{"dp_type": "Dataset", "free_text": "Mercer Ice Stream"}
[{"awards": "0087144 Conway, Howard", "bounds_geometry": ["POLYGON((-150 -83.5,-148 -83.5,-146 -83.5,-144 -83.5,-142 -83.5,-140 -83.5,-138 -83.5,-136 -83.5,-134 -83.5,-132 -83.5,-130 -83.5,-130 -83.65,-130 -83.8,-130 -83.95,-130 -84.1,-130 -84.25,-130 -84.4,-130 -84.55,-130 -84.7,-130 -84.85,-130 -85,-132 -85,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-150 -84.85,-150 -84.7,-150 -84.55,-150 -84.4,-150 -84.25,-150 -84.1,-150 -83.95,-150 -83.8,-150 -83.65,-150 -83.5))"], "date_created": "Mon, 22 Jul 2024 00:00:00 GMT", "description": "Marine ice sheets are low-pass filters of climate variability that take centuries to adjust to interior and near-terminus changes in mass balance. Constraining these century-scale changes from satellite observations that span only the last 40 years is challenging. Here, we take a different approach of carefully synthesizing different data sets to infer changes in the configurations of van der Veen and Mercer Ice Streams on the Siple Coast over the past 3000 years from englacial features encoded in ice-penetrating radar data. Englacial radar data from Conway Ridge reveal smooth, surface conformal layers overlying disrupted stratigraphy that suggest the van der Veen Ice Stream was 40 km wider over 3000 years ago. Englacial layer dating indicates that the ice stream narrowed to its present configuration between $\\sim3000$ and $\\sim1000$ years ago. Similarly disrupted stratigraphy and buried crevasses suggest that ice flowing from Mercer to Whillans Ice Stream across the northwestern tip of the ridge slowed shortly after. Using an ice-flow model capable of simulating shear margin migration, we evaluate whether small changes in ice thickness can lead to large changes in shear margin location. Our results suggest that the tip of Conway Ridge is sensitive to thinning and thickening, and that when the basal strength at the tip of the ridge increases with the height above flotation, the ice sheet shear margins can change quickly.", "east": -130.0, "geometry": ["POINT(-140 -84.25)"], "keywords": "Antarctica; Cryosphere; Siple Coast", "locations": "Antarctica; Siple Coast", "north": -83.5, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Hoffman, Andrew; Conway, Howard; Christianson, Knut", "project_titles": "Glacial History of Ridge AB, West Antarctica", "projects": [{"proj_uid": "p0010470", "repository": "USAP-DC", "title": "Glacial History of Ridge AB, West Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Impulse HF radar data from Conway Ridge", "uid": "601810", "west": -150.0}, {"awards": "1842021 Campbell, Seth", "bounds_geometry": ["POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.6,-111 -83.2,-111 -83.8,-111 -84.4,-111 -85,-111 -85.6,-111 -86.2,-111 -86.8,-111 -87.4,-111 -88,-116.7 -88,-122.4 -88,-128.1 -88,-133.8 -88,-139.5 -88,-145.2 -88,-150.9 -88,-156.6 -88,-162.3 -88,-168 -88,-168 -87.4,-168 -86.8,-168 -86.2,-168 -85.6,-168 -85,-168 -84.4,-168 -83.8,-168 -83.2,-168 -82.6,-168 -82))"], "date_created": "Sat, 12 Dec 2020 00:00:00 GMT", "description": "The dataset includes initialization and output files of a numerical ice flow simulation of the Whillans and Mercer Ice Streams . The Ice Sheet System Model (ISSM) model was used to solve a 100-year transient stress balance solution of the region with ~10 kPA/yr friction increase downstream of the shear margin between the Whillans and Mercer ice streams. \r\n", "east": -111.0, "geometry": ["POINT(-139.5 -85)"], "keywords": "Antarctica; Glaciology; Ice Sheet Flow Model; Ice Shelf Dynamics; Mercer Ice Stream; Model Data; Snow/ice; Snow/Ice; Whillans Ice Stream", "locations": "Whillans Ice Stream; Mercer Ice Stream; Antarctica", "north": -82.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Kaluzienski, Lynn", "project_titles": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence", "projects": [{"proj_uid": "p0010145", "repository": "USAP-DC", "title": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -88.0, "title": "Whillans and Mercer Shear Margin Ice Flow simulation in ISSM", "uid": "601404", "west": -168.0}, {"awards": "1842021 Campbell, Seth", "bounds_geometry": ["POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.5,-111 -83,-111 -83.5,-111 -84,-111 -84.5,-111 -85,-111 -85.5,-111 -86,-111 -86.5,-111 -87,-116.7 -87,-122.4 -87,-128.1 -87,-133.8 -87,-139.5 -87,-145.2 -87,-150.9 -87,-156.6 -87,-162.3 -87,-168 -87,-168 -86.5,-168 -86,-168 -85.5,-168 -85,-168 -84.5,-168 -84,-168 -83.5,-168 -83,-168 -82.5,-168 -82))"], "date_created": "Sat, 12 Dec 2020 00:00:00 GMT", "description": "The dataset includes GPS coordinates for crevasse/fracture locations picked from 350MHz and 400Mhz frequency GPR dataset in the Whillans/Mercer Shear Margin along the SALSA traverse route with associated kinematic outputs for each feature (shear strain rate, vorticity, dilatation). GPS coordinates are in the Antarctic Polar Stereographic projection (EPSG:3031). ", "east": -111.0, "geometry": ["POINT(-139.5 -84.5)"], "keywords": "Antarctica; Crevasses; Glaciology; GPR; GPS; Ice Sheet Flow Model; Ice Shelf Dynamics; Snow/ice; Snow/Ice; Whillans Ice Stream", "locations": "Whillans Ice Stream; Antarctica", "north": -82.0, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Kaluzienski, Lynn", "project_titles": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence", "projects": [{"proj_uid": "p0010145", "repository": "USAP-DC", "title": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.0, "title": "2017 GPR Observations of the Whillans and Mercer Ice Streams", "uid": "601403", "west": -168.0}]
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Bounds Geometry | Geometry | Selected | Visible |
---|---|---|---|---|---|---|---|---|---|
Impulse HF radar data from Conway Ridge
|
0087144 |
2024-07-22 | Hoffman, Andrew; Conway, Howard; Christianson, Knut |
Glacial History of Ridge AB, West Antarctica |
Marine ice sheets are low-pass filters of climate variability that take centuries to adjust to interior and near-terminus changes in mass balance. Constraining these century-scale changes from satellite observations that span only the last 40 years is challenging. Here, we take a different approach of carefully synthesizing different data sets to infer changes in the configurations of van der Veen and Mercer Ice Streams on the Siple Coast over the past 3000 years from englacial features encoded in ice-penetrating radar data. Englacial radar data from Conway Ridge reveal smooth, surface conformal layers overlying disrupted stratigraphy that suggest the van der Veen Ice Stream was 40 km wider over 3000 years ago. Englacial layer dating indicates that the ice stream narrowed to its present configuration between $\sim3000$ and $\sim1000$ years ago. Similarly disrupted stratigraphy and buried crevasses suggest that ice flowing from Mercer to Whillans Ice Stream across the northwestern tip of the ridge slowed shortly after. Using an ice-flow model capable of simulating shear margin migration, we evaluate whether small changes in ice thickness can lead to large changes in shear margin location. Our results suggest that the tip of Conway Ridge is sensitive to thinning and thickening, and that when the basal strength at the tip of the ridge increases with the height above flotation, the ice sheet shear margins can change quickly. | ["POLYGON((-150 -83.5,-148 -83.5,-146 -83.5,-144 -83.5,-142 -83.5,-140 -83.5,-138 -83.5,-136 -83.5,-134 -83.5,-132 -83.5,-130 -83.5,-130 -83.65,-130 -83.8,-130 -83.95,-130 -84.1,-130 -84.25,-130 -84.4,-130 -84.55,-130 -84.7,-130 -84.85,-130 -85,-132 -85,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-150 -84.85,-150 -84.7,-150 -84.55,-150 -84.4,-150 -84.25,-150 -84.1,-150 -83.95,-150 -83.8,-150 -83.65,-150 -83.5))"] | ["POINT(-140 -84.25)"] | false | false |
Whillans and Mercer Shear Margin Ice Flow simulation in ISSM
|
1842021 |
2020-12-12 | Kaluzienski, Lynn |
RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence |
The dataset includes initialization and output files of a numerical ice flow simulation of the Whillans and Mercer Ice Streams . The Ice Sheet System Model (ISSM) model was used to solve a 100-year transient stress balance solution of the region with ~10 kPA/yr friction increase downstream of the shear margin between the Whillans and Mercer ice streams. | ["POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.6,-111 -83.2,-111 -83.8,-111 -84.4,-111 -85,-111 -85.6,-111 -86.2,-111 -86.8,-111 -87.4,-111 -88,-116.7 -88,-122.4 -88,-128.1 -88,-133.8 -88,-139.5 -88,-145.2 -88,-150.9 -88,-156.6 -88,-162.3 -88,-168 -88,-168 -87.4,-168 -86.8,-168 -86.2,-168 -85.6,-168 -85,-168 -84.4,-168 -83.8,-168 -83.2,-168 -82.6,-168 -82))"] | ["POINT(-139.5 -85)"] | false | false |
2017 GPR Observations of the Whillans and Mercer Ice Streams
|
1842021 |
2020-12-12 | Kaluzienski, Lynn |
RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence |
The dataset includes GPS coordinates for crevasse/fracture locations picked from 350MHz and 400Mhz frequency GPR dataset in the Whillans/Mercer Shear Margin along the SALSA traverse route with associated kinematic outputs for each feature (shear strain rate, vorticity, dilatation). GPS coordinates are in the Antarctic Polar Stereographic projection (EPSG:3031). | ["POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.5,-111 -83,-111 -83.5,-111 -84,-111 -84.5,-111 -85,-111 -85.5,-111 -86,-111 -86.5,-111 -87,-116.7 -87,-122.4 -87,-128.1 -87,-133.8 -87,-139.5 -87,-145.2 -87,-150.9 -87,-156.6 -87,-162.3 -87,-168 -87,-168 -86.5,-168 -86,-168 -85.5,-168 -85,-168 -84.5,-168 -84,-168 -83.5,-168 -83,-168 -82.5,-168 -82))"] | ["POINT(-139.5 -84.5)"] | false | false |