{"dp_type": "Project", "free_text": "Ice Dynamic"}
[{"awards": "2336328 Larochelle, Stacy", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 08 Oct 2024 00:00:00 GMT", "description": "Ice sheets lose ice mass through gravity-driven flow to the ocean where ice breaks into icebergs and melts, contributing to global sea level rise. Water commonly found at the base of ice sheets facilitates this process by lubricating the ice-rock interface. The recent discovery of vast, kilometer-thick groundwater reservoirs beneath the Antarctic Ice Sheet thus raises important questions about the potential impact of groundwater on ice flow. It has been hypothesized that groundwater flow to the ice-sheet bed may accelerate ice flow as the ice sheet shrinks in response to global warming. Evaluating this hypothesis is challenging due to poorly understood interactions between water, ice, and rock, but is crucial for anticipating the response of ice sheets and sea level to climate change. Understanding how groundwater responds to a changing ice sheet also has important implications for the heat, chemical elements, and microorganisms it stores and transports.\u003cbr/\u003e\u003cbr/\u003eTo assess the impact of groundwater processes on ice dynamics, a new idealized modeling framework will be developed, incorporating several novel hydromechanical couplings between ice sheets, subglacial drainage systems, and groundwater aquifers. This framework will enable testing the hypotheses that (1) aquifers decelerate ice mass loss in the absence of a well-developed subglacial drainage system, but that (2) an efficient, channelized drainage system can reduce and even reverse this decelerating effect, and that (3) the impact of these phenomena is most pronounced for steep ice flowing rapidly over thick sedimentary basins and depends in a complex way on aquifer permeability. Existing geodetic, seismic, and other geophysical datasets at well-studied Thwaites Glacier and Whillans Ice Stream will be used to constrain model parameters and investigate the impact of groundwater processes in contrasting glaciologic settings. This work will help rule out or highlight subglacial groundwater as one of the next major challenges for efforts to predict the future of the Antarctic Ice Sheet and sea-level rise on decadal to millennial timescales. The project will contribute to educating the next generation of scientists by supporting an early-career PI and a graduate student, as well as participation in a field and research educational program in Alaska and the production of chapters for an online, open-source, free interactive textbook.\u003cbr/\u003e\u003cbr/\u003eThis 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": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GROUND WATER; GLACIERS/ICE SHEETS; Antarctica", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Larochelle, Stacy; Kingslake, Jonathan", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Modeling the Coupled Dynamics of Groundwater, Subglacial Hydrology and Ice Sheets", "uid": "p0010479", "west": null}, {"awards": "1149085 Bassis, Jeremy", "bounds_geometry": "POLYGON((66 -68,66.9 -68,67.8 -68,68.7 -68,69.6 -68,70.5 -68,71.4 -68,72.3 -68,73.2 -68,74.1 -68,75 -68,75 -68.6,75 -69.2,75 -69.8,75 -70.4,75 -71,75 -71.6,75 -72.2,75 -72.8,75 -73.4,75 -74,74.1 -74,73.2 -74,72.3 -74,71.4 -74,70.5 -74,69.6 -74,68.7 -74,67.8 -74,66.9 -74,66 -74,66 -73.4,66 -72.8,66 -72.2,66 -71.6,66 -71,66 -70.4,66 -69.8,66 -69.2,66 -68.6,66 -68))", "dataset_titles": "Antarctic Ice Shelf Rift Propagation Rates", "datasets": [{"dataset_uid": "601740", "doi": "10.15784/601740", "keywords": "Amery Ice Shelf; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; MODIS", "people": "Walker, Catherine; Bassis, Jeremy", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Shelf Rift Propagation Rates", "url": "https://www.usap-dc.org/view/dataset/601740"}], "date_created": "Fri, 13 Oct 2023 00:00:00 GMT", "description": "This CAREER award supports a project to develop physically based bounds on the amount ice sheets can contribute to sea level rise in the coming centuries. To simulate these limits, a three-dimensional discrete element model will be developed and applied to simulate regions of interest in the Greenland and Antarctic ice sheets. These regions will include Helheim Glacier, Jakobshavn Isbr\u00e4e, Pine Island Glacier and sections of the Larsen Ice Shelf. In the discrete element model the ice will be discretized into distinct blocks or boulders of ice that interact through inelastic collisions, frictional forces and bonds. The spectrum of best to worst case scenarios will be examined by varying the strength and number of bonds between neighboring blocks of ice. The worst case scenario corresponds to completely disarticulated ice that behaves in a manner akin to a granular material while the best case scenario corresponds to completely intact ice with no preexisting flaws or fractures. Results from the discrete element model will be compared with those from analogous continuum models that incorporate a plastic yield stress into the more traditional viscous flow approximations used to simulate ice sheets. This will be done to assess if a fracture permitting plastic rheology can be efficiently incorporated into large-scale ice sheet models to simulate the evolution of ice sheets over the coming centuries. This award will also support to forge a partnership with two science teachers in the Ypsilanti school district in southeastern Michigan. The Ypsilanti school district is a low income, resource- poor region with a population that consists of ~70% underrepresented minorities and ~69% of students qualify for a free or reduced cost lunch. The cornerstone of the proposed partnership is the development of lesson plans and content associated with a hands-on ice sheet dynamics activity for 6th and 7th grade science students. The activity will be designed so that it integrates into existing classroom lesson plans and is aligned with State of Michigan Science Technology, Engineering and Math (STEM) curriculum goals. The aim of this program is to not only influence the elementary school students, but also to educate the teachers to extend the impact of the partnership beyond the duration of this study. Graduate students will be mentored and engaged in outreach activities and assist in supervising undergraduate students. Undergraduates will play a key role in developing an experimental, analogue ice dynamics lab designed to illustrate how ice sheets and glaciers flow and allow experimental validation of the proposed research activities. The research program advances ice sheet modeling infrastructure by distributing results through the community based Community Ice Sheet Model.", "east": 75.0, "geometry": "POINT(70.5 -71)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Amery Ice Shelf", "locations": "Amery Ice Shelf", "north": -68.0, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Bassis, Jeremy", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "CAREER: Bound to Improve - Improved Estimates of the Glaciological Contribution to Sea Level Rise", "uid": "p0010437", "west": 66.0}, {"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": "2302832 Reilly, Brendan", "bounds_geometry": "POLYGON((-70 -55,-67 -55,-64 -55,-61 -55,-58 -55,-55 -55,-52 -55,-49 -55,-46 -55,-43 -55,-40 -55,-40 -56.1,-40 -57.2,-40 -58.3,-40 -59.4,-40 -60.5,-40 -61.6,-40 -62.7,-40 -63.8,-40 -64.9,-40 -66,-43 -66,-46 -66,-49 -66,-52 -66,-55 -66,-58 -66,-61 -66,-64 -66,-67 -66,-70 -66,-70 -64.9,-70 -63.8,-70 -62.7,-70 -61.6,-70 -60.5,-70 -59.4,-70 -58.3,-70 -57.2,-70 -56.1,-70 -55))", "dataset_titles": "NRM, ARM, IRM, and magnetic susceptibility investigations on U1537 and U1538 cube samples; Rock magnetic data from IODP Exp. 382 Sites U1537 and U1538 to support Reilly et al. \"A geochemical mechanism for \u003e10 m offsets of magnetic reversals inferred from the comparison of two Scotia Sea drill sites\"", "datasets": [{"dataset_uid": "200412", "doi": "10.7288/V4/MAGIC/19778", "keywords": null, "people": null, "repository": "MagIC (EarthRef)", "science_program": null, "title": "NRM, ARM, IRM, and magnetic susceptibility investigations on U1537 and U1538 cube samples", "url": "http://dx.doi.org/10.7288/V4/MAGIC/19778"}, {"dataset_uid": "200411", "doi": "10.5281/zenodo.10035106", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Rock magnetic data from IODP Exp. 382 Sites U1537 and U1538 to support Reilly et al. \"A geochemical mechanism for \u003e10 m offsets of magnetic reversals inferred from the comparison of two Scotia Sea drill sites\"", "url": "https://zenodo.org/records/10035107"}], "date_created": "Wed, 12 Jul 2023 00:00:00 GMT", "description": "The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica\u0027s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica\u0027s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth\u0027s most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change.\r\n\r\nThe proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica\u0027s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene.", "east": -40.0, "geometry": "POINT(-55 -60.5)", "instruments": null, "is_usap_dc": true, "keywords": "PALEOMAGNETISM; SEDIMENTS; Scotia Sea", "locations": "Scotia Sea", "north": -55.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE; PHANEROZOIC \u003e CENOZOIC", "persons": "Reilly, Brendan", "platforms": null, "repo": "MagIC (EarthRef)", "repositories": "MagIC (EarthRef); Zenodo", "science_programs": null, "south": -66.0, "title": "Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation", "uid": "p0010424", "west": -70.0}, {"awards": "1643961 Anandakrishnan, Sridhar", "bounds_geometry": "POLYGON((-80 -83,-79.8 -83,-79.6 -83,-79.4 -83,-79.2 -83,-79 -83,-78.8 -83,-78.6 -83,-78.4 -83,-78.2 -83,-78 -83,-78 -83.2,-78 -83.4,-78 -83.6,-78 -83.8,-78 -84,-78 -84.2,-78 -84.4,-78 -84.6,-78 -84.8,-78 -85,-78.2 -85,-78.4 -85,-78.6 -85,-78.8 -85,-79 -85,-79.2 -85,-79.4 -85,-79.6 -85,-79.8 -85,-80 -85,-80 -84.8,-80 -84.6,-80 -84.4,-80 -84.2,-80 -84,-80 -83.8,-80 -83.6,-80 -83.4,-80 -83.2,-80 -83))", "dataset_titles": "Rutford Ice Stream short period data", "datasets": [{"dataset_uid": "200336", "doi": "https://doi.org/10.7914/SN/5B_2018", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Rutford Ice Stream short period data", "url": "http://fdsn.adc1.iris.edu/networks/detail/5B_2018/"}], "date_created": "Wed, 16 Nov 2022 00:00:00 GMT", "description": "Anandakrishnan/1643961\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study conditions under the Rutford Ice Stream, a large glacier that flows from the interior of the West Antarctic Ice Sheet to the Filchner Ronne Ice Shelf and then on to the ocean. The speed and volume of ice delivered to the ocean by this and similar glaciers is central to the question of sea-level change in the coming decades: if the volume of ice carried by Rutford to the ocean increases, then it will contribute to a rise in sea level. Numerical models of glacier flow that are used to forecast future conditions must include a component that accounts for the sliding of the ice over its bed. The sliding process is poorly modeled because of lack of detailed information about the bottom of glaciers, leading to increased uncertainty in the ice-flow models. Data from this project will provide such information. \u003cbr/\u003e\u003cbr/\u003eDuring this project, in collaboration with researchers at the British Antarctic Survey, a detailed survey of the properties of the bed of Rutford Ice Stream will be carried out. These surveys include using seismic instruments (which are sensitive to naturally occurring earthquakes within glaciers--called icequakes) to monitor the distribution of those icequakes at the bed. The locations, size, and timing of icequakes are controlled by the properties of the bed such as porosity, water pressure, and stress. As part of this project, a hole will be drilled to the bed of the glacier to monitor water pressures and to extract a sample of the basal material. By comparing the pressure variations with icequake production, the properties of the basal material over a large area can be better determined. Those results will aid in the application of numerical models by informing their description of the sliding process. This award requires field work in 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": -78.0, "geometry": "POINT(-79 -84)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Seismicity; Ice Dynamic; Rutford Ice Stream", "locations": "Rutford Ice Stream", "north": -83.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "platforms": null, "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -85.0, "title": "Rutford Ice Stream Cooperative Research Program with British Antarctic Survey", "uid": "p0010392", "west": -80.0}, {"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": "Horlings, Annika; Hoffman, Andrew; Christian, John; Holschuh, Nicholas; Christianson, Knut; Hills, Benjamin; O\u0027Connor, Gemma", "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": "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": "Fudge, Tyler J; Christianson, Knut; Steig, Eric J.; Erwin, Emma; Horlings, Annika; 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; Jacobel, Robert; Christianson, Knut; Hoffman, Andrew", "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": "Christianson, Knut; Hoffman, Andrew; Holschuh, Nicholas; Paden, John", "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"}, {"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"}], "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": "1643431 Bitz, Cecilia", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Analysis code, processed observational data and climate model output required to produce figures for Roach et al (2022); Model output: CICE experiments with varying floe and wave physics described in Roach et al. (2019); Model output from experiments (FSD-M21) described in Cooper et al 2022.; Model output from experiments (IC4M1) described in Cooper et al 2022.; Model output from experiments (IC4M2) described in Cooper et al 2022.; Model output from experiments (IC4M3rad) described in Cooper et al 2022.; Model output from experiments (IC4M4) described in Cooper et al 2022.; Model output from experiments (IC4M5) described in Cooper et al 2022.; Model output from experiments (IC4M7) described in Cooper et al 2022.; Model output: NEMO-CICE with an emergent sea ice floe size distribution described in Roach et al (2018)", "datasets": [{"dataset_uid": "200301", "doi": "10.5281/zenodo.6213441", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M1) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6213441"}, {"dataset_uid": "200303", "doi": "10.5281/zenodo.6214364", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M3rad) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6214364"}, {"dataset_uid": "200304", "doi": "10. 5281/zenodo.6214555", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M4) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6214555"}, {"dataset_uid": "200305", "doi": "10.5281/zenodo.6214998", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M5) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6214998"}, {"dataset_uid": "200306", "doi": "10.5281/zenodo.6212423", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M7) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6212423"}, {"dataset_uid": "200307", "doi": "10.5281/zenodo.6212232", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (FSD-M21) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6212232"}, {"dataset_uid": "200308", "doi": "10.5281/zenodo.5913959", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Analysis code, processed observational data and climate model output required to produce figures for Roach et al (2022)", "url": "https://zenodo.org/record/5913959"}, {"dataset_uid": "200302", "doi": "10.5281/zenodo.6213793", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M2) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6213793"}, {"dataset_uid": "200309", "doi": "10.5281/zenodo.3463580", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output: CICE experiments with varying floe and wave physics described in Roach et al. (2019)", "url": "https://zenodo.org/record/3463580"}, {"dataset_uid": "200310", "doi": "10.5281/zenodo.1193930", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output: NEMO-CICE with an emergent sea ice floe size distribution described in Roach et al (2018)", "url": "https://zenodo.org/record/1193930"}], "date_created": "Tue, 19 Jul 2022 00:00:00 GMT", "description": "Sea-ice coverage surrounding Antarctica has expanded during the era of satellite observations, in contrast to rapidly shrinking Arctic sea ice. Most climate models predict Antarctic sea ice loss, rather than growth, indicating that there is much to learn about Antarctic sea ice in terms of its natural variability, processes and interactions affecting annual growth and retreat, and the impact of atmospheric factors such increasing greenhouse gases and stratospheric ozone depletion. This project is designed to improve model simulations of sea ice and examine the role of wind and wave forcing on changes in sea ice around Antarctica.\u003cbr/\u003e\u003cbr/\u003eThis project seeks to explain basic interactions of the coupled atmosphere, ocean, and ice dynamics in the Antarctic climate system, especially in the region near the sea ice edge. The summer evolution of sea ice cover and the near surface heat exchange of atmosphere and ocean depend on the geometric distribution of floes and the open water surrounding them. The distribution of floes has the greatest impact on the sea ice state in the marginal seas, where the distribution itself can vary rapidly. This project would develop and implement a model of sea ice floes in the Los Alamos sea ice model, known as CICE5. This sea ice component would be coupled to the third generation WaveWatch model within the Community Climate System Model Version 2. The coupled model would be used to study sea ice-wave interactions and the role of modeling sea ice floes in the Antarctic. The broader impacts of this project include outreach, support of female scientists, and improvement of the sea-ice codes in widely used climate models.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE FLOES; Southern Ocean; SEA ICE", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Bitz, Cecilia", "platforms": null, "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "The Role of Wave-sea Ice Floe Interactions in Recent Antarctic Sea Ice Change", "uid": "p0010350", "west": -180.0}, {"awards": "1644277 Aschwanden, Andy", "bounds_geometry": "POLYGON((-75 -60,-72 -60,-69 -60,-66 -60,-63 -60,-60 -60,-57 -60,-54 -60,-51 -60,-48 -60,-45 -60,-45 -61.5,-45 -63,-45 -64.5,-45 -66,-45 -67.5,-45 -69,-45 -70.5,-45 -72,-45 -73.5,-45 -75,-48 -75,-51 -75,-54 -75,-57 -75,-60 -75,-63 -75,-66 -75,-69 -75,-72 -75,-75 -75,-75 -73.5,-75 -72,-75 -70.5,-75 -69,-75 -67.5,-75 -66,-75 -64.5,-75 -63,-75 -61.5,-75 -60))", "dataset_titles": "Linear Theory of Orographic Precipitation QGIS Plugin; Parallel Ice Sheet Model (PISM) v2", "datasets": [{"dataset_uid": "601590", "doi": "10.15784/601590", "keywords": "Antarctica", "people": "Aschwanden, Andy", "repository": "USAP-DC", "science_program": null, "title": "Linear Theory of Orographic Precipitation QGIS Plugin", "url": "https://www.usap-dc.org/view/dataset/601590"}, {"dataset_uid": "601589", "doi": "10.15784/601589", "keywords": "Antarctica", "people": "Aschwanden, Andy", "repository": "USAP-DC", "science_program": null, "title": "Parallel Ice Sheet Model (PISM) v2", "url": "https://www.usap-dc.org/view/dataset/601589"}], "date_created": "Thu, 14 Jul 2022 00:00:00 GMT", "description": "Aschwanden/1644277\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study the phenomenon of the rain shadow (technically called orographic precipitation) in the Antarctic Peninsula and its interaction with a mountain range covered in ice and snow. Orographic precipitation gives rise to the largest climatic and ecological gradients on Earth. Air ascending on the windward side of the mountain range expands and cools, condensing the water vapor it carries and producing heavy rain- or snow-fall. As the air descends on the leeward flank, the air warms and dries out, leaving little-to-no precipitation. This pattern of snowfall, caused by the interaction of winds and the landscape, is hypothesized to control the shape of the ice cap itself. The investigators hypothesize that feedbacks between precipitation and topography control ice flux and temperature, impacting basal conditions (frozen versus wet) and motion, which over long time scales can affect basal topography via erosion.\u003cbr/\u003e\u003cbr/\u003eThe authors propose to investigate the feedbacks between orographically driven precipitation, ice dynamics, thermodynamics, and basal erosion and uplift over the northern Antarctic Peninsula by coupling an orographic precipitation model to the Parallel Ice Sheet Model (PISM). Using idealized and more realistic geometries, they will begin with a 2-D flow band model, which will be expanded into three dimensions to determine the strength of the feedbacks as a function of bedrock geometry and the intensity of the orographic precipitation gradient. The Antarctic Peninsula is targeted as the ideal case study, in the context of its rapid modern and future change as well as its deflation since the Last Glacial Maximum. The broader impacts of the work include the strengthening of predictive models by capturing feedbacks related to orographic precipitation not included in current models. This is likely to provide a more realistic assessment of the impacts of orographic precipitation in a regime of changing climate. The project will support an early career scientist and a female mid-career scientist and will support one PhD student, and provide summer research experience for one undergraduate student as an REU supplement. The project does not require field work in the Antarctic.", "east": -45.0, "geometry": "POINT(-60 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Antarctic Ice Sheet", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aschwanden, Andy; Pettit, Erin", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0, "title": "Collaborative Research: Feedbacks between Orographic Precipitation and Ice Dynamics", "uid": "p0010348", "west": -75.0}, {"awards": "1745068 Booth, Robert; 1745082 Beilman, David", "bounds_geometry": "POLYGON((-64.4 -62.4,-63.910000000000004 -62.4,-63.42 -62.4,-62.93000000000001 -62.4,-62.440000000000005 -62.4,-61.95 -62.4,-61.46 -62.4,-60.97 -62.4,-60.480000000000004 -62.4,-59.99 -62.4,-59.5 -62.4,-59.5 -62.7,-59.5 -63,-59.5 -63.3,-59.5 -63.6,-59.5 -63.900000000000006,-59.5 -64.2,-59.5 -64.5,-59.5 -64.80000000000001,-59.5 -65.10000000000001,-59.5 -65.4,-59.99 -65.4,-60.480000000000004 -65.4,-60.97 -65.4,-61.46 -65.4,-61.95 -65.4,-62.440000000000005 -65.4,-62.93000000000001 -65.4,-63.42 -65.4,-63.910000000000004 -65.4,-64.4 -65.4,-64.4 -65.10000000000001,-64.4 -64.80000000000001,-64.4 -64.5,-64.4 -64.2,-64.4 -63.900000000000006,-64.4 -63.6,-64.4 -63.3,-64.4 -63,-64.4 -62.7,-64.4 -62.4))", "dataset_titles": "LMG2002 Expedtition Data", "datasets": [{"dataset_uid": "200222", "doi": "10.7284/908802", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "LMG2002 Expedtition Data", "url": "https://www.rvdata.us/search/cruise/LMG2002"}], "date_created": "Fri, 10 Jun 2022 00:00:00 GMT", "description": "Warming on the western Antarctic Peninsula in the later 20th century has caused widespread changes in the cryosphere (ice and snow) and terrestrial ecosystems. These recent changes along with longer-term climate and ecosystem histories will be deciphered using peat deposits. Peat accumulation can be used to assess the rate of glacial retreat and provide insight into ecological processes on newly deglaciated landscapes in the Antarctic Peninsula. This project builds on data suggesting recent ecosystem transformations that are linked to past climate of the western Antarctic Peninsula and provide a timeline to assess the extent and rate of recent glacial change. The study will produce a climate record for the coastal low-elevation terrestrial region, which will refine the major climate shifts of up to 6 degrees C in the recent past (last 12,000 years). A novel terrestrial record of the recent glacial history will provide insight into observed changes in climate and sea-ice dynamics in the western Antarctic Peninsula and allow for comparison with off-shore climate records captured in sediments. Observations and discoveries from this project will be disseminated to local schools and science centers. The project provides training and career development for a postdoctoral scientist as well as graduate and undergraduate students.\u003cbr/\u003e\u003cbr/\u003eThe research presents a new systematic survey to reconstruct ecosystem and climate change for the coastal low-elevation areas on the western Antarctic Peninsula (AP) using proxy records preserved in late Holocene peat deposits. Moss and peat samples will be collected and analyzed to generate a comprehensive data set of late-Holocene climate change and ecosystem dynamics. The goal is to document and understand the transformations of landscape and terrestrial ecosystems on the western AP during the late Holocene. The testable hypothesis is that coastal regions have experienced greater climate variability than evidenced in ice-core records and that past warmth has facilitated dramatic ecosystem and cryosphere response. A primary product of the project is a robust reconstruction of late Holocene climate changes for coastal low-elevation terrestrial areas using multiple lines of evidence from peat-based biological and geochemical proxies, which will be used to compare with climate records derived from marine sediments and ice cores from the AP region. These data will be used to test several ideas related to novel peat-forming ecosystems (such as Antarctic hairgrass bogs) in past warmer climates and climate controls over ecosystem establishment and migration to help assess the nature of the Little Ice Age cooling and cryosphere response. The chronology of peat cores will be established by radiocarbon dating of macrofossils and Bayesian modeling. The high-resolution time series of ecosystem and climate changes will help put the observed recent changes into a long-term context to bridge climate dynamics over different time scales.\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": -59.5, "geometry": "POINT(-61.95 -63.900000000000006)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; ISOTOPES; USAP-DC; PALEOCLIMATE RECONSTRUCTIONS; SEDIMENTS; Amd/Us; FIELD INVESTIGATION; Antarctic Peninsula; AMD; TERRESTRIAL ECOSYSTEMS; USA/NSF; RADIOCARBON", "locations": "Antarctic Peninsula", "north": -62.4, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Beilman, David; Booth, Robert", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -65.4, "title": "Collaborative Research: Reconstructing Late Holocene Ecosystem and Climate Shifts from Peat Records in the Western Antarctic Peninsula", "uid": "p0010337", "west": -64.4}, {"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": "200314", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "icepack", "url": "https://github.com/icepack/icepack"}, {"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"}], "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 Glaciology; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences", "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": "1643534 Cassar, Nicolas", "bounds_geometry": "POLYGON((-83 -62,-80.3 -62,-77.6 -62,-74.9 -62,-72.2 -62,-69.5 -62,-66.8 -62,-64.1 -62,-61.4 -62,-58.7 -62,-56 -62,-56 -63.1,-56 -64.2,-56 -65.3,-56 -66.4,-56 -67.5,-56 -68.6,-56 -69.7,-56 -70.8,-56 -71.9,-56 -73,-58.7 -73,-61.4 -73,-64.1 -73,-66.8 -73,-69.5 -73,-72.2 -73,-74.9 -73,-77.6 -73,-80.3 -73,-83 -73,-83 -71.9,-83 -70.8,-83 -69.7,-83 -68.6,-83 -67.5,-83 -66.4,-83 -65.3,-83 -64.2,-83 -63.1,-83 -62))", "dataset_titles": "Palmer LTER 18S rRNA gene metabarcodin; rDNA amplicon sequencing of WAP microbial community", "datasets": [{"dataset_uid": "200286", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "rDNA amplicon sequencing of WAP microbial community", "url": "https://www.ncbi.nlm.nih.gov/sra/SRR6162326/"}, {"dataset_uid": "200285", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "Palmer LTER 18S rRNA gene metabarcodin", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA508517"}], "date_created": "Thu, 03 Mar 2022 00:00:00 GMT", "description": "This project seeks to make detailed measurements of the oxygen content of the surface ocean along the Western Antarctic Peninsula. Detailed maps of changes in net oxygen content will be combined with measurements of the surface water chemistry and phytoplankton distributions. The project will determine the extent to which on-shore or offshore phytoplankton blooms along the peninsula are likely to lead to different amounts of carbon being exported to the deeper ocean. \r\n\r\nThe project will analyze oxygen in relation to argon that will allow determination of the physical and biological contributions to surface ocean oxygen dynamics. These assessments will be combined with spatial and temporal distributions of nutrients (iron and macronutrients) and irradiances. This will allow the investigators to unravel the complex interplay between ice dynamics, iron and physical mixing dynamics as they relate to Net Community Production (NCP) in the region. NCP measurements will be normalized to Particulate Organic Carbon (POC) and be used to help identify area of \"High Biomass and Low NCP\" and those with \"Low Biomass and High NCP\" as a function of microbial plankton community composition. The team will use machine learning methods- including decision tree assemblages and genetic programming- to identify plankton groups key to facilitating biological carbon fluxes. Decomposing the oxygen signal along the West Antarctic Peninsula will also help elucidate biotic and abiotic drivers of the O2 saturation to further contextualize the growing inventory of oxygen measurements (e.g. by Argo floats) throughout the global oceans.", "east": -56.0, "geometry": "POINT(-69.5 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "West Antarctica; USAP-DC; BIOGEOCHEMICAL CYCLES; AMD; USA/NSF; LABORATORY; Amd/Us", "locations": "West Antarctica", "north": -62.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cassar, Nicolas", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NCBI", "repositories": "NCBI", "science_programs": null, "south": -73.0, "title": "Biological and Physical Drivers of Oxygen Saturation and Net Community Production Variability along the Western Antarctic Peninsula", "uid": "p0010303", "west": -83.0}, {"awards": "0944150 Hall, Brenda", "bounds_geometry": "POLYGON((163.6 -77.5,163.7 -77.5,163.8 -77.5,163.9 -77.5,164 -77.5,164.1 -77.5,164.2 -77.5,164.3 -77.5,164.4 -77.5,164.5 -77.5,164.6 -77.5,164.6 -77.57,164.6 -77.64,164.6 -77.71,164.6 -77.78,164.6 -77.85,164.6 -77.92,164.6 -77.99,164.6 -78.06,164.6 -78.13,164.6 -78.2,164.5 -78.2,164.4 -78.2,164.3 -78.2,164.2 -78.2,164.1 -78.2,164 -78.2,163.9 -78.2,163.8 -78.2,163.7 -78.2,163.6 -78.2,163.6 -78.13,163.6 -78.06,163.6 -77.99,163.6 -77.92,163.6 -77.85,163.6 -77.78,163.6 -77.71,163.6 -77.64,163.6 -77.57,163.6 -77.5))", "dataset_titles": "Marshall Valley Radiocarbon Data; Marshall Valley U-Series Data; Royal Society Range Headland Moraine Belt Radiocarbon Data; Salmon Valley Radiocarbon Data", "datasets": [{"dataset_uid": "601555", "doi": "10.15784/601555", "keywords": "Antarctica; Last Glacial Maximum; McMurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Royal Society Range Headland Moraine Belt Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601555"}, {"dataset_uid": "601556", "doi": "10.15784/601556", "keywords": "Antarctica; Last Glacial Maximum; McMurdo Sound; Radiocarbon Dates; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Salmon Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601556"}, {"dataset_uid": "601529", "doi": "10.15784/601529", "keywords": "Algae; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marshall Valley; Radiocarbon; Ross Sea Drift; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601529"}, {"dataset_uid": "601528", "doi": "10.15784/601528", "keywords": "234U/230Th Dating; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Last Glacial Maximum; Marshall Drift; Marshall Valley; MIS 6; Royal Society Range", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Marshall Valley U-Series Data", "url": "https://www.usap-dc.org/view/dataset/601528"}], "date_created": "Thu, 03 Mar 2022 00:00:00 GMT", "description": "This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth\u0027s climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area. ", "east": 164.6, "geometry": "POINT(164.1 -77.85)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; Amd/Us; AMD; USA/NSF; GLACIAL LANDFORMS; USAP-DC; Royal Society Range; GLACIER ELEVATION/ICE SHEET ELEVATION", "locations": "Royal Society Range", "north": -77.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Denton, George", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.2, "title": "Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles", "uid": "p0010302", "west": 163.6}, {"awards": "2114786 Warnock, Jonathan", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 09 Sep 2021 00:00:00 GMT", "description": "The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica\u2019s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica\u2019s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth\u0027s most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change.\r\nThe proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica\u2019s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "MICROFOSSILS; FIELD SURVEYS; Weddell Sea Embayment; USA/NSF; SEA ICE; USAP-DC; PALEOCLIMATE RECONSTRUCTIONS; SEA SURFACE TEMPERATURE; AMD; Amd/Us", "locations": "Weddell Sea Embayment", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Warnock, Jonathan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation", "uid": "p0010260", "west": null}, {"awards": "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": "1643618 Arrigo, Kevin; 1643652 Hofmann, Eileen", "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 biological model output; Antarctic dFe model dyes", "datasets": [{"dataset_uid": "200211", "doi": "10.26008/1912/bco-dmo.858663.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic biological model output", "url": "https://www.bco-dmo.org/dataset/858663"}, {"dataset_uid": "200210", "doi": "10.26008/1912/bco-dmo.782848.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic dFe model dyes", "url": "https://www.bco-dmo.org/dataset/782848"}], "date_created": "Thu, 29 Apr 2021 00:00:00 GMT", "description": "Coastal waters surrounding Antarctica represent some of the most biologically rich and most untouched ecosystems on Earth. In large part, this biological richness is concentrated within the numerous openings that riddle the expansive sea ice (these openings are known as polynyas) near the Antarctic continent. These polynyas represent regions of enhanced production known as hot-spots and support the highest animal densities in the Southern Ocean. Many of them are also located adjacent to floating extensions of the vast Antarctic Ice Sheet and receive a substantial amount of meltwater runoff each year during the summer. However, little is known about the specific processes that make these ecosystems so biologically productive. Of the 46 Antarctic coastal polynyas that are presently known, only a handful have been investigated in detail.\r\nThis project will develop ecosystem models for the Ross Sea polynya, Amundsen polynya, and Pine Island polynya; three of the most productive Antarctic coastal polynyas. The primary goal is to use these models to better understand the fundamental physical, chemical, and biological interacting processes and differences in these processes that make these systems so biologically productive yet different in some respects (e.g. size and productivity) during the present day settings. Modeling efforts will also be extended to potentially assess how these ecosystems may have functioned in the past and how they might change in the future under different physical and chemical and climatic settings.\r\nThe project will advance the education of underrepresented minorities through Stanford?s Summer Undergraduate Research in Geoscience and Engineering (SURGE) Program. SURGE will provide undergraduates the opportunity to gain mentored research experiences at Stanford University in engineering and the geosciences. Old Dominion University also will utilize an outreach programs for local public and private schools as well as an ongoing program supporting the Boy Scout Oceanography merit badge program to create outreach and education impacts.\r\n\r\nPolynyas (areas of open water surrounded by sea ice) are disproportionately productive regions of polar ecosystems, yet controls on their high rates of production are not well understood. This project will provide quantitative assessments of the physical and chemical processes that control phytoplankton abundance and productivity within polynyas, how these differ for different polynyas, and how polynyas may change in the future. Of particular interest are the interactions among processes within the polynyas and the summertime melting of nearby ice sheets, including the Thwaites and Pine Island glaciers.\r\nIn this proposed study, we will develop a set of comprehensive, high resolution coupled physical-biological models and implement these for three major, but diverse, Antarctic polynyas. These polynyas, the Ross Sea polynya, the Amundsen polynya, and Pine Island polynya, account for \u003e50% of the total Antarctic polynya production.\r\nThe research questions to be addressed are: 1) What environmental factors exert the greatest control of primary production in polynyas around Antarctica? 2) What are the controlling physics that leads to the heterogeneity of dissolved iron (dFe) supply to the euphotic zone in polynyas around the Antarctic continental shelf? What effect does this have on local rates of primary production? 3) What are the likely changes in the supply of dFe to the euphotic zone in the next several decades due to climate-induced changes in the physics (winds, sea-ice, ice shelf basal melt, cross-shelf exchange, stratification and vertical mixing) and how will this affect primary productivity around the continent?\r\nThe Ross Sea, Amundsen, and Pine Island polynyas are some of the best-sampled polynyas in Antarctica, facilitating model parameterization and validation. Furthermore, these polynyas differ widely in their size, location, sea ice dynamics, relationship to melting ice shelves, and distance from the continental shelf break, making them ideal case studies. For comparison, the western Antarctic Peninsula (wAP), a productive continental shelf where polynyas are a relatively minor contributor to biological production, will also be modeled. Investigating specific processes within different types Antarctic coastal waters will provide a better understand of how these important biological oases function and how they might change under different environmental conditions.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Trace Metal; AMD; PELAGIC; POLYNYAS; PHYTOPLANKTON; MODELS; Amd/Us; USAP-DC; MICROALGAE; USA/NSF; Polynya; TRACE ELEMENTS; ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "van Dijken, Gert; Arrigo, Kevin; Dinniman, Michael; Hofmann, Eileen", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Elucidating Environmental Controls of Productivity in Polynas and the Western Antarctic Peninsula", "uid": "p0010175", "west": -180.0}, {"awards": "1929991 Pettit, Erin C; 1738992 Pettit, Erin C", "bounds_geometry": "POLYGON((-114 -74,-113 -74,-112 -74,-111 -74,-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-104 -74.2,-104 -74.4,-104 -74.6,-104 -74.8,-104 -75,-104 -75.2,-104 -75.4,-104 -75.6,-104 -75.8,-104 -76,-105 -76,-106 -76,-107 -76,-108 -76,-109 -76,-110 -76,-111 -76,-112 -76,-113 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74))", "dataset_titles": "AMIGOS-IIIa \"Cavity\" Aquadopp current data Jan 2020 - Mar 2021; AMIGOS-IIIa \"Cavity\" Seabird CTD data Jan 2020 - Dec 2021; AMIGOS-III Cavity and Channel Snow Height and Thermistor Snow Temperature Data; AMIGOS-IIIc \"Channel\" Aquadopp current data Jan 2020 - Mar 2021; AMIGOS-IIIc \"Channel\" Seabird CTD data Jan 2020 - Dec 2021; CTD data from the NBP 19/02 cruise as part of the TARSAN project in the Amundsen Sea during austral summer 2018/2019; Dotson-Crosson Ice Shelf data from a tale of two ice shelves paper; SIIOS Temporary Deployment; Sub-ice-shelf seafloor elevation derived from point-source active-seismic data on Thwaites Eastern Ice Shelf and Dotson Ice Shelf, December 2019 and January 2020; Thwaites Glacier grounding lines for 2014 and 2019/20 from height above flotation; Two-year velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2001-2020; Visala WXT520 weather station data at the Cavity and Channel AMIGOS-III sites", "datasets": [{"dataset_uid": "200204", "doi": "https://doi.org/10.7914/SN/1L_2019", "keywords": null, "people": null, "repository": "International Federation of Digital Seismograph Networks", "science_program": null, "title": "SIIOS Temporary Deployment", "url": "http://www.fdsn.org/networks/detail/1L_2019/"}, {"dataset_uid": "601552", "doi": "10.15784/601552", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Pine Island Bay; Snow Accumulation; Snow Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-III Cavity and Channel Snow Height and Thermistor Snow Temperature Data", "url": "https://www.usap-dc.org/view/dataset/601552"}, {"dataset_uid": "601549", "doi": "10.15784/601549", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Pine Island Bay; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Visala WXT520 weather station data at the Cavity and Channel AMIGOS-III sites", "url": "https://www.usap-dc.org/view/dataset/601549"}, {"dataset_uid": "601548", "doi": "10.15784/601548", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIc \"Channel\" Aquadopp current data Jan 2020 - Mar 2021", "url": "https://www.usap-dc.org/view/dataset/601548"}, {"dataset_uid": "601547", "doi": "10.15784/601547", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIa \"Cavity\" Aquadopp current data Jan 2020 - Mar 2021", "url": "https://www.usap-dc.org/view/dataset/601547"}, {"dataset_uid": "601578", "doi": "10.15784/601578", "keywords": "Antarctica; Dotson Ice Shelf; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Segabinazzi-Dotto, Tiago; Wild, Christian", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Dotson-Crosson Ice Shelf data from a tale of two ice shelves paper", "url": "https://www.usap-dc.org/view/dataset/601578"}, {"dataset_uid": "601545", "doi": "10.15784/601545", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Salinity; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIc \"Channel\" Seabird CTD data Jan 2020 - Dec 2021", "url": "https://www.usap-dc.org/view/dataset/601545"}, {"dataset_uid": "601544", "doi": "10.15784/601544", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Salinity; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIa \"Cavity\" Seabird CTD data Jan 2020 - Dec 2021", "url": "https://www.usap-dc.org/view/dataset/601544"}, {"dataset_uid": "200321", "doi": "10.5285/e338af5d-8622-05de-e053-6c86abc06489", "keywords": null, "people": null, "repository": "British Oceanographic Data Centre", "science_program": null, "title": "CTD data from the NBP 19/02 cruise as part of the TARSAN project in the Amundsen Sea during austral summer 2018/2019", "url": "https://www.bodc.ac.uk/data/published_data_library/catalogue/10.5285/e338af5d-8622-05de-e053-6c86abc06489/"}, {"dataset_uid": "601499", "doi": "10.15784/601499", "keywords": "Amundsen Sea; Antarctica; Glaciology; Grounding Line; Ice Shelf; Thwaites Glacier", "people": "Alley, Karen; Scambos, Ted; Truffer, Martin; Wild, Christian; Pettit, Erin; Muto, Atsu", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Thwaites Glacier grounding lines for 2014 and 2019/20 from height above flotation", "url": "https://www.usap-dc.org/view/dataset/601499"}, {"dataset_uid": "601827", "doi": "10.15784/601827", "keywords": "Antarctica; Cryosphere; Dotson Ice Shelf; Thwaites Glacier", "people": "Wallin, Bruce; Muto, Atsuhiro; Alley, Karen; Roccaro, Alexander; Pettit, Erin; Truffer, Martin; Scambos, Ted; Wild, Christian; Pomraning, Dale", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Sub-ice-shelf seafloor elevation derived from point-source active-seismic data on Thwaites Eastern Ice Shelf and Dotson Ice Shelf, December 2019 and January 2020", "url": "https://www.usap-dc.org/view/dataset/601827"}, {"dataset_uid": "601478", "doi": "10.15784/601478", "keywords": "Antarctica; Glaciology; Ice Shelf; Ice Velocity; Strain Rate; Thwaites Glacier", "people": "Klinger, Marin; Wallin, Bruce; Truffer, Martin; Muto, Atsu; Pettit, Erin; Wild, Christian; Scambos, Ted; Alley, Karen", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Two-year velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2001-2020", "url": "https://www.usap-dc.org/view/dataset/601478"}], "date_created": "Mon, 22 Feb 2021 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites and neighboring glaciers in the Amundsen Sea Embayment are rapidly losing mass in response to recent climate warming and related changes in ocean circulation. Mass loss from the Amundsen Sea Embayment could lead to the eventual collapse of the West Antarctic Ice Sheet, raising the global sea level by up to 2.5 meters (8 feet) in as short as 500 years. The processes driving the loss appear to be warmer ocean circulation and changes in the width and flow speed of the glacier, but a better understanding of these changes is needed to refine predictions of how the glacier will evolve. One highly sensitive process is the transitional flow of glacier ice from land onto the ocean to become a floating ice shelf. This flow of ice from grounded to floating is affected by changes in air temperature and snowfall at the surface; the speed and thickness of ice feeding it from upstream; and the ocean temperature, salinity, bathymetry, and currents that the ice flows into. The project team will gather new measurements of each of these local environmental conditions so that it can better predict how future changes in air, ocean, or the ice will affect the loss of ice to the ocean in this region. \u003cbr/\u003e \u003cbr/\u003eCurrent and anticipated near-future mass loss from Thwaites Glacier and nearby Amundsen Sea Embayment region is mainly attributed to reduction in ice-shelf buttressing due to sub-ice-shelf melting by intrusion of relatively warm Circumpolar Deep Water into sub-ice-shelf cavities. Such predictions for mass loss, however, still lack understanding of the dominant processes at and near grounding zones, especially their spatial and temporal variability, as well as atmospheric and oceanic drivers of these processes. This project aims to constrain and compare these processes for the Thwaites and the Dotson Ice Shelves, which are connected through upstream ice dynamics, but influenced by different submarine troughs. The team\u0027s specific objectives are to: 1) install atmosphere-ice-ocean multi-sensor remote autonomous stations on the ice shelves for two years to provide sub-daily continuous observations of concurrent oceanic, glaciologic, and atmospheric conditions; 2) measure ocean properties on the continental shelf adjacent to ice-shelf fronts (using seal tagging, glider-based and ship-based surveys, and existing moored and conductivity-temperature-depth-cast data), 3) measure ocean properties into sub-ice-shelf cavities (using autonomous underwater vehicles) to detail ocean transports and heat fluxes; and 4) constrain current ice-shelf and sub-ice-shelf cavity geometry, ice flow, and firn properties for the ice-shelves (using radar, active-source seismic, and gravimetric methods) to better understand the impact of ocean and atmosphere on the ice-sheet change. The team will also engage the public and bring awareness to this rapidly changing component of the cryosphere through a \"Live from the Ice\" social media campaign in which the public can follow the action and data collection from the perspective of tagged seals and autonomous stations.\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": -104.0, "geometry": "POINT(-109 -75)", "instruments": null, "is_usap_dc": true, "keywords": "Thwaites Glacier; FIELD SURVEYS; GLACIERS/ICE SHEETS", "locations": "Thwaites Glacier", "north": -74.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Truffer, Martin; Scambos, Ted; Muto, Atsu; Heywood, Karen; Boehme, Lars; Hall, Robert; Wahlin, Anna; Lenaerts, Jan; Pettit, Erin", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "International Federation of Digital Seismograph Networks", "repositories": "British Oceanographic Data Centre; International Federation of Digital Seismograph Networks; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment", "uid": "p0010162", "west": -114.0}, {"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": "1724670 Williams, Trevor", "bounds_geometry": "POLYGON((-70 -60,-65 -60,-60 -60,-55 -60,-50 -60,-45 -60,-40 -60,-35 -60,-30 -60,-25 -60,-20 -60,-20 -62.5,-20 -65,-20 -67.5,-20 -70,-20 -72.5,-20 -75,-20 -77.5,-20 -80,-20 -82.5,-20 -85,-25 -85,-30 -85,-35 -85,-40 -85,-45 -85,-50 -85,-55 -85,-60 -85,-65 -85,-70 -85,-70 -82.5,-70 -80,-70 -77.5,-70 -75,-70 -72.5,-70 -70,-70 -67.5,-70 -65,-70 -62.5,-70 -60))", "dataset_titles": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "datasets": [{"dataset_uid": "601377", "doi": "10.15784/601377", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601377"}, {"dataset_uid": "601379", "doi": "10.15784/601379", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601379"}, {"dataset_uid": "601378", "doi": "10.15784/601378", "keywords": "40Ar/39Ar Thermochronology; Antarctica; Argon; Chemistry:sediment; Chemistry:Sediment; Detrital Minerals; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Sediments; Mass Spectrometer; Provenance; R/v Polarstern; Sediment Core Data; Subglacial Till; Till; Weddell Sea", "people": "Williams, Trevor", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on detrital mineral grains from the Weddell Sea embayment", "url": "https://www.usap-dc.org/view/dataset/601378"}], "date_created": "Thu, 10 Sep 2020 00:00:00 GMT", "description": "Abstract for the general public:\u003cbr/\u003e\u003cbr/\u003eThe margins of the Antarctic ice sheet have advanced and retreated repeatedly over the past few million years. Melting ice from the last retreat, from 19,000 to 9,000 years ago, raised sea levels by 8 meters or more, but the extents of previous retreats are less well known. The main goal of this project is to understand how Antarctic ice retreats: fast or slow, stepped or steady, and which parts of the ice sheet are most prone to retreat. Antarctica loses ice by two main processes: melting of the underside of floating ice shelves and calving of icebergs. Icebergs themselves are ephemeral, but they carry mineral grains and rock fragments that have been scoured from Antarctic bedrock. As the icebergs drift and melt, this \u0027iceberg-rafted debris\u0027 falls to the sea-bed and is steadily buried in marine sediments to form a record of iceberg activity and ice sheet retreat. The investigators will read this record of iceberg-rafted debris to find when and where Antarctic ice destabilized in the past. This information can help to predict how Antarctic ice will behave in a warming climate. \u003cbr/\u003e\u003cbr/\u003eThe study area is the Weddell Sea embayment, in the Atlantic sector of Antarctica. Principal sources of icebergs are the nearby Antarctic Peninsula and Weddell Sea embayment, where ice streams drain about a quarter of Antarctic ice. The provenance of the iceberg-rafted debris (IRD), and the icebergs that carried it, will be found by matching the geochemical fingerprint (such as characteristic argon isotope ages) of individual mineral grains in the IRD to that of the corresponding source area. In more detail, the project will: \u003cbr/\u003e\u003cbr/\u003e1. Define the geochemical fingerprints of the source areas of the glacially-eroded material using samples from each major ice stream entering the Weddell Sea. Existing data indicates that the hinterland of the Weddell embayment is made up of geochemically distinguishable source areas, making it possible to apply geochemical provenance techniques to determine the origin of Antarctica icebergs. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till samples to characterize detritus supplied by the Recovery and Foundation ice streams. \u003cbr/\u003e\u003cbr/\u003e2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information identifies which groups of ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents), and the stratigraphy of the cores shows the relative sequence of ice stream activity through time. A further dimension is added by determining the time lag between fine sediment erosion and deposition, using a new method of uranium-series isotope measurements in fine grained material. \u003cbr/\u003e\u003cbr/\u003eTechnical abstract:\u003cbr/\u003e\u003cbr/\u003e The behavior of the Antarctic ice sheets and ice streams is a critical topic for climate change and future sea level rise. The goal of this proposal is to constrain ice sheet response to changing climate in the Weddell Sea during the three most recent glacial terminations, as analogues for potential future warming. The project will also examine possible contributions to Meltwater Pulse 1A, and test the relative stability of the ice streams draining East and West Antarctica. Much of the West Antarctic ice may have melted during the Eemian (130 to 114 Ka), so it may be an analogue for predicting future ice drawdown over the coming centuries. \u003cbr/\u003e\u003cbr/\u003eGeochemical provenance fingerprinting of glacially eroded detritus provides a novel way to reconstruct the location and relative timing of glacial retreat during these terminations in the Weddell Sea embayment. The two major objectives of the project are to: \u003cbr/\u003e\u003cbr/\u003e1. Define the provenance source areas by characterizing Ar, U-Pb, and Nd isotopic signatures, and heavy mineral and Fe-Ti oxide compositions of detrital minerals from each major ice stream entering the Weddell Sea, using onshore tills and existing sediment cores from the Ronne and Filchner Ice Shelves. Pilot data demonstrate that detritus originating from the east and west sides of the Weddell Sea embayment can be clearly distinguished, and published data indicates that the hinterland of the embayment is made up of geochemically distinguishable source areas. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till to characterize detritus supplied by the Recovery and Foundation ice streams. \u003cbr/\u003e\u003cbr/\u003e2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information will identify which ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents). The stratigraphy of the cores will show the relative sequence of ice stream activity through time. A further time dimension is added by determining the time lag between fine sediment erosion and deposition, using U-series comminution ages.", "east": -20.0, "geometry": "POINT(-45 -72.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "TERRIGENOUS SEDIMENTS; Subglacial Till; USAP-DC; ICEBERGS; AMD; USA/NSF; ISOTOPES; AGE DETERMINATIONS; Argon; Provenance; Till; Amd/Us; R/V POLARSTERN; FIELD INVESTIGATION; SEDIMENT CHEMISTRY; Weddell Sea; Antarctica; LABORATORY", "locations": "Weddell Sea; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Williams, Trevor; Hemming, Sidney R.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V POLARSTERN", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance", "uid": "p0010128", "west": -70.0}, {"awards": "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": "9319854 Bell, Robin; 9319877 Finn, Carol; 9319369 Blankenship, Donald", "bounds_geometry": "POLYGON((-155 -77.5,-150 -77.5,-145 -77.5,-140 -77.5,-135 -77.5,-130 -77.5,-125 -77.5,-120 -77.5,-115 -77.5,-110 -77.5,-105 -77.5,-105 -78.2,-105 -78.9,-105 -79.6,-105 -80.3,-105 -81,-105 -81.7,-105 -82.4,-105 -83.1,-105 -83.8,-105 -84.5,-110 -84.5,-115 -84.5,-120 -84.5,-125 -84.5,-130 -84.5,-135 -84.5,-140 -84.5,-145 -84.5,-150 -84.5,-155 -84.5,-155 -83.8,-155 -83.1,-155 -82.4,-155 -81.7,-155 -81,-155 -80.3,-155 -79.6,-155 -78.9,-155 -78.2,-155 -77.5))", "dataset_titles": "SOAR-BSB Airborne gravity data for the CASERTZ/WAIS project; SOAR-IRE airborne gravity data for the CASERTZ/WAIS project; SOAR-TKD airborne gravity data for the CASERTZ/WAIS project; SOAR-WAZ Airborne gravity data for the CASERTZ/WAIS project", "datasets": [{"dataset_uid": "601291", "doi": "10.15784/601291", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Solid Earth; WAIS", "people": "Arko, Robert A.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WAZ Airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601291"}, {"dataset_uid": "601289", "doi": "10.15784/601289", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Solid Earth; WAIS", "people": "Bell, Robin; Arko, Robert A.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-TKD airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601289"}, {"dataset_uid": "601290", "doi": "10.15784/601290", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Solid Earth; WAIS", "people": "Arko, Robert A.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-IRE airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601290"}, {"dataset_uid": "601288", "doi": "10.15784/601288", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Solid Earth; WAIS", "people": "Arko, Robert A.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-BSB Airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601288"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "This award supports a project to conduct an integrated geophysical survey over a large portion of the West Antarctic Ice Sheet (WAIS) toward an understanding of the dynamic behavior of the ice sheet and the nature of the lithosphere beneath the ice sheet. West Antarctica is characterized by two kinds of the Earth s most dynamic systems, a continental rift (the West Antarctic Rift System) and a marine based ice sheet (the WAIS). Active continental rift systems, caused by divergent plate motions, result in thinned continental crust. Associated with the thin crust are fault-bounded sedimentary basins, active volcanism, and elevated heat flow. Marine ice sheets are characterized by rapidly moving streams of ice, penetrating and draining a slowly moving ice reservoir. Evidence left by past marine ice sheets indicates that they may have a strongly non- linear response to long-term climate change which results in massive and rapid discharges of ice. Understanding the evolution of the ice stream system and its interaction with the interior ice is the key to understanding this non-linear response. Subglacial geology and ice dynamics are generally studied in isolation, but evidence is mounting that the behavior of the West Antarctic ice streams may be closely linked to the nature of the underlying West Antarctic rift system. The fast moving ice streams appear to glide on a lubricating layer of water-saturated till. This till requires easily eroded sediment and a source of water, both of which may be controlled by the geology of the rift system; the sediments from the fault-bounded basins and the water from the elevated heat flux associated with active lithospheric extension. This project represents an interdisciplinary aerogeophysical study to characterize the lithosphere of the West Antarctic rift system beneath critical regions of the WAIS. The objective is to determine the effects of the rift architect ure, as manifested by the distribution of sedimentary basins and volcanic constructs, on the ice stream system. The research tool is a unique geophysical aircraft with laser altimetry, ice penetrating radar, aerogravity, and aeromagnetic systems integrated with a high precision kinematic GPS navigation system. It is capable of imaging both the surface and bed of the ice sheet while simultaneously measuring the gravity and magnetic signature of the subglacial lithosphere. Work to be done under this award will build on work already completed in the southern sector of central West Antarctica and it will focus on the region of the Byrd Subglacial Basin and Ice Stream D. The ice sheet in these regions is completely covered by satellite imagery and so this project will be integrated with remote sensing studies of the ice stream. The changing dynamics of Ice Stream D, as with other West Antarctic ice streams, seem to be correlated with changes in the morphological provinces of the underlying rift system. The experimental targets proceed from the divide of the interior ice, downstream through the onset of streaming to the trunk of Ice Stream D. This study will be coordinated with surface glaciological investigations of Ice Stream D and will be used to guide cooperative over-snow seismic investigations of the central West Antarctic rift system. The data will also be used to select a site for future deep ice coring along the crest of the WAIS. These data represent baseline data for long term global change monitoring work and represent crucial boundary conditions for ice sheet modeling efforts.", "east": -105.0, "geometry": "POINT(-130 -81)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": true, "keywords": "USAP-DC; MAGNETIC FIELD; GRAVITY FIELD; Antarctica; GLACIERS/ICE SHEETS; Marie Byrd Land; Airborne Gravity", "locations": "Marie Byrd Land; Antarctica", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Blankenship, Donald D.; Finn, C. A.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.5, "title": "Collaborative Research: Lithospheric Controls on the Behavior of the West Antarctic Ice Sheet: Corridor Aerogeophysics of Eastern Ross Transect Zone", "uid": "p0010094", "west": -155.0}, {"awards": "1443105 Steig, Eric", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core; South Pole high resolution ice core water stable isotope record for dD, d18O; South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "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": "Morris, Valerie; Jones, Tyler R.; Steig, Eric J.; Schauer, Andrew; Kahle, Emma; Vaughn, Bruce; White, James", "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"}, {"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}, {"dataset_uid": "601239", "doi": "10.15784/601239", "keywords": "Antarctica; Cavity Ring Down Spectrometers; Delta 18O; Delta Deuterium; Deuterium Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Oxygen Isotope; Snow/ice; Snow/Ice; Stable Isotopes", "people": "Morris, Valerie; Kahle, Emma; Jones, Tyler R.; Steig, Eric J.; Vaughn, Bruce; White, James; Schauer, Andrew", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole high resolution ice core water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601239"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Jones, Tyler R.; Kahle, Emma; Steig, Eric J.; Fudge, T. J.; Koutnik, Michelle; Morris, Valerie; Vaughn, Bruce; Schauer, Andrew; Stevens, Max; Conway, Howard; Waddington, Edwin D.; Buizert, Christo; Epifanio, Jenna; White, James", "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"}], "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 Sea Salt and Major Ions; South Pole ice core (SPC14) discrete methane data; South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Jones, Tyler R.; Kahle, Emma; Steig, Eric J.; Fudge, T. J.; Koutnik, Michelle; Morris, Valerie; Vaughn, Bruce; Schauer, Andrew; Stevens, Max; Conway, Howard; Waddington, Edwin D.; Buizert, Christo; Epifanio, Jenna; White, James", "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": "Kahle, Emma; Severinghaus, Jeffrey P.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.; Sowers, Todd A.; Steig, Eric J.; Winski, Dominic A.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601221", "doi": "10.15784/601221", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Depth; Ice Core Records; Snow/ice; Snow/Ice; SPICEcore", "people": "Nicewonger, Melinda R.; Kahle, Emma; Souney, Joseph Jr.; Twickler, Mark; Fegyveresi, John; Casey, Kimberly A.; Aydin, Murat; Steig, Eric J.; Nunn, Richard; Hargreaves, Geoff; Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth", "url": "https://www.usap-dc.org/view/dataset/601221"}, {"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}], "date_created": "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": "1443248 Hall, Brenda; 1443346 Stone, John", "bounds_geometry": "POLYGON((-174 -84.2,-172.4 -84.2,-170.8 -84.2,-169.2 -84.2,-167.6 -84.2,-166 -84.2,-164.4 -84.2,-162.8 -84.2,-161.2 -84.2,-159.6 -84.2,-158 -84.2,-158 -84.36,-158 -84.52,-158 -84.68,-158 -84.84,-158 -85,-158 -85.16,-158 -85.32,-158 -85.48,-158 -85.64,-158 -85.8,-159.6 -85.8,-161.2 -85.8,-162.8 -85.8,-164.4 -85.8,-166 -85.8,-167.6 -85.8,-169.2 -85.8,-170.8 -85.8,-172.4 -85.8,-174 -85.8,-174 -85.64,-174 -85.48,-174 -85.32,-174 -85.16,-174 -85,-174 -84.84,-174 -84.68,-174 -84.52,-174 -84.36,-174 -84.2))", "dataset_titles": "Cosmogenic nuclide data from glacial deposits along the Liv Glacier coast; Ice-D Antarctic Cosmogenic Nuclide database - site DUNCAN; Ice-D Antarctic Cosmogenic Nuclide database - site MAASON; Liv and Amundsen Glacier Radiocarbon Data", "datasets": [{"dataset_uid": "601226", "doi": "10.15784/601226", "keywords": "Antarctica; Be-10; Beryllium-10; Cosmogenic; Cosmogenic Dating; Cosmogenic Radionuclides; Deglaciation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Liv Glacier; Rocks; Ross Ice Sheet; Surface Exposure Dates; Transantarctic Mountains", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Cosmogenic nuclide data from glacial deposits along the Liv Glacier coast", "url": "https://www.usap-dc.org/view/dataset/601226"}, {"dataset_uid": "601208", "doi": "10.15784/601208", "keywords": "Antarctica; Carbon; Glaciology; Holocene; Radiocarbon; Ross Embayment; Ross Sea; Transantarctic Mountains", "people": "Hall, Brenda", "repository": "USAP-DC", "science_program": null, "title": "Liv and Amundsen Glacier Radiocarbon Data", "url": "https://www.usap-dc.org/view/dataset/601208"}, {"dataset_uid": "200088", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Ice-D Antarctic Cosmogenic Nuclide database - site DUNCAN", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200087", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Ice-D Antarctic Cosmogenic Nuclide database - site MAASON", "url": "https://version2.ice-d.org/antarctica/nsf/"}], "date_created": "Thu, 05 Sep 2019 00:00:00 GMT", "description": "The response of the Antarctic Ice Sheet to future climatic changes is recognized as the greatest uncertainty in projections of future sea level. An understanding of past ice fluctuations affords insight into ice-sheet response to climate and sea-level change and thus is critical for improving sea-level predictions. This project will examine deglaciation of the southern Ross Sea over the past few thousand years to document oscillations in Antarctic ice volume during a period of relatively stable climate and sea level. We will help quantify changes in ice volume, improve understanding of the ice dynamics responsible, and examine the implications for future sea-level change. The project will train future scientists through participation of graduate students, as well as undergraduates who will develop research projects in our laboratories.\u003cbr/\u003e\u003cbr/\u003ePrevious research indicates rapid Ross Sea deglaciation as far south as Beardmore Glacier early in the Holocene epoch (which began approximately 11,700 years before present), followed by more gradual recession. However, deglaciation in the later half of the Holocene remains poorly constrained, with no chronological control on grounding-line migration between Beardmore and Scott Glaciers. Thus, we do not know if mid-Holocene recession drove the grounding line rapidly back to its present position at Scott Glacier, or if the ice sheet withdrew gradually in the absence of significant climate forcing or eustatic sea level change. The latter possibility raises concerns for future stability of the Ross Sea grounding line. To address this question, we will map and date glacial deposits on coastal mountains that constrain the thinning history of Liv and Amundsen Glaciers. By extending our chronology down to the level of floating ice at the mouths of these glaciers, we will date their thinning history from glacial maximum to present, as well as migration of the Ross Sea grounding line southwards along the Transantarctic Mountains. High-resolution dating will come from Beryllium-10 surface-exposure ages of erratics collected along elevation transects, as well as Carbon-14 dates of algae within shorelines from former ice-dammed ponds. Sites have been chosen specifically to allow close comparison of these two dating methods, which will afford constraints on Antarctic Beryllium-10 production rates.", "east": -158.0, "geometry": "POINT(-166 -85)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; NOT APPLICABLE; Antarctica; ICE SHEETS; USAP-DC", "locations": "Antarctica", "north": -84.2, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Stone, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "ICE-D; USAP-DC", "science_programs": null, "south": -85.8, "title": "Collaborative Research: High-resolution Reconstruction of Holocene Deglaciation in the Southern Ross Embayment", "uid": "p0010053", "west": -174.0}, {"awards": "1443356 Conway, Howard; 1443552 Paul Winberry, J.", "bounds_geometry": "POLYGON((-175 -82.7,-173.9 -82.7,-172.8 -82.7,-171.7 -82.7,-170.6 -82.7,-169.5 -82.7,-168.4 -82.7,-167.3 -82.7,-166.2 -82.7,-165.1 -82.7,-164 -82.7,-164 -82.77,-164 -82.84,-164 -82.91,-164 -82.98,-164 -83.05,-164 -83.12,-164 -83.19,-164 -83.26,-164 -83.33,-164 -83.4,-165.1 -83.4,-166.2 -83.4,-167.3 -83.4,-168.4 -83.4,-169.5 -83.4,-170.6 -83.4,-171.7 -83.4,-172.8 -83.4,-173.9 -83.4,-175 -83.4,-175 -83.33,-175 -83.26,-175 -83.19,-175 -83.12,-175 -83.05,-175 -82.98,-175 -82.91,-175 -82.84,-175 -82.77,-175 -82.7))", "dataset_titles": "2015_Antarctica_Ground; Geophysical data from Crary Ice Rise, Ross Sea Embayment", "datasets": [{"dataset_uid": "200177", "doi": "", "keywords": null, "people": null, "repository": "CReSIS/ku.edu", "science_program": null, "title": "2015_Antarctica_Ground", "url": "https://data.cresis.ku.edu/data/accum/2015_Antarctica_Ground/"}, {"dataset_uid": "601181", "doi": "10.15784/601181", "keywords": "Antarctica; Bed Elevation; Crary Ice Rise; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Ice Sheet Elevation; Ice Shelf; Ice Thickness; Internal Stratigraphy; Radar; Ross Ice Shelf; Snow/ice; Snow/Ice; Surface Elevation", "people": "Paden, John; Koutnik, Michelle; Winberry, Paul; Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Geophysical data from Crary Ice Rise, Ross Sea Embayment", "url": "https://www.usap-dc.org/view/dataset/601181"}], "date_created": "Mon, 06 May 2019 00:00:00 GMT", "description": "Recent observations and model results suggest that collapse of the Amundsen Sea sector of West Antarctica may already be underway. However, the timeline of collapse and the effects of ongoing climatic and oceanographic changes are key unanswered questions. Complete disintegration of the ice sheet would raise global sea level by more than 3 m, which would have significant societal impacts. Improved understanding of the controls on ice-sheet evolution is needed to make better predictions of ice-sheet behavior. Results from numerical models show that buttressing from surrounding ice shelves and/or from small-scale grounded ice rises should act to slow the retreat and discharge of ice from the interior ice sheet. However, there are very few field observations with which to develop and validate models. Field observations conducted in the early 1980s on Crary Ice Rise in the Ross Sea Embayment are a notable exception. This project will revisit Crary Ice Rise with new tools to make a suite of measurements designed to address questions about how the ice rise affects ice discharge from the Ross Sea sector of West Antarctica. The team will include a graduate and undergraduate student, and will participate in a range of outreach activities.\u003cbr/\u003e\u003cbr/\u003eNew tools including radar, seismic, and GPS instruments will be used to conduct targeted geophysical measurements both on Crary Ice Rise and across its grounding line. The project will use these new measurements, together with available ancillary data to inform a numerical model of grounding line dynamics. The model and measurements will be used to address the (1) How has the ice rise evolved over timescales ranging from: the past few decades; the past millennia after freeze-on; and through the deglaciation? (2) What history of ice dynamics is preserved in the radar-detected internal stratigraphy? (3) What dynamical effect does the presence/absence of the ice rise have on discharge of the Ross Ice Streams today? (4) How is it contributing to the slow-down of the proximal Whillans and Mercer ice streams? (5) What dynamical response will the ice rise have under future environmental change?", "east": -164.0, "geometry": "POINT(-169.5 -83.05)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Amd/Us; FIELD SURVEYS; Antarctica; USA/NSF; AMD; USAP-DC; Radar; GLACIERS/ICE SHEETS", "locations": "Antarctica", "north": -82.7, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Koutnik, Michelle; Winberry, Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "CReSIS/ku.edu", "repositories": "CReSIS/ku.edu; USAP-DC", "science_programs": null, "south": -83.4, "title": "Collaborative Research: Grounding Line Dynamics: Crary Ice Rise Revisited", "uid": "p0010026", "west": -175.0}, {"awards": "1341547 Stroeve, Julienne; 1341558 Ji, Rubao; 1341440 Jin, Meibing", "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 MIZ, Pack Ice and Polynya Maps from Passive Microwave Satellite Data; Ice-ocean-ecosystem model output; Sea ice chlorophyll concentrations in Antarctic coastal polynyas and seasonal ice zones", "datasets": [{"dataset_uid": "601115", "doi": "10.15784/601115", "keywords": "Antarctica; Pack Ice; Polynya; Sea Ice; Southern Ocean", "people": "Stroeve, Julienne", "repository": "USAP-DC", "science_program": null, "title": "Antarctic MIZ, Pack Ice and Polynya Maps from Passive Microwave Satellite Data", "url": "https://www.usap-dc.org/view/dataset/601115"}, {"dataset_uid": "601136", "doi": "10.15784/601136", "keywords": "Antarctica; Biota; Model Data; Oceans; Southern Ocean", "people": "Jin, Meibing", "repository": "USAP-DC", "science_program": null, "title": "Ice-ocean-ecosystem model output", "url": "https://www.usap-dc.org/view/dataset/601136"}, {"dataset_uid": "601219", "doi": "10.15784/601219", "keywords": "Antarctica; Biota; Chlorophyll; Chlorophyll Concentration; Oceans; Polynya; Sea Ice Concentration; Seasonal Ice Zone; Southern Ocean", "people": "Ji, Rubao", "repository": "USAP-DC", "science_program": null, "title": "Sea ice chlorophyll concentrations in Antarctic coastal polynyas and seasonal ice zones", "url": "https://www.usap-dc.org/view/dataset/601219"}], "date_created": "Tue, 20 Nov 2018 00:00:00 GMT", "description": "The aim of study is to understand how climate-related changes in snow and ice affect predator populations in the Antarctic, using the Ad\u00e9lie penguin as a focal species due to its long history as a Southern Ocean \u0027sentinel\u0027 species and the number of long-term research programs monitoring its abundance, distribution, and breeding biology. Understanding the environmental factors that control predator population dynamics is critically important for projecting the state of populations under future climate change scenarios, and for designing better conservation strategies for the Antarctic ecosystem. For the first time, datasets from a network of observational sites for the Ad\u00e9lie penguin across the entire Antarctic will be combined and analyzed, with a focus on linkages among the ice environment, primary production, and the population responses of Ad\u00e9lie penguins. 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 results of this project can be used to illustrate intuitively to the general public the complex interactions between ice, ocean, pelagic food web and top predators. This project also offers an excellent platform to demonstrate the process of climate-change science - how scientists simulate climate change scenarios and interpret model results. This project supports the training of undergraduate and graduate students in the fields of polar oceanography, plankton and seabird ecology, coupled physical-biological modeling and mathematical ecology. The results will be broadly disseminated to the general oceanographic research community through scientific workshops, conferences and peer-reviewed journal articles, and to undergraduate and graduate education communities, K-12 schools and organizations, and the interested public through web-based servers using existing infrastructure at the investigators\u0027 institutions. The key question to be addressed in this project is how climate impacts the timing of periodic biological events (phenology) and how interannual variation in this periodic forcing influences the abundance of penguins in the Antarctic. The focus will be on the timing of ice algae and phytoplankton blooms because the high seasonality of sea ice and associated pulsed primary productivity are major drivers of the Antarctic food web. This study will also examine the responses of Ad\u00e9lie penguins to changes in sea ice dynamics and ice algae-phytoplankton phenology. Ad\u00e9lie penguins, like many other Antarctic seabirds, are long-lived, upper trophic-level predators that integrate the effects of sea ice on the food web at regional scales, and thus serve as a reliable biological indicator of environmental changes. The proposed approach is designed to accommodate the limits of measuring and modeling the intermediate trophic levels between phytoplankton and penguins (e.g., zooplankton and fish) at the pan-Antarctic scale, which are important but latent variables in the Southern Ocean food web. Through the use of remotely sensed and in situ data, along with state of the art statistical approaches (e.g. wavelet analysis) and numerical modeling, this highly interdisciplinary study will advance our understanding of polar ecosystems and improve the projection of future climate change scenarios.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; MARINE ECOSYSTEMS; NOT APPLICABLE; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Jin, Meibing; Stroeve, Julienne; Ji, Rubao", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Phytoplankton Phenology in the Antarctic: Drivers, Patterns, and Implications for the Adelie Penguin", "uid": "p0000001", "west": -180.0}, {"awards": "1246045 Waddington, Edwin", "bounds_geometry": "POLYGON((-180 -70,-144 -70,-108 -70,-72 -70,-36 -70,0 -70,36 -70,72 -70,108 -70,144 -70,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,180 -82,180 -84,180 -86,180 -88,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88,-180 -86,-180 -84,-180 -82,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70))", "dataset_titles": "Code for inference of fabric from sonic velocity and thin-section measurements.; Code for models involving stochastic treatment of ice fabric", "datasets": [{"dataset_uid": "000244", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for models involving stochastic treatment of ice fabric", "url": "https://github.com/mjhay/stochastic_fabric"}, {"dataset_uid": "000243", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for inference of fabric from sonic velocity and thin-section measurements.", "url": "https://github.com/mjhay/neem_sonic_model"}], "date_created": "Mon, 02 Apr 2018 00:00:00 GMT", "description": "Waddington/1246045 \u003cbr/\u003e\u003cbr/\u003eThis award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Waddington, Edwin D.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -90.0, "title": "Anisotropic Ice and Stratigraphic Disturbances", "uid": "p0000073", "west": -180.0}, {"awards": "1245879 Nitsche, Frank O.", "bounds_geometry": null, "dataset_titles": "NBP1503 data collected during field expedition", "datasets": [{"dataset_uid": "200001", "doi": "10.7284/901478", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1503 data collected during field expedition", "url": "https://www.rvdata.us/search/cruise/NBP1503"}], "date_created": "Sun, 30 Jul 2017 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThis project will determine the potential vulnerability of key ice streams to incursions of warmer ocean water onto the continental shelf and if this mechanism could already explain any of the observed thinning of the ice sheet. It will provide important constrains on ice dynamic of the investigated section of the EAIS, and thus will be critical for future ice sheet models and provide mechanisms for EAIS contributions to past sea level high-stand. The PI proposes to investigate four key ice stream systems on the continental shelf between ~90\u00c2\u00b0E and 160\u00c2\u00b0E. They will use multibeam bathymetry to identify if and where cross-shelf troughs exist to help determine whether these troughs could provide potential pathways for warmer ocean water. Furthermore, detailed analysis of morphological features of these troughs could provide information on past ice dynamic, maximum extent, and flow direction of related paleo ice streams. The PIs will also conduct water column measurements along these troughs and on the continental slope to determine whether warmer ocean water could enter the shelf in the near future, or if such water has already entered any troughs, and thus might be causing the observed thinning of some ice streams.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis project includes the participation and support of undergraduate and graduate students in field work and data analysis. The possible involvement of a PolarTREC teacher and the Earth2Class teachers program will reach out to K-12 students.", "east": 134.6, "geometry": "POINT(125.05 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "WATER TEMPERATURE; Polar; SALINITY; Antarctica; Southern Ocean; R/V NBP; BATHYMETRY", "locations": "Polar; Antarctica; Southern Ocean", "north": -63.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Nitsche, Frank O.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -66.0, "title": "Vulnerability of East Antarctic Ice Streams to warm Ocean Water Incursions", "uid": "p0000394", "west": 115.5}, {"awards": "0944348 Taylor, Kendrick; 0944266 Twickler, Mark", "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": "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"}, {"dataset_uid": "601030", "doi": "10.15784/601030", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide Ice Core", "people": "Twickler, Mark; Souney, Joseph Jr.; Taylor, Kendrick C.", "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"}], "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 Earth Sciences; Antarctic Glaciology", "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": "0944197 Waddington, Edwin; 0944191 Taylor, Kendrick", "bounds_geometry": "POLYGON((-180 -79,-173.3 -79,-166.6 -79,-159.9 -79,-153.2 -79,-146.5 -79,-139.8 -79,-133.1 -79,-126.4 -79,-119.7 -79,-113 -79,-113 -79.1,-113 -79.2,-113 -79.3,-113 -79.4,-113 -79.5,-113 -79.6,-113 -79.7,-113 -79.8,-113 -79.9,-113 -80,-119.7 -80,-126.4 -80,-133.1 -80,-139.8 -80,-146.5 -80,-153.2 -80,-159.9 -80,-166.6 -80,-173.3 -80,180 -80,150.9 -80,121.8 -80,92.7 -80,63.6 -80,34.5 -80,5.4 -80,-23.7 -80,-52.8 -80,-81.9 -80,-111 -80,-111 -79.9,-111 -79.8,-111 -79.7,-111 -79.6,-111 -79.5,-111 -79.4,-111 -79.3,-111 -79.2,-111 -79.1,-111 -79,-81.9 -79,-52.8 -79,-23.7 -79,5.4 -79,34.5 -79,63.6 -79,92.7 -79,121.8 -79,150.9 -79,-180 -79))", "dataset_titles": "Accumulation Rates from the WAIS Divide Ice Core; WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica; WAIS Divide Multi Track Electrical Measurements; WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "datasets": [{"dataset_uid": "601015", "doi": "10.15784/601015", "keywords": "Antarctica; Depth-Age-Model; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "url": "https://www.usap-dc.org/view/dataset/601015"}, {"dataset_uid": "601172", "doi": "10.15784/601172", "keywords": "Antarctic; Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; Wais Project; West Antarctic Ice Sheet", "people": "Fudge, T. J.; Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": null, "title": "WAIS Divide Multi Track Electrical Measurements", "url": "https://www.usap-dc.org/view/dataset/601172"}, {"dataset_uid": "601004", "doi": "10.15784/601004", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Snow Accumulation; WAIS Divide Ice Core", "people": "Buizert, Christo; Conway, Howard; Fudge, T. J.; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Accumulation Rates from the WAIS Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/601004"}, {"dataset_uid": "609591", "doi": "10.7265/N5B56GPJ", "keywords": "Antarctica; Electrical Conductivity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "people": "Taylor, Kendrick C.; Fudge, T. J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Electrical Conductance Measurements, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609591"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "This award supports a project to help to establish the depth-age chronology and the histories of accumulation and ice dynamics for the WAIS Divide ice core. The depth-age relationship and the histories of accumulation and ice dynamics are coupled. An accurate age scale is needed to infer histories of accumulation rate and ice-thickness change using ice-flow models. In turn, the accumulation-rate history is needed to calculate the age difference of ice to determine the age of the trapped gases. The accumulation history is also needed to calculate atmospheric concentrations of impurities trapped in the ice and is an important characteristic of climate. The history of ice-thickness change is also fundamental to understanding the stability of the WAIS. The primary goals of the WAIS Divide ice core project are to investigate climate forcing by greenhouse gases, the initiation of climate changes, and the stability of the West Antarctic Ice Sheet (WAIS). An accurate age scale is fundamental for achieving these goals. The first objective of this project is to establish an annually resolved depth-age relationship for the past 40,000 years. This will be done by measuring variations in electrical conductivity along the ice core, which are caused by seasonal variations in chemistry. We expect to be able to resolve annual layers back to 40,000 years before present (3,000 m depth) using this method. The second objective is to search for stratigraphic disturbances in the core that would compromise the paleoclimate record. Irregular layering will be identified by measuring the electrical conductivity of the ice in a vertical plan through the core. The third objective is to derive a preliminary chronology for the entire core. For the deeper ice we will use an ice-flow model to interpolate between known age markers, such as dated volcanic horizons and tie points from the methane gas chronology. The fourth objective is to derive a refined chronology simultaneously with histories of accumulation and ice-sheet thickness. An ice-flow model and all available data will be used to formulate an inverse problem, in which we infer the most appropriate histories of accumulation and ice-thickness, together with estimates of uncertainties. The flow model associated with those preferred histories then produces the best estimate of the chronology. The research contributes directly to the primary goals of the West Antarctic Ice Sheet Initiative. The project will help develop the next generation of scientists through the education and training of one Ph.D. student and several undergraduate students. This project will result in instrumentation for measuring the electrical conductivity of ice cores being available at the National Ice Core Lab for other researchers to use on other projects. All collaborators are committed to fostering diversity and currently participate in scientific outreach and most participate in undergraduate education. Outreach will be accomplished through regularly scheduled community and K-12 outreach events at UW, talks and popular writing by the PIs, as well as through our respective press offices.", "east": -111.0, "geometry": "POINT(-112 -79.5)", "instruments": null, "is_usap_dc": true, "keywords": "Ice Core Depth; National Ice Core Lab; Electrical Conductivity; FIELD INVESTIGATION; Not provided", "locations": null, "north": -79.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Conway, Howard; Fudge, T. J.; Taylor, Kendrick C.; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -80.0, "title": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core", "uid": "p0000026", "west": -113.0}, {"awards": "0838615 Hall, Brenda", "bounds_geometry": "POLYGON((-177.13 -84.55,-177.074 -84.55,-177.018 -84.55,-176.962 -84.55,-176.906 -84.55,-176.85 -84.55,-176.794 -84.55,-176.738 -84.55,-176.682 -84.55,-176.626 -84.55,-176.57 -84.55,-176.57 -84.615,-176.57 -84.68,-176.57 -84.745,-176.57 -84.81,-176.57 -84.875,-176.57 -84.94,-176.57 -85.005,-176.57 -85.07,-176.57 -85.135,-176.57 -85.2,-176.626 -85.2,-176.682 -85.2,-176.738 -85.2,-176.794 -85.2,-176.85 -85.2,-176.906 -85.2,-176.962 -85.2,-177.018 -85.2,-177.074 -85.2,-177.13 -85.2,-177.13 -85.135,-177.13 -85.07,-177.13 -85.005,-177.13 -84.94,-177.13 -84.875,-177.13 -84.81,-177.13 -84.745,-177.13 -84.68,-177.13 -84.615,-177.13 -84.55))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 05 Sep 2013 00:00:00 GMT", "description": "Stone/0838818 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). \u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study the former thickness and retreat history of Shackleton and Beardmore Glaciers which flow through the Transantarctic Mountains (TAMs) into the southern Ross Sea. Lateral moraine deposits along the lower reaches of these major outlet glaciers will be mapped and dated and the results will help to date the LGM and constrain the thickness of ice where it left the Transantarctic Mountains and flowed into the Ross Sea. The intellectual merit of the project is that the results will allow scientists to distinguish between models of ice retreat, which have important implications for former ice configuration and dynamics, and to constrain the contribution from Ross Sea deglaciation to global sea level through the late Holocene. In addition, this will make a significant contribution to a better understanding of the magnitude and timing of postglacial sea-level change and the potential contribution of Antarctica to sea-level rise in future. The broader impacts of the project are that the work will help quantify changes in grounded ice volume since the LGM, improve understanding of the ice dynamics responsible, and examine their implications for future sea level change. The project will train future scientists through participation of two graduate students and undergraduates who will develop self-contained research projects. As in previous Antarctic projects, there will be interaction with K-12 students through classroom visits, web-based expedition journals, letters from the field, and discussions with teachers and will allow the project to be shared with a wide audience. This award has field work in Antarctica.", "east": -176.57, "geometry": "POINT(-176.85 -84.875)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -84.55, "nsf_funding_programs": "Antarctic Instrumentation and Support", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Hall, Brenda", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -85.2, "title": "Collaborative Research: Constraints on the last Ross Ice Sheet from Glacial Deposits in the Southern Transantarctic Mountains", "uid": "p0000094", "west": -177.13}, {"awards": "0732946 Steffen, Konrad", "bounds_geometry": null, "dataset_titles": "Larsen C automatic weather station data 2008\u20132011; Mean surface mass balance over Larsen C ice shelf, Antarctica (1979-2014), assimilated to in situ GPR and snow height data", "datasets": [{"dataset_uid": "601445", "doi": "10.15784/601445", "keywords": "Antarctica; Atmosphere; AWS; Foehn Winds; Ice Shelf; Larsen C Ice Shelf; Larsen Ice Shelf; Meteorology; Weather Station Data", "people": "McGrath, Daniel; Steffen, Konrad; Bayou, Nicolas", "repository": "USAP-DC", "science_program": null, "title": "Larsen C automatic weather station data 2008\u20132011", "url": "https://www.usap-dc.org/view/dataset/601445"}, {"dataset_uid": "601056", "doi": "10.15784/601056", "keywords": "Antarctica; Antarctic Peninsula; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Larsen C Ice Shelf; Radar", "people": "Kuipers Munneke, Peter; Steffen, Konrad; McGrath, Daniel", "repository": "USAP-DC", "science_program": null, "title": "Mean surface mass balance over Larsen C ice shelf, Antarctica (1979-2014), assimilated to in situ GPR and snow height data", "url": "https://www.usap-dc.org/view/dataset/601056"}], "date_created": "Wed, 03 Oct 2012 00:00:00 GMT", "description": "This award supports a field experiment, with partners from Chile and the Netherlands, to determine the state of health and stability of Larsen C ice shelf in response to climate change. Significant glaciological and ecological changes are taking place in the Antarctic Peninsula in response to climate warming that is proceeding at 6 times the global average rate. Following the collapse of Larsen A ice shelf in 1995 and Larsen B in 2002, the outlet glaciers that nourished them with land ice accelerated massively, losing a disproportionate amount of ice to the ocean. Further south, the much larger Larsen C ice shelf is thinning and measurements collected over more than a decade suggest that it is doomed to break up. The intellectual merit of the project will be to contribute to the scientific knowledge of one of the Antarctic sectors where the most significant changes are taking place at present. The project is central to a cluster of International Polar Year activities in the Antarctic Peninsula. It will yield a legacy of international collaboration, instrument networking, education of young scientists, reference data and scientific analysis in a remote but globally relevant glaciological setting. The broader impacts of the project will be to address the contribution to sea level rise from Antarctica and to bring live monitoring of climate and ice dynamics in Antarctica to scientists, students, the non-specialized public, the press and the media via live web broadcasting of progress, data collection, visualization and analysis. Existing data will be combined with new measurements to assess what physical processes are controlling the weakening of the ice shelf, whether a break up is likely, and provide baseline data to quantify the consequences of a breakup. Field activities will include measurements using the Global Positioning System (GPS), installation of automatic weather stations (AWS), ground penetrating radar (GPR) measurements, collection of shallow firn cores and temperature measurements. These data will be used to characterize the dynamic response of the ice shelf to a variety of phenomena (oceanic tides, iceberg calving, ice-front retreat and rifting, time series of weather conditions, structural characteristics of the ice shelf and bottom melting regime, and the ability of firn to collect melt water and subsequently form water ponds that over-deepen and weaken the ice shelf). This effort will complement an analysis of remote sensing data, ice-shelf numerical models and control methods funded independently to provide a more comprehensive analysis of the ice shelf evolution in a changing climate.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; 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; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e TEMPERATURE PROFILERS", "is_usap_dc": false, "keywords": "Climate Warming; Firn; COMPUTERS; Ice Dynamic; USAP-DC; Glaciological; Thinning; Sea Level Rise; FIELD SURVEYS; FIELD INVESTIGATION; USA/NSF; AMD; Ice Edge Retreat; LABORATORY; Climate Change; Antarctic Peninsula; Amd/Us; Melting", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steffen, Konrad", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "IPY: Stability of Larsen C Ice Shelf in a Warming Climate", "uid": "p0000087", "west": null}, {"awards": "0632198 Anandakrishnan, Sridhar", "bounds_geometry": "POINT(110 -74)", "dataset_titles": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Dupont, Todd K.; Holt, John W.; Parizek, Byron R.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}], "date_created": "Wed, 29 Aug 2012 00:00:00 GMT", "description": "This award supports a project to study ice sheet history and dynamics on the Thwaites Glacier and Pine Island Glacier in the Amundsen Sea sector of the West Antarctic Ice Sheet. The international collaboration that has been established with the British Antarctic Survey will enable a fuller suite of geophysical experiments with more-efficient use of people and logistics than we could achieve individually. This project is one of a number of projects to characterize the Amundsen Sea Embayment, which has been identified in numerous planning documents as perhaps the most important target for ice-dynamical research. Taken together, this \"pulse of activity\" will result in a better understanding of this important part of the global system. Field work will measure the subglacial environment of Thwaites and Pine Island Glaciers using three powerful, but relatively simple tools: reflection seismic imaging, GPS motion monitoring of the tidal forcing, and passive seismic monitoring of the seismicity associated with motion. The results of the field work will feed into ice-sheet modeling efforts that are tuned to the case of an ocean-terminating glacier and will assess the influence of these glaciers on current sea level and project into the future. The broader impacts of the project involve the inclusion of a film- and audio-professional to document the work for informal outreach (public radio and TV; museums). In addition, we will train graduate students in polar geophysical and glaciological research and in numerical modeling techniques. The ultimate goal of this project, of assessing the role of Thwaites Glacier in global sea level change, has broad societal impact in coastal regions and small islands.", "east": -110.0, "geometry": "POINT(-110 -74)", "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 GPR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": false, "keywords": "Pine Island Glacier; Bed Reflectivity; Tidal Forcing; FIELD INVESTIGATION; Not provided; Position; Thwaites; Thickness; Amundsen Sea; LABORATORY; FIELD SURVEYS; Subglacial; Ice Dynamic; Ice Sheet Modeling", "locations": "Thwaites; Pine Island Glacier; Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "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": -74.0, "title": "IPY: Flow Dynamics of the Amundsen Sea Glaciers: Thwaites and Pine Island.", "uid": "p0000699", "west": -110.0}, {"awards": "0758274 Parizek, Byron; 0636724 Blankenship, Donald", "bounds_geometry": "POLYGON((-110.058 -74.0548,-109.57993 -74.0548,-109.10186 -74.0548,-108.62379 -74.0548,-108.14572 -74.0548,-107.66765 -74.0548,-107.18958 -74.0548,-106.71151 -74.0548,-106.23344 -74.0548,-105.75537 -74.0548,-105.2773 -74.0548,-105.2773 -74.31383,-105.2773 -74.57286,-105.2773 -74.83189,-105.2773 -75.09092,-105.2773 -75.34995,-105.2773 -75.60898,-105.2773 -75.86801,-105.2773 -76.12704,-105.2773 -76.38607,-105.2773 -76.6451,-105.75537 -76.6451,-106.23344 -76.6451,-106.71151 -76.6451,-107.18958 -76.6451,-107.66765 -76.6451,-108.14572 -76.6451,-108.62379 -76.6451,-109.10186 -76.6451,-109.57993 -76.6451,-110.058 -76.6451,-110.058 -76.38607,-110.058 -76.12704,-110.058 -75.86801,-110.058 -75.60898,-110.058 -75.34995,-110.058 -75.09092,-110.058 -74.83189,-110.058 -74.57286,-110.058 -74.31383,-110.058 -74.0548))", "dataset_titles": "Access to data; AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica; Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica; ICECAP Basal Interface Specularity Content Profiles: IPY and OIB; Subglacial water flow paths under Thwaites Glacier, West Antarctica; Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "002536", "doi": "", "keywords": null, "people": null, "repository": "NASA", "science_program": null, "title": "Access to data", "url": "http://www.giss.nasa.gov/tools/panoply/"}, {"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Young, Duncan A.; Schroeder, Dustin; Greenbaum, Jamin; Blankenship, Donald D.; van Ommen, Tas; Siegert, Martin; Roberts, Jason", "repository": "USAP-DC", "science_program": null, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "url": "https://www.usap-dc.org/view/dataset/601371"}, {"dataset_uid": "609334", "doi": "10.7265/N5HD7SK8", "keywords": "AGASEA; Airborne Altimetry; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Blankenship, Donald D.; Holt, John W.; Morse, David L.; Young, Duncan A.; Kempf, Scott D.", "repository": "USAP-DC", "science_program": null, "title": "Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609334"}, {"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Dupont, Todd K.; Holt, John W.; Parizek, Byron R.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}, {"dataset_uid": "000248", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Access to data", "url": "http://nsidc.org/data/netcdf/tools.html"}, {"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Jackson, Charles; Blankenship, Donald D.; Muldoon, Gail R.; Young, Duncan A.", "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": "609518", "doi": "10.7265/N5RJ4GC8", "keywords": "AGASEA; Airborne Radar; Antarctica; Elevation; Flow Paths; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Carter, Sasha P.; Young, Duncan A.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial water flow paths under Thwaites Glacier, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609518"}, {"dataset_uid": "609517", "doi": "10.7265/N5W95730", "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness", "people": "Holt, John W.; Kempf, Scott D.; Young, Duncan A.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609517"}], "date_created": "Tue, 15 May 2012 00:00:00 GMT", "description": "This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program\u0027s emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: \"investigation of the physics of fast glacier flow with emphasis on processes at glacier beds\"; \"investigation of ice-shelf stability\"; and \"identification and quantification of the feedback between ice dynamics and climate change\". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations.", "east": -105.2773, "geometry": "POINT(-107.66765 -75.34995)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e RADIO \u003e INS", "is_usap_dc": true, "keywords": "Ice Sheet Thickness; Ice Sheet Elevation; Glacier Dynamics; Ice Stream; Numerical Model; West Antarctic; Surface Elevation; Basal Rheology; Ice Surface Velocity; Embayment Geometry; Amundsen Sea; Hydrology; FIELD SURVEYS; Antarctic Ice Sheet; Glacier; Subglacial; DHC-6; West Antarctic Ice Sheet; Model Output; Surface Climate; Glaciers; Basal Topography; Grounding Zone; Model Input Data; Airborne Laser Altimeters; FIELD INVESTIGATION; Thwaites Glacier; Airborne Laser Altimetry; Diagnostic; Ice-Shelf Buttressing; Ice Sheet; Prognostic; Glacier Surface; Airborne Radar Sounding; Digital Elevation Model; Ice Dynamic; Antarctica; Altimetry; Antarctica (agasea); Bed Elevation; Basal Stress; LABORATORY", "locations": "Antarctica; Thwaites Glacier; West Antarctic Ice Sheet; Antarctic Ice Sheet; West Antarctic; Amundsen Sea", "north": -74.0548, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Carter, Sasha P.; Dupont, Todd K.; Holt, John W.; Morse, David L.; Parizek, Byron R.; Young, Duncan A.; Kempf, Scott D.; Blankenship, Donald D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NASA", "repositories": "NASA; NSIDC; USAP-DC", "science_programs": null, "south": -76.6451, "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "uid": "p0000174", "west": -110.058}, {"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": "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": "600384", "doi": "10.15784/600384", "keywords": "Airborne Radar; Antarctica; Basler; Glaciers/ice Sheet; Glaciers/Ice Sheet; Kamb Ice Stream; Radar; Siple Coast; Whillans Ice Stream", "people": "Paden, John; Hale, Richard", "repository": "USAP-DC", "science_program": null, "title": "Airborne radar profiles of the Whillans, Bindschadler, and Kamb Ice Streams", "url": "https://www.usap-dc.org/view/dataset/600384"}, {"dataset_uid": "002497", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Archive of data", "url": "https://www.cresis.ku.edu/data/accumulation"}, {"dataset_uid": "601047", "doi": "10.15784/601047", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MCoRDS; Navigation; Radar", "people": "Li, Jilu; Allen, Chris; Gogineni, Prasad; Rodriguez, Fernando; Paden, John; Leuschen, Carl", "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": "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": "Muldoon, Gail R.; Paden, John; Frezzotti, Massimo; Roberts, Jason; Tozer, Carly; Schroeder, Dustin; Blankenship, Donald D.; Young, Duncan A.; Cavitte, Marie G. P; Ng, Gregory; Kempf, Scott D.; Quartini, Enrica; Mulvaney, Robert; Ritz, Catherine; Greenbaum, Jamin", "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": "601048", "doi": "10.15784/601048", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ku-Band; Navigation; Radar", "people": "Paden, John; Li, Jilu; Allen, Chris; Gogineni, Prasad; Leuschen, Carl; Rodriguez, Fernando", "repository": "USAP-DC", "science_program": null, "title": "Ku-band Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601048"}, {"dataset_uid": "601049", "doi": "10.15784/601049", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Navigation; Radar; Snow", "people": "Paden, John; Leuschen, Carl; Rodriguez, Fernando; Li, Jilu; Allen, Chris; Gogineni, Prasad", "repository": "USAP-DC", "science_program": null, "title": "Snow Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601049"}], "date_created": "Wed, 01 Jun 2011 00:00:00 GMT", "description": "This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbr\u00e6. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.\u003cbr/\u003e\u003cbr/\u003eThe intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. \u003cbr/\u003e\u003cbr/\u003eAs lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets.", "east": -88.0, "geometry": "POINT(-112.5 -77.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Remote Sensing; Not provided; Pine Island; Ice Sheet; DHC-6; Antarctic; Thwaites Region; Antarctica; Mass Balance; Accumulation; Velocity; Insar", "locations": "Antarctica; Antarctic; Pine Island; Thwaites Region", "north": -74.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Glaciology", "paleo_time": null, "persons": "Braaten, David; Joughin, Ian; Steig, Eric J.; Das, Sarah; Paden, John; Gogineni, Prasad", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; Not provided", "repo": "USAP-DC", "repositories": "Project website; USAP-DC", "science_programs": null, "south": -80.5, "title": "Center for Remote Sensing of Ice Sheets (CReSIS)", "uid": "p0000102", "west": -137.0}, {"awards": "0528728 Vernet, Maria; 0529087 Ross, Robin; 0529666 Fritsen, Christian", "bounds_geometry": "POLYGON((-69.08 -64.8,-68.632 -64.8,-68.184 -64.8,-67.736 -64.8,-67.288 -64.8,-66.84 -64.8,-66.392 -64.8,-65.944 -64.8,-65.496 -64.8,-65.048 -64.8,-64.6 -64.8,-64.6 -65.121,-64.6 -65.442,-64.6 -65.763,-64.6 -66.084,-64.6 -66.405,-64.6 -66.726,-64.6 -67.047,-64.6 -67.368,-64.6 -67.689,-64.6 -68.01,-65.048 -68.01,-65.496 -68.01,-65.944 -68.01,-66.392 -68.01,-66.84 -68.01,-67.288 -68.01,-67.736 -68.01,-68.184 -68.01,-68.632 -68.01,-69.08 -68.01,-69.08 -67.689,-69.08 -67.368,-69.08 -67.047,-69.08 -66.726,-69.08 -66.405,-69.08 -66.084,-69.08 -65.763,-69.08 -65.442,-69.08 -65.121,-69.08 -64.8))", "dataset_titles": "Expedition data of NBP0103; The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "datasets": [{"dataset_uid": "002595", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0103", "url": "https://www.rvdata.us/search/cruise/NBP0103"}, {"dataset_uid": "600048", "doi": "10.15784/600048", "keywords": "Bellingshausen Sea; Biota; Oceans; Phytoplankton; Southern Ocean", "people": "Vernet, Maria", "repository": "USAP-DC", "science_program": null, "title": "The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "url": "https://www.usap-dc.org/view/dataset/600048"}, {"dataset_uid": "600049", "doi": "10.15784/600049", "keywords": "Bellingshausen Sea; Biota; Oceans; Southern Ocean", "people": "Quetin, Langdon B.; Ross, Robin Macurda", "repository": "USAP-DC", "science_program": null, "title": "The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "url": "https://www.usap-dc.org/view/dataset/600049"}, {"dataset_uid": "600050", "doi": "10.15784/600050", "keywords": "Bellingshausen Sea; Cryosphere; Oceans; Photosynthetically Active Radiation (par); Sea Ice; Sea Surface; Southern Ocean; Total Integrated Exposure To PAR", "people": "Fritsen, Christian", "repository": "USAP-DC", "science_program": null, "title": "The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "url": "https://www.usap-dc.org/view/dataset/600050"}], "date_created": "Sat, 02 Apr 2011 00:00:00 GMT", "description": "This collaborative study between the Desert Research Institute, the University of California, Santa Barbara (0529087; Robin Ross), and the University of California, San Diego (0528728; Maria Vernet) will examine the relationship between sea ice extent along the Antarctic Peninsula and the life history of krill (Euphausia superba), by developing, refining, and linking diagnostic datasets and models of phytoplankton decreases in the fall, phytoplankton biomass incorporation into sea ice, sea ice growth dynamics, sea ice algal production and biomass accumulation, and larval krill energetics, condition, and survival. Krill is a key species in the food web of the Southern Ocean ecosystem, and one that is intricately involved with seasonal sea ice dynamics. Results from the Southern Ocean experiment of the Global Ocean Ecosystems Dynamics program (SO-Globec) field work as well as historical information on sea ice dynamics and krill recruitment suggest a shift in the paradigm that all pack ice is equally good krill habitat.\u003cbr/\u003e\u003cbr/\u003eSO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with the lower trophic levels, and will be integrated with other synthesis and modeling studies that deal with grazers, predators, and other higher trophic levels.", "east": -64.6, "geometry": "POINT(-66.84 -66.405)", "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": true, "keywords": "R/V NBP; Not provided", "locations": null, "north": -64.8, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Fritsen, Christian; Vernet, Maria; Ross, Robin Macurda; Quetin, Langdon B.", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -68.01, "title": "Collaborative Research: U.S. SO GLOBEC Synthesis and Modeling: Timing is Everything: The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "uid": "p0000522", "west": -69.08}, {"awards": "0632325 Seals, Cheryl; 0632161 Johnson, Jesse; 0632168 Hulbe, Christina; 0632346 Tulaczyk, Slawek", "bounds_geometry": "POLYGON((-180 -50.05,-144 -50.05,-108 -50.05,-72 -50.05,-36 -50.05,0 -50.05,36 -50.05,72 -50.05,108 -50.05,144 -50.05,180 -50.05,180 -54.045,180 -58.04,180 -62.035,180 -66.03,180 -70.025,180 -74.02,180 -78.015,180 -82.01,180 -86.005,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -86.005,-180 -82.01,-180 -78.015,-180 -74.02,-180 -70.025,-180 -66.03,-180 -62.035,-180 -58.04,-180 -54.045,-180 -50.05))", "dataset_titles": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields; Wiki containing the data and provenance.", "datasets": [{"dataset_uid": "609396", "doi": "10.7265/N5K64G1S", "keywords": "Antarctica; Community Ice Sheet Model; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Hulbe, Christina; Daescu, Dacian N.", "repository": "USAP-DC", "science_program": null, "title": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields", "url": "https://www.usap-dc.org/view/dataset/609396"}, {"dataset_uid": "001499", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Wiki containing the data and provenance.", "url": "http://websrv.cs.umt.edu/isis/index.php/Present_Day_Antarctica"}], "date_created": "Fri, 02 Jul 2010 00:00:00 GMT", "description": "Johnson/0632161\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to create a \"Community Ice Sheet Model (CISM)\". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating \"a new generation\" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MODELS; International Polar Year; Derived Basal Temperature Evolution; Ice Sheet; Community Ice Sheet Model; Ice Sheet Model; LABORATORY; Amundsen Sea; Eismint; Modeling; Basal Temperature; Numerical Model; Antarctic Ice Sheet; Environmental Modeling; IPY; Antarctica; Model; Not provided; Ice Dynamic", "locations": "Antarctic Ice Sheet; Antarctica; Amundsen Sea", "north": -50.05, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Hulbe, Christina; Seals, Cheryl; Johnson, Jesse; Daescu, Dacian N.", "platforms": "Not provided; OTHER \u003e MODELS \u003e MODELS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "PI website; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: IPY, The Next Generation: A Community Ice Sheet Model for Scientists and Educators With Demonstration Experiments in Amundsen Sea Embayment Region", "uid": "p0000756", "west": -180.0}, {"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": "0338371 Hallet, Bernard; 0338137 Anderson, John", "bounds_geometry": "POLYGON((-74.59492 -45.98986,-74.072309 -45.98986,-73.549698 -45.98986,-73.027087 -45.98986,-72.504476 -45.98986,-71.981865 -45.98986,-71.459254 -45.98986,-70.936643 -45.98986,-70.414032 -45.98986,-69.891421 -45.98986,-69.36881 -45.98986,-69.36881 -46.835236,-69.36881 -47.680612,-69.36881 -48.525988,-69.36881 -49.371364,-69.36881 -50.21674,-69.36881 -51.062116,-69.36881 -51.907492,-69.36881 -52.752868,-69.36881 -53.598244,-69.36881 -54.44362,-69.891421 -54.44362,-70.414032 -54.44362,-70.936643 -54.44362,-71.459254 -54.44362,-71.981865 -54.44362,-72.504476 -54.44362,-73.027087 -54.44362,-73.549698 -54.44362,-74.072309 -54.44362,-74.59492 -54.44362,-74.59492 -53.598244,-74.59492 -52.752868,-74.59492 -51.907492,-74.59492 -51.062116,-74.59492 -50.21674,-74.59492 -49.371364,-74.59492 -48.525988,-74.59492 -47.680612,-74.59492 -46.835236,-74.59492 -45.98986))", "dataset_titles": "Expedition data of NBP0505; Expedition data of NBP0703; NBP0505 CTD data; NBP0505 sediment core locations", "datasets": [{"dataset_uid": "601363", "doi": "10.15784/601363", "keywords": "Chile; CTD; CTD Data; Depth; Fjord; NBP0505; Oceans; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Temperature", "people": "Anderson, John; Wellner, Julia", "repository": "USAP-DC", "science_program": null, "title": "NBP0505 CTD data", "url": "https://www.usap-dc.org/view/dataset/601363"}, {"dataset_uid": "002642", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0703", "url": "https://www.rvdata.us/search/cruise/NBP0703"}, {"dataset_uid": "002609", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0505", "url": "https://www.rvdata.us/search/cruise/NBP0505"}, {"dataset_uid": "601362", "doi": "10.15784/601362", "keywords": "Chile; Fjord; Marine Geoscience; NBP0505; R/v Nathaniel B. Palmer; Sample/collection Description; Sample/Collection Description; Sediment Core; Sediment Corer; Station List", "people": "Wellner, Julia; Anderson, John", "repository": "USAP-DC", "science_program": null, "title": "NBP0505 sediment core locations", "url": "https://www.usap-dc.org/view/dataset/601362"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project examines the role of glacier dynamics in glacial sediment yields. The results will shed light on how glacial erosion influences both orogenic processes and produces sediments that accumulate in basins, rich archives of climate variability. Our hypothesis is that erosion rates are a function of sliding speed, and should diminish sharply as the glacier\u0027s basal temperatures drop below the melting point. To test this hypothesis, we will determine sediment accumulation rates from seismic studies of fjord sediments for six tidewater glaciers that range from fast-moving temperate glaciers in Patagonia to slow-moving polar glaciers on the Antarctic Peninsula. Two key themes are addressed for each glacier system: 1) sediment yields and erosion rates by determining accumulation rates within the fjords using seismic profiles and core data, and 2) dynamic properties and basin characteristics of each glacier in order to seek an empirical relationship between glacial erosion rates and ice dynamics. The work is based in Patagonia and the Antarctic Peninsula, ideal natural laboratories for these purposes because the large latitudinal range provides a large range of precipitation and thermal regimes over relatively homogeneous lithologies and tectonic settings. Prior studies of these regions noted significant decreases in glaciomarine sediment accumulations in the fjords to the south. As well, the fjords constitute accessible and nearly perfect natural sediment traps.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this study include inter-disciplinary collaboration with Chilean glaciologists and marine geologists, support for one postdoctoral and three doctoral students, inclusion of undergraduates in research, and outreach to under-represented groups in Earth sciences and K-12 educators. The results of the project will also contribute to a better understanding of the linkages between climate and evolution of all high mountain ranges.", "east": -69.36881, "geometry": "POINT(-71.981865 -50.21674)", "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 SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e WATER BOTTLES; 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; Penguin Glacier", "locations": null, "north": -45.98986, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Anderson, John; Hallet, Bernard; Wellner, Julia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -54.44362, "title": "Collaborative Research: Controls on Sediment Yields from Tidewater Glaciers from Patagonia to Antarctica", "uid": "p0000821", "west": -74.59492}, {"awards": "9814349 Hall, Brenda", "bounds_geometry": "POLYGON((-70.4838 -52.3532,-68.92937 -52.3532,-67.37494 -52.3532,-65.82051 -52.3532,-64.26608 -52.3532,-62.71165 -52.3532,-61.15722 -52.3532,-59.60279 -52.3532,-58.04836 -52.3532,-56.49393 -52.3532,-54.9395 -52.3532,-54.9395 -53.61625,-54.9395 -54.8793,-54.9395 -56.14235,-54.9395 -57.4054,-54.9395 -58.66845,-54.9395 -59.9315,-54.9395 -61.19455,-54.9395 -62.4576,-54.9395 -63.72065,-54.9395 -64.9837,-56.49393 -64.9837,-58.04836 -64.9837,-59.60279 -64.9837,-61.15722 -64.9837,-62.71165 -64.9837,-64.26608 -64.9837,-65.82051 -64.9837,-67.37494 -64.9837,-68.92937 -64.9837,-70.4838 -64.9837,-70.4838 -63.72065,-70.4838 -62.4576,-70.4838 -61.19455,-70.4838 -59.9315,-70.4838 -58.66845,-70.4838 -57.4054,-70.4838 -56.14235,-70.4838 -54.8793,-70.4838 -53.61625,-70.4838 -52.3532))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001743", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0209"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award supports a two year program to produce a new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum (LGM) for the South Shetland Islands in the Antarctic Peninsula. One field season on Livingston Island will involve mapping the areal extent and geomorphology of glacial drift and determining the elevation and distribution of trimlines. In addition, ice flow direction will be determined by mapping and measuring the elevation of erosional features and the position of erratic boulders. One of the main goals of this work will be to demonstrate whether or not organic material suitable for radiocarbon dating exists in the South Shetland Islands. If so, the age of the deposits will be determined by measuring the carbon-14 age of plant, algal, and fungal remains preserved at the base of the deposits, as well as incorporated marine shells, seal skin and other organic material that may be found in raised beach deposits. Another goal will be to concentrate on the development of relative sea-level curves from 2-3 key areas to show whether or not construction of such curves for the South Shetland Islands is possible. The new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum for the South Shetland Islands which will be produced by this work will be useful in studies of ocean circulation and ice dynamics in the vicinity of the Drake Passage. It will also contribute to the production of a deglacial chronology which will afford important clues about the mechanisms controlling ice retreat in this region of the southern hemisphere.", "east": -54.9395, "geometry": "POINT(-62.71165 -58.66845)", "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": -52.3532, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hall, Brenda; Taylor, Frederick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.9837, "title": "AMS Radiocarbon Chronology of Glacier Fluctuations in the South Shetland Islands During the Last Glacial/Interglacial Hemicycle:Implications for Global Climate Change", "uid": "p0000596", "west": -70.4838}, {"awards": "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": "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": "Pettit, Erin; Waddington, Edwin D.; Zumberge, Mark; Elsberg, Daniel; Morack, James; Harrison, William", "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": "9420648 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": "Siple Dome Ice Core Age-Depth Scales", "datasets": [{"dataset_uid": "609130", "doi": "10.7265/N5T151KD", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Nereson, Nadine A.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Ice Core Age-Depth Scales", "url": "https://www.usap-dc.org/view/dataset/609130"}], "date_created": "Tue, 09 Sep 2003 00:00:00 GMT", "description": "This award is for support for a three year program to investigate the response of ice domes, such as Siple Dome in West Antarctica, to changing boundary conditions, for example as arising from fluctuations in thickness or position of bounding ice streams. A range of models will be used, from simple one-dimensional analytical models to coupled dynamic-thermodynamic flow models, to investigate the response of the ice dome to boundary forcing, and the record that boundary forcing can leave in the ice core record. Using radar, temperature, and ice core data from the currently funded field programs on Siple Dome, and ice flux and thickness values from the map view model as boundary conditions, a flow line across Siple Dome will be studied and possible ranges of time scales, the likely origin of ice near the bed, and the basal temperature conditions that exist now and existed in the past will be determined.The response of internal stratigraphy patterns to climate and dynamic forcing effects will be investigated and observed internal layers from ice cores will be used to infer the forcing history.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Ice Sheet; Snow; Not provided; Stratigraphy; Shallow Core; Siple Coast; Antarctica; Ice Core; Siple Dome; Glaciology; Density; Siple; WAISCORES; GROUND STATIONS; GROUND-BASED OBSERVATIONS", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Nereson, Nadine A.; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Ice Modelling Study of Siple Dome: WAIS Ice Dynamics, WAISCORES Paleoclimate and Ice Stream/Ice Dome Interactions", "uid": "p0000058", "west": null}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||||||||
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Modeling the Coupled Dynamics of Groundwater, Subglacial Hydrology and Ice Sheets
|
2336328 |
2024-10-08 | Larochelle, Stacy; Kingslake, Jonathan | No dataset link provided | Ice sheets lose ice mass through gravity-driven flow to the ocean where ice breaks into icebergs and melts, contributing to global sea level rise. Water commonly found at the base of ice sheets facilitates this process by lubricating the ice-rock interface. The recent discovery of vast, kilometer-thick groundwater reservoirs beneath the Antarctic Ice Sheet thus raises important questions about the potential impact of groundwater on ice flow. It has been hypothesized that groundwater flow to the ice-sheet bed may accelerate ice flow as the ice sheet shrinks in response to global warming. Evaluating this hypothesis is challenging due to poorly understood interactions between water, ice, and rock, but is crucial for anticipating the response of ice sheets and sea level to climate change. Understanding how groundwater responds to a changing ice sheet also has important implications for the heat, chemical elements, and microorganisms it stores and transports.<br/><br/>To assess the impact of groundwater processes on ice dynamics, a new idealized modeling framework will be developed, incorporating several novel hydromechanical couplings between ice sheets, subglacial drainage systems, and groundwater aquifers. This framework will enable testing the hypotheses that (1) aquifers decelerate ice mass loss in the absence of a well-developed subglacial drainage system, but that (2) an efficient, channelized drainage system can reduce and even reverse this decelerating effect, and that (3) the impact of these phenomena is most pronounced for steep ice flowing rapidly over thick sedimentary basins and depends in a complex way on aquifer permeability. Existing geodetic, seismic, and other geophysical datasets at well-studied Thwaites Glacier and Whillans Ice Stream will be used to constrain model parameters and investigate the impact of groundwater processes in contrasting glaciologic settings. This work will help rule out or highlight subglacial groundwater as one of the next major challenges for efforts to predict the future of the Antarctic Ice Sheet and sea-level rise on decadal to millennial timescales. The project will contribute to educating the next generation of scientists by supporting an early-career PI and a graduate student, as well as participation in a field and research educational program in Alaska and the production of chapters for an online, open-source, free interactive textbook.<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. | None | None | false | false | |||||||||
CAREER: Bound to Improve - Improved Estimates of the Glaciological Contribution to Sea Level Rise
|
1149085 |
2023-10-13 | Bassis, Jeremy |
|
This CAREER award supports a project to develop physically based bounds on the amount ice sheets can contribute to sea level rise in the coming centuries. To simulate these limits, a three-dimensional discrete element model will be developed and applied to simulate regions of interest in the Greenland and Antarctic ice sheets. These regions will include Helheim Glacier, Jakobshavn Isbräe, Pine Island Glacier and sections of the Larsen Ice Shelf. In the discrete element model the ice will be discretized into distinct blocks or boulders of ice that interact through inelastic collisions, frictional forces and bonds. The spectrum of best to worst case scenarios will be examined by varying the strength and number of bonds between neighboring blocks of ice. The worst case scenario corresponds to completely disarticulated ice that behaves in a manner akin to a granular material while the best case scenario corresponds to completely intact ice with no preexisting flaws or fractures. Results from the discrete element model will be compared with those from analogous continuum models that incorporate a plastic yield stress into the more traditional viscous flow approximations used to simulate ice sheets. This will be done to assess if a fracture permitting plastic rheology can be efficiently incorporated into large-scale ice sheet models to simulate the evolution of ice sheets over the coming centuries. This award will also support to forge a partnership with two science teachers in the Ypsilanti school district in southeastern Michigan. The Ypsilanti school district is a low income, resource- poor region with a population that consists of ~70% underrepresented minorities and ~69% of students qualify for a free or reduced cost lunch. The cornerstone of the proposed partnership is the development of lesson plans and content associated with a hands-on ice sheet dynamics activity for 6th and 7th grade science students. The activity will be designed so that it integrates into existing classroom lesson plans and is aligned with State of Michigan Science Technology, Engineering and Math (STEM) curriculum goals. The aim of this program is to not only influence the elementary school students, but also to educate the teachers to extend the impact of the partnership beyond the duration of this study. Graduate students will be mentored and engaged in outreach activities and assist in supervising undergraduate students. Undergraduates will play a key role in developing an experimental, analogue ice dynamics lab designed to illustrate how ice sheets and glaciers flow and allow experimental validation of the proposed research activities. The research program advances ice sheet modeling infrastructure by distributing results through the community based Community Ice Sheet Model. | POLYGON((66 -68,66.9 -68,67.8 -68,68.7 -68,69.6 -68,70.5 -68,71.4 -68,72.3 -68,73.2 -68,74.1 -68,75 -68,75 -68.6,75 -69.2,75 -69.8,75 -70.4,75 -71,75 -71.6,75 -72.2,75 -72.8,75 -73.4,75 -74,74.1 -74,73.2 -74,72.3 -74,71.4 -74,70.5 -74,69.6 -74,68.7 -74,67.8 -74,66.9 -74,66 -74,66 -73.4,66 -72.8,66 -72.2,66 -71.6,66 -71,66 -70.4,66 -69.8,66 -69.2,66 -68.6,66 -68)) | POINT(70.5 -71) | false | false | |||||||||
NSFGEO-NERC: Investigating the Direct Influence of Meltwater on Antarctic Ice Sheet Dynamics
|
2053169 |
2023-09-15 | 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. | None | None | false | false | |||||||||
Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation
|
2302832 |
2023-07-12 | Reilly, Brendan | The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica's response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica's glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth's most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica's ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. | POLYGON((-70 -55,-67 -55,-64 -55,-61 -55,-58 -55,-55 -55,-52 -55,-49 -55,-46 -55,-43 -55,-40 -55,-40 -56.1,-40 -57.2,-40 -58.3,-40 -59.4,-40 -60.5,-40 -61.6,-40 -62.7,-40 -63.8,-40 -64.9,-40 -66,-43 -66,-46 -66,-49 -66,-52 -66,-55 -66,-58 -66,-61 -66,-64 -66,-67 -66,-70 -66,-70 -64.9,-70 -63.8,-70 -62.7,-70 -61.6,-70 -60.5,-70 -59.4,-70 -58.3,-70 -57.2,-70 -56.1,-70 -55)) | POINT(-55 -60.5) | false | false | ||||||||||
Rutford Ice Stream Cooperative Research Program with British Antarctic Survey
|
1643961 |
2022-11-16 | Anandakrishnan, Sridhar |
|
Anandakrishnan/1643961<br/><br/>This award supports a project to study conditions under the Rutford Ice Stream, a large glacier that flows from the interior of the West Antarctic Ice Sheet to the Filchner Ronne Ice Shelf and then on to the ocean. The speed and volume of ice delivered to the ocean by this and similar glaciers is central to the question of sea-level change in the coming decades: if the volume of ice carried by Rutford to the ocean increases, then it will contribute to a rise in sea level. Numerical models of glacier flow that are used to forecast future conditions must include a component that accounts for the sliding of the ice over its bed. The sliding process is poorly modeled because of lack of detailed information about the bottom of glaciers, leading to increased uncertainty in the ice-flow models. Data from this project will provide such information. <br/><br/>During this project, in collaboration with researchers at the British Antarctic Survey, a detailed survey of the properties of the bed of Rutford Ice Stream will be carried out. These surveys include using seismic instruments (which are sensitive to naturally occurring earthquakes within glaciers--called icequakes) to monitor the distribution of those icequakes at the bed. The locations, size, and timing of icequakes are controlled by the properties of the bed such as porosity, water pressure, and stress. As part of this project, a hole will be drilled to the bed of the glacier to monitor water pressures and to extract a sample of the basal material. By comparing the pressure variations with icequake production, the properties of the basal material over a large area can be better determined. Those results will aid in the application of numerical models by informing their description of the sliding process. This award requires field work in 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. | POLYGON((-80 -83,-79.8 -83,-79.6 -83,-79.4 -83,-79.2 -83,-79 -83,-78.8 -83,-78.6 -83,-78.4 -83,-78.2 -83,-78 -83,-78 -83.2,-78 -83.4,-78 -83.6,-78 -83.8,-78 -84,-78 -84.2,-78 -84.4,-78 -84.6,-78 -84.8,-78 -85,-78.2 -85,-78.4 -85,-78.6 -85,-78.8 -85,-79 -85,-79.2 -85,-79.4 -85,-79.6 -85,-79.8 -85,-80 -85,-80 -84.8,-80 -84.6,-80 -84.4,-80 -84.2,-80 -84,-80 -83.8,-80 -83.6,-80 -83.4,-80 -83.2,-80 -83)) | POINT(-79 -84) | false | false | |||||||||
Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets
|
1744649 |
2022-08-02 | Christianson, Knut; Hoffman, Andrew; Holschuh, Nicholas | 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. | 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)) | POINT(-107.5 -86.1) | false | false | ||||||||||
The Role of Wave-sea Ice Floe Interactions in Recent Antarctic Sea Ice Change
|
1643431 |
2022-07-19 | Bitz, Cecilia | Sea-ice coverage surrounding Antarctica has expanded during the era of satellite observations, in contrast to rapidly shrinking Arctic sea ice. Most climate models predict Antarctic sea ice loss, rather than growth, indicating that there is much to learn about Antarctic sea ice in terms of its natural variability, processes and interactions affecting annual growth and retreat, and the impact of atmospheric factors such increasing greenhouse gases and stratospheric ozone depletion. This project is designed to improve model simulations of sea ice and examine the role of wind and wave forcing on changes in sea ice around Antarctica.<br/><br/>This project seeks to explain basic interactions of the coupled atmosphere, ocean, and ice dynamics in the Antarctic climate system, especially in the region near the sea ice edge. The summer evolution of sea ice cover and the near surface heat exchange of atmosphere and ocean depend on the geometric distribution of floes and the open water surrounding them. The distribution of floes has the greatest impact on the sea ice state in the marginal seas, where the distribution itself can vary rapidly. This project would develop and implement a model of sea ice floes in the Los Alamos sea ice model, known as CICE5. This sea ice component would be coupled to the third generation WaveWatch model within the Community Climate System Model Version 2. The coupled model would be used to study sea ice-wave interactions and the role of modeling sea ice floes in the Antarctic. The broader impacts of this project include outreach, support of female scientists, and improvement of the sea-ice codes in widely used climate models. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | ||||||||||
Collaborative Research: Feedbacks between Orographic Precipitation and Ice Dynamics
|
1644277 |
2022-07-14 | Aschwanden, Andy; Pettit, Erin |
|
Aschwanden/1644277<br/><br/>This award supports a project to study the phenomenon of the rain shadow (technically called orographic precipitation) in the Antarctic Peninsula and its interaction with a mountain range covered in ice and snow. Orographic precipitation gives rise to the largest climatic and ecological gradients on Earth. Air ascending on the windward side of the mountain range expands and cools, condensing the water vapor it carries and producing heavy rain- or snow-fall. As the air descends on the leeward flank, the air warms and dries out, leaving little-to-no precipitation. This pattern of snowfall, caused by the interaction of winds and the landscape, is hypothesized to control the shape of the ice cap itself. The investigators hypothesize that feedbacks between precipitation and topography control ice flux and temperature, impacting basal conditions (frozen versus wet) and motion, which over long time scales can affect basal topography via erosion.<br/><br/>The authors propose to investigate the feedbacks between orographically driven precipitation, ice dynamics, thermodynamics, and basal erosion and uplift over the northern Antarctic Peninsula by coupling an orographic precipitation model to the Parallel Ice Sheet Model (PISM). Using idealized and more realistic geometries, they will begin with a 2-D flow band model, which will be expanded into three dimensions to determine the strength of the feedbacks as a function of bedrock geometry and the intensity of the orographic precipitation gradient. The Antarctic Peninsula is targeted as the ideal case study, in the context of its rapid modern and future change as well as its deflation since the Last Glacial Maximum. The broader impacts of the work include the strengthening of predictive models by capturing feedbacks related to orographic precipitation not included in current models. This is likely to provide a more realistic assessment of the impacts of orographic precipitation in a regime of changing climate. The project will support an early career scientist and a female mid-career scientist and will support one PhD student, and provide summer research experience for one undergraduate student as an REU supplement. The project does not require field work in the Antarctic. | POLYGON((-75 -60,-72 -60,-69 -60,-66 -60,-63 -60,-60 -60,-57 -60,-54 -60,-51 -60,-48 -60,-45 -60,-45 -61.5,-45 -63,-45 -64.5,-45 -66,-45 -67.5,-45 -69,-45 -70.5,-45 -72,-45 -73.5,-45 -75,-48 -75,-51 -75,-54 -75,-57 -75,-60 -75,-63 -75,-66 -75,-69 -75,-72 -75,-75 -75,-75 -73.5,-75 -72,-75 -70.5,-75 -69,-75 -67.5,-75 -66,-75 -64.5,-75 -63,-75 -61.5,-75 -60)) | POINT(-60 -67.5) | false | false | |||||||||
Collaborative Research: Reconstructing Late Holocene Ecosystem and Climate Shifts from Peat Records in the Western Antarctic Peninsula
|
1745068 1745082 |
2022-06-10 | Beilman, David; Booth, Robert |
|
Warming on the western Antarctic Peninsula in the later 20th century has caused widespread changes in the cryosphere (ice and snow) and terrestrial ecosystems. These recent changes along with longer-term climate and ecosystem histories will be deciphered using peat deposits. Peat accumulation can be used to assess the rate of glacial retreat and provide insight into ecological processes on newly deglaciated landscapes in the Antarctic Peninsula. This project builds on data suggesting recent ecosystem transformations that are linked to past climate of the western Antarctic Peninsula and provide a timeline to assess the extent and rate of recent glacial change. The study will produce a climate record for the coastal low-elevation terrestrial region, which will refine the major climate shifts of up to 6 degrees C in the recent past (last 12,000 years). A novel terrestrial record of the recent glacial history will provide insight into observed changes in climate and sea-ice dynamics in the western Antarctic Peninsula and allow for comparison with off-shore climate records captured in sediments. Observations and discoveries from this project will be disseminated to local schools and science centers. The project provides training and career development for a postdoctoral scientist as well as graduate and undergraduate students.<br/><br/>The research presents a new systematic survey to reconstruct ecosystem and climate change for the coastal low-elevation areas on the western Antarctic Peninsula (AP) using proxy records preserved in late Holocene peat deposits. Moss and peat samples will be collected and analyzed to generate a comprehensive data set of late-Holocene climate change and ecosystem dynamics. The goal is to document and understand the transformations of landscape and terrestrial ecosystems on the western AP during the late Holocene. The testable hypothesis is that coastal regions have experienced greater climate variability than evidenced in ice-core records and that past warmth has facilitated dramatic ecosystem and cryosphere response. A primary product of the project is a robust reconstruction of late Holocene climate changes for coastal low-elevation terrestrial areas using multiple lines of evidence from peat-based biological and geochemical proxies, which will be used to compare with climate records derived from marine sediments and ice cores from the AP region. These data will be used to test several ideas related to novel peat-forming ecosystems (such as Antarctic hairgrass bogs) in past warmer climates and climate controls over ecosystem establishment and migration to help assess the nature of the Little Ice Age cooling and cryosphere response. The chronology of peat cores will be established by radiocarbon dating of macrofossils and Bayesian modeling. The high-resolution time series of ecosystem and climate changes will help put the observed recent changes into a long-term context to bridge climate dynamics over different time scales.<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. | POLYGON((-64.4 -62.4,-63.910000000000004 -62.4,-63.42 -62.4,-62.93000000000001 -62.4,-62.440000000000005 -62.4,-61.95 -62.4,-61.46 -62.4,-60.97 -62.4,-60.480000000000004 -62.4,-59.99 -62.4,-59.5 -62.4,-59.5 -62.7,-59.5 -63,-59.5 -63.3,-59.5 -63.6,-59.5 -63.900000000000006,-59.5 -64.2,-59.5 -64.5,-59.5 -64.80000000000001,-59.5 -65.10000000000001,-59.5 -65.4,-59.99 -65.4,-60.480000000000004 -65.4,-60.97 -65.4,-61.46 -65.4,-61.95 -65.4,-62.440000000000005 -65.4,-62.93000000000001 -65.4,-63.42 -65.4,-63.910000000000004 -65.4,-64.4 -65.4,-64.4 -65.10000000000001,-64.4 -64.80000000000001,-64.4 -64.5,-64.4 -64.2,-64.4 -63.900000000000006,-64.4 -63.6,-64.4 -63.3,-64.4 -63,-64.4 -62.7,-64.4 -62.4)) | POINT(-61.95 -63.900000000000006) | false | false | |||||||||
Collaborative Research: Modeling ice-ocean interaction for the rapidly evolving ice shelf cavities of Pine Island and Thwaites glaciers, Antarctica
|
1643285 1643174 |
2022-05-13 | Joughin, Ian; Dutrieux, Pierre; Padman, Laurence; Springer, Scott |
|
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. | 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)) | POINT(-95 -77) | false | false | |||||||||
Biological and Physical Drivers of Oxygen Saturation and Net Community Production Variability along the Western Antarctic Peninsula
|
1643534 |
2022-03-03 | Cassar, Nicolas |
|
This project seeks to make detailed measurements of the oxygen content of the surface ocean along the Western Antarctic Peninsula. Detailed maps of changes in net oxygen content will be combined with measurements of the surface water chemistry and phytoplankton distributions. The project will determine the extent to which on-shore or offshore phytoplankton blooms along the peninsula are likely to lead to different amounts of carbon being exported to the deeper ocean. The project will analyze oxygen in relation to argon that will allow determination of the physical and biological contributions to surface ocean oxygen dynamics. These assessments will be combined with spatial and temporal distributions of nutrients (iron and macronutrients) and irradiances. This will allow the investigators to unravel the complex interplay between ice dynamics, iron and physical mixing dynamics as they relate to Net Community Production (NCP) in the region. NCP measurements will be normalized to Particulate Organic Carbon (POC) and be used to help identify area of "High Biomass and Low NCP" and those with "Low Biomass and High NCP" as a function of microbial plankton community composition. The team will use machine learning methods- including decision tree assemblages and genetic programming- to identify plankton groups key to facilitating biological carbon fluxes. Decomposing the oxygen signal along the West Antarctic Peninsula will also help elucidate biotic and abiotic drivers of the O2 saturation to further contextualize the growing inventory of oxygen measurements (e.g. by Argo floats) throughout the global oceans. | POLYGON((-83 -62,-80.3 -62,-77.6 -62,-74.9 -62,-72.2 -62,-69.5 -62,-66.8 -62,-64.1 -62,-61.4 -62,-58.7 -62,-56 -62,-56 -63.1,-56 -64.2,-56 -65.3,-56 -66.4,-56 -67.5,-56 -68.6,-56 -69.7,-56 -70.8,-56 -71.9,-56 -73,-58.7 -73,-61.4 -73,-64.1 -73,-66.8 -73,-69.5 -73,-72.2 -73,-74.9 -73,-77.6 -73,-80.3 -73,-83 -73,-83 -71.9,-83 -70.8,-83 -69.7,-83 -68.6,-83 -67.5,-83 -66.4,-83 -65.3,-83 -64.2,-83 -63.1,-83 -62)) | POINT(-69.5 -67.5) | false | false | |||||||||
Sensitivity of the Antarctic Ice Sheet to Climate Change over the Last Two Glacial/Interglacial Cycles
|
0944150 |
2022-03-03 | Hall, Brenda; Denton, George |
|
This award supports a project to investigate the sensitivity of the Antarctic ice sheet (AIS) to global climate change over the last two Glacial/Interglacial cycles. The intellectual merit of the project is that despite its importance to Earth's climate system, we currently lack a full understanding of AIS sensitivity to global climate change. This project will reconstruct and precisely date the history of marine-based ice in the Ross Sea sector over the last two glacial/interglacial cycles, which will enable a better understanding of the potential driving mechanisms (i.e., sea-level rise, ice dynamics, ocean temperature variations) for ice fluctuations. This will also help to place present ice?]sheet behavior in a long-term context. During the last glacial maximum (LGM), the AIS is known to have filled the Ross Embayment and although much has been done both in the marine and terrestrial settings to constrain its extent, the chronology of the ice sheet, particularly the timing and duration of the maximum and the pattern of initial recession, remains uncertain. In addition, virtually nothing is known of the penultimate glaciation, other than it is presumed to have been generally similar to the LGM. These shortcomings greatly limit our ability to understand AIS evolution and the driving mechanisms behind ice sheet fluctuations. This project will develop a detailed record of ice extent and chronology in the western Ross Embayment for not only the LGM, but also for the penultimate glaciation (Stage 6), from well-dated glacial geologic data in the Royal Society Range. Chronology will come primarily from high-precision Accelerator Mass Spectrometry (AMS) Carbon-14 (14C) and multi-collector Inductively Coupled Plasma (ICP)-Mass Spectrometry (MS) 234Uranium/230Thorium dating of lake algae and carbonates known to be widespread in the proposed field area. | POLYGON((163.6 -77.5,163.7 -77.5,163.8 -77.5,163.9 -77.5,164 -77.5,164.1 -77.5,164.2 -77.5,164.3 -77.5,164.4 -77.5,164.5 -77.5,164.6 -77.5,164.6 -77.57,164.6 -77.64,164.6 -77.71,164.6 -77.78,164.6 -77.85,164.6 -77.92,164.6 -77.99,164.6 -78.06,164.6 -78.13,164.6 -78.2,164.5 -78.2,164.4 -78.2,164.3 -78.2,164.2 -78.2,164.1 -78.2,164 -78.2,163.9 -78.2,163.8 -78.2,163.7 -78.2,163.6 -78.2,163.6 -78.13,163.6 -78.06,163.6 -77.99,163.6 -77.92,163.6 -77.85,163.6 -77.78,163.6 -77.71,163.6 -77.64,163.6 -77.57,163.6 -77.5)) | POINT(164.1 -77.85) | false | false | |||||||||
Collaborative Research: Linking Marine and Terrestrial Sedimentary Evidence for Plio-pleistocene Variability of Weddell Embayment and Antarctic Peninsula Glaciation
|
2114786 |
2021-09-09 | Warnock, Jonathan | No dataset link provided | The potential for future sea level rise from melting and collapse of Antarctic ice sheets and glaciers is concerning. We can improve our understanding of how water is exchanged between Antarctic ice sheets and the ocean by studying how ice sheets behaved in past climates, especially conditions that were similar to or warmer than those at present. For this project, the research team will document Antarctica’s response across an interval when Earth transitioned from the warm Pliocene into the Pleistocene ice ages by combining marine and land evidence for glacier variations from sites near the Antarctic Peninsula, complimented by detailed work on timescales and fossil evidence for environmental change. An important goal is to test whether Antarctica’s glaciers changed at the same time as glaciers in the Northern Hemisphere as Earth's most recent Ice Age intensified, or alternatively responded to regional climate forcing in the Southern Hemisphere. Eleven investigators from seven US institutions, as well as Argentine collaborators, will study new sediment cores from the International Ocean Discovery Program, as well as legacy cores from that program and on-land outcrops on James Ross Island. The group embraces a vertically integrated research program that allows high school, undergraduate, graduate, post-docs and faculty to work together on the same projects. This structure leverages the benefits of near-peer mentoring and the development of a robust collaborative research network while allowing all participants to take ownership of different parts of the project. All members of the team are firmly committed to attracting researchers from under-represented groups and will do this through existing channels as well as via co-creating programming that centers the perspectives of diverse students in conversations about sea-level rise and climate change. The proposed research seeks to understand phasing between Northern and Southern Hemisphere glacier and climate changes, as a means to understand drivers and teleconnections. The dynamics of past Antarctic glaciation can be studied using the unique isotope geochemical and mineralogic fingerprints from glacial sectors tied to a well-constrained time model for the stratigraphic successions. The proposed work would further refine the stratigraphic context through coupled biostratigraphic and magnetostratigraphic work. The magnitude of iceberg calving and paths of icebergs will be revealed using the flux, geochemical and mineralogic signatures, and 40Ar/39Ar and U-Pb geochronology of ice-rafted detritus. These provenance tracers will establish which sectors of Antarctica’s ice sheets are more vulnerable to collapse, and the timing and pacing of these events will be revealed by their stratigraphic context. Additionally, the team will work with Argentine collaborators to connect the marine and terrestrial records by studying glacier records intercalated with volcanic flows on James Ross Island. These new constraints will be integrated with a state of the art ice-sheet model to link changes in ice dynamics with their underlying causes. Together, these tight stratigraphic constraints, geochemical signatures, and ice-sheet model simulations will provide a means to compare to the global records of climate change, understand their primary drivers, and elucidate the role of the Antarctic ice sheet in a major, global climatic shift from the Pliocene into the Pleistocene. | None | None | false | false | |||||||||
Satellite observations and modelling of surface meltwater flow and its impact on ice shelves
|
1743310 |
2021-06-02 | Kingslake, Jonathan |
|
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. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
Collaborative Research: Elucidating Environmental Controls of Productivity in Polynas and the Western Antarctic Peninsula
|
1643618 1643652 |
2021-04-29 | van Dijken, Gert; Arrigo, Kevin; Dinniman, Michael; Hofmann, Eileen |
|
Coastal waters surrounding Antarctica represent some of the most biologically rich and most untouched ecosystems on Earth. In large part, this biological richness is concentrated within the numerous openings that riddle the expansive sea ice (these openings are known as polynyas) near the Antarctic continent. These polynyas represent regions of enhanced production known as hot-spots and support the highest animal densities in the Southern Ocean. Many of them are also located adjacent to floating extensions of the vast Antarctic Ice Sheet and receive a substantial amount of meltwater runoff each year during the summer. However, little is known about the specific processes that make these ecosystems so biologically productive. Of the 46 Antarctic coastal polynyas that are presently known, only a handful have been investigated in detail. This project will develop ecosystem models for the Ross Sea polynya, Amundsen polynya, and Pine Island polynya; three of the most productive Antarctic coastal polynyas. The primary goal is to use these models to better understand the fundamental physical, chemical, and biological interacting processes and differences in these processes that make these systems so biologically productive yet different in some respects (e.g. size and productivity) during the present day settings. Modeling efforts will also be extended to potentially assess how these ecosystems may have functioned in the past and how they might change in the future under different physical and chemical and climatic settings. The project will advance the education of underrepresented minorities through Stanford?s Summer Undergraduate Research in Geoscience and Engineering (SURGE) Program. SURGE will provide undergraduates the opportunity to gain mentored research experiences at Stanford University in engineering and the geosciences. Old Dominion University also will utilize an outreach programs for local public and private schools as well as an ongoing program supporting the Boy Scout Oceanography merit badge program to create outreach and education impacts. Polynyas (areas of open water surrounded by sea ice) are disproportionately productive regions of polar ecosystems, yet controls on their high rates of production are not well understood. This project will provide quantitative assessments of the physical and chemical processes that control phytoplankton abundance and productivity within polynyas, how these differ for different polynyas, and how polynyas may change in the future. Of particular interest are the interactions among processes within the polynyas and the summertime melting of nearby ice sheets, including the Thwaites and Pine Island glaciers. In this proposed study, we will develop a set of comprehensive, high resolution coupled physical-biological models and implement these for three major, but diverse, Antarctic polynyas. These polynyas, the Ross Sea polynya, the Amundsen polynya, and Pine Island polynya, account for >50% of the total Antarctic polynya production. The research questions to be addressed are: 1) What environmental factors exert the greatest control of primary production in polynyas around Antarctica? 2) What are the controlling physics that leads to the heterogeneity of dissolved iron (dFe) supply to the euphotic zone in polynyas around the Antarctic continental shelf? What effect does this have on local rates of primary production? 3) What are the likely changes in the supply of dFe to the euphotic zone in the next several decades due to climate-induced changes in the physics (winds, sea-ice, ice shelf basal melt, cross-shelf exchange, stratification and vertical mixing) and how will this affect primary productivity around the continent? The Ross Sea, Amundsen, and Pine Island polynyas are some of the best-sampled polynyas in Antarctica, facilitating model parameterization and validation. Furthermore, these polynyas differ widely in their size, location, sea ice dynamics, relationship to melting ice shelves, and distance from the continental shelf break, making them ideal case studies. For comparison, the western Antarctic Peninsula (wAP), a productive continental shelf where polynyas are a relatively minor contributor to biological production, will also be modeled. Investigating specific processes within different types Antarctic coastal waters will provide a better understand of how these important biological oases function and how they might change under different environmental conditions. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment
|
1929991 1738992 |
2021-02-22 | Truffer, Martin; Scambos, Ted; Muto, Atsu; Heywood, Karen; Boehme, Lars; Hall, Robert; Wahlin, Anna; Lenaerts, Jan; Pettit, Erin | This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites and neighboring glaciers in the Amundsen Sea Embayment are rapidly losing mass in response to recent climate warming and related changes in ocean circulation. Mass loss from the Amundsen Sea Embayment could lead to the eventual collapse of the West Antarctic Ice Sheet, raising the global sea level by up to 2.5 meters (8 feet) in as short as 500 years. The processes driving the loss appear to be warmer ocean circulation and changes in the width and flow speed of the glacier, but a better understanding of these changes is needed to refine predictions of how the glacier will evolve. One highly sensitive process is the transitional flow of glacier ice from land onto the ocean to become a floating ice shelf. This flow of ice from grounded to floating is affected by changes in air temperature and snowfall at the surface; the speed and thickness of ice feeding it from upstream; and the ocean temperature, salinity, bathymetry, and currents that the ice flows into. The project team will gather new measurements of each of these local environmental conditions so that it can better predict how future changes in air, ocean, or the ice will affect the loss of ice to the ocean in this region. <br/> <br/>Current and anticipated near-future mass loss from Thwaites Glacier and nearby Amundsen Sea Embayment region is mainly attributed to reduction in ice-shelf buttressing due to sub-ice-shelf melting by intrusion of relatively warm Circumpolar Deep Water into sub-ice-shelf cavities. Such predictions for mass loss, however, still lack understanding of the dominant processes at and near grounding zones, especially their spatial and temporal variability, as well as atmospheric and oceanic drivers of these processes. This project aims to constrain and compare these processes for the Thwaites and the Dotson Ice Shelves, which are connected through upstream ice dynamics, but influenced by different submarine troughs. The team's specific objectives are to: 1) install atmosphere-ice-ocean multi-sensor remote autonomous stations on the ice shelves for two years to provide sub-daily continuous observations of concurrent oceanic, glaciologic, and atmospheric conditions; 2) measure ocean properties on the continental shelf adjacent to ice-shelf fronts (using seal tagging, glider-based and ship-based surveys, and existing moored and conductivity-temperature-depth-cast data), 3) measure ocean properties into sub-ice-shelf cavities (using autonomous underwater vehicles) to detail ocean transports and heat fluxes; and 4) constrain current ice-shelf and sub-ice-shelf cavity geometry, ice flow, and firn properties for the ice-shelves (using radar, active-source seismic, and gravimetric methods) to better understand the impact of ocean and atmosphere on the ice-sheet change. The team will also engage the public and bring awareness to this rapidly changing component of the cryosphere through a "Live from the Ice" social media campaign in which the public can follow the action and data collection from the perspective of tagged seals and autonomous stations.<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. | POLYGON((-114 -74,-113 -74,-112 -74,-111 -74,-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-104 -74.2,-104 -74.4,-104 -74.6,-104 -74.8,-104 -75,-104 -75.2,-104 -75.4,-104 -75.6,-104 -75.8,-104 -76,-105 -76,-106 -76,-107 -76,-108 -76,-109 -76,-110 -76,-111 -76,-112 -76,-113 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74)) | POINT(-109 -75) | false | false | ||||||||||
High Resolution Heterogeneity at the Base of Whillans Ice Stream and its Control on Ice Dynamics
|
1443525 |
2021-02-12 | Tulaczyk, Slawek; Schwartz, Susan |
|
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. | 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)) | POINT(-155 -84.4) | false | false | |||||||||
Collaborative Research: Deglacial Ice Dynamics in the Weddell Sea Embayment using Sediment Provenance
|
1724670 |
2020-09-10 | Williams, Trevor; Hemming, Sidney R. | Abstract for the general public:<br/><br/>The margins of the Antarctic ice sheet have advanced and retreated repeatedly over the past few million years. Melting ice from the last retreat, from 19,000 to 9,000 years ago, raised sea levels by 8 meters or more, but the extents of previous retreats are less well known. The main goal of this project is to understand how Antarctic ice retreats: fast or slow, stepped or steady, and which parts of the ice sheet are most prone to retreat. Antarctica loses ice by two main processes: melting of the underside of floating ice shelves and calving of icebergs. Icebergs themselves are ephemeral, but they carry mineral grains and rock fragments that have been scoured from Antarctic bedrock. As the icebergs drift and melt, this 'iceberg-rafted debris' falls to the sea-bed and is steadily buried in marine sediments to form a record of iceberg activity and ice sheet retreat. The investigators will read this record of iceberg-rafted debris to find when and where Antarctic ice destabilized in the past. This information can help to predict how Antarctic ice will behave in a warming climate. <br/><br/>The study area is the Weddell Sea embayment, in the Atlantic sector of Antarctica. Principal sources of icebergs are the nearby Antarctic Peninsula and Weddell Sea embayment, where ice streams drain about a quarter of Antarctic ice. The provenance of the iceberg-rafted debris (IRD), and the icebergs that carried it, will be found by matching the geochemical fingerprint (such as characteristic argon isotope ages) of individual mineral grains in the IRD to that of the corresponding source area. In more detail, the project will: <br/><br/>1. Define the geochemical fingerprints of the source areas of the glacially-eroded material using samples from each major ice stream entering the Weddell Sea. Existing data indicates that the hinterland of the Weddell embayment is made up of geochemically distinguishable source areas, making it possible to apply geochemical provenance techniques to determine the origin of Antarctica icebergs. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till samples to characterize detritus supplied by the Recovery and Foundation ice streams. <br/><br/>2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information identifies which groups of ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents), and the stratigraphy of the cores shows the relative sequence of ice stream activity through time. A further dimension is added by determining the time lag between fine sediment erosion and deposition, using a new method of uranium-series isotope measurements in fine grained material. <br/><br/>Technical abstract:<br/><br/> The behavior of the Antarctic ice sheets and ice streams is a critical topic for climate change and future sea level rise. The goal of this proposal is to constrain ice sheet response to changing climate in the Weddell Sea during the three most recent glacial terminations, as analogues for potential future warming. The project will also examine possible contributions to Meltwater Pulse 1A, and test the relative stability of the ice streams draining East and West Antarctica. Much of the West Antarctic ice may have melted during the Eemian (130 to 114 Ka), so it may be an analogue for predicting future ice drawdown over the coming centuries. <br/><br/>Geochemical provenance fingerprinting of glacially eroded detritus provides a novel way to reconstruct the location and relative timing of glacial retreat during these terminations in the Weddell Sea embayment. The two major objectives of the project are to: <br/><br/>1. Define the provenance source areas by characterizing Ar, U-Pb, and Nd isotopic signatures, and heavy mineral and Fe-Ti oxide compositions of detrital minerals from each major ice stream entering the Weddell Sea, using onshore tills and existing sediment cores from the Ronne and Filchner Ice Shelves. Pilot data demonstrate that detritus originating from the east and west sides of the Weddell Sea embayment can be clearly distinguished, and published data indicates that the hinterland of the embayment is made up of geochemically distinguishable source areas. Few samples of onshore tills are available from this area, so this project includes fieldwork to collect till to characterize detritus supplied by the Recovery and Foundation ice streams. <br/><br/>2. Document the stratigraphic changes in provenance of iceberg-rafted debris (IRD) and glacially-eroded material in two deep water sediment cores in the NW Weddell Sea. Icebergs calved from ice streams in the embayment are carried by the Weddell Gyre and deposit IRD as they pass over the core sites. The provenance information will identify which ice streams were actively eroding and exporting detritus to the ocean (via iceberg rafting and bottom currents). The stratigraphy of the cores will show the relative sequence of ice stream activity through time. A further time dimension is added by determining the time lag between fine sediment erosion and deposition, using U-series comminution ages. | POLYGON((-70 -60,-65 -60,-60 -60,-55 -60,-50 -60,-45 -60,-40 -60,-35 -60,-30 -60,-25 -60,-20 -60,-20 -62.5,-20 -65,-20 -67.5,-20 -70,-20 -72.5,-20 -75,-20 -77.5,-20 -80,-20 -82.5,-20 -85,-25 -85,-30 -85,-35 -85,-40 -85,-45 -85,-50 -85,-55 -85,-60 -85,-65 -85,-70 -85,-70 -82.5,-70 -80,-70 -77.5,-70 -75,-70 -72.5,-70 -70,-70 -67.5,-70 -65,-70 -62.5,-70 -60)) | POINT(-45 -72.5) | false | false | ||||||||||
Investigating Early Miocene Sub-ice Volcanoes in Antarctica for Improved Modeling and understanding of a Large Magmatic Province
|
1443576 |
2020-06-05 | Panter, Kurt |
|
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. | 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)) | POINT(-153.75 -87) | false | false | |||||||||
Collaborative Research: Lithospheric Controls on the Behavior of the West Antarctic Ice Sheet: Corridor Aerogeophysics of Eastern Ross Transect Zone
|
9319854 9319877 9319369 |
2020-04-24 | Bell, Robin; Blankenship, Donald D.; Finn, C. A. | This award supports a project to conduct an integrated geophysical survey over a large portion of the West Antarctic Ice Sheet (WAIS) toward an understanding of the dynamic behavior of the ice sheet and the nature of the lithosphere beneath the ice sheet. West Antarctica is characterized by two kinds of the Earth s most dynamic systems, a continental rift (the West Antarctic Rift System) and a marine based ice sheet (the WAIS). Active continental rift systems, caused by divergent plate motions, result in thinned continental crust. Associated with the thin crust are fault-bounded sedimentary basins, active volcanism, and elevated heat flow. Marine ice sheets are characterized by rapidly moving streams of ice, penetrating and draining a slowly moving ice reservoir. Evidence left by past marine ice sheets indicates that they may have a strongly non- linear response to long-term climate change which results in massive and rapid discharges of ice. Understanding the evolution of the ice stream system and its interaction with the interior ice is the key to understanding this non-linear response. Subglacial geology and ice dynamics are generally studied in isolation, but evidence is mounting that the behavior of the West Antarctic ice streams may be closely linked to the nature of the underlying West Antarctic rift system. The fast moving ice streams appear to glide on a lubricating layer of water-saturated till. This till requires easily eroded sediment and a source of water, both of which may be controlled by the geology of the rift system; the sediments from the fault-bounded basins and the water from the elevated heat flux associated with active lithospheric extension. This project represents an interdisciplinary aerogeophysical study to characterize the lithosphere of the West Antarctic rift system beneath critical regions of the WAIS. The objective is to determine the effects of the rift architect ure, as manifested by the distribution of sedimentary basins and volcanic constructs, on the ice stream system. The research tool is a unique geophysical aircraft with laser altimetry, ice penetrating radar, aerogravity, and aeromagnetic systems integrated with a high precision kinematic GPS navigation system. It is capable of imaging both the surface and bed of the ice sheet while simultaneously measuring the gravity and magnetic signature of the subglacial lithosphere. Work to be done under this award will build on work already completed in the southern sector of central West Antarctica and it will focus on the region of the Byrd Subglacial Basin and Ice Stream D. The ice sheet in these regions is completely covered by satellite imagery and so this project will be integrated with remote sensing studies of the ice stream. The changing dynamics of Ice Stream D, as with other West Antarctic ice streams, seem to be correlated with changes in the morphological provinces of the underlying rift system. The experimental targets proceed from the divide of the interior ice, downstream through the onset of streaming to the trunk of Ice Stream D. This study will be coordinated with surface glaciological investigations of Ice Stream D and will be used to guide cooperative over-snow seismic investigations of the central West Antarctic rift system. The data will also be used to select a site for future deep ice coring along the crest of the WAIS. These data represent baseline data for long term global change monitoring work and represent crucial boundary conditions for ice sheet modeling efforts. | POLYGON((-155 -77.5,-150 -77.5,-145 -77.5,-140 -77.5,-135 -77.5,-130 -77.5,-125 -77.5,-120 -77.5,-115 -77.5,-110 -77.5,-105 -77.5,-105 -78.2,-105 -78.9,-105 -79.6,-105 -80.3,-105 -81,-105 -81.7,-105 -82.4,-105 -83.1,-105 -83.8,-105 -84.5,-110 -84.5,-115 -84.5,-120 -84.5,-125 -84.5,-130 -84.5,-135 -84.5,-140 -84.5,-145 -84.5,-150 -84.5,-155 -84.5,-155 -83.8,-155 -83.1,-155 -82.4,-155 -81.7,-155 -81,-155 -80.3,-155 -79.6,-155 -78.9,-155 -78.2,-155 -77.5)) | POINT(-130 -81) | false | false | ||||||||||
Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole
|
1443105 |
2019-11-17 | Steig, Eric J.; White, James | This project will develop a record of the stable-isotope ratios of water from an ice core at the South Pole, Antarctica. Water-isotope ratio measurements provide a means to determine variability in temperature through time. South Pole is distinct from most other locations in Antarctica in showing no warming in recent decades, but little is known about temperature variability in this location prior to the installation of weather stations in 1957. The measurements made as part of this project will result in a much longer temperature record, extending at least 40,000 years, aiding our ability to understand what controls Antarctic climate, and improving projections of future Antarctic climate change. Data from this project will be critical to other investigators working on the South Pole ice core, and of general interest to other scientists and the public. Data will be provided rapidly to other investigators and made public as soon as possible.<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. | POINT(0 -90) | POINT(0 -90) | false | false | ||||||||||
Collaborative Research: A 1500m Ice Core from South Pole
|
1141839 1142646 1142517 |
2019-10-30 | Twickler, Mark; Souney, Joseph Jr.; Aydin, Murat; Steig, Eric J. | This proposal requests support for a project to drill and recover a new ice core from South Pole, Antarctica. The South Pole ice core will be drilled to a depth of 1500 m, providing an environmental record spanning approximately 40 kyrs. This core will be recovered using a new intermediate drill, which is under development by the U.S. Ice Drilling Design and Operations (IDDO) group in collaboration with Danish scientists. This proposal seeks support to provide: 1) scientific management and oversight for the South Pole ice core project, 2) personnel for ice core drilling and core processing, 3) data management, and 3) scientific coordination and communication via scientific workshops. The intellectual merit of the work is that the analysis of stable isotopes, atmospheric gases, and aerosol-borne chemicals in polar ice has provided unique information about the magnitude and timing of changes in climate and climate forcing through time. The international ice core research community has articulated the goal of developing spatial arrays of ice cores across Antarctica and Greenland, allowing the reconstruction of regional patterns of climate variability in order to provide greater insight into the mechanisms driving climate change. The broader impacts of the project include obtaining the South Pole ice core will support a wide range of ice core science projects, which will contribute to the societal need for a basic understanding of climate and the capability to predict climate and ice sheet stability on long time scales. Second, the project will help train the next generation of ice core scientists by providing the opportunity for hands-on field and core processing experience for graduate students and postdoctoral researchers. A postdoctoral researcher at the University of Washington will be directly supported by this project, and many other young scientists will interact with the project through individual science proposals. Third, the project will result in the development of a new intermediate drill which will become an important resource to US ice core science community. This drill will have a light logistical footprint which will enable a wide range of ice core projects to be carried out that are not currently feasible. Finally, although this project does not request funds for outreach activities, the project will run workshops that will encourage and enable proposals for coordinated outreach activities involving the South Pole ice core science team. | POINT(90 -90) | POINT(90 -90) | false | false | ||||||||||
Collaborative Research: High-resolution Reconstruction of Holocene Deglaciation in the Southern Ross Embayment
|
1443248 1443346 |
2019-09-05 | Hall, Brenda; Stone, John | The response of the Antarctic Ice Sheet to future climatic changes is recognized as the greatest uncertainty in projections of future sea level. An understanding of past ice fluctuations affords insight into ice-sheet response to climate and sea-level change and thus is critical for improving sea-level predictions. This project will examine deglaciation of the southern Ross Sea over the past few thousand years to document oscillations in Antarctic ice volume during a period of relatively stable climate and sea level. We will help quantify changes in ice volume, improve understanding of the ice dynamics responsible, and examine the implications for future sea-level change. The project will train future scientists through participation of graduate students, as well as undergraduates who will develop research projects in our laboratories.<br/><br/>Previous research indicates rapid Ross Sea deglaciation as far south as Beardmore Glacier early in the Holocene epoch (which began approximately 11,700 years before present), followed by more gradual recession. However, deglaciation in the later half of the Holocene remains poorly constrained, with no chronological control on grounding-line migration between Beardmore and Scott Glaciers. Thus, we do not know if mid-Holocene recession drove the grounding line rapidly back to its present position at Scott Glacier, or if the ice sheet withdrew gradually in the absence of significant climate forcing or eustatic sea level change. The latter possibility raises concerns for future stability of the Ross Sea grounding line. To address this question, we will map and date glacial deposits on coastal mountains that constrain the thinning history of Liv and Amundsen Glaciers. By extending our chronology down to the level of floating ice at the mouths of these glaciers, we will date their thinning history from glacial maximum to present, as well as migration of the Ross Sea grounding line southwards along the Transantarctic Mountains. High-resolution dating will come from Beryllium-10 surface-exposure ages of erratics collected along elevation transects, as well as Carbon-14 dates of algae within shorelines from former ice-dammed ponds. Sites have been chosen specifically to allow close comparison of these two dating methods, which will afford constraints on Antarctic Beryllium-10 production rates. | POLYGON((-174 -84.2,-172.4 -84.2,-170.8 -84.2,-169.2 -84.2,-167.6 -84.2,-166 -84.2,-164.4 -84.2,-162.8 -84.2,-161.2 -84.2,-159.6 -84.2,-158 -84.2,-158 -84.36,-158 -84.52,-158 -84.68,-158 -84.84,-158 -85,-158 -85.16,-158 -85.32,-158 -85.48,-158 -85.64,-158 -85.8,-159.6 -85.8,-161.2 -85.8,-162.8 -85.8,-164.4 -85.8,-166 -85.8,-167.6 -85.8,-169.2 -85.8,-170.8 -85.8,-172.4 -85.8,-174 -85.8,-174 -85.64,-174 -85.48,-174 -85.32,-174 -85.16,-174 -85,-174 -84.84,-174 -84.68,-174 -84.52,-174 -84.36,-174 -84.2)) | POINT(-166 -85) | false | false | ||||||||||
Collaborative Research: Grounding Line Dynamics: Crary Ice Rise Revisited
|
1443356 1443552 |
2019-05-06 | Conway, Howard; Koutnik, Michelle; Winberry, Paul |
|
Recent observations and model results suggest that collapse of the Amundsen Sea sector of West Antarctica may already be underway. However, the timeline of collapse and the effects of ongoing climatic and oceanographic changes are key unanswered questions. Complete disintegration of the ice sheet would raise global sea level by more than 3 m, which would have significant societal impacts. Improved understanding of the controls on ice-sheet evolution is needed to make better predictions of ice-sheet behavior. Results from numerical models show that buttressing from surrounding ice shelves and/or from small-scale grounded ice rises should act to slow the retreat and discharge of ice from the interior ice sheet. However, there are very few field observations with which to develop and validate models. Field observations conducted in the early 1980s on Crary Ice Rise in the Ross Sea Embayment are a notable exception. This project will revisit Crary Ice Rise with new tools to make a suite of measurements designed to address questions about how the ice rise affects ice discharge from the Ross Sea sector of West Antarctica. The team will include a graduate and undergraduate student, and will participate in a range of outreach activities.<br/><br/>New tools including radar, seismic, and GPS instruments will be used to conduct targeted geophysical measurements both on Crary Ice Rise and across its grounding line. The project will use these new measurements, together with available ancillary data to inform a numerical model of grounding line dynamics. The model and measurements will be used to address the (1) How has the ice rise evolved over timescales ranging from: the past few decades; the past millennia after freeze-on; and through the deglaciation? (2) What history of ice dynamics is preserved in the radar-detected internal stratigraphy? (3) What dynamical effect does the presence/absence of the ice rise have on discharge of the Ross Ice Streams today? (4) How is it contributing to the slow-down of the proximal Whillans and Mercer ice streams? (5) What dynamical response will the ice rise have under future environmental change? | POLYGON((-175 -82.7,-173.9 -82.7,-172.8 -82.7,-171.7 -82.7,-170.6 -82.7,-169.5 -82.7,-168.4 -82.7,-167.3 -82.7,-166.2 -82.7,-165.1 -82.7,-164 -82.7,-164 -82.77,-164 -82.84,-164 -82.91,-164 -82.98,-164 -83.05,-164 -83.12,-164 -83.19,-164 -83.26,-164 -83.33,-164 -83.4,-165.1 -83.4,-166.2 -83.4,-167.3 -83.4,-168.4 -83.4,-169.5 -83.4,-170.6 -83.4,-171.7 -83.4,-172.8 -83.4,-173.9 -83.4,-175 -83.4,-175 -83.33,-175 -83.26,-175 -83.19,-175 -83.12,-175 -83.05,-175 -82.98,-175 -82.91,-175 -82.84,-175 -82.77,-175 -82.7)) | POINT(-169.5 -83.05) | false | false | |||||||||
Collaborative Research: Phytoplankton Phenology in the Antarctic: Drivers, Patterns, and Implications for the Adelie Penguin
|
1341547 1341558 1341440 |
2018-11-20 | Jin, Meibing; Stroeve, Julienne; Ji, Rubao | The aim of study is to understand how climate-related changes in snow and ice affect predator populations in the Antarctic, using the Adélie penguin as a focal species due to its long history as a Southern Ocean 'sentinel' species and the number of long-term research programs monitoring its abundance, distribution, and breeding biology. Understanding the environmental factors that control predator population dynamics is critically important for projecting the state of populations under future climate change scenarios, and for designing better conservation strategies for the Antarctic ecosystem. For the first time, datasets from a network of observational sites for the Adélie penguin across the entire Antarctic will be combined and analyzed, with a focus on linkages among the ice environment, primary production, and the population responses of Adélie penguins. 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 results of this project can be used to illustrate intuitively to the general public the complex interactions between ice, ocean, pelagic food web and top predators. This project also offers an excellent platform to demonstrate the process of climate-change science - how scientists simulate climate change scenarios and interpret model results. This project supports the training of undergraduate and graduate students in the fields of polar oceanography, plankton and seabird ecology, coupled physical-biological modeling and mathematical ecology. The results will be broadly disseminated to the general oceanographic research community through scientific workshops, conferences and peer-reviewed journal articles, and to undergraduate and graduate education communities, K-12 schools and organizations, and the interested public through web-based servers using existing infrastructure at the investigators' institutions. The key question to be addressed in this project is how climate impacts the timing of periodic biological events (phenology) and how interannual variation in this periodic forcing influences the abundance of penguins in the Antarctic. The focus will be on the timing of ice algae and phytoplankton blooms because the high seasonality of sea ice and associated pulsed primary productivity are major drivers of the Antarctic food web. This study will also examine the responses of Adélie penguins to changes in sea ice dynamics and ice algae-phytoplankton phenology. Adélie penguins, like many other Antarctic seabirds, are long-lived, upper trophic-level predators that integrate the effects of sea ice on the food web at regional scales, and thus serve as a reliable biological indicator of environmental changes. The proposed approach is designed to accommodate the limits of measuring and modeling the intermediate trophic levels between phytoplankton and penguins (e.g., zooplankton and fish) at the pan-Antarctic scale, which are important but latent variables in the Southern Ocean food web. Through the use of remotely sensed and in situ data, along with state of the art statistical approaches (e.g. wavelet analysis) and numerical modeling, this highly interdisciplinary study will advance our understanding of polar ecosystems and improve the projection of future climate change scenarios. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | ||||||||||
Anisotropic Ice and Stratigraphic Disturbances
|
1246045 |
2018-04-02 | Waddington, Edwin D. |
|
Waddington/1246045 <br/><br/>This award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica. | POLYGON((-180 -70,-144 -70,-108 -70,-72 -70,-36 -70,0 -70,36 -70,72 -70,108 -70,144 -70,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,180 -82,180 -84,180 -86,180 -88,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88,-180 -86,-180 -84,-180 -82,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70)) | POINT(0 -89.999) | false | false | |||||||||
Vulnerability of East Antarctic Ice Streams to warm Ocean Water Incursions
|
1245879 |
2017-07-30 | Nitsche, Frank O. |
|
Intellectual Merit: <br/>This project will determine the potential vulnerability of key ice streams to incursions of warmer ocean water onto the continental shelf and if this mechanism could already explain any of the observed thinning of the ice sheet. It will provide important constrains on ice dynamic of the investigated section of the EAIS, and thus will be critical for future ice sheet models and provide mechanisms for EAIS contributions to past sea level high-stand. The PI proposes to investigate four key ice stream systems on the continental shelf between ~90°E and 160°E. They will use multibeam bathymetry to identify if and where cross-shelf troughs exist to help determine whether these troughs could provide potential pathways for warmer ocean water. Furthermore, detailed analysis of morphological features of these troughs could provide information on past ice dynamic, maximum extent, and flow direction of related paleo ice streams. The PIs will also conduct water column measurements along these troughs and on the continental slope to determine whether warmer ocean water could enter the shelf in the near future, or if such water has already entered any troughs, and thus might be causing the observed thinning of some ice streams.<br/><br/>Broader impacts: <br/>This project includes the participation and support of undergraduate and graduate students in field work and data analysis. The possible involvement of a PolarTREC teacher and the Earth2Class teachers program will reach out to K-12 students. | None | POINT(125.05 -64.5) | false | false | |||||||||
Collaborative Research: Climate, Ice Dynamics and Biology using a Deep Ice Core from the West Antarctic Ice Sheet Ice Divide
|
0944348 0944266 |
2017-06-09 | Mark, Twickler; Taylor, Kendrick C. |
|
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. | POINT(-112.1115 -79.481) | POINT(-112.1115 -79.481) | false | false | |||||||||
Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core
|
0944197 0944191 |
2017-04-25 | Conway, Howard; Fudge, T. J.; Taylor, Kendrick C.; Waddington, Edwin D. | This award supports a project to help to establish the depth-age chronology and the histories of accumulation and ice dynamics for the WAIS Divide ice core. The depth-age relationship and the histories of accumulation and ice dynamics are coupled. An accurate age scale is needed to infer histories of accumulation rate and ice-thickness change using ice-flow models. In turn, the accumulation-rate history is needed to calculate the age difference of ice to determine the age of the trapped gases. The accumulation history is also needed to calculate atmospheric concentrations of impurities trapped in the ice and is an important characteristic of climate. The history of ice-thickness change is also fundamental to understanding the stability of the WAIS. The primary goals of the WAIS Divide ice core project are to investigate climate forcing by greenhouse gases, the initiation of climate changes, and the stability of the West Antarctic Ice Sheet (WAIS). An accurate age scale is fundamental for achieving these goals. The first objective of this project is to establish an annually resolved depth-age relationship for the past 40,000 years. This will be done by measuring variations in electrical conductivity along the ice core, which are caused by seasonal variations in chemistry. We expect to be able to resolve annual layers back to 40,000 years before present (3,000 m depth) using this method. The second objective is to search for stratigraphic disturbances in the core that would compromise the paleoclimate record. Irregular layering will be identified by measuring the electrical conductivity of the ice in a vertical plan through the core. The third objective is to derive a preliminary chronology for the entire core. For the deeper ice we will use an ice-flow model to interpolate between known age markers, such as dated volcanic horizons and tie points from the methane gas chronology. The fourth objective is to derive a refined chronology simultaneously with histories of accumulation and ice-sheet thickness. An ice-flow model and all available data will be used to formulate an inverse problem, in which we infer the most appropriate histories of accumulation and ice-thickness, together with estimates of uncertainties. The flow model associated with those preferred histories then produces the best estimate of the chronology. The research contributes directly to the primary goals of the West Antarctic Ice Sheet Initiative. The project will help develop the next generation of scientists through the education and training of one Ph.D. student and several undergraduate students. This project will result in instrumentation for measuring the electrical conductivity of ice cores being available at the National Ice Core Lab for other researchers to use on other projects. All collaborators are committed to fostering diversity and currently participate in scientific outreach and most participate in undergraduate education. Outreach will be accomplished through regularly scheduled community and K-12 outreach events at UW, talks and popular writing by the PIs, as well as through our respective press offices. | POLYGON((-180 -79,-173.3 -79,-166.6 -79,-159.9 -79,-153.2 -79,-146.5 -79,-139.8 -79,-133.1 -79,-126.4 -79,-119.7 -79,-113 -79,-113 -79.1,-113 -79.2,-113 -79.3,-113 -79.4,-113 -79.5,-113 -79.6,-113 -79.7,-113 -79.8,-113 -79.9,-113 -80,-119.7 -80,-126.4 -80,-133.1 -80,-139.8 -80,-146.5 -80,-153.2 -80,-159.9 -80,-166.6 -80,-173.3 -80,180 -80,150.9 -80,121.8 -80,92.7 -80,63.6 -80,34.5 -80,5.4 -80,-23.7 -80,-52.8 -80,-81.9 -80,-111 -80,-111 -79.9,-111 -79.8,-111 -79.7,-111 -79.6,-111 -79.5,-111 -79.4,-111 -79.3,-111 -79.2,-111 -79.1,-111 -79,-81.9 -79,-52.8 -79,-23.7 -79,5.4 -79,34.5 -79,63.6 -79,92.7 -79,121.8 -79,150.9 -79,-180 -79)) | POINT(-112 -79.5) | false | false | ||||||||||
Collaborative Research: Constraints on the last Ross Ice Sheet from Glacial Deposits in the Southern Transantarctic Mountains
|
0838615 |
2013-09-05 | Hall, Brenda | No dataset link provided | Stone/0838818 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). <br/><br/>This award supports a project to study the former thickness and retreat history of Shackleton and Beardmore Glaciers which flow through the Transantarctic Mountains (TAMs) into the southern Ross Sea. Lateral moraine deposits along the lower reaches of these major outlet glaciers will be mapped and dated and the results will help to date the LGM and constrain the thickness of ice where it left the Transantarctic Mountains and flowed into the Ross Sea. The intellectual merit of the project is that the results will allow scientists to distinguish between models of ice retreat, which have important implications for former ice configuration and dynamics, and to constrain the contribution from Ross Sea deglaciation to global sea level through the late Holocene. In addition, this will make a significant contribution to a better understanding of the magnitude and timing of postglacial sea-level change and the potential contribution of Antarctica to sea-level rise in future. The broader impacts of the project are that the work will help quantify changes in grounded ice volume since the LGM, improve understanding of the ice dynamics responsible, and examine their implications for future sea level change. The project will train future scientists through participation of two graduate students and undergraduates who will develop self-contained research projects. As in previous Antarctic projects, there will be interaction with K-12 students through classroom visits, web-based expedition journals, letters from the field, and discussions with teachers and will allow the project to be shared with a wide audience. This award has field work in Antarctica. | POLYGON((-177.13 -84.55,-177.074 -84.55,-177.018 -84.55,-176.962 -84.55,-176.906 -84.55,-176.85 -84.55,-176.794 -84.55,-176.738 -84.55,-176.682 -84.55,-176.626 -84.55,-176.57 -84.55,-176.57 -84.615,-176.57 -84.68,-176.57 -84.745,-176.57 -84.81,-176.57 -84.875,-176.57 -84.94,-176.57 -85.005,-176.57 -85.07,-176.57 -85.135,-176.57 -85.2,-176.626 -85.2,-176.682 -85.2,-176.738 -85.2,-176.794 -85.2,-176.85 -85.2,-176.906 -85.2,-176.962 -85.2,-177.018 -85.2,-177.074 -85.2,-177.13 -85.2,-177.13 -85.135,-177.13 -85.07,-177.13 -85.005,-177.13 -84.94,-177.13 -84.875,-177.13 -84.81,-177.13 -84.745,-177.13 -84.68,-177.13 -84.615,-177.13 -84.55)) | POINT(-176.85 -84.875) | false | false | |||||||||
IPY: Stability of Larsen C Ice Shelf in a Warming Climate
|
0732946 |
2012-10-03 | Steffen, Konrad |
|
This award supports a field experiment, with partners from Chile and the Netherlands, to determine the state of health and stability of Larsen C ice shelf in response to climate change. Significant glaciological and ecological changes are taking place in the Antarctic Peninsula in response to climate warming that is proceeding at 6 times the global average rate. Following the collapse of Larsen A ice shelf in 1995 and Larsen B in 2002, the outlet glaciers that nourished them with land ice accelerated massively, losing a disproportionate amount of ice to the ocean. Further south, the much larger Larsen C ice shelf is thinning and measurements collected over more than a decade suggest that it is doomed to break up. The intellectual merit of the project will be to contribute to the scientific knowledge of one of the Antarctic sectors where the most significant changes are taking place at present. The project is central to a cluster of International Polar Year activities in the Antarctic Peninsula. It will yield a legacy of international collaboration, instrument networking, education of young scientists, reference data and scientific analysis in a remote but globally relevant glaciological setting. The broader impacts of the project will be to address the contribution to sea level rise from Antarctica and to bring live monitoring of climate and ice dynamics in Antarctica to scientists, students, the non-specialized public, the press and the media via live web broadcasting of progress, data collection, visualization and analysis. Existing data will be combined with new measurements to assess what physical processes are controlling the weakening of the ice shelf, whether a break up is likely, and provide baseline data to quantify the consequences of a breakup. Field activities will include measurements using the Global Positioning System (GPS), installation of automatic weather stations (AWS), ground penetrating radar (GPR) measurements, collection of shallow firn cores and temperature measurements. These data will be used to characterize the dynamic response of the ice shelf to a variety of phenomena (oceanic tides, iceberg calving, ice-front retreat and rifting, time series of weather conditions, structural characteristics of the ice shelf and bottom melting regime, and the ability of firn to collect melt water and subsequently form water ponds that over-deepen and weaken the ice shelf). This effort will complement an analysis of remote sensing data, ice-shelf numerical models and control methods funded independently to provide a more comprehensive analysis of the ice shelf evolution in a changing climate. | None | None | false | false | |||||||||
IPY: Flow Dynamics of the Amundsen Sea Glaciers: Thwaites and Pine Island.
|
0632198 |
2012-08-29 | Anandakrishnan, Sridhar |
|
This award supports a project to study ice sheet history and dynamics on the Thwaites Glacier and Pine Island Glacier in the Amundsen Sea sector of the West Antarctic Ice Sheet. The international collaboration that has been established with the British Antarctic Survey will enable a fuller suite of geophysical experiments with more-efficient use of people and logistics than we could achieve individually. This project is one of a number of projects to characterize the Amundsen Sea Embayment, which has been identified in numerous planning documents as perhaps the most important target for ice-dynamical research. Taken together, this "pulse of activity" will result in a better understanding of this important part of the global system. Field work will measure the subglacial environment of Thwaites and Pine Island Glaciers using three powerful, but relatively simple tools: reflection seismic imaging, GPS motion monitoring of the tidal forcing, and passive seismic monitoring of the seismicity associated with motion. The results of the field work will feed into ice-sheet modeling efforts that are tuned to the case of an ocean-terminating glacier and will assess the influence of these glaciers on current sea level and project into the future. The broader impacts of the project involve the inclusion of a film- and audio-professional to document the work for informal outreach (public radio and TV; museums). In addition, we will train graduate students in polar geophysical and glaciological research and in numerical modeling techniques. The ultimate goal of this project, of assessing the role of Thwaites Glacier in global sea level change, has broad societal impact in coastal regions and small islands. | POINT(110 -74) | POINT(-110 -74) | false | false | |||||||||
Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System
|
0758274 0636724 |
2012-05-15 | Carter, Sasha P.; Dupont, Todd K.; Holt, John W.; Morse, David L.; Parizek, Byron R.; Young, Duncan A.; Kempf, Scott D.; Blankenship, Donald D. | This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program's emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: "investigation of the physics of fast glacier flow with emphasis on processes at glacier beds"; "investigation of ice-shelf stability"; and "identification and quantification of the feedback between ice dynamics and climate change". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations. | POLYGON((-110.058 -74.0548,-109.57993 -74.0548,-109.10186 -74.0548,-108.62379 -74.0548,-108.14572 -74.0548,-107.66765 -74.0548,-107.18958 -74.0548,-106.71151 -74.0548,-106.23344 -74.0548,-105.75537 -74.0548,-105.2773 -74.0548,-105.2773 -74.31383,-105.2773 -74.57286,-105.2773 -74.83189,-105.2773 -75.09092,-105.2773 -75.34995,-105.2773 -75.60898,-105.2773 -75.86801,-105.2773 -76.12704,-105.2773 -76.38607,-105.2773 -76.6451,-105.75537 -76.6451,-106.23344 -76.6451,-106.71151 -76.6451,-107.18958 -76.6451,-107.66765 -76.6451,-108.14572 -76.6451,-108.62379 -76.6451,-109.10186 -76.6451,-109.57993 -76.6451,-110.058 -76.6451,-110.058 -76.38607,-110.058 -76.12704,-110.058 -75.86801,-110.058 -75.60898,-110.058 -75.34995,-110.058 -75.09092,-110.058 -74.83189,-110.058 -74.57286,-110.058 -74.31383,-110.058 -74.0548)) | POINT(-107.66765 -75.34995) | false | false | ||||||||||
Self-consistent Ice Dynamics, Accumulation, Delta-age, and Interpolation of Sparse Age Data using an Inverse Approach
|
0636997 |
2012-03-20 | Carns, Regina; Hay, Mike; Waddington, Edwin D. | No dataset link provided | 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. | None | None | false | false | |||||||||
Center for Remote Sensing of Ice Sheets (CReSIS)
|
0424589 |
2011-06-01 | Braaten, David; Joughin, Ian; Steig, Eric J.; Das, Sarah; Paden, John; Gogineni, Prasad | This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbræ. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.<br/><br/>The intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. <br/><br/>As lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets. | POLYGON((-137 -74,-132.1 -74,-127.2 -74,-122.3 -74,-117.4 -74,-112.5 -74,-107.6 -74,-102.7 -74,-97.8 -74,-92.9 -74,-88 -74,-88 -74.65,-88 -75.3,-88 -75.95,-88 -76.6,-88 -77.25,-88 -77.9,-88 -78.55,-88 -79.2,-88 -79.85,-88 -80.5,-92.9 -80.5,-97.8 -80.5,-102.7 -80.5,-107.6 -80.5,-112.5 -80.5,-117.4 -80.5,-122.3 -80.5,-127.2 -80.5,-132.1 -80.5,-137 -80.5,-137 -79.85,-137 -79.2,-137 -78.55,-137 -77.9,-137 -77.25,-137 -76.6,-137 -75.95,-137 -75.3,-137 -74.65,-137 -74)) | POINT(-112.5 -77.25) | false | false | ||||||||||
Collaborative Research: U.S. SO GLOBEC Synthesis and Modeling: Timing is Everything: The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)
|
0528728 0529087 0529666 |
2011-04-02 | Fritsen, Christian; Vernet, Maria; Ross, Robin Macurda; Quetin, Langdon B. | This collaborative study between the Desert Research Institute, the University of California, Santa Barbara (0529087; Robin Ross), and the University of California, San Diego (0528728; Maria Vernet) will examine the relationship between sea ice extent along the Antarctic Peninsula and the life history of krill (Euphausia superba), by developing, refining, and linking diagnostic datasets and models of phytoplankton decreases in the fall, phytoplankton biomass incorporation into sea ice, sea ice growth dynamics, sea ice algal production and biomass accumulation, and larval krill energetics, condition, and survival. Krill is a key species in the food web of the Southern Ocean ecosystem, and one that is intricately involved with seasonal sea ice dynamics. Results from the Southern Ocean experiment of the Global Ocean Ecosystems Dynamics program (SO-Globec) field work as well as historical information on sea ice dynamics and krill recruitment suggest a shift in the paradigm that all pack ice is equally good krill habitat.<br/><br/>SO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with the lower trophic levels, and will be integrated with other synthesis and modeling studies that deal with grazers, predators, and other higher trophic levels. | POLYGON((-69.08 -64.8,-68.632 -64.8,-68.184 -64.8,-67.736 -64.8,-67.288 -64.8,-66.84 -64.8,-66.392 -64.8,-65.944 -64.8,-65.496 -64.8,-65.048 -64.8,-64.6 -64.8,-64.6 -65.121,-64.6 -65.442,-64.6 -65.763,-64.6 -66.084,-64.6 -66.405,-64.6 -66.726,-64.6 -67.047,-64.6 -67.368,-64.6 -67.689,-64.6 -68.01,-65.048 -68.01,-65.496 -68.01,-65.944 -68.01,-66.392 -68.01,-66.84 -68.01,-67.288 -68.01,-67.736 -68.01,-68.184 -68.01,-68.632 -68.01,-69.08 -68.01,-69.08 -67.689,-69.08 -67.368,-69.08 -67.047,-69.08 -66.726,-69.08 -66.405,-69.08 -66.084,-69.08 -65.763,-69.08 -65.442,-69.08 -65.121,-69.08 -64.8)) | POINT(-66.84 -66.405) | false | false | ||||||||||
Collaborative Research: IPY, The Next Generation: A Community Ice Sheet Model for Scientists and Educators With Demonstration Experiments in Amundsen Sea Embayment Region
|
0632325 0632161 0632168 0632346 |
2010-07-02 | Hulbe, Christina; Seals, Cheryl; Johnson, Jesse; Daescu, Dacian N. |
|
Johnson/0632161<br/><br/>This award supports a project to create a "Community Ice Sheet Model (CISM)". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating "a new generation" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities. | POLYGON((-180 -50.05,-144 -50.05,-108 -50.05,-72 -50.05,-36 -50.05,0 -50.05,36 -50.05,72 -50.05,108 -50.05,144 -50.05,180 -50.05,180 -54.045,180 -58.04,180 -62.035,180 -66.03,180 -70.025,180 -74.02,180 -78.015,180 -82.01,180 -86.005,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -86.005,-180 -82.01,-180 -78.015,-180 -74.02,-180 -70.025,-180 -66.03,-180 -62.035,-180 -58.04,-180 -54.045,-180 -50.05)) | POINT(0 -89.999) | false | false | |||||||||
Antarctic Pack Ice Seals: Ecological Interactions with Prey and the Environment
|
9815961 |
2010-05-04 | Bengtson, John |
|
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. | 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)) | POINT(0 -89.999) | false | false | |||||||||
Collaborative Research: Controls on Sediment Yields from Tidewater Glaciers from Patagonia to Antarctica
|
0338371 0338137 |
2010-05-04 | Anderson, John; Hallet, Bernard; Wellner, Julia |
|
This project examines the role of glacier dynamics in glacial sediment yields. The results will shed light on how glacial erosion influences both orogenic processes and produces sediments that accumulate in basins, rich archives of climate variability. Our hypothesis is that erosion rates are a function of sliding speed, and should diminish sharply as the glacier's basal temperatures drop below the melting point. To test this hypothesis, we will determine sediment accumulation rates from seismic studies of fjord sediments for six tidewater glaciers that range from fast-moving temperate glaciers in Patagonia to slow-moving polar glaciers on the Antarctic Peninsula. Two key themes are addressed for each glacier system: 1) sediment yields and erosion rates by determining accumulation rates within the fjords using seismic profiles and core data, and 2) dynamic properties and basin characteristics of each glacier in order to seek an empirical relationship between glacial erosion rates and ice dynamics. The work is based in Patagonia and the Antarctic Peninsula, ideal natural laboratories for these purposes because the large latitudinal range provides a large range of precipitation and thermal regimes over relatively homogeneous lithologies and tectonic settings. Prior studies of these regions noted significant decreases in glaciomarine sediment accumulations in the fjords to the south. As well, the fjords constitute accessible and nearly perfect natural sediment traps.<br/><br/>The broader impacts of this study include inter-disciplinary collaboration with Chilean glaciologists and marine geologists, support for one postdoctoral and three doctoral students, inclusion of undergraduates in research, and outreach to under-represented groups in Earth sciences and K-12 educators. The results of the project will also contribute to a better understanding of the linkages between climate and evolution of all high mountain ranges. | POLYGON((-74.59492 -45.98986,-74.072309 -45.98986,-73.549698 -45.98986,-73.027087 -45.98986,-72.504476 -45.98986,-71.981865 -45.98986,-71.459254 -45.98986,-70.936643 -45.98986,-70.414032 -45.98986,-69.891421 -45.98986,-69.36881 -45.98986,-69.36881 -46.835236,-69.36881 -47.680612,-69.36881 -48.525988,-69.36881 -49.371364,-69.36881 -50.21674,-69.36881 -51.062116,-69.36881 -51.907492,-69.36881 -52.752868,-69.36881 -53.598244,-69.36881 -54.44362,-69.891421 -54.44362,-70.414032 -54.44362,-70.936643 -54.44362,-71.459254 -54.44362,-71.981865 -54.44362,-72.504476 -54.44362,-73.027087 -54.44362,-73.549698 -54.44362,-74.072309 -54.44362,-74.59492 -54.44362,-74.59492 -53.598244,-74.59492 -52.752868,-74.59492 -51.907492,-74.59492 -51.062116,-74.59492 -50.21674,-74.59492 -49.371364,-74.59492 -48.525988,-74.59492 -47.680612,-74.59492 -46.835236,-74.59492 -45.98986)) | POINT(-71.981865 -50.21674) | false | false | |||||||||
AMS Radiocarbon Chronology of Glacier Fluctuations in the South Shetland Islands During the Last Glacial/Interglacial Hemicycle:Implications for Global Climate Change
|
9814349 |
2010-05-04 | Hall, Brenda; Taylor, Frederick |
|
This award supports a two year program to produce a new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum (LGM) for the South Shetland Islands in the Antarctic Peninsula. One field season on Livingston Island will involve mapping the areal extent and geomorphology of glacial drift and determining the elevation and distribution of trimlines. In addition, ice flow direction will be determined by mapping and measuring the elevation of erosional features and the position of erratic boulders. One of the main goals of this work will be to demonstrate whether or not organic material suitable for radiocarbon dating exists in the South Shetland Islands. If so, the age of the deposits will be determined by measuring the carbon-14 age of plant, algal, and fungal remains preserved at the base of the deposits, as well as incorporated marine shells, seal skin and other organic material that may be found in raised beach deposits. Another goal will be to concentrate on the development of relative sea-level curves from 2-3 key areas to show whether or not construction of such curves for the South Shetland Islands is possible. The new reconstruction of ice extent, elevation and thickness at the Last Glacial Maximum for the South Shetland Islands which will be produced by this work will be useful in studies of ocean circulation and ice dynamics in the vicinity of the Drake Passage. It will also contribute to the production of a deglacial chronology which will afford important clues about the mechanisms controlling ice retreat in this region of the southern hemisphere. | POLYGON((-70.4838 -52.3532,-68.92937 -52.3532,-67.37494 -52.3532,-65.82051 -52.3532,-64.26608 -52.3532,-62.71165 -52.3532,-61.15722 -52.3532,-59.60279 -52.3532,-58.04836 -52.3532,-56.49393 -52.3532,-54.9395 -52.3532,-54.9395 -53.61625,-54.9395 -54.8793,-54.9395 -56.14235,-54.9395 -57.4054,-54.9395 -58.66845,-54.9395 -59.9315,-54.9395 -61.19455,-54.9395 -62.4576,-54.9395 -63.72065,-54.9395 -64.9837,-56.49393 -64.9837,-58.04836 -64.9837,-59.60279 -64.9837,-61.15722 -64.9837,-62.71165 -64.9837,-64.26608 -64.9837,-65.82051 -64.9837,-67.37494 -64.9837,-68.92937 -64.9837,-70.4838 -64.9837,-70.4838 -63.72065,-70.4838 -62.4576,-70.4838 -61.19455,-70.4838 -59.9315,-70.4838 -58.66845,-70.4838 -57.4054,-70.4838 -56.14235,-70.4838 -54.8793,-70.4838 -53.61625,-70.4838 -52.3532)) | POINT(-62.71165 -58.66845) | false | false | |||||||||
Investigation of Climate, Ice Dynamics and Biology using a Deep Ice Core from the West Antarctic Ice Sheet Ice Divide
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0440817 |
2010-02-10 | McGwire, Kenneth C. |
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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. | None | None | false | false | |||||||||
Ice Dynamics, the Flow Law, and Vertical Strain at Siple Dome
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9615502 |
2007-02-22 | Harrison, William; Morack, James; Pettit, Erin; Zumberge, Mark; Elsberg, Daniel; Waddington, Edwin D. |
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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. | POINT(-148.822 -81.655) | POINT(-148.822 -81.655) | false | false | |||||||||
Ice Modelling Study of Siple Dome: WAIS Ice Dynamics, WAISCORES Paleoclimate and Ice Stream/Ice Dome Interactions
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9420648 |
2003-09-09 | Nereson, Nadine A.; Waddington, Edwin D. |
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This award is for support for a three year program to investigate the response of ice domes, such as Siple Dome in West Antarctica, to changing boundary conditions, for example as arising from fluctuations in thickness or position of bounding ice streams. A range of models will be used, from simple one-dimensional analytical models to coupled dynamic-thermodynamic flow models, to investigate the response of the ice dome to boundary forcing, and the record that boundary forcing can leave in the ice core record. Using radar, temperature, and ice core data from the currently funded field programs on Siple Dome, and ice flux and thickness values from the map view model as boundary conditions, a flow line across Siple Dome will be studied and possible ranges of time scales, the likely origin of ice near the bed, and the basal temperature conditions that exist now and existed in the past will be determined.The response of internal stratigraphy patterns to climate and dynamic forcing effects will be investigated and observed internal layers from ice cores will be used to infer the forcing history. | None | None | false | false |