is the largest existing ice shelf in Antarctica, and is currently stabilizing significant portions of the land ice atop the Antarctic continent. An ice shelf begins where the land ice goes afloat on the ocean, and as such, the Ross Ice Shelf interacts with the ocean and seafloor below, and the land ice behind. Currently, the Ross Ice Shelf slows down, or buttresses, the fast flowing ice streams of the West Antarctic Ice Sheet (WAIS), a marine-based ice sheet, which if melted, would raise global sea level by 3-4 meters. The Ross Ice Shelf average ice thickness is approximately 350 meters, and it covers approximately 487,000 square kilometers, an area slightly larger than the state of California. The Ross Ice Shelf has disappeared during prior interglacial periods, suggesting in the future it may disappear again. Understanding the dynamics, stability and future of the West Antarctic Ice Sheet therefore requires in-depth knowledge of the Ross Ice Shelf. The ROSETTA-ICE project brings together scientists from 4 US institutions and from the Institute of Geological and Nuclear Sciences Limited, known as GNS Science, New Zealand. The ROSETTA-ICE data on the ice shelf, the water beneath the ice shelf, and the underlying rocks, will allow better predictions of how the Ross Ice Shelf will respond to changing climate, and therefore how the WAIS will behave in the future. The interdisciplinary ROSETTA-ICE team will train undergraduate and high school students in cutting edge research techniques, and will also work to educate the public via a series of vignettes integrating ROSETTA-ICE science with the scientific and human history of Antarctic research.\u003cbr/\u003e\u003cbr/\u003eThe ROSETTA-ICE survey will acquire gravity and magnetics data to determine the water depth beneath the ice shelf. Radar, LIDAR and imagery systems will be used to map the Ross Ice Shelf thickness and fine structure, crevasses, channels, debris, surface accumulation and distribution of marine ice. The high resolution aerogeophysical data over the Ross Ice Shelf region in Antarctica will be acquired using the IcePod sensor suite mounted externally on an LC-130 aircraft operating from McMurdo Station, Antarctica. Field activities will include ~36 flights on LC-130 aircraft over two field seasons in Antarctica. The IcePod instrument suite leverages the unique experience of the New York Air National Guard operating in Antarctica for NSF scientific research as well as infrastructure and logistics. The project will answer questions about the stability of the Ross Ice Shelf in future climate, and the geotectonic evolution of the Ross Ice Shelf Region, a key component of the West Antarctic Rift system. The comprehensive benchmark data sets acquired will enable broad, interdisciplinary analyses and modeling, which will also be performed as part of the project. ROSETTA-ICE will illuminate Ross ice sheet-ice shelf-ocean dynamics as the system nears a critical juncture but still is intact. Through interacting with an online data visualization tool, and comparing the ROSETTA-ICE data and results from earlier studies, we will engage students and young investigators, equipping them with new capabilities for the study of critical earth systems that influence global climate.", "east": 161.0, "geometry": "POINT(-174.5 -81.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LIDAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e PROTON MAGNETOMETER", "is_usap_dc": true, "keywords": "Airborne Radar; LIDAR; Ross Ice Shelf; SALINITY; SALINITY/DENSITY; CONDUCTIVITY; ICE DEPTH/THICKNESS; Tidal Models; GRAVITY ANOMALIES; Ross Sea; Antarctica; BATHYMETRY; C-130; MAGNETIC ANOMALIES; USAP-DC; Airborne Gravity", "locations": "Ross Sea; Antarctica; Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Bell, Robin; Frearson, Nicholas; Das, Indrani; Fricker, Helen; Padman, Laurence; Springer, Scott; Siddoway, Christine; Tinto, Kirsty", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e C-130", "repo": "USAP-DC", "repositories": "PI website; USAP-DC", "science_programs": null, "south": -86.0, "title": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE)", "uid": "p0010035", "west": -150.0}, {"awards": "1443263 Higgins, John; 1443306 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores; Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores; Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores; Greenhouse gas composition in the Allan Hills S27 ice core; Methane concentration in Allan Hills ice cores; Stable isotope composition of the trapped air in the Allan Hills S27 ice core; Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "datasets": [{"dataset_uid": "601203", "doi": "10.15784/601203", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Chemistry:ice; Chemistry:Ice; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenhouse Gas; Ice; Ice Core Data; Ice Core Gas Records; Methane; Snow/ice; Snow/Ice", "people": "Brook, Edward J.; Yan, Yuzhen; Bender, Michael; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Methane concentration in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601203"}, {"dataset_uid": "601512", "doi": "10.15784/601512", "keywords": "Allan Hills; Antarctica; Blue Ice; Ice Core; Ice Core Gas Records; Isotope; Nitrogen; Oxygen", "people": "Higgins, John; Yan, Yuzhen; Bender, Michael", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable isotope composition of the trapped air in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601512"}, {"dataset_uid": "601201", "doi": "10.15784/601201", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Argon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Data; Ice Core Gas Records; Krypton; Mass Spectrometer; Noble Gas; Snow/ice; Snow/Ice; Xenon", "people": "Bender, Michael; Higgins, John; Yan, Yuzhen; Ng, Jessica; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601201"}, {"dataset_uid": "601483", "doi": "10.15784/601483", "keywords": "Allan Hills; Antarctica; Argon; Ice; Ice Core Data; Ice Core Gas Records; Isotope; Mass Spectrometry; Nitrogen; Oxygen", "people": "Bender, Michael; Yan, Yuzhen; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601483"}, {"dataset_uid": "601130", "doi": "10.15784/601130", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Delta Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Gas Records; Ice Core Records; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Introne, Douglas; Kurbatov, Andrei V.; Mayewski, Paul A.; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601130"}, {"dataset_uid": "601129", "doi": "10.15784/601129", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Isotope Data; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Yan, Yuzhen; Kurbatov, Andrei V.; Introne, Douglas; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601129"}, {"dataset_uid": "601128", "doi": "10.15784/601128", "keywords": "Allan Hills; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Record; Mass Spectrometry; Stable Water Isotopes", "people": "Mayewski, Paul A.; Kurbatov, Andrei V.; Yan, Yuzhen; Introne, Douglas", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601128"}, {"dataset_uid": "601425", "doi": "10.15784/601425", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Ice Core; Methane", "people": "Yan, Yuzhen; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Greenhouse gas composition in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601425"}, {"dataset_uid": "601202", "doi": "10.15784/601202", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Carbon Dioxide; Carbon Isotopes; Chemistry:ice; Chemistry:Ice; CO2; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Gas Records; Ice Core Records; Mass Spectrometer; Mass Spectrometry; Methane; Snow/ice; Snow/Ice", "people": "Bender, Michael; Yan, Yuzhen; Higgins, John; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601202"}], "date_created": "Thu, 18 Oct 2018 00:00:00 GMT", "description": "Bubbles of ancient air trapped in ice cores permit the direct reconstruction of atmospheric composition and allow us to link greenhouse gases and global climate over the last 800,000 years. Previous field expeditions to the Allan Hills blue ice area, Antarctica, have recovered ice cores that date to one million years, the oldest ice cores yet recovered from Antarctica. These records have revealed that interglacial CO2 concentrations decreased by 800,000 years ago and that, in the warmer world 1 million years ago, CO2 and Antarctic temperature were linked as during the last 800,000 years. This project will return to the Allan Hills blue ice area to recover additional ice cores that date to 1 million years or older. The climate records developed from the drilled ice cores will provide new insights into the chemical composition of the atmosphere and Antarctic climate during times of comparable or even greater warmth than the present day. Our results will help answer questions about issues associated with anthropogenic change. These include the relationship between temperature change and the mass balance of Antarctic ice; precipitation and aridity variations associated with radiatively forced climate change; and the climate significance of sea ice extent. The project will entrain two graduate students and a postdoctoral scholar, and will conduct outreach including workshops to engage teachers in carbon science and ice cores.\u003cbr/\u003e\u003cbr/\u003eBetween about 2.8-0.9 million years ago, Earth\u0027s climate was characterized by 40,000-year cycles, driven or paced by changes in the tilt of Earth\u0027s spin axis. Much is known about the \"40,000-year\" world from studies of deep-sea sediments, but our understanding of climate change during this period is incomplete because we lack records of Antarctic climate and direct records of atmospheric greenhouse gas concentrations. We propose to address these issues by building on our recent studies of ancient ice from the Main Ice Field, Allan Hills, Antarctica. During previous field seasons we recovered ice extending, discontinuously, from 0.1-1.0 million years old. Ice was dated by measuring the 40Ar/38Ar (Argon) ratio of the trapped gases. Our discovery of million year-old ice demonstrates that there is gas-record-quality ice from the 40,000-year world in the Allan Hills Main Ice Field. We have identified two different sites, each overlying bedrock at ~ 200 m depth, that are attractive targets for coring ice dating to 1 million years and older. This project aims to core the ice at these two sites, re-occupy a previous site with million year-old ice and drill it down to the bedrock, and generate 10-20 short (~10-meter) cores in areas where our previous work and terrestrial meteorite ages suggest ancient surface ice. We plan to date the ice using the 40Ar/38Ar ages of trapped Argon. We also plan to characterize the continuity of our cores by measuring the deuterium and oxygen isotope ratios in the ice, methane, ratios of Oxygen and Argon to Nitrogen in trapped gas, the Nitrogen-15 isotope (d15N) of Nitrogen, and the Oxygen-18 isotope (d18O) of Oxygen. As the ice may be stratigraphically disturbed, these measurements will provide diagnostic properties for assessing the continuity of the ice-core records. Successful retrieval of ice older than one million years will provide the opportunity for follow-up work to measure the CO2 concentration and other properties within the ice to inform on the temperature history of the Allan Hills region, dust sources and source-area aridity, moisture sources, densification conditions, global average ocean temperature, and greenhouse gas concentrations. We will analyze the data in the context of leading hypotheses of the 40,000-year world and the Mid-Pleistocene Transition to the 100,000-year world. We expect to advance understanding of climate dynamics during these periods.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Amd/Us; AMD; Allan Hills; USA/NSF; FIELD INVESTIGATION; USAP-DC; Ice Core; LABORATORY", "locations": "Allan Hills", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Kurbatov, Andrei V.; Higgins, John; Bender, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": null, "title": "Collaborative Research: Window into the World with 40,000-year Glacial Cycles from Climate Records in Million Year-old Ice from the Allan Hills Blue Ice Area", "uid": "p0000760", "west": null}, {"awards": "1245899 Kowalewski, Douglas", "bounds_geometry": "POLYGON((-180 -70,-174 -70,-168 -70,-162 -70,-156 -70,-150 -70,-144 -70,-138 -70,-132 -70,-126 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,178 -85,176 -85,174 -85,172 -85,170 -85,168 -85,166 -85,164 -85,162 -85,160 -85,160 -83.5,160 -82,160 -80.5,160 -79,160 -77.5,160 -76,160 -74.5,160 -73,160 -71.5,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": "Region Climate Model Output Plio-Pleistocene", "datasets": [{"dataset_uid": "601080", "doi": "10.15784/601080", "keywords": "Antarctica; Climate Model; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Mcmurdo; Paleoclimate; Ross Sea", "people": "Kowalewski, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Region Climate Model Output Plio-Pleistocene", "url": "https://www.usap-dc.org/view/dataset/601080"}], "date_created": "Tue, 16 Jan 2018 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThe PIs propose to complement the ANDRILL marine record with a terrestrial project that will provide chronological control for past fluctuations of the West Antarctic Ice Sheet (WAIS) and alpine glaciers in McMurdo Sound. The project will develop high-resolution maps of drifts deposited from grounded marine-based ice and alpine glaciers on islands and peninsulas in McMurdo Sound. In addition, the PIs will acquire multi-clast/multi-nuclide cosmogenic analyses of these mapped drift sheets and alpine moraines and use regional climate modeling to shed light on the range of possible environmental conditions in the McMurdo region during periods of grounded ice expansion and recession. The PIs will make use of geological records for ice sheet and alpine glacier fluctuations preserved on the flanks of Mount Discovery, Black Island, and Brown Peninsula. Drifts deposited from grounded, marine-based ice will yield spatial constraints for former advances and retreats of the WAIS. Moraines from alpine glaciers, hypothesized to be of interglacial origin, could yield a first-order record of hydrologic change in the region. Synthesizing the field data, the team proposes to improve the resolution of existing regional-scale climate models for the Ross Embayment. The overall approach and anticipated results will provide the first steps towards linking the marine and terrestrial records in this critical sector of Antarctica.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eResults from the proposed work will be integrated with outreach programs at Boston University, Columbia University, and Worcester State University. The team will actively collaborate with the American Museum of Natural History to feature this project prominently in museum outreach. The team will also include a PolarTREC teacher as a member of the research team. The geomorphological results will be presented in 3D at Boston University?s Antarctic Digital Image Analyses Lab. The research will form the basis of a PhD dissertation at Boston University.", "east": -120.0, "geometry": "POINT(-160 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kowalewski, Douglas", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: West Antarctic Ice Sheet stability, Alpine Glaciation, and Climate Variability: a Terrestrial Perspective from Cosmogenic-nuclide Dating in McMurdo Sound", "uid": "p0000391", "west": 160.0}, {"awards": "1246378 Shevenell, Amelia", "bounds_geometry": "POLYGON((-65.32 -64.15,-65.309 -64.15,-65.298 -64.15,-65.287 -64.15,-65.276 -64.15,-65.265 -64.15,-65.254 -64.15,-65.243 -64.15,-65.232 -64.15,-65.221 -64.15,-65.21 -64.15,-65.21 -64.186,-65.21 -64.222,-65.21 -64.258,-65.21 -64.294,-65.21 -64.33,-65.21 -64.366,-65.21 -64.402,-65.21 -64.438,-65.21 -64.474,-65.21 -64.51,-65.221 -64.51,-65.232 -64.51,-65.243 -64.51,-65.254 -64.51,-65.265 -64.51,-65.276 -64.51,-65.287 -64.51,-65.298 -64.51,-65.309 -64.51,-65.32 -64.51,-65.32 -64.474,-65.32 -64.438,-65.32 -64.402,-65.32 -64.366,-65.32 -64.33,-65.32 -64.294,-65.32 -64.258,-65.32 -64.222,-65.32 -64.186,-65.32 -64.15))", "dataset_titles": "Anvers Trough Foraminifer Stable Isotope data; Geochemical and sedimentologic data from NBP01-01 JPC-34", "datasets": [{"dataset_uid": "601064", "doi": "10.15784/601064", "keywords": "Antarctica; Antarctic Peninsula; Anvers Trough; Chemistry:sediment; Chemistry:Sediment; Foraminifera; Geochemistry; Isotope; LMG1211; LMG1311; Marine Sediments; Oceans; Paleoclimate; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "Anvers Trough Foraminifer Stable Isotope data", "url": "https://www.usap-dc.org/view/dataset/601064"}, {"dataset_uid": "601180", "doi": "10.15784/601180", "keywords": "Antarctica; Be-10; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Late Quaternary; Magnetic Susceptibility; Mass Spectrometry; NBP0101; Paleoenvironment; Prydz Bay; Radiocarbon; R/v Nathaniel B. Palmer; Sediment; Sediment Core; Sediment Core Data", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "Geochemical and sedimentologic data from NBP01-01 JPC-34", "url": "https://www.usap-dc.org/view/dataset/601180"}], "date_created": "Fri, 27 Oct 2017 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eSouthern Ocean processes play an important role in Late Quaternary glacial-interglacial climate change. However, the direct influence of newly upwelled warm nutrient-rich Circumpolar Deep Water on the Antarctic cryosphere remains speculative. The PI proposes to test the hypothesis that Circumpolar Deep Water-derived ocean heat negatively impacts the mass-balance of Antarctica?s ice sheets during deglaciations using precisely dated late Quaternary paleoceanographic studies of Antarctic margin sediments and a suite of geochemical proxies measured on three existing glacial marine sediment cores from the Prydz Channel, Antarctica. Specifically, the PI will use these data to reconstruct the Late Quaternary history of the Lambert Glacier/Amery Ice Shelf system; evaluate the timing, speed, and style of retreat of the Lambert Glacier/Amery Ice Shelf system during the last deglaciation, and to assess the impact of Circumpolar Deep Water intrusions on the Lambert Glacier/Amery Ice Shelf system in the Late Quaternary. Diatom bound radiocarbon and optically stimulated luminescence techniques will be used to obtain precise stratigraphic age control for the Prydz Channel siliceous muddy ooze intervals. In addition, the PI will measure sedimentary 10Be concentrations to determine the origin of the siliceous muddy ooze units and to track past changes in the position of the ice shelf front.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis proposal will support an early career female scientist and will provide professional development and research experiences for women/minority graduate and undergraduate students. The PI will take advantage of USF?s Oceanography Camp for Girls.", "east": -65.21, "geometry": "POINT(-65.265 -64.33)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": true, "keywords": "Amd/Us; R/V NBP; USAP-DC", "locations": null, "north": -64.15, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.51, "title": "Late Quaternary Evolution of the Lambert Glacier/Amery Ice Shelf System, Prydz Bay, Antarctica", "uid": "p0000381", "west": -65.32}, {"awards": "1246378 Shevenell, Amelia", "bounds_geometry": "POLYGON((70 -68,70.5 -68,71 -68,71.5 -68,72 -68,72.5 -68,73 -68,73.5 -68,74 -68,74.5 -68,75 -68,75 -68.2,75 -68.4,75 -68.6,75 -68.8,75 -69,75 -69.2,75 -69.4,75 -69.6,75 -69.8,75 -70,74.5 -70,74 -70,73.5 -70,73 -70,72.5 -70,72 -70,71.5 -70,71 -70,70.5 -70,70 -70,70 -69.8,70 -69.6,70 -69.4,70 -69.2,70 -69,70 -68.8,70 -68.6,70 -68.4,70 -68.2,70 -68))", "dataset_titles": "Anvers Trough Foraminifer Stable Isotope data; Geochemical and sedimentologic data from NBP01-01 JPC-34", "datasets": [{"dataset_uid": "601064", "doi": "10.15784/601064", "keywords": "Antarctica; Antarctic Peninsula; Anvers Trough; Chemistry:sediment; Chemistry:Sediment; Foraminifera; Geochemistry; Isotope; LMG1211; LMG1311; Marine Sediments; Oceans; Paleoclimate; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "Anvers Trough Foraminifer Stable Isotope data", "url": "https://www.usap-dc.org/view/dataset/601064"}, {"dataset_uid": "601180", "doi": "10.15784/601180", "keywords": "Antarctica; Be-10; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Late Quaternary; Magnetic Susceptibility; Mass Spectrometry; NBP0101; Paleoenvironment; Prydz Bay; Radiocarbon; R/v Nathaniel B. Palmer; Sediment; Sediment Core; Sediment Core Data", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": null, "title": "Geochemical and sedimentologic data from NBP01-01 JPC-34", "url": "https://www.usap-dc.org/view/dataset/601180"}], "date_created": "Fri, 27 Oct 2017 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eSouthern Ocean processes play an important role in Late Quaternary glacial-interglacial climate change. However, the direct influence of newly upwelled warm nutrient-rich Circumpolar Deep Water on the Antarctic cryosphere remains speculative. The PI proposes to test the hypothesis that Circumpolar Deep Water-derived ocean heat negatively impacts the mass-balance of Antarctica?s ice sheets during deglaciations using precisely dated late Quaternary paleoceanographic studies of Antarctic margin sediments and a suite of geochemical proxies measured on three existing glacial marine sediment cores from the Prydz Channel, Antarctica. Specifically, the PI will use these data to reconstruct the Late Quaternary history of the Lambert Glacier/Amery Ice Shelf system; evaluate the timing, speed, and style of retreat of the Lambert Glacier/Amery Ice Shelf system during the last deglaciation, and to assess the impact of Circumpolar Deep Water intrusions on the Lambert Glacier/Amery Ice Shelf system in the Late Quaternary. Diatom bound radiocarbon and optically stimulated luminescence techniques will be used to obtain precise stratigraphic age control for the Prydz Channel siliceous muddy ooze intervals. In addition, the PI will measure sedimentary 10Be concentrations to determine the origin of the siliceous muddy ooze units and to track past changes in the position of the ice shelf front.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis proposal will support an early career female scientist and will provide professional development and research experiences for women/minority graduate and undergraduate students. The PI will take advantage of USF?s Oceanography Camp for Girls.", "east": 75.0, "geometry": "POINT(72.5 -69)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": true, "keywords": "Amd/Us; R/V NBP; USAP-DC", "locations": null, "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "Late Quaternary Evolution of the Lambert Glacier/Amery Ice Shelf System, Prydz Bay, Antarctica", "uid": "p0000381", "west": 70.0}, {"awards": "1443260 Conway, Howard", "bounds_geometry": "POLYGON((159 -76.68,159.03 -76.68,159.06 -76.68,159.09 -76.68,159.12 -76.68,159.15 -76.68,159.18 -76.68,159.21 -76.68,159.24 -76.68,159.27 -76.68,159.3 -76.68,159.3 -76.697,159.3 -76.714,159.3 -76.731,159.3 -76.748,159.3 -76.765,159.3 -76.782,159.3 -76.799,159.3 -76.816,159.3 -76.833,159.3 -76.85,159.27 -76.85,159.24 -76.85,159.21 -76.85,159.18 -76.85,159.15 -76.85,159.12 -76.85,159.09 -76.85,159.06 -76.85,159.03 -76.85,159 -76.85,159 -76.833,159 -76.816,159 -76.799,159 -76.782,159 -76.765,159 -76.748,159 -76.731,159 -76.714,159 -76.697,159 -76.68))", "dataset_titles": "2015-2016 GPR Field Report for Allan Hills Shallow Ice Coring; Ground-based ice-penetrating radar profiles collected on the Allan Hills blue ice region", "datasets": [{"dataset_uid": "601005", "doi": "10.15784/601005", "keywords": "Allan Hills; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Navigation; Radar", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Ground-based ice-penetrating radar profiles collected on the Allan Hills blue ice region", "url": "https://www.usap-dc.org/view/dataset/601005"}, {"dataset_uid": "601668", "doi": "10.15784/601668", "keywords": "Allan Hills; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; GPR; Ice Core; Report", "people": "Brook, Edward; MacKay, Sean", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "2015-2016 GPR Field Report for Allan Hills Shallow Ice Coring", "url": "https://www.usap-dc.org/view/dataset/601668"}], "date_created": "Tue, 02 May 2017 00:00:00 GMT", "description": "Marine paleoclimate archives show that approximately one million years ago Earth\u0027s climate transitioned from 40,000-year glacial /interglacial cycles to 100,000-year cycles. This award will support a study designed to map the distribution of one million year-old ice in the Allan Hills Blue Ice Area, Antarctica using state-of-the-art ground penetrating radar. The Allen Hills was demonstrated to contain a continuous record of the past 400,000 years and is also the collection location of the oldest ice samples (990,000 years) yet recovered. The maps resulting from this study will be used to select an ice-core drilling site at which a million-plus year-old continuous record of climate could be recovered. Ice cores contain the only kind of record to directly capture atmospheric gases and aerosols, but no ice-core-based climate record yet extends continuously beyond the past 800,000 years. A million-plus year-old record will allow better understanding of the major mechanisms and driving forces of natural climate variability in a world with 100,000-year glacial/interglacial cycles. The project will support two early career scientists in collaboration with senior scientists, as well as a graduate student, and will conduct outreach to schools and the public.\r\nThe Allan Hills Blue Ice Area preserves a continuous climate record covering the last 400,000 years along an established glaciological flow line. Two kilometers to the east of this flow line, the oldest ice on Earth (~1 million years old) is found only 120 m below the surface. Meteorites collected in the area are reported to be as old as 1.8 million years, suggesting still older ice may be present. Combined, these data strongly suggest that the Allen Hills area could contain a continuous, well-resolved environmental record, spanning at least the last million years. As such, this area has been selected as an upcoming target for the new Intermediate Depth Ice Core Drill by the US Ice Core Working Group. This drill will recover a higher-quality core than previous dry drilling attempts. This project will conduct a comprehensive ground penetrating radar survey aimed at tracing the signature of the million-year-old ice layer throughout the region. The resulting map will be used to select a drill site from which an ice core containing the million-plus year-old continuous climate record will be collected. The proposed activities are a necessary precursor to the collection of the oldest known ice on Earth. Ice cores provide a robust reconstruction of past climate and extending this record beyond the 800,000 years currently available will open new opportunities to study the climate system. The data collected will also be used to investigate the bedrock and ice flow parameters favorable to the preservation of old ice, which may allow targeted investigation of other blue ice areas in Antarctica.", "east": 159.3, "geometry": "POINT(159.15 -76.765)", "instruments": null, "is_usap_dc": true, "keywords": "Allan Hills; FIELD SURVEYS; ICE SHEETS", "locations": "Allan Hills", "north": -76.68, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.85, "title": "Collaborative Research: Allan HILLs Englacial Site (AHILLES) Selection", "uid": "p0000385", "west": 159.0}, {"awards": "1142162 Stone, John", "bounds_geometry": "POLYGON((-104.14 -81.07,-102.24 -81.07,-100.34 -81.07,-98.44 -81.07,-96.54 -81.07,-94.64 -81.07,-92.74 -81.07,-90.84 -81.07,-88.94 -81.07,-87.04 -81.07,-85.14 -81.07,-85.14 -81.207,-85.14 -81.344,-85.14 -81.481,-85.14 -81.618,-85.14 -81.755,-85.14 -81.892,-85.14 -82.029,-85.14 -82.166,-85.14 -82.303,-85.14 -82.44,-87.04 -82.44,-88.94 -82.44,-90.84 -82.44,-92.74 -82.44,-94.64 -82.44,-96.54 -82.44,-98.44 -82.44,-100.34 -82.44,-102.24 -82.44,-104.14 -82.44,-104.14 -82.303,-104.14 -82.166,-104.14 -82.029,-104.14 -81.892,-104.14 -81.755,-104.14 -81.618,-104.14 -81.481,-104.14 -81.344,-104.14 -81.207,-104.14 -81.07))", "dataset_titles": "Cosmogenic nuclide data at ICE-D; Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "datasets": [{"dataset_uid": "600162", "doi": "10.15784/600162", "keywords": "Antarctica; Be-10; Chemistry:rock; Chemistry:Rock; Cosmogenic Dating; Glaciology; Nunataks; Sample/collection Description; Sample/Collection Description; Solid Earth; Whitmore Mountains", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "url": "https://www.usap-dc.org/view/dataset/600162"}, {"dataset_uid": "200299", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nuclide data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Wed, 16 Mar 2016 00:00:00 GMT", "description": "1142162/Stone\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to conduct a reconnaissance geological and radar-sounding study of promising sites in West Antarctica as a prelude to a future project to conduct subglacial cosmogenic nuclide measurements. Field work will take place in the Whitmore Mountains, close to the WAIS divide, and on the Nash and Pirrit Hills, downflow from the divide in the Weddell Sea drainage. At each site geological indicators of higher (and lower) ice levels in the past will be mapped and evidence of subglacial erosion or its absence will be documented. Elevation transects of both glacial erratics and adjacent bedrock samples will be collected to establish the timing of recent deglaciation at the sites and provide a complement to similar measurements on material from depth transects obtained by future subglacial drilling. At each site, bedrock ridges will be traced into the subsurface with closely-spaced ice-penetrating radar surveys, using a combination of instruments and frequencies to obtain meter-scale surface detail, using synthetic aperture techniques. Collectively the results will define prospective sites for subglacial sampling, and maximize the potential information to be obtained from such samples in future studies. The intellectual merit of this project is that measurements of cosmogenic nuclides in subglacial bedrock hold promise for resolving the questions of whether the West Antarctic ice sheet collapsed completely in the past, whether it is prone to repeated large deglaciations, and if so, what is their magnitude and frequency. Such studies will require careful choice of targets, to locate sites where bedrock geology is favorable, cosmogenic nuclide records are likely to have been protected from subglacial erosion, and the local ice-surface response is indicative of large-scale ice sheet behavior. The broader impacts of this work include helping to determine whether subglacial surfaces in West Antarctica were ever exposed to cosmic rays, which will provide unambiguous evidence for or against a smaller ice sheet in the past. This is an important step towards establishing whether the WAIS is vulnerable to collapse in future, and will ultimately help to address uncertainty in forecasting sea level change. The results will also provide ground truth for models of ice-sheet dynamics and long-term ice sheet evolution, and will help researchers use these models to identify paleoclimate conditions responsible for WAIS deglaciation. The education and training of students (both undergraduate and graduate students) will play an important role in the project, which will involve Antarctic fieldwork, technically challenging labwork, data collection and interpretation, and communication of the outcome to scientists and the general public.", "east": -85.14, "geometry": "POINT(-94.64 -81.755)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided; Antarctica; ICE SHEETS", "locations": "Antarctica", "north": -81.07, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John; Conway, Howard; Winebrenner, Dale", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -82.44, "title": "Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling", "uid": "p0000335", "west": -104.14}, {"awards": "0948247 Pettit, Erin", "bounds_geometry": "POINT(-123.35 -75.1)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 06 Jan 2016 00:00:00 GMT", "description": "Pettit/0948247\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study of the relationship between fabric and climate for the ice near the EPICA Dome C ice core site, East Antarctica. The work builds on an ongoing study at Siple Dome, West Antarctica and takes advantage of collaborations with European scientists and access to the Dome C borehole to make measurements of sonic velocity. The intellectual merit of the project is that a better understanding of how fabric preserves past climate information can improve models of the ice flow near ice core sites and the interpreta-tion of ice core data (particularly paleo-accumulation), and it may allow us to extract climate information directly from fabric data. In addition, because ice deformation is sensitive to the orientation of crystals, ice flow patterns are sensitive to the fabric. Thus, variations in the fabric between glacial and interglacial ice can affect how ice deforms and how fabric in the ice sheet develops. The Dome C site is particularly important for answering these questions, because the ice core shows evidence of eight glacial cycles, not just one as found at Siple Dome or the Greenland sites. The research will improve the understanding of the proxy relationship between sonic-velocity data and fabric; will help to model the pattern of ice flow caused by the fabric variation between glacial and interglacial time periods using these data, existing ice core chemistry and existing and new thin section data, improved surface strain data, and borehole deformation data; and will help to better understand the positive feedback mechanism that enhances fabric (and corresponding rheological) variability through a focused study of several climate transitions and the associated fabric changes. Borehole compressional-wave sonic-velocity will be measured which will complement the sonic-velocity data that already exist for boreholes in Greenland and West Antarctica. These will be the first sonic-velocity measurements in East Antarctica and the first measurements that extend for more than a single glacial/interglacial transition. The project will ultimately contribute to better interpretation of ice core records for both paleoclimate studies and for ice flow history, both of which connect to the broader questions of the role of ice in the climate system. This project will also strengthen the international collaborations within the paleoclimate and ice sheet modeling communities. This project will partially support a graduate student at the University of Alaska Fairbanks who is currently working on modeling ice including anisotropy and it will support the growth of a young scientist through a Post-Doc position. This Post Doc will gain important experience collaborating with the EPICA scientists in studying the climate-fabric relationship. Erin Pettit is active in field-science education for high school students, under-graduates, teachers, and adults. This project will help support the continued development and enhancement of Girls on Ice a program that encourages young women to explore science and the natural world.", "east": -123.35, "geometry": "POINT(-123.35 -75.1)", "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY; Crystals; Deformation; FIELD INVESTIGATION; Model; Sonic Logger; Ice Flow; Rheology; FIELD SURVEYS; Borehole; Climate; Ice Fabric; Antarctica; Interglacial", "locations": "Antarctica", "north": -75.1, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Hansen, Sharon", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -75.1, "title": "The Relationship between Climate and Ice Rheology at Dome C, East Antarctica", "uid": "p0000708", "west": -123.35}, {"awards": "1043780 Aydin, Murat", "bounds_geometry": null, "dataset_titles": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core; Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "datasets": [{"dataset_uid": "609659", "doi": "10.7265/N5CV4FPK", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "url": "https://www.usap-dc.org/view/dataset/609659"}, {"dataset_uid": "601361", "doi": "10.15784/601361", "keywords": "Antarctica; Carbonyl Sulfide; Trace Gases", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/601361"}], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "Aydin/1043780\u003cbr/\u003eThis award supports the analysis of the trace gas carbonyl sulfide (COS) in a deep ice core from West Antarctic Ice Sheet Divide (WAIS-D), Antarctica. COS is the most abundant sulfur gas in the troposphere and a precursor of stratospheric sulfate. It has a large terrestrial COS sink that is tightly coupled to the photosynthetic uptake of atmospheric carbon dioxide (CO2). The primary goal of this project is to develop high a resolution Holocene record of COS from the WAIS-D 06A ice core. The main objectives are 1) to assess the natural variability of COS and the extent to which its atmospheric variability was influenced by climate variability, and 2) to examine the relationship between changes in atmospheric COS and CO2. This project also includes low-resolution sampling and analysis of COS from 10,000-30,000 yrs BP, covering the transition from the Last Glacial Maximum into the early Holocene. The goal of this work is to assess the stability of COS in ice core air over long time scales and to establish the COS levels during the last glacial maximum and the magnitude of the change between glacial and interglacial conditions. The results of this work will be disseminated via peer-review publications and will contribute to environmental assessments such as the WMO Stratospheric Ozone Assessment and IPCC Climate Assessment. This project will support a PhD student and undergraduate researcher in the Department of Earth System Science at the University of California, Irvine, and will create summer research opportunities for undergraduates from non-research active Universities.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ethane; LABORATORY; N-Butane; Carbonyl Sulfide; Propane; Methyl Bromide; Methyl Chloride; Carbon Disulfide", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat; Saltzman, Eric", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Carbonyl Sulfide Measurements in the Deep West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000055", "west": null}, {"awards": "1042883 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "LA-ICP-MS Results: 3 Siple Dome A Glacial Age Archives; Roosevelt Island Climate Evolution Ice Core ICP-MS data", "datasets": [{"dataset_uid": "609621", "doi": "10.7265/N52J68SQ", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; ICP-MS; Roosevelt Island; Ross Ice Shelf", "people": "Mayewski, Paul A.; Beers, Thomas M.; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Climate Evolution Ice Core ICP-MS data", "url": "https://www.usap-dc.org/view/dataset/609621"}, {"dataset_uid": "609636", "doi": "10.7265/N5WS8R6H", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; ICP-MS; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Kurbatov, Andrei V.; Mayewski, Paul A.; Haines, Skylar", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "LA-ICP-MS Results: 3 Siple Dome A Glacial Age Archives", "url": "https://www.usap-dc.org/view/dataset/609636"}], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "1042883/Mayewski\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to analyze a deep ice core which will be drilled by a New Zealand research team at Roosevelt Island. The objectives are to process the ice core at very high resolution to (a) better understand phasing sequences in Arctic/Antarctic abrupt climate change, even at the level of individual storm events; (b) determine the impact of changes in the Westerlies and the Amundsen Sea Low on past/present/future climate change; (c) determine how sea ice extent has varied in the area; (d) compare the response of West Antarctica climate to other regions during glacial/interglacial cycles; and (e) determine how climate of the Ross Sea Embayment changed during the transition from Ross Ice Sheet to Ross Ice Shelf. The intellectual merit of the RICE deep ice core project is that it is expected to provide a 30kyr long (and possibly 150kyr long) extremely high-resolution view of climate change in the Ross Sea Embayment Region and data essential to test and understand critical questions that have emerged as a consequence of the recent synthesis of Antarctic and Southern Ocean climate change presented in the Scientific Commission for Antarctic Research document: Antarctic Climate Change and the Environment (ACCE, 2009). Ice core processing and analysis will be performed jointly by University of Maine and the collaborators from New Zealand. Co-registered sampling for all chemical analyses will be accomplished by a joint laboratory effort at the IGNS NZ ice core facility using a continuous melter system developed by the University of Maine. The RICE deep ice core record will provide information necessary in unraveling the significance of multi-millennial underpinning for climate change and in the understanding of observed and projected climate change in light of current dramatic human impact on Antarctica and the Southern Ocean. The broader impacts of the project include the fact that two CCI graduate students will be funded through the project, and will be involved in all aspects of field research, core sampling, sample processing, analytical and numerical analyses, data interpretation, writing of manuscripts, and presentation of results at national and international conferences. Data and ideas developed in this project and associated work will be used in several courses taught at the University of Maine. Innovative cyberinfrastructure will be incorporated into this work and ground breaking analytical technologies, and data access/storage tools will be used.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e LA-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS", "is_usap_dc": true, "keywords": "LABORATORY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Haines, Skylar; Kurbatov, Andrei V.; Mayewski, Paul A.; Beers, Thomas M.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Roosevelt Island Climate Evolution Project (RICE): US Deep Ice Core Glaciochemistry Contribution (2011- 2014)", "uid": "p0000193", "west": null}, {"awards": "1245821 Brook, Edward; 1245659 Petrenko, Vasilii; 1246148 Severinghaus, Jeffrey", "bounds_geometry": "POINT(162.167 -77.733)", "dataset_titles": "Gas and Dust Measurements for Taylor Glacier and Taylor Dome Ice Cores; Last Interglacial Mean Ocean Temperature; Mean Ocean Temperature in Marine Isotope Stage 4; Measurements of 14CH4 and 14CO in ice from Taylor Glacier: Last Deglaciation; N2O Concentration and Isotope Data for 74-59 ka from Taylor Glacier, Antarctica; Taylor Glacier CO2 Isotope Data 74-59 kyr; Taylor Glacier Noble Gases - Younger Dryas; The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "datasets": [{"dataset_uid": "601218", "doi": "10.15784/601218", "keywords": "Antarctica; Carbon-14; Carbon Dioxide; Chemistry:ice; Chemistry:Ice; CO2; Dome C Ice Core; Epica; Epica Dome C; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Chemistry; Ice Core Data; Ice Core Gas Records; Ice Core Records; Isotope Data; Last Interglacial; Mass Spectrometer; Mass Spectrometry; Methane; Oxygen; Oxygen Isotope; Paleotemperature; Pleistocene; Snow/ice; Snow/Ice; Taylor Dome Ice Core; Taylor Glacier", "people": "Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Last Interglacial Mean Ocean Temperature", "url": "https://www.usap-dc.org/view/dataset/601218"}, {"dataset_uid": "601260", "doi": "10.15784/601260", "keywords": "Antarctica; Carbon-14; Cosmogenic; Ice Core; Methane", "people": "Dyonisius, Michael; Petrenko, Vasilii", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Measurements of 14CH4 and 14CO in ice from Taylor Glacier: Last Deglaciation", "url": "https://www.usap-dc.org/view/dataset/601260"}, {"dataset_uid": "601198", "doi": "10.15784/601198", "keywords": "Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; CO2; Dust; Gas; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Mass Spectrometer; Methane; Nitrogen Isotopes; Oxygen Isotope; Paleoclimate; Snow/ice; Snow/Ice; Taylor Dome; Taylor Dome Ice Core", "people": "Severinghaus, Jeffrey P.; Menking, James; Brook, Edward J.; Marcott, Shaun; Barker, Stephen; Shackleton, Sarah; Dyonisius, Michael; Petrenko, Vasilii; McConnell, Joseph; Rhodes, Rachel; Bauska, Thomas; Baggenstos, Daniel", "repository": "USAP-DC", "science_program": null, "title": "Gas and Dust Measurements for Taylor Glacier and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/601198"}, {"dataset_uid": "601415", "doi": "10.15784/601415", "keywords": "Antarctica; Glaciology; Ice Core Data; Ice Core Records; Paleoclimate; Paleotemperature; Taylor Glacier", "people": "Shackleton, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Mean Ocean Temperature in Marine Isotope Stage 4", "url": "https://www.usap-dc.org/view/dataset/601415"}, {"dataset_uid": "601600", "doi": "10.15784/601600", "keywords": "Antarctica; Taylor Glacier", "people": "Severinghaus, Jeffrey P.; Menking, Andy; Petrenko, Vasilii; Dyonisius, Michael; Barker, Stephen; Brook, Edward J.; Buffen, Aron; Bauska, Thomas; Shackleton, Sarah; Menking, James", "repository": "USAP-DC", "science_program": null, "title": "Taylor Glacier CO2 Isotope Data 74-59 kyr", "url": "https://www.usap-dc.org/view/dataset/601600"}, {"dataset_uid": "601176", "doi": "10.15784/601176", "keywords": "Antarctica; CO2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; Noble Gas; Noble Gas Isotopes; Snow/ice; Snow/Ice; Taylor Glacier; Younger Dryas", "people": "Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Taylor Glacier Noble Gases - Younger Dryas", "url": "https://www.usap-dc.org/view/dataset/601176"}, {"dataset_uid": "601398", "doi": "10.15784/601398", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Gas Records; Ice Core Records; Marine Isotope Stage 4; MIS 4; Nitrous Oxide; Pleistocene; Taylor Dome Ice Core; Taylor Glacier", "people": "Schilt, Adrian; Menking, James; Shackleton, Sarah; Severinghaus, Jeffrey P.; Dyonisius, Michael; Brook, Edward J.; Petrenko, Vasilii", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "N2O Concentration and Isotope Data for 74-59 ka from Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601398"}, {"dataset_uid": "600163", "doi": "10.15784/600163", "keywords": "Antarctica; Atmosphere; Geochemistry; Ice Core Records; Isotope; Paleoclimate; Taylor Glacier; Transantarctic Mountains", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": null, "title": "The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "url": "https://www.usap-dc.org/view/dataset/600163"}, {"dataset_uid": "601218", "doi": "10.15784/601218", "keywords": "Antarctica; Carbon-14; Carbon Dioxide; Chemistry:ice; Chemistry:Ice; CO2; Dome C Ice Core; Epica; Epica Dome C; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Chemistry; Ice Core Data; Ice Core Gas Records; Ice Core Records; Isotope Data; Last Interglacial; Mass Spectrometer; Mass Spectrometry; Methane; Oxygen; Oxygen Isotope; Paleotemperature; Pleistocene; Snow/ice; Snow/Ice; Taylor Dome Ice Core; Taylor Glacier", "people": "Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Last Interglacial Mean Ocean Temperature", "url": "https://www.usap-dc.org/view/dataset/601218"}], "date_created": "Mon, 13 Jul 2015 00:00:00 GMT", "description": "This award supports a project to use the Taylor Glacier, Antarctica, ablation zone to collect ice samples for a range of paleoenvironmental studies. A record of carbon-14 of atmospheric methane (14CH4) will be obtained for the last deglaciation and the Early Holocene, together with a supporting record of CH4 stable isotopes. In-situ cosmogenic 14C content and partitioning of 14C between different species (14CH4, C-14 carbon monoxide (14CO) and C-14 carbon dioxide (14CO2)) will be determined with unprecedented precision in ice from the surface down to ~67 m. Further age-mapping of the ablating ice stratigraphy will take place using a combination of CH4, CO2, \u0026#948;18O of oxygen gas and H2O stable isotopes. High precision, high-resolution records of CO2, \u0026#948;13C of CO2, nitrous oxide (N2O) and N2O isotopes will be obtained for the last deglaciation and intervals during the last glacial period. The potential of 14CO2 and Krypton-81 (81Kr) as absolute dating tools for glacial ice will be investigated. The intellectual merit of proposed work includes the fact that the response of natural methane sources to continuing global warming is uncertain, and available evidence is insufficient to rule out the possibility of catastrophic releases from large 14C-depleted reservoirs such as CH4 clathrates and permafrost. The proposed paleoatmospheric 14CH4 record will improve our understanding of the possible magnitude and timing of CH4 release from these reservoirs during a large climatic warming. A thorough understanding of in-situ cosmogenic 14C in glacial ice (production rates by different mechanisms and partitioning between species) is currently lacking. Such an understanding will likely enable the use of in-situ 14CO in ice at accumulation sites as a reliable, uncomplicated tracer of the past cosmic ray flux and possibly past solar activity, as well as the use of 14CO2 at both ice accumulation and ice ablation sites as an absolute dating tool. Significant gaps remain in our understanding of the natural carbon cycle, as well as in its responses to global climate change. The proposed high-resolution, high-precision records of \u0026#948;13C of CO2 would provide new information on carbon cycle changes both during times of rising CO2 in a warming climate and falling CO2 in a cooling climate. N2O is an important greenhouse gas that increased by ~30% during the last deglaciation. The causes of this increase are still largely uncertain, and the proposed high-precision record of N2O concentration and isotopes would provide further insights into N2O source changes in a warming world. The broader impacts of proposed work include an improvement in our understanding of the response of these greenhouse gas budgets to global warming and inform societally important model projections of future climate change. The continued age-mapping of Taylor Glacier ablation ice will add value to this high-quality, easily accessible archive of natural environmental variability. Establishing 14CO as a robust new tracer for past cosmic ray flux would inform paleoclimate studies and constitute a valuable contribution to the study of the societally important issue of climate change. The proposed work will contribute to the development of new laboratory and field analytical systems. The data from the study will be made available to the scientific community and the broad public through the NSIDC and NOAA Paleoclimatology data centers. 1 graduate student each will be trained at UR, OSU and SIO, and the work will contribute to the training of a postdoc at OSU. 3 UR undergraduates will be involved in fieldwork and research. The work will support a new, junior UR faculty member, Petrenko. All PIs have a strong history of and commitment to scientific outreach in the forms of media interviews, participation in filming of field projects, as well as speaking to schools and the public about their research, and will continue these activities as part of the proposed work. This award has field work in Antarctica.", "east": 162.167, "geometry": "POINT(162.167 -77.733)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Not provided; USAP-DC; FIELD INVESTIGATION; Stratigraphy; FIELD SURVEYS; Antarctica; Paleoenvironment; Methane; Ice Core; Carbon Dioxide; FIXED OBSERVATION STATIONS; Stable Isotopes; Ablation Zone; Taylor Glacier; Nitrous Oxide; USA/NSF; LABORATORY; AMD; Cosmogenic; Amd/Us", "locations": "Taylor Glacier; Antarctica", "north": -77.733, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Petrenko, Vasilii; Brook, Edward J.; Severinghaus, Jeffrey P.; PETRENKO, VASILLI", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e FIXED OBSERVATION STATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": -77.733, "title": "Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive", "uid": "p0000283", "west": 162.167}, {"awards": "0839078 Brook, Edward", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 31 Oct 2013 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to develop a robust analytical technique for measuring the stable isotopes of CO2 in air trapped in polar ice, and to reconstruct the \u00e413C of CO2 over the last glacial to interglacial transition (20,000 to 10,000 years BP) and through the Holocene. The bulk of these measurements will be made on newly cored ice from the WAIS Divide Ice Core. A robust record \u00e413C of CO2 will be a valuable addition to the rich data produced from this project. The intellectual merit of the proposed work relates to the fact that explaining glacial-interglacial changes in atmospheric CO2 remains a major challenge for paleoclimatology. The lack of a coherent, widely accepted explanation underscores uncertainties in the basic mechanisms that control the carbon cycle, and that lack of understanding limits our ability to confidently predict how the carbon cycle will change in the future, in the face of a potentially major perturbation of both global temperature and the CO2 content of the atmosphere. A widely accepted record of this parameter could transform our understanding of how the carbon cycle and climate change are linked. The broader impacts of the work include training of graduate student at OSU who will conduct much of the lab work and will also participate in fieldwork at the WAIS Divide Core site. The student will also participate in a number of organized outreach efforts and will develop his own outreach effort, through weblogs and other communication of his research. The PIs will communicate the results from this project to a variety of audiences through academic courses and public talks. The proposed work addresses a major topic in biogeochemistry, the origin of glacial-interglacial CO2 cycles. The results are relevant to understanding changes in the carbon cycle due to human activities because the lack of clear understanding of past variations contributes to public uncertainty about the importance of modern climate change. The proposed funding will also contribute to analytical infrastructure at OSU and develop an analytical capability for an ice core measurement currently not available in the United States.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.; Mix, Alan", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Developing a glacial-interglacial record of delta-13C of atmospheric CO2", "uid": "p0000260", "west": null}, {"awards": "0838973 Nyblade, Andrew; 0838934 Wiens, Douglas", "bounds_geometry": "POLYGON((40 -76,50 -76,60 -76,70 -76,80 -76,90 -76,100 -76,110 -76,120 -76,130 -76,140 -76,140 -76.8,140 -77.6,140 -78.4,140 -79.2,140 -80,140 -80.8,140 -81.6,140 -82.4,140 -83.2,140 -84,130 -84,120 -84,110 -84,100 -84,90 -84,80 -84,70 -84,60 -84,50 -84,40 -84,40 -83.2,40 -82.4,40 -81.6,40 -80.8,40 -80,40 -79.2,40 -78.4,40 -77.6,40 -76.8,40 -76))", "dataset_titles": "Seismological Record ID# ZM 2007-12; Seismological Record Network Code# ZM (full data link not provided)", "datasets": [{"dataset_uid": "000149", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismological Record ID# ZM 2007-12", "url": "http://www.iris.edu/"}, {"dataset_uid": "000152", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismological Record Network Code# ZM (full data link not provided)", "url": "http://www.iris.edu/"}], "date_created": "Mon, 21 Jan 2013 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The high elevations of East Antarctica are critical in localizing the initial Cenozoic glaciation and stabilizing it with respect to melting during warm interglacials. However, the geological history for this region and the geophysical mechanism for maintaining the highlands are poorly understood. In 2007-2009, an array of 24 broadband seismographs (named GAMSEIS) was installed across the Gamburtsev Mountains area of the East Antarctic Plateau as part of the Antarctica?s Gamburtsev Province (AGAP) International Polar Year project. The IPY AGAP/GAMSEIS program included plans by other international partners to install seismographs at locations along the flanks of the Gamburtsev Mountains and in other East Antarctic regions. The proposed project will continue operating six of the deployed AGAP/GAMSEIS stations for two more years together with two new broadband seismic stations added to broaden the geographic scope of the array. Most stations will be located at the existing U.S. Autonomous Geophysical Observatories and the USAP fuel cache locations in order to minimize logistical support. This array, combined with seismographs deployed by China and Japan (and possibly Australia, France, and Italy in near future) will provide a sparse but large-scale network of seismometers for the longer-term studies of the crustal and upper mantle structures underneath the East Antarctic Plateau. Continued reliance on students provides a broader impact to this proposed research and firmly grounds this effort in its educational mission.", "east": 140.0, "geometry": "POINT(90 -80)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wiens, Douglas; Nyblade, Andrew", "platforms": "Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -84.0, "title": "Collaborative Research: Polenet East: An International Seismological Network for East Antarctica", "uid": "p0000504", "west": 40.0}, {"awards": "0733025 Blankenship, Donald", "bounds_geometry": "POLYGON((95 -65,103.5 -65,112 -65,120.5 -65,129 -65,137.5 -65,146 -65,154.5 -65,163 -65,171.5 -65,180 -65,180 -66.7,180 -68.4,180 -70.1,180 -71.8,180 -73.5,180 -75.2,180 -76.9,180 -78.6,180 -80.3,180 -82,171.5 -82,163 -82,154.5 -82,146 -82,137.5 -82,129 -82,120.5 -82,112 -82,103.5 -82,95 -82,95 -80.3,95 -78.6,95 -76.9,95 -75.2,95 -73.5,95 -71.8,95 -70.1,95 -68.4,95 -66.7,95 -65))", "dataset_titles": "Gravity anomaly data; Gravity raw data; ICECAP Basal Interface Specularity Content Profiles: IPY and OIB; ICECAP flight reports; ICECAP ice thickness data over the Darwin and Hatherton Glaciers, Transantarctic Mountains, Antarctica; ICECAP radargrams (HiCARS 1); ICECAP radargrams (HiCARS 2); Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau; Ice thickness and bed reflectivity data (HiCARS 1); Ice thickness and bed reflectivity data (HiCARS 2); Laser altimetry raw data; Laser surface elevation data; Magnetic anomaly data; Magnetic raw data", "datasets": [{"dataset_uid": "200112", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "ICECAP radargrams (HiCARS 2)", "url": "https://nsidc.org/data/IR2HI1B/versions/1"}, {"dataset_uid": "200111", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "ICECAP radargrams (HiCARS 1)", "url": "https://nsidc.org/data/IR1HI1B/versions/1"}, {"dataset_uid": "601411", "doi": "10.15784/601411", "keywords": "Antarctica; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ICECAP; Ice Penetrating Radar; Internal Reflecting Horizons", "people": "Cavitte, Marie G. P; Blankenship, Donald D.; Schroeder, Dustin; Tozer, Carly; Roberts, Jason; Frezzotti, Massimo; Paden, John; Muldoon, Gail R.; Quartini, Enrica; Kempf, Scott D.; Young, Duncan A.; Mulvaney, Robert; Ritz, Catherine; Greenbaum, Jamin; Ng, Gregory", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau", "url": "https://www.usap-dc.org/view/dataset/601411"}, {"dataset_uid": "601605", "doi": "10.15784/601605", "keywords": "Airborne Radar; Antarctica; Basler; Darwin Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hatherton Glacier; Hicars; ICECAP; Ice Penetrating Radar; Ice Thickness; Transantarctic Mountains", "people": "Gillespie, Mette; Young, Duncan A.; Blankenship, Donald D.; Siegert, Martin; Holt, John W.; Greenbaum, Jamin; Schroeder, Dustin", "repository": "USAP-DC", "science_program": null, "title": "ICECAP ice thickness data over the Darwin and Hatherton Glaciers, Transantarctic Mountains, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601605"}, {"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Greenbaum, Jamin; Schroeder, Dustin; Young, Duncan A.; Blankenship, Donald D.; Roberts, Jason; Siegert, Martin; van Ommen, Tas", "repository": "USAP-DC", "science_program": null, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "url": "https://www.usap-dc.org/view/dataset/601371"}, {"dataset_uid": "200121", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "ICECAP flight reports", "url": "https://nsidc.org/data/ifltrpt"}, {"dataset_uid": "200120", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Laser surface elevation data", "url": "https://nsidc.org/data/ilutp2"}, {"dataset_uid": "200119", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Laser altimetry raw data", "url": "https://nsidc.org/data/ilutp1b"}, {"dataset_uid": "200118", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Gravity anomaly data", "url": "https://nsidc.org/data/igbgm2/"}, {"dataset_uid": "200117", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Gravity raw data", "url": "https://nsidc.org/data/igbgm1b/"}, {"dataset_uid": "200116", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Magnetic anomaly data", "url": "https://nsidc.org/data/imgeo2"}, {"dataset_uid": "200115", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Magnetic raw data", "url": "https://nsidc.org/data/imgeo1b"}, {"dataset_uid": "200114", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Ice thickness and bed reflectivity data (HiCARS 2)", "url": "https://nsidc.org/data/IR2HI2/versions/1"}, {"dataset_uid": "200113", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Ice thickness and bed reflectivity data (HiCARS 1)", "url": "https://nsidc.org/data/IR1HI2/versions/1"}], "date_created": "Tue, 04 Sep 2012 00:00:00 GMT", "description": "This project is an aerogeophysical survey to explore unknown terrain in East Antarctica to answer questions of climate change and earth science. The methods include ice-penetrating radar, gravity, and magnetic measurements. The project?s main goal is to investigate the stability and migration of ice divides that guide flow of the East Antarctic ice sheet, the world?s largest. The project also maps ice accumulation over the last interglacial, identifies subglacial lakes, and characterizes the catchment basins of the very largest glacial basins, including Wilkes and Aurora. The outcomes contribute to ice sheet models relevant to understanding sea level rise in a warming world. The work will also help understand the regional geology. Buried beneath miles-thick ice, East Antarctica is virtually uncharacterized, but is considered a keystone for tectonic reconstructions and other geologic questions. The region also hosts subglacial lakes, whose geologic histories are unknown. \u003cbr/\u003e\u003cbr/\u003eThe broader impacts are extensive, and include societal relevance for understanding sea level rise, outreach in various forms, and education at the K12 through postdoctoral levels. The project contributes to the International Polar Year (2007-2009) by addressing key IPY themes on frontiers in polar exploration and climate change. It also includes extensive international collaboration with the United Kingdom, Australia, France and other nations; and offers explicit opportunities for early career scientists.", "east": 180.0, "geometry": "POINT(137.5 -73.5)", "instruments": null, "is_usap_dc": false, "keywords": "DOME C; Aurora Subglacial Basin; BT-67; East Antarctica; Wilkes Land; Totten Glacier; ICE SHEETS; Byrd Glacier; Wilkes Subglacial Basin", "locations": "East Antarctica; DOME C; Byrd Glacier; Totten Glacier; Aurora Subglacial Basin; Wilkes Subglacial Basin; Wilkes Land", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Siegert, Martin; Roberts, Jason; Van Ommen, Tas; Warner, Roland; Richter, Thomas; Greenbaum, Jamin; Holt, John W.; Young, Duncan A.; Blankenship, Donald D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e BT-67", "repo": "NSIDC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": -82.0, "title": "IPY Research: Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP)", "uid": "p0000719", "west": 95.0}, {"awards": "0739766 Brook, Edward", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "WAIS Divide Ice Core CO2", "datasets": [{"dataset_uid": "609651", "doi": "10.7265/N5DV1GTZ", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Marcott, Shaun; Brook, Edward J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core CO2", "url": "https://www.usap-dc.org/view/dataset/609651"}], "date_created": "Wed, 30 May 2012 00:00:00 GMT", "description": "Brook 0739766\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to create a 25,000-year high-resolution record of atmospheric CO2 from the WAIS Divide ice core. The site has high ice accumulation rate, relatively cold temperatures, and annual layering that should be preserved back to 40,000 years, all prerequisite for preserving a high quality, well-dated CO2 record. The new record will be used to examine relationships between Antarctic climate, Northern Hemisphere climate, and atmospheric CO2 on glacial-interglacial to centennial time scales, at unprecedented temporal resolution. The intellectual merit of the proposed work is simply that CO2 is the most important greenhouse gas that humans directly impact, and understanding the sources, sinks, and controls of atmospheric CO2 is a major goal for the global scientific community. Accurate chronology and detailed records are primary requirements for developing and testing models that explain and predict CO2 variability. The proposed work has several broader impacts. It contributes to the training of a post-doctoral researcher, who will transfer to a research faculty position during the award period and who will participate in graduate teaching and guest lecture in undergraduate courses. An undergraduate researcher will gain valuable lab training and conduct independent research. Bringing the results of\u003cbr/\u003ethe proposed work to the classroom will enrich courses taught by the PI. Outreach efforts will expose pre-college students to ice core research. The proposed work will enhance the laboratory facilities for ice core research at OSU, insuring that the capability for CO2 measurements exists for future projects. All data will be archived at the National Snow and Ice Data Center and other similar archives, per OPP policy. Highly significant results will be disseminated to the news media through OSU?s very effective News and Communications group. Carbon dioxide is the most important greenhouse gas that humans are directly changing. Understanding how CO2 and climate are linked on all time scales is necessary for predicting the future behavior of the carbon cycle and climate system, primarily to insure that the appropriate processes are represented in carbon cycle/climate models. Part of the proposed work emphasizes the relationship of CO2 and abrupt climate change. Understanding how future abrupt change might impact the carbon cycle is an important issue for society.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Carbon Dioxide; FIELD INVESTIGATION; CO2; Wais Divide-project; Ice Core; Antarctica; Climate; Gas Chromatography; Antarctic Ice Core; LABORATORY", "locations": "Antarctica", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Marcott, Shaun; Ahn, Jinho; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Atmospheric Carbon Dioxide and Climate Change: The WAIS Divide Ice Core Record", "uid": "p0000044", "west": -112.08}, {"awards": "0537661 Cuffey, Kurt; 0537930 Steig, Eric; 0537593 White, James", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "Stable Isotope Lab at INSTAAR, University of Colorado; WAIS ice core isotope data #342, 347, 348, 349, 350, 351 (full data link not provided)", "datasets": [{"dataset_uid": "000140", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "WAIS ice core isotope data #342, 347, 348, 349, 350, 351 (full data link not provided)", "url": "http://www.waisdivide.unh.edu/"}, {"dataset_uid": "002561", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Stable Isotope Lab at INSTAAR, University of Colorado", "url": "http://instaar.colorado.edu/sil/about/index.php"}], "date_created": "Mon, 09 Apr 2012 00:00:00 GMT", "description": "This award supports analyses of stable isotopes of water, dD, d18O and deuterium excess in the proposed West Antarctic Ice Sheet Divide (WAIS) deep ice core. The project will produce a continuous and high-resolution reconstruction of stable isotope ratios for the new core. dD and d18O values provide estimates of temperature change at the ice core site. Deuterium excess provides estimates of ocean surface conditions, such as sea surface temperature, at the moisture source areas. This new ice core is ideally situated to address questions ranging from ice sheet stability to abrupt climate change. WAIS Divide has high enough snowfall rates to record climate changes on annual to decadal time scales. It should also have ice old enough to capture the last interglacial period in detail. The West Antarctic ice sheet is the subject of great scrutiny as our modern climate warms and sea level rises. What are the prospects for added sea level rise from ice released by this ice sheet? Understanding how this ice sheet has responded to climate change in the past, which the data collected in this project will help to assess, is critical to answering this question. The high temporal resolution available in the WAIS Divide core will provide the best available basis for inter-comparison of millennial-scale climate changes between the poles, and thus a better understanding of the spatial expression and dynamics of rapid climate change events. Finally, the location of this core in the Pacific sector of West Antarctica makes it well situated for examining the influence of the tropical Pacific on Antarctica climate, on longer timescales than are available from the instrumental climate record. Analyses will include the measurement of sub-annually resolved isotope variations in the uppermost parts of the core, measurements at annual resolution throughout the last 10,000 years and during periods of rapid climate change prior to that, and measurements at 50-year resolution throughout the entire length of the core that is collected and processed during the period of this grant. We anticipate that this will be about half of the full core expected to be drilled. In terms of broader impacts, the PIs will share the advising of two graduate students, who will make this ice core the focus of their thesis projects. It will be done in an innovative multi-campus approach designed to foster a broader educational experience. As noted above, the data and interpretations generated by this proposal will address climate change questions not only of direct and immediate scientific interest, but also of direct and immediate policy interest.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES", "is_usap_dc": true, "keywords": "West Antarctic Ice Sheet Divide; Not provided; Ice Core; WAIS Divide; LABORATORY; FIELD SURVEYS; Isotope; FIELD INVESTIGATION; Antarctica; West Antarctica; Stable Isotope Ratios; Antarctic; Ice Sheet; Deuterium", "locations": "WAIS Divide; West Antarctica; Antarctic; Antarctica; West Antarctic Ice Sheet Divide", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "White, James; Steig, Eric J.; Cuffey, Kurt M.; Souney, Joseph Jr.; Vaughn, Bruce", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "Project website", "repositories": "Project website", "science_programs": null, "south": -79.47, "title": "Collaborative Research: Stable Isotopes of Ice in the WAIS Divide Deep Ice Core", "uid": "p0000294", "west": -112.08}, {"awards": "0636898 Winckler, Gisela", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 30 Nov 2011 00:00:00 GMT", "description": "Winckler/0636898\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study dust sources in Antarctic ice cores. Atmospheric aerosols play an important role both in global biogeochemical cycles as well as in the climate system of the Earth. Records extracted from Antarctic ice cores inform us that dust deposition from the atmosphere to the ice sheet was 15-20 times greater during glacial periods than during interglacials, which raises the possibility that dust may be a key player in climate change on glacial-interglacial timescales. By characterizing potential source areas from South America, South Africa, and Australia as well as fresh glacial flour from Patagonia, the project will determine if the interglacial dust was mobilized from a distinct geographical region (e.g., Australia) or from a more heavily weathered source region in South America. The intellectual merit of the project is that it will contribute to reconstructing climate-related changes in the rate of dust deposition, and in the provenance of the dust, it will provide critical constraints on hydrology and vegetation in the source regions, as well as on the nature of the atmospheric circulation transporting dust to the archive location. In a recent pilot study it was found that there is a dramatic glacial to Holocene change in the 4He/Ca ratio in the dust extracted from ice from Dronning Maud Land, Antarctica, indicating a shift in the source of dust transported to Antarctica. The broader impacts of the project are that Helium isotopes and calcium measurements provide a wealth of information that can then be turned into critical input for dust-climate models. Improved models, which are able to accurately reconstruct paleo dust distribution, will help us to predict changes in dust in response to future climate variability. This information will contribute to an improvement of our integrated understanding of the Earth\u0027s climate system and, in turn, will better inform policy makers of those processes and conditions most susceptible to perturbation by climate change, thereby leading to more meaningful climate-change policy. The project will support a graduate student in the dual masters Earth and Environmental Science Journalism program. The lead-PI manages the rock noble gas laboratory at Lamont. Her leadership role in this facility impacts the training of undergraduate and graduate students as well as visiting scientists.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": false, "keywords": "Deposition; LABORATORY; Dust; Climate; Not provided; Climate Change; Helium Isotopes; FIELD INVESTIGATION; Biogeochemical Cycles", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Winckler, Gisela", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Tracing Glacial-interglacial Changes in the Dust Source to Antarctica using Helium Isotopes", "uid": "p0000265", "west": null}, {"awards": "0732467 Domack, Eugene", "bounds_geometry": null, "dataset_titles": "Cosmogenic-Nuclide Data at ICe-D; Expedition data of LMG0903; Expedition data of NBP1001; NBP1001 cruise data; Processed CTD Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001; Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001", "datasets": [{"dataset_uid": "200297", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic-Nuclide Data at ICe-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "601345", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; CTD; CTD Data; LARISSA; Larsen Ice Shelf; NBP1001; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Temperature", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Processed CTD Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601345"}, {"dataset_uid": "002715", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0903", "url": "https://www.rvdata.us/search/cruise/LMG0903"}, {"dataset_uid": "000142", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1001 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP1001"}, {"dataset_uid": "601346", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Current Measurements; LADCP; Larsen Ice Shelf; NBP1001; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601346"}, {"dataset_uid": "002651", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1001", "url": "https://www.rvdata.us/search/cruise/NBP1001"}], "date_created": "Thu, 03 Mar 2011 00:00:00 GMT", "description": "This award supports a research cruise to perform geologic studies in the area under and surrounding the former Larsen B ice shelf, on the Antarctic Peninsula. The ice shelf\u0027s disintegration in 2002 coupled with the unique marine geology of the area make it possible to understand the conditions leading to ice shelf collapse. Bellwethers of climate change that reflect both oceanographic and atmospheric conditions, ice shelves also hold back glacial flow in key areas of the polar regions. Their collapse results in glacial surging and could cause rapid rise in global sea levels. This project characterizes the Larsen ice shelf\u0027s history and conditions leading to its collapse by determining: 1) the size of the Larsen B during warmer climates and higher sea levels back to the Eemian interglacial, 125,000 years ago; 2) the configuration of the Antarctic Peninsula ice sheet during the LGM and its subsequent retreat; 3) the causes of the Larsen B\u0027s stability through the Holocene, during which other shelves have come and gone; 4) the controls on the dynamics of ice shelf margins, especially the roles of surface melting and oceanic processes, and 5) the changes in sediment flux, both biogenic and lithogenic, after large ice shelf breakup. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThe broader impacts include graduate and undergraduate education through research projects and workshops; outreach to the general public through a television documentary and websites, and international collaboration with scientists from Belgium, Spain, Argentina, Canada, Germany and the UK. The work also has important societal relevance. Improving our understanding of how ice shelves behave in a warming world will improve models of sea level rise.\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThe project is supported under NSF\u0027s International Polar Year (IPY) research emphasis area on \"Understanding Environmental Change in Polar Regions\".", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG; Larsen Ice Shelf; R/V NBP; Antarctic Peninsula; ICE SHEETS", "locations": "Antarctic Peninsula; Larsen Ice Shelf", "north": null, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Domack, Eugene Walter; Blanchette, Robert", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "ICE-D", "repositories": "ICE-D; R2R; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach - Marine and Quaternary Geosciences", "uid": "p0000841", "west": null}, {"awards": "9909367 Leventer, Amy", "bounds_geometry": "POLYGON((26.27227 -42.81742,38.414467 -42.81742,50.556664 -42.81742,62.698861 -42.81742,74.841058 -42.81742,86.983255 -42.81742,99.125452 -42.81742,111.267649 -42.81742,123.409846 -42.81742,135.552043 -42.81742,147.69424 -42.81742,147.69424 -45.454494,147.69424 -48.091568,147.69424 -50.728642,147.69424 -53.365716,147.69424 -56.00279,147.69424 -58.639864,147.69424 -61.276938,147.69424 -63.914012,147.69424 -66.551086,147.69424 -69.18816,135.552043 -69.18816,123.409846 -69.18816,111.267649 -69.18816,99.125452 -69.18816,86.983255 -69.18816,74.841058 -69.18816,62.698861 -69.18816,50.556664 -69.18816,38.414467 -69.18816,26.27227 -69.18816,26.27227 -66.551086,26.27227 -63.914012,26.27227 -61.276938,26.27227 -58.639864,26.27227 -56.00279,26.27227 -53.365716,26.27227 -50.728642,26.27227 -48.091568,26.27227 -45.454494,26.27227 -42.81742))", "dataset_titles": "Diatom assemblages from Edward VIII Gulf, Kemp Coast, East Antarctica; NB0101 Expedition Data; Quantitative Diatom Assemblage Data from Iceberg Alley, Mac. Robertson Shelf, East Antarctica acquired during expedition NBP0101", "datasets": [{"dataset_uid": "001879", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NB0101 Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0101"}, {"dataset_uid": "601177", "doi": "10.15784/601177", "keywords": "Antarctica; Biota; Diatom; East Antarctica; Microscopy; NBP0101; Oceans; Paleoceanography; Paleoclimate; R/v Nathaniel B. Palmer; Sediment Corer", "people": "Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "Diatom assemblages from Edward VIII Gulf, Kemp Coast, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601177"}, {"dataset_uid": "601307", "doi": null, "keywords": "Antarctica; Biota; Diatom; East Antarctica; Mac. Robertson Shelf; Marine Geoscience; Microscope; NBP0101; Paleoclimate; Piston Corer; R/v Nathaniel B. Palmer; Sediment Core; Species Abundance", "people": "Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "Quantitative Diatom Assemblage Data from Iceberg Alley, Mac. Robertson Shelf, East Antarctica acquired during expedition NBP0101", "url": "https://www.usap-dc.org/view/dataset/601307"}], "date_created": "Thu, 03 Mar 2011 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a multi-institutional, international (US - Australia) marine geologic and geophysical investigation of Prydz Bay and the MacRobertson Shelf, to be completed during an approximately 60-day cruise aboard the RVIB N.B. Palmer. The primary objective is to develop a record of climate and oceanographic change during the Quaternary, using sediment cores collected via kasten and jumbo piston coring. Core sites will be selected based on seismic profiling (Seabeam 2112 and Bathy2000). Recognition of the central role of the Antarctic Ice Sheet to global oceanic and atmospheric systems is based primarily on data collected along the West Antarctic margin, while similar extensive and high resolution data sets from the much more extensive East Antarctic margin are sparse. Goals of this project include (1) development of a century- to millennial-scale record of Holocene paleoenvironments, and (2) testing of hypotheses concerning the sedimentary record of previous glacial and interglacial events on the shelf, and evaluation of the timing and extent of maximum glaciation along this 500 km stretch of the East Antarctic margin. \u003cbr/\u003e\u003cbr/\u003eHigh-resolution seismic mapping and coring of sediments deposited in inner shelf depressions will be used to reconstruct Holocene paleoenvironments. In similar depositional settings in the Antarctic Peninsula and Ross Sea, sedimentary records demonstrate millennial- and century- scale variability in primary production and sea-ice extent during the Holocene, which have been linked to chronological periodicities in radiocarbon distribution, suggesting the possible role of solar variability in driving some changes in Holocene climate. Similar high-resolution Holocene records from the East Antarctic margin will be used to develop a circum-Antarctic suite of data regarding the response of southern glacial and oceanographic systems to late Quaternary climate change. In addition, these data will help us to evaluate the response of the East Antarctic margin to global warming. \u003cbr/\u003e\u003cbr/\u003eInitial surveys of the Prydz Channel - Amery Depression region reveal sequences deposited during previous Pleistocene interglacials. The upper Holocene and lower (undated) siliceous units can be traced over 15,000 km2 of the Prydz Channel, but more sub-bottom seismic reflection profiling in conjunction with dense coring over this region is needed to define the spatial distribution and extent of the units. Chronological work will determine the timing and duration of previous periods of glacial marine sedimentation on the East Antarctic margin during the late Pleistocene. \u003cbr/\u003e\u003cbr/\u003eAnalyses will focus on detailed sedimentologic, geochemical, micropaleontological, and paleomagnetic techniques. This multi-parameter approach is the most effective way to extract a valuable paleoenvironmental signal in these glacial marine sediments. These results are expected to lead to a significant advance in understanding of the behavior of the Antarctic ice-sheet and ocean system in the recent geologic past.\u003cbr/\u003e\u003cbr/\u003eThe combination of investigators, all with many years of experience working in high latitude marine settings, will provide an effective team to complete the project. University and College faculty (Principal Investigators on this project) will supervise a combination of undergraduate and post-graduate students involved in all stages of the project so that educational objectives will be met in tandem with the research goals of the project.", "east": 147.69424, "geometry": "POINT(86.983255 -56.00279)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": false, "keywords": "R/V NBP; USAP-DC", "locations": null, "north": -42.81742, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Leventer, Amy", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -69.18816, "title": "Quaternary Glacial History and Paleoenvironments of the East Antarctic Margin", "uid": "p0000609", "west": 26.27227}, {"awards": "0538097 Anandakrishnan, Sridhar", "bounds_geometry": "POLYGON((140 -89.8,144 -89.8,148 -89.8,152 -89.8,156 -89.8,160 -89.8,164 -89.8,168 -89.8,172 -89.8,176 -89.8,180 -89.8,180 -89.82,180 -89.84,180 -89.86,180 -89.88,180 -89.9,180 -89.92,180 -89.94,180 -89.96,180 -89.98,180 -90,176 -90,172 -90,168 -90,164 -90,160 -90,156 -90,152 -90,148 -90,144 -90,140 -90,140 -89.98,140 -89.96,140 -89.94,140 -89.92,140 -89.9,140 -89.88,140 -89.86,140 -89.84,140 -89.82,140 -89.8))", "dataset_titles": "IRIS Data Management Center (DMC) holds the full resolution seismic data. Keyword: POLELAKE. Dataset ID: 10-019; seismic data. Keyword: POLELAKE. Dataset ID: 10-019", "datasets": [{"dataset_uid": "000102", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "seismic data. Keyword: POLELAKE. Dataset ID: 10-019", "url": "http://ds.iris.edu/ds/nodes/dmc/"}, {"dataset_uid": "001466", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IRIS Data Management Center (DMC) holds the full resolution seismic data. Keyword: POLELAKE. Dataset ID: 10-019", "url": "http://www.iris.edu/dms/dmc"}], "date_created": "Wed, 08 Sep 2010 00:00:00 GMT", "description": "0538097\u003cbr/\u003eAnandakrishnan\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to intensively study a subglacial Antarctic lake near the geographic South Pole using seismic and radar methods. These ground-based experiments are better suited to determine the presence of water and its thickness than are airborne methods. We hypothesize that there are two end-member explanations for this feature: either the lake is thawed, but freezing on (and likely to have been freezing on through much of the current interglacial period), or it is a frozen, relict lake for which the high basal radar reflectivity is due to intergranular water in a permafrost-like layer beneath the ice. The seismic experiment we propose is ideally suited to examine these alternatives. Intermediate cases of, e.g., a thawed saturated sedimentary base or a smooth crystalline basement layer would also be resolved by this experiment. Seismic reflections are sensitive to changes in acoustic impedance which is strongly variable with fluid content, porosity, and lithology. Water has low density relative to most rocks and low seismic velocity (and nil shear wave velocity) relative to both ice and rock. Thus, discriminating between subglacial water and subglacial rock is a task ideally suited to the seismic reflection technique. This project has significant impacts outside the directly affected fields of Antarctic glaciology and geology. The lake (either thawed or sediments with thin liquid layers around the matrix particles) will have the potential for harboring novel life forms. The experiment has the potential for expanding our information about the newest frontier in life on Earth. The collaboration between PIs in the seismic community and the marine acoustics community will foster cross-disciplinary pollination of ideas, techniques, and tools. In addition to traditional seismic techniques, new methods of data analysis that have been developed by acousticians will be applied to this problem as an independent measure of lake properties. We will train students who will have a wider view of seismology than would be possible in a traditional ocean acoustics or traditional geoscience seismology program of study.", "east": 180.0, "geometry": "POINT(160 -89.9)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS", "is_usap_dc": false, "keywords": "Antarctica; South Pole; Porosity; Not provided; Seismic; Lithology; FIELD INVESTIGATION; Subglacial; Subglacial Lake; FIELD SURVEYS; LABORATORY; Fluid Content; Acoustic Impedance", "locations": "Antarctica; South Pole", "north": -89.8, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar; Holland, Charles", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -90.0, "title": "Characterization of Lake Amundsen-Scott, S. Pole: A Ground Geophysical Program", "uid": "p0000693", "west": 140.0}, {"awards": "9814349 Hall, Brenda", "bounds_geometry": "POLYGON((-70.4838 -52.3532,-68.92937 -52.3532,-67.37494 -52.3532,-65.82051 -52.3532,-64.26608 -52.3532,-62.71165 -52.3532,-61.15722 -52.3532,-59.60279 -52.3532,-58.04836 -52.3532,-56.49393 -52.3532,-54.9395 -52.3532,-54.9395 -53.61625,-54.9395 -54.8793,-54.9395 -56.14235,-54.9395 -57.4054,-54.9395 -58.66845,-54.9395 -59.9315,-54.9395 -61.19455,-54.9395 -62.4576,-54.9395 -63.72065,-54.9395 -64.9837,-56.49393 -64.9837,-58.04836 -64.9837,-59.60279 -64.9837,-61.15722 -64.9837,-62.71165 -64.9837,-64.26608 -64.9837,-65.82051 -64.9837,-67.37494 -64.9837,-68.92937 -64.9837,-70.4838 -64.9837,-70.4838 -63.72065,-70.4838 -62.4576,-70.4838 -61.19455,-70.4838 -59.9315,-70.4838 -58.66845,-70.4838 -57.4054,-70.4838 -56.14235,-70.4838 -54.8793,-70.4838 -53.61625,-70.4838 -52.3532))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001743", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0209"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award supports a two year program to produce a new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum (LGM) for the South Shetland Islands in the Antarctic Peninsula. One field season on Livingston Island will involve mapping the areal extent and geomorphology of glacial drift and determining the elevation and distribution of trimlines. In addition, ice flow direction will be determined by mapping and measuring the elevation of erosional features and the position of erratic boulders. One of the main goals of this work will be to demonstrate whether or not organic material suitable for radiocarbon dating exists in the South Shetland Islands. If so, the age of the deposits will be determined by measuring the carbon-14 age of plant, algal, and fungal remains preserved at the base of the deposits, as well as incorporated marine shells, seal skin and other organic material that may be found in raised beach deposits. Another goal will be to concentrate on the development of relative sea-level curves from 2-3 key areas to show whether or not construction of such curves for the South Shetland Islands is possible. The new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum for the South Shetland Islands which will be produced by this work will be useful in studies of ocean circulation and ice dynamics in the vicinity of the Drake Passage. It will also contribute to the production of a deglacial chronology which will afford important clues about the mechanisms controlling ice retreat in this region of the southern hemisphere.", "east": -54.9395, "geometry": "POINT(-62.71165 -58.66845)", "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": -52.3532, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Taylor, Frederick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.9837, "title": "AMS Radiocarbon Chronology of Glacier Fluctuations in the South Shetland Islands During the Last Glacial/Interglacial Hemicycle:Implications for Global Climate Change", "uid": "p0000596", "west": -70.4838}, {"awards": "9615053 Domack, Eugene", "bounds_geometry": null, "dataset_titles": "Expedition data of LMG9802", "datasets": [{"dataset_uid": "002718", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9802", "url": "https://www.rvdata.us/search/cruise/LMG9802"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Domack: OPP 9615053 Manley: OPP 9615670 Banerjee: OPP 9615695 Dunbar: OPP 9615668 Ishman: OPP 9615669 Leventer: OPP 9714371 Abstract This award supports a multi-disciplinary, multi-institutional effort to elucidate the detailed climate history of the Antarctic Peninsula during the Holocene epoch (the last 10,000 years). The Holocene is an important, but often overlooked, portion of the Antarctic paleoclimatic record because natural variability in Holocene climate on time scales of decades to millennia can be evaluated as a model for our present \"interglacial\" world. This project builds on over ten years of prior investigation into the depositional processes, productivity patterns and climate regime of the Antarctic Peninsula. This previous work identified key locations that contain ultra-high resolution records of past climatic variation. These data indicate that solar cycles operating on multi-century and millennial time scales are important regulators of meltwater production and paleoproductivity. These marine records can be correlated with ice core records in Greenland and Antarctica. This project will focus on sediment dispersal patterns across the Palmer Deep region. The objective is to understand the present links between the modern climatic and oceanographic systems and sediment distribution. In particular, additional information is needed regarding the influence of sea ice on the distribution of both biogenic and terrigenous sediment distribution. Sediment samples will be collected with a variety of grab sampling and coring devices. Analytical work will include carbon-14 dating of surface sediments using accellerator mass spectrometry and standard sedimentologic, micropaleontologic and magnetic granulometric analyses. This multiparameter approach is the most effective way to extract the paleoclimatic signals contained in the marine sediment cores. Two additional objectives are the deployment of sediment traps in front of the Muller Ice Shelf in Lallemand Fjord and seismic reflection work in conjunction with site augmentation funded through the Joint Oceanographic Institute. The goal of sediment trap work is to address whether sand transport and deposition adjacent to the ice shelf calving line results from meltwater or aeolian processes. In addition, the relationship between sea ice conditions and primary productivity will be investigated. The collection of a short series of seismic lines across the Palmer Deep basins will fully resolve the question of depth to acoustic basement. The combination of investigators on this project, all with many years of experience working in high latitude settings, provides an effective team to complete the project in a timely fashion. A combination of undergraduate, graduate and post-graduate students will be involved in all stages of the project so that educational objectives will be met in-tandem with research goals of the project.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Domack, Eugene Walter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Holocene Paleoenvironmental Change Along the Antarctic Peninsula: A Test of the Solar/Bi-Polar Signal", "uid": "p0000869", "west": null}, {"awards": "0453680 Sigman, Daniel", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Robinson et al. 2004 Southern Ocean Diatom-bound Nitrogen and d15N Data", "datasets": [{"dataset_uid": "000119", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Robinson et al. 2004 Southern Ocean Diatom-bound Nitrogen and d15N Data", "url": "https://www.ncdc.noaa.gov/paleo-search/study/8751"}], "date_created": "Wed, 20 May 2009 00:00:00 GMT", "description": "The Southern Ocean may play a central role in causing ice ages and general global climate change. This work will reveal key characteristics of the glacial ocean, and may explain the cause of glacial/interglacial cycles by measuring the abundances of certain isotopes of nitrogen found in fossil diatoms from Antarctic marine sediments. Diatom-bound N is a potentially important recorder of nutrient utilization. The Southern Ocean\u0027s nutrient status, productivity and circulation may be central to setting global atmospheric CO2 contents and other aspects of climate. Previous attempts to make these measurements have yielded ambiguous results. This project includes both technique development and analyses, including measurements on diatoms from both sediment traps and culture experiments. With regard to broader impacts, this grant is focused around the education and academic development of a graduate student, by coupling their research with mentorship of an undergraduate researcher", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sigman, Daniel", "platforms": "Not provided", "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -90.0, "title": "Application of a New Method for Isotopic Analysis of Diatom Microfossil-bound Nitrogen", "uid": "p0000550", "west": -180.0}, {"awards": "0230268 Anderson, Robert", "bounds_geometry": "POLYGON((-180 -50,-169 -50,-158 -50,-147 -50,-136 -50,-125 -50,-114 -50,-103 -50,-92 -50,-81 -50,-70 -50,-70 -51.5,-70 -53,-70 -54.5,-70 -56,-70 -57.5,-70 -59,-70 -60.5,-70 -62,-70 -63.5,-70 -65,-81 -65,-92 -65,-103 -65,-114 -65,-125 -65,-136 -65,-147 -65,-158 -65,-169 -65,180 -65,177 -65,174 -65,171 -65,168 -65,165 -65,162 -65,159 -65,156 -65,153 -65,150 -65,150 -63.5,150 -62,150 -60.5,150 -59,150 -57.5,150 -56,150 -54.5,150 -53,150 -51.5,150 -50,153 -50,156 -50,159 -50,162 -50,165 -50,168 -50,171 -50,174 -50,177 -50,-180 -50))", "dataset_titles": "Southern Ocean Deglacial Opal, Radionuclide, and Diatom Upwelling Data", "datasets": [{"dataset_uid": "000199", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Southern Ocean Deglacial Opal, Radionuclide, and Diatom Upwelling Data", "url": "https://www.ncdc.noaa.gov/paleo/study/8439"}], "date_created": "Mon, 12 Jan 2009 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the \"Silicic Acid Leakage Hypothesis\" as it relates to global carbon dioxide fluctuations during glacial-interglacial cycles.\u003cbr/\u003e\u003cbr/\u003eIntellectual Merit\u003cbr/\u003eThis project will evaluate the burial rate of biogenic opal in the Pacific sector of the Southern Ocean, both during the Last Glacial Maximum (LGM) and during the Holocene, as a critical test of the \"Silicic Acid Leakage Hypothesis\". \u003cbr/\u003e\u003cbr/\u003eThe \"Silicic Acid Leakage Hypothesis\" has been proposed recently to explain the glacial reduction in the carbon dioxide content of the atmosphere that has been reconstructed from Antarctic ice cores. Vast amounts of dissolved Si (silicic acid) are supplied to surface waters of the Southern Ocean by wind-driven upwelling of deep waters. Today, that dissolved Si is consumed almost quantitatively by diatoms who form skeletal structures composed of biogenic opal (a mineral form of silicon). According to the \"Silicic Acid Leakage Hypothesis\", environmental conditions in the Southern Ocean during glacial periods were unfavorable for diatom growth, leading to reduced (compared to interglacials) efficiency of dissolved Si utilization. Dissolved Si that was not consumed biologically in the glacial Southern ocean was then exported to the tropics in waters that sink in winter to depths of a few hundred meters along the northern fringes of the Antarctic Circumpolar Current, and return some decades later to the sunlit surface in tropical regions of wind-driven upwelling. \u003cbr/\u003e\u003cbr/\u003eAn increase in the amount of dissolved Si that \"leaks\" out of the Southern Ocean and later upwells at low latitudes could shift the global average composition of phytoplankton toward a greater abundance of diatoms and fewer CaCO3-secreting taxa (especially coccolithophorids). Consequences of such a taxonomic shift in the ocean\u0027s phytoplankton assemblage include:\u003cbr/\u003e a) an increase in the global average organic carbon/calcium carbonate ratio of particulate biogenic material sinking into the deep sea;\u003cbr/\u003e b) a reduction in the preservation and burial of calcium carbonate in marine sediments;\u003cbr/\u003e c) an increase in ocean alkalinity as a consequence of the first two changes mentioned above, and;\u003cbr/\u003e d) a lowering of atmospheric CO2 concentrations in response to increased alkalinity of ocean waters. \u003cbr/\u003e\u003cbr/\u003eA complete assessment of the Silicic acid leakage hypothesis will require an evaluation of: (1) Si utilization efficiencies using newly-developed stable isotopic techniques; (2) opal burial rates in low-latitude upwelling regions; and (3) opal burial rates in the Southern Ocean. This project addresses the last of these topics. \u003cbr/\u003e\u003cbr/\u003ePrevious work has shown that there was little change in opal burial rate between the LGM and the Holocene in the Atlantic and Indian sectors of the Southern Ocean. Preliminary results (summarized in this proposal) suggest that the Pacific may have been different, however, in that opal burial rates in the Pacific sector seem to have been lower during the LGM than during the Holocene, allowing for the possibility of \"Si leakage\" from this region. However, available results are too sparse to make any quantitative conclusions at this time. For that reason, we propose to make a comprehensive evaluation of opal burial rates in the Pacific sector of the Southern Ocean. \u003cbr/\u003e\u003cbr/\u003eSignificance and Broader Impacts\u003cbr/\u003eDetermining the mechanism(s) by which the ocean has regulated climate-related changes in the CO2 content of the atmosphere has been the focus of a substantial effort by paleoceanographers over the past two decades. The Silicic Acid Leakage Hypothesis is a viable new candidate mechanism that warrants further exploration and testing. Completion of the proposed work will contribute significantly to that effort. \u003cbr/\u003e\u003cbr/\u003eDuring the course of this work, several undergraduates will be exposed to paleoclimate research through their involvement in this project. Burckle and Anderson are both dedicated to the education and training of young scientists, and to the recruitment of women and under-represented minorities. To illustrate, two summer students (undergraduates) worked in Burckle\u0027s lab during the summer of 2002. One was a woman and the other (male) was a member of an under-represented minority. Anderson and Burckle will continue with similar recruitment efforts during the course of the proposed study. A minority student who has expressed an interest in working on this research during the summer of 2003 has already been identified.", "east": -70.0, "geometry": "POINT(-140 -57.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -50.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, Robert; Burckle, Lloyd", "platforms": "Not provided", "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -65.0, "title": "Opal Burial in the Pacific Sector of the Southern Ocean: A Test of the \"Silicic Acid Leakage Hypothesis.\"", "uid": "p0000457", "west": 150.0}, {"awards": "9526556 Sowers, Todd", "bounds_geometry": "POINT(-148.3023 -81.403)", "dataset_titles": "Carbon-13 Isotopic Composition of Atmospheric Methane in Firn Air, South Pole and Siple Dome, Antarctica", "datasets": [{"dataset_uid": "609310", "doi": "10.7265/N5ST7MR2", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Siple Dome; Snow/ice; Snow/Ice; South Pole", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Carbon-13 Isotopic Composition of Atmospheric Methane in Firn Air, South Pole and Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609310"}], "date_created": "Mon, 09 Jul 2007 00:00:00 GMT", "description": "This award is for support for a program to reconstruct records of the isotopic composition of paleoatmospheric methane and nitrous oxide covering the last 200,000 years. High resolution measurements of the carbon-13 isotopic composition of methane from shallow ice cores will help to determine the relative contributions of biogenic (wetlands, rice fields and ruminants) and abiogenic (biomass burning and natural gas) methane emissions which have caused the concentrations of this gas to increase at an exponential rate during the anthropogenic period. Isotopic data on methane and nitrous oxide over glacial/interglacial timescales will help determine the underlying cause of the large concentration variations that are known to occur. This project will make use of a new generation mass spectrometer which is capable of generating precise isotopic information on nanomolar quantities of methane and nitrous oxide, which means that samples can be 1000 times smaller than those needed for a standard isotope ratio instrument. The primary objective of the work is to further our understanding of the biogeochemical cycles of these two greenhouse gases throughout the anthropogenic period as well as over glacial interglacial timescales.", "east": -148.3023, "geometry": "POINT(-148.3023 -81.403)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Ice Core; Firn Air Isotope Measurements; Ice Core Chemistry; Firn Isotopes; Stable Isotopes; Methane; Carbon; Paleoclimate; LABORATORY; Siple Dome; Antarctica; Ice Core Data; Firn Air Isotopes; Antarctic Ice Sheet", "locations": "Antarctica; Antarctic Ice Sheet; Siple Dome", "north": -81.403, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Sowers, Todd A.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.403, "title": "Constructing Paleoatmospheric Records of the Isotopic Composition of Methane and Nitrous Oxide", "uid": "p0000611", "west": -148.3023}, {"awards": "9615333 Saltzman, Eric", "bounds_geometry": "POINT(-148.8 -81.7)", "dataset_titles": "Biogenic Sulfur in the Siple Dome Ice Core", "datasets": [{"dataset_uid": "609201", "doi": "10.7265/N5S180F1", "keywords": "Antarctica; Biota; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Finley, Brandon; Dioumaeva, Irina; Saltzman, Eric", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Biogenic Sulfur in the Siple Dome Ice Core", "url": "https://www.usap-dc.org/view/dataset/609201"}], "date_created": "Tue, 09 Mar 2004 00:00:00 GMT", "description": "This award is for support for four years of funding for a program of biogenic sulfur measurements on the Siple Dome ice core. Biogenic sulfur is a major aerosol-forming constituent of the atmosphere and has potentially important links to the earth\u0027s radiation budget. Previous work on the Vostok ice core has demonstrated a remarkable climate-related variability in biogenic sulfur, suggesting that the sulfur cycle may act to stabilize climate (keep the glacial atmosphere cool and the interglacial atmosphere warm) in the Southern Hemisphere. In this study, methane-sulfonate (MSA) will be measured on the Siple Dome ice core as part of the West Antarctic ice sheet program (WAIS). Siple Dome is located in a region which is strongly impacted by the incursion of marine air onto the Antarctic plateau. Because of its proximity to the coast and meteorological setting, it is expected that variability in high-latitude marine biogenic sulfur emissions should dominate the MSA record at this site. In addition to the deep ice core record, samples from shallow cores will also be analyzed to provide information about regional variability and decadal-to-centennial scale variability in the deposition of sulfur-containing aerosols from high latitude source regions over the past 200 years.", "east": -148.8, "geometry": "POINT(-148.8 -81.7)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Siple Dome; GROUND-BASED OBSERVATIONS; Biogenic Sulfur; FIELD INVESTIGATION; Not provided; LABORATORY; Methane Sulfonate", "locations": "Siple Dome", "north": -81.7, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Saltzman, Eric; Dioumaeva, Irina; Finley, Brandon", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.7, "title": "Biogenic Sulfur in the Siple Dome Ice Core", "uid": "p0000251", "west": -148.8}]

View results on map Help on results map