USAP-DC

{"dp_type": "Project", "free_text": "Vertical Velocity"}

[{"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": "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": "Christianson, Knut; Hills, Benjamin; Holschuh, Nicholas; Hoffman, Andrew; Fudge, Tyler J; Horlings, Annika; Erwin, Emma; Steig, Eric J.", "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": "601606", "doi": "10.15784/601606", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Christianson, Knut", "repository": "USAP-DC", "science_program": null, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "url": "https://www.usap-dc.org/view/dataset/601606"}, {"dataset_uid": "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": "Hills, Benjamin; Hoffman, Andrew; Christianson, Knut; Christian, John; Holschuh, Nicholas; Horlings, Annika; 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": "601711", "doi": "10.15784/601711", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Holschuh, Nicholas; Hoffman, Andrew; Christianson, Knut; 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": "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"}], "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. 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. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -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": "1643353 Christianson, Knut; 1643301 Gerbi, Christopher", "bounds_geometry": null, "dataset_titles": "ImpDAR: an impulse radar processor; SeidarT; South Pole Lake ApRES Radar; South Pole Lake GNSS; South Pole Lake: ground-based ice-penetrating radar", "datasets": [{"dataset_uid": "200244", "doi": " https://zenodo.org/badge/latestdoi/382590632", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "SeidarT", "url": "https://github.com/UMainedynamics/SeidarT"}, {"dataset_uid": "200203", "doi": "", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "South Pole Lake: ground-based ice-penetrating radar", "url": "http://hdl.handle.net/1773/45293"}, {"dataset_uid": "601502", "doi": "10.15784/601502", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GNSS; GPS; GPS Data; South Pole; Subglacial Lakes", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake GNSS", "url": "https://www.usap-dc.org/view/dataset/601502"}, {"dataset_uid": "200202", "doi": "http://doi.org/10.5281/zenodo.3833057", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "ImpDAR: an impulse radar processor", "url": "https://www.github.com/dlilien/ImpDAR"}, {"dataset_uid": "601503", "doi": "10.15784/601503", "keywords": "Antarctica; Apres; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; South Pole; Subglacial Lakes; Vertical Velocity", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake ApRES Radar", "url": "https://www.usap-dc.org/view/dataset/601503"}], "date_created": "Wed, 17 Feb 2021 00:00:00 GMT", "description": "Gerbi/1643301 This award supports a project to develop software that will allow researchers considering seismic or radar field surveys to test, ahead of time, whether the data they plan to collect will have sufficient resolution to measure the natural variations in the mechanical properties of ice, which determine the response of flowing ice to changing climatic conditions. The mechanical properties of ice depend largely on the temperature and the orientation of the crystals that make up the ice. The most accurate method for measuring ice crystal orientation and temperature is through drilling and direct analysis of an ice core. However, this method is very costly, time-consuming, and limited in spatial coverage. Geophysical techniques, such as seismic and radar, can cover much more area, but we have little knowledge about the practical limitations of these techniques as they relate to calculating mechanical properties. This project addresses that knowledge gap through construction of a computational toolbox that will allow accurate assessment of the ability of geophysical surveys to image crystal orientation and ice temperature. Researchers can then use these tools to adjust the field survey plans to maximize the return on investment. By working to improve the efficiency and effectiveness of future geophysical work related to glacial flow, this proposal will improve scientists? ability to quantify sea-level variations within the larger context of climate change. The project includes building new user-friendly, publicly accessible software and instructional modules. The work will provide training for graduate and undergraduate students, who will play a role in research and develop instructional materials. Ice viscosity, the resistance of ice to flow, exerts significant control over ice velocity. Therefore, mapping ice viscosity is important for understanding the current and future behavior of glaciers and ice sheets. To do so, scientists must determine the temperature and crystal orientation fabric throughout the ice. Seismic and radar techniques can survey large areas quickly, and thus are promising, yet not fully tested, methods to efficiently measure the thermal and mechanical structure of flowing ice. As part of this project, scientists will develop and use a computational framework to quantify the degree to which seismic and radar techniques can resolve the crystal orientation fabric and temperature of streaming ice, and then test how sensitive ice flow is to the attendant uncertainty. To meet these goals, a numerical toolbox will be built which will allow the glacier/ice stream geometry and physical properties (temperature, crystal orientation fabric, density and acidity) to be varied. The toolbox will be capable of both creating synthetic radar and seismic profiles through forward modeling and inverting synthetic profiles to allow evaluation of how well geophysical techniques can image the original thermal and mechanical structure. These simulated radar and seismic data will allow scientists to better quantify the influence of the variability in mechanical properties of the ice on flow velocities and patterns. The results of this work will guide planning for future field campaigns, making them more effective and efficient. This project does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; GLACIERS/ICE SHEETS; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; South Pole; USA/NSF; AMD; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; FIELD SURVEYS; Amd/Us", "locations": "South Pole; United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Gerbi, Christopher; Campbell, Seth; Vel, Senthil", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "GitHub", "repositories": "GitHub; Uni. Washington ResearchWorks Archive; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Computational Methods Supporting Joint Seismic and Radar Inversion for Ice Fabric and Temperature in Streaming Flow", "uid": "p0010160", "west": null}, {"awards": "0636996 Waddington, Edwin; 0940650 Pettit, Erin", "bounds_geometry": "POLYGON((-165 -75,-159 -75,-153 -75,-147 -75,-141 -75,-135 -75,-129 -75,-123 -75,-117 -75,-111 -75,-105 -75,-105 -76,-105 -77,-105 -78,-105 -79,-105 -80,-105 -81,-105 -82,-105 -83,-105 -84,-105 -85,-111 -85,-117 -85,-123 -85,-129 -85,-135 -85,-141 -85,-147 -85,-153 -85,-159 -85,-165 -85,-165 -84,-165 -83,-165 -82,-165 -81,-165 -80,-165 -79,-165 -78,-165 -77,-165 -76,-165 -75))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 16 Mar 2012 00:00:00 GMT", "description": "Pettit/0636795\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to constrain the accumulation rate, thickness, and temperature history for Siple Dome using a vertical velocity profile that includes the effects of an evolving fabric on deformation through time, to invert the depth-profile of fabric determined from sonic velocity measurements and grain size observed in thin sections in Siple Dome for the surface temperature and accumulation rate changes in the past, focusing on the apparent abrupt climate change events at 22ka and 15ka. The intellectual merit of the work is that it will extract past climate information from a number of physical properties of the deep ice using a coupled fabric evolution and ice-sheet flow model. The focus will be on the deep ice-age ice at Siple Dome, where the ice-core record shows puzzling signals and where modeling results imply intriguing deformation patterns. The method will also be applied to the records from Byrd Station and Taylor Dome to ultimately form a basis for future analysis of the West Antarctic Divide core. The broader impacts of the project are that it will ultimately contribute to our understanding of the effects of anisotropy on ice flow dynamics in West Antarctica. It will contribute to our understanding of the connection between ice flow and the paleoclimate record in ice cores, particularly with respect to the relationship between the chemical record and ice deformation. And it will contribute a new ice-flow model that includes the effects of anisotropy and fabric evolution. The project will also contribute to advancing the career of a new, young, female investigator and will support a couple of graduate students. Finally, the work will encouraging diversity in the physical sciences by directly helping to support the Girls on Ice a program that encourages young women to explore science and the natural world.", "east": -105.0, "geometry": "POINT(-135 -80)", "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY; FIELD SURVEYS; FIELD INVESTIGATION; Vertical Velocity; COMPUTERS; Ice Core; Firn; Accumulation Rate; Siple Dome; Ice Thickness; Abrupt Climate Change; Ice Temperature; Metamorphism; Anisotropy; Antarctica", "locations": "Siple Dome; Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Waddington, Edwin D.", "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", "repositories": null, "science_programs": null, "south": -85.0, "title": "Collaborative Research: Anisotropy, Abrupt Climate Change, and the Deep Ice in West Antarctica", "uid": "p0000741", "west": -165.0}]

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