Comparison of Ice-shelf Creep Flow Simulations with Ice-front Motion of Filchner-Ronne Ice Shelf, Antarctica, Detected by SAR Interferometry
Comparison between numerical model ice-shelf flow simulations and synthetic aperture radar (SAR) interferograms is used to study ice-flow dynamics at the Hemmen Ice Rise (HIR) and Lassiter Coast (LC) corners of the iceberg-calving front of the Filchner-Ronne Ice Shelf, Antarctica. The interferograms...
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ftportlandstate:oai:pdxscholar.library.pdx.edu:geology_fac-1018 2023-05-15T13:58:46+02:00 Comparison of Ice-shelf Creep Flow Simulations with Ice-front Motion of Filchner-Ronne Ice Shelf, Antarctica, Detected by SAR Interferometry Hulbe, Christina L. Rignot, Eric MacAyeal, D. R. 1998-04-01T08:00:00Z application/pdf https://pdxscholar.library.pdx.edu/geology_fac/19 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1018&context=geology_fac unknown PDXScholar https://pdxscholar.library.pdx.edu/geology_fac/19 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1018&context=geology_fac Geology Faculty Publications and Presentations Filchner Ice Shelf (Antarctica) Glaciers -- Antarctica -- Filchner Ice Shelf Glaciers -- Antarctica -- Ronne Ice Shelf Glaciology -- Antarctica Ice shelves -- Antarctica -- Mathematical models Geology text 1998 ftportlandstate 2022-01-09T19:24:25Z Comparison between numerical model ice-shelf flow simulations and synthetic aperture radar (SAR) interferograms is used to study ice-flow dynamics at the Hemmen Ice Rise (HIR) and Lassiter Coast (LC) corners of the iceberg-calving front of the Filchner-Ronne Ice Shelf, Antarctica. The interferograms are constructed from SAR images provided by the European Space Agency's remote-sensing satellites (ERS-lj2). Narrow bands of large shear strain rate are observed along the boundaries between fastflowing ice-shelf ice and no-flow boundaries. Large rifts, opened where the ice shelf separates from the coast, appear to be filled with a melange of sea ice, ice-shelf fragments, and snow. Trial and error is used to find the best match between artificial interferograms, constructed from modelled ice flow, and the observed interferograms. We find that at both HIR and LC, ice within the coastal boundary layers must be significantly softer than adjacent ice. At HIR the rift-filling ice melange transmits stress from one ice-shelf fragment to another; thus it must have mechanical competence and must moderate both separation of the ice shelf from the coast and the release of icebergs. However, the ice melange along the LC does not. The difference may be related to melange thickness, which could vary in the two locations due to differences in sub-ice-shelf oceanography or perhaps to regional atmospheric warming, currently under way along the Antarctic Peninsula. Future warming could weaken the melange ice around HIR as well, causing the ice shelf to lose contact with that shelf-front anchor. Text Antarc* Antarctic Antarctic Peninsula Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ice Shelves Iceberg* Ronne Ice Shelf Sea ice Portland State University: PDXScholar Antarctic Antarctic Peninsula Filchner Ice Shelf ENVELOPE(-40.000,-40.000,-79.000,-79.000) Hemmen Ice Rise ENVELOPE(-49.767,-49.767,-77.950,-77.950) Lassiter ENVELOPE(-62.000,-62.000,-73.750,-73.750) Lassiter Coast ENVELOPE(-62.000,-62.000,-74.000,-74.000) Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) The Antarctic |
institution |
Open Polar |
collection |
Portland State University: PDXScholar |
op_collection_id |
ftportlandstate |
language |
unknown |
topic |
Filchner Ice Shelf (Antarctica) Glaciers -- Antarctica -- Filchner Ice Shelf Glaciers -- Antarctica -- Ronne Ice Shelf Glaciology -- Antarctica Ice shelves -- Antarctica -- Mathematical models Geology |
spellingShingle |
Filchner Ice Shelf (Antarctica) Glaciers -- Antarctica -- Filchner Ice Shelf Glaciers -- Antarctica -- Ronne Ice Shelf Glaciology -- Antarctica Ice shelves -- Antarctica -- Mathematical models Geology Hulbe, Christina L. Rignot, Eric MacAyeal, D. R. Comparison of Ice-shelf Creep Flow Simulations with Ice-front Motion of Filchner-Ronne Ice Shelf, Antarctica, Detected by SAR Interferometry |
topic_facet |
Filchner Ice Shelf (Antarctica) Glaciers -- Antarctica -- Filchner Ice Shelf Glaciers -- Antarctica -- Ronne Ice Shelf Glaciology -- Antarctica Ice shelves -- Antarctica -- Mathematical models Geology |
description |
Comparison between numerical model ice-shelf flow simulations and synthetic aperture radar (SAR) interferograms is used to study ice-flow dynamics at the Hemmen Ice Rise (HIR) and Lassiter Coast (LC) corners of the iceberg-calving front of the Filchner-Ronne Ice Shelf, Antarctica. The interferograms are constructed from SAR images provided by the European Space Agency's remote-sensing satellites (ERS-lj2). Narrow bands of large shear strain rate are observed along the boundaries between fastflowing ice-shelf ice and no-flow boundaries. Large rifts, opened where the ice shelf separates from the coast, appear to be filled with a melange of sea ice, ice-shelf fragments, and snow. Trial and error is used to find the best match between artificial interferograms, constructed from modelled ice flow, and the observed interferograms. We find that at both HIR and LC, ice within the coastal boundary layers must be significantly softer than adjacent ice. At HIR the rift-filling ice melange transmits stress from one ice-shelf fragment to another; thus it must have mechanical competence and must moderate both separation of the ice shelf from the coast and the release of icebergs. However, the ice melange along the LC does not. The difference may be related to melange thickness, which could vary in the two locations due to differences in sub-ice-shelf oceanography or perhaps to regional atmospheric warming, currently under way along the Antarctic Peninsula. Future warming could weaken the melange ice around HIR as well, causing the ice shelf to lose contact with that shelf-front anchor. |
format |
Text |
author |
Hulbe, Christina L. Rignot, Eric MacAyeal, D. R. |
author_facet |
Hulbe, Christina L. Rignot, Eric MacAyeal, D. R. |
author_sort |
Hulbe, Christina L. |
title |
Comparison of Ice-shelf Creep Flow Simulations with Ice-front Motion of Filchner-Ronne Ice Shelf, Antarctica, Detected by SAR Interferometry |
title_short |
Comparison of Ice-shelf Creep Flow Simulations with Ice-front Motion of Filchner-Ronne Ice Shelf, Antarctica, Detected by SAR Interferometry |
title_full |
Comparison of Ice-shelf Creep Flow Simulations with Ice-front Motion of Filchner-Ronne Ice Shelf, Antarctica, Detected by SAR Interferometry |
title_fullStr |
Comparison of Ice-shelf Creep Flow Simulations with Ice-front Motion of Filchner-Ronne Ice Shelf, Antarctica, Detected by SAR Interferometry |
title_full_unstemmed |
Comparison of Ice-shelf Creep Flow Simulations with Ice-front Motion of Filchner-Ronne Ice Shelf, Antarctica, Detected by SAR Interferometry |
title_sort |
comparison of ice-shelf creep flow simulations with ice-front motion of filchner-ronne ice shelf, antarctica, detected by sar interferometry |
publisher |
PDXScholar |
publishDate |
1998 |
url |
https://pdxscholar.library.pdx.edu/geology_fac/19 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1018&context=geology_fac |
long_lat |
ENVELOPE(-40.000,-40.000,-79.000,-79.000) ENVELOPE(-49.767,-49.767,-77.950,-77.950) ENVELOPE(-62.000,-62.000,-73.750,-73.750) ENVELOPE(-62.000,-62.000,-74.000,-74.000) ENVELOPE(-61.000,-61.000,-78.500,-78.500) |
geographic |
Antarctic Antarctic Peninsula Filchner Ice Shelf Hemmen Ice Rise Lassiter Lassiter Coast Ronne Ice Shelf The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula Filchner Ice Shelf Hemmen Ice Rise Lassiter Lassiter Coast Ronne Ice Shelf The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ice Shelves Iceberg* Ronne Ice Shelf Sea ice |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ice Shelves Iceberg* Ronne Ice Shelf Sea ice |
op_source |
Geology Faculty Publications and Presentations |
op_relation |
https://pdxscholar.library.pdx.edu/geology_fac/19 https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1018&context=geology_fac |
_version_ |
1766267101559914496 |