[{"awards": "2215771 Kreutz, Karl", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 01 Apr 2024 00:00:00 GMT", "description": "This award is for acquisition of new instrumentation to support acquisition of the new LA-HR-ICPMS instrumentation for the trace-element analysis of various environmental samples. This instrumentation will replace the original (and heavily used over two decades) ThermoScientific Element2 ICP-MS installed at the University of Maine?s Climate Change Institute (CCI). The new acquisition will significantly expand research capabilities of the CCI/ICP-MS Facility to improve the analysis of aqueous samples, supplemented with a laser ablation (LA) front end for ice, biological, and other solid materials. The current ICP-MS Facility was established in 2002 with an NSF/MRI award, which since then has served as a vital resource for climate, environmental, ecosystem, and engineering research and training at the U. Maine, across the state of Maine and beyond. The routine use and primary support of the Facility come from the Principal Investigators and their collaborators that group under three research areas: glaciochemistry and climate/environmental reconstruction; paleoceanography and marine biogeochemistry; and environmental sensor development and material science engineering. The U. Maine is the State?s Land \u0026 Sea Grant university and only PhD granting institution, so the campus is the de facto academic research and research training hub of the state of Maine. The proposed advances of this research \u0026 training instrumentation will immediately impact current and future NSF-funded research projects that support extensive national and international collaborations. Specific to this proposal are collaborations with the University of Venice (Italy) and the University of Cambridge/British Antarctic Survey to develop laser ablation ICP-MS imaging of ice cores, and collaborations with New Zealand, Swiss, Chinese, Canadian, and Brazilian colleagues to analyze ice, thereby maintaining our leadership role in global ice core and climate change research. Likewise, the enhanced carbonate analysis capacity of the Element XR will have an immediate impact on NSF-funded research projects in the Gulf of Maine and in the South Pacific. The proposed instrumentation will facilitate new and important collaborations between academic colleges (College of Natural Science, Forestry, and Agriculture and the College of Engineering) and research units - the CCI and the Frontier Institute for Research in Sensor Technology - across the campus, as well as enabling new and broader scientific collaborations with other academic and scientific institutions across Maine.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "; OCEAN CHEMISTRY; GLACIERS/ICE SHEETS", "locations": "", "north": null, "nsf_funding_programs": "Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Kreutz, Karl", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "MRI: Acquisition of LA-HR-ICPMS instrumentation for climate, environmental, ecosystem, and engineering research at the University of Maine", "uid": "p0010456", "west": null}, {"awards": "1939139 Scherer, Reed", "bounds_geometry": "POLYGON((-120 -66,-117.5 -66,-115 -66,-112.5 -66,-110 -66,-107.5 -66,-105 -66,-102.5 -66,-100 -66,-97.5 -66,-95 -66,-95 -67.1,-95 -68.2,-95 -69.3,-95 -70.4,-95 -71.5,-95 -72.6,-95 -73.7,-95 -74.8,-95 -75.9,-95 -77,-97.5 -77,-100 -77,-102.5 -77,-105 -77,-107.5 -77,-110 -77,-112.5 -77,-115 -77,-117.5 -77,-120 -77,-120 -75.9,-120 -74.8,-120 -73.7,-120 -72.6,-120 -71.5,-120 -70.4,-120 -69.3,-120 -68.2,-120 -67.1,-120 -66))", "dataset_titles": "Last Interglacial Southern Ocean paleothermometry from diatom morphometrics: Analysis and application of the F. kerguelensis Valve Rectangularity Sea Surface Temperature proxy.; Pliocene diatom abundance, IODP 397-U1532", "datasets": [{"dataset_uid": "601769", "doi": null, "keywords": "Antarctica; Biogenic Silica; Diatom", "people": "Scherer, Reed Paul", "repository": "USAP-DC", "science_program": null, "title": "Pliocene diatom abundance, IODP 397-U1532", "url": "https://www.usap-dc.org/view/dataset/601769"}, {"dataset_uid": "601767", "doi": null, "keywords": "Amundsen Sea; Antarctica; Sabrina Coast; Southern Ocean", "people": "Ruggiero, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Last Interglacial Southern Ocean paleothermometry from diatom morphometrics: Analysis and application of the F. kerguelensis Valve Rectangularity Sea Surface Temperature proxy.", "url": "https://www.usap-dc.org/view/dataset/601767"}], "date_created": "Tue, 20 Feb 2024 00:00:00 GMT", "description": "Part I, Non-technical Abstract \u003cbr/\u003eConcerns that the West Antarctic Ice Sheet (WAIS) might be susceptible to releasing its ice as giant icebergs into the Southern Ocean due to a warming climate, raising global sea level, were first expressed more than 40 years ago. To best-assess this threat, scientists need to know whether such events occurred in the geologically recent past, during warm intervals of past glacial-interglacial cycles. Ocean drilling near the most vulnerable sector of the WAIS, in 2019, yielded seafloor geologic records demonstrating times when icebergs dropped large volumes of sands and pebbles, called ice-rafted detritus (IRD) in deep water of the Amundsen Sea. Occurring together with IRD that was eroded from bedrock beneath the ice sheets, there are abundant microfossils of diatoms (algal plankton), which indicate high biological productivity in the open ocean. The new sediment cores provide a complete, uninterrupted record of a time of dramatic fluctuations of ice sheet extent that occurred over the last 3 million years. Therefore, they provide the means to obtain clear answers to the question whether ice sheet collapse occurred in the past and offering clues to its potential future. This project will investigate sediment intervals where IRD coincides with evidence of high diatom production, to test whether these two criteria indicate rapid ice sheet collapse. Geochemical analysis of IRD pebbles will help trace the source of the icebergs to likely on-land sites. By analyzing conditions of high diatom and IRD accumulation in deep ocean sediment, where local coastal influences can be avoided, we will assess oceanographic and climatic conditions associated with past ice sheet collapse events. Diatoms provide powerful evidence of temperature and ocean productivity changes in the past, that, when linked to time, can translate into rates of ice sheet drawdown. These results will provide critical data for designing, constraining and testing the next suite computer models that can determine the likelihood and timing of future ice sheet collapse in a warming world. The project will include training of undergraduate and graduate students from diverse backgrounds, and the public will be introduced to Antarctic science and engaged through several different outreach efforts.\u003cbr/\u003e\u003cbr/\u003ePart 2, Technical Abstract\u003cbr/\u003e\u003cbr/\u003eNew drillcores from the Amundsen Sea, Antarctica (IODP Expedition 379) contain a continuous record of oceanographic changes and iceberg rafted debris (IRD) spanning the last 5 million years. This study aims to identify the signature of retreat/collapse of the West Antarctic Ice Sheet (WAIS) in these continental margin, deep-sea sediments by quantitatively analyzing, in detail, diatom and IRD records across glacial-interglacial lithostratigraphic transitions to establish the timing and frequency of Late Pliocene and Pleistocene WAIS collapse events. The investigators will secure age constraints and diagnostic observations of marine paleoenvironmental conditions for selected interglacial intervals of cores from sites U1532 and U1533, using high resolution micropaleontology of diatom assemblages coupled with microstratigraphic analysis of IRD depositional events, while petrography, geochronology and thermochronology of iceberg rafted clasts will provide evidence of iceberg sources and pathways. Depositional paleotemperatures will be assessed via a new paleotemperature proxy based on quantitative assessment of morphologic changes in the dominant Southern Ocean diatom Fragilariopsis kerguelensis. Their results will contribute to parameterization of new ice sheet models that seek to reconstruct and forecast West Antarctic Ice Sheet behavior. This project will directly contribute to undergraduate education at an undergraduate-only college and at a public university that serves a demographic typified by first generation university students and underrepresented groups. Spanning geology, geochemistry, sedimentology, paleontology and paleoceanography, the proposed work will allow undergraduate students to develop diverse skills through hands-on research within a collaborative team that is dedicated to societally relevant research. The two graduate students will conduct original research and work alongside/mentor undergraduates, making for a well-rounded research experience that prepares them for success in future academic or employment sectors. The discoveries that come from this deep-sea record from West Antarctica will be communicated by students and investigators at national and international conferences and an array of public science outreach events.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -71.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICEBERGS; SEA SURFACE TEMPERATURE; Amundsen Sea; MICROFOSSILS", "locations": "Amundsen Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE", "persons": "Scherer, Reed Paul", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Collaborative Research: Testing the Linchpin of WAIS Collapse with Diatoms and IRD in Pleistocene and Late Pliocene Strata of the Resolution Drift, Amundsen Sea, Antarctica", "uid": "p0010451", "west": -120.0}, {"awards": "2053169 Kingslake, Jonathan", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 15 Sep 2023 00:00:00 GMT", "description": "When ice sheets and glaciers lose ice faster than it accumulates from snowfall, they shrink and contribute to sea-level rise. This has consequences for coastal communities around the globe by, for example, increasing the frequency of damaging storm surges. Sea-level rise is already underway and a major challenge for the geoscience community is improving predictions of how this will evolve. The Antarctic Ice Sheet is the largest potential contributor to sea-level rise and its future is highly uncertain. It loses ice through two main mechanisms: the formation of icebergs and melting at the base of floating ice shelves on its periphery. Ice flows under gravity towards the ocean and the rate of ice flow controls how fast ice sheets and glaciers shrink. In Greenland and Antarctica, ice flow is focused into outlet glaciers and ice streams, which flow much faster than surrounding areas. Moreover, parts of the Greenland Ice Sheet speed up and slow down substantially on hourly to seasonal time scales, particularly where meltwater from the surface reaches the base of the ice. Meltwater reaching the base changes ice flow by altering basal water pressure and consequently the friction exerted on the ice by the rock and sediment beneath. This phenomenon has been observed frequently in Greenland but not in Antarctica. Recent satellite observations suggest this phenomenon also occurs on outlet glaciers in the Antarctic Peninsula. Meltwater reaching the base of the Antarctic Ice Sheet is likely to become more common as air temperature and surface melting are predicted to increase around Antarctica this century. This project aims to confirm the recent satellite observations, establish a baseline against which to compare future changes, and improve understanding of the direct influence of meltwater on Antarctic Ice Sheet dynamics. This is a project jointly funded by the National Science Foundation?s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries.\r\n\r\nThis project will include a field campaign on Flask Glacier, an Antarctic Peninsula outlet glacier, and a continent-wide remote sensing survey. These activities will allow the team to test three hypotheses related to the Antarctic Ice Sheet?s dynamic response to surface meltwater: (1) short-term changes in ice velocity indicated by satellite data result from surface meltwater reaching the bed, (2) this is widespread in Antarctica today, and (3) this results in a measurable increase in mean annual ice discharge. The project is a collaboration between US- and UK-based researchers and will be supported logistically by the British Antarctic Survey. The project aims to provide insights into both the drivers and implications of short-term changes in ice flow velocity caused by surface melting. For example, showing conclusively that meltwater directly influences Antarctic ice dynamics would have significant implications for understanding the response of Antarctica to atmospheric warming, as it did in Greenland when the phenomenon was first detected there twenty years ago. This work will also potentially influence other fields, as surface meltwater reaching the bed of the Antarctic Ice Sheet may affect ice rheology, subglacial hydrology, submarine melting, calving, ocean circulation, and ocean biogeochemistry. The project aims to have broader impacts on science and society by supporting early-career scientists, UK-US collaboration, education and outreach, and adoption of open data science approaches within the glaciological community.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; GLACIER MOTION/ICE SHEET MOTION; Antarctic Peninsula; BASAL SHEAR STRESS", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kingslake, Jonathan; Sole, Andrew; Livingstone, Stephen; Winter, Kate; Ely, Jeremy", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "NSFGEO-NERC: Investigating the Direct Influence of Meltwater on Antarctic Ice Sheet Dynamics", "uid": "p0010436", "west": null}, {"awards": null, "bounds_geometry": null, "dataset_titles": "Direct observations of melting, freezing, and ocean circulation in an ice shelf basal crevasse", "datasets": [{"dataset_uid": "601733", "doi": "10.15784/601733", "repository": "USAP-DC", "science_program": null, "title": "Direct observations of melting, freezing, and ocean circulation in an ice shelf basal crevasse", "url": "http://www.usap-dc.org/view/dataset/601733"}], "date_created": "Tue, 12 Sep 2023 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Basal Crevassing; Basal Freezing; Basal Melting; Ice Shelf; Kamb Ice Stream; Oceanography", "locations": "Kamb Ice Stream; Antarctica", "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": "Washam, Peter", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "2317263 Cross, Andrew", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 14 Aug 2023 00:00:00 GMT", "description": "The seaward motion of ice sheets and glaciers is primarily controlled by basal sliding below, and internal viscous flow within, ice masses. The latter of these\u2014viscous flow\u2014is dependent on various factors, including temperature, stress, grain size, and the alignment of ice crystals during flow to produce a crystal orientation fabric (COF). Historically, ice flow has been modeled using a constitutive equation, termed \u201cGlen\u2019s law\u201d, that describes ice flow rate as a function of temperature and stress. Glen\u2019s law was constrained under relatively high-stress conditions, and is often attributed to the motion of crystal defects within ice grains. More recently, however, grain boundary sliding (GBS) has been invoked as the rate-controlling process under low-stress, \u201csuperplastic\u201d conditions. The grain boundary sliding hypothesis is contentious because GBS is not thought to produce a COF, whereas geophysical measurements and polar ice cores demonstrate strong COFs in polar ice masses. However, very few COF measurements have been conducted on ice samples subjected to superplastic flow conditions in the laboratory. In this project, the PI primarily seeks to measure the evolution of ice COF across the transition from superplastic to Glen-type creep. Results will be used to interrogate the role of superplastic GBS creep within polar ice masses, and thereby provide constraints on polar ice discharge models.\r\n\r\nPolycrystalline ice samples with grain sizes ranging from 5 \u00b5m to 1000 \u00b5m will be fabricated and deformed in the PI\u2019s laboratory at WHOI, using a 1-atm cryogenic axial-torsion apparatus. Experiments will be conducted at temperatures of \u221230\u00b0C to \u221210\u00b0C, and at a constant uniaxial strain rate of 10-7 s-1. Under these conditions, 5% to 99.99% of strain should be accommodated by superplastic, GBS-limited creep, depending on the sample grain size. The deformed samples will then be imaged using cryogenic electron backscatter diffraction (cryo-EBSD) and high-angular-resolution electron backscatter diffraction (HR-EBSD) to quantify COF, grain size, grain shape, and crystal defect (dislocation) densities, among other microstructural properties. These measurements will be used to decipher the rate-controlling mechanisms operating within different thermomechanical regimes, and resolve a long-standing debate over whether superplastic creep can produce a COF in ice. In addition to the polycrystal experiments, ice bicrystals will be fabricated and deformed to investigate the micromechanical behavior of individual grain boundaries under superplastic conditions. Ultimately, these results will be used to provide a microstructural toolbox for identifying superplastic creep using geophysical (e.g., seismic, radar) and glaciological (e.g., ice core) observations. This project will support one graduate student within the MIT-WHOI Joint Program, one or more undergraduate summer students, and a junior faculty member (the PI). In addition, the PI will host a workshop aimed at bringing together experimentalists, glaciologists, and ice modelers to facilitate cross-disciplinary knowledge sharing and collaborative problem solving.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; Rheology; ROCKS/MINERALS/CRYSTALS; GLACIERS/ICE SHEETS", "locations": "United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cross, Andrew", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Microstructural Evolution during Superplastic Ice Creep", "uid": "p0010430", "west": null}, {"awards": "1841844 Steig, Eric; 1841858 Souney, Joseph; 1841879 Aydin, Murat", "bounds_geometry": "POINT(-105 -86)", "dataset_titles": null, "datasets": null, "date_created": "Mon, 06 Feb 2023 00:00:00 GMT", "description": "The goal of this project is to drill and recover an ice core from Hercules Dome, Antarctica. The geographic setting of Hercules Dome makes it well-situated to investigate changes in the size of the West Antarctic ice sheet over long time periods. The base of the West Antarctic ice sheet lies below sea level, which makes this part of Antarctica vulnerable to melting from the relatively warm deep water of the Southern Ocean. An important research question is whether the West Antarctic Ice Sheet collapsed during Earth\u0027s last prolonged warm period, about 125,000 years ago, when the ocean was warmer and sea level was several meters higher than today. Evidence for or against such a collapse will be recorded in the chemistry and physical properties of the ice. The Hercules Dome ice core will be obtained over three to four field seasons in Antarctica using efficient drilling technology. This grant includes support for project management, pre-drilling science community engagement, ice-core recovery, and education and outreach activities. \u003cbr/\u003e\u003cbr/\u003eHercules Dome is located at the edge of the East Antarctic ice sheet, south of the Transantarctic Mountains at 86 degrees South, 105 degrees West. Glaciological conditions at Hercules Dome are simple, with well-defined layering to the bed, optimal for the recovery of a deep ice core reaching to the last interglacial period at depths between 1600 and 2800 meters. An ice core from Hercules Dome will provide a research opportunity for ice-core analysts and others to make progress on a number of science priorities, including the environmental conditions of the last interglacial period, the history of gases and aerosols, and the magnitude and timing of changes in temperature and snow accumulation over the last 150,000 years. Together with the network of ice cores obtained by U.S. and international researchers over the last few decades, results from Hercules Dome will yield improved estimates of the boundary conditions necessary for the implementation and validation of ice-sheet models critical to the projection of future Antarctic ice-sheet change and sea level.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -105.0, "geometry": "POINT(-105 -86)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Hercules Dome; FIELD SURVEYS; AIR TEMPERATURE; SNOW/ICE CHEMISTRY; GLACIER ELEVATION/ICE SHEET ELEVATION; PALEOCLIMATE RECONSTRUCTIONS", "locations": "Hercules Dome", "north": -86.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.; Fudge, T. J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": "Hercules Dome Ice Core", "south": -86.0, "title": "Collaborative Research: An Ice Core from Hercules Dome, East Antarctica", "uid": "p0010401", "west": -105.0}, {"awards": "2219065 Hood, John", "bounds_geometry": "POINT(0 -90)", "dataset_titles": null, "datasets": null, "date_created": "Mon, 19 Dec 2022 00:00:00 GMT", "description": "\\Millimeter-wave (mm-wave) observations of active galactic nucleus (AGN) variability have the potential to shed light on some of the key questions of AGN physics, such as the origin of blazar gamma-ray emission and the possible connection of AGN to the high-energy neutrinos detected by IceCube. While continuous, high-cadence monitoring of AGN is now common at gamma-ray, optical, and radio frequencies, AGN monitoring in the mm band has mostly been restricted to short campaigns on targeted sources. Cosmic Microwave Background (CMB) telescopes are now providing an option for daily monitoring of these objects within limited fields of view. I propose to use the South Pole Telescope (SPT), which was designed to observe the CMB at arcminute and larger angular scales, to monitor AGN, and then to expand this monitoring program to other CMB experiments such as Advanced ACTPol and the upcoming Simons Observatory and CMB-S4 experiments. A pilot project using data from the SPTpol camera on the SPT has enabled the monitoring of tens of mm-bright AGN on timescales from years to days at high signal to noise (S/N \u003e 10 in a 36-hour coadd). A study focused on the blazar PKS 2326-502, which has extensive, day-timescale monitoring data in gamma-ray, optical, and now mm-wave data between 2013 and 2016 shows intriguing evidence of correlated variability between SPTpol (150 GHz), SMARTS (O/IR) and Fermi (gamma-rays) observations. I propose to carry out such multi-wavelength correlation studies on a large statistical sample of mm-wave-bright AGN, enabled by the repurposing of existing and future CMB data. This large sample (covering nearly 70 % of the sky) will also be key to investigating hints of correlations between mm-bright blazar flares and high-energy neutrinos. I further propose to build a public-facing server that will provide the mm lightcurves I construct from CMB data to the wider community.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": null, "is_usap_dc": true, "keywords": "SOLAR ENERGETIC PARTICLE FLUX; South Pole Station", "locations": "South Pole Station", "north": -90.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Hood, John", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "OPP-PRF: Millimeter-wave Blazar Monitoring With Cosmic Microwave Background Experiments: A New Tool for Probing Blazar Physics", "uid": "p0010399", "west": 0.0}, {"awards": "1542756 Koutnik, Michelle", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.9,-175 -78.8,-175 -79.7,-175 -80.6,-175 -81.5,-175 -82.4,-175 -83.3,-175 -84.2,-175 -85.1,-175 -86,-175.5 -86,-176 -86,-176.5 -86,-177 -86,-177.5 -86,-178 -86,-178.5 -86,-179 -86,-179.5 -86,180 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77))", "dataset_titles": "Beardmore Glacier model in \u0027icepack\u0027", "datasets": [{"dataset_uid": "200339", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beardmore Glacier model in \u0027icepack\u0027", "url": "https://github.com/danshapero/beardmore"}], "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "In this project we investigated glaciers that drain ice from the East Antarctic Ice Sheet through the Transantarctic Mountains into the present-day Ross Ice Shelf. The outlet glaciers that flow through the Transantarctic Mountains have thinned significantly over the past 15,000 years, especially as they retreated from Last Glacial Maximum highstands to their present-day grounding lines. At certain locations and for certain glaciers, rocks or bedrock have been sampled to provide constraints on the timing of when ice retreated from these locations. In the locations where geochronological data are available we can use these data as direct constraints on ice-flow models that simulate ice elevation change over time. The intellectual merit of this work is using ice-flow models to spatially and temporally extrapolate between these limited geochronological data points, which enables new understanding of glacier evolution. \r\n\r\nThe mountainous topography in this region is complex, and there are limited measurements of the topography beneath the ice of the Transantarctic outlet glaciers. Since the topography of the glacier bed is an important control on ice flow and is a necessary boundary condition in models we developed a new gridded bed product at Beardmore Glacier, the one location where sufficient data were available, and we compared this to continent-scale gridded bed products. We found that for this glacier, the BedMachine v1 product was reasonably similar to the Beardmore Glacier bed topography measurements; our limited evaluation suggests that the BedMachine product may be sufficient at other Transantarctic outlets where bed measurements are not available, but that other compilations of bed topography data that do not include information about ice flow directions do not provide reliable results. Using these data and available geochronological constraints we investigated Beardmore Glacier evolution since the Last Glacial Maximum using simplified (flowline) models of ice flow.\r\n\r\nIn addition to flowline modeling at Beardmore Glacier, we developed a flow-model setup using the open-source \u0027icepack\u0027 model that uses the shallow stream equations and resolves flow in both the x and y directions. The key value added over flowline (or parameterized flowband) models is that this can capture converging and diverging ice flow, variable side wall and bottom drag, and other geometric complexities. In these simulations we can evaluate the past accumulation, ice influx, and ice outflux to compare controls on deglaciation to data constraints on the chronology of deglaciation.\r\n\r\nWe also used a flowline model to investigate the Darwin-Hatherton Glacier System. Exposure ages and radiocarbon ages of glacial deposits at four locations alongside Hatherton and Darwin glaciers record several hundred meters of late Pleistocene to early Holocene thickening relative to present. Deglaciation was relatively complex at this site, and we also found that Byrd glacier likely contributed ice to the catchment of the Darwin-Hatherton glacier system during the last glacial maximum, and that subsequent convergent flow from Byrd and Mulock glaciers during deglaciation complicated the response of the Darwin-Hatherton system. These new insights can be used on their own to better understand local deglaciation, and can also be used to evaluate regional or continent-scale model calculations.\r\n\r\nSeparately, we investigated the general response of outlet glaciers to different sources of climate forcing. We found that outlet glaciers have a characteristically different response over time to surface-mass-balance forcing applied over the interior than to oceanic forcing applied at the grounding line. Our models demonstrated that ocean forcing first engages the fast, local response and then the slow adjustment of interior ice, whereas surface-mass-balance forcing is dominated by the slow interior adjustment. These insights contributed to our general understanding of how outlet glaciers may have evolved over time.\r\n\r\nOur new model investigations provide a framework that can be applied at other Transantarctic outlet glaciers where geochronological data are available. In particular, our \u0027icepack\u0027 setup is an archived and documented resource for the community. These tools are available for future investigations, including additional investigations at Beardmore Glacier and at other Transantarctic Mountain outlet glaciers. Scientific broader impacts include that this contributes to our understanding of the past behavior of East Antarctic ice, which provides an important constraint on the future evolution of Antarctica. Our team has engaged in public outreach and has engaged students in this research. Two graduate students led in aspects of this work, and have since gone on to research positions after their PhD.", "east": -175.0, "geometry": "POINT(170 -81.5)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS; Transantarctic Mountains; GLACIER THICKNESS/ICE SHEET THICKNESS", "locations": "Transantarctic Mountains", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Smith, Ben; Conway, Howard; Shapero, Daniel", "platforms": null, "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -86.0, "title": "Holocene Deglaciation of the Western Ross Embayment: Constraints from East Antarctic Outlet Glaciers", "uid": "p0010398", "west": 155.0}, {"awards": "1644234 Phillips, Fred", "bounds_geometry": "POLYGON((166.17 -77.3,166.32799999999997 -77.3,166.486 -77.3,166.644 -77.3,166.802 -77.3,166.95999999999998 -77.3,167.118 -77.3,167.276 -77.3,167.434 -77.3,167.59199999999998 -77.3,167.75 -77.3,167.75 -77.34,167.75 -77.38,167.75 -77.42,167.75 -77.46,167.75 -77.5,167.75 -77.54,167.75 -77.58,167.75 -77.62,167.75 -77.66,167.75 -77.7,167.59199999999998 -77.7,167.434 -77.7,167.276 -77.7,167.118 -77.7,166.95999999999998 -77.7,166.802 -77.7,166.644 -77.7,166.486 -77.7,166.32799999999997 -77.7,166.17 -77.7,166.17 -77.66,166.17 -77.62,166.17 -77.58,166.17 -77.54,166.17 -77.5,166.17 -77.46,166.17 -77.42,166.17 -77.38,166.17 -77.34,166.17 -77.3))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "Nontechnical Description: The age of rocks and soils at the surface of the Earth can help answer multiple questions that are important for human welfare, including: when did volcanoes erupt and are they likely to erupt again? when did glaciers advance and what do they tell us about climate? what is the frequency of hazards such as landslides, floods, and debris flows? how long does it take soils to form and is erosion of soils going to make farming unsustainable? One method that is used thousands of times every year to address these questions is called \u0027cosmogenic surface-exposure dating\u0027. This method takes advantage of cosmic rays, which are powerful protons and neutrons produced by supernova that constantly bombard the Earth\u0027s atmosphere. Some cosmic rays reach Earth\u0027s surface and produce nuclear reactions that result in rare isotopes. Measuring the quantity of the rare isotopes enables the length of time that the rock or soil has been exposed to the atmosphere to be calculated. The distribution of cosmic rays around the globe depends on Earth\u0027s magnetic field, and this distribution must be accurately known if useful exposure ages are to be obtained. Currently there are two remaining theories, narrowed down from many, of how to calculate this distribution. Measurements from a site that is at both high altitude and high latitude (close to the poles) are needed to test the two theories. This study involves both field and lab research and includes a Ph.D. student and an undergraduate student. The research team will collect rocks from lava flows on an active volcano in Antarctica named Mount Erebus and measure the amounts of two rare isotopes: 36Cl and 3He. The age of eruption of the samples will be determined using a highly accurate method that does not depend on cosmic rays, called 40Ar/39Ar dating. The two cosmic-ray theories will be used to calculate the ages of the samples using the 36Cl and 3He concentrations and will then be compared to the ages calculated from the 40Ar/39Ar dating. The accurate cosmic-ray theory will be the one that gives the same ages as the 40Ar/39Ar dating. Identification of the accurate theory will enable use of the cosmogenic surface dating methods anywhere on earth. \u003cbr/\u003eTechnical Description: Nuclides produced by cosmic rays in rocks at the surface of the earth are widely used for Quaternary geochronology and geomorphic studies and their use is increasing every year. The recently completed CRONUS-Earth Project (Cosmic-Ray Produced Nuclides on Earth) has systematically evaluated the production rates and theoretical underpinnings of cosmogenic nuclides. However, the CRONUS-Earth Project was not able to discriminate between the two leading theoretical approaches: the original Lal model (St) and the new Lifton-Sato-Dunai model (LSD). Mathematical models used to scale the production of the nuclides as a function of location on the earth, elevation, and magnetic field configuration are an essential component of this dating method. The inability to distinguish between the two models was because the predicted production rates did not differ sufficiently at the location of the calibration sites. \u003cbr/\u003e\u003cbr/\u003eThe cosmogenic-nuclide production rates that are predicted by the two models differ significantly from each other at Erebus volcano, Antarctica. Mount Erebus is therefore an excellent site for testing which production model best describes actual cosmogenic-nuclide production variations over the globe. The research team recently measured 3He and 36Cl in mineral separates extracted from Erebus lava flows. The exposure ages for each nuclide were reproducible within each flow (~2% standard deviation) and in very good agreement between the 3He and the 36Cl ages. However, the ages calculated by the St and LSD scaling methods differ by ~15-25% due to the sensitivity of the production rate to the scaling at this latitude and elevation. These results lend confidence that Erebus qualifies as a suitable high- latitude/high-elevation calibration site. The remaining component that is still lacking is accurate and reliable independent (i.e., non-cosmogenic) ages, however, published 40Ar/39Ar ages are too imprecise and typically biased to older ages due to excess argon contained in melt inclusions.\u003cbr/\u003eThe research team\u0027s new 40Ar/39Ar data show that previous problems with Erebus anorthoclase geochronology are now overcome with modern mass spectrometry and better sample preparation. This indicates a high likelihood of success for this proposal in defining an accurate global scaling model. Although encouraging, much remains to be accomplished. This project will sample lava flows over 3 km in elevation and determine their 40Ar/39Ar and exposure ages. These combined data will discriminate between the two scaling methods, resulting in a preferred scaling model for global cosmogenic geochronology. The LSD method contains two sub-methods, the \u0027plain\u0027 LSD scales all nuclides the same, whereas LSDn scales each nuclide individually. The project can discriminate between these models using 3He and 36Cl data from lava flows at different elevations, because the first model predicts that the production ratio for these two nuclides will be invariant with elevation and the second that there should be ~10% difference over the range of elevations to be sampled. Finally, the project will provide a local, finite-age calibration site for cosmogenic-nuclide investigations in Antarctica.", "east": 167.75, "geometry": "POINT(166.95999999999998 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "AGE DETERMINATIONS; Mount Erebus; VOLCANO", "locations": "Mount Erebus", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Phillips, Fred; Kyle, Philip; Heizler, Matthew T", "platforms": null, "repositories": null, "science_programs": null, "south": -77.7, "title": "A Test of Global and Antarctic Models for Cosmogenic-nuclide Production Rates using High-precision Dating of 40Ar/39Ar Lava Flows from Mount Erebus", "uid": "p0010397", "west": 166.17}, {"awards": "1739003 Holland, David", "bounds_geometry": null, "dataset_titles": "Icefin raw and processed ice, seafloor, and hydrographic data beneath Thwaites Eastern Ice Shelf", "datasets": [{"dataset_uid": "601618", "doi": "10.15784/601618", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Icefin raw and processed ice, seafloor, and hydrographic data beneath Thwaites Eastern Ice Shelf", "url": "http://www.usap-dc.org/view/dataset/601618"}], "date_created": "Thu, 10 Nov 2022 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Thwaites Glacier", "locations": "Thwaites Glacier; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Washam, Peter", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Thwaites (ITGC)", "south": null, "title": null, "uid": null, "west": null}, {"awards": "2135696 Polito, Michael; 2135695 Emslie, Steven", "bounds_geometry": "POLYGON((-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70,-180 -70.8,-180 -71.6,-180 -72.4,-180 -73.2,-180 -74,-180 -74.8,-180 -75.6,-180 -76.4,-180 -77.2,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,-180 -78,180 -78,178 -78,176 -78,174 -78,172 -78,170 -78,168 -78,166 -78,164 -78,162 -78,160 -78,160 -77.2,160 -76.4,160 -75.6,160 -74.8,160 -74,160 -73.2,160 -72.4,160 -71.6,160 -70.8,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 28 Oct 2022 00:00:00 GMT", "description": "Stable isotope analyses of carbon and nitrogen (\u03b413C and \u03b415N) are commonly used to investigate animal migration, foraging locations and diet, especially in marine species that can travel over great distances. One other stable isotope, sulfur (\u03b434S), is not as commonly used but is increasingly being applied to refine and corroborate data obtained from carbon and nitrogen analyses. Collagen is one of the best tissues for these analyses as it is abundant in bone, preserves well, and can be easily extracted for analysis. In the Ross Sea region, the cold, dry environment has been conductive for the preservation of Ad\u00e9lie penguin (Pygoscelis adeliae) bones, feathers, eggshell and even mummified remains, at active and abandoned colonies that date from before the Last Glacial Maximum (\u003e45,000 yrs ago) through the Holocene. Most of these colonies are associated with one of three polynyas, or highly productive areas of open water surrounded by sea ice in the Ross Sea. Thus, this species is an excellent bioindicator for marine conditions, past and present, and its colonies have appeared and disappeared throughout this region with changing climate and sea ice regimes for millennia. Current warming trends are inducing relatively rapid ecological responses by this species and some of the largest colonies in the Ross Sea are likely to be abandoned in the next 50 years from rising sea level. The recently established Ross Sea Marine Protected Area aims to protect Ad\u00e9lie penguins and other species in this region from human impacts and knowledge on how this species responds to climate change, past and present, will support this goal. \r\n\r\nWe propose to investigate ecological responses in diet and foraging behavior of the Ad\u00e9lie penguin to known climatic events that occurred in the middle to late Holocene, specifically, before, during and after a warming period known as the penguin \u2018optimum\u2019 at 2000 - 4000 cal yr before present (BP). We will apply for the first time a suite of three stable isotope analyses (\u03b413C, \u03b415N, \u03b434S) on chick bones and feathers, as well as prey remains, from active and abandoned colonies in the Ross Sea. We will use existing tissue samples (~60-80 bones) collected by PI Emslie with NSF support since 2001 and supplement these with newly collected samples of bones and feathers in this project. We will conduct compound-specific isotope analyses of carbon on essential amino acids from collagen from a selected sample of 30-40 bones that span the past 5000 yrs to provide corroboratory information. We will apply three-dimensional Bayesian niche models and/or community metrics using R scripts in these analyses to identify isotopic \u2018signatures\u2019 of existing and past foraging grounds and polynyas used by Ad\u00e9lie penguins in the southern, central, and northern Ross Sea. This four-year study will the first of its kind to apply multiple stable isotope analyses to investigate a living species of seabird over millennia in a region where it still exists today. \r\n\r\nBroader Impacts:\r\nThe PIs are committed to public engagement and enhancement of K-12 education in the STEM sciences. Broader impacts of this research will include support and training for one Ph.D., two M.S., and eight undergraduate students in the Department of Biology and Marine Biology, and two M.A. students in the Watson School of Education at the University of North Carolina Wilmington (UNCW). The last two students will continue to expand on a detailed polar curriculum that was initiated in previous NSF grants for 2nd and 4th grade students, and most recently for 9-12th grade students now available on PI Emslie\u2019s website (www.uncw.edu/penguins). Additional curricula for K-12 students will be designed and tested in this project, which will include visitation to local K-12 schools. As in previous awards, we will focus on schools that serve historically under-represented groups in the sciences. We will work with the UNCW Center for Education in STEM Sciences to assess the efficacy of this new curricula. All curricula will be uploaded on the Educational Resource Commons website. Field work will include blogs and active question-answer sessions with students at these schools. We will continue to post project information and updates on PI Emslie\u2019s website and YouTube channel. Our partnership with tour ship companies will provide a platform for onboard lectures on the importance of scientific research as well as citizen science opportunities for another sector of the public. This proposal requires fieldwork in the Antarctic.\r\n", "east": -180.0, "geometry": "POINT(170 -74)", "instruments": null, "is_usap_dc": true, "keywords": "Climate Change; Adelie Penguin; Foraging Ecology; Ross Sea; PENGUINS; Holocene; Stable Isotopes", "locations": "Ross Sea", "north": -70.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Emslie, Steven; Lane, Chad S; Polito, Michael", "platforms": null, "repositories": null, "science_programs": null, "south": -78.0, "title": "Collaborative Research: Using Multiple Stable Isotopes to Investigate Middle to Late Holocene Ecological Responses by Adelie Penguins in the Ross Sea", "uid": "p0010388", "west": 160.0}, {"awards": "1917176 Siddoway, Christine; 1916982 Teyssier, Christian; 1917009 Thomson, Stuart", "bounds_geometry": "POLYGON((-160.16 -67.15,-154.572 -67.15,-148.984 -67.15,-143.39600000000002 -67.15,-137.808 -67.15,-132.22 -67.15,-126.632 -67.15,-121.04400000000001 -67.15,-115.456 -67.15,-109.868 -67.15,-104.28 -67.15,-104.28 -68.165,-104.28 -69.18,-104.28 -70.19500000000001,-104.28 -71.21000000000001,-104.28 -72.225,-104.28 -73.24,-104.28 -74.255,-104.28 -75.27,-104.28 -76.285,-104.28 -77.3,-109.868 -77.3,-115.456 -77.3,-121.044 -77.3,-126.632 -77.3,-132.22 -77.3,-137.808 -77.3,-143.396 -77.3,-148.98399999999998 -77.3,-154.572 -77.3,-160.16 -77.3,-160.16 -76.285,-160.16 -75.27,-160.16 -74.255,-160.16 -73.24,-160.16 -72.225,-160.16 -71.21000000000001,-160.16 -70.19500000000001,-160.16 -69.18,-160.16 -68.165,-160.16 -67.15))", "dataset_titles": "Apatite fission track thermochronology data for detrital minerals, offshore clasts, and bedrock; U-Pb detrital zircon geochronological data, obtained by LA-ICP-MS", "datasets": [{"dataset_uid": "200332", "doi": "", "keywords": null, "people": null, "repository": "in progress", "science_program": null, "title": "U-Pb detrital zircon geochronological data, obtained by LA-ICP-MS", "url": ""}, {"dataset_uid": "200333", "doi": "", "keywords": null, "people": null, "repository": "in progress", "science_program": null, "title": "Apatite fission track thermochronology data for detrital minerals, offshore clasts, and bedrock", "url": ""}], "date_created": "Wed, 19 Oct 2022 00:00:00 GMT", "description": "Sediment records off the coast of Marie Byrd Land (MBL), Antarctica suggest frequent and dramatic changes in the size of the West Antarctic Ice Sheet (WAIS) over short (tens of thousands of years) and long (millions of years) time frames in the past. WAIS currently overrides much of MBL and covers the rugged and scoured bedrock landscape. The ice sheet carved narrow linear troughs that reach depths of two to three thousand meters below sea level as outlet glaciers flowed from the interior of the continent to the oceans. As a result, large volumes of fragmented continental bedrock were carried out to the seabed. The glaciers cut downward into a region of crystalline rocks (i.e. granite) that display a significant temperature change as a function of rock depth. The strong geothermal gradient in the bedrock is favorable for determining when the bedrock became exhumed, or \"uncovered\" by action of the overriding icesheet or other processes. Our approach takes advantage of a reference horizon, or paleogeotherm, established when high-T mineral thermochronometers across Marie Byrd Land (MBL) cooled from temperatures of \u003e800\u00b0 C to 300\u00b0 C, due to rapid regional extension at ~100 Ma . The event imparted a signature through which the subsequent Cenozoic landscape history can be explored: MBL\u0027s elevated geothermal gradient, sustained during the Cenozoic, created favorable conditions for sensitive apatite and zircon low-T thermochronometers to record bedrock cooling related to glacial incision. \r\n\r\nAnalyzing the chemistry of minerals (zircon and apatite) within fragments of eroded rock will reveal the rate and timing of the bedrock erosion and development of topography in West Antarctica. This collaborative project addresses the following questions: When did the land become high enough for a large ice sheet to form? What was the regional pre-glacial topography? Under what climate conditions, and at what point in the growth of an ice sheet, did glaciers begin to cut sharply into bedrock to form the narrow troughs that flow seaward? The research will lead to greater understanding of past Antarctic ice sheet fluctuations and identify precise timing of glacial incisionm which will clarify the onset of WAIS glacier incision and assess the evolution of Cenozoic paleo-topography. The collaborative project provides training for one graduate and 8 undergraduate students in STEM. These students, together with PIs, will refine West Antarctic ice sheet history and obtain results that pertain to the international societal response to contemporary ice sheet change and its global consequences. \r\n\r\nThe methods used for the research include: \r\n\u2022Low-temperature (T) thermochronology and Pecube 3-D thermo-kinematic modeling, applied to the timing and characterizatio episodes of glacial erosional incision. \r\n\u2022Single-grain double- and triple-dating of zircon and apatite, to determine the detailed crustal thermal evolution of the region, enabling the research team to identify the comparative topographic influences on glaciation versus bedrock uplift induced by Eocene to present tectonism/magmatism. \r\n\r\nStudents and PIs employed state-of-the-art analytical facilities in Arizona and Minnesota, expanding the geo- and thermochronologic history of MBL from bedrock samples and offshore sedimentary deposits. The temperature and time data we acquired will provide constraints on paleotopography, isostasy, and the thermal evolution of MBL that will be modeled in 3D using Pecube model simulations. Within hot crust, less incision is required to expose bedrock containing the distinct thermochronometric profile; a prediction we are testing through use of inverse Pecube 3-D models of the thermal field through which bedrock and detrital samples cooled. Using results from Pecube, the ICI-Hot team will examine time-varying topography formed in response to changes in erosion rates, topographic relief, geothermal gradient and/or flexural isostatic rigidity. These effects are manifestations of dynamic processes in the WAIS, including ice sheet loading, ice volume fluctuations, relative motion upon crustal faults, and magmatism-related elevation increase across the MBL dome. The project makes use of pre-existing sample collections housed at the US Polar Rock Repository, IODP\u0027s Gulf Coast Core Repository, and the OSU Marine and Geology Repository. 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": -104.28, "geometry": "POINT(-132.22 -72.225)", "instruments": null, "is_usap_dc": true, "keywords": "Marie Byrd Land; GLACIERS/ICE SHEETS; Zircon; Subglacial Topography; FIELD SURVEYS; TECTONICS; Ice Sheet; Thermochronology; Apatite; ROCKS/MINERALS/CRYSTALS; Erosion; United States Of America; LABORATORY", "locations": "United States Of America; Marie Byrd Land", "north": -67.15, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC", "persons": "Siddoway, Christine; Thomson, Stuart; Teyssier, Christian", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "in progress", "repositories": "in progress", "science_programs": null, "south": -77.3, "title": "Collaborative Research: Ice sheet erosional interaction with hot geotherm in West Antarctica", "uid": "p0010386", "west": -160.16}, {"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: \u003cbr/\u003eThis 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.\u003cbr/\u003eTechnical description:\u003cbr/\u003e 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.", "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 Earth Sciences; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Earth Sciences; Antarctic Earth Sciences", "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": "1654922 de la Pena, Santiago", "bounds_geometry": "POINT(0 -90)", "dataset_titles": " South Pole Weather and Accumulation Measurements 2017-2020", "datasets": [{"dataset_uid": "601591", "doi": "10.15784/601591", "keywords": "Accumulation; Antarctica; Snow; South Pole; Surface Mass Balance", "people": "de la Pe\u00f1a, Santiago", "repository": "USAP-DC", "science_program": null, "title": " South Pole Weather and Accumulation Measurements 2017-2020", "url": "https://www.usap-dc.org/view/dataset/601591"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "To obtain observations of temporal variability of firn processes in Antarctica, we designed a cost-efficient, reliable, and easily deployable firn monitoring system capable of operating with little or no maintenance over a period of several seasons. The prototype station was installed in December 2017 in the vicinity of the geographical South Pole and at a short distance from the Amundsen-Scott South Pole Research Station in Antarctica. The data presented was acquired between December of 2017 and January of 2020. During the first year, of the months without sunlight the longest period without SMB measurements was 22 days, yielding enough measurements to obtain monthly estimates of every variable. During the polar night of 2019, a technical issue related to extreme cold prevented the data logger attached to the CRNCs to record correctly so the sensor was placed under a stand-by mode until the 2nd of December 2019 when temperatures raised. Firn compaction, temperature and wind were recorded continuously during the 2-year period with the exception of a couple of weeks during the Austral winter. The project finalized in January 2020 and the system was taken down on January 15th. ", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": null, "is_usap_dc": true, "keywords": "South Pole; SNOW", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Instrumentation and Support; Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "de la Pe\u00f1a, Santiago", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "EAGER: An Operational System to Measure Surface Mass Balance Deep in the Interior of the Antarctic Ice Sheet", "uid": "p0010360", "west": 0.0}, {"awards": "1744649 Christianson, Knut", "bounds_geometry": "POLYGON((-120 -85.5,-117.5 -85.5,-115 -85.5,-112.5 -85.5,-110 -85.5,-107.5 -85.5,-105 -85.5,-102.5 -85.5,-100 -85.5,-97.5 -85.5,-95 -85.5,-95 -85.62,-95 -85.74,-95 -85.86,-95 -85.98,-95 -86.1,-95 -86.22,-95 -86.34,-95 -86.46000000000001,-95 -86.58,-95 -86.7,-97.5 -86.7,-100 -86.7,-102.5 -86.7,-105 -86.7,-107.5 -86.7,-110 -86.7,-112.5 -86.7,-115 -86.7,-117.5 -86.7,-120 -86.7,-120 -86.58,-120 -86.46000000000001,-120 -86.34,-120 -86.22,-120 -86.1,-120 -85.98,-120 -85.86,-120 -85.74,-120 -85.62,-120 -85.5))", "dataset_titles": "Hercules Dome ApRES Data; Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data; Hercules Dome Ice-Penetrating Radar Swath Topographies; Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets; ITASE Impulse Radar Hercules Dome to South Pole", "datasets": [{"dataset_uid": "601710", "doi": "10.15784/601710", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Holschuh, Nicholas; Horlings, Annika; Christian, John; O\u0027Connor, Gemma; Christianson, Knut; Hoffman, Andrew; Hills, Benjamin", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data", "url": "https://www.usap-dc.org/view/dataset/601710"}, {"dataset_uid": "601606", "doi": "10.15784/601606", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Christianson, Knut", "repository": "USAP-DC", "science_program": null, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "url": "https://www.usap-dc.org/view/dataset/601606"}, {"dataset_uid": "601739", "doi": "10.15784/601739", "keywords": "Antarctica; Apres; Crystal Orientation Fabric; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hercules Dome; Ice Dynamic; Ice Penetrating Radar; Radar Interferometry; Radar Polarimetry", "people": "Horlings, Annika; Erwin, Emma; Steig, Eric J.; Christianson, Knut; Fudge, Tyler J; Hoffman, Andrew; Holschuh, Nicholas; Hills, Benjamin", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome ApRES Data", "url": "https://www.usap-dc.org/view/dataset/601739"}, {"dataset_uid": "601712", "doi": "10.15784/601712", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Welch, Brian; Christianson, Knut; Hoffman, Andrew; Jacobel, Robert", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "ITASE Impulse Radar Hercules Dome to South Pole", "url": "https://www.usap-dc.org/view/dataset/601712"}, {"dataset_uid": "601711", "doi": "10.15784/601711", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Holschuh, Nicholas; Christianson, Knut; Paden, John; Hoffman, Andrew", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome Ice-Penetrating Radar Swath Topographies", "url": "https://www.usap-dc.org/view/dataset/601711"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington\u0027s annual Polar Science Weekend in Seattle, and art-science collaboration.\u003cbr/\u003e\u003cbr/\u003eThis project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a \"Raymond Bump\") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -86.1)", "instruments": null, "is_usap_dc": true, "keywords": "West Antarctica; ICE DEPTH/THICKNESS; East Antarctica", "locations": "West Antarctica; East Antarctica", "north": -85.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Hoffman, Andrew; Holschuh, Nicholas", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.7, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "uid": "p0010359", "west": -120.0}, {"awards": "2032029 Gerken, Sarah", "bounds_geometry": "POLYGON((-70 -62,-68.5 -62,-67 -62,-65.5 -62,-64 -62,-62.5 -62,-61 -62,-59.5 -62,-58 -62,-56.5 -62,-55 -62,-55 -62.8,-55 -63.6,-55 -64.4,-55 -65.2,-55 -66,-55 -66.8,-55 -67.6,-55 -68.4,-55 -69.2,-55 -70,-56.5 -70,-58 -70,-59.5 -70,-61 -70,-62.5 -70,-64 -70,-65.5 -70,-67 -70,-68.5 -70,-70 -70,-70 -69.2,-70 -68.4,-70 -67.6,-70 -66.8,-70 -66,-70 -65.2,-70 -64.4,-70 -63.6,-70 -62.8,-70 -62))", "dataset_titles": "Expedition Data of NBP2303; Invertebrate Zoology", "datasets": [{"dataset_uid": "200386", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2303", "url": "https://www.rvdata.us/search/cruise/NBP2303"}, {"dataset_uid": "200385", "doi": "", "keywords": null, "people": null, "repository": "Alabama Museum of Natural History, University of Alabama, Tuscaloosa", "science_program": null, "title": "Invertebrate Zoology", "url": "https://arctos.database.museum/"}], "date_created": "Mon, 13 Jun 2022 00:00:00 GMT", "description": "Ocean communities play an important role in determining the natural and human impacts of global change. The most conspicuous members of those communities are generally large vertebrates such as marine mammals and sea birds. But smaller animals often determine how the changes impact those charismatic animals. In the Antarctic, where some of the most dramatic physical changes are taking place, we do not know much about what small animals exist. This project will sample the sub-Antarctic and three different Antarctic seas with a hope of identifying, quantifying and discovering the variation in species of a group of small invertebrates. Comma shrimp, also called cumaceans, are rarely seen elsewhere but may be common and important in the communities of these locations. Antarctic sampling traditionally used gear that was not very effective at catching cumaceans so we do not know what species exist there and how common they are. This study will utilize modern sampling methods that will allow comma shrimp to be sampled. This will lead to discoveries about the diversity and abundance of comma shrimp, as well as their relationship to other invertebrate species. Major impacts of this work will be an enhancement of museum collections, the development of description of all the comma shrimp of Antarctica including new and unnamed species. Those contributions may be especially important as we strive to understand what drives the dynamics of charismatic vertebrates and fisheries that are tied to Antarctic food webs. \u003cbr/\u003e\u003cbr/\u003eThis project will collect cumaceans from benthic samples from the Antarctic peninsula, Bransfield Strait, and the Weddell Sea using benthic sleds, boxcores and megacores. Specimens will be fixed in 95% ethanol, preserved in 95% ethanol and 5% glycerin to preserve both morphology and DNA, and some specimens will be partially or wholly preserved in RNALater to preserve RNA and DNA. The specimens will form the basis for a monograph synthesizing current knowledge on the Subantarctic and Antarctic Cumacea, including diagnoses of all species, descriptions of new species, additional description for currently unknown life stages of known species, and vouchered gene sequences for all species collected. The monograph will include keys to all families, genera and species known from the region. Monographic revisions that include identification resources are typically useful for decades to a broad spectrum of other scientists.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -55.0, "geometry": "POINT(-62.5 -66)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; NSF/USA; ANIMALS/INVERTEBRATES; SHIPS; USAP-DC; NBP2303; Weddell Sea; Amd/Us; Antarctic Peninsula", "locations": "Antarctic Peninsula; Weddell Sea", "north": -62.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Gerken, Sarah", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "R2R", "repositories": "Alabama Museum of Natural History, University of Alabama, Tuscaloosa; R2R", "science_programs": null, "south": -70.0, "title": "RAPID: Monographing the Antarctic and Subantarctic Cumacea", "uid": "p0010338", "west": -70.0}, {"awards": "1947646 Shevenell, Amelia; 1947657 Dodd, Justin; 1947558 Leckie, R", "bounds_geometry": "POLYGON((-180 -72.5,-177.6 -72.5,-175.2 -72.5,-172.8 -72.5,-170.4 -72.5,-168 -72.5,-165.6 -72.5,-163.2 -72.5,-160.8 -72.5,-158.4 -72.5,-156 -72.5,-156 -73.15,-156 -73.8,-156 -74.45,-156 -75.1,-156 -75.75,-156 -76.4,-156 -77.05,-156 -77.7,-156 -78.35,-156 -79,-158.4 -79,-160.8 -79,-163.2 -79,-165.6 -79,-168 -79,-170.4 -79,-172.8 -79,-175.2 -79,-177.6 -79,180 -79,178.4 -79,176.8 -79,175.2 -79,173.6 -79,172 -79,170.4 -79,168.8 -79,167.2 -79,165.6 -79,164 -79,164 -78.35,164 -77.7,164 -77.05,164 -76.4,164 -75.75,164 -75.1,164 -74.45,164 -73.8,164 -73.15,164 -72.5,165.6 -72.5,167.2 -72.5,168.8 -72.5,170.4 -72.5,172 -72.5,173.6 -72.5,175.2 -72.5,176.8 -72.5,178.4 -72.5,-180 -72.5))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 08 Jun 2022 00:00:00 GMT", "description": "Presently, Antarctica\u0027s glaciers are melting as Earth\u0027s atmosphere and the Southern Ocean warm. Not much is known about how Antarctica\u0027s ice sheets might respond to ongoing and future warming, but such knowledge is important because Antarctica\u0027s ice sheets might raise global sea levels significantly with continued melting. Over time, mud accumulates on the sea floor around Antarctica that is composed of the skeletons and debris of microscopic marine organisms and sediment from the adjacent continent. As this mud is deposited, it creates a record of past environmental and ecological changes, including ocean depth, glacier advance and retreat, ocean temperature, ocean circulation, marine ecosystems, ocean chemistry, and continental weathering. Scientists interested in understanding how Antarctica\u0027s glaciers and ice sheets might respond to ongoing warming can use a variety of physical, biological, and chemical analyses of these mud archives to determine how long ago the mud was deposited and how the ice sheets, oceans, and marine ecosystems responded during intervals in the past when Earth\u0027s climate was warmer. In this project, researchers from the University of South Florida, University of Massachusetts, and Northern Illinois University will reconstruct the depth, ocean temperature, weathering and nutrient input, and marine ecosystems in the central Ross Sea from ~17 to 13 million years ago, when the warm Miocene Climate Optimum transitioned to a cooler interval with more extensive ice sheets. Record will be generated from new sediments recovered during the International Ocean Discovery Program (IODP) Expedition 374 and legacy sequences recovered in the 1970?s during the Deep Sea Drilling Program. Results will be integrated into ice sheet and climate models to improve the accuracy of predictions. ", "east": -156.0, "geometry": "POINT(-176 -75.75)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; LABORATORY; AMD; PALEOCLIMATE RECONSTRUCTIONS; Ross Sea; USAP-DC; USA/NSF", "locations": "Ross Sea", "north": -72.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -79.0, "title": "Collaborative Proposal: Miocene Climate Extremes: A Ross Sea Perspective from IODP Expedition 374 and DSDP Leg 28 Marine Sediments", "uid": "p0010335", "west": 164.0}, {"awards": "2141555 Brooks, Cassandra", "bounds_geometry": "POLYGON((-180 -71.5,-177.1 -71.5,-174.2 -71.5,-171.3 -71.5,-168.4 -71.5,-165.5 -71.5,-162.6 -71.5,-159.7 -71.5,-156.8 -71.5,-153.9 -71.5,-151 -71.5,-151 -72.25,-151 -73,-151 -73.75,-151 -74.5,-151 -75.25,-151 -76,-151 -76.75,-151 -77.5,-151 -78.25,-151 -79,-153.9 -79,-156.8 -79,-159.7 -79,-162.6 -79,-165.5 -79,-168.4 -79,-171.3 -79,-174.2 -79,-177.1 -79,180 -79,178.1 -79,176.2 -79,174.3 -79,172.4 -79,170.5 -79,168.6 -79,166.7 -79,164.8 -79,162.9 -79,161 -79,161 -78.25,161 -77.5,161 -76.75,161 -76,161 -75.25,161 -74.5,161 -73.75,161 -73,161 -72.25,161 -71.5,162.9 -71.5,164.8 -71.5,166.7 -71.5,168.6 -71.5,170.5 -71.5,172.4 -71.5,174.3 -71.5,176.2 -71.5,178.1 -71.5,-180 -71.5))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 27 May 2022 00:00:00 GMT", "description": "The Ross Sea, Antarctica, is one of the last large intact marine ecosystems left in the world, yet is facing increasing pressure from commercial fisheries and environmental change. It is the most productive stretch of the Southern Ocean, supporting an array of marine life, including Antarctic toothfish the regions top fish predator. While a commercial fishery for toothfish continues to grow in the Ross Sea, fundamental knowledge gaps remain regarding toothfish ecology and the impacts of toothfish fishing on the broader Ross Sea ecosystem. Recognizing the global value of the Ross Sea, a large (\u003e2 million km2) marine protected area was adopted by the multi-national Commission for the Conservation of Antarctic Marine Living Resources in 2016. This research will fill a critical gap in the knowledge of Antarctic toothfish and deepen understanding of biological-physical interactions for fish ecology, while contributing to knowledge of impacts of fishing and environmental change on the Ross Sea system. This work will further provide innovative tools for studying connectivity among geographically distinct fish populations and for synthesizing and assessing the efficacy of a large-scale marine protected area. In developing an integrated research and education program in engaged scholarship, this project seeks to train the next generation of scholars to engage across the science-policy-public interface, engage with Southern Ocean stakeholders throughout the research process, and to deepen the publics appreciation of the Antarctic. \r\n\r\nA major research priority among Ross Sea scientists is to better understand the life history of the Antarctic toothfish and test the efficacy of the Ross Sea Marine Protected Area (MPA) in protecting against the impacts of overfishing and climate change. Like growth rings of a tree, fish ear bones, called otoliths, develop annual layers of calcium carbonate that incorporates elements from their environment. Otoliths offer information on the fishs growth and the surrounding ocean conditions. Hypothesizing that much of the Antarctic toothfish life cycle is structured by ocean circulation, this research employs a multi-disciplinary approach combining age and growth work with otolith chemistry testing, while also utilizing GIS mapping. The project will measure life history parameters as well as trace elements and stable isotopes in otoliths in three distinct sets collected over the last four decades in the Ross Sea. The information will be used to quantify the transport pathways Antarctic toothfish use across their life history, and across time, in the Ross Sea. The project will assess if toothfish populations from the Ross Sea are connected more widely across the Antarctic. By comparing life history and otolith chemistry data across time, the researchers will assess change in life history parameters and spatial dynamics and seek to infer if these changes are driven by fishing or climate change. Spatially mapping of these data will allow an assessment of the efficacy of the Ross Sea MPA in protecting toothfish and where further protections might be needed.\r\n\r\nThis award reflects NSF\u0027\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027\u0027s intellectual merit and broader impacts review criteria.", "east": -151.0, "geometry": "POINT(-175 -75.25)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; USA/NSF; FIELD INVESTIGATION; USAP-DC; AMD; FISHERIES; Ross Sea", "locations": "Ross Sea", "north": -71.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Brooks, Cassandra", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -79.0, "title": "CAREER: Using Otolith Chemistry to Reveal the Life History of Antarctic Toothfish in the Ross Sea, Antarctica: Testing Fisheries and Climate Change Impacts on a Top Fish Predator", "uid": "p0010329", "west": 161.0}, {"awards": "1643285 Joughin, Ian; 1643174 Padman, Laurence", "bounds_geometry": "POLYGON((-104 -73,-102.2 -73,-100.4 -73,-98.6 -73,-96.8 -73,-95 -73,-93.2 -73,-91.4 -73,-89.6 -73,-87.8 -73,-86 -73,-86 -73.8,-86 -74.6,-86 -75.4,-86 -76.2,-86 -77,-86 -77.8,-86 -78.6,-86 -79.4,-86 -80.2,-86 -81,-87.8 -81,-89.6 -81,-91.4 -81,-93.2 -81,-95 -81,-96.8 -81,-98.6 -81,-100.4 -81,-102.2 -81,-104 -81,-104 -80.2,-104 -79.4,-104 -78.6,-104 -77.8,-104 -77,-104 -76.2,-104 -75.4,-104 -74.6,-104 -73.8,-104 -73))", "dataset_titles": "Beta Version of Plume Model; Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier; icepack; Pine Island Basin Scale Model", "datasets": [{"dataset_uid": "200315", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Pine Island Basin Scale Model", "url": "https://github.com/fastice/icesheetModels"}, {"dataset_uid": "200290", "doi": "http://hdl.handle.net/1773/46687", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier", "url": "https://doi.org/10.6069/2MZZ-6B61"}, {"dataset_uid": "200313", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beta Version of Plume Model", "url": "https://github.com/icepack/plumes"}, {"dataset_uid": "200314", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "icepack", "url": "https://github.com/icepack/icepack"}], "date_created": "Fri, 13 May 2022 00:00:00 GMT", "description": "Overview: Several recent studies indicate continuing and increasing ice loss from the Amundsen Sea region of West Antarctica (chiefly Pine Island and Thwaites glaciers). This loss is initiated by thinning of the floating ice shelves by basal melting driven by circulation of relatively warm ocean water under the ice shelves. This thinning triggers ice-dynamics related feedbacks, which leads to loss of ice from the grounded ice sheet. Models suggest that, even though long-term committed ice loss might be governed by ice dynamics, the magnitude of ocean-driven melting at the base of the ice shelves plays a critical role in controlling the rate of ice loss. These conclusions, however, are based on simple parameterized models for melt rate that do not take into account how ocean circulation will change in future as large-scale climate forcing changes, and as the ice shelves thin and retreat through both excess melting and accelerated ice flow. Given that present global climate models struggle to resolve the modern ocean state close to the ice shelves around Antarctica, their projections of future impacts on basal melting and time scale of ice loss have large uncertainties.\r\nThis project is aimed at reducing these uncertainties though two approaches: (i) assessing, for a given ocean state, how the melt rates will change as ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of melt rates beneath the Pine Island and Thwaites ice shelves to changes in ocean state on the Amundsen Sea continental shelf. These studies will provide more realistic bounds on ice loss and sea level rise, and lay the groundwork for development of future fully-coupled ice sheet-ocean simulations.\r\nIntellectual Merit: Rather than pursue a strategy of using fully coupled models, this project adopts a simpler semi-coupled approach to understand the sensitivity of ice-shelf melting to future forcing. Specifically, the project focuses on using regional ocean circulation models to understand current and future patterns of melting in ice-shelf cavities. The project\u2019s preliminary stage will focus on developing high-resolution ice-shelf cavity-circulation models driven by modern observed regional ocean state and validated with current patterns of melt inferred from satellite observations. Next, an ice-flow model will be used to estimate the future grounding line at various stages of retreat. Using these results, an iterative process with the ocean-circulation and ice-flow models will be applied to determine melt rates at each stage of grounding line retreat. These results will help assess whether more physically constrained melt-rate estimates substantially alter the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway. Further, by multiple simulations with modified open-ocean boundary conditions, this study will provide a better understanding of the sensitivity of melt to future changes in regional forcing. For example, what is the sensitivity of melt to changes in Circumpolar Deep Water temperature and to changes in the thermocline height driven be changes in wind forcing? Finally, several semi-coupled ice-ocean simulations will be used to investigate the influence of the ocean-circulation driven distribution of melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response.\r\nBroader Impacts: Planning within the current large range of uncertainty in future sea level change leads to high social and economic costs for governments and businesses worldwide. Thus, our project to reduce sea-level rise uncertainty has strong societal as well as scientific interest. The findings and methods will be applicable to ice shelf cavities in other parts of Antarctica and northern Greenland, and will set the stage for future studies with fully coupled models as computational resources improve. This interdisciplinary work combines expertise of glaciologists and oceanographers, and will contribute to the education of new researchers in this field, with participation of graduate students and postdocs. Through several outreach activities, team members will help make the public aware of the dramatic changes occurring in Antarctica along with the likely consequences.\r\n\r\nThis proposal does not require fieldwork in the Antarctic.\r\n", "east": -86.0, "geometry": "POINT(-95 -77)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; USA/NSF; ICE SHEETS; AMD; USAP-DC; MODELS; Amd/Us; Pine Island Glacier", "locations": "Pine Island Glacier", "north": -73.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Joughin, Ian; Dutrieux, Pierre; Padman, Laurence; Springer, Scott", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "GitHub", "repositories": "GitHub; Uni. Washington ResearchWorks Archive", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Modeling ice-ocean interaction for the rapidly evolving ice shelf cavities of Pine Island and Thwaites glaciers, Antarctica ", "uid": "p0010318", "west": -104.0}, {"awards": "1932876 Ball, Becky", "bounds_geometry": "POLYGON((-59.666116 -62.15,-59.5128377 -62.15,-59.3595594 -62.15,-59.2062811 -62.15,-59.0530028 -62.15,-58.8997245 -62.15,-58.7464462 -62.15,-58.5931679 -62.15,-58.4398896 -62.15,-58.2866113 -62.15,-58.133333 -62.15,-58.133333 -62.1731502,-58.133333 -62.1963004,-58.133333 -62.2194506,-58.133333 -62.2426008,-58.133333 -62.265751,-58.133333 -62.2889012,-58.133333 -62.3120514,-58.133333 -62.3352016,-58.133333 -62.3583518,-58.133333 -62.381502,-58.2866113 -62.381502,-58.4398896 -62.381502,-58.5931679 -62.381502,-58.7464462 -62.381502,-58.8997245 -62.381502,-59.0530028 -62.381502,-59.2062811 -62.381502,-59.3595594 -62.381502,-59.5128377 -62.381502,-59.666116 -62.381502,-59.666116 -62.3583518,-59.666116 -62.3352016,-59.666116 -62.3120514,-59.666116 -62.2889012,-59.666116 -62.265751,-59.666116 -62.2426008,-59.666116 -62.2194506,-59.666116 -62.1963004,-59.666116 -62.1731502,-59.666116 -62.15))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 14 Apr 2022 00:00:00 GMT", "description": "Part I: Non-technical summary\u003cbr/\u003eThe Antarctic Peninsula warmed very rapidly in the late part of the 20th century, much faster than the global average, and this warming is predicted to resume and continue over the rest of the 21st century. One consequence of this rapid warming is the melting and subsequent retreat of glaciers, leading to an increase in newly-exposed land on the Peninsula that was previously covered with ice. Once new terrain is exposed, the process of ecological succession begins, with the arrival of early-colonizing plants, such as moss and lichens, and soil organisms - a process commonly referred to as the \u201cgreening\u201d of Antarctica. Early stages of succession will be an increasingly common feature on the Antarctic Peninsula, but the mechanisms by which they occur on the Antarctic continent is not well understood. Once the plants have established on the newly-exposed soil, they can change many important properties, such as water dynamics, nutrient recycling, soil development, and habitat for microscopic organisms, which will ultimately determine the structure and functioning of the future ecosystem as it develops. These relationships between vegetation, soil, and the associated microorganisms, referred to as \u201cplant-soil\u201d interactions, are something we know virtually nothing about. This project will be the first to make a comprehensive study of how the type of colonizing plant, and the expansion of those plants from climate change, will influence terrestrial ecosystems in Antarctica. Understanding these processes is critical to understanding how the greening Antarctica is occurring and how soil communities and processes are influenced by these expanding plant communities. Through this work the research team, will also be intensively training undergraduate and graduate students, including training of students from underrepresented groups and collaborative training of students from Chile and the US. Additionally, the research groups will continue their focus on scientific outreach with K-12 schools and the general public to expand awareness of the effects of climate change in Antarctica.\u003cbr/\u003e\u003cbr/\u003ePart II: Technical summary\u003cbr/\u003eIn this study, the researchers will use surveys across succession sites along the Antarctic Peninsula and Scotia Arc as well as a manipulative field experiment at glacier succession sites to test how species-specific plant functional traits impact soil properties and associated microbial and invertebrate communities in a greening Antarctica. In doing so, they will pursue three integrated aims to understand how Antarctic plant functional traits alter their soil environment and soil communities during succession after glacial retreat. AIM 1) Characterize six fundamental plant functional traits (thermal conductivity, water holding capacity, albedo, decomposability, tissue nutrient content, and secondary chemistry) among diverse Antarctica flora; AIM 2) Measure the relative effects of fundamental plant functional traits on soil physical properties and soil biogeochemistry across glacial succession gradients in Antarctica; and AIM 3) Measure the relative effects of fundamental plant functional traits on soil microbial and invertebrate communities across glacial succession gradients in Antarctica. They will explore how early-colonizing plants, especially mosses and lichens, alter soil physical, biogeochemical, and biological components, potentially impacting later patterns of succession. The researhcers will use intensive surveys of plant-soil interactions across succession sites and a manipulative transplant experiment in the South Shetland Islands, Antarctica to address their aims. The investigators will collect data on plant functional traits and their effects on soil physical properties, biogeochemistry, biotic abundance, and microbial metagenomics. The data collected will be the first comprehensive measures of the relative importance of plant functional types during glacial retreat and vegetative expansion from climate change in Antarctica, aiding our understanding of how plant functional group diversity and abundance are changing in a greening Antarctica.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -58.133333, "geometry": "POINT(-58.8997245 -62.265751)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; FIELD SURVEYS; ECOLOGICAL DYNAMICS; USA/NSF; SOIL CHEMISTRY; 25 De Mayo/King George Island; Antarctic Peninsula; PLANTS; Amd/Us; FUNGI; ANIMALS/INVERTEBRATES; USAP-DC; TERRESTRIAL ECOSYSTEMS; BACTERIA/ARCHAEA", "locations": "25 De Mayo/King George Island; Antarctic Peninsula", "north": -62.15, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ball, Becky", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -62.381502, "title": "Collaborative Research: Exploring the Functional Role of Antarctic Plants during Terrestrial Succession", "uid": "p0010315", "west": -59.666116}, {"awards": "1744954 Lubin, Dan", "bounds_geometry": "POINT(-148.81 -81.65)", "dataset_titles": "Siple Dome Surface Energy Flux", "datasets": [{"dataset_uid": "601540", "doi": "10.15784/601540", "keywords": "Antarctica; Siple Dome; Spectroscopy", "people": "Ghiz, Madison; Lubin, Dan", "repository": "USAP-DC", "science_program": null, "title": "Siple Dome Surface Energy Flux", "url": "https://www.usap-dc.org/view/dataset/601540"}], "date_created": "Wed, 02 Feb 2022 00:00:00 GMT", "description": "We will measure the surface energy balance on West Antarctica as it relates to atmospheric forcing of surface melt and hydrofracturing of ice shelves and grounding-line ice cliffs. In this program we build upon recent experience with a major campaign jointly supported by the US Antarctic Program (USAP) and US Department of Energy (DOE), the Atmospheric Radiation Measurement (ARM) West Antarctic Radiation Experiment (AWARE). AWARE deployed a highly advanced suite of atmospheric and climate science instrumentation to McMurdo Station from December 2015 through December 2016, including spectral radiometers, research radars and lidars, and comprehensive meteorological equipment. AWARE also deployed a smaller suite of radiometers, lidars, and rawinsonde equipment to the West Antarctic Ice Sheet (WAIS) Divide Ice Camp during December 2015 and January 2016. This project\u2019s principal investigator, Dr. Lubin (Scripps Institution of Oceanography, SIO), was the AWARE lead scientist. For this program we will deploy a suite instruments to measure downwelling and net shortwave and longwave fluxes, sensible and latent heat fluxes, and near-surface meteorology. This suite of instruments will be self-reliant with power requirements and will be supportable in the field with flexible resources, for example a single Twin Otter aircraft mission. These measurements will be analyzed and interpreted to determine synoptic and mesoscale conditions that govern surface melt in West Antarctica, in the context of improving coupled climate model parameterizations.\r\n", "east": -148.81, "geometry": "POINT(-148.81 -81.65)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Siple Dome; USAP-DC; ATMOSPHERIC RADIATION; AMD; FIELD SURVEYS; Amd/Us; USA/NSF", "locations": "Siple Dome", "north": -81.65, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Lubin, Dan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -81.65, "title": "Surface Energy Balance on West Antarctica and the Ross Ice Shelf", "uid": "p0010296", "west": -148.81}, {"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": "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": "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": "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": "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"}, {"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"}], "date_created": "Fri, 31 Dec 2021 00:00:00 GMT", "description": "The research focus of this collaborative proposal was to collect fossil plants, fossil wood, stratigraphic, sedimentologic, paleosol, and geochemical data from plants and the rocks that contain them in order to reconstruct the extent of the Gondwana glaciation in the Shackleton Glacier (SHK) area, the invasion and subsequent flourishing of life following glacial retreat, changes to the physical environment, and the eventual recovery of plant life after the Late Permian biotic events. Only in Antarctica does a complete polar-to-near-polar succession occur across this climatic and biologic transition. The SHK 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. In addition, outcrops in the SHK area extend from the glacigenic deposits of the Upper Carboniferous-Lower Permian through to the Upper Triassic and thus record ecosystems and the plants that inhabited them from the Gondwana icehouse into the Late Permian-Early Triassic greenhouse and into presumed \"full recovery\" of floras from the PTB extinctions in the Late Triassic.\r\n\r\nThe project encompassed a multidisciplinary plan that used various types of paleobotanical expertise, integrated with detailed sedimentology, stratigraphy, and geochemistry, in order to reconstruct Permian-Triassic plant communities and their paleoenvironments. This interdisciplinary approach is a powerful tool to uncover details of Antarctica\u2019s complex late Paleozoic and Mesozoic environmental, climatic, and biotic history which included: 1) glaciation/deglaciation, 2) development and evolution of a post-glacial landscape and biota, 3) environmental and biotic change associated with the end-Permian mass extinction events, 4) earliest ecosystems in the Triassic, 5) greenhouse conditions in the Triassic, 6) full \u2019recovery\u2019 of floras and ecosystems by the Late Triassic, and, through all of these events, 7) development and changes in a foreland basin system. Three interrelated focus areas, each delimited by distinct hypotheses and action strategies, provided the framework to trace floral diversity and environmental evolution after the retreat of glaciers through to the Late Triassic. Antarctica is the only place on Earth that includes extensive outcrops of high-paleolatitude terrestrial rocks, combined with widespread and well-preserved plant fossils, and that spans this crucial time.\r\n\r\nThe research and broader impacts of this proposal were integrated into action strategies that have been successful in the past. Compression floras were collected (constrained by stratigraphy) both quantitatively and qualitatively in order to obtain biodiversity and abundance data, and as a data source for paleoecological analysis. Even in formations where megafossils were unknown (e.g., Lower Permian), fossil wood is present so that anatomy and geochemistry of tree rings were examined. Standard sedimentologic and stratigraphic analyses were 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.\r\n\r\nThe Broader Impacts of the project involved education and outreach initiatives that included women and under-represented groups in the excitement of Antarctic earth sciences: 1) Continuing successful public outreach, teaching, and mentoring of women and under-represented students in Antarctic research; 2) Participation in workshops for under-represented groups via the Expanding Your Horizons Program in Kansas, the TRIO program (KU), and the STELAR summer workshop (UWM) for high-school students. 3) Outreach via the KU Natural History Museum; 4) Exploring Antarctic geosciences through continued presentations to pre K-12 school groups, and field and lab activities at UWM, as well as links from McMurdo Station and satellite conferences from the field with K-12 science classes in Wisconsin and Illinois.", "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": "2039419 Swanger, Kate", "bounds_geometry": "POLYGON((161 -77.3,161.2 -77.3,161.4 -77.3,161.6 -77.3,161.8 -77.3,162 -77.3,162.2 -77.3,162.4 -77.3,162.6 -77.3,162.8 -77.3,163 -77.3,163 -77.35,163 -77.4,163 -77.45,163 -77.5,163 -77.55,163 -77.6,163 -77.65,163 -77.7,163 -77.75,163 -77.8,162.8 -77.8,162.6 -77.8,162.4 -77.8,162.2 -77.8,162 -77.8,161.8 -77.8,161.6 -77.8,161.4 -77.8,161.2 -77.8,161 -77.8,161 -77.75,161 -77.7,161 -77.65,161 -77.6,161 -77.55,161 -77.5,161 -77.45,161 -77.4,161 -77.35,161 -77.3))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 16 Dec 2021 00:00:00 GMT", "description": "The McMurdo Dry Valleys are the largest ice-free region in Antarctica and home to a seasonally active hydrologic system, with streams and saline lakes. Streams are fed by summer meltwater from local glaciers and snowbanks. Therefore, streamflow is tied to summer climate conditions such as air temperatures, ground temperatures, winds, and incoming solar radiation. Based on 50 years of monitoring, summer stream activity has been observed to change, and it likely varied during the geologic past in response to regional climate change and fluctuating glaciers. Thus, deposits from these streams can address questions about past climate, meltwater, and lake level changes in this region. How did meltwater streamflow respond to past climate change? How did streamflow vary during periods of glacial advance and retreat? At what times did large lakes fill many of the valleys and what was their extent? The researchers plan to acquire a record of stream activity for the Dry Valleys that will span the three largest valleys and a time period of about 100,000 years. This record will come from a series of active and ancient alluvial fans that were deposited by streams as they flowed from valley sidewalls onto valley floors. The study will provide a long-term context with which to assess recent observed changes to stream activity and lake levels. The research will be led by two female mid-career investigators and contribute significantly to student research opportunities and education. The research will contribute to graduate and undergraduate education by including students in both field and laboratory research, as well as incorporating data and results into the classroom. The research will be disseminated to K-12 and non-scientific communities through outreach that includes professional development training for K-12 teachers in eastern Massachusetts, development of hands-on activities, visits to K-12 classrooms, and STEM education and literacy activities in North Carolina.\r\n\r\nThe PIs propose to constrain rates of fluvial deposition and periods of increased fluvial activity in the McMurdo Dry Valleys during the Holocene and late Pleistocene. During 50 years of hydrologic monitoring in the Dry Valleys, scientists have observed that streams exhibit significant response to summer conditions. Previous studies of glacial and lacustrine deposits indicate regional glacier advance in the Dry Valleys during recent interglacial periods and high lake levels during and after the Last Glacial Maximum (LGM), with potentially significant low and high stands during the Holocene. However, the geologic record of meltwater activity is poorly constrained. The PIs seek to develop the first spatially-extensive record of stream deposition in the Dry Valleys by analyzing and dating alluvial fans. Given that alluvial fans are deposited by summer meltwater streams in a relatively stable tectonic setting, this record will serve as a proxy of regional summer climate conditions. Meltwater streams are an important component of the regional hydrologic system, connecting glaciers to lakes and affecting ecosystems and soils. A record of fluvial deposition is key to understanding the relationship between past climate change and regional hydrology. The proposed research will include remote- and field-based mapping of alluvial fans, stream channels, and meltwater sources as well as modeling potential incoming solar radiation to the fans and moisture sources during the austral summer. In the field, the PIs will document stratigraphy, collect near-surface sediments from 25 fans across four valleys (Taylor, Pearse, Wright, and Victoria), and collect 2- to 3-m vertical cores of ice-cemented sediments from three alluvial fan complexes. The PIs will then conduct depositional dating of fluvial sands via optically stimulated luminescence, and analyze mineralogy and bulk major element chemistry with X-ray powder diffraction and X-ray fluorescence. From these analyses, the PIs propose to (1) determine the timing of local- to regional-scale periods of high fluvial deposition, (2) calculate depositional rates, and (3) constrain depositional environments and sediment provenance. Given that many of the alluvial fans occur below the hypothesized maximum extents of glacially-dammed lakes in Wright and Victoria valleys, detailed stratigraphy, sediment provenance, and OSL dating of these fans could shed light on ongoing debates regarding the timing and extent of LGM and post-LGM lakes. The work will support a postdoctoral researcher, a PhD student, and many undergraduate and master\u2019s students in cross-disciplinary research that spans stratigraphy, geochemistry, paleoclimatology and physics.", "east": 163.0, "geometry": "POINT(162 -77.55)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Amd/Us; SEDIMENTS; USA/NSF; AMD; Dry Valleys; USAP-DC", "locations": "Dry Valleys", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Swanger, Kate", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -77.8, "title": "Collaborative Research: Holocene and Late Pleistocene Stream Deposition in the McMurdo Dry Valleys, Antarctica as a Proxy for Glacial Meltwater and Paleoclimate", "uid": "p0010285", "west": 161.0}, {"awards": "1744998 Fogt, Ryan; 1745089 Raphael, Marilyn", "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": "Antarctic Sea Ice Reconstructions", "datasets": [{"dataset_uid": "200261", "doi": "https://doi.org/10.6084/m9.figshare.c.5709767.v1", "keywords": null, "people": null, "repository": "Figshare", "science_program": null, "title": "Antarctic Sea Ice Reconstructions", "url": "https://figshare.com/collections/Antarctic_Sea_Ice_Reconstructions/5709767"}], "date_created": "Fri, 10 Dec 2021 00:00:00 GMT", "description": "In contrast to the Arctic, sea ice cover in most Antarctic regions has increased since 1979. The area-integrated total sea ice extent grew to record maximum values in four of the last six years, yet the 2015-16 summer was marked by record low ice cover. While impressive, it is difficult to assess the significance of these very recent records in the context of longer term variability, since the continuous satellite record only dates back to 1978. The limited length of the continuous sea ice record, is a significant confounding factor in ascertaining whether the observed current changes are due to natural variability alone, or represent a forced anthropogenic response. As a result, the scientific understanding of the Antarctic sea ice trends remains poor, as does confidence in projections of future Antarctic sea ice trends. \r\n\r\nTo address this challenge, this project seeks to reconstruct sea ice extent and sea ice concentration, using the relationships between satellite-observed sea ice, sea level pressure, tropical sea surface temperature, ENSO indices, some proxy data (ice cores, etc.), and in situ Southern Ocean temperature data. The aim of the study is to collect and combine these ancillary records as accurately as possible while retaining the variability associated with the intrinsic uncertainty in the available field data. \r\nA range of statistical methods for modelling the relationship between satellite era sea-ice data using flexible regression, Bayesian and multivariate dynamic spatial temporal (MDST) methods will be used.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; Antarctica; NOT APPLICABLE; Amd/Us; SEA ICE; USAP-DC; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Fogt, Ryan", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "Figshare", "repositories": "Figshare", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Understanding Contemporary Variability in Antarctic Sea Ice: Ensemble Reconstruction of Sea Ice Extent and Concentration for the 20th Century", "uid": "p0010284", "west": -180.0}, {"awards": "1744785 Barrett, John", "bounds_geometry": "POLYGON((-180 -77.62,-145.683 -77.62,-111.366 -77.62,-77.049 -77.62,-42.732 -77.62,-8.415 -77.62,25.902 -77.62,60.219 -77.62,94.536 -77.62,128.853 -77.62,163.17 -77.62,163.17 -77.618,163.17 -77.616,163.17 -77.614,163.17 -77.612,163.17 -77.61,163.17 -77.608,163.17 -77.606,163.17 -77.604,163.17 -77.602,163.17 -77.6,128.853 -77.6,94.536 -77.6,60.219 -77.6,25.902 -77.6,-8.415 -77.6,-42.732 -77.6,-77.049 -77.6,-111.366 -77.6,-145.683 -77.6,180 -77.6,178.319 -77.6,176.638 -77.6,174.957 -77.6,173.276 -77.6,171.595 -77.6,169.914 -77.6,168.233 -77.6,166.552 -77.6,164.871 -77.6,163.19 -77.6,163.19 -77.602,163.19 -77.604,163.19 -77.606,163.19 -77.608,163.19 -77.61,163.19 -77.612,163.19 -77.614,163.19 -77.616,163.19 -77.618,163.19 -77.62,164.871 -77.62,166.552 -77.62,168.233 -77.62,169.914 -77.62,171.595 -77.62,173.276 -77.62,174.957 -77.62,176.638 -77.62,178.319 -77.62,-180 -77.62))", "dataset_titles": "McMurdo Dry Valleys LTER: Microbial mat biomass and Normalized Difference Vegetation Index (NDVI) values from Lake Fryxell Basin, Antarctica", "datasets": [{"dataset_uid": "200260", "doi": "doi:10.6073/pasta/9acbbde9abc1e013f8c9fd9c383327f4", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "McMurdo Dry Valleys LTER: Microbial mat biomass and Normalized Difference Vegetation Index (NDVI) values from Lake Fryxell Basin, Antarctica", "url": "https://doi.org/10.6073/pasta/9acbbde9abc1e013f8c9fd9c383327f4"}], "date_created": "Tue, 30 Nov 2021 00:00:00 GMT", "description": "This package contains data collected from microbial mat surveys (i.e., percent cover, ash-free dry mass (AFDM), and pigment concentrations \u2013 chlorophyll-a, scytonemin, and carotenoids) associated with satellite-derived Normalized Difference Vegetation Index (NDVI) values from the Lake Fryxell Basin of Taylor Valley, located in the McMurdo Dry Valleys of Antarctica. The purpose of this study was to quantitatively compare key microbial mat characteristics to NDVI. Data were collected at seven plot locations within the Canada Glacier Antarctic Specially Protected Area (ASPA) near Canada Stream, as well as alongside Green Creek and McKnight Creek. NDVI values were derived from a WorldView-2 multispectral satellite image taken of the Lake Fryxell Basin on January 19, 2018, while biological ground surveying and sampling were conducted during the 2nd and 4th weeks of January 2018. ", "east": 163.19, "geometry": "POINT(-16.82 -77.61)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; ECOSYSTEM FUNCTIONS; FIELD SURVEYS; USAP-DC; USA/NSF; Taylor Valley; Amd/Us", "locations": "Taylor Valley", "north": -77.6, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Barrett, John; Salvatore, Mark", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "EDI", "repositories": "EDI", "science_programs": null, "south": -77.62, "title": "Collaborative Research: Remote characterization of microbial mats in Taylor Valley, Antarctica through in situ sampling and spectral validation", "uid": "p0010281", "west": 163.17}, {"awards": "1644094 Caffee, Marc; 1644128 Welten, Kees", "bounds_geometry": "POINT(-112.12 -79.48)", "dataset_titles": "WAIS Divide Core 10Be data, 2850-3240 m", "datasets": [{"dataset_uid": "601692", "doi": "10.15784/601692", "keywords": "10Be; Antarctica; Beryllium; Cosmogenic Radionuclides; Ice Core Data; WAIS Divide", "people": "Welten, Kees; Caffee, Marc; Woodruff, Thomas", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Core 10Be data, 2850-3240 m", "url": "https://www.usap-dc.org/view/dataset/601692"}], "date_created": "Mon, 15 Nov 2021 00:00:00 GMT", "description": "The award supports a project to use existing samples from the West Antarctic Ice Sheet (WAIS) Divide ice core to align its timescale with that of the Greenland ice cores using common chronological markers. The upper 2850 m of the WAIS Divide core, which was drilled to a depth of 3405 m, has been dated with high precision. The timescale of the remaining (bottom) 550 m of the core has larger uncertainties, limiting our understanding of the timing of abrupt climate events in Antarctica relative to those in Greenland during the last ice age. The intellectual merit of this project is to further constrain the relative timing of these abrupt climate events in Greenland and Antarctica to obtain crucial insight into the underlying mechanism. The main objective of this project is to improve the current timescale of the WAIS Divide core from 31,000 to 65,000 years ago by synchronizing this core with the Greenland ice cores using common signals in Beryllium-10, a radioactive isotope of Be that is produced in the atmosphere by cosmic rays and is deposited onto the snow within 1-2 years of its production. The 10Be flux is largely independent of climate signals since its production varies with solar activity and the geomagnetic field. This project will further strengthen collaborations between the PI\u2019s in Berkeley and Purdue with ice core researchers in the US and Europe, involve undergraduate students in many aspects of its research, and continue out-reach to under-represented students.\r\n\r\nThe direct ice-to-ice synchronization of the WAIS Divide ice core with the Greenland Ice Core Chronology (GICC05) using cosmogenic 10Be is expected to reduce the uncertainty in the relative timing of more than 20 abrupt climate events in Greenland and Antarctica to a few decades. To achieve this goal we will obtain a continuous high-resolution record of 10Be in the WAIS Divide core from 2850 to 3390 m depth, and compare the obtained 10Be record with existing 10Be records of the Greenland ice cores, including GISP2 and NGRIP. We will separate 10Be from ~1000 ice samples of the WAIS Divide core and measure the 10Be concentration in each sample using accelerator mass spectrometry (AMS). Broader impacts of the 10Be measurements are that they will also provide information on the Laschamp event, a ~2000 year long period of low geomagnetic field strength around 41,000 years ago, and improve the calibration of the 14C dating method for organic samples older than 30,000 years. The broader impacts of the project include (1) the involvement and training of undergraduate students in ice core research and accelerator mass spectrometry measurements, (2) the incorporation of ice core and climate research into ongoing outreach programs at Purdue University and Berkeley SSL, (3) better understanding of abrupt climate changes in the past will improve our ability to predict future climate change, (4) evaluating the possible threat of a future geomagnetic excursion in the next few hundred years. This award does not require support in Antarctica.\r\n", "east": -112.12, "geometry": "POINT(-112.12 -79.48)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; LABORATORY; Amd/Us; WAIS Divide; AMD; USAP-DC; DEPTH AT SPECIFIC AGES", "locations": "WAIS Divide", "north": -79.48, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Welten, Kees; Caffee, Marc", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.48, "title": "Synchronizing the WAIS Divide and Greenland Ice Cores from 30-65 ka BP using high-resolution 10Be measurements", "uid": "p0010280", "west": -112.12}, {"awards": "2139051 Guitard, Michelle", "bounds_geometry": "POLYGON((-45 -57,-44.3 -57,-43.6 -57,-42.9 -57,-42.2 -57,-41.5 -57,-40.8 -57,-40.1 -57,-39.4 -57,-38.7 -57,-38 -57,-38 -57.5,-38 -58,-38 -58.5,-38 -59,-38 -59.5,-38 -60,-38 -60.5,-38 -61,-38 -61.5,-38 -62,-38.7 -62,-39.4 -62,-40.1 -62,-40.8 -62,-41.5 -62,-42.2 -62,-42.9 -62,-43.6 -62,-44.3 -62,-45 -62,-45 -61.5,-45 -61,-45 -60.5,-45 -60,-45 -59.5,-45 -59,-45 -58.5,-45 -58,-45 -57.5,-45 -57))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "The Mid-Pleistocene Transition (MPT; ~1.25\u20130.7 Ma) marks the shift from glacial-interglacial cycles paced by obliquity (~41 kyr cycles) to those paced by eccentricity (~100-kyr cycles). This transition occurred despite little variation in Earth\u2019s orbital parameters, suggesting a role for internal climate feedbacks. The MPT was accompanied by decreasing atmospheric pCO2, increasing deep ocean carbon storage, and changes in deep water formation and distribution, all of which are linked to Antarctic margin atmosphere-ice-ocean interactions. However, Pleistocene records that document such interactions are rarely preserved on the shelf due to repeated Antarctic Ice Sheet (AIS) advance; instead, they are preserved in deep Southern Ocean basins. This project takes advantage of the excellent preservation and recovery of continuous Pleistocene sediment sequences collected from the Scotia Sea during International Ocean Discovery Program Expedition 382 to test the following hypotheses: 1) Southern Ocean upper ocean temperatures vary on orbital timescales during the early to middle Pleistocene (2.6\u20130.7 Ma), and 2) Southern Ocean temperatures co-vary with AIS advance/retreat cycles. Paleotemperatures will be reconstructed using the TetraEther indeX of tetraethers containing 86 carbons (TEX86), a proxy that utilizes marine archaeal biomarkers. The Scotia Sea TEX86-based paleotemperature record will be compared to records of AIS variability, including ice rafted debris. Expedition 382 records will be compared to orbitally paced climatic time series and the benthic oxygen isotope record of global ice volume and bottom water temperature to determine if a correlation exists between upper ocean temperature, AIS retreat/advance, and orbital climate forcing. ", "east": -38.0, "geometry": "POINT(-41.5 -59.5)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; SEA SURFACE TEMPERATURE; USAP-DC; USA/NSF; LABORATORY; AMD; Scotia Sea", "locations": "Scotia Sea", "north": -57.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Michelle, Guitard", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -62.0, "title": "Investigating the influence of ocean temperature on Antarctic Ice Sheet evolution during the early to middle Pleistocene ", "uid": "p0010275", "west": -45.0}, {"awards": "1744927 Mitrovica, Jerry; 1745015 Zimmerer, Matthew; 1744949 Campbell, Seth", "bounds_geometry": "POLYGON((-145 -74,-141.6 -74,-138.2 -74,-134.8 -74,-131.4 -74,-128 -74,-124.6 -74,-121.2 -74,-117.8 -74,-114.4 -74,-111 -74,-111 -74.6,-111 -75.2,-111 -75.8,-111 -76.4,-111 -77,-111 -77.6,-111 -78.2,-111 -78.8,-111 -79.4,-111 -80,-114.4 -80,-117.8 -80,-121.2 -80,-124.6 -80,-128 -80,-131.4 -80,-134.8 -80,-138.2 -80,-141.6 -80,-145 -80,-145 -79.4,-145 -78.8,-145 -78.2,-145 -77.6,-145 -77,-145 -76.4,-145 -75.8,-145 -75.2,-145 -74.6,-145 -74))", "dataset_titles": "Mt. Waesche ground-penetrating radar data 2018-2019", "datasets": [{"dataset_uid": "601490", "doi": "10.15784/601490", "keywords": "Antarctica; GPR; Mt. Waesche", "people": "Braddock, Scott", "repository": "USAP-DC", "science_program": null, "title": "Mt. Waesche ground-penetrating radar data 2018-2019", "url": "https://www.usap-dc.org/view/dataset/601490"}], "date_created": "Fri, 22 Oct 2021 00:00:00 GMT", "description": "Projecting future changes in West Antarctic Ice Sheet (WAIS) volume and global sea level rise in response to anthropogenic climate warming requires dynamic ice sheet models, which are enhanced by testing and calibrating with geologic evidence. Successfully modeling WAIS behavior during past collapse events \r\nprovides a basis for predictions of future sea level change. Exposure ages of erratics and bedrock throughout west Antarctica constrain higher-than-present WAIS geometry during the LGM and the last deglaciation. Quantifying the past surface elevation from the interior of the ice sheet is especially useful as it directly constrains ice thickness and volume where most of the mass is located. Data that determines WAIS geometry during the last interglacial, the last time that climate was warmer than present and when global sea level was 3-6 m higher, is critical for empirically constraining changes in WAIS volume and its contribution to sea level, as well as, to calibrate ice sheet models. These datasets are essentially non-\r\nexistent, as such evidence is now covered by the WAIS. Initial results from ground-penetrating radar surveys indicate ice depths around 1200 m. ", "east": -111.0, "geometry": "POINT(-128 -77)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Mt. Waesche; USA/NSF; SNOW/ICE; GLACIER THICKNESS/ICE SHEET THICKNESS; PALEOCLIMATE RECONSTRUCTIONS; LABORATORY; LAVA COMPOSITION/TEXTURE; Amd/Us; AMD; USAP-DC", "locations": "Mt. Waesche", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Braddock, Scott; Campbell, Seth; Ackert, Robert; Zimmerer, Matthew; Mitrovica, Jerry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Collaborative Research: Constraining West Antarctic Ice Sheet elevation during the last interglacial", "uid": "p0010272", "west": -145.0}, {"awards": "9910267 Grunow, Anne; 1141906 Grunow, Anne; 2137467 Grunow, Anne; 0440695 Grunow, Anne; 1643713 Grunow, Anne; 0739480 Grunow, Anne", "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": "Marine Geoscience Data System - cruise links; Polar Rock Repository; SESAR sample registration", "datasets": [{"dataset_uid": "200359", "doi": "", "keywords": null, "people": null, "repository": "PRR", "science_program": null, "title": "Polar Rock Repository", "url": "http://research.bpcrc.osu.edu/rr/"}, {"dataset_uid": "200241", "doi": "", "keywords": null, "people": null, "repository": "SESAR", "science_program": null, "title": "SESAR sample registration", "url": "https://www.geosamples.org/about/services#igsnregistration"}, {"dataset_uid": "200242", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Marine Geoscience Data System - cruise links", "url": "https://www.marine-geo.org/"}, {"dataset_uid": "200243", "doi": "", "keywords": null, "people": null, "repository": "PRR", "science_program": null, "title": "Polar Rock Repository", "url": "https://prr.osu.edu/"}], "date_created": "Thu, 09 Sep 2021 00:00:00 GMT", "description": "The Polar Rock Repository (PRR) was established to curate and loan geologic samples from polar regions to researchers and educators. OPP established the PRR in part to avoid redundant sample collection and thus reduce the environmental impact of polar research. The PRR also provides the research community with an important resource for developing new research projects. The PRR acquires rock collections through donations from institutions and scientists and makes these samples available as no-cost loans for research, education and museum exhibits. Sample metadata are available in an on-line database. The database also includes rock property information useful for geophysical studies. Researchers may request samples for analysis using an online request form. The PRR fulfills several data management directives, including the Scientific Committee on Antarctic Research, Antarctic Data Management directive of providing free, full and open access to both metadata and the samples.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; FIELD SURVEYS; Pacific Ocean; ROCKS/MINERALS/CRYSTALS; GLACIATION; AMD; Weddell Sea; Scotia Sea; TECTONICS; Antarctica; Southern Ocean; Amd/Us; USA/NSF; Amundsen Sea", "locations": "Pacific Ocean; Amundsen Sea; Scotia Sea; Weddell Sea; Antarctica; Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Grunow, Anne", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "PRR", "repositories": "MGDS; PRR; SESAR", "science_programs": null, "south": -90.0, "title": "Continuing Operations Proposal: \r\nThe Polar Rock Repository as a Resource for Earth Systems Science\r\n", "uid": "p0010259", "west": -180.0}, {"awards": "1745006 Brook, Edward; 1745007 Mayewski, Paul; 0838843 Kurbatov, Andrei; 1744993 Higgins, John; 1744832 Severinghaus, Jeffrey", "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; I-165-M GPR Field Report 2019-2020", "datasets": [{"dataset_uid": "601696", "doi": "10.15784/601696", "keywords": "Allan Hills; Antarctica; Ice Core", "people": "Shackleton, Sarah; Brook, Edward", "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": "601669", "doi": "10.15784/601669", "keywords": "Allan Hills; Antarctica; GPR; Ice Core; Report", "people": "Brook, Edward; Nesbitt, Ian", "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": "609541", "doi": "10.7265/N5NP22DF", "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope", "people": "Kurbatov, Andrei V.; Spaulding, Nicole; Introne, Douglas; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills Stable Water Isotopes", "url": "https://www.usap-dc.org/view/dataset/609541"}, {"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"}], "date_created": "Fri, 27 Aug 2021 00:00:00 GMT", "description": " Between about 2.8-0.9 Ma, Earth\u2019s climate was characterized by 40 kyr cycles, driven or paced by changes in the tilt of Earth\u2019s spin axis. Much is known about the 40k world from studies of deep-sea sediments, but our understanding of climate change during this period and the transition between the 40kyr glacial cycles from 2.8-0.9 Ma and the 100kyr glacial cycles of the last 0.9 Myr 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 \u003e1 Ma ice discovered in shallow ice cores in the Allan Hills Blue Ice Area (BIA), Antarctica. During the 2015-2016 field season we recovered ice from two nearby drill cores that dates to \u003e 2 million years in age using the 40Ar/38Ar ratio of the trapped gases. Our discovery of ice of this antiquity in two cores demonstrates that there is gas-record quality ice from the 40k world in the Allan Hills BIA. To further characterize the composition of Earth\u2019s atmosphere and Antarctic climate during the 40k world we request support for two field seasons to drill new large-volume (4\u201d or 9\u201d diameter) ice cores at sites where we have previously identified \u003e1 Ma ice and nearby sites where ground penetrating radar has identified bedrock features conducive to the preservation of old ice. ", "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": "2046800 Thurber, Andrew", "bounds_geometry": "POLYGON((162 -77,162.6 -77,163.2 -77,163.8 -77,164.4 -77,165 -77,165.6 -77,166.2 -77,166.8 -77,167.4 -77,168 -77,168 -77.1,168 -77.2,168 -77.3,168 -77.4,168 -77.5,168 -77.6,168 -77.7,168 -77.8,168 -77.9,168 -78,167.4 -78,166.8 -78,166.2 -78,165.6 -78,165 -78,164.4 -78,163.8 -78,163.2 -78,162.6 -78,162 -78,162 -77.9,162 -77.8,162 -77.7,162 -77.6,162 -77.5,162 -77.4,162 -77.3,162 -77.2,162 -77.1,162 -77))", "dataset_titles": null, "datasets": null, "date_created": "Sat, 21 Aug 2021 00:00:00 GMT", "description": "Due to persistent cold temperatures, geographical isolation, and resulting evolutionary distinctness of Southern Ocean fauna, the study of Antarctic reducing habitats has the potential to fundamentally alter our understanding of the biologic processes that inhibit greenhouse gas emissions from our oceans. Marine methane, a greenhouse gas 25x as potent as carbon dioxide for warming our atmosphere, is currently a minor component of atmospheric forcing due to the microbial oxidation of methane within the oceans. Based on studies of persistent deep-sea seeps at mid- and northern latitudes we have learned that bacteria and archaea create a \u2018sediment filter\u2019 that oxidizes methane prior to its release. As increasing global temperatures have and will continue to alter the rate and variance of methane release, the ability of the microbial filter to respond to fluctuations in methane cycles is a critical yet unexplored avenue of research. Antarctica contains vast reservoirs of methane, equivalent to all of the permafrost in the Arctic, and yet we know almost nothing about the fauna that may mitigate its release, as until recently, we had not discovered an active methane seep.\r\n\r\nIn 2012, a methane seep was discovered in the Ross Sea, Antarctica that formed in 2011 providing the first opportunity to study an active Antarctic methane-fueled habitat and simultaneously the impact of microbial succession on the oxidation of methane, a critical ecosystem service. Previous work has shown that after 5 years of seepage, the community was at an early stage of succession and unable to mitigate the release of methane from the seafloor. In addition, additional areas of seepage had begun nearby. This research aims to quantify the community trajectory of these seeps in relation to their role in the Antarctic Ecosystem, from greenhouse gas mitigation through supporting the food web. Through the application of genomic and transcriptomic approaches, taxa involved in methane cycling and genes activated by the addition of methane will be identified and contrasted with those from other geographical locations. These comparisons will elucidate how taxa have evolved and adapted to the polar environment.\r\n\r\nThis research uses a \u2018genome to ecosystem\u2019 approach to advance our understanding of organismal and systems ecology in Antarctica. By quantifying the trajectory of community succession following the onset of methane emission, the research will decipher temporal shifts in biodiversity/ecosystem function relationships. Phylogenomic approaches focusing on taxa involved in methane cycling will advance the burgeoning field of microbial biogeography on a continent where earth\u2019s history may have had a profound yet unquantified impact on microbial evolution. Further, the research will empirically quantify the role of chemosynthesis as a form of export production from seeps and in non-seep habitats in the nearshore Ross Sea benthos, informing our understanding of Antarctic carbon cycling.\r\n", "east": 168.0, "geometry": "POINT(165 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; Mcmurdo Sound; USA/NSF; USAP-DC; BACTERIA/ARCHAEA; BENTHIC; FIELD SURVEYS; Amd/Us; ECOSYSTEM FUNCTIONS", "locations": "Mcmurdo Sound", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Thurber, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -78.0, "title": "CAREER: Ecosystem Impacts of Microbial Succession and Production at Antarctic Methane Seeps", "uid": "p0010250", "west": 162.0}, {"awards": "1341649 Johnson, Leah; 1740239 Johnson, Leah", "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": null, "datasets": null, "date_created": "Fri, 13 Aug 2021 00:00:00 GMT", "description": "Albatrosses (family Diomedeidae) are among the most threatened of bird species. Of the 22 species that are currently recognized, all are considered at least Threatened or Near-Threatened, and 9 are listed as Endangered or Critically Endangered. Because of the decline in albatross populations and the birds\u0027 role as a top predator in the pelagic ecosystem, it is vitally important to understand the factors affecting the population dynamics of these birds to better inform strategies for conservation and mitigating environmental change. The goal of this project is to answer the question: What are the population consequences of albatross bioenergetics and foraging strategies? The project took a two pronged approach: 1) constructing, parameterizing, and validating a Dynamic Energy Budget model to understand growth and constraints on foraging; and 2) undertaking an in-depth meta-analysis of existing individual tracking and life history data from multiple albatross species across successive life stages. This theoretical work will be grounded with a unique and extensive data set on albatrosses provided by collaborator Richard Phillips from the British Antarctic Survey. Bioenergetics constrain a variety of behaviors. A more complete understanding of how individuals use energy can give insight into how behaviors from foraging to breeding and survival, and resulting population attributes, might change with environmental factors, due to anthropogenic and other drivers. This work will further a general understanding of how bioenergetics shapes behavior and drives population level processes, while providing an approach that can be used to guide conservation strategies for endangered populations. The research findings and activities were made accessible to public audiences through websites and a blog maintained for the project by a postdoctoral researcher. The project involved undergraduate researchers in the project, within formal laboratory groups and also through in-classroom presentations and activities. This project also involved public outreach through twitter and other venues. All project publications are open access, the resulting open source software was released to the public, and metadata and analyses are fully documented to promote further collaborative exploration of this system.\r\n\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "BIRDS; Amd/Us; USAP-DC; AMD; USA/NSF; MODELS; United States Of America", "locations": "United States Of America", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Johnson, Leah; Ryan, Sadie", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Quantifying how Bioenergetics and Foraging Determine Population Dynamics in Threatened Antarctic Albatrosses", "uid": "p0010242", "west": -180.0}, {"awards": "1927742 Fleming, Alyson; 1947453 Hunt, Kathleen; 1927709 Friedlaender, Ari", "bounds_geometry": "POLYGON((150 -60,153 -60,156 -60,159 -60,162 -60,165 -60,168 -60,171 -60,174 -60,177 -60,180 -60,180 -61.5,180 -63,180 -64.5,180 -66,180 -67.5,180 -69,180 -70.5,180 -72,180 -73.5,180 -75,177 -75,174 -75,171 -75,168 -75,165 -75,162 -75,159 -75,156 -75,153 -75,150 -75,150 -73.5,150 -72,150 -70.5,150 -69,150 -67.5,150 -66,150 -64.5,150 -63,150 -61.5,150 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 10 Aug 2021 00:00:00 GMT", "description": "An archive of baleen plates from 800 Antarctic blue and fin whales harvested between 1946 and 1948 was recently rediscovered in the Smithsonian\u2019s National Museum of Natural History. As baleen grows, it incorporates compounds from the whale\u2019s diet and surroundings, recording continuous biological and oceanographic information across multiple years. The baleen record forms an ideal experimental platform for studying bottom-up, top-down and anthropogenic impacts on blue and fin whales. Such insights are likely impossible to obtain through any other means as blue and fin whales now number ~1 and 4% of their pre-whaling abundances. The baleen archive includes years with strong climate and temperature anomalies allowing the influence of climate variability on predators and the ecosystems that support them to be examined. Additionally, the impact of whaling on whale stress levels will be investigated by comparing years of intensive whaling with the non-whaling years of WWII, both of which are captured in the time series. We will use 1) bulk stable isotopes to examine the trophic dynamics of Antarctic blue and fin whales, 2) compound-specific stable isotope analysis (CSIA-AA) to characterize the biogeochemistry of the base of the Antarctic food web and 3) hormone analyses to examine the population biology of these species. These investigations will fill major gaps in our understanding of the largest krill predators, their response to disturbance and environmental change, and the impact that commercial whaling has had on the structure and function of the Antarctic marine ecosystem.", "east": 180.0, "geometry": "POINT(165 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; PELAGIC; MAMMALS; LABORATORY; AMD; Amd/Us; Southern Ocean; USAP-DC; USA/NSF", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Fleming, Alyson; Friedlaender, Ari; McCarthy, Matthew; Hunt, Kathleen", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -75.0, "title": "Collaborative Research: A New Baseline for Antarctic Blue and Fin Whales", "uid": "p0010240", "west": 150.0}, {"awards": "2031442 Learman, Deric", "bounds_geometry": "POLYGON((-180 -60,-167.5 -60,-155 -60,-142.5 -60,-130 -60,-117.5 -60,-105 -60,-92.5 -60,-80 -60,-67.5 -60,-55 -60,-55 -62,-55 -64,-55 -66,-55 -68,-55 -70,-55 -72,-55 -74,-55 -76,-55 -78,-55 -80,-67.5 -80,-80 -80,-92.5 -80,-105 -80,-117.5 -80,-130 -80,-142.5 -80,-155 -80,-167.5 -80,180 -80,178 -80,176 -80,174 -80,172 -80,170 -80,168 -80,166 -80,164 -80,162 -80,160 -80,160 -78,160 -76,160 -74,160 -72,160 -70,160 -68,160 -66,160 -64,160 -62,160 -60,162 -60,164 -60,166 -60,168 -60,170 -60,172 -60,174 -60,176 -60,178 -60,-180 -60))", "dataset_titles": "Physical and geochemical data from shelf sediments near the Antartic Pennisula", "datasets": [{"dataset_uid": "601607", "doi": "10.15784/601607", "keywords": "Antarctica; Antarctic Peninsula; Grain Size; Grain Size Analysis; Marine Geoscience; Marine Sediments; Organic Matter Geochemistry; Sediment Core Data; Shelf Sediments; Weddell Sea", "people": "Learman, Deric", "repository": "USAP-DC", "science_program": null, "title": "Physical and geochemical data from shelf sediments near the Antartic Pennisula", "url": "https://www.usap-dc.org/view/dataset/601607"}], "date_created": "Wed, 28 Jul 2021 00:00:00 GMT", "description": "This proposal will provide genetic and enzymatic insight into how microbial communities in benthic sediments on the coastal shelf of Antarctica degrade complex organic matter. The current understanding of how benthic microbial communities respond and also degrade complex organic matter in Antarctica is fragmented. Recent work suggests benthic microbial communities are shaped by organic matter availability (encompassing both quantity and quality), however, these studies were observational and did not directly examine community function (e.g. enzyme activity and/or gene expression). Preliminary metagenomic data, collected from western Antarctica marine sediments, document gene potential for organic matter degradation throughout the entire sample set (spanning the Amundsen Sea, Bellingshausen Sea, and Ross Sea), but functional data was not collected. To date, studies have examined either enzyme activity or metagenomic potential but few have been able to directly connect the two. To address these gaps in knowledge, this proposal will utilize powerful tools such as metagenomics and metatranscriptomics, coupled with microcosm experiments, enzyme assays, and geochemical data. This hypothesis driven proposal will examine microbial communities from the continental shelf of Antarctica from two different regions (Bransfield Strait and Weddell Sea) to document the communities\u2019 enzymatic activity and genes used to degrade complex organic matter. These data will expand our current knowledge of genetic potential towards a more direct understanding of enzyme function as it relates to degradation of complex organic matter in marine sediments from Antarctica. ", "east": 160.0, "geometry": "POINT(-127.5 -70)", "instruments": null, "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; USAP-DC; Antarctic Peninsula; BENTHIC; SHIPS; SEDIMENT CHEMISTRY; Amd/Us; AMD; USA/NSF; Weddell Sea", "locations": "Antarctic Peninsula; Weddell Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Learman, Deric", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "RAPID: Meta-genomic and Transcriptomic Investigation of Complex Organic Matter Degradation in Antarctic Benthic Sediments", "uid": "p0010235", "west": -55.0}, {"awards": "1445205 Putkonen, Jaakko", "bounds_geometry": "POLYGON((157.6 -83.2,157.62 -83.2,157.64 -83.2,157.66 -83.2,157.68 -83.2,157.7 -83.2,157.72 -83.2,157.74 -83.2,157.76 -83.2,157.78 -83.2,157.8 -83.2,157.8 -83.21,157.8 -83.22,157.8 -83.23,157.8 -83.24,157.8 -83.25,157.8 -83.26,157.8 -83.27,157.8 -83.28,157.8 -83.29,157.8 -83.3,157.78 -83.3,157.76 -83.3,157.74 -83.3,157.72 -83.3,157.7 -83.3,157.68 -83.3,157.66 -83.3,157.64 -83.3,157.62 -83.3,157.6 -83.3,157.6 -83.29,157.6 -83.28,157.6 -83.27,157.6 -83.26,157.6 -83.25,157.6 -83.24,157.6 -83.23,157.6 -83.22,157.6 -83.21,157.6 -83.2))", "dataset_titles": "Cosmogenic-Nuclide data at ICE-D; Old Ice, Ong Valley, Transantarctic Mountains", "datasets": [{"dataset_uid": "601665", "doi": "10.15784/601665", "keywords": "Antarctica; Buried Ice; Cosmogenic Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Old Ice; Ong Valley", "people": "Bergelin, Marie; Putkonen, Jaakko", "repository": "USAP-DC", "science_program": null, "title": "Old Ice, Ong Valley, Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601665"}, {"dataset_uid": "200295", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic-Nuclide data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Fri, 16 Jul 2021 00:00:00 GMT", "description": "Finding the oldest ice on Earth can tell us about the climate and life forms in the distant past\r\n\r\nRecently we discovered a mile wide and hundreds of feet thick ice body in Antarctica that is buried under just a few feet of dirt. Thus far our analyses of the dirt suggest that the ice is over million years old. Generally, glacial ice contains tiny bubbles and dirt that was deposited and locked in the ice by the ancient snowfall and today still holds small samples of the atmospheric gases and everything else that was carried by the winds in the past. Such samples may include the amount of greenhouse gases, plant pollen, microbes, and mineral dust. Therefore the glaciers are like archives where we can access and study the Earth\u2019s history with samples that are unavailable anywhere else. Ice survives poorly on Earth\u2019s surface and therefore currently only few ice samples are known that are approximately million years old. Our site has a high potential to harbor perhaps the oldest ice on Earth. However, first we need to sample and date the ice. Our research will also help us understand how these pockets of buried ice can survive such unusually long periods of time. Such understanding will help us study the landforms and history of not only Antarctica but also the Mars where similar dirt covered glaciers are found today.\r\n\r\nWe propose to collect regolith samples through the approximately 1 m thick cover and to core the buried ice in Ong Valley down to 10 m depth to determine the cosmogenic nuclide concentrations both in the regolith and in the embedded mineral matter suspended in the ice. The systematics of the target cosmogenic nuclides (10Be, 26Al, and 21Ne) such as half-lives, isotope production rates, production pathways, and related attenuation lengths allow us to uniquely determine the age of the ice and the rate the ice is sublimating. Our existing samples and analyses reveal accumulation of mineral matter at the base of surficial debris layer and the surface erosion of this debris by eolian processes. The intellectual merit of the proposed activity: Our main objective is to unequivocally determine the age and sublimation rate of two buried massive ice bodies in time scale of thousands to millions of years. The slow sublimation is a fundamentally Antarctic process, and may have altered most of the currently ice-free areas throughout the continent. Similar large, debris covered ice bodies have been recently discovered in Mars as well. Our results may transform the understanding of the longevity of the buried ice bodies and potentially reveal the oldest ice ever found in the interior of the Antarctica. If proven old and slowly sublimating, this buried ice can potentially yield direct information about the atmospheric chemistry, ancient life forms, and geology of greater antiquity than the currently available and sampled ice bodies. The broader impacts resulting from the proposed activity: The results will be relevant to researchers in glaciology, paleoclimatology, planetary geology, and biology. Several students will participate in the project and do field work in Antarctica, work in lab, attend meetings, attend outreach activities, and produce videos. A graduate student will prepare his/her thesis on a topic closely related to the objectives of the proposed research. The results of the research will be published in scientific meetings and publications.\r\n", "east": 157.8, "geometry": "POINT(157.7 -83.25)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; FIELD SURVEYS; Transantarctic Mountains; GLACIERS/ICE SHEETS; AMD; Amd/Us", "locations": "Transantarctic Mountains", "north": -83.2, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "putkonen, jaakko; Balco, Gregory; Morgan, Daniel", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -83.3, "title": "Collaborative Research: Long Term Sublimation/Preservation of Two Separate, Buried Glacier Ice Masses, Ong Valley, Southern Transantarctic Mountains", "uid": "p0010231", "west": 157.6}, {"awards": "1746148 Sirovic, Ana", "bounds_geometry": "POLYGON((140 -65.5,140.8 -65.5,141.6 -65.5,142.4 -65.5,143.2 -65.5,144 -65.5,144.8 -65.5,145.6 -65.5,146.4 -65.5,147.2 -65.5,148 -65.5,148 -65.57,148 -65.64,148 -65.71,148 -65.78,148 -65.85,148 -65.92,148 -65.99,148 -66.06,148 -66.13,148 -66.2,147.2 -66.2,146.4 -66.2,145.6 -66.2,144.8 -66.2,144 -66.2,143.2 -66.2,142.4 -66.2,141.6 -66.2,140.8 -66.2,140 -66.2,140 -66.13,140 -66.06,140 -65.99,140 -65.92,140 -65.85,140 -65.78,140 -65.71,140 -65.64,140 -65.57,140 -65.5))", "dataset_titles": "Passive acoustic recording metadata from East Antarctica, Feb 2019", "datasets": [{"dataset_uid": "601465", "doi": "10.15784/601465", "keywords": "Antarctica; East Antarctica", "people": "Sirovic, Ana", "repository": "USAP-DC", "science_program": null, "title": "Passive acoustic recording metadata from East Antarctica, Feb 2019", "url": "https://www.usap-dc.org/view/dataset/601465"}], "date_created": "Tue, 13 Jul 2021 00:00:00 GMT", "description": "In austral summer 2019, a 48 day, multi-country, interdisciplinary research voyage mapped Antarctic krill (Euphausia superba) and baleen whale, blue whale (Balaenoptera musculus) and fin whale (B. physalus) distributions in particular off East Antarctica. We detected, tracked and localized blue whales and mapped prey fields in the vicinity of a fixed acoustic mooring that combined passive and active acoustics for collection of concurrent predator and prey data. By coupling moored data collection with the ship-based survey focusing on Antarctic blue whale behaviour and krill dynamics, we investigated the dynamics of blue whales and their prey. We found that the production of social calls, D calls of blue whales and 40 Hz calls of fin whales, was correlated with the krill biomass over a week-long period. ", "east": 148.0, "geometry": "POINT(144 -65.85)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; USAP-DC; SPECIES/POPULATION INTERACTIONS; MAMMALS; PELAGIC; East Antarctica; USA/NSF; ACOUSTIC SCATTERING; FIELD SURVEYS; ARTHROPODS", "locations": "East Antarctica", "north": -65.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sirovic, Ana; Stafford, Kathleen", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -66.2, "title": "EAGER: Collaborative Research: Acoustic Ecology of Foraging Antarctic Blue Whales in the Vicinity of Antarctic Krill", "uid": "p0010228", "west": 140.0}, {"awards": "1947094 Sidor, Christian", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "The research supported by this grant centers on the evolution of fossil amphibians (temnospondyls) from the Early Triassic, a crucial time interval in the evolution of life on Earth following the end-Permian mass extinction, specifically based on fossil material from Antarctica, a high-latitude paleoenvironment that may have served as a refuge for tetrapods across the extinction event. Previous records of temnospondyls, mostly reported several decades ago, are highly fragmentary, and their original interpretations are considered dubious or demonstrably erroneous by contemporary workers. The Antarctic record of temnospondyls is of great import in understanding the biotic recovery in terrestrial environments for several reasons. Firstly, temnospondyls, like amphibians today, were highly speciose in the Triassic but were also some of the most susceptible to environmental perturbations and instability. Therefore, temnospondyls provide key insights into the paleoenvironmental conditions, either in place of or alongside other lines of data. Secondly, the record of temnospondyls from the Early Triassic is quite rich, but it is also restricted to a few densely sampled regions, such as the Karoo Basin of South Africa. In order to ascertain whether observed patterns such as an unusual abundance of small-bodied taxa or a lack of faunal overlap between different depositional basins (endemism) are real or merely artifactual, study of additional, less sampled regions takes on great import. Recent collection of substantial new temnospondyl material from several horizons in the Triassic exposure of Antarctica provides the requisite data to begin to address these questions. Finally, correlating the Triassic rocks of Antarctica with those of adjacent regions is largely reliant on comparisons of faunal assemblages. In particular, the middle Fremouw Formation, one of the horizons from which new temnospondyl material was collected, remains of uncertain relation and age due to the paucity of described material. ", "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": "1643119 Zabotin, Nikolay", "bounds_geometry": "POLYGON((-180 -73,-177 -73,-174 -73,-171 -73,-168 -73,-165 -73,-162 -73,-159 -73,-156 -73,-153 -73,-150 -73,-150 -74.2,-150 -75.4,-150 -76.6,-150 -77.8,-150 -79,-150 -80.2,-150 -81.4,-150 -82.6,-150 -83.8,-150 -85,-153 -85,-156 -85,-159 -85,-162 -85,-165 -85,-168 -85,-171 -85,-174 -85,-177 -85,180 -85,178 -85,176 -85,174 -85,172 -85,170 -85,168 -85,166 -85,164 -85,162 -85,160 -85,160 -83.8,160 -82.6,160 -81.4,160 -80.2,160 -79,160 -77.8,160 -76.6,160 -75.4,160 -74.2,160 -73,162 -73,164 -73,166 -73,168 -73,170 -73,172 -73,174 -73,176 -73,178 -73,-180 -73))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 22 Jun 2021 00:00:00 GMT", "description": "Recent theoretical and experimental work indicates that in a wide range of altitudes and for periods from a few minutes to several hours, a significant part of the wave activity observed in the thermosphere is due to acoustic gravity waves radiated by infragravity waves in the ocean. It is proposed to study this impressive connection between geospheres in Antarctica, at the location where close proximity of the Ross Ice Shelf makes it very special. Infragravity waves are able to excite the fundamental mode and low-order oscillations in the Ross Ice Shelf at its resonance frequencies, with the latter creating standing wave structures throughout the atmosphere. It is likely that this effect was recently detected using lidar observations at McMurdo. This project will study implications of this phenomenon, as well as more general aspects of wave activity in Antarctic geospheres, using data from a unique combination of recently installed instruments: the Dynasonde at Korean Jang Bogo station, the NSF-sponsored network of seismographs and microbarometers on the Ross Ice Shelf, and the IMS-affiliated infrasound station near McMurdo.\r\n\r\nThe goal of this research is to study atmospheric waves in the thermosphere in Antarctica and to investigate the roles that the Ross Ice Shelf and the Southern Ocean play in generation of the atmospheric waves. Anticipated results are of interest also for general aeronomy and for glaciology. This project will verify the hypothesis that the persistent atmospheric waves in mesosphere and lower thermosphere, which are observed with a lidar instrument at McMurdo, are related to the low-frequency vibration resonances of the Ross Ice Shelf excited by infragravity waves in the ocean. An accurate characterization will be achieved for low-frequency oscillations of the Ross Ice Shelf and the quality factors of its resonances will be assessed. Investigation of a consistency between observed and predicted vertical distributions of the wave intensity is expected to provide insights into where the horizontal momentum carried by AGWs is transferred to the mean motion, i.e., to the large-scale dynamics of the Antarctic thermosphere. A determination of whether accurate measurements of the acoustic resonant frequencies and their variations can provide useful constraints on the neutral temperature profile in the atmosphere will be done. Extensive use of Jang Bogo Dynasonde data in all mentioned tasks will allow further developing Dynasonde techniques.", "east": -150.0, "geometry": "POINT(-175 -79)", "instruments": null, "is_usap_dc": true, "keywords": "Ronne Ice Shelf; USA/NSF; Amd/Us; AMD; SEA ICE MOTION; FIELD INVESTIGATION; USAP-DC", "locations": "Ronne Ice Shelf", "north": -73.0, "nsf_funding_programs": "Antarctic Astrophysics and Geospace Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Godin, Oleg; Zabotin, Nikolay", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -85.0, "title": "Resonance Properties of the Ross Ice Shelf, Antarctica, as a Factor in Regional Wave Interaction between Ocean and Atmosphere", "uid": "p0010195", "west": 160.0}, {"awards": "1744970 Shevenell, Amelia", "bounds_geometry": "POLYGON((120 -66,120.1 -66,120.2 -66,120.3 -66,120.4 -66,120.5 -66,120.6 -66,120.7 -66,120.8 -66,120.9 -66,121 -66,121 -66.1,121 -66.2,121 -66.3,121 -66.4,121 -66.5,121 -66.6,121 -66.7,121 -66.8,121 -66.9,121 -67,120.9 -67,120.8 -67,120.7 -67,120.6 -67,120.5 -67,120.4 -67,120.3 -67,120.2 -67,120.1 -67,120 -67,120 -66.9,120 -66.8,120 -66.7,120 -66.6,120 -66.5,120 -66.4,120 -66.3,120 -66.2,120 -66.1,120 -66))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 22 Jun 2021 00:00:00 GMT", "description": "At present, Antarctica\u2019s glaciers are melting as the Southern Ocean warms. While glacial retreat in West Antarctica is linked to ocean warming, less is known about the response of East Antarctica\u2019s glaciers. Totten Glacier, located on the Sabrina Coast, East Antarctica is presently retreating. Totten\u2019s retreat is important because it is associated with warm ocean waters and because the glacier drains part of the East Antarctic Ice Sheet that contains enough ice to raise global sea levels ~3.5 meters. Mud accumulating on the seafloor around Antarctica is composed of sediment from the adjacent continent, as well as the skeletons and debris from microscopic marine organisms. As mud accumulates, so does a record of past environmental changes, including ocean temperatures and the advance and retreat of glaciers. Scientists use a variety of physical and chemical analyses to determine how long ago this mud was deposited, the temperature of the ocean at that location through time, and the relative location of glacial ice. In this project, researchers from the University of South Florida will refine and test new geochemical thermometers to better understand the influence of ocean temperatures on East Antarctic glacier extent over the last ~16,000 years. Results will be integrated into ice sheet and climate models to improve the accuracy of predictions.", "east": 121.0, "geometry": "POINT(120.5 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; FIELD INVESTIGATION; USA/NSF; USAP-DC; PALEOCLIMATE RECONSTRUCTIONS; Sabrina Coast; AMD; Amd/Us", "locations": "Sabrina Coast", "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -67.0, "title": "Deglacial to Recent Paleoceanography of the Sabrina Coast, East Antarctica: A Multi-proxy Study of Ice-ocean Interactions at the Outlet of the Aurora Subglacial Basin", "uid": "p0010194", "west": 120.0}, {"awards": "1750888 Aronson, Richard; 1750630 Smith, Craig; 1750903 Ingels, Jeroen", "bounds_geometry": "POLYGON((-64 -66,-63.3 -66,-62.6 -66,-61.9 -66,-61.2 -66,-60.5 -66,-59.8 -66,-59.1 -66,-58.4 -66,-57.7 -66,-57 -66,-57 -66.3,-57 -66.6,-57 -66.9,-57 -67.2,-57 -67.5,-57 -67.8,-57 -68.1,-57 -68.4,-57 -68.7,-57 -69,-57.7 -69,-58.4 -69,-59.1 -69,-59.8 -69,-60.5 -69,-61.2 -69,-61.9 -69,-62.6 -69,-63.3 -69,-64 -69,-64 -68.7,-64 -68.4,-64 -68.1,-64 -67.8,-64 -67.5,-64 -67.2,-64 -66.9,-64 -66.6,-64 -66.3,-64 -66))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 21 Jun 2021 00:00:00 GMT", "description": "Worldwide publicity surrounding the calving of an iceberg the size of Delaware in July 2017 from the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula presents a unique and time-sensitive opportunity for research and education on polar ecosystems in a changing climate. The goal of this project was to convene a workshop, drawing from the large fund of intellectual capital in the US and international Antarctic research communities. The two-day workshop was designed to bring scientists with expertise in Antarctic biological, ecological, and ecosystem sciences to Florida State University to share knowledge, identify important research knowledge gaps, and outline strategic plans for research. Major outcomes from the project were as follows. The international workshop to share and review knowledge concerning the response of Antarctic ecosystems to ice-shelf collapse was held at the Florida State University Coastal and Marine Laboratory (FSUCML) on 18-19 November 2017. Thirty-eight U.S. and international scientists attended the workshop, providing expertise in biological, ecological, geological, biogeographical, and glaciological sciences. Twenty-six additional scientists were either not able to attend or were declined because of having reached maximum capacity of the venue or for not responding to our invitation before the registration deadline. The latest results of ice-shelf research were presented, providing an overview of the current scientific knowledge and understanding of the biological, ecological, geological and cryospheric processes associated with ice-shelf collapse and its ecosystem-level consequences. In addition, several presentations focused on future plans to investigate the impacts of the recent Larsen C collapse. The following presentations were given at the meeting: 1) Cryospheric dynamics and ice-shelf collapse \u2013 past and future (M. Truffer, University of Alaska, Fairbanks) 2) The geological history and geological impacts of ice-shelf collapse on the Antarctic Peninsula (Scottt Ishman, Amy Leventer) 3) Pelagic ecosystem responses to ice-shelf collapse (Mattias Cape, Amy Leventer) 4) Benthic ecosystem response to ice-shelf collapse (Craig Smith, Pavica Sr\u0161en, Ann Vanreusel) 5) Larsen C and biotic homogenization of the benthos (Richard Aronson, James McClintock, Kathryn Smith, Brittany Steffel) 6) British Antarctic Survey: plans for Larsen C investigations early 2018 and in the future (Huw Griffiths) 7) Feedback on the workshop \u201cClimate change impacts on marine ecosystems: implications for management of living resources and conservation\u201d held 19-22 September 2017, Cambridge, UK (Alex Rogers) 8) Past research activities and plans for Larsen field work by the Alfred Wegener Institute, Germany (Charlotte Havermans, Dieter Piepenburg. One of the salient points emerging from the presentations and ensuing discussions was that, given our poor abilities to predict ecological outcomes of ice-shelf collapses, major cross-disciplinary efforts are needed on a variety of spatial and temporal scales to achieve a broader, predictive understanding of ecosystem consequences of climatic warming and ice-shelf failure. As part of the workshop, the FSUCML Polar Academy Team\u2014Dr. Emily Dolan, Dr. Heidi Geisz, Barbara Shoplock, and Dr. Jeroen Ingels\u2014initiated AntICE: \"Antarctic Influences of Climate Change on Ecosystems\" (AntICE). They reached out to various groups of school children in the local area (and continue to do so). The AntICE Team have been interacting with these children at Wakulla High School and Wakulla Elementary in Crawfordville; children from the Cornerstone Learning Community, Maclay Middle School, Gilchrist Elementary, and the School of Arts and Sciences in Tallahassee; and the Tallahassee-area homeschooling community to educate them about Antarctic ecosystems and ongoing climate change. The underlying idea was to make the children aware of climatic changes in the Antarctic and their effect on ecosystems so they, in turn, can spread this knowledge to their communities, family and friends \u2013 acting as \u2018Polar Ambassadors\u2019. We collaborated with the Polar-ICE project, an NSF-funded educational project that established the Polar Literacy Initiative. This program developed the Polar Literacy Principles, which outline essential concepts to improve public understanding of Antarctic and Arctic ecosystems. In the Polar Academy work, we used the Polar Literacy principles, the Polar Academy Team\u2019s own Antarctic scientific efforts, and the experience of the FSU outreach and education program to engage with the children. We focused on the importance of Antarctic organisms and ecosystems, the uniqueness of its biota and the significance of its food webs, as well as how all these are changing and will change further with climate change. Using general presentations, case studies, scientific methodology, individual experiences, interactive discussions and Q\u0026A sessions, the children were guided through the many issues Antarctic ecosystems are facing. Over 300 \u0027\u0027Polar ambassadors\u0027\u0027 attended the interactive lectures and afterwards took their creativity to high latitudes by creating welcome letters, displays, dioramas, sculptures, videos and online media to present at the scientific workshop. Over 50 projects were created by the children (Please see supporting files for images). We were also joined by a photographer, Ryan David Reines, to document the event. More information, media and links to online outreach products are available at https://marinelab.fsu.edu/labs/ingels/outreach/polar-academy/\n\nFurther concrete products of the workshop: 1) a position-paper focusing on ideas, hypotheses and priorities for investigating the ecological impacts of ice-shelf collapse along the Antarctic Peninsula (Ingels et al., 2018; \u201cThe scientific response to Antarctic ice-shelf loss; Nature Climate Change 8, 848-851), and 2) a publication reviewing what is known and unknown about ecological responses to ice-shelf melt and collapse, outlining expected ecological outcomes of ice-shelf disintegration along the Antarctic Peninsula (Ingels et al., 2020; \u201cAntarctic ecosystem responses following ice\u2010shelf collapse and iceberg calving: Science review and future research\u201d, WIREs Climate Change, e682). The second publication was covered in the The Scientist and by a press-release in Germany, see https://www.altmetric.com/details/91826381. Other products included a poster presentation at the MEASO2018 conference in Hobart, Australia in 2018, and the above-mentioned visits to schools and institutes to talk about the research in invited seminars. We also conducted and active online outreach campaign, with dissemination of our work in various news outlets, blogs, and social media (e.g. reaching \u003e750k total followers on twitter with the publications alone).\u0027", "east": -57.0, "geometry": "POINT(-60.5 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "MARINE ECOSYSTEMS; USAP-DC; LABORATORY; AMD; Weddell Sea; GLACIERS/ICE SHEETS; ECOLOGICAL DYNAMICS; USA/NSF; SEA ICE; Amd/Us; Antarctica", "locations": "Antarctica; Weddell Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ingels, Jeroen; Aronson, Richard; Smith, Craig", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -69.0, "title": "Collaborative Research: RAPID/Workshop - Antarctic Ecosystem Research following Ice Shelf Collapse and Iceberg Calving Events", "uid": "p0010189", "west": -64.0}, {"awards": "1745130 Moran, Amy", "bounds_geometry": "POLYGON((163 -76,163.3 -76,163.6 -76,163.9 -76,164.2 -76,164.5 -76,164.8 -76,165.1 -76,165.4 -76,165.7 -76,166 -76,166 -76.2,166 -76.4,166 -76.6,166 -76.8,166 -77,166 -77.2,166 -77.4,166 -77.6,166 -77.8,166 -78,165.7 -78,165.4 -78,165.1 -78,164.8 -78,164.5 -78,164.2 -78,163.9 -78,163.6 -78,163.3 -78,163 -78,163 -77.8,163 -77.6,163 -77.4,163 -77.2,163 -77,163 -76.8,163 -76.6,163 -76.4,163 -76.2,163 -76))", "dataset_titles": "Egg diameters of Colossendeis megalonyx; Video of Colossendeis megalonyx behavior around egg mass", "datasets": [{"dataset_uid": "601717", "doi": "10.15784/601717", "keywords": "Antarctica; Mcmurdo", "people": "Moran, Amy", "repository": "USAP-DC", "science_program": null, "title": "Egg diameters of Colossendeis megalonyx", "url": "https://www.usap-dc.org/view/dataset/601717"}, {"dataset_uid": "601716", "doi": "10.15784/601716", "keywords": "Antarctica; Mcmurdo; Pycnogonida; Sea Spider", "people": "Lobert, Graham; Moran, Amy", "repository": "USAP-DC", "science_program": null, "title": "Video of Colossendeis megalonyx behavior around egg mass", "url": "https://www.usap-dc.org/view/dataset/601716"}], "date_created": "Wed, 09 Jun 2021 00:00:00 GMT", "description": "Antarctic marine ectotherms exhibit universally slow growth, low metabolic rates, and extended development, yet many of their rate processes related to physiology and metabolism are highly thermally sensitive. This suggests that small changes in temperature may result in dramatic changes to energy metabolism, growth, and the rate and duration of development. This project will measure the effects of temperature on metabolism, developmental rate, and the energetic cost of development of four common and ecologically important species of benthic Antarctic marine invertebrates. These effects will be measured over the functional ranges of the organisms and in the context of environmentally relevant seasonal shifts in temperature around McMurdo Sound. Recent data show that seasonal warming of ~1\u00b0C near McMurdo Station is accompanied by long-lasting hyperoxic events that impact the benthos in the nearshore boundary layer. This research will provide a more comprehensive understanding of both annual variation in environmental oxygen and temperature across the Sound, and whether this variation drives changes in developmental rate and energetics that are consistent with physiological acclimatization. These data will provide key information about potential impacts of warming Antarctic ectotherms. In addition, this project will support undergraduate and graduate research and partner with large-enrollment undergraduate courses and REU programs at an ANNH and AANAPISI Title III minority-serving institution. \r\nWe have completed one of our two scheduled field and data-collecting seasons, but our research was put on hold by COVID and by equipment and sea ice conditions at McMurdo. We have established baseline information on energy utilization by embryos of several species under ambient conditions and early data suggest that metabolism is highly affected by temperature in the range of -2.0 C to 1 C, and less so thereafter.", "east": 166.0, "geometry": "POINT(164.5 -77)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; Amd/Us; AMD; BENTHIC; USA/NSF; FIELD INVESTIGATION; Mcmurdo Sound", "locations": "Mcmurdo Sound", "north": -76.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Moran, Amy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Thermal Sensitivity of Antarctic Embryos and Larvae: Effects of Temperature on Metabolism, Developmental Rate, and the Metabolic Cost of Development ", "uid": "p0010187", "west": 163.0}, {"awards": "1443556 Thomson, Stuart; 1443342 Licht, Kathy", "bounds_geometry": null, "dataset_titles": "Apatite (U-Th)/He and TREE Data Central Transantarctic Mountains", "datasets": [{"dataset_uid": "601462", "doi": "10.15784/601462", "keywords": "Antarctica; Beardmore Glacier; Erosion; Landscape Evolution; Shackleton Glacier; Transantarctic Mountains; (U-Th)/He", "people": "Thomson, Stuart; Hemming, Sidney R.; Reiners, Peter; He, John; Licht, Kathy", "repository": "USAP-DC", "science_program": null, "title": "Apatite (U-Th)/He and TREE Data Central Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601462"}], "date_created": "Wed, 09 Jun 2021 00:00:00 GMT", "description": "Antarctica is almost entirely covered by ice, in places over two miles thick. This ice hides a landscape that is less well known than the surface of Mars and represents one of Earth\u0027s last unexplored frontiers. Ice-penetrating radar images provide a remote glimpse of this landscape including ice-buried mountains larger than the European Alps and huge fjords twice as deep as the Grand Canyon. The goal of this project is to collect sediment samples derived from these landscapes to determine when and under what conditions these features formed. Specifically, the project seeks to understand the landscape in the context of the history and dynamics of the overlying ice sheet and past mountain-building episodes. This project accomplishes this goal by analyzing sand collected during previous sea-floor drilling expeditions off the coast of Antarctica. This sand was supplied from the continent interior by ancient rivers when it was ice-free over 34 million year ago, and later by glaciers. The project will also study bedrock samples from rare ice-free parts of the Transantarctic Mountains. The primary activity is to apply multiple advanced dating techniques to single mineral grains contained within this sand and rock. Different methods and minerals yield different dates that provide insight into how Antarctica?s landscape has eroded over the many tens of millions of years during which sand was deposited offshore. The dating techniques that are being developed and enhanced for this study have broad application in many branches of geoscience research and industry. The project makes cost-effective use of pre-existing sample collections housed at NSF facilities including the US Polar Rock Repository, the Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. The project will contribute to the STEM training of two graduate and two undergraduate students, and includes collaboration among four US universities as well as international collaboration between the US and France. The project also supports outreach in the form of a two-week open workshop giving ten students the opportunity to visit the University of Arizona to conduct STEM-based analytical work and training on Antarctic-based projects. Results from both the project and workshop will be disseminated through presentations at professional meetings, peer-reviewed publications, and through public outreach and media.\r\n\r\n\r\nThe main objective of this project is to reconstruct a chronology of East Antarctic subglacial landscape evolution to understand the tectonic and climatic forcing behind landscape modification, and how it has influenced past ice sheet inception and dynamics. Our approach focuses on acquiring a record of the cooling and erosion history contained in East Antarctic-derived detrital mineral grains and clasts in offshore sediments deposited both before and after the onset of Antarctic glaciation. Samples will be taken from existing drill core and marine sediment core material from offshore Wilkes Land (100\u00b0E-160\u00b0E) and the Ross Sea. Multiple geo- and thermo-chronometers will be employed to reconstruct source region cooling history including U-Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar. This offshore record will be augmented and tested by applying the same methods to onshore bedrock samples in the Transantarctic Mountains obtained from the US Polar Rock Repository and through fieldwork. The onshore work will additionally address the debated incision history of the large glacial troughs that cut the range, now occupied by glaciers draining the East Antarctic Ice Sheet. This includes collection of samples from several age-elevation transects, apatite 4He/3He thermochronometry, and Pecube thermo-kinematic modeling. Acquiring an extensive geo- and thermo-chronologic database will also provide valuable new information on the poorly known ice-hidden geology and tectonics of subglacial East Antarctica that has implications for improving supercontinent reconstructions and understanding continental break-up.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; LANDSCAPE; AGE DETERMINATIONS; FIELD INVESTIGATION; GLACIAL PROCESSES; Transantarctic Mountains; USA/NSF; Thermochronology; Amd/Us; USAP-DC; TRACE ELEMENTS; Provenance Analysis; AMD; LANDFORMS; GLACIAL LANDFORMS", "locations": "Transantarctic Mountains", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Thomson, Stuart; Reiners, Peter; Licht, Kathy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: East Antarctic Glacial Landscape Evolution (EAGLE): A Study using Combined Thermochronology, Geochronology and Provenance Analysis", "uid": "p0010188", "west": null}, {"awards": "1743310 Kingslake, Jonathan", "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": "Vulnerability of Antarctica\u2019s ice shelves to meltwater-driven fracture", "datasets": [{"dataset_uid": "601395", "doi": "10.15784/601395", "keywords": "Antarctica; Computer Model; Fractures; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meltwater; Model Data", "people": "Lai, Ching-Yao", "repository": "USAP-DC", "science_program": null, "title": "Vulnerability of Antarctica\u2019s ice shelves to meltwater-driven fracture", "url": "https://www.usap-dc.org/view/dataset/601395"}], "date_created": "Wed, 02 Jun 2021 00:00:00 GMT", "description": "Ice shelves slow the movement of the grounded ice sheets that feed them. This reduces the rate at which ice sheets loose mass to the oceans and contribute to sea-level rise. But ice shelves can be susceptible to collapse, particularly when surface meltwater accumulates in vulnerable areas. Meltwater lakes can create and enlarge fractures within the ice shelves, thereby triggering or hastening ice-shelf collapse. The drainage of water across the surface of Antarctica and where it accumulates has received little attention. This drainage was assumed to be insignificant, but recent work shows that meltwater can drain for tens of kilometers across ice-shelf surfaces and access areas that would otherwise not accumulate meltwater. Surface meltwater drainage could play a major role in the future stability of ice sheets. This drainage is the focus of this project.\r\n\r\nThe team will develop and test physics-based mathematical models of water flow and ice-shelf fracture, closely informed by remote sensing observations, to examine (1) how do surface drainage systems respond to inter-annual changes in surface melting, (2) how this drainage is influenced by ice dynamics and (3) whether enlarged drainage systems could deliver meltwater to areas of ice shelves that are vulnerable to water-driven collapse. The project will examine these issues by (1) conducting a remote sensing survey of the structure and temporal evolution of meltwater systems around Antarctica, (2) developing and analyzing mathematical models of water flow across ice shelves, and (3) developing and testing simple models of ice-shelf fracture. An outreach activity will make use of the emerging technology of Augmented Reality to visualize the dynamics of ice sheets in three dimensions to excite the public about glaciology at outreach events around New York City. This approach will be made publicly available for wider use as Augmented Reality continues to grow in popularity.\r\n\r\nThree aspects of the project will produce data and code that will be archived in USAP-DC:\r\n1. Mapped ice-shelf drainage system characteristics.\r\n2. Computed continent-wide fields of ice-shelf vulnerability to hydrofracture.\r\n3. An open source augmented reality ice sheet app.\r\n\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; USAP-DC; Antarctica; ICE SHEETS; Amd/Us; Ice Shelf; COMPUTERS; Surface Meltwater", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kingslake, Jonathan", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Satellite observations and modelling of surface meltwater flow and its impact on ice shelves", "uid": "p0010184", "west": -180.0}, {"awards": "1543344 Soreghan, Gerilyn", "bounds_geometry": null, "dataset_titles": "Data and metadata for \"Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems\"", "datasets": [{"dataset_uid": "601599", "doi": "10.15784/601599", "keywords": "Antarctica; Anza Borrego; Iceland; Mcmurdo Dry Valleys; Norway; Peru; Puerto Rico; Taylor Valley; Washington; Wright Valley", "people": "Demirel-Floyd, Cansu", "repository": "USAP-DC", "science_program": null, "title": "Data and metadata for \"Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems\"", "url": "https://www.usap-dc.org/view/dataset/601599"}], "date_created": "Tue, 18 May 2021 00:00:00 GMT", "description": "As glaciers creep across the landscape, they can act as earthmovers, plucking up rocks and grinding them into fine sediments. Glaciers have moved across the Antarctic landscape over thousands to millions of years, leaving these ground-up sediments in their wake. This study builds on pilot discoveries by the investigators that revealed remarkably large and variable measurements of surface area in glacially-derived fine-grained sediments found in the McMurdo Dry Valleys (MDV), one of the few landscapes on the Antarctic continent not currently covered by ice. Surface area is key to chemical weathering, the process by which rock is converted to soils as ions are carried away in streams and groundwater. These chemical weathering processes are also one of the primary means by which the Earth system naturally removes carbon dioxide from the atmosphere. Hence, high surface areas observed in sediments implies high \"weatherability\" which in turn translates to more potential carbon dioxide removed from the atmosphere. Therefore, chemical weathering in high surface area glacial sediments may have significant impacts on Earth\u0027s carbon cycle. The researchers will measure the chemical and physical properties of sediments previously collected from the Dry Valleys to understand what factors lead to production of sediment with high-surface area and potential \"weather ability\" and investigate how sediment produced in these glacial systems could ultimately impact Earth\u0027s carbon budget. Results from this research will help scientists (including modelers) refine predictions of the effects of melting glaciers- and attendant exposure of glacial sediment? on atmospheric carbon levels. These results may also contribute to applied research efforts on development of carbon-dioxide removal technologies utilizing principles of rock weathering. In addition to the scientific benefits, this research will involve several students at the undergraduate, graduate, and post-doctoral levels, including science education undergraduates, thus contributing to training of the next-generation STEM workforce.\r\n\r\nPhysical weathering produces fresh surfaces, greatly enhancing specific surface area (SSA) and reactive surface area (RSA) of primary minerals. Quantifying SSA and RSA of sediments is key to determining dissolution and leaching rates during natural weathering, but few data exist on distribution of sediment SA, particularly in glacial and fluvial systems. Pilot data from glacial stream systems in Taylor Valley and Wright Valley (located in the MDV) exhibit remarkably high and variable values in both SSA and RSA, values that in some cases greatly exceed values from muds in temperate glacial systems. This discovery motivates the current research, which aims to investigate the hypothesis that high and variable SAs of muds within Wright and Taylor Valleys reflect textural and/or compositional inheritance from the differing depositional settings within the MDV, biologic controls, dust additions, and/or pedogenic processes. These hypotheses will be tested by sedimentologically, mineralogically, and geochemically characterizing muds from glacially derived sediment deposited in various environments (cold vs. wet based glaciation; fluvial, lacustrine, dust, and drift deposits) and of varying age (Miocene to Modern) from the MDV and quantifying variation of SA and reactivity. Comparisons with analyzed muds from temperate glacial systems will enable polar-temperate comparisons. Analyses will focus on muds of previously collected sediment from the MDVs. Grain size and SSA will be measured by Laser Analysis and N2 adsorption BET, respectively. After carbonate removal, samples will be re-analyzed for SSA, and muds characterized geochemically. Mineralogy and bulk chemistry will also be assessed on co-occurring sand fractions, and textural attributes documented. SSA-normalized dissolution experiments will be used to compare solutes released from sediments to determine RSAs. Results will be integrated with the various sedimentologic and geochemical analyses to test the posed hypotheses. Ultimately, this research should shed light on how weathering in Antarctic systems contributes to global carbon cycling.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; AMD; FIELD INVESTIGATION; USA/NSF; Dry Valleys; SEDIMENT CHEMISTRY; Amd/Us; Antarctica; Weathering", "locations": "Antarctica; Dry Valleys", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Soreghan, Gerilyn; Elwood Madden, Megan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems", "uid": "p0010181", "west": null}, {"awards": "1246151 Bromirski, Peter; 1246416 Stephen, Ralph", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.4,-175 -77.8,-175 -78.2,-175 -78.6,-175 -79,-175 -79.4,-175 -79.8,-175 -80.2,-175 -80.6,-175 -81,-175.5 -81,-176 -81,-176.5 -81,-177 -81,-177.5 -81,-178 -81,-178.5 -81,-179 -81,-179.5 -81,180 -81,179 -81,178 -81,177 -81,176 -81,175 -81,174 -81,173 -81,172 -81,171 -81,170 -81,170 -80.6,170 -80.2,170 -79.8,170 -79.4,170 -79,170 -78.6,170 -78.2,170 -77.8,170 -77.4,170 -77,171 -77,172 -77,173 -77,174 -77,175 -77,176 -77,177 -77,178 -77,179 -77,-180 -77))", "dataset_titles": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ; Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "datasets": [{"dataset_uid": "200207", "doi": "10.7914/SN/XH_2014", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ", "url": "http://www.fdsn.org/networks/detail/XH_2014/"}, {"dataset_uid": "200209", "doi": "10.7283/58E3-GA46", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "url": "https://doi.org/10.7283/58E3-GA46"}], "date_created": "Thu, 15 Apr 2021 00:00:00 GMT", "description": "This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is \"locally\" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.\n\r\nUnderstanding and being able to anticipate changes in the glaciological regime of the Ross Ice Shelf (RIS) and West Antarctic Ice Sheet (WAIS) are key to improving sea level rise projections due to ongoing ice mass loss in West Antarctica. The fate of the WAIS is a first-order climate change and global societal issue for this century and beyond that affects coastal communities and coastal infrastructure globally. \r\n\r\nIce shelf--ocean interactions include impacts from tsunami, ocean swell (10-30s period), and very long period ocean waves that impact ice shelves and produce vibrations that induce a variety of seismic signals detected by seismometers buried in the ice shelf surface layer, called firn. To study the wave-induced vibrations in the RIS, an extensive seismic array was deployed from Nov. 2014 to Nov. 2016. This unique seismometer array deployment on an ice shelf made continuous observations of the response of the RIS to ocean wave impacts from ocean swell and very long period waves. An extensive description of the project motivation and background (including photos and videos of the deployment operations), and list of published studies of analyses of the seismic data collected by this project, are available at the project website https://iceshelfvibes.ucsd.edu. \r\n\r\nTwo types of seismic signals detected by the seismic array are most prevalent: flexural gravity waves (plate waves) and icequakes (signals analogous to those from earthquakes but from fracturing of the ice). \r\nLong period ocean waves flex the ice shelf at the same period as the ocean waves, with wave energy at periods greater than ocean swell more efficient at coupling energy into flexing the ice shelf. Termed flexural gravity waves or plate waves (Chen et al., 2018), their wave-induced vibrations can reach 100\u2019s of km from the ice edge where they are excited, with long period wave energy propagating in the water layer below the shelf coupled with the ice shelf flexure. Flexural gravity waves at very long periods (\u003e 300 s period), such as from tsunami impacts (Bromirski et al., 2017), can readily reach grounding zones and may play a role in long-term grounding zone evolution. \r\nSwell-induced icequake activity was found to be most prevalent at the shelf front during the austral summer (January \u2013 March) when seasonal sea ice is absent and the associated damping of swell by sea ice is minimal (Chen et al., 2019). \r\n\r\nIn addition to the seismic array, a 14 station GPS (global positioning system) array was installed during seismic data retrieval and station servicing operations in October-November 2015. The GPS stations, co-located with seismic stations, extended from the shelf front southward to about 415 km at interior station RS18. Due to logistical constraints associated with battery weight during installation, only one station (at DR10) operated year-round. The GPS data collected give a detailed record of changes in iceflow velocity that are in close agreement with the increasing velocity estimates approaching the shelf front from satellite observations. Importantly, the year-round data at DR10 show an unprecedented seasonal cycle of changes in iceflow velocity, with a speed-up in northward (seaward) ice flow during Jan.-May and then a velocity decrease from June-Sep. (returning to the long-term mean flow velocity). This annual ice flow velocity change cycle has been attributed in part to seasonal changes in ice shelf mass (thinning, reducing buttressing) due to melting at the RIS basal (bottom) surface from intrusion of warmer ocean water (Klein et al., 2020). ", "east": 170.0, "geometry": "POINT(177.5 -79)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; GLACIER MOTION/ICE SHEET MOTION; USAP-DC; Amd/Us; AMD; USA/NSF; Iris; Ross Ice Shelf", "locations": "Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Bromirski, Peter; Gerstoft, Peter; Stephen, Ralph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "IRIS", "repositories": "IRIS; UNAVCO", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations", "uid": "p0010169", "west": -175.0}, {"awards": "2042807 Halzen, Francis; 0937462 Halzen, Francis; 1600823 Halzen, Francis; 0639286 Halzen, Francis", "bounds_geometry": "POINT(-180 -90)", "dataset_titles": "Amanda 7 Year Data Set; IceCube data releases", "datasets": [{"dataset_uid": "200374", "doi": "", "keywords": null, "people": null, "repository": "IceCube", "science_program": null, "title": "IceCube data releases", "url": "https://icecube.wisc.edu/science/data-releases/"}, {"dataset_uid": "601438", "doi": "10.15784/601438", "keywords": "Amanda-ii; Antarctica; Neutrino; Neutrino Candidate Events; Neutrino Telescope; South Pole", "people": "Halzen, Francis; Riedel, Benedikt", "repository": "USAP-DC", "science_program": "IceCube", "title": "Amanda 7 Year Data Set", "url": "https://www.usap-dc.org/view/dataset/601438"}], "date_created": "Wed, 07 Apr 2021 00:00:00 GMT", "description": "This award funds the continued management and operations (M\u0026O) of the IceCube Neutrino Observatory (ICNO) located at the South Pole Station. The core team of researchers and engineers maintain the existing ICNO infrastructure at the South Pole and home institution, guaranteeing an uninterrupted stream of scientifically unique, high-quality data. The M\u0026O activities are built upon eight highly successful years of managing the overall ICNO operations after the start of science operations in 2008. Construction of ICNO was supported by NSF\u0027s Major Research Equipment and Facilities Construction (MREFC) account and was completed on schedule and within budget in 2010. Effective coordination of efforts by the core M\u0026O personnel and efforts by personnel within the IceCube Collaboration has yielded significant increases in the performance of this cubic-kilometer detector over time. The scientific output from the IceCube Collaboration during the past five years has been outstanding. \u003cbr/\u003e\u003cbr/\u003eThe broader impacts of the ICNO/M\u0026O activities are strong, involving postdoctoral, graduate, and (in some cases) undergraduate students in the day-today operation \u0026 calibration of the neutrino detector. The extraordinary physics results recently produced by ICNO and its extraordinary location at South Pole have a high potential to excite the imagination of high school children and the public in general at a national and international level.\u003cbr/\u003e\u003cbr/\u003eThe current ICNO/M\u0026O effort produces better energy and angular resolution information about detected neutrino events, has more efficient data filters and more accurate detector simulations, and enables continuous software development for systems that are needed to acquire and analyze data. This has produced data acquisition and data management systems with high robustness, traceability, and maintainability. The current ICNO/M\u0026O effort includes: (1) resources for both distributed and centrally managed activities, and (2) additional accountability mechanisms for \"in-kind\" and institutional contributions. Both are necessary to ensure that the detector maintains its capability to produce quality scientific data at the level required to achieve the detector\u0027s scientific discovery objectives. Recent ICNO discoveries of cosmic high-energy neutrinos (some reaching energies close to and over 2.5 PeV) and oscillating atmospheric neutrinos in a previously unexplored energy range from 10 to 60 GeV became possible because of the \"state-of-the-art\" detector configuration, excellently supported infrastructure, and cutting-edge science analyses. The ICNO has set limits on Dark Matter annihilations, made precision measurements of the angular distribution of cosmic ray muons, and characterized in detail physical properties of the Antarctic 2.5-km thick ice sheet at South Pole. The discovery of high-energy cosmic neutrinos by IceCube with a flux at the level anticipated for those associated with high-energy gamma- and cosmic-ray accelerators brightens the prospect for identifying the sources of the highest energy particles.", "east": -180.0, "geometry": "POINT(-180 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e ICECUBE", "is_usap_dc": true, "keywords": "USA/NSF; South Pole; OBSERVATORIES; Amd/Us; AMD; GLACIERS/ICE SHEETS; Icecube; Neutrino; USAP-DC", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "Halzen, Francis; Karle, Albrecht", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e OBSERVATORIES", "repo": "IceCube", "repositories": "IceCube; USAP-DC", "science_programs": "IceCube", "south": -90.0, "title": "Management and Operations of the IceCube Neutrino Observatory 2021-2026", "uid": "p0010168", "west": -180.0}, {"awards": "1643301 Gerbi, Christopher; 1643353 Christianson, Knut", "bounds_geometry": null, "dataset_titles": "ImpDAR: an impulse radar processor; SeidarT; South Pole Lake ApRES Radar; South Pole Lake GNSS; South Pole Lake: ground-based ice-penetrating radar", "datasets": [{"dataset_uid": "200244", "doi": " https://zenodo.org/badge/latestdoi/382590632", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "SeidarT", "url": "https://github.com/UMainedynamics/SeidarT"}, {"dataset_uid": "200202", "doi": "http://doi.org/10.5281/zenodo.3833057", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "ImpDAR: an impulse radar processor", "url": "https://www.github.com/dlilien/ImpDAR"}, {"dataset_uid": "601502", "doi": "10.15784/601502", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GNSS; GPS; GPS Data; South Pole; Subglacial Lakes", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake GNSS", "url": "https://www.usap-dc.org/view/dataset/601502"}, {"dataset_uid": "200203", "doi": "", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "South Pole Lake: ground-based ice-penetrating radar", "url": "http://hdl.handle.net/1773/45293"}, {"dataset_uid": "601503", "doi": "10.15784/601503", "keywords": "Antarctica; Apres; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; South Pole; Subglacial Lakes; Vertical Velocity", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake ApRES Radar", "url": "https://www.usap-dc.org/view/dataset/601503"}], "date_created": "Wed, 17 Feb 2021 00:00:00 GMT", "description": "This award supports a project to develop software that will allow researchers considering seismic or radar field surveys to test, ahead of time, whether the data they plan to collect will have sufficient resolution to measure the natural variations in the mechanical properties of ice, which determine the response of flowing ice to changing climatic conditions. The mechanical properties of ice depend largely on the temperature and the orientation of the crystals that make up the ice. The most accurate method for measuring ice crystal orientation and temperature is through drilling and direct analysis of an ice core. However, this method is very costly, time-consuming, and limited in spatial coverage. Geophysical techniques, such as seismic and radar, can cover much more area, but we have little knowledge about the practical limitations of these techniques as they relate to calculating mechanical properties. This project addresses that knowledge gap through construction of a computational toolbox that will allow accurate assessment of the ability of geophysical surveys to image crystal orientation and ice temperature. Researchers can then use these tools to adjust the field survey plans to maximize the return on investment. By working to improve the efficiency and effectiveness of future geophysical work related to glacial flow, this proposal will improve scientists? ability to quantify sea-level variations within the larger context of climate change. The project includes building new user-friendly, publicly accessible software and instructional modules. The work will provide training for graduate and undergraduate students, who will play a role in research and develop instructional materials. \r\n\r\nIce viscosity, the resistance of ice to flow, exerts significant control over ice velocity. Therefore, mapping ice viscosity is important for understanding the current and future behavior of glaciers and ice sheets. To do so, scientists must determine the temperature and crystal orientation fabric throughout the ice. Seismic and radar techniques can survey large areas quickly, and thus are promising, yet not fully tested, methods to efficiently measure the thermal and mechanical structure of flowing ice. As part of this project, scientists will develop and use a computational framework to quantify the degree to which seismic and radar techniques can resolve the crystal orientation fabric and temperature of streaming ice, and then test how sensitive ice flow is to the attendant uncertainty. To meet these goals, a numerical toolbox will be built which will allow the glacier/ice stream geometry and physical properties (temperature, crystal orientation fabric, density and acidity) to be varied. The toolbox will be capable of both creating synthetic radar and seismic profiles through forward modeling and inverting synthetic profiles to allow evaluation of how well geophysical techniques can image the original thermal and mechanical structure. These simulated radar and seismic data will allow scientists to better quantify the influence of the variability in mechanical properties of the ice on flow velocities and patterns. The results of this work will guide planning for future field campaigns, making them more effective and efficient. This project does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; GLACIERS/ICE SHEETS; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; South Pole; USA/NSF; AMD; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; FIELD SURVEYS; Amd/Us", "locations": "South Pole; United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Gerbi, Christopher; Campbell, Seth; Vel, Senthil", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "GitHub", "repositories": "GitHub; Uni. Washington ResearchWorks Archive; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Computational Methods Supporting Joint Seismic and Radar Inversion for Ice Fabric and Temperature in Streaming Flow", "uid": "p0010160", "west": null}, {"awards": "1443525 Schwartz, Susan", "bounds_geometry": "POLYGON((-165 -83.8,-163 -83.8,-161 -83.8,-159 -83.8,-157 -83.8,-155 -83.8,-153 -83.8,-151 -83.8,-149 -83.8,-147 -83.8,-145 -83.8,-145 -83.92,-145 -84.04,-145 -84.16,-145 -84.28,-145 -84.4,-145 -84.52,-145 -84.64,-145 -84.76,-145 -84.88,-145 -85,-147 -85,-149 -85,-151 -85,-153 -85,-155 -85,-157 -85,-159 -85,-161 -85,-163 -85,-165 -85,-165 -84.88,-165 -84.76,-165 -84.64,-165 -84.52,-165 -84.4,-165 -84.28,-165 -84.16,-165 -84.04,-165 -83.92,-165 -83.8))", "dataset_titles": "YD (2012-2017): Whillians Ice Stream Subglacial Access Research Drilling", "datasets": [{"dataset_uid": "200201", "doi": "https://doi.org/10.7914/SN/YD_2012", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "YD (2012-2017): Whillians Ice Stream Subglacial Access Research Drilling", "url": "http://www.fdsn.org/networks/detail/YD_2012/"}], "date_created": "Fri, 12 Feb 2021 00:00:00 GMT", "description": "Ice fracturing plays a crucial role in mechanical processes that influence the contribution of glaciers and ice sheets to the global sea-level rise. Such processes include, among others, ice shelf disintegration, iceberg calving, and fast ice sliding. Over the last century, seismology developed highly sensitive instrumentation and sophisticated data processing techniques to study earthquakes. This interdisciplinary project used seismological research methods to investigate fracturing beneath and within ice on a fast-moving ice stream in West Antarctica that is experiencing rapid sliding and flexure driven by ocean tides. Data were collected from two strategically located clusters of seismometers. One was located in the epicenter zone where tidally triggered rapid sliding events of the ice stream start. The other was placed in the grounding zone, where the ice stream flexes with tides where it goes afloat and becomes an ice shelf.\r\n\r\n Seismometers in the epicenter cluster recorded many thousands of microearthquakes coming from beneath ice during ice stream sliding events. Analyses of these microearthquakes suggest that the geologic materials beneath the ice stream are fracturing. The spatial pattern of fracturing is not random but forms elongated stripes that resemble well-known glacial landforms called megascale glacial lineations. These findings indicate that the frictional resistance to ice sliding may change through time due to these landforms changing as a result of erosion and sedimentation beneath ice. This may have implications for the rate of ice loss from Antarctic ice streams that drain about 90% of all ice discharged into the Southern Ocean. In addition to microearthquakes, the epicenter cluster of seismometers also recorded vibrations (tremors) from beneath the ice stream. These may be caused by the rapid repetition of many microearthquakes coming from the same source.\r\n\r\n The grounding zone cluster of seismometers recorded many thousands of microearthquakes as well. However, they are caused by ice fracturing near the ice stream\u0027s surface rather than at its base. These microearthquakes originate when the grounding zone experiences strong tension caused by ice flexure during dropping ocean tide. This tension causes the opening of near-surface fractures (crevasses) just before the lowest tide, rather than at the lowest tide as expected from elasticity of solids. This unexpected timing of ice fracturing indicates that ice in the grounding zone behaves like a viscoelastic material, i.e., partly like a solid and partly like a fluid. This is an important general finding that will be useful to other scientists who are modeling interactions of ice with ocean water in the Antarctic grounding zones. Overall, the observed pervasive fracturing in the grounding zone, where an ice stream becomes an ice shelf, may make ice shelves potentially vulnerable to catastrophic collapses. It also may weaken ice shelves and make it easier for large icebergs to break off at their fronts.\r\n\r\n In addition to Antarctic research, this award supported education and outreach activities, including presentations and field trips during several summer schools at UCSC for talented and diverse high school students. The students were exposed to glaciological and seismological concepts and performed hands-on scientific exercises. The field trips focused on the marine terrace landscape around Santa Cruz. This landscape resulted from interactions between the uplift of rocks along the San Andreas fault with global-sea level changes caused by the waxing and waning of polar ice sheets in response to Ice Age climate cycles.\r\n\r\n", "east": -145.0, "geometry": "POINT(-155 -84.4)", "instruments": null, "is_usap_dc": true, "keywords": "Whillans Ice Stream; GLACIERS/ICE SHEETS; FIELD INVESTIGATION", "locations": "Whillans Ice Stream", "north": -83.8, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek; Schwartz, Susan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "IRIS", "repositories": "IRIS", "science_programs": "WISSARD", "south": -85.0, "title": "High Resolution Heterogeneity at the Base of Whillans Ice Stream and its Control on Ice Dynamics", "uid": "p0010159", "west": -165.0}, {"awards": "1443329 Balco, Gregory; 1443321 Bromley, Gordon", "bounds_geometry": "POLYGON((-180 -85.40705,-179.659078 -85.40705,-179.318156 -85.40705,-178.977234 -85.40705,-178.636312 -85.40705,-178.29539 -85.40705,-177.954468 -85.40705,-177.613546 -85.40705,-177.272624 -85.40705,-176.931702 -85.40705,-176.59078 -85.40705,-176.59078 -85.422615,-176.59078 -85.43818,-176.59078 -85.453745,-176.59078 -85.46931,-176.59078 -85.484875,-176.59078 -85.50044,-176.59078 -85.516005,-176.59078 -85.53157,-176.59078 -85.547135,-176.59078 -85.5627,-176.931702 -85.5627,-177.272624 -85.5627,-177.613546 -85.5627,-177.954468 -85.5627,-178.29539 -85.5627,-178.636312 -85.5627,-178.977234 -85.5627,-179.318156 -85.5627,-179.659078 -85.5627,180 -85.5627,179.277561 -85.5627,178.555122 -85.5627,177.832683 -85.5627,177.110244 -85.5627,176.387805 -85.5627,175.665366 -85.5627,174.942927 -85.5627,174.220488 -85.5627,173.498049 -85.5627,172.77561 -85.5627,172.77561 -85.547135,172.77561 -85.53157,172.77561 -85.516005,172.77561 -85.50044,172.77561 -85.484875,172.77561 -85.46931,172.77561 -85.453745,172.77561 -85.43818,172.77561 -85.422615,172.77561 -85.40705,173.498049 -85.40705,174.220488 -85.40705,174.942927 -85.40705,175.665366 -85.40705,176.387805 -85.40705,177.110244 -85.40705,177.832683 -85.40705,178.555122 -85.40705,179.277561 -85.40705,-180 -85.40705))", "dataset_titles": "Interface for viewing observational data related to exposure ages measurements and calculated geologic ages derived therefrom", "datasets": [{"dataset_uid": "200199", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Interface for viewing observational data related to exposure ages measurements and calculated geologic ages derived therefrom", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Sun, 20 Dec 2020 00:00:00 GMT", "description": "This investigation will reconstruct past behavior of the East Antarctic Ice Sheet during periods of warmer-than-present climate, such as the Pliocene, in order to better project the likely response of Earth\u0027s largest ice sheet to anthropogenic warming. Containing the equivalent of ~55 m sea-level rise, the future evolution of the East Antarctic Ice Sheet has clear societal ramifications on a global scale as temperatures continue to rise. Therefore, determining ice-sheet sensitivity to climate on the scale predicted for the next two centuries is a matter of increasing urgency, particularly in light of evidence suggesting the East Antarctic Ice Sheet is more dynamic than previously thought. This research will provide a terrestrial geologic record of long-term ice-sheet behavior from sites immediately adjacent the East Antarctic Ice Sheet in the Transantarctic Mountains, with which the project will help ascertain how the ice sheet responded to past warm periods. The project will focus primarily on the Pliocene warm period, 5 to 3 million years ago, as this represents the closest analogue to 21st Century climate conditions.\u003cbr/\u003e\u003cbr/\u003eThe proposed research will investigate glacial deposits corresponding to the East Antarctic Ice Sheet in the central Transantarctic Mountains in order to expand the geologic record of past ice-sheet behavior. The overarching research objectives are to improve understanding of the East Antarctic Ice Sheet\u0027s configuration during periods of warmer-than-present climate, such as the Pliocene warm period, and to determine whether the ice sheet underwent significant volume changes or remained relatively stable in response to warming. To address these goals, the investigation will map and date glacial deposits preserved at mountain sites immediately adjacent the ice sheet. Specifically, we will: (i) employ multiple cosmogenic nuclides (10Be, 26Al, 21Ne) to establish more fully ice-thickness histories for the upper Shackleton and Beardmore Glaciers, where they exit the ice sheet; (ii) use this record to identify periods during which the East Antarctic Ice Sheet was at least as extensive as today; and (iii) use these data to assess long-term ice-sheet variability in East Antarctica, with particular emphasis on Pliocene warm episodes. This research will require Antarctic fieldwork, glacial-geologic mapping, and cosmogenic surface-exposure dating.", "east": -176.59078, "geometry": "POINT(178.092415 -85.484875)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Transantarctic Mountains; GLACIERS/ICE SHEETS; AMD; GLACIER THICKNESS/ICE SHEET THICKNESS; GLACIER ELEVATION/ICE SHEET ELEVATION; NOT APPLICABLE; Antarctica", "locations": "Antarctica; Transantarctic Mountains", "north": -85.40705, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Balco, Gregory; Bromley, Gorden; BROMLEY, GORDON", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -85.5627, "title": "Collaborative Research: Potential Direct Geologic Constraint of Ice Sheet Thickness in the Central Transantarctic Mountains during the Pliocene Warm Period", "uid": "p0010153", "west": 172.77561}, {"awards": "1842059 Huber, Matthew; 1842176 Bizimis, Michael; 1842115 Jahn, Alexandra; 1842049 Kim, Sora", "bounds_geometry": "POLYGON((-56.693516 -64.209061,-56.6823452 -64.209061,-56.6711744 -64.209061,-56.6600036 -64.209061,-56.6488328 -64.209061,-56.637662 -64.209061,-56.6264912 -64.209061,-56.6153204 -64.209061,-56.6041496 -64.209061,-56.5929788 -64.209061,-56.581808 -64.209061,-56.581808 -64.2143344,-56.581808 -64.2196078,-56.581808 -64.2248812,-56.581808 -64.2301546,-56.581808 -64.235428,-56.581808 -64.2407014,-56.581808 -64.2459748,-56.581808 -64.2512482,-56.581808 -64.2565216,-56.581808 -64.261795,-56.5929788 -64.261795,-56.6041496 -64.261795,-56.6153204 -64.261795,-56.6264912 -64.261795,-56.637662 -64.261795,-56.6488328 -64.261795,-56.6600036 -64.261795,-56.6711744 -64.261795,-56.6823452 -64.261795,-56.693516 -64.261795,-56.693516 -64.2565216,-56.693516 -64.2512482,-56.693516 -64.2459748,-56.693516 -64.2407014,-56.693516 -64.235428,-56.693516 -64.2301546,-56.693516 -64.2248812,-56.693516 -64.2196078,-56.693516 -64.2143344,-56.693516 -64.209061))", "dataset_titles": "Data from: Probing the ecology and climate of the Eocene Southern Ocean with sand tiger sharks Striatolamia macrota", "datasets": [{"dataset_uid": "200183", "doi": "https://doi.org/10.6071/M34T1Z", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Data from: Probing the ecology and climate of the Eocene Southern Ocean with sand tiger sharks Striatolamia macrota", "url": "https://datadryad.org/stash/dataset/doi:10.6071/M34T1Z"}], "date_created": "Tue, 15 Dec 2020 00:00:00 GMT", "description": "The Earth\u0027s climate has changed through time and during the Eocene Epoch (56 to 34 million years ago) there was a transition from \u0027greenhouse\u0027 to \u0027icehouse\u0027 conditions. During the Eocene, a shift to cooler temperatures at high latitudes resulted in the inception of polar glaciation. This in turn affected the environment for living organisms. This project looks to uncover the interaction between biological, oceanographic, and climate systems for the Eocene in Antarctica using chemical analysis of fossil shark teeth collected during past expeditions. The combination of paleontological and geochemical analyses will provide insight to the past ecology and ocean conditions; climate models will be applied to test the role of tectonics, greenhouse gas concentration and ocean circulation on environmental change during this time period. The study contributes to understanding the interaction of increased atmospheric carbon dioxide and ocean circulation. This project also seeks to improve diversity, equity, and inclusion within the geosciences workforce with efforts targeted to undergraduate, graduate, postdoctoral, and early career faculty.\u003cbr/\u003e\u003cbr/\u003eThe research goal is to elucidate the processes leading from the Eocene greenhouse to Oligocene icehouse conditions. Previous explanations for this climate shift centers on Antarctica, where tectonic configurations influenced oceanic gateways, ocean circulation reduced heat transport, and/or greenhouse gas declines prompted glaciation. The team will reconstruct watermass, current, and climate fluctuations proximal to the Antarctic Peninsula using geochemical indicators (oxygen and neodymium isotope composition) from fossil shark teeth collected from Seymour Island. The approach builds on previous shark paleontological studies, incorporates geochemical analyses for environmental reconstruction (i.e., temperature gradients and ocean circulation), and tests hypotheses on Earth System dynamics using novel global climate model simulations with geochemical tracers. This project will advance global climate modeling capabilities with experiments that consider Eocene tectonic configuration within isotope-enabled climate model simulations. A comparison of geochemical results from Eocene climate simulations and empirical records of shark teeth will reveal processes and mechanisms central to the Eocene Antarctic climatic shift.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -56.581808, "geometry": "POINT(-56.637662 -64.235428)", "instruments": null, "is_usap_dc": true, "keywords": "FISH; USA/NSF; OXYGEN ISOTOPE ANALYSIS; WATER MASSES; Amd/Us; AMD; USAP-DC; OXYGEN ISOTOPES; LABORATORY; Seymour Island; Sharks; Striatolamia Macrota", "locations": "Seymour Island", "north": -64.209061, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Integrated System Science", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e PALEOGENE \u003e EOCENE", "persons": "Kim, Sora; Scher, Howard; Huber, Matthew; Jahn, Alexandra", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "Dryad", "repositories": "Dryad", "science_programs": null, "south": -64.261795, "title": "Collaborative Research: Integrating Eocene Shark Paleoecology and Climate Modeling to reveal Southern Ocean Circulation and Antarctic Glaciation", "uid": "p0010146", "west": -56.693516}, {"awards": "1908399 Bizimis, Michael; 1908548 Feakins, Sarah", "bounds_geometry": "POLYGON((74.787 -67.27617,74.816483 -67.27617,74.845966 -67.27617,74.875449 -67.27617,74.904932 -67.27617,74.934415 -67.27617,74.963898 -67.27617,74.993381 -67.27617,75.022864 -67.27617,75.052347 -67.27617,75.08183 -67.27617,75.08183 -67.31817,75.08183 -67.36017,75.08183 -67.40217,75.08183 -67.44417,75.08183 -67.48617,75.08183 -67.52817,75.08183 -67.57017,75.08183 -67.61217,75.08183 -67.65417,75.08183 -67.69617,75.052347 -67.69617,75.022864 -67.69617,74.993381 -67.69617,74.963898 -67.69617,74.934415 -67.69617,74.904932 -67.69617,74.875449 -67.69617,74.845966 -67.69617,74.816483 -67.69617,74.787 -67.69617,74.787 -67.65417,74.787 -67.61217,74.787 -67.57017,74.787 -67.52817,74.787 -67.48617,74.787 -67.44417,74.787 -67.40217,74.787 -67.36017,74.787 -67.31817,74.787 -67.27617))", "dataset_titles": "Ejtibbett/EOTproxymodel: Proxy Model Comparison for the Eocene-Oligocene Transition [Computational Notebook]; Paleoceanography and biomarker data from the Antarctic Peninsula over the past 37-3 million years; Prydz Bay East Antarctica, biomarkers and pollen, 36-33 million years; Sabrina Coast East Antarctica, Pollen and Biomarker Data from 59-38 million years ago; Southern High Latitude Temperature Proxies from the Late Eocene and Early Oligocene [Dataset]", "datasets": [{"dataset_uid": "200335", "doi": "10.5281/zenodo.7254536", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Southern High Latitude Temperature Proxies from the Late Eocene and Early Oligocene [Dataset]", "url": "https://zenodo.org/record/7254536#.Y2BLgOTMI2w"}, {"dataset_uid": "200334", "doi": "10.5281/zenodo.7254786", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Ejtibbett/EOTproxymodel: Proxy Model Comparison for the Eocene-Oligocene Transition [Computational Notebook]", "url": "https://zenodo.org/record/7254786#.Y2BLAeTMI2w"}, {"dataset_uid": "200317", "doi": "10.25921/n9kg-yw91", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Paleoceanography and biomarker data from the Antarctic Peninsula over the past 37-3 million years", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/35613"}, {"dataset_uid": "200206", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Prydz Bay East Antarctica, biomarkers and pollen, 36-33 million years", "url": "https://www.ncdc.noaa.gov/paleo-search/study/32052"}, {"dataset_uid": "200259", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Sabrina Coast East Antarctica, Pollen and Biomarker Data from 59-38 million years ago", "url": "https://www.ncdc.noaa.gov/paleo/study/34772"}], "date_created": "Sat, 05 Dec 2020 00:00:00 GMT", "description": "The East Antarctic Ice Sheet holds the largest volume of freshwater on the planet, in total enough to raise sea level by almost two hundred feet. Even minor adjustments in the volume of ice stored have major implications for coastlines and climates around the world. The question motivating this project is how did the ice grow to cover the continent over thirty million years ago when Antarctica changed from a warmer environment to an ice-covered southern continent? The seafloor of Prydz Bay, a major drainage basin of the East Antarctic Ice Sheet (EAIS), has been drilled previously to recover sediments dating from millions of years prior to and across the time when inception of continental ice sheets occurred in Antarctica. The last remnants of plant material found as \u0027biomarkers\u0027 in the ocean sediments record the chemical signatures of rain and snowfall that fed the plants and later the expanding glaciers. Sediment carried by glaciers was also deposited on the seafloor and can be analyzed to discover how glaciers flowed across the landscape. Here, the researchers will identify precipitation changes that result from, and drive, ice sheet growth. This study will gather data and further analyze samples from the seafloor sediment archives of the International Ocean Discovery Program\u0027s (IODP) core repositories. Ultimately these findings can help inform temperature-precipitation-ice linkages within climate and ice sheet models. The project will support the training of three female, early career scientists (PhD \u0026 MS students, and research technician) and both PIs and the PhD student will continue their engagement with broadening participation efforts (e.g., Women in Science and Engineering Program; local chapters of Society for the advancement of Native Americans and Chicanos in Science and other access programs) to recruit undergraduate student participants from underrepresented minorities at both campuses and from local community colleges. Antarctic earth science education materials will be assisted by professional illustrations to be open access and used in public education and communication efforts to engage local communities in Los Angeles CA and Columbia SC. \u003cbr/\u003e\u003cbr/\u003eThe researchers at the University of Southern California and the University of South Carolina will together study the penultimate moment of the early Cenozoic greenhouse climate state: the ~4 million years of global cooling that culminated in the Eocene/Oligocene transition (~34 Ma). Significant gaps remain in the understanding of the conditions that preceded ice expansion on Antarctica. In particular, the supply of raw material for ice sheets (i.e., moisture) and the timing, frequency, and duration of precursor glaciations is poorly constrained. This collaborative proposal combines organic and inorganic proxies to examine how Antarctic hydroclimate changed during the greenhouse to icehouse transition. The central hypothesis is that the hydrological cycle weakened as cooling proceeded. Plant-wax hydrogen and carbon isotopes (hydroclimate proxies) and Hf-Nd isotopes of lithogenous and hydrogenous sediments (mechanical weathering proxies) respond strongly and rapidly to precipitation and glacial advance. This detailed and sensitive combined approach will test whether there were hidden glaciations (and/or warm events) that punctuated the pre-icehouse interval. Studies will be conducted on Prydz Bay marine sediment cores in a depositional area for products of weathering and erosion that were (and are) transported through Lambert Graben from the center of Antarctica. The project will yield proxy information about the presence of plants and the hydroclimate of Antarctica and the timing of glacial advance, and is expected to show drying associated with cooling and ice-sheet growth. The dual approach will untangle climate signals from changes in fluvial versus glacial erosion of plant biomarkers. This proposal is potentially transformative because the combination of organic and inorganic proxies can reveal rapid transitions in aridity and glacial expansion, that may have been missed in slower-response proxies and more distal archives. The research is significant as hydroclimate seems to be a key player in the temperature-cryosphere hysteresis.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 75.08183, "geometry": "POINT(74.934415 -67.48617)", "instruments": null, "is_usap_dc": true, "keywords": "MICROFOSSILS; Prydz Bay; PALEOCLIMATE RECONSTRUCTIONS; Sabrina Coast; DROUGHT/PRECIPITATION RECONSTRUCTION; ISOTOPES; AIR TEMPERATURE RECONSTRUCTION", "locations": "Prydz Bay; Sabrina Coast", "north": -67.27617, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Feakins, Sarah; Scher, Howard", "platforms": null, "repo": "Zenodo", "repositories": "NCEI; Zenodo", "science_programs": null, "south": -67.69617, "title": "Collaborative Research: Organic and Inorganic Geochemical Investigation of Hydrologic Change in East Antarctica in the 4 Million Years Before Full Glaciation", "uid": "p0010143", "west": 74.787}, {"awards": "1542962 Anderson, Robert", "bounds_geometry": "POLYGON((-171 -57,-170.8 -57,-170.6 -57,-170.4 -57,-170.2 -57,-170 -57,-169.8 -57,-169.6 -57,-169.4 -57,-169.2 -57,-169 -57,-169 -57.72,-169 -58.44,-169 -59.16,-169 -59.88,-169 -60.6,-169 -61.32,-169 -62.04,-169 -62.76,-169 -63.48,-169 -64.2,-169.2 -64.2,-169.4 -64.2,-169.6 -64.2,-169.8 -64.2,-170 -64.2,-170.2 -64.2,-170.4 -64.2,-170.6 -64.2,-170.8 -64.2,-171 -64.2,-171 -63.48,-171 -62.76,-171 -62.04,-171 -61.32,-171 -60.6,-171 -59.88,-171 -59.16,-171 -58.44,-171 -57.72,-171 -57))", "dataset_titles": "Expedition Data of NBP1702; Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean ; Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean (SNOWBIRDS)", "datasets": [{"dataset_uid": "200126", "doi": "10.7284/907211", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP1702", "url": "https://www.rvdata.us/search/cruise/NBP1702"}, {"dataset_uid": "200165", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean (SNOWBIRDS)", "url": "https://www.bco-dmo.org/dataset/813379/data"}, {"dataset_uid": "200166", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean ", "url": "https://www.ncdc.noaa.gov/paleo/study/31312"}], "date_created": "Fri, 25 Sep 2020 00:00:00 GMT", "description": "General:\r\nScientists established more than 30 years ago that the climate-related variability of carbon dioxide levels in the atmosphere over Earth\u2019s ice-age cycles was regulated by the ocean. Hypotheses to explain how the ocean that regulates atmospheric carbon dioxide have long been debated, but they have proven to be difficult to test. This project was designed test one leading hypothesis, specifically that the ocean experienced greater density stratification during the ice ages. That is, with greater stratification during the ice ages and the slower replacement of deep water by cold dense water formed near the poles, the deep ocean would have held more carbon dioxide, which is produced by biological respiration of the organic carbon that constantly rains to the abyss in the form of dead organisms and organic debris that sink from the sunlit surface ocean. To test this hypothesis, the degree of ocean stratification during the last ice age and the rate of deep-water replacement was to be constrained by comparing the radiocarbon ages of organisms that grew in the surface ocean and at the sea floor within a critical region around Antarctica, where most of the replacement of deep waters occurs. Completing this work was expected to contribute toward improved models of future climate change. Climate scientists rely on models to estimate the amount of fossil fuel carbon dioxide that will be absorbed by the ocean in the future. Currently the ocean absorbs about 25% of the carbon dioxide produced by burning fossil fuels. Most of this carbon is absorbed in the Southern Ocean (the region around Antarctica). How this will change in the future is poorly known. Models have difficulty representing physical conditions in the Southern Ocean accurately, thereby adding substantial uncertainty to projections of future ocean uptake of carbon dioxide. Results of the proposed study will provide a benchmark to test the ability of models to simulate ocean processes under climate conditions distinctly different from those that occur today, ultimately leading to improvement of the models and to more reliable projections of future absorption of carbon dioxide by the ocean. \r\n\r\nTechnical:\r\nThe project added a research component to an existing scientific expedition to the Southern Ocean, in the region between the Ross Sea and New Zealand, that collected sediment cores at locations down the northern flank of the Pacific-Antarctic Ridge at approximately 170\u00b0W. The goal was to collect sediments at each location deposited since early in the peak of the last ice age. This region is unusual in the Southern Ocean in that sediments deposited during the last ice age contain foraminifera, tiny organisms with calcium carbonate shells, in much greater abundance than in other regions of the Southern Ocean. Foraminifera are widely used as an archive of several geochemical tracers of past ocean conditions. We proposed to compare the radiocarbon age of foraminifera that inhabited the surface ocean with the age of contemporary specimens that grew on the seabed. The difference in age between surface and deep-swelling organisms would have been used to discriminate between two proposed mechanisms of deep water renewal during the ice age: formation in coastal polynyas around the edge of Antarctica, much as occurs today, versus formation by open-ocean convection in deep-water regions far from the continent. If the latter mechanism prevails, then it was expected that surface and deep-dwelling foraminifera would exhibit similar radiocarbon ages. In the case of dominance of deep-water formation in coastal polynyas, one expects to find very different radiocarbon ages in the two populations of foraminifera. In the extreme case of greater ocean stratification during the last ice age, one even expects the surface dwellers to appear to be older than contemporary bottom dwellers because the targeted core sites lie directly under the region where the oldest deep waters outcrop at the surface following their long circuitous transit through the deep ocean. The primary objective of the proposed work was to reconstruct the water mass age structure of the Southern Ocean during the last ice age, which, in turn, is a primary factor that controls the amount of carbon dioxide stored in the deep sea. In addition, the presence of foraminifera in the cores to be recovered provides a valuable resource for many other paleoceanographic applications, such as: 1) the application of nitrogen isotopes to constrain the level of nutrient utilization in the Southern Ocean and, thus, the efficiency of the ocean\u2019s biological pump, 2) the application of neodymium isotopes to constrain the transport history of deep water masses, 3) the application of boron isotopes and boron/calcium ratios to constrain the pH and inorganic carbon system parameters of ice-age seawater, and 4) the exploitation of metal/calcium ratios in foraminifera to reconstruct the temperature (Mg/Ca) and nutrient content (Cd/Ca) of deep waters during the last ice age at a location near their source near Antarctica. \r\n\r\nUnfortunately, the cores were shipped to the core repository in a horizontal orientation and there was sufficient distortion of the sediment that the radiocarbon ages of benthic foraminifera were uninterpretable. Therefore, we report only the radiocarbon dates for planktonic foraminifera as well as the total counts of elemental relative abundance from X-ray Fluorescence analysis of the cores. In addition, we used the expedition as an opportunity to collect water samples from which dissolved concentrations of long-lived isotope of thorium and protactinium were determined. Results from those analyses showed that lateral transport by isopycnal mixing dominates the supply of Pa to the Southern Ocean. We have also developed a new algorithm to correct for supply of Th by isopycnal mixing and thereby derive estimates of dust flux to the Southern Ocean. \r\n", "east": -169.0, "geometry": "POINT(-170 -60.6)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; SEDIMENT CHEMISTRY; South Pacific Ocean; SHIPS", "locations": "South Pacific Ocean", "north": -57.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, Robert; Fleisher, Martin; Pavia, Frank", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "R2R", "repositories": "BCO-DMO; NCEI; R2R", "science_programs": null, "south": -64.2, "title": "Water Mass Structure and Bottom Water Formation in the Ice-age Southern Ocean", "uid": "p0010130", "west": -171.0}, {"awards": "1745116 Scambos, Ted", "bounds_geometry": "POLYGON((-75 -69,-74 -69,-73 -69,-72 -69,-71 -69,-70 -69,-69 -69,-68 -69,-67 -69,-66 -69,-65 -69,-65 -69.5,-65 -70,-65 -70.5,-65 -71,-65 -71.5,-65 -72,-65 -72.5,-65 -73,-65 -73.5,-65 -74,-66 -74,-67 -74,-68 -74,-69 -74,-70 -74,-71 -74,-72 -74,-73 -74,-74 -74,-75 -74,-75 -73.5,-75 -73,-75 -72.5,-75 -72,-75 -71.5,-75 -71,-75 -70.5,-75 -70,-75 -69.5,-75 -69))", "dataset_titles": "Density, hydrology and geophysical measurements from the Wilkins Ice Shelf firn aquifer", "datasets": [{"dataset_uid": "601390", "doi": "10.15784/601390", "keywords": "Airborne Radar; Antarctica; Antarctic Peninsula; Firn; Firn Aquifer; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hydrology; Snow/ice; Snow/Ice; Wilkins Ice Shelf", "people": "Mi\u00e8ge, Cl\u00e9ment; Koenig, Lora; Forster, Richard; Solomon, Kip; Miller, Olivia; Wallin, Bruce; Scambos, Ted; Miller, Julie; Montgomery, Lynn", "repository": "USAP-DC", "science_program": null, "title": "Density, hydrology and geophysical measurements from the Wilkins Ice Shelf firn aquifer", "url": "https://www.usap-dc.org/view/dataset/601390"}], "date_created": "Tue, 08 Sep 2020 00:00:00 GMT", "description": "Snow or firn aquifers are areas of subsurface meltwater storage that form in glaciated regions experiencing intense summer surface melting and high snowfall. Aquifers can induce hydrofracturing, and thereby accelerate flow or trigger ice-shelf instability leading to increased ice-sheet mass loss. Widespread aquifers have recently been discovered in Greenland. These have been modelled and mapped using new satellite and airborne remote-sensing techniques. In Antarctica, a series of catastrophic break-ups at the Wilkins Ice Shelf on the Antarctic Peninsula that was previously attributed to effects of surface melting and brine infiltration is now recognized as being consistent with a firn aquifer--possibly stimulated by long-period ocean swell--that enhanced ice-shelf hydrofracture. This project will verify inferences (from the same mapping approach used in Greenland) that such aquifers are indeed present in Antarctica. The team will survey two high-probability sites: the Wilkins Ice Shelf, and the southern George VI Ice Shelf. \u003cbr/\u003e\u003cbr/\u003eThis two-year study will characterize the firn at the two field sites, drill shallow (~60 m maximum) ice cores, examine snow pits (~2 m), and install two AMIGOS (Automated Met-Ice-Geophysics Observing System) stations that include weather, GPS, and firn temperature sensors that will collect and transmit measurements for at least a year before retrieval. Ground-penetrating radar survey in areas surrounding the field sites will track aquifer extent and depth variations. Ice and microwave model studies will be combined with the field-observed properties to further explore the range of firn aquifers and related upper-snow-layer conditions. This study will provide valuable experience for three early-career scientists. An outreach effort through field blogging, social media posts, K-12 presentations, and public lectures is planned to engage the public in the team\u0027s Antarctic scientific exploration and discovery.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -65.0, "geometry": "POINT(-70 -71.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": true, "keywords": "USAP-DC; Firn Aquifer; USA/NSF; FIELD INVESTIGATION; AMD; GLACIERS/ICE SHEETS; Wilkens Ice Shelf; Antarctic Peninsula; Amd/Us", "locations": "Antarctic Peninsula; Wilkens Ice Shelf", "north": -69.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "Antarctic Firn Aquifers: Extent, Characteristics, and Comparison with Greenland Occurrences", "uid": "p0010126", "west": -75.0}, {"awards": "1935945 Tremblay, Marissa; 1935907 Balco, Gregory; 1935755 Lamp, Jennifer", "bounds_geometry": "POLYGON((160 -77.25,160.4 -77.25,160.8 -77.25,161.2 -77.25,161.6 -77.25,162 -77.25,162.4 -77.25,162.8 -77.25,163.2 -77.25,163.6 -77.25,164 -77.25,164 -77.325,164 -77.4,164 -77.475,164 -77.55,164 -77.625,164 -77.7,164 -77.775,164 -77.85,164 -77.925,164 -78,163.6 -78,163.2 -78,162.8 -78,162.4 -78,162 -78,161.6 -78,161.2 -78,160.8 -78,160.4 -78,160 -78,160 -77.925,160 -77.85,160 -77.775,160 -77.7,160 -77.625,160 -77.55,160 -77.475,160 -77.4,160 -77.325,160 -77.25))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 25 Aug 2020 00:00:00 GMT", "description": "Part I: Nontechnical\r\nScientists study the Earth\u0027s past climate in order to understand how the climate will respond to ongoing global change in the future. One of the best analogs for future climate might the period that occurred approximately 3 million years ago, during an interval known as the mid-Pliocene Warm Period. During this period, the concentration of carbon dioxide in the atmosphere was similar to today\u0027s and sea level was 15 or more meters higher, due primarily to warming and consequent ice sheet melting in polar regions. However, the temperatures in polar regions during the mid-Pliocene Warm Period are not well determined, in part because we do not have records like ice cores that extend this far back in time. This project will provide constraints on surface temperatures in Antarctica during the mid-Pliocene Warm Period using a new type of climate proxy, known as cosmogenic noble gas paleothermometry. This project focuses on an area of Antarctica called the McMurdo Dry Valleys. In this area, climate models suggest that temperatures were more than 10 \u00baC warmer during the mid-Pliocene than they are today, but indirect geologic observations suggest that temperatures may have been similar to today. The McMurdo Dry Valleys are also a place where rocks have been exposed to Earth surface conditions for several million years, and where this new climate proxy can be readily applied. The team will reconstruct temperatures in the McMurdo Dry Valleys during the mid-Pliocene Warm Period in order to resolve the discrepancy between models and indirect geologic observations and provide much-needed constraints on the sensitivity of Antarctic ice sheets to warming temperatures. The temperature reconstructions generated in this project will have scientific impact in multiple disciplines, including climate science, glaciology, geomorphology, and planetary science. In addition, the project will (1) broaden the participation of underrepresented groups by supporting two early-career female principal investigators, (2) build STEM talent through the education and training of a graduate student, (3) enhance infrastructure for research via publication of a publicly-accessible, open-source code library, and (4) be broadly disseminated via social media, blog posts, publications, and conference presentations. \r\n\r\nPart II: Technical Description\r\nThe mid-Pliocene Warm Period (3\u20133.3 million years ago) is the most recent interval of the geologic past when atmospheric CO2 concentrations exceeded 400 ppm, and is widely considered an analog for how Earths climate system will respond to current global change. Climate models predict polar amplification the occurrence of larger changes in temperatures at high latitudes than the global average due to a radiative forcing both during the mid-Pliocene Warm Period and due to current climate warming. However, the predicted magnitude of polar amplification is highly uncertain in both cases. The magnitude of polar amplification has important implications for the sensitivity of ice sheets to warming and the contribution of ice sheet melting to sea level change. Proxy-based constraints on polar surface air temperatures during the mid-Pliocene Warm Period are sparse to non-existent. In Antarctica, there is only indirect evidence for the magnitude of warming during this time. This project will provide constraints on surface temperatures in the McMurdo Dry Valleys of Antarctica during the mid-Pliocene Warm Period using a newly developed technique called cosmogenic noble gas (CNG) paleothermometry. CNG paleothermometry utilizes the diffusive behavior of cosmogenic 3He in quartz to quantify the temperatures rocks experience while exposed to cosmic-ray particles within a few meters of the Earths surface. The very low erosion rates and subzero temperatures characterizing the McMurdo Dry Valleys make this region uniquely suited for the application of CNG paleothermometry for addressing the question: what temperatures characterized the McMurdo Dry Valleys during the mid-Pliocene Warm Period? To address this question, the team will collect bedrock samples at several locations in the McMurdo Dry Valleys where erosion rates are known to be low enough that cosmic ray exposure extends into the mid-Pliocene or earlier. They will pair cosmogenic 3He measurements, which will record the thermal histories of our samples, with measurements of cosmogenic 10Be, 26Al, and 21Ne, which record samples exposure and erosion histories. We will also make in situ measurements of rock and air temperatures at sample sites in order to quantify the effect of radiative heating and develop a statistical relationship between rock and air temperatures, as well as conduct diffusion experiments to quantify the kinetics of 3He diffusion specific to each sample. This suite of observations will be used to model permissible thermal histories and place constraints on temperatures during the mid-Pliocene Warm Period interval of cosmic-ray exposure.", "east": 164.0, "geometry": "POINT(162 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; AMD; LABORATORY; USA/NSF; Amd/Us; ISOTOPES; Dry Valleys; AIR TEMPERATURE RECONSTRUCTION; GEOCHEMISTRY; USAP-DC", "locations": "Dry Valleys", "north": -77.25, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Tremblay, Marissa; Granger, Darryl; Balco, Gregory; Lamp, Jennifer", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -78.0, "title": "Collaborative \r\nResearch: Reconstructing Temperatures during the Mid-Pliocene Warm \r\nPeriod in the McMurdo Dry Valleys with Cosmogenic Noble Gases", "uid": "p0010123", "west": 160.0}, {"awards": "1543450 Countway, Peter", "bounds_geometry": "POLYGON((-66 -63,-65.7 -63,-65.4 -63,-65.1 -63,-64.8 -63,-64.5 -63,-64.2 -63,-63.9 -63,-63.6 -63,-63.3 -63,-63 -63,-63 -63.3,-63 -63.6,-63 -63.9,-63 -64.2,-63 -64.5,-63 -64.8,-63 -65.1,-63 -65.4,-63 -65.7,-63 -66,-63.3 -66,-63.6 -66,-63.9 -66,-64.2 -66,-64.5 -66,-64.8 -66,-65.1 -66,-65.4 -66,-65.7 -66,-66 -66,-66 -65.7,-66 -65.4,-66 -65.1,-66 -64.8,-66 -64.5,-66 -64.2,-66 -63.9,-66 -63.6,-66 -63.3,-66 -63))", "dataset_titles": "Biogenic Sulfur Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments; Dissolved Inorganic Nutrient Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments ; Dissolved Organic Carbon (DOC) and Total Dissolved Nitrogen (TDN) Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments; Flow Cytometry Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments; Heterotrophic Bacterial Production Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments; Western Antarctic Peninsula plankton raw sequence reads", "datasets": [{"dataset_uid": "601648", "doi": "10.15784/601648", "keywords": "Antarctica; Biota; Dimethyl Sulfide; Dimethylsulfoniopropionate; Dimethylsulfoxide; DMSP; DMSP Lyase; Palmer Station", "people": "Countway, Peter; Matrai, Patricia", "repository": "USAP-DC", "science_program": null, "title": "Biogenic Sulfur Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "url": "https://www.usap-dc.org/view/dataset/601648"}, {"dataset_uid": "601647", "doi": "10.15784/601647", "keywords": "Antarctica; Palmer Station; Phytoplankton", "people": "Matrai, Patricia; Countway, Peter", "repository": "USAP-DC", "science_program": null, "title": "Flow Cytometry Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "url": "https://www.usap-dc.org/view/dataset/601647"}, {"dataset_uid": "601646", "doi": "10.15784/601646", "keywords": "Antarctica; Carbon; Dissolved Organic Carbon; Nitrogen; Palmer Station; TDN; Total Dissolved Nitrogen", "people": "Matrai, Patricia; Countway, Peter", "repository": "USAP-DC", "science_program": null, "title": "Dissolved Organic Carbon (DOC) and Total Dissolved Nitrogen (TDN) Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "url": "https://www.usap-dc.org/view/dataset/601646"}, {"dataset_uid": "601645", "doi": "10.15784/601645", "keywords": "Antarctica; Nitrate; Nitrite; Palmer Station; Phosphate", "people": "Matrai, Patricia; Countway, Peter", "repository": "USAP-DC", "science_program": null, "title": "Dissolved Inorganic Nutrient Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments ", "url": "https://www.usap-dc.org/view/dataset/601645"}, {"dataset_uid": "601644", "doi": "10.15784/601644", "keywords": "3H-Leu; Antarctica; Bacteria; Biota; DMSP; Heterotrophic Bacterial Production; Palmer Station", "people": "Matrai, Patricia; Countway, Peter", "repository": "USAP-DC", "science_program": null, "title": "Heterotrophic Bacterial Production Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "url": "https://www.usap-dc.org/view/dataset/601644"}, {"dataset_uid": "200337", "doi": "", "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Western Antarctic Peninsula plankton raw sequence reads", "url": "https://dataview.ncbi.nlm.nih.gov/object/PRJNA870587?reviewer=bmud2tbbrqbus79i2n2hb83uio"}], "date_created": "Sat, 01 Aug 2020 00:00:00 GMT", "description": "The Southern Ocean in the vicinity of Antarctica is a region characterized by seasonally-driven marine phytoplankton blooms that are often dominated by microalgal species which produce large amounts of dimethylsulfoniopropionate (DMSP). DMSP can be converted to the compound dimethylsulfide (DMS) which is a molecule that can escape into the atmosphere where it is known to have strong condensation properties that are involved in regional cloud formation. Production of DMSP can influence the diversity and composition of microbial assemblages in seawater and the types and activities of microbes in the seawater will likely affect the magnitude of DMSP\\DMS production. The project examined the role of DMSP in structuring the microbial communities in Antarctic waters and how this structuring may influence DMSP cycling. The project interacted with elementary students in Maine and brought undergraduate students to Bigelow Laboratory. The project also engaged with a science writer and illustrator who joined the team in Palmer Station in 2018. Many posts are available at xxx\r\n\r\nThe project is examining (1) the extent to which the cycling of DMSP in southern ocean waters influenced the composition and diversity of bacterial and protistan assemblages; (2) conversely, whether the composition and diversity of southern ocean protistan and bacterial assemblages influenced the magnitude and rates of DMSP cycling; we are awaiting results on (3) the expression of DMSP degradation genes by marine bacteria seasonally and in response to field experimental additions of DMSP; and, this year (2020-21), we will synthesize these results by quantifying (4) the microbial networks resulting from the presence of DMSP-producers and DMSP-consumers along with their predators, all involved in the cycling of DMSP in southern ocean waters. The work was accomplished by conducting continuous growth experiments with DMSP-amended natural samples of different microbial communities present in summer (2016-17) and fall (2018) at Palmer Station, WAP. Data from the molecular (such as 16S/ 18S tag sequences, DMSP-cycle gene transcripts) and biogeochemical (such as biogenic sulfur cycling, bacterial production, microbial biomass) investigations will be integrated via network analysis in the coming year (2020-21). ", "east": -63.0, "geometry": "POINT(-64.5 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; COMMUNITY DYNAMICS; FIELD INVESTIGATION; AMD; PLANKTON; Amd/Us; BIOGEOCHEMICAL CYCLES; Palmer Station; USA/NSF", "locations": "Palmer Station", "north": -63.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Countway, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "GenBank; USAP-DC", "science_programs": null, "south": -66.0, "title": "Microbial Community Structure and Expression of Functional Genes Involved in the Seasonal Cycling of DMSP in the Southern Ocean", "uid": "p0010120", "west": -66.0}, {"awards": "1341658 Mukhopadhyay, Sujoy", "bounds_geometry": "POLYGON((-116.45 -84.786,-116.443 -84.786,-116.436 -84.786,-116.429 -84.786,-116.422 -84.786,-116.415 -84.786,-116.408 -84.786,-116.401 -84.786,-116.394 -84.786,-116.387 -84.786,-116.38 -84.786,-116.38 -84.7864,-116.38 -84.7868,-116.38 -84.7872,-116.38 -84.7876,-116.38 -84.788,-116.38 -84.7884,-116.38 -84.7888,-116.38 -84.7892,-116.38 -84.7896,-116.38 -84.79,-116.387 -84.79,-116.394 -84.79,-116.401 -84.79,-116.408 -84.79,-116.415 -84.79,-116.422 -84.79,-116.429 -84.79,-116.436 -84.79,-116.443 -84.79,-116.45 -84.79,-116.45 -84.7896,-116.45 -84.7892,-116.45 -84.7888,-116.45 -84.7884,-116.45 -84.788,-116.45 -84.7876,-116.45 -84.7872,-116.45 -84.7868,-116.45 -84.7864,-116.45 -84.786))", "dataset_titles": "Ohio Range Subglacial rock core cosmogenic nuclide data", "datasets": [{"dataset_uid": "601351", "doi": "10.15784/601351", "keywords": "Aluminum-26; Antarctica; Beryllium-10; Cosmogenic Dating; Cosmogenic Radionuclides; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Fluctuations; Ohio Range; Rocks", "people": "Mukhopadhyay, Sujoy", "repository": "USAP-DC", "science_program": null, "title": "Ohio Range Subglacial rock core cosmogenic nuclide data", "url": "https://www.usap-dc.org/view/dataset/601351"}], "date_created": "Sun, 28 Jun 2020 00:00:00 GMT", "description": "Modeling fluctuations in the extent of the West Antarctic Ice Sheet (WAIS) over time is a principal goal of the glaciological community. These models will provide a critical basis for predictions of future sea level change, and therefore this work great societal relevance. The mid-Pliocene time interval is of particular interest, as it is the most recent period in which global temperatures were warmer and atmospheric CO2 concentrations may have been higher than current levels. However, observational constraints on fluctuations in the WAIS older than the last glacial maximum are rare.\r\nTo test model predictions,sub-glacial rock cores were obtained from the Ohio Range along the Transantarctic Mountains near the present-day WAIS divide using a Winkie drill. Rock cores were recovered from 10 to ~30 m under the present-day ice levels. At the Ohio Range, the glacial to interglacial variations in ice sheet levels is ~120 meters. So 30 meters represent a significant fraction of the variation over the course of an ice age.\r\nHigh concentrations of the cosmic ray produced isotopes were detected in the rock cores, indicating extensive periods of ice-free exposure to cosmic irradiation during the last 2 million years. Modeling of the data suggest that bedrock surfaces at the Ohio Range that are currently covered by 30 meters of ice experienced more exposure than ice cover, especially in the Pleistocene. An ice sheet model prediction for the Ohio Range subglacial sample sites however, significantly underestimates exposure in the last 2 million years, and over-predicts ice cover in the Pleistocene. To adjust for the higher amounts of exposure we observe in our samples, the ice sheet model simulations require more frequent and/or longer-lasting WAIS ice drawdowns. This has important implications for future sea-level change as the model maybe under-predicting the magnitude of sea-level contributions from WAIS during the ice-age cycles. Improving the accuracy of the ice sheet models through model-data comparison should remain a prime objective in the face of a warming planet as understanding WAIS behavior is going to be key for predicting and planning for the effects of sea-level change. The project helped support and train a graduate student in climate research related to Antarctica, cosmogenic nuclide analyses and led to a Master\u2019s Thesis. The project also provide partial support to a postdoctoral scholar obtaining cosmogenic neon measurements and for training and mentoring the graduate student\u0027s cosmogenic neon measurements and interpretation. The project results were communicated to the scientific community at conferences and through seminars. The broader community was engaged through the University of California Davis\u0027s Picnic Day celebration, an annual open house that attracts over 70,000 people to the campus, and through classroom visit at a local elementary school.", "east": -116.38, "geometry": "POINT(-116.415 -84.788)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Sheet Fluctuations; ALUMINUM-26 ANALYSIS; BERYLLIUM-10 ANALYSIS; Cosmogenic Radionuclides; USAP-DC; FIELD INVESTIGATION; AMD; Ohio Range; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; LABORATORY", "locations": "Ohio Range", "north": -84.786, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Mukhopadhyay, Sujoy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.79, "title": "Constraining Plio-Pleistocene West Antarctic Ice Sheet Behavior from the Ohio Range and Scott Glacier", "uid": "p0010113", "west": -116.45}, {"awards": "1443576 Panter, Kurt", "bounds_geometry": "POLYGON((-154.1 -86.9,-154.03 -86.9,-153.96 -86.9,-153.89 -86.9,-153.82 -86.9,-153.75 -86.9,-153.68 -86.9,-153.61 -86.9,-153.54 -86.9,-153.47 -86.9,-153.4 -86.9,-153.4 -86.92,-153.4 -86.94,-153.4 -86.96,-153.4 -86.98,-153.4 -87,-153.4 -87.02,-153.4 -87.04,-153.4 -87.06,-153.4 -87.08,-153.4 -87.1,-153.47 -87.1,-153.54 -87.1,-153.61 -87.1,-153.68 -87.1,-153.75 -87.1,-153.82 -87.1,-153.89 -87.1,-153.96 -87.1,-154.03 -87.1,-154.1 -87.1,-154.1 -87.08,-154.1 -87.06,-154.1 -87.04,-154.1 -87.02,-154.1 -87,-154.1 -86.98,-154.1 -86.96,-154.1 -86.94,-154.1 -86.92,-154.1 -86.9))", "dataset_titles": "Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica ", "datasets": [{"dataset_uid": "601331", "doi": "10.15784/601331", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochronology; Glacial Volcanism; Magma Differentiation; Major Elements; Mantle Melting; Solid Earth; Trace Elements; Transantarctic Mountains", "people": "Panter, Kurt", "repository": "USAP-DC", "science_program": null, "title": "Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601331"}], "date_created": "Fri, 05 Jun 2020 00:00:00 GMT", "description": "Predictions of future sea level rise require better understanding of the changing dynamics of the Greenland and Antarctic ice sheets. One way to better understand the past history of the ice sheets is to obtain records from inland ice for past geological periods, particularly in Antarctica, the world\u0027s largest remaining ice sheet. Such records are exceedingly rare, and can be acquired at volcanic outcrops in the La Gorce Mountains of the central Transantarctic Mountains. Volcanoes now exposed within the La Gorce Mountains erupted beneath the East Antarctic ice sheet and the data collected will record how thick the ice sheet was in the past. In addition, information will be used to determine the thermal conditions at the base of the ice sheet, which impacts ice sheet stability. The project will also investigate the origin of volcanic activity in Antarctica and links to the West Antarctic Rift System (WARS). The WARS is a broad area of extended (i.e. stretched) continental crust, similar to that found in East Africa, and volcanism is wide spread and long-lived (65 million years to currently active) and despite more than 50 years of research, the fundamental cause of volcanism and rifting in Antarctica is still vigorously debated. The results of this award therefore also potentially impact the study of oceanic volcanism in the entire southwestern Pacific region (e.g., New Zealand and Australia), where volcanic fields of similar composition and age have been linked by common magma sources and processes. The field program includes a graduate student who will work on the collection, analysis, and interpretation of petrological data as part of his/her Masters project. The experience and specialized analytical training being offered will improve the quality of the student\u0027s research and optimize their opportunities for their future. The proposed work fosters faculty and student national and international collaboration, including working with multi-user facilities that provide advanced technological mentoring of science students. Results will be broadly disseminated in peer-reviewed journals, public presentations at science meetings, and in outreach activities. Petrologic and geochemical data will be disseminated to be the community through the Polar Rock Repository. The study of subglacially erupted volcanic rocks has been developed to the extent that it is now the most powerful proxy methodology for establishing precise \u0027snapshots\u0027 of ice sheets, including multiple critical ice parameters. Such data should include measurements of ice thickness, surface elevation and stability, which will be used to verify, or reject, published semi-empirical models relating ice dynamics to sea level changes. In addition to establishing whether East Antarctic ice was present during the formation of the volcanoes, data will be used to derive the coeval ice thicknesses, surface elevations and basal thermal regime(s) in concert with a precise new geochronology using the 40Ar/39Ar dating method. Inferences from measurement of standard geochemical characteristics (major, trace elements and Sr, Nd, Pb, O isotopes) will be used to investigate a possible relationship between the volcanoes and the recently discovered subglacial ridge under the East Antarctic ice, which may be a rift flank uplift. The ridge has never been sampled, is undated and its significance is uncertain. The data will provide important new information about the deep Earth and geodynamic processes beneath this mostly ice covered and poorly understood sector of the Antarctic continent.", "east": -153.4, "geometry": "POINT(-153.75 -87)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; Mantle Melting; Magma Differentiation; Geochronology; Glacial Volcanism; GEOCHEMISTRY; Major Elements; ISOTOPES; Trace Elements; Transantarctic Mountains; LABORATORY; LAVA COMPOSITION/TEXTURE; USAP-DC; LAND RECORDS", "locations": "Transantarctic Mountains", "north": -86.9, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Panter, Kurt", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.1, "title": "Investigating Early Miocene Sub-ice Volcanoes in Antarctica for Improved Modeling and understanding of a Large Magmatic Province", "uid": "p0010105", "west": -154.1}, {"awards": "1807522 Jones, Tyler", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Mid-Holocene high-resolution water isotope time series for the WAIS Divide ice core; Seasonal temperatures in West Antarctica during the Holocene ; Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "datasets": [{"dataset_uid": "601603", "doi": "10.15784/601603", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Seasonality; Seasonal Temperatures; Temperature; Water Isotopes; West Antarctic Ice Sheet", "people": "Jones, Tyler R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal temperatures in West Antarctica during the Holocene ", "url": "https://www.usap-dc.org/view/dataset/601603"}, {"dataset_uid": "601326", "doi": "10.15784/601326", "keywords": "Antarctica; Delta 18O; Delta Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Snow/ice; Snow/Ice; WAIS Divide Ice Core; Water Isotopes; West Antarctic Ice Sheet", "people": "White, James; Morris, Valerie; Jones, Tyler R.; Vaughn, Bruce", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Mid-Holocene high-resolution water isotope time series for the WAIS Divide ice core", "url": "https://www.usap-dc.org/view/dataset/601326"}, {"dataset_uid": "601274", "doi": "10.15784/601274", "keywords": "Antarctica; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Price, Michael; Garland, Joshua; Bradley, Elizabeth; Morris, Valerie; Jones, Tyler R.; White, James; Vaughn, Bruce", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/601274"}], "date_created": "Tue, 26 May 2020 00:00:00 GMT", "description": "Ice cores contain detailed accounts of Earth\u0027s climate history. The collection of an ice core can be logistically challenging, and extraction of data from the core can be time-consuming as well as susceptible to both human and machine error. Furthermore, locked in measurements from ice cores is information that scientists have not yet found ways to recover. This project will apply techniques from information theory to ice-core data to unlock that information. The primary goal is to demonstrate that information theory can (a) identify regions of a specific ice-core record that are in need of further analysis and (b) provide some specific guidance for that analysis. A secondary goal is to demonstrate that information theory has practical and scientific utility for studies of past climate. This project aims to use information theory in two distinct ways: first, to identify regions of a core where information appears to be damaged or missing, perhaps due to human and/or machine error. In the segment of the West Antarctic Ice Sheet Divide core that is 5000-8000 years old, for instance, information-theoretic methods reveal significant levels of noise, probably due to a laboratory instrument, and something that was not visible in the raw data. This is a particularly important segment of the record, as it contains valuable clues about climatic shifts and the onset of the Holocene. Targeted re-sampling of this segment of the core and reanalysis with newer laboratory apparatus could resolve the data issues. The second way in which information theory can potentially aid in ice-core analysis is by extracting climate signals from the data--such as the accumulation rate at the core site over the period of its formation. This quantity usually requires significant time and effort to produce, but information theory could help to streamline that process.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": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "AMD; West Antarctic Ice Sheet; ISOTOPES; Amd/Us; USAP-DC; USA/NSF; Water Isotopes; WAIS Divide Ice Core; Deuterium; LABORATORY", "locations": "West Antarctic Ice Sheet", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Garland, Joshua; Jones, Tyler R.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Targeted resampling of deep polar ice cores using information theory", "uid": "p0010100", "west": -112.085}, {"awards": "1419979 Severinghaus, Jeffrey", "bounds_geometry": "POLYGON((166.65 -78.62,166.654 -78.62,166.658 -78.62,166.662 -78.62,166.666 -78.62,166.67 -78.62,166.674 -78.62,166.678 -78.62,166.682 -78.62,166.686 -78.62,166.69 -78.62,166.69 -78.6205,166.69 -78.621,166.69 -78.6215,166.69 -78.622,166.69 -78.6225,166.69 -78.623,166.69 -78.6235,166.69 -78.624,166.69 -78.6245,166.69 -78.625,166.686 -78.625,166.682 -78.625,166.678 -78.625,166.674 -78.625,166.67 -78.625,166.666 -78.625,166.662 -78.625,166.658 -78.625,166.654 -78.625,166.65 -78.625,166.65 -78.6245,166.65 -78.624,166.65 -78.6235,166.65 -78.623,166.65 -78.6225,166.65 -78.622,166.65 -78.6215,166.65 -78.621,166.65 -78.6205,166.65 -78.62))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 18 May 2020 00:00:00 GMT", "description": "The PIs have designed and built a new type of rapid access ice drill (RAID) for use in Antarctica. This community tool has the ability to rapidly drill through ice up to 3300 m thick and then collect samples of the ice, ice-sheet bed interface, and bedrock substrate below. This drilling technology will provide a new way to obtain in situ measurements and samples for interdisciplinary studies in geology, glaciology, paleoclimatology, microbiology, and astrophysics. The RAID drilling platform will give the scientific community access to records of geologic and climatic change on a variety of timescales, from the billion-year rock record to million-year ice and climate histories. Development of this platform will enable scientists to address critical questions about the deep interface between the Antarctic ice sheets and the substrate below. Phase I was for design and work with the research community to develop detailed science requirements for the drill. This proposal, Phase II, constructed, assembled and tested the RAID drilling platform at a site near McMurdo (Minna Bluff) where 700-m thick ice sits on bedrock.", "east": 166.69, "geometry": "POINT(166.67 -78.6225)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "WAIS Divide Ice Core; ICE CORE AIR BUBBLES; FIELD INVESTIGATION; USAP-DC; Minna Bluff", "locations": "Minna Bluff", "north": -78.62, "nsf_funding_programs": "Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -78.625, "title": "Collaborative Research: Phase 2 Development of A Rapid Access Ice Drilling (RAID) Platform for Research in Antarctica", "uid": "p0010099", "west": 166.65}, {"awards": "9615704 Bell, Robin; 9615832 Blankenship, Donald", "bounds_geometry": "POLYGON((-180 -74,-176 -74,-172 -74,-168 -74,-164 -74,-160 -74,-156 -74,-152 -74,-148 -74,-144 -74,-140 -74,-140 -75.6,-140 -77.2,-140 -78.8,-140 -80.4,-140 -82,-140 -83.6,-140 -85.2,-140 -86.8,-140 -88.4,-140 -90,-144 -90,-148 -90,-152 -90,-156 -90,-160 -90,-164 -90,-168 -90,-172 -90,-176 -90,180 -90,174 -90,168 -90,162 -90,156 -90,150 -90,144 -90,138 -90,132 -90,126 -90,120 -90,120 -88.4,120 -86.8,120 -85.2,120 -83.6,120 -82,120 -80.4,120 -78.8,120 -77.2,120 -75.6,120 -74,126 -74,132 -74,138 -74,144 -74,150 -74,156 -74,162 -74,168 -74,174 -74,-180 -74))", "dataset_titles": "SOAR-PPT Airborne gravity data; SOAR-WLK Airborne gravity data", "datasets": [{"dataset_uid": "601292", "doi": "10.15784/601292", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Potential Field; Solid Earth; Transantarctic Mountains", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-PPT Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601292"}, {"dataset_uid": "601293", "doi": "10.15784/601293", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Potential Field; Solid Earth; Transantarctic Mountains", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WLK Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601293"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "Continental extension produces a great variety of structures from the linear narrow rifts of the East African Rift to the diffuse extension of the Basin and Range Province of the Western U.S. Rift shoulder uplift varies dramatically between rift flanks. The cause of variable rift width and crustal thinning is fairly well explained by variable initial heat flow and crustal thickness. Mechanical stretching of the lithosphere has been linked to rift shoulder uplift but the cause of variable rift flank uplift remains poorly understood. The Transantarctic Mountains (TAM) are an extreme example of rift flank uplift, extending over 3500 km across Antarctica and reaching elevations up to 4500 m and thus constitute a unique feature of EarthOs crust. The range was formed in the extensional environment associated with the Mesozoic and Cenozoic breakup of Gondwanaland. Geological and geophysical work has shown that the TAM developed along the long-lived lithospheric boundary between East and West Antarctica reactivated by a complex history of extensional and translational microplate motions. The TAM are not uniform along strike. Along the OWilkes FrontO, the northern segment of the rift extends from North Victoria Land to Byrd Glacier. The Wilkes Front architecture consists of (1) thin, extended crust forming the Victoria Land Basin in the Ross Sea, (2) the TAM rift shoulder, and (3) a long-wavelength down- ward forming the Wilkes Basin. Contrasting structures are mapped along the OPensacola/PoleO Front, the southern segment of the rift extending from the Nimrod Glacier to the Pensacola Mountains. Along this southern section no rift basin has been mapped to date and the down-ward along the East Antarctic, or ObacksideO, edge of the mountains is less pronounced. A flexural model linking the extension in the Ross Sea to the formation of both the mountains and the Wilkes Basin has been considered as a me chanism for uplift of the entire mountain range. The variability in fundamental architecture along the TAM indicates that neither a single event nor a sequence of identical events produced the rift flank uplift. The observation of variable architecture suggests complex mechanisms and possibly a fundamental limitation in maximum sustainable rift flank elevation. The motivation for studying the TAM is to try to understand the geodynamics of this extreme elevation rift flank. Are the geodynamics of the area unique, or does the history of glaciation and related erosion contribute to the extreme uplift? With the existing data sets it is difficult to confidently constrain the geological architecture across representative sections of the TAM. Any effort to refine geodynamic mechanisms requires this basic understanding of the TAM architecture. The goal of this project is to (1) constrain the architecture of the rift system as well as the distribution and structure of sedimentary basins, glacial erosion and mafic igneous rocks surrounding the rift flank by acquiring three long wavelength geophysical transects with integrated gravity, magnetics, ice- penetrating radar, and ice surface measurements, (2) quantify the contribution of various geodynamic mechanisms to understand the geological conditions which can lead to extreme rift flank uplift, and (3) use the improved understanding of architecture and geophysical data to test geodynamic models in order to improve our understanding both of the TAM geodynamics and the general problem of the geodynamics of rift flank uplift worldwide. This project will allow development of a generalized framework for understanding the development of rift flank uplift as well as address the question of the specific geodynamic evolution of the TAM.", "east": -140.0, "geometry": "POINT(170 -82)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": true, "keywords": "USAP-DC; Transantarctic Mountains; GRAVITY FIELD; TECTONICS", "locations": "Transantarctic Mountains", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Buck, W. Roger; Blankenship, Donald D.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Contrasting Architecture and Dynamics of the Transantarctic Mountains", "uid": "p0010095", "west": 120.0}, {"awards": "1341661 Near, Thomas", "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": "Phylogenomics of Antarctic notothenioid fishes", "datasets": [{"dataset_uid": "601264", "doi": null, "keywords": "Adaptive Radiation; Antarctica; Fish; Notothenioidei; Phylogeny; Southern Ocean; Speciation", "people": "Near, Thomas; Dornburg, Alex", "repository": "USAP-DC", "science_program": null, "title": "Phylogenomics of Antarctic notothenioid fishes", "url": "https://www.usap-dc.org/view/dataset/601264"}, {"dataset_uid": "601262", "doi": "10.15784/601262", "keywords": "Adaptive Radiation; Antarctica; Fish; Notothenioidei; Phylogeny; Southern Ocean; Speciation", "people": "Dornburg, Alex; Near, Thomas", "repository": "USAP-DC", "science_program": null, "title": "Phylogenomics of Antarctic notothenioid fishes", "url": "https://www.usap-dc.org/view/dataset/601262"}], "date_created": "Sat, 29 Feb 2020 00:00:00 GMT", "description": "Understanding how groups of organisms respond to climate change is fundamentally important to assessing the impacts of human activities as well as understanding how past climatic shifts have shaped biological diversity over deep stretches of time. The fishes occupying the near-shore marine habitats around Antarctica are dominated by one group of closely related species called notothenioids. It appears dramatic changes in Antarctic climate were important in the origin and evolutionary diversification of this economically important lineage of fishes. Deposits of fossil fishes in Antarctica that were formed when the continent was experiencing milder temperatures show that the area was home to a much more diverse array of fish lineages. Today the waters of the Southern Ocean are very cold, and often below freezing, but notothenioids fishes exhibit a number of adaptions to live in this harsh set of marine habitats, including the presence of anti-freeze proteins. This research project will collect DNA sequences from hundreds of genes to infer the genealogical relationships of nearly all 124 notothenioid species, and use mathematical techniques to estimate the ages of species and lineages. Knowledge on the timing of evolutionary divergence in notothenioids will allow investigators to assess if timing of previous major climatic shifts in Antarctica are correlated with key events in the formation of the modern Southern Ocean fish fauna. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. The project will support educational outreach activities to teenager groups and to the general public through a natural history museum exhibit and other public lectures. It will provide professional training opportunities for graduate students and a postdoctoral research scholar. \u003cbr/\u003e\u003cbr/\u003eAdaptive radiation, where lineages experience high rates of evolutionary diversification coincident with ecological divergence, is mostly studied in island ecosystems. Notothenioids dominate the fish fauna of the Southern Ocean and exhibit antifreeze glycoproteins that allow occupation of the subzero waters. Notothenioids are noted as one of the only examples of adaptive radiation among marine fishes, but the evolutionary history of diversification and radiation into different ecological habitats is poorly understood. This research will generate a species phylogeny (evolutionary history) for nearly all of the 124 recognized notothenioid species to investigate the mechanisms of adaptive radiation in this lineage. The phylogeny is inferred from approximately 350 genes sampled using next generation DNA sequencing and related techniques. Morphometric data are taken for museum specimens to investigate the tempo of morphological diversification and to determine if there are correlations between rates of lineage diversification and the origin of morphological disparity. The patterns of lineage, morphological, and ecological diversification in the notothenioid radiation will be compared to the paleoclimatic record to determine if past instances of global climate change have shaped the evolutionary diversification of this lineage of polar-adapted fishes.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "FISH; Fish; AMD; USA/NSF; Southern Ocean; Amd/Us; NOT APPLICABLE; USAP-DC; MARINE ECOSYSTEMS; Notothenioidei; Phylogeny", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Near, Thomas", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Phylogenomic Study of Adaptive Radiation in Antarctic Fishes", "uid": "p0010087", "west": -180.0}, {"awards": "1743035 Saba, Grace", "bounds_geometry": "POLYGON((164 -72.2,165 -72.2,166 -72.2,167 -72.2,168 -72.2,169 -72.2,170 -72.2,171 -72.2,172 -72.2,173 -72.2,174 -72.2,174 -72.74,174 -73.28,174 -73.82,174 -74.36,174 -74.9,174 -75.44,174 -75.98,174 -76.52,174 -77.06,174 -77.6,173 -77.6,172 -77.6,171 -77.6,170 -77.6,169 -77.6,168 -77.6,167 -77.6,166 -77.6,165 -77.6,164 -77.6,164 -77.06,164 -76.52,164 -75.98,164 -75.44,164 -74.9,164 -74.36,164 -73.82,164 -73.28,164 -72.74,164 -72.2))", "dataset_titles": "Grazing rates of Euphausia crystallorophias from RVIB Nathaniel B. Palmer NBP1801 in the Ross Sea, Jan.-Feb. 2018; NBP1801 Expedition data; ru32-20180109T0531; Zooplankton abundance from Isaacs-Kid Midwater Trawl (IKMT) hauls from RVIB Nathaniel B. Palmer NBP1801 in the Ross Sea, Jan.-Feb. 2018; Zooplankton abundance from ring net tows from RVIB Nathaniel B. Palmer NBP1801 in the Ross Sea, January 2018", "datasets": [{"dataset_uid": "200139", "doi": "10.1575/1912/bco-dmo.792478.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Grazing rates of Euphausia crystallorophias from RVIB Nathaniel B. Palmer NBP1801 in the Ross Sea, Jan.-Feb. 2018", "url": "https://www.bco-dmo.org/dataset/792478"}, {"dataset_uid": "200137", "doi": "10.1575/1912/bco-dmo.789299.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Zooplankton abundance from ring net tows from RVIB Nathaniel B. Palmer NBP1801 in the Ross Sea, January 2018", "url": "https://www.bco-dmo.org/dataset/789299"}, {"dataset_uid": "200138", "doi": "10.1575/1912/bco-dmo.792385.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Zooplankton abundance from Isaacs-Kid Midwater Trawl (IKMT) hauls from RVIB Nathaniel B. Palmer NBP1801 in the Ross Sea, Jan.-Feb. 2018", "url": "https://www.bco-dmo.org/dataset/792385"}, {"dataset_uid": "200056", "doi": "10.7284/907753", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1801 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1801"}, {"dataset_uid": "200140", "doi": "", "keywords": null, "people": null, "repository": "ERDDAP", "science_program": null, "title": "ru32-20180109T0531", "url": "http://slocum-data.marine.rutgers.edu/erddap/tabledap/ru32-20180109T0531-profile-sci-delayed.html"}], "date_created": "Thu, 27 Feb 2020 00:00:00 GMT", "description": "Terra Nova Bay (western Ross Sea, Antarctica) supports dense populations of several key species in the Ross Sea food web, including copepods, crystal krill (Euphausia crystallorophias), Antarctic silverfish (Pleuragramma antarcticum), and colonies of Ad\u00e9lie and Emperor penguins that feed primarily on crystal krill and silverfish. Absent from our understanding of the Ross Sea food web is zooplankton and silverfish mesoscale distribution, spatial structure of age/maturity classes, and their interactions with physical drivers and each other. The quantitative linkages between primary producers and the higher trophic levels, specifically, the processes responsible for the regulation of abundance and rates of middle trophic levels dominated by copepods and crystal krill (Euphausia crystallorophias), is virtually unknown. Given that the next century will see extensive changes in the Ross Sea\u2019s ice distributions and oceanography as a result of climate change, understanding the basic controls of zooplankton and silverfish abundance and distribution is essential. \r\nDuring a January \u2013 March 2018 cruise in the western Ross Sea, we deployed a glider equipped with an echo sounder (Acoustic Zooplankton Fish Profiler) that simultaneously measured depth, temperature, conductivity, chlorophyll fluorescence, and dissolved oxygen. Additionally, net tows, mid-water trawls, and crystal krill grazing experiments were conducted. Our study provided the first glider-based acoustic assessment of simultaneous distributions of multiple trophic levels in the Ross Sea, from which predator-prey interactions and the relationships between organisms and physics drivers (sea ice, circulation features) were investigated. We illustrated high variability in ocean physics, phytoplankton biomass, and crystal krill biomass and aggregation over time and between locations within Terra Nova Bay. Biomass of krill was highest in locations characterized by deeper mixed layers and highest integrated chlorophyll concentrations. Krill aggregations were consistently located at depth well below the mixed layer and chlorophyll maximum. Experiments investigating krill grazing, in combination with krill depth distributions relative to chlorophyll biomass, illuminate high krill grazing rates could be attributed to the occupation of a unique niche whereby they are opportunistically feeding on sinking high concentrations of detritus derived from surface blooms. The information on the abundance, distribution, and interactions of key species in multiple trophic levels resulting from this project provide a conceptual background to understand how this ecosystem might respond to future conditions under climate change.\r\nOur project tested the capability of a multi-frequency echo sounder on a glider for the first time. The production of consistent, vertically-resolved, high resolution glider-based acoustic measurements will pave the way for cost-effective, automated examination of entire food webs and ecosystems in regions all over the global ocean. A wide range of users including academic and government scientists, ecosystem-based fisheries managers, and monitoring programs including those conducted by OOI, IOOS, and NOAA will benefit from this project. This project also provided the opportunity to focus on broadening participation in research and articulating the societal benefits through education and innovative outreach programs. A data set from this project is being included in the new NSF-funded Polar CAP initiative, that will be used by a diverse and young audience to increase understanding of the polar system and the ability to reason with data. Finally, this project provided a unique field opportunity and excellent hand-on training for a post-doctoral researcher, a graduate student, and two undergraduate students.", "east": 174.0, "geometry": "POINT(169 -74.9)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; FISH; Terra Nova Bay; AQUATIC SCIENCES; PELAGIC; PLANKTON; USAP-DC; ANIMALS/VERTEBRATES", "locations": "Terra Nova Bay", "north": -72.2, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Saba, Grace", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "BCO-DMO", "repositories": "BCO-DMO; ERDDAP; R2R", "science_programs": null, "south": -77.6, "title": "Using Bio-acoustics on an Autonomous Surveying Platform for the Examination of Phytoplankton-zooplankton and Fish Interactions in the Western Ross Sea", "uid": "p0010086", "west": 164.0}, {"awards": "1543383 Postlethwait, John", "bounds_geometry": "POLYGON((-66 -62,-65.2 -62,-64.4 -62,-63.6 -62,-62.8 -62,-62 -62,-61.2 -62,-60.4 -62,-59.6 -62,-58.8 -62,-58 -62,-58 -62.4,-58 -62.8,-58 -63.2,-58 -63.6,-58 -64,-58 -64.4,-58 -64.8,-58 -65.2,-58 -65.6,-58 -66,-58.8 -66,-59.6 -66,-60.4 -66,-61.2 -66,-62 -66,-62.8 -66,-63.6 -66,-64.4 -66,-65.2 -66,-66 -66,-66 -65.6,-66 -65.2,-66 -64.8,-66 -64.4,-66 -64,-66 -63.6,-66 -63.2,-66 -62.8,-66 -62.4,-66 -62))", "dataset_titles": "C. aceratus pronephric kidney (head kidney) miRNA; mirtop\r\ncommand lines tool to annotate miRNAs with a standard mirna/isomir naming; Patagonotothen cornucola isolate Pcor_18_01 cytochrome oxidase subunit 1 (COI) gene, partial cds; mitochondrial; Patagonotothen sima isolate Psim_18_11 cardiac muscle myosin heavy chain 6 (myh6) gene, partial cds; Patagonotothen sima isolate Psim_18_11 cytochrome oxidase subunit 1 (COI) gene, partial cds; mitochondrial; Patagonotothen sima isolate Psim_18_12 cytochrome oxidase subunit 1 (COI) gene, partial cds; mitochondrial; Prost!, a tool for miRNA annotation and next generation smallRNA sequencing experiment analysis; Quantifying expression levels of smallRNAs between tissues in Danio Rerio strain AB.; Quantifying expression levels of smallRNAs between tissues in three-spined stickleback", "datasets": [{"dataset_uid": "200131", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Prost!, a tool for miRNA annotation and next generation smallRNA sequencing experiment analysis", "url": "https://github.com/uoregon-postlethwait/prost"}, {"dataset_uid": "200128", "doi": "", "keywords": null, "people": null, "repository": "NCBI SRA", "science_program": null, "title": "Quantifying expression levels of smallRNAs between tissues in three-spined stickleback", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=SRP157992"}, {"dataset_uid": "200135", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Patagonotothen sima isolate Psim_18_12 cytochrome oxidase subunit 1 (COI) gene, partial cds; mitochondrial", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=MN136233+"}, {"dataset_uid": "200130", "doi": "", "keywords": null, "people": null, "repository": "NCBI SRA", "science_program": null, "title": "C. aceratus pronephric kidney (head kidney) miRNA", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=SRP069031"}, {"dataset_uid": "200133", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Patagonotothen cornucola isolate Pcor_18_01 cytochrome oxidase subunit 1 (COI) gene, partial cds; mitochondrial", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=MN136231"}, {"dataset_uid": "200134", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Patagonotothen sima isolate Psim_18_11 cytochrome oxidase subunit 1 (COI) gene, partial cds; mitochondrial", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=MN136232"}, {"dataset_uid": "200136", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Patagonotothen sima isolate Psim_18_11 cardiac muscle myosin heavy chain 6 (myh6) gene, partial cds", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=MN136234+"}, {"dataset_uid": "200132", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "mirtop\r\ncommand lines tool to annotate miRNAs with a standard mirna/isomir naming", "url": "https://github.com/miRTop"}, {"dataset_uid": "200129", "doi": "", "keywords": null, "people": null, "repository": "NCBI SRA", "science_program": null, "title": "Quantifying expression levels of smallRNAs between tissues in Danio Rerio strain AB.", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=SRP039502"}], "date_created": "Wed, 26 Feb 2020 00:00:00 GMT", "description": "microRNAs (miRNAs) are key post-transcriptional regulators of gene expression that modulate development and physiology in temperate animals. Although miRNAs act by binding to messenger RNAs (mRNAs), a process that is strongly sensitive to temperature, miRNAs have yet not been studied in Antarctic animals, including Notothenioid fish, which dominate the Southern Ocean. This project will compare miRNA regulation in 1) Antarctic vs. temperate fish to learn the roles of miRNA regulation in adaptation to constant cold; and in 2) bottom-dwelling, dense-boned, red-blooded Nototheniods vs. high buoyancy, osteopenic, white-blooded icefish to understand miRNA regulation in specialized organs after the evolution of the loss of hemoglobin genes and red blood cells, the origin of enlarged heart and vasculature, and the evolution of increased buoyancy, which arose by decreased bone mineralization and increased lipid deposition. Aim 1 is to test the hypothesis that Antarctic fish evolved miRNA-related genome specializations in response to constant cold. The project will compare four Antarctic Notothenioid species to two temperate Notothenioids and two temperate laboratory species to test the hypotheses that (a) Antarctic fish evolved miRNA genome repertoires by loss of ancestral genes and/or gain of new genes, (b) express miRNAs that are involved in cold tolerance, and (c) respond to temperature change by changing miRNA gene expression. Aim 2 is to test the hypothesis that the evolution of icefish from red-blooded bottom-dwelling ancestors was accompanied by an altered miRNA genomic repertoire, sequence, and/or expression. The project will test the hypotheses that (a) miRNAs in icefish evolved in sequence and/or in expression in icefish specializations, including head kidney (origin of red blood cells); heart (changes in vascular system), cranium and pectoral girdle (reduced bone mineral density); and skeletal muscle (lipid deposition), and (b) miRNAs that evolved in icefish specializations had ancestral functions related to their derived roles in icefish, as determined by functional tests of zebrafish orthologs of icefish miRNAs in developing zebrafish. The program will isolate, sequence, and determine the expression of miRNAs and mRNAs using high-throughput transcriptomics and novel software. Results will show how the microRNA system evolves in vertebrate animals pushed to physiological extremes and provide insights into the prospects of key species in the most rapidly warming part of the globe.", "east": -58.0, "geometry": "POINT(-62 -64)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; Palmer Station; NOT APPLICABLE; FISH", "locations": "Palmer Station", "north": -62.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Postlethwait, John; Desvignes, Thomas", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "GitHub", "repositories": "GitHub; NCBI GenBank; NCBI SRA", "science_programs": null, "south": -66.0, "title": "Antarctic Fish and MicroRNA Control of Development and Physiology", "uid": "p0010085", "west": -66.0}, {"awards": "1644020 Sims, Kenneth W.; 1644013 Gaetani, Glenn; 1644027 Wallace, Paul", "bounds_geometry": "POLYGON((164.1 -77.1,164.65 -77.1,165.2 -77.1,165.75 -77.1,166.3 -77.1,166.85 -77.1,167.4 -77.1,167.95 -77.1,168.5 -77.1,169.05 -77.1,169.6 -77.1,169.6 -77.235,169.6 -77.37,169.6 -77.505,169.6 -77.64,169.6 -77.775,169.6 -77.91,169.6 -78.045,169.6 -78.18,169.6 -78.315,169.6 -78.45,169.05 -78.45,168.5 -78.45,167.95 -78.45,167.4 -78.45,166.85 -78.45,166.3 -78.45,165.75 -78.45,165.2 -78.45,164.65 -78.45,164.1 -78.45,164.1 -78.315,164.1 -78.18,164.1 -78.045,164.1 -77.91,164.1 -77.775,164.1 -77.64,164.1 -77.505,164.1 -77.37,164.1 -77.235,164.1 -77.1))", "dataset_titles": "G170 Electron Microprobe Analyses of Melt Inclusions and Host Olivines; G170 Raman Spectroscopy \u0026 Tomography Volumes of Melt Inclusions and Vapor Bubbles; G170 Sample Locations Ross Island \u0026 Discovery Province; G170 Secondary Ion Mass Spectrometry Analses of Melt Inclusion Volatiles; G170 Secondary Ion Mass Spectrometry Analyses of Melt Inclusion Hydrogen Isotopes; Location and Description of Tephra Samples from the Erebus and Discovery Sub-provinces", "datasets": [{"dataset_uid": "601250", "doi": "10.15784/601250", "keywords": "Antarctica; Hut Point Peninsula; Mt. Bird; Mt. Morning; Mt. Terror; Ross Island; Turks Head; Turtle Rock", "people": "Pamukcu, Ayla; Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "Location and Description of Tephra Samples from the Erebus and Discovery Sub-provinces", "url": "https://www.usap-dc.org/view/dataset/601250"}, {"dataset_uid": "601506", "doi": "10.15784/601506", "keywords": "Antarctica; Ion Mass Spectrometry; Ross Island; Volatiles", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Secondary Ion Mass Spectrometry Analses of Melt Inclusion Volatiles", "url": "https://www.usap-dc.org/view/dataset/601506"}, {"dataset_uid": "601508", "doi": "10.15784/601508", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Melt Inclusions; Raman Spectroscopy; Ross Island; Vapor Bubbles; Volcanic", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Raman Spectroscopy \u0026 Tomography Volumes of Melt Inclusions and Vapor Bubbles", "url": "https://www.usap-dc.org/view/dataset/601508"}, {"dataset_uid": "601504", "doi": "10.15784/601504", "keywords": "Antarctica; Ross Island; Sample/collection Description; Sample/Collection Description; Sample Location", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Sample Locations Ross Island \u0026 Discovery Province", "url": "https://www.usap-dc.org/view/dataset/601504"}, {"dataset_uid": "601507", "doi": "10.15784/601507", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Hydrogen; Ion Mass Spectrometry; Ross Island", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Secondary Ion Mass Spectrometry Analyses of Melt Inclusion Hydrogen Isotopes", "url": "https://www.usap-dc.org/view/dataset/601507"}, {"dataset_uid": "601505", "doi": "10.15784/601505", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Electron Microprobe Analyses; Olivine; Petrography; Ross Island", "people": "Gaetani, Glenn", "repository": "USAP-DC", "science_program": null, "title": "G170 Electron Microprobe Analyses of Melt Inclusions and Host Olivines", "url": "https://www.usap-dc.org/view/dataset/601505"}], "date_created": "Sat, 08 Feb 2020 00:00:00 GMT", "description": "The depths at which magmas are stored, their pre-eruptive volatile contents, and the rates at which they ascend to the Earth\u0027s surface are important controls on the dynamics of volcanic eruptions. Basaltic magmas are likely to be vapor undersaturated as they begin their ascent from the mantle through the crust, but volatile solubility drops with decreasing pressure. Once vapor saturation is achieved and the magma begins to degas, its pre-eruptive volatile content is determined largely by the depth at which it resides within the crust. Magma stored in deeper reservoirs tend to experience less pre-eruptive degassing and to be richer in volatiles than magma shallower reservoirs. Eruptive style is influenced by the rate at which a magma ascends from the reservoir to the surface through its effect on the efficiency of vapor bubble nucleation, growth, and coalescence. The proposed work will advance our understanding of pre-eruptive storage conditions and syn-eruptive ascent rates through a combined field and analytical research program. Volatile measurements from olivine-hosted melt inclusions will be used to systematically investigate magma storage depths and ascent rates associated with alkaline volcanism in the Erebus volcanic province. A central goal of the project is to provide a spatial and temporal framework for interpreting results from studies of present-day volcanic processes at Mt Erebus volcano. The Erebus volcanic province of Antarctica is especially well suited to this type of investigation because: (1) there are many exposed mafic scoria cones, fissure vents, and hyaloclastites (exposed in sea cliffs) that produced rapidly quenched, olivine-rich tephra; (2) existing volatile data for Ross Island MIs show that magma storage was relatively deep compared to many mafic volcanic systems; (3) some of the eruptive centers ejected mantle xenoliths, allowing for comparison of ascent rates for xenolith-bearing and xenolith-free eruptions, and comparison of ascent rates for those bearing xenoliths with times estimated from settling velocities; and (4) the cold, dry conditions in Antarctica result in excellent tephra preservation compared to tropical and even many temperate localities. The project provides new tools for assessing volcanic hazards, facilitates collaboration involving researchers from three different institutions (WHOI, U Wyoming, and U Oregon), supports the researchers\u0027 involvement in teaching, advising, and outreach, and provides an educational opportunity for a promising young postdoctoral researcher. Understanding the interrelationships among magma volatile contents, reservoir depths, and ascent rates is vital for assessing volcanic hazards associated with alkaline volcanism across the globe.\r\n\r\n", "east": 169.6, "geometry": "POINT(166.85 -77.775)", "instruments": null, "is_usap_dc": true, "keywords": "Tephra; Turtle Rock; USA/NSF; Amd/Us; LABORATORY; AMD; Ross Island; Turks Head; Hut Point Peninsula; LAVA SPEED/FLOW; USAP-DC; Mt. Morning; Mt. Terror; ROCKS/MINERALS/CRYSTALS; Mt. Bird; FIELD INVESTIGATION", "locations": "Ross Island; Mt. Morning; Mt. Bird; Mt. Terror; Hut Point Peninsula; Turtle Rock; Turks Head", "north": -77.1, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Gaetani, Glenn; Le Roux, Veronique; Sims, Kenneth; Wallace, Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.45, "title": "Collaborative Research: Determining Magma Storage Depths and Ascent Rates for the Erebus Volcanic Province, Antarctica Using Diffusive Water Loss from Olivine-hosted Melt Inclusion", "uid": "p0010081", "west": 164.1}, {"awards": "1443437 Carlson, Anders; 1443268 Beard, Brian", "bounds_geometry": "POLYGON((-80 -65,-79 -65,-78 -65,-77 -65,-76 -65,-75 -65,-74 -65,-73 -65,-72 -65,-71 -65,-70 -65,-70 -65.5,-70 -66,-70 -66.5,-70 -67,-70 -67.5,-70 -68,-70 -68.5,-70 -69,-70 -69.5,-70 -70,-71 -70,-72 -70,-73 -70,-74 -70,-75 -70,-76 -70,-77 -70,-78 -70,-79 -70,-80 -70,-80 -69.5,-80 -69,-80 -68.5,-80 -68,-80 -67.5,-80 -67,-80 -66.5,-80 -66,-80 -65.5,-80 -65))", "dataset_titles": "Radiogenic isotopes of ODP Site 178-1096; Sand content of ODP Site 178-1096", "datasets": [{"dataset_uid": "200108", "doi": " doi:10.1594/PANGAEA.909407 ", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Radiogenic isotopes of ODP Site 178-1096", "url": "https://doi.pangaea.de/10.1594/PANGAEA.909407"}, {"dataset_uid": "200109", "doi": " doi:10.1594/PANGAEA.909411", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Sand content of ODP Site 178-1096", "url": "https://doi.pangaea.de/10.1594/PANGAEA.909411 "}], "date_created": "Fri, 31 Jan 2020 00:00:00 GMT", "description": "This project developed sediment provenance proxies to trace the sources of sediment discharged by the WAIS to the continental rise. The WAIS erodes sediments from various West Antarctic geologic terranes that are deposited in adjacent drift sites. The geochemistry and magnetic properties of drift sediments reflect the tectono-metamorphic history of their source terranes. Deglaciation of a terrane during WAIS collapse should be detectable by the loss of the terrane\u2019s geochemical and magnetic signature in continental-rise detrital sediments. Continental shelf late-Holocene sediments from near the current WAIS groundling line were analyzed for silt- and claysize Sr-Nd-Pb isotopes and major-trace elements. The suite of cores spans from the eastern Ross Sea to the northern tip of the Antarctic Peninsula and established the provenance signatures of the Ross and Amundsen Provinces of Marie Byrd Land, Pine Island Bay, Thurston Island/Eight Coast Block, Ellsworth-Whitmore Crustal Block, and Antarctic Peninsula terranes. Many of these terranes have similar tectono-metamorphic histories but Sr-Nd isotope data from detrital sediments suggest at least 3 distinct provenance signatures. This comprehensive grain-size-specific provenance data adds to on-going collection of glacial till mineral and bulk provenance data. An initial down core study of Ocean Drilling Program Site 1096 in the Bellingshausen Sea was used to assess the utility of these new grain-size-specific provenance proxies in documenting WAIS collapse. We found the presence of both the WAIS and APIS over the last 115,000 years, but absence of the WAIS before 115,000 years ago. This means that the WAIS was gone during the last interglacial period, an interval when sea level was at least 6 meters above present. ", "east": -70.0, "geometry": "POINT(-75 -67.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "West Antarctic Ice Sheet; GLACIERS/ICE SHEETS; West Antarctica; PALEOCLIMATE RECONSTRUCTIONS; NOT APPLICABLE; USAP-DC; ISOTOPES; GEOCHEMISTRY; Bellingshausen Sea", "locations": "West Antarctic Ice Sheet; West Antarctica; Bellingshausen Sea", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Anders, Carlson; Beard, Brian; Stoner, Joseph", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "PANGAEA", "repositories": "PANGAEA", "science_programs": null, "south": -70.0, "title": "Collaborative Research: Development of a Suite of Proxies to Detect Past Collapse of the West Antarctic Ice Sheet", "uid": "p0010079", "west": -80.0}, {"awards": "1246111 Dalziel, Ian", "bounds_geometry": "POLYGON((-44 -53,-42.9 -53,-41.8 -53,-40.7 -53,-39.6 -53,-38.5 -53,-37.4 -53,-36.3 -53,-35.2 -53,-34.1 -53,-33 -53,-33 -53.4,-33 -53.8,-33 -54.2,-33 -54.6,-33 -55,-33 -55.4,-33 -55.8,-33 -56.2,-33 -56.6,-33 -57,-34.1 -57,-35.2 -57,-36.3 -57,-37.4 -57,-38.5 -57,-39.6 -57,-40.7 -57,-41.8 -57,-42.9 -57,-44 -57,-44 -56.6,-44 -56.2,-44 -55.8,-44 -55.4,-44 -55,-44 -54.6,-44 -54.2,-44 -53.8,-44 -53.4,-44 -53))", "dataset_titles": "BAS Geological Collection: Central Scotia Sea (full data link not provided); Nathaniel B Palmer NBP 1408; South Georgia: SOG1, SOG2, SOG3", "datasets": [{"dataset_uid": "200105", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "South Georgia: SOG1, SOG2, SOG3", "url": "https://www.unavco.org/data/gps-gnss/gps-gnss.html"}, {"dataset_uid": "200107", "doi": "", "keywords": null, "people": null, "repository": "British Antarctic Survey", "science_program": null, "title": "BAS Geological Collection: Central Scotia Sea (full data link not provided)", "url": "https://www.bas.ac.uk/data/our-data/collections/geological-collections/"}, {"dataset_uid": "200106", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Nathaniel B Palmer NBP 1408", "url": "http://www.marine-geo.org/tools/search/entry.php?id=NBP1408"}], "date_created": "Tue, 28 Jan 2020 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eOpening of Drake Passage and the West Scotia Sea south of Tierra del Fuego broke the final continental barrier to onset of a complete Antarctic Circumpolar Current (ACC). Initiation of the ACC has been associated in time with a major, abrupt, drop in global temperatures and the rapid expansion of the Antarctic ice sheets at 33-34 Ma. Events leading to the formation of the Drake Passage gateway are poorly known. Understanding the tectonic evolution of the floor of the Central Scotia Sea (CSS) and the North Scotia Ridge is a key to this understanding. Previous work has demonstrated that superimposed constructs formed a volcanic arc that likely blocked direct eastward flow from the Pacific to the Atlantic through the opening Drake Passage gateway as the active South Sandwich arc does today. The PIs propose a cruise to test, develop and refine, with further targeted mapping and dredging, their theory of CSS tectonics and the influence it had on the onset and development of the ACC. In addition they propose an installation of GPS receiver to test their paleogeographic reconstructions and determine whether South Georgia is moving as part of the South American plate. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eA graduate student will be involved in all stages of the research. Undergraduate students will also be involved as watch-standers. A community college teacher will participate in the cruise. The PIs will have a website on which there will be images of the actual ocean floor dredging in operation. The teacher will participate with web and outreach support through PolarTREC. Results of the cruise are of broad interest to paleoceanographers, paleoclimate modelers and paleobiogeographers.A network of four continuous Global Navigational Satellite Systems (GNSS) receivers was installed on the bedrock of South Georgia in the Southern Ocean in 2013 and 2014. An additional receiver on a concrete foundation provides a tie to a tide gauge, part of the United Kingdom South Atlantic Tide Gauge Network. The GNSS receivers have already provided data suggesting that the South Georgia microcontinent (SGM) is moving independent of both the South American plate to the north and the Scotia plate to the south. The data also demonstrate that the SGM is being uplifted. ", "east": -33.0, "geometry": "POINT(-38.5 -55)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Scotia Sea; PLATE BOUNDARIES; TECTONIC PROCESSES; NOT APPLICABLE; COASTAL ELEVATION; Southern Ocean; USAP-DC", "locations": "Scotia Sea; Southern Ocean", "north": -53.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Dalziel, Ian W.; Lawver, Lawrence; Krissek, Lawrence", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "UNAVCO", "repositories": "British Antarctic Survey; MGDS; UNAVCO", "science_programs": null, "south": -57.0, "title": "Collaborative Research: Role of the Central Scotia Sea Floor and North Scotia Ridge in the Onset and Development of the Antarctic Circumpolar Current", "uid": "p0010078", "west": -44.0}, {"awards": "1341680 Sletten, Ronald", "bounds_geometry": "POLYGON((160 -77,160.2 -77,160.4 -77,160.6 -77,160.8 -77,161 -77,161.2 -77,161.4 -77,161.6 -77,161.8 -77,162 -77,162 -77.1,162 -77.2,162 -77.3,162 -77.4,162 -77.5,162 -77.6,162 -77.7,162 -77.8,162 -77.9,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,160.8 -78,160.6 -78,160.4 -78,160.2 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))", "dataset_titles": "Chemical and physical characterization of Beacon Valley and Victoria Valley permafrost cores", "datasets": [{"dataset_uid": "601247", "doi": "10.15784/601247", "keywords": "Aluminum-26; Antarctica; Be-10; Cosmogenic; Dry Valleys; Geochemistry; Permafrost", "people": "Sletten, Ronald S.", "repository": "USAP-DC", "science_program": null, "title": "Chemical and physical characterization of Beacon Valley and Victoria Valley permafrost cores", "url": "https://www.usap-dc.org/view/dataset/601247"}], "date_created": "Thu, 21 Nov 2019 00:00:00 GMT", "description": "Intellectual Merit: This project will yield new information on the long term Antarctic climate and landscape evolution from measurements of cosmogenic nuclides in quartz sand from two unique permafrost cores collected in Beacon Valley, Antarctica. The two cores have already been drilled in ice-cemented, sand-rich permafrost at 5.5 and 30.6 meters depth, and are currently in cold storage at the University of Washington. The cores are believed to record the monotonic accumulation of sand that has been blown into lower Beacon Valley and inflated the surface over time. The rate of accumulation and any hiatus in the accumulation are believed to reflect in part the advance and retreat of the Taylor Glacier. Preliminary measurements of cosmogenically-produced beryllium (10Be) and aluminum (26Al) in quartz sand in the 5.5-meter depth core reveal that it has been accreting at a rate of 2.5 meters/Myr for the past million years. Furthermore, prior to that time, lower Beacon Valley was most likely covered (shielded from the atmosphere thereby having no or very low production of cosmogenic nuclides in quartz) by Taylor Glacier from 1 to 3.5 Myr BP. These preliminary measurements also suggest that the 30.6 meter core may provide a record of over 10 million years. The emphasis is the full characterization of the core and analysis of cosmogenic nuclides (including cosmogenic neon) in the 30.6 meter permafrost core to develop a burial history of the sands and potentially a record the waxing and waning of the Taylor Glacier. This will allow new tests of our current understanding of surface dynamics and climate history in the McMurdo Dry Valleys (MDV) based on the dated stratigraphy of eolian sand that has been accumulating and inflating the surface for millions of years. This is a new process of surface inflation whose extent has not been well documented, and holds the potential to develop a continuous history of surface burial and glacial expansion. This project will provide a new proxy for understanding the climatic history of the Dry Valleys and will test models for the evolution of permafrost in Beacon Valley.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003e\u003cbr/\u003eThe landscape history of the McMurdo Dry Valleys is important because geological deposits there comprise the richest terrestrial record available from Antarctica. By testing the current age model for these deposits, we will improve understanding of Antarctica?s role in global climate change. This project will train one graduate and one undergraduate student in geochemistry, geochronology, and glacial and periglacial geology. They will participate substantively in the research and are expected to develop their own original ideas. Results from this work will be incorporated into undergraduate and graduate teaching curricula, will be published in the peer reviewed literature, and the data will be made public.", "east": 162.0, "geometry": "POINT(161 -77.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; NOT APPLICABLE; BOREHOLES; Antarctica", "locations": "Antarctica", "north": -77.0, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Earth Sciences", "paleo_time": null, "persons": "Sletten, Ronald S.; Stone, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Ancient landscape-active Surfaces: Periglacial Hyperinflation in soils of Beacon Valley, Antarctica", "uid": "p0010068", "west": 160.0}, {"awards": "1643550 Sletten, Ronald", "bounds_geometry": "POLYGON((160.5 -77.3,160.67 -77.3,160.84 -77.3,161.01 -77.3,161.18 -77.3,161.35 -77.3,161.52 -77.3,161.69 -77.3,161.86 -77.3,162.03 -77.3,162.2 -77.3,162.2 -77.35,162.2 -77.4,162.2 -77.45,162.2 -77.5,162.2 -77.55,162.2 -77.6,162.2 -77.65,162.2 -77.7,162.2 -77.75,162.2 -77.8,162.03 -77.8,161.86 -77.8,161.69 -77.8,161.52 -77.8,161.35 -77.8,161.18 -77.8,161.01 -77.8,160.84 -77.8,160.67 -77.8,160.5 -77.8,160.5 -77.75,160.5 -77.7,160.5 -77.65,160.5 -77.6,160.5 -77.55,160.5 -77.5,160.5 -77.45,160.5 -77.4,160.5 -77.35,160.5 -77.3))", "dataset_titles": "Timelapse photography of Don Juan Pond and surrounding basin", "datasets": [{"dataset_uid": "601487", "doi": "10.15784/601487", "keywords": "Antarctica; Brine; CaCl2; Don Juan Pond; Dry Valleys; Salt", "people": "Toner, Jonathan; Mushkin, Amit; Sletten, Ronald S.", "repository": "USAP-DC", "science_program": null, "title": "Timelapse photography of Don Juan Pond and surrounding basin", "url": "https://www.usap-dc.org/view/dataset/601487"}], "date_created": "Thu, 21 Nov 2019 00:00:00 GMT", "description": "This study aims to better understand salt accumulation in cold deserts and develop a model of salt transport by groundwater. Cold deserts, like the Antarctic McMurdo Dry Valleys (MDV), are similar to hot deserts in that they accumulate high concentrations of salts because there is not enough water to flush the salts out of the soils into the ocean. The accumulation of salt allows for the creation of brine-rich groundwater that freezes at much lower temperatures. Field work will focus on several groundwater features in the MDV including Don Juan Pond, a shallow lake that accumulates extremely high levels of salts and does not freeze until the temperature reaches -51 degrees C (-60 degrees F). The setting offers the potential to better understand this unique water environment including life at its extremes. It also serves as an analog environment for Mars, a planet that is entirely underlain by permafrost, similar to the MDV. This project will support a doctoral student at the University of Washington Department of Earth and Space Sciences, who will be trained in chemical analysis, chemical and physical modeling, and remote field work in a polar desert environment.\u003cbr/\u003e\u003cbr/\u003ePast research suggests that the movement of soluble ions in sediment and soil is controlled by the water activity, permeability, and the thermal regime; however, processes controlling the ionic redistribution in Antarctic environments are poorly constrained. This project aims to better understand the formation, salt redistribution, and water activity of pervasive brine-rich groundwater that is enriched in calcium chloride. A primary goal is to develop a brine thermal;reactive;transport model for the MDV region using data collected from the field to constrain model inputs and ground-truth model outputs. The model will develop a Pitzer-type thermodynamic, reactive transport model and couple it to a ground temperature model. The model will test mechanisms of groundwater formation in the MDV and the properties (e.g. composition, temperature, and water activity) of widespread shallow brine-rich waters. Water is an essential ingredient for life and defining processes that control the availability of water is critical for understanding the habitability of extreme environments, including Mars.", "east": 162.2, "geometry": "POINT(161.35 -77.55)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA", "is_usap_dc": true, "keywords": "Amd/Us; AMD; Antarctica; USA/NSF; USAP-DC; SOIL CHEMISTRY; FIELD INVESTIGATION", "locations": "Antarctica", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sletten, Ronald S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8, "title": "Formation and Characteristics of Brine-rich Water in the Dry Valleys, Antarctica", "uid": "p0010069", "west": 160.5}, {"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; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601399", "doi": "10.15784/601399", "keywords": "Antarctica; 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/601399"}, {"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": "Schauer, Andrew; Jones, Tyler R.; White, James; Steig, Eric J.; Morris, Valerie; Vaughn, Bruce; Kahle, Emma", "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": "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": "Vaughn, Bruce; White, James; Epifanio, Jenna; Buizert, Christo; Waddington, Edwin D.; Conway, Howard; Stevens, Max; Schauer, Andrew; Morris, Valerie; Koutnik, Michelle; Fudge, T. J.; Jones, Tyler R.; Steig, Eric J.; Kahle, Emma", "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": "Steig, Eric J.; White, James; Kahle, Emma; Schauer, Andrew; Vaughn, Bruce; Jones, Tyler R.; Morris, Valerie", "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.\u003cbr/\u003e\u003cbr/\u003eThis 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 (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": "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": "Vaughn, Bruce; White, James; Epifanio, Jenna; Buizert, Christo; Waddington, Edwin D.; Conway, Howard; Stevens, Max; Schauer, Andrew; Morris, Valerie; Koutnik, Michelle; Fudge, T. J.; Jones, Tyler R.; Steig, Eric J.; Kahle, Emma", "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": "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": "Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Aydin, Murat", "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": "601399", "doi": "10.15784/601399", "keywords": "Antarctica; 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/601399"}, {"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": "Souney, Joseph Jr.; Twickler, Mark; Kahle, Emma; Nicewonger, Melinda R.; Fudge, T. J.; Hargreaves, Geoff; Nunn, Richard; Steig, Eric J.; Aydin, Murat; Casey, Kimberly A.; Fegyveresi, John", "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"}], "date_created": "Wed, 30 Oct 2019 00:00:00 GMT", "description": "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": "1744645 Young, Jodi", "bounds_geometry": "POLYGON((-64.4 -64.2,-64.38 -64.2,-64.36 -64.2,-64.34 -64.2,-64.32 -64.2,-64.3 -64.2,-64.28 -64.2,-64.26 -64.2,-64.24 -64.2,-64.22 -64.2,-64.2 -64.2,-64.2 -64.26,-64.2 -64.32,-64.2 -64.38,-64.2 -64.44,-64.2 -64.5,-64.2 -64.56,-64.2 -64.62,-64.2 -64.68,-64.2 -64.74,-64.2 -64.8,-64.22 -64.8,-64.24 -64.8,-64.26 -64.8,-64.28 -64.8,-64.3 -64.8,-64.32 -64.8,-64.34 -64.8,-64.36 -64.8,-64.38 -64.8,-64.4 -64.8,-64.4 -64.74,-64.4 -64.68,-64.4 -64.62,-64.4 -64.56,-64.4 -64.5,-64.4 -64.44,-64.4 -64.38,-64.4 -64.32,-64.4 -64.26,-64.4 -64.2))", "dataset_titles": "Dataset: Particulate Organic Carbon and Particulate Nitrogen; Dataset: Photosynthetic Pigments; Dataset: Physical Profiles of Temperature, Salinity, and Brine Volume; Sea-ice diatom compatible solute shifts", "datasets": [{"dataset_uid": "200378", "doi": "10.26008/1912/bco-dmo.913655.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Physical Profiles of Temperature, Salinity, and Brine Volume", "url": "https://www.bco-dmo.org/dataset/913655"}, {"dataset_uid": "200376", "doi": "10.26008/1912/bco-dmo.913566.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Particulate Organic Carbon and Particulate Nitrogen", "url": "https://www.bco-dmo.org/dataset/913566"}, {"dataset_uid": "200377", "doi": "10.26008/1912/bco-dmo.913222.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Photosynthetic Pigments", "url": "https://www.bco-dmo.org/dataset/913222"}, {"dataset_uid": "200322", "doi": "10.21228/M84386", "keywords": null, "people": null, "repository": "Metabolomics workbench", "science_program": null, "title": "Sea-ice diatom compatible solute shifts", "url": "https://www.metabolomicsworkbench.org/data/DRCCMetadata.php?Mode=Study\u0026StudyID=ST001393"}], "date_created": "Tue, 23 Jul 2019 00:00:00 GMT", "description": "Rapid changes in the extent and thickness of sea ice during the austral spring subject microorganisms within or attached to the ice to large fluctuations in temperature, salinity, light and nutrients. This project aims to identify cellular responses in sea-ice algae to increasing temperature and decreasing salinity during the spring melt along the western Antarctic Peninsula and to determine how associated changes at the cellular level can potentially affect dynamic, biologically driven processes. Understanding how sea-ice algae cope with, and are adapted to, their environment will not only help predict how polar ecosystems may change as the extent and thickness of sea ice change, but will also provide a better understanding of the widespread success of photosynthetic life on Earth. The scientific context and resulting advances from the research will be communicated to the general public through outreach activities that includes work with Science Communication Fellows and the popular Polar Science Weekend at the Pacific Science Center in Seattle, Washington. The project will provide student training to college students as well as provide for educational experiences for K-12 school children. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThere is currently a poor understanding of feedback relationships that exist between the rapidly changing environment in the western Antarctic Peninsula region and sea-ice algal production. The large shifts in temperature and salinity that algae experience during the spring melt affect critical cellular processes, including rates of enzyme-catalyzed reactions involved in photosynthesis and respiration, and the production of stress-protective compounds. These changes in cellular processes are poorly constrained but can be large and may have impacts on local ecosystem productivity and biogeochemical cycles. In particular, this study will focus on the thermal sensitivity of enzymes and the cycling of compatible solutes and exopolymers used for halo- and cryo-protection, and how they influence primary production and the biogeochemical cycling of carbon and nitrogen. Approaches will include field sampling during spring melt, incubation experiments of natural sea-ice communities under variable temperature and salinity conditions, and controlled manipulation of sea-ice algal species in laboratory culture. Employment of a range of techniques, from fast repetition rate fluorometry and gross and net photosynthetic measurements to metabolomics and enzyme kinetics, will tease apart the mechanistic effects of temperature and salinity on cell metabolism and primary production with the goal of quantifying how these changes will impact biogeochemical processes along the western Antarctic Peninsula.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -64.2, "geometry": "POINT(-64.3 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; SHIPS; DIATOMS; Antarctic Peninsula", "locations": "Antarctic Peninsula", "north": -64.2, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Young, Jodi; Deming, Jody", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "BCO-DMO", "repositories": "BCO-DMO; Metabolomics workbench", "science_programs": null, "south": -64.8, "title": "Spring Blooms of Sea Ice Algae Along the Western Antarctic Peninsula: Effects of Warming and Freshening on Cell Physiology and Biogeochemical Cycles.", "uid": "p0010039", "west": -64.4}, {"awards": "1543267 Brook, Edward; 1543229 Severinghaus, Jeffrey", "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": "Multi-site ice core Krypton stable isotope ratios; Noble Gas Data from recent ice in Antarctica for 86Kr problem", "datasets": [{"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Mulvaney, Robert; Severinghaus, Jeffrey P.; Buizert, Christo; Pyne, Rebecca L.; Brook, Edward J.; Shackleton, Sarah; Baggenstos, Daniel; Mosley-Thompson, Ellen; Bertler, Nancy; Etheridge, David; Bereiter, Bernhard", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}, {"dataset_uid": "601195", "doi": "10.15784/601195", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Krypton; Noble Gas; Xenon", "people": "Shackleton, Sarah; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Noble Gas Data from recent ice in Antarctica for 86Kr problem", "url": "https://www.usap-dc.org/view/dataset/601195"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Bertler, Nancy; Etheridge, David; Baggenstos, Daniel; Brook, Edward J.; Severinghaus, Jeffrey P.; Pyne, Rebecca L.; Mulvaney, Robert; Buizert, Christo; Mosley-Thompson, Ellen; Bereiter, Bernhard; Shackleton, Sarah", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Buizert, Christo; Severinghaus, Jeffrey P.; Shackleton, Sarah; Bertler, Nancy; Brook, Edward J.; Baggenstos, Daniel; Bereiter, Bernhard; Mosley-Thompson, Ellen; Etheridge, David; Pyne, Rebecca L.; Mulvaney, Robert", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}], "date_created": "Wed, 10 Jul 2019 00:00:00 GMT", "description": "Overview: The funded work investigated whether ice core 86Kr acts as a proxy for barometric pressure variability, and whether this proxy can be used in Antarctic ice cores to infer past movement of the Southern Hemisphere (SH) westerly winds. Pressure variations drive macroscopic air movement in the firn column, which reduces the gravitational isotopic enrichment of slow-diffusing gases (such as Kr). The 86Kr deviation from gravitational equilibrium (denoted D86Kr) thus reflects the magnitude of pressure variations (among other things). Atmospheric reanalysis data suggest that pressure variability over Antarctica is linked to the Southern Annular Mode (SAM) index and the position of the SH westerly winds. Preliminary data from the WAIS Divide ice core show a large excursion in D86Kr during the last deglaciation (20-9 ka before present). In this project the investigators (1) performed high-precision 86Kr analysis on ice core and firn air samples to establish whether D86Kr is linked to pressure variability; (2) Refined the deglacial WAIS Divide record of Kr isotopes; (3) Investigated the role of pressure variability in firn air transport using firn air models with firn microtomography data and Lattice- Boltzmann modeling; and (4) Investigated how barometric pressure variability in Antarctica is linked to the SAM index and the position/strength of the SH westerlies in past and present climates using GCM and reanalysis data. A key finding was that D86Kr in recent ice samples (e.g. last 50 years) from a broad spatial array of sites in Antarctica and Greenland showed a significant correlation with directly measured barometric pressure variability at the ice core site. This strongly supports the hypothesis that 86Kr can be used as a paleo-proxy for storminess.\r\nIntellectual Merit: The SH westerlies are a key component of the global climate system; they are an important control on the global oceanic overturning circulation and possibly on atmospheric CO2 concentrations. Poleward movement of the SH westerlies during the last deglaciation has been hypothesized, yet evidence from proxy and modeling studies remains inconclusive. The funded work could provide valuable new constraints on deglacial movement of the SH westerlies. This record can be compared to high-resolution CO2 data from the same core, allowing us to test hypotheses that link CO2 to the SH westerlies. Climate proxies are at the heart of paleoclimate research. The funded work has apparently led to the discovery of a completely new proxy, opening up exciting new research possibilities and increasing the scientific value of existing ice cores. Once validated, the 86Kr proxy could be applied to other time periods as well, providing a long-term perspective on the movement of the SH westerlies. The funded work has furthermore provided valuable new insights into firn air transport. \r\n\r\nBroader impact: The Southern Ocean is presently an important sink of atmospheric CO2, thereby reducing the warming associated with anthropogenic CO2 emissions. Stratospheric ozone depletion and greenhouse warming have displaced the SH westerlies poleward, with potential consequences for the future magnitude of this oceanic carbon uptake. The funded work may provide a paleo-perspective on past movement of the SH westerlies and its link to atmospheric CO2, which could guide projections of future oceanic CO2 uptake, with strong societal benefits. The awarded funds supported and trained an early-career postdoctoral scholar at OSU, and fostered (international) collaboration. Data from the study will be available to the scientific community and the broad public through recognized data centers. During this project the PI and senior personnel have continued their commitment to public outreach through media interviews and speaking to schools and the public about their work. The PI provides services to the community by chairing the IPICS (International Partnership in Ice Core Sciences) working group and organizing annual PIRE (Partnerships in International Research and Education) workshops.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USA/NSF; FIRN; ICE CORE RECORDS; USAP-DC; Greenland; Xenon; Noble Gas; Ice Core; Amd/Us; Antarctica; AMD; LABORATORY; Krypton; ATMOSPHERIC PRESSURE", "locations": "Greenland; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Brook, Edward J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative research: Kr-86 as a proxy for barometric pressure variability and movement of the SH westerlies during the last\r\ndeglaciation", "uid": "p0010037", "west": -180.0}, {"awards": "1745036 Marchetti, Adrian; 1744760 Hopkinson, Brian", "bounds_geometry": "POLYGON((-77 -61,-75.2 -61,-73.4 -61,-71.6 -61,-69.8 -61,-68 -61,-66.2 -61,-64.4 -61,-62.6 -61,-60.8 -61,-59 -61,-59 -62.1,-59 -63.2,-59 -64.3,-59 -65.4,-59 -66.5,-59 -67.6,-59 -68.7,-59 -69.8,-59 -70.9,-59 -72,-60.8 -72,-62.6 -72,-64.4 -72,-66.2 -72,-68 -72,-69.8 -72,-71.6 -72,-73.4 -72,-75.2 -72,-77 -72,-77 -70.9,-77 -69.8,-77 -68.7,-77 -67.6,-77 -66.5,-77 -65.4,-77 -64.3,-77 -63.2,-77 -62.1,-77 -61))", "dataset_titles": "Photosynthetic physiological data of Proteorhodopsin containing diatoms under differing iron availabilities", "datasets": [{"dataset_uid": "601530", "doi": "10.15784/601530", "keywords": "Antarctica; Diatom", "people": "Hopkinson, Brian; Andrew, Sarah; Marchetti, Adrian; Plumb, Kaylie", "repository": "USAP-DC", "science_program": null, "title": "Photosynthetic physiological data of Proteorhodopsin containing diatoms under differing iron availabilities", "url": "https://www.usap-dc.org/view/dataset/601530"}], "date_created": "Sun, 16 Jun 2019 00:00:00 GMT", "description": "Proteorhodopsins (PR) are retinal-binding membrane proteins that can act as light-driven proton pumps to generate energy that can be used for metabolism and growth. The discovery of PRs in many diverse marine prokaryotic microbes has initiated extensive investigations into their distributions and functional roles. Recently, a rhodopsin-like gene of the proton-pumping variety was identified in diatoms thus revealing their presence within obligate marine eukaryotic photoautotrophs. Since this time, PRs have been identified in a number of diatom isolates although there appears to be a much higher frequency of\r\nPR in diatoms residing in cold, iron-limited regions of the ocean, particularly in the Southern Ocean (SO). PR is especially suited for use in SO phytoplankton since unlike conventional photosynthesis, it uses no iron and its reaction rate is insensitive to temperature. The overall objective of our proposed project is to characterize Antarctic diatom-PR and determine its role in the adaptation of SO diatoms to the prevailing conditions of low iron concentrations and extremely low temperatures. Our research objectives will be achieved through a combination of molecular, biochemical and physiological measurements in diatom isolates recently obtained from the Western Antarctic Peninsula region. We will determine the proton-pumping characteristics and pumping rates of PR as a function of light intensity and wavelength, the resultant PR-linked intracellular ATP production rates, and the cellular localization of the protein. We will examine under which environmental conditions Antarctic diatom-PR is most highly expressed and construct a cellular energy budget that includes diatom-PR when grown under these different growth conditions. Estimates of the energy flux generated by PR in PR-containing diatoms will be compared to total energy generation by the photosynthetic light reactions and metabolically coupled respiration rates. Finally, we will compare the characteristics and gene expression of diatom-PR in Antarctic diatoms to PR-containing diatoms isolated from temperate regions in order to investigate if there is a preferential dependence on energy production through diatom-PR in diatoms residing in cold, iron-limited regions of the ocean.", "east": -59.0, "geometry": "POINT(-68 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; NSF/USA; Southern Ocean; AMD; Amd/Us; LABORATORY; USAP-DC; BIOGEOCHEMICAL CYCLES", "locations": "Southern Ocean", "north": -61.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Marchetti, Adrian; Septer, Alecia; Hopkinson, Brian", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.0, "title": "Collaborative research: Antarctic diatom proteorhodopsins: Characterization and a potential role in the iron-limitation response", "uid": "p0010033", "west": -77.0}, {"awards": "1642570 Thurber, Andrew", "bounds_geometry": "POINT(166.666 -77.8)", "dataset_titles": "Microbial community composition of the Cinder Cones Cold Seep", "datasets": [{"dataset_uid": "200035", "doi": "DOI:10.1575/1912/bco-dmo.756997.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Microbial community composition of the Cinder Cones Cold Seep", "url": "https://www.bco-dmo.org/dataset/756997"}], "date_created": "Fri, 24 May 2019 00:00:00 GMT", "description": "Methane is a potent greenhouse gas that is naturally emitted into the oceans by geologic seeps and microbial production. Based on studies of persistent deep-sea seeps at mid- and northern latitudes, researchers have learned that bacteria and archaea can create a \"sediment filter\" that oxidizes methane prior to its release. Antarctica is thought to contain large reservoirs of organic carbon buried beneath its ice which could a quantity of methane equivalent to all of the permafrost in the Arctic and yet we know almost nothing about the methane oxidizing microbes in this region. How these microbial communities develop and potentially respond to fluctuations in methane levels is an under-explored avenue of research. A bacterial mat was recently discovered at 78 degrees south, suggesting the possible presence of a methane seep, and associated microbial communities. This project will explore this environment in detail to assess the levels and origin of methane, and the nature of the microbial ecosystem present. \u003cbr/\u003e \u003cbr/\u003eAn expansive bacterial mat appeared and/or was discovered at 78 degrees south in 2011. This site, near McMurdo Station Antarctica, has been visited since the mid-1960s, but this mat was not observed until 2011. The finding of this site provides an unusual opportunity to study an Antarctic marine benthic habitat with active methane cycling and to examine the dynamics of recruitment and community succession of seep fauna including bacteria, archaea, protists and metazoans. This project will collect the necessary baseline data to facilitate further studies of Antarctic methane cycling. The concentration and source of methane will be determined at this site and at potentially analogous sites in McMurdo Sound. In addition to biogeochemical characterization of the sites, molecular analysis of the microbial community will quantify the time scales on which bacteria and archaea respond to methane input and provide information on rates of community development and succession in the Southern Ocean. Project activities will facilitate the training of at least one graduate student and results will be shared at both local and international levels. A female graduate student will be mentored as part of this project and data collected will form part of her dissertation. Lectures will be given in K-12 classrooms in Oregon to excite students about polar science. National and international audiences will be reached through blogs and presentations at a scientific conference. The PI\u0027s previous blogs have been used by K-12 classrooms as part of their lesson plans and followed in over 65 countries.\u003cbr/\u003e", "east": 166.666, "geometry": "POINT(166.666 -77.8)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Sea Floor; USAP-DC; Ross Sea; BACTERIA/ARCHAEA; NOT APPLICABLE", "locations": "Ross Sea; Sea Floor", "north": -77.8, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Thurber, Andrew", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -77.8, "title": "EAGER: Elucidating the Antarctic Methane Cycle at the Cinder Cones Reducing Habitat.", "uid": "p0010030", "west": 166.666}, {"awards": "1543031 Ivany, Linda", "bounds_geometry": null, "dataset_titles": "NetCDF outputs from middle Eocene climate simulation using the GENESIS global circulation model ; Organic carbon isotope data from serially sampled Eocene driftwood from the La Meseta Fm., Seymour ; Oxygen isotope data from serially sampled Eocene bivalves from the La Meseta Fm., Seymour Island, Antarctica ", "datasets": [{"dataset_uid": "601175", "doi": "10.15784/601175 ", "keywords": "Antarctica; Atmosphere; Climate Model; Computer Model; Eocene; Genesis; Global Circulation Model; Modeling; Model Output; Seasonality; Temperature", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "NetCDF outputs from middle Eocene climate simulation using the GENESIS global circulation model ", "url": "https://www.usap-dc.org/view/dataset/601175"}, {"dataset_uid": "601173", "doi": "10.15784/601173 ", "keywords": "Antarctica; Carbon Isotopes; Driftwood; Eocene; Geochemistry; Geochronology; Isotope Data; La Meseta Formation; Mass Spectrometer; Mass Spectrometry; Organic Carbon Isotopes; Seasonality; Seymour Island; Wood", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "Organic carbon isotope data from serially sampled Eocene driftwood from the La Meseta Fm., Seymour ", "url": "https://www.usap-dc.org/view/dataset/601173"}, {"dataset_uid": "601174", "doi": "10.15784/601174", "keywords": "Antarctica; Biota; Bivalves; Cucullaea; Eocene; Glaciers/ice Sheet; Glaciers/Ice Sheet; Isotope Data; La Meseta Formation; Mass Spectrometer; Mass Spectrometry; Oxygen Isotope; Paleotemperature; Retrotapes; Seasonality; Seymour Island", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "Oxygen isotope data from serially sampled Eocene bivalves from the La Meseta Fm., Seymour Island, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601174"}], "date_created": "Tue, 23 Apr 2019 00:00:00 GMT", "description": "In order to understand what environmental conditions might look like for future generations, we need to turn to archives of past times when the world was indeed warmer, before anyone was around to commit them to collective memory. The geologic record of Earth\u0027s past offers a glimpse of what could be in store for the future. Research by Ivany and her team looks to Antarctica during a time of past global warmth to see how seasonality of temperature and rainfall in coastal settings are likely to change in the future. They will use the chemistry of fossils (a natural archive of these variables) to test a provocative hypothesis about near-monsoonal conditions in the high latitudes when the oceans are warm. If true, we can expect high-latitude shipping lanes to become more hazardous and fragile marine ecosystems adapted to constant cold temperatures to suffer. With growing information about how human activities are likely to affect the planet in the future, we will be able to make more informed decisions about policies today. This research involves an international team of scholars, including several women scientists, training of graduate students, and a public museum exhibit to educate children about how we study Earth\u0027s ancient climate and what we can learn from it.\u003cbr/\u003e\u003cbr/\u003eAntarctica is key to an understanding how Earth?s climate system works under conditions of elevated CO2. The poles are the most sensitive regions on the planet to climate change, and the equator-to-pole temperature gradient and the degree to which high-latitude warming is amplified are important components for climate models to capture. Accurate proxy data with good age control are therefore critical for testing numerical models and establishing global patterns. The La Meseta Formation on Seymour Island is the only documented marine section from the globally warm Eocene Epoch exposed in outcrop on the continent; hence its climate record is integral to studies of warming. Early data suggest the potential for strongly seasonal precipitation and runoff in coastal settings. This collaboration among paleontologists, geochemists, and climate modelers will test this using seasonally resolved del-18O data from fossil shallow marine bivalves to track the evolution of seasonality through the section, in combination with independent proxies for the composition of summer precipitation (leaf wax del-D) and local seawater (clumped isotopes). The impact of the anticipated salinity stratification on regional climate will be evaluated in the context of numerical climate model simulations. In addition to providing greater clarity on high-latitude conditions during this time of high CO2, the combination of proxy and model results will provide insights about how Eocene warmth may have been maintained and how subsequent cooling came about. As well, a new approach to the analysis of shell carbonates for 87Sr/86Sr will allow refinements in age control so as to allow correlation of this important section with other regions to clarify global climate gradients. The project outlined here will develop new and detailed paleoclimate records from existing samples using well-tuned as well as newer proxies applied here in novel ways. Seasonal extremes are climate parameters generally inaccessible to most studies but critical to an understanding of climate change; these are possible to resolve in this well-preserved, accretionary-macrofossil-bearing section. This is an integrated study that links marine and terrestrial climate records for a key region of the planet across the most significant climate transition in the Cenozoic.", "east": -56.0, "geometry": "POINT(-56.5 -64.25)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "PALEOCLIMATE RECONSTRUCTIONS; USAP-DC; ISOTOPES; NOT APPLICABLE; MACROFOSSILS; Antarctica", "locations": "Antarctica", "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Ivany, Linda; Lu, Zunli; Junium, Christopher; Samson, Scott", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.5, "title": "Seasonality, Summer Cooling, and Calibrating the Approach of the Icehouse in Late Eocene Antarctica", "uid": "p0010025", "west": -57.0}, {"awards": "1543412 Reinfelder, John", "bounds_geometry": null, "dataset_titles": "16S rRNA gene libraries of krill gut microbial communities; Microbial gene libraries of krill gut microbial communities", "datasets": [{"dataset_uid": "601171", "doi": "10.15784/601171", "keywords": "Antarctica; Biota; Krill; LTER Palmer Station; Microbiome; Oceans; Southern Ocean", "people": "Reinfelder, John", "repository": "USAP-DC", "science_program": "LTER", "title": "16S rRNA gene libraries of krill gut microbial communities", "url": "https://www.usap-dc.org/view/dataset/601171"}, {"dataset_uid": "200024", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Microbial gene libraries of krill gut microbial communities", "url": "https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fbioproject%2F531145\u0026amp;data=02%7C01%7Creinfeld%40envsci.rutgers.edu%7C7e30a0192dc748ab271408d6b9d57d08%7Cb92d2b234d35447093ff69aca6632ffe%7C1%7C0%7C636900723909188941\u0026amp;sdata=G6cNg4bBHzeikrWSCYITcT6XS3NLWwjQ1yNdwtrALPc%3D\u0026amp;reserved=0"}], "date_created": "Sun, 31 Mar 2019 00:00:00 GMT", "description": "The goal of this project was to conduct a preliminary assessment of gut microbiomes in Antarctic krill (Euphasia superba) collected in coastal waters west of the Antarctic Peninsula and identify organisms potentially capable of catalyzing the production of methylmercury. DNA was extracted from composite krill digestive tracts and eukaryotic DNA removed. Prokaryotic microbial DNA extracted from krill digestive tracts was sequenced and gene libraries were constructed. Genera of anaerobic microorganisms which are known to support mercury methylation were identified.", "east": -68.2816, "geometry": "POINT(-69.09295 -66.8017)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; NOT APPLICABLE; BACTERIA/ARCHAEA", "locations": "Antarctica", "north": -65.8708, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Schaefer, Jeffra; Reinfelder, John; Barkar, T.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "NCBI GenBank; USAP-DC", "science_programs": "LTER", "south": -67.7326, "title": "Methylmercury in Antarctic Krill Microbiomes", "uid": "p0010023", "west": -69.9043}, {"awards": "1457577 Wise, Sherwood", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 21 Feb 2019 00:00:00 GMT", "description": "The grant was for the re-curation of the Antarctic Sediment collection and prepare the collection for transportation to Oregon State University. The move of the cores took place in July and August of 2018. A total of 18,512 m of core was transferred which consisted of 8,787 large diameter D-tubes, 2,968 small diameteer D-tubed and 4,998 core boxes. In addition that were an additional 729 totes with samples. \u003c/br\u003e In addition in the last two years of the core facility at FSU we filled 20 sample requests and accommodated 6 visits to the collection for sampling by the PI. ", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "MARINE SEDIMENTS; USAP-DC; NOT APPLICABLE; Antarctica", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Salters, Vincent", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": null, "title": "Curation of National Antarctic Sediment Collections", "uid": "p0010014", "west": null}, {"awards": "1249513 Dalziel, Ian; 1246666 Huerta, Audrey; 1419268 Aster, Richard; 1247518 Smalley, Robert; 1249631 Wilson, Terry; 1246776 Nyblade, Andrew; 1246712 Wiens, Douglas", "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": "Network/Campaign: Antarctica POLENET - ANET; POLENET - Network YT", "datasets": [{"dataset_uid": "200012", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "POLENET - Network YT", "url": "http://ds.iris.edu/mda/YT/?timewindow=2007-2018"}, {"dataset_uid": "200011", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Network/Campaign: Antarctica POLENET - ANET", "url": "https://www.unavco.org/data/gps-gnss/data-access-methods/dai2/app/dai2.html#grouping=Antarctica%20POLENET%20-%20ANET;scope=Station;sampleRate=normal;groupingMod=contains"}], "date_created": "Sun, 17 Feb 2019 00:00:00 GMT", "description": "Intellectual Merit: The PIs continued and expanded GPS and seismic measurements for ANET-POLENET to advance understanding of geodynamic processes and their influence on the West Antarctic Ice Sheet. ANET-POLENET science themes include: 1) determining ice mass change since the last glacial maximum, including modern ice mass balance; 2) solid earth influence on ice sheet dynamics; and 3) tectonic evolution of West Antarctica and feedbacks with ice sheet evolution. Nine new remote continuous GPS stations augmented ANET-POLENET instrumentation deployed during Phase 1. Siting was designed to better constrain uplift centers predicted by GIA models and indicated by Phase 1 results. A mini-array of temporary seismic sites was deployed to improve resolution of earth structure below West Antarctica. ANET-POLENET Phase 2 achievements included 1) seismic images of crust and mantle structure that resolve the highly heterogeneous thermal and viscosity structure of the Antarctic lithosphere and underlying mantle; 2) improved estimates of intraplate vertical and horizontal bedrock crustal motions; and 3) elucidation of controls on glacial isostatic adjustment-induced crustal motions due to laterally varying earth structure. \r\n\r\nBroader impacts: Monitoring and understanding mass change and dynamic behavior of the Antarctic ice sheet using in situ GPS and seismological studies has improved understanding of how Antarctic ice sheets respond to a warming world and how this response impacts sea-level and other global changes. Seismic and geodetic data collected by the ANET-POLENET network are openly available to the scientific community. ANET-POLENET has been integral in the development and realization of technological and logistical innovations for year-round operation of instrumentation at remote polar sites, helping to advance scientifically and geographically broad studies of the polar regions. The ANET-POLENET carried out a training initiative to mentor young polar scientists in complex, multidisciplinary and internationally collaborative research, including 2 week-long training schools on \"Glacial Isostatic Adjustment\" and \"Glacial Seismology\". ANET-POLENET continued broad public outreach about polar science through the polenet.org website, university lectures, and K-12 school visits. This research involved multiple international partners.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Geodesy; USAP-DC; SEISMIC SURFACE WAVES; CRUSTAL MOTION; TECTONICS; Broadband Seismic; NOT APPLICABLE; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wilson, Terry; Dalziel, Ian W.; Bevis, Michael; Aster, Richard; Huerta, Audrey D.; Winberry, Paul; Anandakrishnan, Sridhar; Nyblade, Andrew; Wiens, Douglas; Smalley, Robert", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "IRIS", "repositories": "IRIS; UNAVCO", "science_programs": "POLENET", "south": -90.0, "title": "Collaborative Research: POLENET-Antarctica: Investigating Links Between Geodynamics and Ice Sheets - Phase 2", "uid": "p0010013", "west": -180.0}, {"awards": "1750630 Smith, Craig", "bounds_geometry": "POLYGON((-64 -66,-63.3 -66,-62.6 -66,-61.9 -66,-61.2 -66,-60.5 -66,-59.8 -66,-59.1 -66,-58.4 -66,-57.7 -66,-57 -66,-57 -66.3,-57 -66.6,-57 -66.9,-57 -67.2,-57 -67.5,-57 -67.8,-57 -68.1,-57 -68.4,-57 -68.7,-57 -69,-57.7 -69,-58.4 -69,-59.1 -69,-59.8 -69,-60.5 -69,-61.2 -69,-61.9 -69,-62.6 -69,-63.3 -69,-64 -69,-64 -68.7,-64 -68.4,-64 -68.1,-64 -67.8,-64 -67.5,-64 -67.2,-64 -66.9,-64 -66.6,-64 -66.3,-64 -66))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 15 Feb 2019 00:00:00 GMT", "description": "Worldwide publicity surrounding the calving of an iceberg the size of Delaware in July 2017 from the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula presents a unique and time-sensitive opportunity for research and education on polar ecosystems in a changing climate. The goal of this project was to convene a workshop, drawing from the large fund of intellectual capital in the US and international Antarctic research communities. The two-day workshop was designed to bring scientists with expertise in Antarctic biological, ecological, and ecosystem sciences to Florida State University to share knowledge, identify important research knowledge gaps, and outline strategic plans for research. \r\n\r\nMajor outcomes from the project were as follows. The international workshop to share and review knowledge concerning the response of Antarctic ecosystems to ice-shelf collapse was held at the Florida State University Coastal and Marine Laboratory (FSUCML) on 18-19 November 2017. Thirty-eight U.S. and international scientists attended the workshop, providing expertise in biological, ecological, geological, biogeographical, and glaciological sciences. Twenty-six additional scientists were either not able to attend or were declined because of having reached maximum capacity of the venue or for not responding to our invitation before the registration deadline.\r\n\r\nThe latest results of ice-shelf research were presented, providing an overview of the current scientific knowledge and understanding of the biological, ecological,\r\ngeological and cryospheric processes associated with ice-shelf collapse and its\r\necosystem-level consequences. In addition, several presentations focused on future plans to investigate the impacts of the recent Larsen C collapse. The following presentations were given at the meeting:\r\n\r\n1) Cryospheric dynamics and ice-shelf collapse \u2013 past and future (M. Truffer,\r\nUniversity of Alaska, Fairbanks)\r\n2) The geological history and geological impacts of ice-shelf collapse on the Antarctic Peninsula (Scottt Ishman, Amy Leventer)\r\n3) Pelagic ecosystem responses to ice-shelf collapse (Mattias Cape, Amy Leventer)\r\n4) Benthic ecosystem response to ice-shelf collapse (Craig Smith, Pavica Sr\u0161en, Ann Vanreusel)\r\n5) Larsen C and biotic homogenization of the benthos (Richard Aronson, James\r\nMcClintock, Kathryn Smith, Brittany Steffel)\r\n6) British Antarctic Survey: plans for Larsen C investigations early 2018 and in the\r\nfuture (Huw Griffiths)\r\n7) Feedback on the workshop \u201cClimate change impacts on marine ecosystems:\r\nimplications for management of living resources and conservation\u201d held 19-22\r\nSeptember 2017, Cambridge, UK (Alex Rogers)\r\n8) Past research activities and plans for Larsen field work by the Alfred Wegener\r\nInstitute, Germany (Charlotte Havermans, Dieter Piepenburg.\r\n\r\nOne of the salient points emerging from the presentations and ensuing discussions was that, given our poor abilities to predict ecological outcomes of ice-shelf collapses, major cross-disciplinary efforts are needed on a variety of spatial and temporal scales to achieve a broader, predictive understanding of ecosystem\r\nconsequences of climatic warming and ice-shelf failure. As part of the workshop, the FSUCML Polar Academy Team\u2014Dr. Emily Dolan, Dr. Heidi Geisz, Barbara Shoplock, and Dr. Jeroen Ingels\u2014initiated AntICE: \"Antarctic Influences of Climate Change on Ecosystems\" (AntICE). They reached out to various groups of school children in the local area (and continue to do so). The AntICE Team have been interacting with these children at Wakulla High School and Wakulla Elementary in Crawfordville; children from the Cornerstone Learning Community, Maclay Middle School, Gilchrist Elementary, and the School of Arts and Sciences in Tallahassee; and the Tallahassee-area homeschooling community to educate them about Antarctic ecosystems and ongoing climate change. The underlying idea was to\r\nmake the children aware of climatic changes in the Antarctic and their effect on\r\necosystems so they, in turn, can spread this knowledge to their communities, family\r\nand friends \u2013 acting as \u2018Polar Ambassadors\u2019. We collaborated with the Polar-ICE\r\nproject, an NSF-funded educational project that established the Polar Literacy\r\nInitiative. This program developed the Polar Literacy Principles, which outline\r\nessential concepts to improve public understanding of Antarctic and Arctic\r\necosystems. In the Polar Academy work, we used the Polar Literacy principles, the\r\nPolar Academy Team\u2019s own Antarctic scientific efforts, and the experience of the FSU outreach and education program to engage with the children. We focused on the importance of Antarctic organisms and ecosystems, the uniqueness of its biota and the significance of its food webs, as well as how all these are changing and will\r\nchange further with climate change. Using general presentations, case studies,\r\nscientific methodology, individual experiences, interactive discussions and Q\u0026A\r\nsessions, the children were guided through the many issues Antarctic ecosystems\r\nare facing. Over 300 \u0027Polar ambassadors\u0027 attended the interactive lectures and\r\nafterwards took their creativity to high latitudes by creating welcome letters, displays, dioramas, sculptures, videos and online media to present at the scientific workshop. Over 50 projects were created by the children (Please see supporting files for images). We were also joined by a photographer, Ryan David Reines, to document the event. More information, media and links to online outreach products are available at https://marinelab.fsu.edu/labs/ingels/outreach/polar-academy/", "east": -57.0, "geometry": "POINT(-60.5 -67.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; USAP-DC; ECOLOGICAL DYNAMICS; NOT APPLICABLE; MARINE ECOSYSTEMS; Weddell Sea", "locations": "Weddell Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Craig", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -69.0, "title": "Collaborative Research: RAPID/Workshop- Antarctic Ecosystem Research following Ice Shelf Collapse and Iceberg Calving Events", "uid": "p0010012", "west": -64.0}, {"awards": "1824677 Karentz, Deneb", "bounds_geometry": null, "dataset_titles": "2018 SCAR OSC Travel Award Data", "datasets": [{"dataset_uid": "601156", "doi": "10.15784/601156", "keywords": "Antarctica; Human Dimensions", "people": "Karentz, Deneb", "repository": "USAP-DC", "science_program": null, "title": "2018 SCAR OSC Travel Award Data", "url": "https://www.usap-dc.org/view/dataset/601156"}], "date_created": "Wed, 06 Feb 2019 00:00:00 GMT", "description": "This award supported the attendance of 39 U.S. scientists at the 35th SCAR Open Science Conference (OSC) to enable them to present their scientific findings, develop new collaborations with international scientists and become involved in SCAR-related activities and SCAR specialist groups. In previous symposia, U.S. scientists have made important and significant contributions to the success of the SCAR Open Science Conferences. The SCAR-OSC provides a key platform for generating or augmenting international collaborations not generally available for graduate students and early-career researchers. The 35th SCAR-OSC meeting: Polar 2018 brought together Antarctic and Arctic researchers for a unique bi-polar event and exchange of information in Davos, Switzerland, June 19-23, 2018.\r\n\r\nThe scientific program for the SCAR Open Science Conference (OSC)/POLAR2018 emphasized interdisciplinary research that places Antarctica and the Southern Ocean in a global context, providing essential perspective for students and early-career researchers. The meeting was organized around 12 science themes that included polar (Arctic and Antarctic) physical, biological, and social sciences. In addition, there were a myriad of side-meetings, activities, trainings, and workshops surrounding the main sessions. NSF support for travel allowed a more diverse group of researchers to participate in defining the future direction of international Antarctic and polar research and encouraged global collaboration and cooperation. It augmented the training and development of graduate students and young investigators as they benefited from the opportunity to interact with the international community of Antarctic and Arctic researchers. Individuals at all levels (students to senior researchers) interested in engaging in international collaborative activities and, potentially, assuming active leadership roles in SCAR groups, were supported. 90% of the travel awards were made to students (undergraduate, MS and PhD) and post-doctoral scholar (\u003c5 y from earned PhD). ", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; ECOLOGICAL DYNAMICS; United States Of America; NOT APPLICABLE", "locations": "United States Of America", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Organisms and Ecosystems; Polar Special Initiatives; Antarctic Astrophysics and Geospace Sciences; Antarctic Instrumentation and Support; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Karentz, Deneb", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Group Travel Award: XXXVth SCAR Open Science Conference", "uid": "p0010008", "west": null}, {"awards": "1704236 Karentz, Deneb", "bounds_geometry": null, "dataset_titles": "2017 SCAR Biology Symposium travel award data", "datasets": [{"dataset_uid": "601155", "doi": "10.15784/601155", "keywords": "Antarctica; Human Dimensions", "people": "Karentz, Deneb", "repository": "USAP-DC", "science_program": null, "title": "2017 SCAR Biology Symposium travel award data", "url": "https://www.usap-dc.org/view/dataset/601155"}], "date_created": "Mon, 04 Feb 2019 00:00:00 GMT", "description": "This project supported US participation in the XIIth Scientific Committee on Antarctic Research (SCAR) International Biology Symposium. The theme of this meeting and ancillary workshops was Scale Matters. Meeting sessions specifically addressed biodiversity and physiology spanning from molecular through ecosystem scales. \r\n\r\nThe project provided partial support (airfare and meeting registration) for 20 US scientists to travel to Leuven, Belgium and attend the SCAR International Biology Symposium in July 2017. Preference was given to applicants who were students and early career scientists. The call for applications was broadly disseminated to encourage participation by underrepresented groups in the sciences. The SCAR International Biology Symposium is a unique opportunity for US scientists to present their work and learn about the most recent findings on all aspects of Antarctic organisms and ecosystems research, to establish and strengthen international contacts, and to be actively involved in the development of new directions and the establishment of new frontiers in polar biology.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "ECOLOGICAL DYNAMICS; North America; NOT APPLICABLE; USAP-DC", "locations": "North America", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science", "paleo_time": null, "persons": "Karentz, Deneb", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Group Travel Award: XIIth SCAR International Biology Symposium", "uid": "p0010006", "west": null}, {"awards": "1443347 Condron, Alan; 1443394 Pollard, 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": "Antarctic Ice Sheet simulations for role of freshwater in future warming scenarios; Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming; Simulated changes in Southern Ocean salinity", "datasets": [{"dataset_uid": "601154", "doi": "10.15784/601154 ", "keywords": "Antarctic; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Sheet Model; Meltwater; Model Data; Modeling; Model Output", "people": "Pollard, David", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Sheet simulations for role of freshwater in future warming scenarios", "url": "https://www.usap-dc.org/view/dataset/601154"}, {"dataset_uid": "601442", "doi": "10.15784/601442", "keywords": "Antarctica; Computer Model; Freshwater; Glaciers/ice Sheet; Glaciers/Ice Sheet; Model Data; Ocean Model; Oceans; Salinity", "people": "Condron, Alan", "repository": "USAP-DC", "science_program": null, "title": "Simulated changes in Southern Ocean salinity", "url": "https://www.usap-dc.org/view/dataset/601442"}, {"dataset_uid": "601449", "doi": "10.15784/601449", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meltwater", "people": "Condron, Alan", "repository": "USAP-DC", "science_program": null, "title": "Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming", "url": "https://www.usap-dc.org/view/dataset/601449"}], "date_created": "Mon, 04 Feb 2019 00:00:00 GMT", "description": "A great deal of uncertainty remains over how changes in high-latitude freshwater forcing will impact the stability of global ocean circulation, and in particular the strength of the Atlantic Meridional Overturning Circulation (AMOC) in the next 100-300 years, especially in realistic models. Indeed, it is still not understood whether increased Southern Ocean freshwater forcing will act to intensify the AMOC and warm the Northern Hemisphere or weaken it and trigger a cooling. The requirement to accurately assess climate sensitivity to freshwater forcing is heightened by increasing evidence that the marine-based West Antarctic Ice Sheet (WAIS) is vulnerable to rapid retreat and collapse on multidecadal-to-centennial timescales. Observations collected over the last 30 years indicate that WAIS is losing ice at an accelerated rate and may signal that the ice sheet has already begun a rapid and irreversible collapse. In addition, future simulations of the Antarctic ice sheet by members of our Project Team show the potential for far more rapid Antarctic ice sheet retreat in the future than previously simulated, suggesting that the discharge of enormous fluxes of icebergs and freshwater to the Southern Ocean should be considered a possibility in the near-future. Here, we performed a suite of coupled numerical climate model simulations to more accurately determine the sensitivity of global ocean circulation to freshwater and iceberg discharge from the Antarctic Ice Sheet (AIS) in the future under IPCC RCP scenarios 4.5 and 8.5. In our model, the input of freshwater and ice was provided by a dynamic ice sheet-shelf model that predicts a full collapse of the WAIS in the next ~100 years. Significantly, we find that accounting for Antarctic discharge raises subsurface ocean temperatures by \u003e1\u00b0C at the ice sheet grounding line, relative to model simulations that are unable to capture this discharge. In contrast, we find that the increased meltwater causes a dramatic expansion of sea ice and a 2\u00b0 - 10\u00b0C cooling of the surface air and surface ocean temperatures over the Southern Ocean that would have the potential to stabilize/reduce projected future ice sheet melt rates. Our work thus highlights that the future stability of the Antarctic ice sheet will likely be governed by whether any surface cooling can counteract any increased rates of subsurface melt.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e DATA ANALYSIS \u003e ENVIRONMENTAL MODELING \u003e COMPUTER", "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; AMD; MODELS; Amd/Us; Antarctica; GLACIERS/ICE SHEETS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Pollard, David; Condron, Alan; DeConto, Robert", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Assessing the Global Climate Response to Melting of the Antarctic Ice Sheet", "uid": "p0010007", "west": -180.0}, {"awards": "1443472 Brook, Edward; 1443464 Sowers, Todd; 1443710 Severinghaus, Jeffrey", "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": "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": "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"}, {"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": "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": "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": "Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Aydin, Murat", "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"}], "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. \u003cbr/\u003e \u003cbr/\u003eThis 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.\u003cbr/\u003e\u003cbr/\u003eThe 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. \u003cbr/\u003e\u003cbr/\u003eThe 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": "1144176 Lyons, W. Berry; 1727387 Mikucki, Jill; 1144177 Pettit, Erin; 1144192 Tulaczyk, Slawek", "bounds_geometry": "POLYGON((161.8 -77.7,161.88 -77.7,161.96 -77.7,162.04000000000002 -77.7,162.12 -77.7,162.2 -77.7,162.28 -77.7,162.36 -77.7,162.44 -77.7,162.51999999999998 -77.7,162.6 -77.7,162.6 -77.70700000000001,162.6 -77.714,162.6 -77.721,162.6 -77.728,162.6 -77.735,162.6 -77.742,162.6 -77.749,162.6 -77.756,162.6 -77.76299999999999,162.6 -77.77,162.51999999999998 -77.77,162.44 -77.77,162.36 -77.77,162.28 -77.77,162.2 -77.77,162.12 -77.77,162.04000000000002 -77.77,161.96 -77.77,161.88 -77.77,161.8 -77.77,161.8 -77.76299999999999,161.8 -77.756,161.8 -77.749,161.8 -77.742,161.8 -77.735,161.8 -77.728,161.8 -77.721,161.8 -77.714,161.8 -77.70700000000001,161.8 -77.7))", "dataset_titles": "Ablation Stake Data from of Taylor Glacier near Blood Falls; Antarctica Support 2014/2015 - C-528 Blood Falls GPS/GNSS Observations Dataset; Blood Falls, McMurdo Dry Va. International Federation of Digital Seismograph Networks. Dataset/Seismic Network; FLIR thermal imaging data near Blood Falls, Taylor Glacier; Ground Penetrating Radar Data near Blood Falls, Taylor Glacier; Ice Temperature in Shallow Boreholes Near Blood Falls at the Terminus of Taylor Glacier, McMurdo Dry Valleys, Antarctica; NCBI short read archive -Metagenomic survey of Antarctic Groundwater; Terrestrial Radar Interferometry near Blood Falls, Taylor Glacier; The Geochemistry of englacial brine from Taylor Glacier, Antarctica; Time Lapse imagery of the Blood Falls feature, Antarctica ; Vaisala Integrated Met Station near Blood Falls, Taylor Glacier", "datasets": [{"dataset_uid": "601167", "doi": "10.15784/601167", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Photo; Photo/video; Photo/Video; Snow/ice; Snow/Ice; Taylor Glacier; Timelaps Images", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Time Lapse imagery of the Blood Falls feature, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601167"}, {"dataset_uid": "601168", "doi": "10.15784/601168", "keywords": "Antarctica; Atmosphere; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meteorology; Taylor Glacier; Temperature; Weather Station Data; Wind Speed", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Vaisala Integrated Met Station near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601168"}, {"dataset_uid": "200028", "doi": "10.7283/FCEN-8050", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica Support 2014/2015 - C-528 Blood Falls GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/fcen-8050"}, {"dataset_uid": "200029", "doi": "10.7914/SN/YW_2013", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Blood Falls, McMurdo Dry Va. International Federation of Digital Seismograph Networks. Dataset/Seismic Network", "url": "http://www.fdsn.org/networks/detail/YW_2013/"}, {"dataset_uid": "601169", "doi": "10.15784/601169", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Infrared Imagery; Photo/video; Photo/Video; Taylor Glacier; Thermal Camera; Timelaps Images", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "FLIR thermal imaging data near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601169"}, {"dataset_uid": "601179", "doi": "10.15784/601179", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Subglacial Brine", "people": "Gardner, Christopher B.; Lyons, W. Berry", "repository": "USAP-DC", "science_program": null, "title": "The Geochemistry of englacial brine from Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601179"}, {"dataset_uid": "601139", "doi": "10.15784/601139", "keywords": "Antarctica; Borehole; Borehole Logging; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Temperature; Snow/ice; Snow/Ice; Temperature; Temperature Profiles", "people": "Tulaczyk, Slawek", "repository": "USAP-DC", "science_program": null, "title": "Ice Temperature in Shallow Boreholes Near Blood Falls at the Terminus of Taylor Glacier, McMurdo Dry Valleys, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601139"}, {"dataset_uid": "601164", "doi": "10.15784/601164", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Snow/ice; Snow/Ice", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Ablation Stake Data from of Taylor Glacier near Blood Falls", "url": "https://www.usap-dc.org/view/dataset/601164"}, {"dataset_uid": "601165", "doi": "10.15784/601165", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Snow/ice; Snow/Ice; Taylor Glacier", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Ground Penetrating Radar Data near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601165"}, {"dataset_uid": "200074", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI short read archive -Metagenomic survey of Antarctic Groundwater", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRR6667787"}, {"dataset_uid": "601166", "doi": "10.15784/601166", "keywords": "Antarctica; Basal Crevassing; Glacier Hydrology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Snow/ice; Snow/Ice; Taylor Glacier", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Terrestrial Radar Interferometry near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601166"}], "date_created": "Wed, 28 Nov 2018 00:00:00 GMT", "description": "Recent discoveries of widespread liquid water and microbial ecosystems below the Antarctic ice sheets have generated considerable interest in studying Antarctic subglacial environments. Understanding subglacial hydrology, the persistence of life in extended isolation and the evolution and stability of subglacial habitats requires an integrated, interdisciplinary approach. The collaborative project, Minimally Invasive Direct Glacial Exploration (MIDGE) of the Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys will integrate geophysical measurements, molecular microbial ecology and geochemical analyses to explore a unique Antarctic subglacial system known as Blood Falls. Blood Falls is a hypersaline, subglacial brine that supports an active microbial community. The subglacial brine is released from a crevasse at the surface of the Taylor Glacier providing an accessible portal into an Antarctic subglacial ecosystem. Recent geochemical and molecular analyses support a marine source for the salts and microorganisms in Blood Falls. The last time marine waters inundated this part of the McMurdo Dry Valleys was during the Late Tertiary, which suggests the brine is ancient. Still, no direct samples have been collected from the subglacial source to Blood Falls and little is known about the origin of this brine or the amount of time it has been sealed below Taylor Glacier. Radar profiles collected near Blood Falls delineate a possible fault in the subglacial substrate that may help explain the localized and episodic nature of brine release. However it remains unclear what triggers the episodic release of brine exclusively at the Blood Falls crevasse or the extent to which the brine is altered as it makes its way to the surface. \u003cbr/\u003e\u003cbr/\u003eThe MIDGE project aims to determine the mechanism of brine release at Blood Falls, evaluate changes in the geochemistry and the microbial community within the englacial conduit and assess if Blood Falls waters have a distinct impact on the thermal and stress state of Taylor Glacier, one of the most studied polar glaciers in Antarctica. The geophysical study of the glaciological structure and mechanism of brine release will use GPR, GPS, and a small passive seismic network. Together with international collaborators, the \u0027Ice Mole\u0027 team from FH Aachen University of Applied Sciences, Germany (funded by the German Aerospace Center, DLR), MIDGE will develop and deploy innovative, minimally invasive technologies for clean access and brine sample retrieval from deep within the Blood Falls drainage system. These technologies will allow for the collection of samples of the brine away from the surface (up to tens of meters) for geochemical analyses and microbial structure-function experiments. There is concern over the contamination of pristine subglacial environments from chemical and biological materials inherent in the drilling process; and MIDGE will provide data on the efficacy of thermoelectric probes for clean access and retrieval of representative subglacial samples. Antarctic subglacial environments provide an excellent opportunity for researching survivability and adaptability of microbial life and are potential terrestrial analogues for life habitats on icy planetary bodies. The MIDGE project offers a portable, versatile, clean alternative to hot water and mechanical drilling and will enable the exploration of subglacial hydrology and ecosystem function while making significant progress towards developing technologies for minimally invasive and clean sampling of icy systems.", "east": 162.6, "geometry": "POINT(162.2 -77.735)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; BACTERIA/ARCHAEA; USAP-DC", "locations": null, "north": -77.7, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek; Pettit, Erin; Lyons, W. Berry; Mikucki, Jill", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "IRIS; NCBI GenBank; UNAVCO; USAP-DC", "science_programs": null, "south": -77.77, "title": "Collaborative Research: MIDGE: Minimally Invasive Direct Glacial Exploration of Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys", "uid": "p0000002", "west": 161.8}, {"awards": "1644245 Aydin, Murat", "bounds_geometry": null, "dataset_titles": "Ice Core Air Ethane and Acetylene Measurements - South Pole SPC14 Ice Core (SPICEcore project); Ice core ethane measurements, Greenland and Antarctica, 1000-1900 CE.", "datasets": [{"dataset_uid": "601367", "doi": "10.15784/601367", "keywords": "Antarctica; Ethane", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Ice Core Air Ethane and Acetylene Measurements - South Pole SPC14 Ice Core (SPICEcore project)", "url": "https://www.usap-dc.org/view/dataset/601367"}, {"dataset_uid": "002574", "doi": "", "keywords": null, "people": null, "repository": "Arctic Data Center", "science_program": null, "title": "Ice core ethane measurements, Greenland and Antarctica, 1000-1900 CE.", "url": "https://arcticdata.io/catalog/view/doi:10.18739/A2CR5NC1B"}], "date_created": "Tue, 13 Nov 2018 00:00:00 GMT", "description": "Aydin/1644245\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to measure ethane in ice core air extracted from the recently drilled intermediate depth South Pole ice core (SPICECORE). Ethane is an abundant hydrocarbon in the atmosphere. The ice core samples that will be used in this analysis will span about 150 years before present to about 55,000 years before present and therefore, ethane emissions linked to human activities are not a subject of this study. The study will focus on quantifying the variability in the natural sources of ethane and the processes that govern its removal from the atmosphere. A long-term ice core ethane record will provide new knowledge on the chemistry of Earth?s atmosphere during time periods when human influence was either much smaller than present day or non-existent. The broader impacts of this work include education and training of students and a contribution to a better understanding of the chemistry of the atmosphere in the past and how it has been impacted by past changes in climate.\u003cbr/\u003e\u003cbr/\u003eNatural sources that emit ethane are both geologic (e.g. seeps, vents, mud volcanoes etc.) and pyrogenic (wild fires) which is commonly called biomass burning. Ethane is removed from the atmosphere via oxidation reactions. The ice core ethane measurements have great potential as a proxy for gaseous emissions from biomass burning. This is especially true for time periods preceding the industrial revolution when atmospheric variability of trace gases was largely controlled by natural processes. Another objective of this study is to improve understanding of the causes of atmospheric methane variability apparent which are in the existing ice core records. Methane is a simpler hydrocarbon than ethane and more abundant in the atmosphere. Even though the project does not include any methane measurements; the commonalities between the sources and removal of atmospheric ethane and methane mean that ethane measurements can be used to gain insight into the causes of changes in atmospheric methane levels. The broader impacts of the project include partial support for one Ph.D. student and support for undergraduate researchers at UC Irvine. The PIs group currently has 4 undergraduate researchers. The PI and the graduate students in the UCI ice core laboratory regularly participate in on- and off-campus activities such as laboratory tours and lectures directed towards educating high-school students and science teachers, and the local community at large about the scientific value of polar ice cores as an environmental record of our planet\u0027s past. The results of this research will be disseminated via peer-review publications and will contribute to policy-relevant activities such as the IPCC Climate Assessment. Data resulting from this project will be archived in a national data repository. This award does not have field work in Antarctica.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; NOT APPLICABLE", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "Arctic Data Center; USAP-DC", "science_programs": "SPICEcore", "south": null, "title": "Ethane Measurements in the Intermediate Depth South Pole Ice Core (SPICECORE)", "uid": "p0000762", "west": null}, {"awards": "1543313 VanTongeren, Jill", "bounds_geometry": null, "dataset_titles": "U-Pb ages and mineral compositions from Dufek Intrusion", "datasets": [{"dataset_uid": "601132", "doi": "10.15784/601132", "keywords": "Antarctica; Chemical Composition; Chemistry:rock; Chemistry:Rock; Crystallization; Dufek Complex; Geochemistry; Magma Chamber Procesess; Mass Spectrometry; Rocks; Snow/ice; Snow/Ice; Solid Earth; TIMS; Volcanic Deposits", "people": "VanTongeren, Jill", "repository": "USAP-DC", "science_program": null, "title": "U-Pb ages and mineral compositions from Dufek Intrusion", "url": "https://www.usap-dc.org/view/dataset/601132"}], "date_created": "Mon, 29 Oct 2018 00:00:00 GMT", "description": "The solidified remnants of large magma bodies within the continental crust hold the key to understanding the chemical and physical evolution of volcanic provinces through time. These deposits also commonly contain some of the world\u0027s most important ore deposits. Exposed deposits in South Africa, Greenland, USA, Canada, and Antarctica have led researchers to propose that the bigger the magma body, the faster it will crystallize. While this might seem counter-intuitive (typically it is thought that more magma = hotter = harder to cool), the comparison of these exposures show that bigger magma chambers maintain a molten top that is always in contact with the colder crust; whereas smaller magma chambers insulate themselves by crystallizing at the margins. The process is similar to the difference between a large cup of coffee with no lid, and a smaller cup of coffee held in a thermos. The large unprotected cup of coffee will cool down much faster than that held in the thermos. This research project of VanTongeren and Schoene will use previously collected rocks from the large (~8-9 km thick) Dufek Intrusion in Antarctica to precisely quantify how fast the magma chamber crystallized, and compare that rate to the much smaller magma chamber exposed in the Skaergaard Intrusion of E. Greenland. The work is an important step towards improving our understanding of time-scales associated with the thermal and chemical evolution of nearly all magma chambers on Earth, which will ultimately lead to better predictions of volcanic hazards globally. The work will also yield important insights into the timescales and conditions necessary for developing vast magmatic ore deposits, which is essential to the platinum and steel industries in the USA and abroad.\u003cbr/\u003e\u003cbr/\u003eBased on observations of solidification fronts in six of the world\u0027s most completely exposed layered mafic intrusions, it was recently proposed that bigger magma chambers must crystallize faster than small magma chambers. While this is initially counter-intuitive, the hypothesis falls out of simple heat balance equations and the observation that the thickness of cumulates at the roofs of such intrusions is negatively proportional to the size of the intrusion. In this study, VanTongeren and Schoene will directly test the hypothesis that bigger magma chambers crystallize faster by applying high precision U-Pb zircon geochronology on 5-10 samples throughout the large Dufek Intrusion of Antarctica. Due to uncertainties in even the highest-precision ID-TIMS analyses, the Dufek Intrusion of Antarctica is the only large layered mafic intrusion on Earth where this research can be accomplished. VanTongeren and Schoene will place the geochronological measurements of the Dufek Intrusion into a comprehensive petrologic framework by linking zircon crystallization to other liquidus phases using mineral geochemistry, zircon saturation models, and petrologic models for intrusion crystallization. The research has the potential to radically change the way that we understand the formation and differentiation of large magma bodies within the shallow crust. Layered intrusions are typically thought to cool and crystallize over very long timescales allowing for significant differentiation of the magmas and reorganization of the cumulate rocks. If the \u0027bigger magma chambers crystallize faster hypothesis\u0027 holds this could reduce the calculated solidification time scales of the early earth and lunar magma oceans and have important implications for magma chamber dynamics of active intraplate volcanism and long-lived continental arcs. Furthermore, while the Dufek Intrusion is one of only two large layered intrusions exposed on Earth, very little is known about its petrologic evolution. The detailed geochemical and petrologic work of VanTongeren and Schoene based on analyses of previously collected samples will provide important observations with which to compare the Dufek and other large magma chambers.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "VanTongeren, Jill", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Testing the Hypothesis that Bigger Magma Chambers Crystallize Faster", "uid": "p0000135", "west": null}, {"awards": "1141916 Aster, Richard", "bounds_geometry": null, "dataset_titles": "Dynamic Response of the Ross Ice Shelf to Ocean Waves and Structure and Dynamics of the Ross Sea", "datasets": [{"dataset_uid": "002573", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Dynamic Response of the Ross Ice Shelf to Ocean Waves and Structure and Dynamics of the Ross Sea", "url": "http://www.iris.washington.edu/mda/XH?timewindow=2014-2017"}], "date_created": "Mon, 22 Oct 2018 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003e\u003cbr/\u003eThe PIs propose to establish an ice shelf network of 18 broadband seismographs deployed for two years to obtain high-resolution, mantle-scale images of Earth structure underlying the Ross Sea Embayment. Prior marine geophysical work provides good crustal velocity models for the region seaward of the ice shelf but mantle structure is constrained by only low-resolution images due to the lack of prior seismic deployments. The proposed stations would be established between Ross Island and Marie Byrd Land. These stations would fill a major geological gap within this extensional continental province and would link data sets collected in the Transantarctic Mountain transition/Plateau region (TAMSEIS) and in West Antarctica (POLENET) to improve resolution of mantle features beneath Antarctica. The proposed deployment would allow the PIs to collect seismic data without the expense, logistical complexity, and iceberg hazards associated with ocean bottom seismograph deployments. Tomographic models developed from the proposed data will be used to choose between competing models for the dynamics of the Ross Sea. In particular, the PIs will investigate whether a broad region of hot mantle, including the Eastern Ross Sea, indicates distributed recent tectonic activity, which would call into question models proposing that Eastern Ross extension ceased during the Mesozoic. These data will also allow the PIs to investigate the deeper earth structure to evaluate the possible role of mantle plumes and/or small-scale convection in driving regional volcanism and tectonism across the region.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003e\u003cbr/\u003eData from this deployment will be of broad interdisciplinary use. This project will support three graduate and two undergraduate students. At least one student will be an underrepresented minority student. The PIs will interact with the media and include K-12 educators in their fieldwork.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Aster, Richard", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": null, "title": "Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf", "uid": "p0000761", "west": null}, {"awards": "1443263 Higgins, John; 1443306 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores; Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores; Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores; Greenhouse gas composition in the Allan Hills S27 ice core; Methane concentration in Allan Hills ice cores; Stable isotope composition of the trapped air in the Allan Hills S27 ice core; Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area; Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "datasets": [{"dataset_uid": "601203", "doi": "10.15784/601203", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Chemistry:ice; Chemistry:Ice; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenhouse Gas; Ice; Ice Core Data; Ice Core Gas Records; Methane; Snow/ice; Snow/Ice", "people": "Brook, Edward J.; Yan, Yuzhen; Bender, Michael; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Methane concentration in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601203"}, {"dataset_uid": "601512", "doi": "10.15784/601512", "keywords": "Allan Hills; Antarctica; Blue Ice; Ice Core; Ice Core Gas Records; Isotope; Nitrogen; Oxygen", "people": "Higgins, John; Yan, Yuzhen; Bender, Michael", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable isotope composition of the trapped air in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601512"}, {"dataset_uid": "601201", "doi": "10.15784/601201", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Argon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Data; Ice Core Gas Records; Krypton; Mass Spectrometer; Noble Gas; Snow/ice; Snow/Ice; Xenon", "people": "Bender, Michael; Higgins, John; Yan, Yuzhen; Ng, Jessica; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of heavy noble gases in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601201"}, {"dataset_uid": "601483", "doi": "10.15784/601483", "keywords": "Allan Hills; Antarctica; Argon; Ice; Ice Core Data; Ice Core Gas Records; Isotope; Mass Spectrometry; Nitrogen; Oxygen", "people": "Bender, Michael; Yan, Yuzhen; Higgins, John", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Elemental and isotopic composition of nitrogen, oxygen, and argon in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601483"}, {"dataset_uid": "601130", "doi": "10.15784/601130", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Delta Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Gas Records; Ice Core Records; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Introne, Douglas; Kurbatov, Andrei V.; Mayewski, Paul A.; Yan, Yuzhen", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the surface samples collected at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601130"}, {"dataset_uid": "601129", "doi": "10.15784/601129", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Blue Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Isotope Data; Oxygen; Snow/ice; Snow/Ice; Stable Water Isotopes; Transantarctic Mountains", "people": "Yan, Yuzhen; Kurbatov, Andrei V.; Introne, Douglas; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1502 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601129"}, {"dataset_uid": "601128", "doi": "10.15784/601128", "keywords": "Allan Hills; Antarctica; Blue Ice; Chemistry:ice; Chemistry:Ice; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope Record; Mass Spectrometry; Stable Water Isotopes", "people": "Mayewski, Paul A.; Kurbatov, Andrei V.; Yan, Yuzhen; Introne, Douglas", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Stable water isotope data for the AH-1503 ice core drilled at the Allan Hills Blue ice area", "url": "https://www.usap-dc.org/view/dataset/601128"}, {"dataset_uid": "601425", "doi": "10.15784/601425", "keywords": "Allan Hills; Antarctica; Blue Ice; Carbon Dioxide; Ice Core; Methane", "people": "Yan, Yuzhen; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Greenhouse gas composition in the Allan Hills S27 ice core", "url": "https://www.usap-dc.org/view/dataset/601425"}, {"dataset_uid": "601202", "doi": "10.15784/601202", "keywords": "Allan Hills; Allan Hills Project; Antarctica; Carbon Dioxide; Carbon Isotopes; Chemistry:ice; Chemistry:Ice; CO2; Gas Chromatography; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Gas Records; Ice Core Records; Mass Spectrometer; Mass Spectrometry; Methane; Snow/ice; Snow/Ice", "people": "Bender, Michael; Yan, Yuzhen; Higgins, John; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Carbon dioxide concentration and its stable carbon isotope composition in Allan Hills ice cores", "url": "https://www.usap-dc.org/view/dataset/601202"}], "date_created": "Thu, 18 Oct 2018 00:00:00 GMT", "description": "Bubbles of ancient air trapped in ice cores permit the direct reconstruction of atmospheric composition and allow us to link greenhouse gases and global climate over the last 800,000 years. Previous field expeditions to the Allan Hills blue ice area, Antarctica, have recovered ice cores that date to one million years, the oldest ice cores yet recovered from Antarctica. These records have revealed that interglacial CO2 concentrations decreased by 800,000 years ago and that, in the warmer world 1 million years ago, CO2 and Antarctic temperature were linked as during the last 800,000 years. This project will return to the Allan Hills blue ice area to recover additional ice cores that date to 1 million years or older. The climate records developed from the drilled ice cores will provide new insights into the chemical composition of the atmosphere and Antarctic climate during times of comparable or even greater warmth than the present day. Our results will help answer questions about issues associated with anthropogenic change. These include the relationship between temperature change and the mass balance of Antarctic ice; precipitation and aridity variations associated with radiatively forced climate change; and the climate significance of sea ice extent. The project will entrain two graduate students and a postdoctoral scholar, and will conduct outreach including workshops to engage teachers in carbon science and ice cores.\u003cbr/\u003e\u003cbr/\u003eBetween about 2.8-0.9 million years ago, Earth\u0027s climate was characterized by 40,000-year cycles, driven or paced by changes in the tilt of Earth\u0027s spin axis. Much is known about the \"40,000-year\" world from studies of deep-sea sediments, but our understanding of climate change during this period is incomplete because we lack records of Antarctic climate and direct records of atmospheric greenhouse gas concentrations. We propose to address these issues by building on our recent studies of ancient ice from the Main Ice Field, Allan Hills, Antarctica. During previous field seasons we recovered ice extending, discontinuously, from 0.1-1.0 million years old. Ice was dated by measuring the 40Ar/38Ar (Argon) ratio of the trapped gases. Our discovery of million year-old ice demonstrates that there is gas-record-quality ice from the 40,000-year world in the Allan Hills Main Ice Field. We have identified two different sites, each overlying bedrock at ~ 200 m depth, that are attractive targets for coring ice dating to 1 million years and older. This project aims to core the ice at these two sites, re-occupy a previous site with million year-old ice and drill it down to the bedrock, and generate 10-20 short (~10-meter) cores in areas where our previous work and terrestrial meteorite ages suggest ancient surface ice. We plan to date the ice using the 40Ar/38Ar ages of trapped Argon. We also plan to characterize the continuity of our cores by measuring the deuterium and oxygen isotope ratios in the ice, methane, ratios of Oxygen and Argon to Nitrogen in trapped gas, the Nitrogen-15 isotope (d15N) of Nitrogen, and the Oxygen-18 isotope (d18O) of Oxygen. As the ice may be stratigraphically disturbed, these measurements will provide diagnostic properties for assessing the continuity of the ice-core records. Successful retrieval of ice older than one million years will provide the opportunity for follow-up work to measure the CO2 concentration and other properties within the ice to inform on the temperature history of the Allan Hills region, dust sources and source-area aridity, moisture sources, densification conditions, global average ocean temperature, and greenhouse gas concentrations. We will analyze the data in the context of leading hypotheses of the 40,000-year world and the Mid-Pleistocene Transition to the 100,000-year world. We expect to advance understanding of climate dynamics during these periods.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Amd/Us; AMD; Allan Hills; USA/NSF; FIELD INVESTIGATION; USAP-DC; Ice Core; LABORATORY", "locations": "Allan Hills", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Mayewski, Paul A.; Kurbatov, Andrei V.; Higgins, John; Bender, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": null, "title": "Collaborative Research: Window into the World with 40,000-year Glacial Cycles from Climate Records in Million Year-old Ice from the Allan Hills Blue Ice Area", "uid": "p0000760", "west": null}, {"awards": "1341311 Timmermann, Axel", "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": "784 ka transient Antarctic ice-sheet model simulation data", "datasets": [{"dataset_uid": "000247", "doi": "", "keywords": null, "people": null, "repository": "IBS Center for Climate Physics ICCP", "science_program": null, "title": "784 ka transient Antarctic ice-sheet model simulation data", "url": "http://climatedata.ibs.re.kr/grav/data/psu-love/antarctic-ice-sheet"}], "date_created": "Tue, 26 Jun 2018 00:00:00 GMT", "description": "This award supports a project to study the physical processes that synchronize glacial-scale variability between the Northern Hemisphere ice sheets and the Antarctic ice-sheet. Using a coupled numerical ice-sheet earth-system model, the research team will explore the cryospheric responses to past changes in greenhouse gas concentrations and variations in earth\u0027s orbit and tilt. First capturing the sensitivity of each individual ice-sheet to these forcings and then determining their joint variability induced by changes in sea level, ocean temperatures and atmospheric circulation, the researchers will quantify the relative roles of local versus remote effects on long-term ice volume variability. The numerical experiments will provide deeper physical insights into the underlying dynamics of past Antarctic ice-volume changes and their contribution to global sea level. Output from the transient earth system model simulations will be directly compared with ice-core data from previous and ongoing drilling efforts, such as West Antarctic Ice Sheet (WAIS) Divide. Specific questions that will be addressed include: 1) Did the high-latitude Southern Hemispheric atmospheric and oceanic climate, relevant to Antarctic ice sheet forcing, respond to local insolation variations, CO2, Northern Hemispheric changes, or a combination thereof?; 2) How did WAIS and East Antarctic Ice Sheet (EAIS) vary through the Last Glacial Termination and into the Holocene (21 ka- present)?; 3) Did the WAIS (or EAIS) contribute to rapid sea-level fluctuations during this period, such as Meltwater Pulse 1A? 4) Did WAIS collapse fully at Stage 5e (~ 125 ka), and what was its timing relative to the maximum Greenland retreat?; and 5) How did the synchronized behavior of Northern Hemisphere and Southern Hemisphere ice-sheet variations affect the strength of North Atlantic Deep Water and Antarctic Bottom Water formation and the respective overturning cells? The transient earth-system model simulations conducted as part of this project will be closely compared with paleo-climate reconstructions from ice cores, sediment cores and terrestrial data. This will generate an integrated understanding of the hemispheric contributions of deglacial climate change, the origin of meltwater pulses, and potential thresholds in the coupled ice-sheet climate system in response to different types of forcings. A well-informed long-term societal response to sea level rise requires a detailed understanding of ice-sheet sensitivities to external forcing. The proposed research will strongly contribute to this task through numerical modeling and paleo-data analysis. The research team will make the resulting model simulations available on the web-based data server at the Asia Pacific Data Research Center (APDRC) to enable further analysis by the scientific community. As part of this project a female graduate student and a postdoctoral researcher will receive training in earth-system and ice-sheet modeling and paleo-climate dynamics. This award has no 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": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Timmermann, Axel", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "IBS Center for Climate Physics ICCP", "repositories": "IBS Center for Climate Physics ICCP", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Bipolar Coupling of late Quaternary Ice Sheet Variability", "uid": "p0000379", "west": -180.0}, {"awards": "2023425 Schofield, Oscar; 1440435 Ducklow, Hugh", "bounds_geometry": "POLYGON((-80 -63,-78.3 -63,-76.6 -63,-74.9 -63,-73.2 -63,-71.5 -63,-69.8 -63,-68.1 -63,-66.4 -63,-64.7 -63,-63 -63,-63 -63.8,-63 -64.6,-63 -65.4,-63 -66.2,-63 -67,-63 -67.8,-63 -68.6,-63 -69.4,-63 -70.2,-63 -71,-64.7 -71,-66.4 -71,-68.1 -71,-69.8 -71,-71.5 -71,-73.2 -71,-74.9 -71,-76.6 -71,-78.3 -71,-80 -71,-80 -70.2,-80 -69.4,-80 -68.6,-80 -67.8,-80 -67,-80 -66.2,-80 -65.4,-80 -64.6,-80 -63.8,-80 -63))", "dataset_titles": "Environmental Data Initiative Repository, Supporting LTER; Expedition Data; Expedition data of LMG1501; Expedition data of LMG1601; Expedition data of LMG1701; Expedition data of LMG1801; Expedition data of LMG1901; UAV images and video of whales in the Antarctic Penisula during LMG1802", "datasets": [{"dataset_uid": "200125", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1901", "url": "https://www.rvdata.us/search/cruise/LMG1901"}, {"dataset_uid": "000246", "doi": "", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "Environmental Data Initiative Repository, Supporting LTER", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=PAL"}, {"dataset_uid": "002729", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1701", "url": "https://www.rvdata.us/search/cruise/LMG1701"}, {"dataset_uid": "601318", "doi": "10.15784/601318", "keywords": "Aerial Imagery; Antarctica; Antarctic Peninsula; Biota; Camera; Humpback Whales; LMG1802; LTER; Minke Whales; Oceans; Palmer Station; Photo; Photo/video; Photo/Video; R/v Laurence M. Gould; Species Size; UAV; Video Data; Whales", "people": "Dale, Julian; Bierlich, KC; Nowacek, Douglas; Friedlaender, Ari; Boyer, Keyvi", "repository": "USAP-DC", "science_program": "LTER", "title": "UAV images and video of whales in the Antarctic Penisula during LMG1802", "url": "https://www.usap-dc.org/view/dataset/601318"}, {"dataset_uid": "001367", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1701"}, {"dataset_uid": "200124", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1801", "url": "https://www.rvdata.us/search/cruise/LMG1801"}, {"dataset_uid": "200123", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1601", "url": "https://www.rvdata.us/search/cruise/LMG1601"}, {"dataset_uid": "200122", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1501", "url": "https://www.rvdata.us/search/cruise/LMG1501"}], "date_created": "Fri, 11 May 2018 00:00:00 GMT", "description": "The Palmer Antarctica LTER (Long Term Ecological Research) site has been in operation since 1990. The goal of all the LTER sites is to conduct policy-relevant research on ecological questions that require tens of years of data, and cover large geographical areas. For the Palmer Antarctica LTER, the questions are centered around how the marine ecosystem west of the Antarctica peninsula is responding to a climate that is changing as rapidly as any place on the Earth. For example, satellite observations over the past 35 years indicate the average duration of sea ice cover is now ~90 days (3 months!) shorter than it was. The extended period of open water has implications for many aspects of ecosystem research, with the concurrent decrease of Ad\u00c3\u00a8lie penguins within this region regularly cited as an exemplar of climate change impacts in Antarctica. Cutting edge technologies such as autonomous underwater (and possibly airborne) vehicles, seafloor moorings, and numerical modeling, coupled with annual oceanographic cruises, and weekly environmental sampling, enables the Palmer Antarctica LTER to expand and bridge the time and space scales needed to assess climatic impacts. This award includes for the first time study of the roles of whales as major predators in the seasonal sea ice zone ecosystem. The team will also focus on submarine canyons, special regions of enhanced biological activity, along the Western Antarctic Peninsula (WAP).\u003cbr/\u003e\u003cbr/\u003eThe current award\u0027s overarching research question is: How do seasonality, interannual variability, and long term trends in sea ice extent and duration influence the structure and dynamics of marine ecosystems and biogeochemical cycling? Specific foci within the broad question include: 1. Long-term change and ecosystem transitions. What is the sensitivity or resilience of the ecosystem to external perturbations as a function of the ecosystem state? 2. Lateral connectivity and vertical stratification. What are the effects of lateral transports of freshwater, heat and nutrients on local ocean stratification and productivity and how do they drive changes in the ecosystem? 3. Top-down controls and shifting baselines. How is the ecosystem responding to the cessation of whaling and subsequent long-term recovery of whale stocks? 4. Foodweb structure and biogeochemical processes. How do temporal and spatial variations in foodweb structure influence carbon and nutrient cycling, export, and storage? The broader impacts of the award leverage local educational partnerships including the Sandwich, MA STEM Academy, the New England Aquarium, and the NSF funded Polar Learning and Responding (PoLAR) Climate Change Education Partnership at Columbia\u0027s Earth Institute to build new synergies between Arctic and Antarctic, marine and terrestrial scientists and students, governments and NGOs. The Palmer Antarctic LTER will also conduct appropriate cross LTER site comparisons, and serve as a leader in information management to enable knowledge-building within and beyond the Antarctic, oceanographic, and LTER communities.", "east": -63.0, "geometry": "POINT(-71.5 -67)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; 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", "is_usap_dc": true, "keywords": "PELAGIC; USAP-DC; R/V LMG; NOT APPLICABLE; Palmer Station; LMG1701", "locations": "Palmer Station", "north": -63.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ducklow, Hugh; Martinson, Doug; Schofield, Oscar", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "EDI; R2R; USAP-DC", "science_programs": "LTER", "south": -71.0, "title": "LTER Palmer, Antarctica (PAL): Land-Shelf-Ocean Connectivity, Ecosystem Resilience and Transformation in a Sea-Ice Influenced Pelagic Ecosystem", "uid": "p0000133", "west": -80.0}, {"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": "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"}, {"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"}], "date_created": "Fri, 27 Apr 2018 00:00:00 GMT", "description": "Non-Technical Summary:\u003cbr/\u003e 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\u00c3\u00a1rtico 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. \u003cbr/\u003e 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.\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eTechnical Description of Project \u003cbr/\u003eThe 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).\u003cbr/\u003eThis 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": "USAP-DC", "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": "1115245 McKnight, Diane", "bounds_geometry": "POLYGON((160.5 -77.35,160.83 -77.35,161.16 -77.35,161.49 -77.35,161.82 -77.35,162.15 -77.35,162.48 -77.35,162.81 -77.35,163.14 -77.35,163.47 -77.35,163.8 -77.35,163.8 -77.4,163.8 -77.45,163.8 -77.5,163.8 -77.55,163.8 -77.6,163.8 -77.65,163.8 -77.7,163.8 -77.75,163.8 -77.8,163.8 -77.85,163.47 -77.85,163.14 -77.85,162.81 -77.85,162.48 -77.85,162.15 -77.85,161.82 -77.85,161.49 -77.85,161.16 -77.85,160.83 -77.85,160.5 -77.85,160.5 -77.8,160.5 -77.75,160.5 -77.7,160.5 -77.65,160.5 -77.6,160.5 -77.55,160.5 -77.5,160.5 -77.45,160.5 -77.4,160.5 -77.35))", "dataset_titles": "McMurdo Dry Valleys LTER data at EDI Data Portal", "datasets": [{"dataset_uid": "000204", "doi": "", "keywords": null, "people": null, "repository": "LTER", "science_program": null, "title": "McMurdo Dry Valleys LTER data at EDI Data Portal", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=MCM "}], "date_created": "Mon, 08 Jan 2018 00:00:00 GMT", "description": "The McMurdo Dry Valleys (MDV) is a polar desert on the coast of East Antarctica, a region that has not yet experienced climate warming. The McMurdo Dry Valleys Long Term Ecological Research (MCMLTER) project has documented the ecological responses of the glacier, soil, stream and lake ecosystems in the MDV during a cooling trend (from 1986 to 2000) which was associated with the depletion of atmospheric ozone. In the past decade, warming events with strong katabatic winds occurred during two summers and the resulting high streamflows and sediment deposition changed the dry valley landscape, possibly presaging conditions that will occur when the ozone hole recovers. In anticipation of future warming in Antarctica, the overarching hypothesis of the proposed project is: Climate warming in the McMurdo Dry Valley ecosystem will amplify connectivity among landscape units leading to enhanced coupling of nutrient cycles across landscapes, and increased biodiversity and productivity within the ecosystem. Warming in the MDV is hypothesized to act as a slowly developing, long-term press of warmer summers, upon which transient pulse events of high summer flows and strong katabatic winds will be overprinted. Four specific hypotheses address the ways in which pulses of water and wind will influence contemporary and future ecosystem structure, function and connectivity. Because windborne transport of biota is a key aspect of enhanced connectivity from katabatic winds, new monitoring will include high-resolution measurements of aeolian particle flux. Importantly, integrative genomics will be employed to understand the responses of specific organisms to the increased connectivity. The project will also include a novel social science component that will use environmental history to examine interactions between human activity, scientific research, and environmental change in the MDV over the past 100 years. To disseminate this research broadly, MCM scientists will participate in a wide array of outreach efforts ranging from presentations in K-12 classrooms to bringing undergraduates and teachers to the MDV to gain research experience. Planned outreach programs will build upon activities conducted during the International Polar Year (2007-2008), which include development of an interactive DVD for high school students and teachers and publication of a children\u0027s book in the LTER Schoolyard Book Series. A teacher\u0027s edition of the book with a CD containing lesson plans will be distributed. The project will develop programs for groups traditionally underrepresented in science arenas by publishing some outreach materials in Spanish.", "east": 163.8, "geometry": "POINT(162.15 -77.6)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.35, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Instrumentation and Support; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "McKnight, Diane; Gooseff, Michael N.", "platforms": "Not provided", "repo": "LTER", "repositories": "LTER", "science_programs": "LTER", "south": -77.85, "title": "Increased Connectivity in a Polar Desert Resulting from Climate Warming: McMurdo Dry Valley LTER Program", "uid": "p0000301", "west": 160.5}, {"awards": "1425989 Sarmiento, Jorge", "bounds_geometry": "POLYGON((-180 -52.6153,-168.67689 -52.6153,-157.35378 -52.6153,-146.03067 -52.6153,-134.70756 -52.6153,-123.38445 -52.6153,-112.06134 -52.6153,-100.73823 -52.6153,-89.41512 -52.6153,-78.09201 -52.6153,-66.7689 -52.6153,-66.7689 -55.18958,-66.7689 -57.76386,-66.7689 -60.33814,-66.7689 -62.91242,-66.7689 -65.4867,-66.7689 -68.06098,-66.7689 -70.63526,-66.7689 -73.20954,-66.7689 -75.78382,-66.7689 -78.3581,-78.09201 -78.3581,-89.41512 -78.3581,-100.73823 -78.3581,-112.06134 -78.3581,-123.38445 -78.3581,-134.70756 -78.3581,-146.03067 -78.3581,-157.35378 -78.3581,-168.67689 -78.3581,180 -78.3581,178.62318 -78.3581,177.24636 -78.3581,175.86954 -78.3581,174.49272 -78.3581,173.1159 -78.3581,171.73908 -78.3581,170.36226 -78.3581,168.98544 -78.3581,167.60862 -78.3581,166.2318 -78.3581,166.2318 -75.78382,166.2318 -73.20954,166.2318 -70.63526,166.2318 -68.06098,166.2318 -65.4867,166.2318 -62.91242,166.2318 -60.33814,166.2318 -57.76386,166.2318 -55.18958,166.2318 -52.6153,167.60862 -52.6153,168.98544 -52.6153,170.36226 -52.6153,171.73908 -52.6153,173.1159 -52.6153,174.49272 -52.6153,175.86954 -52.6153,177.24636 -52.6153,178.62318 -52.6153,-180 -52.6153))", "dataset_titles": "Biogeochemical profiling float data from the Southern Ocean Carbon and Climate Observation and Modeling (SOCCOM) program.UCSD Research Data Collections DOI:10.6075/J09021PC; Expedition Data; Model output NOAA GFDL CM2_6 Cant Hant storage", "datasets": [{"dataset_uid": "601144", "doi": "10.15784/601144", "keywords": "Antarctica; Anthropogenic Heat; Atmosphere; Carbon Storage; Climate Change; Eddy; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Heat Budget; Modeling; Model Output; Oceans; Paleoclimate; Snow/ice; Snow/Ice; Southern Ocean", "people": "Chen, Haidi", "repository": "USAP-DC", "science_program": null, "title": "Model output NOAA GFDL CM2_6 Cant Hant storage", "url": "https://www.usap-dc.org/view/dataset/601144"}, {"dataset_uid": "001369", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1701"}, {"dataset_uid": "000208", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Biogeochemical profiling float data from the Southern Ocean Carbon and Climate Observation and Modeling (SOCCOM) program.UCSD Research Data Collections DOI:10.6075/J09021PC", "url": "http://library.ucsd.edu/dc/object/bb66239018"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project seeks to drive a transformative shift in our understanding of the crucial role of the Southern Ocean in taking up anthropogenic carbon and heat, and resupplying nutrients from the abyss to the surface. An observational program will generate vast amounts of new biogeochemical data that will provide a greatly improved view of the dynamics and ecosystem responses of the Southern Ocean. A modeling component will apply these observations to enhancing understanding of the current ocean, reducing uncertainty in projections of future carbon and nutrient cycles and climate.\u003cbr/\u003e\u003cbr/\u003eBecause it serves as the primary gateway through which the intermediate, deep, and bottom waters of the ocean interact with the surface layers and thus the atmosphere, the Southern Ocean has a profound influence on the oceanic uptake of anthropogenic carbon and heat as well as nutrient resupply from the abyss to the surface. Yet it is the least observed and understood region of the world ocean. The oceanographic community is on the cusp of two major advances that have the potential to transform understanding of the Southern Ocean. The first is the development of new biogeochemical sensors mounted on autonomous profiling floats that allow sampling of ocean biogeochemistry and acidification in 3-dimensional space with a temporal resolution of five to ten days. The SOCCOM float program proposed will increase the average number of biogeochemical profiles measured per month in the Southern Ocean by ~10-30x. The second is that the climate modeling community now has the computational resources and physical understanding to develop fully coupled climate models that can represent crucial mesoscale processes in the Southern Ocean, as well as corresponding models that assimilate observations to produce a state estimate. Together with the observations, this new generation of models provides the tools to vastly improve understanding of Southern Ocean processes and the ability to quantitatively assess uptake of anthropogenic carbon and heat, as well as nutrient resupply, both today and into the future.\u003cbr/\u003e\u003cbr/\u003eIn order to take advantage of the above technological and modeling breakthroughs, SOCCOM will implement the following research programs:\u003cbr/\u003e* Theme 1: Observations. Scripps Institution of Oceanography will lead a field program to expand the number of Southern Ocean autonomous profiling floats and equip them with sensors to measure pH, nitrate, and oxygen. The University of Washington and Monterey Bay Aquarium Research Institute will design, build, and oversee deployment of the floats. Scripps will also develop a mesoscale eddying Southern Ocean state estimate that assimilates physical and biogeochemical data into the MIT ocean general circulation model.\u003cbr/\u003e* Theme 2: Modeling. University of Arizona and Princeton University, together with NOAA\u0027s Geophysical Fluid Dynamics Laboratory (GFDL), will use SOCCOM observations to develop data/model assessment metrics and next-generation model analysis and evaluation, with the goal of improving process level understanding and reducing the uncertainty in projections of our future climate.\u003cbr/\u003e\u003cbr/\u003eLed by Climate Central, an independent, non-profit journalism and research organization that promotes understanding of climate science, SOCCOM will collaborate with educators and media professionals to inform policymakers and the public about the challenges of climate change and its impacts on marine life in the context of the Southern Ocean. In addition, the integrated team of SOCCOM scientists and educators will:\u003cbr/\u003e* communicate data and results of the SOCCOM efforts quickly to the public through established data networks, publications, broadcast media, and a public portal;\u003cbr/\u003e* train a new generation of diverse ocean scientists, including undergraduate students, graduate students, and postdoctoral fellows versed in field techniques, data calibration, modeling, and communication of research to non-scientists;\u003cbr/\u003e* transfer new sensor technology and related software to autonomous instrument providers and manufacturers to ensure that they become widely useable.", "east": -66.7689, "geometry": "POINT(-130.26855 -65.4867)", "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 ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; R/V NBP; NBP1701; CLIMATE MODELS", "locations": null, "north": -52.6153, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Sarmiento, Jorge; Rynearson, Tatiana", "platforms": "OTHER \u003e MODELS \u003e CLIMATE MODELS; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "PI website; R2R; USAP-DC", "science_programs": null, "south": -78.3581, "title": "Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM)", "uid": "p0000197", "west": 166.2318}, {"awards": "1543256 Shuster, David", "bounds_geometry": null, "dataset_titles": "Detrital low-temperature thermochronometry from Bourgeois Fjord, AP; Expedition Data; Expedition data of LMG1702", "datasets": [{"dataset_uid": "002733", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1702", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "601259", "doi": "10.15784/601259", "keywords": "Antarctica; Antarctic Peninsula", "people": "Clinger, Anna", "repository": "USAP-DC", "science_program": null, "title": "Detrital low-temperature thermochronometry from Bourgeois Fjord, AP", "url": "https://www.usap-dc.org/view/dataset/601259"}, {"dataset_uid": "000402", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "The extreme mountain topographies of alpine landscapes at mid latitudes (e.g., European Alps, Patagonia, Alaska) are thought to have formed by the erosive action of glaciers, yet our understanding of exactly when and how those topographies developed is limited. If glacial ice was responsible for forming them, then those landscapes must have developed primarily over the last 2-3 million years when ice was present at those latitudes; this timing has only recently been confirmed by observations. In contrast, the Antarctic Peninsula, which contains similarly spectacular topographic relief, is known to have hosted alpine glaciers as early as 37 million years ago, and is currently covered by ice. Thus, if caused by glacial erosion, the high relief of the peninsula should have formed much earlier than what has been observed at mid latitude sites, yet we know nearly nothing about the timing of its development. The primary benefit of this research will be to study the timing of topography development along the Antarctic Peninsula by applying state of the art chemical analyses to sediments collected offshore. This research is important because studying a high latitude site will enable comparison with sites at mid latitudes and test current hypotheses on the development of glacial landscapes in general.\u003cbr/\u003e\u003cbr/\u003eThis project aims to apply low-temperature thermochronometry based on the (U-Th)/He system in apatite to investigate the exhumation history, the development of the present topography, and the pattern of glacial erosion in the central Antarctic Peninsula. A number of recent studies have used this approach to study the dramatic, high-relief landscapes formed by Pleistocene alpine glacial erosion in temperate latitudes: New Zealand, the Alps, British Columbia, Alaska, and Patagonia. These studies have not only revealed when these landscapes formed, but have also provided new insights into the physical mechanisms of glacial erosion. The Antarctic Peninsula is broadly akin to temperate alpine landscapes in that the dominant landforms are massive glacial troughs. However, what we know about Antarctic glacial history suggests that the timing and history of glacial erosion was most likely very different from the temperate alpine setting: The Antarctic Peninsula has been glaciated since the Eocene, and Pleistocene climate cooling is hypothesized to have suppressed, rather than enhanced, glacial erosion. Our goal is to evaluate these hypotheses by developing a direct thermochronometric record of when and how the present glacial valley relief formed. We propose to learn about the timing and process of glacial valley formation through apatite (U-Th)/He and 4He/3He measurements on glacial sediment collected near the grounding lines of major glaciers draining the Peninsula. In effect, since we cannot sample bedrock directly that is currently covered by ice, we will rely on these glaciers to do it for us.", "east": null, "geometry": null, "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 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", "is_usap_dc": false, "keywords": "R/V LMG; LMG1702; Antarctic Peninsula; ICE SHEETS", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kohut, Josh; Shuster, David; Balco, Gregory; Jenkins, Bethany", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-Temperature Detrital Thermochronometry", "uid": "p0000876", "west": null}, {"awards": "1143981 Domack, Eugene", "bounds_geometry": "POLYGON((-69.9517 -52.7581,-69.02971 -52.7581,-68.10772 -52.7581,-67.18573 -52.7581,-66.26374 -52.7581,-65.34175 -52.7581,-64.41976 -52.7581,-63.49777 -52.7581,-62.57578 -52.7581,-61.65379 -52.7581,-60.7318 -52.7581,-60.7318 -54.31551,-60.7318 -55.87292,-60.7318 -57.43033,-60.7318 -58.98774,-60.7318 -60.54515,-60.7318 -62.10256,-60.7318 -63.65997,-60.7318 -65.21738,-60.7318 -66.77479,-60.7318 -68.3322,-61.65379 -68.3322,-62.57578 -68.3322,-63.49777 -68.3322,-64.41976 -68.3322,-65.34175 -68.3322,-66.26374 -68.3322,-67.18573 -68.3322,-68.10772 -68.3322,-69.02971 -68.3322,-69.9517 -68.3322,-69.9517 -66.77479,-69.9517 -65.21738,-69.9517 -63.65997,-69.9517 -62.10256,-69.9517 -60.54515,-69.9517 -58.98774,-69.9517 -57.43033,-69.9517 -55.87292,-69.9517 -54.31551,-69.9517 -52.7581))", "dataset_titles": "Expedition Data; Processed Camera Images acquired during the Laurence M. Gould expedition LMG1311", "datasets": [{"dataset_uid": "001366", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "000402", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "601311", "doi": "10.15784/601311", "keywords": "Antarctica; Antarctic Peninsula; Benthic Images; Camera; LARISSA; LMG1311; Marine Geoscience; Photo; Photo/video; Photo/Video; R/v Laurence M. Gould", "people": "Domack, Eugene Walter", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Processed Camera Images acquired during the Laurence M. Gould expedition LMG1311", "url": "https://www.usap-dc.org/view/dataset/601311"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "This project aims to identify which portions of the glacial cover in the Antarctic Peninsula are losing mass to the ocean. This is an important issue to resolve because the Antarctic Peninsula is warming at a faster rate than any other region across the earth. Even though glaciers across the Antarctic Peninsula are small, compared to the continental ice sheet, defining how rapidly they respond to both ocean and atmospheric temperature rise is critical. It is critical because it informs us about the exact mechanisms which regulate ice flow and melting into the ocean. For instance, after the break- up of the Larsen Ice Shelf in 2002 many glaciers began to flow rapidly into the sea. Measuring how much ice was involved is difficult and depends upon accurate estimates of volume and area. One way to increase the accuracy of our estimates is to measure how fast the Earth\u0027s crust is rebounding or bouncing back, after the ice has been removed. This rebound effect can be measured with very precise techniques using instruments locked into ice free bedrock surrounding the area of interest. These instruments are monitored by a set of positioning satellites (the Global Positioning System or GPS) in a continuous fashion. Of course the movement of the Earth\u0027s bedrock relates not only to the immediate response but also the longer term rate that reflects the long vanished ice masses that once covered the entire Antarctic Peninsula?at the time of the last glaciation. These rebound measurements can, therefore, also tell us about the amount of ice which covered the Antarctic Peninsula thousands of years ago. Glacial isostatic rebound is one of the complicating factors in allowing us to understand how much the larger ice sheets are losing today, something that can be estimated by satellite techniques but only within large errors when the isostatic (rebound) correction is unknown.\u003cbr/\u003e\u003cbr/\u003eThe research proposed consists of maintaining a set of six rebound stations until the year 2016, allowing for a longer time series and thus more accurate estimates of immediate elastic and longer term rebound effects. It also involves the establishment of two additional GPS stations that will focus on constraining the \"bull\u0027s eye\" of rebound suggested by measurements over the past two years. In addition, several more geologic data points will be collected that will help to reconstruct the position of the ice sheet margin during its recession from the full ice sheet of the last glacial maximum. These will be based upon the coring of marine sediment sequences now recognized to have been deposited along the margins of retreating ice sheets and outlets. Precise dating of the ice margin along with the new and improved rebound data will help to constrain past ice sheet configurations and refine geophysical models related to the nature of post glacial rebound. Data management will be under the auspices of the UNAVCO polar geophysical network or POLENET and will be publically available at the time of station installation. This project is a small scale extension of the ongoing LARsen Ice Shelf, Antarctica Project (LARISSA), an IPY (International Polar Year)-funded interdisciplinary study aimed at understanding earth system connections related to the Larsen Ice Shelf and the northern Antarctic Peninsula.", "east": -60.7318, "geometry": "POINT(-65.34175 -60.54515)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; 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", "is_usap_dc": false, "keywords": "LMG1702; R/V LMG", "locations": null, "north": -52.7581, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Kohut, Josh; Domack, Eugene Walter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -68.3322, "title": "Continuation of the LARISSA Continuous GPS Network in View of Observed Dynamic Response to Antarctic Peninsula Ice Mass Balance and Required Geologic Constraints", "uid": "p0000233", "west": -69.9517}, {"awards": "1141906 Grunow, Anne", "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": "Rock Samples", "datasets": [{"dataset_uid": "000224", "doi": "", "keywords": null, "people": null, "repository": "PRR", "science_program": null, "title": "Rock Samples", "url": "http://research.bpcrc.osu.edu/rr/"}], "date_created": "Tue, 07 Nov 2017 00:00:00 GMT", "description": "Project Summary\u003cbr/\u003e\u003cbr/\u003eIntellectual Merit: \u003cbr/\u003eThe United States Polar Rock Repository (USPRR) was established to curate and loan geologic samples from polar regions to researchers and educators. OPP established the USPRR in part to avoid redundant sample collection and thus reduce the environmental impact of polar research. The USPRR also provides the research community with an important resource for developing new research projects. The USPRR acquires rock collections through donations from institutions and scientists and makes these samples available as no-cost loans for research, education and museum exhibits. Sample metadata is available in an on-line database. The database also includes rock property information, such as magnetic susceptibility and specific gravity, which are useful for geophysical studies. Researchers may request samples for analysis using an online request form. The USPRR fulfills several data management directives, including the Scientific Committee on Antarctic Research, Antarctic Data Management directive of providing free, full and open access to both metadata and the samples. The intellectual merit of the USPRR lies in the global dissemination of scientific information to researchers. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThe broader impacts of the USPRR include lessening environmental impacts resulting from redundant fieldwork in Polar Regions. The USPRR provides educational information about Antarctica via the website, by visiting the repository or borrowing a \"USPRR rock box\". Working at the repository provides students with opportunities to learn about the geology of Antarctica as well as doing research, learning new skills in digital imaging, curation and database management.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Grunow, Anne", "platforms": "Not provided", "repo": "PRR", "repositories": "PRR", "science_programs": null, "south": -90.0, "title": "Continuing Operations Proposal: The United States Polar Rock Repository as a Research Tool for Understanding Antarctica\u0027s Geological Evolution", "uid": "p0000387", "west": -180.0}, {"awards": "1341420 Balco, Gregory; 1341364 Todd, Claire; 1460449 Goehring, Brent", "bounds_geometry": "POLYGON((164.08 -74.6,164.0842 -74.6,164.0884 -74.6,164.0926 -74.6,164.0968 -74.6,164.101 -74.6,164.1052 -74.6,164.1094 -74.6,164.1136 -74.6,164.1178 -74.6,164.122 -74.6,164.122 -74.6023,164.122 -74.6046,164.122 -74.6069,164.122 -74.6092,164.122 -74.6115,164.122 -74.6138,164.122 -74.6161,164.122 -74.6184,164.122 -74.6207,164.122 -74.623,164.1178 -74.623,164.1136 -74.623,164.1094 -74.623,164.1052 -74.623,164.101 -74.623,164.0968 -74.623,164.0926 -74.623,164.0884 -74.623,164.0842 -74.623,164.08 -74.623,164.08 -74.6207,164.08 -74.6184,164.08 -74.6161,164.08 -74.6138,164.08 -74.6115,164.08 -74.6092,164.08 -74.6069,164.08 -74.6046,164.08 -74.6023,164.08 -74.6))", "dataset_titles": "Interface to observational data associated with exposure-age measurements and resulting calculated ages. Dynamic content, updated.", "datasets": [{"dataset_uid": "200196", "doi": null, "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Interface to observational data associated with exposure-age measurements and resulting calculated ages. Dynamic content, updated.", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Wed, 18 Oct 2017 00:00:00 GMT", "description": "The investigators will map glacial deposits and date variations in glacier variability at several ice-free regions in northern Victoria Land, Antarctica. These data will constrain the nature and timing of past ice thickness changes for major glaciers that drain into the northwestern Ross Sea. This is important because during the Last Glacial Maximum (15,000 - 18,000 years ago) these glaciers were most likely flowing together with grounded ice from both the East and West Antarctic Ice Sheets that expanded across the Ross Sea continental shelf to near the present shelf edge. Thus, the thickness of these glaciers was most likely controlled in part by the extent and thickness of the Ross Sea ice sheet and ice shelf. The data the PIs propose to collect can provide constraints on the position of the grounding line in the western Ross Sea during the Last Glacial Maximum, the time that position was reached, and ice thickness changes that occurred after that time. The primary intellectual merit of this project will be to improve understanding of a period of Antarctic ice sheet history that is relatively unconstrained at present and also potentially important in understanding past ice sheet-sea level interactions. \u003cbr/\u003e\u003cbr/\u003eThis proposal will support an early career researcher\u0027s ongoing program of undergraduate education and research that is building a socio-economically diverse student body with students from backgrounds underrepresented in the geosciences. This proposal will also bring an early career researcher into Antarctic research.", "east": 164.122, "geometry": "POINT(164.101 -74.6115)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; Cosmogenic Dating; Exposure Age; LABORATORY; NOT APPLICABLE; Amd/Us; Ross Sea", "locations": "Ross Sea", "north": -74.6, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Goehring, Brent; Balco, Gregory; Todd, Claire", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "ICE-D", "repositories": "ICE-D", "science_programs": null, "south": -74.623, "title": "Collaborative Research: Terrestrial Exposure-Age Constraints on the last Glacial Maximum Extent of the Antarctic Ice Sheet in the Western Ross Sea", "uid": "p0000306", "west": 164.08}, {"awards": "1341712 Hallet, Bernard", "bounds_geometry": "POLYGON((160.9 -76.7,161.08 -76.7,161.26 -76.7,161.44 -76.7,161.62 -76.7,161.8 -76.7,161.98 -76.7,162.16 -76.7,162.34 -76.7,162.52 -76.7,162.7 -76.7,162.7 -76.79,162.7 -76.88,162.7 -76.97,162.7 -77.06,162.7 -77.15,162.7 -77.24,162.7 -77.33,162.7 -77.42,162.7 -77.51,162.7 -77.6,162.52 -77.6,162.34 -77.6,162.16 -77.6,161.98 -77.6,161.8 -77.6,161.62 -77.6,161.44 -77.6,161.26 -77.6,161.08 -77.6,160.9 -77.6,160.9 -77.51,160.9 -77.42,160.9 -77.33,160.9 -77.24,160.9 -77.15,160.9 -77.06,160.9 -76.97,160.9 -76.88,160.9 -76.79,160.9 -76.7))", "dataset_titles": "Long-term rock abrasion study in the Dry Valleys", "datasets": [{"dataset_uid": "601060", "doi": "10.15784/601060", "keywords": "Antarctica; Dry Valleys; Geology/Geophysics - Other; Rocks", "people": "Sletten, Ronald S.; Malin, Michael; Hallet, Bernard", "repository": "USAP-DC", "science_program": null, "title": "Long-term rock abrasion study in the Dry Valleys", "url": "https://www.usap-dc.org/view/dataset/601060"}], "date_created": "Fri, 13 Oct 2017 00:00:00 GMT", "description": "Many of the natural processes that modify the landscape inhabited by humans occur over very long timescales, making them difficult to observe. Exceptions include rare catastrophic events such as earthquakes, volcanic eruptions, and floods that occur on short timescales. Many significant processes that affect the land and landscape that we inhabit operate on time scales imperceptible to humans. One of these processes is wind transport of sand, with related impacts to exposed rock surfaces and man-made objects, including buildings, windshields, solar panels and wind-farm turbine blades. The goal of this project is to gain an understanding of wind erosion processes over long timescales, in the Antarctic Dry Valleys, a cold desert environment where there were no competing processes (such as rain and vegetation) that might mask the effects. The main objective is recovery of rock samples that were deployed in 1983/1984 at 11 locations in the Antarctic Dry Valleys, along with measurements on the rock samples and characterization of the sites. In the late 1980s and early 1990s some of these samples were returned and indicated more time was needed to accumulate information about the timescales and impacts of the wind erosion processes. This project will allow collection of the remaining samples from this experiment after 30 to 31 years of exposure. The field work will be carried out during the 2014/15 Austral summer. The results will allow direct measurement of the abrasion rate and hence the volumes and timescales of sand transport; this will conclude the longest direct examination of such processes ever conducted. Appropriate scaling of the results may be applied to buildings, vegetation (crops), and other aspects of human presence in sandy and windy locations, in order to better determine the impact of these processes and possible mitigation of the impacts. The project is a collaborative effort between a small business, Malin Space Science Systems (MSSS), and the University of Washington (UW). MSSS will highlight this Antarctic research on its web site, by developing thematic presentations describing our research and providing a broad range of visual materials. The public will be engaged through daily updates on a website and through links to material prepared for viewing in Google Earth. UW students will be involved in the laboratory work and in the interpretation of the results.\u003cbr\u003eTechnical Description of Project:\u003cbr\u003eThe goal of this project is to study the role of wind abrasion by entrained particles in the evolution of the McMurdo Dry Valleys in the Transantarctic Mountains. During the 1983 to 1984 field seasons, over 5000 rock targets were installed at five heights facing the 4 cardinal directions at 10 locations (with an additional site containing fewer targets) to study rates of physical weathering due primarily to eolian abrasion. In addition, rock cubes and cylinders were deployed at each site to examine effects of chemical weathering. The initial examination of samples returned after 1, 5, and 10 years of exposure, showed average contemporary abrasion rates consistent with those determined by cosmogenic isotope studies, but further stress that \"average\" should not be interpreted as meaning \"uniform.\" The samples will be characterized using mass measurements wtih 0.01 mg precision balances, digital microphotography to compare the evolution of their surface features and textures, SEM imaging to examine the micro textures of abraded rock surfaces, and optical microscopy of thin sections of a few samples to examine the consequences of particle impacts extending below the abraded surfaces. As much as 60-80% of the abrasion measured in samples from 1984-1994 appears to have occurred during a few brief hours in 1984. This is consistent with theoretical models that suggest abrasion scales as the 5th power of wind velocity. The field work will allow return of multiple samples after three decades of exposure, which will provide a statistical sampling (beyond what is acquired by studying a single sample), and will yield the mass loss data in light of complementary environmental and sand kinetic energy flux data from other sources (e.g. LTER meteorology stations). This study promises to improve insights into one of the principal active geomorphic process in the Dry Valleys, an important cold desert environment, and the solid empirical database will provide general constraints on eolian abrasion under natural conditions.", "east": 162.7, "geometry": "POINT(161.8 -77.15)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.7, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Hallet, Bernard; Sletten, Ronald S.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.6, "title": "Collaborative Proposal: Decades-long Experiment on Wind-Driven Rock Abrasion in the Ice-Free Valleys, Antarctica", "uid": "p0000074", "west": 160.9}, {"awards": "1142129 Lamanna, Matthew", "bounds_geometry": "POLYGON((-60 -63.5,-59.6 -63.5,-59.2 -63.5,-58.8 -63.5,-58.4 -63.5,-58 -63.5,-57.6 -63.5,-57.2 -63.5,-56.8 -63.5,-56.4 -63.5,-56 -63.5,-56 -63.7,-56 -63.9,-56 -64.1,-56 -64.3,-56 -64.5,-56 -64.7,-56 -64.9,-56 -65.1,-56 -65.3,-56 -65.5,-56.4 -65.5,-56.8 -65.5,-57.2 -65.5,-57.6 -65.5,-58 -65.5,-58.4 -65.5,-58.8 -65.5,-59.2 -65.5,-59.6 -65.5,-60 -65.5,-60 -65.3,-60 -65.1,-60 -64.9,-60 -64.7,-60 -64.5,-60 -64.3,-60 -64.1,-60 -63.9,-60 -63.7,-60 -63.5))", "dataset_titles": "2008-2016 AMNH accessioned vertebrate fossils from Seymour Island; 3D digital reconstructions of vocal organs of Antarctic Cretaceous bird Vegavis and Paleogene bird Presbyornis", "datasets": [{"dataset_uid": "601112", "doi": "10.15784/601112", "keywords": "Antarctica; Biota; Penguin; Seymour Island; Vertebrates", "people": "MacPhee, Ross", "repository": "USAP-DC", "science_program": null, "title": "2008-2016 AMNH accessioned vertebrate fossils from Seymour Island", "url": "https://www.usap-dc.org/view/dataset/601112"}, {"dataset_uid": "601035", "doi": "10.15784/601035", "keywords": "Antarctica; Biota; Birds", "people": "Salisbury, Steven; Clarke, Julia; Lamanna, Matthew", "repository": "USAP-DC", "science_program": null, "title": "3D digital reconstructions of vocal organs of Antarctic Cretaceous bird Vegavis and Paleogene bird Presbyornis", "url": "https://www.usap-dc.org/view/dataset/601035"}], "date_created": "Wed, 12 Jul 2017 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThe role that Antarctica has played in vertebrate evolution and paleobiogeography during the Late Cretaceous and early Paleogene is largely unknown. Evidence indicates that Antarctica was home to a diverse flora during the Late Cretaceous and Paleogene, yet the vertebrates that must have existed on the continent remain virtually unknown. To fill this gap, the PIs have formed the Antarctic Vertebrate Paleontology Initiative (AVPI), whose goal is to search for and collect Late Cretaceous-Paleogene vertebrate fossils in Antarctica at localities that have never been properly surveyed, as well as in areas of proven potential. Two field seasons are proposed for the James Ross Island Group on the northeastern margin of the Antarctic Peninsula. Expected finds include chondrichthyan and osteichthyan fishes, marine reptiles, ornithischian and non-avian theropod dinosaurs, ornithurine birds, and therian and non-therian mammals. Hypotheses to be tested include: 1) multiple extant bird and/or therian mammal lineages originated during the Cretaceous and survived the K-Pg boundary extinction event; 2) the \"Scotia Portal\" permitted the dispersal of continental vertebrates between Antarctica and South America prior to the latest Cretaceous and through to the late Paleocene or early Eocene; 3) Late Cretaceous non-avian dinosaurs from Antarctica are closely related to coeval taxa from other Gondwanan landmasses; 4) terminal Cretaceous marine reptile faunas from southern Gondwana differed from contemporaneous but more northerly assemblages; and 5) the collapse of Antarctic ichthyofaunal diversity during the K-Pg transition was triggered by a catastrophic extinction.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThe PIs will communicate discoveries to audiences through a variety of channels, such as the Dinosaurs in Their Time exhibition at Carnegie Museum of Natural History and the outreach programs of the Environmental Science Institute of the University of Texas at Austin. In addition, Carnegie Museum will launch a student-oriented programming initiative using AVPI research as a primary focus. This array of activities will help some 2,000 Pittsburgh-area undergraduates to explore the relevance of deep-time discoveries to critical modern issues. The AVPI will provide research opportunities for eight undergraduate and three graduate students, several of whom will receive field training in Antarctica. Fossils will be accessioned into the Carnegie Museum collection, and made accessible virtually through the NSF-funded Digital Morphology library at University of Texas.", "east": -56.0, "geometry": "POINT(-58 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; Not provided", "locations": null, "north": -63.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Lamanna, Matthew", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.5, "title": "Collaborative Research: Late Cretaceous-Paleogene Vertebrates from Antarctica: Implications for Paleobiogeography, Paleoenvironment, and Extinction in Polar Gondwana", "uid": "p0000380", "west": -60.0}, {"awards": "0944266 Twickler, Mark; 0944348 Taylor, Kendrick", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "Summary of Results from the WAIS Divide Ice Core Project; WAIS Divide WDC06A Core Quality Versus Depth", "datasets": [{"dataset_uid": "601030", "doi": "10.15784/601030", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide Ice Core", "people": "Taylor, Kendrick C.; Souney, Joseph Jr.; Twickler, Mark", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide WDC06A Core Quality Versus Depth", "url": "https://www.usap-dc.org/view/dataset/601030"}, {"dataset_uid": "601021", "doi": "10.15784/601021", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide Ice Core", "people": "Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Summary of Results from the WAIS Divide Ice Core Project", "url": "https://www.usap-dc.org/view/dataset/601021"}], "date_created": "Fri, 09 Jun 2017 00:00:00 GMT", "description": "Taylor/0944348\u003cbr/\u003e\u003cbr/\u003eThis award supports renewal of funding of the WAIS Divide Science Coordination Office (SCO). The Science Coordination Office (SCO) was established to represent the research community and facilitates the project by working with support organizations responsible for logistics, drilling, and core curation. During the last five years, 26 projects have been individually funded to work on this effort and 1,511 m of the total 3,470 m of ice at the site has been collected. This proposal seeks funding to continue the SCO and related field operations needed to complete the WAIS Divide ice core project. Tasks for the SCO during the second five years include planning and oversight of logistics, drilling, and core curation; coordinating research activities in the field; assisting in curation of the core in the field; allocating samples to individual projects; coordinating the sampling effort; collecting, archiving, and distributing data and other information about the project; hosting an annual science meeting; and facilitating collaborative efforts among the research groups. The intellectual merit of the WAIS Divide project is to better predict how human-caused increases in greenhouse gases will alter climate requires an improved understanding of how previous natural changes in greenhouse gases influenced climate in the past. Information on previous climate changes is used to validate the physics and results of climate models that are used to predict future climate. Antarctic ice cores are the only source of samples of the paleo-atmosphere that can be used to determine previous concentrations of carbon dioxide. Ice cores also contain records of other components of the climate system such as the paleo air and ocean temperature, atmospheric loading of aerosols, and indicators of atmospheric transport. The WAIS Divide ice core project has been designed to obtain the best possible record of greenhouse gases during the last glacial cycle (last ~100,000 years). The site was selected because it has the best balance of high annual snowfall (23 cm of ice equivalent/year), low dust Antarctic ice that does not compromise the carbon dioxide record, and favorable glaciology. The main science objectives of the project are to investigate climate forcing by greenhouse gases, initiation of climate changes, stability of the West Antarctic Ice Sheet, and cryobiology in the ice core. The project has numerous broader impacts. An established provider of educational material (Teachers? Domain) will develop and distribute web-based resources related to the project and climate change for use in K?12 classrooms. These resources will consist of video and interactive graphics that explain how and why ice cores are collected, and what they tell us about future climate change. Members of the national media will be included in the field team and the SCO will assist in presenting information to the general public. Video of the project will be collected and made available for general use. Finally, an opportunity will be created for cryosphere students and early career scientists to participate in field activities and core analysis. An ice core archive will be available for future projects and scientific discoveries from the project can be used by policy makers to make informed decisions.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.481, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Mark, Twickler; Taylor, Kendrick C.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Collaborative Research: Climate, Ice Dynamics and Biology using a Deep Ice Core from the West Antarctic Ice Sheet Ice Divide", "uid": "p0000080", "west": -112.1115}, {"awards": "1341360 Steig, Eric", "bounds_geometry": "POINT(106 -77.5)", "dataset_titles": "Seasonal 17O Isotope Data from Lake Vostok and WAIS Divide Snow Pits", "datasets": [{"dataset_uid": "601031", "doi": "10.15784/601031", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Lake Vostok; Snow Pit; WAIS Divide Ice Core", "people": "Schoenemann, Spruce; Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal 17O Isotope Data from Lake Vostok and WAIS Divide Snow Pits", "url": "https://www.usap-dc.org/view/dataset/601031"}], "date_created": "Tue, 06 Jun 2017 00:00:00 GMT", "description": "Steig/1341360\u003cbr/\u003e\u003cbr/\u003eThis award supports a two-year project to develop a method for rapid and precise measurements of the difference in 18O/16O and 17O/16O isotope ratios in water, referred to as the 17O-excess. Measurement of 17O-excess is a recent innovation in geochemistry, complementing traditional measurements of the ratios of hydrogen (D/H) and oxygen (18O/16O). Conventional measurements of 17O/16O are limited in number because of the time-consuming and laborious nature of the analyses, which involves the conversion of water to oxygen via fluorination, followed by high-precision mass spectrometry. This project will use a novel cavity ring-down spectroscopy (CRDS) system developed by a joint effort of the University of Washington and Picarro, Inc. (Santa Clara, CA), along with the Centre for Ice and Climate (Neils Bohr Institute, Copenhagen). The primary intellectual merit of the research is the improvement of the CRDS method for measurements of 17Oexcess of discrete samples of water, to obtain precision and accuracy competitive with conventional methods using mass spectrometry. This will be achieved by quantification of the effects of water vapor concentration variability and instrument memory, precise calibration of the instrument against standard waters, and improvements to the spectroscopic analyses. The CRDS system will also be coupled to continuous-flow systems for ice core analysis, in collaboration with the University of Colorado, Boulder. The goal is to have an operational system available for ice core processing associated with the next major U.S.-led ice core project at South Pole, in 2015-2017. The broader impacts of the research include the ability to measure 17O-excess in ambient atmospheric water vapor, which can be used to improve understanding of convection, moisture transport, and condensation. The instrument development work proposed here is relevant to research supported by several NSF-GEO programs, including Hydrology, Climate and Large Scale Dynamics, Paleoclimate, Atmosphere Chemistry, and both the Arctic and Antarctic Programs. This proposal will support a postdoctoral researcher.", "east": 106.0, "geometry": "POINT(106 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.5, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -77.5, "title": "Development of a Laser Spectroscopy System for Analysis of 17Oexcess on Ice Cores", "uid": "p0000316", "west": 106.0}, {"awards": "1443260 Conway, Howard", "bounds_geometry": "POLYGON((159 -76.68,159.03 -76.68,159.06 -76.68,159.09 -76.68,159.12 -76.68,159.15 -76.68,159.18 -76.68,159.21 -76.68,159.24 -76.68,159.27 -76.68,159.3 -76.68,159.3 -76.697,159.3 -76.714,159.3 -76.731,159.3 -76.748,159.3 -76.765,159.3 -76.782,159.3 -76.799,159.3 -76.816,159.3 -76.833,159.3 -76.85,159.27 -76.85,159.24 -76.85,159.21 -76.85,159.18 -76.85,159.15 -76.85,159.12 -76.85,159.09 -76.85,159.06 -76.85,159.03 -76.85,159 -76.85,159 -76.833,159 -76.816,159 -76.799,159 -76.782,159 -76.765,159 -76.748,159 -76.731,159 -76.714,159 -76.697,159 -76.68))", "dataset_titles": "2015-2016 GPR Field Report for Allan Hills Shallow Ice Coring; Ground-based ice-penetrating radar profiles collected on the Allan Hills blue ice region", "datasets": [{"dataset_uid": "601005", "doi": "10.15784/601005", "keywords": "Allan Hills; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Navigation; Radar", "people": "Conway, Howard", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Ground-based ice-penetrating radar profiles collected on the Allan Hills blue ice region", "url": "https://www.usap-dc.org/view/dataset/601005"}, {"dataset_uid": "601668", "doi": "10.15784/601668", "keywords": "Allan Hills; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; GPR; Ice Core; Report", "people": "Brook, Edward; MacKay, Sean", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "2015-2016 GPR Field Report for Allan Hills Shallow Ice Coring", "url": "https://www.usap-dc.org/view/dataset/601668"}], "date_created": "Tue, 02 May 2017 00:00:00 GMT", "description": "Marine paleoclimate archives show that approximately one million years ago Earth\u0027s climate transitioned from 40,000-year glacial /interglacial cycles to 100,000-year cycles. This award will support a study designed to map the distribution of one million year-old ice in the Allan Hills Blue Ice Area, Antarctica using state-of-the-art ground penetrating radar. The Allen Hills was demonstrated to contain a continuous record of the past 400,000 years and is also the collection location of the oldest ice samples (990,000 years) yet recovered. The maps resulting from this study will be used to select an ice-core drilling site at which a million-plus year-old continuous record of climate could be recovered. Ice cores contain the only kind of record to directly capture atmospheric gases and aerosols, but no ice-core-based climate record yet extends continuously beyond the past 800,000 years. A million-plus year-old record will allow better understanding of the major mechanisms and driving forces of natural climate variability in a world with 100,000-year glacial/interglacial cycles. The project will support two early career scientists in collaboration with senior scientists, as well as a graduate student, and will conduct outreach to schools and the public.\r\nThe Allan Hills Blue Ice Area preserves a continuous climate record covering the last 400,000 years along an established glaciological flow line. Two kilometers to the east of this flow line, the oldest ice on Earth (~1 million years old) is found only 120 m below the surface. Meteorites collected in the area are reported to be as old as 1.8 million years, suggesting still older ice may be present. Combined, these data strongly suggest that the Allen Hills area could contain a continuous, well-resolved environmental record, spanning at least the last million years. As such, this area has been selected as an upcoming target for the new Intermediate Depth Ice Core Drill by the US Ice Core Working Group. This drill will recover a higher-quality core than previous dry drilling attempts. This project will conduct a comprehensive ground penetrating radar survey aimed at tracing the signature of the million-year-old ice layer throughout the region. The resulting map will be used to select a drill site from which an ice core containing the million-plus year-old continuous climate record will be collected. The proposed activities are a necessary precursor to the collection of the oldest known ice on Earth. Ice cores provide a robust reconstruction of past climate and extending this record beyond the 800,000 years currently available will open new opportunities to study the climate system. The data collected will also be used to investigate the bedrock and ice flow parameters favorable to the preservation of old ice, which may allow targeted investigation of other blue ice areas in Antarctica.", "east": 159.3, "geometry": "POINT(159.15 -76.765)", "instruments": null, "is_usap_dc": true, "keywords": "Allan Hills; FIELD SURVEYS; ICE SHEETS", "locations": "Allan Hills", "north": -76.68, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.85, "title": "Collaborative Research: Allan HILLs Englacial Site (AHILLES) Selection", "uid": "p0000385", "west": 159.0}, {"awards": "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": "601453", "doi": "10.15784/601453", "keywords": "Antarctica; Eocene; Marine Geoscience; ODP739; 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 739, Prydz Bay", "url": "https://www.usap-dc.org/view/dataset/601453"}, {"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"}, {"dataset_uid": "601455", "doi": "10.15784/601455", "keywords": "Antarctica; Eocene; Marine Geoscience; ODP1166; Particle Size; Prydz Bay; Sediment Core Data", "people": "Passchier, Sandra; Ciarletta, Daniel", "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": "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": "601454", "doi": "10.15784/601454", "keywords": "Antarctica; Eocene; Marine Geoscience; ODP742; 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 742, Prydz Bay", "url": "https://www.usap-dc.org/view/dataset/601454"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThis 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. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis 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": "0947821 Ashworth, Allan", "bounds_geometry": "POLYGON((-180 -85.095235,-145.3719418 -85.095235,-110.7438836 -85.095235,-76.1158254 -85.095235,-41.4877672 -85.095235,-6.859709 -85.095235,27.7683492 -85.095235,62.3964074 -85.095235,97.0244656 -85.095235,131.6525238 -85.095235,166.280582 -85.095235,166.280582 -85.0996451,166.280582 -85.1040552,166.280582 -85.1084653,166.280582 -85.1128754,166.280582 -85.1172855,166.280582 -85.1216956,166.280582 -85.1261057,166.280582 -85.1305158,166.280582 -85.1349259,166.280582 -85.139336,131.6525238 -85.139336,97.0244656 -85.139336,62.3964074 -85.139336,27.7683492 -85.139336,-6.859709 -85.139336,-41.4877672 -85.139336,-76.1158254 -85.139336,-110.7438836 -85.139336,-145.3719418 -85.139336,180 -85.139336,178.6280582 -85.139336,177.2561164 -85.139336,175.8841746 -85.139336,174.5122328 -85.139336,173.140291 -85.139336,171.7683492 -85.139336,170.3964074 -85.139336,169.0244656 -85.139336,167.6525238 -85.139336,166.280582 -85.139336,166.280582 -85.1349259,166.280582 -85.1305158,166.280582 -85.1261057,166.280582 -85.1216956,166.280582 -85.1172855,166.280582 -85.1128754,166.280582 -85.1084653,166.280582 -85.1040552,166.280582 -85.0996451,166.280582 -85.095235,167.6525238 -85.095235,169.0244656 -85.095235,170.3964074 -85.095235,171.7683492 -85.095235,173.140291 -85.095235,174.5122328 -85.095235,175.8841746 -85.095235,177.2561164 -85.095235,178.6280582 -85.095235,-180 -85.095235))", "dataset_titles": "Neogene Paleoecology of the Beardmore Glacier Region", "datasets": [{"dataset_uid": "600387", "doi": "10.15784/600387", "keywords": "Antarctica; Beardmore Glacier; Biota; Fossil; GPS; Oliver Bluffs; Paleoclimate; Sample/collection Description; Sample/Collection Description; Seeds; Solid Earth; Transantarctic Mountains", "people": "Ashworth, Allan", "repository": "USAP-DC", "science_program": null, "title": "Neogene Paleoecology of the Beardmore Glacier Region", "url": "https://www.usap-dc.org/view/dataset/600387"}], "date_created": "Thu, 12 Jan 2017 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThe primary goal of this project is to sample two beds in the Meyer Desert Formation, which are known to be especially fossiliferous containing plants, insects, other arthropods, freshwater mollusks, and fish. There is a possibility that the teeth and bones of a small marsupial could also be found. Previous studies have demonstrated that these horizons contain unique fossil assemblages that provide information used to reconstruct paleoenvironments and paleoclimate. The fossils represent organisms previously not found in Antarctica and consequently their study will lead to the development of new hypotheses concerning southern hemisphere biogeography. The new discoveries will also increase knowledge of paleoenvironments and paleoclimates as well as biogeographic relationships of the biota of the southern hemisphere. For some organisms, such as Nothofagus (Southern Beech) or the trechine groundbeetle, fossils would confirm that Antarctica was inhabited as part of Gondwana. For other fossils, such as the cyclorrhaphan fly or freshwater mollusks not expected to have inhabited Antarctica, the discoveries will require a reassessment of phylogenetic interpretations and a reinvestigation of the role of Antarctica in the evolutionary history of those organisms. The new fossil-based knowledge will require integration with interpretations from cladistics and molecular genetics to develop more comprehensive phylogenetic hypotheses for a range of organisms.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThe discovery of fossils in Antarctica and implications for climate change has proven to be popular with the media. This attention will help disseminate the results of this study. Before the field season, the PI will work with local media and with area schools to set up field interviews and web casts from Antarctica. The project will also involve the training of a graduate student in the field and in the follow up studies of the fossils in the laboratory.", "east": 166.280582, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -85.095235, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Ashworth, Allan", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.139336, "title": "Neogene Paleoecology of the Beardmore Glacier Region", "uid": "p0000424", "west": 166.280582}, {"awards": "1043167 White, James; 1043092 Steig, Eric", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "Resampling of Deep Polar Ice Cores using Information Theory; Seasonal temperatures in West Antarctica during the Holocene ; Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core; WAIS Divide Ice Core Discrete CH4 (80-3403m)", "datasets": [{"dataset_uid": "600169", "doi": "10.15784/600169", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; Snow Accumulation; WAIS Divide; WAIS Divide Ice Core", "people": "Jones, Tyler R.; Morris, Valerie; Vaughn, Bruce; White, James", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/600169"}, {"dataset_uid": "601741", "doi": "10.15784/601741", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; WAIS", "people": "Sowers, Todd A.; Brook, Edward", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Discrete CH4 (80-3403m)", "url": "https://www.usap-dc.org/view/dataset/601741"}, {"dataset_uid": "601365", "doi": "10.15784/601365", "keywords": "Antarctica; Delta 18O; Isotope; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "White, James; Jones, Tyler R.; Garland, Joshua; Vaughn, Bruce; Morris, Valerie", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Resampling of Deep Polar Ice Cores using Information Theory", "url": "https://www.usap-dc.org/view/dataset/601365"}, {"dataset_uid": "601603", "doi": "10.15784/601603", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Seasonality; Seasonal Temperatures; Temperature; Water Isotopes; West Antarctic Ice Sheet", "people": "Jones, Tyler R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal temperatures in West Antarctica during the Holocene ", "url": "https://www.usap-dc.org/view/dataset/601603"}, {"dataset_uid": "601274", "doi": "10.15784/601274", "keywords": "Antarctica; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Price, Michael; Garland, Joshua; Bradley, Elizabeth; Morris, Valerie; Jones, Tyler R.; White, James; Vaughn, Bruce", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/601274"}], "date_created": "Thu, 15 Sep 2016 00:00:00 GMT", "description": "Steig/1043092\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY", "locations": null, "north": -79.47, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "White, James; Vaughn, Bruce; Jones, Tyler R.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "uid": "p0000078", "west": -112.08}, {"awards": "1141973 Tedesco, Marco", "bounds_geometry": "POLYGON((-94.7374 -56.9464,-89.23679 -56.9464,-83.73618 -56.9464,-78.23557 -56.9464,-72.73496 -56.9464,-67.23435 -56.9464,-61.73374 -56.9464,-56.23313 -56.9464,-50.73252 -56.9464,-45.23191 -56.9464,-39.7313 -56.9464,-39.7313 -59.19838,-39.7313 -61.45036,-39.7313 -63.70234,-39.7313 -65.95432,-39.7313 -68.2063,-39.7313 -70.45828,-39.7313 -72.71026,-39.7313 -74.96224,-39.7313 -77.21422,-39.7313 -79.4662,-45.23191 -79.4662,-50.73252 -79.4662,-56.23313 -79.4662,-61.73374 -79.4662,-67.23435 -79.4662,-72.73496 -79.4662,-78.23557 -79.4662,-83.73618 -79.4662,-89.23679 -79.4662,-94.7374 -79.4662,-94.7374 -77.21422,-94.7374 -74.96224,-94.7374 -72.71026,-94.7374 -70.45828,-94.7374 -68.2063,-94.7374 -65.95432,-94.7374 -63.70234,-94.7374 -61.45036,-94.7374 -59.19838,-94.7374 -56.9464))", "dataset_titles": "Enhanced Spatial Resolution Surface Melting over the Antarctic Peninsula (1958 - to date) from a Regional Climate Model Validated through Remote Sensing Observations", "datasets": [{"dataset_uid": "600160", "doi": "10.15784/600160", "keywords": "Antarctica; Atmosphere; Climate; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meteorology; Model", "people": "Tedesco, Marco", "repository": "USAP-DC", "science_program": null, "title": "Enhanced Spatial Resolution Surface Melting over the Antarctic Peninsula (1958 - to date) from a Regional Climate Model Validated through Remote Sensing Observations", "url": "https://www.usap-dc.org/view/dataset/600160"}], "date_created": "Fri, 10 Jun 2016 00:00:00 GMT", "description": "1141973/Tedesco\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to generate first-time validated enhanced spatial resolution (5-10 km) maps of surface melting over the Antarctic Peninsula for the period 1958 - to date from the outputs of a regional climate model and different downscaling techniques. These maps will be assessed and validated through new high spatial resolution (2.25 km) surface melting maps obtained from the QuikSCAT satellite for the period 1999 - 2009. The intellectual merit of this work is that it would be the first time that the outputs of a regional climate model would be used to study surface melting over Antarctica at such high spatial resolution and the first time that such results are validated by means of an observational tool that has such a large spatial coverage and high spatial resolution. The results generated in this study would also provide a first-time opportunity to study the melt distribution over the Peninsula and its correlation with climate drivers, such as the Southern Annual Mode (SAM) and the El Nino-Southern Oscillation (ENSO) at these unprecedented spatial scales. The enhanced resolution melting maps will also offer a unique opportunity to study melting trends and patterns over specific regions of the Peninsula, such as the Wilkins and the Larsen A and B ice shelves and evaluate whether the extreme melting observed during the recent collapses was unprecedented over the + 50 years. The broader impacts of the project are that it will integrate research and education by fully supporting one female undergrad student, a PhD student and partially supporting a PostDoc. The work will be done at a minority-serving institution and the PhD student who worked on the development of the high-resolution melting data set from QuikSCAT will become the PostDoc who will work on this project. Teaching and learning will be supported by incorporating research results into graduate and undergrad level courses and will be disseminated over the web and through appropriate channels. Results from this project will also benefit the society at large as they will improve our understanding of the links between atmospheric patterns and surface melting and they will contribute to improving estimates of sea level rise from the Antarctica continent.", "east": -39.7313, "geometry": "POINT(-67.23435 -68.2063)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -56.9464, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Tedesco, Marco", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.4662, "title": "Enhanced Spatial Resolution Surface Melting over the Antarctic Peninsula (1958 - to date) from a Regional Climate Model Validated through Remote Sensing Observations", "uid": "p0000313", "west": -94.7374}, {"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": "1142052 MacPhee, Ross", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP1602", "datasets": [{"dataset_uid": "002666", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1602", "url": "https://www.rvdata.us/search/cruise/NBP1602"}], "date_created": "Tue, 26 Apr 2016 00:00:00 GMT", "description": "The role that Antarctica has played in vertebrate evolution and paleobiogeography during the Late Cretaceous and early Paleogene is largely unknown. Evidence indicates that Antarctica was home to a diverse flora during the Late Cretaceous and Paleogene, yet the vertebrates that must have existed on the continent remain virtually unknown. To fill this gap, the PIs have formed the Antarctic Vertebrate Paleontology Initiative (AVPI), whose goal is to search for and collect Late Cretaceous-Paleogene vertebrate fossils in Antarctica at localities that have never been properly surveyed, as well as in areas of proven potential. Two field seasons are proposed for the James Ross Island Group on the northeastern margin of the Antarctic Peninsula. Expected finds include chondrichthyan and osteichthyan fishes, marine reptiles, ornithischian and non-avian theropod dinosaurs, ornithurine birds, and therian and non-therian mammals. Hypotheses to be tested include: 1) multiple extant bird and/or therian mammal lineages originated during the Cretaceous and survived the K-Pg boundary extinction event; 2) the ?Scotia Portal? permitted the dispersal of continental vertebrates between Antarctica and South America prior to the latest Cretaceous and through to the late Paleocene or early Eocene; 3) Late Cretaceous non-avian dinosaurs from Antarctica are closely related to coeval taxa from other Gondwanan landmasses; 4) terminal Cretaceous marine reptile faunas from southern Gondwana differed from contemporaneous but more northerly assemblages; and 5) the collapse of Antarctic ichthyofaunal diversity during the K-Pg transition was triggered by a catastrophic extinction.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThe PIs will communicate discoveries to audiences through a variety of channels, such as the Dinosaurs in Their Time exhibition at Carnegie Museum of Natural History and the outreach programs of the Environmental Science Institute of the University of Texas at Austin. In addition, Carnegie Museum will launch a student-oriented programming initiative using AVPI research as a primary focus. This array of activities will help some 2,000 Pittsburgh-area undergraduates to explore the relevance of deep-time discoveries to critical modern issues. The AVPI will provide research opportunities for eight undergraduate and three graduate students, several of whom will receive field training in Antarctica. Fossils will be accessioned into the Carnegie Museum collection, and made accessible virtually through the NSF-funded Digital Morphology library at University of Texas.", "east": null, "geometry": null, "instruments": "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", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Lamanna, Matthew", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Late Cretaceous-Paleogene Vertebrates from Antarctica: Implications for Paleobiogeography, Paleoenvironment, and Extinction in Polar Gondwana", "uid": "p0000854", "west": null}, {"awards": "1043649 Hock, Regine", "bounds_geometry": null, "dataset_titles": "King George and Livingston Islands: Velocities and Digital Elevation Model", "datasets": [{"dataset_uid": "609667", "doi": "10.7265/N5R49NR1", "keywords": "Antarctica; Antarctic Peninsula; Digital Elevation Model; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness; Ice Velocity", "people": "Osmanoglu, Batuhan; Hock, Regine", "repository": "USAP-DC", "science_program": null, "title": "King George and Livingston Islands: Velocities and Digital Elevation Model", "url": "https://www.usap-dc.org/view/dataset/609667"}], "date_created": "Wed, 17 Feb 2016 00:00:00 GMT", "description": "1043649/Braun\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to determine the current mass balance of selected glaciers of the Western Antarctic Peninsula (WAP) and adjacent islands, including King George Island and Livingston Island. A major goal is to discriminate the climatic and dynamic components of the current mass budget. The dynamic component will be assessed using a flux gate approach. Glacier velocity fields will be derived by offset tracking on repeat SAR satellite imagery, and ice thicknesses across grounding lines or near terminus will be approximated from a new methods based on mass continuity. The surface mass balance will be computed from a spatially distributed temperature-index mass-balance model forced by temperature and precipitation data from regional climate models. Our results will provide improved mass budget estimates of Western Antarctic Peninsula glaciers and a more thorough understanding of the ratio between the climatic and dynamic components. The techniques to be developed will be applicable to other glaciers in the region allowing regional scale mass budgets to be derived. The broader impacts of this work are that glacier wastage is currently the most important contributor to global sea level rise and the Antarctic Peninsula has been identified as one of the largest single contributors. Future sea-level rise has major societal, economic and ecological implications. The activity will foster new partnerships through collaboration with European and South American colleagues. The project will form the base of of a postdoctoral research fellowship. It will also provide training of undergraduate and graduate students through inclusion of data and results in course curriculums.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e PALSAR", "is_usap_dc": true, "keywords": "ALOS; Digital Elevation Model", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology", "paleo_time": null, "persons": "Hock, Regine; Osmanoglu, Batuhan", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e ADVANCED LAND OBSERVING SATELLITE (ALOS) \u003e ALOS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Contribution of Western Antarctic Peninsula glaciers to sea level rise: Separation of the dynamic and climatic components", "uid": "p0000054", "west": null}, {"awards": "1043780 Aydin, Murat", "bounds_geometry": null, "dataset_titles": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core; Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "datasets": [{"dataset_uid": "609659", "doi": "10.7265/N5CV4FPK", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "url": "https://www.usap-dc.org/view/dataset/609659"}, {"dataset_uid": "601361", "doi": "10.15784/601361", "keywords": "Antarctica; Carbonyl Sulfide; Trace Gases", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/601361"}], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "Aydin/1043780\u003cbr/\u003eThis award supports the analysis of the trace gas carbonyl sulfide (COS) in a deep ice core from West Antarctic Ice Sheet Divide (WAIS-D), Antarctica. COS is the most abundant sulfur gas in the troposphere and a precursor of stratospheric sulfate. It has a large terrestrial COS sink that is tightly coupled to the photosynthetic uptake of atmospheric carbon dioxide (CO2). The primary goal of this project is to develop high a resolution Holocene record of COS from the WAIS-D 06A ice core. The main objectives are 1) to assess the natural variability of COS and the extent to which its atmospheric variability was influenced by climate variability, and 2) to examine the relationship between changes in atmospheric COS and CO2. This project also includes low-resolution sampling and analysis of COS from 10,000-30,000 yrs BP, covering the transition from the Last Glacial Maximum into the early Holocene. The goal of this work is to assess the stability of COS in ice core air over long time scales and to establish the COS levels during the last glacial maximum and the magnitude of the change between glacial and interglacial conditions. The results of this work will be disseminated via peer-review publications and will contribute to environmental assessments such as the WMO Stratospheric Ozone Assessment and IPCC Climate Assessment. This project will support a PhD student and undergraduate researcher in the Department of Earth System Science at the University of California, Irvine, and will create summer research opportunities for undergraduates from non-research active Universities.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ethane; LABORATORY; N-Butane; Carbonyl Sulfide; Propane; Methyl Bromide; Methyl Chloride; Carbon Disulfide", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat; Saltzman, Eric", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Carbonyl Sulfide Measurements in the Deep West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000055", "west": null}, {"awards": "1142156 Marschall, Horst", "bounds_geometry": "POLYGON((-6.44 -71.93,-5.378 -71.93,-4.316 -71.93,-3.254 -71.93,-2.192 -71.93,-1.13 -71.93,-0.068 -71.93,0.994 -71.93,2.056 -71.93,3.118 -71.93,4.18 -71.93,4.18 -71.998,4.18 -72.066,4.18 -72.134,4.18 -72.202,4.18 -72.27,4.18 -72.338,4.18 -72.406,4.18 -72.474,4.18 -72.542,4.18 -72.61,3.118 -72.61,2.056 -72.61,0.994 -72.61,-0.068 -72.61,-1.13 -72.61,-2.192 -72.61,-3.254 -72.61,-4.316 -72.61,-5.378 -72.61,-6.44 -72.61,-6.44 -72.542,-6.44 -72.474,-6.44 -72.406,-6.44 -72.338,-6.44 -72.27,-6.44 -72.202,-6.44 -72.134,-6.44 -72.066,-6.44 -71.998,-6.44 -71.93))", "dataset_titles": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica", "datasets": [{"dataset_uid": "600135", "doi": "10.15784/600135", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Dronning Maud Land; Geochemistry; Geochronology; Solid Earth", "people": "Marschall, Horst", "repository": "USAP-DC", "science_program": null, "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/600135"}], "date_created": "Fri, 23 Oct 2015 00:00:00 GMT", "description": "Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth?s crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica.\u003cbr/\u003e\u003cbr/\u003eDronning Maud Land (DML) occupied a central location during the formation of supercontinents ? large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth?s history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007?2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML.", "east": 4.18, "geometry": "POINT(-1.13 -72.27)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -71.93, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Marschall, Horst", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.61, "title": "Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica", "uid": "p0000448", "west": -6.44}, {"awards": "0632282 Jacobs, Stanley", "bounds_geometry": "POLYGON((-129.6 -54.2,-124.44 -54.2,-119.28 -54.2,-114.12 -54.2,-108.96 -54.2,-103.8 -54.2,-98.64 -54.2,-93.48 -54.2,-88.32 -54.2,-83.16 -54.2,-78 -54.2,-78 -56.29,-78 -58.38,-78 -60.47,-78 -62.56,-78 -64.65,-78 -66.74,-78 -68.83,-78 -70.92,-78 -73.01,-78 -75.1,-83.16 -75.1,-88.32 -75.1,-93.48 -75.1,-98.64 -75.1,-103.8 -75.1,-108.96 -75.1,-114.12 -75.1,-119.28 -75.1,-124.44 -75.1,-129.6 -75.1,-129.6 -73.01,-129.6 -70.92,-129.6 -68.83,-129.6 -66.74,-129.6 -64.65,-129.6 -62.56,-129.6 -60.47,-129.6 -58.38,-129.6 -56.29,-129.6 -54.2))", "dataset_titles": "Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901; NBP07-09 cruise data; NBP07-09 processed CTD data; NBP09-01 cruise data; NBP09-01 processed CTD data; Processed Temperature, Salinity, and Current Measurement Data from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "datasets": [{"dataset_uid": "000130", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP09-01 processed CTD data", "url": "http://accession.nodc.noaa.gov/0071179"}, {"dataset_uid": "000127", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP07-09 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0709"}, {"dataset_uid": "000128", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP07-09 processed CTD data", "url": "http://accession.nodc.noaa.gov/0120761"}, {"dataset_uid": "000129", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP09-01 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0901"}, {"dataset_uid": "601350", "doi": null, "keywords": "Amundsen Sea; Antarctic; Antarctica; CTD; CTD Data; Current Measurements; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; Pine Island Glacier; R/v Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Jacobs, Stanley; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed Temperature, Salinity, and Current Measurement Data from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601350"}, {"dataset_uid": "601349", "doi": null, "keywords": "Amundsen Sea; Antarctica; Current Measurements; LADCP; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; R/v Nathaniel B. Palmer; Southern Ocean", "people": "Thurnherr, Andreas", "repository": "USAP-DC", "science_program": null, "title": "Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601349"}], "date_created": "Fri, 25 Sep 2015 00:00:00 GMT", "description": "The Office of Polar Programs, Antarctic Science Division, Ocean \u0026 Climate Systems Program has made this award to support a multidisciplinary effort to study the upwelling of relatively warm deep water onto the Amundsen Sea continental shelf and how it relates to atmospheric forcing and bottom bathymetry and how the warm waters interact with both glacial and sea ice. This study constitutes a contribution of a coordinated research effort in the region known as the Amundsen Sea Embayment Project or ASEP. Previous work by the PI and others has shown that the West Antarctic Ice Sheet has been found to be melting faster, perhaps by orders of magnitude, than ice sheets elsewhere around Antarctica, excluding those on the Peninsula. Submarine channels that incise the continental shelf are thought to provide fairly direct access of relatively warm circum polar deep water to the cavity under the floating extension of the ice shelf. Interactions with sea ice en route can modify the upwelled waters. The proposed investigations build on previous efforts by the PI and colleagues to use hydrographic measurements to put quantitative bounds on the rate of glacial ice melt by relatively warm seawater. \u003cbr/\u003eThe region can be quite difficult to access due to sea ice conditions and previous hydrographic measurements have been restricted to the austral summer time frame. In this project it was proposed to obtain the first austral spring hydrographic data via CTD casts and XBT drops (September-October 2007) as part of a separately funded cruise (PI Steve Ackley) the primary focus of which is sea-ice conditions to be studied while the RV Nathanial B Palmer (RV NBP) drifts in the ice pack. This includes opportunistic sampling for pCO2 and TCO2. A dedicated cruise in austral summer 2009 will follow this opportunity. The principal objectives of the dedicated field program are to deploy a set of moorings with which to characterize temporal variability in warm water intrusions onto the shelf and to conduct repeat hydrographic surveying and swath mapping in targeted areas, ice conditions permitting. Automatic weather stations are to be deployed in concert with the program, sea-ice observations will be undertaken from the vessel and the marine cavity beneath the Pine Island may be explored pending availability of the British autonomous underwater vehicle Autosub 3. These combined ocean-sea ice-atmosphere observations are aimed at a range of model validations. A well-defined plan for making data available as well as archiving in a timely fashion should facilitate a variety of modeling efforts and so extend the value of the spatially limited observations. \u003cbr/\u003eBroader impacts: This project is relevant to an International Polar Year research emphasis on ice sheet dynamics focusing in particular on the seaward ocean-ice sheet interactions. Such interactions must be clarified for understanding the potential for sea level rise by melt of the West Antarctic ice Sheet. The project entails substantive international partnerships (British Antarctic Survey and Alfred Wegner Institute) and complements other Amundsen Sea Embayment Project proposals covering other elements of ice sheet dynamics. The proposal includes partial support for 2 graduate students and 2 post docs. Participants from the Antarctic Artists and Writers program are to take part in the cruise and so aid in outreach. In addition, the project is to be represented in the Lamont-Doherty annual open house.", "east": -78.0, "geometry": "POINT(-103.8 -64.65)", "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 PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; 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": true, "keywords": "Not provided; R/V NBP", "locations": null, "north": -54.2, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley; Hellmer, Hartmut; Jenkins, Adrian", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "NCEI", "repositories": "NCEI; R2R; USAP-DC", "science_programs": null, "south": -75.1, "title": "IPY/ASEP - Collaborative International Research: Amundsen Sea Influence on West Antarctic Ice Sheet Stability and Sea Level Rise.", "uid": "p0000332", "west": -129.6}, {"awards": "1043421 Severinghaus, Jeffrey; 1043522 Brook, Edward", "bounds_geometry": "POINT(-112.09 -79.47)", "dataset_titles": "WAIS Divide Replicate Core Methane Isotopic Data Set", "datasets": [{"dataset_uid": "601059", "doi": "10.15784/601059", "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": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Replicate Core Methane Isotopic Data Set", "url": "https://www.usap-dc.org/view/dataset/601059"}], "date_created": "Mon, 13 Jul 2015 00:00:00 GMT", "description": "1043421/Severinghaus\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to obtain samples of ice in selected intervals for replication and verification of the validity and spatial representativeness of key results in the WAIS Divide ice core, and to obtain additional ice samples in areas of intense scientific interest where demand is high. The US Ice Core Working Group recommended in 2003 that NSF pursue the means to take replicate samples, termed \"replicate coring\". This recommendation was part of an agreement to reduce the diameter of the (then) new drilling system (the DISC drill) core to 12.2 cm to lighten logistics burdens, and the science community accepted the reduction in ice sample with the understanding that replicate coring would be able to provide extra sample volume in key intervals. The WAIS Divide effort would particularly benefit from replicate coring, because of the unique quality of the expected gas record and the large samples needed for gases and gas isotopes; thus this proposal to employ replicate coring at WAIS Divide. In addition, scientific demand for ice samples has been, and will continue to be, very unevenly distributed, with the ice core archive being completely depleted in depth intervals of high scientific interest (abrupt climate changes, volcanic sulfate horizons, meteor impact horizons, for example). The broader impacts of the proposed research may include identification of leads and lags between Greenland, tropical, and Antarctic climate change, enabling critical tests of hypotheses for the mechanism of abrupt climate change. Improved understanding of volcanic impacts on atmospheric chemistry and climate may also emerge. This understanding may ultimately help improve climate models and prediction of the Earth System feedback response to ongoing human perturbation in coming centuries. Outreach and public education about climate change are integral components of the PIs\u0027 activities and the proposed work will enhance these efforts. Broader impacts also include education and training of 2 postdoctoral scholars and 1 graduate student, and invaluable field experience for the graduate and undergraduate students who will likely make up the core processing team at WAIS Divide.", "east": -112.09, "geometry": "POINT(-112.09 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": false, "keywords": "Ice Core Gas Records; Firn Air Isotopes; LABORATORY; FIELD SURVEYS; Mass Spectrometry; Not provided; FIELD INVESTIGATION; Ice Core; WAIS Divide", "locations": "WAIS Divide", "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Brook, Edward J.", "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": -79.47, "title": "Collaborative Research: Replicate Coring at WAIS Divide to Obtain Additional Samples at Events of High Scientific Interest", "uid": "p0000751", "west": -112.09}, {"awards": "1141890 Huber, Bruce", "bounds_geometry": "POLYGON((-62.176502 -57.913998,-61.4764715 -57.913998,-60.776441 -57.913998,-60.0764105 -57.913998,-59.37638 -57.913998,-58.6763495 -57.913998,-57.976319 -57.913998,-57.2762885 -57.913998,-56.576258 -57.913998,-55.8762275 -57.913998,-55.176197 -57.913998,-55.176197 -58.6469082,-55.176197 -59.3798184,-55.176197 -60.1127286,-55.176197 -60.8456388,-55.176197 -61.578549,-55.176197 -62.3114592,-55.176197 -63.0443694,-55.176197 -63.7772796,-55.176197 -64.5101898,-55.176197 -65.2431,-55.8762275 -65.2431,-56.576258 -65.2431,-57.2762885 -65.2431,-57.976319 -65.2431,-58.6763495 -65.2431,-59.37638 -65.2431,-60.0764105 -65.2431,-60.776441 -65.2431,-61.4764715 -65.2431,-62.176502 -65.2431,-62.176502 -64.5101898,-62.176502 -63.7772796,-62.176502 -63.0443694,-62.176502 -62.3114592,-62.176502 -61.578549,-62.176502 -60.8456388,-62.176502 -60.1127286,-62.176502 -59.3798184,-62.176502 -58.6469082,-62.176502 -57.913998))", "dataset_titles": "Expedition Data of NBP1203; Processed CTD Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203; Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203", "datasets": [{"dataset_uid": "601347", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Current Measurements; LADCP; LARISSA; Larsen Ice Shelf; NBP1203; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601347"}, {"dataset_uid": "601348", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; CTD; CTD Data; LARISSA; Larsen Ice Shelf; NBP1203; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Temperature", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed CTD Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601348"}, {"dataset_uid": "001438", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP1203", "url": "https://www.rvdata.us/search/cruise/NBP1203"}], "date_created": "Wed, 17 Jun 2015 00:00:00 GMT", "description": "Time series data, from ocean moorings, on key aspects of evolving ocean properties are of considerable importance in assessing the condition of the ocean system. They are needed, for example, their understand how the oceans are warming, and how they continue to uptake greenhouse gases such as CO2. \u003cbr/\u003e\u003cbr/\u003eThe Cape Adare Long Term Mooring (CALM) program goal was to observe the bottom water export from the Ross Sea to the deep ocean. To accomplish this two instrumented moorings were set on the continental slope off Cape Adare (western Ross Sea, Antarctica), positioned to capture the export of Antarctic Bottom Water (AABW), some of the coldest and densest water found in the global ocean. Data records for the moorings spans over some four years in this very remote part of the ocean. The CALM analysis will address some specific objectives:\u003cbr/\u003e? Characterize the temperature, salinity and current variability associated with the Ross Sea AABW export.\u003cbr/\u003e? Examine the linkages between observed variability to regional tides, atmosphere and sea ice forcing.\u003cbr/\u003e? Relate the Ross Sea AABW export fluctuations to the larger scale climate system dynamics, such as ENSO and SAM, and to AABW formation along other margins of Antarctica, e.g. the Weddell Sea", "east": -55.176197, "geometry": "POINT(-58.6763495 -61.578549)", "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 RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e XBT; 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 ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -57.913998, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Huber, Bruce; Vernet, Maria", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -65.2431, "title": "Cape Adare Long Term Moorings (CALM): Analysis Phase", "uid": "p0000495", "west": -62.176502}, {"awards": "0229314 Stone, John", "bounds_geometry": null, "dataset_titles": "Reedy Glacier Exposure Ages, Antarctica", "datasets": [{"dataset_uid": "609601", "doi": "10.7265/N5MG7MF1", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Cosmogenic; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Reedy Glacier; Sample/collection Description; Sample/Collection Description", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Reedy Glacier Exposure Ages, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609601"}], "date_created": "Mon, 30 Mar 2015 00:00:00 GMT", "description": "The stability of the marine West Antarctic Ice Sheet (WAIS) remains an important, unresolved problem for predicting future sea level change. Recent studies indicate that the mass balance of the ice sheet today may be negative or positive. The apparent differences may stem in part from short-term fluctuations in flow. By comparison, geologic observations provide evidence of behavior over much longer time scales. Recent work involving glacial-geologic mapping, dating and ice-penetrating radar surveys suggests that deglaciation of both the Ross Sea Embayment and coastal Marie Byrd Land continued into the late Holocene, and leaves open the possibility of ongoing deglaciation and grounding-line retreat. However, previous work in the Ross Sea Embayment was based on data from just three locations that are all far to the north of the present grounding line. Additional data from farther south in the Ross Sea Embayment are needed to investigate whether recession has ended, or if the rate and pattern of deglaciation inferred from our previous study still apply to the present grounding line. This award provides support to reconstruct the evolution of Reedy Glacier, in the southern Transantarctic Mountains, since the Last Glacial Maximum (LGM). Because Reedy Glacier emerges from the mountains above the grounding line, its surface slope and elevation should record changes in thickness of grounded ice in the Ross Sea up to the present day. The deglaciation chronology of Reedy Glacier therefore can indicate whether Holocene retreat of the WAIS ended thousands of years ago, or is still continuing at present. This integrated glaciologic, glacial-geologic, and cosmogenic-isotope exposure- dating project will reconstruct past levels of Reedy Glacier. Over two field seasons, moraines will be mapped, dated and correlated at sites along the length of the glacier. Radar and GPS measurements will be made to supplement existing ice thickness and velocity data, which are needed as input for a model of glacier dynamics. The model will be used to relate geologic measurements to the grounding-line position downstream. Ultimately, the mapping, dating and ice-modeling components of the study will be integrated into a reconstruction that defines changes in ice thickness in the southern Ross Sea since the LGM, and relates these changes to the history of grounding-line retreat. This work directly addresses key goals of the West Antarctic Ice Sheet Initiative, which are to understand the dynamics, recent history and possible future behavior of the West Antarctic Ice Sheet.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "Surface Exposure Dates; FIELD SURVEYS; Aluminum-26; Erosion; Rock Samples; Beryllium-10; Exposure Age", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Late Quaternary History of Reedy Glacier", "uid": "p0000029", "west": null}, {"awards": "1141275 Warren, Stephen", "bounds_geometry": null, "dataset_titles": "Antarctic field campaign data page", "datasets": [{"dataset_uid": "001399", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Antarctic field campaign data page", "url": "http://www.atmos.washington.edu/articles/EastAntarctica_SeaIceAlbedos_SnowImpurities/"}], "date_created": "Fri, 30 Jan 2015 00:00:00 GMT", "description": "The albedo, or reflection coefficient, is a measure of the diffuse reflectivity of an irradiated surface. With the sunlit atmosphere as a light source, and sea-ice as a diffuse reflecting surface, the albedo would be the fraction of incident light that is returned to the atmosphere. A perfect (white) reflecting surface would have an albedo of 1; a perfect (black) absorbing surface would have an albedo of 0. The albedo of sea-ice is needed to assess the solar energy budget of the marginal ice zone, to compute the partial solar bands in radiation budgets in general circulation and earth system models, and is also needed to interpret remote sensing imagery data products.\u003cbr/\u003eApplications requiring albedos further into the near IR, out to 2500nm, are assumed or approximated. Modern spectral radiometers, such as will be used in this campaign on a Southern Ocean voyage from Hobart to Antarctica, can extend these measurements of albedo from 350 to 2500nm, allowing earlier estimates to be verified, or corrected. \u003cbr/\u003e\u003cbr/\u003eSurfaces to be encountered on this research cruise are expected to include open water, grease ice, nila ice, pancake ice, young grey ice, young grey-white ice, along with first year ice. The presence of variable amounts of snow on these surfaces is also of interest. Light absorbing impurities in the snow and ice, including black carbon and organic matter (brown carbon) are different from those found in Arctic Sea ice, the Antarctic being so remote from combustion sources. This may allow better understanding of the seasonal cycles, energy budgets and their recent trends in spatial extent and thickness. The project will also broaden the educational experiences of both US and Australian students participating in the measurement campaign", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Radiometers; Radiation Budgets; Sea Ice; Energy Budgets; Impurities; COMPUTERS; Albedo; Spectral; LABORATORY; Antarctica; Snow Temperature; Reflecting Surface; Snow Density; R/V AA", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Warren, Stephen; Zatko, Maria", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V AA", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": null, "title": "Spectral and Broadband Albedo of Antarctic Sea-ice Types", "uid": "p0000375", "west": null}, {"awards": "0732906 Nowicki, Sophie; 0732804 McPhee, Miles; 0732869 Holland, David; 0732730 Truffer, Martin", "bounds_geometry": "POINT(-100.728 -75.0427)", "dataset_titles": "Automatic Weather Station Pine Island Glacier; Borehole Temperatures at Pine Island Glacier, Antarctica; Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "datasets": [{"dataset_uid": "609627", "doi": "10.7265/N5T151MV", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Pine Island Glacier; Temperature", "people": "Truffer, Martin; Stanton, Timothy", "repository": "USAP-DC", "science_program": null, "title": "Borehole Temperatures at Pine Island Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609627"}, {"dataset_uid": "601216", "doi": "10.15784/601216", "keywords": "Antarctica; Atmosphere; Automated Weather Station; Flux; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meteorology; Pine Island Glacier; Weather Station Data", "people": "Mojica Moncada, Jhon F.; Holland, David", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Automatic Weather Station Pine Island Glacier", "url": "https://www.usap-dc.org/view/dataset/601216"}, {"dataset_uid": "600072", "doi": "10.15784/600072", "keywords": "Antarctica; Atmosphere; Mcmurdo; Meteorology; Oceans; Ross Island; Southern Ocean", "people": "McPhee, Miles G.", "repository": "USAP-DC", "science_program": null, "title": "Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "url": "https://www.usap-dc.org/view/dataset/600072"}], "date_created": "Tue, 30 Dec 2014 00:00:00 GMT", "description": "Collaborative With: McPhee 0732804, Holland 0732869, Truffer 0732730, Stanton 0732926, Anandakrishnan 0732844 \u003cbr/\u003eTitle: Collaborative Research: IPY: Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica\u003cbr/\u003e\u003cbr/\u003eThe Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the \"Multidisciplinary Study of the Amundsen Sea Embayment\" proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded \"Polar Palooza\" education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project.", "east": -100.728, "geometry": "POINT(-100.728 -75.0427)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": true, "keywords": "West Antarctica; Seismic; LABORATORY; Amundsen Sea; Ocean-Ice Interaction; Remote Sensing; COMPUTERS; FIELD SURVEYS; LANDSAT-8; FIELD INVESTIGATION; Ocean Profiling; AUVS; Sea Level Rise; Stability; Not provided; Deformation; SATELLITES; Ice Movement; GROUND-BASED OBSERVATIONS; Ice Temperature; International Polar Year; Borehole", "locations": "West Antarctica; Amundsen Sea", "north": -75.0427, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Truffer, Martin; Stanton, Timothy; Bindschadler, Robert; Behar, Alberto; Nowicki, Sophie; Anandakrishnan, Sridhar; Holland, David; McPhee, Miles G.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-8; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES; WATER-BASED PLATFORMS \u003e UNCREWED VEHICLES \u003e SUBSURFACE \u003e AUVS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0427, "title": "Collaborative Research; IPY: Ocean-Ice Interaction in the Amundsen Sea sector of West Antarctica", "uid": "p0000043", "west": -100.728}, {"awards": "1043167 White, James; 1043092 Steig, Eric", "bounds_geometry": null, "dataset_titles": "17O excess from WAIS Divide, 0 to 25 ka BP; WAIS Divide Ice Core Discrete CH4 (80-3403m); WAIS Divide WDC06A Oxygen Isotope Record", "datasets": [{"dataset_uid": "609629", "doi": "10.7265/N5GT5K41", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide WDC06A Oxygen Isotope Record", "url": "https://www.usap-dc.org/view/dataset/609629"}, {"dataset_uid": "601413", "doi": "10.15784/601413", "keywords": "Antarctica; Ice Core; Oxygen Isotope; WAIS Divide", "people": "Schoenemann, Spruce; Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "17O excess from WAIS Divide, 0 to 25 ka BP", "url": "https://www.usap-dc.org/view/dataset/601413"}, {"dataset_uid": "601741", "doi": "10.15784/601741", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; WAIS", "people": "Sowers, Todd A.; Brook, Edward", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Discrete CH4 (80-3403m)", "url": "https://www.usap-dc.org/view/dataset/601741"}], "date_created": "Sat, 06 Dec 2014 00:00:00 GMT", "description": "This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e INFRARED LASER SPECTROSCOPY; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e INFRARED LASER SPECTROSCOPY", "is_usap_dc": true, "keywords": "AMD; ANALYTICAL LAB; USAP-DC; Amd/Us; LABORATORY; ICE CORE RECORDS; Antarctica; Wais Divide-project; FIELD SURVEYS; USA/NSF", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "uid": "p0000010", "west": null}, {"awards": "0538672 Palo, Scott", "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": null, "datasets": null, "date_created": "Thu, 31 Jul 2014 00:00:00 GMT", "description": "The mesosphere and lower thermosphere (MLT), at an altitude between 80 and 120 km above the Earth\u0027s surface, is a highly dynamic region that couples the lower terrestrial atmosphere (troposphere and stratosphere) with the upper atmosphere near-Earth space environment (thermosphere and ionosphere). Of particular importance in this region are both the upward propagating thermally forced atmospheric tides and global scale planetary waves. Both of these phenomena transport heat and momentum from the lower atmosphere into the upper atmosphere. Studies in recent years have indicated that the Arctic and Antarctic MLT possess a rich spectrum waves and may be more sensitive to global change than the lower atmosphere. The primary goal of this research is to observe, quantify, model, and further understand the spatial-temporal structure and variability of the MLT circulation above Antarctica and its commonalities with the Arctic. A secondary goal is to quantify and understand the deposition of mass into the upper atmosphere through the ablation of meteors and the resulting effect on local and regional aeronomic processes. This includes the effect of meteor flux, temperature and dynamics on the seasonal distribution of sodium over the South Pole. Meteor radar was installed at the South Pole Amundsen-Scott station and has been running continuously since January 2002. A new sodium nightglow imager will be installed at the South Pole to infer the sodium abundance in the MLT. Observations from this instrument will be combined with the South Pole Fabry-Perot interferometer temperature measurements and the meteor radar wind and meteor flux measurements to improve our understanding of the sodium chemistry and dynamics. These observations will be interpreted using sophisticated numerical models and interpreted in conjunction with Arctic measurements along with current linear and nonlinear atmospheric models to advance the current understanding of processes important to the MLT region. This research also contributes to the training and education of the graduate and undergraduate students, a postdoc and early career tenure track faculty.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": null, "paleo_time": null, "persons": "Palo, Scott; Avery, James; Avery, Susan", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Studies of the Antarctic Mesosphere and Lower Thermosphere", "uid": "p0000491", "west": -180.0}, {"awards": "0839122 Saltzman, Eric; 0839093 McConnell, Joseph; 0839075 Priscu, John", "bounds_geometry": "POINT(112.05 -79.28)", "dataset_titles": "Fluorescence spectroscopy data from the West Antarctic Ice Sheet (WAIS) Divide ice core, WDC06A; Holocene Black Carbon in Antarctica; Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core; Prokaryotic cell concentration record from the WAIS Divide ice core", "datasets": [{"dataset_uid": "601361", "doi": "10.15784/601361", "keywords": "Antarctica; Carbonyl Sulfide; Trace Gases", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/601361"}, {"dataset_uid": "601072", "doi": "10.15784/601072", "keywords": "Antarctica; Biota; Cell Counts; Glaciology; Microbiology; WAIS Divide; WAIS Divide Ice Core", "people": "Santibanez, Pamela; Priscu, John", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Prokaryotic cell concentration record from the WAIS Divide ice core", "url": "https://www.usap-dc.org/view/dataset/601072"}, {"dataset_uid": "601034", "doi": "10.15784/601034", "keywords": "Antarctica; Atmosphere; Black Carbon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph; Arienzo, Monica", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Holocene Black Carbon in Antarctica", "url": "https://www.usap-dc.org/view/dataset/601034"}, {"dataset_uid": "601006", "doi": "10.15784/601006", "keywords": "Antarctica; Fluorescence Spectroscopy; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Priscu, John; D\u0027Andrilli, Juliana", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Fluorescence spectroscopy data from the West Antarctic Ice Sheet (WAIS) Divide ice core, WDC06A", "url": "https://www.usap-dc.org/view/dataset/601006"}], "date_created": "Fri, 30 May 2014 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to use the WAIS Divide deep core to investigate the Last Deglaciation at sub-annual resolution through an integrated set of chemical and biological analyses. The intellectual merit of the project is that these analyses, combined with others, will take advantage of the high snow accumulation WAIS Divide site yielding the highest time resolution glacio-biogeochemical and gas record of any deep Antarctic ice core. With other high resolution Greenland cores (GISP2 and GRIP) and lower resolution Antarctic cores, the combined record will yield new insights into worldwide climate dynamics and abrupt change. The proposed chemical, biological, and elemental tracer measurements will also be used to address all of the WAIS Divide science themes. The broader impacts of the project include education and outreach activities such as numerous presentations to local K-12 students; opportunities for student and teacher involvement in the laboratory work; a teacher training program in Earth sciences in the heavily minority Santa Ana, Compton, and Costa Mesa, California school districts; and development of high school curricula. Extensive graduate and undergraduate student involvement also is planned and will include one post doctoral associate, one graduate student, and undergraduate hourly involvement at DRI; a graduate student and undergraduates at University of California, Irvine (UCI); and a post doctoral fellow at MSU. Student recruitment will be made from underrepresented groups building on a long track record of involvement and will include the NSF funded California Alliance for Minority Participation (CAMP) and the Montana American Indian Research Opportunities (AIRO).\u003cbr/\u003e\u003cbr/\u003eThis award does not involve field work in Antarctica.", "east": 112.05, "geometry": "POINT(112.05 -79.28)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e CARBON ANALYZERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e WAS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e ICE CORE MELTER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Bacteria Ice Core; LABORATORY; Ice Core; FIELD INVESTIGATION; West Antarctica; Not provided; Dissolved Organic Carbon", "locations": "West Antarctica", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Foreman, Christine; Skidmore, Mark; Saltzman, Eric; McConnell, Joseph; Priscu, John", "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": "WAIS Divide Ice Core", "south": -79.28, "title": "Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core", "uid": "p0000273", "west": 112.05}, {"awards": "1043690 Scherer, Reed", "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": "Southern Ocean Diatom Taphonomy and Paleoproductivity: A Laboratory Study of Silica Degradation and Export", "datasets": [{"dataset_uid": "600127", "doi": "10.15784/600127", "keywords": "Antarctica; Biota; Diatom; Marine Sediments; Oceans; Sediment Core; Southern Ocean", "people": "Haji-Sheikh, Michael; Scherer, Reed Paul", "repository": "USAP-DC", "science_program": null, "title": "Southern Ocean Diatom Taphonomy and Paleoproductivity: A Laboratory Study of Silica Degradation and Export", "url": "https://www.usap-dc.org/view/dataset/600127"}], "date_created": "Fri, 14 Feb 2014 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eDiatom abundance in sediment cores is typically used as a proxy for paleo primary productivity. This record is complicated by variable preservation, with most loss occurring in the water column via dissolution and zooplankton grazing. This study will investigate preservational biases via a series of controlled experiments to create proxies of original productivity based on morphological changes associated with diatom dissolution and fracture. The PIs will utilize fresh diatoms from culture. Specific objectives include: (1) Linking changes in diatom morphology to availability of dissolved silica and other physical and chemical parameters; (2) Documenting the dissolution process under controlled conditions; (3) Assessment of changes in morphology and diatom surface roughness with increased dissolution; (4) Documenting the physical effects of grazing and fecal pellet formation on diatom fragmentation and dissolution; and (5) Analyzing the impact of diatom dissolution on silica and carbon export. These objectives will be achieved by growing Southern Ocean diatom species in the laboratory under differing physical and chemical conditions; controlled serial dissolution experiments on cultured diatoms; analysis of the dissolution process by imaging frustules under scanning electron microscopy (SEM) and with micro-analysis of surface texture by atomic force microscopy (AFM); making the cultures available to krill and other live zooplankton crustaceans in order to analyze the specific effects of grazing and pelletization on diatom morphology; and comparing experimental results with natural plankton, sediment trap material, and selected Holocene, Pleistocene and Pliocene sediment core material. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis work will contribute to understanding of the use of diatom abundance as an indicator of paleoproductivity. The proposed experiments are multi-disciplinary in nature. Importantly, the project was designed, and the proposal largely written, by a Ph.D. candidate. The research proposed here will lead to peer-reviewed publications and provide a base for future studies over the course of an extremely promising scientific career. The project will also support an undergraduate research student at NIU. The PI is heavily involved in science outreach, including classroom visits, museum events and webinars related to evolution and climate change, and is active with NSF-funded outreach activities linked to the ANDRILL and WISSARD programs. He will continue these efforts with this project.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Haji-Sheikh, Michael; Scherer, Reed Paul", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Southern Ocean Diatom Taphonomy and Paleoproductivity: A Laboratory Study of Silica Degradation and Export", "uid": "p0000360", "west": -180.0}, {"awards": "0739779 Warren, Stephen; 1142963 Warren, Stephen", "bounds_geometry": "POLYGON((157 -76,158.1 -76,159.2 -76,160.3 -76,161.4 -76,162.5 -76,163.6 -76,164.7 -76,165.8 -76,166.9 -76,168 -76,168 -76.2,168 -76.4,168 -76.6,168 -76.8,168 -77,168 -77.2,168 -77.4,168 -77.6,168 -77.8,168 -78,166.9 -78,165.8 -78,164.7 -78,163.6 -78,162.5 -78,161.4 -78,160.3 -78,159.2 -78,158.1 -78,157 -78,157 -77.8,157 -77.6,157 -77.4,157 -77.2,157 -77,157 -76.8,157 -76.6,157 -76.4,157 -76.2,157 -76))", "dataset_titles": "Ice on the Oceans of Snowball Earth Project Data", "datasets": [{"dataset_uid": "000183", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Ice on the Oceans of Snowball Earth Project Data", "url": "https://digital.lib.washington.edu/researchworks/handle/1773/37320"}], "date_created": "Wed, 10 Jul 2013 00:00:00 GMT", "description": "The climatic changes of late Precambrian time, 600-800 million years ago, included episodes of extreme glaciation, during which ice may have covered nearly the entire ocean for several million years, according to the Snowball Earth hypothesis. These episodes would hold an important place in Earth?s evolutionary history; they could have encouraged biodiversity by trapping life forms in small isolated ice-free areas, or they could have caused massive extinctions that cleared the path for new life forms to fill empty niches. What caused the Earth to become iced over, and what later caused the ice to melt? Scientific investigation of these questions will result in greater understanding of the climatic changes that the Earth can experience, and will enable better predictions of future climate. This project involves Antarctic field observations as well as laboratory studies and computer modeling.\u003cbr/\u003e\u003cbr/\u003eThe aim of this project is not to prove or disprove the Snowball Earth hypothesis but rather to quantify processes that are important for simulating snowball events in climate models. The principal goal is to identify the types of ice that would have been present on the frozen ocean, and to determine how much sunlight they would reflect back to space. Reflection of sunlight by bright surfaces of snow and ice is what would maintain the cold climate at low latitudes. The melting of the ocean required buildup of greenhouse gases, but it was probably aided by deposition of desert dust and volcanic ash darkening the snow and ice. With so much ice on the Earth?s surface, even small differences in the amount of light that the ice absorbed or reflected could cause significant changes in climate. The properties of the ice would also determine where, and in what circumstances, photosynthetic life could have survived. Some kinds of ice that are rare on the modern Earth may have been pivotal in allowing the tropical ocean to freeze. The ocean surfaces would have included some ice types that now exist only in Antarctica: bare cold sea ice with precipitated salts, and \"blue ice\" areas of the Transantarctic Mountains that were exposed by sublimation and have not experienced melting. Field expeditions were mounted to examine these ice types, and the data analysis is underway. A third ice type, sea ice with a salt crust, is being studied in a freezer laboratory. Modeling will show how sunlight would interact with ice containing light-absorbing dust and volcanic ash. Aside from its reflection of sunlight, ice on the Snowball ocean would have been thick enough to flow under its own weight, invading all parts of the ocean. Yet evidence for the survival of photosynthetic life indicates that some regions of liquid water were maintained at the ocean surface. One possible refuge for photosynthetic organisms is a bay at the far end of a nearly enclosed tropical sea, formed by continental rifting and surrounded by desert, such as the modern Red Sea. A model of glacier flow is being developed to determine the dimensions of the channel, connecting the sea to the ocean, necessary to prevent invasion by the flowing ice yet maintain a water supply to replenish evaporation.", "east": 168.0, "geometry": "POINT(162.5 -77)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Warren, Stephen; Light, Bonnie; Campbell, Adam; Carns, Regina; Dadic, Ruzica; Mullen, Peter; Brandt, Richard; Waddington, Edwin D.", "platforms": "Not provided", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -78.0, "title": "Ocean Surfaces on Snowball Earth", "uid": "p0000402", "west": 157.0}, {"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. \u003cbr/\u003eThe 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": "0838973 Nyblade, Andrew; 0838934 Wiens, Douglas", "bounds_geometry": "POLYGON((40 -76,50 -76,60 -76,70 -76,80 -76,90 -76,100 -76,110 -76,120 -76,130 -76,140 -76,140 -76.8,140 -77.6,140 -78.4,140 -79.2,140 -80,140 -80.8,140 -81.6,140 -82.4,140 -83.2,140 -84,130 -84,120 -84,110 -84,100 -84,90 -84,80 -84,70 -84,60 -84,50 -84,40 -84,40 -83.2,40 -82.4,40 -81.6,40 -80.8,40 -80,40 -79.2,40 -78.4,40 -77.6,40 -76.8,40 -76))", "dataset_titles": "Seismological Record ID# ZM 2007-12; Seismological Record Network Code# ZM (full data link not provided)", "datasets": [{"dataset_uid": "000149", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismological Record ID# ZM 2007-12", "url": "http://www.iris.edu/"}, {"dataset_uid": "000152", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismological Record Network Code# ZM (full data link not provided)", "url": "http://www.iris.edu/"}], "date_created": "Mon, 21 Jan 2013 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The high elevations of East Antarctica are critical in localizing the initial Cenozoic glaciation and stabilizing it with respect to melting during warm interglacials. However, the geological history for this region and the geophysical mechanism for maintaining the highlands are poorly understood. In 2007-2009, an array of 24 broadband seismographs (named GAMSEIS) was installed across the Gamburtsev Mountains area of the East Antarctic Plateau as part of the Antarctica?s Gamburtsev Province (AGAP) International Polar Year project. The IPY AGAP/GAMSEIS program included plans by other international partners to install seismographs at locations along the flanks of the Gamburtsev Mountains and in other East Antarctic regions. The proposed project will continue operating six of the deployed AGAP/GAMSEIS stations for two more years together with two new broadband seismic stations added to broaden the geographic scope of the array. Most stations will be located at the existing U.S. Autonomous Geophysical Observatories and the USAP fuel cache locations in order to minimize logistical support. This array, combined with seismographs deployed by China and Japan (and possibly Australia, France, and Italy in near future) will provide a sparse but large-scale network of seismometers for the longer-term studies of the crustal and upper mantle structures underneath the East Antarctic Plateau. Continued reliance on students provides a broader impact to this proposed research and firmly grounds this effort in its educational mission.", "east": 140.0, "geometry": "POINT(90 -80)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wiens, Douglas; Nyblade, Andrew", "platforms": "Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -84.0, "title": "Collaborative Research: Polenet East: An International Seismological Network for East Antarctica", "uid": "p0000504", "west": 40.0}, {"awards": "0739444 Rice, James", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 16 Jan 2013 00:00:00 GMT", "description": "Rice 0739444\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study the mode of formation and causes of glacial earthquakes. The paradigm for glacial flow has been that glaciers flow in a viscous manner, with major changes in the force balance occurring on the decade timescale or longer. The recent discovery of a number of even shorter timescale events has challenged this paradigm. In 2003, it was discovered that Whillans Ice Stream in West Antarctica displays stick-slip behavior on the 10-30 minute timescale, with ice stream speed increasing by a factor of 30 from already high speeds. In the past year, the minimum timescale has been pushed shorter by recognition that a class of recently discovered 50-second-long, magnitude-5 earthquakes are closely associated with changes in the force balance near the calving fronts of large outlet glaciers in both Greenland and East Antarctica. With no adequate theory existing to explain these relatively large earthquakes associated with outlet glaciers, we have begun to investigate the physical mechanisms that must be involved in allowing such a response in a system traditionally not thought capable of generating large variations in forces over timescales less than 100 seconds. The intellectual merit of the work is that large-amplitude, short-timescale variability of glaciers is an important mode of glacier dynamics that has not yet been understood from a first-principles physics perspective. The proposed research addresses this gap in understanding, tying together knowledge from numerous disciplines including glaciology, seismology and fault rupture dynamics, laboratory rock physics, granular flow, fracture mechanics, and hydrogeology. The broader impacts of the work are that there is societal as well as general scientific interest in the stability of the major ice sheets. However, without an understanding of the physical processes governing short time scale variability, it is unlikely that we will be able accurately predict the future of these ice sheets and their impact on sea level changes. The project will also contribute to the development and education of young scientists.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Rapid Glacial Motions; Not provided; Hydrogeology; Fracture Mechanics; Glacier Dynamics; Glacial Earthquakes; Granular Flow; Glacial Underflooding; Glaciology; Ice Stream Margins; Outlet Glaciers", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Rice, James; Platt, John; Suckale, Jenny; Perol, Thibaut; Tsai, Victor", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Transient and Rapid Glacial Motions, including Glacial Earthquakes", "uid": "p0000709", "west": null}, {"awards": "0632031 Das, Sarah; 0631973 Joughin, Ian", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 20 Jun 2012 00:00:00 GMT", "description": "Joughin 0631973\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to gather data to better understand the mass balance of the West Antarctic Ice Sheet, in the Pine Island and Thwaites region, through the combination of radar altimetry and surface-based ice-core measurements of accumulation. The intellectual merit of the project is that the results of the field work will provide information on decadal-scale average accumulation extending back through the last century and will help constrain a modeling effort to determine how coastal changes propagate inland, to allow better prediction of future change. Comparison of the basin averaged accumulation with ice discharge determined using Interferometric Synthetic Aperture Radar (InSAR) velocity data will provide improved mass-balance estimates. Study of changes in flow speed will produce a record of mass balance over the last three decades. Analysis of the satellite altimeter record in conjunction with annual accumulation estimates also will provide estimates of changes and variability in mass balance. The broader impacts of the work are that it will make a significant contribution to future IPCC estimates of sea level, which are important for projection of the impacts of increased sea level on coastal communities. The research will contribute to the graduate education of students at the Universities of Washington and Kansas and will enrich K-12 education through the direct participation of the PIs in classroom activities. Informal science education includes 4-day glacier flow demonstrations at the Polar Science Weekend held annually at the Pacific Science Center in Seattle. The project also will communicate results through Center for the Remote Sensing of Ice Sheets (CReSIS) outreach effort. All field and remotely-sensed data sets will be archived and distributed by the National Snow and Ice Data Center. This project is relevant to IPY in that the West Antarctic Ice Sheet is losing mass, in large part because of rapid thinning of the Amundsen Coast glaciers so, it will directly address the NSF IPY emphasis on \"ice sheet history and dynamics.\" The project is also international in scope.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": false, "keywords": "Not provided; FIELD INVESTIGATION; Flow Speed; Antarctic; LABORATORY; Ice Sheet Accumulation Rate; Mass Balance; Accumulation; Insar; SATELLITES; FIELD SURVEYS; Ice Core; Radar Altimetry; Ice Velocity", "locations": "Antarctic", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Joughin, Ian; Medley, Brooke; Das, Sarah", "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; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repositories": null, "science_programs": null, "south": null, "title": "IPY: Collaborative Proposal: Constraining the Mass-Balance Deficit of the Amundsen Coast\u0027s Glaciers", "uid": "p0000542", "west": null}, {"awards": "0440819 Taylor, Kendrick", "bounds_geometry": "POINT(112.1 -79.46667)", "dataset_titles": null, "datasets": null, "date_created": "Tue, 19 Jun 2012 00:00:00 GMT", "description": "This award supports a project that is part of the West Antarctic Ice Sheet Divide (WAIS Divide) program; which is a multi-disciplinary multi-institutional program to investigate the causes of natural changes in climate, the influence of the West Antarctic ice sheet on sea level, and the biology of deep ice. The WAIS Divide core will be unique among Antarctic ice cores in that it will have discernable annual layers for the last 40,000 years. A critical element of the program is to determine the age of the ice so that the climate proxies measured on the core can be interpreted in terms of age, not just depth. This project will make electrical measurements that can identify the annual layers. This information will be combined with information from other investigators to develop an annually resolved timescale over the last 40,000 years. This timescale will be the foundation on which the recent climate records are interpreted. Electrical measurements will also be used to produce two-dimensional images of the ice core stratigraphy; allowing sections of the core with abnormal stratigraphy to be identified. The broader impacts of this project include exposing a diverse group of undergraduate and graduate students to ice core research and assisting the Smithsonian National Museum of Natural History in Washington, D.C to develop a paleoclimate/ice core display.", "east": 112.1, "geometry": "POINT(112.1 -79.46667)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": false, "keywords": "Annual Layers; Time Scale; FIELD INVESTIGATION; Stratigraphy; FIELD SURVEYS; Glaciology; Electrical Measurements; Antarctic; Not provided; Ice Sheet; Ice Core; LABORATORY; Climate Proxies", "locations": "Antarctic", "north": -79.46667, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Taylor, Kendrick C.", "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": -79.46667, "title": "Investigation of the Stratigraphy and Time Scale of the WAIS Divide Ice Core Using Electrical Methods", "uid": "p0000373", "west": 112.1}, {"awards": "0636997 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 20 Mar 2012 00:00:00 GMT", "description": "Waddington/0636997\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to integrate three lines of glaciology research, previously treated independently. First, internal layers in ice sheets, detected by ice-penetrating radar, retain information about past spatial and temporal patterns of ice accumulation. Ice-flow modelers can recover this information, using geophysical inverse methods; however, the ages of the layers must be known, through interpolation where they intersect a well-dated ice core. \u003cbr/\u003eSecond, concentrations of methane and some other atmospheric constituents vary through time as climate changes. However, the atmosphere is always well mixed, and concentrations are similar world-wide at any one time, so gas variations from an undated core can be correlated with those in a well-dated core such as GISP2. Because air in near-surface firn mixes readily with the atmosphere above, the air that is trapped in bubbles deep in the firn is typically hundreds to thousands of years younger than that firn. Gas geochemists must calculate this age difference, called delta-age, with a firn-densification model before the ice enclosing the gas can be dated accurately. To calculate delta-age, they must know the temperature and the snow accumulation rate at the time and place where the snow fell. Third, gases can be correlated between cores only at times when the atmosphere changed, so ice-core dates must be interpolated at depths between the sparse dated points. Simplistic interpolation schemes can create undesirable artifacts in the depth-age profile. The intellectual merit of this project is that it will develop new interpolation methods that calculate layer thinning over time due to ice-flow mechanics. Accurate interpolation also requires a spatial and temporal accumulation history. These three issues are coupled through accumulation patterns and ice-core dates. This project will develop an integrated inversion procedure to solve all three problems simultaneously. The new method will incorporate ice-penetrating radar profile data and ice-core data, and will find self-consistent: spatial/temporal accumulation patterns; delta-age profiles for ice cores; and reliably interpolated depth-age profiles. The project will then: recalculate the depth-age profile at Byrd Station, Antarctica; provide a preliminary depth-age at the West Antarctic Ice Sheet (WAIS) in the initial stages of drilling, using radar layers with estimated ages traced from Byrd Station; and generate a self-consistent depth-age relationship for Taylor Dome, Antarctica over the past 20ka, where low accumulation has created uncertainty in dating, accumulation, and controversy over delta-age estimates. The broader impacts of the project are that it will support the PhD research of a female graduate student, and her continued outreach work with Making Connections, a non-profit program through the University of Washington Women\u0027s Center, which matches professional women mentors with minority high-school women interested in mathematics and science, disciplines where they are traditionally under-represented. The graduate student will also work with Girls on Ice, a ten-day glacier field program, taught by women scientist instructors, emphasizing scientific observation through immersion, leadership skills and safety awareness.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Internal Layers; LABORATORY; Ice Core; FIELD SURVEYS; Firn; FIELD INVESTIGATION; Accumulation; Glaciology; Climate Change; Ice Sheet", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Carns, Regina; Hay, Mike; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Self-consistent Ice Dynamics, Accumulation, Delta-age, and Interpolation of Sparse Age Data using an Inverse Approach", "uid": "p0000376", "west": null}, {"awards": "0636898 Winckler, Gisela", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 30 Nov 2011 00:00:00 GMT", "description": "Winckler/0636898\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study dust sources in Antarctic ice cores. Atmospheric aerosols play an important role both in global biogeochemical cycles as well as in the climate system of the Earth. Records extracted from Antarctic ice cores inform us that dust deposition from the atmosphere to the ice sheet was 15-20 times greater during glacial periods than during interglacials, which raises the possibility that dust may be a key player in climate change on glacial-interglacial timescales. By characterizing potential source areas from South America, South Africa, and Australia as well as fresh glacial flour from Patagonia, the project will determine if the interglacial dust was mobilized from a distinct geographical region (e.g., Australia) or from a more heavily weathered source region in South America. The intellectual merit of the project is that it will contribute to reconstructing climate-related changes in the rate of dust deposition, and in the provenance of the dust, it will provide critical constraints on hydrology and vegetation in the source regions, as well as on the nature of the atmospheric circulation transporting dust to the archive location. In a recent pilot study it was found that there is a dramatic glacial to Holocene change in the 4He/Ca ratio in the dust extracted from ice from Dronning Maud Land, Antarctica, indicating a shift in the source of dust transported to Antarctica. The broader impacts of the project are that Helium isotopes and calcium measurements provide a wealth of information that can then be turned into critical input for dust-climate models. Improved models, which are able to accurately reconstruct paleo dust distribution, will help us to predict changes in dust in response to future climate variability. This information will contribute to an improvement of our integrated understanding of the Earth\u0027s climate system and, in turn, will better inform policy makers of those processes and conditions most susceptible to perturbation by climate change, thereby leading to more meaningful climate-change policy. The project will support a graduate student in the dual masters Earth and Environmental Science Journalism program. The lead-PI manages the rock noble gas laboratory at Lamont. Her leadership role in this facility impacts the training of undergraduate and graduate students as well as visiting scientists.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": false, "keywords": "Deposition; LABORATORY; Dust; Climate; Not provided; Climate Change; Helium Isotopes; FIELD INVESTIGATION; Biogeochemical Cycles", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Winckler, Gisela", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Tracing Glacial-interglacial Changes in the Dust Source to Antarctica using Helium Isotopes", "uid": "p0000265", "west": null}, {"awards": "0944474 Robinson, Laura", "bounds_geometry": "POLYGON((-70.5 -54.5,-66.95 -54.5,-63.4 -54.5,-59.85 -54.5,-56.3 -54.5,-52.75 -54.5,-49.2 -54.5,-45.65 -54.5,-42.1 -54.5,-38.55 -54.5,-35 -54.5,-35 -55.2,-35 -55.9,-35 -56.6,-35 -57.3,-35 -58,-35 -58.7,-35 -59.4,-35 -60.1,-35 -60.8,-35 -61.5,-38.55 -61.5,-42.1 -61.5,-45.65 -61.5,-49.2 -61.5,-52.75 -61.5,-56.3 -61.5,-59.85 -61.5,-63.4 -61.5,-66.95 -61.5,-70.5 -61.5,-70.5 -60.8,-70.5 -60.1,-70.5 -59.4,-70.5 -58.7,-70.5 -58,-70.5 -57.3,-70.5 -56.6,-70.5 -55.9,-70.5 -55.2,-70.5 -54.5))", "dataset_titles": "Expedition Data; Historic Perspectives on Climate and Biogeography from Deep-Sea Corals in the Drake Passage", "datasets": [{"dataset_uid": "001451", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1103"}, {"dataset_uid": "600114", "doi": "10.15784/600114", "keywords": "Biota; Corals; Cruise Report; Drake Passage; NBP1103; Oceans; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Robinson, Laura", "repository": "USAP-DC", "science_program": null, "title": "Historic Perspectives on Climate and Biogeography from Deep-Sea Corals in the Drake Passage", "url": "https://www.usap-dc.org/view/dataset/600114"}], "date_created": "Wed, 24 Aug 2011 00:00:00 GMT", "description": "Polar oceans are the main sites of deep-water formation and are critical to the exchange of heat and carbon between the deep ocean and the atmosphere. This award ?Historic perspectives on climate and biogeography from deep-sea corals in the Drake Passage? will address the following specific research questions: What was the radiocarbon content of the Southern Ocean during the last glacial maximum and during past rapid climate change events? and What are the major controls on the past and present distribution of cold-water corals within the Drake Passage and adjacent continental shelves? Testing these overall questions will allow the researchers to better understand how processes in the Southern Ocean are linked to climate change over millennia. This award is being funded by the Antarctic Earth Sciences Program of NSF?s Office of Polar Programs, Antarctic Division. \u003cbr/\u003e\u003cbr/\u003eINTELLECTUAL MERIT: The skeletons of deep-sea corals are abundant in the Southern Ocean, and can be dated using U-series techniques making them a useful archive of oceanographic history. By pairing U-series and radiocarbon analyses the awardees can reconstruct the radiocarbon content of seawater in the past, allowing them to address the research questions raised above. Collection of living deep-sea corals along with environmental data will allow them to address the broader biogeography questions posed above as well. The awardees are uniquely qualified to answer these questions in their respective labs via cutting edge technologies, and they have shown promising results from a preliminary pilot cruise to the area in 2008.\u003cbr/\u003e\u003cbr/\u003eBROADER IMPACTS: Societal Relevance: The proposed paleoclimate research will make significant advances toward constraining the Southern Ocean?s influence on global climate, specifically it should help set the bounds for the upper limits on how fast the ocean circulation might change in this region of the world, which is of high societal relevance in this era of changing climate. Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating undergraduate through post-doctoral students into research programs; ii) promotion of K-12 teaching and learning programs by providing information via a cruise website and in-school talks, iii) making the data collected available to the wider research community via data archives such as Seamounts Online and the Seamount Biogeographic Network and iv) reaching a larger public audience through such venues as interviews in the popular media.", "east": -35.0, "geometry": "POINT(-52.75 -58)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "R/V NBP", "locations": null, "north": -54.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Robinson, Laura", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -61.5, "title": "Collaborative Research: Historic Perspectives on Climate and Biogeography from Deep-sea Corals in the Drake Passage", "uid": "p0000514", "west": -70.5}, {"awards": "0636818 Stone, John", "bounds_geometry": "POLYGON((-157 -85,-156 -85,-155 -85,-154 -85,-153 -85,-152 -85,-151 -85,-150 -85,-149 -85,-148 -85,-147 -85,-147 -85.3,-147 -85.6,-147 -85.9,-147 -86.2,-147 -86.5,-147 -86.8,-147 -87.1,-147 -87.4,-147 -87.7,-147 -88,-148 -88,-149 -88,-150 -88,-151 -88,-152 -88,-153 -88,-154 -88,-155 -88,-156 -88,-157 -88,-157 -87.7,-157 -87.4,-157 -87.1,-157 -86.8,-157 -86.5,-157 -86.2,-157 -85.9,-157 -85.6,-157 -85.3,-157 -85))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Aug 2011 00:00:00 GMT", "description": "Hall/0636687\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to investigate late Pleistocene and Holocene changes in Scott Glacier, a key outlet glacier that flows directly into the Ross Sea just west of the present-day West Antarctic Ice Sheet (WAIS) grounding line. The overarching goals are to understand changes in WAIS configuration in the Ross Sea sector at and since the last glacial maximum (LGM) and to determine whether Holocene retreat observed in the Ross Embayment has ended or if it is still ongoing. To address these goals, moraine and drift sequences associated with Scott Glacier will be mapped and dated and ice thickness, surface velocity and surface mass balance will be measured to constrain an ice-flow model of the glacier. This model will be used to help interpret the dated geologic sequences. The intellectual merit of the project relates to gaining a better understanding of the West Antarctic Ice Sheet and how changing activity of fast-flowing outlet glaciers and ice streams exerts strong control on the mass balance of the ice sheet. Previous work suggests that grounding-line retreat in the Ross Sea continued into the late Holocene and left open the possibility of ongoing deglaciation as part of a long-term trend. Results from Reedy Glacier, an outlet glacier just behind the grounding line, suggest that retreat may have slowed substantially over the past 2000 years and perhaps even stopped. By coupling the work on Scott Glacier with recent data from Reedy Glacier, the grounding-line position will be bracketed and it should be possible to establish whether the retreat has truly ended or if it is ongoing. The broader impacts of the work relate to the societal relevance of an improved understanding of the West Antarctic ice sheet to establish how it will respond to current and possible future environmental changes. The work addresses this key goal of the West Antarctic Ice Sheet Initiative, as well as the International Polar Year focus on ice sheet history and dynamics. The work will develop future scientists through the education and training of one undergraduate and two Ph.D. students, interaction with K-12 students through classroom visits, web-based \u0027expedition\u0027 journals, letters from the field, and discussions with teachers. Results from this project will be posted with previous exposure dating results from Antarctica, on the University of Washington Cosmogenic Nuclide Lab website, which also provides information about chemical procedures and calculation methods to other scientists working with cosmogenic nuclides.", "east": -147.0, "geometry": "POINT(-152 -86.5)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -85.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John; Conway, Howard", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -88.0, "title": "Collaborative Research:Grounding-line Retreat in the Southern Ross Sea - Constraints from Scott Glacier", "uid": "p0000149", "west": -157.0}, {"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": "601411", "doi": "10.15784/601411", "keywords": "Antarctica; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ICECAP; Ice Penetrating Radar; Internal Reflecting Horizons", "people": "Cavitte, Marie G. P; Blankenship, Donald D.; Schroeder, Dustin; Tozer, Carly; Roberts, Jason; Frezzotti, Massimo; Paden, John; Muldoon, Gail R.; Quartini, Enrica; Kempf, Scott D.; Young, Duncan A.; Mulvaney, Robert; Ritz, Catherine; Greenbaum, Jamin; Ng, Gregory", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau", "url": "https://www.usap-dc.org/view/dataset/601411"}, {"dataset_uid": "601049", "doi": "10.15784/601049", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Navigation; Radar; Snow", "people": "Gogineni, Prasad; Leuschen, Carl; Allen, Chris; Li, Jilu; Rodriguez, Fernando; Paden, John", "repository": "USAP-DC", "science_program": null, "title": "Snow Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601049"}, {"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": "601048", "doi": "10.15784/601048", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ku-Band; Navigation; Radar", "people": "Li, Jilu; Paden, John; Leuschen, Carl; Rodriguez, Fernando; Gogineni, Prasad; Allen, Chris", "repository": "USAP-DC", "science_program": null, "title": "Ku-band Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601048"}, {"dataset_uid": "601047", "doi": "10.15784/601047", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MCoRDS; Navigation; Radar", "people": "Li, Jilu; Leuschen, Carl; Allen, Chris; Rodriguez, Fernando; Paden, John; Gogineni, Prasad", "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": "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"}], "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 Glaciology; Antarctic Organisms and Ecosystems", "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": "0439906 Koch, Paul", "bounds_geometry": "POLYGON((162 -72,162.6 -72,163.2 -72,163.8 -72,164.4 -72,165 -72,165.6 -72,166.2 -72,166.8 -72,167.4 -72,168 -72,168 -72.6,168 -73.2,168 -73.8,168 -74.4,168 -75,168 -75.6,168 -76.2,168 -76.8,168 -77.4,168 -78,167.4 -78,166.8 -78,166.2 -78,165.6 -78,165 -78,164.4 -78,163.8 -78,163.2 -78,162.6 -78,162 -78,162 -77.4,162 -76.8,162 -76.2,162 -75.6,162 -75,162 -74.4,162 -73.8,162 -73.2,162 -72.6,162 -72))", "dataset_titles": "Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic, Isotopic, and Geologic Approaches toward Understanding Holocene Environmental Change", "datasets": [{"dataset_uid": "600041", "doi": "10.15784/600041", "keywords": "Biota; Isotope; Penguin; Ross Sea; Seals; Southern Ocean", "people": "Koch, Paul", "repository": "USAP-DC", "science_program": null, "title": "Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic, Isotopic, and Geologic Approaches toward Understanding Holocene Environmental Change", "url": "https://www.usap-dc.org/view/dataset/600041"}], "date_created": "Sat, 30 Oct 2010 00:00:00 GMT", "description": "During previous NSF-sponsored research, the PI\u0027s discovered that southern elephant seal colonies once existed along the Victoria Land coast (VLC) of Antarctica, a region where they are no longer observed. Molted seal skin and hair occur along 300 km of coastline, more than 1000 km from any extant colony. The last record of a seal at a former colony site is at ~A.D. 1600. Because abandonment occurred prior to subantarctic sealing, disappearance of the VLC colony probably was due to environmental factors, possibly cooling and encroachment of land-fast, perennial sea ice that made access to haul-out sites difficult. The record of seal inhabitation along the VLC, therefore, has potential as a proxy for climate change. Elephant seals are a predominantly subantarctic species with circumpolar distribution. Genetic studies have revealed significant differentiation among populations, particularly with regard to that at Macquarie I., which is the extant population nearest to the abandoned VLC colony. Not only is the Macquarie population unique genetically, but it is has undergone unexplained decline of 2%/yr over the last 50 years3. In a pilot study, genetic analyses showed a close relationship between the VLC seals and those at Macquarie I. An understanding of the relationship between the two populations, as well as of the environmental pressures that led to the demise of the VLC colonies, will provide a better understanding of present-day population genetic structure, the effect of environmental change on seal populations, and possibly the reasons underlying the modern decline at Macquarie Island.\u003cbr/\u003eThis project addresses several key research problems: (1) Why did elephant seals colonize and then abandon the VLC? (2) What does the elephant seal record reveal about Holocene climate change and sea-ice conditions? (3) What were the foraging strategies of the seals and did these strategies change over time as climate varied? (4) How does the genetic structure of the VLC seals relate to extant populations? (5) How did genetic diversity change over time and with colony decline? (6) Using ancient samples to estimate mtDNA mutation rates, what can be learned about VLC population dynamics over time? (7) What was the ecological relationship between elephant seals and Adelie penguins that occupied the same sites, but apparently at different times? The proposed work includes the professional training of young researchers and incorporation of data into graduate and undergraduate courses.", "east": 168.0, "geometry": "POINT(165 -75)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS", "locations": null, "north": -72.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Earth Sciences", "paleo_time": null, "persons": "Koch, Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research: Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic, Isotopic, and Geologic Approaches toward Understanding Holocene Environmental Change", "uid": "p0000533", "west": 162.0}, {"awards": "0737168 Prentice, Michael; 0541054 Sletten, Ronald", "bounds_geometry": "POLYGON((162.2335 -77.5047,162.3803 -77.5047,162.5271 -77.5047,162.6739 -77.5047,162.8207 -77.5047,162.9675 -77.5047,163.1143 -77.5047,163.2611 -77.5047,163.4079 -77.5047,163.5547 -77.5047,163.7015 -77.5047,163.7015 -77.52814,163.7015 -77.55158,163.7015 -77.57502,163.7015 -77.59846,163.7015 -77.6219,163.7015 -77.64534,163.7015 -77.66878,163.7015 -77.69222,163.7015 -77.71566,163.7015 -77.7391,163.5547 -77.7391,163.4079 -77.7391,163.2611 -77.7391,163.1143 -77.7391,162.9675 -77.7391,162.8207 -77.7391,162.6739 -77.7391,162.5271 -77.7391,162.3803 -77.7391,162.2335 -77.7391,162.2335 -77.71566,162.2335 -77.69222,162.2335 -77.66878,162.2335 -77.64534,162.2335 -77.6219,162.2335 -77.59846,162.2335 -77.57502,162.2335 -77.55158,162.2335 -77.52814,162.2335 -77.5047))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 06 Oct 2010 00:00:00 GMT", "description": "This award supports a project to examine the stratigraphy of near-surface sediments in Taylor Valley, Antarctica. Two contrasting hypotheses have been proposed for surface sediments in lower Taylor Valley, which have important and very different implications for how the West Antarctic Ice Sheet (WAIS) responded to the sea-level rise of the last deglaciation and Holocene environmental changes. One hypothesis holds that the sediments, designated Ross I drift, directly reflect \u003e10,000 14C-years of WAIS shrinkage in the Ross Sea during and perhaps driven by deglacial sea-level rise. The other hypothesis, holds that the Taylor sediments have little significance for WAIS change during the deglaciation. These two hypotheses reflect fundamentally different interpretations of the sediment record. Over the course of two field seasons and a third year at the home institutions, the project will test these two hypotheses using glacial geology, geochemistry, ground penetrating radar (GPR) at both 100 MHz and 400 MHz, and portable sediment coring. The intellectual merit of the proposed work is that it will test these two hypotheses and make novel use of the subsurface record that may result in new insights into WAIS sensitivity during the deglaciation. The study will also directly test the conclusion that Glacial Lake Washburn was much larger than previously proposed during the Last Glacial Maximum (LGM). This occurrence, if real, represents a stunning climate anomaly. Answers to these local ice sheet and lake questions directly pertain to larger scale issues concerning the influences of sea-level rise, climate change, and internal ice-sheet dynamics on the recession of the WAIS since the LGM. There are numerous broader impacts to this project. Understanding the glacial and lake history in the McMurdo Sound region has important implications for the role that the WAIS will play in future sea-level and global climate change. Moreover, the history of Taylor Valley has significance for the ecosystem studies currently being conducted by the LTER group. Lastly, during the course of the proposed research, the project will train two graduate and undergraduate students and the research will be featured prominently in the teaching of students.", "east": 163.7015, "geometry": "POINT(162.9675 -77.6219)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": false, "keywords": "Not provided; Salt", "locations": null, "north": -77.5047, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Prentice, Michael; Sletten, Ronald S.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -77.7391, "title": "Collaborative Research: Fluctuations of the West Antarctic Ice Sheet in Relation to Lake History in Taylor Valley, Antarctica, Since the Last Glacial Maximum", "uid": "p0000656", "west": 162.2335}, {"awards": "0742818 Kovac, John", "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": "Harvard-Smithsonian Center for Astrophysics (full data link not provided)", "datasets": [{"dataset_uid": "000182", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Harvard-Smithsonian Center for Astrophysics (full data link not provided)", "url": "http://bicepkeck.org/"}], "date_created": "Fri, 02 Jul 2010 00:00:00 GMT", "description": "ANT-0742818, PI: John M. Kovac, California Institute of Technology\u003cbr/\u003eANT-0742592, PI: Clement L. Pryke, University of Chicago\u003cbr/\u003eCollaborative Research: BICEP2 and SPUD - A Search for Inflation with Degree-Scale Polarimetry from the South Pole\u003cbr/\u003e\u003cbr/\u003eThe proposed work is a four-year program of research activities directed toward upgrading the BICEP (Background Imaging of Cosmic Extragalactic Polarization) telescope operating at South Pole since early 2006 to reach far =stretching goals of detection of the Cosmic Gravitational-wave Background (CGB) . This telescope is a first Cosmic Microwave Background (CMB) B-mode polarimeter, specifically designed to search for CGB signatures while mapping ~2% of the southern sky that is free of the Milky Way foreground galactic radiation at 100 GH and 150 GHz. The BICEP1 telescope will reach its designed sensitivity by the end of 2008. A coordinated series of upgrades to BICEP1 will provide the increased sensitivity and more exacting control of instrumental effects and potential confusion from galactic foregrounds necessary to search for the B-mode signal more deeply through space. A powerful new 150 GHz receiver, BICEP2, will replace the current detector at the beginning of 2009, increasing the mapping speed almost ten-fold. In 2010, the first of a series of compact, mechanically-cooled receivers (called SPUD - Small Polarimeter Upgrade for DASI) will be deployed on the existing DASI mount and tower, providing similar mapping speed at 100 GHz in parallel with BICEP2. The latter instrument will reach (and exceed with the addition of a SPUD polarimeter) the target sensitivity r = 0.15 set forth by the Interagency (NSF/NASA/DoE) Task Force on CMB Research for a future space mission dedicated to the detection and characterization of primordial gravitational waves. This Task Force has identified detection of the Inflation\u0027s gravitational waves as the number one priority for the modern cosmology. More broadly, as the cosmology captures a lot of the public imagination, it is a remarkably effective vehicle for stimulating interest in basic science. The CGB detection would be to Inflation what the discovery of the CMB radiation was to the Big Bang. The project will contribute to the training of the next generation of cosmologists by integrating graduate and undergraduate education with the technology and instrumentation development, astronomical observations and scientific analysis. Sharing of the forefront research results with public extends the new knowledge beyond the universities. This project will be undertaken in collaboration between the California Institute of Technology and the University of Chicago.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "Kovac, John", "platforms": "Not provided", "repo": "Project website", "repositories": "Project website", "science_programs": null, "south": -90.0, "title": "Collaborative Research: BICEP2 and SPUD - A Search for Inflation with Degree-Scale Polarimetry from the South Pole", "uid": "p0000296", "west": -180.0}, {"awards": "9527255 Mopper, Kenneth", "bounds_geometry": null, "dataset_titles": "Expedition data of LMG9809", "datasets": [{"dataset_uid": "002719", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9809", "url": "https://www.rvdata.us/search/cruise/LMG9809"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "ACT K. Mopper \u0026 D. Kieber OPP 9527255 \u0026 OPP 9527314 PHOTOCHEMICAL AND OPTICAL PROPERTIES OF ANTARCTIC WATERS IN RESPONSE TO CHANGING UV-B FLUXES The decrease in stratospheric ozone over the Antarctic results in an increase in the UV-B flux in the euphotic zone. The increase leads to cellular damage to aquatic organisms, as documented by photo-inhibition and decreased productivity. Cellular damage can occur either intracellularly, or externally at the cell surface from biomolecular reactions with externally-generated reactive transients. The extent of this extracellular damage will depend on the photochemistry of the seawater surrounding the cell. Until recently, nothing was known about the type of photochemical processes, rates, and steady state concentrations of transients in Antarctic waters. It is proposed that field experiments be performed which will allow the construction of predictive models of photochemical production rates in surface waters and with depth. These studies will involve further quantum yield measurementts, development of a sensitive underwater actinometer system, and use of a new underwater multichannel photometer. The model will allow the prediction of the impact of varying levels of UV-B on the photoproduction and steady state concentration of several key reactive transient species in the upper water column. In addition to this effort, experiments will also be performed to study the photodegradation of dissolved organic matter and to determine whether biologically utilizable substrates that are formed photochemically can enhance secondary productivity in Antarctic waters.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Mopper, Kenneth", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Photochemical and Optical Properties of Antarctic Waters in Response to Changing UV-B Fluxes", "uid": "p0000870", "west": null}, {"awards": "0337159 McPhee, Miles", "bounds_geometry": "POLYGON((-64.71659 -53.00174,-57.631677 -53.00174,-50.546764 -53.00174,-43.461851 -53.00174,-36.376938 -53.00174,-29.292025 -53.00174,-22.207112 -53.00174,-15.122199 -53.00174,-8.037286 -53.00174,-0.952373 -53.00174,6.13254 -53.00174,6.13254 -54.292069,6.13254 -55.582398,6.13254 -56.872727,6.13254 -58.163056,6.13254 -59.453385,6.13254 -60.743714,6.13254 -62.034043,6.13254 -63.324372,6.13254 -64.614701,6.13254 -65.90503,-0.952373 -65.90503,-8.037286 -65.90503,-15.122199 -65.90503,-22.207112 -65.90503,-29.292025 -65.90503,-36.376938 -65.90503,-43.461851 -65.90503,-50.546764 -65.90503,-57.631677 -65.90503,-64.71659 -65.90503,-64.71659 -64.614701,-64.71659 -63.324372,-64.71659 -62.034043,-64.71659 -60.743714,-64.71659 -59.453385,-64.71659 -58.163056,-64.71659 -56.872727,-64.71659 -55.582398,-64.71659 -54.292069,-64.71659 -53.00174))", "dataset_titles": "Expedition Data; Processed ADCP Sonar and CTD Data from the Maud Rise acquired during the Nathaniel B. Palmer expedition NBP0506", "datasets": [{"dataset_uid": "001590", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0506"}, {"dataset_uid": "601342", "doi": null, "keywords": "ADCP Acoustic Doppler Current Profiler; Antarctica; CTD; Maud Rise; NBP0506; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature; Turbulance; Weddell Sea", "people": "McPhee, Miles G.", "repository": "USAP-DC", "science_program": null, "title": "Processed ADCP Sonar and CTD Data from the Maud Rise acquired during the Nathaniel B. Palmer expedition NBP0506", "url": "https://www.usap-dc.org/view/dataset/601342"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is an investigation into one mechanism by which deep ocean convection can evolve from stable initial conditions, to the extent that it becomes well enough established to bring warm water to the surface and melt an existing ice cover in late, or possibly even mid-winter. The specific study will investigate how the non-linear dependence of seawater density on temperature and salinity (the equation of state) can enhance vertical convection under typical antarctic conditions. When layers of seawater with similar densities but strong contrasts in temperature and salinity interact, there are a number of possible non-linear instabilities that can convert existing potential energy to turbulent energy. In the Weddell Sea, a cold surface mixed layer is often separated from the underlying warm, more saline water by a thin, weak pycnocline, making the water column particularly susceptible to an instability associated with thermobaricity (the pressure dependence of the thermal expansion coefficient). The project is a collaboration between New York University, Earth and Space Research, the University of Washington, the Naval Postgraduate School, and McPhee Research Company.\u003cbr/\u003eThe work has strong practical applications in contributing to the explanation for the existence of the Weddell Polynya, a 300,000 square kilometer area of open water within the seasonal sea ice of the Weddell Sea, from approximately 1975 to 1979. It has not recurred since, although indications of much smaller and less persistent areas of open water do occur in the vicinity of the Maud Rise seamount. \u003cbr/\u003e The experimental component will be carried out on board the RVIB Nathaniel B. Palmer between July and September, 2005.", "east": 6.13254, "geometry": "POINT(-29.292025 -59.453385)", "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 PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; 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": -53.00174, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "McPhee, Miles G.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -65.90503, "title": "Collaborative Research: The Maud Rise Nonlinear Equation of State Study (MaudNESS)", "uid": "p0000579", "west": -64.71659}, {"awards": "0088143 Luyendyk, Bruce; 0087392 Bartek, Louis", "bounds_geometry": "POLYGON((-179.99786 -75.91667,-143.99852 -75.91667,-107.99918 -75.91667,-71.99984 -75.91667,-36.0005 -75.91667,-0.00115999999997 -75.91667,35.99818 -75.91667,71.99752 -75.91667,107.99686 -75.91667,143.9962 -75.91667,179.99554 -75.91667,179.99554 -76.183531,179.99554 -76.450392,179.99554 -76.717253,179.99554 -76.984114,179.99554 -77.250975,179.99554 -77.517836,179.99554 -77.784697,179.99554 -78.051558,179.99554 -78.318419,179.99554 -78.58528,143.9962 -78.58528,107.99686 -78.58528,71.99752 -78.58528,35.99818 -78.58528,-0.00116000000003 -78.58528,-36.0005 -78.58528,-71.99984 -78.58528,-107.99918 -78.58528,-143.99852 -78.58528,-179.99786 -78.58528,-179.99786 -78.318419,-179.99786 -78.051558,-179.99786 -77.784697,-179.99786 -77.517836,-179.99786 -77.250975,-179.99786 -76.984114,-179.99786 -76.717253,-179.99786 -76.450392,-179.99786 -76.183531,-179.99786 -75.91667))", "dataset_titles": "Expedition Data; NBP0301 data; NBP0306 data", "datasets": [{"dataset_uid": "001724", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0301"}, {"dataset_uid": "000104", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0301 data", "url": "https://www.rvdata.us/search/cruise/NBP0301"}, {"dataset_uid": "001668", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0306"}, {"dataset_uid": "000105", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0306 data", "url": "https://www.rvdata.us/search/cruise/NBP0306"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Luyendyk et.al.: OPP 0088143\u003cbr/\u003eBartek: OPP 0087392\u003cbr/\u003eDiebold: OPP 0087983\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program in marine geology and geophysics in the southern central and eastern Ross Sea. The project will conduct sites surveys for drilling from the Ross Ice Shelf into the seafloor beneath it. Many of the outstanding problems concerning the evolution of the East and West Antarctic Ice Sheets, Antarctic climate, global sea level, and the tectonic history of the West Antarctic Rift System can be addressed by drilling into the seafloor of the Ross Sea. Climate data for Cretaceous and Early Cenozoic time are lacking for this sector of Antarctica. Climate questions include: Was there any ice in Late Cretaceous time? What was the Antarctic climate during the Paleocene-Eocene global warming? When was the Cenozoic onset of Antarctic glaciation, when did glaciers reach the coast and when did they advance out onto the margin? Was the Ross Sea shelf non-marine in Late Cretaceous time; when did it become marine? Tectonic questions include: What was the timing of the Cretaceous extension in the Ross Sea rift; where was it located? What is the basement composition and structure? Where are the time and space limits of the effects of Adare Trough spreading? Another drilling objective is to sample and date the sedimentary section bounding the mapped RSU6 unconformity in the Eastern Basin and Central Trough to resolve questions about its age and regional extent. Deep Sea Drilling Project (DSDP) Leg 28 completed sampling at four drill sites in the early 1970\u0027s but had low recovery and did not sample the Early Cenozoic. Other drilling has been restricted to the McMurdo Sound area of the western Ross Sea and results can be correlated into the Victoria Land Basin but not eastward across basement highs. Further, Early Cenozoic and Cretaceous rocks have not been sampled. A new opportunity is developing to drill from the Ross Ice Shelf. This is a successor program to the Cape Roberts Drilling Project. One overriding difficulty is the need for site surveys at drilling locations under the ice shelf. This project will overcome this impediment by conducting marine geophysical drill site surveys at the front of the Ross Ice Shelf in the Central Trough and Eastern Basin. The surveys will be conducted a kilometer or two north of the ice shelf front where recent calving events have resulted in a southerly position of the ice shelf edge. In several years the northward advance of the ice shelf will override the surveyed locations and drilling could be accomplished. Systems to be used include swath bathymetry, gravity, magnetics, chirp sonar, high resolution seismic profiling, and 48 fold seismics. Cores will be collected to obtain samples for geotechnical properties, to study sub-ice shelf modern sedimentary processes, and at locations where deeper section is exposed.\u003cbr/\u003e\u003cbr/\u003eThis survey will include long profiles and detailed grids over potential drill sites. Survey lines will be tied to existing geophysical profiles and DSDP 270. A recent event that makes this plan timely is the calving of giant iceberg B-15 (in March, 2000) and others from the ice front in the eastern Ross Sea. This new calving event and one in 1987 have exposed 16,000 square kilometers of seafloor that had been covered by ice shelf for decades and is not explored. Newly exposed territory can now be mapped by modern geophysical methods. This project will map geological structure and stratigraphy below unconformity RSU6 farther south and east, study the place of Roosevelt Island in the Ross Sea rifting history, and determine subsidence history during Late Cenozoic time (post RSU6) in the far south and east. Finally the project will observe present day sedimentary processes beneath the ice shelf in the newly exposed areas.", "east": 179.99554, "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": true, "keywords": "R/V NBP", "locations": null, "north": -75.91667, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bartek, Louis; Luyendyk, Bruce P.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -78.58528, "title": "Collaborative Research: Antarctic Cretaceous-Cenozoic Climate, Glaciation, and Tectonics: Site surveys for drilling from the edge of the Ross Ice Shelf", "uid": "p0000425", "west": -179.99786}, {"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": "8915730 Foster, Theodore", "bounds_geometry": "POLYGON((-70.9 -52.3533,-67.79577 -52.3533,-64.69154 -52.3533,-61.58731 -52.3533,-58.48308 -52.3533,-55.37885 -52.3533,-52.27462 -52.3533,-49.17039 -52.3533,-46.06616 -52.3533,-42.96193 -52.3533,-39.8577 -52.3533,-39.8577 -53.78259,-39.8577 -55.21188,-39.8577 -56.64117,-39.8577 -58.07046,-39.8577 -59.49975,-39.8577 -60.92904,-39.8577 -62.35833,-39.8577 -63.78762,-39.8577 -65.21691,-39.8577 -66.6462,-42.96193 -66.6462,-46.06616 -66.6462,-49.17039 -66.6462,-52.27462 -66.6462,-55.37885 -66.6462,-58.48308 -66.6462,-61.58731 -66.6462,-64.69154 -66.6462,-67.79577 -66.6462,-70.9 -66.6462,-70.9 -65.21691,-70.9 -63.78762,-70.9 -62.35833,-70.9 -60.92904,-70.9 -59.49975,-70.9 -58.07046,-70.9 -56.64117,-70.9 -55.21188,-70.9 -53.78259,-70.9 -52.3533))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002310", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9207"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is a two-year investigation into the dynamics and processes of deep water mass formation in the western Weddell Sea, combining physical and chemical oceanographic techniques to produce a coherent picture of the importance of this unique region to the structure of the world ocean. In the global context, this area is a major water mass modification site, involving open ocean convective events, the continental margin, and the ice cover. At this time the various water types that combine to form Weddell Sea Deep Water and Antarctic Bottom Water, and the conditions under which these water masses form, are not known well enough to establish direct physical links and volumetric budgets. It is suspected that the outflow from the Weddell Sea is restricted to quite narrow boundary currents flowing near the base of the continental shelf, and consequently may be observed with conventional current meter moorings from the shelf into the deep ocean. Two oceanographic expeditions to the western Weddell Sea are planned as part of this study: the first in the 1990/91, and the second in 1991/92. The objectives will be to measure the flow of newly-formed bottom water and to explore the sinking process of near-surface waters in the open ocean to see how these affect the deep water flows. In the first year the primary objective will be to set out an array of eight current meters in the bottom water core, while a secondary objective will be to grapple for an existing array that was set out in early 1988 but could not be recovered in 1989 because Antarctic Program ship resources had to be diverted to deal with the oil spill at Palmer Station. In the second year the array will be retrieved. Hydrographic cruises in order to define the upper ocean temperatures and salinity structure in the outflow region where unusually large step structures have been found in the past. A chemistry program consistent with the objectives of the World Ocean Circulation Experiment (WOCE) and presently planned experiments in the South Atlantic Ocean, will be integrated into the cruises carried out under this project.", "east": -39.8577, "geometry": "POINT(-55.37885 -59.49975)", "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.3533, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Foster, Theodore; Foster, Ted", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -66.6462, "title": "Antarctic Bottom Water Formation", "uid": "p0000654", "west": -70.9}, {"awards": "9815961 Bengtson, John", "bounds_geometry": "POLYGON((-179.99905 -43.56728,-143.99915 -43.56728,-107.99925 -43.56728,-71.99935 -43.56728,-35.99945 -43.56728,0.000450000000001 -43.56728,36.00035 -43.56728,72.00025 -43.56728,108.00015 -43.56728,144.00005 -43.56728,179.99995 -43.56728,179.99995 -47.058498,179.99995 -50.549716,179.99995 -54.040934,179.99995 -57.532152,179.99995 -61.02337,179.99995 -64.514588,179.99995 -68.005806,179.99995 -71.497024,179.99995 -74.988242,179.99995 -78.47946,144.00005 -78.47946,108.00015 -78.47946,72.00025 -78.47946,36.00035 -78.47946,0.000450000000001 -78.47946,-35.99945 -78.47946,-71.99935 -78.47946,-107.99925 -78.47946,-143.99915 -78.47946,-179.99905 -78.47946,-179.99905 -74.988242,-179.99905 -71.497024,-179.99905 -68.005806,-179.99905 -64.514588,-179.99905 -61.02337,-179.99905 -57.532152,-179.99905 -54.040934,-179.99905 -50.549716,-179.99905 -47.058498,-179.99905 -43.56728))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001997", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9909"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "9815961 \u003cbr/\u003eBENGTSON\u003cbr/\u003eThe pack ice region surrounding Antarctica contains at least fifty percent of the world\u0027s population of seals, comprising about eighty percent of the world\u0027s total pinniped biomass. As a group, these seals are among the dominant top predators in Southern Ocean ecosystems, and the fluctuation in their abundance, growth patterns, life histories, and behavior provide a potential source of information about environmental variability integrated over a wide range of spatial and temporal scales. This proposal was developed as part of the international Antarctic Pack Ice Seals (APIS) program, which is aimed to better understand the ecological relationships between the distribution of pack ice seals and their environment. During January-February, 2000, a research cruise through the pack ice zone of the eastern Ross Sea and western Amundsen Sea will be conducted to survey and sample along six transects perpendicular to the continental shelf. Each of these transects will pass through five environmental sampling strata: continental shelf zone, Antarctic slope front, pelagic zone, the ice edge front, and the open water outside the pack ice zone. All zones but open water will be ice-covered to some degree. Surveys along each transect will gather data on bathymetry, hydrography, sea ice dynamics and characteristics, phytoplankton and ice algae stocks, prey species (e.g., fish, cephalopods and euphausiids), and seal distribution, abundance and diet. This physical and trophic approach to investigating ecological interactions among pack ice seals, prey and the physical environment will allow the interdisciplinary research team to test the hypothesis that there are measurable physical and biological features in the Southern Ocean that result in area of high biological activity by upper trophic level predators. Better insight into the interplay among pack ice seals and biological and physical features of Antarctic marine ecosystems will allow for a better prediction of fluctuation in seal population in the context of environmental change.", "east": 179.99995, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -43.56728, "nsf_funding_programs": null, "paleo_time": null, "persons": "Bengtson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -78.47946, "title": "Antarctic Pack Ice Seals: Ecological Interactions with Prey and the Environment", "uid": "p0000614", "west": -179.99905}, {"awards": "9814622 Wiens, Douglas", "bounds_geometry": "POLYGON((-70.90604 -52.35474,-69.307306 -52.35474,-67.708572 -52.35474,-66.109838 -52.35474,-64.511104 -52.35474,-62.91237 -52.35474,-61.313636 -52.35474,-59.714902 -52.35474,-58.116168 -52.35474,-56.517434 -52.35474,-54.9187 -52.35474,-54.9187 -53.658393,-54.9187 -54.962046,-54.9187 -56.265699,-54.9187 -57.569352,-54.9187 -58.873005,-54.9187 -60.176658,-54.9187 -61.480311,-54.9187 -62.783964,-54.9187 -64.087617,-54.9187 -65.39127,-56.517434 -65.39127,-58.116168 -65.39127,-59.714902 -65.39127,-61.313636 -65.39127,-62.91237 -65.39127,-64.511104 -65.39127,-66.109838 -65.39127,-67.708572 -65.39127,-69.307306 -65.39127,-70.90604 -65.39127,-70.90604 -64.087617,-70.90604 -62.783964,-70.90604 -61.480311,-70.90604 -60.176658,-70.90604 -58.873005,-70.90604 -57.569352,-70.90604 -56.265699,-70.90604 -54.962046,-70.90604 -53.658393,-70.90604 -52.35474))", "dataset_titles": "Expedition Data; Expedition data of LMG0003A", "datasets": [{"dataset_uid": "002688", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0003A", "url": "https://www.rvdata.us/search/cruise/LMG0003A"}, {"dataset_uid": "002059", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9905"}, {"dataset_uid": "001854", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0106"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided jointly by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research to transform three temporary seismometers in the Antarctic Peninsula into semi-permanent stations and to continue basic research using these data. During 1997 and 1998, a network of 11 broadband seismographs in the Antarctic Peninsula region and southernmost Chilean Patagonia were installed and maintained. Data return from this project has been excellent and interesting initial results have been produced. The continued operation of these instruments over a longer time period would be highly beneficial because the number of larger magnitude regional earthquakes is small and so a longer time is needed to acquire data. However, instruments from this project are borrowed from the IRIS-PASSCAL instrument pool and must be returned to PASSCAL in April, 1999. This award provides funds to convert three stations at permanent Chilean bases in the Antarctic to permanent stations, and to continue the seismological investigation of the region for a period of four years. As part of this project, a fourth station, in Chilean Patagonia, will continue to be operated using Washington University equipment. The funding of this project will enable continued collaboration between Washington University and the Universidad de Chile in the operation of these stations, and the data will be forwarded to the IRIS data center as well as to other international seismological collaborators. Mutual data exchanges with other national groups with Antarctic seismology research programs will provide access to broadband data from a variety of other proprietary broadband stations in the region. The data will be used to study the seismicity and upper mantle velocity structure of several complicated tectonic regions in the area, including the South Shetland subduction zone, the Bransfield backarc rift, and diffuse plate boundaries in Patagonia, Drake Passage, and along the South Scotia Ridge. In particular, the operation of these stations over a longer time period will allow a better understanding of the seismicity of the South Shetland Trench, an unusual subduction zone showing very slow subduction of young lithosphere. These seismometers will also be used to record airgun shots during a geophysical cruise in the Bransfield Strait that is being planned by the University of Texas for April, 2000. These data will provide important constraints on the crustal structure beneath the stations, and the improved structural models will enable implementation of more precise earthquake location procedures in support of a seismological understanding of the region.", "east": -54.9187, "geometry": "POINT(-62.91237 -58.873005)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V LMG; R/V NBP", "locations": null, "north": -52.35474, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wiens, Douglas; Visbeck, Martin", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -65.39127, "title": "Acquisition and Operation of Broadband Seismograph Equipment at Chilean Bases in the Antarctic Peninsula Region", "uid": "p0000604", "west": -70.90604}, {"awards": "0125526 Wise, Sherwood", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0602A", "datasets": [{"dataset_uid": "001571", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}, {"dataset_uid": "002616", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0602A", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}], "date_created": "Tue, 04 May 2010 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 demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.", "east": null, "geometry": null, "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 CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; 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": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Proposal: SHALDRIL - A Demonstration Drilling Cruise to the James Ross Basin", "uid": "p0000828", "west": null}, {"awards": "9908828 Aronson, Richard", "bounds_geometry": "POLYGON((-70.906 -52.350166,-69.4494 -52.350166,-67.9928 -52.350166,-66.5362 -52.350166,-65.0796 -52.350166,-63.623 -52.350166,-62.1664 -52.350166,-60.7098 -52.350166,-59.2532 -52.350166,-57.7966 -52.350166,-56.34 -52.350166,-56.34 -53.6028324,-56.34 -54.8554988,-56.34 -56.1081652,-56.34 -57.3608316,-56.34 -58.613498,-56.34 -59.8661644,-56.34 -61.1188308,-56.34 -62.3714972,-56.34 -63.6241636,-56.34 -64.87683,-57.7966 -64.87683,-59.2532 -64.87683,-60.7098 -64.87683,-62.1664 -64.87683,-63.623 -64.87683,-65.0796 -64.87683,-66.5362 -64.87683,-67.9928 -64.87683,-69.4494 -64.87683,-70.906 -64.87683,-70.906 -63.6241636,-70.906 -62.3714972,-70.906 -61.1188308,-70.906 -59.8661644,-70.906 -58.613498,-70.906 -57.3608316,-70.906 -56.1081652,-70.906 -54.8554988,-70.906 -53.6028324,-70.906 -52.350166))", "dataset_titles": "Expedition Data; Expedition data of NBP0107", "datasets": [{"dataset_uid": "002656", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0107", "url": "https://www.rvdata.us/search/cruise/NBP0107"}, {"dataset_uid": "001962", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0011"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "9908828\u003cbr/\u003eAronson\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a paleoecological and paleoenvironmental study of Seymour Island. Global climate change late in the Eocene epoch had an important influence in Antarctica. This was the beginning of the transition from a cool-temperate climate in Antarctica to the polar climate that exists there today. The cooling trend strongly influenced the structure of shallow-water, Antarctic marine communities, and these effects are still evident in the peculiar ecological relationships among species living in modern Antarctic communities. Cooling late in the Eocene reduced the abundance of fish and crabs, which in turn reduced skeleton-crushing predation on invertebrates. Reduced predation allowed dense populations of ophiuroids (brittlestars) and crinoids (sea lilies) to appear in shallow-water settings at the end of the Eocene. These low-predation communities appear as dense fossil echinoderm assemblages in the upper portion of the late Eocene La Meseta Formation on Seymour Island, off the Antarctic Peninsula. Today, dense ophiuroid and crinoid populations are common in shallow-water habitats in Antarctica but generally have been eliminated by predators from similar habitats at temperate and tropical latitudes; their persistence in Antarctica to this day is an important ecological legacy of climatic cooling in the Eocene. Although the influence of declining predation on Antarctic ophiuroids and crinoids is now well documented, the effects of cooling on the more abundant mollusks have not been investigated. This study will examine the evolutionary ecology of gastropods (snails) and bivalves (clams) in the late Eocene.\u003cbr/\u003e\u003cbr/\u003eA series of hypotheses will be tested in the La Meseta Formation, based on the predicted responses of mollusks to declining temperature and changing levels of predation. The shapes of gastropod shells, the activities of gastropods that prey on other mollusks by drilling holes in their shells, and the effects of predation on the thickness of mollusk shells should have changed significantly through late Eocene time. First, defensive features of gastropod shells, such as spines and ribbing, should decline as temperature and, therefore, the activity of skeleton-crushing predators declined. Second, drilling of bivalve prey by predatory gastropods should increase with time since the drillers should themselves have been subject to lower predation pressure as temperature declined. Drilled shells, therefore, should become more common through time. Third, patterns in the thickness of shells through time will make it possible to separate the direct, physiological effects of declining temperature (shells are more difficult to produce at cooler temperatures, and so should be thinner) from the indirect effects of temperature on evolving biological interactions (increased drilling predation should result in thicker shells). \u003cbr/\u003e\u003cbr/\u003eSeymour Island contains the only fossil outcrops readily accessible in Antarctica from this crucial period in Earth history. The La Meseta Formation on Seymour Island thus provides a unique opportunity to learn how climate change affected Antarctic marine communities. In practical terms, global climate change will probably increase upwelling over the next few decades to centuries in some temperate coastal regions. Recent ecological evidence suggests that the resultant lowering of sea temperatures could lower predation in those areas. Understanding the response of the La Meseta faunas to global cooling in the late Eocene will provide direct insight into the rapidly changing structure of modern benthic communities.", "east": -56.34, "geometry": "POINT(-63.623 -58.613498)", "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; Hugo Island; R/V LMG; Palmer Deep", "locations": "Hugo Island", "north": -52.350166, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Aronson, Richard; Domack, Eugene Walter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.87683, "title": "Global Climate Change and the Evolutionary Ecology of Antarctic Mollusks in the Late Eocene", "uid": "p0000617", "west": -70.906}, {"awards": "9615342 Neale, Patrick", "bounds_geometry": null, "dataset_titles": "Expedition data of LMG9809", "datasets": [{"dataset_uid": "002720", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9809", "url": "https://www.rvdata.us/search/cruise/LMG9809"}, {"dataset_uid": "002719", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9809", "url": "https://www.rvdata.us/search/cruise/LMG9809"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Increases in ultraviolet-B radiation (UV-B, 280-320) associated with the Antarctic ozone hole have been shown to inhibit the photosynthesis of phytoplankton, but the overall effect on water column production is still a matter of debate and continued investigation. Investigations have also revealed that even at \"normal\" levels of Antarctic stratospheric ozone, UV-B and UV-A (320-400 nm) appear to have strong effects on water column production. The role of UV in the ecology of phytoplankton primary production has probably been underappreciated in the past and could be particularly important to the estimation of primary production in the presence of vertical mixing. This research focuses on quantifying UV effects on photosynthesis of Antarctic phytoplankton by defining biological weighting functions for UV-inhibition. In the past, techniques were developed to describe photosynthesis as a function of UV and visible irradiance using laboratory cultures. Further experimentation with natural assemblages from McMurdo Station in Antarctica showed that biological weighting functions are strongly related to light history. Most recently, measurements in the open waters of the Southern Ocean confirmed that there is substantial variability in the susceptibility of phytoplankton assemblages to UV. It was also discovered that inhibition of photosynthesis in Antarctic phytoplankton got progressively worse on the time scale of hours, with no evidence of recovery. Even under benign conditions, losses of photosynthetic capability persisted unchanged for several hours. This was in contrast with laboratory cultures and some natural assemblages which quickly attained a steady- state rate of photosynthesis during exposure to UV, reflecting a balance between damage and recovery processes. Slow reversal of UV-induced damage has profound consequences for water-column photosynthesis, especially during vertical mixing. Results to date have been used to model th e influence of UV, ozone depletion and vertical mixing on photosynthesis in Antarctic waters. Data indicate that normal levels of UV can have a significant impact on natural phytoplankton and that the effects can be exacerbated by ozone depletion as well as vertical mixing. Critical questions remain poorly resolved, however, and these are the focus of the present proposal. New theoretical and experimental approaches will be used to investigate UV responses in both the open waters of the Weddell-Scotia confluence and coastal waters near Palmer Station. In particular, measurements will be made of the kinetics of UV inhibition and recovery on time scales ranging from minutes to days. Variability in biological weighting functions between will be calculated for pelagic and coastal phytoplankton in the Southern Ocean. The results will provide absolute estimates of photosynthesis under in situ, as well as under altered, UV irradiance; broaden the range of assemblages for which biological weighting functions have been determined; and clarify how kinetics of inhibition and recovery should be represented in mixed layer models.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Mopper, Kenneth; Neale, Patrick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "New Approaches to Measuring and Understanding the Effects of Ultraviolet Radiation on Photosynthesis by Antarctic Phytoplankton", "uid": "p0000871", "west": null}, {"awards": "0125480 Manley, Patricia", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0602A", "datasets": [{"dataset_uid": "001571", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}, {"dataset_uid": "002618", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0602A", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}], "date_created": "Tue, 04 May 2010 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 demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.", "east": null, "geometry": null, "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 CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; 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": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: SHALDRIL - A Demonstration Drilling Cruise to the James Ross Basin", "uid": "p0000830", "west": null}, {"awards": "0125562 Zachos, James", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0602A", "datasets": [{"dataset_uid": "002617", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0602A", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}, {"dataset_uid": "001571", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}], "date_created": "Tue, 04 May 2010 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 demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.", "east": null, "geometry": null, "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 CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; 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": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Proposal: SHALDRIL - A Demonstration Drilling Cruise to the James Ross Basin", "uid": "p0000829", "west": null}, {"awards": "9908856 Blake, Daniel", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG0309", "datasets": [{"dataset_uid": "001683", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0309"}, {"dataset_uid": "002675", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0309", "url": "https://www.rvdata.us/search/cruise/LMG0309"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a paleoecological and paleoenvironmental study of Seymour Island. Global climate change late in the Eocene epoch had an important influence in Antarctica. This was the beginning of the transition from a cool-temperate climate in Antarctica to the polar climate that exists there today. The cooling trend strongly influenced the structure of shallow-water, Antarctic marine communities, and these effects are still evident in the peculiar ecological relationships among species living in modern Antarctic communities. Cooling late in the Eocene reduced the abundance of fish and crabs, which in turn reduced skeleton-crushing predation on invertebrates. Reduced predation allowed dense populations of ophiuroids (brittlestars) and crinoids (sea lilies) to appear in shallow-water settings at the end of the Eocene. These low-predation communities appear as dense fossil echinoderm assemblages in the upper portion of the late Eocene La Meseta Formation on Seymour Island, off the Antarctic Peninsula. Today, dense ophiuroid and crinoid populations are common in shallow-water habitats in Antarctica but generally have been eliminated by predators from similar habitats at temperate and tropical latitudes; their persistence in Antarctica to this day is an important ecological legacy of climatic cooling in the Eocene. Although the influence of declining predation on Antarctic ophiuroids and crinoids is now well documented, the effects of cooling on the more abundant mollusks have not been investigated. This study will examine the evolutionary ecology of gastropods (snails) and bivalves (clams) in the late Eocene.\u003cbr/\u003e\u003cbr/\u003eA series of hypotheses will be tested in the La Meseta Formation, based on the predicted responses of mollusks to declining temperature and changing levels of predation. The shapes of gastropod shells, the activities of gastropods that prey on other mollusks by drilling holes in their shells, and the effects of predation on the thickness of mollusk shells should have changed significantly through late Eocene time. First, defensive features of gastropod shells, such as spines and ribbing, should decline as temperature and, therefore, the activity of skeleton-crushing predators declined. Second, drilling of bivalve prey by predatory gastropods should increase with time since the drillers should themselves have been subject to lower predation pressure as temperature declined. Drilled shells, therefore, should become more common through time. Third, patterns in the thickness of shells through time will make it possible to separate the direct, physiological effects of declining temperature (shells are more difficult to produce at cooler temperatures, and so should be thinner) from the indirect effects of temperature on evolving biological interactions (increased drilling predation should result in thicker shells). \u003cbr/\u003e\u003cbr/\u003eSeymour Island contains the only fossil outcrops readily accessible in Antarctica from this crucial period in Earth history. The La Meseta Formation on Seymour Island thus provides a unique opportunity to learn how climate change affected Antarctic marine communities. In practical terms, global climate change will probably increase upwelling over the next few decades to centuries in some temperate coastal regions. Recent ecological evidence suggests that the resultant lowering of sea temperatures could lower predation in those areas. Understanding the response of the La Meseta faunas to global cooling in the late Eocene will provide direct insight into the rapidly changing structure of modern benthic communities.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blake, Daniel", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Global Climate Change and the Evolutionary Ecology of Antarctic Mollusks in the Late Eocene.", "uid": "p0000857", "west": null}, {"awards": "0126472 Taylor, Frederick", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG0209", "datasets": [{"dataset_uid": "002672", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0209", "url": "https://www.rvdata.us/search/cruise/LMG0209"}, {"dataset_uid": "001743", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0209"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds and field support to continue a study of plate motions in the Antarctic Peninsula and Scotia Sea region. The principal aim of the original \"Scotia Arc GPS Project (SCARP)\" was to determine motions of the Scotia Plate relative to adjacent plates and to measure crustal deformation along its margins with special attention to the South Sandwich microplate and Bransfield Strait extension. The focus of the present proposal is confined to the part of the SCARP project that includes GPS sites at Elephant Island, the South Shetland Islands and on the Antarctic Peninsula. The British Antarctic Survey provides data from two sites on the Scotia arc for this project. The northern margin of the Scotia Plate is not included herein because that region is not covered under Polar Programs. A separate proposal will request support for re-measuring SCARP GPS stations in South America. With regard to the Antarctic Peninsula area, continuously operating GPS stations were established at Frei Base, King George Island (in 1996) and at the Argentine Base, South Orkney Islands (in 1998). A number of monumented sites were established in the Antarctic Peninsula region in 1997 to support campaign-style GPS work in December 1997 and December 1998. Because of the expected slow crustal motion in the Bransfield Strait and expiration of the initial grant, no further data collection will be done until enough time has passed so that new measurements can be expected to yield precise results.\u003cbr/\u003e\u003cbr/\u003eThe primary aim of this work is to complete the measurements required to quantify crustal deformation related to opening of the Bransfield Strait, the South Shetland microplate, and to identify any other independent tectonic blocks that the GPS data may reveal. The measurements to be completed under this award will be done using ship support during the 2002-2003 season. This would be five years after the first measurements and would provide quite precise horizontal velocities. This project will complete the acquisition, processing, and interpretation of a single data set to continue this initial phase of the NSF-funded project to measure crustal motions along the southern margin of the Scotia plate. A principal investigator and one graduate student from the University of Texas will perform fieldwork. A graduate student from the University of Hawaii will process the new data consistent with previous data, and all of the SCARP investigators (Bevis, Dalziel, Smalley, Taylor: from U. Texas, U. Hawaii, and U. Memphis) will participate in interpreting the data. The British Antarctic Survey (BAS) and Alfred Wegener Institute (AWI) also recognized the importance of the Scotia plate and the Bransfield system in both global and local plate tectonic frameworks. They, too, have used GPS to measure crustal motions in this region and duplicate a number of our sites. They began earlier than we, have taken data more recently, presumably will continue taking data, and they have published some results. The collaboration between SCARP, BAS, and AWI begun earlier, will continue into this new work. Joint and separate publications are anticipated. The existing SCARP network has several advantages that justify collection and analysis of another set of data. One is that SCARP has established and measured GPS sites on Smith, Low, and Livingston Islands, where other groups have not. These sites significantly extend the dimensions of the South Shetland microplate so that we can determine a more precise pole of rotation and recognize any sub-blocks within the South Shetland arc. Smith and Low Islands are near the end of the Bransfield Basin where relative motion between the South Shetland Microplate must somehow terminate, perhaps by faulting along an extension of the Hero fracture zone. Another advantage is that measurements under SCARP were made using fixed-height masts that eliminate all but a fraction of a millimeter of vertical error in exactly re-occupying each site. Vertical motion associated with postglacial rebound should be on the order of several mm/yr, which will eventually be measurable. Mid-Holocene shorelines that emerged to more than 20m on some South Shetland arc islands suggest that vertical motion is significant. Thus, this work will contribute to understanding both plate motions and post-glacial rebound from ice mass loss in the region.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Taylor, Frederick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "The Scotia Arc GPS Project: Focus on the Antarctic Peninsula and South Shetland Islands", "uid": "p0000855", "west": null}, {"awards": "0125922 Anderson, John", "bounds_geometry": "POLYGON((-69.84264 -52.35215,-68.086508 -52.35215,-66.330376 -52.35215,-64.574244 -52.35215,-62.818112 -52.35215,-61.06198 -52.35215,-59.305848 -52.35215,-57.549716 -52.35215,-55.793584 -52.35215,-54.037452 -52.35215,-52.28132 -52.35215,-52.28132 -53.546701,-52.28132 -54.741252,-52.28132 -55.935803,-52.28132 -57.130354,-52.28132 -58.324905,-52.28132 -59.519456,-52.28132 -60.714007,-52.28132 -61.908558,-52.28132 -63.103109,-52.28132 -64.29766,-54.037452 -64.29766,-55.793584 -64.29766,-57.549716 -64.29766,-59.305848 -64.29766,-61.06198 -64.29766,-62.818112 -64.29766,-64.574244 -64.29766,-66.330376 -64.29766,-68.086508 -64.29766,-69.84264 -64.29766,-69.84264 -63.103109,-69.84264 -61.908558,-69.84264 -60.714007,-69.84264 -59.519456,-69.84264 -58.324905,-69.84264 -57.130354,-69.84264 -55.935803,-69.84264 -54.741252,-69.84264 -53.546701,-69.84264 -52.35215))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001571", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0602A"}, {"dataset_uid": "001602", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0502"}], "date_created": "Tue, 04 May 2010 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 demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this \"demonstration cruise\" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the \"Greenhouse-Icehouse\" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program\u0027s technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the \"no man\u0027s land\" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program\u0027s vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.", "east": -52.28132, "geometry": "POINT(-61.06198 -58.324905)", "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 CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; 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": -52.35215, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John; Wellner, Julia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.29766, "title": "Collaborative Research: SHALDRIL - A Demonstration Drilling Cruise to the James Ross Basin", "uid": "p0000571", "west": -69.84264}, {"awards": "9119683 Anderson, John", "bounds_geometry": "POLYGON((-179.999 -72.1543,-143.9991 -72.1543,-107.9992 -72.1543,-71.9993 -72.1543,-35.9994 -72.1543,0.000500000000017 -72.1543,36.0004 -72.1543,72.0003 -72.1543,108.0002 -72.1543,144.0001 -72.1543,180 -72.1543,180 -72.72384,180 -73.29338,180 -73.86292,180 -74.43246,180 -75.002,180 -75.57154,180 -76.14108,180 -76.71062,180 -77.28016,180 -77.8497,144.0001 -77.8497,108.0002 -77.8497,72.0003 -77.8497,36.0004 -77.8497,0.000499999999988 -77.8497,-35.9994 -77.8497,-71.9993 -77.8497,-107.9992 -77.8497,-143.9991 -77.8497,-179.999 -77.8497,-179.999 -77.28016,-179.999 -76.71062,-179.999 -76.14108,-179.999 -75.57154,-179.999 -75.002,-179.999 -74.43246,-179.999 -73.86292,-179.999 -73.29338,-179.999 -72.72384,-179.999 -72.1543))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002241", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9501"}, {"dataset_uid": "002258", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9401"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Marine geological and geophysical studies of the Ross Sea and Weddell Sea continental shelves provide evidence that the ice sheet grounded near the shelf edge in these areas during the late Wisconsinan, and that the retreat of the ice sheet to its present position was rapid and probably episodic. This Award supports a project which will establish the most recent (late Wisconsin- Holocene) history of ice sheet advance and retreat in Ross Sea. The objectives include: 1) reconstruction the late Wisconsin paleodrainage regime, including ice stream divides; 2) reconstruction of former grounding zone positions; 3) constraint of the timing of ice sheet retreat from the shelf; and 4) acquisition of geophysical, sedimentological, and paleontological data which may provide indicators the environmental factors that may have influenced to ice sheet retreat. This is a joint effort between Rice University, the University of Colorado, and Hamilton College. The project involves experts in a wide variety of fields, and will interface with glaciologists, physical oceanographers and climatologists who will address the problem of ice sheet stability and the record of climatic and glaciological change.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -72.1543, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -77.8497, "title": "Geologic Record of Late Wisconsinan/Holocene Ice Sheet Advance and Retreat from Ross Sea", "uid": "p0000641", "west": -179.999}, {"awards": "0732995 Barbeau, David", "bounds_geometry": "POLYGON((-67.9988 -52.7596,-66.83756 -52.7596,-65.67632 -52.7596,-64.51508 -52.7596,-63.35384 -52.7596,-62.1926 -52.7596,-61.03136 -52.7596,-59.87012 -52.7596,-58.70888 -52.7596,-57.54764 -52.7596,-56.3864 -52.7596,-56.3864 -54.15258,-56.3864 -55.54556,-56.3864 -56.93854,-56.3864 -58.33152,-56.3864 -59.7245,-56.3864 -61.11748,-56.3864 -62.51046,-56.3864 -63.90344,-56.3864 -65.29642,-56.3864 -66.6894,-57.54764 -66.6894,-58.70888 -66.6894,-59.87012 -66.6894,-61.03136 -66.6894,-62.1926 -66.6894,-63.35384 -66.6894,-64.51508 -66.6894,-65.67632 -66.6894,-66.83756 -66.6894,-67.9988 -66.6894,-67.9988 -65.29642,-67.9988 -63.90344,-67.9988 -62.51046,-67.9988 -61.11748,-67.9988 -59.7245,-67.9988 -58.33152,-67.9988 -56.93854,-67.9988 -55.54556,-67.9988 -54.15258,-67.9988 -52.7596))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001520", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0717"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project studies the relationship between opening of the Drake Passage and formation of the Antarctic ice sheet. Its goal is to answer the question: What drove the transition from a greenhouse to icehouse world thirty-four million years ago? Was it changes in circulation of the Southern Ocean caused by the separation of Antarctica from South America or was it a global effect such as decreasing atmospheric CO2 content? This study constrains the events and timing through fieldwork in South America and Antarctica and new work on marine sediment cores previously collected by the Ocean Drilling Program. It also involves an extensive, multidisciplinary analytical program. Compositional analyses of sediments and their sources will be combined with (U-Th)/He, fission-track, and Ar-Ar thermochronometry to constrain uplift and motion of the continental crust bounding the Drake Passage. Radiogenic isotope studies of fossil fish teeth found in marine sediment cores will be used to trace penetration of Pacific seawater into the Atlantic. Oxygen isotope and trace metal measurements on foraminifera will provide additional information on the timing and magnitude of ice volume changes. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThe broader impacts include graduate and undergraduate education; outreach to the general public through museum exhibits and presentations, and international collaboration with scientists from Argentina, Ukraine, UK and Germany.\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThe project is supported under NSF\u0027s International Polar Year (IPY) research emphasis area on \"Understanding Environmental Change in Polar Regions\". This project is also a key component of the IPY Plates \u0026 Gates initiative (IPY Project #77), focused on determining the role of tectonic gateways in instigating polar environmental change.", "east": -56.3864, "geometry": "POINT(-62.1926 -59.7245)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": -52.7596, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "MacPhee, Ross", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -66.6894, "title": "Collaborative Research: IPY: Testing the Polar Gateway Hypothesis: An Integrated Record of Drake Passage Opening \u0026 Antarctic Glaciation", "uid": "p0000120", "west": -67.9988}, {"awards": "9811427 Felbeck, Horst", "bounds_geometry": null, "dataset_titles": "Expedition data of LMG9902", "datasets": [{"dataset_uid": "002716", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9902", "url": "https://www.rvdata.us/search/cruise/LMG9902"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Deception Island is a flooded caldera in the South Shetland Islands, Antarctica. The most recent eruption was in the 1970s causing the formation of new islands in the caldera and various other structures. It harbors many hot springs and fumaroles submerged in the caldera and intertidally. Sulfide and methane are prominent chemicals in the outflowing waters. Bacterial densities in the caldera reach unusually high values probably due to the input of reduced chemicals as energy sources. The environment around the springs resembles that found at hydrothermal vents where whole communities are based on the input of chemical energy by the hot waters. Similarities to hydrothermal vent environments include cold waters surrounding the hot springs resulting in large distances to the next warm water habitat and a lack of external food sources. The latter is due to ice cover during winter at Deception Island and the large distance to the euphotic zone at the vent sites. These parameters encourage the evolution of alternative ways to support life such as the establishment of a bacterial symbiosis. This Small Grant for Exploratory Research project will focus on an examination of the warm springs around Deception Island for the presence of marine invertebrates with chemoautotrophic symbionts. Maps will be made of any submerged fumaroles and of warm and hot springs in the intertidal zone. If animals are found near the fumaroles or in the hot springs, specimens will be collected. Collected specimens will be examined for the presence of chemoautotrophic bacteria and other adaptations to a hot sulfide- and methane-rich environment using enzyme text experimental incubations to analyze metabolic pathways and microscopic examination.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Ken", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Adaptations of Organisms at the Sulfide- and Methane-Containing Hydrothermal Areas of Deception Island, Antarctica", "uid": "p0000868", "west": null}, {"awards": "0440666 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": "Histories of Accumulation, Thickness, and WAIS Divide Location, Antarctica", "datasets": [{"dataset_uid": "609473", "doi": "10.7265/N5QR4V2J", "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; WAIS Divide; WAIS Divide Ice Core", "people": "Koutnik, Michelle; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Histories of Accumulation, Thickness, and WAIS Divide Location, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609473"}], "date_created": "Thu, 04 Mar 2010 00:00:00 GMT", "description": "This award supports development of a new modeling approach that will extract information about past snow accumulation rate in both space and time in the vicinity of the future ice core near the Ross-Amundsen divide of the West Antarctic Ice Sheet (WAIS). Internal layers, detected by ice-penetrating radar, are isochrones, or former ice-sheet surfaces that have been buried by subsequent snowfall, and distorted by ice flow. Extensive ice-penetrating radar data are available over the inland portion of the WAIS. Layers have been dated back to 17,000 years before present. The radar data add the spatial dimension to the temporally resolved accumulation record from ice cores. Accumulation rates are traditionally derived from the depths of young, shallow layers, corrected for strain using a local 1-D ice-flow model. Older, deeper layers have been more affected by flow over large horizontal distances. However, it is these deeper layers that contain information on longer-term climate patterns. This project will use geophysical inverse theory and a 2.5D flow-band ice-flow forward model comprising ice-surface and layer-evolution modules, to extract robust transient accumulation patterns by assimilating multiple deeper, more-deformed layers that have previously been intractable. Histories of divide migration, geothermal flux, and surface evolution will also be produced. The grant will support the PhD research of a female graduate student who is a mentor to female socio-economically disadvantaged high-school students interested in science, through the University of Washington Women\u0027s Center. It will also provide a research\u003cbr/\u003eexperience for an undergraduate student, and contribute to a freshman seminar on Scientific Research.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS", "is_usap_dc": true, "keywords": "Ross-Amundsen Divide; FIELD SURVEYS; Internal Layers; Ice Flow Model; West Antarctic Ice Sheet; Accumulation; Glacier; Ice Penetrating Radar; Model; MODELS; Snow Accumulation; GPS; Antarctica; Isochron; Not provided; Snowfall; Radar", "locations": "West Antarctic Ice Sheet; Antarctica; Ross-Amundsen Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e MODELS; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach", "uid": "p0000018", "west": null}, {"awards": "0440817 Taylor, Kendrick", "bounds_geometry": null, "dataset_titles": "WAIS Divide Ice Core Images, Antarctica", "datasets": [{"dataset_uid": "609375", "doi": "10.7265/N5348H8T", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Optical Images; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "McGwire, Kenneth C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Images, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609375"}], "date_created": "Wed, 10 Feb 2010 00:00:00 GMT", "description": "This award supports the coordination of an interdisciplinary and multi institutional deep ice coring program in West Antarctica. The program will develop interrelated climate, ice dynamics, and biologic records focused on understanding interactions of global earth systems. The records will have a year-by-year chronology for the most recent 40,000 years. Lower temporal resolution records will extend to 100,000 years before present. The intellectual activity of this project includes enhancing our understanding of the natural mechanisms that cause climate change. The study site was selected to obtain the best possible material, available from anywhere, to determine the role of greenhouse gas in the last series of major climate changes. The project will study the how natural changes in greenhouse gas concentrations influence climate. The influence of sea ice and atmospheric circulation on climate changes will also be investigated. Other topics that will be investigated include the influence of the West Antarctic ice sheet on changes in sea level and the biology deep in the ice sheet. The broader impacts of this project include developing information required by other science communities to improve predictions of future climate change. The \u003cbr/\u003eproject will use mass media to explain climate, glaciology, and biology issues to a broad audience. The next generation of ice core investigators will be trained and there will be an emphasis on exposing a diverse group of students to climate, glaciology and biology research.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Antarctica; Not provided; Ice Core Data; West Antarctica; LABORATORY; Ice Core; FIELD INVESTIGATION", "locations": "Antarctica; West Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McGwire, Kenneth C.", "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": "WAIS Divide Ice Core", "south": null, "title": "Investigation of Climate, Ice Dynamics and Biology using a Deep Ice Core from the West Antarctic Ice Sheet Ice Divide", "uid": "p0000182", "west": null}, {"awards": "0440954 Miller, Molly; 0551163 Sidor, Christian; 0440919 Isbell, John", "bounds_geometry": "POLYGON((159.3 -76.59,159.542 -76.59,159.784 -76.59,160.026 -76.59,160.268 -76.59,160.51 -76.59,160.752 -76.59,160.994 -76.59,161.236 -76.59,161.478 -76.59,161.72 -76.59,161.72 -76.811,161.72 -77.032,161.72 -77.253,161.72 -77.474,161.72 -77.695,161.72 -77.916,161.72 -78.137,161.72 -78.358,161.72 -78.579,161.72 -78.8,161.478 -78.8,161.236 -78.8,160.994 -78.8,160.752 -78.8,160.51 -78.8,160.268 -78.8,160.026 -78.8,159.784 -78.8,159.542 -78.8,159.3 -78.8,159.3 -78.579,159.3 -78.358,159.3 -78.137,159.3 -77.916,159.3 -77.695,159.3 -77.474,159.3 -77.253,159.3 -77.032,159.3 -76.811,159.3 -76.59))", "dataset_titles": "Burke Museum of Natural History and Culture, University of Washington ID#s UWBM 88593-88601, UWBM 88617; Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica", "datasets": [{"dataset_uid": "600045", "doi": "10.15784/600045", "keywords": "Allan Hills; Antarctica; Paleontology; Sample/collection Description; Sample/Collection Description; Solid Earth", "people": "Miller, Molly", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600045"}, {"dataset_uid": "000124", "doi": "", "keywords": null, "people": null, "repository": "Burke Museum", "science_program": null, "title": "Burke Museum of Natural History and Culture, University of Washington ID#s UWBM 88593-88601, UWBM 88617", "url": "http://www.washington.edu/burkemuseum/collections/"}], "date_created": "Mon, 12 Oct 2009 00:00:00 GMT", "description": "This project studies fossils from two to three hundred million year old rocks in the Allan Hills area of Antarctica. Similar deposits from lower latitudes have been used to develop a model of Permo-Triassic climate, wherein melting of continental glaciers in the early Permian leads to the establishment of forests in a cold, wet climate. Conditions became warmer and dryer by the early Triassic, inhibiting plant growth until a moistening climate in the late Triassic allowed plant to flourish once again. This project will test and refine this model and investigate the general effects of climate change on landscapes and ecosystems using the unique exposures and well-preserved fossil and sediment records in the Allan Hills area. The area will be searched for fossil forests, vertebrate tracks and burrows, arthropod trackways, and subaqueously produced biogenic structures, which have been found in other areas of Antarctica. Finds will be integrated with previous paleobiologic studies to reconstruct and interpret ecosystems and their changes. Structures and rock types documenting the end phases of continental glaciation and other major episodic sedimentations will also be described and interpreted. This project contributes to understanding the: (1) evolution of terrestrial and freshwater ecosystems and how they were affected by the end-Permian extinction, (2) abundance and diversity of terrestrial and aquatic arthropods at high latitudes, (3) paleogeographic distribution and evolution of vertebrates and invertebrates as recorded by trace and body fossils; and (3) response of landscapes to changes in climate.\u003cbr/\u003e\u003cbr/\u003eIn terms of broader impacts, this project will provide an outstanding introduction to field research for graduate and undergraduate students, and generate related opportunities for several undergraduates. It will also stimulate exchange of ideas among research and primarily undergraduate institutions. Novel outreach activities are also planned to convey Earth history to the general public, including a short film on the research process and products, and paintings by a professional scientific illustrator of Permo-Traissic landscapes and ecosystems.", "east": 161.72, "geometry": "POINT(160.51 -77.695)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.59, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e PALEOZOIC \u003e CARBONIFEROUS \u003e PENNSYLVANIAN; PHANEROZOIC \u003e PALEOZOIC \u003e PERMIAN; PHANEROZOIC \u003e MESOZOIC \u003e TRIASSIC", "persons": "Miller, Molly; Sidor, Christian; Isbell, John", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "Burke Museum; USAP-DC", "science_programs": "Allan Hills", "south": -78.8, "title": "Collaborative Research: Reconstructing the High Latitude Permian-Triassic: Life, Landscapes, and Climate Recorded in the Allan Hills, South Victoria Land, Antarctica", "uid": "p0000207", "west": 159.3}, {"awards": "0636747 Warny, Sophie", "bounds_geometry": "POINT(-54.44917 -63.86)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 26 Aug 2009 00:00:00 GMT", "description": "Abstract\u003cbr/\u003eThis project studies microfossils of plants and algae to understand climate during the earliest glaciations of Antarctica. The microfossils are from marine sediment cores collected by the 2006 SHALDRIL campaign to the Antarctic Peninsula. The work will offer constraints on sea surface temperature, ocean salinity, and terrestrial vegetation to help answer questions such as: What were conditions like on the Antarctic Peninsula during the initial formation of Antarctica\u0027s ice sheets? How rapidly did the ice sheets grow? Was their growth driven by global factors such as low atmospheric CO2 or local events like opening of the Drake Passage? \u003cbr/\u003e\u003cbr/\u003eThe broader impacts include postdoctoral fellow research and outreach via a museum exhibit and a web-based activity book for children.", "east": -54.44917, "geometry": "POINT(-54.44917 -63.86)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -63.86, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Warny, Sophie", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -63.86, "title": "Past Environmental Conditions on the Antarctic Peninsula: a Palynological Characterization of In-situ Sediments recovered during the 2006 SHALDRIL campaign", "uid": "p0000484", "west": -54.44917}, {"awards": "0739512 Walker, Sally; 0739583 Bowser, Samuel; 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": "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/"}, {"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": null, "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Gillikin, David; Camarra, Steve; Cronin, Kelly; Walker, Sally; Verheyden, Anouk; Puhalski, Emma", "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"}], "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": "0739693 Ashworth, Allan; 0739700 Marchant, David", "bounds_geometry": "POLYGON((160 -77,160.2 -77,160.4 -77,160.6 -77,160.8 -77,161 -77,161.2 -77,161.4 -77,161.6 -77,161.8 -77,162 -77,162 -77.1,162 -77.2,162 -77.3,162 -77.4,162 -77.5,162 -77.6,162 -77.7,162 -77.8,162 -77.9,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,160.8 -78,160.6 -78,160.4 -78,160.2 -78,160 -78,160 -77.9,160 -77.8,160 -77.7,160 -77.6,160 -77.5,160 -77.4,160 -77.3,160 -77.2,160 -77.1,160 -77))", "dataset_titles": "Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "datasets": [{"dataset_uid": "600081", "doi": "10.15784/600081", "keywords": "Antarctica; Geochronology; Geology/Geophysics - Other; GPS; Solid Earth", "people": "Ashworth, Allan; Lewis, Adam", "repository": "USAP-DC", "science_program": null, "title": "Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/600081"}], "date_created": "Mon, 22 Jun 2009 00:00:00 GMT", "description": "This project studies the last vestiges of life in Antarctica from exceptionally well-preserved fossils of tundra life--mosses, diatoms, ostracods, Nothofagus leaves, wood, and insect remains recently discovered in ancient lake sediments from the McMurdo Dry Valleys. The area will be studied by an interdisciplinary team to elucidate information about climate and biogeography. These deposits offer unique and direct information about the characteristics of Antarctica during a key period in its history, the time when it was freezing. This information is critical for correlation with indirect proxies, such as though obtained from drill cores, for climate and state of the ice sheet. The results will also help understand the origin and migration of similar organisms found in South America, India and Australia.\u003cbr/\u003e\u003cbr/\u003eIn terms of broader impacts, this project supports an early career researcher, undergraduate and graduate student research, various forms of outreach to K12 students, and extensive international collaboration. The work also has societal relevance in that the outcomes will offer direct constraints on Antarctica\u0027s ice sheet during a time with atmospheric CO2 contents similar to those of the earth in the coming centuries, and thus may help predictive models of sea level rise.", "east": 162.0, "geometry": "POINT(161 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided; Antarctica; Vegetation; Paleoclimate; Middle Miocene; Tundra; Bu/es Data Repository; Mcmurdo Dry Valleys; Lacustrine; Fossil", "locations": "Antarctica; Mcmurdo Dry Valleys", "north": -77.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Ashworth, Allan; Lewis, Adam", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research: Integrating Geomorphological and Paleoecological Studies to Reconstruct Neogene Environments of the Transantarctic Mountains", "uid": "p0000188", "west": 160.0}, {"awards": "0742057 Gallager, Scott", "bounds_geometry": "POLYGON((-168.291 -64.846,-165.018 -64.846,-161.745 -64.846,-158.472 -64.846,-155.199 -64.846,-151.926 -64.846,-148.653 -64.846,-145.38 -64.846,-142.107 -64.846,-138.834 -64.846,-135.561 -64.846,-135.561 -66.0269,-135.561 -67.2078,-135.561 -68.3887,-135.561 -69.5696,-135.561 -70.7505,-135.561 -71.9314,-135.561 -73.1123,-135.561 -74.2932,-135.561 -75.4741,-135.561 -76.655,-138.834 -76.655,-142.107 -76.655,-145.38 -76.655,-148.653 -76.655,-151.926 -76.655,-155.199 -76.655,-158.472 -76.655,-161.745 -76.655,-165.018 -76.655,-168.291 -76.655,-168.291 -75.4741,-168.291 -74.2932,-168.291 -73.1123,-168.291 -71.9314,-168.291 -70.7505,-168.291 -69.5696,-168.291 -68.3887,-168.291 -67.2078,-168.291 -66.0269,-168.291 -64.846))", "dataset_titles": "SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions", "datasets": [{"dataset_uid": "600086", "doi": "10.15784/600086", "keywords": "Amundsen Sea; Biota; Microbiology; Navigation; Oceans; Oden; OSO2007; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Dennett, Mark; Gallager, Scott", "repository": "USAP-DC", "science_program": null, "title": "SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions", "url": "https://www.usap-dc.org/view/dataset/600086"}], "date_created": "Mon, 16 Mar 2009 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003eThe research will continue and extend the study in the Southern Ocean that was initiated during the Oden Southern Ocean 2006 expedition in collaboration with Swedish scientist Mellissa Chierici. We will quantify carbon flux through the food web in the marginal ice zone (MIZ) by measuring size fractionated primary and secondary production, grazing and carbon flux through nanoplankton (2-20 um), microplankton (20-200um), and mesoplankton (200-2000 um). Community structure, species abundance and size specific grazing rates will be quantified using a variety of techniques both underway and at ice stations along the MIZ. The proposed cruise track extends across the Drake Passage to the Western Antarctic Peninsula (WAP) with three station transects along a gradient from the open ocean through the marginal ice zone (MIZ) in the Bellinghausen and Amundsen Seas and into the Ross Sea Polynya. Ice stations along each transect will provide material to characterize production associated with annual ice. Underway measurements of primary and secondary production (chlorophyll, CDOM, microplankton, and mesoplankton) and hydrography (temperature, salinity, pH, DO, turbidity) will establish a baseline for future cruises and as support for other projects such as biogeochemical studies on carbon dioxide drawdown and trace metal work on primary production. The outcome of these measurements will be a description of nano to mesoplankton standing stocks, community structure, and carbon flux along the MIZ in the Bellinghausen and Amundsen Seas and the Ross Sea Polynya.", "east": -135.561, "geometry": "POINT(-151.926 -70.7505)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -64.846, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Gallager, Scott; Dennett, Mark", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.655, "title": "SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions", "uid": "p0000563", "west": -168.291}, {"awards": "9911617 Blankenship, Donald; 9319379 Blankenship, Donald", "bounds_geometry": null, "dataset_titles": "Antarctic Aerogeophysics Data; Antarctic Subglacial Lake Classification Inventory; RBG - Robb Glacier Survey; SOAR-Lake Vostok Survey airborne radar data; SOAR-Lake Vostok Survey bed elevation data; SOAR-Lake Vostok Survey Gravity data; SOAR-Lake Vostok Survey ice thickness data; SOAR-Lake Vostok survey magnetic anomaly data; SOAR-Lake Vostok Survey surface elevation data", "datasets": [{"dataset_uid": "609336", "doi": "10.7265/N5CN71VX", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Subglacial Lake", "people": "Blankenship, Donald D.; Carter, Sasha P.; Holt, John W.", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Subglacial Lake Classification Inventory", "url": "https://www.usap-dc.org/view/dataset/609336"}, {"dataset_uid": "609240", "doi": "", "keywords": "Airborne Radar; Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Navigation; Potential Field; SOAR; Solid Earth", "people": "Blankenship, Donald D.; Holt, John W.; Dalziel, Ian W.; Morse, David L.", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Aerogeophysics Data", "url": "https://www.usap-dc.org/view/dataset/609240"}, {"dataset_uid": "601298", "doi": "10.1594/IEDA/306566", "keywords": "Airborne Altimetry; Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Sheet Elevation; Ice Surface; Lake Vostok; Radar Echo Sounder; SOAR; Surface Elevation", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey surface elevation data", "url": "https://www.usap-dc.org/view/dataset/601298"}, {"dataset_uid": "601296", "doi": " 10.1594/IEDA/306564", "keywords": "Airborne Magnetic; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Lake Vostok; Magnetic; Magnetic Anomaly; Magnetometer; Potential Field; SOAR; Solid Earth", "people": "Studinger, Michael S.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok survey magnetic anomaly data", "url": "https://www.usap-dc.org/view/dataset/601296"}, {"dataset_uid": "601604", "doi": "10.15784/601604", "keywords": "Airborne Radar; Antarctica; Bed Elevation; Geophysics; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Surface Elevation; Ice Thickness; Robb Glacier; Transantarctic Mountains", "people": "Young, Duncan A.; Buck, W. Roger; Blankenship, Donald D.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "RBG - Robb Glacier Survey", "url": "https://www.usap-dc.org/view/dataset/601604"}, {"dataset_uid": "601297", "doi": "10.1594/IEDA/306567", "keywords": "Airborne Laser Altimeters; Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Sheet; Ice Stratigraphy; Ice Thickness; Ice Thickness Distribution; Lake Vostok; Radar; Radar Altimetry; Radar Echo Sounder; SOAR; Subglacial Lake", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey ice thickness data", "url": "https://www.usap-dc.org/view/dataset/601297"}, {"dataset_uid": "601295", "doi": "10.1594/IEDA/306563", "keywords": "Airborne Gravity; Airplane; Antarctica; East Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Lake Vostok; Potential Field; Solid Earth", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey Gravity data", "url": "https://www.usap-dc.org/view/dataset/601295"}, {"dataset_uid": "601300", "doi": "10.1594/IEDA/306568", "keywords": "Airborne Radar; Airplane; Antarctica; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Navigation; Radar; SOAR; Subglacial Lakes", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey airborne radar data", "url": "https://www.usap-dc.org/view/dataset/601300"}, {"dataset_uid": "601299", "doi": "10.1594/IEDA/306565", "keywords": "Airborne Laser Altimeters; Airborne Laser Altimetry; Airborne Radar; Airplane; Antarctica; Bed Elevation; Bedrock Elevation; Digital Elevation Model; East Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Lake Vostok; Radar; Radar Echo Sounder; SOAR", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-Lake Vostok Survey bed elevation data", "url": "https://www.usap-dc.org/view/dataset/601299"}], "date_created": "Fri, 06 Feb 2009 00:00:00 GMT", "description": "9911617\u003cbr/\u003eBlankenship\u003cbr/\u003e\u003cbr/\u003eThis award, provided jointly by the Antarctic Geology and Geophysics Program, the Antarctic Glaciology Program, and the Polar Research Support Section of the Office of Polar Programs, provides funds for continuation of the Support Office for Aerogeophysical Research (SOAR). From July 1994 to July 2000, SOAR served as a facility to accomplish aerogeophysical research in Antarctica under an agreement between the University of Texas at Austin and the National Science Foundation\u0027s Office of Polar Programs (NSF/OPP). SOAR operated and maintained an aerogeophysical instrument package that consists of an ice-penetrating radar sounder, a laser altimeter, a gravimeter and a magnetometer that are tightly integrated with each other as well as with the aircraft\u0027s avionics and power packages. An array of aircraft and ground-based GPS receivers supported kinematic differential positioning using carrier-phase observations. SOAR activities included: developing aerogeophysical research projects with NSF/OPP investigators; upgrading of the aerogeophysical instrumentation package to accommodate new science projects and advances in technology; fielding this instrument package to accomplish SOAR-developed projects; and management, reduction, and analysis of the acquired aerogeophysical data. In pursuit of 9 NSF-OPP funded aerogeophysical research projects (involving 14 investigators from 9 institutions), SOAR carried out six field campaigns over a six-year period and accomplished approximately 200,000 line kilometers of aerogeophysical surveying over both East and West Antarctica in 377 flights.\u003cbr/\u003e\u003cbr/\u003eThis award supports SOAR to undertake a one year and 8 month program of aerogeophysical activities that are consistent with continuing U.S. support for geophysical research in Antarctica. \u003cbr/\u003e- SOAR will conduct an aerogeophysical campaign during the 200/01 austral summer to accomplish surveys for two SOAR-developed projects: \"Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Studies\" (Co-PI\u0027s Bell and Studinger, LDEO); and \"Collaborative Research: Seismic Investigation of the Deep Continental Structure Across the East-West Antarctic Boundary\" (Co-PI\u0027s Weins, Washington U. and Anandakrishnan, U. Alabama). After configuration and testing of the survey aircraft in McMurdo, SOAR will conduct survey flights from an NSF-supported base adjacent to the Russian Station above Lake Vostok and briefly occupy one or two remote bases on the East Antarctic ice sheet.\u003cbr/\u003e- SOAR will reduce these aerogeophysical data and produce profiles and maps of surface elevation, bed elevation, gravity and magnetic field intensity. These results will be provided to the respective project investigators within nine months of conclusion of field activities. We will also submit a technical manuscript that describes these results to a refereed scientific journal and distribute these results to appropriate national geophysical data centers within approximately 24 months of completion of field activities.\u003cbr/\u003e- SOAR will standardize all previously reduced SOAR data products and transfer them to the appropriate national geophysical data centers by the end of this grant.\u003cbr/\u003e- SOAR will convene a workshop to establish a community consensus for future U.S. Antarctic aerogeophysical research. This workshop will be co-convened by Ian Dalziel and Richard Alley and will take place during the spring of 2001.\u003cbr/\u003e- SOAR will upgrade the existing SOAR in-field quality control procedures to serve as a web-based interface for efficient browsing of many low-level SOAR data streams.\u003cbr/\u003e- SOAR will repair and/or refurbish equipment that was used during the 2000/01 field campaign.\u003cbr/\u003e\u003cbr/\u003eSupport for SOAR is essential for accomplishing major geophysical investigations in Antarctica. Following data interpretation by the science teams, these data will provide valuable insights to the structure and evolution of the Antarctic continent.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS; 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 GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LIDAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e PROTON MAGNETOMETER", "is_usap_dc": true, "keywords": "Ice Sheet; Ice Sheet Elevation; Surface Winds; Snow Temperature; Atmospheric Pressure; Antarctic; West Antarctic Ice Sheet; Surface Temperature Measurements; FIELD INVESTIGATION; Surface Wind Speed Measurements; Subglacial Topography; Atmospheric Humidity Measurements; Not provided; Aerogeophysics; FIELD SURVEYS; GROUND STATIONS; Antarctica; SOAR; Snow Temperature Measurements; West Antarctica; Antarctic Ice Sheet; East Antarctic Plateau", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; West Antarctica; West Antarctic Ice Sheet; East Antarctic Plateau", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Carter, Sasha P.; Holt, John W.; Blankenship, Donald D.; Morse, David L.; Dalziel, Ian W.", "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 STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Continuation of Activities for the Support Office for Aerogeophysical Research (SOAR)", "uid": "p0000125", "west": null}, {"awards": "0225110 Garrott, Robert", "bounds_geometry": "POLYGON((163.1 -70.3,163.59 -70.3,164.08 -70.3,164.57 -70.3,165.06 -70.3,165.55 -70.3,166.04 -70.3,166.53 -70.3,167.02 -70.3,167.51 -70.3,168 -70.3,168 -70.98,168 -71.66,168 -72.34,168 -73.02,168 -73.7,168 -74.38,168 -75.06,168 -75.74,168 -76.42,168 -77.1,167.51 -77.1,167.02 -77.1,166.53 -77.1,166.04 -77.1,165.55 -77.1,165.06 -77.1,164.57 -77.1,164.08 -77.1,163.59 -77.1,163.1 -77.1,163.1 -76.42,163.1 -75.74,163.1 -75.06,163.1 -74.38,163.1 -73.7,163.1 -73.02,163.1 -72.34,163.1 -71.66,163.1 -70.98,163.1 -70.3))", "dataset_titles": "Weddell Seal data", "datasets": [{"dataset_uid": "000120", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Weddell Seal data", "url": "http://www.montana.edu/weddellseals/"}], "date_created": "Wed, 28 Jan 2009 00:00:00 GMT", "description": "The Erebus Bay Weddell seal population study in eastern McMurdo Sound, Antarctica was initiated in 1968 and represents one of the longest intensive field investigations of a long-lived mammal in existence. Over the thirty-four year period of this study a total of 15,636 animals have been tagged with 144,927 re-sighting records logged in the current database. As such, this study is an extremely valuable resource for understanding population dynamics of not only Weddell seals, but also other species of both terrestrial and marine mammals with similar life-history characteristics. With the retirement of the original investigator, Dr. Donald Siniff, this proposal represents an effort to transition the long-term studies to a new team of investigators. Dr. Robert Garrott and Dr. Jay Rotella propose building upon the foundation with two lines of investigation that combine use of the long-term database with new field initiatives. The continuity of the demographic data will be maintained by annually marking all pups born, replace lost or broken tags, and perform multiple mark-recapture censuses of the Erebus Bay seal colonies. The new data will be combined with the existing database and a progressively complex series of analyses will be performed using recently developed mark-recapture methods to decompose, evaluate, and integrate the demographic characteristics of the Erebus Bay Weddell seal population. These analyses will allow the testing of specific hypotheses about population regulation as well as temporal and spatial patterns of variation in vital rates among colonies within the population that have been posed by previous investigators, but have not been adequately evaluated due to data and analytical limitations. The primary new field initiative will involve an intensive study of mass dynamics of both pups and adult females as a surrogate measure for assessing annual variation in marine resources and their potential role in limiting and/or regulating the population. In conjunction with the collection of data on body mass dynamics the investigators will use satellite imagery to develop an extended time series of sea ice extent in McMurdo Sound. Regional extent of sea ice affects both regional primary productivity and availability of haul out areas for Weddell seals. Increased primary productivity may increase marine resources which would be expected to have a positive affect on Weddell seal foraging efficiency, leading to increased body mass. These data combined with the large proportion of known-aged seals in the current study population (\u003e60%) will allow the investigators to develop a powerful database to test specific hypotheses about ecological processes affecting Weddell seals. Knowledge of the mechanisms that limit and/or regulate Weddell seal populations and the specific bio-physical linkages between climate, oceans, ice, and Antarctic food webs can provide important contributions to understanding of pinniped population dynamics, as well as contribute more generally to theoretical understanding of population, community, and ecosystem patterns and processes. Such knowledge can be readily applied elsewhere to enhance the ability of natural resource managers to effectively maintain assemblages of other large-mammal species and the ecological processes that they facilitate. Continuation of this long-term study may also contribute to understanding the potential impacts of human activities such as global climate warming and the commercial exploitation of Antarctic marine resources. And finally, the study can contribute significantly to the development and testing of new research and analytical methodologies that will almost certainly have many other applications.", "east": 168.0, "geometry": "POINT(165.55 -73.7)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.3, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Garrott, Robert; Siniff, Donald; Rotella, Jay", "platforms": "Not provided", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -77.1, "title": "Patterns and Processes: Dynamics of the Erebus Bay Weddell Seal Population", "uid": "p0000109", "west": 163.1}, {"awards": "0230268 Anderson, Robert", "bounds_geometry": "POLYGON((-180 -50,-169 -50,-158 -50,-147 -50,-136 -50,-125 -50,-114 -50,-103 -50,-92 -50,-81 -50,-70 -50,-70 -51.5,-70 -53,-70 -54.5,-70 -56,-70 -57.5,-70 -59,-70 -60.5,-70 -62,-70 -63.5,-70 -65,-81 -65,-92 -65,-103 -65,-114 -65,-125 -65,-136 -65,-147 -65,-158 -65,-169 -65,180 -65,177 -65,174 -65,171 -65,168 -65,165 -65,162 -65,159 -65,156 -65,153 -65,150 -65,150 -63.5,150 -62,150 -60.5,150 -59,150 -57.5,150 -56,150 -54.5,150 -53,150 -51.5,150 -50,153 -50,156 -50,159 -50,162 -50,165 -50,168 -50,171 -50,174 -50,177 -50,-180 -50))", "dataset_titles": "Southern Ocean Deglacial Opal, Radionuclide, and Diatom Upwelling Data", "datasets": [{"dataset_uid": "000199", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Southern Ocean Deglacial Opal, Radionuclide, and Diatom Upwelling Data", "url": "https://www.ncdc.noaa.gov/paleo/study/8439"}], "date_created": "Mon, 12 Jan 2009 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the \"Silicic Acid Leakage Hypothesis\" as it relates to global carbon dioxide fluctuations during glacial-interglacial cycles.\u003cbr/\u003e\u003cbr/\u003eIntellectual Merit\u003cbr/\u003eThis project will evaluate the burial rate of biogenic opal in the Pacific sector of the Southern Ocean, both during the Last Glacial Maximum (LGM) and during the Holocene, as a critical test of the \"Silicic Acid Leakage Hypothesis\". \u003cbr/\u003e\u003cbr/\u003eThe \"Silicic Acid Leakage Hypothesis\" has been proposed recently to explain the glacial reduction in the carbon dioxide content of the atmosphere that has been reconstructed from Antarctic ice cores. Vast amounts of dissolved Si (silicic acid) are supplied to surface waters of the Southern Ocean by wind-driven upwelling of deep waters. Today, that dissolved Si is consumed almost quantitatively by diatoms who form skeletal structures composed of biogenic opal (a mineral form of silicon). According to the \"Silicic Acid Leakage Hypothesis\", environmental conditions in the Southern Ocean during glacial periods were unfavorable for diatom growth, leading to reduced (compared to interglacials) efficiency of dissolved Si utilization. Dissolved Si that was not consumed biologically in the glacial Southern ocean was then exported to the tropics in waters that sink in winter to depths of a few hundred meters along the northern fringes of the Antarctic Circumpolar Current, and return some decades later to the sunlit surface in tropical regions of wind-driven upwelling. \u003cbr/\u003e\u003cbr/\u003eAn increase in the amount of dissolved Si that \"leaks\" out of the Southern Ocean and later upwells at low latitudes could shift the global average composition of phytoplankton toward a greater abundance of diatoms and fewer CaCO3-secreting taxa (especially coccolithophorids). Consequences of such a taxonomic shift in the ocean\u0027s phytoplankton assemblage include:\u003cbr/\u003e a) an increase in the global average organic carbon/calcium carbonate ratio of particulate biogenic material sinking into the deep sea;\u003cbr/\u003e b) a reduction in the preservation and burial of calcium carbonate in marine sediments;\u003cbr/\u003e c) an increase in ocean alkalinity as a consequence of the first two changes mentioned above, and;\u003cbr/\u003e d) a lowering of atmospheric CO2 concentrations in response to increased alkalinity of ocean waters. \u003cbr/\u003e\u003cbr/\u003eA complete assessment of the Silicic acid leakage hypothesis will require an evaluation of: (1) Si utilization efficiencies using newly-developed stable isotopic techniques; (2) opal burial rates in low-latitude upwelling regions; and (3) opal burial rates in the Southern Ocean. This project addresses the last of these topics. \u003cbr/\u003e\u003cbr/\u003ePrevious work has shown that there was little change in opal burial rate between the LGM and the Holocene in the Atlantic and Indian sectors of the Southern Ocean. Preliminary results (summarized in this proposal) suggest that the Pacific may have been different, however, in that opal burial rates in the Pacific sector seem to have been lower during the LGM than during the Holocene, allowing for the possibility of \"Si leakage\" from this region. However, available results are too sparse to make any quantitative conclusions at this time. For that reason, we propose to make a comprehensive evaluation of opal burial rates in the Pacific sector of the Southern Ocean. \u003cbr/\u003e\u003cbr/\u003eSignificance and Broader Impacts\u003cbr/\u003eDetermining the mechanism(s) by which the ocean has regulated climate-related changes in the CO2 content of the atmosphere has been the focus of a substantial effort by paleoceanographers over the past two decades. The Silicic Acid Leakage Hypothesis is a viable new candidate mechanism that warrants further exploration and testing. Completion of the proposed work will contribute significantly to that effort. \u003cbr/\u003e\u003cbr/\u003eDuring the course of this work, several undergraduates will be exposed to paleoclimate research through their involvement in this project. Burckle and Anderson are both dedicated to the education and training of young scientists, and to the recruitment of women and under-represented minorities. To illustrate, two summer students (undergraduates) worked in Burckle\u0027s lab during the summer of 2002. One was a woman and the other (male) was a member of an under-represented minority. Anderson and Burckle will continue with similar recruitment efforts during the course of the proposed study. A minority student who has expressed an interest in working on this research during the summer of 2003 has already been identified.", "east": -70.0, "geometry": "POINT(-140 -57.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -50.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, Robert; Burckle, Lloyd", "platforms": "Not provided", "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -65.0, "title": "Opal Burial in the Pacific Sector of the Southern Ocean: A Test of the \"Silicic Acid Leakage Hypothesis.\"", "uid": "p0000457", "west": 150.0}, {"awards": "0338279 Siddoway, Christine", "bounds_geometry": "POLYGON((-157 -75,-155.3 -75,-153.6 -75,-151.9 -75,-150.2 -75,-148.5 -75,-146.8 -75,-145.1 -75,-143.4 -75,-141.7 -75,-140 -75,-140 -75.3,-140 -75.6,-140 -75.9,-140 -76.2,-140 -76.5,-140 -76.8,-140 -77.1,-140 -77.4,-140 -77.7,-140 -78,-141.7 -78,-143.4 -78,-145.1 -78,-146.8 -78,-148.5 -78,-150.2 -78,-151.9 -78,-153.6 -78,-155.3 -78,-157 -78,-157 -77.7,-157 -77.4,-157 -77.1,-157 -76.8,-157 -76.5,-157 -76.2,-157 -75.9,-157 -75.6,-157 -75.3,-157 -75))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 09 Jul 2008 00:00:00 GMT", "description": "This project will study migmatite domes found in the Fosdick Mountains of the Ford Ranges, western Marie Byrd Land, Antarctica. This area offers unique, three-dimensional exposures that may offer new insight into dome formation, which is a fundamental process of mountain building. These domes are derived from sedimentary and plutonic protoliths that are complexly interfolded at decimeter to kilometer scales. Preliminary findings from geobarometry and U-Pb monazite dating of anatexite suggest that peak metamorphism was underway at 105 Ma at crustal depths of ~25 km, followed by decompression as the Fosdick dome was emplaced to 16-17 km, or possibly as low as 8.5 km, in the crust by 99 Ma. Near-isothermal conditions were maintained during ascent, favorable for producing substantial volumes of melt through biotite-dehydration melting. This dome has been interpreted as a product of extensional exhumation. This is a viable interpretation from the regional standpoint, because the dome was emplaced in mid-Cretaceous time during the rapid onset of divergent tectonics along the proto- Pacific margin of Gondwana. However, the complex internal structures of the Fosdick Mountains have yet to be considered and may be more consistent with alternative intepretations such as upward extrusion within a contractional setting or lateral flow within a transcurrent attachment zone. This proposal is for detailed structural analysis, paired with geothermobarometry and geochronology, to determine the flow behavior and structural style that produced the internal architecture of the Fosdick dome. The results will improve our general understanding of the role of gneiss domes in transferring material and heat during mountain-building, and will characterize the behavior of the middle crust during a time of rapid transition from divergent to convergent tectonics along the active margin of Gondwana. In terms of broader impacts, this work will train undergraduate and graduate students, and involve them as collaborators in the development of curricular materials. It will also foster mentoring relationships between graduate and undergraduate students.", "east": -140.0, "geometry": "POINT(-148.5 -76.5)", "instruments": null, "is_usap_dc": false, "keywords": "Transcurrent Faults; Geochronology; Tectonic; Detachment Faults; Structural Geology; Not provided; Gneiss Dome; Migmatite", "locations": null, "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Siddoway, Christine; Teyssier, Christian", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -78.0, "title": "Gneiss Dome architecture: Investigation of Form and Process in the Fosdick Mountains, W. Antarctica", "uid": "p0000744", "west": -157.0}, {"awards": "0337656 Lee, Richard", "bounds_geometry": "POLYGON((-64.1 -64.75,-64.085 -64.75,-64.07 -64.75,-64.055 -64.75,-64.04 -64.75,-64.025 -64.75,-64.01 -64.75,-63.995 -64.75,-63.98 -64.75,-63.965 -64.75,-63.95 -64.75,-63.95 -64.757,-63.95 -64.764,-63.95 -64.771,-63.95 -64.778,-63.95 -64.785,-63.95 -64.792,-63.95 -64.799,-63.95 -64.806,-63.95 -64.813,-63.95 -64.82,-63.965 -64.82,-63.98 -64.82,-63.995 -64.82,-64.01 -64.82,-64.025 -64.82,-64.04 -64.82,-64.055 -64.82,-64.07 -64.82,-64.085 -64.82,-64.1 -64.82,-64.1 -64.813,-64.1 -64.806,-64.1 -64.799,-64.1 -64.792,-64.1 -64.785,-64.1 -64.778,-64.1 -64.771,-64.1 -64.764,-64.1 -64.757,-64.1 -64.75))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 06 Jun 2008 00:00:00 GMT", "description": "Polar terrestrial environments are often described as deserts, where water availability is recognized as one of the most important limits on the distribution of terrestrial organisms. In addition, prolonged low winter temperatures threaten survival, and summer temperatures challenge organisms with extensive diel variations and rapid transitions from freezing to desiccating conditions. Global warming has further impacted the extreme thermal and hydric conditions experienced by Antarctic terrestrial plant and arthropod communities, especially as a result of glacial retreat along the Antarctic Peninsula. This research will focus on thermal and hydric adaptations in the terrestrial midge, Belgica antarctica, the largest and most southerly holometabolous insect living in this challenging and changing environment. \u003cbr/\u003eOverwintering midge larvae encased in the frozen substrate must endure desert-like conditions for more than 300 days since free water is biologically unavailable as ice. During the summer, larvae may be immersed in melt water or outwash from penguin colonies and seal wallows, in addition to saltwater splash. Alternatively, the larvae may be subjected to extended periods of desiccation as their microhabitats dry out. Due to their small size, relative immobility and the patchiness of suitable microhabitats, larvae may thus be subjected to stresses that include desiccation, hypo- or hyperosmotic conditions, high salinity exposure, and anoxia for extended periods. Research efforts will focus in three areas relevant to the stress tolerance mechanisms operating in these midges:(1) obtaining a detailed characterization of microclimatic conditions experienced by B. antarctica, especially those related to thermal and hydric diversity, both seasonally and among microhabitat types in the vicinity of Palmer Station, Antarctica; (2) examining the effects of extreme fluctuations in water availability and effects on physiological and molecular responses - to determine if midge larvae utilize the mechanism of cryoprotective dehydration for winter survival, and if genes encoding heat shock proteins and other genes are upregulated in larval responses to dehydration and rehydration; (3) investigating the dietary transmission of cryoprotectants from plant to insect host, which will test the hypothesis that midge larvae acquire increased resistance to desiccation and temperature stress by acquiring cryoprotectants from their host plants. \u003cbr/\u003eThis project will provide outreach to both elementary and secondary educators and their students. The team will include a teacher who will benefit professionally by full participation in the research, and will also assist in providing outreach to other teachers and their students. From Palmer Station, the field team will communicate daily research progress by e-mail supplemented with digital pictures with teachers and their elementary students to stimulate interest in an Antarctic biology and scientific research. These efforts will be supplemented with presentations at local schools and national teacher meetings, and by publishing hands-on, inquiry-based articles related to cryobiology and polar biology in education journals. Furthermore, the principal investigators will maintain major commitments to training graduate students and postdoctoral scholars, as well as undergraduate students by providing extended research experience that includes publication of scientific papers and presentations at national meetings.", "east": -63.95, "geometry": "POINT(-64.025 -64.785)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -64.75, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Denlinger, David; Lee, Richard", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -64.82, "title": "Physiological and Molecular Mechanisms of Stress Tolerance in a Polar Insect", "uid": "p0000742", "west": -64.1}, {"awards": "9980452 Harvey, Ralph", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 20 Mar 2008 00:00:00 GMT", "description": "9980452\u003cbr/\u003eHarvey\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for continuation of the Antarctic Search for Meteorites (ANSMET). Since 1976, ANSMET has recovered more than 10,000 meteorite specimens from locations along the Transantarctic Mountains. This award supports continued recovery of Antarctic meteorites during six successive austral summer field seasons, starting with the 2000-2001 season and ending with the 2005-2006 season. Under this project, systematic searches for meteorite specimens will take place at previously discovered stranding surfaces, and reconnaissance work will be conducted to discover and explore the extent of new areas with meteorite concentrations. ANSMET recovery teams will deploy by air to locations in the deep field for periods of 5-7 weeks. While at the meteorite stranding surface, field team members will search the ice visually, traversing on foot or on snowmobile. Specimens will be collected under the most sterile conditions practical and samples will remain frozen until returned to the Johnson Space Center (JSC) in Houston, Texas. At the JSC, initial characterization and sample distribution to all interested researchers takes place under the auspices of an interagency agreement between NSF, NASA, and the Smithsonian Institution.\u003cbr/\u003e\u003cbr/\u003eThe impact of ANSMET has been substantial and this will continue under this award. The meteorites recovered by ANSMET are the best and most reliable source of new, non-microscopic extraterrestrial material, providing essential \"ground-truth\" concerning the materials that make up the asteroids, planets and other bodies of our solar system. The system for their characterization and distribution is unparalleled and their subsequent study has fundamentally changed our understanding of the solar system. ANSMET meteorites have helped researchers explore the conditions that were present in the nebula from which our solar system was born 4.556 billion years ago and provided samples of asteroids, ranging from primitive bodies unchanged since the formation of the solar system to complex, geologically active miniature planets. ANSMET samples proved, against the conventional wisdom, that some meteorites actually represent planetary materials, delivered to us from the Moon and Mars, completely changing our view of the geology of those bodies. ANSMET meteorites have even generated a new kind of inquiry into one of the most fundamental scientific questions possible; the question of biological activity in the universe as a whole. Over the past twenty years, ANSMET meteorites have economically provided a continuous and readily available supply of extraterrestrial materials for research, and should continue to do so in the future.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": false, "keywords": "FIELD SURVEYS; FIELD INVESTIGATION", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harvey, Ralph", "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": null, "title": "The Antarctic Search for Meteorites", "uid": "p0000118", "west": null}, {"awards": "0337891 Brook, Edward", "bounds_geometry": "POINT(158 -77.666667)", "dataset_titles": "Atmospheric CO2 and Climate: Byrd Ice Core, Antarctica; Atmospheric CO2 and Climate: Taylor Dome Ice Core, Antarctica", "datasets": [{"dataset_uid": "609315", "doi": "10.7265/N5542KJK", "keywords": "Antarctica; Atmosphere; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "people": "Brook, Edward J.; Ahn, Jinho", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Atmospheric CO2 and Climate: Taylor Dome Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609315"}, {"dataset_uid": "609314", "doi": "10.7265/N58W3B80", "keywords": "Antarctica; Atmosphere; Byrd Glacier; Byrd Ice Core; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate", "people": "Ahn, Jinho; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Byrd Ice Core", "title": "Atmospheric CO2 and Climate: Byrd Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609314"}], "date_created": "Mon, 05 Nov 2007 00:00:00 GMT", "description": "This award supports the development of a new laboratory capability in the U.S. to measure CO2 in ice cores and investigate millennial-scale changes in CO2 during the last glacial period using samples from the Byrd and Siple Dome ice cores. Both cores have precise relative chronologies based on correlation of methane and the isotopic composition of atmospheric oxygen with counterpart records from Greenland ice cores. The proposed work will therefore allow comparison of the timing of CO2 change, Antarctic temperature change, and Greenland temperature change on common time scales. Such comparisons are vital for evaluating models that explain changes in atmospheric CO2. The techniques being developed will also be available for future projects, specifically the proposed Inland WAIS ice core, for which a highly detailed CO2 record is a major objective, and studies greenhouse and other atmospheric gases and their isotopic composition for which dry extraction is necessary (stable isotopes in CO2, for example). There are many broad impacts of the proposed work. Ice core greenhouse gas records are central contributions of paleoclimatology to research and policy-making concerning global change. The proposed work will enhance those contributions by improving our understanding of the natural cycling of the most important greenhouse gas. It will contribute to the training of a postdoctoral researcher, who will be an integral part of an established research group and benefit from the diverse paleoclimate and geochemistry community at OSU. The PI teaches major and non-major undergraduate and graduate courses on climate and global change. The proposed work will enrich those courses and the courses will provide an opportunity for the postdoctoral researcher to participate in teaching by giving guest lectures. The PI also participates in a summer climate workshop for high school teachers at Washington State University and the proposed work will enrich that contribution. The extraction device that is built and the expertise gained in using it will be resources for the ice core community and available for future projects. Data will be made available through established national data center and the equipment designs will also be made available to other researchers.", "east": 158.0, "geometry": "POINT(158 -77.666667)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Core; Climate Change; CO2; Atmospheric Chemistry; Atmospheric CO2; LABORATORY; Not provided; Ice Core Data; Climate; Ice Core Chemistry; Atmospheric Gases; Ice Core Gas Records; GROUND STATIONS; Climate Research", "locations": null, "north": -77.666667, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Ahn, Jinho; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": -77.666667, "title": "Developing Dry Extraction of Ice Core Gases and Application to Millennial-Scale Variability in Atmospheric CO2", "uid": "p0000268", "west": 158.0}, {"awards": "0540915 Scambos, Ted", "bounds_geometry": "POLYGON((-57.9857 -48.444,-55.95557 -48.444,-53.92544 -48.444,-51.89531 -48.444,-49.86518 -48.444,-47.83505 -48.444,-45.80492 -48.444,-43.77479 -48.444,-41.74466 -48.444,-39.71453 -48.444,-37.6844 -48.444,-37.6844 -50.12802,-37.6844 -51.81204,-37.6844 -53.49606,-37.6844 -55.18008,-37.6844 -56.8641,-37.6844 -58.54812,-37.6844 -60.23214,-37.6844 -61.91616,-37.6844 -63.60018,-37.6844 -65.2842,-39.71453 -65.2842,-41.74466 -65.2842,-43.77479 -65.2842,-45.80492 -65.2842,-47.83505 -65.2842,-49.86518 -65.2842,-51.89531 -65.2842,-53.92544 -65.2842,-55.95557 -65.2842,-57.9857 -65.2842,-57.9857 -63.60018,-57.9857 -61.91616,-57.9857 -60.23214,-57.9857 -58.54812,-57.9857 -56.8641,-57.9857 -55.18008,-57.9857 -53.49606,-57.9857 -51.81204,-57.9857 -50.12802,-57.9857 -48.444))", "dataset_titles": "Atlas of the Cryosphere - View dynamic maps of snow, sea ice, glaciers, ice sheets, permafrost, and more.; Climate, Drift, and Image Data from Antarctic Icebergs A22A and UK211, 2006-2007; MODIS Mosaic of Antarctica (MOA)", "datasets": [{"dataset_uid": "000189", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Atlas of the Cryosphere - View dynamic maps of snow, sea ice, glaciers, ice sheets, permafrost, and more.", "url": "http://nsidc.org/MMS/atlas/cryosphere_atlas_north.html"}, {"dataset_uid": "609466", "doi": "10.7265/N5N014GW", "keywords": "Ablation; Atmosphere; Glaciology; GPS; Meteorology; Oceans; Photo/video; Photo/Video; Sea Ice; Southern Ocean; Temperature", "people": "Yermolin, Yevgeny; Bauer, Rob; Scambos, Ted; Thom, Jonathan; Bohlander, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Climate, Drift, and Image Data from Antarctic Icebergs A22A and UK211, 2006-2007", "url": "https://www.usap-dc.org/view/dataset/609466"}, {"dataset_uid": "000190", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "MODIS Mosaic of Antarctica (MOA)", "url": "http://nsidc.org/data/nsidc-0280.html"}], "date_created": "Thu, 16 Aug 2007 00:00:00 GMT", "description": "This award supports a small grant for exploratory research to study the processes that contribute to the melting and break-up of tabular polar icebergs as they drift north. This work will enable the participation of a group of U.S. scientists in this international project which is collaborative with the Instituto Antartico Argentino. The field team will place weather instruments, firn sensors, and a video camera on the iceberg to measure the processes that affect it as it drifts north. In contrast to icebergs in other sectors of Antarctica, icebergs in the northwestern Weddell Sea drift northward along relatively predictable paths, and reach climate and ocean conditions that lead to break-up within a few years. The timing of this study is critical due to the anticipated presence of iceberg A43A, which broke off the Ronne Ice Shelf in February 2000 and which is expected to be accessible from Marambio Station in early 2006. It has recently been recognized that the end stages of break-up of these icebergs can imitate the rapid disintegrations due to melt ponding and surface fracturing observed for the Larsen A and Larsen B ice shelves. However, in some cases, basal melting may play a significant role in shelf break-up. Resolving the processes (surface ponding/ fracturing versus basal melt) and observing other processes of iceberg drift and break up in-situ are of high scientific interest. An understanding of the mechanisms that lead to the distintegration of icebergs as they drift north may enable scientists to use icebergs as proxies for understanding the processes that could cause ice shelves to disintegrate in a warming climate. A broader impact would thus be an ability to predict ice shelf disintegration in a warming world. Glacier mass balance and ice shelf stability are of critical importance to sea level change, which also has broader societal relevance.", "east": -37.6844, "geometry": "POINT(-47.83505 -56.8641)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ICE AUGERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SNOW DENSITY CUTTER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e MODIS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e MMS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Air Temperature; Weddell Sea; Edge-Wasting; Ice Shelf Meltwater; TERRA; Antarctic; GPS; Iceberg; Ice Breakup; South Atlantic Ocean; AQUA; Tabular; Photo; Not provided; Icetrek; HELICOPTER; Antarctica", "locations": "Antarctic; Weddell Sea; Antarctica; South Atlantic Ocean", "north": -48.444, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted; Bohlander, Jennifer; Bauer, Rob; Yermolin, Yevgeny; Thom, Jonathan", "platforms": "AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER \u003e HELICOPTER; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e AQUA; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e TERRA; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "NSIDC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": -65.2842, "title": "Investigating Iceberg Evolution During Drift and Break-Up: A Proxy for Climate-Related Changes in Antarctic Ice Shelves", "uid": "p0000003", "west": -57.9857}, {"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": "9615398 Encarnacion, John", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 11 Jul 2007 00:00:00 GMT", "description": "Encarnaci_n OPP 9615398 Abstract Basement rocks of the Transantarctic Mountains are believed to record a change in the paleo-Pacific margin of Gondwana from a rifted passive margin to a tectonically active margin (Ross orogen). Recent hypothesis suggest that the passive margin phase resulted from Neoproterozoic rifting of Laurentia from Antarctica (\"SWEAT\" hypothesis). The succeeding active margin phase (Ross orogeny) was one of several tectonic events (\"Pan African\" events) that resulted from plate convergence/transpression that was probably a consequence of the assembly of components of the Gondwana supercontinent. Although these basement units provide one of the keys for understanding the break up and assembly of these major continental masses, few precise ages are available to address the following important issues: (1) Is there any pre-rift high-grade cratonal basement exposed along the Transantarctic Mountains, and what is/are its precise age? Is this age compatible with a Laurentia connection? (2) What is the age of potential rift/passive margin sediments (Beardmore Group) along the Queen Maud Mountains sector of the orogen? (3) What is the relative and absolute timing of magmatism and contractional deformation of supracrustal units in the orogen? Was deformation diachronous and thus possibly related to transpressional tectonics, or did it occur in a discrete pulse that is more compatible with a collision? How does contraction of the orogen fit in with emplacement of voluminous plutonic and volcanic rocks? The answers to these questions are central to understanding the kinematic evolution of this major orogenic belt and its role in Neoproterozoic-Early Paleozoic continental reconstructions and plate kinematics. Hence, this award supports funding for precise U-Pb dating, using zircon, monazite, baddeleyite, and/or titanite from a variety of magmatic rocks in the Queen Ma ud Mountains, which can address the foregoing problems. In addition to the issues above, precise dating of volcanics that are interbedded with carbonates containing probable Middle Cambrian fauna could potentially provide a calibration point for the Middle Cambrian, which will fill a gap in the absolute time scale for the early Paleozoic.", "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": "Encarnacion, John", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Constraints on the Tectonomagmatic Evolution of the Pacific Margin of Gondwana from U-Pb Geochronology of Magmatic Rocks in the Transantarctic Basement", "uid": "p0000277", "west": null}, {"awards": "0233303 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 09 Jul 2007 00:00:00 GMT", "description": "Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.\u003cbr/\u003eThis award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.\u003cbr/\u003eA better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Ice Sheet; Basal Melting; Ice Shelf Meltwater; Not provided; Oceanography; Ice Velocity; Glaciology; Sea Level Rise; Ice Sheet Stability; Mass; Ross Ice Sheet; Numerical Model; Basal Freezing; Ice Cavity Circulations; George VI Ice Shelf; Outflow", "locations": "Ross Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Melting and Calving of Antarctic Ice Shelves", "uid": "p0000730", "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": "0538475 Bart, Philip", "bounds_geometry": "POLYGON((-180 -75,-178 -75,-176 -75,-174 -75,-172 -75,-170 -75,-168 -75,-166 -75,-164 -75,-162 -75,-160 -75,-160 -75.3,-160 -75.6,-160 -75.9,-160 -76.2,-160 -76.5,-160 -76.8,-160 -77.1,-160 -77.4,-160 -77.7,-160 -78,-162 -78,-164 -78,-166 -78,-168 -78,-170 -78,-172 -78,-174 -78,-176 -78,-178 -78,-180 -78,-180 -77.7,-180 -77.4,-180 -77.1,-180 -76.8,-180 -76.5,-180 -76.2,-180 -75.9,-180 -75.6,-180 -75.3,-180 -75))", "dataset_titles": "NBP0802 and NBP0803 Sediment samples (full data link not provided); NBP0802 data; NBP0803 data", "datasets": [{"dataset_uid": "000123", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0803 data", "url": "https://www.rvdata.us/search/cruise/NBP0803"}, {"dataset_uid": "000138", "doi": "", "keywords": null, "people": null, "repository": "AMGRF", "science_program": null, "title": "NBP0802 and NBP0803 Sediment samples (full data link not provided)", "url": "http://www.arf.fsu.edu/"}, {"dataset_uid": "000122", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0802 data", "url": "https://www.rvdata.us/search/cruise/NBP0802"}], "date_created": "Thu, 29 Mar 2007 00:00:00 GMT", "description": "This project determines the recent history of the West Antarctic Ice Sheet (WAIS) through a multidisciplinary study of the seabed in the Ross Sea of Antarctica. WAIS is perhaps the world\u0027s most critical ice sheet to sea level rise dut to near-future global warming. its history has been a key focus for the past decade, but there are significant questions as to whether WAIS was stable during the last glacial maximum--about 20,000 years ago--or undergoing advance and retreat. This project studies grounding zone translantions in Eastern Basin to constrain WAIS movements using a multidisciplinary approach that integrates multibeam bathymetry, seismic stratigraphy, sedimentology, diatom biostratigraphy, radiocarbon dating, 10Be concentration analyses, and numerical modeling.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts include improving society\u0027s understanding of sea level rise linked to global warming; postdoctoral, graduate, and undergraduate education; and expanding the participation of groups underrepresented in Earth sciences through links with LSU\u0027s Geoscience Alliance to Encourage Minority Participation.", "east": -160.0, "geometry": "POINT(-170 -76.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; 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 MSBS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e WATERGUNS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES", "is_usap_dc": true, "keywords": "Ross Sea; R/V NBP; Ice Sheet; Last Glacial Maximum; Seismic Stratigraphy", "locations": "Ross Sea", "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Bart, Philip; Tomkin, Jonathan", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "AMGRF; R2R", "science_programs": null, "south": -78.0, "title": "WAIS grounding-zone migrations in Eastern Basin, Ross Sea and the LGM dilemma: New strategies to resolve the style and timing of outer continental shelf grounding events", "uid": "p0000539", "west": -180.0}, {"awards": "9615502 Harrison, William", "bounds_geometry": "POINT(-148.822 -81.655)", "dataset_titles": "Vertical Strain at Siple Dome, Antarctica, 1999-2002", "datasets": [{"dataset_uid": "609214", "doi": "10.7265/N5HH6H00", "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Siple Dome; Siple Dome Ice Core; Strain; WAISCORES", "people": "Elsberg, Daniel; Pettit, Erin; Zumberge, Mark; Waddington, Edwin D.; Harrison, William; Morack, James", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Vertical Strain at Siple Dome, Antarctica, 1999-2002", "url": "https://www.usap-dc.org/view/dataset/609214"}], "date_created": "Thu, 22 Feb 2007 00:00:00 GMT", "description": "This award is for support for a three year project to measure the vertical strain rate as a function of depth at two sites on Siple Dome Antarctica. Ice flow near a divide such as Siple Dome is unique in that it is predominantly vertical. As a consequence, the component of ice deformation in the vertical direction, the \"vertical strain rate\" is dominant. Its measurement is therefore important for the calibration of dynamic models of ice flow. Two different, relatively new, high resolution systems for its measurement in hot water drilled holes will be employed. The ice flow model resulting from the measurements and flow law determination will be used to interpret the shapes of radar internal layering in terms of the dynamic history and accumulation patterns of Siple Dome over the past 10,000 years. The resulting improved model will also be applied to the interpretation of annual layers thicknesses (to produce annual accumulation rates) and borehole temperatures from the ice core to be drilled at Siple Dome during the 1997/98 field season. The results should permit an improved analysis of the ice core, relative to what was possible at recent coring sites in central Greenland. This is a collaborative project between the University of Alaska, the University of California, San Diego and the University of Washington.", "east": -148.822, "geometry": "POINT(-148.822 -81.655)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e STRAIN GAUGE WHEATSTONE BRIDGE", "is_usap_dc": true, "keywords": "Ice Core Data; GROUND-BASED OBSERVATIONS; Antarctica; USAP-DC; Ice Core; Ice Analysis; Ice Flow; Ice Deformation; Antarctic Ice Sheet; West Antarctic Ice Sheet; Vertical Strain Rate; Ice Sheet; Glaciology; West Antarctica; Ice; Ice Movement", "locations": "Antarctica; Antarctic Ice Sheet; West Antarctica; West Antarctic Ice Sheet", "north": -81.655, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Harrison, William; Morack, James; Pettit, Erin; Zumberge, Mark; Elsberg, Daniel; Waddington, Edwin D.", "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": -81.655, "title": "Ice Dynamics, the Flow Law, and Vertical Strain at Siple Dome", "uid": "p0000601", "west": -148.822}, {"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": "0230197 Holt, John", "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": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; Amundsen Sea Sector Data Set; Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "datasets": [{"dataset_uid": "609312", "doi": "10.7265/N5J9649Q", "keywords": "Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Fastook, James L.", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Sector Data Set", "url": "https://www.usap-dc.org/view/dataset/609312"}, {"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Young, Duncan A.; Muldoon, Gail R.; Blankenship, Donald D.; Jackson, Charles", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}, {"dataset_uid": "609292", "doi": "10.7265/N59W0CDC", "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Solid Earth", "people": "Holt, John W.; Blankenship, Donald D.; Morse, David L.; Vaughan, David G.; Corr, Hugh F. J.; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609292"}], "date_created": "Mon, 01 Jan 2007 00:00:00 GMT", "description": "This award supports a comprehensive aerogeophysical survey of the Amundsen Sea Embayment (ASE) in West Antarctica. The University of Texas will join forces with the British Antarctic Survey to use both US and UK aircraft and instrumentation to achieve this survey. Analyses of the new aerogeophysical\u003cbr/\u003edata will result in the generation of maps of ice sheet surface, volume and bottom-interface characteristics. These maps will support the efforts of a community of US and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE.\u003cbr/\u003eThe West Antarctic ice sheet has been the subject of intensive interdisciplinary study by both the European and U.S. scientific communities since it was recognized to be a potential source for up to 5 meters of sea\u003cbr/\u003elevel rise, possibly on short timescales. In terms of ice discharge, the ASE is the largest drainage system in West Antarctica. Yet it has been comparatively unstudied, primarily due to its remoteness from logistical\u003cbr/\u003ecenters. The ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change.\u003cbr/\u003eThe results from our surveys are required to achieve the fundamental research objectives outlined by the US scientific community in an ASE Science Plan. The surveys and analyses will be achieved through international collaboration and will involve graduate students, undergraduates and high school apprentices.\u003cbr/\u003eThrough its potential for influencing sea level, the future behavior of the ASE is of primary societal importance. Given the substantial public and scientific interest that recent reports of change in West Antarctica have generated, we expect fundamental research in the Amundsen Sea Embayment, enabled by our surveys, will have widespread impact.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "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 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 ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS", "is_usap_dc": true, "keywords": "Thwaites Glacier; Ice Velocity; Ablation; Amundsen Sea; Pine Island Glacier; Elevation; Antarctica (agasea); Ice Sheet Elevation; West Antarctic Ice Sheet; Ice Temperature; Amundsen Basin; Subglacial Topography; Ice Melt; West Antarctica; Velocity Measurements; Snow Accumulation; Antarctica; Bedrock Elevation; Modeling", "locations": "Antarctica; West Antarctica; Amundsen Basin; Pine Island Glacier; Thwaites Glacier; West Antarctic Ice Sheet; Amundsen Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Blankenship, Donald D.; Fastook, James L.; Corr, Hugh F. J.; Holt, John W.; Morse, David L.; Vaughan, David G.; Young, Duncan A.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)", "uid": "p0000243", "west": -180.0}, {"awards": "0230021 Sowers, Todd; 0230348 Dunbar, Nelia; 0230316 White, James", "bounds_geometry": "POINT(135.1333 -76.05)", "dataset_titles": "Mount Moulton Isotopes and Other Ice Core Data", "datasets": [{"dataset_uid": "609640", "doi": "10.7265/N5FT8J0N", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Epica Dome C; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Lake Vostok; Mount Moulton; Paleoclimate; Talos Dome; Taylor Dome", "people": "Popp, Trevor; White, James; Steig, Eric J.", "repository": "USAP-DC", "science_program": null, "title": "Mount Moulton Isotopes and Other Ice Core Data", "url": "https://www.usap-dc.org/view/dataset/609640"}], "date_created": "Tue, 01 Aug 2006 00:00:00 GMT", "description": "The summit crater of Mt. Moulton, in West Antarctica, contains a 600-m thick horizontally-exposed section of ice with intercalated tephra layers from nearby Mt Berlin. Argon-40/Argon-39 dating of the thick, near-source tephra indicates that the age of the horizontal ice section ranges between 15,000 and 492,000 years. Thus, the Mt Moulton site offers an unparalleled repository of ancient West Antarctic snow and trapped air that can be used to investigate West Antarctic climate over much of the past 500,000 years. The planar nature and consistent dips of the tephra layers suggests that, although the ice section has thinned, it is otherwise undeformed. The Mt. Moulton site was visited during the 1999/2000 field season, at which time a horizontal ice core representing approximately 400 meters of ice was collected, ranging in age from 15,000 to older than 480,000 years. In addition to this horizontal core, samples of ice at a range of depths were collected in order to test the quality of the climate record in the ice. Forty tephra layers intercalated in the ice were also collected in order to provide chronology for the ice section. The results of this first effort are extremely encouraging. Based on the d?18 O of ice, for example, there is clearly a useable record of past climate at Mt. Moulton extending back beyond 140,000 years. There is work to do, however, to realize the full potential of this horizontal ice core. The elemental and isotopic composition of trapped gases suggest some contamination with modern air, for example. As gas cross-dating of ice cores is the current standard by which climate records are intercompared, we need to understand why and how the gas record is compromised before adding Moulton to our arsenal of ice core paleoclimate records. This award supports a collaborative effort between three institutions with following objectives: 1) to evaluate more thoroughly the integrity of the climatic record through shallow drilling of the blue ice area, as well as the snow field upslope from the blue ice; 2) to improve the radioisotopic dating of specific tephra layers; 3) to obtain baseline information about modern snowfall deposition, mean annual temperature, and wind pumping around the summit of Mt. Moulton; and 4) to study how firn densification differs when surface accumulation changes from net accumulation to net ablation.", "east": 135.1333, "geometry": "POINT(135.1333 -76.05)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e ELECTRON MICROPROBES", "is_usap_dc": true, "keywords": "LABORATORY; Climate; Argon-40; 40Ar; Argon-39; FIELD SURVEYS; Chronology; Ice Core Gas Age; Gas Record; Ice Core; FIELD INVESTIGATION; Tephra; Mount Moulton; Not provided; Caldera; 39Ar; Stratigraphy; Ice Core Depth", "locations": "Mount Moulton", "north": -76.05, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "White, James; Popp, Trevor; Dunbar, Nelia; Sowers, Todd A.; Steig, Eric J.", "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": -76.05, "title": "Collaborative Research: Refining a 500-kry Climate Record From the Moulton Blue Ice Field in West Antarctica", "uid": "p0000755", "west": 135.1333}, {"awards": "0126343 Nishiizumi, Kunihiko", "bounds_geometry": "POINT(-148.812 -81.6588)", "dataset_titles": "Cosmogenic Radionuclides in the Siple Dome A Ice Core", "datasets": [{"dataset_uid": "609307", "doi": "10.7265/N5XK8CGS", "keywords": "Antarctica; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Nishiizumi, Kunihiko; Finkel, R. C.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Cosmogenic Radionuclides in the Siple Dome A Ice Core", "url": "https://www.usap-dc.org/view/dataset/609307"}], "date_created": "Mon, 12 Jun 2006 00:00:00 GMT", "description": "This award supports a three-year renewal project to complete measurement of cosmogenic nuclides in the Siple Dome ice core as part of the West Antarctic ice core program. The investigators will continue to measure profiles of Beryllium-10 (half-life = 1.5x10 6 years) and Chlorine-36 (half-life = 3.0x10 5 years) in the entire ice core which spans the time period from the present to about 100 kyr. It will be particularly instructive to compare the Antarctic record with the detailed Arctic record that was measured by these investigators as part of the GISP2 project. This comparison will help separate global from local effects at the different drill sites. Cosmogenic radionuclides in polar ice cores have been used to study the long-term variations in several important geophysical variables, including solar activity, geomagnetic field strength, atmospheric circulation, snow accumulation rates, and others. The time series of nuclide concentrations resulting from this work will be applied to several problem areas: perfecting the ice core chronology, deducing the history of solar activity, deducing the history of variations in the geomagnetic field, and studying the possible role of solar variations on climate. Comparison of Beryllium-10 and Chlorine-36 profiles in different cores will allow us to improve the ice core chronology and directly compare ice cores from different regions of the globe. Additional comparison with the Carbon-14 record will allow correlation of the ice core paleoenvironment record to other, Carbon-14 dated, paleoclimate records.", "east": -148.812, "geometry": "POINT(-148.812 -81.6588)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Core Chemistry; Antarctica; Ice Core; Cosmogenic Radionuclides; Chlorine-36; GROUND STATIONS; Beryllium-10; Siple Dome; West Antarctica", "locations": "Antarctica; Siple Dome; West Antarctica", "north": -81.6588, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Finkel, R. C.; Nishiizumi, Kunihiko", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.6588, "title": "Cosmogenic Radionuclides in the Siple Dome Ice Core", "uid": "p0000358", "west": -148.812}, {"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": "0232042 Finn, Carol", "bounds_geometry": "POLYGON((139.27539 -82.35733,142.369695 -82.35733,145.464 -82.35733,148.558305 -82.35733,151.65261 -82.35733,154.746915 -82.35733,157.84122 -82.35733,160.935525 -82.35733,164.02983 -82.35733,167.124135 -82.35733,170.21844 -82.35733,170.21844 -82.516831,170.21844 -82.676332,170.21844 -82.835833,170.21844 -82.995334,170.21844 -83.154835,170.21844 -83.314336,170.21844 -83.473837,170.21844 -83.633338,170.21844 -83.792839,170.21844 -83.95234,167.124135 -83.95234,164.02983 -83.95234,160.935525 -83.95234,157.84122 -83.95234,154.746915 -83.95234,151.65261 -83.95234,148.558305 -83.95234,145.464 -83.95234,142.369695 -83.95234,139.27539 -83.95234,139.27539 -83.792839,139.27539 -83.633338,139.27539 -83.473837,139.27539 -83.314336,139.27539 -83.154835,139.27539 -82.995334,139.27539 -82.835833,139.27539 -82.676332,139.27539 -82.516831,139.27539 -82.35733))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 16 Aug 2005 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the Transantarctic Mountains and an adjacent region of East Antarctica. The East Antarctic shield is one of Earth\u0027s oldest and largest cratonic assemblies, with a long-lived Archean to early Paleozoic history. Long-standing interest in the geologic evolution of this shield has been rekindled over the past decade by tectonic models linking East Antarctica with other Precambrian crustal elements in the Rodinia and Gondwanaland supercontinents. It is postulated that the Pacific margin of East Antarctica was rifted from Laurentia during late Neoproterozoic breakup of Rodinia, and it then developed as an active plate boundary during subsequent amalgamation of Gondwanaland in the earliest Paleozoic. If true, the East Antarctic shield played a key role in supercontinent transformation at a time of global changes in plate configuration, terrestrial surficial process, sea level, and marine geochemistry and biota. A better understanding of the geological evolution of the East Antarctic shield is therefore critical for studying Precambrian crustal evolution in general, as well as resource distribution, biosphere evolution, and glacial and climate history during later periods of Earth history. Because of nearly complete coverage by the polar ice cap, however, Antarctica remains the single most geologically unexplored continent. Exposures of cratonic basement are largely limited to coastal outcrops in George V Land and Terre Adelie (Australian sector), the Prince Charles Mountains and Enderby Land (Indian sector), and Queen Maud Land (African sector), where the geology is reasonably well-known. By contrast, little is known about the composition and structure of the shield interior. Given the extensive ice cover, collection of airborne geophysical data is the most cost-effective method to characterize broad areas of sub-ice basement and expand our knowledge of the East Antarctic shield interior. \u003cbr/\u003e\u003cbr/\u003eThis project will conduct an airborne magnetic survey (coupled with ground-based gravity measurements) across an important window into the shield where it is exposed in the Nimrod Glacier area of the central Transantarctic Mountains. Specific goals are to:\u003cbr/\u003e1. Characterize the magnetic and gravity signature of East Antarctic crustal basement exposed at the Ross margin (Nimrod Group),\u003cbr/\u003e2. Extend the magnetic data westward along a corridor across the polar ice cap in order to image the crust in ice-covered areas,\u003cbr/\u003e3. Obtain magnetic data over the Ross Orogen in order to image the ice-covered boundary between basement and supracrustal rocks, allowing us to better constrain the geometry of fundamental Ross structures, and\u003cbr/\u003e4. Use the shape, trends, wavelengths, and amplitudes of magnetic anomalies to define magnetic domains in the shield, common building blocks for continent-scale studies of Precambrian geologic structure and evolution.\u003cbr/\u003e\u003cbr/\u003eHigh-resolution airborne magnetic data will be collected along a transect extending from exposed rocks of the Nimrod Group across the adjacent polar ice cap. The Nimrod Group represents the only bona fide Archean-Proterozoic shield basement exposed for over 2500 km of the Pacific margin of Antarctica. This survey will characterize the geologically well-known shield terrain in this sector using geophysical methods for the first time. This baseline over the exposed shield will allow for better interpretation of geophysical patterns in other ice-covered regions and can be used to target future investigations. In collaboration with colleagues from the BGR (Germany), a tightly-spaced, \"draped\" helicopter magnetic survey will be flown during the 2003-04 austral summer, to be complemented by ground measurements of gravity over the exposed basement. Data reduction, interpretation and geological correlation will be completed in the second year. This project will enhance the education of students, the advancement of under-represented groups, the research instrumentation of the U.S. Antarctic Program, partnerships between the federal government and institutions of higher education, and cooperation between national research programs. It will benefit society through the creation of new basic knowledge about the Antarctic continent, which in turn may help with applied research in other fields such as the glacial history of Antarctica.", "east": 170.21844, "geometry": "POINT(154.746915 -83.154835)", "instruments": "SOLAR/SPACE OBSERVING INSTRUMENTS \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e MAM", "is_usap_dc": false, "keywords": "Central Transantarctic Mountains; Aeromagnetic Data; HELICOPTER; DHC-6; Not provided", "locations": "Central Transantarctic Mountains", "north": -82.35733, "nsf_funding_programs": null, "paleo_time": null, "persons": "Finn, C. A.; FINN, CAROL", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER \u003e HELICOPTER; Not provided", "repositories": null, "science_programs": null, "south": -83.95234, "title": "Collaborative Research: Geophysical Mapping of the East Antarctic Shield Adjacent to the Transantarctic Mountains", "uid": "p0000249", "west": 139.27539}, {"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": "9316338 Jacobel, Robert", "bounds_geometry": null, "dataset_titles": "Siple Dome Glaciology and Ice Stream History 1994, 1996", "datasets": [{"dataset_uid": "609085", "doi": "10.7265/N5Z31WJQ", "keywords": "Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Sample/collection Description; Sample/Collection Description; Siple Dome; Siple Dome Ice Core", "people": "Jacobel, Robert", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Glaciology and Ice Stream History 1994, 1996", "url": "https://www.usap-dc.org/view/dataset/609085"}], "date_created": "Fri, 01 Jan 1999 00:00:00 GMT", "description": "9316338 Jacobel This award is for support for a program of glaciological studies of Siple Dome and its surroundings between Ice Streams C and D. The purpose of the work is to characterize the dynamic environment and ice stratigraphy to aid in the assessment of Siple Dome as a potential deep ice core site, and to determine whether the configuration of ice stream flow in the region was different in the past than now. The work involves measurements of the configuration and continuity of internal layers in the ice, using radar echo sounding and determination of velocity field, based on standard GPS surveying. The goals of the work are relevant to understanding the dynamics of the West Antarctic Ice Sheet (WAIS), its past history and its potential future behavior, including possible effects on global sea level. This work is a collaborative project between the University of Washington, the University of Colorado and St. Olaf College. ***", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": true, "keywords": "Siple Dome; Antarctic; Glaciology; Radar; GROUND-BASED OBSERVATIONS; Ice Stream", "locations": "Antarctic; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobel, Robert", "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": "Siple Dome Glaciology and Ice Stream History", "uid": "p0000190", "west": null}]
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This award is for acquisition of new instrumentation to support acquisition of the new LA-HR-ICPMS instrumentation for the trace-element analysis of various environmental samples. This instrumentation will replace the original (and heavily used over two decades) ThermoScientific Element2 ICP-MS installed at the University of Maine?s Climate Change Institute (CCI). The new acquisition will significantly expand research capabilities of the CCI/ICP-MS Facility to improve the analysis of aqueous samples, supplemented with a laser ablation (LA) front end for ice, biological, and other solid materials. The current ICP-MS Facility was established in 2002 with an NSF/MRI award, which since then has served as a vital resource for climate, environmental, ecosystem, and engineering research and training at the U. Maine, across the state of Maine and beyond. The routine use and primary support of the Facility come from the Principal Investigators and their collaborators that group under three research areas: glaciochemistry and climate/environmental reconstruction; paleoceanography and marine biogeochemistry; and environmental sensor development and material science engineering. The U. Maine is the State?s Land & Sea Grant university and only PhD granting institution, so the campus is the de facto academic research and research training hub of the state of Maine. The proposed advances of this research & training instrumentation will immediately impact current and future NSF-funded research projects that support extensive national and international collaborations. Specific to this proposal are collaborations with the University of Venice (Italy) and the University of Cambridge/British Antarctic Survey to develop laser ablation ICP-MS imaging of ice cores, and collaborations with New Zealand, Swiss, Chinese, Canadian, and Brazilian colleagues to analyze ice, thereby maintaining our leadership role in global ice core and climate change research. Likewise, the enhanced carbonate analysis capacity of the Element XR will have an immediate impact on NSF-funded research projects in the Gulf of Maine and in the South Pacific. The proposed instrumentation will facilitate new and important collaborations between academic colleges (College of Natural Science, Forestry, and Agriculture and the College of Engineering) and research units - the CCI and the Frontier Institute for Research in Sensor Technology - across the campus, as well as enabling new and broader scientific collaborations with other academic and scientific institutions across Maine.
Part I, Non-technical Abstract <br/>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.<br/><br/>Part 2, Technical Abstract<br/><br/>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.<br/><br/>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.
Kingslake, Jonathan; Sole, Andrew; Livingstone, Stephen; Winter, Kate; Ely, Jeremy
No dataset link provided
When ice sheets and glaciers lose ice faster than it accumulates from snowfall, they shrink and contribute to sea-level rise. This has consequences for coastal communities around the globe by, for example, increasing the frequency of damaging storm surges. Sea-level rise is already underway and a major challenge for the geoscience community is improving predictions of how this will evolve. The Antarctic Ice Sheet is the largest potential contributor to sea-level rise and its future is highly uncertain. It loses ice through two main mechanisms: the formation of icebergs and melting at the base of floating ice shelves on its periphery. Ice flows under gravity towards the ocean and the rate of ice flow controls how fast ice sheets and glaciers shrink. In Greenland and Antarctica, ice flow is focused into outlet glaciers and ice streams, which flow much faster than surrounding areas. Moreover, parts of the Greenland Ice Sheet speed up and slow down substantially on hourly to seasonal time scales, particularly where meltwater from the surface reaches the base of the ice. Meltwater reaching the base changes ice flow by altering basal water pressure and consequently the friction exerted on the ice by the rock and sediment beneath. This phenomenon has been observed frequently in Greenland but not in Antarctica. Recent satellite observations suggest this phenomenon also occurs on outlet glaciers in the Antarctic Peninsula. Meltwater reaching the base of the Antarctic Ice Sheet is likely to become more common as air temperature and surface melting are predicted to increase around Antarctica this century. This project aims to confirm the recent satellite observations, establish a baseline against which to compare future changes, and improve understanding of the direct influence of meltwater on Antarctic Ice Sheet dynamics. This is a project jointly funded by the National Science Foundation?s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries.
This project will include a field campaign on Flask Glacier, an Antarctic Peninsula outlet glacier, and a continent-wide remote sensing survey. These activities will allow the team to test three hypotheses related to the Antarctic Ice Sheet?s dynamic response to surface meltwater: (1) short-term changes in ice velocity indicated by satellite data result from surface meltwater reaching the bed, (2) this is widespread in Antarctica today, and (3) this results in a measurable increase in mean annual ice discharge. The project is a collaboration between US- and UK-based researchers and will be supported logistically by the British Antarctic Survey. The project aims to provide insights into both the drivers and implications of short-term changes in ice flow velocity caused by surface melting. For example, showing conclusively that meltwater directly influences Antarctic ice dynamics would have significant implications for understanding the response of Antarctica to atmospheric warming, as it did in Greenland when the phenomenon was first detected there twenty years ago. This work will also potentially influence other fields, as surface meltwater reaching the bed of the Antarctic Ice Sheet may affect ice rheology, subglacial hydrology, submarine melting, calving, ocean circulation, and ocean biogeochemistry. The project aims to have broader impacts on science and society by supporting early-career scientists, UK-US collaboration, education and outreach, and adoption of open data science approaches within the glaciological community.
The seaward motion of ice sheets and glaciers is primarily controlled by basal sliding below, and internal viscous flow within, ice masses. The latter of these—viscous flow—is dependent on various factors, including temperature, stress, grain size, and the alignment of ice crystals during flow to produce a crystal orientation fabric (COF). Historically, ice flow has been modeled using a constitutive equation, termed “Glen’s law”, that describes ice flow rate as a function of temperature and stress. Glen’s law was constrained under relatively high-stress conditions, and is often attributed to the motion of crystal defects within ice grains. More recently, however, grain boundary sliding (GBS) has been invoked as the rate-controlling process under low-stress, “superplastic” conditions. The grain boundary sliding hypothesis is contentious because GBS is not thought to produce a COF, whereas geophysical measurements and polar ice cores demonstrate strong COFs in polar ice masses. However, very few COF measurements have been conducted on ice samples subjected to superplastic flow conditions in the laboratory. In this project, the PI primarily seeks to measure the evolution of ice COF across the transition from superplastic to Glen-type creep. Results will be used to interrogate the role of superplastic GBS creep within polar ice masses, and thereby provide constraints on polar ice discharge models.
Polycrystalline ice samples with grain sizes ranging from 5 µm to 1000 µm will be fabricated and deformed in the PI’s laboratory at WHOI, using a 1-atm cryogenic axial-torsion apparatus. Experiments will be conducted at temperatures of −30°C to −10°C, and at a constant uniaxial strain rate of 10-7 s-1. Under these conditions, 5% to 99.99% of strain should be accommodated by superplastic, GBS-limited creep, depending on the sample grain size. The deformed samples will then be imaged using cryogenic electron backscatter diffraction (cryo-EBSD) and high-angular-resolution electron backscatter diffraction (HR-EBSD) to quantify COF, grain size, grain shape, and crystal defect (dislocation) densities, among other microstructural properties. These measurements will be used to decipher the rate-controlling mechanisms operating within different thermomechanical regimes, and resolve a long-standing debate over whether superplastic creep can produce a COF in ice. In addition to the polycrystal experiments, ice bicrystals will be fabricated and deformed to investigate the micromechanical behavior of individual grain boundaries under superplastic conditions. Ultimately, these results will be used to provide a microstructural toolbox for identifying superplastic creep using geophysical (e.g., seismic, radar) and glaciological (e.g., ice core) observations. This project will support one graduate student within the MIT-WHOI Joint Program, one or more undergraduate summer students, and a junior faculty member (the PI). In addition, the PI will host a workshop aimed at bringing together experimentalists, glaciologists, and ice modelers to facilitate cross-disciplinary knowledge sharing and collaborative problem solving.
The goal of this project is to drill and recover an ice core from Hercules Dome, Antarctica. The geographic setting of Hercules Dome makes it well-situated to investigate changes in the size of the West Antarctic ice sheet over long time periods. The base of the West Antarctic ice sheet lies below sea level, which makes this part of Antarctica vulnerable to melting from the relatively warm deep water of the Southern Ocean. An important research question is whether the West Antarctic Ice Sheet collapsed during Earth's last prolonged warm period, about 125,000 years ago, when the ocean was warmer and sea level was several meters higher than today. Evidence for or against such a collapse will be recorded in the chemistry and physical properties of the ice. The Hercules Dome ice core will be obtained over three to four field seasons in Antarctica using efficient drilling technology. This grant includes support for project management, pre-drilling science community engagement, ice-core recovery, and education and outreach activities. <br/><br/>Hercules Dome is located at the edge of the East Antarctic ice sheet, south of the Transantarctic Mountains at 86 degrees South, 105 degrees West. Glaciological conditions at Hercules Dome are simple, with well-defined layering to the bed, optimal for the recovery of a deep ice core reaching to the last interglacial period at depths between 1600 and 2800 meters. An ice core from Hercules Dome will provide a research opportunity for ice-core analysts and others to make progress on a number of science priorities, including the environmental conditions of the last interglacial period, the history of gases and aerosols, and the magnitude and timing of changes in temperature and snow accumulation over the last 150,000 years. Together with the network of ice cores obtained by U.S. and international researchers over the last few decades, results from Hercules Dome will yield improved estimates of the boundary conditions necessary for the implementation and validation of ice-sheet models critical to the projection of future Antarctic ice-sheet change and sea level.<br/><br/>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.
\Millimeter-wave (mm-wave) observations of active galactic nucleus (AGN) variability have the potential to shed light on some of the key questions of AGN physics, such as the origin of blazar gamma-ray emission and the possible connection of AGN to the high-energy neutrinos detected by IceCube. While continuous, high-cadence monitoring of AGN is now common at gamma-ray, optical, and radio frequencies, AGN monitoring in the mm band has mostly been restricted to short campaigns on targeted sources. Cosmic Microwave Background (CMB) telescopes are now providing an option for daily monitoring of these objects within limited fields of view. I propose to use the South Pole Telescope (SPT), which was designed to observe the CMB at arcminute and larger angular scales, to monitor AGN, and then to expand this monitoring program to other CMB experiments such as Advanced ACTPol and the upcoming Simons Observatory and CMB-S4 experiments. A pilot project using data from the SPTpol camera on the SPT has enabled the monitoring of tens of mm-bright AGN on timescales from years to days at high signal to noise (S/N > 10 in a 36-hour coadd). A study focused on the blazar PKS 2326-502, which has extensive, day-timescale monitoring data in gamma-ray, optical, and now mm-wave data between 2013 and 2016 shows intriguing evidence of correlated variability between SPTpol (150 GHz), SMARTS (O/IR) and Fermi (gamma-rays) observations. I propose to carry out such multi-wavelength correlation studies on a large statistical sample of mm-wave-bright AGN, enabled by the repurposing of existing and future CMB data. This large sample (covering nearly 70 % of the sky) will also be key to investigating hints of correlations between mm-bright blazar flares and high-energy neutrinos. I further propose to build a public-facing server that will provide the mm lightcurves I construct from CMB data to the wider community.
In this project we investigated glaciers that drain ice from the East Antarctic Ice Sheet through the Transantarctic Mountains into the present-day Ross Ice Shelf. The outlet glaciers that flow through the Transantarctic Mountains have thinned significantly over the past 15,000 years, especially as they retreated from Last Glacial Maximum highstands to their present-day grounding lines. At certain locations and for certain glaciers, rocks or bedrock have been sampled to provide constraints on the timing of when ice retreated from these locations. In the locations where geochronological data are available we can use these data as direct constraints on ice-flow models that simulate ice elevation change over time. The intellectual merit of this work is using ice-flow models to spatially and temporally extrapolate between these limited geochronological data points, which enables new understanding of glacier evolution.
The mountainous topography in this region is complex, and there are limited measurements of the topography beneath the ice of the Transantarctic outlet glaciers. Since the topography of the glacier bed is an important control on ice flow and is a necessary boundary condition in models we developed a new gridded bed product at Beardmore Glacier, the one location where sufficient data were available, and we compared this to continent-scale gridded bed products. We found that for this glacier, the BedMachine v1 product was reasonably similar to the Beardmore Glacier bed topography measurements; our limited evaluation suggests that the BedMachine product may be sufficient at other Transantarctic outlets where bed measurements are not available, but that other compilations of bed topography data that do not include information about ice flow directions do not provide reliable results. Using these data and available geochronological constraints we investigated Beardmore Glacier evolution since the Last Glacial Maximum using simplified (flowline) models of ice flow.
In addition to flowline modeling at Beardmore Glacier, we developed a flow-model setup using the open-source 'icepack' model that uses the shallow stream equations and resolves flow in both the x and y directions. The key value added over flowline (or parameterized flowband) models is that this can capture converging and diverging ice flow, variable side wall and bottom drag, and other geometric complexities. In these simulations we can evaluate the past accumulation, ice influx, and ice outflux to compare controls on deglaciation to data constraints on the chronology of deglaciation.
We also used a flowline model to investigate the Darwin-Hatherton Glacier System. Exposure ages and radiocarbon ages of glacial deposits at four locations alongside Hatherton and Darwin glaciers record several hundred meters of late Pleistocene to early Holocene thickening relative to present. Deglaciation was relatively complex at this site, and we also found that Byrd glacier likely contributed ice to the catchment of the Darwin-Hatherton glacier system during the last glacial maximum, and that subsequent convergent flow from Byrd and Mulock glaciers during deglaciation complicated the response of the Darwin-Hatherton system. These new insights can be used on their own to better understand local deglaciation, and can also be used to evaluate regional or continent-scale model calculations.
Separately, we investigated the general response of outlet glaciers to different sources of climate forcing. We found that outlet glaciers have a characteristically different response over time to surface-mass-balance forcing applied over the interior than to oceanic forcing applied at the grounding line. Our models demonstrated that ocean forcing first engages the fast, local response and then the slow adjustment of interior ice, whereas surface-mass-balance forcing is dominated by the slow interior adjustment. These insights contributed to our general understanding of how outlet glaciers may have evolved over time.
Our new model investigations provide a framework that can be applied at other Transantarctic outlet glaciers where geochronological data are available. In particular, our 'icepack' setup is an archived and documented resource for the community. These tools are available for future investigations, including additional investigations at Beardmore Glacier and at other Transantarctic Mountain outlet glaciers. Scientific broader impacts include that this contributes to our understanding of the past behavior of East Antarctic ice, which provides an important constraint on the future evolution of Antarctica. Our team has engaged in public outreach and has engaged students in this research. Two graduate students led in aspects of this work, and have since gone on to research positions after their PhD.
Nontechnical Description: The age of rocks and soils at the surface of the Earth can help answer multiple questions that are important for human welfare, including: when did volcanoes erupt and are they likely to erupt again? when did glaciers advance and what do they tell us about climate? what is the frequency of hazards such as landslides, floods, and debris flows? how long does it take soils to form and is erosion of soils going to make farming unsustainable? One method that is used thousands of times every year to address these questions is called 'cosmogenic surface-exposure dating'. This method takes advantage of cosmic rays, which are powerful protons and neutrons produced by supernova that constantly bombard the Earth's atmosphere. Some cosmic rays reach Earth's surface and produce nuclear reactions that result in rare isotopes. Measuring the quantity of the rare isotopes enables the length of time that the rock or soil has been exposed to the atmosphere to be calculated. The distribution of cosmic rays around the globe depends on Earth's magnetic field, and this distribution must be accurately known if useful exposure ages are to be obtained. Currently there are two remaining theories, narrowed down from many, of how to calculate this distribution. Measurements from a site that is at both high altitude and high latitude (close to the poles) are needed to test the two theories. This study involves both field and lab research and includes a Ph.D. student and an undergraduate student. The research team will collect rocks from lava flows on an active volcano in Antarctica named Mount Erebus and measure the amounts of two rare isotopes: 36Cl and 3He. The age of eruption of the samples will be determined using a highly accurate method that does not depend on cosmic rays, called 40Ar/39Ar dating. The two cosmic-ray theories will be used to calculate the ages of the samples using the 36Cl and 3He concentrations and will then be compared to the ages calculated from the 40Ar/39Ar dating. The accurate cosmic-ray theory will be the one that gives the same ages as the 40Ar/39Ar dating. Identification of the accurate theory will enable use of the cosmogenic surface dating methods anywhere on earth. <br/>Technical Description: Nuclides produced by cosmic rays in rocks at the surface of the earth are widely used for Quaternary geochronology and geomorphic studies and their use is increasing every year. The recently completed CRONUS-Earth Project (Cosmic-Ray Produced Nuclides on Earth) has systematically evaluated the production rates and theoretical underpinnings of cosmogenic nuclides. However, the CRONUS-Earth Project was not able to discriminate between the two leading theoretical approaches: the original Lal model (St) and the new Lifton-Sato-Dunai model (LSD). Mathematical models used to scale the production of the nuclides as a function of location on the earth, elevation, and magnetic field configuration are an essential component of this dating method. The inability to distinguish between the two models was because the predicted production rates did not differ sufficiently at the location of the calibration sites. <br/><br/>The cosmogenic-nuclide production rates that are predicted by the two models differ significantly from each other at Erebus volcano, Antarctica. Mount Erebus is therefore an excellent site for testing which production model best describes actual cosmogenic-nuclide production variations over the globe. The research team recently measured 3He and 36Cl in mineral separates extracted from Erebus lava flows. The exposure ages for each nuclide were reproducible within each flow (~2% standard deviation) and in very good agreement between the 3He and the 36Cl ages. However, the ages calculated by the St and LSD scaling methods differ by ~15-25% due to the sensitivity of the production rate to the scaling at this latitude and elevation. These results lend confidence that Erebus qualifies as a suitable high- latitude/high-elevation calibration site. The remaining component that is still lacking is accurate and reliable independent (i.e., non-cosmogenic) ages, however, published 40Ar/39Ar ages are too imprecise and typically biased to older ages due to excess argon contained in melt inclusions.<br/>The research team's new 40Ar/39Ar data show that previous problems with Erebus anorthoclase geochronology are now overcome with modern mass spectrometry and better sample preparation. This indicates a high likelihood of success for this proposal in defining an accurate global scaling model. Although encouraging, much remains to be accomplished. This project will sample lava flows over 3 km in elevation and determine their 40Ar/39Ar and exposure ages. These combined data will discriminate between the two scaling methods, resulting in a preferred scaling model for global cosmogenic geochronology. The LSD method contains two sub-methods, the 'plain' LSD scales all nuclides the same, whereas LSDn scales each nuclide individually. The project can discriminate between these models using 3He and 36Cl data from lava flows at different elevations, because the first model predicts that the production ratio for these two nuclides will be invariant with elevation and the second that there should be ~10% difference over the range of elevations to be sampled. Finally, the project will provide a local, finite-age calibration site for cosmogenic-nuclide investigations in Antarctica.
Stable isotope analyses of carbon and nitrogen (δ13C and δ15N) are commonly used to investigate animal migration, foraging locations and diet, especially in marine species that can travel over great distances. One other stable isotope, sulfur (δ34S), is not as commonly used but is increasingly being applied to refine and corroborate data obtained from carbon and nitrogen analyses. Collagen is one of the best tissues for these analyses as it is abundant in bone, preserves well, and can be easily extracted for analysis. In the Ross Sea region, the cold, dry environment has been conductive for the preservation of Adélie penguin (Pygoscelis adeliae) bones, feathers, eggshell and even mummified remains, at active and abandoned colonies that date from before the Last Glacial Maximum (>45,000 yrs ago) through the Holocene. Most of these colonies are associated with one of three polynyas, or highly productive areas of open water surrounded by sea ice in the Ross Sea. Thus, this species is an excellent bioindicator for marine conditions, past and present, and its colonies have appeared and disappeared throughout this region with changing climate and sea ice regimes for millennia. Current warming trends are inducing relatively rapid ecological responses by this species and some of the largest colonies in the Ross Sea are likely to be abandoned in the next 50 years from rising sea level. The recently established Ross Sea Marine Protected Area aims to protect Adélie penguins and other species in this region from human impacts and knowledge on how this species responds to climate change, past and present, will support this goal.
We propose to investigate ecological responses in diet and foraging behavior of the Adélie penguin to known climatic events that occurred in the middle to late Holocene, specifically, before, during and after a warming period known as the penguin ‘optimum’ at 2000 - 4000 cal yr before present (BP). We will apply for the first time a suite of three stable isotope analyses (δ13C, δ15N, δ34S) on chick bones and feathers, as well as prey remains, from active and abandoned colonies in the Ross Sea. We will use existing tissue samples (~60-80 bones) collected by PI Emslie with NSF support since 2001 and supplement these with newly collected samples of bones and feathers in this project. We will conduct compound-specific isotope analyses of carbon on essential amino acids from collagen from a selected sample of 30-40 bones that span the past 5000 yrs to provide corroboratory information. We will apply three-dimensional Bayesian niche models and/or community metrics using R scripts in these analyses to identify isotopic ‘signatures’ of existing and past foraging grounds and polynyas used by Adélie penguins in the southern, central, and northern Ross Sea. This four-year study will the first of its kind to apply multiple stable isotope analyses to investigate a living species of seabird over millennia in a region where it still exists today.
Broader Impacts:
The PIs are committed to public engagement and enhancement of K-12 education in the STEM sciences. Broader impacts of this research will include support and training for one Ph.D., two M.S., and eight undergraduate students in the Department of Biology and Marine Biology, and two M.A. students in the Watson School of Education at the University of North Carolina Wilmington (UNCW). The last two students will continue to expand on a detailed polar curriculum that was initiated in previous NSF grants for 2nd and 4th grade students, and most recently for 9-12th grade students now available on PI Emslie’s website (www.uncw.edu/penguins). Additional curricula for K-12 students will be designed and tested in this project, which will include visitation to local K-12 schools. As in previous awards, we will focus on schools that serve historically under-represented groups in the sciences. We will work with the UNCW Center for Education in STEM Sciences to assess the efficacy of this new curricula. All curricula will be uploaded on the Educational Resource Commons website. Field work will include blogs and active question-answer sessions with students at these schools. We will continue to post project information and updates on PI Emslie’s website and YouTube channel. Our partnership with tour ship companies will provide a platform for onboard lectures on the importance of scientific research as well as citizen science opportunities for another sector of the public. This proposal requires fieldwork in the Antarctic.
Siddoway, Christine; Thomson, Stuart; Teyssier, Christian
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Sediment records off the coast of Marie Byrd Land (MBL), Antarctica suggest frequent and dramatic changes in the size of the West Antarctic Ice Sheet (WAIS) over short (tens of thousands of years) and long (millions of years) time frames in the past. WAIS currently overrides much of MBL and covers the rugged and scoured bedrock landscape. The ice sheet carved narrow linear troughs that reach depths of two to three thousand meters below sea level as outlet glaciers flowed from the interior of the continent to the oceans. As a result, large volumes of fragmented continental bedrock were carried out to the seabed. The glaciers cut downward into a region of crystalline rocks (i.e. granite) that display a significant temperature change as a function of rock depth. The strong geothermal gradient in the bedrock is favorable for determining when the bedrock became exhumed, or "uncovered" by action of the overriding icesheet or other processes. Our approach takes advantage of a reference horizon, or paleogeotherm, established when high-T mineral thermochronometers across Marie Byrd Land (MBL) cooled from temperatures of >800° C to 300° C, due to rapid regional extension at ~100 Ma . The event imparted a signature through which the subsequent Cenozoic landscape history can be explored: MBL's elevated geothermal gradient, sustained during the Cenozoic, created favorable conditions for sensitive apatite and zircon low-T thermochronometers to record bedrock cooling related to glacial incision.
Analyzing the chemistry of minerals (zircon and apatite) within fragments of eroded rock will reveal the rate and timing of the bedrock erosion and development of topography in West Antarctica. This collaborative project addresses the following questions: When did the land become high enough for a large ice sheet to form? What was the regional pre-glacial topography? Under what climate conditions, and at what point in the growth of an ice sheet, did glaciers begin to cut sharply into bedrock to form the narrow troughs that flow seaward? The research will lead to greater understanding of past Antarctic ice sheet fluctuations and identify precise timing of glacial incisionm which will clarify the onset of WAIS glacier incision and assess the evolution of Cenozoic paleo-topography. The collaborative project provides training for one graduate and 8 undergraduate students in STEM. These students, together with PIs, will refine West Antarctic ice sheet history and obtain results that pertain to the international societal response to contemporary ice sheet change and its global consequences.
The methods used for the research include:
•Low-temperature (T) thermochronology and Pecube 3-D thermo-kinematic modeling, applied to the timing and characterizatio episodes of glacial erosional incision.
•Single-grain double- and triple-dating of zircon and apatite, to determine the detailed crustal thermal evolution of the region, enabling the research team to identify the comparative topographic influences on glaciation versus bedrock uplift induced by Eocene to present tectonism/magmatism.
Students and PIs employed state-of-the-art analytical facilities in Arizona and Minnesota, expanding the geo- and thermochronologic history of MBL from bedrock samples and offshore sedimentary deposits. The temperature and time data we acquired will provide constraints on paleotopography, isostasy, and the thermal evolution of MBL that will be modeled in 3D using Pecube model simulations. Within hot crust, less incision is required to expose bedrock containing the distinct thermochronometric profile; a prediction we are testing through use of inverse Pecube 3-D models of the thermal field through which bedrock and detrital samples cooled. Using results from Pecube, the ICI-Hot team will examine time-varying topography formed in response to changes in erosion rates, topographic relief, geothermal gradient and/or flexural isostatic rigidity. These effects are manifestations of dynamic processes in the WAIS, including ice sheet loading, ice volume fluctuations, relative motion upon crustal faults, and magmatism-related elevation increase across the MBL dome. The project makes use of pre-existing sample collections housed at the US Polar Rock Repository, IODP's Gulf Coast Core Repository, and the OSU Marine and Geology Repository. 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.
Non-technical description: <br/>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.<br/>Technical description:<br/> 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.
To obtain observations of temporal variability of firn processes in Antarctica, we designed a cost-efficient, reliable, and easily deployable firn monitoring system capable of operating with little or no maintenance over a period of several seasons. The prototype station was installed in December 2017 in the vicinity of the geographical South Pole and at a short distance from the Amundsen-Scott South Pole Research Station in Antarctica. The data presented was acquired between December of 2017 and January of 2020. During the first year, of the months without sunlight the longest period without SMB measurements was 22 days, yielding enough measurements to obtain monthly estimates of every variable. During the polar night of 2019, a technical issue related to extreme cold prevented the data logger attached to the CRNCs to record correctly so the sensor was placed under a stand-by mode until the 2nd of December 2019 when temperatures raised. Firn compaction, temperature and wind were recorded continuously during the 2-year period with the exception of a couple of weeks during the Austral winter. The project finalized in January 2020 and the system was taken down on January 15th.
The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington's annual Polar Science Weekend in Seattle, and art-science collaboration.<br/><br/>This project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a "Raymond Bump") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow.<br/><br/>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.
Alabama Museum of Natural History, University of Alabama, Tuscaloosa
Ocean communities play an important role in determining the natural and human impacts of global change. The most conspicuous members of those communities are generally large vertebrates such as marine mammals and sea birds. But smaller animals often determine how the changes impact those charismatic animals. In the Antarctic, where some of the most dramatic physical changes are taking place, we do not know much about what small animals exist. This project will sample the sub-Antarctic and three different Antarctic seas with a hope of identifying, quantifying and discovering the variation in species of a group of small invertebrates. Comma shrimp, also called cumaceans, are rarely seen elsewhere but may be common and important in the communities of these locations. Antarctic sampling traditionally used gear that was not very effective at catching cumaceans so we do not know what species exist there and how common they are. This study will utilize modern sampling methods that will allow comma shrimp to be sampled. This will lead to discoveries about the diversity and abundance of comma shrimp, as well as their relationship to other invertebrate species. Major impacts of this work will be an enhancement of museum collections, the development of description of all the comma shrimp of Antarctica including new and unnamed species. Those contributions may be especially important as we strive to understand what drives the dynamics of charismatic vertebrates and fisheries that are tied to Antarctic food webs. <br/><br/>This project will collect cumaceans from benthic samples from the Antarctic peninsula, Bransfield Strait, and the Weddell Sea using benthic sleds, boxcores and megacores. Specimens will be fixed in 95% ethanol, preserved in 95% ethanol and 5% glycerin to preserve both morphology and DNA, and some specimens will be partially or wholly preserved in RNALater to preserve RNA and DNA. The specimens will form the basis for a monograph synthesizing current knowledge on the Subantarctic and Antarctic Cumacea, including diagnoses of all species, descriptions of new species, additional description for currently unknown life stages of known species, and vouchered gene sequences for all species collected. The monograph will include keys to all families, genera and species known from the region. Monographic revisions that include identification resources are typically useful for decades to a broad spectrum of other scientists.<br/><br/>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.
Presently, Antarctica's glaciers are melting as Earth's atmosphere and the Southern Ocean warm. Not much is known about how Antarctica's ice sheets might respond to ongoing and future warming, but such knowledge is important because Antarctica's ice sheets might raise global sea levels significantly with continued melting. Over time, mud accumulates on the sea floor around Antarctica that is composed of the skeletons and debris of microscopic marine organisms and sediment from the adjacent continent. As this mud is deposited, it creates a record of past environmental and ecological changes, including ocean depth, glacier advance and retreat, ocean temperature, ocean circulation, marine ecosystems, ocean chemistry, and continental weathering. Scientists interested in understanding how Antarctica's glaciers and ice sheets might respond to ongoing warming can use a variety of physical, biological, and chemical analyses of these mud archives to determine how long ago the mud was deposited and how the ice sheets, oceans, and marine ecosystems responded during intervals in the past when Earth's climate was warmer. In this project, researchers from the University of South Florida, University of Massachusetts, and Northern Illinois University will reconstruct the depth, ocean temperature, weathering and nutrient input, and marine ecosystems in the central Ross Sea from ~17 to 13 million years ago, when the warm Miocene Climate Optimum transitioned to a cooler interval with more extensive ice sheets. Record will be generated from new sediments recovered during the International Ocean Discovery Program (IODP) Expedition 374 and legacy sequences recovered in the 1970?s during the Deep Sea Drilling Program. Results will be integrated into ice sheet and climate models to improve the accuracy of predictions.
The Ross Sea, Antarctica, is one of the last large intact marine ecosystems left in the world, yet is facing increasing pressure from commercial fisheries and environmental change. It is the most productive stretch of the Southern Ocean, supporting an array of marine life, including Antarctic toothfish the regions top fish predator. While a commercial fishery for toothfish continues to grow in the Ross Sea, fundamental knowledge gaps remain regarding toothfish ecology and the impacts of toothfish fishing on the broader Ross Sea ecosystem. Recognizing the global value of the Ross Sea, a large (>2 million km2) marine protected area was adopted by the multi-national Commission for the Conservation of Antarctic Marine Living Resources in 2016. This research will fill a critical gap in the knowledge of Antarctic toothfish and deepen understanding of biological-physical interactions for fish ecology, while contributing to knowledge of impacts of fishing and environmental change on the Ross Sea system. This work will further provide innovative tools for studying connectivity among geographically distinct fish populations and for synthesizing and assessing the efficacy of a large-scale marine protected area. In developing an integrated research and education program in engaged scholarship, this project seeks to train the next generation of scholars to engage across the science-policy-public interface, engage with Southern Ocean stakeholders throughout the research process, and to deepen the publics appreciation of the Antarctic.
A major research priority among Ross Sea scientists is to better understand the life history of the Antarctic toothfish and test the efficacy of the Ross Sea Marine Protected Area (MPA) in protecting against the impacts of overfishing and climate change. Like growth rings of a tree, fish ear bones, called otoliths, develop annual layers of calcium carbonate that incorporates elements from their environment. Otoliths offer information on the fishs growth and the surrounding ocean conditions. Hypothesizing that much of the Antarctic toothfish life cycle is structured by ocean circulation, this research employs a multi-disciplinary approach combining age and growth work with otolith chemistry testing, while also utilizing GIS mapping. The project will measure life history parameters as well as trace elements and stable isotopes in otoliths in three distinct sets collected over the last four decades in the Ross Sea. The information will be used to quantify the transport pathways Antarctic toothfish use across their life history, and across time, in the Ross Sea. The project will assess if toothfish populations from the Ross Sea are connected more widely across the Antarctic. By comparing life history and otolith chemistry data across time, the researchers will assess change in life history parameters and spatial dynamics and seek to infer if these changes are driven by fishing or climate change. Spatially mapping of these data will allow an assessment of the efficacy of the Ross Sea MPA in protecting toothfish and where further protections might be needed.
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.
Overview: Several recent studies indicate continuing and increasing ice loss from the Amundsen Sea region of West Antarctica (chiefly Pine Island and Thwaites glaciers). This loss is initiated by thinning of the floating ice shelves by basal melting driven by circulation of relatively warm ocean water under the ice shelves. This thinning triggers ice-dynamics related feedbacks, which leads to loss of ice from the grounded ice sheet. Models suggest that, even though long-term committed ice loss might be governed by ice dynamics, the magnitude of ocean-driven melting at the base of the ice shelves plays a critical role in controlling the rate of ice loss. These conclusions, however, are based on simple parameterized models for melt rate that do not take into account how ocean circulation will change in future as large-scale climate forcing changes, and as the ice shelves thin and retreat through both excess melting and accelerated ice flow. Given that present global climate models struggle to resolve the modern ocean state close to the ice shelves around Antarctica, their projections of future impacts on basal melting and time scale of ice loss have large uncertainties.
This project is aimed at reducing these uncertainties though two approaches: (i) assessing, for a given ocean state, how the melt rates will change as ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of melt rates beneath the Pine Island and Thwaites ice shelves to changes in ocean state on the Amundsen Sea continental shelf. These studies will provide more realistic bounds on ice loss and sea level rise, and lay the groundwork for development of future fully-coupled ice sheet-ocean simulations.
Intellectual Merit: Rather than pursue a strategy of using fully coupled models, this project adopts a simpler semi-coupled approach to understand the sensitivity of ice-shelf melting to future forcing. Specifically, the project focuses on using regional ocean circulation models to understand current and future patterns of melting in ice-shelf cavities. The project’s preliminary stage will focus on developing high-resolution ice-shelf cavity-circulation models driven by modern observed regional ocean state and validated with current patterns of melt inferred from satellite observations. Next, an ice-flow model will be used to estimate the future grounding line at various stages of retreat. Using these results, an iterative process with the ocean-circulation and ice-flow models will be applied to determine melt rates at each stage of grounding line retreat. These results will help assess whether more physically constrained melt-rate estimates substantially alter the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway. Further, by multiple simulations with modified open-ocean boundary conditions, this study will provide a better understanding of the sensitivity of melt to future changes in regional forcing. For example, what is the sensitivity of melt to changes in Circumpolar Deep Water temperature and to changes in the thermocline height driven be changes in wind forcing? Finally, several semi-coupled ice-ocean simulations will be used to investigate the influence of the ocean-circulation driven distribution of melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response.
Broader Impacts: Planning within the current large range of uncertainty in future sea level change leads to high social and economic costs for governments and businesses worldwide. Thus, our project to reduce sea-level rise uncertainty has strong societal as well as scientific interest. The findings and methods will be applicable to ice shelf cavities in other parts of Antarctica and northern Greenland, and will set the stage for future studies with fully coupled models as computational resources improve. This interdisciplinary work combines expertise of glaciologists and oceanographers, and will contribute to the education of new researchers in this field, with participation of graduate students and postdocs. Through several outreach activities, team members will help make the public aware of the dramatic changes occurring in Antarctica along with the likely consequences.
This proposal does not require fieldwork in the Antarctic.
Part I: Non-technical summary<br/>The Antarctic Peninsula warmed very rapidly in the late part of the 20th century, much faster than the global average, and this warming is predicted to resume and continue over the rest of the 21st century. One consequence of this rapid warming is the melting and subsequent retreat of glaciers, leading to an increase in newly-exposed land on the Peninsula that was previously covered with ice. Once new terrain is exposed, the process of ecological succession begins, with the arrival of early-colonizing plants, such as moss and lichens, and soil organisms - a process commonly referred to as the “greening” of Antarctica. Early stages of succession will be an increasingly common feature on the Antarctic Peninsula, but the mechanisms by which they occur on the Antarctic continent is not well understood. Once the plants have established on the newly-exposed soil, they can change many important properties, such as water dynamics, nutrient recycling, soil development, and habitat for microscopic organisms, which will ultimately determine the structure and functioning of the future ecosystem as it develops. These relationships between vegetation, soil, and the associated microorganisms, referred to as “plant-soil” interactions, are something we know virtually nothing about. This project will be the first to make a comprehensive study of how the type of colonizing plant, and the expansion of those plants from climate change, will influence terrestrial ecosystems in Antarctica. Understanding these processes is critical to understanding how the greening Antarctica is occurring and how soil communities and processes are influenced by these expanding plant communities. Through this work the research team, will also be intensively training undergraduate and graduate students, including training of students from underrepresented groups and collaborative training of students from Chile and the US. Additionally, the research groups will continue their focus on scientific outreach with K-12 schools and the general public to expand awareness of the effects of climate change in Antarctica.<br/><br/>Part II: Technical summary<br/>In this study, the researchers will use surveys across succession sites along the Antarctic Peninsula and Scotia Arc as well as a manipulative field experiment at glacier succession sites to test how species-specific plant functional traits impact soil properties and associated microbial and invertebrate communities in a greening Antarctica. In doing so, they will pursue three integrated aims to understand how Antarctic plant functional traits alter their soil environment and soil communities during succession after glacial retreat. AIM 1) Characterize six fundamental plant functional traits (thermal conductivity, water holding capacity, albedo, decomposability, tissue nutrient content, and secondary chemistry) among diverse Antarctica flora; AIM 2) Measure the relative effects of fundamental plant functional traits on soil physical properties and soil biogeochemistry across glacial succession gradients in Antarctica; and AIM 3) Measure the relative effects of fundamental plant functional traits on soil microbial and invertebrate communities across glacial succession gradients in Antarctica. They will explore how early-colonizing plants, especially mosses and lichens, alter soil physical, biogeochemical, and biological components, potentially impacting later patterns of succession. The researhcers will use intensive surveys of plant-soil interactions across succession sites and a manipulative transplant experiment in the South Shetland Islands, Antarctica to address their aims. The investigators will collect data on plant functional traits and their effects on soil physical properties, biogeochemistry, biotic abundance, and microbial metagenomics. The data collected will be the first comprehensive measures of the relative importance of plant functional types during glacial retreat and vegetative expansion from climate change in Antarctica, aiding our understanding of how plant functional group diversity and abundance are changing in a greening Antarctica.<br/><br/>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.
We will measure the surface energy balance on West Antarctica as it relates to atmospheric forcing of surface melt and hydrofracturing of ice shelves and grounding-line ice cliffs. In this program we build upon recent experience with a major campaign jointly supported by the US Antarctic Program (USAP) and US Department of Energy (DOE), the Atmospheric Radiation Measurement (ARM) West Antarctic Radiation Experiment (AWARE). AWARE deployed a highly advanced suite of atmospheric and climate science instrumentation to McMurdo Station from December 2015 through December 2016, including spectral radiometers, research radars and lidars, and comprehensive meteorological equipment. AWARE also deployed a smaller suite of radiometers, lidars, and rawinsonde equipment to the West Antarctic Ice Sheet (WAIS) Divide Ice Camp during December 2015 and January 2016. This project’s principal investigator, Dr. Lubin (Scripps Institution of Oceanography, SIO), was the AWARE lead scientist. For this program we will deploy a suite instruments to measure downwelling and net shortwave and longwave fluxes, sensible and latent heat fluxes, and near-surface meteorology. This suite of instruments will be self-reliant with power requirements and will be supportable in the field with flexible resources, for example a single Twin Otter aircraft mission. These measurements will be analyzed and interpreted to determine synoptic and mesoscale conditions that govern surface melt in West Antarctica, in the context of improving coupled climate model parameterizations.
The research focus of this collaborative proposal was to collect fossil plants, fossil wood, stratigraphic, sedimentologic, paleosol, and geochemical data from plants and the rocks that contain them in order to reconstruct the extent of the Gondwana glaciation in the Shackleton Glacier (SHK) area, the invasion and subsequent flourishing of life following glacial retreat, changes to the physical environment, and the eventual recovery of plant life after the Late Permian biotic events. Only in Antarctica does a complete polar-to-near-polar succession occur across this climatic and biologic transition. The SHK 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. In addition, outcrops in the SHK area extend from the glacigenic deposits of the Upper Carboniferous-Lower Permian through to the Upper Triassic and thus record ecosystems and the plants that inhabited them from the Gondwana icehouse into the Late Permian-Early Triassic greenhouse and into presumed "full recovery" of floras from the PTB extinctions in the Late Triassic.
The project encompassed a multidisciplinary plan that used various types of paleobotanical expertise, integrated with detailed sedimentology, stratigraphy, and geochemistry, in order to reconstruct Permian-Triassic plant communities and their paleoenvironments. This interdisciplinary approach is a powerful tool to uncover details of Antarctica’s complex late Paleozoic and Mesozoic environmental, climatic, and biotic history which included: 1) glaciation/deglaciation, 2) development and evolution of a post-glacial landscape and biota, 3) environmental and biotic change associated with the end-Permian mass extinction events, 4) earliest ecosystems in the Triassic, 5) greenhouse conditions in the Triassic, 6) full ’recovery’ of floras and ecosystems by the Late Triassic, and, through all of these events, 7) development and changes in a foreland basin system. Three interrelated focus areas, each delimited by distinct hypotheses and action strategies, provided the framework to trace floral diversity and environmental evolution after the retreat of glaciers through to the Late Triassic. Antarctica is the only place on Earth that includes extensive outcrops of high-paleolatitude terrestrial rocks, combined with widespread and well-preserved plant fossils, and that spans this crucial time.
The research and broader impacts of this proposal were integrated into action strategies that have been successful in the past. Compression floras were collected (constrained by stratigraphy) both quantitatively and qualitatively in order to obtain biodiversity and abundance data, and as a data source for paleoecological analysis. Even in formations where megafossils were unknown (e.g., Lower Permian), fossil wood is present so that anatomy and geochemistry of tree rings were examined. Standard sedimentologic and stratigraphic analyses were 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.
The Broader Impacts of the project involved education and outreach initiatives that included women and under-represented groups in the excitement of Antarctic earth sciences: 1) Continuing successful public outreach, teaching, and mentoring of women and under-represented students in Antarctic research; 2) Participation in workshops for under-represented groups via the Expanding Your Horizons Program in Kansas, the TRIO program (KU), and the STELAR summer workshop (UWM) for high-school students. 3) Outreach via the KU Natural History Museum; 4) Exploring Antarctic geosciences through continued presentations to pre K-12 school groups, and field and lab activities at UWM, as well as links from McMurdo Station and satellite conferences from the field with K-12 science classes in Wisconsin and Illinois.
The McMurdo Dry Valleys are the largest ice-free region in Antarctica and home to a seasonally active hydrologic system, with streams and saline lakes. Streams are fed by summer meltwater from local glaciers and snowbanks. Therefore, streamflow is tied to summer climate conditions such as air temperatures, ground temperatures, winds, and incoming solar radiation. Based on 50 years of monitoring, summer stream activity has been observed to change, and it likely varied during the geologic past in response to regional climate change and fluctuating glaciers. Thus, deposits from these streams can address questions about past climate, meltwater, and lake level changes in this region. How did meltwater streamflow respond to past climate change? How did streamflow vary during periods of glacial advance and retreat? At what times did large lakes fill many of the valleys and what was their extent? The researchers plan to acquire a record of stream activity for the Dry Valleys that will span the three largest valleys and a time period of about 100,000 years. This record will come from a series of active and ancient alluvial fans that were deposited by streams as they flowed from valley sidewalls onto valley floors. The study will provide a long-term context with which to assess recent observed changes to stream activity and lake levels. The research will be led by two female mid-career investigators and contribute significantly to student research opportunities and education. The research will contribute to graduate and undergraduate education by including students in both field and laboratory research, as well as incorporating data and results into the classroom. The research will be disseminated to K-12 and non-scientific communities through outreach that includes professional development training for K-12 teachers in eastern Massachusetts, development of hands-on activities, visits to K-12 classrooms, and STEM education and literacy activities in North Carolina.
The PIs propose to constrain rates of fluvial deposition and periods of increased fluvial activity in the McMurdo Dry Valleys during the Holocene and late Pleistocene. During 50 years of hydrologic monitoring in the Dry Valleys, scientists have observed that streams exhibit significant response to summer conditions. Previous studies of glacial and lacustrine deposits indicate regional glacier advance in the Dry Valleys during recent interglacial periods and high lake levels during and after the Last Glacial Maximum (LGM), with potentially significant low and high stands during the Holocene. However, the geologic record of meltwater activity is poorly constrained. The PIs seek to develop the first spatially-extensive record of stream deposition in the Dry Valleys by analyzing and dating alluvial fans. Given that alluvial fans are deposited by summer meltwater streams in a relatively stable tectonic setting, this record will serve as a proxy of regional summer climate conditions. Meltwater streams are an important component of the regional hydrologic system, connecting glaciers to lakes and affecting ecosystems and soils. A record of fluvial deposition is key to understanding the relationship between past climate change and regional hydrology. The proposed research will include remote- and field-based mapping of alluvial fans, stream channels, and meltwater sources as well as modeling potential incoming solar radiation to the fans and moisture sources during the austral summer. In the field, the PIs will document stratigraphy, collect near-surface sediments from 25 fans across four valleys (Taylor, Pearse, Wright, and Victoria), and collect 2- to 3-m vertical cores of ice-cemented sediments from three alluvial fan complexes. The PIs will then conduct depositional dating of fluvial sands via optically stimulated luminescence, and analyze mineralogy and bulk major element chemistry with X-ray powder diffraction and X-ray fluorescence. From these analyses, the PIs propose to (1) determine the timing of local- to regional-scale periods of high fluvial deposition, (2) calculate depositional rates, and (3) constrain depositional environments and sediment provenance. Given that many of the alluvial fans occur below the hypothesized maximum extents of glacially-dammed lakes in Wright and Victoria valleys, detailed stratigraphy, sediment provenance, and OSL dating of these fans could shed light on ongoing debates regarding the timing and extent of LGM and post-LGM lakes. The work will support a postdoctoral researcher, a PhD student, and many undergraduate and master’s students in cross-disciplinary research that spans stratigraphy, geochemistry, paleoclimatology and physics.
In contrast to the Arctic, sea ice cover in most Antarctic regions has increased since 1979. The area-integrated total sea ice extent grew to record maximum values in four of the last six years, yet the 2015-16 summer was marked by record low ice cover. While impressive, it is difficult to assess the significance of these very recent records in the context of longer term variability, since the continuous satellite record only dates back to 1978. The limited length of the continuous sea ice record, is a significant confounding factor in ascertaining whether the observed current changes are due to natural variability alone, or represent a forced anthropogenic response. As a result, the scientific understanding of the Antarctic sea ice trends remains poor, as does confidence in projections of future Antarctic sea ice trends.
To address this challenge, this project seeks to reconstruct sea ice extent and sea ice concentration, using the relationships between satellite-observed sea ice, sea level pressure, tropical sea surface temperature, ENSO indices, some proxy data (ice cores, etc.), and in situ Southern Ocean temperature data. The aim of the study is to collect and combine these ancillary records as accurately as possible while retaining the variability associated with the intrinsic uncertainty in the available field data.
A range of statistical methods for modelling the relationship between satellite era sea-ice data using flexible regression, Bayesian and multivariate dynamic spatial temporal (MDST) methods will be used.
This package contains data collected from microbial mat surveys (i.e., percent cover, ash-free dry mass (AFDM), and pigment concentrations – chlorophyll-a, scytonemin, and carotenoids) associated with satellite-derived Normalized Difference Vegetation Index (NDVI) values from the Lake Fryxell Basin of Taylor Valley, located in the McMurdo Dry Valleys of Antarctica. The purpose of this study was to quantitatively compare key microbial mat characteristics to NDVI. Data were collected at seven plot locations within the Canada Glacier Antarctic Specially Protected Area (ASPA) near Canada Stream, as well as alongside Green Creek and McKnight Creek. NDVI values were derived from a WorldView-2 multispectral satellite image taken of the Lake Fryxell Basin on January 19, 2018, while biological ground surveying and sampling were conducted during the 2nd and 4th weeks of January 2018.
The award supports a project to use existing samples from the West Antarctic Ice Sheet (WAIS) Divide ice core to align its timescale with that of the Greenland ice cores using common chronological markers. The upper 2850 m of the WAIS Divide core, which was drilled to a depth of 3405 m, has been dated with high precision. The timescale of the remaining (bottom) 550 m of the core has larger uncertainties, limiting our understanding of the timing of abrupt climate events in Antarctica relative to those in Greenland during the last ice age. The intellectual merit of this project is to further constrain the relative timing of these abrupt climate events in Greenland and Antarctica to obtain crucial insight into the underlying mechanism. The main objective of this project is to improve the current timescale of the WAIS Divide core from 31,000 to 65,000 years ago by synchronizing this core with the Greenland ice cores using common signals in Beryllium-10, a radioactive isotope of Be that is produced in the atmosphere by cosmic rays and is deposited onto the snow within 1-2 years of its production. The 10Be flux is largely independent of climate signals since its production varies with solar activity and the geomagnetic field. This project will further strengthen collaborations between the PI’s in Berkeley and Purdue with ice core researchers in the US and Europe, involve undergraduate students in many aspects of its research, and continue out-reach to under-represented students.
The direct ice-to-ice synchronization of the WAIS Divide ice core with the Greenland Ice Core Chronology (GICC05) using cosmogenic 10Be is expected to reduce the uncertainty in the relative timing of more than 20 abrupt climate events in Greenland and Antarctica to a few decades. To achieve this goal we will obtain a continuous high-resolution record of 10Be in the WAIS Divide core from 2850 to 3390 m depth, and compare the obtained 10Be record with existing 10Be records of the Greenland ice cores, including GISP2 and NGRIP. We will separate 10Be from ~1000 ice samples of the WAIS Divide core and measure the 10Be concentration in each sample using accelerator mass spectrometry (AMS). Broader impacts of the 10Be measurements are that they will also provide information on the Laschamp event, a ~2000 year long period of low geomagnetic field strength around 41,000 years ago, and improve the calibration of the 14C dating method for organic samples older than 30,000 years. The broader impacts of the project include (1) the involvement and training of undergraduate students in ice core research and accelerator mass spectrometry measurements, (2) the incorporation of ice core and climate research into ongoing outreach programs at Purdue University and Berkeley SSL, (3) better understanding of abrupt climate changes in the past will improve our ability to predict future climate change, (4) evaluating the possible threat of a future geomagnetic excursion in the next few hundred years. This award does not require support in Antarctica.
The Mid-Pleistocene Transition (MPT; ~1.25–0.7 Ma) marks the shift from glacial-interglacial cycles paced by obliquity (~41 kyr cycles) to those paced by eccentricity (~100-kyr cycles). This transition occurred despite little variation in Earth’s orbital parameters, suggesting a role for internal climate feedbacks. The MPT was accompanied by decreasing atmospheric pCO2, increasing deep ocean carbon storage, and changes in deep water formation and distribution, all of which are linked to Antarctic margin atmosphere-ice-ocean interactions. However, Pleistocene records that document such interactions are rarely preserved on the shelf due to repeated Antarctic Ice Sheet (AIS) advance; instead, they are preserved in deep Southern Ocean basins. This project takes advantage of the excellent preservation and recovery of continuous Pleistocene sediment sequences collected from the Scotia Sea during International Ocean Discovery Program Expedition 382 to test the following hypotheses: 1) Southern Ocean upper ocean temperatures vary on orbital timescales during the early to middle Pleistocene (2.6–0.7 Ma), and 2) Southern Ocean temperatures co-vary with AIS advance/retreat cycles. Paleotemperatures will be reconstructed using the TetraEther indeX of tetraethers containing 86 carbons (TEX86), a proxy that utilizes marine archaeal biomarkers. The Scotia Sea TEX86-based paleotemperature record will be compared to records of AIS variability, including ice rafted debris. Expedition 382 records will be compared to orbitally paced climatic time series and the benthic oxygen isotope record of global ice volume and bottom water temperature to determine if a correlation exists between upper ocean temperature, AIS retreat/advance, and orbital climate forcing.
Projecting future changes in West Antarctic Ice Sheet (WAIS) volume and global sea level rise in response to anthropogenic climate warming requires dynamic ice sheet models, which are enhanced by testing and calibrating with geologic evidence. Successfully modeling WAIS behavior during past collapse events
provides a basis for predictions of future sea level change. Exposure ages of erratics and bedrock throughout west Antarctica constrain higher-than-present WAIS geometry during the LGM and the last deglaciation. Quantifying the past surface elevation from the interior of the ice sheet is especially useful as it directly constrains ice thickness and volume where most of the mass is located. Data that determines WAIS geometry during the last interglacial, the last time that climate was warmer than present and when global sea level was 3-6 m higher, is critical for empirically constraining changes in WAIS volume and its contribution to sea level, as well as, to calibrate ice sheet models. These datasets are essentially non-
existent, as such evidence is now covered by the WAIS. Initial results from ground-penetrating radar surveys indicate ice depths around 1200 m.
The Polar Rock Repository (PRR) was established to curate and loan geologic samples from polar regions to researchers and educators. OPP established the PRR in part to avoid redundant sample collection and thus reduce the environmental impact of polar research. The PRR also provides the research community with an important resource for developing new research projects. The PRR acquires rock collections through donations from institutions and scientists and makes these samples available as no-cost loans for research, education and museum exhibits. Sample metadata are available in an on-line database. The database also includes rock property information useful for geophysical studies. Researchers may request samples for analysis using an online request form. The PRR fulfills several data management directives, including the Scientific Committee on Antarctic Research, Antarctic Data Management directive of providing free, full and open access to both metadata and the samples.
Between about 2.8-0.9 Ma, Earth’s climate was characterized by 40 kyr cycles, driven or paced by changes in the tilt of Earth’s spin axis. Much is known about the 40k world from studies of deep-sea sediments, but our understanding of climate change during this period and the transition between the 40kyr glacial cycles from 2.8-0.9 Ma and the 100kyr glacial cycles of the last 0.9 Myr 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 >1 Ma ice discovered in shallow ice cores in the Allan Hills Blue Ice Area (BIA), Antarctica. During the 2015-2016 field season we recovered ice from two nearby drill cores that dates to > 2 million years in age using the 40Ar/38Ar ratio of the trapped gases. Our discovery of ice of this antiquity in two cores demonstrates that there is gas-record quality ice from the 40k world in the Allan Hills BIA. To further characterize the composition of Earth’s atmosphere and Antarctic climate during the 40k world we request support for two field seasons to drill new large-volume (4” or 9” diameter) ice cores at sites where we have previously identified >1 Ma ice and nearby sites where ground penetrating radar has identified bedrock features conducive to the preservation of old ice.
Due to persistent cold temperatures, geographical isolation, and resulting evolutionary distinctness of Southern Ocean fauna, the study of Antarctic reducing habitats has the potential to fundamentally alter our understanding of the biologic processes that inhibit greenhouse gas emissions from our oceans. Marine methane, a greenhouse gas 25x as potent as carbon dioxide for warming our atmosphere, is currently a minor component of atmospheric forcing due to the microbial oxidation of methane within the oceans. Based on studies of persistent deep-sea seeps at mid- and northern latitudes we have learned that bacteria and archaea create a ‘sediment filter’ that oxidizes methane prior to its release. As increasing global temperatures have and will continue to alter the rate and variance of methane release, the ability of the microbial filter to respond to fluctuations in methane cycles is a critical yet unexplored avenue of research. Antarctica contains vast reservoirs of methane, equivalent to all of the permafrost in the Arctic, and yet we know almost nothing about the fauna that may mitigate its release, as until recently, we had not discovered an active methane seep.
In 2012, a methane seep was discovered in the Ross Sea, Antarctica that formed in 2011 providing the first opportunity to study an active Antarctic methane-fueled habitat and simultaneously the impact of microbial succession on the oxidation of methane, a critical ecosystem service. Previous work has shown that after 5 years of seepage, the community was at an early stage of succession and unable to mitigate the release of methane from the seafloor. In addition, additional areas of seepage had begun nearby. This research aims to quantify the community trajectory of these seeps in relation to their role in the Antarctic Ecosystem, from greenhouse gas mitigation through supporting the food web. Through the application of genomic and transcriptomic approaches, taxa involved in methane cycling and genes activated by the addition of methane will be identified and contrasted with those from other geographical locations. These comparisons will elucidate how taxa have evolved and adapted to the polar environment.
This research uses a ‘genome to ecosystem’ approach to advance our understanding of organismal and systems ecology in Antarctica. By quantifying the trajectory of community succession following the onset of methane emission, the research will decipher temporal shifts in biodiversity/ecosystem function relationships. Phylogenomic approaches focusing on taxa involved in methane cycling will advance the burgeoning field of microbial biogeography on a continent where earth’s history may have had a profound yet unquantified impact on microbial evolution. Further, the research will empirically quantify the role of chemosynthesis as a form of export production from seeps and in non-seep habitats in the nearshore Ross Sea benthos, informing our understanding of Antarctic carbon cycling.
Albatrosses (family Diomedeidae) are among the most threatened of bird species. Of the 22 species that are currently recognized, all are considered at least Threatened or Near-Threatened, and 9 are listed as Endangered or Critically Endangered. Because of the decline in albatross populations and the birds' role as a top predator in the pelagic ecosystem, it is vitally important to understand the factors affecting the population dynamics of these birds to better inform strategies for conservation and mitigating environmental change. The goal of this project is to answer the question: What are the population consequences of albatross bioenergetics and foraging strategies? The project took a two pronged approach: 1) constructing, parameterizing, and validating a Dynamic Energy Budget model to understand growth and constraints on foraging; and 2) undertaking an in-depth meta-analysis of existing individual tracking and life history data from multiple albatross species across successive life stages. This theoretical work will be grounded with a unique and extensive data set on albatrosses provided by collaborator Richard Phillips from the British Antarctic Survey. Bioenergetics constrain a variety of behaviors. A more complete understanding of how individuals use energy can give insight into how behaviors from foraging to breeding and survival, and resulting population attributes, might change with environmental factors, due to anthropogenic and other drivers. This work will further a general understanding of how bioenergetics shapes behavior and drives population level processes, while providing an approach that can be used to guide conservation strategies for endangered populations. The research findings and activities were made accessible to public audiences through websites and a blog maintained for the project by a postdoctoral researcher. The project involved undergraduate researchers in the project, within formal laboratory groups and also through in-classroom presentations and activities. This project also involved public outreach through twitter and other venues. All project publications are open access, the resulting open source software was released to the public, and metadata and analyses are fully documented to promote further collaborative exploration of this system.
An archive of baleen plates from 800 Antarctic blue and fin whales harvested between 1946 and 1948 was recently rediscovered in the Smithsonian’s National Museum of Natural History. As baleen grows, it incorporates compounds from the whale’s diet and surroundings, recording continuous biological and oceanographic information across multiple years. The baleen record forms an ideal experimental platform for studying bottom-up, top-down and anthropogenic impacts on blue and fin whales. Such insights are likely impossible to obtain through any other means as blue and fin whales now number ~1 and 4% of their pre-whaling abundances. The baleen archive includes years with strong climate and temperature anomalies allowing the influence of climate variability on predators and the ecosystems that support them to be examined. Additionally, the impact of whaling on whale stress levels will be investigated by comparing years of intensive whaling with the non-whaling years of WWII, both of which are captured in the time series. We will use 1) bulk stable isotopes to examine the trophic dynamics of Antarctic blue and fin whales, 2) compound-specific stable isotope analysis (CSIA-AA) to characterize the biogeochemistry of the base of the Antarctic food web and 3) hormone analyses to examine the population biology of these species. These investigations will fill major gaps in our understanding of the largest krill predators, their response to disturbance and environmental change, and the impact that commercial whaling has had on the structure and function of the Antarctic marine ecosystem.
This proposal will provide genetic and enzymatic insight into how microbial communities in benthic sediments on the coastal shelf of Antarctica degrade complex organic matter. The current understanding of how benthic microbial communities respond and also degrade complex organic matter in Antarctica is fragmented. Recent work suggests benthic microbial communities are shaped by organic matter availability (encompassing both quantity and quality), however, these studies were observational and did not directly examine community function (e.g. enzyme activity and/or gene expression). Preliminary metagenomic data, collected from western Antarctica marine sediments, document gene potential for organic matter degradation throughout the entire sample set (spanning the Amundsen Sea, Bellingshausen Sea, and Ross Sea), but functional data was not collected. To date, studies have examined either enzyme activity or metagenomic potential but few have been able to directly connect the two. To address these gaps in knowledge, this proposal will utilize powerful tools such as metagenomics and metatranscriptomics, coupled with microcosm experiments, enzyme assays, and geochemical data. This hypothesis driven proposal will examine microbial communities from the continental shelf of Antarctica from two different regions (Bransfield Strait and Weddell Sea) to document the communities’ enzymatic activity and genes used to degrade complex organic matter. These data will expand our current knowledge of genetic potential towards a more direct understanding of enzyme function as it relates to degradation of complex organic matter in marine sediments from Antarctica.
Finding the oldest ice on Earth can tell us about the climate and life forms in the distant past
Recently we discovered a mile wide and hundreds of feet thick ice body in Antarctica that is buried under just a few feet of dirt. Thus far our analyses of the dirt suggest that the ice is over million years old. Generally, glacial ice contains tiny bubbles and dirt that was deposited and locked in the ice by the ancient snowfall and today still holds small samples of the atmospheric gases and everything else that was carried by the winds in the past. Such samples may include the amount of greenhouse gases, plant pollen, microbes, and mineral dust. Therefore the glaciers are like archives where we can access and study the Earth’s history with samples that are unavailable anywhere else. Ice survives poorly on Earth’s surface and therefore currently only few ice samples are known that are approximately million years old. Our site has a high potential to harbor perhaps the oldest ice on Earth. However, first we need to sample and date the ice. Our research will also help us understand how these pockets of buried ice can survive such unusually long periods of time. Such understanding will help us study the landforms and history of not only Antarctica but also the Mars where similar dirt covered glaciers are found today.
We propose to collect regolith samples through the approximately 1 m thick cover and to core the buried ice in Ong Valley down to 10 m depth to determine the cosmogenic nuclide concentrations both in the regolith and in the embedded mineral matter suspended in the ice. The systematics of the target cosmogenic nuclides (10Be, 26Al, and 21Ne) such as half-lives, isotope production rates, production pathways, and related attenuation lengths allow us to uniquely determine the age of the ice and the rate the ice is sublimating. Our existing samples and analyses reveal accumulation of mineral matter at the base of surficial debris layer and the surface erosion of this debris by eolian processes. The intellectual merit of the proposed activity: Our main objective is to unequivocally determine the age and sublimation rate of two buried massive ice bodies in time scale of thousands to millions of years. The slow sublimation is a fundamentally Antarctic process, and may have altered most of the currently ice-free areas throughout the continent. Similar large, debris covered ice bodies have been recently discovered in Mars as well. Our results may transform the understanding of the longevity of the buried ice bodies and potentially reveal the oldest ice ever found in the interior of the Antarctica. If proven old and slowly sublimating, this buried ice can potentially yield direct information about the atmospheric chemistry, ancient life forms, and geology of greater antiquity than the currently available and sampled ice bodies. The broader impacts resulting from the proposed activity: The results will be relevant to researchers in glaciology, paleoclimatology, planetary geology, and biology. Several students will participate in the project and do field work in Antarctica, work in lab, attend meetings, attend outreach activities, and produce videos. A graduate student will prepare his/her thesis on a topic closely related to the objectives of the proposed research. The results of the research will be published in scientific meetings and publications.
In austral summer 2019, a 48 day, multi-country, interdisciplinary research voyage mapped Antarctic krill (Euphausia superba) and baleen whale, blue whale (Balaenoptera musculus) and fin whale (B. physalus) distributions in particular off East Antarctica. We detected, tracked and localized blue whales and mapped prey fields in the vicinity of a fixed acoustic mooring that combined passive and active acoustics for collection of concurrent predator and prey data. By coupling moored data collection with the ship-based survey focusing on Antarctic blue whale behaviour and krill dynamics, we investigated the dynamics of blue whales and their prey. We found that the production of social calls, D calls of blue whales and 40 Hz calls of fin whales, was correlated with the krill biomass over a week-long period.
The research supported by this grant centers on the evolution of fossil amphibians (temnospondyls) from the Early Triassic, a crucial time interval in the evolution of life on Earth following the end-Permian mass extinction, specifically based on fossil material from Antarctica, a high-latitude paleoenvironment that may have served as a refuge for tetrapods across the extinction event. Previous records of temnospondyls, mostly reported several decades ago, are highly fragmentary, and their original interpretations are considered dubious or demonstrably erroneous by contemporary workers. The Antarctic record of temnospondyls is of great import in understanding the biotic recovery in terrestrial environments for several reasons. Firstly, temnospondyls, like amphibians today, were highly speciose in the Triassic but were also some of the most susceptible to environmental perturbations and instability. Therefore, temnospondyls provide key insights into the paleoenvironmental conditions, either in place of or alongside other lines of data. Secondly, the record of temnospondyls from the Early Triassic is quite rich, but it is also restricted to a few densely sampled regions, such as the Karoo Basin of South Africa. In order to ascertain whether observed patterns such as an unusual abundance of small-bodied taxa or a lack of faunal overlap between different depositional basins (endemism) are real or merely artifactual, study of additional, less sampled regions takes on great import. Recent collection of substantial new temnospondyl material from several horizons in the Triassic exposure of Antarctica provides the requisite data to begin to address these questions. Finally, correlating the Triassic rocks of Antarctica with those of adjacent regions is largely reliant on comparisons of faunal assemblages. In particular, the middle Fremouw Formation, one of the horizons from which new temnospondyl material was collected, remains of uncertain relation and age due to the paucity of described material.
Recent theoretical and experimental work indicates that in a wide range of altitudes and for periods from a few minutes to several hours, a significant part of the wave activity observed in the thermosphere is due to acoustic gravity waves radiated by infragravity waves in the ocean. It is proposed to study this impressive connection between geospheres in Antarctica, at the location where close proximity of the Ross Ice Shelf makes it very special. Infragravity waves are able to excite the fundamental mode and low-order oscillations in the Ross Ice Shelf at its resonance frequencies, with the latter creating standing wave structures throughout the atmosphere. It is likely that this effect was recently detected using lidar observations at McMurdo. This project will study implications of this phenomenon, as well as more general aspects of wave activity in Antarctic geospheres, using data from a unique combination of recently installed instruments: the Dynasonde at Korean Jang Bogo station, the NSF-sponsored network of seismographs and microbarometers on the Ross Ice Shelf, and the IMS-affiliated infrasound station near McMurdo.
The goal of this research is to study atmospheric waves in the thermosphere in Antarctica and to investigate the roles that the Ross Ice Shelf and the Southern Ocean play in generation of the atmospheric waves. Anticipated results are of interest also for general aeronomy and for glaciology. This project will verify the hypothesis that the persistent atmospheric waves in mesosphere and lower thermosphere, which are observed with a lidar instrument at McMurdo, are related to the low-frequency vibration resonances of the Ross Ice Shelf excited by infragravity waves in the ocean. An accurate characterization will be achieved for low-frequency oscillations of the Ross Ice Shelf and the quality factors of its resonances will be assessed. Investigation of a consistency between observed and predicted vertical distributions of the wave intensity is expected to provide insights into where the horizontal momentum carried by AGWs is transferred to the mean motion, i.e., to the large-scale dynamics of the Antarctic thermosphere. A determination of whether accurate measurements of the acoustic resonant frequencies and their variations can provide useful constraints on the neutral temperature profile in the atmosphere will be done. Extensive use of Jang Bogo Dynasonde data in all mentioned tasks will allow further developing Dynasonde techniques.
At present, Antarctica’s glaciers are melting as the Southern Ocean warms. While glacial retreat in West Antarctica is linked to ocean warming, less is known about the response of East Antarctica’s glaciers. Totten Glacier, located on the Sabrina Coast, East Antarctica is presently retreating. Totten’s retreat is important because it is associated with warm ocean waters and because the glacier drains part of the East Antarctic Ice Sheet that contains enough ice to raise global sea levels ~3.5 meters. Mud accumulating on the seafloor around Antarctica is composed of sediment from the adjacent continent, as well as the skeletons and debris from microscopic marine organisms. As mud accumulates, so does a record of past environmental changes, including ocean temperatures and the advance and retreat of glaciers. Scientists use a variety of physical and chemical analyses to determine how long ago this mud was deposited, the temperature of the ocean at that location through time, and the relative location of glacial ice. In this project, researchers from the University of South Florida will refine and test new geochemical thermometers to better understand the influence of ocean temperatures on East Antarctic glacier extent over the last ~16,000 years. Results will be integrated into ice sheet and climate models to improve the accuracy of predictions.
Worldwide publicity surrounding the calving of an iceberg the size of Delaware in July 2017 from the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula presents a unique and time-sensitive opportunity for research and education on polar ecosystems in a changing climate. The goal of this project was to convene a workshop, drawing from the large fund of intellectual capital in the US and international Antarctic research communities. The two-day workshop was designed to bring scientists with expertise in Antarctic biological, ecological, and ecosystem sciences to Florida State University to share knowledge, identify important research knowledge gaps, and outline strategic plans for research. Major outcomes from the project were as follows. The international workshop to share and review knowledge concerning the response of Antarctic ecosystems to ice-shelf collapse was held at the Florida State University Coastal and Marine Laboratory (FSUCML) on 18-19 November 2017. Thirty-eight U.S. and international scientists attended the workshop, providing expertise in biological, ecological, geological, biogeographical, and glaciological sciences. Twenty-six additional scientists were either not able to attend or were declined because of having reached maximum capacity of the venue or for not responding to our invitation before the registration deadline. The latest results of ice-shelf research were presented, providing an overview of the current scientific knowledge and understanding of the biological, ecological, geological and cryospheric processes associated with ice-shelf collapse and its ecosystem-level consequences. In addition, several presentations focused on future plans to investigate the impacts of the recent Larsen C collapse. The following presentations were given at the meeting: 1) Cryospheric dynamics and ice-shelf collapse – past and future (M. Truffer, University of Alaska, Fairbanks) 2) The geological history and geological impacts of ice-shelf collapse on the Antarctic Peninsula (Scottt Ishman, Amy Leventer) 3) Pelagic ecosystem responses to ice-shelf collapse (Mattias Cape, Amy Leventer) 4) Benthic ecosystem response to ice-shelf collapse (Craig Smith, Pavica Sršen, Ann Vanreusel) 5) Larsen C and biotic homogenization of the benthos (Richard Aronson, James McClintock, Kathryn Smith, Brittany Steffel) 6) British Antarctic Survey: plans for Larsen C investigations early 2018 and in the future (Huw Griffiths) 7) Feedback on the workshop “Climate change impacts on marine ecosystems: implications for management of living resources and conservation” held 19-22 September 2017, Cambridge, UK (Alex Rogers) 8) Past research activities and plans for Larsen field work by the Alfred Wegener Institute, Germany (Charlotte Havermans, Dieter Piepenburg. One of the salient points emerging from the presentations and ensuing discussions was that, given our poor abilities to predict ecological outcomes of ice-shelf collapses, major cross-disciplinary efforts are needed on a variety of spatial and temporal scales to achieve a broader, predictive understanding of ecosystem consequences of climatic warming and ice-shelf failure. As part of the workshop, the FSUCML Polar Academy Team—Dr. Emily Dolan, Dr. Heidi Geisz, Barbara Shoplock, and Dr. Jeroen Ingels—initiated AntICE: "Antarctic Influences of Climate Change on Ecosystems" (AntICE). They reached out to various groups of school children in the local area (and continue to do so). The AntICE Team have been interacting with these children at Wakulla High School and Wakulla Elementary in Crawfordville; children from the Cornerstone Learning Community, Maclay Middle School, Gilchrist Elementary, and the School of Arts and Sciences in Tallahassee; and the Tallahassee-area homeschooling community to educate them about Antarctic ecosystems and ongoing climate change. The underlying idea was to make the children aware of climatic changes in the Antarctic and their effect on ecosystems so they, in turn, can spread this knowledge to their communities, family and friends – acting as ‘Polar Ambassadors’. We collaborated with the Polar-ICE project, an NSF-funded educational project that established the Polar Literacy Initiative. This program developed the Polar Literacy Principles, which outline essential concepts to improve public understanding of Antarctic and Arctic ecosystems. In the Polar Academy work, we used the Polar Literacy principles, the Polar Academy Team’s own Antarctic scientific efforts, and the experience of the FSU outreach and education program to engage with the children. We focused on the importance of Antarctic organisms and ecosystems, the uniqueness of its biota and the significance of its food webs, as well as how all these are changing and will change further with climate change. Using general presentations, case studies, scientific methodology, individual experiences, interactive discussions and Q&A sessions, the children were guided through the many issues Antarctic ecosystems are facing. Over 300 ''Polar ambassadors'' attended the interactive lectures and afterwards took their creativity to high latitudes by creating welcome letters, displays, dioramas, sculptures, videos and online media to present at the scientific workshop. Over 50 projects were created by the children (Please see supporting files for images). We were also joined by a photographer, Ryan David Reines, to document the event. More information, media and links to online outreach products are available at https://marinelab.fsu.edu/labs/ingels/outreach/polar-academy/
Further concrete products of the workshop: 1) a position-paper focusing on ideas, hypotheses and priorities for investigating the ecological impacts of ice-shelf collapse along the Antarctic Peninsula (Ingels et al., 2018; “The scientific response to Antarctic ice-shelf loss; Nature Climate Change 8, 848-851), and 2) a publication reviewing what is known and unknown about ecological responses to ice-shelf melt and collapse, outlining expected ecological outcomes of ice-shelf disintegration along the Antarctic Peninsula (Ingels et al., 2020; “Antarctic ecosystem responses following ice‐shelf collapse and iceberg calving: Science review and future research”, WIREs Climate Change, e682). The second publication was covered in the The Scientist and by a press-release in Germany, see https://www.altmetric.com/details/91826381. Other products included a poster presentation at the MEASO2018 conference in Hobart, Australia in 2018, and the above-mentioned visits to schools and institutes to talk about the research in invited seminars. We also conducted and active online outreach campaign, with dissemination of our work in various news outlets, blogs, and social media (e.g. reaching >750k total followers on twitter with the publications alone).'
Antarctic marine ectotherms exhibit universally slow growth, low metabolic rates, and extended development, yet many of their rate processes related to physiology and metabolism are highly thermally sensitive. This suggests that small changes in temperature may result in dramatic changes to energy metabolism, growth, and the rate and duration of development. This project will measure the effects of temperature on metabolism, developmental rate, and the energetic cost of development of four common and ecologically important species of benthic Antarctic marine invertebrates. These effects will be measured over the functional ranges of the organisms and in the context of environmentally relevant seasonal shifts in temperature around McMurdo Sound. Recent data show that seasonal warming of ~1°C near McMurdo Station is accompanied by long-lasting hyperoxic events that impact the benthos in the nearshore boundary layer. This research will provide a more comprehensive understanding of both annual variation in environmental oxygen and temperature across the Sound, and whether this variation drives changes in developmental rate and energetics that are consistent with physiological acclimatization. These data will provide key information about potential impacts of warming Antarctic ectotherms. In addition, this project will support undergraduate and graduate research and partner with large-enrollment undergraduate courses and REU programs at an ANNH and AANAPISI Title III minority-serving institution.
We have completed one of our two scheduled field and data-collecting seasons, but our research was put on hold by COVID and by equipment and sea ice conditions at McMurdo. We have established baseline information on energy utilization by embryos of several species under ambient conditions and early data suggest that metabolism is highly affected by temperature in the range of -2.0 C to 1 C, and less so thereafter.
Antarctica is almost entirely covered by ice, in places over two miles thick. This ice hides a landscape that is less well known than the surface of Mars and represents one of Earth's last unexplored frontiers. Ice-penetrating radar images provide a remote glimpse of this landscape including ice-buried mountains larger than the European Alps and huge fjords twice as deep as the Grand Canyon. The goal of this project is to collect sediment samples derived from these landscapes to determine when and under what conditions these features formed. Specifically, the project seeks to understand the landscape in the context of the history and dynamics of the overlying ice sheet and past mountain-building episodes. This project accomplishes this goal by analyzing sand collected during previous sea-floor drilling expeditions off the coast of Antarctica. This sand was supplied from the continent interior by ancient rivers when it was ice-free over 34 million year ago, and later by glaciers. The project will also study bedrock samples from rare ice-free parts of the Transantarctic Mountains. The primary activity is to apply multiple advanced dating techniques to single mineral grains contained within this sand and rock. Different methods and minerals yield different dates that provide insight into how Antarctica?s landscape has eroded over the many tens of millions of years during which sand was deposited offshore. The dating techniques that are being developed and enhanced for this study have broad application in many branches of geoscience research and industry. The project makes cost-effective use of pre-existing sample collections housed at NSF facilities including the US Polar Rock Repository, the Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. The project will contribute to the STEM training of two graduate and two undergraduate students, and includes collaboration among four US universities as well as international collaboration between the US and France. The project also supports outreach in the form of a two-week open workshop giving ten students the opportunity to visit the University of Arizona to conduct STEM-based analytical work and training on Antarctic-based projects. Results from both the project and workshop will be disseminated through presentations at professional meetings, peer-reviewed publications, and through public outreach and media.
The main objective of this project is to reconstruct a chronology of East Antarctic subglacial landscape evolution to understand the tectonic and climatic forcing behind landscape modification, and how it has influenced past ice sheet inception and dynamics. Our approach focuses on acquiring a record of the cooling and erosion history contained in East Antarctic-derived detrital mineral grains and clasts in offshore sediments deposited both before and after the onset of Antarctic glaciation. Samples will be taken from existing drill core and marine sediment core material from offshore Wilkes Land (100°E-160°E) and the Ross Sea. Multiple geo- and thermo-chronometers will be employed to reconstruct source region cooling history including U-Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar. This offshore record will be augmented and tested by applying the same methods to onshore bedrock samples in the Transantarctic Mountains obtained from the US Polar Rock Repository and through fieldwork. The onshore work will additionally address the debated incision history of the large glacial troughs that cut the range, now occupied by glaciers draining the East Antarctic Ice Sheet. This includes collection of samples from several age-elevation transects, apatite 4He/3He thermochronometry, and Pecube thermo-kinematic modeling. Acquiring an extensive geo- and thermo-chronologic database will also provide valuable new information on the poorly known ice-hidden geology and tectonics of subglacial East Antarctica that has implications for improving supercontinent reconstructions and understanding continental break-up.
Ice shelves slow the movement of the grounded ice sheets that feed them. This reduces the rate at which ice sheets loose mass to the oceans and contribute to sea-level rise. But ice shelves can be susceptible to collapse, particularly when surface meltwater accumulates in vulnerable areas. Meltwater lakes can create and enlarge fractures within the ice shelves, thereby triggering or hastening ice-shelf collapse. The drainage of water across the surface of Antarctica and where it accumulates has received little attention. This drainage was assumed to be insignificant, but recent work shows that meltwater can drain for tens of kilometers across ice-shelf surfaces and access areas that would otherwise not accumulate meltwater. Surface meltwater drainage could play a major role in the future stability of ice sheets. This drainage is the focus of this project.
The team will develop and test physics-based mathematical models of water flow and ice-shelf fracture, closely informed by remote sensing observations, to examine (1) how do surface drainage systems respond to inter-annual changes in surface melting, (2) how this drainage is influenced by ice dynamics and (3) whether enlarged drainage systems could deliver meltwater to areas of ice shelves that are vulnerable to water-driven collapse. The project will examine these issues by (1) conducting a remote sensing survey of the structure and temporal evolution of meltwater systems around Antarctica, (2) developing and analyzing mathematical models of water flow across ice shelves, and (3) developing and testing simple models of ice-shelf fracture. An outreach activity will make use of the emerging technology of Augmented Reality to visualize the dynamics of ice sheets in three dimensions to excite the public about glaciology at outreach events around New York City. This approach will be made publicly available for wider use as Augmented Reality continues to grow in popularity.
Three aspects of the project will produce data and code that will be archived in USAP-DC:
1. Mapped ice-shelf drainage system characteristics.
2. Computed continent-wide fields of ice-shelf vulnerability to hydrofracture.
3. An open source augmented reality ice sheet app.
As glaciers creep across the landscape, they can act as earthmovers, plucking up rocks and grinding them into fine sediments. Glaciers have moved across the Antarctic landscape over thousands to millions of years, leaving these ground-up sediments in their wake. This study builds on pilot discoveries by the investigators that revealed remarkably large and variable measurements of surface area in glacially-derived fine-grained sediments found in the McMurdo Dry Valleys (MDV), one of the few landscapes on the Antarctic continent not currently covered by ice. Surface area is key to chemical weathering, the process by which rock is converted to soils as ions are carried away in streams and groundwater. These chemical weathering processes are also one of the primary means by which the Earth system naturally removes carbon dioxide from the atmosphere. Hence, high surface areas observed in sediments implies high "weatherability" which in turn translates to more potential carbon dioxide removed from the atmosphere. Therefore, chemical weathering in high surface area glacial sediments may have significant impacts on Earth's carbon cycle. The researchers will measure the chemical and physical properties of sediments previously collected from the Dry Valleys to understand what factors lead to production of sediment with high-surface area and potential "weather ability" and investigate how sediment produced in these glacial systems could ultimately impact Earth's carbon budget. Results from this research will help scientists (including modelers) refine predictions of the effects of melting glaciers- and attendant exposure of glacial sediment? on atmospheric carbon levels. These results may also contribute to applied research efforts on development of carbon-dioxide removal technologies utilizing principles of rock weathering. In addition to the scientific benefits, this research will involve several students at the undergraduate, graduate, and post-doctoral levels, including science education undergraduates, thus contributing to training of the next-generation STEM workforce.
Physical weathering produces fresh surfaces, greatly enhancing specific surface area (SSA) and reactive surface area (RSA) of primary minerals. Quantifying SSA and RSA of sediments is key to determining dissolution and leaching rates during natural weathering, but few data exist on distribution of sediment SA, particularly in glacial and fluvial systems. Pilot data from glacial stream systems in Taylor Valley and Wright Valley (located in the MDV) exhibit remarkably high and variable values in both SSA and RSA, values that in some cases greatly exceed values from muds in temperate glacial systems. This discovery motivates the current research, which aims to investigate the hypothesis that high and variable SAs of muds within Wright and Taylor Valleys reflect textural and/or compositional inheritance from the differing depositional settings within the MDV, biologic controls, dust additions, and/or pedogenic processes. These hypotheses will be tested by sedimentologically, mineralogically, and geochemically characterizing muds from glacially derived sediment deposited in various environments (cold vs. wet based glaciation; fluvial, lacustrine, dust, and drift deposits) and of varying age (Miocene to Modern) from the MDV and quantifying variation of SA and reactivity. Comparisons with analyzed muds from temperate glacial systems will enable polar-temperate comparisons. Analyses will focus on muds of previously collected sediment from the MDVs. Grain size and SSA will be measured by Laser Analysis and N2 adsorption BET, respectively. After carbonate removal, samples will be re-analyzed for SSA, and muds characterized geochemically. Mineralogy and bulk chemistry will also be assessed on co-occurring sand fractions, and textural attributes documented. SSA-normalized dissolution experiments will be used to compare solutes released from sediments to determine RSAs. Results will be integrated with the various sedimentologic and geochemical analyses to test the posed hypotheses. Ultimately, this research should shed light on how weathering in Antarctic systems contributes to global carbon cycling.
This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is "locally" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.
Understanding and being able to anticipate changes in the glaciological regime of the Ross Ice Shelf (RIS) and West Antarctic Ice Sheet (WAIS) are key to improving sea level rise projections due to ongoing ice mass loss in West Antarctica. The fate of the WAIS is a first-order climate change and global societal issue for this century and beyond that affects coastal communities and coastal infrastructure globally.
Ice shelf--ocean interactions include impacts from tsunami, ocean swell (10-30s period), and very long period ocean waves that impact ice shelves and produce vibrations that induce a variety of seismic signals detected by seismometers buried in the ice shelf surface layer, called firn. To study the wave-induced vibrations in the RIS, an extensive seismic array was deployed from Nov. 2014 to Nov. 2016. This unique seismometer array deployment on an ice shelf made continuous observations of the response of the RIS to ocean wave impacts from ocean swell and very long period waves. An extensive description of the project motivation and background (including photos and videos of the deployment operations), and list of published studies of analyses of the seismic data collected by this project, are available at the project website https://iceshelfvibes.ucsd.edu.
Two types of seismic signals detected by the seismic array are most prevalent: flexural gravity waves (plate waves) and icequakes (signals analogous to those from earthquakes but from fracturing of the ice).
Long period ocean waves flex the ice shelf at the same period as the ocean waves, with wave energy at periods greater than ocean swell more efficient at coupling energy into flexing the ice shelf. Termed flexural gravity waves or plate waves (Chen et al., 2018), their wave-induced vibrations can reach 100’s of km from the ice edge where they are excited, with long period wave energy propagating in the water layer below the shelf coupled with the ice shelf flexure. Flexural gravity waves at very long periods (> 300 s period), such as from tsunami impacts (Bromirski et al., 2017), can readily reach grounding zones and may play a role in long-term grounding zone evolution.
Swell-induced icequake activity was found to be most prevalent at the shelf front during the austral summer (January – March) when seasonal sea ice is absent and the associated damping of swell by sea ice is minimal (Chen et al., 2019).
In addition to the seismic array, a 14 station GPS (global positioning system) array was installed during seismic data retrieval and station servicing operations in October-November 2015. The GPS stations, co-located with seismic stations, extended from the shelf front southward to about 415 km at interior station RS18. Due to logistical constraints associated with battery weight during installation, only one station (at DR10) operated year-round. The GPS data collected give a detailed record of changes in iceflow velocity that are in close agreement with the increasing velocity estimates approaching the shelf front from satellite observations. Importantly, the year-round data at DR10 show an unprecedented seasonal cycle of changes in iceflow velocity, with a speed-up in northward (seaward) ice flow during Jan.-May and then a velocity decrease from June-Sep. (returning to the long-term mean flow velocity). This annual ice flow velocity change cycle has been attributed in part to seasonal changes in ice shelf mass (thinning, reducing buttressing) due to melting at the RIS basal (bottom) surface from intrusion of warmer ocean water (Klein et al., 2020).
This award funds the continued management and operations (M&O) of the IceCube Neutrino Observatory (ICNO) located at the South Pole Station. The core team of researchers and engineers maintain the existing ICNO infrastructure at the South Pole and home institution, guaranteeing an uninterrupted stream of scientifically unique, high-quality data. The M&O activities are built upon eight highly successful years of managing the overall ICNO operations after the start of science operations in 2008. Construction of ICNO was supported by NSF's Major Research Equipment and Facilities Construction (MREFC) account and was completed on schedule and within budget in 2010. Effective coordination of efforts by the core M&O personnel and efforts by personnel within the IceCube Collaboration has yielded significant increases in the performance of this cubic-kilometer detector over time. The scientific output from the IceCube Collaboration during the past five years has been outstanding. <br/><br/>The broader impacts of the ICNO/M&O activities are strong, involving postdoctoral, graduate, and (in some cases) undergraduate students in the day-today operation & calibration of the neutrino detector. The extraordinary physics results recently produced by ICNO and its extraordinary location at South Pole have a high potential to excite the imagination of high school children and the public in general at a national and international level.<br/><br/>The current ICNO/M&O effort produces better energy and angular resolution information about detected neutrino events, has more efficient data filters and more accurate detector simulations, and enables continuous software development for systems that are needed to acquire and analyze data. This has produced data acquisition and data management systems with high robustness, traceability, and maintainability. The current ICNO/M&O effort includes: (1) resources for both distributed and centrally managed activities, and (2) additional accountability mechanisms for "in-kind" and institutional contributions. Both are necessary to ensure that the detector maintains its capability to produce quality scientific data at the level required to achieve the detector's scientific discovery objectives. Recent ICNO discoveries of cosmic high-energy neutrinos (some reaching energies close to and over 2.5 PeV) and oscillating atmospheric neutrinos in a previously unexplored energy range from 10 to 60 GeV became possible because of the "state-of-the-art" detector configuration, excellently supported infrastructure, and cutting-edge science analyses. The ICNO has set limits on Dark Matter annihilations, made precision measurements of the angular distribution of cosmic ray muons, and characterized in detail physical properties of the Antarctic 2.5-km thick ice sheet at South Pole. The discovery of high-energy cosmic neutrinos by IceCube with a flux at the level anticipated for those associated with high-energy gamma- and cosmic-ray accelerators brightens the prospect for identifying the sources of the highest energy particles.
This award supports a project to develop software that will allow researchers considering seismic or radar field surveys to test, ahead of time, whether the data they plan to collect will have sufficient resolution to measure the natural variations in the mechanical properties of ice, which determine the response of flowing ice to changing climatic conditions. The mechanical properties of ice depend largely on the temperature and the orientation of the crystals that make up the ice. The most accurate method for measuring ice crystal orientation and temperature is through drilling and direct analysis of an ice core. However, this method is very costly, time-consuming, and limited in spatial coverage. Geophysical techniques, such as seismic and radar, can cover much more area, but we have little knowledge about the practical limitations of these techniques as they relate to calculating mechanical properties. This project addresses that knowledge gap through construction of a computational toolbox that will allow accurate assessment of the ability of geophysical surveys to image crystal orientation and ice temperature. Researchers can then use these tools to adjust the field survey plans to maximize the return on investment. By working to improve the efficiency and effectiveness of future geophysical work related to glacial flow, this proposal will improve scientists? ability to quantify sea-level variations within the larger context of climate change. The project includes building new user-friendly, publicly accessible software and instructional modules. The work will provide training for graduate and undergraduate students, who will play a role in research and develop instructional materials.
Ice viscosity, the resistance of ice to flow, exerts significant control over ice velocity. Therefore, mapping ice viscosity is important for understanding the current and future behavior of glaciers and ice sheets. To do so, scientists must determine the temperature and crystal orientation fabric throughout the ice. Seismic and radar techniques can survey large areas quickly, and thus are promising, yet not fully tested, methods to efficiently measure the thermal and mechanical structure of flowing ice. As part of this project, scientists will develop and use a computational framework to quantify the degree to which seismic and radar techniques can resolve the crystal orientation fabric and temperature of streaming ice, and then test how sensitive ice flow is to the attendant uncertainty. To meet these goals, a numerical toolbox will be built which will allow the glacier/ice stream geometry and physical properties (temperature, crystal orientation fabric, density and acidity) to be varied. The toolbox will be capable of both creating synthetic radar and seismic profiles through forward modeling and inverting synthetic profiles to allow evaluation of how well geophysical techniques can image the original thermal and mechanical structure. These simulated radar and seismic data will allow scientists to better quantify the influence of the variability in mechanical properties of the ice on flow velocities and patterns. The results of this work will guide planning for future field campaigns, making them more effective and efficient. This project does not require fieldwork in the Antarctic.
Ice fracturing plays a crucial role in mechanical processes that influence the contribution of glaciers and ice sheets to the global sea-level rise. Such processes include, among others, ice shelf disintegration, iceberg calving, and fast ice sliding. Over the last century, seismology developed highly sensitive instrumentation and sophisticated data processing techniques to study earthquakes. This interdisciplinary project used seismological research methods to investigate fracturing beneath and within ice on a fast-moving ice stream in West Antarctica that is experiencing rapid sliding and flexure driven by ocean tides. Data were collected from two strategically located clusters of seismometers. One was located in the epicenter zone where tidally triggered rapid sliding events of the ice stream start. The other was placed in the grounding zone, where the ice stream flexes with tides where it goes afloat and becomes an ice shelf.
Seismometers in the epicenter cluster recorded many thousands of microearthquakes coming from beneath ice during ice stream sliding events. Analyses of these microearthquakes suggest that the geologic materials beneath the ice stream are fracturing. The spatial pattern of fracturing is not random but forms elongated stripes that resemble well-known glacial landforms called megascale glacial lineations. These findings indicate that the frictional resistance to ice sliding may change through time due to these landforms changing as a result of erosion and sedimentation beneath ice. This may have implications for the rate of ice loss from Antarctic ice streams that drain about 90% of all ice discharged into the Southern Ocean. In addition to microearthquakes, the epicenter cluster of seismometers also recorded vibrations (tremors) from beneath the ice stream. These may be caused by the rapid repetition of many microearthquakes coming from the same source.
The grounding zone cluster of seismometers recorded many thousands of microearthquakes as well. However, they are caused by ice fracturing near the ice stream's surface rather than at its base. These microearthquakes originate when the grounding zone experiences strong tension caused by ice flexure during dropping ocean tide. This tension causes the opening of near-surface fractures (crevasses) just before the lowest tide, rather than at the lowest tide as expected from elasticity of solids. This unexpected timing of ice fracturing indicates that ice in the grounding zone behaves like a viscoelastic material, i.e., partly like a solid and partly like a fluid. This is an important general finding that will be useful to other scientists who are modeling interactions of ice with ocean water in the Antarctic grounding zones. Overall, the observed pervasive fracturing in the grounding zone, where an ice stream becomes an ice shelf, may make ice shelves potentially vulnerable to catastrophic collapses. It also may weaken ice shelves and make it easier for large icebergs to break off at their fronts.
In addition to Antarctic research, this award supported education and outreach activities, including presentations and field trips during several summer schools at UCSC for talented and diverse high school students. The students were exposed to glaciological and seismological concepts and performed hands-on scientific exercises. The field trips focused on the marine terrace landscape around Santa Cruz. This landscape resulted from interactions between the uplift of rocks along the San Andreas fault with global-sea level changes caused by the waxing and waning of polar ice sheets in response to Ice Age climate cycles.
This investigation will reconstruct past behavior of the East Antarctic Ice Sheet during periods of warmer-than-present climate, such as the Pliocene, in order to better project the likely response of Earth's largest ice sheet to anthropogenic warming. Containing the equivalent of ~55 m sea-level rise, the future evolution of the East Antarctic Ice Sheet has clear societal ramifications on a global scale as temperatures continue to rise. Therefore, determining ice-sheet sensitivity to climate on the scale predicted for the next two centuries is a matter of increasing urgency, particularly in light of evidence suggesting the East Antarctic Ice Sheet is more dynamic than previously thought. This research will provide a terrestrial geologic record of long-term ice-sheet behavior from sites immediately adjacent the East Antarctic Ice Sheet in the Transantarctic Mountains, with which the project will help ascertain how the ice sheet responded to past warm periods. The project will focus primarily on the Pliocene warm period, 5 to 3 million years ago, as this represents the closest analogue to 21st Century climate conditions.<br/><br/>The proposed research will investigate glacial deposits corresponding to the East Antarctic Ice Sheet in the central Transantarctic Mountains in order to expand the geologic record of past ice-sheet behavior. The overarching research objectives are to improve understanding of the East Antarctic Ice Sheet's configuration during periods of warmer-than-present climate, such as the Pliocene warm period, and to determine whether the ice sheet underwent significant volume changes or remained relatively stable in response to warming. To address these goals, the investigation will map and date glacial deposits preserved at mountain sites immediately adjacent the ice sheet. Specifically, we will: (i) employ multiple cosmogenic nuclides (10Be, 26Al, 21Ne) to establish more fully ice-thickness histories for the upper Shackleton and Beardmore Glaciers, where they exit the ice sheet; (ii) use this record to identify periods during which the East Antarctic Ice Sheet was at least as extensive as today; and (iii) use these data to assess long-term ice-sheet variability in East Antarctica, with particular emphasis on Pliocene warm episodes. This research will require Antarctic fieldwork, glacial-geologic mapping, and cosmogenic surface-exposure dating.
The Earth's climate has changed through time and during the Eocene Epoch (56 to 34 million years ago) there was a transition from 'greenhouse' to 'icehouse' conditions. During the Eocene, a shift to cooler temperatures at high latitudes resulted in the inception of polar glaciation. This in turn affected the environment for living organisms. This project looks to uncover the interaction between biological, oceanographic, and climate systems for the Eocene in Antarctica using chemical analysis of fossil shark teeth collected during past expeditions. The combination of paleontological and geochemical analyses will provide insight to the past ecology and ocean conditions; climate models will be applied to test the role of tectonics, greenhouse gas concentration and ocean circulation on environmental change during this time period. The study contributes to understanding the interaction of increased atmospheric carbon dioxide and ocean circulation. This project also seeks to improve diversity, equity, and inclusion within the geosciences workforce with efforts targeted to undergraduate, graduate, postdoctoral, and early career faculty.<br/><br/>The research goal is to elucidate the processes leading from the Eocene greenhouse to Oligocene icehouse conditions. Previous explanations for this climate shift centers on Antarctica, where tectonic configurations influenced oceanic gateways, ocean circulation reduced heat transport, and/or greenhouse gas declines prompted glaciation. The team will reconstruct watermass, current, and climate fluctuations proximal to the Antarctic Peninsula using geochemical indicators (oxygen and neodymium isotope composition) from fossil shark teeth collected from Seymour Island. The approach builds on previous shark paleontological studies, incorporates geochemical analyses for environmental reconstruction (i.e., temperature gradients and ocean circulation), and tests hypotheses on Earth System dynamics using novel global climate model simulations with geochemical tracers. This project will advance global climate modeling capabilities with experiments that consider Eocene tectonic configuration within isotope-enabled climate model simulations. A comparison of geochemical results from Eocene climate simulations and empirical records of shark teeth will reveal processes and mechanisms central to the Eocene Antarctic climatic shift.<br/><br/>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.
The East Antarctic Ice Sheet holds the largest volume of freshwater on the planet, in total enough to raise sea level by almost two hundred feet. Even minor adjustments in the volume of ice stored have major implications for coastlines and climates around the world. The question motivating this project is how did the ice grow to cover the continent over thirty million years ago when Antarctica changed from a warmer environment to an ice-covered southern continent? The seafloor of Prydz Bay, a major drainage basin of the East Antarctic Ice Sheet (EAIS), has been drilled previously to recover sediments dating from millions of years prior to and across the time when inception of continental ice sheets occurred in Antarctica. The last remnants of plant material found as 'biomarkers' in the ocean sediments record the chemical signatures of rain and snowfall that fed the plants and later the expanding glaciers. Sediment carried by glaciers was also deposited on the seafloor and can be analyzed to discover how glaciers flowed across the landscape. Here, the researchers will identify precipitation changes that result from, and drive, ice sheet growth. This study will gather data and further analyze samples from the seafloor sediment archives of the International Ocean Discovery Program's (IODP) core repositories. Ultimately these findings can help inform temperature-precipitation-ice linkages within climate and ice sheet models. The project will support the training of three female, early career scientists (PhD & MS students, and research technician) and both PIs and the PhD student will continue their engagement with broadening participation efforts (e.g., Women in Science and Engineering Program; local chapters of Society for the advancement of Native Americans and Chicanos in Science and other access programs) to recruit undergraduate student participants from underrepresented minorities at both campuses and from local community colleges. Antarctic earth science education materials will be assisted by professional illustrations to be open access and used in public education and communication efforts to engage local communities in Los Angeles CA and Columbia SC. <br/><br/>The researchers at the University of Southern California and the University of South Carolina will together study the penultimate moment of the early Cenozoic greenhouse climate state: the ~4 million years of global cooling that culminated in the Eocene/Oligocene transition (~34 Ma). Significant gaps remain in the understanding of the conditions that preceded ice expansion on Antarctica. In particular, the supply of raw material for ice sheets (i.e., moisture) and the timing, frequency, and duration of precursor glaciations is poorly constrained. This collaborative proposal combines organic and inorganic proxies to examine how Antarctic hydroclimate changed during the greenhouse to icehouse transition. The central hypothesis is that the hydrological cycle weakened as cooling proceeded. Plant-wax hydrogen and carbon isotopes (hydroclimate proxies) and Hf-Nd isotopes of lithogenous and hydrogenous sediments (mechanical weathering proxies) respond strongly and rapidly to precipitation and glacial advance. This detailed and sensitive combined approach will test whether there were hidden glaciations (and/or warm events) that punctuated the pre-icehouse interval. Studies will be conducted on Prydz Bay marine sediment cores in a depositional area for products of weathering and erosion that were (and are) transported through Lambert Graben from the center of Antarctica. The project will yield proxy information about the presence of plants and the hydroclimate of Antarctica and the timing of glacial advance, and is expected to show drying associated with cooling and ice-sheet growth. The dual approach will untangle climate signals from changes in fluvial versus glacial erosion of plant biomarkers. This proposal is potentially transformative because the combination of organic and inorganic proxies can reveal rapid transitions in aridity and glacial expansion, that may have been missed in slower-response proxies and more distal archives. The research is significant as hydroclimate seems to be a key player in the temperature-cryosphere hysteresis.<br/><br/>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.
General:
Scientists established more than 30 years ago that the climate-related variability of carbon dioxide levels in the atmosphere over Earth’s ice-age cycles was regulated by the ocean. Hypotheses to explain how the ocean that regulates atmospheric carbon dioxide have long been debated, but they have proven to be difficult to test. This project was designed test one leading hypothesis, specifically that the ocean experienced greater density stratification during the ice ages. That is, with greater stratification during the ice ages and the slower replacement of deep water by cold dense water formed near the poles, the deep ocean would have held more carbon dioxide, which is produced by biological respiration of the organic carbon that constantly rains to the abyss in the form of dead organisms and organic debris that sink from the sunlit surface ocean. To test this hypothesis, the degree of ocean stratification during the last ice age and the rate of deep-water replacement was to be constrained by comparing the radiocarbon ages of organisms that grew in the surface ocean and at the sea floor within a critical region around Antarctica, where most of the replacement of deep waters occurs. Completing this work was expected to contribute toward improved models of future climate change. Climate scientists rely on models to estimate the amount of fossil fuel carbon dioxide that will be absorbed by the ocean in the future. Currently the ocean absorbs about 25% of the carbon dioxide produced by burning fossil fuels. Most of this carbon is absorbed in the Southern Ocean (the region around Antarctica). How this will change in the future is poorly known. Models have difficulty representing physical conditions in the Southern Ocean accurately, thereby adding substantial uncertainty to projections of future ocean uptake of carbon dioxide. Results of the proposed study will provide a benchmark to test the ability of models to simulate ocean processes under climate conditions distinctly different from those that occur today, ultimately leading to improvement of the models and to more reliable projections of future absorption of carbon dioxide by the ocean.
Technical:
The project added a research component to an existing scientific expedition to the Southern Ocean, in the region between the Ross Sea and New Zealand, that collected sediment cores at locations down the northern flank of the Pacific-Antarctic Ridge at approximately 170°W. The goal was to collect sediments at each location deposited since early in the peak of the last ice age. This region is unusual in the Southern Ocean in that sediments deposited during the last ice age contain foraminifera, tiny organisms with calcium carbonate shells, in much greater abundance than in other regions of the Southern Ocean. Foraminifera are widely used as an archive of several geochemical tracers of past ocean conditions. We proposed to compare the radiocarbon age of foraminifera that inhabited the surface ocean with the age of contemporary specimens that grew on the seabed. The difference in age between surface and deep-swelling organisms would have been used to discriminate between two proposed mechanisms of deep water renewal during the ice age: formation in coastal polynyas around the edge of Antarctica, much as occurs today, versus formation by open-ocean convection in deep-water regions far from the continent. If the latter mechanism prevails, then it was expected that surface and deep-dwelling foraminifera would exhibit similar radiocarbon ages. In the case of dominance of deep-water formation in coastal polynyas, one expects to find very different radiocarbon ages in the two populations of foraminifera. In the extreme case of greater ocean stratification during the last ice age, one even expects the surface dwellers to appear to be older than contemporary bottom dwellers because the targeted core sites lie directly under the region where the oldest deep waters outcrop at the surface following their long circuitous transit through the deep ocean. The primary objective of the proposed work was to reconstruct the water mass age structure of the Southern Ocean during the last ice age, which, in turn, is a primary factor that controls the amount of carbon dioxide stored in the deep sea. In addition, the presence of foraminifera in the cores to be recovered provides a valuable resource for many other paleoceanographic applications, such as: 1) the application of nitrogen isotopes to constrain the level of nutrient utilization in the Southern Ocean and, thus, the efficiency of the ocean’s biological pump, 2) the application of neodymium isotopes to constrain the transport history of deep water masses, 3) the application of boron isotopes and boron/calcium ratios to constrain the pH and inorganic carbon system parameters of ice-age seawater, and 4) the exploitation of metal/calcium ratios in foraminifera to reconstruct the temperature (Mg/Ca) and nutrient content (Cd/Ca) of deep waters during the last ice age at a location near their source near Antarctica.
Unfortunately, the cores were shipped to the core repository in a horizontal orientation and there was sufficient distortion of the sediment that the radiocarbon ages of benthic foraminifera were uninterpretable. Therefore, we report only the radiocarbon dates for planktonic foraminifera as well as the total counts of elemental relative abundance from X-ray Fluorescence analysis of the cores. In addition, we used the expedition as an opportunity to collect water samples from which dissolved concentrations of long-lived isotope of thorium and protactinium were determined. Results from those analyses showed that lateral transport by isopycnal mixing dominates the supply of Pa to the Southern Ocean. We have also developed a new algorithm to correct for supply of Th by isopycnal mixing and thereby derive estimates of dust flux to the Southern Ocean.
Snow or firn aquifers are areas of subsurface meltwater storage that form in glaciated regions experiencing intense summer surface melting and high snowfall. Aquifers can induce hydrofracturing, and thereby accelerate flow or trigger ice-shelf instability leading to increased ice-sheet mass loss. Widespread aquifers have recently been discovered in Greenland. These have been modelled and mapped using new satellite and airborne remote-sensing techniques. In Antarctica, a series of catastrophic break-ups at the Wilkins Ice Shelf on the Antarctic Peninsula that was previously attributed to effects of surface melting and brine infiltration is now recognized as being consistent with a firn aquifer--possibly stimulated by long-period ocean swell--that enhanced ice-shelf hydrofracture. This project will verify inferences (from the same mapping approach used in Greenland) that such aquifers are indeed present in Antarctica. The team will survey two high-probability sites: the Wilkins Ice Shelf, and the southern George VI Ice Shelf. <br/><br/>This two-year study will characterize the firn at the two field sites, drill shallow (~60 m maximum) ice cores, examine snow pits (~2 m), and install two AMIGOS (Automated Met-Ice-Geophysics Observing System) stations that include weather, GPS, and firn temperature sensors that will collect and transmit measurements for at least a year before retrieval. Ground-penetrating radar survey in areas surrounding the field sites will track aquifer extent and depth variations. Ice and microwave model studies will be combined with the field-observed properties to further explore the range of firn aquifers and related upper-snow-layer conditions. This study will provide valuable experience for three early-career scientists. An outreach effort through field blogging, social media posts, K-12 presentations, and public lectures is planned to engage the public in the team's Antarctic scientific exploration and discovery.<br/><br/>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.
Tremblay, Marissa; Granger, Darryl; Balco, Gregory; Lamp, Jennifer
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Part I: Nontechnical
Scientists study the Earth's past climate in order to understand how the climate will respond to ongoing global change in the future. One of the best analogs for future climate might the period that occurred approximately 3 million years ago, during an interval known as the mid-Pliocene Warm Period. During this period, the concentration of carbon dioxide in the atmosphere was similar to today's and sea level was 15 or more meters higher, due primarily to warming and consequent ice sheet melting in polar regions. However, the temperatures in polar regions during the mid-Pliocene Warm Period are not well determined, in part because we do not have records like ice cores that extend this far back in time. This project will provide constraints on surface temperatures in Antarctica during the mid-Pliocene Warm Period using a new type of climate proxy, known as cosmogenic noble gas paleothermometry. This project focuses on an area of Antarctica called the McMurdo Dry Valleys. In this area, climate models suggest that temperatures were more than 10 ºC warmer during the mid-Pliocene than they are today, but indirect geologic observations suggest that temperatures may have been similar to today. The McMurdo Dry Valleys are also a place where rocks have been exposed to Earth surface conditions for several million years, and where this new climate proxy can be readily applied. The team will reconstruct temperatures in the McMurdo Dry Valleys during the mid-Pliocene Warm Period in order to resolve the discrepancy between models and indirect geologic observations and provide much-needed constraints on the sensitivity of Antarctic ice sheets to warming temperatures. The temperature reconstructions generated in this project will have scientific impact in multiple disciplines, including climate science, glaciology, geomorphology, and planetary science. In addition, the project will (1) broaden the participation of underrepresented groups by supporting two early-career female principal investigators, (2) build STEM talent through the education and training of a graduate student, (3) enhance infrastructure for research via publication of a publicly-accessible, open-source code library, and (4) be broadly disseminated via social media, blog posts, publications, and conference presentations.
Part II: Technical Description
The mid-Pliocene Warm Period (3–3.3 million years ago) is the most recent interval of the geologic past when atmospheric CO2 concentrations exceeded 400 ppm, and is widely considered an analog for how Earths climate system will respond to current global change. Climate models predict polar amplification the occurrence of larger changes in temperatures at high latitudes than the global average due to a radiative forcing both during the mid-Pliocene Warm Period and due to current climate warming. However, the predicted magnitude of polar amplification is highly uncertain in both cases. The magnitude of polar amplification has important implications for the sensitivity of ice sheets to warming and the contribution of ice sheet melting to sea level change. Proxy-based constraints on polar surface air temperatures during the mid-Pliocene Warm Period are sparse to non-existent. In Antarctica, there is only indirect evidence for the magnitude of warming during this time. This project will provide constraints on surface temperatures in the McMurdo Dry Valleys of Antarctica during the mid-Pliocene Warm Period using a newly developed technique called cosmogenic noble gas (CNG) paleothermometry. CNG paleothermometry utilizes the diffusive behavior of cosmogenic 3He in quartz to quantify the temperatures rocks experience while exposed to cosmic-ray particles within a few meters of the Earths surface. The very low erosion rates and subzero temperatures characterizing the McMurdo Dry Valleys make this region uniquely suited for the application of CNG paleothermometry for addressing the question: what temperatures characterized the McMurdo Dry Valleys during the mid-Pliocene Warm Period? To address this question, the team will collect bedrock samples at several locations in the McMurdo Dry Valleys where erosion rates are known to be low enough that cosmic ray exposure extends into the mid-Pliocene or earlier. They will pair cosmogenic 3He measurements, which will record the thermal histories of our samples, with measurements of cosmogenic 10Be, 26Al, and 21Ne, which record samples exposure and erosion histories. We will also make in situ measurements of rock and air temperatures at sample sites in order to quantify the effect of radiative heating and develop a statistical relationship between rock and air temperatures, as well as conduct diffusion experiments to quantify the kinetics of 3He diffusion specific to each sample. This suite of observations will be used to model permissible thermal histories and place constraints on temperatures during the mid-Pliocene Warm Period interval of cosmic-ray exposure.
The Southern Ocean in the vicinity of Antarctica is a region characterized by seasonally-driven marine phytoplankton blooms that are often dominated by microalgal species which produce large amounts of dimethylsulfoniopropionate (DMSP). DMSP can be converted to the compound dimethylsulfide (DMS) which is a molecule that can escape into the atmosphere where it is known to have strong condensation properties that are involved in regional cloud formation. Production of DMSP can influence the diversity and composition of microbial assemblages in seawater and the types and activities of microbes in the seawater will likely affect the magnitude of DMSP\DMS production. The project examined the role of DMSP in structuring the microbial communities in Antarctic waters and how this structuring may influence DMSP cycling. The project interacted with elementary students in Maine and brought undergraduate students to Bigelow Laboratory. The project also engaged with a science writer and illustrator who joined the team in Palmer Station in 2018. Many posts are available at xxx
The project is examining (1) the extent to which the cycling of DMSP in southern ocean waters influenced the composition and diversity of bacterial and protistan assemblages; (2) conversely, whether the composition and diversity of southern ocean protistan and bacterial assemblages influenced the magnitude and rates of DMSP cycling; we are awaiting results on (3) the expression of DMSP degradation genes by marine bacteria seasonally and in response to field experimental additions of DMSP; and, this year (2020-21), we will synthesize these results by quantifying (4) the microbial networks resulting from the presence of DMSP-producers and DMSP-consumers along with their predators, all involved in the cycling of DMSP in southern ocean waters. The work was accomplished by conducting continuous growth experiments with DMSP-amended natural samples of different microbial communities present in summer (2016-17) and fall (2018) at Palmer Station, WAP. Data from the molecular (such as 16S/ 18S tag sequences, DMSP-cycle gene transcripts) and biogeochemical (such as biogenic sulfur cycling, bacterial production, microbial biomass) investigations will be integrated via network analysis in the coming year (2020-21).
Modeling fluctuations in the extent of the West Antarctic Ice Sheet (WAIS) over time is a principal goal of the glaciological community. These models will provide a critical basis for predictions of future sea level change, and therefore this work great societal relevance. The mid-Pliocene time interval is of particular interest, as it is the most recent period in which global temperatures were warmer and atmospheric CO2 concentrations may have been higher than current levels. However, observational constraints on fluctuations in the WAIS older than the last glacial maximum are rare.
To test model predictions,sub-glacial rock cores were obtained from the Ohio Range along the Transantarctic Mountains near the present-day WAIS divide using a Winkie drill. Rock cores were recovered from 10 to ~30 m under the present-day ice levels. At the Ohio Range, the glacial to interglacial variations in ice sheet levels is ~120 meters. So 30 meters represent a significant fraction of the variation over the course of an ice age.
High concentrations of the cosmic ray produced isotopes were detected in the rock cores, indicating extensive periods of ice-free exposure to cosmic irradiation during the last 2 million years. Modeling of the data suggest that bedrock surfaces at the Ohio Range that are currently covered by 30 meters of ice experienced more exposure than ice cover, especially in the Pleistocene. An ice sheet model prediction for the Ohio Range subglacial sample sites however, significantly underestimates exposure in the last 2 million years, and over-predicts ice cover in the Pleistocene. To adjust for the higher amounts of exposure we observe in our samples, the ice sheet model simulations require more frequent and/or longer-lasting WAIS ice drawdowns. This has important implications for future sea-level change as the model maybe under-predicting the magnitude of sea-level contributions from WAIS during the ice-age cycles. Improving the accuracy of the ice sheet models through model-data comparison should remain a prime objective in the face of a warming planet as understanding WAIS behavior is going to be key for predicting and planning for the effects of sea-level change. The project helped support and train a graduate student in climate research related to Antarctica, cosmogenic nuclide analyses and led to a Master’s Thesis. The project also provide partial support to a postdoctoral scholar obtaining cosmogenic neon measurements and for training and mentoring the graduate student's cosmogenic neon measurements and interpretation. The project results were communicated to the scientific community at conferences and through seminars. The broader community was engaged through the University of California Davis's Picnic Day celebration, an annual open house that attracts over 70,000 people to the campus, and through classroom visit at a local elementary school.
Predictions of future sea level rise require better understanding of the changing dynamics of the Greenland and Antarctic ice sheets. One way to better understand the past history of the ice sheets is to obtain records from inland ice for past geological periods, particularly in Antarctica, the world's largest remaining ice sheet. Such records are exceedingly rare, and can be acquired at volcanic outcrops in the La Gorce Mountains of the central Transantarctic Mountains. Volcanoes now exposed within the La Gorce Mountains erupted beneath the East Antarctic ice sheet and the data collected will record how thick the ice sheet was in the past. In addition, information will be used to determine the thermal conditions at the base of the ice sheet, which impacts ice sheet stability. The project will also investigate the origin of volcanic activity in Antarctica and links to the West Antarctic Rift System (WARS). The WARS is a broad area of extended (i.e. stretched) continental crust, similar to that found in East Africa, and volcanism is wide spread and long-lived (65 million years to currently active) and despite more than 50 years of research, the fundamental cause of volcanism and rifting in Antarctica is still vigorously debated. The results of this award therefore also potentially impact the study of oceanic volcanism in the entire southwestern Pacific region (e.g., New Zealand and Australia), where volcanic fields of similar composition and age have been linked by common magma sources and processes. The field program includes a graduate student who will work on the collection, analysis, and interpretation of petrological data as part of his/her Masters project. The experience and specialized analytical training being offered will improve the quality of the student's research and optimize their opportunities for their future. The proposed work fosters faculty and student national and international collaboration, including working with multi-user facilities that provide advanced technological mentoring of science students. Results will be broadly disseminated in peer-reviewed journals, public presentations at science meetings, and in outreach activities. Petrologic and geochemical data will be disseminated to be the community through the Polar Rock Repository. The study of subglacially erupted volcanic rocks has been developed to the extent that it is now the most powerful proxy methodology for establishing precise 'snapshots' of ice sheets, including multiple critical ice parameters. Such data should include measurements of ice thickness, surface elevation and stability, which will be used to verify, or reject, published semi-empirical models relating ice dynamics to sea level changes. In addition to establishing whether East Antarctic ice was present during the formation of the volcanoes, data will be used to derive the coeval ice thicknesses, surface elevations and basal thermal regime(s) in concert with a precise new geochronology using the 40Ar/39Ar dating method. Inferences from measurement of standard geochemical characteristics (major, trace elements and Sr, Nd, Pb, O isotopes) will be used to investigate a possible relationship between the volcanoes and the recently discovered subglacial ridge under the East Antarctic ice, which may be a rift flank uplift. The ridge has never been sampled, is undated and its significance is uncertain. The data will provide important new information about the deep Earth and geodynamic processes beneath this mostly ice covered and poorly understood sector of the Antarctic continent.
Ice cores contain detailed accounts of Earth's climate history. The collection of an ice core can be logistically challenging, and extraction of data from the core can be time-consuming as well as susceptible to both human and machine error. Furthermore, locked in measurements from ice cores is information that scientists have not yet found ways to recover. This project will apply techniques from information theory to ice-core data to unlock that information. The primary goal is to demonstrate that information theory can (a) identify regions of a specific ice-core record that are in need of further analysis and (b) provide some specific guidance for that analysis. A secondary goal is to demonstrate that information theory has practical and scientific utility for studies of past climate. This project aims to use information theory in two distinct ways: first, to identify regions of a core where information appears to be damaged or missing, perhaps due to human and/or machine error. In the segment of the West Antarctic Ice Sheet Divide core that is 5000-8000 years old, for instance, information-theoretic methods reveal significant levels of noise, probably due to a laboratory instrument, and something that was not visible in the raw data. This is a particularly important segment of the record, as it contains valuable clues about climatic shifts and the onset of the Holocene. Targeted re-sampling of this segment of the core and reanalysis with newer laboratory apparatus could resolve the data issues. The second way in which information theory can potentially aid in ice-core analysis is by extracting climate signals from the data--such as the accumulation rate at the core site over the period of its formation. This quantity usually requires significant time and effort to produce, but information theory could help to streamline that process.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.
The PIs have designed and built a new type of rapid access ice drill (RAID) for use in Antarctica. This community tool has the ability to rapidly drill through ice up to 3300 m thick and then collect samples of the ice, ice-sheet bed interface, and bedrock substrate below. This drilling technology will provide a new way to obtain in situ measurements and samples for interdisciplinary studies in geology, glaciology, paleoclimatology, microbiology, and astrophysics. The RAID drilling platform will give the scientific community access to records of geologic and climatic change on a variety of timescales, from the billion-year rock record to million-year ice and climate histories. Development of this platform will enable scientists to address critical questions about the deep interface between the Antarctic ice sheets and the substrate below. Phase I was for design and work with the research community to develop detailed science requirements for the drill. This proposal, Phase II, constructed, assembled and tested the RAID drilling platform at a site near McMurdo (Minna Bluff) where 700-m thick ice sits on bedrock.
Continental extension produces a great variety of structures from the linear narrow rifts of the East African Rift to the diffuse extension of the Basin and Range Province of the Western U.S. Rift shoulder uplift varies dramatically between rift flanks. The cause of variable rift width and crustal thinning is fairly well explained by variable initial heat flow and crustal thickness. Mechanical stretching of the lithosphere has been linked to rift shoulder uplift but the cause of variable rift flank uplift remains poorly understood. The Transantarctic Mountains (TAM) are an extreme example of rift flank uplift, extending over 3500 km across Antarctica and reaching elevations up to 4500 m and thus constitute a unique feature of EarthOs crust. The range was formed in the extensional environment associated with the Mesozoic and Cenozoic breakup of Gondwanaland. Geological and geophysical work has shown that the TAM developed along the long-lived lithospheric boundary between East and West Antarctica reactivated by a complex history of extensional and translational microplate motions. The TAM are not uniform along strike. Along the OWilkes FrontO, the northern segment of the rift extends from North Victoria Land to Byrd Glacier. The Wilkes Front architecture consists of (1) thin, extended crust forming the Victoria Land Basin in the Ross Sea, (2) the TAM rift shoulder, and (3) a long-wavelength down- ward forming the Wilkes Basin. Contrasting structures are mapped along the OPensacola/PoleO Front, the southern segment of the rift extending from the Nimrod Glacier to the Pensacola Mountains. Along this southern section no rift basin has been mapped to date and the down-ward along the East Antarctic, or ObacksideO, edge of the mountains is less pronounced. A flexural model linking the extension in the Ross Sea to the formation of both the mountains and the Wilkes Basin has been considered as a me chanism for uplift of the entire mountain range. The variability in fundamental architecture along the TAM indicates that neither a single event nor a sequence of identical events produced the rift flank uplift. The observation of variable architecture suggests complex mechanisms and possibly a fundamental limitation in maximum sustainable rift flank elevation. The motivation for studying the TAM is to try to understand the geodynamics of this extreme elevation rift flank. Are the geodynamics of the area unique, or does the history of glaciation and related erosion contribute to the extreme uplift? With the existing data sets it is difficult to confidently constrain the geological architecture across representative sections of the TAM. Any effort to refine geodynamic mechanisms requires this basic understanding of the TAM architecture. The goal of this project is to (1) constrain the architecture of the rift system as well as the distribution and structure of sedimentary basins, glacial erosion and mafic igneous rocks surrounding the rift flank by acquiring three long wavelength geophysical transects with integrated gravity, magnetics, ice- penetrating radar, and ice surface measurements, (2) quantify the contribution of various geodynamic mechanisms to understand the geological conditions which can lead to extreme rift flank uplift, and (3) use the improved understanding of architecture and geophysical data to test geodynamic models in order to improve our understanding both of the TAM geodynamics and the general problem of the geodynamics of rift flank uplift worldwide. This project will allow development of a generalized framework for understanding the development of rift flank uplift as well as address the question of the specific geodynamic evolution of the TAM.
Understanding how groups of organisms respond to climate change is fundamentally important to assessing the impacts of human activities as well as understanding how past climatic shifts have shaped biological diversity over deep stretches of time. The fishes occupying the near-shore marine habitats around Antarctica are dominated by one group of closely related species called notothenioids. It appears dramatic changes in Antarctic climate were important in the origin and evolutionary diversification of this economically important lineage of fishes. Deposits of fossil fishes in Antarctica that were formed when the continent was experiencing milder temperatures show that the area was home to a much more diverse array of fish lineages. Today the waters of the Southern Ocean are very cold, and often below freezing, but notothenioids fishes exhibit a number of adaptions to live in this harsh set of marine habitats, including the presence of anti-freeze proteins. This research project will collect DNA sequences from hundreds of genes to infer the genealogical relationships of nearly all 124 notothenioid species, and use mathematical techniques to estimate the ages of species and lineages. Knowledge on the timing of evolutionary divergence in notothenioids will allow investigators to assess if timing of previous major climatic shifts in Antarctica are correlated with key events in the formation of the modern Southern Ocean fish fauna. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. The project will support educational outreach activities to teenager groups and to the general public through a natural history museum exhibit and other public lectures. It will provide professional training opportunities for graduate students and a postdoctoral research scholar. <br/><br/>Adaptive radiation, where lineages experience high rates of evolutionary diversification coincident with ecological divergence, is mostly studied in island ecosystems. Notothenioids dominate the fish fauna of the Southern Ocean and exhibit antifreeze glycoproteins that allow occupation of the subzero waters. Notothenioids are noted as one of the only examples of adaptive radiation among marine fishes, but the evolutionary history of diversification and radiation into different ecological habitats is poorly understood. This research will generate a species phylogeny (evolutionary history) for nearly all of the 124 recognized notothenioid species to investigate the mechanisms of adaptive radiation in this lineage. The phylogeny is inferred from approximately 350 genes sampled using next generation DNA sequencing and related techniques. Morphometric data are taken for museum specimens to investigate the tempo of morphological diversification and to determine if there are correlations between rates of lineage diversification and the origin of morphological disparity. The patterns of lineage, morphological, and ecological diversification in the notothenioid radiation will be compared to the paleoclimatic record to determine if past instances of global climate change have shaped the evolutionary diversification of this lineage of polar-adapted fishes.
Terra Nova Bay (western Ross Sea, Antarctica) supports dense populations of several key species in the Ross Sea food web, including copepods, crystal krill (Euphausia crystallorophias), Antarctic silverfish (Pleuragramma antarcticum), and colonies of Adélie and Emperor penguins that feed primarily on crystal krill and silverfish. Absent from our understanding of the Ross Sea food web is zooplankton and silverfish mesoscale distribution, spatial structure of age/maturity classes, and their interactions with physical drivers and each other. The quantitative linkages between primary producers and the higher trophic levels, specifically, the processes responsible for the regulation of abundance and rates of middle trophic levels dominated by copepods and crystal krill (Euphausia crystallorophias), is virtually unknown. Given that the next century will see extensive changes in the Ross Sea’s ice distributions and oceanography as a result of climate change, understanding the basic controls of zooplankton and silverfish abundance and distribution is essential.
During a January – March 2018 cruise in the western Ross Sea, we deployed a glider equipped with an echo sounder (Acoustic Zooplankton Fish Profiler) that simultaneously measured depth, temperature, conductivity, chlorophyll fluorescence, and dissolved oxygen. Additionally, net tows, mid-water trawls, and crystal krill grazing experiments were conducted. Our study provided the first glider-based acoustic assessment of simultaneous distributions of multiple trophic levels in the Ross Sea, from which predator-prey interactions and the relationships between organisms and physics drivers (sea ice, circulation features) were investigated. We illustrated high variability in ocean physics, phytoplankton biomass, and crystal krill biomass and aggregation over time and between locations within Terra Nova Bay. Biomass of krill was highest in locations characterized by deeper mixed layers and highest integrated chlorophyll concentrations. Krill aggregations were consistently located at depth well below the mixed layer and chlorophyll maximum. Experiments investigating krill grazing, in combination with krill depth distributions relative to chlorophyll biomass, illuminate high krill grazing rates could be attributed to the occupation of a unique niche whereby they are opportunistically feeding on sinking high concentrations of detritus derived from surface blooms. The information on the abundance, distribution, and interactions of key species in multiple trophic levels resulting from this project provide a conceptual background to understand how this ecosystem might respond to future conditions under climate change.
Our project tested the capability of a multi-frequency echo sounder on a glider for the first time. The production of consistent, vertically-resolved, high resolution glider-based acoustic measurements will pave the way for cost-effective, automated examination of entire food webs and ecosystems in regions all over the global ocean. A wide range of users including academic and government scientists, ecosystem-based fisheries managers, and monitoring programs including those conducted by OOI, IOOS, and NOAA will benefit from this project. This project also provided the opportunity to focus on broadening participation in research and articulating the societal benefits through education and innovative outreach programs. A data set from this project is being included in the new NSF-funded Polar CAP initiative, that will be used by a diverse and young audience to increase understanding of the polar system and the ability to reason with data. Finally, this project provided a unique field opportunity and excellent hand-on training for a post-doctoral researcher, a graduate student, and two undergraduate students.
microRNAs (miRNAs) are key post-transcriptional regulators of gene expression that modulate development and physiology in temperate animals. Although miRNAs act by binding to messenger RNAs (mRNAs), a process that is strongly sensitive to temperature, miRNAs have yet not been studied in Antarctic animals, including Notothenioid fish, which dominate the Southern Ocean. This project will compare miRNA regulation in 1) Antarctic vs. temperate fish to learn the roles of miRNA regulation in adaptation to constant cold; and in 2) bottom-dwelling, dense-boned, red-blooded Nototheniods vs. high buoyancy, osteopenic, white-blooded icefish to understand miRNA regulation in specialized organs after the evolution of the loss of hemoglobin genes and red blood cells, the origin of enlarged heart and vasculature, and the evolution of increased buoyancy, which arose by decreased bone mineralization and increased lipid deposition. Aim 1 is to test the hypothesis that Antarctic fish evolved miRNA-related genome specializations in response to constant cold. The project will compare four Antarctic Notothenioid species to two temperate Notothenioids and two temperate laboratory species to test the hypotheses that (a) Antarctic fish evolved miRNA genome repertoires by loss of ancestral genes and/or gain of new genes, (b) express miRNAs that are involved in cold tolerance, and (c) respond to temperature change by changing miRNA gene expression. Aim 2 is to test the hypothesis that the evolution of icefish from red-blooded bottom-dwelling ancestors was accompanied by an altered miRNA genomic repertoire, sequence, and/or expression. The project will test the hypotheses that (a) miRNAs in icefish evolved in sequence and/or in expression in icefish specializations, including head kidney (origin of red blood cells); heart (changes in vascular system), cranium and pectoral girdle (reduced bone mineral density); and skeletal muscle (lipid deposition), and (b) miRNAs that evolved in icefish specializations had ancestral functions related to their derived roles in icefish, as determined by functional tests of zebrafish orthologs of icefish miRNAs in developing zebrafish. The program will isolate, sequence, and determine the expression of miRNAs and mRNAs using high-throughput transcriptomics and novel software. Results will show how the microRNA system evolves in vertebrate animals pushed to physiological extremes and provide insights into the prospects of key species in the most rapidly warming part of the globe.
The depths at which magmas are stored, their pre-eruptive volatile contents, and the rates at which they ascend to the Earth's surface are important controls on the dynamics of volcanic eruptions. Basaltic magmas are likely to be vapor undersaturated as they begin their ascent from the mantle through the crust, but volatile solubility drops with decreasing pressure. Once vapor saturation is achieved and the magma begins to degas, its pre-eruptive volatile content is determined largely by the depth at which it resides within the crust. Magma stored in deeper reservoirs tend to experience less pre-eruptive degassing and to be richer in volatiles than magma shallower reservoirs. Eruptive style is influenced by the rate at which a magma ascends from the reservoir to the surface through its effect on the efficiency of vapor bubble nucleation, growth, and coalescence. The proposed work will advance our understanding of pre-eruptive storage conditions and syn-eruptive ascent rates through a combined field and analytical research program. Volatile measurements from olivine-hosted melt inclusions will be used to systematically investigate magma storage depths and ascent rates associated with alkaline volcanism in the Erebus volcanic province. A central goal of the project is to provide a spatial and temporal framework for interpreting results from studies of present-day volcanic processes at Mt Erebus volcano. The Erebus volcanic province of Antarctica is especially well suited to this type of investigation because: (1) there are many exposed mafic scoria cones, fissure vents, and hyaloclastites (exposed in sea cliffs) that produced rapidly quenched, olivine-rich tephra; (2) existing volatile data for Ross Island MIs show that magma storage was relatively deep compared to many mafic volcanic systems; (3) some of the eruptive centers ejected mantle xenoliths, allowing for comparison of ascent rates for xenolith-bearing and xenolith-free eruptions, and comparison of ascent rates for those bearing xenoliths with times estimated from settling velocities; and (4) the cold, dry conditions in Antarctica result in excellent tephra preservation compared to tropical and even many temperate localities. The project provides new tools for assessing volcanic hazards, facilitates collaboration involving researchers from three different institutions (WHOI, U Wyoming, and U Oregon), supports the researchers' involvement in teaching, advising, and outreach, and provides an educational opportunity for a promising young postdoctoral researcher. Understanding the interrelationships among magma volatile contents, reservoir depths, and ascent rates is vital for assessing volcanic hazards associated with alkaline volcanism across the globe.
This project developed sediment provenance proxies to trace the sources of sediment discharged by the WAIS to the continental rise. The WAIS erodes sediments from various West Antarctic geologic terranes that are deposited in adjacent drift sites. The geochemistry and magnetic properties of drift sediments reflect the tectono-metamorphic history of their source terranes. Deglaciation of a terrane during WAIS collapse should be detectable by the loss of the terrane’s geochemical and magnetic signature in continental-rise detrital sediments. Continental shelf late-Holocene sediments from near the current WAIS groundling line were analyzed for silt- and claysize Sr-Nd-Pb isotopes and major-trace elements. The suite of cores spans from the eastern Ross Sea to the northern tip of the Antarctic Peninsula and established the provenance signatures of the Ross and Amundsen Provinces of Marie Byrd Land, Pine Island Bay, Thurston Island/Eight Coast Block, Ellsworth-Whitmore Crustal Block, and Antarctic Peninsula terranes. Many of these terranes have similar tectono-metamorphic histories but Sr-Nd isotope data from detrital sediments suggest at least 3 distinct provenance signatures. This comprehensive grain-size-specific provenance data adds to on-going collection of glacial till mineral and bulk provenance data. An initial down core study of Ocean Drilling Program Site 1096 in the Bellingshausen Sea was used to assess the utility of these new grain-size-specific provenance proxies in documenting WAIS collapse. We found the presence of both the WAIS and APIS over the last 115,000 years, but absence of the WAIS before 115,000 years ago. This means that the WAIS was gone during the last interglacial period, an interval when sea level was at least 6 meters above present.
Intellectual Merit: <br/>Opening of Drake Passage and the West Scotia Sea south of Tierra del Fuego broke the final continental barrier to onset of a complete Antarctic Circumpolar Current (ACC). Initiation of the ACC has been associated in time with a major, abrupt, drop in global temperatures and the rapid expansion of the Antarctic ice sheets at 33-34 Ma. Events leading to the formation of the Drake Passage gateway are poorly known. Understanding the tectonic evolution of the floor of the Central Scotia Sea (CSS) and the North Scotia Ridge is a key to this understanding. Previous work has demonstrated that superimposed constructs formed a volcanic arc that likely blocked direct eastward flow from the Pacific to the Atlantic through the opening Drake Passage gateway as the active South Sandwich arc does today. The PIs propose a cruise to test, develop and refine, with further targeted mapping and dredging, their theory of CSS tectonics and the influence it had on the onset and development of the ACC. In addition they propose an installation of GPS receiver to test their paleogeographic reconstructions and determine whether South Georgia is moving as part of the South American plate. <br/><br/>Broader impacts: <br/>A graduate student will be involved in all stages of the research. Undergraduate students will also be involved as watch-standers. A community college teacher will participate in the cruise. The PIs will have a website on which there will be images of the actual ocean floor dredging in operation. The teacher will participate with web and outreach support through PolarTREC. Results of the cruise are of broad interest to paleoceanographers, paleoclimate modelers and paleobiogeographers.A network of four continuous Global Navigational Satellite Systems (GNSS) receivers was installed on the bedrock of South Georgia in the Southern Ocean in 2013 and 2014. An additional receiver on a concrete foundation provides a tie to a tide gauge, part of the United Kingdom South Atlantic Tide Gauge Network. The GNSS receivers have already provided data suggesting that the South Georgia microcontinent (SGM) is moving independent of both the South American plate to the north and the Scotia plate to the south. The data also demonstrate that the SGM is being uplifted.
Intellectual Merit: This project will yield new information on the long term Antarctic climate and landscape evolution from measurements of cosmogenic nuclides in quartz sand from two unique permafrost cores collected in Beacon Valley, Antarctica. The two cores have already been drilled in ice-cemented, sand-rich permafrost at 5.5 and 30.6 meters depth, and are currently in cold storage at the University of Washington. The cores are believed to record the monotonic accumulation of sand that has been blown into lower Beacon Valley and inflated the surface over time. The rate of accumulation and any hiatus in the accumulation are believed to reflect in part the advance and retreat of the Taylor Glacier. Preliminary measurements of cosmogenically-produced beryllium (10Be) and aluminum (26Al) in quartz sand in the 5.5-meter depth core reveal that it has been accreting at a rate of 2.5 meters/Myr for the past million years. Furthermore, prior to that time, lower Beacon Valley was most likely covered (shielded from the atmosphere thereby having no or very low production of cosmogenic nuclides in quartz) by Taylor Glacier from 1 to 3.5 Myr BP. These preliminary measurements also suggest that the 30.6 meter core may provide a record of over 10 million years. The emphasis is the full characterization of the core and analysis of cosmogenic nuclides (including cosmogenic neon) in the 30.6 meter permafrost core to develop a burial history of the sands and potentially a record the waxing and waning of the Taylor Glacier. This will allow new tests of our current understanding of surface dynamics and climate history in the McMurdo Dry Valleys (MDV) based on the dated stratigraphy of eolian sand that has been accumulating and inflating the surface for millions of years. This is a new process of surface inflation whose extent has not been well documented, and holds the potential to develop a continuous history of surface burial and glacial expansion. This project will provide a new proxy for understanding the climatic history of the Dry Valleys and will test models for the evolution of permafrost in Beacon Valley.<br/><br/>Broader impacts: <br/><br/>The landscape history of the McMurdo Dry Valleys is important because geological deposits there comprise the richest terrestrial record available from Antarctica. By testing the current age model for these deposits, we will improve understanding of Antarctica?s role in global climate change. This project will train one graduate and one undergraduate student in geochemistry, geochronology, and glacial and periglacial geology. They will participate substantively in the research and are expected to develop their own original ideas. Results from this work will be incorporated into undergraduate and graduate teaching curricula, will be published in the peer reviewed literature, and the data will be made public.
This study aims to better understand salt accumulation in cold deserts and develop a model of salt transport by groundwater. Cold deserts, like the Antarctic McMurdo Dry Valleys (MDV), are similar to hot deserts in that they accumulate high concentrations of salts because there is not enough water to flush the salts out of the soils into the ocean. The accumulation of salt allows for the creation of brine-rich groundwater that freezes at much lower temperatures. Field work will focus on several groundwater features in the MDV including Don Juan Pond, a shallow lake that accumulates extremely high levels of salts and does not freeze until the temperature reaches -51 degrees C (-60 degrees F). The setting offers the potential to better understand this unique water environment including life at its extremes. It also serves as an analog environment for Mars, a planet that is entirely underlain by permafrost, similar to the MDV. This project will support a doctoral student at the University of Washington Department of Earth and Space Sciences, who will be trained in chemical analysis, chemical and physical modeling, and remote field work in a polar desert environment.<br/><br/>Past research suggests that the movement of soluble ions in sediment and soil is controlled by the water activity, permeability, and the thermal regime; however, processes controlling the ionic redistribution in Antarctic environments are poorly constrained. This project aims to better understand the formation, salt redistribution, and water activity of pervasive brine-rich groundwater that is enriched in calcium chloride. A primary goal is to develop a brine thermal;reactive;transport model for the MDV region using data collected from the field to constrain model inputs and ground-truth model outputs. The model will develop a Pitzer-type thermodynamic, reactive transport model and couple it to a ground temperature model. The model will test mechanisms of groundwater formation in the MDV and the properties (e.g. composition, temperature, and water activity) of widespread shallow brine-rich waters. Water is an essential ingredient for life and defining processes that control the availability of water is critical for understanding the habitability of extreme environments, including Mars.
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.<br/><br/>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.
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.
Rapid changes in the extent and thickness of sea ice during the austral spring subject microorganisms within or attached to the ice to large fluctuations in temperature, salinity, light and nutrients. This project aims to identify cellular responses in sea-ice algae to increasing temperature and decreasing salinity during the spring melt along the western Antarctic Peninsula and to determine how associated changes at the cellular level can potentially affect dynamic, biologically driven processes. Understanding how sea-ice algae cope with, and are adapted to, their environment will not only help predict how polar ecosystems may change as the extent and thickness of sea ice change, but will also provide a better understanding of the widespread success of photosynthetic life on Earth. The scientific context and resulting advances from the research will be communicated to the general public through outreach activities that includes work with Science Communication Fellows and the popular Polar Science Weekend at the Pacific Science Center in Seattle, Washington. The project will provide student training to college students as well as provide for educational experiences for K-12 school children. <br/><br/><br/>There is currently a poor understanding of feedback relationships that exist between the rapidly changing environment in the western Antarctic Peninsula region and sea-ice algal production. The large shifts in temperature and salinity that algae experience during the spring melt affect critical cellular processes, including rates of enzyme-catalyzed reactions involved in photosynthesis and respiration, and the production of stress-protective compounds. These changes in cellular processes are poorly constrained but can be large and may have impacts on local ecosystem productivity and biogeochemical cycles. In particular, this study will focus on the thermal sensitivity of enzymes and the cycling of compatible solutes and exopolymers used for halo- and cryo-protection, and how they influence primary production and the biogeochemical cycling of carbon and nitrogen. Approaches will include field sampling during spring melt, incubation experiments of natural sea-ice communities under variable temperature and salinity conditions, and controlled manipulation of sea-ice algal species in laboratory culture. Employment of a range of techniques, from fast repetition rate fluorometry and gross and net photosynthetic measurements to metabolomics and enzyme kinetics, will tease apart the mechanistic effects of temperature and salinity on cell metabolism and primary production with the goal of quantifying how these changes will impact biogeochemical processes along the western Antarctic Peninsula.<br/><br/>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.
Overview: The funded work investigated whether ice core 86Kr acts as a proxy for barometric pressure variability, and whether this proxy can be used in Antarctic ice cores to infer past movement of the Southern Hemisphere (SH) westerly winds. Pressure variations drive macroscopic air movement in the firn column, which reduces the gravitational isotopic enrichment of slow-diffusing gases (such as Kr). The 86Kr deviation from gravitational equilibrium (denoted D86Kr) thus reflects the magnitude of pressure variations (among other things). Atmospheric reanalysis data suggest that pressure variability over Antarctica is linked to the Southern Annular Mode (SAM) index and the position of the SH westerly winds. Preliminary data from the WAIS Divide ice core show a large excursion in D86Kr during the last deglaciation (20-9 ka before present). In this project the investigators (1) performed high-precision 86Kr analysis on ice core and firn air samples to establish whether D86Kr is linked to pressure variability; (2) Refined the deglacial WAIS Divide record of Kr isotopes; (3) Investigated the role of pressure variability in firn air transport using firn air models with firn microtomography data and Lattice- Boltzmann modeling; and (4) Investigated how barometric pressure variability in Antarctica is linked to the SAM index and the position/strength of the SH westerlies in past and present climates using GCM and reanalysis data. A key finding was that D86Kr in recent ice samples (e.g. last 50 years) from a broad spatial array of sites in Antarctica and Greenland showed a significant correlation with directly measured barometric pressure variability at the ice core site. This strongly supports the hypothesis that 86Kr can be used as a paleo-proxy for storminess.
Intellectual Merit: The SH westerlies are a key component of the global climate system; they are an important control on the global oceanic overturning circulation and possibly on atmospheric CO2 concentrations. Poleward movement of the SH westerlies during the last deglaciation has been hypothesized, yet evidence from proxy and modeling studies remains inconclusive. The funded work could provide valuable new constraints on deglacial movement of the SH westerlies. This record can be compared to high-resolution CO2 data from the same core, allowing us to test hypotheses that link CO2 to the SH westerlies. Climate proxies are at the heart of paleoclimate research. The funded work has apparently led to the discovery of a completely new proxy, opening up exciting new research possibilities and increasing the scientific value of existing ice cores. Once validated, the 86Kr proxy could be applied to other time periods as well, providing a long-term perspective on the movement of the SH westerlies. The funded work has furthermore provided valuable new insights into firn air transport.
Broader impact: The Southern Ocean is presently an important sink of atmospheric CO2, thereby reducing the warming associated with anthropogenic CO2 emissions. Stratospheric ozone depletion and greenhouse warming have displaced the SH westerlies poleward, with potential consequences for the future magnitude of this oceanic carbon uptake. The funded work may provide a paleo-perspective on past movement of the SH westerlies and its link to atmospheric CO2, which could guide projections of future oceanic CO2 uptake, with strong societal benefits. The awarded funds supported and trained an early-career postdoctoral scholar at OSU, and fostered (international) collaboration. Data from the study will be available to the scientific community and the broad public through recognized data centers. During this project the PI and senior personnel have continued their commitment to public outreach through media interviews and speaking to schools and the public about their work. The PI provides services to the community by chairing the IPICS (International Partnership in Ice Core Sciences) working group and organizing annual PIRE (Partnerships in International Research and Education) workshops.
Proteorhodopsins (PR) are retinal-binding membrane proteins that can act as light-driven proton pumps to generate energy that can be used for metabolism and growth. The discovery of PRs in many diverse marine prokaryotic microbes has initiated extensive investigations into their distributions and functional roles. Recently, a rhodopsin-like gene of the proton-pumping variety was identified in diatoms thus revealing their presence within obligate marine eukaryotic photoautotrophs. Since this time, PRs have been identified in a number of diatom isolates although there appears to be a much higher frequency of
PR in diatoms residing in cold, iron-limited regions of the ocean, particularly in the Southern Ocean (SO). PR is especially suited for use in SO phytoplankton since unlike conventional photosynthesis, it uses no iron and its reaction rate is insensitive to temperature. The overall objective of our proposed project is to characterize Antarctic diatom-PR and determine its role in the adaptation of SO diatoms to the prevailing conditions of low iron concentrations and extremely low temperatures. Our research objectives will be achieved through a combination of molecular, biochemical and physiological measurements in diatom isolates recently obtained from the Western Antarctic Peninsula region. We will determine the proton-pumping characteristics and pumping rates of PR as a function of light intensity and wavelength, the resultant PR-linked intracellular ATP production rates, and the cellular localization of the protein. We will examine under which environmental conditions Antarctic diatom-PR is most highly expressed and construct a cellular energy budget that includes diatom-PR when grown under these different growth conditions. Estimates of the energy flux generated by PR in PR-containing diatoms will be compared to total energy generation by the photosynthetic light reactions and metabolically coupled respiration rates. Finally, we will compare the characteristics and gene expression of diatom-PR in Antarctic diatoms to PR-containing diatoms isolated from temperate regions in order to investigate if there is a preferential dependence on energy production through diatom-PR in diatoms residing in cold, iron-limited regions of the ocean.
Methane is a potent greenhouse gas that is naturally emitted into the oceans by geologic seeps and microbial production. Based on studies of persistent deep-sea seeps at mid- and northern latitudes, researchers have learned that bacteria and archaea can create a "sediment filter" that oxidizes methane prior to its release. Antarctica is thought to contain large reservoirs of organic carbon buried beneath its ice which could a quantity of methane equivalent to all of the permafrost in the Arctic and yet we know almost nothing about the methane oxidizing microbes in this region. How these microbial communities develop and potentially respond to fluctuations in methane levels is an under-explored avenue of research. A bacterial mat was recently discovered at 78 degrees south, suggesting the possible presence of a methane seep, and associated microbial communities. This project will explore this environment in detail to assess the levels and origin of methane, and the nature of the microbial ecosystem present. <br/> <br/>An expansive bacterial mat appeared and/or was discovered at 78 degrees south in 2011. This site, near McMurdo Station Antarctica, has been visited since the mid-1960s, but this mat was not observed until 2011. The finding of this site provides an unusual opportunity to study an Antarctic marine benthic habitat with active methane cycling and to examine the dynamics of recruitment and community succession of seep fauna including bacteria, archaea, protists and metazoans. This project will collect the necessary baseline data to facilitate further studies of Antarctic methane cycling. The concentration and source of methane will be determined at this site and at potentially analogous sites in McMurdo Sound. In addition to biogeochemical characterization of the sites, molecular analysis of the microbial community will quantify the time scales on which bacteria and archaea respond to methane input and provide information on rates of community development and succession in the Southern Ocean. Project activities will facilitate the training of at least one graduate student and results will be shared at both local and international levels. A female graduate student will be mentored as part of this project and data collected will form part of her dissertation. Lectures will be given in K-12 classrooms in Oregon to excite students about polar science. National and international audiences will be reached through blogs and presentations at a scientific conference. The PI's previous blogs have been used by K-12 classrooms as part of their lesson plans and followed in over 65 countries.<br/>
In order to understand what environmental conditions might look like for future generations, we need to turn to archives of past times when the world was indeed warmer, before anyone was around to commit them to collective memory. The geologic record of Earth's past offers a glimpse of what could be in store for the future. Research by Ivany and her team looks to Antarctica during a time of past global warmth to see how seasonality of temperature and rainfall in coastal settings are likely to change in the future. They will use the chemistry of fossils (a natural archive of these variables) to test a provocative hypothesis about near-monsoonal conditions in the high latitudes when the oceans are warm. If true, we can expect high-latitude shipping lanes to become more hazardous and fragile marine ecosystems adapted to constant cold temperatures to suffer. With growing information about how human activities are likely to affect the planet in the future, we will be able to make more informed decisions about policies today. This research involves an international team of scholars, including several women scientists, training of graduate students, and a public museum exhibit to educate children about how we study Earth's ancient climate and what we can learn from it.<br/><br/>Antarctica is key to an understanding how Earth?s climate system works under conditions of elevated CO2. The poles are the most sensitive regions on the planet to climate change, and the equator-to-pole temperature gradient and the degree to which high-latitude warming is amplified are important components for climate models to capture. Accurate proxy data with good age control are therefore critical for testing numerical models and establishing global patterns. The La Meseta Formation on Seymour Island is the only documented marine section from the globally warm Eocene Epoch exposed in outcrop on the continent; hence its climate record is integral to studies of warming. Early data suggest the potential for strongly seasonal precipitation and runoff in coastal settings. This collaboration among paleontologists, geochemists, and climate modelers will test this using seasonally resolved del-18O data from fossil shallow marine bivalves to track the evolution of seasonality through the section, in combination with independent proxies for the composition of summer precipitation (leaf wax del-D) and local seawater (clumped isotopes). The impact of the anticipated salinity stratification on regional climate will be evaluated in the context of numerical climate model simulations. In addition to providing greater clarity on high-latitude conditions during this time of high CO2, the combination of proxy and model results will provide insights about how Eocene warmth may have been maintained and how subsequent cooling came about. As well, a new approach to the analysis of shell carbonates for 87Sr/86Sr will allow refinements in age control so as to allow correlation of this important section with other regions to clarify global climate gradients. The project outlined here will develop new and detailed paleoclimate records from existing samples using well-tuned as well as newer proxies applied here in novel ways. Seasonal extremes are climate parameters generally inaccessible to most studies but critical to an understanding of climate change; these are possible to resolve in this well-preserved, accretionary-macrofossil-bearing section. This is an integrated study that links marine and terrestrial climate records for a key region of the planet across the most significant climate transition in the Cenozoic.
The goal of this project was to conduct a preliminary assessment of gut microbiomes in Antarctic krill (Euphasia superba) collected in coastal waters west of the Antarctic Peninsula and identify organisms potentially capable of catalyzing the production of methylmercury. DNA was extracted from composite krill digestive tracts and eukaryotic DNA removed. Prokaryotic microbial DNA extracted from krill digestive tracts was sequenced and gene libraries were constructed. Genera of anaerobic microorganisms which are known to support mercury methylation were identified.
The grant was for the re-curation of the Antarctic Sediment collection and prepare the collection for transportation to Oregon State University. The move of the cores took place in July and August of 2018. A total of 18,512 m of core was transferred which consisted of 8,787 large diameter D-tubes, 2,968 small diameteer D-tubed and 4,998 core boxes. In addition that were an additional 729 totes with samples. </br> In addition in the last two years of the core facility at FSU we filled 20 sample requests and accommodated 6 visits to the collection for sampling by the PI.
Intellectual Merit: The PIs continued and expanded GPS and seismic measurements for ANET-POLENET to advance understanding of geodynamic processes and their influence on the West Antarctic Ice Sheet. ANET-POLENET science themes include: 1) determining ice mass change since the last glacial maximum, including modern ice mass balance; 2) solid earth influence on ice sheet dynamics; and 3) tectonic evolution of West Antarctica and feedbacks with ice sheet evolution. Nine new remote continuous GPS stations augmented ANET-POLENET instrumentation deployed during Phase 1. Siting was designed to better constrain uplift centers predicted by GIA models and indicated by Phase 1 results. A mini-array of temporary seismic sites was deployed to improve resolution of earth structure below West Antarctica. ANET-POLENET Phase 2 achievements included 1) seismic images of crust and mantle structure that resolve the highly heterogeneous thermal and viscosity structure of the Antarctic lithosphere and underlying mantle; 2) improved estimates of intraplate vertical and horizontal bedrock crustal motions; and 3) elucidation of controls on glacial isostatic adjustment-induced crustal motions due to laterally varying earth structure.
Broader impacts: Monitoring and understanding mass change and dynamic behavior of the Antarctic ice sheet using in situ GPS and seismological studies has improved understanding of how Antarctic ice sheets respond to a warming world and how this response impacts sea-level and other global changes. Seismic and geodetic data collected by the ANET-POLENET network are openly available to the scientific community. ANET-POLENET has been integral in the development and realization of technological and logistical innovations for year-round operation of instrumentation at remote polar sites, helping to advance scientifically and geographically broad studies of the polar regions. The ANET-POLENET carried out a training initiative to mentor young polar scientists in complex, multidisciplinary and internationally collaborative research, including 2 week-long training schools on "Glacial Isostatic Adjustment" and "Glacial Seismology". ANET-POLENET continued broad public outreach about polar science through the polenet.org website, university lectures, and K-12 school visits. This research involved multiple international partners.
Worldwide publicity surrounding the calving of an iceberg the size of Delaware in July 2017 from the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula presents a unique and time-sensitive opportunity for research and education on polar ecosystems in a changing climate. The goal of this project was to convene a workshop, drawing from the large fund of intellectual capital in the US and international Antarctic research communities. The two-day workshop was designed to bring scientists with expertise in Antarctic biological, ecological, and ecosystem sciences to Florida State University to share knowledge, identify important research knowledge gaps, and outline strategic plans for research.
Major outcomes from the project were as follows. The international workshop to share and review knowledge concerning the response of Antarctic ecosystems to ice-shelf collapse was held at the Florida State University Coastal and Marine Laboratory (FSUCML) on 18-19 November 2017. Thirty-eight U.S. and international scientists attended the workshop, providing expertise in biological, ecological, geological, biogeographical, and glaciological sciences. Twenty-six additional scientists were either not able to attend or were declined because of having reached maximum capacity of the venue or for not responding to our invitation before the registration deadline.
The latest results of ice-shelf research were presented, providing an overview of the current scientific knowledge and understanding of the biological, ecological,
geological and cryospheric processes associated with ice-shelf collapse and its
ecosystem-level consequences. In addition, several presentations focused on future plans to investigate the impacts of the recent Larsen C collapse. The following presentations were given at the meeting:
1) Cryospheric dynamics and ice-shelf collapse – past and future (M. Truffer,
University of Alaska, Fairbanks)
2) The geological history and geological impacts of ice-shelf collapse on the Antarctic Peninsula (Scottt Ishman, Amy Leventer)
3) Pelagic ecosystem responses to ice-shelf collapse (Mattias Cape, Amy Leventer)
4) Benthic ecosystem response to ice-shelf collapse (Craig Smith, Pavica Sršen, Ann Vanreusel)
5) Larsen C and biotic homogenization of the benthos (Richard Aronson, James
McClintock, Kathryn Smith, Brittany Steffel)
6) British Antarctic Survey: plans for Larsen C investigations early 2018 and in the
future (Huw Griffiths)
7) Feedback on the workshop “Climate change impacts on marine ecosystems:
implications for management of living resources and conservation” held 19-22
September 2017, Cambridge, UK (Alex Rogers)
8) Past research activities and plans for Larsen field work by the Alfred Wegener
Institute, Germany (Charlotte Havermans, Dieter Piepenburg.
One of the salient points emerging from the presentations and ensuing discussions was that, given our poor abilities to predict ecological outcomes of ice-shelf collapses, major cross-disciplinary efforts are needed on a variety of spatial and temporal scales to achieve a broader, predictive understanding of ecosystem
consequences of climatic warming and ice-shelf failure. As part of the workshop, the FSUCML Polar Academy Team—Dr. Emily Dolan, Dr. Heidi Geisz, Barbara Shoplock, and Dr. Jeroen Ingels—initiated AntICE: "Antarctic Influences of Climate Change on Ecosystems" (AntICE). They reached out to various groups of school children in the local area (and continue to do so). The AntICE Team have been interacting with these children at Wakulla High School and Wakulla Elementary in Crawfordville; children from the Cornerstone Learning Community, Maclay Middle School, Gilchrist Elementary, and the School of Arts and Sciences in Tallahassee; and the Tallahassee-area homeschooling community to educate them about Antarctic ecosystems and ongoing climate change. The underlying idea was to
make the children aware of climatic changes in the Antarctic and their effect on
ecosystems so they, in turn, can spread this knowledge to their communities, family
and friends – acting as ‘Polar Ambassadors’. We collaborated with the Polar-ICE
project, an NSF-funded educational project that established the Polar Literacy
Initiative. This program developed the Polar Literacy Principles, which outline
essential concepts to improve public understanding of Antarctic and Arctic
ecosystems. In the Polar Academy work, we used the Polar Literacy principles, the
Polar Academy Team’s own Antarctic scientific efforts, and the experience of the FSU outreach and education program to engage with the children. We focused on the importance of Antarctic organisms and ecosystems, the uniqueness of its biota and the significance of its food webs, as well as how all these are changing and will
change further with climate change. Using general presentations, case studies,
scientific methodology, individual experiences, interactive discussions and Q&A
sessions, the children were guided through the many issues Antarctic ecosystems
are facing. Over 300 'Polar ambassadors' attended the interactive lectures and
afterwards took their creativity to high latitudes by creating welcome letters, displays, dioramas, sculptures, videos and online media to present at the scientific workshop. Over 50 projects were created by the children (Please see supporting files for images). We were also joined by a photographer, Ryan David Reines, to document the event. More information, media and links to online outreach products are available at https://marinelab.fsu.edu/labs/ingels/outreach/polar-academy/
This award supported the attendance of 39 U.S. scientists at the 35th SCAR Open Science Conference (OSC) to enable them to present their scientific findings, develop new collaborations with international scientists and become involved in SCAR-related activities and SCAR specialist groups. In previous symposia, U.S. scientists have made important and significant contributions to the success of the SCAR Open Science Conferences. The SCAR-OSC provides a key platform for generating or augmenting international collaborations not generally available for graduate students and early-career researchers. The 35th SCAR-OSC meeting: Polar 2018 brought together Antarctic and Arctic researchers for a unique bi-polar event and exchange of information in Davos, Switzerland, June 19-23, 2018.
The scientific program for the SCAR Open Science Conference (OSC)/POLAR2018 emphasized interdisciplinary research that places Antarctica and the Southern Ocean in a global context, providing essential perspective for students and early-career researchers. The meeting was organized around 12 science themes that included polar (Arctic and Antarctic) physical, biological, and social sciences. In addition, there were a myriad of side-meetings, activities, trainings, and workshops surrounding the main sessions. NSF support for travel allowed a more diverse group of researchers to participate in defining the future direction of international Antarctic and polar research and encouraged global collaboration and cooperation. It augmented the training and development of graduate students and young investigators as they benefited from the opportunity to interact with the international community of Antarctic and Arctic researchers. Individuals at all levels (students to senior researchers) interested in engaging in international collaborative activities and, potentially, assuming active leadership roles in SCAR groups, were supported. 90% of the travel awards were made to students (undergraduate, MS and PhD) and post-doctoral scholar (<5 y from earned PhD).
This project supported US participation in the XIIth Scientific Committee on Antarctic Research (SCAR) International Biology Symposium. The theme of this meeting and ancillary workshops was Scale Matters. Meeting sessions specifically addressed biodiversity and physiology spanning from molecular through ecosystem scales.
The project provided partial support (airfare and meeting registration) for 20 US scientists to travel to Leuven, Belgium and attend the SCAR International Biology Symposium in July 2017. Preference was given to applicants who were students and early career scientists. The call for applications was broadly disseminated to encourage participation by underrepresented groups in the sciences. The SCAR International Biology Symposium is a unique opportunity for US scientists to present their work and learn about the most recent findings on all aspects of Antarctic organisms and ecosystems research, to establish and strengthen international contacts, and to be actively involved in the development of new directions and the establishment of new frontiers in polar biology.
A great deal of uncertainty remains over how changes in high-latitude freshwater forcing will impact the stability of global ocean circulation, and in particular the strength of the Atlantic Meridional Overturning Circulation (AMOC) in the next 100-300 years, especially in realistic models. Indeed, it is still not understood whether increased Southern Ocean freshwater forcing will act to intensify the AMOC and warm the Northern Hemisphere or weaken it and trigger a cooling. The requirement to accurately assess climate sensitivity to freshwater forcing is heightened by increasing evidence that the marine-based West Antarctic Ice Sheet (WAIS) is vulnerable to rapid retreat and collapse on multidecadal-to-centennial timescales. Observations collected over the last 30 years indicate that WAIS is losing ice at an accelerated rate and may signal that the ice sheet has already begun a rapid and irreversible collapse. In addition, future simulations of the Antarctic ice sheet by members of our Project Team show the potential for far more rapid Antarctic ice sheet retreat in the future than previously simulated, suggesting that the discharge of enormous fluxes of icebergs and freshwater to the Southern Ocean should be considered a possibility in the near-future. Here, we performed a suite of coupled numerical climate model simulations to more accurately determine the sensitivity of global ocean circulation to freshwater and iceberg discharge from the Antarctic Ice Sheet (AIS) in the future under IPCC RCP scenarios 4.5 and 8.5. In our model, the input of freshwater and ice was provided by a dynamic ice sheet-shelf model that predicts a full collapse of the WAIS in the next ~100 years. Significantly, we find that accounting for Antarctic discharge raises subsurface ocean temperatures by >1°C at the ice sheet grounding line, relative to model simulations that are unable to capture this discharge. In contrast, we find that the increased meltwater causes a dramatic expansion of sea ice and a 2° - 10°C cooling of the surface air and surface ocean temperatures over the Southern Ocean that would have the potential to stabilize/reduce projected future ice sheet melt rates. Our work thus highlights that the future stability of the Antarctic ice sheet will likely be governed by whether any surface cooling can counteract any increased rates of subsurface melt.
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. <br/> <br/>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.<br/><br/>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. <br/><br/>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.
Recent discoveries of widespread liquid water and microbial ecosystems below the Antarctic ice sheets have generated considerable interest in studying Antarctic subglacial environments. Understanding subglacial hydrology, the persistence of life in extended isolation and the evolution and stability of subglacial habitats requires an integrated, interdisciplinary approach. The collaborative project, Minimally Invasive Direct Glacial Exploration (MIDGE) of the Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys will integrate geophysical measurements, molecular microbial ecology and geochemical analyses to explore a unique Antarctic subglacial system known as Blood Falls. Blood Falls is a hypersaline, subglacial brine that supports an active microbial community. The subglacial brine is released from a crevasse at the surface of the Taylor Glacier providing an accessible portal into an Antarctic subglacial ecosystem. Recent geochemical and molecular analyses support a marine source for the salts and microorganisms in Blood Falls. The last time marine waters inundated this part of the McMurdo Dry Valleys was during the Late Tertiary, which suggests the brine is ancient. Still, no direct samples have been collected from the subglacial source to Blood Falls and little is known about the origin of this brine or the amount of time it has been sealed below Taylor Glacier. Radar profiles collected near Blood Falls delineate a possible fault in the subglacial substrate that may help explain the localized and episodic nature of brine release. However it remains unclear what triggers the episodic release of brine exclusively at the Blood Falls crevasse or the extent to which the brine is altered as it makes its way to the surface. <br/><br/>The MIDGE project aims to determine the mechanism of brine release at Blood Falls, evaluate changes in the geochemistry and the microbial community within the englacial conduit and assess if Blood Falls waters have a distinct impact on the thermal and stress state of Taylor Glacier, one of the most studied polar glaciers in Antarctica. The geophysical study of the glaciological structure and mechanism of brine release will use GPR, GPS, and a small passive seismic network. Together with international collaborators, the 'Ice Mole' team from FH Aachen University of Applied Sciences, Germany (funded by the German Aerospace Center, DLR), MIDGE will develop and deploy innovative, minimally invasive technologies for clean access and brine sample retrieval from deep within the Blood Falls drainage system. These technologies will allow for the collection of samples of the brine away from the surface (up to tens of meters) for geochemical analyses and microbial structure-function experiments. There is concern over the contamination of pristine subglacial environments from chemical and biological materials inherent in the drilling process; and MIDGE will provide data on the efficacy of thermoelectric probes for clean access and retrieval of representative subglacial samples. Antarctic subglacial environments provide an excellent opportunity for researching survivability and adaptability of microbial life and are potential terrestrial analogues for life habitats on icy planetary bodies. The MIDGE project offers a portable, versatile, clean alternative to hot water and mechanical drilling and will enable the exploration of subglacial hydrology and ecosystem function while making significant progress towards developing technologies for minimally invasive and clean sampling of icy systems.
Aydin/1644245<br/><br/>This award supports a project to measure ethane in ice core air extracted from the recently drilled intermediate depth South Pole ice core (SPICECORE). Ethane is an abundant hydrocarbon in the atmosphere. The ice core samples that will be used in this analysis will span about 150 years before present to about 55,000 years before present and therefore, ethane emissions linked to human activities are not a subject of this study. The study will focus on quantifying the variability in the natural sources of ethane and the processes that govern its removal from the atmosphere. A long-term ice core ethane record will provide new knowledge on the chemistry of Earth?s atmosphere during time periods when human influence was either much smaller than present day or non-existent. The broader impacts of this work include education and training of students and a contribution to a better understanding of the chemistry of the atmosphere in the past and how it has been impacted by past changes in climate.<br/><br/>Natural sources that emit ethane are both geologic (e.g. seeps, vents, mud volcanoes etc.) and pyrogenic (wild fires) which is commonly called biomass burning. Ethane is removed from the atmosphere via oxidation reactions. The ice core ethane measurements have great potential as a proxy for gaseous emissions from biomass burning. This is especially true for time periods preceding the industrial revolution when atmospheric variability of trace gases was largely controlled by natural processes. Another objective of this study is to improve understanding of the causes of atmospheric methane variability apparent which are in the existing ice core records. Methane is a simpler hydrocarbon than ethane and more abundant in the atmosphere. Even though the project does not include any methane measurements; the commonalities between the sources and removal of atmospheric ethane and methane mean that ethane measurements can be used to gain insight into the causes of changes in atmospheric methane levels. The broader impacts of the project include partial support for one Ph.D. student and support for undergraduate researchers at UC Irvine. The PIs group currently has 4 undergraduate researchers. The PI and the graduate students in the UCI ice core laboratory regularly participate in on- and off-campus activities such as laboratory tours and lectures directed towards educating high-school students and science teachers, and the local community at large about the scientific value of polar ice cores as an environmental record of our planet's past. The results of this research will be disseminated via peer-review publications and will contribute to policy-relevant activities such as the IPCC Climate Assessment. Data resulting from this project will be archived in a national data repository. This award does not have field work in Antarctica.
The solidified remnants of large magma bodies within the continental crust hold the key to understanding the chemical and physical evolution of volcanic provinces through time. These deposits also commonly contain some of the world's most important ore deposits. Exposed deposits in South Africa, Greenland, USA, Canada, and Antarctica have led researchers to propose that the bigger the magma body, the faster it will crystallize. While this might seem counter-intuitive (typically it is thought that more magma = hotter = harder to cool), the comparison of these exposures show that bigger magma chambers maintain a molten top that is always in contact with the colder crust; whereas smaller magma chambers insulate themselves by crystallizing at the margins. The process is similar to the difference between a large cup of coffee with no lid, and a smaller cup of coffee held in a thermos. The large unprotected cup of coffee will cool down much faster than that held in the thermos. This research project of VanTongeren and Schoene will use previously collected rocks from the large (~8-9 km thick) Dufek Intrusion in Antarctica to precisely quantify how fast the magma chamber crystallized, and compare that rate to the much smaller magma chamber exposed in the Skaergaard Intrusion of E. Greenland. The work is an important step towards improving our understanding of time-scales associated with the thermal and chemical evolution of nearly all magma chambers on Earth, which will ultimately lead to better predictions of volcanic hazards globally. The work will also yield important insights into the timescales and conditions necessary for developing vast magmatic ore deposits, which is essential to the platinum and steel industries in the USA and abroad.<br/><br/>Based on observations of solidification fronts in six of the world's most completely exposed layered mafic intrusions, it was recently proposed that bigger magma chambers must crystallize faster than small magma chambers. While this is initially counter-intuitive, the hypothesis falls out of simple heat balance equations and the observation that the thickness of cumulates at the roofs of such intrusions is negatively proportional to the size of the intrusion. In this study, VanTongeren and Schoene will directly test the hypothesis that bigger magma chambers crystallize faster by applying high precision U-Pb zircon geochronology on 5-10 samples throughout the large Dufek Intrusion of Antarctica. Due to uncertainties in even the highest-precision ID-TIMS analyses, the Dufek Intrusion of Antarctica is the only large layered mafic intrusion on Earth where this research can be accomplished. VanTongeren and Schoene will place the geochronological measurements of the Dufek Intrusion into a comprehensive petrologic framework by linking zircon crystallization to other liquidus phases using mineral geochemistry, zircon saturation models, and petrologic models for intrusion crystallization. The research has the potential to radically change the way that we understand the formation and differentiation of large magma bodies within the shallow crust. Layered intrusions are typically thought to cool and crystallize over very long timescales allowing for significant differentiation of the magmas and reorganization of the cumulate rocks. If the 'bigger magma chambers crystallize faster hypothesis' holds this could reduce the calculated solidification time scales of the early earth and lunar magma oceans and have important implications for magma chamber dynamics of active intraplate volcanism and long-lived continental arcs. Furthermore, while the Dufek Intrusion is one of only two large layered intrusions exposed on Earth, very little is known about its petrologic evolution. The detailed geochemical and petrologic work of VanTongeren and Schoene based on analyses of previously collected samples will provide important observations with which to compare the Dufek and other large magma chambers.
Intellectual Merit: <br/><br/>The PIs propose to establish an ice shelf network of 18 broadband seismographs deployed for two years to obtain high-resolution, mantle-scale images of Earth structure underlying the Ross Sea Embayment. Prior marine geophysical work provides good crustal velocity models for the region seaward of the ice shelf but mantle structure is constrained by only low-resolution images due to the lack of prior seismic deployments. The proposed stations would be established between Ross Island and Marie Byrd Land. These stations would fill a major geological gap within this extensional continental province and would link data sets collected in the Transantarctic Mountain transition/Plateau region (TAMSEIS) and in West Antarctica (POLENET) to improve resolution of mantle features beneath Antarctica. The proposed deployment would allow the PIs to collect seismic data without the expense, logistical complexity, and iceberg hazards associated with ocean bottom seismograph deployments. Tomographic models developed from the proposed data will be used to choose between competing models for the dynamics of the Ross Sea. In particular, the PIs will investigate whether a broad region of hot mantle, including the Eastern Ross Sea, indicates distributed recent tectonic activity, which would call into question models proposing that Eastern Ross extension ceased during the Mesozoic. These data will also allow the PIs to investigate the deeper earth structure to evaluate the possible role of mantle plumes and/or small-scale convection in driving regional volcanism and tectonism across the region.<br/><br/>Broader impacts: <br/><br/>Data from this deployment will be of broad interdisciplinary use. This project will support three graduate and two undergraduate students. At least one student will be an underrepresented minority student. The PIs will interact with the media and include K-12 educators in their fieldwork.
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.<br/><br/>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.
This award supports a project to study the physical processes that synchronize glacial-scale variability between the Northern Hemisphere ice sheets and the Antarctic ice-sheet. Using a coupled numerical ice-sheet earth-system model, the research team will explore the cryospheric responses to past changes in greenhouse gas concentrations and variations in earth's orbit and tilt. First capturing the sensitivity of each individual ice-sheet to these forcings and then determining their joint variability induced by changes in sea level, ocean temperatures and atmospheric circulation, the researchers will quantify the relative roles of local versus remote effects on long-term ice volume variability. The numerical experiments will provide deeper physical insights into the underlying dynamics of past Antarctic ice-volume changes and their contribution to global sea level. Output from the transient earth system model simulations will be directly compared with ice-core data from previous and ongoing drilling efforts, such as West Antarctic Ice Sheet (WAIS) Divide. Specific questions that will be addressed include: 1) Did the high-latitude Southern Hemispheric atmospheric and oceanic climate, relevant to Antarctic ice sheet forcing, respond to local insolation variations, CO2, Northern Hemispheric changes, or a combination thereof?; 2) How did WAIS and East Antarctic Ice Sheet (EAIS) vary through the Last Glacial Termination and into the Holocene (21 ka- present)?; 3) Did the WAIS (or EAIS) contribute to rapid sea-level fluctuations during this period, such as Meltwater Pulse 1A? 4) Did WAIS collapse fully at Stage 5e (~ 125 ka), and what was its timing relative to the maximum Greenland retreat?; and 5) How did the synchronized behavior of Northern Hemisphere and Southern Hemisphere ice-sheet variations affect the strength of North Atlantic Deep Water and Antarctic Bottom Water formation and the respective overturning cells? The transient earth-system model simulations conducted as part of this project will be closely compared with paleo-climate reconstructions from ice cores, sediment cores and terrestrial data. This will generate an integrated understanding of the hemispheric contributions of deglacial climate change, the origin of meltwater pulses, and potential thresholds in the coupled ice-sheet climate system in response to different types of forcings. A well-informed long-term societal response to sea level rise requires a detailed understanding of ice-sheet sensitivities to external forcing. The proposed research will strongly contribute to this task through numerical modeling and paleo-data analysis. The research team will make the resulting model simulations available on the web-based data server at the Asia Pacific Data Research Center (APDRC) to enable further analysis by the scientific community. As part of this project a female graduate student and a postdoctoral researcher will receive training in earth-system and ice-sheet modeling and paleo-climate dynamics. This award has no field work in Antarctica.
The Palmer Antarctica LTER (Long Term Ecological Research) site has been in operation since 1990. The goal of all the LTER sites is to conduct policy-relevant research on ecological questions that require tens of years of data, and cover large geographical areas. For the Palmer Antarctica LTER, the questions are centered around how the marine ecosystem west of the Antarctica peninsula is responding to a climate that is changing as rapidly as any place on the Earth. For example, satellite observations over the past 35 years indicate the average duration of sea ice cover is now ~90 days (3 months!) shorter than it was. The extended period of open water has implications for many aspects of ecosystem research, with the concurrent decrease of Adèlie penguins within this region regularly cited as an exemplar of climate change impacts in Antarctica. Cutting edge technologies such as autonomous underwater (and possibly airborne) vehicles, seafloor moorings, and numerical modeling, coupled with annual oceanographic cruises, and weekly environmental sampling, enables the Palmer Antarctica LTER to expand and bridge the time and space scales needed to assess climatic impacts. This award includes for the first time study of the roles of whales as major predators in the seasonal sea ice zone ecosystem. The team will also focus on submarine canyons, special regions of enhanced biological activity, along the Western Antarctic Peninsula (WAP).<br/><br/>The current award's overarching research question is: How do seasonality, interannual variability, and long term trends in sea ice extent and duration influence the structure and dynamics of marine ecosystems and biogeochemical cycling? Specific foci within the broad question include: 1. Long-term change and ecosystem transitions. What is the sensitivity or resilience of the ecosystem to external perturbations as a function of the ecosystem state? 2. Lateral connectivity and vertical stratification. What are the effects of lateral transports of freshwater, heat and nutrients on local ocean stratification and productivity and how do they drive changes in the ecosystem? 3. Top-down controls and shifting baselines. How is the ecosystem responding to the cessation of whaling and subsequent long-term recovery of whale stocks? 4. Foodweb structure and biogeochemical processes. How do temporal and spatial variations in foodweb structure influence carbon and nutrient cycling, export, and storage? The broader impacts of the award leverage local educational partnerships including the Sandwich, MA STEM Academy, the New England Aquarium, and the NSF funded Polar Learning and Responding (PoLAR) Climate Change Education Partnership at Columbia's Earth Institute to build new synergies between Arctic and Antarctic, marine and terrestrial scientists and students, governments and NGOs. The Palmer Antarctic LTER will also conduct appropriate cross LTER site comparisons, and serve as a leader in information management to enable knowledge-building within and beyond the Antarctic, oceanographic, and LTER communities.
Non-Technical Summary:<br/> 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. <br/> 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.<br/><br/><br/>Technical Description of Project <br/>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).<br/>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.
The McMurdo Dry Valleys (MDV) is a polar desert on the coast of East Antarctica, a region that has not yet experienced climate warming. The McMurdo Dry Valleys Long Term Ecological Research (MCMLTER) project has documented the ecological responses of the glacier, soil, stream and lake ecosystems in the MDV during a cooling trend (from 1986 to 2000) which was associated with the depletion of atmospheric ozone. In the past decade, warming events with strong katabatic winds occurred during two summers and the resulting high streamflows and sediment deposition changed the dry valley landscape, possibly presaging conditions that will occur when the ozone hole recovers. In anticipation of future warming in Antarctica, the overarching hypothesis of the proposed project is: Climate warming in the McMurdo Dry Valley ecosystem will amplify connectivity among landscape units leading to enhanced coupling of nutrient cycles across landscapes, and increased biodiversity and productivity within the ecosystem. Warming in the MDV is hypothesized to act as a slowly developing, long-term press of warmer summers, upon which transient pulse events of high summer flows and strong katabatic winds will be overprinted. Four specific hypotheses address the ways in which pulses of water and wind will influence contemporary and future ecosystem structure, function and connectivity. Because windborne transport of biota is a key aspect of enhanced connectivity from katabatic winds, new monitoring will include high-resolution measurements of aeolian particle flux. Importantly, integrative genomics will be employed to understand the responses of specific organisms to the increased connectivity. The project will also include a novel social science component that will use environmental history to examine interactions between human activity, scientific research, and environmental change in the MDV over the past 100 years. To disseminate this research broadly, MCM scientists will participate in a wide array of outreach efforts ranging from presentations in K-12 classrooms to bringing undergraduates and teachers to the MDV to gain research experience. Planned outreach programs will build upon activities conducted during the International Polar Year (2007-2008), which include development of an interactive DVD for high school students and teachers and publication of a children's book in the LTER Schoolyard Book Series. A teacher's edition of the book with a CD containing lesson plans will be distributed. The project will develop programs for groups traditionally underrepresented in science arenas by publishing some outreach materials in Spanish.
Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project seeks to drive a transformative shift in our understanding of the crucial role of the Southern Ocean in taking up anthropogenic carbon and heat, and resupplying nutrients from the abyss to the surface. An observational program will generate vast amounts of new biogeochemical data that will provide a greatly improved view of the dynamics and ecosystem responses of the Southern Ocean. A modeling component will apply these observations to enhancing understanding of the current ocean, reducing uncertainty in projections of future carbon and nutrient cycles and climate.<br/><br/>Because it serves as the primary gateway through which the intermediate, deep, and bottom waters of the ocean interact with the surface layers and thus the atmosphere, the Southern Ocean has a profound influence on the oceanic uptake of anthropogenic carbon and heat as well as nutrient resupply from the abyss to the surface. Yet it is the least observed and understood region of the world ocean. The oceanographic community is on the cusp of two major advances that have the potential to transform understanding of the Southern Ocean. The first is the development of new biogeochemical sensors mounted on autonomous profiling floats that allow sampling of ocean biogeochemistry and acidification in 3-dimensional space with a temporal resolution of five to ten days. The SOCCOM float program proposed will increase the average number of biogeochemical profiles measured per month in the Southern Ocean by ~10-30x. The second is that the climate modeling community now has the computational resources and physical understanding to develop fully coupled climate models that can represent crucial mesoscale processes in the Southern Ocean, as well as corresponding models that assimilate observations to produce a state estimate. Together with the observations, this new generation of models provides the tools to vastly improve understanding of Southern Ocean processes and the ability to quantitatively assess uptake of anthropogenic carbon and heat, as well as nutrient resupply, both today and into the future.<br/><br/>In order to take advantage of the above technological and modeling breakthroughs, SOCCOM will implement the following research programs:<br/>* Theme 1: Observations. Scripps Institution of Oceanography will lead a field program to expand the number of Southern Ocean autonomous profiling floats and equip them with sensors to measure pH, nitrate, and oxygen. The University of Washington and Monterey Bay Aquarium Research Institute will design, build, and oversee deployment of the floats. Scripps will also develop a mesoscale eddying Southern Ocean state estimate that assimilates physical and biogeochemical data into the MIT ocean general circulation model.<br/>* Theme 2: Modeling. University of Arizona and Princeton University, together with NOAA's Geophysical Fluid Dynamics Laboratory (GFDL), will use SOCCOM observations to develop data/model assessment metrics and next-generation model analysis and evaluation, with the goal of improving process level understanding and reducing the uncertainty in projections of our future climate.<br/><br/>Led by Climate Central, an independent, non-profit journalism and research organization that promotes understanding of climate science, SOCCOM will collaborate with educators and media professionals to inform policymakers and the public about the challenges of climate change and its impacts on marine life in the context of the Southern Ocean. In addition, the integrated team of SOCCOM scientists and educators will:<br/>* communicate data and results of the SOCCOM efforts quickly to the public through established data networks, publications, broadcast media, and a public portal;<br/>* train a new generation of diverse ocean scientists, including undergraduate students, graduate students, and postdoctoral fellows versed in field techniques, data calibration, modeling, and communication of research to non-scientists;<br/>* transfer new sensor technology and related software to autonomous instrument providers and manufacturers to ensure that they become widely useable.
The extreme mountain topographies of alpine landscapes at mid latitudes (e.g., European Alps, Patagonia, Alaska) are thought to have formed by the erosive action of glaciers, yet our understanding of exactly when and how those topographies developed is limited. If glacial ice was responsible for forming them, then those landscapes must have developed primarily over the last 2-3 million years when ice was present at those latitudes; this timing has only recently been confirmed by observations. In contrast, the Antarctic Peninsula, which contains similarly spectacular topographic relief, is known to have hosted alpine glaciers as early as 37 million years ago, and is currently covered by ice. Thus, if caused by glacial erosion, the high relief of the peninsula should have formed much earlier than what has been observed at mid latitude sites, yet we know nearly nothing about the timing of its development. The primary benefit of this research will be to study the timing of topography development along the Antarctic Peninsula by applying state of the art chemical analyses to sediments collected offshore. This research is important because studying a high latitude site will enable comparison with sites at mid latitudes and test current hypotheses on the development of glacial landscapes in general.<br/><br/>This project aims to apply low-temperature thermochronometry based on the (U-Th)/He system in apatite to investigate the exhumation history, the development of the present topography, and the pattern of glacial erosion in the central Antarctic Peninsula. A number of recent studies have used this approach to study the dramatic, high-relief landscapes formed by Pleistocene alpine glacial erosion in temperate latitudes: New Zealand, the Alps, British Columbia, Alaska, and Patagonia. These studies have not only revealed when these landscapes formed, but have also provided new insights into the physical mechanisms of glacial erosion. The Antarctic Peninsula is broadly akin to temperate alpine landscapes in that the dominant landforms are massive glacial troughs. However, what we know about Antarctic glacial history suggests that the timing and history of glacial erosion was most likely very different from the temperate alpine setting: The Antarctic Peninsula has been glaciated since the Eocene, and Pleistocene climate cooling is hypothesized to have suppressed, rather than enhanced, glacial erosion. Our goal is to evaluate these hypotheses by developing a direct thermochronometric record of when and how the present glacial valley relief formed. We propose to learn about the timing and process of glacial valley formation through apatite (U-Th)/He and 4He/3He measurements on glacial sediment collected near the grounding lines of major glaciers draining the Peninsula. In effect, since we cannot sample bedrock directly that is currently covered by ice, we will rely on these glaciers to do it for us.
This project aims to identify which portions of the glacial cover in the Antarctic Peninsula are losing mass to the ocean. This is an important issue to resolve because the Antarctic Peninsula is warming at a faster rate than any other region across the earth. Even though glaciers across the Antarctic Peninsula are small, compared to the continental ice sheet, defining how rapidly they respond to both ocean and atmospheric temperature rise is critical. It is critical because it informs us about the exact mechanisms which regulate ice flow and melting into the ocean. For instance, after the break- up of the Larsen Ice Shelf in 2002 many glaciers began to flow rapidly into the sea. Measuring how much ice was involved is difficult and depends upon accurate estimates of volume and area. One way to increase the accuracy of our estimates is to measure how fast the Earth's crust is rebounding or bouncing back, after the ice has been removed. This rebound effect can be measured with very precise techniques using instruments locked into ice free bedrock surrounding the area of interest. These instruments are monitored by a set of positioning satellites (the Global Positioning System or GPS) in a continuous fashion. Of course the movement of the Earth's bedrock relates not only to the immediate response but also the longer term rate that reflects the long vanished ice masses that once covered the entire Antarctic Peninsula?at the time of the last glaciation. These rebound measurements can, therefore, also tell us about the amount of ice which covered the Antarctic Peninsula thousands of years ago. Glacial isostatic rebound is one of the complicating factors in allowing us to understand how much the larger ice sheets are losing today, something that can be estimated by satellite techniques but only within large errors when the isostatic (rebound) correction is unknown.<br/><br/>The research proposed consists of maintaining a set of six rebound stations until the year 2016, allowing for a longer time series and thus more accurate estimates of immediate elastic and longer term rebound effects. It also involves the establishment of two additional GPS stations that will focus on constraining the "bull's eye" of rebound suggested by measurements over the past two years. In addition, several more geologic data points will be collected that will help to reconstruct the position of the ice sheet margin during its recession from the full ice sheet of the last glacial maximum. These will be based upon the coring of marine sediment sequences now recognized to have been deposited along the margins of retreating ice sheets and outlets. Precise dating of the ice margin along with the new and improved rebound data will help to constrain past ice sheet configurations and refine geophysical models related to the nature of post glacial rebound. Data management will be under the auspices of the UNAVCO polar geophysical network or POLENET and will be publically available at the time of station installation. This project is a small scale extension of the ongoing LARsen Ice Shelf, Antarctica Project (LARISSA), an IPY (International Polar Year)-funded interdisciplinary study aimed at understanding earth system connections related to the Larsen Ice Shelf and the northern Antarctic Peninsula.
Project Summary<br/><br/>Intellectual Merit: <br/>The United States Polar Rock Repository (USPRR) was established to curate and loan geologic samples from polar regions to researchers and educators. OPP established the USPRR in part to avoid redundant sample collection and thus reduce the environmental impact of polar research. The USPRR also provides the research community with an important resource for developing new research projects. The USPRR acquires rock collections through donations from institutions and scientists and makes these samples available as no-cost loans for research, education and museum exhibits. Sample metadata is available in an on-line database. The database also includes rock property information, such as magnetic susceptibility and specific gravity, which are useful for geophysical studies. Researchers may request samples for analysis using an online request form. The USPRR fulfills several data management directives, including the Scientific Committee on Antarctic Research, Antarctic Data Management directive of providing free, full and open access to both metadata and the samples. The intellectual merit of the USPRR lies in the global dissemination of scientific information to researchers. <br/><br/>Broader impacts: <br/>The broader impacts of the USPRR include lessening environmental impacts resulting from redundant fieldwork in Polar Regions. The USPRR provides educational information about Antarctica via the website, by visiting the repository or borrowing a "USPRR rock box". Working at the repository provides students with opportunities to learn about the geology of Antarctica as well as doing research, learning new skills in digital imaging, curation and database management.
The investigators will map glacial deposits and date variations in glacier variability at several ice-free regions in northern Victoria Land, Antarctica. These data will constrain the nature and timing of past ice thickness changes for major glaciers that drain into the northwestern Ross Sea. This is important because during the Last Glacial Maximum (15,000 - 18,000 years ago) these glaciers were most likely flowing together with grounded ice from both the East and West Antarctic Ice Sheets that expanded across the Ross Sea continental shelf to near the present shelf edge. Thus, the thickness of these glaciers was most likely controlled in part by the extent and thickness of the Ross Sea ice sheet and ice shelf. The data the PIs propose to collect can provide constraints on the position of the grounding line in the western Ross Sea during the Last Glacial Maximum, the time that position was reached, and ice thickness changes that occurred after that time. The primary intellectual merit of this project will be to improve understanding of a period of Antarctic ice sheet history that is relatively unconstrained at present and also potentially important in understanding past ice sheet-sea level interactions. <br/><br/>This proposal will support an early career researcher's ongoing program of undergraduate education and research that is building a socio-economically diverse student body with students from backgrounds underrepresented in the geosciences. This proposal will also bring an early career researcher into Antarctic research.
Many of the natural processes that modify the landscape inhabited by humans occur over very long timescales, making them difficult to observe. Exceptions include rare catastrophic events such as earthquakes, volcanic eruptions, and floods that occur on short timescales. Many significant processes that affect the land and landscape that we inhabit operate on time scales imperceptible to humans. One of these processes is wind transport of sand, with related impacts to exposed rock surfaces and man-made objects, including buildings, windshields, solar panels and wind-farm turbine blades. The goal of this project is to gain an understanding of wind erosion processes over long timescales, in the Antarctic Dry Valleys, a cold desert environment where there were no competing processes (such as rain and vegetation) that might mask the effects. The main objective is recovery of rock samples that were deployed in 1983/1984 at 11 locations in the Antarctic Dry Valleys, along with measurements on the rock samples and characterization of the sites. In the late 1980s and early 1990s some of these samples were returned and indicated more time was needed to accumulate information about the timescales and impacts of the wind erosion processes. This project will allow collection of the remaining samples from this experiment after 30 to 31 years of exposure. The field work will be carried out during the 2014/15 Austral summer. The results will allow direct measurement of the abrasion rate and hence the volumes and timescales of sand transport; this will conclude the longest direct examination of such processes ever conducted. Appropriate scaling of the results may be applied to buildings, vegetation (crops), and other aspects of human presence in sandy and windy locations, in order to better determine the impact of these processes and possible mitigation of the impacts. The project is a collaborative effort between a small business, Malin Space Science Systems (MSSS), and the University of Washington (UW). MSSS will highlight this Antarctic research on its web site, by developing thematic presentations describing our research and providing a broad range of visual materials. The public will be engaged through daily updates on a website and through links to material prepared for viewing in Google Earth. UW students will be involved in the laboratory work and in the interpretation of the results.<br>Technical Description of Project:<br>The goal of this project is to study the role of wind abrasion by entrained particles in the evolution of the McMurdo Dry Valleys in the Transantarctic Mountains. During the 1983 to 1984 field seasons, over 5000 rock targets were installed at five heights facing the 4 cardinal directions at 10 locations (with an additional site containing fewer targets) to study rates of physical weathering due primarily to eolian abrasion. In addition, rock cubes and cylinders were deployed at each site to examine effects of chemical weathering. The initial examination of samples returned after 1, 5, and 10 years of exposure, showed average contemporary abrasion rates consistent with those determined by cosmogenic isotope studies, but further stress that "average" should not be interpreted as meaning "uniform." The samples will be characterized using mass measurements wtih 0.01 mg precision balances, digital microphotography to compare the evolution of their surface features and textures, SEM imaging to examine the micro textures of abraded rock surfaces, and optical microscopy of thin sections of a few samples to examine the consequences of particle impacts extending below the abraded surfaces. As much as 60-80% of the abrasion measured in samples from 1984-1994 appears to have occurred during a few brief hours in 1984. This is consistent with theoretical models that suggest abrasion scales as the 5th power of wind velocity. The field work will allow return of multiple samples after three decades of exposure, which will provide a statistical sampling (beyond what is acquired by studying a single sample), and will yield the mass loss data in light of complementary environmental and sand kinetic energy flux data from other sources (e.g. LTER meteorology stations). This study promises to improve insights into one of the principal active geomorphic process in the Dry Valleys, an important cold desert environment, and the solid empirical database will provide general constraints on eolian abrasion under natural conditions.
Intellectual Merit: <br/>The role that Antarctica has played in vertebrate evolution and paleobiogeography during the Late Cretaceous and early Paleogene is largely unknown. Evidence indicates that Antarctica was home to a diverse flora during the Late Cretaceous and Paleogene, yet the vertebrates that must have existed on the continent remain virtually unknown. To fill this gap, the PIs have formed the Antarctic Vertebrate Paleontology Initiative (AVPI), whose goal is to search for and collect Late Cretaceous-Paleogene vertebrate fossils in Antarctica at localities that have never been properly surveyed, as well as in areas of proven potential. Two field seasons are proposed for the James Ross Island Group on the northeastern margin of the Antarctic Peninsula. Expected finds include chondrichthyan and osteichthyan fishes, marine reptiles, ornithischian and non-avian theropod dinosaurs, ornithurine birds, and therian and non-therian mammals. Hypotheses to be tested include: 1) multiple extant bird and/or therian mammal lineages originated during the Cretaceous and survived the K-Pg boundary extinction event; 2) the "Scotia Portal" permitted the dispersal of continental vertebrates between Antarctica and South America prior to the latest Cretaceous and through to the late Paleocene or early Eocene; 3) Late Cretaceous non-avian dinosaurs from Antarctica are closely related to coeval taxa from other Gondwanan landmasses; 4) terminal Cretaceous marine reptile faunas from southern Gondwana differed from contemporaneous but more northerly assemblages; and 5) the collapse of Antarctic ichthyofaunal diversity during the K-Pg transition was triggered by a catastrophic extinction.<br/><br/>Broader impacts: <br/>The PIs will communicate discoveries to audiences through a variety of channels, such as the Dinosaurs in Their Time exhibition at Carnegie Museum of Natural History and the outreach programs of the Environmental Science Institute of the University of Texas at Austin. In addition, Carnegie Museum will launch a student-oriented programming initiative using AVPI research as a primary focus. This array of activities will help some 2,000 Pittsburgh-area undergraduates to explore the relevance of deep-time discoveries to critical modern issues. The AVPI will provide research opportunities for eight undergraduate and three graduate students, several of whom will receive field training in Antarctica. Fossils will be accessioned into the Carnegie Museum collection, and made accessible virtually through the NSF-funded Digital Morphology library at University of Texas.
Taylor/0944348<br/><br/>This award supports renewal of funding of the WAIS Divide Science Coordination Office (SCO). The Science Coordination Office (SCO) was established to represent the research community and facilitates the project by working with support organizations responsible for logistics, drilling, and core curation. During the last five years, 26 projects have been individually funded to work on this effort and 1,511 m of the total 3,470 m of ice at the site has been collected. This proposal seeks funding to continue the SCO and related field operations needed to complete the WAIS Divide ice core project. Tasks for the SCO during the second five years include planning and oversight of logistics, drilling, and core curation; coordinating research activities in the field; assisting in curation of the core in the field; allocating samples to individual projects; coordinating the sampling effort; collecting, archiving, and distributing data and other information about the project; hosting an annual science meeting; and facilitating collaborative efforts among the research groups. The intellectual merit of the WAIS Divide project is to better predict how human-caused increases in greenhouse gases will alter climate requires an improved understanding of how previous natural changes in greenhouse gases influenced climate in the past. Information on previous climate changes is used to validate the physics and results of climate models that are used to predict future climate. Antarctic ice cores are the only source of samples of the paleo-atmosphere that can be used to determine previous concentrations of carbon dioxide. Ice cores also contain records of other components of the climate system such as the paleo air and ocean temperature, atmospheric loading of aerosols, and indicators of atmospheric transport. The WAIS Divide ice core project has been designed to obtain the best possible record of greenhouse gases during the last glacial cycle (last ~100,000 years). The site was selected because it has the best balance of high annual snowfall (23 cm of ice equivalent/year), low dust Antarctic ice that does not compromise the carbon dioxide record, and favorable glaciology. The main science objectives of the project are to investigate climate forcing by greenhouse gases, initiation of climate changes, stability of the West Antarctic Ice Sheet, and cryobiology in the ice core. The project has numerous broader impacts. An established provider of educational material (Teachers? Domain) will develop and distribute web-based resources related to the project and climate change for use in K?12 classrooms. These resources will consist of video and interactive graphics that explain how and why ice cores are collected, and what they tell us about future climate change. Members of the national media will be included in the field team and the SCO will assist in presenting information to the general public. Video of the project will be collected and made available for general use. Finally, an opportunity will be created for cryosphere students and early career scientists to participate in field activities and core analysis. An ice core archive will be available for future projects and scientific discoveries from the project can be used by policy makers to make informed decisions.
Steig/1341360<br/><br/>This award supports a two-year project to develop a method for rapid and precise measurements of the difference in 18O/16O and 17O/16O isotope ratios in water, referred to as the 17O-excess. Measurement of 17O-excess is a recent innovation in geochemistry, complementing traditional measurements of the ratios of hydrogen (D/H) and oxygen (18O/16O). Conventional measurements of 17O/16O are limited in number because of the time-consuming and laborious nature of the analyses, which involves the conversion of water to oxygen via fluorination, followed by high-precision mass spectrometry. This project will use a novel cavity ring-down spectroscopy (CRDS) system developed by a joint effort of the University of Washington and Picarro, Inc. (Santa Clara, CA), along with the Centre for Ice and Climate (Neils Bohr Institute, Copenhagen). The primary intellectual merit of the research is the improvement of the CRDS method for measurements of 17Oexcess of discrete samples of water, to obtain precision and accuracy competitive with conventional methods using mass spectrometry. This will be achieved by quantification of the effects of water vapor concentration variability and instrument memory, precise calibration of the instrument against standard waters, and improvements to the spectroscopic analyses. The CRDS system will also be coupled to continuous-flow systems for ice core analysis, in collaboration with the University of Colorado, Boulder. The goal is to have an operational system available for ice core processing associated with the next major U.S.-led ice core project at South Pole, in 2015-2017. The broader impacts of the research include the ability to measure 17O-excess in ambient atmospheric water vapor, which can be used to improve understanding of convection, moisture transport, and condensation. The instrument development work proposed here is relevant to research supported by several NSF-GEO programs, including Hydrology, Climate and Large Scale Dynamics, Paleoclimate, Atmosphere Chemistry, and both the Arctic and Antarctic Programs. This proposal will support a postdoctoral researcher.
Marine paleoclimate archives show that approximately one million years ago Earth's climate transitioned from 40,000-year glacial /interglacial cycles to 100,000-year cycles. This award will support a study designed to map the distribution of one million year-old ice in the Allan Hills Blue Ice Area, Antarctica using state-of-the-art ground penetrating radar. The Allen Hills was demonstrated to contain a continuous record of the past 400,000 years and is also the collection location of the oldest ice samples (990,000 years) yet recovered. The maps resulting from this study will be used to select an ice-core drilling site at which a million-plus year-old continuous record of climate could be recovered. Ice cores contain the only kind of record to directly capture atmospheric gases and aerosols, but no ice-core-based climate record yet extends continuously beyond the past 800,000 years. A million-plus year-old record will allow better understanding of the major mechanisms and driving forces of natural climate variability in a world with 100,000-year glacial/interglacial cycles. The project will support two early career scientists in collaboration with senior scientists, as well as a graduate student, and will conduct outreach to schools and the public.
The Allan Hills Blue Ice Area preserves a continuous climate record covering the last 400,000 years along an established glaciological flow line. Two kilometers to the east of this flow line, the oldest ice on Earth (~1 million years old) is found only 120 m below the surface. Meteorites collected in the area are reported to be as old as 1.8 million years, suggesting still older ice may be present. Combined, these data strongly suggest that the Allen Hills area could contain a continuous, well-resolved environmental record, spanning at least the last million years. As such, this area has been selected as an upcoming target for the new Intermediate Depth Ice Core Drill by the US Ice Core Working Group. This drill will recover a higher-quality core than previous dry drilling attempts. This project will conduct a comprehensive ground penetrating radar survey aimed at tracing the signature of the million-year-old ice layer throughout the region. The resulting map will be used to select a drill site from which an ice core containing the million-plus year-old continuous climate record will be collected. The proposed activities are a necessary precursor to the collection of the oldest known ice on Earth. Ice cores provide a robust reconstruction of past climate and extending this record beyond the 800,000 years currently available will open new opportunities to study the climate system. The data collected will also be used to investigate the bedrock and ice flow parameters favorable to the preservation of old ice, which may allow targeted investigation of other blue ice areas in Antarctica.
Intellectual Merit: <br/>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. <br/><br/>Broader impacts: <br/>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.
Intellectual Merit: <br/>The primary goal of this project is to sample two beds in the Meyer Desert Formation, which are known to be especially fossiliferous containing plants, insects, other arthropods, freshwater mollusks, and fish. There is a possibility that the teeth and bones of a small marsupial could also be found. Previous studies have demonstrated that these horizons contain unique fossil assemblages that provide information used to reconstruct paleoenvironments and paleoclimate. The fossils represent organisms previously not found in Antarctica and consequently their study will lead to the development of new hypotheses concerning southern hemisphere biogeography. The new discoveries will also increase knowledge of paleoenvironments and paleoclimates as well as biogeographic relationships of the biota of the southern hemisphere. For some organisms, such as Nothofagus (Southern Beech) or the trechine groundbeetle, fossils would confirm that Antarctica was inhabited as part of Gondwana. For other fossils, such as the cyclorrhaphan fly or freshwater mollusks not expected to have inhabited Antarctica, the discoveries will require a reassessment of phylogenetic interpretations and a reinvestigation of the role of Antarctica in the evolutionary history of those organisms. The new fossil-based knowledge will require integration with interpretations from cladistics and molecular genetics to develop more comprehensive phylogenetic hypotheses for a range of organisms.<br/><br/>Broader impacts: <br/>The discovery of fossils in Antarctica and implications for climate change has proven to be popular with the media. This attention will help disseminate the results of this study. Before the field season, the PI will work with local media and with area schools to set up field interviews and web casts from Antarctica. The project will also involve the training of a graduate student in the field and in the follow up studies of the fossils in the laboratory.
Steig/1043092<br/><br/>This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.
1141973/Tedesco<br/><br/>This award supports a project to generate first-time validated enhanced spatial resolution (5-10 km) maps of surface melting over the Antarctic Peninsula for the period 1958 - to date from the outputs of a regional climate model and different downscaling techniques. These maps will be assessed and validated through new high spatial resolution (2.25 km) surface melting maps obtained from the QuikSCAT satellite for the period 1999 - 2009. The intellectual merit of this work is that it would be the first time that the outputs of a regional climate model would be used to study surface melting over Antarctica at such high spatial resolution and the first time that such results are validated by means of an observational tool that has such a large spatial coverage and high spatial resolution. The results generated in this study would also provide a first-time opportunity to study the melt distribution over the Peninsula and its correlation with climate drivers, such as the Southern Annual Mode (SAM) and the El Nino-Southern Oscillation (ENSO) at these unprecedented spatial scales. The enhanced resolution melting maps will also offer a unique opportunity to study melting trends and patterns over specific regions of the Peninsula, such as the Wilkins and the Larsen A and B ice shelves and evaluate whether the extreme melting observed during the recent collapses was unprecedented over the + 50 years. The broader impacts of the project are that it will integrate research and education by fully supporting one female undergrad student, a PhD student and partially supporting a PostDoc. The work will be done at a minority-serving institution and the PhD student who worked on the development of the high-resolution melting data set from QuikSCAT will become the PostDoc who will work on this project. Teaching and learning will be supported by incorporating research results into graduate and undergrad level courses and will be disseminated over the web and through appropriate channels. Results from this project will also benefit the society at large as they will improve our understanding of the links between atmospheric patterns and surface melting and they will contribute to improving estimates of sea level rise from the Antarctica continent.
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.
The role that Antarctica has played in vertebrate evolution and paleobiogeography during the Late Cretaceous and early Paleogene is largely unknown. Evidence indicates that Antarctica was home to a diverse flora during the Late Cretaceous and Paleogene, yet the vertebrates that must have existed on the continent remain virtually unknown. To fill this gap, the PIs have formed the Antarctic Vertebrate Paleontology Initiative (AVPI), whose goal is to search for and collect Late Cretaceous-Paleogene vertebrate fossils in Antarctica at localities that have never been properly surveyed, as well as in areas of proven potential. Two field seasons are proposed for the James Ross Island Group on the northeastern margin of the Antarctic Peninsula. Expected finds include chondrichthyan and osteichthyan fishes, marine reptiles, ornithischian and non-avian theropod dinosaurs, ornithurine birds, and therian and non-therian mammals. Hypotheses to be tested include: 1) multiple extant bird and/or therian mammal lineages originated during the Cretaceous and survived the K-Pg boundary extinction event; 2) the ?Scotia Portal? permitted the dispersal of continental vertebrates between Antarctica and South America prior to the latest Cretaceous and through to the late Paleocene or early Eocene; 3) Late Cretaceous non-avian dinosaurs from Antarctica are closely related to coeval taxa from other Gondwanan landmasses; 4) terminal Cretaceous marine reptile faunas from southern Gondwana differed from contemporaneous but more northerly assemblages; and 5) the collapse of Antarctic ichthyofaunal diversity during the K-Pg transition was triggered by a catastrophic extinction.<br/><br/>Broader impacts: <br/>The PIs will communicate discoveries to audiences through a variety of channels, such as the Dinosaurs in Their Time exhibition at Carnegie Museum of Natural History and the outreach programs of the Environmental Science Institute of the University of Texas at Austin. In addition, Carnegie Museum will launch a student-oriented programming initiative using AVPI research as a primary focus. This array of activities will help some 2,000 Pittsburgh-area undergraduates to explore the relevance of deep-time discoveries to critical modern issues. The AVPI will provide research opportunities for eight undergraduate and three graduate students, several of whom will receive field training in Antarctica. Fossils will be accessioned into the Carnegie Museum collection, and made accessible virtually through the NSF-funded Digital Morphology library at University of Texas.
1043649/Braun<br/><br/><br/>This award supports a project to determine the current mass balance of selected glaciers of the Western Antarctic Peninsula (WAP) and adjacent islands, including King George Island and Livingston Island. A major goal is to discriminate the climatic and dynamic components of the current mass budget. The dynamic component will be assessed using a flux gate approach. Glacier velocity fields will be derived by offset tracking on repeat SAR satellite imagery, and ice thicknesses across grounding lines or near terminus will be approximated from a new methods based on mass continuity. The surface mass balance will be computed from a spatially distributed temperature-index mass-balance model forced by temperature and precipitation data from regional climate models. Our results will provide improved mass budget estimates of Western Antarctic Peninsula glaciers and a more thorough understanding of the ratio between the climatic and dynamic components. The techniques to be developed will be applicable to other glaciers in the region allowing regional scale mass budgets to be derived. The broader impacts of this work are that glacier wastage is currently the most important contributor to global sea level rise and the Antarctic Peninsula has been identified as one of the largest single contributors. Future sea-level rise has major societal, economic and ecological implications. The activity will foster new partnerships through collaboration with European and South American colleagues. The project will form the base of of a postdoctoral research fellowship. It will also provide training of undergraduate and graduate students through inclusion of data and results in course curriculums.
Aydin/1043780<br/>This award supports the analysis of the trace gas carbonyl sulfide (COS) in a deep ice core from West Antarctic Ice Sheet Divide (WAIS-D), Antarctica. COS is the most abundant sulfur gas in the troposphere and a precursor of stratospheric sulfate. It has a large terrestrial COS sink that is tightly coupled to the photosynthetic uptake of atmospheric carbon dioxide (CO2). The primary goal of this project is to develop high a resolution Holocene record of COS from the WAIS-D 06A ice core. The main objectives are 1) to assess the natural variability of COS and the extent to which its atmospheric variability was influenced by climate variability, and 2) to examine the relationship between changes in atmospheric COS and CO2. This project also includes low-resolution sampling and analysis of COS from 10,000-30,000 yrs BP, covering the transition from the Last Glacial Maximum into the early Holocene. The goal of this work is to assess the stability of COS in ice core air over long time scales and to establish the COS levels during the last glacial maximum and the magnitude of the change between glacial and interglacial conditions. The results of this work will be disseminated via peer-review publications and will contribute to environmental assessments such as the WMO Stratospheric Ozone Assessment and IPCC Climate Assessment. This project will support a PhD student and undergraduate researcher in the Department of Earth System Science at the University of California, Irvine, and will create summer research opportunities for undergraduates from non-research active Universities.
Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth?s crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica.<br/><br/>Dronning Maud Land (DML) occupied a central location during the formation of supercontinents ? large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth?s history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007?2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML.
The Office of Polar Programs, Antarctic Science Division, Ocean & Climate Systems Program has made this award to support a multidisciplinary effort to study the upwelling of relatively warm deep water onto the Amundsen Sea continental shelf and how it relates to atmospheric forcing and bottom bathymetry and how the warm waters interact with both glacial and sea ice. This study constitutes a contribution of a coordinated research effort in the region known as the Amundsen Sea Embayment Project or ASEP. Previous work by the PI and others has shown that the West Antarctic Ice Sheet has been found to be melting faster, perhaps by orders of magnitude, than ice sheets elsewhere around Antarctica, excluding those on the Peninsula. Submarine channels that incise the continental shelf are thought to provide fairly direct access of relatively warm circum polar deep water to the cavity under the floating extension of the ice shelf. Interactions with sea ice en route can modify the upwelled waters. The proposed investigations build on previous efforts by the PI and colleagues to use hydrographic measurements to put quantitative bounds on the rate of glacial ice melt by relatively warm seawater. <br/>The region can be quite difficult to access due to sea ice conditions and previous hydrographic measurements have been restricted to the austral summer time frame. In this project it was proposed to obtain the first austral spring hydrographic data via CTD casts and XBT drops (September-October 2007) as part of a separately funded cruise (PI Steve Ackley) the primary focus of which is sea-ice conditions to be studied while the RV Nathanial B Palmer (RV NBP) drifts in the ice pack. This includes opportunistic sampling for pCO2 and TCO2. A dedicated cruise in austral summer 2009 will follow this opportunity. The principal objectives of the dedicated field program are to deploy a set of moorings with which to characterize temporal variability in warm water intrusions onto the shelf and to conduct repeat hydrographic surveying and swath mapping in targeted areas, ice conditions permitting. Automatic weather stations are to be deployed in concert with the program, sea-ice observations will be undertaken from the vessel and the marine cavity beneath the Pine Island may be explored pending availability of the British autonomous underwater vehicle Autosub 3. These combined ocean-sea ice-atmosphere observations are aimed at a range of model validations. A well-defined plan for making data available as well as archiving in a timely fashion should facilitate a variety of modeling efforts and so extend the value of the spatially limited observations. <br/>Broader impacts: This project is relevant to an International Polar Year research emphasis on ice sheet dynamics focusing in particular on the seaward ocean-ice sheet interactions. Such interactions must be clarified for understanding the potential for sea level rise by melt of the West Antarctic ice Sheet. The project entails substantive international partnerships (British Antarctic Survey and Alfred Wegner Institute) and complements other Amundsen Sea Embayment Project proposals covering other elements of ice sheet dynamics. The proposal includes partial support for 2 graduate students and 2 post docs. Participants from the Antarctic Artists and Writers program are to take part in the cruise and so aid in outreach. In addition, the project is to be represented in the Lamont-Doherty annual open house.
1043421/Severinghaus<br/><br/>This award supports a project to obtain samples of ice in selected intervals for replication and verification of the validity and spatial representativeness of key results in the WAIS Divide ice core, and to obtain additional ice samples in areas of intense scientific interest where demand is high. The US Ice Core Working Group recommended in 2003 that NSF pursue the means to take replicate samples, termed "replicate coring". This recommendation was part of an agreement to reduce the diameter of the (then) new drilling system (the DISC drill) core to 12.2 cm to lighten logistics burdens, and the science community accepted the reduction in ice sample with the understanding that replicate coring would be able to provide extra sample volume in key intervals. The WAIS Divide effort would particularly benefit from replicate coring, because of the unique quality of the expected gas record and the large samples needed for gases and gas isotopes; thus this proposal to employ replicate coring at WAIS Divide. In addition, scientific demand for ice samples has been, and will continue to be, very unevenly distributed, with the ice core archive being completely depleted in depth intervals of high scientific interest (abrupt climate changes, volcanic sulfate horizons, meteor impact horizons, for example). The broader impacts of the proposed research may include identification of leads and lags between Greenland, tropical, and Antarctic climate change, enabling critical tests of hypotheses for the mechanism of abrupt climate change. Improved understanding of volcanic impacts on atmospheric chemistry and climate may also emerge. This understanding may ultimately help improve climate models and prediction of the Earth System feedback response to ongoing human perturbation in coming centuries. Outreach and public education about climate change are integral components of the PIs' activities and the proposed work will enhance these efforts. Broader impacts also include education and training of 2 postdoctoral scholars and 1 graduate student, and invaluable field experience for the graduate and undergraduate students who will likely make up the core processing team at WAIS Divide.
Time series data, from ocean moorings, on key aspects of evolving ocean properties are of considerable importance in assessing the condition of the ocean system. They are needed, for example, their understand how the oceans are warming, and how they continue to uptake greenhouse gases such as CO2. <br/><br/>The Cape Adare Long Term Mooring (CALM) program goal was to observe the bottom water export from the Ross Sea to the deep ocean. To accomplish this two instrumented moorings were set on the continental slope off Cape Adare (western Ross Sea, Antarctica), positioned to capture the export of Antarctic Bottom Water (AABW), some of the coldest and densest water found in the global ocean. Data records for the moorings spans over some four years in this very remote part of the ocean. The CALM analysis will address some specific objectives:<br/>? Characterize the temperature, salinity and current variability associated with the Ross Sea AABW export.<br/>? Examine the linkages between observed variability to regional tides, atmosphere and sea ice forcing.<br/>? Relate the Ross Sea AABW export fluctuations to the larger scale climate system dynamics, such as ENSO and SAM, and to AABW formation along other margins of Antarctica, e.g. the Weddell Sea
The stability of the marine West Antarctic Ice Sheet (WAIS) remains an important, unresolved problem for predicting future sea level change. Recent studies indicate that the mass balance of the ice sheet today may be negative or positive. The apparent differences may stem in part from short-term fluctuations in flow. By comparison, geologic observations provide evidence of behavior over much longer time scales. Recent work involving glacial-geologic mapping, dating and ice-penetrating radar surveys suggests that deglaciation of both the Ross Sea Embayment and coastal Marie Byrd Land continued into the late Holocene, and leaves open the possibility of ongoing deglaciation and grounding-line retreat. However, previous work in the Ross Sea Embayment was based on data from just three locations that are all far to the north of the present grounding line. Additional data from farther south in the Ross Sea Embayment are needed to investigate whether recession has ended, or if the rate and pattern of deglaciation inferred from our previous study still apply to the present grounding line. This award provides support to reconstruct the evolution of Reedy Glacier, in the southern Transantarctic Mountains, since the Last Glacial Maximum (LGM). Because Reedy Glacier emerges from the mountains above the grounding line, its surface slope and elevation should record changes in thickness of grounded ice in the Ross Sea up to the present day. The deglaciation chronology of Reedy Glacier therefore can indicate whether Holocene retreat of the WAIS ended thousands of years ago, or is still continuing at present. This integrated glaciologic, glacial-geologic, and cosmogenic-isotope exposure- dating project will reconstruct past levels of Reedy Glacier. Over two field seasons, moraines will be mapped, dated and correlated at sites along the length of the glacier. Radar and GPS measurements will be made to supplement existing ice thickness and velocity data, which are needed as input for a model of glacier dynamics. The model will be used to relate geologic measurements to the grounding-line position downstream. Ultimately, the mapping, dating and ice-modeling components of the study will be integrated into a reconstruction that defines changes in ice thickness in the southern Ross Sea since the LGM, and relates these changes to the history of grounding-line retreat. This work directly addresses key goals of the West Antarctic Ice Sheet Initiative, which are to understand the dynamics, recent history and possible future behavior of the West Antarctic Ice Sheet.
The albedo, or reflection coefficient, is a measure of the diffuse reflectivity of an irradiated surface. With the sunlit atmosphere as a light source, and sea-ice as a diffuse reflecting surface, the albedo would be the fraction of incident light that is returned to the atmosphere. A perfect (white) reflecting surface would have an albedo of 1; a perfect (black) absorbing surface would have an albedo of 0. The albedo of sea-ice is needed to assess the solar energy budget of the marginal ice zone, to compute the partial solar bands in radiation budgets in general circulation and earth system models, and is also needed to interpret remote sensing imagery data products.<br/>Applications requiring albedos further into the near IR, out to 2500nm, are assumed or approximated. Modern spectral radiometers, such as will be used in this campaign on a Southern Ocean voyage from Hobart to Antarctica, can extend these measurements of albedo from 350 to 2500nm, allowing earlier estimates to be verified, or corrected. <br/><br/>Surfaces to be encountered on this research cruise are expected to include open water, grease ice, nila ice, pancake ice, young grey ice, young grey-white ice, along with first year ice. The presence of variable amounts of snow on these surfaces is also of interest. Light absorbing impurities in the snow and ice, including black carbon and organic matter (brown carbon) are different from those found in Arctic Sea ice, the Antarctic being so remote from combustion sources. This may allow better understanding of the seasonal cycles, energy budgets and their recent trends in spatial extent and thickness. The project will also broaden the educational experiences of both US and Australian students participating in the measurement campaign
Collaborative With: McPhee 0732804, Holland 0732869, Truffer 0732730, Stanton 0732926, Anandakrishnan 0732844 <br/>Title: Collaborative Research: IPY: Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica<br/><br/>The Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. <br/><br/>Broader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the "Multidisciplinary Study of the Amundsen Sea Embayment" proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded "Polar Palooza" education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project.
This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.
The mesosphere and lower thermosphere (MLT), at an altitude between 80 and 120 km above the Earth's surface, is a highly dynamic region that couples the lower terrestrial atmosphere (troposphere and stratosphere) with the upper atmosphere near-Earth space environment (thermosphere and ionosphere). Of particular importance in this region are both the upward propagating thermally forced atmospheric tides and global scale planetary waves. Both of these phenomena transport heat and momentum from the lower atmosphere into the upper atmosphere. Studies in recent years have indicated that the Arctic and Antarctic MLT possess a rich spectrum waves and may be more sensitive to global change than the lower atmosphere. The primary goal of this research is to observe, quantify, model, and further understand the spatial-temporal structure and variability of the MLT circulation above Antarctica and its commonalities with the Arctic. A secondary goal is to quantify and understand the deposition of mass into the upper atmosphere through the ablation of meteors and the resulting effect on local and regional aeronomic processes. This includes the effect of meteor flux, temperature and dynamics on the seasonal distribution of sodium over the South Pole. Meteor radar was installed at the South Pole Amundsen-Scott station and has been running continuously since January 2002. A new sodium nightglow imager will be installed at the South Pole to infer the sodium abundance in the MLT. Observations from this instrument will be combined with the South Pole Fabry-Perot interferometer temperature measurements and the meteor radar wind and meteor flux measurements to improve our understanding of the sodium chemistry and dynamics. These observations will be interpreted using sophisticated numerical models and interpreted in conjunction with Arctic measurements along with current linear and nonlinear atmospheric models to advance the current understanding of processes important to the MLT region. This research also contributes to the training and education of the graduate and undergraduate students, a postdoc and early career tenure track faculty.
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 use the WAIS Divide deep core to investigate the Last Deglaciation at sub-annual resolution through an integrated set of chemical and biological analyses. The intellectual merit of the project is that these analyses, combined with others, will take advantage of the high snow accumulation WAIS Divide site yielding the highest time resolution glacio-biogeochemical and gas record of any deep Antarctic ice core. With other high resolution Greenland cores (GISP2 and GRIP) and lower resolution Antarctic cores, the combined record will yield new insights into worldwide climate dynamics and abrupt change. The proposed chemical, biological, and elemental tracer measurements will also be used to address all of the WAIS Divide science themes. The broader impacts of the project include education and outreach activities such as numerous presentations to local K-12 students; opportunities for student and teacher involvement in the laboratory work; a teacher training program in Earth sciences in the heavily minority Santa Ana, Compton, and Costa Mesa, California school districts; and development of high school curricula. Extensive graduate and undergraduate student involvement also is planned and will include one post doctoral associate, one graduate student, and undergraduate hourly involvement at DRI; a graduate student and undergraduates at University of California, Irvine (UCI); and a post doctoral fellow at MSU. Student recruitment will be made from underrepresented groups building on a long track record of involvement and will include the NSF funded California Alliance for Minority Participation (CAMP) and the Montana American Indian Research Opportunities (AIRO).<br/><br/>This award does not involve field work in Antarctica.
Intellectual Merit: <br/>Diatom abundance in sediment cores is typically used as a proxy for paleo primary productivity. This record is complicated by variable preservation, with most loss occurring in the water column via dissolution and zooplankton grazing. This study will investigate preservational biases via a series of controlled experiments to create proxies of original productivity based on morphological changes associated with diatom dissolution and fracture. The PIs will utilize fresh diatoms from culture. Specific objectives include: (1) Linking changes in diatom morphology to availability of dissolved silica and other physical and chemical parameters; (2) Documenting the dissolution process under controlled conditions; (3) Assessment of changes in morphology and diatom surface roughness with increased dissolution; (4) Documenting the physical effects of grazing and fecal pellet formation on diatom fragmentation and dissolution; and (5) Analyzing the impact of diatom dissolution on silica and carbon export. These objectives will be achieved by growing Southern Ocean diatom species in the laboratory under differing physical and chemical conditions; controlled serial dissolution experiments on cultured diatoms; analysis of the dissolution process by imaging frustules under scanning electron microscopy (SEM) and with micro-analysis of surface texture by atomic force microscopy (AFM); making the cultures available to krill and other live zooplankton crustaceans in order to analyze the specific effects of grazing and pelletization on diatom morphology; and comparing experimental results with natural plankton, sediment trap material, and selected Holocene, Pleistocene and Pliocene sediment core material. <br/><br/>Broader impacts: <br/>This work will contribute to understanding of the use of diatom abundance as an indicator of paleoproductivity. The proposed experiments are multi-disciplinary in nature. Importantly, the project was designed, and the proposal largely written, by a Ph.D. candidate. The research proposed here will lead to peer-reviewed publications and provide a base for future studies over the course of an extremely promising scientific career. The project will also support an undergraduate research student at NIU. The PI is heavily involved in science outreach, including classroom visits, museum events and webinars related to evolution and climate change, and is active with NSF-funded outreach activities linked to the ANDRILL and WISSARD programs. He will continue these efforts with this project.
The climatic changes of late Precambrian time, 600-800 million years ago, included episodes of extreme glaciation, during which ice may have covered nearly the entire ocean for several million years, according to the Snowball Earth hypothesis. These episodes would hold an important place in Earth?s evolutionary history; they could have encouraged biodiversity by trapping life forms in small isolated ice-free areas, or they could have caused massive extinctions that cleared the path for new life forms to fill empty niches. What caused the Earth to become iced over, and what later caused the ice to melt? Scientific investigation of these questions will result in greater understanding of the climatic changes that the Earth can experience, and will enable better predictions of future climate. This project involves Antarctic field observations as well as laboratory studies and computer modeling.<br/><br/>The aim of this project is not to prove or disprove the Snowball Earth hypothesis but rather to quantify processes that are important for simulating snowball events in climate models. The principal goal is to identify the types of ice that would have been present on the frozen ocean, and to determine how much sunlight they would reflect back to space. Reflection of sunlight by bright surfaces of snow and ice is what would maintain the cold climate at low latitudes. The melting of the ocean required buildup of greenhouse gases, but it was probably aided by deposition of desert dust and volcanic ash darkening the snow and ice. With so much ice on the Earth?s surface, even small differences in the amount of light that the ice absorbed or reflected could cause significant changes in climate. The properties of the ice would also determine where, and in what circumstances, photosynthetic life could have survived. Some kinds of ice that are rare on the modern Earth may have been pivotal in allowing the tropical ocean to freeze. The ocean surfaces would have included some ice types that now exist only in Antarctica: bare cold sea ice with precipitated salts, and "blue ice" areas of the Transantarctic Mountains that were exposed by sublimation and have not experienced melting. Field expeditions were mounted to examine these ice types, and the data analysis is underway. A third ice type, sea ice with a salt crust, is being studied in a freezer laboratory. Modeling will show how sunlight would interact with ice containing light-absorbing dust and volcanic ash. Aside from its reflection of sunlight, ice on the Snowball ocean would have been thick enough to flow under its own weight, invading all parts of the ocean. Yet evidence for the survival of photosynthetic life indicates that some regions of liquid water were maintained at the ocean surface. One possible refuge for photosynthetic organisms is a bay at the far end of a nearly enclosed tropical sea, formed by continental rifting and surrounded by desert, such as the modern Red Sea. A model of glacier flow is being developed to determine the dimensions of the channel, connecting the sea to the ocean, necessary to prevent invasion by the flowing ice yet maintain a water supply to replenish evaporation.
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. <br/>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.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The high elevations of East Antarctica are critical in localizing the initial Cenozoic glaciation and stabilizing it with respect to melting during warm interglacials. However, the geological history for this region and the geophysical mechanism for maintaining the highlands are poorly understood. In 2007-2009, an array of 24 broadband seismographs (named GAMSEIS) was installed across the Gamburtsev Mountains area of the East Antarctic Plateau as part of the Antarctica?s Gamburtsev Province (AGAP) International Polar Year project. The IPY AGAP/GAMSEIS program included plans by other international partners to install seismographs at locations along the flanks of the Gamburtsev Mountains and in other East Antarctic regions. The proposed project will continue operating six of the deployed AGAP/GAMSEIS stations for two more years together with two new broadband seismic stations added to broaden the geographic scope of the array. Most stations will be located at the existing U.S. Autonomous Geophysical Observatories and the USAP fuel cache locations in order to minimize logistical support. This array, combined with seismographs deployed by China and Japan (and possibly Australia, France, and Italy in near future) will provide a sparse but large-scale network of seismometers for the longer-term studies of the crustal and upper mantle structures underneath the East Antarctic Plateau. Continued reliance on students provides a broader impact to this proposed research and firmly grounds this effort in its educational mission.
Rice, James; Platt, John; Suckale, Jenny; Perol, Thibaut; Tsai, Victor
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Rice 0739444<br/><br/>This award supports a project to study the mode of formation and causes of glacial earthquakes. The paradigm for glacial flow has been that glaciers flow in a viscous manner, with major changes in the force balance occurring on the decade timescale or longer. The recent discovery of a number of even shorter timescale events has challenged this paradigm. In 2003, it was discovered that Whillans Ice Stream in West Antarctica displays stick-slip behavior on the 10-30 minute timescale, with ice stream speed increasing by a factor of 30 from already high speeds. In the past year, the minimum timescale has been pushed shorter by recognition that a class of recently discovered 50-second-long, magnitude-5 earthquakes are closely associated with changes in the force balance near the calving fronts of large outlet glaciers in both Greenland and East Antarctica. With no adequate theory existing to explain these relatively large earthquakes associated with outlet glaciers, we have begun to investigate the physical mechanisms that must be involved in allowing such a response in a system traditionally not thought capable of generating large variations in forces over timescales less than 100 seconds. The intellectual merit of the work is that large-amplitude, short-timescale variability of glaciers is an important mode of glacier dynamics that has not yet been understood from a first-principles physics perspective. The proposed research addresses this gap in understanding, tying together knowledge from numerous disciplines including glaciology, seismology and fault rupture dynamics, laboratory rock physics, granular flow, fracture mechanics, and hydrogeology. The broader impacts of the work are that there is societal as well as general scientific interest in the stability of the major ice sheets. However, without an understanding of the physical processes governing short time scale variability, it is unlikely that we will be able accurately predict the future of these ice sheets and their impact on sea level changes. The project will also contribute to the development and education of young scientists.
Joughin 0631973<br/><br/>This award supports a project to gather data to better understand the mass balance of the West Antarctic Ice Sheet, in the Pine Island and Thwaites region, through the combination of radar altimetry and surface-based ice-core measurements of accumulation. The intellectual merit of the project is that the results of the field work will provide information on decadal-scale average accumulation extending back through the last century and will help constrain a modeling effort to determine how coastal changes propagate inland, to allow better prediction of future change. Comparison of the basin averaged accumulation with ice discharge determined using Interferometric Synthetic Aperture Radar (InSAR) velocity data will provide improved mass-balance estimates. Study of changes in flow speed will produce a record of mass balance over the last three decades. Analysis of the satellite altimeter record in conjunction with annual accumulation estimates also will provide estimates of changes and variability in mass balance. The broader impacts of the work are that it will make a significant contribution to future IPCC estimates of sea level, which are important for projection of the impacts of increased sea level on coastal communities. The research will contribute to the graduate education of students at the Universities of Washington and Kansas and will enrich K-12 education through the direct participation of the PIs in classroom activities. Informal science education includes 4-day glacier flow demonstrations at the Polar Science Weekend held annually at the Pacific Science Center in Seattle. The project also will communicate results through Center for the Remote Sensing of Ice Sheets (CReSIS) outreach effort. All field and remotely-sensed data sets will be archived and distributed by the National Snow and Ice Data Center. This project is relevant to IPY in that the West Antarctic Ice Sheet is losing mass, in large part because of rapid thinning of the Amundsen Coast glaciers so, it will directly address the NSF IPY emphasis on "ice sheet history and dynamics." The project is also international in scope.
This award supports a project that is part of the West Antarctic Ice Sheet Divide (WAIS Divide) program; which is a multi-disciplinary multi-institutional program to investigate the causes of natural changes in climate, the influence of the West Antarctic ice sheet on sea level, and the biology of deep ice. The WAIS Divide core will be unique among Antarctic ice cores in that it will have discernable annual layers for the last 40,000 years. A critical element of the program is to determine the age of the ice so that the climate proxies measured on the core can be interpreted in terms of age, not just depth. This project will make electrical measurements that can identify the annual layers. This information will be combined with information from other investigators to develop an annually resolved timescale over the last 40,000 years. This timescale will be the foundation on which the recent climate records are interpreted. Electrical measurements will also be used to produce two-dimensional images of the ice core stratigraphy; allowing sections of the core with abnormal stratigraphy to be identified. The broader impacts of this project include exposing a diverse group of undergraduate and graduate students to ice core research and assisting the Smithsonian National Museum of Natural History in Washington, D.C to develop a paleoclimate/ice core display.
Waddington/0636997<br/><br/>This award supports a project to integrate three lines of glaciology research, previously treated independently. First, internal layers in ice sheets, detected by ice-penetrating radar, retain information about past spatial and temporal patterns of ice accumulation. Ice-flow modelers can recover this information, using geophysical inverse methods; however, the ages of the layers must be known, through interpolation where they intersect a well-dated ice core. <br/>Second, concentrations of methane and some other atmospheric constituents vary through time as climate changes. However, the atmosphere is always well mixed, and concentrations are similar world-wide at any one time, so gas variations from an undated core can be correlated with those in a well-dated core such as GISP2. Because air in near-surface firn mixes readily with the atmosphere above, the air that is trapped in bubbles deep in the firn is typically hundreds to thousands of years younger than that firn. Gas geochemists must calculate this age difference, called delta-age, with a firn-densification model before the ice enclosing the gas can be dated accurately. To calculate delta-age, they must know the temperature and the snow accumulation rate at the time and place where the snow fell. Third, gases can be correlated between cores only at times when the atmosphere changed, so ice-core dates must be interpolated at depths between the sparse dated points. Simplistic interpolation schemes can create undesirable artifacts in the depth-age profile. The intellectual merit of this project is that it will develop new interpolation methods that calculate layer thinning over time due to ice-flow mechanics. Accurate interpolation also requires a spatial and temporal accumulation history. These three issues are coupled through accumulation patterns and ice-core dates. This project will develop an integrated inversion procedure to solve all three problems simultaneously. The new method will incorporate ice-penetrating radar profile data and ice-core data, and will find self-consistent: spatial/temporal accumulation patterns; delta-age profiles for ice cores; and reliably interpolated depth-age profiles. The project will then: recalculate the depth-age profile at Byrd Station, Antarctica; provide a preliminary depth-age at the West Antarctic Ice Sheet (WAIS) in the initial stages of drilling, using radar layers with estimated ages traced from Byrd Station; and generate a self-consistent depth-age relationship for Taylor Dome, Antarctica over the past 20ka, where low accumulation has created uncertainty in dating, accumulation, and controversy over delta-age estimates. The broader impacts of the project are that it will support the PhD research of a female graduate student, and her continued outreach work with Making Connections, a non-profit program through the University of Washington Women's Center, which matches professional women mentors with minority high-school women interested in mathematics and science, disciplines where they are traditionally under-represented. The graduate student will also work with Girls on Ice, a ten-day glacier field program, taught by women scientist instructors, emphasizing scientific observation through immersion, leadership skills and safety awareness.
Winckler/0636898<br/><br/>This award supports a project to study dust sources in Antarctic ice cores. Atmospheric aerosols play an important role both in global biogeochemical cycles as well as in the climate system of the Earth. Records extracted from Antarctic ice cores inform us that dust deposition from the atmosphere to the ice sheet was 15-20 times greater during glacial periods than during interglacials, which raises the possibility that dust may be a key player in climate change on glacial-interglacial timescales. By characterizing potential source areas from South America, South Africa, and Australia as well as fresh glacial flour from Patagonia, the project will determine if the interglacial dust was mobilized from a distinct geographical region (e.g., Australia) or from a more heavily weathered source region in South America. The intellectual merit of the project is that it will contribute to reconstructing climate-related changes in the rate of dust deposition, and in the provenance of the dust, it will provide critical constraints on hydrology and vegetation in the source regions, as well as on the nature of the atmospheric circulation transporting dust to the archive location. In a recent pilot study it was found that there is a dramatic glacial to Holocene change in the 4He/Ca ratio in the dust extracted from ice from Dronning Maud Land, Antarctica, indicating a shift in the source of dust transported to Antarctica. The broader impacts of the project are that Helium isotopes and calcium measurements provide a wealth of information that can then be turned into critical input for dust-climate models. Improved models, which are able to accurately reconstruct paleo dust distribution, will help us to predict changes in dust in response to future climate variability. This information will contribute to an improvement of our integrated understanding of the Earth's climate system and, in turn, will better inform policy makers of those processes and conditions most susceptible to perturbation by climate change, thereby leading to more meaningful climate-change policy. The project will support a graduate student in the dual masters Earth and Environmental Science Journalism program. The lead-PI manages the rock noble gas laboratory at Lamont. Her leadership role in this facility impacts the training of undergraduate and graduate students as well as visiting scientists.
Polar oceans are the main sites of deep-water formation and are critical to the exchange of heat and carbon between the deep ocean and the atmosphere. This award ?Historic perspectives on climate and biogeography from deep-sea corals in the Drake Passage? will address the following specific research questions: What was the radiocarbon content of the Southern Ocean during the last glacial maximum and during past rapid climate change events? and What are the major controls on the past and present distribution of cold-water corals within the Drake Passage and adjacent continental shelves? Testing these overall questions will allow the researchers to better understand how processes in the Southern Ocean are linked to climate change over millennia. This award is being funded by the Antarctic Earth Sciences Program of NSF?s Office of Polar Programs, Antarctic Division. <br/><br/>INTELLECTUAL MERIT: The skeletons of deep-sea corals are abundant in the Southern Ocean, and can be dated using U-series techniques making them a useful archive of oceanographic history. By pairing U-series and radiocarbon analyses the awardees can reconstruct the radiocarbon content of seawater in the past, allowing them to address the research questions raised above. Collection of living deep-sea corals along with environmental data will allow them to address the broader biogeography questions posed above as well. The awardees are uniquely qualified to answer these questions in their respective labs via cutting edge technologies, and they have shown promising results from a preliminary pilot cruise to the area in 2008.<br/><br/>BROADER IMPACTS: Societal Relevance: The proposed paleoclimate research will make significant advances toward constraining the Southern Ocean?s influence on global climate, specifically it should help set the bounds for the upper limits on how fast the ocean circulation might change in this region of the world, which is of high societal relevance in this era of changing climate. Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating undergraduate through post-doctoral students into research programs; ii) promotion of K-12 teaching and learning programs by providing information via a cruise website and in-school talks, iii) making the data collected available to the wider research community via data archives such as Seamounts Online and the Seamount Biogeographic Network and iv) reaching a larger public audience through such venues as interviews in the popular media.
Hall/0636687<br/><br/>This award supports a project to investigate late Pleistocene and Holocene changes in Scott Glacier, a key outlet glacier that flows directly into the Ross Sea just west of the present-day West Antarctic Ice Sheet (WAIS) grounding line. The overarching goals are to understand changes in WAIS configuration in the Ross Sea sector at and since the last glacial maximum (LGM) and to determine whether Holocene retreat observed in the Ross Embayment has ended or if it is still ongoing. To address these goals, moraine and drift sequences associated with Scott Glacier will be mapped and dated and ice thickness, surface velocity and surface mass balance will be measured to constrain an ice-flow model of the glacier. This model will be used to help interpret the dated geologic sequences. The intellectual merit of the project relates to gaining a better understanding of the West Antarctic Ice Sheet and how changing activity of fast-flowing outlet glaciers and ice streams exerts strong control on the mass balance of the ice sheet. Previous work suggests that grounding-line retreat in the Ross Sea continued into the late Holocene and left open the possibility of ongoing deglaciation as part of a long-term trend. Results from Reedy Glacier, an outlet glacier just behind the grounding line, suggest that retreat may have slowed substantially over the past 2000 years and perhaps even stopped. By coupling the work on Scott Glacier with recent data from Reedy Glacier, the grounding-line position will be bracketed and it should be possible to establish whether the retreat has truly ended or if it is ongoing. The broader impacts of the work relate to the societal relevance of an improved understanding of the West Antarctic ice sheet to establish how it will respond to current and possible future environmental changes. The work addresses this key goal of the West Antarctic Ice Sheet Initiative, as well as the International Polar Year focus on ice sheet history and dynamics. The work will develop future scientists through the education and training of one undergraduate and two Ph.D. students, interaction with K-12 students through classroom visits, web-based 'expedition' journals, letters from the field, and discussions with teachers. Results from this project will be posted with previous exposure dating results from Antarctica, on the University of Washington Cosmogenic Nuclide Lab website, which also provides information about chemical procedures and calculation methods to other scientists working with cosmogenic nuclides.
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.
During previous NSF-sponsored research, the PI's discovered that southern elephant seal colonies once existed along the Victoria Land coast (VLC) of Antarctica, a region where they are no longer observed. Molted seal skin and hair occur along 300 km of coastline, more than 1000 km from any extant colony. The last record of a seal at a former colony site is at ~A.D. 1600. Because abandonment occurred prior to subantarctic sealing, disappearance of the VLC colony probably was due to environmental factors, possibly cooling and encroachment of land-fast, perennial sea ice that made access to haul-out sites difficult. The record of seal inhabitation along the VLC, therefore, has potential as a proxy for climate change. Elephant seals are a predominantly subantarctic species with circumpolar distribution. Genetic studies have revealed significant differentiation among populations, particularly with regard to that at Macquarie I., which is the extant population nearest to the abandoned VLC colony. Not only is the Macquarie population unique genetically, but it is has undergone unexplained decline of 2%/yr over the last 50 years3. In a pilot study, genetic analyses showed a close relationship between the VLC seals and those at Macquarie I. An understanding of the relationship between the two populations, as well as of the environmental pressures that led to the demise of the VLC colonies, will provide a better understanding of present-day population genetic structure, the effect of environmental change on seal populations, and possibly the reasons underlying the modern decline at Macquarie Island.<br/>This project addresses several key research problems: (1) Why did elephant seals colonize and then abandon the VLC? (2) What does the elephant seal record reveal about Holocene climate change and sea-ice conditions? (3) What were the foraging strategies of the seals and did these strategies change over time as climate varied? (4) How does the genetic structure of the VLC seals relate to extant populations? (5) How did genetic diversity change over time and with colony decline? (6) Using ancient samples to estimate mtDNA mutation rates, what can be learned about VLC population dynamics over time? (7) What was the ecological relationship between elephant seals and Adelie penguins that occupied the same sites, but apparently at different times? The proposed work includes the professional training of young researchers and incorporation of data into graduate and undergraduate courses.
This award supports a project to examine the stratigraphy of near-surface sediments in Taylor Valley, Antarctica. Two contrasting hypotheses have been proposed for surface sediments in lower Taylor Valley, which have important and very different implications for how the West Antarctic Ice Sheet (WAIS) responded to the sea-level rise of the last deglaciation and Holocene environmental changes. One hypothesis holds that the sediments, designated Ross I drift, directly reflect >10,000 14C-years of WAIS shrinkage in the Ross Sea during and perhaps driven by deglacial sea-level rise. The other hypothesis, holds that the Taylor sediments have little significance for WAIS change during the deglaciation. These two hypotheses reflect fundamentally different interpretations of the sediment record. Over the course of two field seasons and a third year at the home institutions, the project will test these two hypotheses using glacial geology, geochemistry, ground penetrating radar (GPR) at both 100 MHz and 400 MHz, and portable sediment coring. The intellectual merit of the proposed work is that it will test these two hypotheses and make novel use of the subsurface record that may result in new insights into WAIS sensitivity during the deglaciation. The study will also directly test the conclusion that Glacial Lake Washburn was much larger than previously proposed during the Last Glacial Maximum (LGM). This occurrence, if real, represents a stunning climate anomaly. Answers to these local ice sheet and lake questions directly pertain to larger scale issues concerning the influences of sea-level rise, climate change, and internal ice-sheet dynamics on the recession of the WAIS since the LGM. There are numerous broader impacts to this project. Understanding the glacial and lake history in the McMurdo Sound region has important implications for the role that the WAIS will play in future sea-level and global climate change. Moreover, the history of Taylor Valley has significance for the ecosystem studies currently being conducted by the LTER group. Lastly, during the course of the proposed research, the project will train two graduate and undergraduate students and the research will be featured prominently in the teaching of students.
ANT-0742818, PI: John M. Kovac, California Institute of Technology<br/>ANT-0742592, PI: Clement L. Pryke, University of Chicago<br/>Collaborative Research: BICEP2 and SPUD - A Search for Inflation with Degree-Scale Polarimetry from the South Pole<br/><br/>The proposed work is a four-year program of research activities directed toward upgrading the BICEP (Background Imaging of Cosmic Extragalactic Polarization) telescope operating at South Pole since early 2006 to reach far =stretching goals of detection of the Cosmic Gravitational-wave Background (CGB) . This telescope is a first Cosmic Microwave Background (CMB) B-mode polarimeter, specifically designed to search for CGB signatures while mapping ~2% of the southern sky that is free of the Milky Way foreground galactic radiation at 100 GH and 150 GHz. The BICEP1 telescope will reach its designed sensitivity by the end of 2008. A coordinated series of upgrades to BICEP1 will provide the increased sensitivity and more exacting control of instrumental effects and potential confusion from galactic foregrounds necessary to search for the B-mode signal more deeply through space. A powerful new 150 GHz receiver, BICEP2, will replace the current detector at the beginning of 2009, increasing the mapping speed almost ten-fold. In 2010, the first of a series of compact, mechanically-cooled receivers (called SPUD - Small Polarimeter Upgrade for DASI) will be deployed on the existing DASI mount and tower, providing similar mapping speed at 100 GHz in parallel with BICEP2. The latter instrument will reach (and exceed with the addition of a SPUD polarimeter) the target sensitivity r = 0.15 set forth by the Interagency (NSF/NASA/DoE) Task Force on CMB Research for a future space mission dedicated to the detection and characterization of primordial gravitational waves. This Task Force has identified detection of the Inflation's gravitational waves as the number one priority for the modern cosmology. More broadly, as the cosmology captures a lot of the public imagination, it is a remarkably effective vehicle for stimulating interest in basic science. The CGB detection would be to Inflation what the discovery of the CMB radiation was to the Big Bang. The project will contribute to the training of the next generation of cosmologists by integrating graduate and undergraduate education with the technology and instrumentation development, astronomical observations and scientific analysis. Sharing of the forefront research results with public extends the new knowledge beyond the universities. This project will be undertaken in collaboration between the California Institute of Technology and the University of Chicago.
ACT K. Mopper & D. Kieber OPP 9527255 & OPP 9527314 PHOTOCHEMICAL AND OPTICAL PROPERTIES OF ANTARCTIC WATERS IN RESPONSE TO CHANGING UV-B FLUXES The decrease in stratospheric ozone over the Antarctic results in an increase in the UV-B flux in the euphotic zone. The increase leads to cellular damage to aquatic organisms, as documented by photo-inhibition and decreased productivity. Cellular damage can occur either intracellularly, or externally at the cell surface from biomolecular reactions with externally-generated reactive transients. The extent of this extracellular damage will depend on the photochemistry of the seawater surrounding the cell. Until recently, nothing was known about the type of photochemical processes, rates, and steady state concentrations of transients in Antarctic waters. It is proposed that field experiments be performed which will allow the construction of predictive models of photochemical production rates in surface waters and with depth. These studies will involve further quantum yield measurementts, development of a sensitive underwater actinometer system, and use of a new underwater multichannel photometer. The model will allow the prediction of the impact of varying levels of UV-B on the photoproduction and steady state concentration of several key reactive transient species in the upper water column. In addition to this effort, experiments will also be performed to study the photodegradation of dissolved organic matter and to determine whether biologically utilizable substrates that are formed photochemically can enhance secondary productivity in Antarctic waters.
This project is an investigation into one mechanism by which deep ocean convection can evolve from stable initial conditions, to the extent that it becomes well enough established to bring warm water to the surface and melt an existing ice cover in late, or possibly even mid-winter. The specific study will investigate how the non-linear dependence of seawater density on temperature and salinity (the equation of state) can enhance vertical convection under typical antarctic conditions. When layers of seawater with similar densities but strong contrasts in temperature and salinity interact, there are a number of possible non-linear instabilities that can convert existing potential energy to turbulent energy. In the Weddell Sea, a cold surface mixed layer is often separated from the underlying warm, more saline water by a thin, weak pycnocline, making the water column particularly susceptible to an instability associated with thermobaricity (the pressure dependence of the thermal expansion coefficient). The project is a collaboration between New York University, Earth and Space Research, the University of Washington, the Naval Postgraduate School, and McPhee Research Company.<br/>The work has strong practical applications in contributing to the explanation for the existence of the Weddell Polynya, a 300,000 square kilometer area of open water within the seasonal sea ice of the Weddell Sea, from approximately 1975 to 1979. It has not recurred since, although indications of much smaller and less persistent areas of open water do occur in the vicinity of the Maud Rise seamount. <br/> The experimental component will be carried out on board the RVIB Nathaniel B. Palmer between July and September, 2005.
Luyendyk et.al.: OPP 0088143<br/>Bartek: OPP 0087392<br/>Diebold: OPP 0087983<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program in marine geology and geophysics in the southern central and eastern Ross Sea. The project will conduct sites surveys for drilling from the Ross Ice Shelf into the seafloor beneath it. Many of the outstanding problems concerning the evolution of the East and West Antarctic Ice Sheets, Antarctic climate, global sea level, and the tectonic history of the West Antarctic Rift System can be addressed by drilling into the seafloor of the Ross Sea. Climate data for Cretaceous and Early Cenozoic time are lacking for this sector of Antarctica. Climate questions include: Was there any ice in Late Cretaceous time? What was the Antarctic climate during the Paleocene-Eocene global warming? When was the Cenozoic onset of Antarctic glaciation, when did glaciers reach the coast and when did they advance out onto the margin? Was the Ross Sea shelf non-marine in Late Cretaceous time; when did it become marine? Tectonic questions include: What was the timing of the Cretaceous extension in the Ross Sea rift; where was it located? What is the basement composition and structure? Where are the time and space limits of the effects of Adare Trough spreading? Another drilling objective is to sample and date the sedimentary section bounding the mapped RSU6 unconformity in the Eastern Basin and Central Trough to resolve questions about its age and regional extent. Deep Sea Drilling Project (DSDP) Leg 28 completed sampling at four drill sites in the early 1970's but had low recovery and did not sample the Early Cenozoic. Other drilling has been restricted to the McMurdo Sound area of the western Ross Sea and results can be correlated into the Victoria Land Basin but not eastward across basement highs. Further, Early Cenozoic and Cretaceous rocks have not been sampled. A new opportunity is developing to drill from the Ross Ice Shelf. This is a successor program to the Cape Roberts Drilling Project. One overriding difficulty is the need for site surveys at drilling locations under the ice shelf. This project will overcome this impediment by conducting marine geophysical drill site surveys at the front of the Ross Ice Shelf in the Central Trough and Eastern Basin. The surveys will be conducted a kilometer or two north of the ice shelf front where recent calving events have resulted in a southerly position of the ice shelf edge. In several years the northward advance of the ice shelf will override the surveyed locations and drilling could be accomplished. Systems to be used include swath bathymetry, gravity, magnetics, chirp sonar, high resolution seismic profiling, and 48 fold seismics. Cores will be collected to obtain samples for geotechnical properties, to study sub-ice shelf modern sedimentary processes, and at locations where deeper section is exposed.<br/><br/>This survey will include long profiles and detailed grids over potential drill sites. Survey lines will be tied to existing geophysical profiles and DSDP 270. A recent event that makes this plan timely is the calving of giant iceberg B-15 (in March, 2000) and others from the ice front in the eastern Ross Sea. This new calving event and one in 1987 have exposed 16,000 square kilometers of seafloor that had been covered by ice shelf for decades and is not explored. Newly exposed territory can now be mapped by modern geophysical methods. This project will map geological structure and stratigraphy below unconformity RSU6 farther south and east, study the place of Roosevelt Island in the Ross Sea rifting history, and determine subsidence history during Late Cenozoic time (post RSU6) in the far south and east. Finally the project will observe present day sedimentary processes beneath the ice shelf in the newly exposed areas.
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.
This project is a two-year investigation into the dynamics and processes of deep water mass formation in the western Weddell Sea, combining physical and chemical oceanographic techniques to produce a coherent picture of the importance of this unique region to the structure of the world ocean. In the global context, this area is a major water mass modification site, involving open ocean convective events, the continental margin, and the ice cover. At this time the various water types that combine to form Weddell Sea Deep Water and Antarctic Bottom Water, and the conditions under which these water masses form, are not known well enough to establish direct physical links and volumetric budgets. It is suspected that the outflow from the Weddell Sea is restricted to quite narrow boundary currents flowing near the base of the continental shelf, and consequently may be observed with conventional current meter moorings from the shelf into the deep ocean. Two oceanographic expeditions to the western Weddell Sea are planned as part of this study: the first in the 1990/91, and the second in 1991/92. The objectives will be to measure the flow of newly-formed bottom water and to explore the sinking process of near-surface waters in the open ocean to see how these affect the deep water flows. In the first year the primary objective will be to set out an array of eight current meters in the bottom water core, while a secondary objective will be to grapple for an existing array that was set out in early 1988 but could not be recovered in 1989 because Antarctic Program ship resources had to be diverted to deal with the oil spill at Palmer Station. In the second year the array will be retrieved. Hydrographic cruises in order to define the upper ocean temperatures and salinity structure in the outflow region where unusually large step structures have been found in the past. A chemistry program consistent with the objectives of the World Ocean Circulation Experiment (WOCE) and presently planned experiments in the South Atlantic Ocean, will be integrated into the cruises carried out under this project.
9815961 <br/>BENGTSON<br/>The pack ice region surrounding Antarctica contains at least fifty percent of the world's population of seals, comprising about eighty percent of the world's total pinniped biomass. As a group, these seals are among the dominant top predators in Southern Ocean ecosystems, and the fluctuation in their abundance, growth patterns, life histories, and behavior provide a potential source of information about environmental variability integrated over a wide range of spatial and temporal scales. This proposal was developed as part of the international Antarctic Pack Ice Seals (APIS) program, which is aimed to better understand the ecological relationships between the distribution of pack ice seals and their environment. During January-February, 2000, a research cruise through the pack ice zone of the eastern Ross Sea and western Amundsen Sea will be conducted to survey and sample along six transects perpendicular to the continental shelf. Each of these transects will pass through five environmental sampling strata: continental shelf zone, Antarctic slope front, pelagic zone, the ice edge front, and the open water outside the pack ice zone. All zones but open water will be ice-covered to some degree. Surveys along each transect will gather data on bathymetry, hydrography, sea ice dynamics and characteristics, phytoplankton and ice algae stocks, prey species (e.g., fish, cephalopods and euphausiids), and seal distribution, abundance and diet. This physical and trophic approach to investigating ecological interactions among pack ice seals, prey and the physical environment will allow the interdisciplinary research team to test the hypothesis that there are measurable physical and biological features in the Southern Ocean that result in area of high biological activity by upper trophic level predators. Better insight into the interplay among pack ice seals and biological and physical features of Antarctic marine ecosystems will allow for a better prediction of fluctuation in seal population in the context of environmental change.
This award, provided jointly by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research to transform three temporary seismometers in the Antarctic Peninsula into semi-permanent stations and to continue basic research using these data. During 1997 and 1998, a network of 11 broadband seismographs in the Antarctic Peninsula region and southernmost Chilean Patagonia were installed and maintained. Data return from this project has been excellent and interesting initial results have been produced. The continued operation of these instruments over a longer time period would be highly beneficial because the number of larger magnitude regional earthquakes is small and so a longer time is needed to acquire data. However, instruments from this project are borrowed from the IRIS-PASSCAL instrument pool and must be returned to PASSCAL in April, 1999. This award provides funds to convert three stations at permanent Chilean bases in the Antarctic to permanent stations, and to continue the seismological investigation of the region for a period of four years. As part of this project, a fourth station, in Chilean Patagonia, will continue to be operated using Washington University equipment. The funding of this project will enable continued collaboration between Washington University and the Universidad de Chile in the operation of these stations, and the data will be forwarded to the IRIS data center as well as to other international seismological collaborators. Mutual data exchanges with other national groups with Antarctic seismology research programs will provide access to broadband data from a variety of other proprietary broadband stations in the region. The data will be used to study the seismicity and upper mantle velocity structure of several complicated tectonic regions in the area, including the South Shetland subduction zone, the Bransfield backarc rift, and diffuse plate boundaries in Patagonia, Drake Passage, and along the South Scotia Ridge. In particular, the operation of these stations over a longer time period will allow a better understanding of the seismicity of the South Shetland Trench, an unusual subduction zone showing very slow subduction of young lithosphere. These seismometers will also be used to record airgun shots during a geophysical cruise in the Bransfield Strait that is being planned by the University of Texas for April, 2000. These data will provide important constraints on the crustal structure beneath the stations, and the improved structural models will enable implementation of more precise earthquake location procedures in support of a seismological understanding of the region.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.
9908828<br/>Aronson<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a paleoecological and paleoenvironmental study of Seymour Island. Global climate change late in the Eocene epoch had an important influence in Antarctica. This was the beginning of the transition from a cool-temperate climate in Antarctica to the polar climate that exists there today. The cooling trend strongly influenced the structure of shallow-water, Antarctic marine communities, and these effects are still evident in the peculiar ecological relationships among species living in modern Antarctic communities. Cooling late in the Eocene reduced the abundance of fish and crabs, which in turn reduced skeleton-crushing predation on invertebrates. Reduced predation allowed dense populations of ophiuroids (brittlestars) and crinoids (sea lilies) to appear in shallow-water settings at the end of the Eocene. These low-predation communities appear as dense fossil echinoderm assemblages in the upper portion of the late Eocene La Meseta Formation on Seymour Island, off the Antarctic Peninsula. Today, dense ophiuroid and crinoid populations are common in shallow-water habitats in Antarctica but generally have been eliminated by predators from similar habitats at temperate and tropical latitudes; their persistence in Antarctica to this day is an important ecological legacy of climatic cooling in the Eocene. Although the influence of declining predation on Antarctic ophiuroids and crinoids is now well documented, the effects of cooling on the more abundant mollusks have not been investigated. This study will examine the evolutionary ecology of gastropods (snails) and bivalves (clams) in the late Eocene.<br/><br/>A series of hypotheses will be tested in the La Meseta Formation, based on the predicted responses of mollusks to declining temperature and changing levels of predation. The shapes of gastropod shells, the activities of gastropods that prey on other mollusks by drilling holes in their shells, and the effects of predation on the thickness of mollusk shells should have changed significantly through late Eocene time. First, defensive features of gastropod shells, such as spines and ribbing, should decline as temperature and, therefore, the activity of skeleton-crushing predators declined. Second, drilling of bivalve prey by predatory gastropods should increase with time since the drillers should themselves have been subject to lower predation pressure as temperature declined. Drilled shells, therefore, should become more common through time. Third, patterns in the thickness of shells through time will make it possible to separate the direct, physiological effects of declining temperature (shells are more difficult to produce at cooler temperatures, and so should be thinner) from the indirect effects of temperature on evolving biological interactions (increased drilling predation should result in thicker shells). <br/><br/>Seymour Island contains the only fossil outcrops readily accessible in Antarctica from this crucial period in Earth history. The La Meseta Formation on Seymour Island thus provides a unique opportunity to learn how climate change affected Antarctic marine communities. In practical terms, global climate change will probably increase upwelling over the next few decades to centuries in some temperate coastal regions. Recent ecological evidence suggests that the resultant lowering of sea temperatures could lower predation in those areas. Understanding the response of the La Meseta faunas to global cooling in the late Eocene will provide direct insight into the rapidly changing structure of modern benthic communities.
Increases in ultraviolet-B radiation (UV-B, 280-320) associated with the Antarctic ozone hole have been shown to inhibit the photosynthesis of phytoplankton, but the overall effect on water column production is still a matter of debate and continued investigation. Investigations have also revealed that even at "normal" levels of Antarctic stratospheric ozone, UV-B and UV-A (320-400 nm) appear to have strong effects on water column production. The role of UV in the ecology of phytoplankton primary production has probably been underappreciated in the past and could be particularly important to the estimation of primary production in the presence of vertical mixing. This research focuses on quantifying UV effects on photosynthesis of Antarctic phytoplankton by defining biological weighting functions for UV-inhibition. In the past, techniques were developed to describe photosynthesis as a function of UV and visible irradiance using laboratory cultures. Further experimentation with natural assemblages from McMurdo Station in Antarctica showed that biological weighting functions are strongly related to light history. Most recently, measurements in the open waters of the Southern Ocean confirmed that there is substantial variability in the susceptibility of phytoplankton assemblages to UV. It was also discovered that inhibition of photosynthesis in Antarctic phytoplankton got progressively worse on the time scale of hours, with no evidence of recovery. Even under benign conditions, losses of photosynthetic capability persisted unchanged for several hours. This was in contrast with laboratory cultures and some natural assemblages which quickly attained a steady- state rate of photosynthesis during exposure to UV, reflecting a balance between damage and recovery processes. Slow reversal of UV-induced damage has profound consequences for water-column photosynthesis, especially during vertical mixing. Results to date have been used to model th e influence of UV, ozone depletion and vertical mixing on photosynthesis in Antarctic waters. Data indicate that normal levels of UV can have a significant impact on natural phytoplankton and that the effects can be exacerbated by ozone depletion as well as vertical mixing. Critical questions remain poorly resolved, however, and these are the focus of the present proposal. New theoretical and experimental approaches will be used to investigate UV responses in both the open waters of the Weddell-Scotia confluence and coastal waters near Palmer Station. In particular, measurements will be made of the kinetics of UV inhibition and recovery on time scales ranging from minutes to days. Variability in biological weighting functions between will be calculated for pelagic and coastal phytoplankton in the Southern Ocean. The results will provide absolute estimates of photosynthesis under in situ, as well as under altered, UV irradiance; broaden the range of assemblages for which biological weighting functions have been determined; and clarify how kinetics of inhibition and recovery should be represented in mixed layer models.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a paleoecological and paleoenvironmental study of Seymour Island. Global climate change late in the Eocene epoch had an important influence in Antarctica. This was the beginning of the transition from a cool-temperate climate in Antarctica to the polar climate that exists there today. The cooling trend strongly influenced the structure of shallow-water, Antarctic marine communities, and these effects are still evident in the peculiar ecological relationships among species living in modern Antarctic communities. Cooling late in the Eocene reduced the abundance of fish and crabs, which in turn reduced skeleton-crushing predation on invertebrates. Reduced predation allowed dense populations of ophiuroids (brittlestars) and crinoids (sea lilies) to appear in shallow-water settings at the end of the Eocene. These low-predation communities appear as dense fossil echinoderm assemblages in the upper portion of the late Eocene La Meseta Formation on Seymour Island, off the Antarctic Peninsula. Today, dense ophiuroid and crinoid populations are common in shallow-water habitats in Antarctica but generally have been eliminated by predators from similar habitats at temperate and tropical latitudes; their persistence in Antarctica to this day is an important ecological legacy of climatic cooling in the Eocene. Although the influence of declining predation on Antarctic ophiuroids and crinoids is now well documented, the effects of cooling on the more abundant mollusks have not been investigated. This study will examine the evolutionary ecology of gastropods (snails) and bivalves (clams) in the late Eocene.<br/><br/>A series of hypotheses will be tested in the La Meseta Formation, based on the predicted responses of mollusks to declining temperature and changing levels of predation. The shapes of gastropod shells, the activities of gastropods that prey on other mollusks by drilling holes in their shells, and the effects of predation on the thickness of mollusk shells should have changed significantly through late Eocene time. First, defensive features of gastropod shells, such as spines and ribbing, should decline as temperature and, therefore, the activity of skeleton-crushing predators declined. Second, drilling of bivalve prey by predatory gastropods should increase with time since the drillers should themselves have been subject to lower predation pressure as temperature declined. Drilled shells, therefore, should become more common through time. Third, patterns in the thickness of shells through time will make it possible to separate the direct, physiological effects of declining temperature (shells are more difficult to produce at cooler temperatures, and so should be thinner) from the indirect effects of temperature on evolving biological interactions (increased drilling predation should result in thicker shells). <br/><br/>Seymour Island contains the only fossil outcrops readily accessible in Antarctica from this crucial period in Earth history. The La Meseta Formation on Seymour Island thus provides a unique opportunity to learn how climate change affected Antarctic marine communities. In practical terms, global climate change will probably increase upwelling over the next few decades to centuries in some temperate coastal regions. Recent ecological evidence suggests that the resultant lowering of sea temperatures could lower predation in those areas. Understanding the response of the La Meseta faunas to global cooling in the late Eocene will provide direct insight into the rapidly changing structure of modern benthic communities.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds and field support to continue a study of plate motions in the Antarctic Peninsula and Scotia Sea region. The principal aim of the original "Scotia Arc GPS Project (SCARP)" was to determine motions of the Scotia Plate relative to adjacent plates and to measure crustal deformation along its margins with special attention to the South Sandwich microplate and Bransfield Strait extension. The focus of the present proposal is confined to the part of the SCARP project that includes GPS sites at Elephant Island, the South Shetland Islands and on the Antarctic Peninsula. The British Antarctic Survey provides data from two sites on the Scotia arc for this project. The northern margin of the Scotia Plate is not included herein because that region is not covered under Polar Programs. A separate proposal will request support for re-measuring SCARP GPS stations in South America. With regard to the Antarctic Peninsula area, continuously operating GPS stations were established at Frei Base, King George Island (in 1996) and at the Argentine Base, South Orkney Islands (in 1998). A number of monumented sites were established in the Antarctic Peninsula region in 1997 to support campaign-style GPS work in December 1997 and December 1998. Because of the expected slow crustal motion in the Bransfield Strait and expiration of the initial grant, no further data collection will be done until enough time has passed so that new measurements can be expected to yield precise results.<br/><br/>The primary aim of this work is to complete the measurements required to quantify crustal deformation related to opening of the Bransfield Strait, the South Shetland microplate, and to identify any other independent tectonic blocks that the GPS data may reveal. The measurements to be completed under this award will be done using ship support during the 2002-2003 season. This would be five years after the first measurements and would provide quite precise horizontal velocities. This project will complete the acquisition, processing, and interpretation of a single data set to continue this initial phase of the NSF-funded project to measure crustal motions along the southern margin of the Scotia plate. A principal investigator and one graduate student from the University of Texas will perform fieldwork. A graduate student from the University of Hawaii will process the new data consistent with previous data, and all of the SCARP investigators (Bevis, Dalziel, Smalley, Taylor: from U. Texas, U. Hawaii, and U. Memphis) will participate in interpreting the data. The British Antarctic Survey (BAS) and Alfred Wegener Institute (AWI) also recognized the importance of the Scotia plate and the Bransfield system in both global and local plate tectonic frameworks. They, too, have used GPS to measure crustal motions in this region and duplicate a number of our sites. They began earlier than we, have taken data more recently, presumably will continue taking data, and they have published some results. The collaboration between SCARP, BAS, and AWI begun earlier, will continue into this new work. Joint and separate publications are anticipated. The existing SCARP network has several advantages that justify collection and analysis of another set of data. One is that SCARP has established and measured GPS sites on Smith, Low, and Livingston Islands, where other groups have not. These sites significantly extend the dimensions of the South Shetland microplate so that we can determine a more precise pole of rotation and recognize any sub-blocks within the South Shetland arc. Smith and Low Islands are near the end of the Bransfield Basin where relative motion between the South Shetland Microplate must somehow terminate, perhaps by faulting along an extension of the Hero fracture zone. Another advantage is that measurements under SCARP were made using fixed-height masts that eliminate all but a fraction of a millimeter of vertical error in exactly re-occupying each site. Vertical motion associated with postglacial rebound should be on the order of several mm/yr, which will eventually be measurable. Mid-Holocene shorelines that emerged to more than 20m on some South Shetland arc islands suggest that vertical motion is significant. Thus, this work will contribute to understanding both plate motions and post-glacial rebound from ice mass loss in the region.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.
Marine geological and geophysical studies of the Ross Sea and Weddell Sea continental shelves provide evidence that the ice sheet grounded near the shelf edge in these areas during the late Wisconsinan, and that the retreat of the ice sheet to its present position was rapid and probably episodic. This Award supports a project which will establish the most recent (late Wisconsin- Holocene) history of ice sheet advance and retreat in Ross Sea. The objectives include: 1) reconstruction the late Wisconsin paleodrainage regime, including ice stream divides; 2) reconstruction of former grounding zone positions; 3) constraint of the timing of ice sheet retreat from the shelf; and 4) acquisition of geophysical, sedimentological, and paleontological data which may provide indicators the environmental factors that may have influenced to ice sheet retreat. This is a joint effort between Rice University, the University of Colorado, and Hamilton College. The project involves experts in a wide variety of fields, and will interface with glaciologists, physical oceanographers and climatologists who will address the problem of ice sheet stability and the record of climatic and glaciological change.
This project studies the relationship between opening of the Drake Passage and formation of the Antarctic ice sheet. Its goal is to answer the question: What drove the transition from a greenhouse to icehouse world thirty-four million years ago? Was it changes in circulation of the Southern Ocean caused by the separation of Antarctica from South America or was it a global effect such as decreasing atmospheric CO2 content? This study constrains the events and timing through fieldwork in South America and Antarctica and new work on marine sediment cores previously collected by the Ocean Drilling Program. It also involves an extensive, multidisciplinary analytical program. Compositional analyses of sediments and their sources will be combined with (U-Th)/He, fission-track, and Ar-Ar thermochronometry to constrain uplift and motion of the continental crust bounding the Drake Passage. Radiogenic isotope studies of fossil fish teeth found in marine sediment cores will be used to trace penetration of Pacific seawater into the Atlantic. Oxygen isotope and trace metal measurements on foraminifera will provide additional information on the timing and magnitude of ice volume changes. <br/><br/><br/><br/>The broader impacts include graduate and undergraduate education; outreach to the general public through museum exhibits and presentations, and international collaboration with scientists from Argentina, Ukraine, UK and Germany.<br/><br/><br/><br/>The project is supported under NSF's International Polar Year (IPY) research emphasis area on "Understanding Environmental Change in Polar Regions". This project is also a key component of the IPY Plates & Gates initiative (IPY Project #77), focused on determining the role of tectonic gateways in instigating polar environmental change.
Deception Island is a flooded caldera in the South Shetland Islands, Antarctica. The most recent eruption was in the 1970s causing the formation of new islands in the caldera and various other structures. It harbors many hot springs and fumaroles submerged in the caldera and intertidally. Sulfide and methane are prominent chemicals in the outflowing waters. Bacterial densities in the caldera reach unusually high values probably due to the input of reduced chemicals as energy sources. The environment around the springs resembles that found at hydrothermal vents where whole communities are based on the input of chemical energy by the hot waters. Similarities to hydrothermal vent environments include cold waters surrounding the hot springs resulting in large distances to the next warm water habitat and a lack of external food sources. The latter is due to ice cover during winter at Deception Island and the large distance to the euphotic zone at the vent sites. These parameters encourage the evolution of alternative ways to support life such as the establishment of a bacterial symbiosis. This Small Grant for Exploratory Research project will focus on an examination of the warm springs around Deception Island for the presence of marine invertebrates with chemoautotrophic symbionts. Maps will be made of any submerged fumaroles and of warm and hot springs in the intertidal zone. If animals are found near the fumaroles or in the hot springs, specimens will be collected. Collected specimens will be examined for the presence of chemoautotrophic bacteria and other adaptations to a hot sulfide- and methane-rich environment using enzyme text experimental incubations to analyze metabolic pathways and microscopic examination.
This award supports development of a new modeling approach that will extract information about past snow accumulation rate in both space and time in the vicinity of the future ice core near the Ross-Amundsen divide of the West Antarctic Ice Sheet (WAIS). Internal layers, detected by ice-penetrating radar, are isochrones, or former ice-sheet surfaces that have been buried by subsequent snowfall, and distorted by ice flow. Extensive ice-penetrating radar data are available over the inland portion of the WAIS. Layers have been dated back to 17,000 years before present. The radar data add the spatial dimension to the temporally resolved accumulation record from ice cores. Accumulation rates are traditionally derived from the depths of young, shallow layers, corrected for strain using a local 1-D ice-flow model. Older, deeper layers have been more affected by flow over large horizontal distances. However, it is these deeper layers that contain information on longer-term climate patterns. This project will use geophysical inverse theory and a 2.5D flow-band ice-flow forward model comprising ice-surface and layer-evolution modules, to extract robust transient accumulation patterns by assimilating multiple deeper, more-deformed layers that have previously been intractable. Histories of divide migration, geothermal flux, and surface evolution will also be produced. The grant will support the PhD research of a female graduate student who is a mentor to female socio-economically disadvantaged high-school students interested in science, through the University of Washington Women's Center. It will also provide a research<br/>experience for an undergraduate student, and contribute to a freshman seminar on Scientific Research.
This award supports the coordination of an interdisciplinary and multi institutional deep ice coring program in West Antarctica. The program will develop interrelated climate, ice dynamics, and biologic records focused on understanding interactions of global earth systems. The records will have a year-by-year chronology for the most recent 40,000 years. Lower temporal resolution records will extend to 100,000 years before present. The intellectual activity of this project includes enhancing our understanding of the natural mechanisms that cause climate change. The study site was selected to obtain the best possible material, available from anywhere, to determine the role of greenhouse gas in the last series of major climate changes. The project will study the how natural changes in greenhouse gas concentrations influence climate. The influence of sea ice and atmospheric circulation on climate changes will also be investigated. Other topics that will be investigated include the influence of the West Antarctic ice sheet on changes in sea level and the biology deep in the ice sheet. The broader impacts of this project include developing information required by other science communities to improve predictions of future climate change. The <br/>project will use mass media to explain climate, glaciology, and biology issues to a broad audience. The next generation of ice core investigators will be trained and there will be an emphasis on exposing a diverse group of students to climate, glaciology and biology research.
This project studies fossils from two to three hundred million year old rocks in the Allan Hills area of Antarctica. Similar deposits from lower latitudes have been used to develop a model of Permo-Triassic climate, wherein melting of continental glaciers in the early Permian leads to the establishment of forests in a cold, wet climate. Conditions became warmer and dryer by the early Triassic, inhibiting plant growth until a moistening climate in the late Triassic allowed plant to flourish once again. This project will test and refine this model and investigate the general effects of climate change on landscapes and ecosystems using the unique exposures and well-preserved fossil and sediment records in the Allan Hills area. The area will be searched for fossil forests, vertebrate tracks and burrows, arthropod trackways, and subaqueously produced biogenic structures, which have been found in other areas of Antarctica. Finds will be integrated with previous paleobiologic studies to reconstruct and interpret ecosystems and their changes. Structures and rock types documenting the end phases of continental glaciation and other major episodic sedimentations will also be described and interpreted. This project contributes to understanding the: (1) evolution of terrestrial and freshwater ecosystems and how they were affected by the end-Permian extinction, (2) abundance and diversity of terrestrial and aquatic arthropods at high latitudes, (3) paleogeographic distribution and evolution of vertebrates and invertebrates as recorded by trace and body fossils; and (3) response of landscapes to changes in climate.<br/><br/>In terms of broader impacts, this project will provide an outstanding introduction to field research for graduate and undergraduate students, and generate related opportunities for several undergraduates. It will also stimulate exchange of ideas among research and primarily undergraduate institutions. Novel outreach activities are also planned to convey Earth history to the general public, including a short film on the research process and products, and paintings by a professional scientific illustrator of Permo-Traissic landscapes and ecosystems.
Abstract<br/>This project studies microfossils of plants and algae to understand climate during the earliest glaciations of Antarctica. The microfossils are from marine sediment cores collected by the 2006 SHALDRIL campaign to the Antarctic Peninsula. The work will offer constraints on sea surface temperature, ocean salinity, and terrestrial vegetation to help answer questions such as: What were conditions like on the Antarctic Peninsula during the initial formation of Antarctica's ice sheets? How rapidly did the ice sheets grow? Was their growth driven by global factors such as low atmospheric CO2 or local events like opening of the Drake Passage? <br/><br/>The broader impacts include postdoctoral fellow research and outreach via a museum exhibit and a web-based activity book for children.
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.
This project studies the last vestiges of life in Antarctica from exceptionally well-preserved fossils of tundra life--mosses, diatoms, ostracods, Nothofagus leaves, wood, and insect remains recently discovered in ancient lake sediments from the McMurdo Dry Valleys. The area will be studied by an interdisciplinary team to elucidate information about climate and biogeography. These deposits offer unique and direct information about the characteristics of Antarctica during a key period in its history, the time when it was freezing. This information is critical for correlation with indirect proxies, such as though obtained from drill cores, for climate and state of the ice sheet. The results will also help understand the origin and migration of similar organisms found in South America, India and Australia.<br/><br/>In terms of broader impacts, this project supports an early career researcher, undergraduate and graduate student research, various forms of outreach to K12 students, and extensive international collaboration. The work also has societal relevance in that the outcomes will offer direct constraints on Antarctica's ice sheet during a time with atmospheric CO2 contents similar to those of the earth in the coming centuries, and thus may help predictive models of sea level rise.
Abstract<br/><br/>The research will continue and extend the study in the Southern Ocean that was initiated during the Oden Southern Ocean 2006 expedition in collaboration with Swedish scientist Mellissa Chierici. We will quantify carbon flux through the food web in the marginal ice zone (MIZ) by measuring size fractionated primary and secondary production, grazing and carbon flux through nanoplankton (2-20 um), microplankton (20-200um), and mesoplankton (200-2000 um). Community structure, species abundance and size specific grazing rates will be quantified using a variety of techniques both underway and at ice stations along the MIZ. The proposed cruise track extends across the Drake Passage to the Western Antarctic Peninsula (WAP) with three station transects along a gradient from the open ocean through the marginal ice zone (MIZ) in the Bellinghausen and Amundsen Seas and into the Ross Sea Polynya. Ice stations along each transect will provide material to characterize production associated with annual ice. Underway measurements of primary and secondary production (chlorophyll, CDOM, microplankton, and mesoplankton) and hydrography (temperature, salinity, pH, DO, turbidity) will establish a baseline for future cruises and as support for other projects such as biogeochemical studies on carbon dioxide drawdown and trace metal work on primary production. The outcome of these measurements will be a description of nano to mesoplankton standing stocks, community structure, and carbon flux along the MIZ in the Bellinghausen and Amundsen Seas and the Ross Sea Polynya.
9911617<br/>Blankenship<br/><br/>This award, provided jointly by the Antarctic Geology and Geophysics Program, the Antarctic Glaciology Program, and the Polar Research Support Section of the Office of Polar Programs, provides funds for continuation of the Support Office for Aerogeophysical Research (SOAR). From July 1994 to July 2000, SOAR served as a facility to accomplish aerogeophysical research in Antarctica under an agreement between the University of Texas at Austin and the National Science Foundation's Office of Polar Programs (NSF/OPP). SOAR operated and maintained an aerogeophysical instrument package that consists of an ice-penetrating radar sounder, a laser altimeter, a gravimeter and a magnetometer that are tightly integrated with each other as well as with the aircraft's avionics and power packages. An array of aircraft and ground-based GPS receivers supported kinematic differential positioning using carrier-phase observations. SOAR activities included: developing aerogeophysical research projects with NSF/OPP investigators; upgrading of the aerogeophysical instrumentation package to accommodate new science projects and advances in technology; fielding this instrument package to accomplish SOAR-developed projects; and management, reduction, and analysis of the acquired aerogeophysical data. In pursuit of 9 NSF-OPP funded aerogeophysical research projects (involving 14 investigators from 9 institutions), SOAR carried out six field campaigns over a six-year period and accomplished approximately 200,000 line kilometers of aerogeophysical surveying over both East and West Antarctica in 377 flights.<br/><br/>This award supports SOAR to undertake a one year and 8 month program of aerogeophysical activities that are consistent with continuing U.S. support for geophysical research in Antarctica. <br/>- SOAR will conduct an aerogeophysical campaign during the 200/01 austral summer to accomplish surveys for two SOAR-developed projects: "Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Studies" (Co-PI's Bell and Studinger, LDEO); and "Collaborative Research: Seismic Investigation of the Deep Continental Structure Across the East-West Antarctic Boundary" (Co-PI's Weins, Washington U. and Anandakrishnan, U. Alabama). After configuration and testing of the survey aircraft in McMurdo, SOAR will conduct survey flights from an NSF-supported base adjacent to the Russian Station above Lake Vostok and briefly occupy one or two remote bases on the East Antarctic ice sheet.<br/>- SOAR will reduce these aerogeophysical data and produce profiles and maps of surface elevation, bed elevation, gravity and magnetic field intensity. These results will be provided to the respective project investigators within nine months of conclusion of field activities. We will also submit a technical manuscript that describes these results to a refereed scientific journal and distribute these results to appropriate national geophysical data centers within approximately 24 months of completion of field activities.<br/>- SOAR will standardize all previously reduced SOAR data products and transfer them to the appropriate national geophysical data centers by the end of this grant.<br/>- SOAR will convene a workshop to establish a community consensus for future U.S. Antarctic aerogeophysical research. This workshop will be co-convened by Ian Dalziel and Richard Alley and will take place during the spring of 2001.<br/>- SOAR will upgrade the existing SOAR in-field quality control procedures to serve as a web-based interface for efficient browsing of many low-level SOAR data streams.<br/>- SOAR will repair and/or refurbish equipment that was used during the 2000/01 field campaign.<br/><br/>Support for SOAR is essential for accomplishing major geophysical investigations in Antarctica. Following data interpretation by the science teams, these data will provide valuable insights to the structure and evolution of the Antarctic continent.
The Erebus Bay Weddell seal population study in eastern McMurdo Sound, Antarctica was initiated in 1968 and represents one of the longest intensive field investigations of a long-lived mammal in existence. Over the thirty-four year period of this study a total of 15,636 animals have been tagged with 144,927 re-sighting records logged in the current database. As such, this study is an extremely valuable resource for understanding population dynamics of not only Weddell seals, but also other species of both terrestrial and marine mammals with similar life-history characteristics. With the retirement of the original investigator, Dr. Donald Siniff, this proposal represents an effort to transition the long-term studies to a new team of investigators. Dr. Robert Garrott and Dr. Jay Rotella propose building upon the foundation with two lines of investigation that combine use of the long-term database with new field initiatives. The continuity of the demographic data will be maintained by annually marking all pups born, replace lost or broken tags, and perform multiple mark-recapture censuses of the Erebus Bay seal colonies. The new data will be combined with the existing database and a progressively complex series of analyses will be performed using recently developed mark-recapture methods to decompose, evaluate, and integrate the demographic characteristics of the Erebus Bay Weddell seal population. These analyses will allow the testing of specific hypotheses about population regulation as well as temporal and spatial patterns of variation in vital rates among colonies within the population that have been posed by previous investigators, but have not been adequately evaluated due to data and analytical limitations. The primary new field initiative will involve an intensive study of mass dynamics of both pups and adult females as a surrogate measure for assessing annual variation in marine resources and their potential role in limiting and/or regulating the population. In conjunction with the collection of data on body mass dynamics the investigators will use satellite imagery to develop an extended time series of sea ice extent in McMurdo Sound. Regional extent of sea ice affects both regional primary productivity and availability of haul out areas for Weddell seals. Increased primary productivity may increase marine resources which would be expected to have a positive affect on Weddell seal foraging efficiency, leading to increased body mass. These data combined with the large proportion of known-aged seals in the current study population (>60%) will allow the investigators to develop a powerful database to test specific hypotheses about ecological processes affecting Weddell seals. Knowledge of the mechanisms that limit and/or regulate Weddell seal populations and the specific bio-physical linkages between climate, oceans, ice, and Antarctic food webs can provide important contributions to understanding of pinniped population dynamics, as well as contribute more generally to theoretical understanding of population, community, and ecosystem patterns and processes. Such knowledge can be readily applied elsewhere to enhance the ability of natural resource managers to effectively maintain assemblages of other large-mammal species and the ecological processes that they facilitate. Continuation of this long-term study may also contribute to understanding the potential impacts of human activities such as global climate warming and the commercial exploitation of Antarctic marine resources. And finally, the study can contribute significantly to the development and testing of new research and analytical methodologies that will almost certainly have many other applications.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the "Silicic Acid Leakage Hypothesis" as it relates to global carbon dioxide fluctuations during glacial-interglacial cycles.<br/><br/>Intellectual Merit<br/>This project will evaluate the burial rate of biogenic opal in the Pacific sector of the Southern Ocean, both during the Last Glacial Maximum (LGM) and during the Holocene, as a critical test of the "Silicic Acid Leakage Hypothesis". <br/><br/>The "Silicic Acid Leakage Hypothesis" has been proposed recently to explain the glacial reduction in the carbon dioxide content of the atmosphere that has been reconstructed from Antarctic ice cores. Vast amounts of dissolved Si (silicic acid) are supplied to surface waters of the Southern Ocean by wind-driven upwelling of deep waters. Today, that dissolved Si is consumed almost quantitatively by diatoms who form skeletal structures composed of biogenic opal (a mineral form of silicon). According to the "Silicic Acid Leakage Hypothesis", environmental conditions in the Southern Ocean during glacial periods were unfavorable for diatom growth, leading to reduced (compared to interglacials) efficiency of dissolved Si utilization. Dissolved Si that was not consumed biologically in the glacial Southern ocean was then exported to the tropics in waters that sink in winter to depths of a few hundred meters along the northern fringes of the Antarctic Circumpolar Current, and return some decades later to the sunlit surface in tropical regions of wind-driven upwelling. <br/><br/>An increase in the amount of dissolved Si that "leaks" out of the Southern Ocean and later upwells at low latitudes could shift the global average composition of phytoplankton toward a greater abundance of diatoms and fewer CaCO3-secreting taxa (especially coccolithophorids). Consequences of such a taxonomic shift in the ocean's phytoplankton assemblage include:<br/> a) an increase in the global average organic carbon/calcium carbonate ratio of particulate biogenic material sinking into the deep sea;<br/> b) a reduction in the preservation and burial of calcium carbonate in marine sediments;<br/> c) an increase in ocean alkalinity as a consequence of the first two changes mentioned above, and;<br/> d) a lowering of atmospheric CO2 concentrations in response to increased alkalinity of ocean waters. <br/><br/>A complete assessment of the Silicic acid leakage hypothesis will require an evaluation of: (1) Si utilization efficiencies using newly-developed stable isotopic techniques; (2) opal burial rates in low-latitude upwelling regions; and (3) opal burial rates in the Southern Ocean. This project addresses the last of these topics. <br/><br/>Previous work has shown that there was little change in opal burial rate between the LGM and the Holocene in the Atlantic and Indian sectors of the Southern Ocean. Preliminary results (summarized in this proposal) suggest that the Pacific may have been different, however, in that opal burial rates in the Pacific sector seem to have been lower during the LGM than during the Holocene, allowing for the possibility of "Si leakage" from this region. However, available results are too sparse to make any quantitative conclusions at this time. For that reason, we propose to make a comprehensive evaluation of opal burial rates in the Pacific sector of the Southern Ocean. <br/><br/>Significance and Broader Impacts<br/>Determining the mechanism(s) by which the ocean has regulated climate-related changes in the CO2 content of the atmosphere has been the focus of a substantial effort by paleoceanographers over the past two decades. The Silicic Acid Leakage Hypothesis is a viable new candidate mechanism that warrants further exploration and testing. Completion of the proposed work will contribute significantly to that effort. <br/><br/>During the course of this work, several undergraduates will be exposed to paleoclimate research through their involvement in this project. Burckle and Anderson are both dedicated to the education and training of young scientists, and to the recruitment of women and under-represented minorities. To illustrate, two summer students (undergraduates) worked in Burckle's lab during the summer of 2002. One was a woman and the other (male) was a member of an under-represented minority. Anderson and Burckle will continue with similar recruitment efforts during the course of the proposed study. A minority student who has expressed an interest in working on this research during the summer of 2003 has already been identified.
This project will study migmatite domes found in the Fosdick Mountains of the Ford Ranges, western Marie Byrd Land, Antarctica. This area offers unique, three-dimensional exposures that may offer new insight into dome formation, which is a fundamental process of mountain building. These domes are derived from sedimentary and plutonic protoliths that are complexly interfolded at decimeter to kilometer scales. Preliminary findings from geobarometry and U-Pb monazite dating of anatexite suggest that peak metamorphism was underway at 105 Ma at crustal depths of ~25 km, followed by decompression as the Fosdick dome was emplaced to 16-17 km, or possibly as low as 8.5 km, in the crust by 99 Ma. Near-isothermal conditions were maintained during ascent, favorable for producing substantial volumes of melt through biotite-dehydration melting. This dome has been interpreted as a product of extensional exhumation. This is a viable interpretation from the regional standpoint, because the dome was emplaced in mid-Cretaceous time during the rapid onset of divergent tectonics along the proto- Pacific margin of Gondwana. However, the complex internal structures of the Fosdick Mountains have yet to be considered and may be more consistent with alternative intepretations such as upward extrusion within a contractional setting or lateral flow within a transcurrent attachment zone. This proposal is for detailed structural analysis, paired with geothermobarometry and geochronology, to determine the flow behavior and structural style that produced the internal architecture of the Fosdick dome. The results will improve our general understanding of the role of gneiss domes in transferring material and heat during mountain-building, and will characterize the behavior of the middle crust during a time of rapid transition from divergent to convergent tectonics along the active margin of Gondwana. In terms of broader impacts, this work will train undergraduate and graduate students, and involve them as collaborators in the development of curricular materials. It will also foster mentoring relationships between graduate and undergraduate students.
Polar terrestrial environments are often described as deserts, where water availability is recognized as one of the most important limits on the distribution of terrestrial organisms. In addition, prolonged low winter temperatures threaten survival, and summer temperatures challenge organisms with extensive diel variations and rapid transitions from freezing to desiccating conditions. Global warming has further impacted the extreme thermal and hydric conditions experienced by Antarctic terrestrial plant and arthropod communities, especially as a result of glacial retreat along the Antarctic Peninsula. This research will focus on thermal and hydric adaptations in the terrestrial midge, Belgica antarctica, the largest and most southerly holometabolous insect living in this challenging and changing environment. <br/>Overwintering midge larvae encased in the frozen substrate must endure desert-like conditions for more than 300 days since free water is biologically unavailable as ice. During the summer, larvae may be immersed in melt water or outwash from penguin colonies and seal wallows, in addition to saltwater splash. Alternatively, the larvae may be subjected to extended periods of desiccation as their microhabitats dry out. Due to their small size, relative immobility and the patchiness of suitable microhabitats, larvae may thus be subjected to stresses that include desiccation, hypo- or hyperosmotic conditions, high salinity exposure, and anoxia for extended periods. Research efforts will focus in three areas relevant to the stress tolerance mechanisms operating in these midges:(1) obtaining a detailed characterization of microclimatic conditions experienced by B. antarctica, especially those related to thermal and hydric diversity, both seasonally and among microhabitat types in the vicinity of Palmer Station, Antarctica; (2) examining the effects of extreme fluctuations in water availability and effects on physiological and molecular responses - to determine if midge larvae utilize the mechanism of cryoprotective dehydration for winter survival, and if genes encoding heat shock proteins and other genes are upregulated in larval responses to dehydration and rehydration; (3) investigating the dietary transmission of cryoprotectants from plant to insect host, which will test the hypothesis that midge larvae acquire increased resistance to desiccation and temperature stress by acquiring cryoprotectants from their host plants. <br/>This project will provide outreach to both elementary and secondary educators and their students. The team will include a teacher who will benefit professionally by full participation in the research, and will also assist in providing outreach to other teachers and their students. From Palmer Station, the field team will communicate daily research progress by e-mail supplemented with digital pictures with teachers and their elementary students to stimulate interest in an Antarctic biology and scientific research. These efforts will be supplemented with presentations at local schools and national teacher meetings, and by publishing hands-on, inquiry-based articles related to cryobiology and polar biology in education journals. Furthermore, the principal investigators will maintain major commitments to training graduate students and postdoctoral scholars, as well as undergraduate students by providing extended research experience that includes publication of scientific papers and presentations at national meetings.
9980452<br/>Harvey<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for continuation of the Antarctic Search for Meteorites (ANSMET). Since 1976, ANSMET has recovered more than 10,000 meteorite specimens from locations along the Transantarctic Mountains. This award supports continued recovery of Antarctic meteorites during six successive austral summer field seasons, starting with the 2000-2001 season and ending with the 2005-2006 season. Under this project, systematic searches for meteorite specimens will take place at previously discovered stranding surfaces, and reconnaissance work will be conducted to discover and explore the extent of new areas with meteorite concentrations. ANSMET recovery teams will deploy by air to locations in the deep field for periods of 5-7 weeks. While at the meteorite stranding surface, field team members will search the ice visually, traversing on foot or on snowmobile. Specimens will be collected under the most sterile conditions practical and samples will remain frozen until returned to the Johnson Space Center (JSC) in Houston, Texas. At the JSC, initial characterization and sample distribution to all interested researchers takes place under the auspices of an interagency agreement between NSF, NASA, and the Smithsonian Institution.<br/><br/>The impact of ANSMET has been substantial and this will continue under this award. The meteorites recovered by ANSMET are the best and most reliable source of new, non-microscopic extraterrestrial material, providing essential "ground-truth" concerning the materials that make up the asteroids, planets and other bodies of our solar system. The system for their characterization and distribution is unparalleled and their subsequent study has fundamentally changed our understanding of the solar system. ANSMET meteorites have helped researchers explore the conditions that were present in the nebula from which our solar system was born 4.556 billion years ago and provided samples of asteroids, ranging from primitive bodies unchanged since the formation of the solar system to complex, geologically active miniature planets. ANSMET samples proved, against the conventional wisdom, that some meteorites actually represent planetary materials, delivered to us from the Moon and Mars, completely changing our view of the geology of those bodies. ANSMET meteorites have even generated a new kind of inquiry into one of the most fundamental scientific questions possible; the question of biological activity in the universe as a whole. Over the past twenty years, ANSMET meteorites have economically provided a continuous and readily available supply of extraterrestrial materials for research, and should continue to do so in the future.
This award supports the development of a new laboratory capability in the U.S. to measure CO2 in ice cores and investigate millennial-scale changes in CO2 during the last glacial period using samples from the Byrd and Siple Dome ice cores. Both cores have precise relative chronologies based on correlation of methane and the isotopic composition of atmospheric oxygen with counterpart records from Greenland ice cores. The proposed work will therefore allow comparison of the timing of CO2 change, Antarctic temperature change, and Greenland temperature change on common time scales. Such comparisons are vital for evaluating models that explain changes in atmospheric CO2. The techniques being developed will also be available for future projects, specifically the proposed Inland WAIS ice core, for which a highly detailed CO2 record is a major objective, and studies greenhouse and other atmospheric gases and their isotopic composition for which dry extraction is necessary (stable isotopes in CO2, for example). There are many broad impacts of the proposed work. Ice core greenhouse gas records are central contributions of paleoclimatology to research and policy-making concerning global change. The proposed work will enhance those contributions by improving our understanding of the natural cycling of the most important greenhouse gas. It will contribute to the training of a postdoctoral researcher, who will be an integral part of an established research group and benefit from the diverse paleoclimate and geochemistry community at OSU. The PI teaches major and non-major undergraduate and graduate courses on climate and global change. The proposed work will enrich those courses and the courses will provide an opportunity for the postdoctoral researcher to participate in teaching by giving guest lectures. The PI also participates in a summer climate workshop for high school teachers at Washington State University and the proposed work will enrich that contribution. The extraction device that is built and the expertise gained in using it will be resources for the ice core community and available for future projects. Data will be made available through established national data center and the equipment designs will also be made available to other researchers.
This award supports a small grant for exploratory research to study the processes that contribute to the melting and break-up of tabular polar icebergs as they drift north. This work will enable the participation of a group of U.S. scientists in this international project which is collaborative with the Instituto Antartico Argentino. The field team will place weather instruments, firn sensors, and a video camera on the iceberg to measure the processes that affect it as it drifts north. In contrast to icebergs in other sectors of Antarctica, icebergs in the northwestern Weddell Sea drift northward along relatively predictable paths, and reach climate and ocean conditions that lead to break-up within a few years. The timing of this study is critical due to the anticipated presence of iceberg A43A, which broke off the Ronne Ice Shelf in February 2000 and which is expected to be accessible from Marambio Station in early 2006. It has recently been recognized that the end stages of break-up of these icebergs can imitate the rapid disintegrations due to melt ponding and surface fracturing observed for the Larsen A and Larsen B ice shelves. However, in some cases, basal melting may play a significant role in shelf break-up. Resolving the processes (surface ponding/ fracturing versus basal melt) and observing other processes of iceberg drift and break up in-situ are of high scientific interest. An understanding of the mechanisms that lead to the distintegration of icebergs as they drift north may enable scientists to use icebergs as proxies for understanding the processes that could cause ice shelves to disintegrate in a warming climate. A broader impact would thus be an ability to predict ice shelf disintegration in a warming world. Glacier mass balance and ice shelf stability are of critical importance to sea level change, which also has broader societal relevance.
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.
Encarnaci_n OPP 9615398 Abstract Basement rocks of the Transantarctic Mountains are believed to record a change in the paleo-Pacific margin of Gondwana from a rifted passive margin to a tectonically active margin (Ross orogen). Recent hypothesis suggest that the passive margin phase resulted from Neoproterozoic rifting of Laurentia from Antarctica ("SWEAT" hypothesis). The succeeding active margin phase (Ross orogeny) was one of several tectonic events ("Pan African" events) that resulted from plate convergence/transpression that was probably a consequence of the assembly of components of the Gondwana supercontinent. Although these basement units provide one of the keys for understanding the break up and assembly of these major continental masses, few precise ages are available to address the following important issues: (1) Is there any pre-rift high-grade cratonal basement exposed along the Transantarctic Mountains, and what is/are its precise age? Is this age compatible with a Laurentia connection? (2) What is the age of potential rift/passive margin sediments (Beardmore Group) along the Queen Maud Mountains sector of the orogen? (3) What is the relative and absolute timing of magmatism and contractional deformation of supracrustal units in the orogen? Was deformation diachronous and thus possibly related to transpressional tectonics, or did it occur in a discrete pulse that is more compatible with a collision? How does contraction of the orogen fit in with emplacement of voluminous plutonic and volcanic rocks? The answers to these questions are central to understanding the kinematic evolution of this major orogenic belt and its role in Neoproterozoic-Early Paleozoic continental reconstructions and plate kinematics. Hence, this award supports funding for precise U-Pb dating, using zircon, monazite, baddeleyite, and/or titanite from a variety of magmatic rocks in the Queen Ma ud Mountains, which can address the foregoing problems. In addition to the issues above, precise dating of volcanics that are interbedded with carbonates containing probable Middle Cambrian fauna could potentially provide a calibration point for the Middle Cambrian, which will fill a gap in the absolute time scale for the early Paleozoic.
Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.<br/>This award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.<br/>A better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.
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.
This project determines the recent history of the West Antarctic Ice Sheet (WAIS) through a multidisciplinary study of the seabed in the Ross Sea of Antarctica. WAIS is perhaps the world's most critical ice sheet to sea level rise dut to near-future global warming. its history has been a key focus for the past decade, but there are significant questions as to whether WAIS was stable during the last glacial maximum--about 20,000 years ago--or undergoing advance and retreat. This project studies grounding zone translantions in Eastern Basin to constrain WAIS movements using a multidisciplinary approach that integrates multibeam bathymetry, seismic stratigraphy, sedimentology, diatom biostratigraphy, radiocarbon dating, 10Be concentration analyses, and numerical modeling.<br/><br/>The broader impacts include improving society's understanding of sea level rise linked to global warming; postdoctoral, graduate, and undergraduate education; and expanding the participation of groups underrepresented in Earth sciences through links with LSU's Geoscience Alliance to Encourage Minority Participation.
This award is for support for a three year project to measure the vertical strain rate as a function of depth at two sites on Siple Dome Antarctica. Ice flow near a divide such as Siple Dome is unique in that it is predominantly vertical. As a consequence, the component of ice deformation in the vertical direction, the "vertical strain rate" is dominant. Its measurement is therefore important for the calibration of dynamic models of ice flow. Two different, relatively new, high resolution systems for its measurement in hot water drilled holes will be employed. The ice flow model resulting from the measurements and flow law determination will be used to interpret the shapes of radar internal layering in terms of the dynamic history and accumulation patterns of Siple Dome over the past 10,000 years. The resulting improved model will also be applied to the interpretation of annual layers thicknesses (to produce annual accumulation rates) and borehole temperatures from the ice core to be drilled at Siple Dome during the 1997/98 field season. The results should permit an improved analysis of the ice core, relative to what was possible at recent coring sites in central Greenland. This is a collaborative project between the University of Alaska, the University of California, San Diego and the University of Washington.
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.
This award supports a comprehensive aerogeophysical survey of the Amundsen Sea Embayment (ASE) in West Antarctica. The University of Texas will join forces with the British Antarctic Survey to use both US and UK aircraft and instrumentation to achieve this survey. Analyses of the new aerogeophysical<br/>data will result in the generation of maps of ice sheet surface, volume and bottom-interface characteristics. These maps will support the efforts of a community of US and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE.<br/>The West Antarctic ice sheet has been the subject of intensive interdisciplinary study by both the European and U.S. scientific communities since it was recognized to be a potential source for up to 5 meters of sea<br/>level rise, possibly on short timescales. In terms of ice discharge, the ASE is the largest drainage system in West Antarctica. Yet it has been comparatively unstudied, primarily due to its remoteness from logistical<br/>centers. The ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change.<br/>The results from our surveys are required to achieve the fundamental research objectives outlined by the US scientific community in an ASE Science Plan. The surveys and analyses will be achieved through international collaboration and will involve graduate students, undergraduates and high school apprentices.<br/>Through its potential for influencing sea level, the future behavior of the ASE is of primary societal importance. Given the substantial public and scientific interest that recent reports of change in West Antarctica have generated, we expect fundamental research in the Amundsen Sea Embayment, enabled by our surveys, will have widespread impact.
The summit crater of Mt. Moulton, in West Antarctica, contains a 600-m thick horizontally-exposed section of ice with intercalated tephra layers from nearby Mt Berlin. Argon-40/Argon-39 dating of the thick, near-source tephra indicates that the age of the horizontal ice section ranges between 15,000 and 492,000 years. Thus, the Mt Moulton site offers an unparalleled repository of ancient West Antarctic snow and trapped air that can be used to investigate West Antarctic climate over much of the past 500,000 years. The planar nature and consistent dips of the tephra layers suggests that, although the ice section has thinned, it is otherwise undeformed. The Mt. Moulton site was visited during the 1999/2000 field season, at which time a horizontal ice core representing approximately 400 meters of ice was collected, ranging in age from 15,000 to older than 480,000 years. In addition to this horizontal core, samples of ice at a range of depths were collected in order to test the quality of the climate record in the ice. Forty tephra layers intercalated in the ice were also collected in order to provide chronology for the ice section. The results of this first effort are extremely encouraging. Based on the d?18 O of ice, for example, there is clearly a useable record of past climate at Mt. Moulton extending back beyond 140,000 years. There is work to do, however, to realize the full potential of this horizontal ice core. The elemental and isotopic composition of trapped gases suggest some contamination with modern air, for example. As gas cross-dating of ice cores is the current standard by which climate records are intercompared, we need to understand why and how the gas record is compromised before adding Moulton to our arsenal of ice core paleoclimate records. This award supports a collaborative effort between three institutions with following objectives: 1) to evaluate more thoroughly the integrity of the climatic record through shallow drilling of the blue ice area, as well as the snow field upslope from the blue ice; 2) to improve the radioisotopic dating of specific tephra layers; 3) to obtain baseline information about modern snowfall deposition, mean annual temperature, and wind pumping around the summit of Mt. Moulton; and 4) to study how firn densification differs when surface accumulation changes from net accumulation to net ablation.
This award supports a three-year renewal project to complete measurement of cosmogenic nuclides in the Siple Dome ice core as part of the West Antarctic ice core program. The investigators will continue to measure profiles of Beryllium-10 (half-life = 1.5x10 6 years) and Chlorine-36 (half-life = 3.0x10 5 years) in the entire ice core which spans the time period from the present to about 100 kyr. It will be particularly instructive to compare the Antarctic record with the detailed Arctic record that was measured by these investigators as part of the GISP2 project. This comparison will help separate global from local effects at the different drill sites. Cosmogenic radionuclides in polar ice cores have been used to study the long-term variations in several important geophysical variables, including solar activity, geomagnetic field strength, atmospheric circulation, snow accumulation rates, and others. The time series of nuclide concentrations resulting from this work will be applied to several problem areas: perfecting the ice core chronology, deducing the history of solar activity, deducing the history of variations in the geomagnetic field, and studying the possible role of solar variations on climate. Comparison of Beryllium-10 and Chlorine-36 profiles in different cores will allow us to improve the ice core chronology and directly compare ice cores from different regions of the globe. Additional comparison with the Carbon-14 record will allow correlation of the ice core paleoenvironment record to other, Carbon-14 dated, paleoclimate records.
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.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the Transantarctic Mountains and an adjacent region of East Antarctica. The East Antarctic shield is one of Earth's oldest and largest cratonic assemblies, with a long-lived Archean to early Paleozoic history. Long-standing interest in the geologic evolution of this shield has been rekindled over the past decade by tectonic models linking East Antarctica with other Precambrian crustal elements in the Rodinia and Gondwanaland supercontinents. It is postulated that the Pacific margin of East Antarctica was rifted from Laurentia during late Neoproterozoic breakup of Rodinia, and it then developed as an active plate boundary during subsequent amalgamation of Gondwanaland in the earliest Paleozoic. If true, the East Antarctic shield played a key role in supercontinent transformation at a time of global changes in plate configuration, terrestrial surficial process, sea level, and marine geochemistry and biota. A better understanding of the geological evolution of the East Antarctic shield is therefore critical for studying Precambrian crustal evolution in general, as well as resource distribution, biosphere evolution, and glacial and climate history during later periods of Earth history. Because of nearly complete coverage by the polar ice cap, however, Antarctica remains the single most geologically unexplored continent. Exposures of cratonic basement are largely limited to coastal outcrops in George V Land and Terre Adelie (Australian sector), the Prince Charles Mountains and Enderby Land (Indian sector), and Queen Maud Land (African sector), where the geology is reasonably well-known. By contrast, little is known about the composition and structure of the shield interior. Given the extensive ice cover, collection of airborne geophysical data is the most cost-effective method to characterize broad areas of sub-ice basement and expand our knowledge of the East Antarctic shield interior. <br/><br/>This project will conduct an airborne magnetic survey (coupled with ground-based gravity measurements) across an important window into the shield where it is exposed in the Nimrod Glacier area of the central Transantarctic Mountains. Specific goals are to:<br/>1. Characterize the magnetic and gravity signature of East Antarctic crustal basement exposed at the Ross margin (Nimrod Group),<br/>2. Extend the magnetic data westward along a corridor across the polar ice cap in order to image the crust in ice-covered areas,<br/>3. Obtain magnetic data over the Ross Orogen in order to image the ice-covered boundary between basement and supracrustal rocks, allowing us to better constrain the geometry of fundamental Ross structures, and<br/>4. Use the shape, trends, wavelengths, and amplitudes of magnetic anomalies to define magnetic domains in the shield, common building blocks for continent-scale studies of Precambrian geologic structure and evolution.<br/><br/>High-resolution airborne magnetic data will be collected along a transect extending from exposed rocks of the Nimrod Group across the adjacent polar ice cap. The Nimrod Group represents the only bona fide Archean-Proterozoic shield basement exposed for over 2500 km of the Pacific margin of Antarctica. This survey will characterize the geologically well-known shield terrain in this sector using geophysical methods for the first time. This baseline over the exposed shield will allow for better interpretation of geophysical patterns in other ice-covered regions and can be used to target future investigations. In collaboration with colleagues from the BGR (Germany), a tightly-spaced, "draped" helicopter magnetic survey will be flown during the 2003-04 austral summer, to be complemented by ground measurements of gravity over the exposed basement. Data reduction, interpretation and geological correlation will be completed in the second year. This project will enhance the education of students, the advancement of under-represented groups, the research instrumentation of the U.S. Antarctic Program, partnerships between the federal government and institutions of higher education, and cooperation between national research programs. It will benefit society through the creation of new basic knowledge about the Antarctic continent, which in turn may help with applied research in other fields such as the glacial history of Antarctica.
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.
9316338 Jacobel This award is for support for a program of glaciological studies of Siple Dome and its surroundings between Ice Streams C and D. The purpose of the work is to characterize the dynamic environment and ice stratigraphy to aid in the assessment of Siple Dome as a potential deep ice core site, and to determine whether the configuration of ice stream flow in the region was different in the past than now. The work involves measurements of the configuration and continuity of internal layers in the ice, using radar echo sounding and determination of velocity field, based on standard GPS surveying. The goals of the work are relevant to understanding the dynamics of the West Antarctic Ice Sheet (WAIS), its past history and its potential future behavior, including possible effects on global sea level. This work is a collaborative project between the University of Washington, the University of Colorado and St. Olaf College. ***