{"dp_type": "Project", "free_text": "Ice Movement"}
[{"awards": "1543399 Peng, Zhigang; 1745135 Walter, Jacob; 1543286 Walter, Jacob", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 19 May 2021 00:00:00 GMT", "description": "The continent of Antarctica has approximately the same surface area as the continental United States, though we know significantly less about its underlying geology and seismic activity. Multinational investments in geophysical infrastructure over the last few decades, especially broadband seismometers operating for several years, are allowing us to observe many interesting natural phenomena, including iceberg calving, ice stream slip, and tectonic earthquakes. To specifically leverage those past investments, we will analyze past and current data to gain a better understanding of Antarctic seismicity. Our recent research revealed that certain large earthquakes occurring elsewhere in the world triggered ice movement near various stations throughout Antarctica. We plan to conduct an exhaustive search of the terabytes of available data, using cutting-edge computational techniques, to uncover additional evidence for ice crevassing, ice stream slip, and earth movement during earthquakes. One specific focus of our research will include investigating whether some of these phenomena may be triggered by external influences, including passing surface waves from distant earthquakes, ocean tides, or seasonal melt. We plan to produce a catalog of the identified activity and share it publicly, so the public and researchers can easily access it. To reach a broader audience, we will present talks to high school classes, including Advanced Placement classes, in the Austin, Texas and Atlanta, Georgia metropolitan areas with emphasis on general aspects of seismic hazard, climate variability, and the geographies of Antarctica. This project will provide research opportunities for undergraduates, training for graduate students, and support for an early-career scientist.\r\n\r\nIn recent years, a new generation of geodetic and seismic instrumentation has been deployed as permanent stations throughout Antarctica (POLENET), in addition to stations deployed for shorter duration (less than 3 years) experiments (e.g. AGAP/TAMSEIS). These efforts are providing critical infrastructure needed to address fundamental questions about both crustal-scale tectonic structures and ice sheets, and their interactions. We plan to conduct a systematic detection of tectonic and icequake activities in Antarctica, focusing primarily on background seismicity, remotely-triggered seismicity, and glacier slip events. Our proposed tasks include: (1) Identification of seismicity throughout the Antarctic continent for both tectonic and ice sources. (2) An exhaustive search for additional triggered events in Antarctica during the last ~15 years of global significant earthquakes. (3) Determination of triggered source mechanisms and whether those triggered events also occur at other times, by analyzing years of data using a matched-filter analysis (where the triggered local event is used to detect similar events). (4) Further analysis of GPS measurements over a ~5.5 year period from Whillans Ice Plain, which suggests that triggering of stick-slip events occurred after the largest earthquakes. An improved knowledge of how the Antarctic ice sheet responds to external perturbations such as dynamic stresses from large distant earthquakes and recent ice unloading could lead to a better understanding of ice failure and related dynamic processes. By leveraging the vast logistical investment to install seismometers in Antarctica over the last decade, our project will build an exhaustive catalog of tectonic earthquakes, icequakes, calving events, and any other detectable near-surface seismic phenomena.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; GLACIERS/ICE SHEETS; USA/NSF; TECTONICS; AMD; USAP-DC; SEISMOLOGICAL STATIONS; AMD/US", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walter, Jacob; Peng, Zhigang", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Triggering of Antarctic Icequakes, Slip Events, and other Tectonic Phenomena by Distant Earthquakes", "uid": "p0010182", "west": -180.0}, {"awards": "9615502 Harrison, William", "bounds_geometry": "POINT(-148.822 -81.655)", "dataset_titles": "Vertical Strain at Siple Dome, Antarctica, 1999-2002", "datasets": [{"dataset_uid": "609214", "doi": "10.7265/N5HH6H00", "keywords": "Antarctica; Cryosphere; Geodetic; Geology/Geophysics - Other; Glaciers/Ice Sheet; Glaciology; Siple Dome; Siple Dome Ice Core; Strain; WAISCORES", "people": "Waddington, Edwin D.; Harrison, William; Zumberge, Mark; Elsberg, Daniel; Pettit, Erin; Morack, James", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Vertical Strain at Siple Dome, Antarctica, 1999-2002", "url": "https://www.usap-dc.org/view/dataset/609214"}], "date_created": "Thu, 22 Feb 2007 00:00:00 GMT", "description": "This award is for support for a three year project to measure the vertical strain rate as a function of depth at two sites on Siple Dome Antarctica. Ice flow near a divide such as Siple Dome is unique in that it is predominantly vertical. As a consequence, the component of ice deformation in the vertical direction, the \"vertical strain rate\" is dominant. Its measurement is therefore important for the calibration of dynamic models of ice flow. Two different, relatively new, high resolution systems for its measurement in hot water drilled holes will be employed. The ice flow model resulting from the measurements and flow law determination will be used to interpret the shapes of radar internal layering in terms of the dynamic history and accumulation patterns of Siple Dome over the past 10,000 years. The resulting improved model will also be applied to the interpretation of annual layers thicknesses (to produce annual accumulation rates) and borehole temperatures from the ice core to be drilled at Siple Dome during the 1997/98 field season. The results should permit an improved analysis of the ice core, relative to what was possible at recent coring sites in central Greenland. This is a collaborative project between the University of Alaska, the University of California, San Diego and the University of Washington.", "east": -148.822, "geometry": "POINT(-148.822 -81.655)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e STRAIN GAUGE WHEATSTONE BRIDGE", "is_usap_dc": true, "keywords": "Ice Core Data; GROUND-BASED OBSERVATIONS; Antarctica; USAP-DC; Ice Core; Ice Analysis; AGDC; Ice Motion; 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": "0088035 Arcone, Steven", "bounds_geometry": "POLYGON((-135 -75,-130.5 -75,-126 -75,-121.5 -75,-117 -75,-112.5 -75,-108 -75,-103.5 -75,-99 -75,-94.5 -75,-90 -75,-90 -76.5,-90 -78,-90 -79.5,-90 -81,-90 -82.5,-90 -84,-90 -85.5,-90 -87,-90 -88.5,-90 -90,-94.5 -90,-99 -90,-103.5 -90,-108 -90,-112.5 -90,-117 -90,-121.5 -90,-126 -90,-130.5 -90,-135 -90,-135 -88.5,-135 -87,-135 -85.5,-135 -84,-135 -82.5,-135 -81,-135 -79.5,-135 -78,-135 -76.5,-135 -75))", "dataset_titles": "US International Trans-Antarctic Scientific Expedition 400 MHz Subsurface Radar Profiles; US International Trans-Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping", "datasets": [{"dataset_uid": "609269", "doi": "10.7265/N5GH9FV6", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ground Penetrating Radar; ITASE; WAIS", "people": "Mayewski, Paul A.; Arcone, Steven; Spikes, Vandy Blue; Hamilton, Gordon S.; Kaspari, Susan", "repository": "USAP-DC", "science_program": "ITASE", "title": "US International Trans-Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping", "url": "https://www.usap-dc.org/view/dataset/609269"}, {"dataset_uid": "609254", "doi": "10.7265/N58050J7", "keywords": "Airborne Radar; Antarctica; Bathymetry/Topography; Cryosphere; Glaciers/Ice Sheet; Glaciology; ITASE; Radar; WAIS", "people": "Arcone, Steven", "repository": "USAP-DC", "science_program": null, "title": "US International Trans-Antarctic Scientific Expedition 400 MHz Subsurface Radar Profiles", "url": "https://www.usap-dc.org/view/dataset/609254"}], "date_created": "Sun, 01 May 2005 00:00:00 GMT", "description": "This award supports continued acquisition of high resolution, radar reflection profiles of the snow and ice stratigraphy between core sites planned along traverse routes of the U.S. component of the International\u003cbr/\u003eTrans-Antarctic Scientific Expedition (U.S.-ITASE). The purpose is to use the profiles to establish the structure and continuity of firn stratigraphic horizons over hundreds of kilometers and to quantitatively\u003cbr/\u003eassess topographic and ice movement effects upon snow deposition. Other objectives are to establish the climatic extent that a single site represents and to investigate the cause of firn reflections. The radar\u003cbr/\u003ewill also be used to identify crevasses ahead of the traverse vehicles in order to protect the safety of the scientists and support personnel on the traverse. Collaboration with other ITASE investigators will use the radar horizons as continuous isochronic references fixed by the core dating to calculate historical snow accumulation rates. The primary radar system uses 400-MHz (center frequency) short-pulse antennas, which (with processing) gives the penetration of 50-70 meters. This is the depth which is required to exceed the 200-year deposition horizon along the traverse routes. Profiles at 200 MHz will also be recorded if depths greater than 70 meters are of interest. Processing will be accomplished by data compression (stacking) to reveal long distance stratigraphic deformation, range gain corrections to give proper weight to signal amplitudes, and GPS corrections to adjust the records for the present ice sheet topography. Near surface stratigraphy will allow topographic and ice movement effects to be separated. This work is critical to the success of the U.S.-ITASE program.", "east": -90.0, "geometry": "POINT(-112.5 -82.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": true, "keywords": "Ice; USAP-DC; Ice Cover; West Antarctic Ice Sheet; Snow Accumulation; Radar Echo Sounders; CRREL; AGDC; Antarctic Ice Sheet; NSIDC \u003e National Snow and Ice Data Center; U.S. ITASE; Radar; Ice Surveys; ITASE; Ice Sheet; Radar Echo Sounding; GROUND-BASED OBSERVATIONS; Ice Thickness; Mass Balance; Office of Polar Programs", "locations": "Antarctic Ice Sheet; West Antarctic Ice Sheet", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Spikes, Vandy Blue; Arcone, Steven; Kaspari, Susan; Hamilton, Gordon S.; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -90.0, "title": "High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet", "uid": "p0000146", "west": -135.0}, {"awards": "9909469 Scambos, Ted", "bounds_geometry": null, "dataset_titles": "Ice Motion and Topography Near Margin Areas of Kamb Ice Stream, Antarctica", "datasets": [{"dataset_uid": "609141", "doi": "10.7265/N5WS8R52", "keywords": "Antarctica; Cryosphere; Geodetic; Geology/Geophysics - Other; Glaciers/Ice Sheet; Glaciology; Kamb Ice Stream", "people": "Gades, Anthony; Raymond, Charles; Conway, Howard; Scambos, Ted; Catania, Ginny", "repository": "USAP-DC", "science_program": null, "title": "Ice Motion and Topography Near Margin Areas of Kamb Ice Stream, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609141"}], "date_created": "Fri, 01 Aug 2003 00:00:00 GMT", "description": "9909469\u003cbr/\u003eScambos\u003cbr/\u003e\u003cbr/\u003eThis award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide \"shutdown\" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Ice Velocity; Ice Acceleration; Ice Sheet Elevation; Ice Motion; GROUND-BASED OBSERVATIONS; Ice Stream; Antarctic Ice Sheet; Ice Sheet; Ice Surface Elevation; Ice Position; Ice Surface; Ice Stream C Velocities; Ice Movement; Ice; Cryosphere", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted; Catania, Ginny; Conway, Howard; Gades, Anthony; Raymond, Charles", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: History and Evolution of the Siple Coast Ice Stream System as Recorded by Former Shear-Margin Scars", "uid": "p0000165", "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 | |||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Collaborative Research: Triggering of Antarctic Icequakes, Slip Events, and other Tectonic Phenomena by Distant Earthquakes
|
1543399 1745135 1543286 |
2021-05-19 | Walter, Jacob; Peng, Zhigang | No dataset link provided | The continent of Antarctica has approximately the same surface area as the continental United States, though we know significantly less about its underlying geology and seismic activity. Multinational investments in geophysical infrastructure over the last few decades, especially broadband seismometers operating for several years, are allowing us to observe many interesting natural phenomena, including iceberg calving, ice stream slip, and tectonic earthquakes. To specifically leverage those past investments, we will analyze past and current data to gain a better understanding of Antarctic seismicity. Our recent research revealed that certain large earthquakes occurring elsewhere in the world triggered ice movement near various stations throughout Antarctica. We plan to conduct an exhaustive search of the terabytes of available data, using cutting-edge computational techniques, to uncover additional evidence for ice crevassing, ice stream slip, and earth movement during earthquakes. One specific focus of our research will include investigating whether some of these phenomena may be triggered by external influences, including passing surface waves from distant earthquakes, ocean tides, or seasonal melt. We plan to produce a catalog of the identified activity and share it publicly, so the public and researchers can easily access it. To reach a broader audience, we will present talks to high school classes, including Advanced Placement classes, in the Austin, Texas and Atlanta, Georgia metropolitan areas with emphasis on general aspects of seismic hazard, climate variability, and the geographies of Antarctica. This project will provide research opportunities for undergraduates, training for graduate students, and support for an early-career scientist. In recent years, a new generation of geodetic and seismic instrumentation has been deployed as permanent stations throughout Antarctica (POLENET), in addition to stations deployed for shorter duration (less than 3 years) experiments (e.g. AGAP/TAMSEIS). These efforts are providing critical infrastructure needed to address fundamental questions about both crustal-scale tectonic structures and ice sheets, and their interactions. We plan to conduct a systematic detection of tectonic and icequake activities in Antarctica, focusing primarily on background seismicity, remotely-triggered seismicity, and glacier slip events. Our proposed tasks include: (1) Identification of seismicity throughout the Antarctic continent for both tectonic and ice sources. (2) An exhaustive search for additional triggered events in Antarctica during the last ~15 years of global significant earthquakes. (3) Determination of triggered source mechanisms and whether those triggered events also occur at other times, by analyzing years of data using a matched-filter analysis (where the triggered local event is used to detect similar events). (4) Further analysis of GPS measurements over a ~5.5 year period from Whillans Ice Plain, which suggests that triggering of stick-slip events occurred after the largest earthquakes. An improved knowledge of how the Antarctic ice sheet responds to external perturbations such as dynamic stresses from large distant earthquakes and recent ice unloading could lead to a better understanding of ice failure and related dynamic processes. By leveraging the vast logistical investment to install seismometers in Antarctica over the last decade, our project will build an exhaustive catalog of tectonic earthquakes, icequakes, calving events, and any other detectable near-surface seismic phenomena. | 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 | |||
Ice Dynamics, the Flow Law, and Vertical Strain at Siple Dome
|
9615502 |
2007-02-22 | Harrison, William; Morack, James; Pettit, Erin; Zumberge, Mark; Elsberg, Daniel; Waddington, Edwin D. |
|
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 | |||
High Resolution Radar Profiling of the Snow and Ice Stratigraphy beneath the ITASE Traverses, West Antarctic Ice Sheet
|
0088035 |
2005-05-01 | Spikes, Vandy Blue; Arcone, Steven; Kaspari, Susan; Hamilton, Gordon S.; Mayewski, Paul A. | This award supports continued acquisition of high resolution, radar reflection profiles of the snow and ice stratigraphy between core sites planned along traverse routes of the U.S. component of the International<br/>Trans-Antarctic Scientific Expedition (U.S.-ITASE). The purpose is to use the profiles to establish the structure and continuity of firn stratigraphic horizons over hundreds of kilometers and to quantitatively<br/>assess topographic and ice movement effects upon snow deposition. Other objectives are to establish the climatic extent that a single site represents and to investigate the cause of firn reflections. The radar<br/>will also be used to identify crevasses ahead of the traverse vehicles in order to protect the safety of the scientists and support personnel on the traverse. Collaboration with other ITASE investigators will use the radar horizons as continuous isochronic references fixed by the core dating to calculate historical snow accumulation rates. The primary radar system uses 400-MHz (center frequency) short-pulse antennas, which (with processing) gives the penetration of 50-70 meters. This is the depth which is required to exceed the 200-year deposition horizon along the traverse routes. Profiles at 200 MHz will also be recorded if depths greater than 70 meters are of interest. Processing will be accomplished by data compression (stacking) to reveal long distance stratigraphic deformation, range gain corrections to give proper weight to signal amplitudes, and GPS corrections to adjust the records for the present ice sheet topography. Near surface stratigraphy will allow topographic and ice movement effects to be separated. This work is critical to the success of the U.S.-ITASE program. | POLYGON((-135 -75,-130.5 -75,-126 -75,-121.5 -75,-117 -75,-112.5 -75,-108 -75,-103.5 -75,-99 -75,-94.5 -75,-90 -75,-90 -76.5,-90 -78,-90 -79.5,-90 -81,-90 -82.5,-90 -84,-90 -85.5,-90 -87,-90 -88.5,-90 -90,-94.5 -90,-99 -90,-103.5 -90,-108 -90,-112.5 -90,-117 -90,-121.5 -90,-126 -90,-130.5 -90,-135 -90,-135 -88.5,-135 -87,-135 -85.5,-135 -84,-135 -82.5,-135 -81,-135 -79.5,-135 -78,-135 -76.5,-135 -75)) | POINT(-112.5 -82.5) | false | false | ||||
Collaborative Research: History and Evolution of the Siple Coast Ice Stream System as Recorded by Former Shear-Margin Scars
|
9909469 |
2003-08-01 | Scambos, Ted; Catania, Ginny; Conway, Howard; Gades, Anthony; Raymond, Charles |
|
9909469<br/>Scambos<br/><br/>This award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide "shutdown" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time. | None | None | false | false |