{"dp_type": "Project", "free_text": "stratigraphic"}
[{"awards": "1939139 Scherer, Reed; 1939146 Siddoway, Christine", "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": "Pliocene diatom abundance, IODP 379-U1532; Population morphometrics of the Southern Ocean diatom Fragilariopsis kerguelensis related to Sea Surface Temperature; U-Pb zircon and apatite fission track dates for IRD (ice-rafted cobbles and mineral grains) from IODP379 drill sites", "datasets": [{"dataset_uid": "601769", "doi": null, "keywords": "Antarctica; Biogenic Silica; Diatom", "people": "Furlong, Heather; Scherer, Reed Paul", "repository": "USAP-DC", "science_program": null, "title": "Pliocene diatom abundance, IODP 379-U1532", "url": "https://www.usap-dc.org/view/dataset/601769"}, {"dataset_uid": "601828", "doi": "10.15784/601828", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Geochronology; Marie Byrd Land; Subglacial Bedrock; Thermochronology", "people": "Siddoway, Christine", "repository": "USAP-DC", "science_program": null, "title": "U-Pb zircon and apatite fission track dates for IRD (ice-rafted cobbles and mineral grains) from IODP379 drill sites", "url": "https://www.usap-dc.org/view/dataset/601828"}, {"dataset_uid": "601804", "doi": "10.15784/601804", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Oceanography; Sabrina Coast; Sea Surface Temperature; Southern Ocean", "people": "Ruggiero, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Population morphometrics of the Southern Ocean diatom Fragilariopsis kerguelensis related to Sea Surface Temperature", "url": "https://www.usap-dc.org/view/dataset/601804"}], "date_created": "Tue, 20 Feb 2024 00:00:00 GMT", "description": "Part I, Non-technical Abstract Concerns 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. Part 2, Technical Abstract New 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. This 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; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE", "persons": "Scherer, Reed Paul; Siddoway, Christine", "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": "2302832 Reilly, Brendan", "bounds_geometry": "POLYGON((-70 -55,-67 -55,-64 -55,-61 -55,-58 -55,-55 -55,-52 -55,-49 -55,-46 -55,-43 -55,-40 -55,-40 -56.1,-40 -57.2,-40 -58.3,-40 -59.4,-40 -60.5,-40 -61.6,-40 -62.7,-40 -63.8,-40 -64.9,-40 -66,-43 -66,-46 -66,-49 -66,-52 -66,-55 -66,-58 -66,-61 -66,-64 -66,-67 -66,-70 -66,-70 -64.9,-70 -63.8,-70 -62.7,-70 -61.6,-70 -60.5,-70 -59.4,-70 -58.3,-70 -57.2,-70 -56.1,-70 -55))", "dataset_titles": "NRM, ARM, IRM, and magnetic susceptibility investigations on U1537 and U1538 cube samples; Rock magnetic data from IODP Exp. 382 Sites U1537 and U1538 to support Reilly et al. \"A geochemical mechanism for \u003e10 m offsets of magnetic reversals inferred from the comparison of two Scotia Sea drill sites\"", "datasets": [{"dataset_uid": "200412", "doi": "10.7288/V4/MAGIC/19778", "keywords": null, "people": null, "repository": "MagIC (EarthRef)", "science_program": null, "title": "NRM, ARM, IRM, and magnetic susceptibility investigations on U1537 and U1538 cube samples", "url": "http://dx.doi.org/10.7288/V4/MAGIC/19778"}, {"dataset_uid": "200411", "doi": "10.5281/zenodo.10035106", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Rock magnetic data from IODP Exp. 382 Sites U1537 and U1538 to support Reilly et al. \"A geochemical mechanism for \u003e10 m offsets of magnetic reversals inferred from the comparison of two Scotia Sea drill sites\"", "url": "https://zenodo.org/records/10035107"}], "date_created": "Wed, 12 Jul 2023 00:00:00 GMT", "description": "The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica\u2019s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica\u2019s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth\u0027s most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica\u2019s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. This 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": -40.0, "geometry": "POINT(-55 -60.5)", "instruments": null, "is_usap_dc": true, "keywords": "PALEOMAGNETISM; SEDIMENTS; Scotia Sea", "locations": "Scotia Sea", "north": -55.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE; PHANEROZOIC \u003e CENOZOIC", "persons": "Reilly, Brendan", "platforms": null, "repo": "MagIC (EarthRef)", "repositories": "MagIC (EarthRef); Zenodo", "science_programs": null, "south": -66.0, "title": "Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation", "uid": "p0010424", "west": -70.0}, {"awards": "2228257 Michaud, Alexander", "bounds_geometry": "POINT(-112.05 -79.28)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 31 May 2023 00:00:00 GMT", "description": "Ice cores from glaciers and ice sheets provide detailed archives of past environmental conditions, furthering our understanding of Earth\u2019s climate. Microorganisms in the West Antarctic Ice Sheet are buried over glaciological time and form a stratigraphy record providing the opportunity of analysis of the order and position of layers of geological events, with potential links to Southern Hemisphere climate. However, microbial cells that land on the ice sheet are subject to the stresses of changing habitat conditions due to burial and conditions associated with long-term isolation in ice. These processes may lead to a loss of fidelity within the stratigraphic record of microbial cells. We know little about how and if microorganisms survive burial and remain alive over glacial-interglacial time periods within an ice sheet. This analysis will identify the viable and preserved community of microorganisms and core genomic adaptation that permit cell viability, which will advance knowledge in the areas of microbiology and glaciology while increasing fidelity of ice core measurements relevant to past climate and potential future global climate impacts. This exploratory endeavor has the potential to be a transformative step toward understanding the ecology of one of the most understudied environments on Earth. The project will partner with the Museum of Science, Boston, to increase public scientific literacy via education and outreach. Additionally, this project will support two early-career scientists and two undergraduates in interdisciplinary research at the intersection of microbiology and climate science. Results from this project will provide the first DNA data based on single-cell whole genomic sequencing from the Antarctic Ice Sheet and inform whether post-depositional processes impact the interpretations of paleoenvironmental conditions from microbes. The goals to determine the taxonomic identity of viable and preserved microbial cells, and decode the genetic repertoire that confers survival of burial and long-term viability within glacial ice, will be achieved by utilizing subsamples from a ~60,000 year old record of the West Antarctic Ice Sheet Divide (WD) Ice Core. WD samples will be melted using the Desert Research Institute\u2019s ice core melting system that is optimized for glaciobiological sampling. Microbial cells from the meltwater will be sorted using fluorescence-activated cell sorting, and individually sorted cells will have their genomes sequenced. The fluorescence-based methods will discern the viable (metabolically active) cells from those cells that are non-viable but preserved in the ice (DNA-containing). The genomic analysis will identify the taxonomy of each cell, presence of known genes that confer survival in permanently frozen environments, and comparatively analyze genomes to determine the core set of genes required by viable cells to persist in an ice sheet. The outcomes of this work will expand the potential for biological measurements and contamination control from archived ice cores. This 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": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": null, "is_usap_dc": true, "keywords": "WAIS Divide; TERRESTRIAL ECOSYSTEMS; ICE SHEETS; BACTERIA/ARCHAEA; ICE CORE RECORDS", "locations": "WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Michaud, Alexander; Winski, Dominic A.", "platforms": null, "repositories": null, "science_programs": null, "south": -79.28, "title": "EAGER: ANT LIA: Persist or Perish: Records of Microbial Survival and Long-term Persistence from the West Antarctic Ice Sheet", "uid": "p0010421", "west": -112.05}, {"awards": "2026648 Tobin, Thomas; 2025724 Harwood, David; 2020728 Huber, Brian", "bounds_geometry": "POLYGON((-56.93 -64.2,-56.894 -64.2,-56.858 -64.2,-56.822 -64.2,-56.786 -64.2,-56.75 -64.2,-56.714 -64.2,-56.678 -64.2,-56.642 -64.2,-56.606 -64.2,-56.57 -64.2,-56.57 -64.214,-56.57 -64.22800000000001,-56.57 -64.242,-56.57 -64.256,-56.57 -64.27000000000001,-56.57 -64.284,-56.57 -64.298,-56.57 -64.312,-56.57 -64.32600000000001,-56.57 -64.34,-56.606 -64.34,-56.642 -64.34,-56.678 -64.34,-56.714 -64.34,-56.75 -64.34,-56.786 -64.34,-56.822 -64.34,-56.858 -64.34,-56.894 -64.34,-56.93 -64.34,-56.93 -64.32600000000001,-56.93 -64.312,-56.93 -64.298,-56.93 -64.284,-56.93 -64.27000000000001,-56.93 -64.256,-56.93 -64.242,-56.93 -64.22800000000001,-56.93 -64.214,-56.93 -64.2))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 15 Sep 2022 00:00:00 GMT", "description": "Non-technical description: This 4-year project is evaluating evidence of extinction patterns and depositional conditions from a high southern latitude Cretaceous-Paleogene (K-Pg) outcrop section found on Seymore Island, in the Western Antarctic Peninsula. The team is using sediment samples collected below the weathering horizon to evaluate detailed sedimentary structures, geochemistry, and microfossils in targeted stratigraphic intervals. The study will help determine if the K-Pg mass extinction was a single or double phased event and whether Seymour Island region in the geological past was a restricted, suboxic marine environment or an open well-mixed shelf. The award includes an integrated plan for student training at all levels, enhanced by a highlighted partnership with a high school earth sciences teacher working in a school serving underrepresented students. Technical description: The proposed research is applying multiple techniques to address an overarching research question for which recent studies are in disagreement: Is the fossil evidence from a unique outcropping on Seymour Island, Antarctica consistent with a single or double phased extinction? In a two-phased model, the first extinction would affect primarily benthic organisms and would have occurred ~150 kiloyears prior to a separate extinction at the K-Pg boundary. However, this early extinction could plausibly be explained by an unrecognized facies control that is obscured by surficial weathering. This team is using microfossil evidence with detailed sedimentary petrology and geochemistry data to evaluate if the fossil evidence from Seymour Island is consistent with a single or double phased extinction process. The team is using detailed sedimentary petrology and geochemistry methods to test for facies changes across the K-PG interval that would explain the apparent early extinction. Samples of core sedimentary foraminifera, siliceous microfossils, and calcareous nannofossils are being evaluated to provide a high-resolution stratigraphic resolution and to evaluate whether evidence for an early extinction is present. Additionally, the team is using multiple geochemical methods to evaluate whether there is evidence for intermittent anoxia or euxinia and/or physical restriction of the Seymore region basin. Data from this analysis will indicate if this region was a restricted, suboxic marine environment or an open well-mixed shelf. This 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": -56.57, "geometry": "POINT(-56.75 -64.27000000000001)", "instruments": null, "is_usap_dc": true, "keywords": "Seymour Island; PALEOCLIMATE RECONSTRUCTIONS; SEDIMENTARY ROCKS; MICROFOSSILS; FIELD INVESTIGATION", "locations": "Seymour Island", "north": -64.2, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Tobin, Thomas; Totten, Rebecca", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -64.34, "title": "Collaborative Research: Coring Seymour Island (CSI) Antarctica: Evaluating Causes and Effects of the End Cretaceous Mass Extinction", "uid": "p0010377", "west": -56.93}, {"awards": "1543367 Shubin, Neil", "bounds_geometry": "POLYGON((158.3 -77.5,158.54000000000002 -77.5,158.78 -77.5,159.02 -77.5,159.26 -77.5,159.5 -77.5,159.74 -77.5,159.98 -77.5,160.22 -77.5,160.45999999999998 -77.5,160.7 -77.5,160.7 -77.605,160.7 -77.71,160.7 -77.815,160.7 -77.92,160.7 -78.025,160.7 -78.13,160.7 -78.235,160.7 -78.34,160.7 -78.445,160.7 -78.55,160.45999999999998 -78.55,160.22 -78.55,159.98 -78.55,159.74 -78.55,159.5 -78.55,159.26 -78.55,159.02 -78.55,158.78 -78.55,158.54000000000002 -78.55,158.3 -78.55,158.3 -78.445,158.3 -78.34,158.3 -78.235,158.3 -78.13,158.3 -78.025,158.3 -77.92,158.3 -77.815,158.3 -77.71,158.3 -77.605,158.3 -77.5))", "dataset_titles": "Vertebrate Fossils from the Aztec Siltstone (Mid-Late Devonian); Vertebrate Fossils from the Aztec Siltstone (Mid-Late Devonian) 2 (2018-2019)", "datasets": [{"dataset_uid": "601580", "doi": "10.15784/601580", "keywords": "Acanthodii; Antarctica; Chondrichthyes; Early Vertebrates; Osteolepiformes; Paleontology; Placodermi; Transantarctic Mountains; Vertebrate Evolution", "people": "Daeschler, Ted", "repository": "USAP-DC", "science_program": null, "title": "Vertebrate Fossils from the Aztec Siltstone (Mid-Late Devonian)", "url": "https://www.usap-dc.org/view/dataset/601580"}, {"dataset_uid": "601584", "doi": "10.15784/601584", "keywords": "Acanthodii; Antarctica; Chondrichthyes; Early Vertebrates; Osteolepiformes; Paleontology; Placodermi; Transantarctic Mountains; Vertebrate Evolution", "people": "Daeschler, Ted", "repository": "USAP-DC", "science_program": null, "title": "Vertebrate Fossils from the Aztec Siltstone (Mid-Late Devonian) 2 (2018-2019)", "url": "https://www.usap-dc.org/view/dataset/601584"}], "date_created": "Fri, 17 Jun 2022 00:00:00 GMT", "description": "This research will provide new insights into the relationships and history of sharks, fish and limbed animals. Understanding these relationships forms the backbone for both basic and applied science because fish often serve as models of human traits and diseases. Some of the main lines of evidence for these relationships come from fossils in rocks over 380 million years old that were originally deposited as ancient rivers and streams. Because rocks of this type and age are abundantly exposed along a number of the dry valleys and mountains of Antarctica, the investigation of these areas holds exceptional promise for discoveries that can have a broad impact. The fieldwork will involve geological mapping and assessment of the rocks with detailed reconnaissance for the fossils that they may hold. Fossil discoveries form the backbone for public communication of the methods and results of scientific research-- these studies will be used as vehicles for training of students at multiple levels as well as communication of science to the broader non-science citizen base. The discovery, description, and analysis of Middle to Late Devonian (390-355 Million years ago) vertebrates and depositional environments provide important data on the emergence of novel anatomical structures, faunas, and habitats during a critical interval in the history of life and earth. Biological innovation during this time includes the early evolution of freshwater fish, the origins of major groups of vertebrates (e.g., sharks, lobe and ray-finned fish, tetrapods), and the expansion and elaboration of non-marine ecosystems. Accordingly, expanding our knowledge of vertebrate diversity during the Middle and Late Devonian will provide new evidence on the relationships of the major groups of vertebrates, the assembly of novelties that ultimately enabled tetrapods to invade land, the origin and early evolution of sharks and their relatives, and the assembly and expansion of non-marine ecosystems generally. The Aztec Siltstone of Antarctica Middle-Late Devonian; Givetian-Frasnian Stages) has exceptional potential to produce new paleontological evidence of these events and to illuminate the temporal, ecological, and geographic context in which they occurred. It is essentially fossiliferous throughout its known exposure range, something that is rare for Middle-Late Devonian non-marine rocks anywhere in the world. In addition, fine-grained meandering stream deposits are abundantly exposed in the Aztec Siltstone and are recognized as an important locus for the discovery of well-preserved Devonian fish, including stem tetrapods and their relatives. Given the exceedingly fossiliferous nature of the Aztec Siltstone, the large number of taxa known only from partial material, and the amount of promising exposure yet to be worked, a dedicated reconnaissance, collection, and research effort is designed to recover important new fossil material and embed it in a stratigraphic and sedimentological context. The first major objective of this study is the recovery, preparation, and description of Middle-Late Devonian fossil taxa. Ensuing investigation of the phylogenetic affinities, taphonomic occurrence, and stratigraphic position of fossil assemblages will allow both local and global comparisons of biotic diversity. These analyses will inform: 1) higher level phylogenetic hypotheses of jawed vertebrates, 2) biostratigraphic and biogeographic analysis of the distribution of the Middle-Late Devonian fish, and 3) paleobiological investigation of the elaboration of terrestrial and freshwater habitats. The broader impacts are derived from the utility of paleontology and Antarctic expeditionary science as educational tools with powerful narratives. Specific goals include affiliations with local urban secondary schools (using established relationships for broadening participation) and collegiate and graduate training. Wider dissemination of knowledge to the general public is a direct product of ongoing interactions with national and international media (print, television, internet).", "east": 160.7, "geometry": "POINT(159.5 -78.025)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; FIELD INVESTIGATION; Transantarctic Mountains; USA/NSF; MACROFOSSILS; Fossils; USAP-DC", "locations": "Transantarctic Mountains", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e PALEOZOIC \u003e DEVONIAN", "persons": "Shubin, Neil; Daeschler, Edward B", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.55, "title": "Middle-Late Devonian Vertebrates of Antarctica", "uid": "p0010340", "west": 158.3}, {"awards": "2019719 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": "2019-2020 Allan Hills Field Report; 2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report; 2023-2024 Allan Hills End-of-Season Science Report; Airborne Radar Data: 2022-23 (CXA1) flight based HDF5/matlab format data; Airborne Radar Data: 2022-23 (CXA1) transect based (science organized) unfocused data; Airborne Radar Data: 2023-24 (CXA2) flight based data HDF5/matlab format; Airborne Radar Data: 2023-24 (CXA2) transect based (science organized) unfocused data; ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations; Allan Hills 2022-23 Shallow Ice Core Field Report; Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022; Allan Hills I-188 Field Season Report 2022-2023; Allan Hills ice water stable isotope record for dD, d18O; Basal Ice Unit Thickness Mapped by the NSF COLDEX MARFA Ice Penetrating Radar; CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903; COLDEX VHF MARFA Open Polar Radar radargrams; Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area; Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903; I-165-M GPR Field Report 2019-2020; MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903; NSF COLDEX 2022-23 Level 2 Basal Specularity Content Profiles; NSF COLDEX 2022-23 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets; NSF COLDEX 2023-24 Level 2 Basal Specularity Content Profiles; NSF COLDEX 2023-24 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets; NSF COLDEX Ice Penetrating Radar Derived Grids of the Southern Flank of Dome C; NSF COLDEX/Open Polar Radar Example Delay Doppler Classification of Englacial Reflectors; NSF COLDEX Raw MARFA Ice Penetrating Radar data; Oxygen and hydrogen isotope compositions and associated d-excess 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; Replicate O-17-excess by continuous flow laser spectroscopy for an ice core section at Summit, Greenland; Rising Seas: Representations of Antarctica, Climate Change, and Sea Level Rise in U.S. Newspaper Coverage; Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old; Social network analysis to understand participant engagement in transdisciplinary team science: a large U.S. science and technology center case study; Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "datasets": [{"dataset_uid": "200435", "doi": "10.18738/T8/PNBFOL", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2023-24 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets", "url": "https://doi.org/10.18738/T8/PNBFOL"}, {"dataset_uid": "601768", "doi": "10.15784/601768", "keywords": "Antarctica; Coldex; East Antarctic Plateau; Glaciology; Radar Echo Sounder", "people": "Kempf, Scott D.; Ng, Gregory; Buhl, Dillon; Kerr, Megan; Greenbaum, Jamin; Blankenship, Donald D.; Young, Duncan A.; Chan, Kristian", "repository": "USAP-DC", "science_program": "COLDEX", "title": "NSF COLDEX Raw MARFA Ice Penetrating Radar data", "url": "https://www.usap-dc.org/view/dataset/601768"}, {"dataset_uid": "200419", "doi": "", "keywords": null, "people": null, "repository": "University Digital Conservancy", "science_program": null, "title": "Rising Seas: Representations of Antarctica, Climate Change, and Sea Level Rise in U.S. Newspaper Coverage", "url": "https://hdl.handle.net/11299/265195"}, {"dataset_uid": "200420", "doi": "10.18738/T8/J38CO5", "keywords": null, "people": null, "repository": "OPR", "science_program": null, "title": "Airborne Radar Data: 2022-23 (CXA1) flight based HDF5/matlab format data", "url": "https://data.cresis.ku.edu/data/rds/2022_Antarctica_BaslerMKB/"}, {"dataset_uid": "200421", "doi": "10.18738/T8/J38CO5", "keywords": null, "people": null, "repository": "OPR", "science_program": null, "title": "Airborne Radar Data: 2023-24 (CXA2) flight based data HDF5/matlab format", "url": "https://data.cresis.ku.edu/data/rds/2023_Antarctica_BaslerMKB/"}, {"dataset_uid": "200470", "doi": "doi:10.15784/601822", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "Oxygen and hydrogen isotope compositions and associated d-excess of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601822"}, {"dataset_uid": "200469", "doi": "https://doi.org/10.15784/601821", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "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/601821"}, {"dataset_uid": "200468", "doi": "https://doi.org/10.15784/601820", "keywords": null, "people": null, "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/601820"}, {"dataset_uid": "601819", "doi": "10.15784/601819", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Kuhl, Tanner; Morton, Elizabeth; Zajicek, Anna; Nesbitt, Ian; Carter, Austin; Morgan, Jacob; Shackleton, Sarah; Higgins, John; Epifanio, Jenna", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2019-2020 Allan Hills Field Report", "url": "https://www.usap-dc.org/view/dataset/601819"}, {"dataset_uid": "601824", "doi": "10.15784/601824", "keywords": "Allan Hills; Antarctica; Coldex; Cryosphere", "people": "Brook, Edward J.; Epifanio, Jenna; Mayo, Emalia; Goverman, Ashley; Jayred, Michael; Morton, Elizabeth; Banerjee, Asmita; Hudak, Abigail; Manos, John-Morgan; Carter, Austin; Shackleton, Sarah; Higgins, John; Marks Peterson, Julia", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2023-2024 Allan Hills End-of-Season Science Report", "url": "https://www.usap-dc.org/view/dataset/601824"}, {"dataset_uid": "601826", "doi": "10.15784/601826", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Shaya, Margot; Manos, John-Morgan; Horlings, Annika; Epifanio, Jenna; Conway, Howard", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills I-188 Field Season Report 2022-2023", "url": "https://www.usap-dc.org/view/dataset/601826"}, {"dataset_uid": "601697", "doi": "10.15784/601697", "keywords": "Allan Hills; Antarctica; Apres; Ice Core; Ice Penetrating Radar; Temperature Profiles", "people": "Conway, Howard; Brook, Edward J.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report", "url": "https://www.usap-dc.org/view/dataset/601697"}, {"dataset_uid": "601696", "doi": "10.15784/601696", "keywords": "Allan Hills; Antarctica; Ice Core", "people": "Brook, Edward J.; Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills 2022-23 Shallow Ice Core Field Report", "url": "https://www.usap-dc.org/view/dataset/601696"}, {"dataset_uid": "200467", "doi": "doi:10.15784/601825", "keywords": null, "people": null, "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/601825"}, {"dataset_uid": "200465", "doi": "10.18738/T8/DM10IG", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "COLDEX VHF MARFA Open Polar Radar radargrams", "url": "https://doi.org/10.18738/T8/DM10IG"}, {"dataset_uid": "200464", "doi": "10.18738/T8/DM10IG", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX/Open Polar Radar Example Delay Doppler Classification of Englacial Reflectors", "url": "https://doi.org/10.18738/T8/DM10IG"}, {"dataset_uid": "200463", "doi": "10.18738/T8/M77ANK", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX Ice Penetrating Radar Derived Grids of the Southern Flank of Dome C", "url": "https://doi.org/10.18738/T8/M77ANK"}, {"dataset_uid": "200462", "doi": "10.18738/T8/KHUT1U", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2023-24 Level 2 Basal Specularity Content Profiles", "url": "https://doi.org/10.18738/T8/KHUT1U"}, {"dataset_uid": "200461", "doi": "10.18738/T8/6T5JS6", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2022-23 Level 2 Basal Specularity Content Profiles", "url": "https://doi.org/10.18738/T8/6T5JS6"}, {"dataset_uid": "601669", "doi": "10.15784/601669", "keywords": "Allan Hills; Antarctica; GPR; Ice Core; Report", "people": "Nesbitt, Ian; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "I-165-M GPR Field Report 2019-2020", "url": "https://www.usap-dc.org/view/dataset/601669"}, {"dataset_uid": "601854", "doi": "10.15784/601854", "keywords": "Allan Hills; Antarctica; Cryosphere", "people": "Kirkpatrick, Liam; Carter, Austin; Marks Peterson, Julia; Shackleton, Sarah; Fudge, T. J.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "ALHIC2201 and ALHIC2302 3D ECM and Layer Orientations", "url": "https://www.usap-dc.org/view/dataset/601854"}, {"dataset_uid": "601659", "doi": "10.15784/601659", "keywords": "Antarctica; Continuous Flow; Glaciology; Greenland; Ice Core Data; Laser Spectroscopy; Oxygen Isotope; Triple Oxygen Isotopes", "people": "Davidge, Lindsey", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Replicate O-17-excess by continuous flow laser spectroscopy for an ice core section at Summit, Greenland", "url": "https://www.usap-dc.org/view/dataset/601659"}, {"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Mayewski, Paul A.; Introne, Douglas; Severinghaus, Jeffrey P.; Kurbatov, Andrei V.; Higgins, John; Brook, Edward", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Higgins, John; Introne, Douglas; Brook, Edward; Mayewski, Paul A.; Severinghaus, Jeffrey P.; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"dataset_uid": "200433", "doi": "10.18738/T8/FV6VNT", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "Airborne Radar Data: 2023-24 (CXA2) transect based (science organized) unfocused data", "url": "https://dataverse.tdl.org/dataset.xhtml?persistentId=doi:10.18738/T8/FV6VNT"}, {"dataset_uid": "200434", "doi": "10.18738/T8/99IEOG", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "NSF COLDEX 2022-23 Riegl Laser Altimeter Level 2 Geolocated Surface Elevation Triplets", "url": "https://doi.org/10.18738/T8/99IEOG"}, {"dataset_uid": "601620", "doi": "10.15784/601620", "keywords": "18O; Allan Hills; Allan Hills Blue Ice; Antarctica; Blue Ice; Delta 15N; Delta 18O; Dole Effect; Firn Thickness; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chronology; Ice Core Records", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022", "url": "https://www.usap-dc.org/view/dataset/601620"}, {"dataset_uid": "601878", "doi": "10.15784/601878", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Cryosphere; Methane", "people": "Shackleton, Sarah; Severinghaus, Jeffrey P.; Hishamunda, Valens; Kalk, Michael; Brook, Edward; Marks Peterson, Julia", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old", "url": "https://www.usap-dc.org/view/dataset/601878"}, {"dataset_uid": "200432", "doi": "10.18738/T8/XPMLCC", "keywords": null, "people": null, "repository": "Texas Data Repository", "science_program": null, "title": "Airborne Radar Data: 2022-23 (CXA1) transect based (science organized) unfocused data", "url": "https://dataverse.tdl.org/dataset.xhtml?persistentId=doi:10.18738/T8/XPMLCC"}, {"dataset_uid": "200452", "doi": "https://hdl.handle.net/11299/270020", "keywords": null, "people": null, "repository": "UMN University Digital Conservancy", "science_program": null, "title": "Social network analysis to understand participant engagement in transdisciplinary team science: a large U.S. science and technology center case study", "url": "https://hdl.handle.net/11299/270020"}, {"dataset_uid": "601895", "doi": "10.15784/601895", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Noble Gas", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601895"}, {"dataset_uid": "601896", "doi": "10.15784/601896", "keywords": "Allan Hills; Antarctica; Ch4; CO2; Cryosphere; Glaciology; Glaciology; Ice Core Data; Ice Core Records", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601896"}, {"dataset_uid": "601897", "doi": "10.15784/601897", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciology; Ice Core Data; MOT; Ocean Temperature; Paleoclimate; Xe/Kr", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601897"}, {"dataset_uid": "601912", "doi": "10.15784/601912", "keywords": "Antarctica; Coldex; Cryosphere; East Antarctica; East Antarctic Plateau; Glaciology; Radar Echo Sounder", "people": "Vega Gonzalez, Alejandra; Kerr, Megan; Young, Duncan A.; Yan, Shuai; Blankenship, Donald D.; Singh, Shivangini", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Basal Ice Unit Thickness Mapped by the NSF COLDEX MARFA Ice Penetrating Radar", "url": "https://www.usap-dc.org/view/dataset/601912"}], "date_created": "Sat, 21 May 2022 00:00:00 GMT", "description": "Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth\u2019s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth\u2019s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community. Knowledge of Earth\u2019s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth\u2019s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture. This 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": "USA/NSF; AMD; Antarctica; Amd/Us; Coldex; USAP-DC; FIELD SURVEYS; ICE DEPTH/THICKNESS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Polar Special Initiatives", "paleo_time": null, "persons": "Brook, Edward J.; Neff, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "Texas Data Repository", "repositories": "OPR; Texas Data Repository; UMN University Digital Conservancy; University Digital Conservancy; USAP-DC", "science_programs": "COLDEX", "south": -90.0, "title": "Center for Oldest Ice Exploration", "uid": "p0010321", "west": -180.0}, {"awards": "1543361 Kurbatov, Andrei; 1543454 Dunbar, Nelia", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "Cryptotephra in SPC-14 ice core; SPICEcore visable tephra", "datasets": [{"dataset_uid": "601667", "doi": "10.15784/601667", "keywords": "Antarctica; Electron Microprobe; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; South Pole; Tephra", "people": "Iverson, Nels", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore visable tephra", "url": "https://www.usap-dc.org/view/dataset/601667"}, {"dataset_uid": "601666", "doi": "10.15784/601666", "keywords": "Antarctica; Cryptotephra; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; South Pole; SPICEcore; Tephra", "people": "Yates, Martin; Helmick, Meredith; Hartman, Laura; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Cryptotephra in SPC-14 ice core", "url": "https://www.usap-dc.org/view/dataset/601666"}], "date_created": "Fri, 01 Apr 2022 00:00:00 GMT", "description": "Dunbar/1543454 Antarctic ice cores offer unparalleled records of earth?s climate back to almost one million years and perhaps beyond. Layers of volcanic ash (tephra) embedded in glacial ice can be used to establish an accurate ice core chronology. In order to use a visible or ultrafine volcanic ash layer as a time-stratigraphic marker, a unique geochemical fingerprint must be established, and this forms the basis of our research. This award will investigate the volcanic record in the 1751 m ice core that was completed at the South Pole during the 2015/16 field season. The core is in an ideal location to link the existing, established, volcanic records in East and West Antarctica, and therefore to connect and integrate those records, allowing the climate records of ice cores to be directly compared, as well as to focus research on the most widespread and significant volcanic eruptions from West Antarctica. Tephra derived from well-dated, large, tropical volcanic eruptions that may have had an impact on climate will also be studied. Recent success in identifying and analyzing very fine ash particles from these types of eruptions makes it likely that we will be able to pinpoint some of these eruptions, which will allow the sulfate peaks associated with these layers to be positively identified and dated. Volcanic forcing time series developed from earlier South Pole ice cores based on preserved sulfate were crucial for testing climate models, but without tephra analysis, the origin of these layers remains uncertain. Work on the tephra layers in the South Pole ice core has a number of significant specific objectives, some with practical applications to the basic science goals of Antarctic ice coring, and others that represent independent scientific contributions in their own right. These include: (1) providing independently dated time-intervals in the core, particularly for the deepest ice, (2) quantitatively linking tephra records across Antarctica with the goal of allowing direct and robust climate comparisons between these different parts of the continent, (3) providing information for large local eruptions, that will lead to direct estimates of eruption magnitude and dispersal patterns of Antarctic volcanoes, several of which will likely erupt again. The initial stages of the work will be carried out by identifying silicate-bearing horizons in the ice core, using several methods. Once found, silicate particles will be imaged so that morphological characteristics of the particles can be used to identify volcanic origin. Particles identified as tephra will then be chemically analyzed using electron microprobe and laser ablation ICP-MS. Samples that yield a robust chemical fingerprint will be statistically correlated to known eruptions, and this will be used to address the goals described above. Broader impacts of this project fall into the areas of education of future generation of researchers, outreach and international cooperation. These activities will continue to promote forward progress in integrating the Antarctic tephra record and more broadly tying it to the global volcanic record.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": null, "is_usap_dc": true, "keywords": "VOLCANIC DEPOSITS; South Pole", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Dunbar, Nelia; Iverson, Nels; Kurbatov, Andrei V.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Tephrochronology of a South Pole Ice Core", "uid": "p0010311", "west": 0.0}, {"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": "Candice, Falk; Passchier, Sandra", "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": "1443557 Isbell, John", "bounds_geometry": "POLYGON((-180 -85,-177.1 -85,-174.2 -85,-171.3 -85,-168.4 -85,-165.5 -85,-162.6 -85,-159.7 -85,-156.8 -85,-153.9 -85,-151 -85,-151 -85.2,-151 -85.4,-151 -85.6,-151 -85.8,-151 -86,-151 -86.2,-151 -86.4,-151 -86.6,-151 -86.8,-151 -87,-153.9 -87,-156.8 -87,-159.7 -87,-162.6 -87,-165.5 -87,-168.4 -87,-171.3 -87,-174.2 -87,-177.1 -87,180 -87,179 -87,178 -87,177 -87,176 -87,175 -87,174 -87,173 -87,172 -87,171 -87,170 -87,170 -86.8,170 -86.6,170 -86.4,170 -86.2,170 -86,170 -85.8,170 -85.6,170 -85.4,170 -85.2,170 -85,171 -85,172 -85,173 -85,174 -85,175 -85,176 -85,177 -85,178 -85,179 -85,-180 -85))", "dataset_titles": "A LITHOFACIES ANALYSIS OF A SOUTH POLAR GLACIATION IN THE EARLY PERMIAN: PAGODA FORMATION, SHACKLETON GLACIER REGION, ANTARCTICA; A new stratigraphic framework built on U-Pb single-zircon TIMS agesand implications for the timing ofthe penultimate icehouse (Paran\u00e1 Basin, Brazil); Constraining late Paleozoic ice extent in the Paganzo Basin of western Argentina utilizing U-Pb detrital zircon geochronology for the lower Paganzo Group strata; Coupled stratigraphic and U-Pb zircon age constraints on the late Paleozoic icehouse-to-greenhouse turnover in south-central Gondwana; Isotopes to ice: Constraining provenance of glacial deposits and ice centers in west-central Gondwana; Late Permian soil-forming paleoenvironments on Gondwana: A review; Provenance of late Paleozoic glacial/post-glacial deposits in the eastern Chaco-Paran\u00e1 Basin, Uruguay and southernmost Paran\u00e1 Basin, Brazil; Supplemental material: Nitrogen-fixing symbiosis inferred from stable isotope analysis of fossil tree rings from the Oligocene of Ethiopia; When does large woody debris influence ancient rivers? Dendrochronology\r\napplications in the Permian and Triassic, Antarctica", "datasets": [{"dataset_uid": "200273", "doi": "10.1016/j.palaeo.2018.04.020", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "Isotopes to ice: Constraining provenance of glacial deposits and ice centers in west-central Gondwana", "url": "https://www.sciencedirect.com/science/article/abs/pii/S0031018217309008?via%3Dihub"}, {"dataset_uid": "200272", "doi": "10.1016/j.jsames.2020.102899", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "Constraining late Paleozoic ice extent in the Paganzo Basin of western Argentina utilizing U-Pb detrital zircon geochronology for the lower Paganzo Group strata", "url": "https://www.sciencedirect.com/science/article/pii/S0895981120304429?via%3Dihub#mmc1"}, {"dataset_uid": "200271", "doi": "10.1016/j.palaeo.2019.109544", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "When does large woody debris influence ancient rivers? Dendrochronology\r\napplications in the Permian and Triassic, Antarctica", "url": "https://www.sciencedirect.com/science/article/abs/pii/S0031018219304006?via%3Dihub"}, {"dataset_uid": "200269", "doi": "10.1130/G46740.1", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "Coupled stratigraphic and U-Pb zircon age constraints on the late Paleozoic icehouse-to-greenhouse turnover in south-central Gondwana", "url": "https://gsapubs.figshare.com/articles/journal_contribution/Supplemental_material_Coupled_stratigraphic_and_U-Pb_zircon_age_constraints_on_the_late_Paleozoic_icehouse-to-greenhouse_turnover_in_south-central_Gondwana/12542069"}, {"dataset_uid": "200274", "doi": "10.1130/G39213.1", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "Supplemental material: Nitrogen-fixing symbiosis inferred from stable isotope analysis of fossil tree rings from the Oligocene of Ethiopia", "url": "https://pubs.geoscienceworld.org/gsa/geology/article-standard/45/8/687/207623/Nitrogen-fixing-symbiosis-inferred-from-stable"}, {"dataset_uid": "200266", "doi": "10.2110/jsr.2021.004", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "A LITHOFACIES ANALYSIS OF A SOUTH POLAR GLACIATION IN THE EARLY PERMIAN: PAGODA FORMATION, SHACKLETON GLACIER REGION, ANTARCTICA", "url": "https://www.sepm.org/publications"}, {"dataset_uid": "200270", "doi": "10.1016/j.jsames.2020.102989", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "Provenance of late Paleozoic glacial/post-glacial deposits in the eastern Chaco-Paran\u00e1 Basin, Uruguay and southernmost Paran\u00e1 Basin, Brazil", "url": "https://www.sciencedirect.com/science/article/pii/S0895981120305320#mmc1"}, {"dataset_uid": "200268", "doi": "10.1130/B31775.1.", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "A new stratigraphic framework built on U-Pb single-zircon TIMS agesand implications for the timing ofthe penultimate icehouse (Paran\u00e1 Basin, Brazil)", "url": "https://gsapubs.figshare.com/articles/journal_contribution/Supplemental_material_A_new_stratigraphic_framework_built_on_U-Pb_single-zircon_TIMS_ages_and_implications_for_the_timing_of_the_penultimate_icehouse_Paran_Basin_Brazil_/12535916"}, {"dataset_uid": "200267", "doi": "10.1016/j.palaeo.2021.110762", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "Late Permian soil-forming paleoenvironments on Gondwana: A review", "url": "https://www.sciencedirect.com/science/article/abs/pii/S0031018221005472?via%3Dihub"}], "date_created": "Fri, 31 Dec 2021 00:00:00 GMT", "description": "The focus of this collaborative project is to collect fossil plants, wood, and sedimentary and chemical information from rocks in the Shackleton Glacier (SHK) area of Antarctica. This information will be used to reconstruct plant life and environments during the Permian and Triassic (~295-205 million years ago) in Antarctica. This time interval is important to study as Antarctica experienced a large glaciation in the Permian followed by deglaciation and recovery of plant and animal life, only to be subjected to the largest extinction in Earth history at the end of the Permian. After the extinction events, the climate in Antarctica continued to warm extensively and there were forests growing close to the paleo-South Pole. These ancient environments provide a natural laboratory in which to study the effects of climate change on plant life. The results of this project will advance the field in the areas of changing sedimentary patterns during global cooling and warming, as well as plant evolution during times following glaciation and during global warmth. This project will study the extent of the Gondwana glaciation in the SHK area, the invasion and subsequent flourishing of life following glacial retreat, and the eventual recovery of plant life after Late Permian extinction events. Only in Antarctica does a complete polar-to-near-polar succession occur across this climatic and biologic transition. The SHK area is an important one as it is one of the few regions in the world where the Permian-Triassic boundary (PTB) is exposed within terrestrial rocks. The field and lab work for this project is organized around three hypotheses that address fundamental issues in Earth history, including changes in the extent and diversity of flora during the Permian build up to the Late Paleozoic Ice Age, the possible diachronous nature of the PTB, and that poor fossil preservation during the Early Triassic has given a false impression that Antarctica was devoid of plants during this time. The hypotheses will be tested by integrating various types of paleobotanical approaches with detailed sedimentology, stratigraphy, and geochemistry. Compression floras and petrified wood will be collected (constrained by stratigraphy) both quantitatively and qualitatively in order to obtain biodiversity and abundance data, and as a data source for paleoecological analysis. Standard sedimentologic and stratigraphic analyses will be performed, as well as paleosol analyses, including mineralogic and major- and trace-element geochemistry. Collections will also be made for U-Pb zircon geochronology to better constrain geologic and biotic events through time. Results of the project will be incorporated into educational and outreach activities that are designed to include women and under-represented groups in the excitement of Antarctic earth sciences and paleontology, including workshops in Kansas and Wisconsin, as well as links to science classes during fieldwork.", "east": 170.0, "geometry": "POINT(-170.5 -86)", "instruments": null, "is_usap_dc": true, "keywords": "Shackleton Glacier; SEDIMENTARY ROCKS; GLACIATION", "locations": "Shackleton Glacier", "north": -85.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Isbell, John", "platforms": null, "repo": "Publication", "repositories": "Publication", "science_programs": null, "south": -87.0, "title": "Collaborative Research: Permian and Triassic Icehouse to Greenhouse Paleoenvironments and Paleobotany in the Shackleton Glacier Area, Antarctica", "uid": "p0010287", "west": -151.0}, {"awards": "1643394 Buizert, Christo", "bounds_geometry": "POLYGON((-180 -65,-144 -65,-108 -65,-72 -65,-36 -65,0 -65,36 -65,72 -65,108 -65,144 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.5,-180 -85,-180 -82.5,-180 -80,-180 -77.5,-180 -75,-180 -72.5,-180 -70,-180 -67.5,-180 -65))", "dataset_titles": "Antarctica 40,000 Year Temperature and Elevation Reconstructions; GISP2 and WAIS Divide Ice Cores 60,000 Year Surface Temperature Reconstructions; WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "datasets": [{"dataset_uid": "200256", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/24530"}, {"dataset_uid": "200255", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Antarctica 40,000 Year Temperature and Elevation Reconstructions", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/32632"}, {"dataset_uid": "200257", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "GISP2 and WAIS Divide Ice Cores 60,000 Year Surface Temperature Reconstructions", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/34133"}], "date_created": "Wed, 10 Nov 2021 00:00:00 GMT", "description": "Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ISOTOPES; Antarctica; USA/NSF; AMD; ICE CORE RECORDS; USAP-DC; VOLCANIC DEPOSITS; MODELS; Amd/Us", "locations": "Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Buizert, Christo; Wettstein, Justin", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Timing and Spatial Expression of the Bipolar Seesaw in Antarctica from Synchronized Ice Cores", "uid": "p0010279", "west": -180.0}, {"awards": "2114786 Warnock, Jonathan", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 09 Sep 2021 00:00:00 GMT", "description": "The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica\u2019s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica\u2019s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth\u0027s most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica\u2019s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. This 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": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "MICROFOSSILS; FIELD SURVEYS; Weddell Sea Embayment; USA/NSF; SEA ICE; USAP-DC; PALEOCLIMATE RECONSTRUCTIONS; SEA SURFACE TEMPERATURE; AMD; Amd/Us", "locations": "Weddell Sea Embayment", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Warnock, Jonathan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation", "uid": "p0010260", "west": null}, {"awards": "1744832 Severinghaus, Jeffrey; 1745007 Mayewski, Paul; 1745006 Brook, Edward J.; 0838843 Kurbatov, Andrei; 1744993 Higgins, John", "bounds_geometry": "POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667))", "dataset_titles": "Allan Hills 2022-23 Shallow Ice Core Field Report; Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022; Allan Hills Stable Water Isotopes; CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903; Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903; I-165-M GPR Field Report 2019-2020; MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903; Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old", "datasets": [{"dataset_uid": "601897", "doi": "10.15784/601897", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciology; Ice Core Data; MOT; Ocean Temperature; Paleoclimate; Xe/Kr", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "MOT data (Xe/Kr) from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601897"}, {"dataset_uid": "601896", "doi": "10.15784/601896", "keywords": "Allan Hills; Antarctica; Ch4; CO2; Cryosphere; Glaciology; Glaciology; Ice Core Data; Ice Core Records", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "CO2 and CH4 from Allan Hills ice cores ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601896"}, {"dataset_uid": "601895", "doi": "10.15784/601895", "keywords": "Allan Hills; Antarctica; Cryosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Noble Gas", "people": "Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Heavy noble gases (Ar/Xe/Kr) from ALHIC1901, 1902, and 1903", "url": "https://www.usap-dc.org/view/dataset/601895"}, {"dataset_uid": "601878", "doi": "10.15784/601878", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Cryosphere; Methane", "people": "Shackleton, Sarah; Severinghaus, Jeffrey P.; Hishamunda, Valens; Kalk, Michael; Brook, Edward; Marks Peterson, Julia", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Snapshot record of CO2 and CH4 from the Allan Hills, Antarctica, ranging from 400,000 to 3 million years old", "url": "https://www.usap-dc.org/view/dataset/601878"}, {"dataset_uid": "601620", "doi": "10.15784/601620", "keywords": "18O; Allan Hills; Allan Hills Blue Ice; Antarctica; Blue Ice; Delta 15N; Delta 18O; Dole Effect; Firn Thickness; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chronology; Ice Core Records", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills CMC3 ice core d18Oatm, d15N, dO2/N2, dAr/N2, d40/36Ar, d40/38Ar 2021 \u0026 2022", "url": "https://www.usap-dc.org/view/dataset/601620"}, {"dataset_uid": "601696", "doi": "10.15784/601696", "keywords": "Allan Hills; Antarctica; Ice Core", "people": "Brook, Edward J.; Shackleton, Sarah", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills 2022-23 Shallow Ice Core Field Report", "url": "https://www.usap-dc.org/view/dataset/601696"}, {"dataset_uid": "609541", "doi": "10.7265/N5NP22DF", "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope", "people": "Spaulding, Nicole; Mayewski, Paul A.; Introne, Douglas; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills Stable Water Isotopes", "url": "https://www.usap-dc.org/view/dataset/609541"}, {"dataset_uid": "601669", "doi": "10.15784/601669", "keywords": "Allan Hills; Antarctica; GPR; Ice Core; Report", "people": "Nesbitt, Ian; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "I-165-M GPR Field Report 2019-2020", "url": "https://www.usap-dc.org/view/dataset/601669"}], "date_created": "Fri, 27 Aug 2021 00:00:00 GMT", "description": "Bubbles of ancient air trapped in ice cores have been used to directly reconstruct atmospheric composition, and its links to Antarctic 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 extend as far back as 2.7 million years, by far the oldest polar ice samples yet recovered. These ice cores extend direct observations of atmospheric carbon dioxide and methane concentrations and indirect records of Antarctic climate into a period of Earth\u0027s climate history that represents a plausible geologic analogue to future anthropogenic climate change. The results demonstrate a smaller glacial-interglacial variability of climate and greenhouse gases, and a persistent linkage between Antarctic climate and atmospheric carbon dioxide, between 1 and 2 million years ago. Through this project, the team will return to the Allan Hills Blue Ice Area to recover additional ice cores that date to 2 million years or older. The climate records developed from these 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. Project results will help answer questions about issues associated with anthropogenic change including the relationship between temperature change and the mass balance of Antarctic ice and the relationship between atmospheric greenhouse gases and global climate change. Earth has been cooling, and ice sheets expanding, over the past ~52 million years. Superimposed on this cooling are periodic changes in Earth\u0027s climate system driven by variations in the eccentricity, precession, and obliquity of Earth\u0027s orbit around the Sun. Climate reconstructions based on measurements of oxygen isotopes in foraminiferal calcite indicate that, from ~2.8 to 1.2 million years before present (Ma), Earth\u0027s climate system oscillated between glacial and interglacial states every ~40,000 years (the \"40k world\"). Between 1.2-0.8 Ma and continuing to the present, the period of glacial cycles increased in amplitude and lengthened to ~100,000 years (the \"100k world\"). Ice cores preserve ancient air that allows direct reconstructions of atmospheric carbon dioxide and methane. They also archive proxy records of regional climate, mean ocean temperature, global oxygen cycling, and the aridity of nearby continents. Studies of stratigraphically continuous ice cores, extending to 800,000 years before present, have demonstrated that atmospheric carbon dioxide is strongly linked to climate, and it is of great interest to extend the ice-core record into the 40k world. Recent discoveries of well-preserved ice dating from 1.0 to 2.7 Ma from ice cores drilled in the Allan Hills Blue Ice Area (BIA), Antarctica, demonstrate the potential to retrieve stratigraphically discontinuous old ice at shallow depths (\u003c200 meters). This project will continue this work by retrieving new large-volume ice cores and measuring paleoclimate properties in both new and existing ice from the Allan Hills BIA. The experimental objectives are to more fully characterize fundamental properties of the climate system and the carbon cycle during the 40k world. Project results will have implications for Pleistocene climate change, and will provide new constraints on the processes that regulate atmospheric carbon dioxide, methane, and oxygen on geologic timescales. Given a demonstrated age of the ice at the Allan Hills BIA of at least 2 million years, the team will drill additional cores to prospect for ice that predates the initiation of Northern Hemisphere glaciation at the Plio-Pleistocene transition (~2.8 Ma). This 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": 159.41667, "geometry": "POINT(159.29167 -76.7)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; SNOW/ICE; Allan Hills; FIELD SURVEYS; USA/NSF; Amd/Us; LABORATORY", "locations": "Allan Hills", "north": -76.66667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Kurbatov, Andrei V.; Brook, Edward J.; Severinghaus, Jeffrey P.; Higgins, John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.73333, "title": "Collaborative research: Snapshots of Early and Mid-Pleistocene Climate and Atmospheric Composition from the Allan Hills Blue Ice Area ", "uid": "p0010253", "west": 159.16667}, {"awards": "2114839 Passchier, Sandra", "bounds_geometry": null, "dataset_titles": "Argon thermochronological data on Pliocene ice-rafted detrital mineral grains from IODP Expedition 379 in the Amundsen Sea sector; Grain-size data for the Pliocene section at IODP Site U1533, Amundsen Sea", "datasets": [{"dataset_uid": "601900", "doi": "10.15784/601900", "keywords": "Amundsen Sea Sector; Antarctica; Cryosphere; Glaciation; Grain Size; Pliocene; Sediment Core Data; Sedimentology", "people": "Mino-Moreira, Lisbeth; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Grain-size data for the Pliocene section at IODP Site U1533, Amundsen Sea", "url": "https://www.usap-dc.org/view/dataset/601900"}, {"dataset_uid": "601907", "doi": "10.15784/601907", "keywords": "40Ar/39Ar; Amundsen Sea; Amundsen Sea Sector; Antarctica; Cryosphere; Ice-Rafted Detritus; IODP; Paleoclimate; Pliocene; Provenance; Sedimentology", "people": "Hemming, Sidney R.; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on Pliocene ice-rafted detrital mineral grains from IODP Expedition 379 in the Amundsen Sea sector", "url": "https://www.usap-dc.org/view/dataset/601907"}], "date_created": "Wed, 25 Aug 2021 00:00:00 GMT", "description": "The West Antarctic Ice Sheet is the most vulnerable polar ice mass to warming and already a major contributor to global mean sea level rise. Its fate in the light of prolonged warming is a topic of major uncertainty. Accelerated sea level rise from ice mass loss in the polar regions is a major concern as a cause of increased coastal flooding affecting millions of people. This project will disclose a unique geological archive buried beneath the seafloor off the Amundsen Sea, Antarctica, which will reveal how the West Antarctic Ice Sheet behaved in a warmer climate in the past. The data and insights can be used to inform ice-sheet and ocean modeling used in coastal policy development. The project will also support the development of a competitive U.S. STEM workforce. Online class exercises for introductory geology classes will provide a gateway for qualified students into undergraduate research programs and this project will enhance the participation of women in science by funding the education of current female Ph.D. students. 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. This 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": 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", "repo": "USAP-DC", "repositories": "USAP-DC", "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": "1745064 Perez-Huerta, Alberto; 1745057 Walker, Sally; 1745080 Gillikin, David", "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": "Analysis of striae groups and interstrial increments from Adamussium colbecki valves from Explorers Cove and Bay of Sails; Annual growth of Adamussium colbecki from Explorers Cove and Bay of Sails; Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores; Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.; Stable isotopes of Oxygen and Carbon in Adamissium colbecki from Explorers Cove and Bay of Sails", "datasets": [{"dataset_uid": "601764", "doi": "10.15784/601764", "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Gillikin, David; Puhalski, Emma; Camarra, Steve; Cronin, Kelly; Verheyden, Anouk; Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.", "url": "https://www.usap-dc.org/view/dataset/601764"}, {"dataset_uid": "601468", "doi": "10.15784/601468", "keywords": "Adamussium Colbecki; Antarctica; Growth; McMurdo Sound; Shell Fish", "people": "Walker, Sally; Cronin, Kelly", "repository": "USAP-DC", "science_program": null, "title": "Annual growth of Adamussium colbecki from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601468"}, {"dataset_uid": "601469", "doi": "10.15784/601469", "keywords": "Adamussium Colbecki; Antarctica; McMurdo", "people": "Walker, Sally; Cronin, Kelly", "repository": "USAP-DC", "science_program": null, "title": "Analysis of striae groups and interstrial increments from Adamussium colbecki valves from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601469"}, {"dataset_uid": "601761", "doi": "10.15784/601761", "keywords": "Adamussium Colbecki; Antarctica; Bay Of Sails; Carbon; Explorers Cove; McMurdo Sound; Oxygen; Stable Isotopes", "people": "Walker, Sally; Cronin, Kelly; Puhalski, Emma; Perez-Huerta, Alberto; Bowser, Samuel S.; Verheyden, Anouk; Gillikin, David; Camarra, Steve; Andrus, Fred", "repository": "USAP-DC", "science_program": null, "title": "Stable isotopes of Oxygen and Carbon in Adamissium colbecki from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601761"}, {"dataset_uid": "600077", "doi": "10.15784/600077", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; McMurdo Sound; Oceans; Sample/collection Description; Sample/Collection Description", "people": "Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600077"}], "date_created": "Fri, 06 Aug 2021 00:00:00 GMT", "description": "The goal of this project is to discover whether the Antarctic scallop, Adamussium colbecki, provides a guide to sea-ice conditions in nearshore Antarctica today and in the past. Scallops may grow slower and live longer in habitats where sea ice persists for many years, limited by food, compared to habitats where sea ice melts out annually. Also, the chemicals retained in the shell during growth may provide crucial habitat information related to not only changing sea-ice conditions but also the type of food, whether it is recycled from the seafloor or produced by algae blooming when sea ice has melted. Unlocking the ecological imprint captured within the shell of the Antarctic Scallop will increase our understanding of changing sea-ice conditions in Antarctica. Further, because the Antarctic scallop had relatives living at the time when the Antarctic ice sheet first appeared, the scallop shell record may contain information on the stability of the ice sheet and the history of Antarctic shallow seas. Funding will also be integral for training a new generation of geoscientists in fossil and chemical forensics related to shallow sea habitats in Antarctica. Scallops are worldwide in distribution, are integral for structuring marine communities have an extensive fossil record dating to the late Devonian, and are increasingly recognized as important paleoenvironmental proxies because they are generally well preserved in the sediment and rock record. The primary goal of this project is to assess the differences in growth, lifespan, and chemistry (stable isotopes, trace elements) archived in the shell of the Antarctic scallop that may be indicative of two ice states: persistent (multiannual) sea ice at Explorers Cove (EC) and annual sea ice (that melts out every year) at Bay of Sails (BOS), western McMurdo Sound, Antarctica. This project will investigate growth and lifespan proxies (physical and geochemical) and will use high-resolution records of stable oxygen isotopes to determine if a melt-water signal is archived in A. colbecki shells and whether that signal captures the differing ice behavior at two sites (EC versus BOS). Stable isotopes of carbon and nitrogen in association with trace elements will be used to examine subannual productivity spikes indicative of phytoplankton blooms, which are predicted to be more pronounced during open ocean conditions. Small growth increments in the outer calcite layer will be assessed to determine if they represent fortnightly growth, if so, they could provide a high-resolution proxy for monthly environmental processes. Unlocking the environmental archive preserved in A. colbecki shells may prove to be an important proxy for understanding changing sea-ice conditions in Antarctica\u0027s past. Funding will support a Ph.D. student and undergraduates from multiple institutions working on independent research projects. Web content focused on Antarctic marine communities will be designed for museum outreach, reaching thousands of middle-school children each year. This 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": "Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; AMD; Dry Valleys; USAP-DC; LABORATORY; USA/NSF", "locations": "Dry Valleys", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walker, Sally; Gillikin, David; Perez-Huerta, Alberto; Andrus, Fred", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative research: The Antarctic Scallop as Key to Paleoenvironments and Sea Ice Conditions: Understanding the Modern to Predict the Past", "uid": "p0010238", "west": -180.0}, {"awards": "2000992 Romans, Brian", "bounds_geometry": "POINT(-172.873074 -74.274008)", "dataset_titles": "Grain size of Plio-Pleistocene continental slope and rise sediments, Hillary Canyon, Ross Sea", "datasets": [{"dataset_uid": "601807", "doi": "10.15784/601807", "keywords": "Antarctica; Cryosphere; Grain Size; Ross Sea", "people": "Romans, Brian W.; Varela, Natalia", "repository": "USAP-DC", "science_program": null, "title": "Grain size of Plio-Pleistocene continental slope and rise sediments, Hillary Canyon, Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601807"}], "date_created": "Tue, 06 Jul 2021 00:00:00 GMT", "description": "Part I: Non-technical description: Predicting how polar ice sheets will respond to future global warming is difficult because all the processes that contribute to their melting are not well understood. This is important because the more ice on land that melts, the higher sea levels will rise. The most significant uncertainty in current estimates of sea-level rise in the coming decades is the potential contribution from the Antarctic Ice Sheet. One way to increase our knowledge about how large ice sheets respond to climate change in response to natural factors is to examine the geologic past. Natural global warming (and cooling) events in Earth\u2019s history provide examples that we can use to better understand processes, interactions, and responses we can\u2019t directly observe today. One such time period, approximately three million years ago (known as the Pliocene), was the last time atmospheric carbon dioxide levels were as high as they are today and, therefore, represents a time period to study to better understand the ice sheet response to a warming climate. Specifically, this project is interested in understanding how ocean currents near Antarctica, which transport heat and store carbon, behaved during these past climate events. The history of past ice sheet-ocean interactions are recorded in sediments that were deposited, layer upon layer, in the deep sea offshore Antarctica. In January-February 2018, a team of scientists and crew set sail to the Ross Sea, offshore west Antarctica, on the scientific ocean drilling vessel JOIDES Resolution to recover such sediment archives. This project focuses on a sediment core from that expedition, which captures the relatively warm Pliocene time interval, as well as the subsequent transition into cooler climates typical of the past two million years. The researchers will analyze the sediment with multiple complementary measurements, including: grain size, composition, chemistry of organic matter, physical structures, microfossil type and abundance, and more. These analyses will be done by the research team, including several students, at their respective laboratories and will then integrated into a unified record of ice sheet-ocean interactions. Ultimately, the results will be used to improve modeled projections of how the Antarctic Ice Sheet could respond to future climate change. Part II: Technical 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. The researchers 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, they 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. To test their hypothesis, they will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) They will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. They will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) They 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) They 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. All of these data will be integrated 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. This 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": -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": "Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "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": "1947094 Sidor, Christian", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "Non-technical Abstract Around 252 million years ago, a major mass extinction wiped out over 90% of species on Earth. Coincident with this extinction, the Antarctic portion of the supercontinent of Pangea transitioned to a warmer climatic regime devoid of a permanent ice cap. Compared to lower latitudes, relatively little is known about the survivors of the extinction in Antarctica, although it has been hypothesized that the continents more polar location shielded it from the worst of the extinctions effects. As the result of a NSF-sponsored deep field camp in 2017/2018, a remarkable collection of vertebrate fossils was discovered in the rocks of the Shackleton Glacier region. This collection includes the best preserved and most complete materials of fossil amphibians ever recovered from Antarctica, including two previously undescribed species. This grant supports one postdoctoral researcher with expertise in fossil amphibians to describe and interpret the significance of these fossils, including their identification, relationships, and how they fit into the terrestrial ecosystem of Antarctica and other southern hemisphere terrestrial assemblages in light of the major reorganization of post-extinction environments. Historical collections of fossil amphibians will also be reviewed as part of this work. Undergraduate students at the University of Washington will be actively involved as part of this research and learn skills like hard tissue histology and CT data manipulation. Public engagement in Antarctic science will be accomplished at the University of Washington Burke Museum, which is the Washington State museum of natural history and culture. Specifically, a new exhibit on Antarctic amphibians will be developed as part of the paleontology gallery, which sees over 100,000 visitors per year. Technical Abstract This two-year project will examine the evolution of Triassic temnospondyls based on a remarkable collection of fossils recently recovered from the Shackleton Glacier region of Antarctica. Temnospondyls collected from the middle member of the Fremouw Formation are part of the first collection of identifiable tetrapod fossils from this stratigraphic interval. Thorough anatomical description and comparisons of these fossils will add new faunal information and also aid in determining if this horizon is Early or Middle Triassic in age. Exquisitely preserved temnospondyl material from the lower Fremouw Formation will permit more precise identification than previously possible and will provide insights into the earliest stages of their radiation in the extinction recovery interval. Overall, the Principal Investigator and Postdoctoral Researcher will spearhead an effort to revise the systematics of the Antarctic members of Temnospondyli and properly contextualize them in the framework of Triassic tetrapod evolution. The research team will also take advantage of the climate-sensitive nature of fossil amphibians to better understand patterns of seasonality at high-latitudes during the early Mesozoic by subjecting selected fossils to histological analysis. Preliminary data suggest that temnospondyls were exceptionally diverse and highly endemic immediately after the end-Permian extinction, when compared to their distribution before and after this interval. If confirmed, this macroevolutionary pattern could be used to predict the response of modern amphibians to future climate perturbations. Overall, this research will provide new insights into the vertebrate fauna of the Fremouw Formation, as well as shed light on the evolution of terrestrial ecosystems in southern Pangea in the wake of the Permian-Triassic mass extinction. As part of the broader impacts, the research team will help to develop an exhibit featuring some of the best preserved fossils from Antarctica to explain to the public how paleontologists use fossils and rocks to understand past climates like the Triassic \u0027hot-house\u0027 world that lacked permanent ice caps at the poles. This 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": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Temnospondyls; MACROFOSSILS; USA/NSF; FIELD SURVEYS; Permian Extinction; Triassic; Amd/Us; USAP-DC; AMD; ANIMALS/VERTEBRATES; Shackleton Glacier", "locations": "Shackleton Glacier", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e PALEOZOIC \u003e PERMIAN", "persons": "Sidor, Christian", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": null, "title": "A non-amniote perspective on the recovery from the end-Permian extinction at high latitudes: paleobiology of Early Triassic temnospondyls from Antarctica", "uid": "p0010217", "west": null}, {"awards": "1341376 Tabor, Neil; 1341475 Smith, Nathan; 2001033 Makovicky, Peter; 1341304 Sidor, Christian; 1341645 Makovicky, Peter", "bounds_geometry": "POLYGON((-180 -84,-178 -84,-176 -84,-174 -84,-172 -84,-170 -84,-168 -84,-166 -84,-164 -84,-162 -84,-160 -84,-160 -84.3,-160 -84.6,-160 -84.9,-160 -85.2,-160 -85.5,-160 -85.8,-160 -86.1,-160 -86.4,-160 -86.7,-160 -87,-162 -87,-164 -87,-166 -87,-168 -87,-170 -87,-172 -87,-174 -87,-176 -87,-178 -87,180 -87,178.5 -87,177 -87,175.5 -87,174 -87,172.5 -87,171 -87,169.5 -87,168 -87,166.5 -87,165 -87,165 -86.7,165 -86.4,165 -86.1,165 -85.8,165 -85.5,165 -85.2,165 -84.9,165 -84.6,165 -84.3,165 -84,166.5 -84,168 -84,169.5 -84,171 -84,172.5 -84,174 -84,175.5 -84,177 -84,178.5 -84,-180 -84))", "dataset_titles": "Lower Triassic Antarctic vertebrate fossils at Field Museum, Chicago, IL", "datasets": [{"dataset_uid": "601511", "doi": "10.15784/601511", "keywords": "Allan Hills; Antarctica; Fremouw Formation; Lystrosaurus; Permo-Triassic Extinction; Prolacerta; Sample Location; Thrinaxofon; Triassic", "people": "Makovicky, Peter", "repository": "USAP-DC", "science_program": null, "title": "Lower Triassic Antarctic vertebrate fossils at Field Museum, Chicago, IL", "url": "https://www.usap-dc.org/view/dataset/601511"}], "date_created": "Tue, 29 Jun 2021 00:00:00 GMT", "description": "Around 252 million years ago, a major mass extinction wiped out upwards of 90% of species on Earth. Coincident with this extinction, the Antarctic portion of the supercontinent of Pangea transitioned to a warmer climatic regime and became devoid of glaciers. Little is known about the survivors of the extinction in Antarctica, although it has been hypothesized that the continent\u0027s high latitude location shielded it from the worst of the extinction\u0027s effects. The Shackleton Glacier region is the best place to study this extinction in Antarctica because it exposes an abundance of correct age rocks and relevant fossils were found there in the 1960s and 1980s. For this research, paleontologists will study fossil vertebrates that span from about 260 to 240 million years ago to understand how life evolved at high latitudes in the face of massive climate change. In addition, geologists will use fossil soils and fossil plant matter to more precisely reconstruct the climate of Antarctica across this extinction boundary. These data will allow for a more complete understanding of ancient climates and how Antarctic life compared to that at lower latitudes. Undergraduate and graduate students will be actively involved in this research. Public engagement in Antarctic science will be accomplished at several natural history museums. This three-year project will examine the evolution of Permo-Triassic paleoenvironments and their vertebrate communities by conducting fieldwork in the Shackleton Glacier region of Antarctica. The team will characterize the Permo-Triassic boundary within Shackleton area strata and correlate it to other stratigraphic successions in the region (e.g. via stable carbon isotope stratigraphy of fossilized plant organic matter). The researchers will use multiple types of data to assess the paleoenvironment, including: 1) paleosol morphology; 2) paleosol geochemistry; 3) pedogenic organic matter; and 4) fossil wood chronology and stable isotopes. The Fremouw Formation of Antarctica preserves the highest paleolatitude (~70\u00b0 S) tetrapod fauna of the entire Triassic and thus has the potential to shed important light on the evolution of polar life during the early Mesozoic. The biology of Triassic vertebrates from Antarctica will be compared to conspecifics from lower paleolatitudes through analysis of growth in bone and tusk histology. An interdisciplinary approach will be used to address relationships between environmental change, faunal composition, and biogeographic patterns in the context of the high-latitude strata preserved in the Buckley and Fremouw formations in the Shackleton Glacier region.", "east": -160.0, "geometry": "POINT(-177.5 -85.5)", "instruments": null, "is_usap_dc": true, "keywords": "REPTILES; FIELD SURVEYS; USA/NSF; PALEOCLIMATE RECONSTRUCTIONS; Triassic; USAP-DC; TERRESTRIAL ECOSYSTEMS; MACROFOSSILS; Amd/Us; Fossils; Shackleton Glacier; LAND RECORDS; ANIMALS/VERTEBRATES; AMD", "locations": "Shackleton Glacier", "north": -84.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Sidor, Christian; Smith, Nathan; Makovicky, Peter; Tabor, Neil", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.0, "title": "Collaborative Research: Understanding the evolution of high-latitude Permo-Triassic paleoenvironments and their vertebrate communities", "uid": "p0010213", "west": 165.0}, {"awards": "1643355 Steig, Eric; 1643394 Buizert, Christo", "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": "Antarctica 40,000 Year Temperature and Elevation Reconstructions; Layer and Thinning based Accumulation Rate Reconstructions; WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "datasets": [{"dataset_uid": "601448", "doi": "10.15784/601448", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Snow/ice; Snow/Ice", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Layer and Thinning based Accumulation Rate Reconstructions", "url": "https://www.usap-dc.org/view/dataset/601448"}, {"dataset_uid": "200219", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Antarctica 40,000 Year Temperature and Elevation Reconstructions", "url": "https://www.ncdc.noaa.gov/paleo-search/study/32632"}, {"dataset_uid": "200220", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "url": "https://www.ncdc.noaa.gov/paleo/study/24530"}], "date_created": "Fri, 28 May 2021 00:00:00 GMT", "description": "Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Steig, Eric J.; Buizert, Christo", "platforms": null, "repo": "USAP-DC", "repositories": "NCEI; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Timing and Spatial Expression of the Bipolar Seesaw", "uid": "p0010183", "west": -180.0}, {"awards": "1724670 Williams, Trevor", "bounds_geometry": "POLYGON((-70 -60,-65 -60,-60 -60,-55 -60,-50 -60,-45 -60,-40 -60,-35 -60,-30 -60,-25 -60,-20 -60,-20 -62.5,-20 -65,-20 -67.5,-20 -70,-20 -72.5,-20 -75,-20 -77.5,-20 -80,-20 -82.5,-20 -85,-25 -85,-30 -85,-35 -85,-40 -85,-45 -85,-50 -85,-55 -85,-60 -85,-65 -85,-70 -85,-70 -82.5,-70 -80,-70 -77.5,-70 -75,-70 -72.5,-70 -70,-70 -67.5,-70 -65,-70 -62.5,-70 -60))", "dataset_titles": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "datasets": [{"dataset_uid": "601378", "doi": "10.15784/601378", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601378"}, {"dataset_uid": "601377", "doi": "10.15784/601377", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601377"}, {"dataset_uid": "601379", "doi": "10.15784/601379", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601379"}], "date_created": "Thu, 10 Sep 2020 00:00:00 GMT", "description": "Abstract for the general public: The margins of the Antarctic ice sheet have advanced and retreated repeatedly over the past few million years. Melting ice from the last retreat, from 19,000 to 9,000 years ago, raised sea levels by 8 meters or more, but the extents of previous retreats are less well known. The main goal of this project is to understand how Antarctic ice retreats: fast or slow, stepped or steady, and which parts of the ice sheet are most prone to retreat. Antarctica loses ice by two main processes: melting of the underside of floating ice shelves and calving of icebergs. Icebergs themselves are ephemeral, but they carry mineral grains and rock fragments that have been scoured from Antarctic bedrock. As the icebergs drift and melt, this \u0027iceberg-rafted debris\u0027 falls to the sea-bed and is steadily buried in marine sediments to form a record of iceberg activity and ice sheet retreat. The investigators will read this record of iceberg-rafted debris to find when and where Antarctic ice destabilized in the past. This information can help to predict how Antarctic ice will behave in a warming climate. The study area is the Weddell Sea embayment, in the Atlantic sector of Antarctica. Principal sources of icebergs are the nearby Antarctic Peninsula and Weddell Sea embayment, where ice streams drain about a quarter of Antarctic ice. The provenance of the iceberg-rafted debris (IRD), and the icebergs that carried it, will be found by matching the geochemical fingerprint (such as characteristic argon isotope ages) of individual mineral grains in the IRD to that of the corresponding source area. In more detail, the project will: 1. Define the geochemical fingerprints of the source areas of the glacially-eroded material using samples from each major ice stream entering the Weddell Sea. Existing data indicates that the hinterland of the Weddell embayment is made up of geochemically distinguishable source areas, making it possible to apply geochemical provenance techniques to determine the origin of Antarctica icebergs. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till samples to characterize detritus supplied by the Recovery and Foundation ice streams. 2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information identifies which groups of ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents), and the stratigraphy of the cores shows the relative sequence of ice stream activity through time. A further dimension is added by determining the time lag between fine sediment erosion and deposition, using a new method of uranium-series isotope measurements in fine grained material. Technical abstract: The behavior of the Antarctic ice sheets and ice streams is a critical topic for climate change and future sea level rise. The goal of this proposal is to constrain ice sheet response to changing climate in the Weddell Sea during the three most recent glacial terminations, as analogues for potential future warming. The project will also examine possible contributions to Meltwater Pulse 1A, and test the relative stability of the ice streams draining East and West Antarctica. Much of the West Antarctic ice may have melted during the Eemian (130 to 114 Ka), so it may be an analogue for predicting future ice drawdown over the coming centuries. Geochemical provenance fingerprinting of glacially eroded detritus provides a novel way to reconstruct the location and relative timing of glacial retreat during these terminations in the Weddell Sea embayment. The two major objectives of the project are to: 1. Define the provenance source areas by characterizing Ar, U-Pb, and Nd isotopic signatures, and heavy mineral and Fe-Ti oxide compositions of detrital minerals from each major ice stream entering the Weddell Sea, using onshore tills and existing sediment cores from the Ronne and Filchner Ice Shelves. Pilot data demonstrate that detritus originating from the east and west sides of the Weddell Sea embayment can be clearly distinguished, and published data indicates that the hinterland of the embayment is made up of geochemically distinguishable source areas. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till to characterize detritus supplied by the Recovery and Foundation ice streams. 2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information will identify which ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents). The stratigraphy of the cores will show the relative sequence of ice stream activity through time. A further time dimension is added by determining the time lag between fine sediment erosion and deposition, using U-series comminution ages.", "east": -20.0, "geometry": "POINT(-45 -72.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "TERRIGENOUS SEDIMENTS; Subglacial Till; USAP-DC; ICEBERGS; AMD; USA/NSF; ISOTOPES; AGE DETERMINATIONS; Argon; Provenance; Till; Amd/Us; R/V POLARSTERN; FIELD INVESTIGATION; SEDIMENT CHEMISTRY; Weddell Sea; Antarctica; LABORATORY", "locations": "Weddell Sea; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Williams, Trevor; Hemming, Sidney R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V POLARSTERN", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance", "uid": "p0010128", "west": -70.0}, {"awards": "1443690 Young, Duncan", "bounds_geometry": "POLYGON((95 -68,100.5 -68,106 -68,111.5 -68,117 -68,122.5 -68,128 -68,133.5 -68,139 -68,144.5 -68,150 -68,150 -70.2,150 -72.4,150 -74.6,150 -76.8,150 -79,150 -81.2,150 -83.4,150 -85.6,150 -87.8,150 -90,144.5 -90,139 -90,133.5 -90,128 -90,122.5 -90,117 -90,111.5 -90,106 -90,100.5 -90,95 -90,95 -87.8,95 -85.6,95 -83.4,95 -81.2,95 -79,95 -76.8,95 -74.6,95 -72.4,95 -70.2,95 -68))", "dataset_titles": "Airborne potential fields data from Titan Dome, Antarctica; ICECAP Basal Interface Specularity Content Profiles: IPY and OIB; ICECAP: Gridded boundary conditions for Little Dome C, Antarctica, and extracted subglacial lake locations; ICECAP: High resolution survey of the Little Dome C region in support of the IPICS Old Ice goal; ICECAP radargrams in support of the international old ice search at Dome C - 2016; Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau; SPICECAP/ICECAP II Instrument Measurements (LASER, MAGNETICS and POSITIONING); Titan Dome, East Antarctica, Aerogeophysical Survey", "datasets": [{"dataset_uid": "200235", "doi": "10.26179/jydx-yz69", "keywords": null, "people": null, "repository": "AADC", "science_program": null, "title": "SPICECAP/ICECAP II Instrument Measurements (LASER, MAGNETICS and POSITIONING)", "url": "https://data.aad.gov.au/metadata/records/AAS_4346_ICECAP_OIA_Level1B_AEROGEOPHYSICS"}, {"dataset_uid": "200233", "doi": "http://dx.doi.org/doi:10.26179/5wkf-7361", "keywords": null, "people": null, "repository": "AADC", "science_program": null, "title": "ICECAP radargrams in support of the international old ice search at Dome C - 2016", "url": "https://data.aad.gov.au/metadata/records/AAS_4346_ICECAP_OIA_RADARGRAMS"}, {"dataset_uid": "601355", "doi": "10.15784/601355", "keywords": "Aerogeophysics; Antarctica; Bed Elevation; Bed Reflectivity; Epica Dome C; Ice Thickness", "people": "Blankenship, Donald D.; Young, Duncan A.; van Ommen, Tas; Richter, Thomas; Greenbaum, Jamin; Cavitte, Marie G. P; Beem, Lucas H.; Quartini, Enrica; Tozer, Carly; Ng, Gregory; Habbal, Feras; Roberts, Jason; Kempf, Scott D.; Ritz, Catherine", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "ICECAP: High resolution survey of the Little Dome C region in support of the IPICS Old Ice goal", "url": "https://www.usap-dc.org/view/dataset/601355"}, {"dataset_uid": "601437", "doi": "10.15784/601437", "keywords": "Airborne Laser Altimetry; Airborne Radar; Airplane; Antarctica; Bedrock Elevation; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness; Radar Echo Sounder; Surface Elevation; Titan Dome", "people": "Beem, Lucas H.; Young, Duncan A.; Greenbaum, Jamin; Ng, Gregory; Young, Duncan; Blankenship, Donald D.; Cavitte, Marie G. P; Jingxue, Guo; Bo, Sun", "repository": "USAP-DC", "science_program": null, "title": "Titan Dome, East Antarctica, Aerogeophysical Survey", "url": "https://www.usap-dc.org/view/dataset/601437"}, {"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": "Blankenship, Donald D.; Mulvaney, Robert; Cavitte, Marie G. P; Ritz, Catherine; Greenbaum, Jamin; Ng, Gregory; Kempf, Scott D.; Quartini, Enrica; Muldoon, Gail R.; Paden, John; Frezzotti, Massimo; Roberts, Jason; Tozer, Carly; Young, Duncan A.; Schroeder, Dustin", "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": "601463", "doi": "10.15784/601463", "keywords": "Antarctica; Epica Dome C; ICECAP; Ice Penetrating Radar; Subglacial Lake", "people": "Ritz, Catherine; Roberts, Jason; Young, Duncan A.; Blankenship, Donald D.; Van Ommen, Tas; Corr, Hugh F. J.; Urbini, Stefano; Steinhage, Daniel; Tozer, Carly; Cavitte, Marie G. P; Quartini, Enrica; Frezzotti, Massimo", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "ICECAP: Gridded boundary conditions for Little Dome C, Antarctica, and extracted subglacial lake locations", "url": "https://www.usap-dc.org/view/dataset/601463"}, {"dataset_uid": "601461", "doi": "10.15784/601461", "keywords": "Antarctica; ICECAP; Titan Dome", "people": "Young, Duncan A.; Jingxue, Guo; Bo, Sun; Greenbaum, Jamin; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "Airborne potential fields data from Titan Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601461"}, {"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Schroeder, Dustin; Young, Duncan A.; Roberts, Jason; Blankenship, Donald D.; Siegert, Martin; van Ommen, Tas; Greenbaum, Jamin", "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"}], "date_created": "Tue, 07 Jul 2020 00:00:00 GMT", "description": "Non-technical description: East Antarctica holds a vast, ancient ice sheet. The bedrock hidden beneath this ice sheet may provide clues to how today\u0027s continents formed, while the ice itself contains records of Earth\u0027s atmosphere from distant eras. New drilling technologies are now available to allow for direct sampling of these materials from more than two kilometers below the ice surface. However, getting this material will require knowing where to look. The Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP) project will use internationally collected airborne survey data to search East Antarctica near the South Pole for key locations that will provide insight into Antarctica\u0027s geology and for locating the oldest intact ice on Earth. Ultimately, scientists are interested in obtaining samples of the oldest ice to address fundamental questions about the causes of changes in the timing of ice-age conditions from 40,000 to 100,000 year cycles. SPICECAP data analysis will provide site survey data for future drilling and will increase the overall understanding of Antarctica\u0027s hidden ice and geologic records. The project involves international collaboration and leveraging of internationally collected data. The SPICECAP project will train new interdisciplinary scientists at the undergraduate, graduate, and postdoctoral levels. Technical description: This study focuses on processing and interpretation of internationally collected aerogeophysical data from the Southern Plateau of the East Antarctic Ice Sheet. The data include ice penetrating radar data, laser altimetry, gravity and magnetics.\u00a0 The project will provide information on geological trends under the ice, the topography and character of the ice/rock interface, and the stratigraphy of the ice. The project will also provide baseline site characterization for future drilling. Future drilling sites and deep ice cores for old ice require that the base of the ice sheet be frozen to the bed (i.e. no free water at the interface between rock and ice) and the assessment will map the extent of frozen vs. thawed areas. Specifically, three main outcomes are anticipated for this project. First, the study will provide an assessment of the viability of Titan Dome, a subglacial highland region located near South Pole, as a potential old ice drilling prospect. The assessment will include determining the\u00a0hydraulic context of the bed by processing and interpreting the radar data,\u00a0ice sheet mass balance through time by mapping englacial reflectors in the ice and connecting them to ice stratigraphy in the recent South Pole,\u00a0and ice sheet geometry using laser altimetry. Second, the study will provide an assessment of the geological context of the Titan Dome region with respect to understanding regional geologic boundaries and the potential for bedrock sampling. For these two goals, we will use data opportunistically collected by China, and the recent PolarGAP dataset. Third, the study will provide an assessment of the risk posture for RAID site targeting in the Titan Dome region, and the Dome C region. This will use a high-resolution dataset the team collected previously at Dome C, an area similar to the coarser resolution data collected at Titan Dome, and will enable an understanding of what is missed by the wide lines spacing at Titan Dome. Specifically, we will model subglacial hydrology with and without the high resolution data, and statistically examine the detection of subglacial mountains (which could preserve old ice) and subglacial lakes (which could destroy old ice), as a function of line spacing.", "east": 150.0, "geometry": "POINT(122.5 -79)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e LIDAR ALTIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e NUCLEAR PRECESSION MAGNETOMETER", "is_usap_dc": true, "keywords": "BT-67; MAGNETIC ANOMALIES; Epica Dome C; GRAVITY ANOMALIES; GLACIER ELEVATION/ICE SHEET ELEVATION; GLACIER THICKNESS/ICE SHEET THICKNESS", "locations": "Epica Dome C", "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Young, Duncan A.; Blankenship, Donald D.; Roberts, Jason; Bo, Sun", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e BT-67", "repo": "AADC", "repositories": "AADC; USAP-DC", "science_programs": "Dome C Ice Core", "south": -90.0, "title": "Collaborative Research: Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP)", "uid": "p0010115", "west": 95.0}, {"awards": "1643722 Brook, Edward J.", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "South Pole Ice Core Methane Data and Gas Age Time Scale; South Pole ice core (SPC14) total air content (TAC)", "datasets": [{"dataset_uid": "601329", "doi": "10.15784/601329", "keywords": "Antarctica; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; South Pole", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Methane Data and Gas Age Time Scale", "url": "https://www.usap-dc.org/view/dataset/601329"}, {"dataset_uid": "601546", "doi": "10.15784/601546", "keywords": "Antarctica; South Pole", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) total air content (TAC)", "url": "https://www.usap-dc.org/view/dataset/601546"}], "date_created": "Tue, 02 Jun 2020 00:00:00 GMT", "description": "Brook/1643722 This award supports a project to measure the concentration of the gas methane in air trapped in an ice core collected from the South Pole. The data will provide an age scale (age as a function of depth) by matching the South Pole methane changes with similar data from other ice cores for which the age vs. depth relationship is well known. The ages provided will allow all other gas measurements made on the South Pole core (by the PI and other NSF supported investigators) to be interpreted accurately as a function of time. This is critical because a major goal of the South Pole coring project is to understand the history of rare gases in the atmosphere like carbon monoxide, carbon dioxide, ethane, propane, methyl chloride, and methyl bromide. Relatively little is known about what controls these gases in the atmosphere despite their importance to atmospheric chemistry and climate. Undergraduate assistants will work on the project and be introduced to independent research through their work. The PI will continue visits to local middle schools to introduce students to polar science, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) as part of the project. Methane concentrations from a major portion (2 depth intervals, excluding the brittle ice-zone which is being measured at Penn State University) of the new South Pole ice core will be used to create a gas chronology by matching the new South Pole ice core record with that from the well-dated WAIS Divide ice core record. In combination with measurements made at Penn State, this will provide gas dating for the entire 50,000-year record. Correlation will be made using a simple but powerful mid-point method that has been previously demonstrated, and other methods of matching records will be explored. The intellectual merit of this work is that the gas chronology will be a fundamental component of this ice core project, and will be used by the PI and other investigators for dating records of atmospheric composition, and determining the gas age-ice age difference independently of glaciological models, which will constrain processes that affected firn densification in the past. The methane data will also provide direct stratigraphic markers of important perturbations to global biogeochemical cycles (e.g., rapid methane variations synchronous with abrupt warming and cooling in the Northern Hemisphere) that will tie other ice core gas records directly to those perturbations. A record of the total air content will also be produced as a by-product of the methane measurements and will contribute to understanding of this parameter. The broader impacts include that the work will provide a fundamental data set for the South Pole ice core project and the age scale (or variants of it) will be used by all other investigators working on gas records from the core. The project will employ an undergraduate assistant(s) in both years who will conduct an undergraduate research project which will be part of the student\u0027s senior thesis or other research paper. The project will also offer at least one research position for the Oregon State University Summer REU site program. Visits to local middle schools, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) will also be part of the project.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "AMD; LABORATORY; METHANE; ICE CORE RECORDS; Gas Chromatography; South Pole; USAP-DC", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "A High Resolution Atmospheric Methane Record from the South Pole Ice Core", "uid": "p0010102", "west": 0.0}, {"awards": "1443470 Aydin, Murat", "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": "South Pole ice core (SPC14) discrete methane data; SP19 Gas Chronology; SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "datasets": [{"dataset_uid": "601270", "doi": "10.15784/601270", "keywords": "Antarctica", "people": "Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601270"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Winski, Dominic A.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.; Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}], "date_created": "Thu, 26 Mar 2020 00:00:00 GMT", "description": "In the past, Earth\u0027s climate underwent dramatic changes that influenced physical, chemical, geological, and biological processes on a global scale. Such changes left an imprint in Earth\u0027s atmosphere, as shown by the variability in abundances of trace gases like carbon dioxide and methane. In return, changes in the atmospheric trace gas composition affected Earth\u0027s climate. Studying compositional variations of the past atmosphere helps us understand the history of interactions between global biogeochemical cycles and Earth?s climate. The most reliable information on past atmospheric composition comes from analysis of air entrapped in polar ice cores. This project aims to generate ice-core records of relatively short-lived, very-low-abundance trace gases to determine the range of past variability in their atmospheric levels and investigate the changes in global biogeochemical cycles that caused this variability. This project measures three such gases: carbonyl sulfide, methyl chloride, and methyl bromide. Changes in carbonyl sulfide can indicate changes in primary productivity and photosynthetic update of carbon dioxide. Changes in methyl chloride and methyl bromide significantly impact natural variability in stratospheric ozone. In addition, the processes that control atmospheric levels of methyl chloride and methyl bromide are shared with those controlling levels of atmospheric methane. The measurements will be made in the new ice core from the South Pole, which is expected to provide a 40,000-year record. The primary focus of this project is to develop high-quality trace gas records for the entire Holocene period (the past 11,000 years), with additional, more exploratory measurements from the last glacial period including the period from 29,000-36,000 years ago when there were large changes in atmospheric methane. Due to the cold temperatures of the South Pole ice, the proposed carbonyl sulfide measurements are expected to provide a direct measure of the past atmospheric variability of this gas without the large hydrolysis corrections that are necessary for interpretation of measurements from ice cores in warmer settings. Furthermore, we will test the expectation that contemporaneous measurements from the last glacial period in the deep West Antarctic Ice Sheet Divide ice core will not require hydrolysis loss corrections. With respect to methyl chloride, we aim to verify and improve the existing Holocene atmospheric history from the Taylor Dome ice core in Antarctica. The higher resolution of our measurements compared with those from Taylor Dome will allow us to derive a more statistically significant relationship between methyl chloride and methane. With respect to methyl bromide, we plan to extend the existing 2,000-year database to 11,000 years. Together, the methyl bromide and methyl chloride records will provide strong measurement-based constraints on the natural variability of stratospheric halogens during the Holocene period. In addition, the methyl bromide record will provide insight into the correlation between methyl chloride and methane during the Holocene period due to common sources and sinks.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; CARBONYL SULFIDE; HALOCARBONS AND HALOGENS; TRACE GASES/TRACE SPECIES; Antarctic; USAP-DC", "locations": "Antarctic", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Carbonyl Sulfide, Methyl Chloride, and Methyl Bromide Measurements in the New Intermediate-depth South Pole Ice Core", "uid": "p0010089", "west": -180.0}, {"awards": "1443105 Steig, Eric", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core; South Pole high resolution ice core water stable isotope record for dD, d18O; South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}, {"dataset_uid": "601239", "doi": "10.15784/601239", "keywords": "Antarctica; Cavity Ring Down Spectrometers; Delta 18O; Delta Deuterium; Deuterium Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Oxygen Isotope; Snow/ice; Snow/Ice; Stable Isotopes", "people": "Jones, Tyler R.; Vaughn, Bruce; Kahle, Emma; Steig, Eric J.; Schauer, Andrew; Morris, Valerie; White, James", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole high resolution ice core water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601239"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Jones, Tyler R.; Kahle, Emma; Steig, Eric J.; White, James; Epifanio, Jenna; Buizert, Christo; Waddington, Edwin D.; Conway, Howard; Stevens, Max; Schauer, Andrew; Vaughn, Bruce; Morris, Valerie; Koutnik, Michelle; Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "url": "https://www.usap-dc.org/view/dataset/601396"}, {"dataset_uid": "601429", "doi": "10.15784/601429", "keywords": "Antarctica; Climate; Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrogen; Ice; Ice Core; Ice Core Chemistry; Oxygen; Paleoclimate; Snow/ice; Snow/Ice; South Pole; Stable Isotopes", "people": "Vaughn, Bruce; Jones, Tyler R.; White, James; Morris, Valerie; Schauer, Andrew; Steig, Eric J.; Kahle, Emma", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core", "url": "https://www.usap-dc.org/view/dataset/601429"}], "date_created": "Sun, 17 Nov 2019 00:00:00 GMT", "description": "This project will develop a record of the stable-isotope ratios of water from an ice core at the South Pole, Antarctica. Water-isotope ratio measurements provide a means to determine variability in temperature through time. South Pole is distinct from most other locations in Antarctica in showing no warming in recent decades, but little is known about temperature variability in this location prior to the installation of weather stations in 1957. The measurements made as part of this project will result in a much longer temperature record, extending at least 40,000 years, aiding our ability to understand what controls Antarctic climate, and improving projections of future Antarctic climate change. Data from this project will be critical to other investigators working on the South Pole ice core, and of general interest to other scientists and the public. Data will be provided rapidly to other investigators and made public as soon as possible. This project will obtain records of the stable-isotope ratios of water on the ice core currently being obtained at South Pole. The core will reach a depth of 1500 m and an age of 40,000 years. The project will use laser spectroscopy to obtain both an ultra-high-resolution record of oxygen 18/16 and deuterium-hydrogen ratios, and a lower-resolution record of oxygen 17/16 ratios. The high-resolution measurements will be used to aid in dating the core, and to provide estimates of isotope diffusion that constrain the process of firn densification. The novel 17/16 measurement provides additional constraints on the isotope fractionation due to the temperature-dependent supersaturation ratio, which affects the fractionation of water during the liquid-solid condensate transition. Together, these techniques will allow for improved accuracy in the use of the water isotope ratios as proxies for ice-sheet temperature, sea-surface temperature, and atmospheric circulation. The result will be a record of decadal through centennial and millennial scale climate change in a climatically distinct region in East Antarctica that has not been previously sampled by deep ice coring. The project will support a graduate student who will be co-advised by faculty at the University of Washington and the University of Colorado, and will be involved in all aspects of the work.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "SPICEcore; D18O; LABORATORY; OXYGEN ISOTOPE ANALYSIS; Oxygen Isotope; South Pole; USAP-DC; GLACIERS/ICE SHEETS; Antarctica; AMD; FIELD INVESTIGATION; Ice Core", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Steig, Eric J.; White, James", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole", "uid": "p0010065", "west": 0.0}, {"awards": "1141839 Steig, Eric; 1142646 Twickler, Mark; 1142517 Aydin, Murat", "bounds_geometry": "POINT(90 -90)", "dataset_titles": "South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; South Pole ice core (SPC14) discrete methane data; South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Winski, Dominic A.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.; Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601221", "doi": "10.15784/601221", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Depth; Ice Core Records; Snow/ice; Snow/Ice; SPICEcore", "people": "Steig, Eric J.; Nunn, Richard; Hargreaves, Geoff; Fudge, T. J.; Nicewonger, Melinda R.; Kahle, Emma; Souney, Joseph Jr.; Twickler, Mark; Fegyveresi, John; Casey, Kimberly A.; Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth", "url": "https://www.usap-dc.org/view/dataset/601221"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Jones, Tyler R.; Kahle, Emma; Steig, Eric J.; White, James; Epifanio, Jenna; Buizert, Christo; Waddington, Edwin D.; Conway, Howard; Stevens, Max; Schauer, Andrew; Vaughn, Bruce; Morris, Valerie; Koutnik, Michelle; Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "url": "https://www.usap-dc.org/view/dataset/601396"}], "date_created": "Wed, 30 Oct 2019 00:00:00 GMT", "description": "1142517/Saltzman This proposal requests support for a project to drill and recover a new ice core from South Pole, Antarctica. The South Pole ice core will be drilled to a depth of 1500 m, providing an environmental record spanning approximately 40 kyrs. This core will be recovered using a new intermediate drill, which is under development by the U.S. Ice Drilling Design and Operations (IDDO) group in collaboration with Danish scientists. This proposal seeks support to provide: 1) scientific management and oversight for the South Pole ice core project, 2) personnel for ice core drilling and core processing, 3) data management, and 3) scientific coordination and communication via scientific workshops. The intellectual merit of the work is that the analysis of stable isotopes, atmospheric gases, and aerosol-borne chemicals in polar ice has provided unique information about the magnitude and timing of changes in climate and climate forcing through time. The international ice core research community has articulated the goal of developing spatial arrays of ice cores across Antarctica and Greenland, allowing the reconstruction of regional patterns of climate variability in order to provide greater insight into the mechanisms driving climate change. The broader impacts of the project include obtaining the South Pole ice core will support a wide range of ice core science projects, which will contribute to the societal need for a basic understanding of climate and the capability to predict climate and ice sheet stability on long time scales. Second, the project will help train the next generation of ice core scientists by providing the opportunity for hands-on field and core processing experience for graduate students and postdoctoral researchers. A postdoctoral researcher at the University of Washington will be directly supported by this project, and many other young scientists will interact with the project through individual science proposals. Third, the project will result in the development of a new intermediate drill which will become an important resource to US ice core science community. This drill will have a light logistical footprint which will enable a wide range of ice core projects to be carried out that are not currently feasible. Finally, although this project does not request funds for outreach activities, the project will run workshops that will encourage and enable proposals for coordinated outreach activities involving the South Pole ice core science team.", "east": 90.0, "geometry": "POINT(90 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; Amd/Us; Antarctica; ANALYTICAL LAB; USA/NSF; AMD; South Pole; ICE CORE RECORDS; FIELD INVESTIGATION; Ice Core", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Twickler, Mark; Souney, Joseph Jr.; Aydin, Murat; Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: A 1500m Ice Core from South Pole", "uid": "p0010060", "west": 90.0}, {"awards": "1443663 Cole-Dai, Jihong; 1443397 Kreutz, Karl; 1443336 Osterberg, Erich", "bounds_geometry": "POINT(-180 -90)", "dataset_titles": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.; South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; South Pole ice core (SPC14) discrete methane data; South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements; SPICEcore 400-480 m Major Ions SDSU; The South Pole Ice Core (SPICEcore) chronology and supporting data", "datasets": [{"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Winski, Dominic A.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.; Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601675", "doi": "10.15784/601675", "keywords": "Antarctica; South Pole; SPICEcore", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.", "url": "https://www.usap-dc.org/view/dataset/601675"}, {"dataset_uid": "601553", "doi": "10.15784/601553", "keywords": "Antarctica; Dust; Ice Core; South Pole", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements", "url": "https://www.usap-dc.org/view/dataset/601553"}, {"dataset_uid": "601430", "doi": "10.15784/601430", "keywords": "Antarctica; Ions; South Pole; SPICEcore", "people": "Cole-Dai, Jihong; Larrick, Carleigh", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore 400-480 m Major Ions SDSU", "url": "https://www.usap-dc.org/view/dataset/601430"}, {"dataset_uid": "601206", "doi": "10.15784/601206", "keywords": "Antarctica; Calcium (ca); Chemistry:ice; Chemistry:Ice; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciochemistry; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Ice Core Records; Ice Core Stratigraphy; Nitrate; Nitrogen Isotopes; Paleoclimate; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Buizert, Christo; Severinghaus, Jeffrey P.; Osterberg, Erich; Waddington, Edwin D.; Alley, Richard; Casey, Kimberly A.; Nicewonger, Melinda R.; Aydin, Murat; Ferris, David G.; Kahle, Emma; Morris, Valerie; Steig, Eric J.; Sowers, Todd A.; Beaudette, Ross; Brook, Edward J.; Ortman, Nikolas; Epifanio, Jenna; Kreutz, Karl; Cox, Thomas S.; Thundercloud, Zayta; Cole-Dai, Jihong; Fegyveresi, John; McConnell, Joseph; Sigl, Michael; Souney, Joseph Jr.; Bay, Ryan; Dunbar, Nelia; Fudge, T. J.; Winski, Dominic A.; Iverson, Nels; Jones, Tyler R.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "The South Pole Ice Core (SPICEcore) chronology and supporting data", "url": "https://www.usap-dc.org/view/dataset/601206"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}], "date_created": "Thu, 29 Aug 2019 00:00:00 GMT", "description": "This collaborative project explores the signatures and causes of natural climate change in the region surrounding Antarctica over the last 40,000 years as the Earth transitioned from an ice age into the modern warm period. The researchers will investigate how the wind belts that surround Antarctica changed in their strength and position through time, and document explosive volcanic eruptions and CO2 cycling in the Southern Ocean as potential climate forcing mechanisms over this interval. Understanding how and why the climate varied naturally in the past is critical for improving understanding of modern climate change and projections of future climate under higher levels of atmospheric CO2. The investigators plan to conduct a suite of chemical measurements along the 1500m length of the South Pole Ice Core, including major ion and trace element concentrations, and microparticle (dust) concentrations and size distributions. These measurements will (1) extend the South Pole record of explosive volcanic eruptions to 40,000 years using sulfate and particle data; (2) establish the relative timing of climate changes in dust source regions of Patagonia, New Zealand, and Australia using dust flux data; (3) investigate changes in the strength and position of the westerly wind belt using dust size distribution data; and (4) quantify the flux of bioavailable trace metals deposited as dust to the Southern Ocean over time. These chemistry records will also be critical for creating the timescale that will be used by all researchers studying records from the South Pole core. The project will support four graduate students and several undergraduate students across three different institutions, and become a focus of the investigators\u0027 efforts to disseminate outcomes of climate change science to the broader community.", "east": -180.0, "geometry": "POINT(-180 -90)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; ICE CORE RECORDS; USAP-DC; Amd/Us; USA/NSF; LABORATORY; AMD", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Osterberg, Erich", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "uid": "p0010051", "west": -180.0}, {"awards": "1246357 Bart, Philip", "bounds_geometry": null, "dataset_titles": "NBP1502 Cruise Geophysics and underway data; NBP1502 YoYo camera benthic images from Ross Sea", "datasets": [{"dataset_uid": "000245", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1502 Cruise Geophysics and underway data", "url": "https://www.rvdata.us/search/cruise/NBP1502"}, {"dataset_uid": "601182", "doi": "10.15784/601182", "keywords": "Antarctica; Benthic; Benthic Images; Benthos; Bentic Fauna; Camera Tow; Marine Geoscience; Marine Sediments; NBP1502; Photo; Photo/video; Photo/Video; Ross Sea; R/v Nathaniel B. Palmer; Southern Ocean; Yoyo Camera", "people": "Bart, Philip", "repository": "USAP-DC", "science_program": null, "title": "NBP1502 YoYo camera benthic images from Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601182"}], "date_created": "Mon, 03 Jun 2019 00:00:00 GMT", "description": "Intellectual Merit: Evidence from the eastern Ross Sea continental shelf indicates that the West Antarctic Ice Sheet advanced and retreated during the last glacial cycle, but it is unclear whether the ice sheet advanced to the shelf edge or just to the middle shelf. These two end-member scenarios offer different interpretations as to why, how, and when the West Antarctic Ice Sheet oscillated. The PI proposes to acquire seismic, multibeam, and core data from Whales Deep, to evaluate the timing and duration of two advances of grounded ice to the outer and middle shelf of the Whales Deep Basin, a West Antarctic Ice Sheet paleo ice stream trough in eastern Ross Sea. Grounding events are represented by seismically resolvable Grounding Zone Wedges. The PI will collect radiocarbon dates on in situ benthic foraminifera from the grounding zone diamict as well as ramped pyrolysis radiocarbon dates on acid insoluble organics from open-marine mud overlying the grounding zone diamict. Using these data the PI will calculate the duration of the two grounding events. Furthermore, the PI will test a numerical model prediction that West Antarctic Ice Sheet retreat must have involved melting at the marine terminus of the ice sheet. Pore-water from the grounding zone diamict will be extracted from piston cores to determine salinity and \u0026#948;18O values that should indicate if significant melting occurred at the grounding line. Broader impacts: The data collected will provide constraints on the timing and pattern of Last Glacial Maximum advance and retreat that can be incorporated into interpretations of ice-surface elevation changes. The proposed activities will provide valuable field and research training to undergraduate/graduate students and a Louisiana high-school science teacher. The research will be interactively shared with middle- and high-school science students and with visitors to the LSU Museum of Natural Science Weekend-Science Program.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e AIRGUN ARRAYS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e LONG STREAMERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "STRATIGRAPHIC SEQUENCE; R/V NBP; Ross Sea; Antarctica; MICROFOSSILS; RADIOCARBON; PALEOCLIMATE RECONSTRUCTIONS; SEDIMENTS; Southern Ocean; OCEANS; GEOSCIENTIFIC INFORMATION", "locations": "Antarctica; Ross Sea; Southern Ocean", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bart, Philip; Steinberg, Deborah", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "Timing and Duration of the LGM and Post-LGM Grounding Events in Whales Deep Paleo Ice Stream, Eastern Ross Sea Middle Continental Shelf", "uid": "p0000877", "west": null}, {"awards": "1443710 Severinghaus, Jeffrey; 1443472 Brook, Edward J.; 1443464 Sowers, Todd", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "South Pole CH4 data for termination; South Pole Ice Core Isotopes of N2 and Ar; South Pole ice core (SPC14) discrete methane data; South Pole ice core total air content; South Pole (SPICECORE) 15N, 18O, O2/N2 and Ar/N2; SP19 Gas Chronology", "datasets": [{"dataset_uid": "601517", "doi": "10.15784/601517", "keywords": "Antarctica; Argon; Argon Isotopes; Firn; Firn Temperature Gradient; Firn Thickness; Gas Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Nitrogen; Nitrogen Isotopes; South Pole; SPICEcore", "people": "Severinghaus, Jeffrey P.; Morgan, Jacob", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Isotopes of N2 and Ar", "url": "https://www.usap-dc.org/view/dataset/601517"}, {"dataset_uid": "601230", "doi": "10.15784/601230", "keywords": "Antarctica; Atmospheric CH4; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Data; Methane; Methane Concentration; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole CH4 data for termination", "url": "https://www.usap-dc.org/view/dataset/601230"}, {"dataset_uid": "601231", "doi": "10.15784/601231", "keywords": "Air Content; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core total air content", "url": "https://www.usap-dc.org/view/dataset/601231"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Winski, Dominic A.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.; Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601152", "doi": "10.15784/601152", "keywords": "Antarctica; Antarctic Ice Sheet; Chemistry:gas; Chemistry:Gas; Chemistry:ice; Chemistry:Ice; Delta 18O; Dole Effect; Firn Thickness; Gas Isotopes; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Gravitational Settling; Ice; Ice Core Chemistry; Ice Core Data; Ice Core Gas Records; Ice Core Records; Inert Gases; Nitrogen; Nitrogen Isotopes; Oxygen; Oxygen Isotope; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPICECORE) 15N, 18O, O2/N2 and Ar/N2", "url": "https://www.usap-dc.org/view/dataset/601152"}], "date_created": "Sat, 02 Feb 2019 00:00:00 GMT", "description": "Gases trapped in ice cores have revealed astonishing things about the greenhouse gas composition of the past atmosphere, including the fact that carbon dioxide concentrations never rose above 300 parts per million during the last 800,000 years. This places today\u0027s concentration of 400 parts per million in stark contrast. Furthermore, these gas records show that natural sources of greenhouse gas such as oceans and ecosystems act as amplifiers of climate change by increasing emissions of gases during warmer periods. Such amplification is expected to occur in the future, adding to the human-produced gas burden. The South Pole ice core will build upon these prior findings by expanding the suite of gases to include, for the first time, those potent trace gases that both trapped heat and depleted ozone during the past 40,000 years. The present project on inert gases and methane in the South Pole ice core will improve the dating of this crucial record, to unprecedented precision, so that the relative timing of events can be used to learn about the mechanism of trace gas production and destruction, and consequent climate change amplification. Ultimately, this information will inform predictions of future atmospheric chemical cleansing mechanisms and climate in the context of our rapidly changing atmosphere. This award also engages young people in the excitement of discovery and polar research, helping to entrain the next generations of scientists and educators. Education of graduate students, a young researcher (Buizert), and training of technicians, will add to the nation?s human resource base. This award funds the construction of the gas chronology for the South Pole 1500m ice core, using measured inert gases (d15N and d40Ar--Nitrogen and Argon isotope ratios, respectively) and methane in combination with a next-generation firn densification model that treats the stochastic nature of air trapping and the role of impurities on densification. The project addresses fundamental gaps in scientific understanding that limit the accuracy of gas chronologies, specifically a poor knowledge of the controls on ice-core d15N and the possible role of layering and impurities in firn densification. These gaps will be addressed by studying the gas enclosure process in modern firn at the deep core site. The work will comprise the first-ever firn air pumping experiment that has tightly co-located measurements of firn structural properties on the core taken from the same borehole. The project will test the hypothesis that the lock-in horizon as defined by firn air d15N, CO2, and methane is structurally controlled by impermeable layers, which are in turn created by high-impurity content horizons in which densification is enhanced. Thermal signals will be sought using the inert gas measurements, which improve the temperature record with benefits to the firn densification modeling. Neon, argon, and oxygen will be measured in firn air and a limited number of deep core samples to test whether glacial period layering was enhanced, which could explain low observed d15N in the last glacial period. Drawing on separate volcanic and methane synchronization to well-dated ice cores to create independent ice and gas tie points, independent empirical estimates of the gas age-ice age difference will be made to check the validity of the firn densification model-inert gas approach to calculating the gas age-ice age difference. These points will also be used to test whether the anomalously low d15N seen during the last glacial period in east Antarctic ice cores is due to deep air convection in the firn, or a missing impurity dependence in the firn densification models. The increased physical understanding gained from these studies, combined with new high-precision measurements, will lead to improved accuracy of the gas chronology of the South Pole ice core, which will enhance the overall science return from this gas-oriented core. This will lead to clarification of timing of atmospheric gas variations and temperature, and aid in efforts to understand the biogeochemical feedbacks among trace gases. These feedbacks bear on the future response of the Earth System to anthropogenic forcing. Ozone-depleting substances will be measured in the South Pole ice core record, and a precise gas chronology will add value. Lastly, by seeking a better understanding of the physics of gas entrapment, the project aims to have an impact on ice-core science in general.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "USAP-DC; AMD; LABORATORY; Antarctica; NITROGEN ISOTOPES; USA/NSF; METHANE; Amd/Us; FIELD INVESTIGATION", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Sowers, Todd A.; 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": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core", "uid": "p0010005", "west": 0.0}, {"awards": "1443306 Mayewski, Paul; 1443263 Higgins, John", "bounds_geometry": null, "dataset_titles": "Allan Hills ice water stable isotope record for dD, d18O; 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": "Higgins, John; Yan, Yuzhen; Bender, Michael; Brook, Edward J.", "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": "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": "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": "Ng, Jessica; Severinghaus, Jeffrey P.; Yan, Yuzhen; Bender, Michael; Higgins, John", "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": "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": "Kurbatov, Andrei V.; Yan, Yuzhen; 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": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Mayewski, Paul A.; Introne, Douglas; Severinghaus, Jeffrey P.; Kurbatov, Andrei V.; Higgins, John; Brook, Edward", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"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; Mayewski, Paul A.; Kurbatov, Andrei V.; 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": "601863", "doi": null, "keywords": "Allan Hills; Antarctica; Cryosphere; Isotope Data", "people": "Higgins, John; Introne, Douglas; Brook, Edward; Mayewski, Paul A.; Severinghaus, Jeffrey P.; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "Allan Hills ice water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601863"}, {"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": "Introne, Douglas; Kurbatov, Andrei V.; Yan, Yuzhen; Mayewski, Paul A.", "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": "601483", "doi": "10.15784/601483", "keywords": "Allan Hills; Antarctica; Argon; Ice; Ice Core Data; Ice Core Gas Records; Isotope; Mass Spectrometry; Nitrogen; Oxygen", "people": "Yan, Yuzhen; Bender, Michael; 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": "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": "Yan, Yuzhen; Bender, Michael; Brook, Edward J.; Higgins, John", "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"}, {"dataset_uid": "601512", "doi": "10.15784/601512", "keywords": "Allan Hills; Antarctica; Blue Ice; Ice Core; Ice Core Gas Records; Isotope; Nitrogen; Oxygen", "people": "Bender, Michael; Yan, Yuzhen; Higgins, John", "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"}], "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. Between 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": "0839142 Tulaczyk, Slawek; 0839059 Powell, Ross; 0838764 Anandakrishnan, Sridhar; 0838947 Tulaczyk, Slawek; 0838855 Jacobel, Robert; 0838763 Anandakrishnan, Sridhar; 0839107 Powell, Ross", "bounds_geometry": null, "dataset_titles": "Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line; Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats in W Antarctica - Lake and Ice Stream Subglacial Access Research Drilling (LISSARD); Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES); IRIS ID#s 201035, 201162, 201205; IRIS offers free and open access to a comprehensive data store of raw geophysical time-series data collected from a large variety of sensors, courtesy of a vast array of US and International scientific networks, including seismometers (permanent and temporary), tilt and strain meters, infrasound, temperature, atmospheric pressure and gravimeters, to support basic research aimed at imaging the Earth\u0027s interior.; Paleogene marine and terrestrial development of the West Antarctic Rift System: Biomarker Data Set; Paleogene marine and terrestrial development of the West Antarctic Rift System: Palynomorph Data Set; Radar Studies of Subglacial Lake Whillans and the Whillans Ice Stream Grounding Zone; The IRIS DMC archives and distributes data to support the seismological research community.; UNAVCO ID#s WHL1, WHL2, LA02, LA09 (full data link not provided)", "datasets": [{"dataset_uid": "609594", "doi": "10.7265/N54J0C2W", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; GPS; Radar; Whillans Ice Stream", "people": "Jacobel, Robert", "repository": "USAP-DC", "science_program": null, "title": "Radar Studies of Subglacial Lake Whillans and the Whillans Ice Stream Grounding Zone", "url": "https://www.usap-dc.org/view/dataset/609594"}, {"dataset_uid": "001406", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "The IRIS DMC archives and distributes data to support the seismological research community.", "url": "http://ds.iris.edu/ds/nodes/dmc/"}, {"dataset_uid": "001405", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IRIS offers free and open access to a comprehensive data store of raw geophysical time-series data collected from a large variety of sensors, courtesy of a vast array of US and International scientific networks, including seismometers (permanent and temporary), tilt and strain meters, infrasound, temperature, atmospheric pressure and gravimeters, to support basic research aimed at imaging the Earth\u0027s interior.", "url": "http://www.iris.edu/hq/data_and_software"}, {"dataset_uid": "601234", "doi": "10.15784/601234", "keywords": "ACL; Antarctica; Biomarker; BIT Index; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Stream; Whillans Ice Stream; WISSARD", "people": "Scherer, Reed Paul; Baudoin, Patrick; Warny, Sophie; Coenen, Jason; Askin, Rosemary; Casta\u00f1eda, Isla", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Paleogene marine and terrestrial development of the West Antarctic Rift System: Biomarker Data Set", "url": "https://www.usap-dc.org/view/dataset/601234"}, {"dataset_uid": "601245", "doi": "10.15784/601245", "keywords": "Antarctica; Pollen; West Antarctica; WISSARD", "people": "Baudoin, Patrick; Coenen, Jason; Warny, Sophie; Askin, Rosemary; Scherer, Reed Paul; Casta\u00f1eda, Isla", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Paleogene marine and terrestrial development of the West Antarctic Rift System: Palynomorph Data Set", "url": "https://www.usap-dc.org/view/dataset/601245"}, {"dataset_uid": "601122", "doi": "10.15784/601122", "keywords": "Antarctica; Flexure Zone; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Ice-Shelf Basal Melting; Ice-Shelf Strain Rate", "people": "Begeman, Carolyn", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Basal melt rates of the Ross Ice Shelf near the Whillans Ice Stream grounding line", "url": "https://www.usap-dc.org/view/dataset/601122"}, {"dataset_uid": "600155", "doi": "10.15784/600155", "keywords": "Antarctica; Glaciology; Oceans; Southern Ocean; WISSARD", "people": "Powell, Ross", "repository": "USAP-DC", "science_program": null, "title": "Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES)", "url": "https://www.usap-dc.org/view/dataset/600155"}, {"dataset_uid": "600154", "doi": "10.15784/600154", "keywords": "Antarctica; Biota; Diatom; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Lake Whillans; Paleoclimate; Ross Sea; Southern Ocean; Subglacial Lake; WISSARD", "people": "Powell, Ross", "repository": "USAP-DC", "science_program": null, "title": "Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats in W Antarctica - Lake and Ice Stream Subglacial Access Research Drilling (LISSARD)", "url": "https://www.usap-dc.org/view/dataset/600154"}, {"dataset_uid": "000150", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "UNAVCO ID#s WHL1, WHL2, LA02, LA09 (full data link not provided)", "url": "http://www.unavco.org/"}, {"dataset_uid": "000148", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "IRIS ID#s 201035, 201162, 201205", "url": "http://ds.iris.edu/"}], "date_created": "Mon, 10 Sep 2018 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The LISSARD project (Lake and Ice Stream Subglacial Access Research Drilling) is one of three research components of the WISSARD integrative initiative (Whillans Ice Stream Subglacial Access Research Drilling) that is being funded by the Antarctic Integrated System Science Program of NSF\u0027s Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The LISSARD component of WISSARD focuses on the role of active subglacial lakes in determining how fast the West Antarctic ice sheet loses mass to the global ocean and influences global sea level changes. The importance of Antarctic subglacial lakes has only been recently recognized, and the lakes have been identified as high priority targets for scientific investigations because of their unknown contributions to ice sheet stability under future global warming scenarios. LISSARD has several primary science goals: A) To provide an observational basis for improving treatments of subglacial hydrological and mechanical processes in models of ice sheet mass balance and stability; B) To reconstruct the past history of ice stream stability by analyzing archives of past basal water and ice flow variability contained in subglacial sediments, porewater, lake water, and basal accreted ice; C) To provide background understanding of subglacial lake environments to benefit RAGES and GBASE (the other two components of the WISSARD project); and D) To synthesize data and concepts developed as part of this project to determine whether subglacial lakes play an important role in (de)stabilizing Antarctic ice sheets. We propose an unprecedented synthesis of approaches to studying ice sheet processes, including: (1) satellite remote sensing, (2) surface geophysics, (3) borehole observations and measurements and, (4) basal and subglacial sampling. \u003cbr/\u003e\u003cbr/\u003eINTELLECTUAL MERIT: The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. \u003cbr/\u003e\u003cbr/\u003eBROADER IMPACTS: Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; 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": true, "keywords": "USAP-DC; Ice Penetrating Radar; Antarctic; Subglacial Lake; Subglacial Hydrology; Grounding Line; Sea Level Rise; Bed Reflectivity; Ice Sheet Stability; Stability; Radar; Sub-Ice-Shelf; Geophysics; Biogeochemical; LABORATORY; Sediment; Sea Floor Sediment; Ice Thickness; Model; Ice Stream Stability; Basal Ice; SATELLITES; Ice Sheet Thickness; Subglacial; Antarctica; NOT APPLICABLE; Antarctic Ice Sheet; Ice Sheet; FIELD SURVEYS; Surface Elevation; Geochemistry; FIELD INVESTIGATION; Not provided", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek; Fisher, Andrew; Powell, Ross; Anandakrishnan, Sridhar; Jacobel, Robert; Scherer, Reed Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "USAP-DC", "repositories": "IRIS; UNAVCO; USAP-DC", "science_programs": "WISSARD", "south": null, "title": "Collaborative Research: Integrative Study of Marine Ice Sheet Stability \u0026 Subglacial Life Habitats in W Antarctica - Lake \u0026 Ice Stream Subglacial Access Research Drilling (LISSARD)", "uid": "p0000105", "west": null}, {"awards": "1142115 Dunbar, Nelia", "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": "No data submitted yet, but submission to Antarctic tephra database is planned", "datasets": [{"dataset_uid": "002571", "doi": "", "keywords": null, "people": null, "repository": "in progress", "science_program": null, "title": "No data submitted yet, but submission to Antarctic tephra database is planned", "url": "http://www.tephrochronology.org/AntT/about.html"}], "date_created": "Sun, 10 Jun 2018 00:00:00 GMT", "description": "Dunbar/1142115 This award supports a project to investigate the extremely rich volcanic record in the WAIS Divide ice core as part of this ongoing tephrochronology research in Antarctica. Ice cores in Polar Regions offer unparalleled records of earth\u0027s climate over the past 500,000 years. Accurate chronology of individual ice cores and chronological correlations between different ice cores is critically important to the interpretation of the climate record. The field of Antarctic tephrochronology has been progressing steadily, and is on the cusp of having a fully integrated tephra framework for large parts of the continent. Major advances in this field have been made due to the acquisition of a number of ice cores with strong volcanic records, improvement of analytical techniques and better characterization of source eruptions due in part to through studies of englacial tephra from several major blue ice areas. The intellectual merit of this work is that the tephrochonological studies will provide independently dated time-stratigraphic markers in the ice core, particularly for the deepest ice, linking tephra layers between the WAIS Divide core and the Siple Dome core which will allow detailed comparisons to be made of coastal and inland climate. It will also contribute to a better understanding of eruption magnitude, dispersal patterns and geochemical evolution of West Antarctic volcanoes. The work will also contribute to a new tephra dataset to the literature for use in future ice core studies. The broader impacts of this project fall into the areas of education, outreach and international cooperation. This project will employ one New Mexico Tech graduate student, but will also be featured in outreach programs for NMT undergraduates, as well as teacher and student groups and outreach for the general public in New Mexico. NMT is an Hispanic serving institution (25% Hispanic students) and also found by NSF to rank 15th nationwide in \"baccalaureate-origin\" institutions for doctoral recipients in science and engineering, thereby having a disproportionately large effect on producing Hispanic scientists and engineers. However, probably the most significant broader impact of this project will be the continued efforts of the PI in fostering and promoting of international cooperation in the tephra-in-ice community. Dunbar has been collaborating with European tephra researchers for a number of years, sharing data and working collaboratively on tephra correlations, and these activities have lead to, and will continue to promote, forward progress in integrating the Antarctic tephrochronology record. This proposal does not require field work in the Antarctic.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Dunbar, Nelia", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "in progress", "repositories": "in progress", "science_programs": null, "south": -90.0, "title": "Tephrochronology of the WAIS Divide Ice Core: Linking Ice Cores through Volcanic Records", "uid": "p0000338", "west": -180.0}, {"awards": "1341585 Sorlien, Christopher", "bounds_geometry": "POLYGON((-180 -73.33,-179.1 -73.33,-178.2 -73.33,-177.3 -73.33,-176.4 -73.33,-175.5 -73.33,-174.6 -73.33,-173.7 -73.33,-172.8 -73.33,-171.9 -73.33,-171 -73.33,-171 -73.864,-171 -74.398,-171 -74.932,-171 -75.466,-171 -76,-171 -76.534,-171 -77.068,-171 -77.602,-171 -78.136,-171 -78.67,-171.9 -78.67,-172.8 -78.67,-173.7 -78.67,-174.6 -78.67,-175.5 -78.67,-176.4 -78.67,-177.3 -78.67,-178.2 -78.67,-179.1 -78.67,180 -78.67,178.5 -78.67,177 -78.67,175.5 -78.67,174 -78.67,172.5 -78.67,171 -78.67,169.5 -78.67,168 -78.67,166.5 -78.67,165 -78.67,165 -78.136,165 -77.602,165 -77.068,165 -76.534,165 -76,165 -75.466,165 -74.932,165 -74.398,165 -73.864,165 -73.33,166.5 -73.33,168 -73.33,169.5 -73.33,171 -73.33,172.5 -73.33,174 -73.33,175.5 -73.33,177 -73.33,178.5 -73.33,-180 -73.33))", "dataset_titles": "Ross Sea unconformities digital grids in depth and two-way time", "datasets": [{"dataset_uid": "601098", "doi": "10.15784/601098", "keywords": "Antarctica; Continental Margin; Geology/Geophysics - Other; Marine Geoscience; Miocene; Oligocene; Seismic Reflection", "people": "Sorlien, Christopher; Wilson, Douglas S.", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea unconformities digital grids in depth and two-way time", "url": "https://www.usap-dc.org/view/dataset/601098"}], "date_created": "Fri, 25 May 2018 00:00:00 GMT", "description": "Intellectual Merit: This project will produce a new compilation of Ross Sea seismic stratigraphy, including new interpretations, that can be used to provide boundary conditions on the tectonic and glacial evolution of West Antarctica and the Ross Sea. The principal goals include compilation of, and interpretation of, all available existing seismic reflection data for the Western Ross Sea, coupled with geophysical modeling to produce paleo-bathymetric reconstructions for the entire 800 km-wide Ross Sea. Specific tasks will include: extending existing work on mapping travel time to reflectors, identifying relations in the seismic data that indicate subsidence through sea level, constructing velocity models for converting travel time to thickness, and using the velocity models to estimate density and porosity of sediments for backstripping analysis. Modeling/backstripping efforts will be used to constrain past bathymetry. Digital interpretations and stratigraphic grids will be provided as supplements to publications. In that way the results of this study can be used in thermal subsidence modeling and restoration of eroded rock to other parts of Ross Embayment and Marie Byrd Land by others. Digital products may be provided in advance of publication to modelers in a way that will not hurt publication chances. Broader impacts: The results of this work will be important for paleo-geographic reconstructions of Antarctica and will therefore be of use to a broad range of researchers, particularly those working in the Ross Sea region. The digital products can be used to test models for the past fluctuations of West Antarctic ice sheets, and in planning for future sediment drilling projects. Two undergraduates to be chosen from applicants will be involved in summer internships held at the University of Rhode Island. Outreach will also include a new website and one or more Wikipedia entries related to Ross Sea sub-sea floor characteristics. The project includes an international collaboration with Dr. Chiara Sauli and others at Instituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Italy.", "east": -171.0, "geometry": "POINT(177 -76)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -73.33, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sorlien, Christopher; Luyendyk, Bruce P.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.67, "title": "Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea", "uid": "p0000271", "west": 165.0}, {"awards": "1443232 Waddington, Edwin", "bounds_geometry": "POLYGON((110 -89,117 -89,124 -89,131 -89,138 -89,145 -89,152 -89,159 -89,166 -89,173 -89,180 -89,180 -89.1,180 -89.2,180 -89.3,180 -89.4,180 -89.5,180 -89.6,180 -89.7,180 -89.8,180 -89.9,180 -90,173 -90,166 -90,159 -90,152 -90,145 -90,138 -90,131 -90,124 -90,117 -90,110 -90,110 -89.9,110 -89.8,110 -89.7,110 -89.6,110 -89.5,110 -89.4,110 -89.3,110 -89.2,110 -89.1,110 -89))", "dataset_titles": "AC-ECM for SPICEcore; ECM (DC and AC) multi-track data and images from 2016 processing season", "datasets": [{"dataset_uid": "601189", "doi": " 10.15784/601189 ", "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; South Pole; SPICEcore; Volcanic", "people": "Fudge, T. J.; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "AC-ECM for SPICEcore", "url": "https://www.usap-dc.org/view/dataset/601189"}, {"dataset_uid": "601366", "doi": "10.15784/601366", "keywords": "Antarctica", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "ECM (DC and AC) multi-track data and images from 2016 processing season", "url": "https://www.usap-dc.org/view/dataset/601366"}], "date_created": "Tue, 08 May 2018 00:00:00 GMT", "description": "Ice cores record detailed histories of past climate variations. The South Pole ice core will allow investigation of atmospheric trace gases and fill an important gap in understanding the pattern of climate variability across Antarctica. An accurate timescale that assigns an age to the ice at each depth in the core is essential to interpretation of the ice-core records. This work will use electrical methods to identify volcanic eruptions throughout the past ~40,000 years in the core by detecting the enhanced electrical conductance in those layers due to volcanic impurities in the ice. These eruptions will be pattern-matched to other cores across Antarctica, synchronizing the timing of climate variations among cores and allowing the precise timescales developed for other Antarctic ice cores to be transferred to the South Pole ice core. The well-dated records of volcanic forcing will be combined with records of atmospheric gases, stable water-isotopes, and aerosols to better understand the large natural climate variations of the past 40,000 years. The electrical conductance method and dielectric profiling measurements will be made along the length of each section of the South Pole ice core at the National Ice Core Lab. These measurements will help to establish a timescale for the core. Electrical measurements will provide a continuous record of volcanic events for the entire core including through the brittle ice (550-1250m representing ~10,000-20,000 year-old ice) where the core quality and thin annual layers may prevent continuous melt analysis and cause discrete measurements to miss volcanic events. The electrical measurements also produce a 2-D image of the electrical layering on a longitudinal cut surface of each core. These data will be used to identify any irregular or absent layering that would indicate a stratigraphic disturbance in the core. A robust chronology is essential to interpretation of the paleoclimate records from the South Pole ice core. The investigators will engage teachers through talks and webinars with the National Science Teachers Association and will share information with the public at events such as Polar Science Weekend at the Pacific Science Center. Results will be disseminated through publications and conference presentations and the data will be archived and publicly available.", "east": 180.0, "geometry": "POINT(145 -89.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; Amd/Us; AMD; LABORATORY", "locations": null, "north": -89.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Waddington, Edwin D.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Using Electrical Conductance Measurements to Develop the South Pole Ice Core Chronology", "uid": "p0000378", "west": 110.0}, {"awards": "1341729 Kirschvink, Joseph", "bounds_geometry": "POLYGON((-58.9 -63.5,-58.63 -63.5,-58.36 -63.5,-58.09 -63.5,-57.82 -63.5,-57.55 -63.5,-57.28 -63.5,-57.01 -63.5,-56.74 -63.5,-56.47 -63.5,-56.2 -63.5,-56.2 -63.62,-56.2 -63.74,-56.2 -63.86,-56.2 -63.98,-56.2 -64.1,-56.2 -64.22,-56.2 -64.34,-56.2 -64.46,-56.2 -64.58,-56.2 -64.7,-56.47 -64.7,-56.74 -64.7,-57.01 -64.7,-57.28 -64.7,-57.55 -64.7,-57.82 -64.7,-58.09 -64.7,-58.36 -64.7,-58.63 -64.7,-58.9 -64.7,-58.9 -64.58,-58.9 -64.46,-58.9 -64.34,-58.9 -64.22,-58.9 -64.1,-58.9 -63.98,-58.9 -63.86,-58.9 -63.74,-58.9 -63.62,-58.9 -63.5))", "dataset_titles": "2016 Paleomagnetic samples from the James Ross Basin, Antarctica; Expedition data of NBP1601", "datasets": [{"dataset_uid": "002665", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1601", "url": "https://www.rvdata.us/search/cruise/NBP1601"}, {"dataset_uid": "601094", "doi": "10.15784/601094", "keywords": "Antarctica; Geochronology; Geology/Geophysics - Other; Glaciology; James Ross Basin; Marine Geoscience; Marine Sediments", "people": "Skinner, Steven; Kirschvink, Joseph", "repository": "USAP-DC", "science_program": null, "title": "2016 Paleomagnetic samples from the James Ross Basin, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601094"}], "date_created": "Fri, 27 Apr 2018 00:00:00 GMT", "description": "Non-Technical Summary: About 80 million years ago, the tip of the Antarctic Peninsula in the vicinity of what is now James Ross Island experienced an episode of rapid subsidence, creating a broad depositional basin that collected sediments eroding from the high mountains to the West. This depression accumulated a thick sequence of fossil-rich, organic-rich sediments of the sort that are known to preserve hydrocarbons, and for which Argentina, Chile, and the United Kingdom have overlapping territorial claims. The rocks preserve one of the highest resolution records of the biological and climatic events that led to the eventual death of the dinosaurs at the Cretaceous-Tertiary boundary (about 66 million years ago). A previous collaboration between scientists from the Instituto Ant\u00e1rtico Argentino (IAA) and NSF-supported teams from Caltech and the University of Washington were able to show that this mass extinction event started nearly 50,000 years before the sudden impact of an asteroid. The asteroid obviously hit the biosphere hard, but something else knocked it off balance well before the asteroid hit. A critical component of the previous work was the use of reversals in the polarity of the Earth?s magnetic field as a dating tool ? magnetostratigraphy. This allowed the teams to correlate the pattern of magnetic reversals from Antarctica with elsewhere on the planet. This includes data from a major volcanic eruption (a flood basalt province) that covered much of India 65 million years ago. The magnetic patterns indicate that the Antarctic extinction started with the first pulse of this massive eruption, which was also coincident with a rapid spike in polar temperature. The Argentinian and US collaborative teams will extend this magnetic polarity record back another ~ 20 million years in time, and expand it laterally to provide magnetic reversal time lines across the depositional basin. They hope to recover the end of the Cretaceous Long Normal interval, which is one of the most distinctive events in the history of Earth?s magnetic field. The new data should refine depositional models of the basin, allow better estimates of potential hydrocarbon reserves, and allow biotic events in the Southern hemisphere to be compared more precisely with those elsewhere on Earth. Other potential benefits of this work include exposing several US students and postdoctoral fellows to field based research in Antarctica, expanding the international aspects of this collaborative work via joint IAA/US field deployments, and follow-up laboratory investigations and personnel exchange of the Junior scientists. Technical Description of Project The proposed research will extend the stratigraphic record in the late Cretaceous and early Tertiary sediments (~ 83 to 65 Ma before present) of the James Ross Basin, Antarctica, using paleo-magnetic methods. Recent efforts provided new methods to analyze these rocks, yielding their primary magnetization, and producing both magnetic polarity patterns and paleomagnetic pole positions. This provided the first reliable age constraints for the younger sediments on Seymour Island, and quantified the sedimentation rate in this part of the basin. The new data will allow resolution of the stable, remnant magnetization of the sediments from the high deposition rate James Ross basin (Tobin et al., 2012), yielding precise chronology/stratigraphy. This approach will be extended to the re-maining portions of this sedimentary basin, and will allow quantitative estimates for tectonic and sedimentary processes between Cretaceous and Early Tertiary time. The proposed field work will refine the position of several geomagnetic reversals that occurred be-tween the end of the Cretaceous long normal period (Chron 34N, ~ 83 Ma), and the lower portion of Chron 31R (~ 71 Ma). Brandy Bay provides the best locality for calibrating the stratigraphic position of the top of the Cretaceous Long Normal Chron, C34N. Although the top of the Cretaceous long normal Chron is one of the most important correlation horizons in the entire geological timescale, it is not properly correlated to the southern hemisphere biostratigraphy. Locating this event, as well as the other reversals, will be a major addition to understanding of the geological history of the Antarctic Peninsula. These data will also help refine tectonic models for the evolution of the Southern continents, which will be of use across the board for workers in Cretaceous stratigraphy (including those involved in oil exploration). This research is a collaborative effort with Dr. Edward Olivero of the Centro Austral de Investigaciones Cientificas (CADIC/CONICET) and Prof. Augusto Rapalini of the University of Buenos Aires. The collaboration will include collection of samples on their future field excursions to important targets on and around James Ross Island, supported by the Argentinian Antarctic Program (IAA). Argentinian scientists and students will also be involved in the US Antarctic program deployments, proposed here for the R/V Laurence Gould, and will continue the pattern of joint international publication of the results.", "east": -56.2, "geometry": "POINT(-57.55 -64.1)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; R/V NBP; USAP-DC", "locations": null, "north": -63.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kirschvink, Joseph; Christensen, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -64.7, "title": "Paleomagnetism and Magnetostratigraphy of the James Ross Basin, Antarctica", "uid": "p0000276", "west": -58.9}, {"awards": "1246045 Waddington, Edwin", "bounds_geometry": "POLYGON((-180 -70,-144 -70,-108 -70,-72 -70,-36 -70,0 -70,36 -70,72 -70,108 -70,144 -70,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,180 -82,180 -84,180 -86,180 -88,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88,-180 -86,-180 -84,-180 -82,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70))", "dataset_titles": "Code for inference of fabric from sonic velocity and thin-section measurements.; Code for models involving stochastic treatment of ice fabric", "datasets": [{"dataset_uid": "000244", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for models involving stochastic treatment of ice fabric", "url": "https://github.com/mjhay/stochastic_fabric"}, {"dataset_uid": "000243", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for inference of fabric from sonic velocity and thin-section measurements.", "url": "https://github.com/mjhay/neem_sonic_model"}], "date_created": "Mon, 02 Apr 2018 00:00:00 GMT", "description": "Waddington/1246045 This award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Waddington, Edwin D.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -90.0, "title": "Anisotropic Ice and Stratigraphic Disturbances", "uid": "p0000073", "west": -180.0}, {"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: Southern 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. Broader impacts: This 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": "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: Southern 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. Broader impacts: This 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": "1341390 Frank, Tracy", "bounds_geometry": null, "dataset_titles": "Stable carbon and oxygen isotope data from drill cores from McMurdo Sound, Antarctica", "datasets": [{"dataset_uid": "000195", "doi": "", "keywords": null, "people": null, "repository": "EarthChem", "science_program": null, "title": "Stable carbon and oxygen isotope data from drill cores from McMurdo Sound, Antarctica", "url": "http://dx.doi.org/10.1594/IEDA/100718"}], "date_created": "Fri, 06 Oct 2017 00:00:00 GMT", "description": "Intellectual Merit: This project will use sediment cores from the Victoria Land Basin (VLB), Antarctica, to study secondary (diagenetic) carbonate minerals, as indicators of the basin?s fluid-flow history, within the well-constrained tectonic, depositional, and climatic context provided by sediment cores. This study will provide insights into subsurface processes in Victoria Land Basin, Antarctica and their relationships with the region?s climatic, cryospheric, and tectonic history. The work will utilize cores previously recovered by US-sponsored stratigraphic drilling projects (CIROS, CRP, and ANDRILL projects). This work is motivated by the unexpected discovery of dense brine in the subsurface of Southern McMurdo Sound during drilling by the ANDRILL Southern McMurdo Sound project. The presence of the brine is intriguing because it contradicts previous models for the origin of subsurface fluids that called upon large contributions from glacial melt water. Project objectives involve documenting the distribution of the brine (and potentially other fluids) via characterization of diagenetic precipitates. The approach will involve integration of petrographic and geochemical data (including conventional carbon, oxygen, and ?clumped? isotopes) to fully characterize diagenetic phases and allow development of a robust paragenetic history. This work will provide novel insights into the Cenozoic evolution of the VLB and, more broadly, the role of glacial processes in generating subsurface fluids. Broader impacts: Results from this project will help understand the origins of brines, groundwater and hydrocarbon reservoirs in analogous modern and ancient deposits elsewhere, which is of broad interest. This project will support the training of one graduate and one undergraduate student at the University of Nebraska-Lincoln (UNL) providing learning opportunities in sedimentary geology and diagenesis, fields with wide applicability. This proposal emphasizes rapid dissemination of results to the scientific community via conference presentations and contributions to peer-reviewed publications. The results will be integrated into education activities designed to develop skills in petrography and diagenesis, which are highly sought after in the energy sector. The project will generate a well-constrained dataset that allows direct linkage of diagenetic phases to environmental and tectonic change across a large sedimentary basin which will provide the basis for a comprehensive case study in an upper-level course (Sedimentary Petrography and Diagenesis) at UNL. In addition, online exercises will be developed and submitted to an open-access site (SEPM Stratigraphy Web) dedicated to sedimentary geology.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Frank, Tracy; Fielding, Christopher", "platforms": "Not provided", "repo": "EarthChem", "repositories": "EarthChem", "science_programs": null, "south": null, "title": "Insights into the Burial, Tectonic, and Hydrologic History of the Cenozoic Succession in McMurdo Sound, Antarctica through Analysis of Diagenetic Phases", "uid": "p0000256", "west": null}, {"awards": "0944191 Taylor, Kendrick; 0944197 Waddington, Edwin", "bounds_geometry": "POLYGON((-180 -79,-173.3 -79,-166.6 -79,-159.9 -79,-153.2 -79,-146.5 -79,-139.8 -79,-133.1 -79,-126.4 -79,-119.7 -79,-113 -79,-113 -79.1,-113 -79.2,-113 -79.3,-113 -79.4,-113 -79.5,-113 -79.6,-113 -79.7,-113 -79.8,-113 -79.9,-113 -80,-119.7 -80,-126.4 -80,-133.1 -80,-139.8 -80,-146.5 -80,-153.2 -80,-159.9 -80,-166.6 -80,-173.3 -80,180 -80,150.9 -80,121.8 -80,92.7 -80,63.6 -80,34.5 -80,5.4 -80,-23.7 -80,-52.8 -80,-81.9 -80,-111 -80,-111 -79.9,-111 -79.8,-111 -79.7,-111 -79.6,-111 -79.5,-111 -79.4,-111 -79.3,-111 -79.2,-111 -79.1,-111 -79,-81.9 -79,-52.8 -79,-23.7 -79,5.4 -79,34.5 -79,63.6 -79,92.7 -79,121.8 -79,150.9 -79,-180 -79))", "dataset_titles": "Accumulation Rates from the WAIS Divide Ice Core; WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica; WAIS Divide Multi Track Electrical Measurements; WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "datasets": [{"dataset_uid": "601004", "doi": "10.15784/601004", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Snow Accumulation; WAIS Divide Ice Core", "people": "Waddington, Edwin D.; Buizert, Christo; Conway, Howard; Fudge, T. J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Accumulation Rates from the WAIS Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/601004"}, {"dataset_uid": "601172", "doi": "10.15784/601172", "keywords": "Antarctic; Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; Wais Project; West Antarctic Ice Sheet", "people": "Taylor, Kendrick C.; Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "WAIS Divide Multi Track Electrical Measurements", "url": "https://www.usap-dc.org/view/dataset/601172"}, {"dataset_uid": "609591", "doi": "10.7265/N5B56GPJ", "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Fudge, T. J.; Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609591"}, {"dataset_uid": "601015", "doi": "10.15784/601015", "keywords": "Antarctica; Depth-Age-Model; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "url": "https://www.usap-dc.org/view/dataset/601015"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "This award supports a project to help to establish the depth-age chronology and the histories of accumulation and ice dynamics for the WAIS Divide ice core. The depth-age relationship and the histories of accumulation and ice dynamics are coupled. An accurate age scale is needed to infer histories of accumulation rate and ice-thickness change using ice-flow models. In turn, the accumulation-rate history is needed to calculate the age difference of ice to determine the age of the trapped gases. The accumulation history is also needed to calculate atmospheric concentrations of impurities trapped in the ice and is an important characteristic of climate. The history of ice-thickness change is also fundamental to understanding the stability of the WAIS. The primary goals of the WAIS Divide ice core project are to investigate climate forcing by greenhouse gases, the initiation of climate changes, and the stability of the West Antarctic Ice Sheet (WAIS). An accurate age scale is fundamental for achieving these goals. The first objective of this project is to establish an annually resolved depth-age relationship for the past 40,000 years. This will be done by measuring variations in electrical conductivity along the ice core, which are caused by seasonal variations in chemistry. We expect to be able to resolve annual layers back to 40,000 years before present (3,000 m depth) using this method. The second objective is to search for stratigraphic disturbances in the core that would compromise the paleoclimate record. Irregular layering will be identified by measuring the electrical conductivity of the ice in a vertical plan through the core. The third objective is to derive a preliminary chronology for the entire core. For the deeper ice we will use an ice-flow model to interpolate between known age markers, such as dated volcanic horizons and tie points from the methane gas chronology. The fourth objective is to derive a refined chronology simultaneously with histories of accumulation and ice-sheet thickness. An ice-flow model and all available data will be used to formulate an inverse problem, in which we infer the most appropriate histories of accumulation and ice-thickness, together with estimates of uncertainties. The flow model associated with those preferred histories then produces the best estimate of the chronology. The research contributes directly to the primary goals of the West Antarctic Ice Sheet Initiative. The project will help develop the next generation of scientists through the education and training of one Ph.D. student and several undergraduate students. This project will result in instrumentation for measuring the electrical conductivity of ice cores being available at the National Ice Core Lab for other researchers to use on other projects. All collaborators are committed to fostering diversity and currently participate in scientific outreach and most participate in undergraduate education. Outreach will be accomplished through regularly scheduled community and K-12 outreach events at UW, talks and popular writing by the PIs, as well as through our respective press offices.", "east": -111.0, "geometry": "POINT(-112 -79.5)", "instruments": null, "is_usap_dc": true, "keywords": "Ice Core Depth; National Ice Core Lab; Electrical Conductivity; FIELD INVESTIGATION; Not provided", "locations": null, "north": -79.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Conway, Howard; Fudge, T. J.; Taylor, Kendrick C.; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -80.0, "title": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core", "uid": "p0000026", "west": -113.0}, {"awards": "1245283 Passchier, Sandra", "bounds_geometry": "POLYGON((66 -68,67.3 -68,68.6 -68,69.9 -68,71.2 -68,72.5 -68,73.8 -68,75.1 -68,76.4 -68,77.7 -68,79 -68,79 -68.2,79 -68.4,79 -68.6,79 -68.8,79 -69,79 -69.2,79 -69.4,79 -69.6,79 -69.8,79 -70,77.7 -70,76.4 -70,75.1 -70,73.8 -70,72.5 -70,71.2 -70,69.9 -70,68.6 -70,67.3 -70,66 -70,66 -69.8,66 -69.6,66 -69.4,66 -69.2,66 -69,66 -68.8,66 -68.6,66 -68.4,66 -68.2,66 -68))", "dataset_titles": "Antarctic Geochemistry Data and Mean Annual Temperature Reconstruction through the Eocene-Oligocene Transition; GSA Data Repository Item 2016298 - Passchier, S., Ciarletta, D.J., Miriagos, T.E., Bijl, P.K., and Bohaty, S.M., 2016, An Antarctic stratigraphic record of step-wise ice growth through the Eocene-Oligocene transition: GSA Bulletin, doi:10.1130/B31482.1.; Particle-size distributions of Eocene-Oligocene sediment from ODP Site 739, Prydz Bay; Particle-size distributions of Eocene-Oligocene sediment from ODP Site 742, Prydz Bay; Particle-size distributions of Eocene sediment from ODP Site 1166, Prydz Bay", "datasets": [{"dataset_uid": "601454", "doi": "10.15784/601454", "keywords": "Antarctica; Eocene; Marine Geoscience; ODP742; Oligocene; Particle Size; Prydz Bay; Sediment Core Data", "people": "Passchier, Sandra; Ciarletta, Daniel", "repository": "USAP-DC", "science_program": null, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 742, Prydz Bay", "url": "https://www.usap-dc.org/view/dataset/601454"}, {"dataset_uid": "200200", "doi": "10.1130/2016298", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": " GSA Data Repository Item 2016298 - Passchier, S., Ciarletta, D.J., Miriagos, T.E., Bijl, P.K., and Bohaty, S.M., 2016, An Antarctic stratigraphic record of step-wise ice growth through the Eocene-Oligocene transition: GSA Bulletin, doi:10.1130/B31482.1.", "url": "https://gsapubs.figshare.com/articles/journal_contribution/Supplemental_material_An_Antarctic_stratigraphic_record_of_step-wise_ice_growth_through_the_Eocene-Oligocene_transition/12534185"}, {"dataset_uid": "601453", "doi": "10.15784/601453", "keywords": "Antarctica; Eocene; Marine Geoscience; ODP739; Oligocene; Particle Size; Prydz Bay; Sediment Core Data", "people": "Ciarletta, Daniel; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 739, Prydz Bay", "url": "https://www.usap-dc.org/view/dataset/601453"}, {"dataset_uid": "601455", "doi": "10.15784/601455", "keywords": "Antarctica; Eocene; Marine Geoscience; ODP1166; Particle Size; Prydz Bay; Sediment Core Data", "people": "Ciarletta, Daniel; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Particle-size distributions of Eocene sediment from ODP Site 1166, Prydz Bay", "url": "https://www.usap-dc.org/view/dataset/601455"}, {"dataset_uid": "000192", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Antarctic Geochemistry Data and Mean Annual Temperature Reconstruction through the Eocene-Oligocene Transition", "url": "https://www.ncdc.noaa.gov/paleo-search/study/21770"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "Intellectual Merit: This project will investigate glacial advance and retreat of the East Antarctic Ice Sheet through the Eocene-Oligocene transition, a major episode of ice growth. In Prydz Bay, East Antarctica, a 130-170 m thick Eocene-Oligocene transition interval of glaciomarine sediments was cored in drillholes of the Ocean Drilling Program at Sites 739, 742 and 1166. Correlations between the Prydz Bay drillholes have recently been made through well-log and multichannel seismic interpretations. Recent drilling on the Wilkes Land margin of East Antarctica recovered earliest Oligocene sediments overlying a major regional unconformity in two drillholes. The PI will study the lithostratigraphy and weathering history of cores in the five drillholes, to establish a unique Eocene-Oligocene transition record within Antarctic continental margin sediments of glacial advance and retreat cycles, the onset of physical weathering, and glacio-isostasy and self-gravitation processes with implications for the margin architecture, sediment routing, and off-shore sediment dispersal. Cores from the five drillholes will be re-examined through detailed core description using an updated classification scheme, so that lithofacies can be compared between drillholes. Samples will be collected for detailed laser particle size and bulk major element geochemistry via ICP-AES to determine the degree of chemical alteration of the sediments. Phases of major ice growth will be recognized as marker beds of physically eroded sediment and will be correlated to isotopic records documenting Antarctic ice growth offshore in the Southern Ocean. Broader impacts: This project will benefit a large minority undergraduate student population through the availability of up to two paid laboratory internships, a classroom exercise, and the availability of research equipment supported by this award. The project also allows support and training of a graduate student.", "east": 79.0, "geometry": "POINT(72.5 -69)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Not provided; Prydz Bay; SEDIMENTS", "locations": "Prydz Bay", "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "NCEI; Publication; USAP-DC", "science_programs": null, "south": -70.0, "title": "The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin", "uid": "p0000309", "west": 66.0}, {"awards": "1043554 Willenbring, Jane", "bounds_geometry": "POINT(161.5 -77.5)", "dataset_titles": "Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "datasets": [{"dataset_uid": "600379", "doi": "10.15784/600379", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Cosmogenic Radionuclides; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope; Sample/collection Description; Sample/Collection Description; Transantarctic Mountains", "people": "Willenbring, Jane", "repository": "USAP-DC", "science_program": null, "title": "Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "url": "https://www.usap-dc.org/view/dataset/600379"}], "date_created": "Wed, 09 Nov 2016 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to address the question of whether ice surface melting zones developed at high elevations during warm climatic phases in the Transantarctic Mountains. Evidence from sediment cores drilled by the ANDRILL program indicates that open water in the Ross Sea could have been a source of warmth during Pliocene and Pleistocene. The question is whether marine warmth penetrated inland to the ice sheet margins. The glacial record may be ill suited to answer this question, as cold-based glaciers may respond too slowly to register brief warmth. Questions also surround possible orbital controls on regional climate and ice sheet margins. Northern Hemisphere insolation at obliquity and precession timescales is thought to control Antarctic climate through oceanic or atmospheric connections, but new thinking suggests that the duration of Southern Hemisphere summer may be more important. The PIs propose to use high elevation alluvial deposits in the Transantarctic Mountains as a proxy for inland warmth. These relatively young fans, channels, and debris flow levees stand out as visible evidence for the presence of melt water in an otherwise ancient, frozen landscape. Based on initial analyses of an alluvial fan in the Olympus Range, these deposits are sensitive recorders of rare melt events that occur at orbital timescales. For their study they will 1) map alluvial deposits using aerial photography, satellite imagery and GPS assisted field surveys to establish water sources and to quantify parameters effecting melt water production, 2) date stratigraphic sequences within these deposits using OSL, cosmogenic nuclide, and interbedded volcanic ash chronologies, 3) use paired nuclide analyses to estimate exposure and burial times, and rates of deposition and erosion, and 4) use micro and regional scale climate modeling to estimate paleoenvironmental conditions associated with melt events. Broader impacts: This study will produce a record of inland melting from sites adjacent to ice sheet margins to help determine controls on regional climate along margins of the East Antarctic Ice Sheet to aid ice sheet and sea level modeling studies. The proposal will support several graduate and undergraduates. A PhD student will be supported on existing funding. The PIs will work with multiple K 12 schools to conduct interviews and webcasts from Antarctica and they will make follow up visits to classrooms after the field season is complete.", "east": 161.5, "geometry": "POINT(161.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Willenbring, Jane", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.5, "title": "Collaborative Research: Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "uid": "p0000429", "west": 161.5}, {"awards": "0944282 Hasiotis, Stephen", "bounds_geometry": "POINT(175 -86)", "dataset_titles": "Paleoenvironmental and Paleoclimatic Analysis of the Beacon Supergroup, Beardmore Glacier Area, Central Transantarctic Mountains, Antarctica", "datasets": [{"dataset_uid": "600156", "doi": "10.15784/600156", "keywords": "Antarctica; Beardmore Glacier; Biota; Fossil; Paleoclimate; Sample/collection Description; Sample/Collection Description; Solid Earth; Transantarctic Mountains", "people": "Hasiotis, Stephen", "repository": "USAP-DC", "science_program": null, "title": "Paleoenvironmental and Paleoclimatic Analysis of the Beacon Supergroup, Beardmore Glacier Area, Central Transantarctic Mountains, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600156"}], "date_created": "Fri, 03 Jun 2016 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThis proposal will study the diversity, abundance, and tiering patterns of ichnofossils in continental and marine deposits of the Beacon Supergroup in the Beardmore Glacier Area (BGA). The PIs will focus on continental strata that contain a variety of ichnofossils and paleosols. Ichnofossils will be evaluated for their architectural and surficial morphologies, and will be compared to modern and ancient traces to interpret the tracemaker behavior and paleoenvironmental setting. Distribution of ichnofossils within these units may indicate the effect of lateral variability of pedogenesis, the magnitude and frequency of depositional events, and the amount of moisture within the sediment, as well as the effects of climate change. The paleoclimatic significance of ichnofossils will be determined by comparing the burrow size, occurrence, tiering, and pedogenic significance of ichnofossils in measured sections of stratigraphic units deposited during global warming and cooling episodes. Comparisons will be made between BGA formations to stratigraphically equivalent rocks deposited at low paleolatitudes with previously determined paleoclimatic settings. The objectives of this project are to address two major questions: what differences existed in ichnodiversity, abundance, and tiering in marine and continental deposits between high- and low-paleolatitudes, and was there a dearth of habitat usage in continental deposits during the late Paleozoic and Mesozoic, particularly in fluvial and lacustrine environments compared to the habitat usage in the marine realm at that time? \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis study will enhance the ability to interpret paleoenvironments to the subenvironmental scale, understand the evolution of soil biota and ecosystems at high paleolatitudes, determine the role of organisms in soil formation at high paleolatitudes, explore the effects of climate change on the body size and diversity of organisms in the soil communities, and develop new tools to interpret paleoclimate in high latitudes. There is a strong education component associated with this proposal.", "east": 175.0, "geometry": "POINT(175 -86)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -86.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Hasiotis, Stephen", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.0, "title": "Paleoenvironmental and Paleoclimatic Analysis of the Beacon Supergroup, Beardmore Glacier Area, Central Transantarctic Mountains, Antarctica", "uid": "p0000423", "west": 175.0}, {"awards": "0839031 Severinghaus, Jeffrey; 0838936 Brook, Edward J.", "bounds_geometry": "POINT(161.75 -77.75)", "dataset_titles": "Measurements of 14C-methane for the Younger Dryas - Preboreal Transition from Taylor Glacier, Antarctica; Measurements of in situ cosmogenic 14C from Taylor Glacier, Antarctica; Taylor Glacier chemistry data and Taylor Dome TD2015 time scale; Taylor Glacier CO2 record; Taylor Glacier Gas Isotope Data", "datasets": [{"dataset_uid": "601033", "doi": "10.15784/601033", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciology; Ice Core Records; Isotope; Solid Earth; Taylor Glacier; Transantarctic Mountains", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Taylor Glacier Gas Isotope Data", "url": "https://www.usap-dc.org/view/dataset/601033"}, {"dataset_uid": "000158", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Taylor Glacier CO2 record", "url": "ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/taylor/taylor2016d13co2.txt"}, {"dataset_uid": "600165", "doi": "10.15784/600165", "keywords": "Antarctica; Cosmogenic; Geochemistry; Ice Core Records; Paleoclimate; Radiocarbon; Taylor Glacier; Transantarctic Mountains", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Measurements of in situ cosmogenic 14C from Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600165"}, {"dataset_uid": "601029", "doi": "10.15784/601029", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Critical Zone; Geochemistry; Methane; Paleoclimate; Sample/collection Description; Sample/Collection Description; Solid Earth; Taylor Glacier; Transantarctic Mountains; Younger Dryas", "people": "Severinghaus, Jeffrey P.; Petrenko, Vasilii", "repository": "USAP-DC", "science_program": null, "title": "Measurements of 14C-methane for the Younger Dryas - Preboreal Transition from Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601029"}, {"dataset_uid": "601103", "doi": "10.15784/601103", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Horizontal Ice Core; Ice Core Records; Taylor Dome; Taylor Dome Ice Core", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Taylor Glacier chemistry data and Taylor Dome TD2015 time scale", "url": "https://www.usap-dc.org/view/dataset/601103"}], "date_created": "Tue, 29 Mar 2016 00:00:00 GMT", "description": "Severinghaus/0839031 \u003cbr/\u003e\u003cbr/\u003eThis 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 precise gas-based chronology for an archive of large-volume samples of the ancient atmosphere, which would enable ultra-trace gas measurements that are currently precluded by sample size limitations of ice cores. The intellectual merit of the proposed work is that it will provide a critical test of the \"clathrate hypothesis\" that methane clathrates contributed to the two abrupt atmospheric methane concentration increases during the last deglaciation 15 and 11 kyr ago. This approach employs large volumes of ice (\u003e1 ton) to measure carbon-14 on past atmospheric methane across the abrupt events. Carbon-14 is an ideal discriminator of fossil sources of methane to the atmosphere, because most methane sources (e.g., wetlands, termites, biomass burning) are rich in carbon-14, whereas clathrates and other fossil sources are devoid of carbon-14. The proposed work is a logical extension to Taylor Glacier, Antarctica, of an approach pioneered at the margin of the Greenland ice sheet over the past 7 years. The Greenland work found higher-than-expected carbon-14 values, likely due in part to contaminants stemming from the high impurity content of Greenland ice and the interaction of the ice with sediments from the glacier bed. The data also pointed to the possibility of a previously unknown process, in-situ cosmogenic production of carbon-14 methane (radiomethane) in the ice matrix. Antarctic ice in Taylor Glacier is orders of magnitude cleaner than the ice at the Greenland site, and is much colder and less stratigraphically disturbed, offering the potential for a clear resolution of this puzzle and a definitive test of the cosmogenic radiomethane hypothesis. Even if cosmogenic radiomethane in ice is found, it still may be possible to reconstruct atmospheric radiomethane with a correction enabled by a detailed understanding of the process, which will be sought by co-measuring carbon-14 in carbon monoxide and carbon dioxide. The broader impacts of the proposed work are that the clathrate test may shed light on the stability of the clathrate reservoir and its potential for climate feedbacks under human-induced warming. Development of Taylor Glacier as a \"horizontal ice core\" would provide a community resource for other researchers. Education of one postdoc, one graduate student, and one undergraduate, would add to human resources. This award has field work in Antarctica.", "east": 161.75, "geometry": "POINT(161.75 -77.75)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; Not provided; USAP-DC", "locations": null, "north": -77.75, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Brook, Edward J.; Severinghaus, Jeffrey P.", "platforms": "Not provided; OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "NCEI; USAP-DC", "science_programs": null, "south": -77.75, "title": "Collaborative Research: A \"Horizontal Ice Core\" for Large-Volume Samples of the Past Atmosphere, Taylor Glacier, Antarctica", "uid": "p0000099", "west": 161.75}, {"awards": "1043518 Brook, Edward J.", "bounds_geometry": "POINT(-112.08648 -79.46763)", "dataset_titles": "Continuous, Ultra-high Resolution WAIS-Divide Ice Core Methane Record 9.8-67.2 ka BP; Early Holocene methane records from Siple Dome, Antarctica; Methan record", "datasets": [{"dataset_uid": "000176", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Methan record", "url": "https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/ice-core"}, {"dataset_uid": "609628", "doi": "10.7265/N5JM27K4", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Rhodes, Rachel; Brook, Edward J.; McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Continuous, Ultra-high Resolution WAIS-Divide Ice Core Methane Record 9.8-67.2 ka BP", "url": "https://www.usap-dc.org/view/dataset/609628"}, {"dataset_uid": "601055", "doi": "10.15784/601055", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Yang, Ji-Woong; Ahn, Jinho", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Early Holocene methane records from Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601055"}, {"dataset_uid": "601055", "doi": "10.15784/601055", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Ahn, Jinho; Yang, Ji-Woong", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Early Holocene methane records from Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601055"}], "date_created": "Tue, 12 Jan 2016 00:00:00 GMT", "description": "1043500/Sowers This award supports a project to develop a 50 yr resolution methane data set that will play a pivotal role in developing the WAIS Divide timescale as well as providing a common stratigraphic framework for comparing climate records from Greenland and West Antarctica. Even higher resolution data are proposed for key intervals to assist in precisely defining the phasing of abrupt climate change between the hemispheres. Concurrent analysis of a suit of samples from both the WAIS Divide and GISP-2 cores throughout the last 110,000 years is also proposed, to establish the interpolar methan (CH4) gradient that will be used to identify geographic areas responsible for the climate related methane emission changes. The intellectual merit of the proposed work is that it will provide chronological control needed to examine the timing of changes in climate proxies, and critical chronological ties to the Greenland ice core records via methane variations. One main objective is to understand the interpolar timing of millennial-scale climate change. This is an important scientific goal relevant to understanding climate change mechanisms in general. The proposed work will help establish a chronological framework for addressing these issues. In addition, this proposal addresses the question of what methane sources were active during the ice age, through the work on the interpolar methane gradient. This work is directed at the fundamental question of what part of the biosphere controlled past methane variations, and is important for developing more sophisticated understanding of those variations. The broader impacts of the work are that the ultra-high resolution CH4 record will directly benefit all ice core paleoclimate research and the chronological refinements will impact paleoclimate studies that rely on ice core timescales for correlation purposes. The project will support both graduate and undergraduate students and the PIs will participate in outreach to the public.", "east": -112.08648, "geometry": "POINT(-112.08648 -79.46763)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e INFRARED LASER SPECTROSCOPY", "is_usap_dc": true, "keywords": "WAIS Divide; Not provided; LABORATORY; Wais Divide-project; Methane Concentration", "locations": "WAIS Divide", "north": -79.46763, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Rhodes, Rachel; Brook, Edward J.; McConnell, Joseph", "platforms": "Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NCEI", "repositories": "NCEI; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.46763, "title": "Collaborative Research: Completing an ultra-high resolution methane record from the WAIS Divide ice core", "uid": "p0000185", "west": -112.08648}, {"awards": "1146399 Sidor, Christian", "bounds_geometry": "POLYGON((162.41 -84.27,163.409 -84.27,164.408 -84.27,165.407 -84.27,166.406 -84.27,167.405 -84.27,168.404 -84.27,169.403 -84.27,170.402 -84.27,171.401 -84.27,172.4 -84.27,172.4 -84.353,172.4 -84.436,172.4 -84.519,172.4 -84.602,172.4 -84.685,172.4 -84.768,172.4 -84.851,172.4 -84.934,172.4 -85.017,172.4 -85.1,171.401 -85.1,170.402 -85.1,169.403 -85.1,168.404 -85.1,167.405 -85.1,166.406 -85.1,165.407 -85.1,164.408 -85.1,163.409 -85.1,162.41 -85.1,162.41 -85.017,162.41 -84.934,162.41 -84.851,162.41 -84.768,162.41 -84.685,162.41 -84.602,162.41 -84.519,162.41 -84.436,162.41 -84.353,162.41 -84.27))", "dataset_titles": "Preparation of Vertebrate Fossils from the Triassic of Antarctica", "datasets": [{"dataset_uid": "600144", "doi": "10.15784/600144", "keywords": "Antarctica; Biota; Fossil; Paleoclimate; Sample/collection Description; Sample/Collection Description; Solid Earth; Transantarctic Mountains; Triassic", "people": "Sidor, Christian", "repository": "USAP-DC", "science_program": null, "title": "Preparation of Vertebrate Fossils from the Triassic of Antarctica", "url": "https://www.usap-dc.org/view/dataset/600144"}], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "Intellectual Merit: The PI requests support for preparation of a large collection of vertebrate fossils recently recovered from the Central Transantarctic Mountains (CTAM) of Antarctica. These fossils will be used to place early Mesozoic Antarctic dinosaurs and other vertebrates into a global evolutionary, biogeographic, and faunal context; assess the degree of endemism in Triassic vertebrate faunas of Antarctica; constrain temporal relationships of the Triassic Antarctic vertebrate faunas; and refine the stratigraphic context for the Triassic Antarctic vertebrate assemblages to establish a paleoenvironmental framework. The lower and middle Triassic fossils offer a rare window on life in terrestrial environments at high-latitudes immediately after the Permian mass extinction. Broader impacts: The PI will use their fossils to educate the public about the geologic, climatic, and biologic history of Antarctica by visiting local schools. They will create and publish at least two new videos to the Burke Museum blog that relate the graduate student?s experience of fieldwork in Antarctica. They will also update the Antarctica section on the UWBM \"Explore Your World\" website with images and findings from their field season.", "east": 172.4, "geometry": "POINT(167.405 -84.685)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -84.27, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sidor, Christian", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.1, "title": "Preparation of Vertebrate Fossils from the Triassic of Antarctica", "uid": "p0000418", "west": 162.41}, {"awards": "1143619 Severinghaus, Jeffrey", "bounds_geometry": "POINT(-112.09 -79.47)", "dataset_titles": null, "datasets": null, "date_created": "Mon, 13 Jul 2015 00:00:00 GMT", "description": "1143619/Severinghaus This award supports a project to extend the study of gases in ice cores to those gases whose small molecular diameters cause them to escape rapidly from ice samples (the so-called \"fugitive gases\"). The work will employ helium, neon, argon, and oxygen measurements in the WAIS Divide ice core to better understand the mechanism of the gas close-off fractionation that occurs while air bubbles are incorporated into ice. The intellectual merit of the proposed work is that corrections for this fractionation using neon (which is constant in the atmosphere) may ultimately enable the first ice core-based atmospheric oxygen and helium records. Neon may also illuminate the mechanistic link between local insolation and oxygen used for astronomical dating of ice cores. Helium measure-ments in the deepest ~100 m of the core will also shed light on the stratigraphic integrity of the basal ice, and serve as a probe of solid earth-ice interaction at the base of the West Antarctic ice sheet. Past atmospheric oxygen records, currently unavailable prior to 1989 CE, would reveal changes in the size of the terrestrial biosphere carbon pool that accompany climate variations and place constraints on the biogeochemical feedback response to future warming. An atmospheric helium-3/helium-4 record would test the hypothesis that the solar wind (which is highly enriched in helium-3) condensed directly into Earth?s atmosphere during the collapse of the geomagnetic field that occurred 41,000 years ago, known as the Laschamp Event. Fugitive-gas samples will be taken on-site immediately after recovery of the ice core by the PI and one postdoctoral scholar, under the umbrella of an existing project to support replicate coring and borehole deepening. This work will add value to the scientific return from field work activity with little additional cost to logistical resources. The broader impacts of the work on atmospheric oxygen are that it may increase understanding of how terrestrial carbon pools and atmospheric greenhouse gas sources will respond in a feedback sense to the coming warming. Long-term atmospheric oxygen trends are also of interest for understanding biogeochemical regulatory mechanisms and the impact of atmospheric evolution on life. Helium records have value in understanding the budget of this non-renewable gas and its implications for space weather and solar activity. The project will train one graduate student and one postdoctoral scholar. The fascination of linking solid earth, cryosphere, atmosphere, and space weather will help to entrain and excite young scientists and efforts to understand the Earth as a whole interlinked system will provide fuel to outreach efforts at all ages.", "east": -112.09, "geometry": "POINT(-112.09 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": false, "keywords": "WAIS Divide; Not provided; Tracers; FIELD INVESTIGATION; Past Biospheric Carbon Storage; LABORATORY; Fugitive Gases; Basal Processes; Neon; Helium; FIELD SURVEYS; Antarctica", "locations": "WAIS Divide; Antarctica", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.", "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", "repositories": null, "science_programs": null, "south": -79.47, "title": "Fugitive Gases (Helium, Neon, and Oxygen) in the WAIS Divide Ice Core as Tracers of Basal Processes and Past Biospheric Carbon Storage", "uid": "p0000441", "west": -112.09}, {"awards": "1303896 Kirschvink, Joseph", "bounds_geometry": "POLYGON((-57 -63,-56.9 -63,-56.8 -63,-56.7 -63,-56.6 -63,-56.5 -63,-56.4 -63,-56.3 -63,-56.2 -63,-56.1 -63,-56 -63,-56 -63.2,-56 -63.4,-56 -63.6,-56 -63.8,-56 -64,-56 -64.2,-56 -64.4,-56 -64.6,-56 -64.8,-56 -65,-56.1 -65,-56.2 -65,-56.3 -65,-56.4 -65,-56.5 -65,-56.6 -65,-56.7 -65,-56.8 -65,-56.9 -65,-57 -65,-57 -64.8,-57 -64.6,-57 -64.4,-57 -64.2,-57 -64,-57 -63.8,-57 -63.6,-57 -63.4,-57 -63.2,-57 -63))", "dataset_titles": "Magnetostratigraphy of Cretaceous Sediments in the James Ross Island Basin, Antarctica", "datasets": [{"dataset_uid": "600136", "doi": "10.15784/600136", "keywords": "Antarctica; GPS; James Ross Basin; Sample/collection Description; Sample/Collection Description; Solid Earth", "people": "Kirschvink, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Magnetostratigraphy of Cretaceous Sediments in the James Ross Island Basin, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600136"}], "date_created": "Sat, 23 May 2015 00:00:00 GMT", "description": "Intellectual Merit: The PI will collect samples to extend the magneto-stratigraphic record of late Cretaceous sediments of the James Ross Basin, Antarctica. RAPID support will allow him to take advantage of an invitation from the Instituto Antartico Argentino (IAA) to participate on an excursion to James Ross Island in the Antarctic Peninsula. The PI hopes to collect samples that will refine the position of several geomagnetic reversals between the end of the Cretaceous long normal Chron and the lower portion of Chron 31R. The Brandy Bay locality targeted by this expedition is the best place in the basin for calibrating the biostratigraphic position of the top of the Cretaceous Long Normal Chron, which is one of the most reliable correlation horizons in the entire Geological Time Scale. Broader impacts: The top of the Cretaceous long normal Chron is not properly correlated to southern hemisphere biostratigraphy. Locating this event will be a major addition to understanding geological time. This expedition will provide opportunities for an undergraduate student. This project is based on a productive collaboration with an Argentine scientist.", "east": -56.0, "geometry": "POINT(-56.5 -64)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -63.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kirschvink, Joseph", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "Magnetostratigraphy of Cretaceous Sediments in the James Ross Island Basin, Antarctica", "uid": "p0000419", "west": -57.0}, {"awards": "1241460 Barbeau, David; 1241574 Hemming, Sidney", "bounds_geometry": "POLYGON((-67 -63.2,-65.97 -63.2,-64.94 -63.2,-63.91 -63.2,-62.88 -63.2,-61.85 -63.2,-60.82 -63.2,-59.79 -63.2,-58.76 -63.2,-57.73 -63.2,-56.7 -63.2,-56.7 -63.54,-56.7 -63.88,-56.7 -64.22,-56.7 -64.56,-56.7 -64.9,-56.7 -65.24,-56.7 -65.58,-56.7 -65.92,-56.7 -66.26,-56.7 -66.6,-57.73 -66.6,-58.76 -66.6,-59.79 -66.6,-60.82 -66.6,-61.85 -66.6,-62.88 -66.6,-63.91 -66.6,-64.94 -66.6,-65.97 -66.6,-67 -66.6,-67 -66.26,-67 -65.92,-67 -65.58,-67 -65.24,-67 -64.9,-67 -64.56,-67 -64.22,-67 -63.88,-67 -63.54,-67 -63.2))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 03 Dec 2014 00:00:00 GMT", "description": "Intellectual Merit: Recent geochemical, sequence stratigraphic, and integrated investigations of marine strata from several continental margins and ocean basins suggest that ephemeral ice sheets may have existed on Antarctica during parts of the Cretaceous and early Paleogene. However, atmospheric carbon dioxide estimates for this time are as much as four times modern levels. With such greenhouse conditions, the presence of Antarctic ice sheets would imply that our current understanding of Earth?s climate system, and specifically the interpreted thresholds of Antarctic glaciation and deglaciation should be reconsidered. The proposed research will compare the quantity and provenance of Cretaceous sediments in the Larsen basin of the eastern Antarctic Peninsula with the exhumation chronology and composition of potential sediment source terranes on the peninsula and in adjacent regions. New outcrop stratigraphic analyses with improvements in the age models from radioisotopic approaches will be integrated to determine the amount of detrital sediment fluxed to the Larsen basin between key chronostratigraphic surfaces. Microtextural analysis of quartz sand and silt grains will help determine whether the Larsen basin detrital sediment originated from glacial weathering. These preliminary results will test the viability of the proposed approach to assess the controversial Cretaceous Antarctic glaciation hypothesis. Broader impacts: The proposed work will partially support a PhD, a MSc, and three undergraduate students at the University of South Carolina. The PIs will publicize this work through volunteer speaking engagements and the development of videos and podcasts. They also commit to prompt publication of the results and timely submission of data to archives. The development/improvement of the Larsen basin age model will benefit ongoing research in paleobiology, paleoclimate and biogeography. Development of the glauconite K-Ar and Rb-Sr chronometers could be an important outcome beyond the direct scope of the proposed research.", "east": -56.7, "geometry": "POINT(-61.85 -64.9)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e LA-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MC-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e IRMS", "is_usap_dc": true, "keywords": "Not provided; Noble-Gas Mass Spectrometer; Antarctic Peninsula", "locations": "Antarctic Peninsula", "north": -63.2, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PROTEROZOIC; PHANEROZOIC \u003e PALEOZOIC; PHANEROZOIC \u003e MESOZOIC; PHANEROZOIC \u003e CENOZOIC; PHANEROZOIC \u003e MESOZOIC \u003e CRETACEOUS; PHANEROZOIC \u003e CENOZOIC \u003e PALEOGENE", "persons": "Barbeau, David; Hemming, Sidney R.; Barbeau, David Jr", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -66.6, "title": "Collaborative Research: EAGER: Evaluating the Larsen basin\u0027s suitability for testing the Cretaceous Glaciation Hypothesis", "uid": "p0000369", "west": -67.0}, {"awards": "1039365 Rimmer, Susan", "bounds_geometry": null, "dataset_titles": "The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter", "datasets": [{"dataset_uid": "600121", "doi": "10.15784/600121", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Solid Earth; Transantarctic Mountains", "people": "Rimmer, Susan", "repository": "USAP-DC", "science_program": null, "title": "The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter", "url": "https://www.usap-dc.org/view/dataset/600121"}], "date_created": "Wed, 30 Jan 2013 00:00:00 GMT", "description": "This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. The broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Rimmer, Susan", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter", "uid": "p0000507", "west": null}, {"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": "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": "200115", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Magnetic raw data", "url": "https://nsidc.org/data/imgeo1b"}, {"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": "200117", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Gravity raw data", "url": "https://nsidc.org/data/igbgm1b/"}, {"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": "200119", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Laser altimetry raw data", "url": "https://nsidc.org/data/ilutp1b"}, {"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": "200121", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "ICECAP flight reports", "url": "https://nsidc.org/data/ifltrpt"}, {"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": "Schroeder, Dustin; Greenbaum, Jamin; Holt, John W.; Siegert, Martin; Young, Duncan A.; Blankenship, Donald D.; Gillespie, Mette", "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": "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": "Blankenship, Donald D.; Mulvaney, Robert; Cavitte, Marie G. P; Ritz, Catherine; Greenbaum, Jamin; Ng, Gregory; Kempf, Scott D.; Quartini, Enrica; Muldoon, Gail R.; Paden, John; Frezzotti, Massimo; Roberts, Jason; Tozer, Carly; Young, Duncan A.; Schroeder, Dustin", "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": "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"}, {"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Schroeder, Dustin; Young, Duncan A.; Roberts, Jason; Blankenship, Donald D.; Siegert, Martin; van Ommen, Tas; Greenbaum, Jamin", "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": "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": "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"}], "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 Integrated System Science; Antarctic Earth Sciences", "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": "0538578 Brook, Edward J.; 0538538 Sowers, Todd", "bounds_geometry": null, "dataset_titles": "Late Holocene Methane Concentrations from WAIS Divide and GISP2; Methane Concentrations from the WAIS Divide Ice Core (WDC06A), 60 to 11,300 ybp; The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "datasets": [{"dataset_uid": "001303", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "The Antarctic Glaciological Data Center (AGDC) at the National Snow and Ice Data Center (NSIDC) archives and distributes Antarctic glaciological and cryospheric system data collected by the U.S. Antarctic Program.", "url": "https://nsidc.org/data/agdc"}, {"dataset_uid": "609509", "doi": "10.7265/N5J1013R", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Methane Concentrations from the WAIS Divide Ice Core (WDC06A), 60 to 11,300 ybp", "url": "https://www.usap-dc.org/view/dataset/609509"}, {"dataset_uid": "609586", "doi": "10.7265/N5W66HQQ", "keywords": "Antarctica; Arctic; Chemistry:fluid; Chemistry:Fluid; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Mitchell, Logan E", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Late Holocene Methane Concentrations from WAIS Divide and GISP2", "url": "https://www.usap-dc.org/view/dataset/609586"}], "date_created": "Thu, 19 Apr 2012 00:00:00 GMT", "description": "Sowers/Brook\u003cbr/\u003e0538538\u003cbr/\u003eThis award supports a project to develop a high-resolution (every 50 yr) methane data set that will play a pivotal role in developing the timescale for the new deep ice core being drilled at the West Antarctic Ice Sheet Divide (WAIS Divde) site as well as providing a common stratigraphic framework for comparing climate records from Greenland and WAIS Divide. Certain key intervals will be measured at even higher resolution to assist in precisely defining the phasing of abrupt climate change between the northern and southern hemispheres. Concurrent analysis of a suit of samples from both the WAIS Divide and GISP2 ice cores throughout the last 110kyr is also proposed, to establish the inter-hemispheric methane gradient which will be used to identify geographic areas responsible for the climate-related methane emission changes. A large gas measurement inter-calibration of numerous laboratories, utilizing both compressed air cylinders and WAIS Divide ice core samples, will also be performed. The intellectual merit of the proposed work is that it will provide the chronological control needed to examine the timing of changes in climate proxies, and critical chronological ties to the Greenland ice core records via methane variations. In addition, the project addresses the question of what methane sources were active during the ice age and will help to answer the fundamental question of what part of the biosphere controlled past methane variations. The broader impact of the proposed work is that it will directly benefit all ice core paleoclimate research and will impact the paleoclimate studies that rely on ice core timescales for correlation purposes. The project will also support a Ph.D. student at Oregon State University who will have the opportunity to be involved in a major new ice coring effort with international elements. Undergraduates at Penn State will gain valuable laboratory experience and participate fully in the project. The proposed work will underpin the WAIS Divide chronology, which will be fundamental to all graduate student projects that involve the core. The international inter-calibration effort will strengthen ties between research institutions on four continents and will be conducted as part of the International Polar Year research agenda.", "east": null, "geometry": null, "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": "Antarctica; Ch4; West Antarctica; Wais Divide-project; GROUND-BASED OBSERVATIONS; FIELD INVESTIGATION; FIELD SURVEYS; Methane Concentration; Methane; Ice Core; WAIS Divide; Antarctic; LABORATORY", "locations": "Antarctic; WAIS Divide; Antarctica; West Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Organisms and Ecosystems; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; NOT APPLICABLE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Lee, James; Buizert, Christo; Brook, Edward J.; Mitchell, Logan E; Sowers, Todd A.", "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; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NSIDC", "repositories": "NSIDC; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Collaborative Research: Constructing an Ultra-high Resolution Atmospheric Methane Record for the Last 140,000 Years from WAIS Divide Core.", "uid": "p0000025", "west": null}, {"awards": "0424589 Gogineni, S. Prasad", "bounds_geometry": "POLYGON((-137 -74,-132.1 -74,-127.2 -74,-122.3 -74,-117.4 -74,-112.5 -74,-107.6 -74,-102.7 -74,-97.8 -74,-92.9 -74,-88 -74,-88 -74.65,-88 -75.3,-88 -75.95,-88 -76.6,-88 -77.25,-88 -77.9,-88 -78.55,-88 -79.2,-88 -79.85,-88 -80.5,-92.9 -80.5,-97.8 -80.5,-102.7 -80.5,-107.6 -80.5,-112.5 -80.5,-117.4 -80.5,-122.3 -80.5,-127.2 -80.5,-132.1 -80.5,-137 -80.5,-137 -79.85,-137 -79.2,-137 -78.55,-137 -77.9,-137 -77.25,-137 -76.6,-137 -75.95,-137 -75.3,-137 -74.65,-137 -74))", "dataset_titles": "Airborne radar profiles of the Whillans, Bindschadler, and Kamb Ice Streams; Archive of data; Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau; Ku-band Radar Echograms; Radar Depth Sounder Echograms and Ice Thickness; Snow Radar Echograms", "datasets": [{"dataset_uid": "601049", "doi": "10.15784/601049", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Navigation; Radar; Snow", "people": "Gogineni, Prasad; Allen, Chris; Paden, John; Li, Jilu; Rodriguez, Fernando; Leuschen, Carl", "repository": "USAP-DC", "science_program": null, "title": "Snow Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601049"}, {"dataset_uid": "600384", "doi": "10.15784/600384", "keywords": "Airborne Radar; Antarctica; Basler; Glaciers/ice Sheet; Glaciers/Ice Sheet; Kamb Ice Stream; Radar; Siple Coast; Whillans Ice Stream", "people": "Paden, John; Hale, Richard", "repository": "USAP-DC", "science_program": null, "title": "Airborne radar profiles of the Whillans, Bindschadler, and Kamb Ice Streams", "url": "https://www.usap-dc.org/view/dataset/600384"}, {"dataset_uid": "002497", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Archive of data", "url": "https://www.cresis.ku.edu/data/accumulation"}, {"dataset_uid": "601047", "doi": "10.15784/601047", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MCoRDS; Navigation; Radar", "people": "Gogineni, Prasad; Li, Jilu; Allen, Chris; Leuschen, Carl; Paden, John; Rodriguez, Fernando", "repository": "USAP-DC", "science_program": null, "title": "Radar Depth Sounder Echograms and Ice Thickness", "url": "https://www.usap-dc.org/view/dataset/601047"}, {"dataset_uid": "601048", "doi": "10.15784/601048", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ku-Band; Navigation; Radar", "people": "Paden, John; Allen, Chris; Li, Jilu; Leuschen, Carl; Gogineni, Prasad; Rodriguez, Fernando", "repository": "USAP-DC", "science_program": null, "title": "Ku-band Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601048"}, {"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": "Blankenship, Donald D.; Mulvaney, Robert; Cavitte, Marie G. P; Ritz, Catherine; Greenbaum, Jamin; Ng, Gregory; Kempf, Scott D.; Quartini, Enrica; Muldoon, Gail R.; Paden, John; Frezzotti, Massimo; Roberts, Jason; Tozer, Carly; Young, Duncan A.; Schroeder, Dustin", "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"}], "date_created": "Wed, 01 Jun 2011 00:00:00 GMT", "description": "This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbr\u00e6. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.\u003cbr/\u003e\u003cbr/\u003eThe intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. \u003cbr/\u003e\u003cbr/\u003eAs lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets.", "east": -88.0, "geometry": "POINT(-112.5 -77.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Remote Sensing; Not provided; Pine Island; Ice Sheet; DHC-6; Antarctic; Thwaites Region; Antarctica; Mass Balance; Accumulation; Velocity; Insar", "locations": "Antarctica; Antarctic; Pine Island; Thwaites Region", "north": -74.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Glaciology", "paleo_time": null, "persons": "Braaten, David; Joughin, Ian; Steig, Eric J.; Das, Sarah; Paden, John; Gogineni, Prasad", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; Not provided", "repo": "USAP-DC", "repositories": "Project website; USAP-DC", "science_programs": null, "south": -80.5, "title": "Center for Remote Sensing of Ice Sheets (CReSIS)", "uid": "p0000102", "west": -137.0}, {"awards": "9909734 Anderson, John", "bounds_geometry": "POLYGON((-73.80311 -52.35021,-71.817373 -52.35021,-69.831636 -52.35021,-67.845899 -52.35021,-65.860162 -52.35021,-63.874425 -52.35021,-61.888688 -52.35021,-59.902951 -52.35021,-57.917214 -52.35021,-55.931477 -52.35021,-53.94574 -52.35021,-53.94574 -53.954842,-53.94574 -55.559474,-53.94574 -57.164106,-53.94574 -58.768738,-53.94574 -60.37337,-53.94574 -61.978002,-53.94574 -63.582634,-53.94574 -65.187266,-53.94574 -66.791898,-53.94574 -68.39653,-55.931477 -68.39653,-57.917214 -68.39653,-59.902951 -68.39653,-61.888688 -68.39653,-63.874425 -68.39653,-65.860162 -68.39653,-67.845899 -68.39653,-69.831636 -68.39653,-71.817373 -68.39653,-73.80311 -68.39653,-73.80311 -66.791898,-73.80311 -65.187266,-73.80311 -63.582634,-73.80311 -61.978002,-73.80311 -60.37337,-73.80311 -58.768738,-73.80311 -57.164106,-73.80311 -55.559474,-73.80311 -53.954842,-73.80311 -52.35021))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001803", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0201"}], "date_created": "Thu, 03 Mar 2011 00:00:00 GMT", "description": "9909734 Anderson This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research on the glaciomarine geology of the continental shelves of West Antarctica and the Antarctic Peninsula. It is hypothesized that the different glacial systems of the Antarctic Peninsula region have been more responsive to climate change and sea-level rise than either the West Antarctic or East Antarctic ice sheets. This is due mainly to the smaller size of these ice masses and the higher latitude location of the peninsula. Indeed, ice shelves of the Antarctic Peninsula are currently retreating at rates of up to a kilometer per year. But are these changes due to recent atmospheric warming in the region or are they simply the final phase of retreat since the last glacial maximum? This project hypothesizes that the deglacial history of the Antarctic Peninsula region has been quite complex, with different glacial systems retreating at different rates and at different times. This complex recessional history reflects the different sizes as well as different climatic and physiographic settings of glacial systems in the region. An understanding of the Late Pleistocene to Holocene glacial history of the Antarctic Peninsula glacial systems is needed to address how these systems responded to sea-level and climate change during that time interval. This investigation acquire new marine geological and geophysical data from the continental shelf to determine if and when different glacial systems were grounded on the shelf, to establish the extent of grounded ice, and to examine the history of glacial retreat. The project will build on an extensive seismic data set and hundreds of sediment cores collected along the Peninsula during earlier (1980\u0027s) cruises. Key to this investigation is the acquisition of swath bathymetry, side-scan sonar and very high-resolution sub-bottom (chirp) profiles from key drainage outlets. These new data will provide the necessary geomorphologic and stratigraphic framework for reconstructing the Antarctic Peninsula glacial record. Anticipated results will help constrain models for future glacier and ice sheet activity.", "east": -53.94574, "geometry": "POINT(-63.874425 -60.37337)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.35021, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John; Anderson, Jason", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -68.39653, "title": "LGM Late Pleistocene to Holocene Glacial History of West Antarctica", "uid": "p0000600", "west": -73.80311}, {"awards": "0636974 Verosub, Kenneth", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 01 Oct 2010 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThis project performs a paleomagnetic survey of sediment cores from Antarctica\u0027s continental margin. Its goal is to refine the magnetostratigraphy to improve regional stratigraphic correlations, help date cores that lack biostratigraphic indicators, and understand paleoenvironmental conditions and climate change. As well, these cores record the earth\u0027s magnetic field near the magnetic pole, which may offer important information to scientists modeling the geodynamo.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this work include postdoctoral and undergraduate education. There are also implications for society\u0027s understanding of global climate change, since these techniques offer a different perspective on climate change from Antarctic marine sediment cores, which are critical to understanding the behavior of the ice sheets and their links to the global climate.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Verosub, Kenneth", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "New Paleomagnetic and Environmental Magnetic Studies of Old Cores from the Ross Sea Sector, Antarctica", "uid": "p0000367", "west": null}, {"awards": "0538657 Severinghaus, Jeffrey", "bounds_geometry": null, "dataset_titles": "Borehole Temperature Measurement in WDC05A in January 2008 and January 2009; d15N and d18O of air in the WAIS Divide ice core; Low-res d15N and d18O of O2 in the WAIS Divide 06A Deep Core; Ultra-High Resolution LA-ICP-MS Results: DO-21 Rapid Warming Event; WAIS Divide d18Oatm and Siple Dome/WAIS Divide composite and individual delta epsilon LAND", "datasets": [{"dataset_uid": "601041", "doi": "10.15784/601041", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Gas; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; WAIS Divide Ice Core", "people": "Seltzer, Alan; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide d18Oatm and Siple Dome/WAIS Divide composite and individual delta epsilon LAND", "url": "https://www.usap-dc.org/view/dataset/601041"}, {"dataset_uid": "609660", "doi": "10.7265/N5S46PWD", "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": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Low-res d15N and d18O of O2 in the WAIS Divide 06A Deep Core", "url": "https://www.usap-dc.org/view/dataset/609660"}, {"dataset_uid": "609637", "doi": "10.7265/N5B27S7S", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Severinghaus, Jeffrey P.; Orsi, Anais J.", "repository": "USAP-DC", "science_program": null, "title": "Borehole Temperature Measurement in WDC05A in January 2008 and January 2009", "url": "https://www.usap-dc.org/view/dataset/609637"}, {"dataset_uid": "609635", "doi": "10.7265/N51J97PS", "keywords": "Arctic; Geochemistry; GISP; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate", "people": "Mayewski, Paul A.; Kurbatov, Andrei V.; Haines, Skylar", "repository": "USAP-DC", "science_program": null, "title": "Ultra-High Resolution LA-ICP-MS Results: DO-21 Rapid Warming Event", "url": "https://www.usap-dc.org/view/dataset/609635"}, {"dataset_uid": "601747", "doi": "10.15784/601747", "keywords": "Antarctica; Delta 15N; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Gas Records; Ice Core Records; Isotope; Nitrogen; Nitrogen Isotopes; Oxygen; Oxygen Isotope; Snow/ice; Snow/Ice; WAIS; WAIS Divide", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "d15N and d18O of air in the WAIS Divide ice core", "url": "https://www.usap-dc.org/view/dataset/601747"}], "date_created": "Thu, 08 Jul 2010 00:00:00 GMT", "description": "0538657\u003cbr/\u003eSeveringhaus\u003cbr/\u003eThis award supports a project to develop high-resolution (20-yr) nitrogen and oxygen isotope records on trapped gases in the WAIS Divide ice core (Antarctica), with a comparison record for chronological purposes in the GISP2 (Greenland) ice core. The main scientific objective is to provide an independent temperature-change record for the past 100,000 years in West Antarctica that is not subject to the uncertainty inherent in ice isotopes (18O and deuterium), the classical paleothermometer. Nitrogen isotopes (Delta 15N) in air bubbles in glacial ice record rapid surface temperature change because of thermal fractionation of air in the porous firn layer, and this isotopic anomaly is recorded in bubbles as the firn becomes ice. Using this gas-based temperature-change record, in combination with methane data as interpolar stratigraphic markers, the proposed work will define the precise relative timing of abrupt warming in Greenland and abrupt cooling at the WAIS Divide site during the millennial-scale climatic oscillations of Marine Isotopic Stage 3 (30-70 kyr BP) and the last glacial termination. The nitrogen isotope record also provides constraints on past firn thickness, which inform temperature and accumulation rate histories from the ice core. A search for possible solar-related cycles will be conducted with the WAIS Divide Holocene (Delta 15N.) Oxygen isotopes of O2 (Delta 18Oatm) are obtained as a byproduct of the (Delta 15N) measurement. The gas-isotopic records will enhance the value of other atmospheric gas measurements in WAIS Divide, which are expected to be of unprecedented quality. The high-resolution (Delta 18Oatm) records will provide chronological control for use by the international ice coring community and for surface glacier ice dating. Education of a graduate student, and training of a staff member in the laboratory, will contribute to the nation\u0027s human resource base. Outreach activities in the context of the International Polar Year will be enhanced. International collaboration is planned with the laboratory of LSCE, University of Paris.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e LA-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Borehole Temperature; LABORATORY; Depth; Not provided; GROUND-BASED OBSERVATIONS; Wais Divide-project; Ice Core; WAIS Divide", "locations": "WAIS Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Haines, Skylar; Mayewski, Paul A.; Orsi, Anais J.; Kurbatov, Andrei V.; Severinghaus, Jeffrey P.", "platforms": "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": "WAIS Divide Ice Core", "south": null, "title": "Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate", "uid": "p0000036", "west": null}, {"awards": "0538494 Meese, Debra", "bounds_geometry": null, "dataset_titles": "Microstructural Location and Composition of Impurities in Polar Ice Cores", "datasets": [{"dataset_uid": "609436", "doi": "10.7265/N5DF6P5P", "keywords": "Antarctica; Arctic; Byrd Glacier; Byrd Ice Core; Chemistry:ice; Chemistry:Ice; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Lake Vostok; Paleoclimate; Vostok Ice Core", "people": "Obbard, Rachel; Baker, Ian", "repository": "USAP-DC", "science_program": null, "title": "Microstructural Location and Composition of Impurities in Polar Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609436"}], "date_created": "Thu, 03 Jun 2010 00:00:00 GMT", "description": "0538494\u003cbr/\u003eMeese\u003cbr/\u003eThis award supports a project for physical properties research on snow pits and firn/ice cores with specific objectives that include stratigraphic analysis including determination of accumulation rates, annual layers, depth hoar, ice and wind crusts and rates of grain growth with depth. Studies of firn densification rates and how these parameters relate to the meteorology and climatology over the last 200 years of snow accumulation in Antarctica will also be investigated. The project will also determine the seasonality of accumulation by co-registration of stratigraphy and chemistry and determination of chemical species at the grain boundaries, how these may change with depth/densification (and therefore temperature), precipitation, and may affect grain growth. Fabric analyses will be made, including variation with depth, location on undulations and if any variation exists with climate/chemistry. The large spatial coverage of the US ITASE program offers the opportunity to determine how these parameters are affected by a large range of temperature, precipitation and topographic effects. The intellectual merit of the project includes the fact that ITASE is the terrestrial equivalent of a polar research vessel that provides a unique, logistically efficient, multi-dimensional (x, y, z and time) view of the atmosphere, ice sheet and their histories. Physical properties measurements/ analyses are an integral part of understanding the dynamic processes to which the accumulated snow is subjected. Recent advancements in the field along with multiple core sites provide an excellent opportunity to gain a much broader understanding of the spatial, temporal and physical variables that impact firnification and the possible resultant impact on climatic interpretation. In terms of broader impacts, the data collected by US ITASE and its international ITASE partners is available to a broad scientific community. US ITASE has an extensive program of public outreach and provides significant opportunities for many students to experience multidisciplinary Antarctic research. A graduate student, a post-doctoral fellow and at least one undergraduate would be funded by this work. Dr. Meese is also a member of the New England Science Collaborative, an organization that educates the public on climate change based on recent scientific advancements.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": false, "keywords": "LABORATORY; Grain Growth; FIELD SURVEYS; Accumulation Rate; Firn Core; FIELD INVESTIGATION; Chemistry; Snow Pit; Depth Hoar; Firn Density; Ice Core; Not provided; Stratigraphic Analysis; Firn; US ITASE; Annual Layers", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Meese, Deb; MEESE, DEBRA", "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": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "The Physical Properties of the US ITASE Firn and Ice Cores from South Pole to Taylor Dome", "uid": "p0000289", "west": null}, {"awards": "0094078 Bart, Philip", "bounds_geometry": "POLYGON((-179.99992 -72.00044,-143.999984 -72.00044,-108.000048 -72.00044,-72.000112 -72.00044,-36.000176 -72.00044,-0.000239999999991 -72.00044,35.999696 -72.00044,71.999632 -72.00044,107.999568 -72.00044,143.999504 -72.00044,179.99944 -72.00044,179.99944 -72.574101,179.99944 -73.147762,179.99944 -73.721423,179.99944 -74.295084,179.99944 -74.868745,179.99944 -75.442406,179.99944 -76.016067,179.99944 -76.589728,179.99944 -77.163389,179.99944 -77.73705,143.999504 -77.73705,107.999568 -77.73705,71.999632 -77.73705,35.999696 -77.73705,-0.000240000000019 -77.73705,-36.000176 -77.73705,-72.000112 -77.73705,-108.000048 -77.73705,-143.999984 -77.73705,-179.99992 -77.73705,-179.99992 -77.163389,-179.99992 -76.589728,-179.99992 -76.016067,-179.99992 -75.442406,-179.99992 -74.868745,-179.99992 -74.295084,-179.99992 -73.721423,-179.99992 -73.147762,-179.99992 -72.574101,-179.99992 -72.00044))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001648", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0301A"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "PROPOSAL NO.: 0094078\u003cbr/\u003ePRINCIPAL INVESTIGATOR: Bart, Philip\u003cbr/\u003eINSTITUTION NAME: Louisiana State University \u0026 Agricultural and Mechanical College\u003cbr/\u003eTITLE: CAREER: Relative frequency and phase of extreme expansions of the Antarctic Ice Sheets during the late Neogene\u003cbr/\u003eNSF RECEIVED DATE: 07/27/2000\u003cbr/\u003e\u003cbr/\u003ePROJECT SUMMARY\u003cbr/\u003e\u003cbr/\u003eExpansions and contractions of the Antarctic Ice Sheets (AISs) have undoubtedly had a profound influence on Earth\u0027s climate and global sea-level. However, rather than being a single entity, the Antarctic cryosphere consists of three primary elements: 1) the East Antarctic Ice Sheet (EAIS); 2) the West Antarctic Ice Sheet (WAIS); and 3) the Antarctic Peninsula Ice Cap (APIC). The distinguishing characteristics include significant differences in: 1) ice volume; 2) substratum elevation; 3) ice-surface elevation; and 4) location with respect to latitude. Various lines of evidence indicate that the AISs have undergone significant fluctuations in the past and that fluctuations will continue to occur in the future. The exact nature of the fluctuations has been the subject of many lively debates. According to one line of reasoning, the land-based EAIS has been relatively stable, experiencing only minor fluctuations since forming in the middle Miocene, whereas the marine-based WAIS has been dynamic, waxing and waning frequently since the late Miocene. According to an alternate hypothesis, the ice sheets advanced and retreated synchronously. These two views are incompatible. \u003cbr/\u003e\u003cbr/\u003eThe first objective of this proposal is to compare the long-term past behavior of the WAIS to that of the EAIS and APIC. The fluctuations of the AISs involve many aspects (the frequency of changes, the overall magnitude of ice-volume change, etc.), and the activities proposed here specifically concern the frequency and phase of extreme advances of the ice sheet to the continental shelf. The project will build upon previous seismic-stratigraphic investigations of the continental shelves. These studies have clarified many issues concerning the minimum frequency of extreme expansions for the individual ice sheets, but some important questions remain. During the course of the project, the following questions will be evaluated.\u003cbr/\u003e\u003cbr/\u003eQuestion 1) Were extreme advances of the EAIS and WAIS across the shelf of a similar frequency and coeval? This evaluation is possible because the western Ross Sea continental shelf (Northern Basin) receives drainage from the EAIS, and the eastern Ross Sea (Eastern Basin) receives drainage from the WAIS. Quantitative analyses of the extreme advances from these two areas have been conducted by Alonso et al. (1992) and Bart et al. (2000), respectively. However, the existing single-channel seismic grids are incomplete and can not be used to determine the stratigraphic correlations from Northern Basin to Eastern Basin. It is proposed that high-resolution seismic data (~2000 kms) be acquired to address this issue.\u003cbr/\u003e\u003cbr/\u003eQuestion 2) Were extreme advances of the APIC across the shelf as frequent as inferred by Bart and Anderson (1995)? Bart and Anderson (1995) inferred that the APIC advanced across the continental shelf at least 30 times since the middle Miocene. This is significant because it suggests that the advances of the small APIC were an order of magnitude more frequent than the advances of the EAIS and WAIS. Others contest the Bart and Anderson (1995) glacial-unconformity interpretation of seismic reflections, and argue that the advances of the APIC were far fewer (i.e., Larter et al., 1997). The recent drilling on the Antarctic Peninsula outer continental shelf has sampled some but not all of the glacial units, but the sediment recovery was poor, and thus, the glacial history interpretation is still ambiguous. The existing high-resolution seismic grids from the Antarctic Peninsula contain only one regional strike line on the outer continental shelf. This is inadequate to address the controversy of the glacial-unconformity interpretation and the regional correlation of the recent ODP results. It is proposed that high-resolution seismic data (~1000 kms) be acquired in a forthcoming (January 2002) cruise to the Antarctic Peninsula to address these issues.\u003cbr/\u003e\u003cbr/\u003eThe second objective of this project is 1) to expand the PI\u0027s effort to integrate his ongoing and the proposed experiments into a graduate-level course at LSU, and 2) to develop a pilot outreach program with a Baton Rouge public high school. The Louisiana Department of Education has adopted scientific standards that apply to all sciences. These standards reflect what 9th through 12th grade-level students should be able to do and know. The PI will target one of these standards, the Science As Inquiry Standard 1 Benchmark. The PI will endeavor to share with the students the excitement of conducting scientific research as a way to encourage the students to pursue earth science as a field of study at the university level.", "east": 179.99944, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; 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; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -72.00044, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Bart, Philip", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -77.73705, "title": "PECASE: Relative frequency and phase of extreme expansions of the Antarctic Ice Sheets during the late Neogene", "uid": "p0000593", "west": -179.99992}, {"awards": "0739583 Bowser, Samuel; 0739512 Walker, Sally; 0739496 Miller, Molly", "bounds_geometry": "POLYGON((163.41667 -77.33333,163.46667 -77.33333,163.51667 -77.33333,163.56667 -77.33333,163.61667 -77.33333,163.66667 -77.33333,163.71667 -77.33333,163.76667 -77.33333,163.81667 -77.33333,163.86667 -77.33333,163.91667 -77.33333,163.91667 -77.369997,163.91667 -77.406664,163.91667 -77.443331,163.91667 -77.479998,163.91667 -77.516665,163.91667 -77.553332,163.91667 -77.589999,163.91667 -77.626666,163.91667 -77.663333,163.91667 -77.7,163.86667 -77.7,163.81667 -77.7,163.76667 -77.7,163.71667 -77.7,163.66667 -77.7,163.61667 -77.7,163.56667 -77.7,163.51667 -77.7,163.46667 -77.7,163.41667 -77.7,163.41667 -77.663333,163.41667 -77.626666,163.41667 -77.589999,163.41667 -77.553332,163.41667 -77.516665,163.41667 -77.479998,163.41667 -77.443331,163.41667 -77.406664,163.41667 -77.369997,163.41667 -77.33333))", "dataset_titles": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores; Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.; Sequence Data", "datasets": [{"dataset_uid": "600076", "doi": "10.15784/600076", "keywords": "Biota; Geochronology; Marine Sediments; Oceans; Southern Ocean", "people": "Miller, Molly; Furbish, David", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600076"}, {"dataset_uid": "600077", "doi": "10.15784/600077", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; McMurdo Sound; Oceans; Sample/collection Description; Sample/Collection Description", "people": "Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600077"}, {"dataset_uid": "601764", "doi": "10.15784/601764", "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Gillikin, David; Puhalski, Emma; Camarra, Steve; Cronin, Kelly; Verheyden, Anouk; Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.", "url": "https://www.usap-dc.org/view/dataset/601764"}, {"dataset_uid": "000144", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Sequence Data", "url": "http://www.ncbi.nlm.nih.gov/sites/myncbi/collections/public/1rMU2lBNcxWAsa9h9WyD8rzA8/"}], "date_created": "Wed, 15 Jul 2009 00:00:00 GMT", "description": "This project answers a simple question: why are there so few fossils in sediment cores from Antarctica?s continental shelf? Antarctica?s benthos are as biologically rich as those of the tropics. Shell-secreting organisms should have left a trail throughout geologic time, but have not. This trail is particularly important because these organisms record regional climate in ways that are critical to interpreting the global climate record. This study uses field experiments and targeted observations of modern benthic systems to examine the biases inflicted by fossil preservation. By examining a spectrum of ice-affected habitats, this project provides paleoenvironmental insights into carbonate preservation, sedimentation rates, and burial processes; and will provide new approaches to reconstructing the Cenozoic history of Antarctica. Broader impacts include graduate and undergraduate research and education, development of undergraduate curricula to link art and science, K12 outreach, public outreach via the web, and societal relevance through improved understanding of records of global climate change.", "east": 163.91667, "geometry": "POINT(163.66667 -77.516665)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.33333, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walker, Sally; Bowser, Samuel; Miller, Molly; Furbish, David", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "NCBI GenBank; USAP-DC", "science_programs": null, "south": -77.7, "title": "Collaborative Research: Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "uid": "p0000203", "west": 163.41667}, {"awards": "0617194 Verosub, Kenneth", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 03 Dec 2007 00:00:00 GMT", "description": "This Small Grant for Exploratory Research supports a paleomagnetic survey of previously collected sediment cores from Antarcticas continental margin. Many of these cores were originally interpreted with methods that, though advanced for their time, were barely adequate. Nonetheless, these results are still used to construct an overall stratigraphic record for marine sediments and major events related to the Southern Ocean, global climate, and Antarcticas glacial history. With the advances in paleomagnetic techniques over the intervening decades and the great interest and current work on Antarctic marine sediments by major projects such as ANDRILL and ShalDrill, a reassessment of these cores is needed. In addition, these new studies will offer insight into the behavior of the geomagnetic field within the Earths tangent cylinder, the region delineated by an imaginary cylinder parallel to the Earths rotation axis and tangent to the equator of the inner core boundary.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this work include support of postdoctoral student research and improving societys understanding of global climate change through an improved understanding of the Antarctic marine sediment record.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Verosub, Kenneth", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "SGER: Feasibility of Using Old Antarctic Cores for New Paleomagnetic Studies", "uid": "p0000365", "west": null}, {"awards": "0338224 Putkonen, Jaakko", "bounds_geometry": "POLYGON((161 -77,161.3 -77,161.6 -77,161.9 -77,162.2 -77,162.5 -77,162.8 -77,163.1 -77,163.4 -77,163.7 -77,164 -77,164 -77.1,164 -77.2,164 -77.3,164 -77.4,164 -77.5,164 -77.6,164 -77.7,164 -77.8,164 -77.9,164 -78,163.7 -78,163.4 -78,163.1 -78,162.8 -78,162.5 -78,162.2 -78,161.9 -78,161.6 -78,161.3 -78,161 -78,161 -77.9,161 -77.8,161 -77.7,161 -77.6,161 -77.5,161 -77.4,161 -77.3,161 -77.2,161 -77.1,161 -77))", "dataset_titles": "Cosmogenic nucilde data at ICE-D", "datasets": [{"dataset_uid": "200298", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic nucilde data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Tue, 20 Nov 2007 00:00:00 GMT", "description": "This work will study cosmogenic isotope profiles of rock and sediment in the Dry Valleys of Antarctica to understand their origin. The results will provide important constraints on the history of the East Antarctic Ice Sheet. The near-perfect preservation of volcanic ash and overlying sediments suggests that hyperarid cold conditions have prevailed in the Dry Valleys for over 10 Myr. The survival of these sediments also suggests that warm-based ice has not entered the valley system and ice sheet expansion has been minimal. Other evidence, however, suggests that the Dry Valleys have experienced considerably more sediment erosion than generally believed: 1) the cosmogenic exposure ages of boulders and bedrock in the Valleys all show generally younger ages than volcanic ash deposits used to determine minimum ages of moraines and drifts, 2) there appears to be a discrepancy between the suggested extreme preservation of unconsolidated slope deposits (\u003e10 Myr) and adjacent bedrock that has eroded 2.6-6 m during the same time interval. The fact that the till and moraine exposure ages generally post date the overlying volcanic ash deposits could reflect expansion of continental ice sheet into the Dry Valleys with cold-based ice, thus both preserving the landscape and shielding the surfaces from cosmic radiation. Another plausible explanation of the young cosmogenic exposure ages is erosion of the sediments and gradual exhumation of formerly buried boulders to the surface. Cosmogenic isotope systematics are especially well suited to address these questions. We will measure multiple cosmogenic isotopes in profiles of rock and sediment to determine the minimum exposure ages, the degree of soil stability or mixing, and the shielding history of surfaces by cold based ice. We expect to obtain unambiguous minimum ages for deposits. In addition, we should be able to identify areas disturbed by periglacial activity, constrain the timing of such activity, and account for the patchy preservation of important stratigraphic markers such as volcanic ash. The broader impacts of this project include graduate and undergraduate education, and improving our understanding of the dynamics of Southern Hemisphere climate on timescales of millions of years, which has major implications for understanding the controls and impacts of global climate change.", "east": 164.0, "geometry": "POINT(162.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Dry Valleys; Not provided", "locations": "Dry Valleys", "north": -77.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Putkonen, Jaakko", "platforms": "Not provided", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -78.0, "title": "Stability of Landscapes and Ice Sheets in Dry Valleys, Antarctica: A Systematic Study of Exposure Ages of Soils and Surface Deposits", "uid": "p0000575", "west": 161.0}, {"awards": "0230469 Wise, Sherwood", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 31 Jul 2007 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports the development of a standardized diatom image catalog or database. Diatoms are considered by many to be the most important microfossil group used today in the study of Antarctic Cenozoic marine deposits south of the Polar Front, from the near shore to deep sea. These microfossils, with walls of silica called frustules, are produced by single-celled plants (algae of the Class Bacillariophyceae) in a great variety of forms. Consequently, they have great biostratigraphic importance in the Southern Ocean and elsewhere for determining the age of marine sediments. Also, paleoclimatic and paleoceanographic studies increasingly rely on fossil diatom data. Changing biogeographic distributions of given taxa indicate shifting paleoecological conditions and provide evidence of the surface productivity and temperatures of ancient oceans. The generality of conclusions, though, is limited by variation in species concepts among workers. The broad research community relies, directly or indirectly, on the accurate identification of diatom species. Current technology can be used to greatly improve upon the standard references that have been used in making these identifications.\u003cbr/\u003e\u003cbr/\u003eThis project will develop an interactive digital-image catalog of modern and Cenozoic fossil diatoms of the Southern Ocean called \"DiatomWare\" for use by specialists and educators as an aid in rapid, accurate, and consistent species identification. As such, this will be a researcher\u0027s resource. It will be especially useful where it is not possible to maintain standard library resources such as onboard research vessels or at remote stations such as McMurdo Station. Major Antarctic geological drilling initiatives such as the new SHALDRIL project and the pending ANDRILL project will benefit from this product because they will rely heavily on diatom biostratigraphy to achieve their research objectives. The DiatomWare image database will be modeled on NannoWare, which was released in October 2002 on CD-ROM as a publication of the International Nannoplankton Association. BugCam will be adapted and modified as necessary to run the DiatomWare database, which can then be run from desktop or laptop computers. Images and text for the database will be scanned from the literature or captured in digital form from light or scanning electron microscopes.\u003cbr/\u003e\u003cbr/\u003eThe software interface will include a number of data fields that can be accessed by the click of a mouse button. Primary information will be the images and descriptions of the holotypes. In addition, representative images of paratypes or hypotypes will be included whenever possible in plain transmitted, differential interference contrast light and, when available, as drawings and SEM images. Also included will be a 35-word or less English diagnosis (\"mini-description\"), the biostratigraphic range in terms of zones and linear time, bibliographic references, lists of species considered junior synonyms, and similar species. The list of similar species will be cross-referenced with their respective image files to enable quick access for direct visual comparison on the viewing screen. Multiple images can be brought to the viewing screen simultaneously, and a zoom feature will permit image examination at a wide range of magnifications. Buttons will allow range charts, a bibliography, and key public-domain publications from the literature to be called up from within the program. The DiatomWare/BugCam package will be distributed at a nominal cost through a major nonprofit society via CD-ROM and free to Internet users on the Worldwide Web. Quality control measures will include critical review of the finalized database by a network of qualified specialists. The completed database will include descriptions and images of between 350 and 400 species, including fossil as well as modern forms that have no fossil record.\u003cbr/\u003e\u003cbr/\u003eThe development of the proposed diatom image database will be important to all research fields that depend on accurate biostratigraphic dating and paleoenvironmental interpretation of Antarctic marine sediments and plankton. The database will also serve as a valuable teaching tool for micropaleontology students and their professors, will provide a rapid means of keying down species for micropaleontologists of varying experience and background, and will promote a uniformity of taxonomic concepts since it will be developed and continuously updated with the advice of a community of nannofossil fossil experts. Broad use of the database is anticipated since it will be widely available through the Internet and on CD-ROM for use on personal computers that do not require large amounts of memory, costly specialized programs, or additional hardware.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wise, Sherwood", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "DiatomWare: An Interactive Digital Image Catalog for Antarctic Cenozoic Diatoms", "uid": "p0000062", "west": null}, {"awards": "0126146 Miller, Molly", "bounds_geometry": "POINT(171 -83.75)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 20 Jun 2007 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a study to investigate paleoenvironmental conditions during the late Paleozoic and Mesozoic in central interior Antarctica. The 4 km thick sequence of sedimentary rocks, known as the Beacon Supergroup, in the Beardmore Glacier area records 90 million years of Permian through Jurassic history of this high-paleolatitude sector of Gondwana. It accumulated in a foreland basin with a rate of subsidence approximately equal to the rate of deposition. The deposits have yielded diverse vertebrate fossils, in situ fossil forests, and exceptionally well preserved plant fossils. They give a unique glimpse of glacial, lake, and stream/river environments and ecosystems and preserve an unparalleled record of the depositional, paleoclimatic, and tectonic history of the area. The excellent work done to date provides a solid base of information on which to build understanding of conditions and processes.\u003cbr/\u003e\u003cbr/\u003eThis project is a collaborative study of this stratigraphic section that will integrate sedimentologic, paleontologic, and ichnologic observations to answer focused questions, including: (1) What are the stratigraphic architecture and alluvial facies of Upper Permian to Jurassic rocks in the Beardmore area?; (2) In what tectonostratigraphic setting were these rocks deposited?; (3) Did vertebrates inhabit the cold, near-polar, Permian floodplains, as indicated by vertebrate burrows, and can these burrows be used to identify, for the first time, the presence of small early mammals in Mesozoic deposits?; and (4) How did bottom-dwelling animals in lakes and streams use substrate ecospace, how did ecospace use at these high paleolatitudes differ from ecospace use in equivalent environments at low paleolatitudes, and what does burrow distribution reveal about seasonality of river flow and thus about paleoclimate? Answers to these questions will (1) clarify the paleoclimatic, basinal, and tectonic history of this part of Gondwana, (2) elucidate the colonization of near-polar ecosystems by vertebrates, (3) provide new information on the environmental and paleolatitudinal distributions of early mammals, and (4) allow semi-quantitative assessment of the activity and abundance of bottom-dwelling animals in different freshwater environments at high and low latitudes. In summary, this project will contribute significantly to an understanding of paleobiology and paleoecology at a high latitude floodplain setting during a time in Earth history when the climate was much different than today.", "east": 171.0, "geometry": "POINT(171 -83.75)", "instruments": null, "is_usap_dc": false, "keywords": "Beardmore Glacier; FIELD SURVEYS; Paleoclimate; Permian; Paleontology; FIELD INVESTIGATION; Sedimentologic; Ichnologic; Stratigraphic; Gondwana", "locations": "Beardmore Glacier", "north": -83.75, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e MESOZOIC \u003e JURASSIC; PHANEROZOIC \u003e PALEOZOIC \u003e PERMIAN; PHANEROZOIC \u003e MESOZOIC \u003e TRIASSIC", "persons": "Miller, Molly", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -83.75, "title": "Collaborative Research: Late Paleozoic-Mesozoic Fauna, Environment, Climate and Basinal History: Beardmore Glacier Area, Transantarctic Mountains", "uid": "p0000736", "west": 171.0}, {"awards": "0230149 McGwire, Kenneth", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 04 Jun 2007 00:00:00 GMT", "description": "This award supports the development of novel methods for digital image analysis of glacial ice cores that are stored at the National Ice Core Laboratory (NICL) in Denver, Colorado. Ice cores are a critical source of information on how Earth has changed over time, since indicators of local climate (snow accumulation, temperature), regional characteristics (wind-blown materials such as sea salt, dust and pollen), global processes (e.g., CO2, methane), and even extraterrestrial influences (cosmogenic isotopes) are stored in the ice on a common time scale. This project will develop a high-resolution optical scanning system for laboratory curation of ice core images, internet-based search and retrieval capabilities, a digital image analysis system specifically for ice core studies, and methods to integrate ice core image analysis with other dating methods. These tools will be developed and tested in conjunction with scientific investigations of NICL holdings. Optical scanning and analysis tools will improve understanding of the historical development of the ice collected from a particular location and will help to resolve challenges such as ice that has lost stratigraphic order through flow processes. \u003cbr/\u003eBy providing permanent online digital archives of ice core images, this project will greatly improve the documentation and availability of ice core data while reducing time and costs for subsequent scientific investigations. Using the internet, ice core scientists will be able to determine the appropriateness of specific NICL holdings for various scientific studies. By optically scanning ice cores as they are processed at NICL, any researcher will be able to examine an ice core in similar detail to the few investigators who were fortunate enough to observe it before modifications from sampling and storage. Re-examination of cores could be done decades later by anyone at any location, which is not possible now because only the interpretation of the original observer is recorded. Integration of digital image data into ice core analysis will speed discovery, allow collaborative interpretation, and enhance consistency of analysis to improve ice core dating, identification of melt layers, location of flow disturbances, and more. The equipment will be housed at NICL and will be available to the broad community, improving scientific infrastructure.\u003cbr/\u003eThis work will also have numerous broader impacts. Ice core science addresses fundamental questions of human interest related to global warming, abrupt climate change, biogeochemical cycling, and more. The principal investigators broadly disseminate their scientific findings through numerous outlets, ranging from meeting with government officials, chairing and serving on NRC panels, writing popular books and articles, publishing in scientific literature, teaching classes, talking to civic groups, and appearing on radio and television. The results from ice core analyses have directly informed policymakers and will continue to do so. Thus, by improving ice core science, this projectl will benefit society.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e VISUAL OBSERVATIONS", "is_usap_dc": false, "keywords": "Image; Ice Core; Not provided; Scanner; Stratigraphy", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McGwire, Kenneth C.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Digital Optical Imaging of Ice Cores for Curation and Scientific Applications", "uid": "p0000735", "west": null}, {"awards": "0229917 Becker, Luann", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 24 Jan 2007 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an interdisciplinary study of fluvial sediments in Antarctica for evidence of what caused the greatest of all mass extinctions in the history of life at the Permian-Triassic boundary. This boundary was, until recently, difficult to locate and thought to be unequivocally disconformable in Antarctica. New studies, particularly of carbon isotopic chemostratigraphy and of paleosols and root traces as paleoecosystem indicators, together with improved fossil plant, reptile and pollen biostratigraphy, now suggest that the precise location of the boundary might be identified and have led to local discovery of iridium anomalies, shocked quartz, and fullerenes with extraterrestrial noble gases. These anomalies are associated with a distinctive claystone breccia bed, similar to strata known in South Africa and Australia, and taken as evidence of deforestation. There is already much evidence from Antarctica and elsewhere that the mass extinction on land was abrupt and synchronous with extinction in the ocean. The problem now is what led to such death and destruction. Carbon isotopic values are so low in these and other Permian-Triassic boundary sections that there was likely to have been some role for catastrophic destabilization of methane clathrates. Getting the modeled amount of methane out of likely reservoirs would require such catastrophic events as bolide impact, flood-basalt eruption or continental-shelf collapse, which have all independently been implicated in the mass extinction and for which there is independent evidence. Teasing apart these various hypotheses requires careful re-examination of beds that appear to represent the Permian-Triassic boundary, and search for more informative sequences, as was the case for the Cretaceous-Tertiary boundary. This collaborative research on geochemistry and petrography of boundary beds and paleosols (by Retallack), on carbon isotopic variation through the boundary interval (by Jahren), and on fullerenes, iridium and helium (by Becker) is designed to test these ideas about the Permian-Triassic boundary in Antarctica and to shed light on processes which contributed to this largest of mass extinctions on Earth. Fieldwork for this research will be conducted in the central Transantarctic Mountains and in Southern Victoria Land with an initial objective of examining the stratigraphic sequences for continuity across the boundary. Stratigraphic continuity is a critical element that must exist for the work to be successful. If fieldwork indicates sufficiently continuous sections, the full analytical program will follow fieldwork.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e PROBES; SOLAR/SPACE OBSERVING INSTRUMENTS \u003e PARTICLE DETECTORS \u003e SEM", "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Becker, Luann", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Permian-Triassic Mass Extinction in Antarctica", "uid": "p0000718", "west": null}, {"awards": "9526566 Bindschadler, Robert", "bounds_geometry": null, "dataset_titles": "Decadal-Length Composite West Antarctic Air Temperature Records", "datasets": [{"dataset_uid": "609097", "doi": "10.7265/N55D8PS0", "keywords": "Antarctica; Atmosphere; Automated Weather Station; Meteorology; Temperature; West Antarctica", "people": "Shuman, Christopher A.; Stearns, Charles R.", "repository": "USAP-DC", "science_program": null, "title": "Decadal-Length Composite West Antarctic Air Temperature Records", "url": "https://www.usap-dc.org/view/dataset/609097"}], "date_created": "Tue, 28 Nov 2006 00:00:00 GMT", "description": "This award is for support for a research program involving the use of passive microwave data to validate key paleoclimate indicators used in glaciologic research. The specific contributions of this research are: 1) to define the timing and spatial extent of hoar complexes, which may serve as visible, annual stratigraphic markers in ice cores, through a combination of satellite passive microwave data and field observations; and 2) to monitor temperature trends at the site with calibrated passive microwave brightness temperatures and to correlate these trends to proxy temperatures provided by oxygen and hydrogen stable isotope ratio profiles from snow pits and/or ice cores. The work will take place at Siple Dome, Antarctica as part of the field activities associated with the ice core drilling program there.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SMMR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SSM/I", "is_usap_dc": true, "keywords": "West Antarctica; Near-Surface Air Temperatures; Surface Temperatures; Special Sensor Microwave/imager; Passive Microwave Brightness Temperatures; Scanning Multichannel Microwave Radiometer; SSM/I; SSMR; AWS Byrd Station; NIMBUS-7; Emissivity Modeling; Antarctica; West Antarctic Ice Sheet; Not provided; DMSP; AWS Siple; Automated Weather Station; AWS Lynn; AWS Lettau; AWS", "locations": "Antarctica; West Antarctica; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bindschadler, Robert; Shuman, Christopher A.; Stearns, Charles R.", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e DEFENSE METEOROLOGICAL SATELLITE PROGRAM (DMSP) \u003e DMSP; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e NIMBUS \u003e NIMBUS-7", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Passive Microwave Remote Sensing for Paleoclimate Indicators at Siple Dome, Antarctica", "uid": "p0000191", "west": null}, {"awards": "0229245 Hamilton, Gordon", "bounds_geometry": "POINT(135 -76)", "dataset_titles": null, "datasets": null, "date_created": "Thu, 30 Mar 2006 00:00:00 GMT", "description": "A \u0027horizontal ice core\u0027 was collected at the Mount Moulton blue ice field in West Antarctica and preliminary analyses of the sample material suggests that a ~500 kyr climate record is preserved in the ice at this site. This award will contribute to the understanding of the Mt Moulton record by assessing the potential for ice-flow induced deformation of the stratigraphic profile. In addition, this award builds on the recognition of blue ice areas as archives of long climate records by conducting reconnaissance studies for a potential horizontal ice core location at the Allan Hills in East Antarctica. The objectives of this project are to contribute to the glaciological understanding of blue ice areas in Antarctica. Ice flow conditions at the Mt Moulton blue ice field will be studied to assess the possibility that the stratigraphic record has been deformed and reconnaissance of a potential horizontal ice core site in the Allan Hills blue ice field will also be accomplished. Short field programs will be undertaken at each location to collect relevant measurements of ice flow and subglacial topography, and to conduct sampling of material that will enable the preservation of the stratigraphic sequences to be assessed.", "east": 135.0, "geometry": "POINT(135 -76)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e ACOUSTIC RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": false, "keywords": "Mount Moulton; Not provided; Subglacial Topography; FIELD INVESTIGATION; Ice Flow; West Antarctica; FIELD SURVEYS; Stratigraphy; Horizontal Ice Core; GROUND-BASED OBSERVATIONS; Blue Ice; Radar", "locations": "Mount Moulton; West Antarctica", "north": -76.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bauer, Rob; Hamilton, Gordon S.", "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", "repositories": null, "science_programs": null, "south": -76.0, "title": "Glaciology of Blue Ice Areas in Antarctica", "uid": "p0000248", "west": 135.0}, {"awards": "0088035 Arcone, Steven", "bounds_geometry": "POLYGON((-135 -75,-130.5 -75,-126 -75,-121.5 -75,-117 -75,-112.5 -75,-108 -75,-103.5 -75,-99 -75,-94.5 -75,-90 -75,-90 -76.5,-90 -78,-90 -79.5,-90 -81,-90 -82.5,-90 -84,-90 -85.5,-90 -87,-90 -88.5,-90 -90,-94.5 -90,-99 -90,-103.5 -90,-108 -90,-112.5 -90,-117 -90,-121.5 -90,-126 -90,-130.5 -90,-135 -90,-135 -88.5,-135 -87,-135 -85.5,-135 -84,-135 -82.5,-135 -81,-135 -79.5,-135 -78,-135 -76.5,-135 -75))", "dataset_titles": "US International Trans-Antarctic Scientific Expedition 400 MHz Subsurface Radar Profiles; US International Trans-Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping", "datasets": [{"dataset_uid": "609269", "doi": "10.7265/N5GH9FV6", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; ITASE; WAIS", "people": "Mayewski, Paul A.; Kaspari, Susan; Arcone, Steven; Spikes, Vandy Blue; Hamilton, Gordon S.", "repository": "USAP-DC", "science_program": "ITASE", "title": "US International Trans-Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping", "url": "https://www.usap-dc.org/view/dataset/609269"}, {"dataset_uid": "609254", "doi": "10.7265/N58050J7", "keywords": "Airborne Radar; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ITASE; Radar; WAIS", "people": "Arcone, Steven", "repository": "USAP-DC", "science_program": null, "title": "US International Trans-Antarctic Scientific Expedition 400 MHz Subsurface Radar Profiles", "url": "https://www.usap-dc.org/view/dataset/609254"}], "date_created": "Sun, 01 May 2005 00:00:00 GMT", "description": "This award supports continued acquisition of high resolution, radar reflection profiles of the snow and ice stratigraphy between core sites planned along traverse routes of the U.S. component of the International\u003cbr/\u003eTrans-Antarctic Scientific Expedition (U.S.-ITASE). The purpose is to use the profiles to establish the structure and continuity of firn stratigraphic horizons over hundreds of kilometers and to quantitatively\u003cbr/\u003eassess topographic and ice movement effects upon snow deposition. Other objectives are to establish the climatic extent that a single site represents and to investigate the cause of firn reflections. The radar\u003cbr/\u003ewill also be used to identify crevasses ahead of the traverse vehicles in order to protect the safety of the scientists and support personnel on the traverse. Collaboration with other ITASE investigators will use the radar horizons as continuous isochronic references fixed by the core dating to calculate historical snow accumulation rates. The primary radar system uses 400-MHz (center frequency) short-pulse antennas, which (with processing) gives the penetration of 50-70 meters. This is the depth which is required to exceed the 200-year deposition horizon along the traverse routes. Profiles at 200 MHz will also be recorded if depths greater than 70 meters are of interest. Processing will be accomplished by data compression (stacking) to reveal long distance stratigraphic deformation, range gain corrections to give proper weight to signal amplitudes, and GPS corrections to adjust the records for the present ice sheet topography. Near surface stratigraphy will allow topographic and ice movement effects to be separated. This work is critical to the success of the U.S.-ITASE program.", "east": -90.0, "geometry": "POINT(-112.5 -82.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": true, "keywords": "Ice; Radar Echo Sounder; USAP-DC; US ITASE; Ice Cover; West Antarctic Ice Sheet; Snow Accumulation; CRREL; Antarctic Ice Sheet; Radar; Ice Surveys; ITASE; Ice Sheet; Radar Echo Sounding; GROUND-BASED OBSERVATIONS; Ice Thickness; Mass Balance", "locations": "Antarctic Ice Sheet; West Antarctic Ice Sheet", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Spikes, Vandy Blue; Arcone, Steven; Kaspari, Susan; Hamilton, Gordon S.; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -90.0, "title": "High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet", "uid": "p0000146", "west": -135.0}, {"awards": "0135989 Wilen, Larry", "bounds_geometry": null, "dataset_titles": "Ice Fabric Characteristics: Siple Dome, A Core", "datasets": [{"dataset_uid": "609255", "doi": "10.7265/N54B2Z7V", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core", "people": "Wilen, Larry", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Ice Fabric Characteristics: Siple Dome, A Core", "url": "https://www.usap-dc.org/view/dataset/609255"}], "date_created": "Wed, 02 Mar 2005 00:00:00 GMT", "description": "0135989\u003cbr/\u003eWilen\u003cbr/\u003e\u003cbr/\u003eThis is a collaborative proposal by Principal Investigators at the University of Washington and Ohio University. Detailed knowledge about the interactions between micro-structure of ice and its deformation is needed to assess the integrity of stratigraphic layering and the depth-age relationship in ice cores, which is essential for interpreting the paleoclimate record. The Principal Investigators will use micro-structure to study fabric, the orientation distribution of crystal c-axes, and texture, the size and shape of crystals. Numerical modeling of ice deformation is a useful tool in understanding these interactions. Accurate modeling of ice deformation is complicated by factors, such as the fabric, grain size, dynamic recrystallization, stress level, and precise knowledge of initial conditions. For example, ice fabric evolves as the ice is strained and the deformation depends on the fabric. This complicated feedback mechanism must be understood to correctly model ice deformation. In another example, the usual assumption is that the initial fabric is isotropic or random, but there are excellent examples of near-surface ice in the ice cores that are apparently not isotropic. One must know the initial fabric to calculate the deformation rate in ice sheets. Dr. Wilen will combine results of his new automatic fabric analyzer (AFA) with predictions of detailed ice deformation models (Dr. Thorsteinsson) to refine and better constrain such models. The AFA gives new information in thin sections because the precision and number of measured c-axis orientations are greatly improved. The Principal Investigators will analyze existing data and collect new data on fabric and texture from ice cores to address questions regarding near-surface fabric, deformation mechanisms, dynamic recrystallization, and potential sources of layer disturbances. The data will be used to constrain models of fabric evolution and recrystallization processes. With the more refined models, scientists can address different questions and important problems related to ice deformation and ice cores. For example, the recent agreement between the climate records from the Greenland Ice Core Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) ice cores of the upper-90%, and the disagreement in the lower-10% emphasizes the need to understand and predict the mechanisms and probable depths of disruption in these and future deep ice cores. Evidence suggests that the stratigraphic disturbances arise from the anisotropic nature of ice crystals at a variety of scales. To properly model the deformation of anisotropic ice, the influence of fabric on deformation must be well known.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GROUND-BASED OBSERVATIONS; Ice Core Data; Siple Dome; Ice Fabric; Ice Core; USAP-DC", "locations": "Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Wilen, Larry", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Collaborative Research: Fabric and Texture Characteristics of Micro-Physical Processes in Ice", "uid": "p0000134", "west": null}, {"awards": "9714687 Brook, Edward J.", "bounds_geometry": null, "dataset_titles": "Byrd Ice Core Microparticle and Chemistry Data", "datasets": [{"dataset_uid": "609247", "doi": "", "keywords": "Antarctica; Byrd; Byrd Ice Core; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate", "people": "Blunier, Thomas; Brook, Edward J.; Thompson, Lonnie G.; Fluckiger, Jacqueline", "repository": "USAP-DC", "science_program": "Byrd Ice Core", "title": "Byrd Ice Core Microparticle and Chemistry Data", "url": "https://www.usap-dc.org/view/dataset/609247"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": "This award is for support for a program to make high resolution studies of variations in the concentration of methane, the oxygenisotope composition of paleoatmospheric oxygen, and the total gas content of deep Antarctic ice cores. Studies of the concentration and isotopic composition of air in the firn of the Antarctic ice sheet will also be continued. One objective of this work is to use the methane concentration and oxygen-isotope composition of oxygen of air in ice as time-stratigraphic markers for the precise intercorrelation of Greenland and Antarctic ice cores as well as the correlation of ice cores to other climatic records. A second objective is to use variations in the concentration and interhemispheric gradient of methane measured in Greenland and Antarctic ice cores to deduce changes in continental climates and biogeochemistry on which the atmospheric methane distribution depends. A third objective is to use data on the variability of total gas content in the Siple Dome ice core to reconstruct aspects of the glacial history of West Antarctica during the last glacial maximum. The fourth objective is to participate in collaborative studies of firn air chemistry at Vostok, Siple Dome, and South Pole which will yield much new information about gas trapping in ice as well as the concentration history and isotopic composition of greenhouse gases, oxygen, trace biogenic gases and trace anthropogenic gases during the last 100 years.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "GROUND STATIONS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Blunier, Thomas; Fluckiger, Jacqueline; Thompson, Lonnie G.; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Studies of Trapped Gases in Firn and Ice from Antarctic Deep Ice Cores", "uid": "p0000168", "west": null}, {"awards": "9615167 Dunbar, Nelia; 9527373 Dunbar, Nelia", "bounds_geometry": null, "dataset_titles": "Blue Ice Tephra II - Brimstone Peak; Blue Ice Tephra II - Mt. DeWitt; Tephra in Siple and Taylor Dome Ice Cores; Volcanic Records in the Siple and Taylor Dome Ice Cores", "datasets": [{"dataset_uid": "609110", "doi": "10.7265/N50P0WXF", "keywords": "Antarctica; Backscattered Electron Images; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core; Taylor Dome Ice Core; WAIS", "people": "Dunbar, Nelia", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Tephra in Siple and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609110"}, {"dataset_uid": "609114", "doi": "10.7265/N5MG7MDK", "keywords": "Antarctica; Blue Ice; Brimstone Peak; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Petrography; Tephra", "people": "Dunbar, Nelia", "repository": "USAP-DC", "science_program": null, "title": "Blue Ice Tephra II - Brimstone Peak", "url": "https://www.usap-dc.org/view/dataset/609114"}, {"dataset_uid": "609110", "doi": "10.7265/N50P0WXF", "keywords": "Antarctica; Backscattered Electron Images; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core; Taylor Dome Ice Core; WAIS", "people": "Dunbar, Nelia", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Tephra in Siple and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609110"}, {"dataset_uid": "609115", "doi": "10.7265/N5GQ6VPV", "keywords": "Antarctica; Blue Ice; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mount Dewitt; Petrography; Tephra", "people": "Dunbar, Nelia", "repository": "USAP-DC", "science_program": null, "title": "Blue Ice Tephra II - Mt. DeWitt", "url": "https://www.usap-dc.org/view/dataset/609115"}, {"dataset_uid": "609126", "doi": "10.7265/N5FQ9TJG", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome Ice Core; Taylor Dome Ice Core; Tephra; WAIS; WAISCORES", "people": "Dunbar, Nelia; Zielinski, Gregory", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Volcanic Records in the Siple and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609126"}, {"dataset_uid": "609126", "doi": "10.7265/N5FQ9TJG", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome Ice Core; Taylor Dome Ice Core; Tephra; WAIS; WAISCORES", "people": "Dunbar, Nelia; Zielinski, Gregory", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Volcanic Records in the Siple and Taylor Dome Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609126"}], "date_created": "Sat, 01 Jun 2002 00:00:00 GMT", "description": "Dunbar/Kyle OPP 9527373 Zielinski OPP 9527824 Abstract The Antarctic ice sheets are ideal places to preserve a record the volcanic ash (tephra) layers and chemical aerosol signatures of volcanic eruptions. This record, which is present both in areas of bare blue ice, as well as in deep ice cores, consists of a combination of local eruptions, as well as eruptions from more distant volcanic sources from which glassy shards can be chemically fingerprinted and related to a source volcano. Field work carried out during the 1994/1995 Antarctic field season in the Allan Hills area of Antarctica, and subsequent microbeam chemical analysis and 40Ar/39Ar dating has shown that tephra layers in deep Antarctic ice preserve a coherent, systematic stratigraphy, and can be successfully mapped, dated, chemically fingerprinted and tied to source volcanoes. The combination of chemical fingerprinting of glass shards, and chemical analysis of volcanic aerosols associated with ash layers will allow establishment of a high-resolution chronology of local and distant volcanism that can help understand patterns of significant explosive volcanisms and atmospheric loading and climactic effects associated with volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas, which have been identified in many places the Transantarctic Mountains, will allow the geometry of ice flow in these areas to be better understood and will provide a useful basis for interpreting ice core records.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES", "is_usap_dc": true, "keywords": "USAP-DC; Siple Coast; Sulfur Dioxide; Siple Dome; Taylor Dome; Chlorine; WAISCORES; Ice Core; Tephra; Geochemistry; Volcanic Deposits; GROUND STATIONS; Brimstone Peak; GROUND-BASED OBSERVATIONS; Magnesium Oxide; Glaciology; Mount Dewitt; Silicon Dioxide; Glass Shards; Ice Sheet; Siple; Nickel Oxide; Potassium Dioxide; Not provided; Manganese Oxide; Volcanic; Snow; Nitrogen; Iron Oxide; Titanium Dioxide; Stratigraphy; Antarctica", "locations": "Antarctica; Siple; Siple Coast; Siple Dome; Taylor Dome; Brimstone Peak; Mount Dewitt", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Dunbar, Nelia; Zielinski, Gregory", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": null, "title": "Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region", "uid": "p0000065", "west": null}, {"awards": "9615292 Wahlen, Martin", "bounds_geometry": null, "dataset_titles": "Carbon-Isotopic Composition of Atmospheric CO2 since the Last Glacial Maximum; Taylor Dome Ice Core Chemistry, Ion, and Isotope Data", "datasets": [{"dataset_uid": "609246", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "people": "Indermuhle, A.; Sowers, Todd A.; Smith, Jesse; Brook, Edward J.; Mayewski, Paul A.; Steig, Eric J.", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Taylor Dome Ice Core Chemistry, Ion, and Isotope Data", "url": "https://www.usap-dc.org/view/dataset/609246"}, {"dataset_uid": "609108", "doi": "10.7265/N54F1NN5", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "people": "Wahlen, Martin", "repository": "USAP-DC", "science_program": null, "title": "Carbon-Isotopic Composition of Atmospheric CO2 since the Last Glacial Maximum", "url": "https://www.usap-dc.org/view/dataset/609108"}], "date_created": "Tue, 01 Jan 2002 00:00:00 GMT", "description": "This award is for support of a program to reconstruct the record of atmospheric carbon dioxide (and the carbon-13 isotopes of carbon dioxide) over several intervals, including the Last Glacial Maximum-Holocene transition, interstadial episodes, the mid-Holocene, the last 1000 years and the penultimate glacial period, using ice from the Taylor Dome and Vostok ice cores. The major objective of this study is to investigate the phase relationship between variations of the greenhouse gases occluded in the ice cores and temperature changes (indicated by oxygen and deuterium isotopes) during the last deglaciation. In addition, the concentration of atmospheric carbon dioxide over the past 1000 years and during the mid-Holocene will be determined in these cores.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "USAP-DC; Ice Core; GROUND-BASED OBSERVATIONS; Carbon; Trapped Gases; Glaciology; GROUND STATIONS; Taylor Dome; Carbon Dioxide; Isotope; Antarctica; Nitrogen", "locations": "Antarctica; Taylor Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.; Wahlen, Martin; Smith, Jesse; Brook, Edward J.; Indermuhle, A.; Mayewski, Paul A.; Sowers, Todd A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": null, "title": "Carbon Dioxide and Carbon Isotopes in the Taylor Dome and Vostok Ice Cores", "uid": "p0000153", "west": null}, {"awards": "9980538 Lohmann, Kyger", "bounds_geometry": "POINT(-56 -64)", "dataset_titles": "Stable isotope and minor element proxies for Eocene climate of Seymour Island, Antarctica", "datasets": [{"dataset_uid": "600019", "doi": "", "keywords": null, "people": "Lohmann, Kyger", "repository": "USAP-DC", "science_program": null, "title": "Stable isotope and minor element proxies for Eocene climate of Seymour Island, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600019"}], "date_created": "Mon, 11 Jun 2001 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research for construction of a long-term record of climate during the late Cretaceous and early Paleogene to assess the annual seasonality in temperature on the coastal margin of Antarctica. Stable isotope and element compositions of well-preserved bivalve shells collected on Seymour Island will be the primary source of data used to reconstruct paleoenvironmental conditions. Seasonal temperature records collected through high-resolution sampling along growth structures in bivalve shells will allow seasonality to be assessed during different climate states and during periods of rapid climate change. In addition, high stratigraphic resolution will enable this project to detect the presence and frequency of short-lived thermal excursions that may have extended to such high latitudes. To compile a reliable temporal record of paleoclimate, two major avenues of investigation will be undertaken: 1) precise stratigraphic (and therefore, temporal) placement of fossils over a large geographic area will be employed through the use of a graphical technique employing geometric projections; 2) stable isotope and elemental analyses will be performed to derive paleotemperatures and to evaluate diagenetic alteration of shell materials. To provide realistic comparisons of paleotemperatures across stratigraphic horizons, this study will focus on a single taxon, thus avoiding complications due to the mixing of faunal assemblages that have been encountered in previous studies of this region. The near-shore marine fossil record on Seymour Island provides a unique opportunity to address many questions about the Antarctic paleoenvironment, including the relation between seasonality and different climate states, the influence of climate on biogeographic distribution of specific taxa, the effect of ice-volume changes on the stable isotope record from the late Cretaceous through the Eocene, and the plausibility of high-latitude bottom water formation during this time interval. In particular, information that will be collected concerning patterns of seasonality and the presence (or absence) of short-lived thermal excursions will be extremely valuable to an understanding of the response of high latitude sites during climate transitions from globally cool to globally warm conditions.", "east": -56.0, "geometry": "POINT(-56 -64)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided; Bivalves; Geochemical Composition; Carbon Isotopes; Climate", "locations": null, "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e PALEOGENE \u003e EOCENE", "persons": "Lohmann, Kyger; Barrera, Enriqueta", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.0, "title": "Evolution of Sea Surface Temperatures in the Coastal Antarctic Paleoenvironment During the Late Cretaceous and Paleogene", "uid": "p0000613", "west": -56.0}, {"awards": "9725305 Severinghaus, Jeffrey", "bounds_geometry": null, "dataset_titles": "Firn Air Isotope and Temperature Measurements from Siple Dome and South Pole", "datasets": [{"dataset_uid": "609098", "doi": "10.7265/N51N7Z2P", "keywords": "Antarctica; Atmosphere; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciology; Isotope; Paleoclimate; Siple Dome; Snow/ice; Snow/Ice; South Pole; Temperature", "people": "Battle, Mark; Severinghaus, Jeffrey P.; Grachev, Alexi", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Firn Air Isotope and Temperature Measurements from Siple Dome and South Pole", "url": "https://www.usap-dc.org/view/dataset/609098"}], "date_created": "Mon, 01 Jan 2001 00:00:00 GMT", "description": "9725305 Severinghaus This award supports a project to develop and apply a new technique for quantifying temperature changes in the past based on the thermodynamic principle of thermal diffusion, in which gas mixtures in a temperature gradient become fractionated. Air in polar firn is fractionated by temperature gradients induced by abrupt climate change, and a record of this air is preserved in bubbles in the ice. The magnitude of the abrupt temperature change, the precise relative timing, and an estimate of the absolute temperature change can be determined. By providing a gas-phase stratigraphic marker of temperature change, the phasing of methane (with decadal precision) and hence widespread climate change (relative to local polar temperature changes) can be determined (across five abrupt warming events during the last glacial period).", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e FLASKS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS", "is_usap_dc": true, "keywords": "Isotopic History; GROUND STATIONS; Thermal Diffusion; Firn Temperature Measurements; Not provided; Oxygen Isotope; Trapped Air Bubbles; Shallow Firn Air; Firn Air Isotope Measurements; Seasonal Temperature Gradients; Mass Spectrometry; GROUND-BASED OBSERVATIONS; Thermal Fractionation; Polar Firn Air; Isotopic Anomalies; Xenon; Atmospheric Gases; Argon Isotopes; Siple Dome; Krypton; Nitrogen Isotopes; Seasonal Temperature Changes; Antarctica; Ice Core Gas Records; Firn Air Isotopes; Mass Spectrometer; South Pole; Firn Isotopes; Borehole", "locations": "Antarctica; Siple Dome; South Pole", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Battle, Mark; Grachev, Alexi; Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Thermal Fractionation of Firn Air and the Ice Core Record of Abrupt Interstadial Climate Change", "uid": "p0000160", "west": null}, {"awards": "9526374 Alley, Richard", "bounds_geometry": null, "dataset_titles": "Visible Stratigraphic Dating, Siple Dome and Upstream C Cores", "datasets": [{"dataset_uid": "609121", "doi": "10.7265/N53F4MHS", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Sample/collection Description; Sample/Collection Description; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Alley, Richard", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Visible Stratigraphic Dating, Siple Dome and Upstream C Cores", "url": "https://www.usap-dc.org/view/dataset/609121"}], "date_created": "Wed, 01 Jan 1997 00:00:00 GMT", "description": "This award is for support for a program of physical and visible studies on the shallow and deep ice cores to be retrieved from Siple Dome, West Antarctica. Visible examination of ice cores has proven to be a powerful technique for dating and paleoclimatic interpretation. Recent examination of a shallow core from Siple Dome indicates that annual-layer dating is possible and that visible examination will contribute significantly to the dating effort at Siple Dome. Once ages are obtained, distances between layers provide snow accumulation after correction for density variations and ice flow thinning. Thin- section examination of the core will contribute to understanding the visible stratigraphy, and will reveal c-axis fabrics which are related to past ice deformation. The results of this study should include a better understanding of rapid climate change in the Antarctic and should contribute to knowledge of the stability of the West Antarctic ice sheet.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Ice Core; GROUND-BASED OBSERVATIONS; Siple; Ice Sheet; Isotope; Stratigraphy; GROUND STATIONS; Accumulation; Siple Dome; WAISCORES; Densification; Antarctica; Siple Coast; Thermometry; Snow; Not provided; Bubble; Glaciology", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Physical Properties of the Siple Dome Deep Ice Core", "uid": "p0000059", "west": null}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||||||
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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
|
1939139 1939146 |
2024-02-20 | Scherer, Reed Paul; Siddoway, Christine | Part I, Non-technical Abstract Concerns 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. Part 2, Technical Abstract New 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. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | 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)) | POINT(-107.5 -71.5) | false | false | ||||||||
Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation
|
2302832 |
2023-07-12 | Reilly, Brendan | The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica’s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica’s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth's most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica’s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | POLYGON((-70 -55,-67 -55,-64 -55,-61 -55,-58 -55,-55 -55,-52 -55,-49 -55,-46 -55,-43 -55,-40 -55,-40 -56.1,-40 -57.2,-40 -58.3,-40 -59.4,-40 -60.5,-40 -61.6,-40 -62.7,-40 -63.8,-40 -64.9,-40 -66,-43 -66,-46 -66,-49 -66,-52 -66,-55 -66,-58 -66,-61 -66,-64 -66,-67 -66,-70 -66,-70 -64.9,-70 -63.8,-70 -62.7,-70 -61.6,-70 -60.5,-70 -59.4,-70 -58.3,-70 -57.2,-70 -56.1,-70 -55)) | POINT(-55 -60.5) | false | false | ||||||||
EAGER: ANT LIA: Persist or Perish: Records of Microbial Survival and Long-term Persistence from the West Antarctic Ice Sheet
|
2228257 |
2023-05-31 | Michaud, Alexander; Winski, Dominic A. | No dataset link provided | Ice cores from glaciers and ice sheets provide detailed archives of past environmental conditions, furthering our understanding of Earth’s climate. Microorganisms in the West Antarctic Ice Sheet are buried over glaciological time and form a stratigraphy record providing the opportunity of analysis of the order and position of layers of geological events, with potential links to Southern Hemisphere climate. However, microbial cells that land on the ice sheet are subject to the stresses of changing habitat conditions due to burial and conditions associated with long-term isolation in ice. These processes may lead to a loss of fidelity within the stratigraphic record of microbial cells. We know little about how and if microorganisms survive burial and remain alive over glacial-interglacial time periods within an ice sheet. This analysis will identify the viable and preserved community of microorganisms and core genomic adaptation that permit cell viability, which will advance knowledge in the areas of microbiology and glaciology while increasing fidelity of ice core measurements relevant to past climate and potential future global climate impacts. This exploratory endeavor has the potential to be a transformative step toward understanding the ecology of one of the most understudied environments on Earth. The project will partner with the Museum of Science, Boston, to increase public scientific literacy via education and outreach. Additionally, this project will support two early-career scientists and two undergraduates in interdisciplinary research at the intersection of microbiology and climate science. Results from this project will provide the first DNA data based on single-cell whole genomic sequencing from the Antarctic Ice Sheet and inform whether post-depositional processes impact the interpretations of paleoenvironmental conditions from microbes. The goals to determine the taxonomic identity of viable and preserved microbial cells, and decode the genetic repertoire that confers survival of burial and long-term viability within glacial ice, will be achieved by utilizing subsamples from a ~60,000 year old record of the West Antarctic Ice Sheet Divide (WD) Ice Core. WD samples will be melted using the Desert Research Institute’s ice core melting system that is optimized for glaciobiological sampling. Microbial cells from the meltwater will be sorted using fluorescence-activated cell sorting, and individually sorted cells will have their genomes sequenced. The fluorescence-based methods will discern the viable (metabolically active) cells from those cells that are non-viable but preserved in the ice (DNA-containing). The genomic analysis will identify the taxonomy of each cell, presence of known genes that confer survival in permanently frozen environments, and comparatively analyze genomes to determine the core set of genes required by viable cells to persist in an ice sheet. The outcomes of this work will expand the potential for biological measurements and contamination control from archived ice cores. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | POINT(-112.05 -79.28) | POINT(-112.05 -79.28) | false | false | |||||||
Collaborative Research: Coring Seymour Island (CSI) Antarctica: Evaluating Causes and Effects of the End Cretaceous Mass Extinction
|
2026648 2025724 2020728 |
2022-09-15 | Tobin, Thomas; Totten, Rebecca | No dataset link provided | Non-technical description: This 4-year project is evaluating evidence of extinction patterns and depositional conditions from a high southern latitude Cretaceous-Paleogene (K-Pg) outcrop section found on Seymore Island, in the Western Antarctic Peninsula. The team is using sediment samples collected below the weathering horizon to evaluate detailed sedimentary structures, geochemistry, and microfossils in targeted stratigraphic intervals. The study will help determine if the K-Pg mass extinction was a single or double phased event and whether Seymour Island region in the geological past was a restricted, suboxic marine environment or an open well-mixed shelf. The award includes an integrated plan for student training at all levels, enhanced by a highlighted partnership with a high school earth sciences teacher working in a school serving underrepresented students. Technical description: The proposed research is applying multiple techniques to address an overarching research question for which recent studies are in disagreement: Is the fossil evidence from a unique outcropping on Seymour Island, Antarctica consistent with a single or double phased extinction? In a two-phased model, the first extinction would affect primarily benthic organisms and would have occurred ~150 kiloyears prior to a separate extinction at the K-Pg boundary. However, this early extinction could plausibly be explained by an unrecognized facies control that is obscured by surficial weathering. This team is using microfossil evidence with detailed sedimentary petrology and geochemistry data to evaluate if the fossil evidence from Seymour Island is consistent with a single or double phased extinction process. The team is using detailed sedimentary petrology and geochemistry methods to test for facies changes across the K-PG interval that would explain the apparent early extinction. Samples of core sedimentary foraminifera, siliceous microfossils, and calcareous nannofossils are being evaluated to provide a high-resolution stratigraphic resolution and to evaluate whether evidence for an early extinction is present. Additionally, the team is using multiple geochemical methods to evaluate whether there is evidence for intermittent anoxia or euxinia and/or physical restriction of the Seymore region basin. Data from this analysis will indicate if this region was a restricted, suboxic marine environment or an open well-mixed shelf. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | POLYGON((-56.93 -64.2,-56.894 -64.2,-56.858 -64.2,-56.822 -64.2,-56.786 -64.2,-56.75 -64.2,-56.714 -64.2,-56.678 -64.2,-56.642 -64.2,-56.606 -64.2,-56.57 -64.2,-56.57 -64.214,-56.57 -64.22800000000001,-56.57 -64.242,-56.57 -64.256,-56.57 -64.27000000000001,-56.57 -64.284,-56.57 -64.298,-56.57 -64.312,-56.57 -64.32600000000001,-56.57 -64.34,-56.606 -64.34,-56.642 -64.34,-56.678 -64.34,-56.714 -64.34,-56.75 -64.34,-56.786 -64.34,-56.822 -64.34,-56.858 -64.34,-56.894 -64.34,-56.93 -64.34,-56.93 -64.32600000000001,-56.93 -64.312,-56.93 -64.298,-56.93 -64.284,-56.93 -64.27000000000001,-56.93 -64.256,-56.93 -64.242,-56.93 -64.22800000000001,-56.93 -64.214,-56.93 -64.2)) | POINT(-56.75 -64.27000000000001) | false | false | |||||||
Middle-Late Devonian Vertebrates of Antarctica
|
1543367 |
2022-06-17 | Shubin, Neil; Daeschler, Edward B |
|
This research will provide new insights into the relationships and history of sharks, fish and limbed animals. Understanding these relationships forms the backbone for both basic and applied science because fish often serve as models of human traits and diseases. Some of the main lines of evidence for these relationships come from fossils in rocks over 380 million years old that were originally deposited as ancient rivers and streams. Because rocks of this type and age are abundantly exposed along a number of the dry valleys and mountains of Antarctica, the investigation of these areas holds exceptional promise for discoveries that can have a broad impact. The fieldwork will involve geological mapping and assessment of the rocks with detailed reconnaissance for the fossils that they may hold. Fossil discoveries form the backbone for public communication of the methods and results of scientific research-- these studies will be used as vehicles for training of students at multiple levels as well as communication of science to the broader non-science citizen base. The discovery, description, and analysis of Middle to Late Devonian (390-355 Million years ago) vertebrates and depositional environments provide important data on the emergence of novel anatomical structures, faunas, and habitats during a critical interval in the history of life and earth. Biological innovation during this time includes the early evolution of freshwater fish, the origins of major groups of vertebrates (e.g., sharks, lobe and ray-finned fish, tetrapods), and the expansion and elaboration of non-marine ecosystems. Accordingly, expanding our knowledge of vertebrate diversity during the Middle and Late Devonian will provide new evidence on the relationships of the major groups of vertebrates, the assembly of novelties that ultimately enabled tetrapods to invade land, the origin and early evolution of sharks and their relatives, and the assembly and expansion of non-marine ecosystems generally. The Aztec Siltstone of Antarctica Middle-Late Devonian; Givetian-Frasnian Stages) has exceptional potential to produce new paleontological evidence of these events and to illuminate the temporal, ecological, and geographic context in which they occurred. It is essentially fossiliferous throughout its known exposure range, something that is rare for Middle-Late Devonian non-marine rocks anywhere in the world. In addition, fine-grained meandering stream deposits are abundantly exposed in the Aztec Siltstone and are recognized as an important locus for the discovery of well-preserved Devonian fish, including stem tetrapods and their relatives. Given the exceedingly fossiliferous nature of the Aztec Siltstone, the large number of taxa known only from partial material, and the amount of promising exposure yet to be worked, a dedicated reconnaissance, collection, and research effort is designed to recover important new fossil material and embed it in a stratigraphic and sedimentological context. The first major objective of this study is the recovery, preparation, and description of Middle-Late Devonian fossil taxa. Ensuing investigation of the phylogenetic affinities, taphonomic occurrence, and stratigraphic position of fossil assemblages will allow both local and global comparisons of biotic diversity. These analyses will inform: 1) higher level phylogenetic hypotheses of jawed vertebrates, 2) biostratigraphic and biogeographic analysis of the distribution of the Middle-Late Devonian fish, and 3) paleobiological investigation of the elaboration of terrestrial and freshwater habitats. The broader impacts are derived from the utility of paleontology and Antarctic expeditionary science as educational tools with powerful narratives. Specific goals include affiliations with local urban secondary schools (using established relationships for broadening participation) and collegiate and graduate training. Wider dissemination of knowledge to the general public is a direct product of ongoing interactions with national and international media (print, television, internet). | POLYGON((158.3 -77.5,158.54000000000002 -77.5,158.78 -77.5,159.02 -77.5,159.26 -77.5,159.5 -77.5,159.74 -77.5,159.98 -77.5,160.22 -77.5,160.45999999999998 -77.5,160.7 -77.5,160.7 -77.605,160.7 -77.71,160.7 -77.815,160.7 -77.92,160.7 -78.025,160.7 -78.13,160.7 -78.235,160.7 -78.34,160.7 -78.445,160.7 -78.55,160.45999999999998 -78.55,160.22 -78.55,159.98 -78.55,159.74 -78.55,159.5 -78.55,159.26 -78.55,159.02 -78.55,158.78 -78.55,158.54000000000002 -78.55,158.3 -78.55,158.3 -78.445,158.3 -78.34,158.3 -78.235,158.3 -78.13,158.3 -78.025,158.3 -77.92,158.3 -77.815,158.3 -77.71,158.3 -77.605,158.3 -77.5)) | POINT(159.5 -78.025) | false | false | |||||||
Center for Oldest Ice Exploration
|
2019719 |
2022-05-21 | Brook, Edward J.; Neff, Peter | Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth’s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth’s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community. Knowledge of Earth’s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth’s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | 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)) | POINT(0 -89.999) | false | false | ||||||||
Collaborative Research: Tephrochronology of a South Pole Ice Core
|
1543361 1543454 |
2022-04-01 | Dunbar, Nelia; Iverson, Nels; Kurbatov, Andrei V. |
|
Dunbar/1543454 Antarctic ice cores offer unparalleled records of earth?s climate back to almost one million years and perhaps beyond. Layers of volcanic ash (tephra) embedded in glacial ice can be used to establish an accurate ice core chronology. In order to use a visible or ultrafine volcanic ash layer as a time-stratigraphic marker, a unique geochemical fingerprint must be established, and this forms the basis of our research. This award will investigate the volcanic record in the 1751 m ice core that was completed at the South Pole during the 2015/16 field season. The core is in an ideal location to link the existing, established, volcanic records in East and West Antarctica, and therefore to connect and integrate those records, allowing the climate records of ice cores to be directly compared, as well as to focus research on the most widespread and significant volcanic eruptions from West Antarctica. Tephra derived from well-dated, large, tropical volcanic eruptions that may have had an impact on climate will also be studied. Recent success in identifying and analyzing very fine ash particles from these types of eruptions makes it likely that we will be able to pinpoint some of these eruptions, which will allow the sulfate peaks associated with these layers to be positively identified and dated. Volcanic forcing time series developed from earlier South Pole ice cores based on preserved sulfate were crucial for testing climate models, but without tephra analysis, the origin of these layers remains uncertain. Work on the tephra layers in the South Pole ice core has a number of significant specific objectives, some with practical applications to the basic science goals of Antarctic ice coring, and others that represent independent scientific contributions in their own right. These include: (1) providing independently dated time-intervals in the core, particularly for the deepest ice, (2) quantitatively linking tephra records across Antarctica with the goal of allowing direct and robust climate comparisons between these different parts of the continent, (3) providing information for large local eruptions, that will lead to direct estimates of eruption magnitude and dispersal patterns of Antarctic volcanoes, several of which will likely erupt again. The initial stages of the work will be carried out by identifying silicate-bearing horizons in the ice core, using several methods. Once found, silicate particles will be imaged so that morphological characteristics of the particles can be used to identify volcanic origin. Particles identified as tephra will then be chemically analyzed using electron microprobe and laser ablation ICP-MS. Samples that yield a robust chemical fingerprint will be statistically correlated to known eruptions, and this will be used to address the goals described above. Broader impacts of this project fall into the areas of education of future generation of researchers, outreach and international cooperation. These activities will continue to promote forward progress in integrating the Antarctic tephra record and more broadly tying it to the global volcanic record. | POINT(0 -90) | POINT(0 -90) | false | false | |||||||
Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change
|
0342484 |
2022-02-04 | Harwood, David; Levy, Richard |
|
ANDRILL is a scientific drilling program to investigate Antarctica's 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's 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's ocean-climate system. <br/><br/>This 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's 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.<br/><br/>The 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's complex tectonic history.<br/><br/>The broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society's 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. <br/><br/>As key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica's ice sheets are important to society's 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's climatic future. | POINT(167.083333 -77.888889) | POINT(167.083333 -77.888889) | false | false | |||||||
Collaborative Research: Permian and Triassic Icehouse to Greenhouse Paleoenvironments and Paleobotany in the Shackleton Glacier Area, Antarctica
|
1443557 |
2021-12-31 | Isbell, John | The focus of this collaborative project is to collect fossil plants, wood, and sedimentary and chemical information from rocks in the Shackleton Glacier (SHK) area of Antarctica. This information will be used to reconstruct plant life and environments during the Permian and Triassic (~295-205 million years ago) in Antarctica. This time interval is important to study as Antarctica experienced a large glaciation in the Permian followed by deglaciation and recovery of plant and animal life, only to be subjected to the largest extinction in Earth history at the end of the Permian. After the extinction events, the climate in Antarctica continued to warm extensively and there were forests growing close to the paleo-South Pole. These ancient environments provide a natural laboratory in which to study the effects of climate change on plant life. The results of this project will advance the field in the areas of changing sedimentary patterns during global cooling and warming, as well as plant evolution during times following glaciation and during global warmth. This project will study the extent of the Gondwana glaciation in the SHK area, the invasion and subsequent flourishing of life following glacial retreat, and the eventual recovery of plant life after Late Permian extinction events. Only in Antarctica does a complete polar-to-near-polar succession occur across this climatic and biologic transition. The SHK area is an important one as it is one of the few regions in the world where the Permian-Triassic boundary (PTB) is exposed within terrestrial rocks. The field and lab work for this project is organized around three hypotheses that address fundamental issues in Earth history, including changes in the extent and diversity of flora during the Permian build up to the Late Paleozoic Ice Age, the possible diachronous nature of the PTB, and that poor fossil preservation during the Early Triassic has given a false impression that Antarctica was devoid of plants during this time. The hypotheses will be tested by integrating various types of paleobotanical approaches with detailed sedimentology, stratigraphy, and geochemistry. Compression floras and petrified wood will be collected (constrained by stratigraphy) both quantitatively and qualitatively in order to obtain biodiversity and abundance data, and as a data source for paleoecological analysis. Standard sedimentologic and stratigraphic analyses will be performed, as well as paleosol analyses, including mineralogic and major- and trace-element geochemistry. Collections will also be made for U-Pb zircon geochronology to better constrain geologic and biotic events through time. Results of the project will be incorporated into educational and outreach activities that are designed to include women and under-represented groups in the excitement of Antarctic earth sciences and paleontology, including workshops in Kansas and Wisconsin, as well as links to science classes during fieldwork. | POLYGON((-180 -85,-177.1 -85,-174.2 -85,-171.3 -85,-168.4 -85,-165.5 -85,-162.6 -85,-159.7 -85,-156.8 -85,-153.9 -85,-151 -85,-151 -85.2,-151 -85.4,-151 -85.6,-151 -85.8,-151 -86,-151 -86.2,-151 -86.4,-151 -86.6,-151 -86.8,-151 -87,-153.9 -87,-156.8 -87,-159.7 -87,-162.6 -87,-165.5 -87,-168.4 -87,-171.3 -87,-174.2 -87,-177.1 -87,180 -87,179 -87,178 -87,177 -87,176 -87,175 -87,174 -87,173 -87,172 -87,171 -87,170 -87,170 -86.8,170 -86.6,170 -86.4,170 -86.2,170 -86,170 -85.8,170 -85.6,170 -85.4,170 -85.2,170 -85,171 -85,172 -85,173 -85,174 -85,175 -85,176 -85,177 -85,178 -85,179 -85,-180 -85)) | POINT(-170.5 -86) | false | false | ||||||||
Collaborative Research: The Timing and Spatial Expression of the Bipolar Seesaw in Antarctica from Synchronized Ice Cores
|
1643394 |
2021-11-10 | Buizert, Christo; Wettstein, Justin | Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation. | POLYGON((-180 -65,-144 -65,-108 -65,-72 -65,-36 -65,0 -65,36 -65,72 -65,108 -65,144 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.5,-180 -85,-180 -82.5,-180 -80,-180 -77.5,-180 -75,-180 -72.5,-180 -70,-180 -67.5,-180 -65)) | POINT(0 -89.999) | false | false | ||||||||
Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation
|
2114786 |
2021-09-09 | Warnock, Jonathan | No dataset link provided | The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica’s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica’s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth's most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica’s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | None | None | false | false | |||||||
Collaborative research: Snapshots of Early and Mid-Pleistocene Climate and Atmospheric Composition from the Allan Hills Blue Ice Area
|
1744832 1745007 1745006 0838843 1744993 |
2021-08-27 | Mayewski, Paul A.; Kurbatov, Andrei V.; Brook, Edward J.; Severinghaus, Jeffrey P.; Higgins, John | Bubbles of ancient air trapped in ice cores have been used to directly reconstruct atmospheric composition, and its links to Antarctic 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 extend as far back as 2.7 million years, by far the oldest polar ice samples yet recovered. These ice cores extend direct observations of atmospheric carbon dioxide and methane concentrations and indirect records of Antarctic climate into a period of Earth's climate history that represents a plausible geologic analogue to future anthropogenic climate change. The results demonstrate a smaller glacial-interglacial variability of climate and greenhouse gases, and a persistent linkage between Antarctic climate and atmospheric carbon dioxide, between 1 and 2 million years ago. Through this project, the team will return to the Allan Hills Blue Ice Area to recover additional ice cores that date to 2 million years or older. The climate records developed from these 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. Project results will help answer questions about issues associated with anthropogenic change including the relationship between temperature change and the mass balance of Antarctic ice and the relationship between atmospheric greenhouse gases and global climate change. Earth has been cooling, and ice sheets expanding, over the past ~52 million years. Superimposed on this cooling are periodic changes in Earth's climate system driven by variations in the eccentricity, precession, and obliquity of Earth's orbit around the Sun. Climate reconstructions based on measurements of oxygen isotopes in foraminiferal calcite indicate that, from ~2.8 to 1.2 million years before present (Ma), Earth's climate system oscillated between glacial and interglacial states every ~40,000 years (the "40k world"). Between 1.2-0.8 Ma and continuing to the present, the period of glacial cycles increased in amplitude and lengthened to ~100,000 years (the "100k world"). Ice cores preserve ancient air that allows direct reconstructions of atmospheric carbon dioxide and methane. They also archive proxy records of regional climate, mean ocean temperature, global oxygen cycling, and the aridity of nearby continents. Studies of stratigraphically continuous ice cores, extending to 800,000 years before present, have demonstrated that atmospheric carbon dioxide is strongly linked to climate, and it is of great interest to extend the ice-core record into the 40k world. Recent discoveries of well-preserved ice dating from 1.0 to 2.7 Ma from ice cores drilled in the Allan Hills Blue Ice Area (BIA), Antarctica, demonstrate the potential to retrieve stratigraphically discontinuous old ice at shallow depths (<200 meters). This project will continue this work by retrieving new large-volume ice cores and measuring paleoclimate properties in both new and existing ice from the Allan Hills BIA. The experimental objectives are to more fully characterize fundamental properties of the climate system and the carbon cycle during the 40k world. Project results will have implications for Pleistocene climate change, and will provide new constraints on the processes that regulate atmospheric carbon dioxide, methane, and oxygen on geologic timescales. Given a demonstrated age of the ice at the Allan Hills BIA of at least 2 million years, the team will drill additional cores to prospect for ice that predates the initiation of Northern Hemisphere glaciation at the Plio-Pleistocene transition (~2.8 Ma). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667)) | POINT(159.29167 -76.7) | false | false | ||||||||
West Antarctic Ice-sheet Change and Paleoceanography in the Amundsen Sea Across the Pliocene Climatic Optimum
|
2114839 |
2021-08-25 | Passchier, Sandra | The West Antarctic Ice Sheet is the most vulnerable polar ice mass to warming and already a major contributor to global mean sea level rise. Its fate in the light of prolonged warming is a topic of major uncertainty. Accelerated sea level rise from ice mass loss in the polar regions is a major concern as a cause of increased coastal flooding affecting millions of people. This project will disclose a unique geological archive buried beneath the seafloor off the Amundsen Sea, Antarctica, which will reveal how the West Antarctic Ice Sheet behaved in a warmer climate in the past. The data and insights can be used to inform ice-sheet and ocean modeling used in coastal policy development. The project will also support the development of a competitive U.S. STEM workforce. Online class exercises for introductory geology classes will provide a gateway for qualified students into undergraduate research programs and this project will enhance the participation of women in science by funding the education of current female Ph.D. students. 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 > 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 “icehouse” period ~3.3 Ma. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | None | None | false | false | ||||||||
Collaborative research: The Antarctic Scallop as Key to Paleoenvironments and Sea Ice Conditions: Understanding the Modern to Predict the Past
|
1745064 1745057 1745080 |
2021-08-06 | Walker, Sally; Gillikin, David; Perez-Huerta, Alberto; Andrus, Fred | The goal of this project is to discover whether the Antarctic scallop, Adamussium colbecki, provides a guide to sea-ice conditions in nearshore Antarctica today and in the past. Scallops may grow slower and live longer in habitats where sea ice persists for many years, limited by food, compared to habitats where sea ice melts out annually. Also, the chemicals retained in the shell during growth may provide crucial habitat information related to not only changing sea-ice conditions but also the type of food, whether it is recycled from the seafloor or produced by algae blooming when sea ice has melted. Unlocking the ecological imprint captured within the shell of the Antarctic Scallop will increase our understanding of changing sea-ice conditions in Antarctica. Further, because the Antarctic scallop had relatives living at the time when the Antarctic ice sheet first appeared, the scallop shell record may contain information on the stability of the ice sheet and the history of Antarctic shallow seas. Funding will also be integral for training a new generation of geoscientists in fossil and chemical forensics related to shallow sea habitats in Antarctica. Scallops are worldwide in distribution, are integral for structuring marine communities have an extensive fossil record dating to the late Devonian, and are increasingly recognized as important paleoenvironmental proxies because they are generally well preserved in the sediment and rock record. The primary goal of this project is to assess the differences in growth, lifespan, and chemistry (stable isotopes, trace elements) archived in the shell of the Antarctic scallop that may be indicative of two ice states: persistent (multiannual) sea ice at Explorers Cove (EC) and annual sea ice (that melts out every year) at Bay of Sails (BOS), western McMurdo Sound, Antarctica. This project will investigate growth and lifespan proxies (physical and geochemical) and will use high-resolution records of stable oxygen isotopes to determine if a melt-water signal is archived in A. colbecki shells and whether that signal captures the differing ice behavior at two sites (EC versus BOS). Stable isotopes of carbon and nitrogen in association with trace elements will be used to examine subannual productivity spikes indicative of phytoplankton blooms, which are predicted to be more pronounced during open ocean conditions. Small growth increments in the outer calcite layer will be assessed to determine if they represent fortnightly growth, if so, they could provide a high-resolution proxy for monthly environmental processes. Unlocking the environmental archive preserved in A. colbecki shells may prove to be an important proxy for understanding changing sea-ice conditions in Antarctica's past. Funding will support a Ph.D. student and undergraduates from multiple institutions working on independent research projects. Web content focused on Antarctic marine communities will be designed for museum outreach, reaching thousands of middle-school children each year. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | 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)) | POINT(0 -89.999) | false | false | ||||||||
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
|
2000992 |
2021-07-06 | Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie |
|
Part I: Non-technical description: Predicting how polar ice sheets will respond to future global warming is difficult because all the processes that contribute to their melting are not well understood. This is important because the more ice on land that melts, the higher sea levels will rise. The most significant uncertainty in current estimates of sea-level rise in the coming decades is the potential contribution from the Antarctic Ice Sheet. One way to increase our knowledge about how large ice sheets respond to climate change in response to natural factors is to examine the geologic past. Natural global warming (and cooling) events in Earth’s history provide examples that we can use to better understand processes, interactions, and responses we can’t directly observe today. One such time period, approximately three million years ago (known as the Pliocene), was the last time atmospheric carbon dioxide levels were as high as they are today and, therefore, represents a time period to study to better understand the ice sheet response to a warming climate. Specifically, this project is interested in understanding how ocean currents near Antarctica, which transport heat and store carbon, behaved during these past climate events. The history of past ice sheet-ocean interactions are recorded in sediments that were deposited, layer upon layer, in the deep sea offshore Antarctica. In January-February 2018, a team of scientists and crew set sail to the Ross Sea, offshore west Antarctica, on the scientific ocean drilling vessel JOIDES Resolution to recover such sediment archives. This project focuses on a sediment core from that expedition, which captures the relatively warm Pliocene time interval, as well as the subsequent transition into cooler climates typical of the past two million years. The researchers will analyze the sediment with multiple complementary measurements, including: grain size, composition, chemistry of organic matter, physical structures, microfossil type and abundance, and more. These analyses will be done by the research team, including several students, at their respective laboratories and will then integrated into a unified record of ice sheet-ocean interactions. Ultimately, the results will be used to improve modeled projections of how the Antarctic Ice Sheet could respond to future climate change. Part II: Technical 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. The researchers 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, they 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. To test their hypothesis, they will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) They will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. They will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) They 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) They 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. All of these data will be integrated 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. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | POINT(-172.873074 -74.274008) | POINT(-172.873074 -74.274008) | false | false | |||||||
A non-amniote perspective on the recovery from the end-Permian extinction at high latitudes: paleobiology of Early Triassic temnospondyls from Antarctica
|
1947094 |
2021-06-30 | Sidor, Christian | No dataset link provided | Non-technical Abstract Around 252 million years ago, a major mass extinction wiped out over 90% of species on Earth. Coincident with this extinction, the Antarctic portion of the supercontinent of Pangea transitioned to a warmer climatic regime devoid of a permanent ice cap. Compared to lower latitudes, relatively little is known about the survivors of the extinction in Antarctica, although it has been hypothesized that the continents more polar location shielded it from the worst of the extinctions effects. As the result of a NSF-sponsored deep field camp in 2017/2018, a remarkable collection of vertebrate fossils was discovered in the rocks of the Shackleton Glacier region. This collection includes the best preserved and most complete materials of fossil amphibians ever recovered from Antarctica, including two previously undescribed species. This grant supports one postdoctoral researcher with expertise in fossil amphibians to describe and interpret the significance of these fossils, including their identification, relationships, and how they fit into the terrestrial ecosystem of Antarctica and other southern hemisphere terrestrial assemblages in light of the major reorganization of post-extinction environments. Historical collections of fossil amphibians will also be reviewed as part of this work. Undergraduate students at the University of Washington will be actively involved as part of this research and learn skills like hard tissue histology and CT data manipulation. Public engagement in Antarctic science will be accomplished at the University of Washington Burke Museum, which is the Washington State museum of natural history and culture. Specifically, a new exhibit on Antarctic amphibians will be developed as part of the paleontology gallery, which sees over 100,000 visitors per year. Technical Abstract This two-year project will examine the evolution of Triassic temnospondyls based on a remarkable collection of fossils recently recovered from the Shackleton Glacier region of Antarctica. Temnospondyls collected from the middle member of the Fremouw Formation are part of the first collection of identifiable tetrapod fossils from this stratigraphic interval. Thorough anatomical description and comparisons of these fossils will add new faunal information and also aid in determining if this horizon is Early or Middle Triassic in age. Exquisitely preserved temnospondyl material from the lower Fremouw Formation will permit more precise identification than previously possible and will provide insights into the earliest stages of their radiation in the extinction recovery interval. Overall, the Principal Investigator and Postdoctoral Researcher will spearhead an effort to revise the systematics of the Antarctic members of Temnospondyli and properly contextualize them in the framework of Triassic tetrapod evolution. The research team will also take advantage of the climate-sensitive nature of fossil amphibians to better understand patterns of seasonality at high-latitudes during the early Mesozoic by subjecting selected fossils to histological analysis. Preliminary data suggest that temnospondyls were exceptionally diverse and highly endemic immediately after the end-Permian extinction, when compared to their distribution before and after this interval. If confirmed, this macroevolutionary pattern could be used to predict the response of modern amphibians to future climate perturbations. Overall, this research will provide new insights into the vertebrate fauna of the Fremouw Formation, as well as shed light on the evolution of terrestrial ecosystems in southern Pangea in the wake of the Permian-Triassic mass extinction. As part of the broader impacts, the research team will help to develop an exhibit featuring some of the best preserved fossils from Antarctica to explain to the public how paleontologists use fossils and rocks to understand past climates like the Triassic 'hot-house' world that lacked permanent ice caps at the poles. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | None | None | false | false | |||||||
Collaborative Research: Understanding the evolution of high-latitude Permo-Triassic paleoenvironments and their vertebrate communities
|
1341376 1341475 2001033 1341304 1341645 |
2021-06-29 | Sidor, Christian; Smith, Nathan; Makovicky, Peter; Tabor, Neil |
|
Around 252 million years ago, a major mass extinction wiped out upwards of 90% of species on Earth. Coincident with this extinction, the Antarctic portion of the supercontinent of Pangea transitioned to a warmer climatic regime and became devoid of glaciers. Little is known about the survivors of the extinction in Antarctica, although it has been hypothesized that the continent's high latitude location shielded it from the worst of the extinction's effects. The Shackleton Glacier region is the best place to study this extinction in Antarctica because it exposes an abundance of correct age rocks and relevant fossils were found there in the 1960s and 1980s. For this research, paleontologists will study fossil vertebrates that span from about 260 to 240 million years ago to understand how life evolved at high latitudes in the face of massive climate change. In addition, geologists will use fossil soils and fossil plant matter to more precisely reconstruct the climate of Antarctica across this extinction boundary. These data will allow for a more complete understanding of ancient climates and how Antarctic life compared to that at lower latitudes. Undergraduate and graduate students will be actively involved in this research. Public engagement in Antarctic science will be accomplished at several natural history museums. This three-year project will examine the evolution of Permo-Triassic paleoenvironments and their vertebrate communities by conducting fieldwork in the Shackleton Glacier region of Antarctica. The team will characterize the Permo-Triassic boundary within Shackleton area strata and correlate it to other stratigraphic successions in the region (e.g. via stable carbon isotope stratigraphy of fossilized plant organic matter). The researchers will use multiple types of data to assess the paleoenvironment, including: 1) paleosol morphology; 2) paleosol geochemistry; 3) pedogenic organic matter; and 4) fossil wood chronology and stable isotopes. The Fremouw Formation of Antarctica preserves the highest paleolatitude (~70° S) tetrapod fauna of the entire Triassic and thus has the potential to shed important light on the evolution of polar life during the early Mesozoic. The biology of Triassic vertebrates from Antarctica will be compared to conspecifics from lower paleolatitudes through analysis of growth in bone and tusk histology. An interdisciplinary approach will be used to address relationships between environmental change, faunal composition, and biogeographic patterns in the context of the high-latitude strata preserved in the Buckley and Fremouw formations in the Shackleton Glacier region. | POLYGON((-180 -84,-178 -84,-176 -84,-174 -84,-172 -84,-170 -84,-168 -84,-166 -84,-164 -84,-162 -84,-160 -84,-160 -84.3,-160 -84.6,-160 -84.9,-160 -85.2,-160 -85.5,-160 -85.8,-160 -86.1,-160 -86.4,-160 -86.7,-160 -87,-162 -87,-164 -87,-166 -87,-168 -87,-170 -87,-172 -87,-174 -87,-176 -87,-178 -87,180 -87,178.5 -87,177 -87,175.5 -87,174 -87,172.5 -87,171 -87,169.5 -87,168 -87,166.5 -87,165 -87,165 -86.7,165 -86.4,165 -86.1,165 -85.8,165 -85.5,165 -85.2,165 -84.9,165 -84.6,165 -84.3,165 -84,166.5 -84,168 -84,169.5 -84,171 -84,172.5 -84,174 -84,175.5 -84,177 -84,178.5 -84,-180 -84)) | POINT(-177.5 -85.5) | false | false | |||||||
Collaborative Research: The Timing and Spatial Expression of the Bipolar Seesaw
|
1643355 1643394 |
2021-05-28 | Fudge, T. J.; Steig, Eric J.; Buizert, Christo | Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation. | 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)) | POINT(0 -89.999) | false | false | ||||||||
Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance
|
1724670 |
2020-09-10 | Williams, Trevor; Hemming, Sidney R. | Abstract for the general public: The margins of the Antarctic ice sheet have advanced and retreated repeatedly over the past few million years. Melting ice from the last retreat, from 19,000 to 9,000 years ago, raised sea levels by 8 meters or more, but the extents of previous retreats are less well known. The main goal of this project is to understand how Antarctic ice retreats: fast or slow, stepped or steady, and which parts of the ice sheet are most prone to retreat. Antarctica loses ice by two main processes: melting of the underside of floating ice shelves and calving of icebergs. Icebergs themselves are ephemeral, but they carry mineral grains and rock fragments that have been scoured from Antarctic bedrock. As the icebergs drift and melt, this 'iceberg-rafted debris' falls to the sea-bed and is steadily buried in marine sediments to form a record of iceberg activity and ice sheet retreat. The investigators will read this record of iceberg-rafted debris to find when and where Antarctic ice destabilized in the past. This information can help to predict how Antarctic ice will behave in a warming climate. The study area is the Weddell Sea embayment, in the Atlantic sector of Antarctica. Principal sources of icebergs are the nearby Antarctic Peninsula and Weddell Sea embayment, where ice streams drain about a quarter of Antarctic ice. The provenance of the iceberg-rafted debris (IRD), and the icebergs that carried it, will be found by matching the geochemical fingerprint (such as characteristic argon isotope ages) of individual mineral grains in the IRD to that of the corresponding source area. In more detail, the project will: 1. Define the geochemical fingerprints of the source areas of the glacially-eroded material using samples from each major ice stream entering the Weddell Sea. Existing data indicates that the hinterland of the Weddell embayment is made up of geochemically distinguishable source areas, making it possible to apply geochemical provenance techniques to determine the origin of Antarctica icebergs. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till samples to characterize detritus supplied by the Recovery and Foundation ice streams. 2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information identifies which groups of ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents), and the stratigraphy of the cores shows the relative sequence of ice stream activity through time. A further dimension is added by determining the time lag between fine sediment erosion and deposition, using a new method of uranium-series isotope measurements in fine grained material. Technical abstract: The behavior of the Antarctic ice sheets and ice streams is a critical topic for climate change and future sea level rise. The goal of this proposal is to constrain ice sheet response to changing climate in the Weddell Sea during the three most recent glacial terminations, as analogues for potential future warming. The project will also examine possible contributions to Meltwater Pulse 1A, and test the relative stability of the ice streams draining East and West Antarctica. Much of the West Antarctic ice may have melted during the Eemian (130 to 114 Ka), so it may be an analogue for predicting future ice drawdown over the coming centuries. Geochemical provenance fingerprinting of glacially eroded detritus provides a novel way to reconstruct the location and relative timing of glacial retreat during these terminations in the Weddell Sea embayment. The two major objectives of the project are to: 1. Define the provenance source areas by characterizing Ar, U-Pb, and Nd isotopic signatures, and heavy mineral and Fe-Ti oxide compositions of detrital minerals from each major ice stream entering the Weddell Sea, using onshore tills and existing sediment cores from the Ronne and Filchner Ice Shelves. Pilot data demonstrate that detritus originating from the east and west sides of the Weddell Sea embayment can be clearly distinguished, and published data indicates that the hinterland of the embayment is made up of geochemically distinguishable source areas. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till to characterize detritus supplied by the Recovery and Foundation ice streams. 2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information will identify which ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents). The stratigraphy of the cores will show the relative sequence of ice stream activity through time. A further time dimension is added by determining the time lag between fine sediment erosion and deposition, using U-series comminution ages. | POLYGON((-70 -60,-65 -60,-60 -60,-55 -60,-50 -60,-45 -60,-40 -60,-35 -60,-30 -60,-25 -60,-20 -60,-20 -62.5,-20 -65,-20 -67.5,-20 -70,-20 -72.5,-20 -75,-20 -77.5,-20 -80,-20 -82.5,-20 -85,-25 -85,-30 -85,-35 -85,-40 -85,-45 -85,-50 -85,-55 -85,-60 -85,-65 -85,-70 -85,-70 -82.5,-70 -80,-70 -77.5,-70 -75,-70 -72.5,-70 -70,-70 -67.5,-70 -65,-70 -62.5,-70 -60)) | POINT(-45 -72.5) | false | false | ||||||||
Collaborative Research: Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP)
|
1443690 |
2020-07-07 | Young, Duncan A.; Blankenship, Donald D.; Roberts, Jason; Bo, Sun | Non-technical description: East Antarctica holds a vast, ancient ice sheet. The bedrock hidden beneath this ice sheet may provide clues to how today's continents formed, while the ice itself contains records of Earth's atmosphere from distant eras. New drilling technologies are now available to allow for direct sampling of these materials from more than two kilometers below the ice surface. However, getting this material will require knowing where to look. The Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP) project will use internationally collected airborne survey data to search East Antarctica near the South Pole for key locations that will provide insight into Antarctica's geology and for locating the oldest intact ice on Earth. Ultimately, scientists are interested in obtaining samples of the oldest ice to address fundamental questions about the causes of changes in the timing of ice-age conditions from 40,000 to 100,000 year cycles. SPICECAP data analysis will provide site survey data for future drilling and will increase the overall understanding of Antarctica's hidden ice and geologic records. The project involves international collaboration and leveraging of internationally collected data. The SPICECAP project will train new interdisciplinary scientists at the undergraduate, graduate, and postdoctoral levels. Technical description: This study focuses on processing and interpretation of internationally collected aerogeophysical data from the Southern Plateau of the East Antarctic Ice Sheet. The data include ice penetrating radar data, laser altimetry, gravity and magnetics. The project will provide information on geological trends under the ice, the topography and character of the ice/rock interface, and the stratigraphy of the ice. The project will also provide baseline site characterization for future drilling. Future drilling sites and deep ice cores for old ice require that the base of the ice sheet be frozen to the bed (i.e. no free water at the interface between rock and ice) and the assessment will map the extent of frozen vs. thawed areas. Specifically, three main outcomes are anticipated for this project. First, the study will provide an assessment of the viability of Titan Dome, a subglacial highland region located near South Pole, as a potential old ice drilling prospect. The assessment will include determining the hydraulic context of the bed by processing and interpreting the radar data, ice sheet mass balance through time by mapping englacial reflectors in the ice and connecting them to ice stratigraphy in the recent South Pole, and ice sheet geometry using laser altimetry. Second, the study will provide an assessment of the geological context of the Titan Dome region with respect to understanding regional geologic boundaries and the potential for bedrock sampling. For these two goals, we will use data opportunistically collected by China, and the recent PolarGAP dataset. Third, the study will provide an assessment of the risk posture for RAID site targeting in the Titan Dome region, and the Dome C region. This will use a high-resolution dataset the team collected previously at Dome C, an area similar to the coarser resolution data collected at Titan Dome, and will enable an understanding of what is missed by the wide lines spacing at Titan Dome. Specifically, we will model subglacial hydrology with and without the high resolution data, and statistically examine the detection of subglacial mountains (which could preserve old ice) and subglacial lakes (which could destroy old ice), as a function of line spacing. | POLYGON((95 -68,100.5 -68,106 -68,111.5 -68,117 -68,122.5 -68,128 -68,133.5 -68,139 -68,144.5 -68,150 -68,150 -70.2,150 -72.4,150 -74.6,150 -76.8,150 -79,150 -81.2,150 -83.4,150 -85.6,150 -87.8,150 -90,144.5 -90,139 -90,133.5 -90,128 -90,122.5 -90,117 -90,111.5 -90,106 -90,100.5 -90,95 -90,95 -87.8,95 -85.6,95 -83.4,95 -81.2,95 -79,95 -76.8,95 -74.6,95 -72.4,95 -70.2,95 -68)) | POINT(122.5 -79) | false | false | ||||||||
A High Resolution Atmospheric Methane Record from the South Pole Ice Core
|
1643722 |
2020-06-02 | Brook, Edward J. |
|
Brook/1643722 This award supports a project to measure the concentration of the gas methane in air trapped in an ice core collected from the South Pole. The data will provide an age scale (age as a function of depth) by matching the South Pole methane changes with similar data from other ice cores for which the age vs. depth relationship is well known. The ages provided will allow all other gas measurements made on the South Pole core (by the PI and other NSF supported investigators) to be interpreted accurately as a function of time. This is critical because a major goal of the South Pole coring project is to understand the history of rare gases in the atmosphere like carbon monoxide, carbon dioxide, ethane, propane, methyl chloride, and methyl bromide. Relatively little is known about what controls these gases in the atmosphere despite their importance to atmospheric chemistry and climate. Undergraduate assistants will work on the project and be introduced to independent research through their work. The PI will continue visits to local middle schools to introduce students to polar science, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) as part of the project. Methane concentrations from a major portion (2 depth intervals, excluding the brittle ice-zone which is being measured at Penn State University) of the new South Pole ice core will be used to create a gas chronology by matching the new South Pole ice core record with that from the well-dated WAIS Divide ice core record. In combination with measurements made at Penn State, this will provide gas dating for the entire 50,000-year record. Correlation will be made using a simple but powerful mid-point method that has been previously demonstrated, and other methods of matching records will be explored. The intellectual merit of this work is that the gas chronology will be a fundamental component of this ice core project, and will be used by the PI and other investigators for dating records of atmospheric composition, and determining the gas age-ice age difference independently of glaciological models, which will constrain processes that affected firn densification in the past. The methane data will also provide direct stratigraphic markers of important perturbations to global biogeochemical cycles (e.g., rapid methane variations synchronous with abrupt warming and cooling in the Northern Hemisphere) that will tie other ice core gas records directly to those perturbations. A record of the total air content will also be produced as a by-product of the methane measurements and will contribute to understanding of this parameter. The broader impacts include that the work will provide a fundamental data set for the South Pole ice core project and the age scale (or variants of it) will be used by all other investigators working on gas records from the core. The project will employ an undergraduate assistant(s) in both years who will conduct an undergraduate research project which will be part of the student's senior thesis or other research paper. The project will also offer at least one research position for the Oregon State University Summer REU site program. Visits to local middle schools, and other outreach activities (e.g. laboratory tours, talks to local civic or professional organizations) will also be part of the project. | POINT(0 -90) | POINT(0 -90) | false | false | |||||||
Carbonyl Sulfide, Methyl Chloride, and Methyl Bromide Measurements in the New Intermediate-depth South Pole Ice Core
|
1443470 |
2020-03-26 | Aydin, Murat |
|
In the past, Earth's climate underwent dramatic changes that influenced physical, chemical, geological, and biological processes on a global scale. Such changes left an imprint in Earth's atmosphere, as shown by the variability in abundances of trace gases like carbon dioxide and methane. In return, changes in the atmospheric trace gas composition affected Earth's climate. Studying compositional variations of the past atmosphere helps us understand the history of interactions between global biogeochemical cycles and Earth?s climate. The most reliable information on past atmospheric composition comes from analysis of air entrapped in polar ice cores. This project aims to generate ice-core records of relatively short-lived, very-low-abundance trace gases to determine the range of past variability in their atmospheric levels and investigate the changes in global biogeochemical cycles that caused this variability. This project measures three such gases: carbonyl sulfide, methyl chloride, and methyl bromide. Changes in carbonyl sulfide can indicate changes in primary productivity and photosynthetic update of carbon dioxide. Changes in methyl chloride and methyl bromide significantly impact natural variability in stratospheric ozone. In addition, the processes that control atmospheric levels of methyl chloride and methyl bromide are shared with those controlling levels of atmospheric methane. The measurements will be made in the new ice core from the South Pole, which is expected to provide a 40,000-year record. The primary focus of this project is to develop high-quality trace gas records for the entire Holocene period (the past 11,000 years), with additional, more exploratory measurements from the last glacial period including the period from 29,000-36,000 years ago when there were large changes in atmospheric methane. Due to the cold temperatures of the South Pole ice, the proposed carbonyl sulfide measurements are expected to provide a direct measure of the past atmospheric variability of this gas without the large hydrolysis corrections that are necessary for interpretation of measurements from ice cores in warmer settings. Furthermore, we will test the expectation that contemporaneous measurements from the last glacial period in the deep West Antarctic Ice Sheet Divide ice core will not require hydrolysis loss corrections. With respect to methyl chloride, we aim to verify and improve the existing Holocene atmospheric history from the Taylor Dome ice core in Antarctica. The higher resolution of our measurements compared with those from Taylor Dome will allow us to derive a more statistically significant relationship between methyl chloride and methane. With respect to methyl bromide, we plan to extend the existing 2,000-year database to 11,000 years. Together, the methyl bromide and methyl chloride records will provide strong measurement-based constraints on the natural variability of stratospheric halogens during the Holocene period. In addition, the methyl bromide record will provide insight into the correlation between methyl chloride and methane during the Holocene period due to common sources and sinks. | 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)) | POINT(0 -89.999) | false | false | |||||||
Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole
|
1443105 |
2019-11-17 | Steig, Eric J.; White, James | This project will develop a record of the stable-isotope ratios of water from an ice core at the South Pole, Antarctica. Water-isotope ratio measurements provide a means to determine variability in temperature through time. South Pole is distinct from most other locations in Antarctica in showing no warming in recent decades, but little is known about temperature variability in this location prior to the installation of weather stations in 1957. The measurements made as part of this project will result in a much longer temperature record, extending at least 40,000 years, aiding our ability to understand what controls Antarctic climate, and improving projections of future Antarctic climate change. Data from this project will be critical to other investigators working on the South Pole ice core, and of general interest to other scientists and the public. Data will be provided rapidly to other investigators and made public as soon as possible. This project will obtain records of the stable-isotope ratios of water on the ice core currently being obtained at South Pole. The core will reach a depth of 1500 m and an age of 40,000 years. The project will use laser spectroscopy to obtain both an ultra-high-resolution record of oxygen 18/16 and deuterium-hydrogen ratios, and a lower-resolution record of oxygen 17/16 ratios. The high-resolution measurements will be used to aid in dating the core, and to provide estimates of isotope diffusion that constrain the process of firn densification. The novel 17/16 measurement provides additional constraints on the isotope fractionation due to the temperature-dependent supersaturation ratio, which affects the fractionation of water during the liquid-solid condensate transition. Together, these techniques will allow for improved accuracy in the use of the water isotope ratios as proxies for ice-sheet temperature, sea-surface temperature, and atmospheric circulation. The result will be a record of decadal through centennial and millennial scale climate change in a climatically distinct region in East Antarctica that has not been previously sampled by deep ice coring. The project will support a graduate student who will be co-advised by faculty at the University of Washington and the University of Colorado, and will be involved in all aspects of the work. | POINT(0 -90) | POINT(0 -90) | false | false | ||||||||
Collaborative Research: A 1500m Ice Core from South Pole
|
1141839 1142646 1142517 |
2019-10-30 | Twickler, Mark; Souney, Joseph Jr.; Aydin, Murat; Steig, Eric J. | 1142517/Saltzman This proposal requests support for a project to drill and recover a new ice core from South Pole, Antarctica. The South Pole ice core will be drilled to a depth of 1500 m, providing an environmental record spanning approximately 40 kyrs. This core will be recovered using a new intermediate drill, which is under development by the U.S. Ice Drilling Design and Operations (IDDO) group in collaboration with Danish scientists. This proposal seeks support to provide: 1) scientific management and oversight for the South Pole ice core project, 2) personnel for ice core drilling and core processing, 3) data management, and 3) scientific coordination and communication via scientific workshops. The intellectual merit of the work is that the analysis of stable isotopes, atmospheric gases, and aerosol-borne chemicals in polar ice has provided unique information about the magnitude and timing of changes in climate and climate forcing through time. The international ice core research community has articulated the goal of developing spatial arrays of ice cores across Antarctica and Greenland, allowing the reconstruction of regional patterns of climate variability in order to provide greater insight into the mechanisms driving climate change. The broader impacts of the project include obtaining the South Pole ice core will support a wide range of ice core science projects, which will contribute to the societal need for a basic understanding of climate and the capability to predict climate and ice sheet stability on long time scales. Second, the project will help train the next generation of ice core scientists by providing the opportunity for hands-on field and core processing experience for graduate students and postdoctoral researchers. A postdoctoral researcher at the University of Washington will be directly supported by this project, and many other young scientists will interact with the project through individual science proposals. Third, the project will result in the development of a new intermediate drill which will become an important resource to US ice core science community. This drill will have a light logistical footprint which will enable a wide range of ice core projects to be carried out that are not currently feasible. Finally, although this project does not request funds for outreach activities, the project will run workshops that will encourage and enable proposals for coordinated outreach activities involving the South Pole ice core science team. | POINT(90 -90) | POINT(90 -90) | false | false | ||||||||
Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements
|
1443663 1443397 1443336 |
2019-08-29 | Osterberg, Erich | This collaborative project explores the signatures and causes of natural climate change in the region surrounding Antarctica over the last 40,000 years as the Earth transitioned from an ice age into the modern warm period. The researchers will investigate how the wind belts that surround Antarctica changed in their strength and position through time, and document explosive volcanic eruptions and CO2 cycling in the Southern Ocean as potential climate forcing mechanisms over this interval. Understanding how and why the climate varied naturally in the past is critical for improving understanding of modern climate change and projections of future climate under higher levels of atmospheric CO2. The investigators plan to conduct a suite of chemical measurements along the 1500m length of the South Pole Ice Core, including major ion and trace element concentrations, and microparticle (dust) concentrations and size distributions. These measurements will (1) extend the South Pole record of explosive volcanic eruptions to 40,000 years using sulfate and particle data; (2) establish the relative timing of climate changes in dust source regions of Patagonia, New Zealand, and Australia using dust flux data; (3) investigate changes in the strength and position of the westerly wind belt using dust size distribution data; and (4) quantify the flux of bioavailable trace metals deposited as dust to the Southern Ocean over time. These chemistry records will also be critical for creating the timescale that will be used by all researchers studying records from the South Pole core. The project will support four graduate students and several undergraduate students across three different institutions, and become a focus of the investigators' efforts to disseminate outcomes of climate change science to the broader community. | POINT(-180 -90) | POINT(-180 -90) | false | false | ||||||||
Timing and Duration of the LGM and Post-LGM Grounding Events in Whales Deep Paleo Ice Stream, Eastern Ross Sea Middle Continental Shelf
|
1246357 |
2019-06-03 | Bart, Philip; Steinberg, Deborah |
|
Intellectual Merit: Evidence from the eastern Ross Sea continental shelf indicates that the West Antarctic Ice Sheet advanced and retreated during the last glacial cycle, but it is unclear whether the ice sheet advanced to the shelf edge or just to the middle shelf. These two end-member scenarios offer different interpretations as to why, how, and when the West Antarctic Ice Sheet oscillated. The PI proposes to acquire seismic, multibeam, and core data from Whales Deep, to evaluate the timing and duration of two advances of grounded ice to the outer and middle shelf of the Whales Deep Basin, a West Antarctic Ice Sheet paleo ice stream trough in eastern Ross Sea. Grounding events are represented by seismically resolvable Grounding Zone Wedges. The PI will collect radiocarbon dates on in situ benthic foraminifera from the grounding zone diamict as well as ramped pyrolysis radiocarbon dates on acid insoluble organics from open-marine mud overlying the grounding zone diamict. Using these data the PI will calculate the duration of the two grounding events. Furthermore, the PI will test a numerical model prediction that West Antarctic Ice Sheet retreat must have involved melting at the marine terminus of the ice sheet. Pore-water from the grounding zone diamict will be extracted from piston cores to determine salinity and δ18O values that should indicate if significant melting occurred at the grounding line. Broader impacts: The data collected will provide constraints on the timing and pattern of Last Glacial Maximum advance and retreat that can be incorporated into interpretations of ice-surface elevation changes. The proposed activities will provide valuable field and research training to undergraduate/graduate students and a Louisiana high-school science teacher. The research will be interactively shared with middle- and high-school science students and with visitors to the LSU Museum of Natural Science Weekend-Science Program. | None | None | false | false | |||||||
Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core
|
1443710 1443472 1443464 |
2019-02-02 | Severinghaus, Jeffrey P.; Sowers, Todd A.; Brook, Edward J. | Gases trapped in ice cores have revealed astonishing things about the greenhouse gas composition of the past atmosphere, including the fact that carbon dioxide concentrations never rose above 300 parts per million during the last 800,000 years. This places today's concentration of 400 parts per million in stark contrast. Furthermore, these gas records show that natural sources of greenhouse gas such as oceans and ecosystems act as amplifiers of climate change by increasing emissions of gases during warmer periods. Such amplification is expected to occur in the future, adding to the human-produced gas burden. The South Pole ice core will build upon these prior findings by expanding the suite of gases to include, for the first time, those potent trace gases that both trapped heat and depleted ozone during the past 40,000 years. The present project on inert gases and methane in the South Pole ice core will improve the dating of this crucial record, to unprecedented precision, so that the relative timing of events can be used to learn about the mechanism of trace gas production and destruction, and consequent climate change amplification. Ultimately, this information will inform predictions of future atmospheric chemical cleansing mechanisms and climate in the context of our rapidly changing atmosphere. This award also engages young people in the excitement of discovery and polar research, helping to entrain the next generations of scientists and educators. Education of graduate students, a young researcher (Buizert), and training of technicians, will add to the nation?s human resource base. This award funds the construction of the gas chronology for the South Pole 1500m ice core, using measured inert gases (d15N and d40Ar--Nitrogen and Argon isotope ratios, respectively) and methane in combination with a next-generation firn densification model that treats the stochastic nature of air trapping and the role of impurities on densification. The project addresses fundamental gaps in scientific understanding that limit the accuracy of gas chronologies, specifically a poor knowledge of the controls on ice-core d15N and the possible role of layering and impurities in firn densification. These gaps will be addressed by studying the gas enclosure process in modern firn at the deep core site. The work will comprise the first-ever firn air pumping experiment that has tightly co-located measurements of firn structural properties on the core taken from the same borehole. The project will test the hypothesis that the lock-in horizon as defined by firn air d15N, CO2, and methane is structurally controlled by impermeable layers, which are in turn created by high-impurity content horizons in which densification is enhanced. Thermal signals will be sought using the inert gas measurements, which improve the temperature record with benefits to the firn densification modeling. Neon, argon, and oxygen will be measured in firn air and a limited number of deep core samples to test whether glacial period layering was enhanced, which could explain low observed d15N in the last glacial period. Drawing on separate volcanic and methane synchronization to well-dated ice cores to create independent ice and gas tie points, independent empirical estimates of the gas age-ice age difference will be made to check the validity of the firn densification model-inert gas approach to calculating the gas age-ice age difference. These points will also be used to test whether the anomalously low d15N seen during the last glacial period in east Antarctic ice cores is due to deep air convection in the firn, or a missing impurity dependence in the firn densification models. The increased physical understanding gained from these studies, combined with new high-precision measurements, will lead to improved accuracy of the gas chronology of the South Pole ice core, which will enhance the overall science return from this gas-oriented core. This will lead to clarification of timing of atmospheric gas variations and temperature, and aid in efforts to understand the biogeochemical feedbacks among trace gases. These feedbacks bear on the future response of the Earth System to anthropogenic forcing. Ozone-depleting substances will be measured in the South Pole ice core record, and a precise gas chronology will add value. Lastly, by seeking a better understanding of the physics of gas entrapment, the project aims to have an impact on ice-core science in general. | POINT(0 -90) | POINT(0 -90) | false | false | ||||||||
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
|
1443306 1443263 |
2018-10-18 | Mayewski, Paul A.; Kurbatov, Andrei V.; Higgins, John; Bender, Michael | 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. Between about 2.8-0.9 million years ago, Earth's climate was characterized by 40,000-year cycles, driven or paced by changes in the tilt of Earth's 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. | None | None | false | false | ||||||||
Collaborative Research: Integrative Study of Marine Ice Sheet Stability & Subglacial Life Habitats in W Antarctica - Lake & Ice Stream Subglacial Access Research Drilling (LISSARD)
|
0839142 0839059 0838764 0838947 0838855 0838763 0839107 |
2018-09-10 | Tulaczyk, Slawek; Fisher, Andrew; Powell, Ross; Anandakrishnan, Sridhar; Jacobel, Robert; Scherer, Reed Paul | This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The LISSARD project (Lake and Ice Stream Subglacial Access Research Drilling) is one of three research components of the WISSARD integrative initiative (Whillans Ice Stream Subglacial Access Research Drilling) that is being funded by the Antarctic Integrated System Science Program of NSF's Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The LISSARD component of WISSARD focuses on the role of active subglacial lakes in determining how fast the West Antarctic ice sheet loses mass to the global ocean and influences global sea level changes. The importance of Antarctic subglacial lakes has only been recently recognized, and the lakes have been identified as high priority targets for scientific investigations because of their unknown contributions to ice sheet stability under future global warming scenarios. LISSARD has several primary science goals: A) To provide an observational basis for improving treatments of subglacial hydrological and mechanical processes in models of ice sheet mass balance and stability; B) To reconstruct the past history of ice stream stability by analyzing archives of past basal water and ice flow variability contained in subglacial sediments, porewater, lake water, and basal accreted ice; C) To provide background understanding of subglacial lake environments to benefit RAGES and GBASE (the other two components of the WISSARD project); and D) To synthesize data and concepts developed as part of this project to determine whether subglacial lakes play an important role in (de)stabilizing Antarctic ice sheets. We propose an unprecedented synthesis of approaches to studying ice sheet processes, including: (1) satellite remote sensing, (2) surface geophysics, (3) borehole observations and measurements and, (4) basal and subglacial sampling. <br/><br/>INTELLECTUAL MERIT: The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. <br/><br/>BROADER IMPACTS: Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars. | None | None | false | false | ||||||||
Tephrochronology of the WAIS Divide Ice Core: Linking Ice Cores through Volcanic Records
|
1142115 |
2018-06-10 | Dunbar, Nelia |
|
Dunbar/1142115 This award supports a project to investigate the extremely rich volcanic record in the WAIS Divide ice core as part of this ongoing tephrochronology research in Antarctica. Ice cores in Polar Regions offer unparalleled records of earth's climate over the past 500,000 years. Accurate chronology of individual ice cores and chronological correlations between different ice cores is critically important to the interpretation of the climate record. The field of Antarctic tephrochronology has been progressing steadily, and is on the cusp of having a fully integrated tephra framework for large parts of the continent. Major advances in this field have been made due to the acquisition of a number of ice cores with strong volcanic records, improvement of analytical techniques and better characterization of source eruptions due in part to through studies of englacial tephra from several major blue ice areas. The intellectual merit of this work is that the tephrochonological studies will provide independently dated time-stratigraphic markers in the ice core, particularly for the deepest ice, linking tephra layers between the WAIS Divide core and the Siple Dome core which will allow detailed comparisons to be made of coastal and inland climate. It will also contribute to a better understanding of eruption magnitude, dispersal patterns and geochemical evolution of West Antarctic volcanoes. The work will also contribute to a new tephra dataset to the literature for use in future ice core studies. The broader impacts of this project fall into the areas of education, outreach and international cooperation. This project will employ one New Mexico Tech graduate student, but will also be featured in outreach programs for NMT undergraduates, as well as teacher and student groups and outreach for the general public in New Mexico. NMT is an Hispanic serving institution (25% Hispanic students) and also found by NSF to rank 15th nationwide in "baccalaureate-origin" institutions for doctoral recipients in science and engineering, thereby having a disproportionately large effect on producing Hispanic scientists and engineers. However, probably the most significant broader impact of this project will be the continued efforts of the PI in fostering and promoting of international cooperation in the tephra-in-ice community. Dunbar has been collaborating with European tephra researchers for a number of years, sharing data and working collaboratively on tephra correlations, and these activities have lead to, and will continue to promote, forward progress in integrating the Antarctic tephrochronology record. This proposal does not require field work in the Antarctic. | 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)) | POINT(0 -89.999) | false | false | |||||||
Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea
|
1341585 |
2018-05-25 | Sorlien, Christopher; Luyendyk, Bruce P. |
|
Intellectual Merit: This project will produce a new compilation of Ross Sea seismic stratigraphy, including new interpretations, that can be used to provide boundary conditions on the tectonic and glacial evolution of West Antarctica and the Ross Sea. The principal goals include compilation of, and interpretation of, all available existing seismic reflection data for the Western Ross Sea, coupled with geophysical modeling to produce paleo-bathymetric reconstructions for the entire 800 km-wide Ross Sea. Specific tasks will include: extending existing work on mapping travel time to reflectors, identifying relations in the seismic data that indicate subsidence through sea level, constructing velocity models for converting travel time to thickness, and using the velocity models to estimate density and porosity of sediments for backstripping analysis. Modeling/backstripping efforts will be used to constrain past bathymetry. Digital interpretations and stratigraphic grids will be provided as supplements to publications. In that way the results of this study can be used in thermal subsidence modeling and restoration of eroded rock to other parts of Ross Embayment and Marie Byrd Land by others. Digital products may be provided in advance of publication to modelers in a way that will not hurt publication chances. Broader impacts: The results of this work will be important for paleo-geographic reconstructions of Antarctica and will therefore be of use to a broad range of researchers, particularly those working in the Ross Sea region. The digital products can be used to test models for the past fluctuations of West Antarctic ice sheets, and in planning for future sediment drilling projects. Two undergraduates to be chosen from applicants will be involved in summer internships held at the University of Rhode Island. Outreach will also include a new website and one or more Wikipedia entries related to Ross Sea sub-sea floor characteristics. The project includes an international collaboration with Dr. Chiara Sauli and others at Instituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Italy. | POLYGON((-180 -73.33,-179.1 -73.33,-178.2 -73.33,-177.3 -73.33,-176.4 -73.33,-175.5 -73.33,-174.6 -73.33,-173.7 -73.33,-172.8 -73.33,-171.9 -73.33,-171 -73.33,-171 -73.864,-171 -74.398,-171 -74.932,-171 -75.466,-171 -76,-171 -76.534,-171 -77.068,-171 -77.602,-171 -78.136,-171 -78.67,-171.9 -78.67,-172.8 -78.67,-173.7 -78.67,-174.6 -78.67,-175.5 -78.67,-176.4 -78.67,-177.3 -78.67,-178.2 -78.67,-179.1 -78.67,180 -78.67,178.5 -78.67,177 -78.67,175.5 -78.67,174 -78.67,172.5 -78.67,171 -78.67,169.5 -78.67,168 -78.67,166.5 -78.67,165 -78.67,165 -78.136,165 -77.602,165 -77.068,165 -76.534,165 -76,165 -75.466,165 -74.932,165 -74.398,165 -73.864,165 -73.33,166.5 -73.33,168 -73.33,169.5 -73.33,171 -73.33,172.5 -73.33,174 -73.33,175.5 -73.33,177 -73.33,178.5 -73.33,-180 -73.33)) | POINT(177 -76) | false | false | |||||||
Using Electrical Conductance Measurements to Develop the South Pole Ice Core Chronology
|
1443232 |
2018-05-08 | Fudge, T. J.; Waddington, Edwin D. |
|
Ice cores record detailed histories of past climate variations. The South Pole ice core will allow investigation of atmospheric trace gases and fill an important gap in understanding the pattern of climate variability across Antarctica. An accurate timescale that assigns an age to the ice at each depth in the core is essential to interpretation of the ice-core records. This work will use electrical methods to identify volcanic eruptions throughout the past ~40,000 years in the core by detecting the enhanced electrical conductance in those layers due to volcanic impurities in the ice. These eruptions will be pattern-matched to other cores across Antarctica, synchronizing the timing of climate variations among cores and allowing the precise timescales developed for other Antarctic ice cores to be transferred to the South Pole ice core. The well-dated records of volcanic forcing will be combined with records of atmospheric gases, stable water-isotopes, and aerosols to better understand the large natural climate variations of the past 40,000 years. The electrical conductance method and dielectric profiling measurements will be made along the length of each section of the South Pole ice core at the National Ice Core Lab. These measurements will help to establish a timescale for the core. Electrical measurements will provide a continuous record of volcanic events for the entire core including through the brittle ice (550-1250m representing ~10,000-20,000 year-old ice) where the core quality and thin annual layers may prevent continuous melt analysis and cause discrete measurements to miss volcanic events. The electrical measurements also produce a 2-D image of the electrical layering on a longitudinal cut surface of each core. These data will be used to identify any irregular or absent layering that would indicate a stratigraphic disturbance in the core. A robust chronology is essential to interpretation of the paleoclimate records from the South Pole ice core. The investigators will engage teachers through talks and webinars with the National Science Teachers Association and will share information with the public at events such as Polar Science Weekend at the Pacific Science Center. Results will be disseminated through publications and conference presentations and the data will be archived and publicly available. | POLYGON((110 -89,117 -89,124 -89,131 -89,138 -89,145 -89,152 -89,159 -89,166 -89,173 -89,180 -89,180 -89.1,180 -89.2,180 -89.3,180 -89.4,180 -89.5,180 -89.6,180 -89.7,180 -89.8,180 -89.9,180 -90,173 -90,166 -90,159 -90,152 -90,145 -90,138 -90,131 -90,124 -90,117 -90,110 -90,110 -89.9,110 -89.8,110 -89.7,110 -89.6,110 -89.5,110 -89.4,110 -89.3,110 -89.2,110 -89.1,110 -89)) | POINT(145 -89.5) | false | false | |||||||
Paleomagnetism and Magnetostratigraphy of the James Ross Basin, Antarctica
|
1341729 |
2018-04-27 | Kirschvink, Joseph; Christensen, John |
|
Non-Technical Summary: About 80 million years ago, the tip of the Antarctic Peninsula in the vicinity of what is now James Ross Island experienced an episode of rapid subsidence, creating a broad depositional basin that collected sediments eroding from the high mountains to the West. This depression accumulated a thick sequence of fossil-rich, organic-rich sediments of the sort that are known to preserve hydrocarbons, and for which Argentina, Chile, and the United Kingdom have overlapping territorial claims. The rocks preserve one of the highest resolution records of the biological and climatic events that led to the eventual death of the dinosaurs at the Cretaceous-Tertiary boundary (about 66 million years ago). A previous collaboration between scientists from the Instituto Antártico Argentino (IAA) and NSF-supported teams from Caltech and the University of Washington were able to show that this mass extinction event started nearly 50,000 years before the sudden impact of an asteroid. The asteroid obviously hit the biosphere hard, but something else knocked it off balance well before the asteroid hit. A critical component of the previous work was the use of reversals in the polarity of the Earth?s magnetic field as a dating tool ? magnetostratigraphy. This allowed the teams to correlate the pattern of magnetic reversals from Antarctica with elsewhere on the planet. This includes data from a major volcanic eruption (a flood basalt province) that covered much of India 65 million years ago. The magnetic patterns indicate that the Antarctic extinction started with the first pulse of this massive eruption, which was also coincident with a rapid spike in polar temperature. The Argentinian and US collaborative teams will extend this magnetic polarity record back another ~ 20 million years in time, and expand it laterally to provide magnetic reversal time lines across the depositional basin. They hope to recover the end of the Cretaceous Long Normal interval, which is one of the most distinctive events in the history of Earth?s magnetic field. The new data should refine depositional models of the basin, allow better estimates of potential hydrocarbon reserves, and allow biotic events in the Southern hemisphere to be compared more precisely with those elsewhere on Earth. Other potential benefits of this work include exposing several US students and postdoctoral fellows to field based research in Antarctica, expanding the international aspects of this collaborative work via joint IAA/US field deployments, and follow-up laboratory investigations and personnel exchange of the Junior scientists. Technical Description of Project The proposed research will extend the stratigraphic record in the late Cretaceous and early Tertiary sediments (~ 83 to 65 Ma before present) of the James Ross Basin, Antarctica, using paleo-magnetic methods. Recent efforts provided new methods to analyze these rocks, yielding their primary magnetization, and producing both magnetic polarity patterns and paleomagnetic pole positions. This provided the first reliable age constraints for the younger sediments on Seymour Island, and quantified the sedimentation rate in this part of the basin. The new data will allow resolution of the stable, remnant magnetization of the sediments from the high deposition rate James Ross basin (Tobin et al., 2012), yielding precise chronology/stratigraphy. This approach will be extended to the re-maining portions of this sedimentary basin, and will allow quantitative estimates for tectonic and sedimentary processes between Cretaceous and Early Tertiary time. The proposed field work will refine the position of several geomagnetic reversals that occurred be-tween the end of the Cretaceous long normal period (Chron 34N, ~ 83 Ma), and the lower portion of Chron 31R (~ 71 Ma). Brandy Bay provides the best locality for calibrating the stratigraphic position of the top of the Cretaceous Long Normal Chron, C34N. Although the top of the Cretaceous long normal Chron is one of the most important correlation horizons in the entire geological timescale, it is not properly correlated to the southern hemisphere biostratigraphy. Locating this event, as well as the other reversals, will be a major addition to understanding of the geological history of the Antarctic Peninsula. These data will also help refine tectonic models for the evolution of the Southern continents, which will be of use across the board for workers in Cretaceous stratigraphy (including those involved in oil exploration). This research is a collaborative effort with Dr. Edward Olivero of the Centro Austral de Investigaciones Cientificas (CADIC/CONICET) and Prof. Augusto Rapalini of the University of Buenos Aires. The collaboration will include collection of samples on their future field excursions to important targets on and around James Ross Island, supported by the Argentinian Antarctic Program (IAA). Argentinian scientists and students will also be involved in the US Antarctic program deployments, proposed here for the R/V Laurence Gould, and will continue the pattern of joint international publication of the results. | POLYGON((-58.9 -63.5,-58.63 -63.5,-58.36 -63.5,-58.09 -63.5,-57.82 -63.5,-57.55 -63.5,-57.28 -63.5,-57.01 -63.5,-56.74 -63.5,-56.47 -63.5,-56.2 -63.5,-56.2 -63.62,-56.2 -63.74,-56.2 -63.86,-56.2 -63.98,-56.2 -64.1,-56.2 -64.22,-56.2 -64.34,-56.2 -64.46,-56.2 -64.58,-56.2 -64.7,-56.47 -64.7,-56.74 -64.7,-57.01 -64.7,-57.28 -64.7,-57.55 -64.7,-57.82 -64.7,-58.09 -64.7,-58.36 -64.7,-58.63 -64.7,-58.9 -64.7,-58.9 -64.58,-58.9 -64.46,-58.9 -64.34,-58.9 -64.22,-58.9 -64.1,-58.9 -63.98,-58.9 -63.86,-58.9 -63.74,-58.9 -63.62,-58.9 -63.5)) | POINT(-57.55 -64.1) | false | false | |||||||
Anisotropic Ice and Stratigraphic Disturbances
|
1246045 |
2018-04-02 | Waddington, Edwin D. |
|
Waddington/1246045 This award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica. | POLYGON((-180 -70,-144 -70,-108 -70,-72 -70,-36 -70,0 -70,36 -70,72 -70,108 -70,144 -70,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,180 -82,180 -84,180 -86,180 -88,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88,-180 -86,-180 -84,-180 -82,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70)) | POINT(0 -89.999) | false | false | |||||||
Late Quaternary Evolution of the Lambert Glacier/Amery Ice Shelf System, Prydz Bay, Antarctica
|
1246378 |
2017-10-27 | Shevenell, Amelia |
|
Intellectual Merit: Southern 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. Broader impacts: This 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. | 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)) | POINT(72.5 -69) | false | false | |||||||
Late Quaternary Evolution of the Lambert Glacier/Amery Ice Shelf System, Prydz Bay, Antarctica
|
1246378 |
2017-10-27 | Shevenell, Amelia |
|
Intellectual Merit: Southern 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. Broader impacts: This 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. | 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)) | POINT(-65.265 -64.33) | false | false | |||||||
Insights into the Burial, Tectonic, and Hydrologic History of the Cenozoic Succession in McMurdo Sound, Antarctica through Analysis of Diagenetic Phases
|
1341390 |
2017-10-06 | Frank, Tracy; Fielding, Christopher |
|
Intellectual Merit: This project will use sediment cores from the Victoria Land Basin (VLB), Antarctica, to study secondary (diagenetic) carbonate minerals, as indicators of the basin?s fluid-flow history, within the well-constrained tectonic, depositional, and climatic context provided by sediment cores. This study will provide insights into subsurface processes in Victoria Land Basin, Antarctica and their relationships with the region?s climatic, cryospheric, and tectonic history. The work will utilize cores previously recovered by US-sponsored stratigraphic drilling projects (CIROS, CRP, and ANDRILL projects). This work is motivated by the unexpected discovery of dense brine in the subsurface of Southern McMurdo Sound during drilling by the ANDRILL Southern McMurdo Sound project. The presence of the brine is intriguing because it contradicts previous models for the origin of subsurface fluids that called upon large contributions from glacial melt water. Project objectives involve documenting the distribution of the brine (and potentially other fluids) via characterization of diagenetic precipitates. The approach will involve integration of petrographic and geochemical data (including conventional carbon, oxygen, and ?clumped? isotopes) to fully characterize diagenetic phases and allow development of a robust paragenetic history. This work will provide novel insights into the Cenozoic evolution of the VLB and, more broadly, the role of glacial processes in generating subsurface fluids. Broader impacts: Results from this project will help understand the origins of brines, groundwater and hydrocarbon reservoirs in analogous modern and ancient deposits elsewhere, which is of broad interest. This project will support the training of one graduate and one undergraduate student at the University of Nebraska-Lincoln (UNL) providing learning opportunities in sedimentary geology and diagenesis, fields with wide applicability. This proposal emphasizes rapid dissemination of results to the scientific community via conference presentations and contributions to peer-reviewed publications. The results will be integrated into education activities designed to develop skills in petrography and diagenesis, which are highly sought after in the energy sector. The project will generate a well-constrained dataset that allows direct linkage of diagenetic phases to environmental and tectonic change across a large sedimentary basin which will provide the basis for a comprehensive case study in an upper-level course (Sedimentary Petrography and Diagenesis) at UNL. In addition, online exercises will be developed and submitted to an open-access site (SEPM Stratigraphy Web) dedicated to sedimentary geology. | None | None | false | false | |||||||
Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core
|
0944191 0944197 |
2017-04-25 | Conway, Howard; Fudge, T. J.; Taylor, Kendrick C.; Waddington, Edwin D. | This award supports a project to help to establish the depth-age chronology and the histories of accumulation and ice dynamics for the WAIS Divide ice core. The depth-age relationship and the histories of accumulation and ice dynamics are coupled. An accurate age scale is needed to infer histories of accumulation rate and ice-thickness change using ice-flow models. In turn, the accumulation-rate history is needed to calculate the age difference of ice to determine the age of the trapped gases. The accumulation history is also needed to calculate atmospheric concentrations of impurities trapped in the ice and is an important characteristic of climate. The history of ice-thickness change is also fundamental to understanding the stability of the WAIS. The primary goals of the WAIS Divide ice core project are to investigate climate forcing by greenhouse gases, the initiation of climate changes, and the stability of the West Antarctic Ice Sheet (WAIS). An accurate age scale is fundamental for achieving these goals. The first objective of this project is to establish an annually resolved depth-age relationship for the past 40,000 years. This will be done by measuring variations in electrical conductivity along the ice core, which are caused by seasonal variations in chemistry. We expect to be able to resolve annual layers back to 40,000 years before present (3,000 m depth) using this method. The second objective is to search for stratigraphic disturbances in the core that would compromise the paleoclimate record. Irregular layering will be identified by measuring the electrical conductivity of the ice in a vertical plan through the core. The third objective is to derive a preliminary chronology for the entire core. For the deeper ice we will use an ice-flow model to interpolate between known age markers, such as dated volcanic horizons and tie points from the methane gas chronology. The fourth objective is to derive a refined chronology simultaneously with histories of accumulation and ice-sheet thickness. An ice-flow model and all available data will be used to formulate an inverse problem, in which we infer the most appropriate histories of accumulation and ice-thickness, together with estimates of uncertainties. The flow model associated with those preferred histories then produces the best estimate of the chronology. The research contributes directly to the primary goals of the West Antarctic Ice Sheet Initiative. The project will help develop the next generation of scientists through the education and training of one Ph.D. student and several undergraduate students. This project will result in instrumentation for measuring the electrical conductivity of ice cores being available at the National Ice Core Lab for other researchers to use on other projects. All collaborators are committed to fostering diversity and currently participate in scientific outreach and most participate in undergraduate education. Outreach will be accomplished through regularly scheduled community and K-12 outreach events at UW, talks and popular writing by the PIs, as well as through our respective press offices. | POLYGON((-180 -79,-173.3 -79,-166.6 -79,-159.9 -79,-153.2 -79,-146.5 -79,-139.8 -79,-133.1 -79,-126.4 -79,-119.7 -79,-113 -79,-113 -79.1,-113 -79.2,-113 -79.3,-113 -79.4,-113 -79.5,-113 -79.6,-113 -79.7,-113 -79.8,-113 -79.9,-113 -80,-119.7 -80,-126.4 -80,-133.1 -80,-139.8 -80,-146.5 -80,-153.2 -80,-159.9 -80,-166.6 -80,-173.3 -80,180 -80,150.9 -80,121.8 -80,92.7 -80,63.6 -80,34.5 -80,5.4 -80,-23.7 -80,-52.8 -80,-81.9 -80,-111 -80,-111 -79.9,-111 -79.8,-111 -79.7,-111 -79.6,-111 -79.5,-111 -79.4,-111 -79.3,-111 -79.2,-111 -79.1,-111 -79,-81.9 -79,-52.8 -79,-23.7 -79,5.4 -79,34.5 -79,63.6 -79,92.7 -79,121.8 -79,150.9 -79,-180 -79)) | POINT(-112 -79.5) | false | false | ||||||||
The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin
|
1245283 |
2017-04-25 | Passchier, Sandra | Intellectual Merit: This project will investigate glacial advance and retreat of the East Antarctic Ice Sheet through the Eocene-Oligocene transition, a major episode of ice growth. In Prydz Bay, East Antarctica, a 130-170 m thick Eocene-Oligocene transition interval of glaciomarine sediments was cored in drillholes of the Ocean Drilling Program at Sites 739, 742 and 1166. Correlations between the Prydz Bay drillholes have recently been made through well-log and multichannel seismic interpretations. Recent drilling on the Wilkes Land margin of East Antarctica recovered earliest Oligocene sediments overlying a major regional unconformity in two drillholes. The PI will study the lithostratigraphy and weathering history of cores in the five drillholes, to establish a unique Eocene-Oligocene transition record within Antarctic continental margin sediments of glacial advance and retreat cycles, the onset of physical weathering, and glacio-isostasy and self-gravitation processes with implications for the margin architecture, sediment routing, and off-shore sediment dispersal. Cores from the five drillholes will be re-examined through detailed core description using an updated classification scheme, so that lithofacies can be compared between drillholes. Samples will be collected for detailed laser particle size and bulk major element geochemistry via ICP-AES to determine the degree of chemical alteration of the sediments. Phases of major ice growth will be recognized as marker beds of physically eroded sediment and will be correlated to isotopic records documenting Antarctic ice growth offshore in the Southern Ocean. Broader impacts: This project will benefit a large minority undergraduate student population through the availability of up to two paid laboratory internships, a classroom exercise, and the availability of research equipment supported by this award. The project also allows support and training of a graduate student. | POLYGON((66 -68,67.3 -68,68.6 -68,69.9 -68,71.2 -68,72.5 -68,73.8 -68,75.1 -68,76.4 -68,77.7 -68,79 -68,79 -68.2,79 -68.4,79 -68.6,79 -68.8,79 -69,79 -69.2,79 -69.4,79 -69.6,79 -69.8,79 -70,77.7 -70,76.4 -70,75.1 -70,73.8 -70,72.5 -70,71.2 -70,69.9 -70,68.6 -70,67.3 -70,66 -70,66 -69.8,66 -69.6,66 -69.4,66 -69.2,66 -69,66 -68.8,66 -68.6,66 -68.4,66 -68.2,66 -68)) | POINT(72.5 -69) | false | false | ||||||||
Collaborative Research: Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins
|
1043554 |
2016-11-09 | Willenbring, Jane |
|
Intellectual Merit: The PIs propose to address the question of whether ice surface melting zones developed at high elevations during warm climatic phases in the Transantarctic Mountains. Evidence from sediment cores drilled by the ANDRILL program indicates that open water in the Ross Sea could have been a source of warmth during Pliocene and Pleistocene. The question is whether marine warmth penetrated inland to the ice sheet margins. The glacial record may be ill suited to answer this question, as cold-based glaciers may respond too slowly to register brief warmth. Questions also surround possible orbital controls on regional climate and ice sheet margins. Northern Hemisphere insolation at obliquity and precession timescales is thought to control Antarctic climate through oceanic or atmospheric connections, but new thinking suggests that the duration of Southern Hemisphere summer may be more important. The PIs propose to use high elevation alluvial deposits in the Transantarctic Mountains as a proxy for inland warmth. These relatively young fans, channels, and debris flow levees stand out as visible evidence for the presence of melt water in an otherwise ancient, frozen landscape. Based on initial analyses of an alluvial fan in the Olympus Range, these deposits are sensitive recorders of rare melt events that occur at orbital timescales. For their study they will 1) map alluvial deposits using aerial photography, satellite imagery and GPS assisted field surveys to establish water sources and to quantify parameters effecting melt water production, 2) date stratigraphic sequences within these deposits using OSL, cosmogenic nuclide, and interbedded volcanic ash chronologies, 3) use paired nuclide analyses to estimate exposure and burial times, and rates of deposition and erosion, and 4) use micro and regional scale climate modeling to estimate paleoenvironmental conditions associated with melt events. Broader impacts: This study will produce a record of inland melting from sites adjacent to ice sheet margins to help determine controls on regional climate along margins of the East Antarctic Ice Sheet to aid ice sheet and sea level modeling studies. The proposal will support several graduate and undergraduates. A PhD student will be supported on existing funding. The PIs will work with multiple K 12 schools to conduct interviews and webcasts from Antarctica and they will make follow up visits to classrooms after the field season is complete. | POINT(161.5 -77.5) | POINT(161.5 -77.5) | false | false | |||||||
Paleoenvironmental and Paleoclimatic Analysis of the Beacon Supergroup, Beardmore Glacier Area, Central Transantarctic Mountains, Antarctica
|
0944282 |
2016-06-03 | Hasiotis, Stephen |
|
Intellectual Merit: <br/>This proposal will study the diversity, abundance, and tiering patterns of ichnofossils in continental and marine deposits of the Beacon Supergroup in the Beardmore Glacier Area (BGA). The PIs will focus on continental strata that contain a variety of ichnofossils and paleosols. Ichnofossils will be evaluated for their architectural and surficial morphologies, and will be compared to modern and ancient traces to interpret the tracemaker behavior and paleoenvironmental setting. Distribution of ichnofossils within these units may indicate the effect of lateral variability of pedogenesis, the magnitude and frequency of depositional events, and the amount of moisture within the sediment, as well as the effects of climate change. The paleoclimatic significance of ichnofossils will be determined by comparing the burrow size, occurrence, tiering, and pedogenic significance of ichnofossils in measured sections of stratigraphic units deposited during global warming and cooling episodes. Comparisons will be made between BGA formations to stratigraphically equivalent rocks deposited at low paleolatitudes with previously determined paleoclimatic settings. The objectives of this project are to address two major questions: what differences existed in ichnodiversity, abundance, and tiering in marine and continental deposits between high- and low-paleolatitudes, and was there a dearth of habitat usage in continental deposits during the late Paleozoic and Mesozoic, particularly in fluvial and lacustrine environments compared to the habitat usage in the marine realm at that time? <br/><br/>Broader impacts: <br/>This study will enhance the ability to interpret paleoenvironments to the subenvironmental scale, understand the evolution of soil biota and ecosystems at high paleolatitudes, determine the role of organisms in soil formation at high paleolatitudes, explore the effects of climate change on the body size and diversity of organisms in the soil communities, and develop new tools to interpret paleoclimate in high latitudes. There is a strong education component associated with this proposal. | POINT(175 -86) | POINT(175 -86) | false | false | |||||||
Collaborative Research: A "Horizontal Ice Core" for Large-Volume Samples of the Past Atmosphere, Taylor Glacier, Antarctica
|
0839031 0838936 |
2016-03-29 | Brook, Edward J.; Severinghaus, Jeffrey P. | Severinghaus/0839031 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a project to develop a precise gas-based chronology for an archive of large-volume samples of the ancient atmosphere, which would enable ultra-trace gas measurements that are currently precluded by sample size limitations of ice cores. The intellectual merit of the proposed work is that it will provide a critical test of the "clathrate hypothesis" that methane clathrates contributed to the two abrupt atmospheric methane concentration increases during the last deglaciation 15 and 11 kyr ago. This approach employs large volumes of ice (>1 ton) to measure carbon-14 on past atmospheric methane across the abrupt events. Carbon-14 is an ideal discriminator of fossil sources of methane to the atmosphere, because most methane sources (e.g., wetlands, termites, biomass burning) are rich in carbon-14, whereas clathrates and other fossil sources are devoid of carbon-14. The proposed work is a logical extension to Taylor Glacier, Antarctica, of an approach pioneered at the margin of the Greenland ice sheet over the past 7 years. The Greenland work found higher-than-expected carbon-14 values, likely due in part to contaminants stemming from the high impurity content of Greenland ice and the interaction of the ice with sediments from the glacier bed. The data also pointed to the possibility of a previously unknown process, in-situ cosmogenic production of carbon-14 methane (radiomethane) in the ice matrix. Antarctic ice in Taylor Glacier is orders of magnitude cleaner than the ice at the Greenland site, and is much colder and less stratigraphically disturbed, offering the potential for a clear resolution of this puzzle and a definitive test of the cosmogenic radiomethane hypothesis. Even if cosmogenic radiomethane in ice is found, it still may be possible to reconstruct atmospheric radiomethane with a correction enabled by a detailed understanding of the process, which will be sought by co-measuring carbon-14 in carbon monoxide and carbon dioxide. The broader impacts of the proposed work are that the clathrate test may shed light on the stability of the clathrate reservoir and its potential for climate feedbacks under human-induced warming. Development of Taylor Glacier as a "horizontal ice core" would provide a community resource for other researchers. Education of one postdoc, one graduate student, and one undergraduate, would add to human resources. This award has field work in Antarctica. | POINT(161.75 -77.75) | POINT(161.75 -77.75) | false | false | ||||||||
Collaborative Research: Completing an ultra-high resolution methane record from the WAIS Divide ice core
|
1043518 |
2016-01-12 | Rhodes, Rachel; Brook, Edward J.; McConnell, Joseph | 1043500/Sowers This award supports a project to develop a 50 yr resolution methane data set that will play a pivotal role in developing the WAIS Divide timescale as well as providing a common stratigraphic framework for comparing climate records from Greenland and West Antarctica. Even higher resolution data are proposed for key intervals to assist in precisely defining the phasing of abrupt climate change between the hemispheres. Concurrent analysis of a suit of samples from both the WAIS Divide and GISP-2 cores throughout the last 110,000 years is also proposed, to establish the interpolar methan (CH4) gradient that will be used to identify geographic areas responsible for the climate related methane emission changes. The intellectual merit of the proposed work is that it will provide chronological control needed to examine the timing of changes in climate proxies, and critical chronological ties to the Greenland ice core records via methane variations. One main objective is to understand the interpolar timing of millennial-scale climate change. This is an important scientific goal relevant to understanding climate change mechanisms in general. The proposed work will help establish a chronological framework for addressing these issues. In addition, this proposal addresses the question of what methane sources were active during the ice age, through the work on the interpolar methane gradient. This work is directed at the fundamental question of what part of the biosphere controlled past methane variations, and is important for developing more sophisticated understanding of those variations. The broader impacts of the work are that the ultra-high resolution CH4 record will directly benefit all ice core paleoclimate research and the chronological refinements will impact paleoclimate studies that rely on ice core timescales for correlation purposes. The project will support both graduate and undergraduate students and the PIs will participate in outreach to the public. | POINT(-112.08648 -79.46763) | POINT(-112.08648 -79.46763) | false | false | ||||||||
Preparation of Vertebrate Fossils from the Triassic of Antarctica
|
1146399 |
2015-10-27 | Sidor, Christian |
|
Intellectual Merit: The PI requests support for preparation of a large collection of vertebrate fossils recently recovered from the Central Transantarctic Mountains (CTAM) of Antarctica. These fossils will be used to place early Mesozoic Antarctic dinosaurs and other vertebrates into a global evolutionary, biogeographic, and faunal context; assess the degree of endemism in Triassic vertebrate faunas of Antarctica; constrain temporal relationships of the Triassic Antarctic vertebrate faunas; and refine the stratigraphic context for the Triassic Antarctic vertebrate assemblages to establish a paleoenvironmental framework. The lower and middle Triassic fossils offer a rare window on life in terrestrial environments at high-latitudes immediately after the Permian mass extinction. Broader impacts: The PI will use their fossils to educate the public about the geologic, climatic, and biologic history of Antarctica by visiting local schools. They will create and publish at least two new videos to the Burke Museum blog that relate the graduate student?s experience of fieldwork in Antarctica. They will also update the Antarctica section on the UWBM "Explore Your World" website with images and findings from their field season. | POLYGON((162.41 -84.27,163.409 -84.27,164.408 -84.27,165.407 -84.27,166.406 -84.27,167.405 -84.27,168.404 -84.27,169.403 -84.27,170.402 -84.27,171.401 -84.27,172.4 -84.27,172.4 -84.353,172.4 -84.436,172.4 -84.519,172.4 -84.602,172.4 -84.685,172.4 -84.768,172.4 -84.851,172.4 -84.934,172.4 -85.017,172.4 -85.1,171.401 -85.1,170.402 -85.1,169.403 -85.1,168.404 -85.1,167.405 -85.1,166.406 -85.1,165.407 -85.1,164.408 -85.1,163.409 -85.1,162.41 -85.1,162.41 -85.017,162.41 -84.934,162.41 -84.851,162.41 -84.768,162.41 -84.685,162.41 -84.602,162.41 -84.519,162.41 -84.436,162.41 -84.353,162.41 -84.27)) | POINT(167.405 -84.685) | false | false | |||||||
Fugitive Gases (Helium, Neon, and Oxygen) in the WAIS Divide Ice Core as Tracers of Basal Processes and Past Biospheric Carbon Storage
|
1143619 |
2015-07-13 | Severinghaus, Jeffrey P. | No dataset link provided | 1143619/Severinghaus This award supports a project to extend the study of gases in ice cores to those gases whose small molecular diameters cause them to escape rapidly from ice samples (the so-called "fugitive gases"). The work will employ helium, neon, argon, and oxygen measurements in the WAIS Divide ice core to better understand the mechanism of the gas close-off fractionation that occurs while air bubbles are incorporated into ice. The intellectual merit of the proposed work is that corrections for this fractionation using neon (which is constant in the atmosphere) may ultimately enable the first ice core-based atmospheric oxygen and helium records. Neon may also illuminate the mechanistic link between local insolation and oxygen used for astronomical dating of ice cores. Helium measure-ments in the deepest ~100 m of the core will also shed light on the stratigraphic integrity of the basal ice, and serve as a probe of solid earth-ice interaction at the base of the West Antarctic ice sheet. Past atmospheric oxygen records, currently unavailable prior to 1989 CE, would reveal changes in the size of the terrestrial biosphere carbon pool that accompany climate variations and place constraints on the biogeochemical feedback response to future warming. An atmospheric helium-3/helium-4 record would test the hypothesis that the solar wind (which is highly enriched in helium-3) condensed directly into Earth?s atmosphere during the collapse of the geomagnetic field that occurred 41,000 years ago, known as the Laschamp Event. Fugitive-gas samples will be taken on-site immediately after recovery of the ice core by the PI and one postdoctoral scholar, under the umbrella of an existing project to support replicate coring and borehole deepening. This work will add value to the scientific return from field work activity with little additional cost to logistical resources. The broader impacts of the work on atmospheric oxygen are that it may increase understanding of how terrestrial carbon pools and atmospheric greenhouse gas sources will respond in a feedback sense to the coming warming. Long-term atmospheric oxygen trends are also of interest for understanding biogeochemical regulatory mechanisms and the impact of atmospheric evolution on life. Helium records have value in understanding the budget of this non-renewable gas and its implications for space weather and solar activity. The project will train one graduate student and one postdoctoral scholar. The fascination of linking solid earth, cryosphere, atmosphere, and space weather will help to entrain and excite young scientists and efforts to understand the Earth as a whole interlinked system will provide fuel to outreach efforts at all ages. | POINT(-112.09 -79.47) | POINT(-112.09 -79.47) | false | false | |||||||
Magnetostratigraphy of Cretaceous Sediments in the James Ross Island Basin, Antarctica
|
1303896 |
2015-05-23 | Kirschvink, Joseph |
|
Intellectual Merit: The PI will collect samples to extend the magneto-stratigraphic record of late Cretaceous sediments of the James Ross Basin, Antarctica. RAPID support will allow him to take advantage of an invitation from the Instituto Antartico Argentino (IAA) to participate on an excursion to James Ross Island in the Antarctic Peninsula. The PI hopes to collect samples that will refine the position of several geomagnetic reversals between the end of the Cretaceous long normal Chron and the lower portion of Chron 31R. The Brandy Bay locality targeted by this expedition is the best place in the basin for calibrating the biostratigraphic position of the top of the Cretaceous Long Normal Chron, which is one of the most reliable correlation horizons in the entire Geological Time Scale. Broader impacts: The top of the Cretaceous long normal Chron is not properly correlated to southern hemisphere biostratigraphy. Locating this event will be a major addition to understanding geological time. This expedition will provide opportunities for an undergraduate student. This project is based on a productive collaboration with an Argentine scientist. | POLYGON((-57 -63,-56.9 -63,-56.8 -63,-56.7 -63,-56.6 -63,-56.5 -63,-56.4 -63,-56.3 -63,-56.2 -63,-56.1 -63,-56 -63,-56 -63.2,-56 -63.4,-56 -63.6,-56 -63.8,-56 -64,-56 -64.2,-56 -64.4,-56 -64.6,-56 -64.8,-56 -65,-56.1 -65,-56.2 -65,-56.3 -65,-56.4 -65,-56.5 -65,-56.6 -65,-56.7 -65,-56.8 -65,-56.9 -65,-57 -65,-57 -64.8,-57 -64.6,-57 -64.4,-57 -64.2,-57 -64,-57 -63.8,-57 -63.6,-57 -63.4,-57 -63.2,-57 -63)) | POINT(-56.5 -64) | false | false | |||||||
Collaborative Research: EAGER: Evaluating the Larsen basin's suitability for testing the Cretaceous Glaciation Hypothesis
|
1241460 1241574 |
2014-12-03 | Barbeau, David; Hemming, Sidney R.; Barbeau, David Jr | No dataset link provided | Intellectual Merit: Recent geochemical, sequence stratigraphic, and integrated investigations of marine strata from several continental margins and ocean basins suggest that ephemeral ice sheets may have existed on Antarctica during parts of the Cretaceous and early Paleogene. However, atmospheric carbon dioxide estimates for this time are as much as four times modern levels. With such greenhouse conditions, the presence of Antarctic ice sheets would imply that our current understanding of Earth?s climate system, and specifically the interpreted thresholds of Antarctic glaciation and deglaciation should be reconsidered. The proposed research will compare the quantity and provenance of Cretaceous sediments in the Larsen basin of the eastern Antarctic Peninsula with the exhumation chronology and composition of potential sediment source terranes on the peninsula and in adjacent regions. New outcrop stratigraphic analyses with improvements in the age models from radioisotopic approaches will be integrated to determine the amount of detrital sediment fluxed to the Larsen basin between key chronostratigraphic surfaces. Microtextural analysis of quartz sand and silt grains will help determine whether the Larsen basin detrital sediment originated from glacial weathering. These preliminary results will test the viability of the proposed approach to assess the controversial Cretaceous Antarctic glaciation hypothesis. Broader impacts: The proposed work will partially support a PhD, a MSc, and three undergraduate students at the University of South Carolina. The PIs will publicize this work through volunteer speaking engagements and the development of videos and podcasts. They also commit to prompt publication of the results and timely submission of data to archives. The development/improvement of the Larsen basin age model will benefit ongoing research in paleobiology, paleoclimate and biogeography. Development of the glauconite K-Ar and Rb-Sr chronometers could be an important outcome beyond the direct scope of the proposed research. | POLYGON((-67 -63.2,-65.97 -63.2,-64.94 -63.2,-63.91 -63.2,-62.88 -63.2,-61.85 -63.2,-60.82 -63.2,-59.79 -63.2,-58.76 -63.2,-57.73 -63.2,-56.7 -63.2,-56.7 -63.54,-56.7 -63.88,-56.7 -64.22,-56.7 -64.56,-56.7 -64.9,-56.7 -65.24,-56.7 -65.58,-56.7 -65.92,-56.7 -66.26,-56.7 -66.6,-57.73 -66.6,-58.76 -66.6,-59.79 -66.6,-60.82 -66.6,-61.85 -66.6,-62.88 -66.6,-63.91 -66.6,-64.94 -66.6,-65.97 -66.6,-67 -66.6,-67 -66.26,-67 -65.92,-67 -65.58,-67 -65.24,-67 -64.9,-67 -64.56,-67 -64.22,-67 -63.88,-67 -63.54,-67 -63.2)) | POINT(-61.85 -64.9) | false | false | |||||||
Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter
|
1039365 |
2013-01-30 | Rimmer, Susan |
|
This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. The broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming. | None | None | false | false | |||||||
IPY Research: Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP)
|
0733025 |
2012-09-04 | Siegert, Martin; Roberts, Jason; Van Ommen, Tas; Warner, Roland; Richter, Thomas; Greenbaum, Jamin; Holt, John W.; Young, Duncan A.; Blankenship, Donald D. | 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. <br/><br/>The 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. | 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)) | POINT(137.5 -73.5) | false | false | ||||||||
Collaborative Research: Constructing an Ultra-high Resolution Atmospheric Methane Record for the Last 140,000 Years from WAIS Divide Core.
|
0538578 0538538 |
2012-04-19 | Lee, James; Buizert, Christo; Brook, Edward J.; Mitchell, Logan E; Sowers, Todd A. | Sowers/Brook<br/>0538538<br/>This award supports a project to develop a high-resolution (every 50 yr) methane data set that will play a pivotal role in developing the timescale for the new deep ice core being drilled at the West Antarctic Ice Sheet Divide (WAIS Divde) site as well as providing a common stratigraphic framework for comparing climate records from Greenland and WAIS Divide. Certain key intervals will be measured at even higher resolution to assist in precisely defining the phasing of abrupt climate change between the northern and southern hemispheres. Concurrent analysis of a suit of samples from both the WAIS Divide and GISP2 ice cores throughout the last 110kyr is also proposed, to establish the inter-hemispheric methane gradient which will be used to identify geographic areas responsible for the climate-related methane emission changes. A large gas measurement inter-calibration of numerous laboratories, utilizing both compressed air cylinders and WAIS Divide ice core samples, will also be performed. The intellectual merit of the proposed work is that it will provide the chronological control needed to examine the timing of changes in climate proxies, and critical chronological ties to the Greenland ice core records via methane variations. In addition, the project addresses the question of what methane sources were active during the ice age and will help to answer the fundamental question of what part of the biosphere controlled past methane variations. The broader impact of the proposed work is that it will directly benefit all ice core paleoclimate research and will impact the paleoclimate studies that rely on ice core timescales for correlation purposes. The project will also support a Ph.D. student at Oregon State University who will have the opportunity to be involved in a major new ice coring effort with international elements. Undergraduates at Penn State will gain valuable laboratory experience and participate fully in the project. The proposed work will underpin the WAIS Divide chronology, which will be fundamental to all graduate student projects that involve the core. The international inter-calibration effort will strengthen ties between research institutions on four continents and will be conducted as part of the International Polar Year research agenda. | None | None | false | false | ||||||||
Center for Remote Sensing of Ice Sheets (CReSIS)
|
0424589 |
2011-06-01 | Braaten, David; Joughin, Ian; Steig, Eric J.; Das, Sarah; Paden, John; Gogineni, Prasad | This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbræ. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.<br/><br/>The intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. <br/><br/>As lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets. | POLYGON((-137 -74,-132.1 -74,-127.2 -74,-122.3 -74,-117.4 -74,-112.5 -74,-107.6 -74,-102.7 -74,-97.8 -74,-92.9 -74,-88 -74,-88 -74.65,-88 -75.3,-88 -75.95,-88 -76.6,-88 -77.25,-88 -77.9,-88 -78.55,-88 -79.2,-88 -79.85,-88 -80.5,-92.9 -80.5,-97.8 -80.5,-102.7 -80.5,-107.6 -80.5,-112.5 -80.5,-117.4 -80.5,-122.3 -80.5,-127.2 -80.5,-132.1 -80.5,-137 -80.5,-137 -79.85,-137 -79.2,-137 -78.55,-137 -77.9,-137 -77.25,-137 -76.6,-137 -75.95,-137 -75.3,-137 -74.65,-137 -74)) | POINT(-112.5 -77.25) | false | false | ||||||||
LGM Late Pleistocene to Holocene Glacial History of West Antarctica
|
9909734 |
2011-03-03 | Anderson, John; Anderson, Jason |
|
9909734 Anderson This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research on the glaciomarine geology of the continental shelves of West Antarctica and the Antarctic Peninsula. It is hypothesized that the different glacial systems of the Antarctic Peninsula region have been more responsive to climate change and sea-level rise than either the West Antarctic or East Antarctic ice sheets. This is due mainly to the smaller size of these ice masses and the higher latitude location of the peninsula. Indeed, ice shelves of the Antarctic Peninsula are currently retreating at rates of up to a kilometer per year. But are these changes due to recent atmospheric warming in the region or are they simply the final phase of retreat since the last glacial maximum? This project hypothesizes that the deglacial history of the Antarctic Peninsula region has been quite complex, with different glacial systems retreating at different rates and at different times. This complex recessional history reflects the different sizes as well as different climatic and physiographic settings of glacial systems in the region. An understanding of the Late Pleistocene to Holocene glacial history of the Antarctic Peninsula glacial systems is needed to address how these systems responded to sea-level and climate change during that time interval. This investigation acquire new marine geological and geophysical data from the continental shelf to determine if and when different glacial systems were grounded on the shelf, to establish the extent of grounded ice, and to examine the history of glacial retreat. The project will build on an extensive seismic data set and hundreds of sediment cores collected along the Peninsula during earlier (1980's) cruises. Key to this investigation is the acquisition of swath bathymetry, side-scan sonar and very high-resolution sub-bottom (chirp) profiles from key drainage outlets. These new data will provide the necessary geomorphologic and stratigraphic framework for reconstructing the Antarctic Peninsula glacial record. Anticipated results will help constrain models for future glacier and ice sheet activity. | POLYGON((-73.80311 -52.35021,-71.817373 -52.35021,-69.831636 -52.35021,-67.845899 -52.35021,-65.860162 -52.35021,-63.874425 -52.35021,-61.888688 -52.35021,-59.902951 -52.35021,-57.917214 -52.35021,-55.931477 -52.35021,-53.94574 -52.35021,-53.94574 -53.954842,-53.94574 -55.559474,-53.94574 -57.164106,-53.94574 -58.768738,-53.94574 -60.37337,-53.94574 -61.978002,-53.94574 -63.582634,-53.94574 -65.187266,-53.94574 -66.791898,-53.94574 -68.39653,-55.931477 -68.39653,-57.917214 -68.39653,-59.902951 -68.39653,-61.888688 -68.39653,-63.874425 -68.39653,-65.860162 -68.39653,-67.845899 -68.39653,-69.831636 -68.39653,-71.817373 -68.39653,-73.80311 -68.39653,-73.80311 -66.791898,-73.80311 -65.187266,-73.80311 -63.582634,-73.80311 -61.978002,-73.80311 -60.37337,-73.80311 -58.768738,-73.80311 -57.164106,-73.80311 -55.559474,-73.80311 -53.954842,-73.80311 -52.35021)) | POINT(-63.874425 -60.37337) | false | false | |||||||
New Paleomagnetic and Environmental Magnetic Studies of Old Cores from the Ross Sea Sector, Antarctica
|
0636974 |
2010-10-01 | Verosub, Kenneth | No dataset link provided | Abstract<br/><br/><br/><br/>This project performs a paleomagnetic survey of sediment cores from Antarctica's continental margin. Its goal is to refine the magnetostratigraphy to improve regional stratigraphic correlations, help date cores that lack biostratigraphic indicators, and understand paleoenvironmental conditions and climate change. As well, these cores record the earth's magnetic field near the magnetic pole, which may offer important information to scientists modeling the geodynamo.<br/><br/>The broader impacts of this work include postdoctoral and undergraduate education. There are also implications for society's understanding of global climate change, since these techniques offer a different perspective on climate change from Antarctic marine sediment cores, which are critical to understanding the behavior of the ice sheets and their links to the global climate. | None | None | false | false | |||||||
Nitrogen and Oxygen Gas Isotopes in the WAIS Divide Ice Core as Constraints on Chronology, Temperature, and Accumulation Rate
|
0538657 |
2010-07-08 | Haines, Skylar; Mayewski, Paul A.; Orsi, Anais J.; Kurbatov, Andrei V.; Severinghaus, Jeffrey P. | 0538657<br/>Severinghaus<br/>This award supports a project to develop high-resolution (20-yr) nitrogen and oxygen isotope records on trapped gases in the WAIS Divide ice core (Antarctica), with a comparison record for chronological purposes in the GISP2 (Greenland) ice core. The main scientific objective is to provide an independent temperature-change record for the past 100,000 years in West Antarctica that is not subject to the uncertainty inherent in ice isotopes (18O and deuterium), the classical paleothermometer. Nitrogen isotopes (Delta 15N) in air bubbles in glacial ice record rapid surface temperature change because of thermal fractionation of air in the porous firn layer, and this isotopic anomaly is recorded in bubbles as the firn becomes ice. Using this gas-based temperature-change record, in combination with methane data as interpolar stratigraphic markers, the proposed work will define the precise relative timing of abrupt warming in Greenland and abrupt cooling at the WAIS Divide site during the millennial-scale climatic oscillations of Marine Isotopic Stage 3 (30-70 kyr BP) and the last glacial termination. The nitrogen isotope record also provides constraints on past firn thickness, which inform temperature and accumulation rate histories from the ice core. A search for possible solar-related cycles will be conducted with the WAIS Divide Holocene (Delta 15N.) Oxygen isotopes of O2 (Delta 18Oatm) are obtained as a byproduct of the (Delta 15N) measurement. The gas-isotopic records will enhance the value of other atmospheric gas measurements in WAIS Divide, which are expected to be of unprecedented quality. The high-resolution (Delta 18Oatm) records will provide chronological control for use by the international ice coring community and for surface glacier ice dating. Education of a graduate student, and training of a staff member in the laboratory, will contribute to the nation's human resource base. Outreach activities in the context of the International Polar Year will be enhanced. International collaboration is planned with the laboratory of LSCE, University of Paris. | None | None | false | false | ||||||||
The Physical Properties of the US ITASE Firn and Ice Cores from South Pole to Taylor Dome
|
0538494 |
2010-06-03 | Meese, Deb; MEESE, DEBRA |
|
0538494<br/>Meese<br/>This award supports a project for physical properties research on snow pits and firn/ice cores with specific objectives that include stratigraphic analysis including determination of accumulation rates, annual layers, depth hoar, ice and wind crusts and rates of grain growth with depth. Studies of firn densification rates and how these parameters relate to the meteorology and climatology over the last 200 years of snow accumulation in Antarctica will also be investigated. The project will also determine the seasonality of accumulation by co-registration of stratigraphy and chemistry and determination of chemical species at the grain boundaries, how these may change with depth/densification (and therefore temperature), precipitation, and may affect grain growth. Fabric analyses will be made, including variation with depth, location on undulations and if any variation exists with climate/chemistry. The large spatial coverage of the US ITASE program offers the opportunity to determine how these parameters are affected by a large range of temperature, precipitation and topographic effects. The intellectual merit of the project includes the fact that ITASE is the terrestrial equivalent of a polar research vessel that provides a unique, logistically efficient, multi-dimensional (x, y, z and time) view of the atmosphere, ice sheet and their histories. Physical properties measurements/ analyses are an integral part of understanding the dynamic processes to which the accumulated snow is subjected. Recent advancements in the field along with multiple core sites provide an excellent opportunity to gain a much broader understanding of the spatial, temporal and physical variables that impact firnification and the possible resultant impact on climatic interpretation. In terms of broader impacts, the data collected by US ITASE and its international ITASE partners is available to a broad scientific community. US ITASE has an extensive program of public outreach and provides significant opportunities for many students to experience multidisciplinary Antarctic research. A graduate student, a post-doctoral fellow and at least one undergraduate would be funded by this work. Dr. Meese is also a member of the New England Science Collaborative, an organization that educates the public on climate change based on recent scientific advancements. | None | None | false | false | |||||||
PECASE: Relative frequency and phase of extreme expansions of the Antarctic Ice Sheets during the late Neogene
|
0094078 |
2010-05-04 | Bart, Philip |
|
PROPOSAL NO.: 0094078<br/>PRINCIPAL INVESTIGATOR: Bart, Philip<br/>INSTITUTION NAME: Louisiana State University & Agricultural and Mechanical College<br/>TITLE: CAREER: Relative frequency and phase of extreme expansions of the Antarctic Ice Sheets during the late Neogene<br/>NSF RECEIVED DATE: 07/27/2000<br/><br/>PROJECT SUMMARY<br/><br/>Expansions and contractions of the Antarctic Ice Sheets (AISs) have undoubtedly had a profound influence on Earth's climate and global sea-level. However, rather than being a single entity, the Antarctic cryosphere consists of three primary elements: 1) the East Antarctic Ice Sheet (EAIS); 2) the West Antarctic Ice Sheet (WAIS); and 3) the Antarctic Peninsula Ice Cap (APIC). The distinguishing characteristics include significant differences in: 1) ice volume; 2) substratum elevation; 3) ice-surface elevation; and 4) location with respect to latitude. Various lines of evidence indicate that the AISs have undergone significant fluctuations in the past and that fluctuations will continue to occur in the future. The exact nature of the fluctuations has been the subject of many lively debates. According to one line of reasoning, the land-based EAIS has been relatively stable, experiencing only minor fluctuations since forming in the middle Miocene, whereas the marine-based WAIS has been dynamic, waxing and waning frequently since the late Miocene. According to an alternate hypothesis, the ice sheets advanced and retreated synchronously. These two views are incompatible. <br/><br/>The first objective of this proposal is to compare the long-term past behavior of the WAIS to that of the EAIS and APIC. The fluctuations of the AISs involve many aspects (the frequency of changes, the overall magnitude of ice-volume change, etc.), and the activities proposed here specifically concern the frequency and phase of extreme advances of the ice sheet to the continental shelf. The project will build upon previous seismic-stratigraphic investigations of the continental shelves. These studies have clarified many issues concerning the minimum frequency of extreme expansions for the individual ice sheets, but some important questions remain. During the course of the project, the following questions will be evaluated.<br/><br/>Question 1) Were extreme advances of the EAIS and WAIS across the shelf of a similar frequency and coeval? This evaluation is possible because the western Ross Sea continental shelf (Northern Basin) receives drainage from the EAIS, and the eastern Ross Sea (Eastern Basin) receives drainage from the WAIS. Quantitative analyses of the extreme advances from these two areas have been conducted by Alonso et al. (1992) and Bart et al. (2000), respectively. However, the existing single-channel seismic grids are incomplete and can not be used to determine the stratigraphic correlations from Northern Basin to Eastern Basin. It is proposed that high-resolution seismic data (~2000 kms) be acquired to address this issue.<br/><br/>Question 2) Were extreme advances of the APIC across the shelf as frequent as inferred by Bart and Anderson (1995)? Bart and Anderson (1995) inferred that the APIC advanced across the continental shelf at least 30 times since the middle Miocene. This is significant because it suggests that the advances of the small APIC were an order of magnitude more frequent than the advances of the EAIS and WAIS. Others contest the Bart and Anderson (1995) glacial-unconformity interpretation of seismic reflections, and argue that the advances of the APIC were far fewer (i.e., Larter et al., 1997). The recent drilling on the Antarctic Peninsula outer continental shelf has sampled some but not all of the glacial units, but the sediment recovery was poor, and thus, the glacial history interpretation is still ambiguous. The existing high-resolution seismic grids from the Antarctic Peninsula contain only one regional strike line on the outer continental shelf. This is inadequate to address the controversy of the glacial-unconformity interpretation and the regional correlation of the recent ODP results. It is proposed that high-resolution seismic data (~1000 kms) be acquired in a forthcoming (January 2002) cruise to the Antarctic Peninsula to address these issues.<br/><br/>The second objective of this project is 1) to expand the PI's effort to integrate his ongoing and the proposed experiments into a graduate-level course at LSU, and 2) to develop a pilot outreach program with a Baton Rouge public high school. The Louisiana Department of Education has adopted scientific standards that apply to all sciences. These standards reflect what 9th through 12th grade-level students should be able to do and know. The PI will target one of these standards, the Science As Inquiry Standard 1 Benchmark. The PI will endeavor to share with the students the excitement of conducting scientific research as a way to encourage the students to pursue earth science as a field of study at the university level. | POLYGON((-179.99992 -72.00044,-143.999984 -72.00044,-108.000048 -72.00044,-72.000112 -72.00044,-36.000176 -72.00044,-0.000239999999991 -72.00044,35.999696 -72.00044,71.999632 -72.00044,107.999568 -72.00044,143.999504 -72.00044,179.99944 -72.00044,179.99944 -72.574101,179.99944 -73.147762,179.99944 -73.721423,179.99944 -74.295084,179.99944 -74.868745,179.99944 -75.442406,179.99944 -76.016067,179.99944 -76.589728,179.99944 -77.163389,179.99944 -77.73705,143.999504 -77.73705,107.999568 -77.73705,71.999632 -77.73705,35.999696 -77.73705,-0.000240000000019 -77.73705,-36.000176 -77.73705,-72.000112 -77.73705,-108.000048 -77.73705,-143.999984 -77.73705,-179.99992 -77.73705,-179.99992 -77.163389,-179.99992 -76.589728,-179.99992 -76.016067,-179.99992 -75.442406,-179.99992 -74.868745,-179.99992 -74.295084,-179.99992 -73.721423,-179.99992 -73.147762,-179.99992 -72.574101,-179.99992 -72.00044)) | POINT(0 -89.999) | false | false | |||||||
Collaborative Research: Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores
|
0739583 0739512 0739496 |
2009-07-15 | Walker, Sally; Bowser, Samuel; Miller, Molly; Furbish, David | This project answers a simple question: why are there so few fossils in sediment cores from Antarctica?s continental shelf? Antarctica?s benthos are as biologically rich as those of the tropics. Shell-secreting organisms should have left a trail throughout geologic time, but have not. This trail is particularly important because these organisms record regional climate in ways that are critical to interpreting the global climate record. This study uses field experiments and targeted observations of modern benthic systems to examine the biases inflicted by fossil preservation. By examining a spectrum of ice-affected habitats, this project provides paleoenvironmental insights into carbonate preservation, sedimentation rates, and burial processes; and will provide new approaches to reconstructing the Cenozoic history of Antarctica. Broader impacts include graduate and undergraduate research and education, development of undergraduate curricula to link art and science, K12 outreach, public outreach via the web, and societal relevance through improved understanding of records of global climate change. | POLYGON((163.41667 -77.33333,163.46667 -77.33333,163.51667 -77.33333,163.56667 -77.33333,163.61667 -77.33333,163.66667 -77.33333,163.71667 -77.33333,163.76667 -77.33333,163.81667 -77.33333,163.86667 -77.33333,163.91667 -77.33333,163.91667 -77.369997,163.91667 -77.406664,163.91667 -77.443331,163.91667 -77.479998,163.91667 -77.516665,163.91667 -77.553332,163.91667 -77.589999,163.91667 -77.626666,163.91667 -77.663333,163.91667 -77.7,163.86667 -77.7,163.81667 -77.7,163.76667 -77.7,163.71667 -77.7,163.66667 -77.7,163.61667 -77.7,163.56667 -77.7,163.51667 -77.7,163.46667 -77.7,163.41667 -77.7,163.41667 -77.663333,163.41667 -77.626666,163.41667 -77.589999,163.41667 -77.553332,163.41667 -77.516665,163.41667 -77.479998,163.41667 -77.443331,163.41667 -77.406664,163.41667 -77.369997,163.41667 -77.33333)) | POINT(163.66667 -77.516665) | false | false | ||||||||
SGER: Feasibility of Using Old Antarctic Cores for New Paleomagnetic Studies
|
0617194 |
2007-12-03 | Verosub, Kenneth | No dataset link provided | This Small Grant for Exploratory Research supports a paleomagnetic survey of previously collected sediment cores from Antarcticas continental margin. Many of these cores were originally interpreted with methods that, though advanced for their time, were barely adequate. Nonetheless, these results are still used to construct an overall stratigraphic record for marine sediments and major events related to the Southern Ocean, global climate, and Antarcticas glacial history. With the advances in paleomagnetic techniques over the intervening decades and the great interest and current work on Antarctic marine sediments by major projects such as ANDRILL and ShalDrill, a reassessment of these cores is needed. In addition, these new studies will offer insight into the behavior of the geomagnetic field within the Earths tangent cylinder, the region delineated by an imaginary cylinder parallel to the Earths rotation axis and tangent to the equator of the inner core boundary.<br/><br/>The broader impacts of this work include support of postdoctoral student research and improving societys understanding of global climate change through an improved understanding of the Antarctic marine sediment record. | None | None | false | false | |||||||
Stability of Landscapes and Ice Sheets in Dry Valleys, Antarctica: A Systematic Study of Exposure Ages of Soils and Surface Deposits
|
0338224 |
2007-11-20 | Putkonen, Jaakko |
|
This work will study cosmogenic isotope profiles of rock and sediment in the Dry Valleys of Antarctica to understand their origin. The results will provide important constraints on the history of the East Antarctic Ice Sheet. The near-perfect preservation of volcanic ash and overlying sediments suggests that hyperarid cold conditions have prevailed in the Dry Valleys for over 10 Myr. The survival of these sediments also suggests that warm-based ice has not entered the valley system and ice sheet expansion has been minimal. Other evidence, however, suggests that the Dry Valleys have experienced considerably more sediment erosion than generally believed: 1) the cosmogenic exposure ages of boulders and bedrock in the Valleys all show generally younger ages than volcanic ash deposits used to determine minimum ages of moraines and drifts, 2) there appears to be a discrepancy between the suggested extreme preservation of unconsolidated slope deposits (>10 Myr) and adjacent bedrock that has eroded 2.6-6 m during the same time interval. The fact that the till and moraine exposure ages generally post date the overlying volcanic ash deposits could reflect expansion of continental ice sheet into the Dry Valleys with cold-based ice, thus both preserving the landscape and shielding the surfaces from cosmic radiation. Another plausible explanation of the young cosmogenic exposure ages is erosion of the sediments and gradual exhumation of formerly buried boulders to the surface. Cosmogenic isotope systematics are especially well suited to address these questions. We will measure multiple cosmogenic isotopes in profiles of rock and sediment to determine the minimum exposure ages, the degree of soil stability or mixing, and the shielding history of surfaces by cold based ice. We expect to obtain unambiguous minimum ages for deposits. In addition, we should be able to identify areas disturbed by periglacial activity, constrain the timing of such activity, and account for the patchy preservation of important stratigraphic markers such as volcanic ash. The broader impacts of this project include graduate and undergraduate education, and improving our understanding of the dynamics of Southern Hemisphere climate on timescales of millions of years, which has major implications for understanding the controls and impacts of global climate change. | POLYGON((161 -77,161.3 -77,161.6 -77,161.9 -77,162.2 -77,162.5 -77,162.8 -77,163.1 -77,163.4 -77,163.7 -77,164 -77,164 -77.1,164 -77.2,164 -77.3,164 -77.4,164 -77.5,164 -77.6,164 -77.7,164 -77.8,164 -77.9,164 -78,163.7 -78,163.4 -78,163.1 -78,162.8 -78,162.5 -78,162.2 -78,161.9 -78,161.6 -78,161.3 -78,161 -78,161 -77.9,161 -77.8,161 -77.7,161 -77.6,161 -77.5,161 -77.4,161 -77.3,161 -77.2,161 -77.1,161 -77)) | POINT(162.5 -77.5) | false | false | |||||||
DiatomWare: An Interactive Digital Image Catalog for Antarctic Cenozoic Diatoms
|
0230469 |
2007-07-31 | Wise, Sherwood | No dataset link provided | This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports the development of a standardized diatom image catalog or database. Diatoms are considered by many to be the most important microfossil group used today in the study of Antarctic Cenozoic marine deposits south of the Polar Front, from the near shore to deep sea. These microfossils, with walls of silica called frustules, are produced by single-celled plants (algae of the Class Bacillariophyceae) in a great variety of forms. Consequently, they have great biostratigraphic importance in the Southern Ocean and elsewhere for determining the age of marine sediments. Also, paleoclimatic and paleoceanographic studies increasingly rely on fossil diatom data. Changing biogeographic distributions of given taxa indicate shifting paleoecological conditions and provide evidence of the surface productivity and temperatures of ancient oceans. The generality of conclusions, though, is limited by variation in species concepts among workers. The broad research community relies, directly or indirectly, on the accurate identification of diatom species. Current technology can be used to greatly improve upon the standard references that have been used in making these identifications.<br/><br/>This project will develop an interactive digital-image catalog of modern and Cenozoic fossil diatoms of the Southern Ocean called "DiatomWare" for use by specialists and educators as an aid in rapid, accurate, and consistent species identification. As such, this will be a researcher's resource. It will be especially useful where it is not possible to maintain standard library resources such as onboard research vessels or at remote stations such as McMurdo Station. Major Antarctic geological drilling initiatives such as the new SHALDRIL project and the pending ANDRILL project will benefit from this product because they will rely heavily on diatom biostratigraphy to achieve their research objectives. The DiatomWare image database will be modeled on NannoWare, which was released in October 2002 on CD-ROM as a publication of the International Nannoplankton Association. BugCam will be adapted and modified as necessary to run the DiatomWare database, which can then be run from desktop or laptop computers. Images and text for the database will be scanned from the literature or captured in digital form from light or scanning electron microscopes.<br/><br/>The software interface will include a number of data fields that can be accessed by the click of a mouse button. Primary information will be the images and descriptions of the holotypes. In addition, representative images of paratypes or hypotypes will be included whenever possible in plain transmitted, differential interference contrast light and, when available, as drawings and SEM images. Also included will be a 35-word or less English diagnosis ("mini-description"), the biostratigraphic range in terms of zones and linear time, bibliographic references, lists of species considered junior synonyms, and similar species. The list of similar species will be cross-referenced with their respective image files to enable quick access for direct visual comparison on the viewing screen. Multiple images can be brought to the viewing screen simultaneously, and a zoom feature will permit image examination at a wide range of magnifications. Buttons will allow range charts, a bibliography, and key public-domain publications from the literature to be called up from within the program. The DiatomWare/BugCam package will be distributed at a nominal cost through a major nonprofit society via CD-ROM and free to Internet users on the Worldwide Web. Quality control measures will include critical review of the finalized database by a network of qualified specialists. The completed database will include descriptions and images of between 350 and 400 species, including fossil as well as modern forms that have no fossil record.<br/><br/>The development of the proposed diatom image database will be important to all research fields that depend on accurate biostratigraphic dating and paleoenvironmental interpretation of Antarctic marine sediments and plankton. The database will also serve as a valuable teaching tool for micropaleontology students and their professors, will provide a rapid means of keying down species for micropaleontologists of varying experience and background, and will promote a uniformity of taxonomic concepts since it will be developed and continuously updated with the advice of a community of nannofossil fossil experts. Broad use of the database is anticipated since it will be widely available through the Internet and on CD-ROM for use on personal computers that do not require large amounts of memory, costly specialized programs, or additional hardware. | None | None | false | false | |||||||
Collaborative Research: Late Paleozoic-Mesozoic Fauna, Environment, Climate and Basinal History: Beardmore Glacier Area, Transantarctic Mountains
|
0126146 |
2007-06-20 | Miller, Molly | No dataset link provided | This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a study to investigate paleoenvironmental conditions during the late Paleozoic and Mesozoic in central interior Antarctica. The 4 km thick sequence of sedimentary rocks, known as the Beacon Supergroup, in the Beardmore Glacier area records 90 million years of Permian through Jurassic history of this high-paleolatitude sector of Gondwana. It accumulated in a foreland basin with a rate of subsidence approximately equal to the rate of deposition. The deposits have yielded diverse vertebrate fossils, in situ fossil forests, and exceptionally well preserved plant fossils. They give a unique glimpse of glacial, lake, and stream/river environments and ecosystems and preserve an unparalleled record of the depositional, paleoclimatic, and tectonic history of the area. The excellent work done to date provides a solid base of information on which to build understanding of conditions and processes.<br/><br/>This project is a collaborative study of this stratigraphic section that will integrate sedimentologic, paleontologic, and ichnologic observations to answer focused questions, including: (1) What are the stratigraphic architecture and alluvial facies of Upper Permian to Jurassic rocks in the Beardmore area?; (2) In what tectonostratigraphic setting were these rocks deposited?; (3) Did vertebrates inhabit the cold, near-polar, Permian floodplains, as indicated by vertebrate burrows, and can these burrows be used to identify, for the first time, the presence of small early mammals in Mesozoic deposits?; and (4) How did bottom-dwelling animals in lakes and streams use substrate ecospace, how did ecospace use at these high paleolatitudes differ from ecospace use in equivalent environments at low paleolatitudes, and what does burrow distribution reveal about seasonality of river flow and thus about paleoclimate? Answers to these questions will (1) clarify the paleoclimatic, basinal, and tectonic history of this part of Gondwana, (2) elucidate the colonization of near-polar ecosystems by vertebrates, (3) provide new information on the environmental and paleolatitudinal distributions of early mammals, and (4) allow semi-quantitative assessment of the activity and abundance of bottom-dwelling animals in different freshwater environments at high and low latitudes. In summary, this project will contribute significantly to an understanding of paleobiology and paleoecology at a high latitude floodplain setting during a time in Earth history when the climate was much different than today. | POINT(171 -83.75) | POINT(171 -83.75) | false | false | |||||||
Collaborative Research: Digital Optical Imaging of Ice Cores for Curation and Scientific Applications
|
0230149 |
2007-06-04 | McGwire, Kenneth C. | No dataset link provided | This award supports the development of novel methods for digital image analysis of glacial ice cores that are stored at the National Ice Core Laboratory (NICL) in Denver, Colorado. Ice cores are a critical source of information on how Earth has changed over time, since indicators of local climate (snow accumulation, temperature), regional characteristics (wind-blown materials such as sea salt, dust and pollen), global processes (e.g., CO2, methane), and even extraterrestrial influences (cosmogenic isotopes) are stored in the ice on a common time scale. This project will develop a high-resolution optical scanning system for laboratory curation of ice core images, internet-based search and retrieval capabilities, a digital image analysis system specifically for ice core studies, and methods to integrate ice core image analysis with other dating methods. These tools will be developed and tested in conjunction with scientific investigations of NICL holdings. Optical scanning and analysis tools will improve understanding of the historical development of the ice collected from a particular location and will help to resolve challenges such as ice that has lost stratigraphic order through flow processes. <br/>By providing permanent online digital archives of ice core images, this project will greatly improve the documentation and availability of ice core data while reducing time and costs for subsequent scientific investigations. Using the internet, ice core scientists will be able to determine the appropriateness of specific NICL holdings for various scientific studies. By optically scanning ice cores as they are processed at NICL, any researcher will be able to examine an ice core in similar detail to the few investigators who were fortunate enough to observe it before modifications from sampling and storage. Re-examination of cores could be done decades later by anyone at any location, which is not possible now because only the interpretation of the original observer is recorded. Integration of digital image data into ice core analysis will speed discovery, allow collaborative interpretation, and enhance consistency of analysis to improve ice core dating, identification of melt layers, location of flow disturbances, and more. The equipment will be housed at NICL and will be available to the broad community, improving scientific infrastructure.<br/>This work will also have numerous broader impacts. Ice core science addresses fundamental questions of human interest related to global warming, abrupt climate change, biogeochemical cycling, and more. The principal investigators broadly disseminate their scientific findings through numerous outlets, ranging from meeting with government officials, chairing and serving on NRC panels, writing popular books and articles, publishing in scientific literature, teaching classes, talking to civic groups, and appearing on radio and television. The results from ice core analyses have directly informed policymakers and will continue to do so. Thus, by improving ice core science, this projectl will benefit society. | None | None | false | false | |||||||
Collaborative Research: Permian-Triassic Mass Extinction in Antarctica
|
0229917 |
2007-01-24 | Becker, Luann | No dataset link provided | This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an interdisciplinary study of fluvial sediments in Antarctica for evidence of what caused the greatest of all mass extinctions in the history of life at the Permian-Triassic boundary. This boundary was, until recently, difficult to locate and thought to be unequivocally disconformable in Antarctica. New studies, particularly of carbon isotopic chemostratigraphy and of paleosols and root traces as paleoecosystem indicators, together with improved fossil plant, reptile and pollen biostratigraphy, now suggest that the precise location of the boundary might be identified and have led to local discovery of iridium anomalies, shocked quartz, and fullerenes with extraterrestrial noble gases. These anomalies are associated with a distinctive claystone breccia bed, similar to strata known in South Africa and Australia, and taken as evidence of deforestation. There is already much evidence from Antarctica and elsewhere that the mass extinction on land was abrupt and synchronous with extinction in the ocean. The problem now is what led to such death and destruction. Carbon isotopic values are so low in these and other Permian-Triassic boundary sections that there was likely to have been some role for catastrophic destabilization of methane clathrates. Getting the modeled amount of methane out of likely reservoirs would require such catastrophic events as bolide impact, flood-basalt eruption or continental-shelf collapse, which have all independently been implicated in the mass extinction and for which there is independent evidence. Teasing apart these various hypotheses requires careful re-examination of beds that appear to represent the Permian-Triassic boundary, and search for more informative sequences, as was the case for the Cretaceous-Tertiary boundary. This collaborative research on geochemistry and petrography of boundary beds and paleosols (by Retallack), on carbon isotopic variation through the boundary interval (by Jahren), and on fullerenes, iridium and helium (by Becker) is designed to test these ideas about the Permian-Triassic boundary in Antarctica and to shed light on processes which contributed to this largest of mass extinctions on Earth. Fieldwork for this research will be conducted in the central Transantarctic Mountains and in Southern Victoria Land with an initial objective of examining the stratigraphic sequences for continuity across the boundary. Stratigraphic continuity is a critical element that must exist for the work to be successful. If fieldwork indicates sufficiently continuous sections, the full analytical program will follow fieldwork. | None | None | false | false | |||||||
Passive Microwave Remote Sensing for Paleoclimate Indicators at Siple Dome, Antarctica
|
9526566 |
2006-11-28 | Bindschadler, Robert; Shuman, Christopher A.; Stearns, Charles R. |
|
This award is for support for a research program involving the use of passive microwave data to validate key paleoclimate indicators used in glaciologic research. The specific contributions of this research are: 1) to define the timing and spatial extent of hoar complexes, which may serve as visible, annual stratigraphic markers in ice cores, through a combination of satellite passive microwave data and field observations; and 2) to monitor temperature trends at the site with calibrated passive microwave brightness temperatures and to correlate these trends to proxy temperatures provided by oxygen and hydrogen stable isotope ratio profiles from snow pits and/or ice cores. The work will take place at Siple Dome, Antarctica as part of the field activities associated with the ice core drilling program there. | None | None | false | false | |||||||
Glaciology of Blue Ice Areas in Antarctica
|
0229245 |
2006-03-30 | Bauer, Rob; Hamilton, Gordon S. | No dataset link provided | A 'horizontal ice core' was collected at the Mount Moulton blue ice field in West Antarctica and preliminary analyses of the sample material suggests that a ~500 kyr climate record is preserved in the ice at this site. This award will contribute to the understanding of the Mt Moulton record by assessing the potential for ice-flow induced deformation of the stratigraphic profile. In addition, this award builds on the recognition of blue ice areas as archives of long climate records by conducting reconnaissance studies for a potential horizontal ice core location at the Allan Hills in East Antarctica. The objectives of this project are to contribute to the glaciological understanding of blue ice areas in Antarctica. Ice flow conditions at the Mt Moulton blue ice field will be studied to assess the possibility that the stratigraphic record has been deformed and reconnaissance of a potential horizontal ice core site in the Allan Hills blue ice field will also be accomplished. Short field programs will be undertaken at each location to collect relevant measurements of ice flow and subglacial topography, and to conduct sampling of material that will enable the preservation of the stratigraphic sequences to be assessed. | POINT(135 -76) | POINT(135 -76) | false | false | |||||||
High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet
|
0088035 |
2005-05-01 | Spikes, Vandy Blue; Arcone, Steven; Kaspari, Susan; Hamilton, Gordon S.; Mayewski, Paul A. | This award supports continued acquisition of high resolution, radar reflection profiles of the snow and ice stratigraphy between core sites planned along traverse routes of the U.S. component of the International<br/>Trans-Antarctic Scientific Expedition (U.S.-ITASE). The purpose is to use the profiles to establish the structure and continuity of firn stratigraphic horizons over hundreds of kilometers and to quantitatively<br/>assess topographic and ice movement effects upon snow deposition. Other objectives are to establish the climatic extent that a single site represents and to investigate the cause of firn reflections. The radar<br/>will also be used to identify crevasses ahead of the traverse vehicles in order to protect the safety of the scientists and support personnel on the traverse. Collaboration with other ITASE investigators will use the radar horizons as continuous isochronic references fixed by the core dating to calculate historical snow accumulation rates. The primary radar system uses 400-MHz (center frequency) short-pulse antennas, which (with processing) gives the penetration of 50-70 meters. This is the depth which is required to exceed the 200-year deposition horizon along the traverse routes. Profiles at 200 MHz will also be recorded if depths greater than 70 meters are of interest. Processing will be accomplished by data compression (stacking) to reveal long distance stratigraphic deformation, range gain corrections to give proper weight to signal amplitudes, and GPS corrections to adjust the records for the present ice sheet topography. Near surface stratigraphy will allow topographic and ice movement effects to be separated. This work is critical to the success of the U.S.-ITASE program. | POLYGON((-135 -75,-130.5 -75,-126 -75,-121.5 -75,-117 -75,-112.5 -75,-108 -75,-103.5 -75,-99 -75,-94.5 -75,-90 -75,-90 -76.5,-90 -78,-90 -79.5,-90 -81,-90 -82.5,-90 -84,-90 -85.5,-90 -87,-90 -88.5,-90 -90,-94.5 -90,-99 -90,-103.5 -90,-108 -90,-112.5 -90,-117 -90,-121.5 -90,-126 -90,-130.5 -90,-135 -90,-135 -88.5,-135 -87,-135 -85.5,-135 -84,-135 -82.5,-135 -81,-135 -79.5,-135 -78,-135 -76.5,-135 -75)) | POINT(-112.5 -82.5) | false | false | ||||||||
Collaborative Research: Fabric and Texture Characteristics of Micro-Physical Processes in Ice
|
0135989 |
2005-03-02 | Wilen, Larry |
|
0135989<br/>Wilen<br/><br/>This is a collaborative proposal by Principal Investigators at the University of Washington and Ohio University. Detailed knowledge about the interactions between micro-structure of ice and its deformation is needed to assess the integrity of stratigraphic layering and the depth-age relationship in ice cores, which is essential for interpreting the paleoclimate record. The Principal Investigators will use micro-structure to study fabric, the orientation distribution of crystal c-axes, and texture, the size and shape of crystals. Numerical modeling of ice deformation is a useful tool in understanding these interactions. Accurate modeling of ice deformation is complicated by factors, such as the fabric, grain size, dynamic recrystallization, stress level, and precise knowledge of initial conditions. For example, ice fabric evolves as the ice is strained and the deformation depends on the fabric. This complicated feedback mechanism must be understood to correctly model ice deformation. In another example, the usual assumption is that the initial fabric is isotropic or random, but there are excellent examples of near-surface ice in the ice cores that are apparently not isotropic. One must know the initial fabric to calculate the deformation rate in ice sheets. Dr. Wilen will combine results of his new automatic fabric analyzer (AFA) with predictions of detailed ice deformation models (Dr. Thorsteinsson) to refine and better constrain such models. The AFA gives new information in thin sections because the precision and number of measured c-axis orientations are greatly improved. The Principal Investigators will analyze existing data and collect new data on fabric and texture from ice cores to address questions regarding near-surface fabric, deformation mechanisms, dynamic recrystallization, and potential sources of layer disturbances. The data will be used to constrain models of fabric evolution and recrystallization processes. With the more refined models, scientists can address different questions and important problems related to ice deformation and ice cores. For example, the recent agreement between the climate records from the Greenland Ice Core Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) ice cores of the upper-90%, and the disagreement in the lower-10% emphasizes the need to understand and predict the mechanisms and probable depths of disruption in these and future deep ice cores. Evidence suggests that the stratigraphic disturbances arise from the anisotropic nature of ice crystals at a variety of scales. To properly model the deformation of anisotropic ice, the influence of fabric on deformation must be well known. | None | None | false | false | |||||||
Collaborative Research: Studies of Trapped Gases in Firn and Ice from Antarctic Deep Ice Cores
|
9714687 |
2004-08-26 | Blunier, Thomas; Fluckiger, Jacqueline; Thompson, Lonnie G.; Brook, Edward J. |
|
This award is for support for a program to make high resolution studies of variations in the concentration of methane, the oxygenisotope composition of paleoatmospheric oxygen, and the total gas content of deep Antarctic ice cores. Studies of the concentration and isotopic composition of air in the firn of the Antarctic ice sheet will also be continued. One objective of this work is to use the methane concentration and oxygen-isotope composition of oxygen of air in ice as time-stratigraphic markers for the precise intercorrelation of Greenland and Antarctic ice cores as well as the correlation of ice cores to other climatic records. A second objective is to use variations in the concentration and interhemispheric gradient of methane measured in Greenland and Antarctic ice cores to deduce changes in continental climates and biogeochemistry on which the atmospheric methane distribution depends. A third objective is to use data on the variability of total gas content in the Siple Dome ice core to reconstruct aspects of the glacial history of West Antarctica during the last glacial maximum. The fourth objective is to participate in collaborative studies of firn air chemistry at Vostok, Siple Dome, and South Pole which will yield much new information about gas trapping in ice as well as the concentration history and isotopic composition of greenhouse gases, oxygen, trace biogenic gases and trace anthropogenic gases during the last 100 years. | None | None | false | false | |||||||
Collaborative Research: Volcanic Record in Antarctic Ice: Implications for Climatic and Eruptive History and Ice Sheet Dynamics of the South Polar Region
|
9615167 9527373 |
2002-06-01 | Dunbar, Nelia; Zielinski, Gregory | Dunbar/Kyle OPP 9527373 Zielinski OPP 9527824 Abstract The Antarctic ice sheets are ideal places to preserve a record the volcanic ash (tephra) layers and chemical aerosol signatures of volcanic eruptions. This record, which is present both in areas of bare blue ice, as well as in deep ice cores, consists of a combination of local eruptions, as well as eruptions from more distant volcanic sources from which glassy shards can be chemically fingerprinted and related to a source volcano. Field work carried out during the 1994/1995 Antarctic field season in the Allan Hills area of Antarctica, and subsequent microbeam chemical analysis and 40Ar/39Ar dating has shown that tephra layers in deep Antarctic ice preserve a coherent, systematic stratigraphy, and can be successfully mapped, dated, chemically fingerprinted and tied to source volcanoes. The combination of chemical fingerprinting of glass shards, and chemical analysis of volcanic aerosols associated with ash layers will allow establishment of a high-resolution chronology of local and distant volcanism that can help understand patterns of significant explosive volcanisms and atmospheric loading and climactic effects associated with volcanic eruptions. Correlation of individual tephra layers, or sets of layers, in blue ice areas, which have been identified in many places the Transantarctic Mountains, will allow the geometry of ice flow in these areas to be better understood and will provide a useful basis for interpreting ice core records. | None | None | false | false | ||||||||
Carbon Dioxide and Carbon Isotopes in the Taylor Dome and Vostok Ice Cores
|
9615292 |
2002-01-01 | Steig, Eric J.; Wahlen, Martin; Smith, Jesse; Brook, Edward J.; Indermuhle, A.; Mayewski, Paul A.; Sowers, Todd A. |
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This award is for support of a program to reconstruct the record of atmospheric carbon dioxide (and the carbon-13 isotopes of carbon dioxide) over several intervals, including the Last Glacial Maximum-Holocene transition, interstadial episodes, the mid-Holocene, the last 1000 years and the penultimate glacial period, using ice from the Taylor Dome and Vostok ice cores. The major objective of this study is to investigate the phase relationship between variations of the greenhouse gases occluded in the ice cores and temperature changes (indicated by oxygen and deuterium isotopes) during the last deglaciation. In addition, the concentration of atmospheric carbon dioxide over the past 1000 years and during the mid-Holocene will be determined in these cores. | None | None | false | false | |||||||
Evolution of Sea Surface Temperatures in the Coastal Antarctic Paleoenvironment During the Late Cretaceous and Paleogene
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9980538 |
2001-06-11 | Lohmann, Kyger; Barrera, Enriqueta |
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This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research for construction of a long-term record of climate during the late Cretaceous and early Paleogene to assess the annual seasonality in temperature on the coastal margin of Antarctica. Stable isotope and element compositions of well-preserved bivalve shells collected on Seymour Island will be the primary source of data used to reconstruct paleoenvironmental conditions. Seasonal temperature records collected through high-resolution sampling along growth structures in bivalve shells will allow seasonality to be assessed during different climate states and during periods of rapid climate change. In addition, high stratigraphic resolution will enable this project to detect the presence and frequency of short-lived thermal excursions that may have extended to such high latitudes. To compile a reliable temporal record of paleoclimate, two major avenues of investigation will be undertaken: 1) precise stratigraphic (and therefore, temporal) placement of fossils over a large geographic area will be employed through the use of a graphical technique employing geometric projections; 2) stable isotope and elemental analyses will be performed to derive paleotemperatures and to evaluate diagenetic alteration of shell materials. To provide realistic comparisons of paleotemperatures across stratigraphic horizons, this study will focus on a single taxon, thus avoiding complications due to the mixing of faunal assemblages that have been encountered in previous studies of this region. The near-shore marine fossil record on Seymour Island provides a unique opportunity to address many questions about the Antarctic paleoenvironment, including the relation between seasonality and different climate states, the influence of climate on biogeographic distribution of specific taxa, the effect of ice-volume changes on the stable isotope record from the late Cretaceous through the Eocene, and the plausibility of high-latitude bottom water formation during this time interval. In particular, information that will be collected concerning patterns of seasonality and the presence (or absence) of short-lived thermal excursions will be extremely valuable to an understanding of the response of high latitude sites during climate transitions from globally cool to globally warm conditions. | POINT(-56 -64) | POINT(-56 -64) | false | false | |||||||
Thermal Fractionation of Firn Air and the Ice Core Record of Abrupt Interstadial Climate Change
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9725305 |
2001-01-01 | Battle, Mark; Grachev, Alexi; Severinghaus, Jeffrey P. |
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9725305 Severinghaus This award supports a project to develop and apply a new technique for quantifying temperature changes in the past based on the thermodynamic principle of thermal diffusion, in which gas mixtures in a temperature gradient become fractionated. Air in polar firn is fractionated by temperature gradients induced by abrupt climate change, and a record of this air is preserved in bubbles in the ice. The magnitude of the abrupt temperature change, the precise relative timing, and an estimate of the absolute temperature change can be determined. By providing a gas-phase stratigraphic marker of temperature change, the phasing of methane (with decadal precision) and hence widespread climate change (relative to local polar temperature changes) can be determined (across five abrupt warming events during the last glacial period). | None | None | false | false | |||||||
Physical Properties of the Siple Dome Deep Ice Core
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9526374 |
1997-01-01 | Alley, Richard |
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This award is for support for a program of physical and visible studies on the shallow and deep ice cores to be retrieved from Siple Dome, West Antarctica. Visible examination of ice cores has proven to be a powerful technique for dating and paleoclimatic interpretation. Recent examination of a shallow core from Siple Dome indicates that annual-layer dating is possible and that visible examination will contribute significantly to the dating effort at Siple Dome. Once ages are obtained, distances between layers provide snow accumulation after correction for density variations and ice flow thinning. Thin- section examination of the core will contribute to understanding the visible stratigraphy, and will reveal c-axis fabrics which are related to past ice deformation. The results of this study should include a better understanding of rapid climate change in the Antarctic and should contribute to knowledge of the stability of the West Antarctic ice sheet. | None | None | false | false |